http://www.dosimetry.com/
Yup!
Wednesday, November 7, 2007
Radiation Effects on the Body
Radiation effects on living tissue
The distinction between absorbed dose (Gy) and dose equivalent (Sv) is based upon the biological effects of the radiation in question and the tissue and organism irradiated. For different types of radiation, the same absorbed dose (measured in Gy) may have very different biological consequences. Therefore, a radiation weighting factor (denoted wr) and tissue/organ weighting factor (WT) have been established, which compare the relative biological effects of various types of radiation and the susceptibility of different organs.
[edit] Organ Dose Weighting Factors
By definition, the weighting factor for the whole body is 1, such that 1 Gy of radiation delivered to the whole body (i.e. an evenly distributed 1 joule of energy deposited per kilogram of body) is equal to one Sievert (for photons with a radiation weighting factor of 1, see below). Therefore, the weighting factors for each organ must sum to 1 as the unit Gray is defined per kilogram and is therefore a local effect. As the table below shows, 1 Gray delivered to the gonads is equivalent to 0.25 Gy to the whole body - in this case, the actual energy deposited to the gonads, being small, would also be small.
Organ or tissue
Wт
Gonads
.25
Breasts
.15
Red Bone Marrow
.12
Lung
.12
Thyroid
.03
Bone surfaces
.03
Remainder
.30
Whole body
1.0
[edit] Radiation Weighting Factors
By definition, x-rays and gamma rays have a weighting factor of unity, such that 1 Gy = 1 Sv (for whole-body irradiation). Values of wr are as high as 20 for alpha particles and neutrons, i.e. for the same absorbed dose in Gy, alpha particles are 20 times as biologically potent as X or gamma rays.
[edit] Dose versus activity
Radiation dose refers to the amount of energy deposited in matter and/or biological effects of radiation, and should not be confused with the unit of radioactive activity (becquerel, Bq). Exposure to a radioactive source will give a dose which is dependent on the activity, time of exposure, energy of the radiation emitted, distance from the source and shielding. The equivalent dose is then dependent upon the weighting factors above. Dose is a measure of deposited dose, and therefore can never go down - removal of a radioactive source can only reduce the rate of increase of absorbed dose, never the total absorbed dose.
The worldwide average background dose for a human being is about 3.5 mSv per year [1], mostly from cosmic radiation and natural isotopes in the earth. The largest single source of radiation exposure to the general public is naturally-occurring radon gas, which comprises approximately 55% of the annual background dose. It is estimated that radon is responsible for 10% of lung cancers in the United States.
[edit] Measuring dose
There are several ways of measuring doses from ionizing radiation. Workers who come in contact with radioactive substances or may be exposed to radiation routinely carry personal dosimeters. In the United States, these dosimeters usually contain materials that can be used in thermoluminescent dosimetry (TLD) or optically stimulated luminescence (OSL). Outside the United States, the most widely-used type of personal dosimeter is the film badge dosimeter, which uses photographic emulsions that are sensitive to ionizing radiation. The equipment used in radiotherapy (linear particle accelerator in external beam therapy) is routinely calibrated using ionization chambers.
[edit] Dose standards
Because the human body is approximately 70% water and has an overall density close to 1 g/cm3, dose measurement is usually calculated and calibrated as dose to water. National standards laboratories suh as the NPL provide calibration factors for ionization chambers and other measurement devices to convert from the instrument's readout to absorbed dose. The standards laboratories operate a Primary Standard, which is normally calibrated by absolute calorimetry, the warming of substances when they absorb energy. A user sends their Secondary Standard to the laboratory, where it is exposed to a known amount of radiation (derived from the Primary Standard) and a factor is issued to convert the instrument's reading to that dose. The user may then use their Secondary Standard to derive calibration factors for other instruments they use, which then become Tertiary Standards, or field instruments. The NPL in the UK operates a graphite-calorimeter for absolute photon dosimetry. Graphite is used instead of water as its specific heat capacity is one-sixth that of water and therefore the temperature rises in graphite are 6 times more than the equivalent in water and measurements are more accurate. Significant problems exist in insulating the graphite from the laboratory in order to measure the tiny temperature changes. A lethal dose of radiation to a human is approximately 10-20 Gy. This is 10-20 joules per kg. A 1 cm3 piece of graphite weighing 2 grams would therefore absorb around 20-40 mJ. With a specific heat capacity of around 700 Jkg-1K-1, this equates to a temperature rise of just 20 mK.
The distinction between absorbed dose (Gy) and dose equivalent (Sv) is based upon the biological effects of the radiation in question and the tissue and organism irradiated. For different types of radiation, the same absorbed dose (measured in Gy) may have very different biological consequences. Therefore, a radiation weighting factor (denoted wr) and tissue/organ weighting factor (WT) have been established, which compare the relative biological effects of various types of radiation and the susceptibility of different organs.
[edit] Organ Dose Weighting Factors
By definition, the weighting factor for the whole body is 1, such that 1 Gy of radiation delivered to the whole body (i.e. an evenly distributed 1 joule of energy deposited per kilogram of body) is equal to one Sievert (for photons with a radiation weighting factor of 1, see below). Therefore, the weighting factors for each organ must sum to 1 as the unit Gray is defined per kilogram and is therefore a local effect. As the table below shows, 1 Gray delivered to the gonads is equivalent to 0.25 Gy to the whole body - in this case, the actual energy deposited to the gonads, being small, would also be small.
Organ or tissue
Wт
Gonads
.25
Breasts
.15
Red Bone Marrow
.12
Lung
.12
Thyroid
.03
Bone surfaces
.03
Remainder
.30
Whole body
1.0
[edit] Radiation Weighting Factors
By definition, x-rays and gamma rays have a weighting factor of unity, such that 1 Gy = 1 Sv (for whole-body irradiation). Values of wr are as high as 20 for alpha particles and neutrons, i.e. for the same absorbed dose in Gy, alpha particles are 20 times as biologically potent as X or gamma rays.
[edit] Dose versus activity
Radiation dose refers to the amount of energy deposited in matter and/or biological effects of radiation, and should not be confused with the unit of radioactive activity (becquerel, Bq). Exposure to a radioactive source will give a dose which is dependent on the activity, time of exposure, energy of the radiation emitted, distance from the source and shielding. The equivalent dose is then dependent upon the weighting factors above. Dose is a measure of deposited dose, and therefore can never go down - removal of a radioactive source can only reduce the rate of increase of absorbed dose, never the total absorbed dose.
The worldwide average background dose for a human being is about 3.5 mSv per year [1], mostly from cosmic radiation and natural isotopes in the earth. The largest single source of radiation exposure to the general public is naturally-occurring radon gas, which comprises approximately 55% of the annual background dose. It is estimated that radon is responsible for 10% of lung cancers in the United States.
[edit] Measuring dose
There are several ways of measuring doses from ionizing radiation. Workers who come in contact with radioactive substances or may be exposed to radiation routinely carry personal dosimeters. In the United States, these dosimeters usually contain materials that can be used in thermoluminescent dosimetry (TLD) or optically stimulated luminescence (OSL). Outside the United States, the most widely-used type of personal dosimeter is the film badge dosimeter, which uses photographic emulsions that are sensitive to ionizing radiation. The equipment used in radiotherapy (linear particle accelerator in external beam therapy) is routinely calibrated using ionization chambers.
[edit] Dose standards
Because the human body is approximately 70% water and has an overall density close to 1 g/cm3, dose measurement is usually calculated and calibrated as dose to water. National standards laboratories suh as the NPL provide calibration factors for ionization chambers and other measurement devices to convert from the instrument's readout to absorbed dose. The standards laboratories operate a Primary Standard, which is normally calibrated by absolute calorimetry, the warming of substances when they absorb energy. A user sends their Secondary Standard to the laboratory, where it is exposed to a known amount of radiation (derived from the Primary Standard) and a factor is issued to convert the instrument's reading to that dose. The user may then use their Secondary Standard to derive calibration factors for other instruments they use, which then become Tertiary Standards, or field instruments. The NPL in the UK operates a graphite-calorimeter for absolute photon dosimetry. Graphite is used instead of water as its specific heat capacity is one-sixth that of water and therefore the temperature rises in graphite are 6 times more than the equivalent in water and measurements are more accurate. Significant problems exist in insulating the graphite from the laboratory in order to measure the tiny temperature changes. A lethal dose of radiation to a human is approximately 10-20 Gy. This is 10-20 joules per kg. A 1 cm3 piece of graphite weighing 2 grams would therefore absorb around 20-40 mJ. With a specific heat capacity of around 700 Jkg-1K-1, this equates to a temperature rise of just 20 mK.
Definition of Dosimetry- Jordan
Dosimetry
From Wikipedia, the free encyclopedia
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Jump to: navigation, search
Radiation dosimetry is the calculation of absorbed dose in matter and tissue resulting from the exposure to ionizing radiation. It is a scientific subspecialty in the fields of health physics and medical physics that is focused on the calculation of internal and external doses from ionizing radiation.
Dose is reported in gray (Gy) for the matter or sieverts (Sv) for biological tissue, where 1 Gy or 1 Sv is equal to 1 joule per kilogram. Non-SI units are still prevalent as well, where dose is often reported in rads and dose equivalent in rems. By definition, 1 Gy = 100 rad and 1 Sv = 100 rem.
From Wikipedia, the free encyclopedia
• Ten things you may not know about images on Wikipedia •
Jump to: navigation, search
Radiation dosimetry is the calculation of absorbed dose in matter and tissue resulting from the exposure to ionizing radiation. It is a scientific subspecialty in the fields of health physics and medical physics that is focused on the calculation of internal and external doses from ionizing radiation.
Dose is reported in gray (Gy) for the matter or sieverts (Sv) for biological tissue, where 1 Gy or 1 Sv is equal to 1 joule per kilogram. Non-SI units are still prevalent as well, where dose is often reported in rads and dose equivalent in rems. By definition, 1 Gy = 100 rad and 1 Sv = 100 rem.
Tuesday, November 6, 2007
Traioning/History
The training of medical physicists
H A B Simons 1968 Phys. Educ. 3 19-23 doi:10.1088/0031-9120/3/1/306
PDF (621 KB)
H A B SimonsRoyal Free Hospital School of Medicine, London
Abstract. The history of medical physics is reviewed, from which it is seen that it is better described as the applications of physics to medicine. The work done by a physicist employed in a hospital is discussed together with the qualities, other than ability as a physicist, that he requires. Methods whereby one can become a medical physicist are given, the conclusion being that the most essential thing is to be a good physicist before becoming a medical physicist.
Print publication
H A B Simons 1968 Phys. Educ. 3 19-23 doi:10.1088/0031-9120/3/1/306
PDF (621 KB)
H A B SimonsRoyal Free Hospital School of Medicine, London
Abstract. The history of medical physics is reviewed, from which it is seen that it is better described as the applications of physics to medicine. The work done by a physicist employed in a hospital is discussed together with the qualities, other than ability as a physicist, that he requires. Methods whereby one can become a medical physicist are given, the conclusion being that the most essential thing is to be a good physicist before becoming a medical physicist.
Print publication
Education Continued... More clear!
Intro
Medical physics is actually part of the larger field of biophysics, but it has become so important that those who work in it have formed their own society. Like so many new and growing fields, the boundaries of the field are far from sharp or decisive. The parent field, biophysics, itself is relatively new.
The original biophysicists were usually people involved with electronics, but today's biophysicist utilizes all the physical sciences, including a heavy dose of mathematics. This challenging profession, on the frontiers of modern science, applies the most modern and sophisticated techniques to the solution of problems in biology, which until recently was largely a descriptive science. The field of study and research is sometimes called molecular biology.
A great deal of overlapping and confusion exists about what is included in the fields of molecular biology, biophysics, medical physics, and even biochemistry. In which field a particular scientist belongs depends more on what he's doing than on his degree or the title of his job: For example, a man with a degree in biology can be in any of these fields, as can a physicist.
There are a number of specialized fields in medical physics and their names indicate pretty clearly what they involve. Hospital physicists and radiation physicists, health physicists and radiation safety physicists are found in hospitals and other installations where any form of ionizing radiation is used, and they are also needed to check on the safety of any facility that may be a source of radioactivity or a radiation hazard. Space travel, for example, presents a problem of the possible effects of high energy particles on the astronauts and so medical physicists have been involved in space medicine also.
The medical physicists is also needed to teach and to train radiobiologists and medical students and doctors. It's not surprising that with so many demands, many jobs are now going begging because there are just not enough people to fill them.
What Does the Medical Physicist Do?
Essentially the medical physicist is involved with patients and so is a key member of the health care team. All of his work, in the last analysis, revolves around diseases and disorders regardless of whether he is studying them, or the basic physical mechanisms of the life processes, or working on the measurement of various vital functions. For even his study of these normal body mechanisms is done with the ultimate aim of understanding and treating diseases or the disturbances producing various disorders.
Medical physicists are especially active in the field of ionizing radiation. This ionization is capable of destroying living cells and so it has been used to attack and destroy cancer cells.
But the medical physicist is engaged in several other areas in addition to radiation. He can be found working on bioelectrical investigations of the heart and brain. Your heart is about the size of your clenched fist. The muscles start their contraction at the top. As this contraction sweeps down from the top to the bottom of your heart there is a changing electrical potential. This is picked up by the electrocardiograph and used to diagnose the condition of your heart. In the brain, electrical changes also take place and these too can be picked up, by a machine called an electroencephalograph. These machines are used for diagnosis and for further research into what goes on in the heart and the brain in both normal and diseased states.
The medical physicist is also involved in the medical uses of ultrasound and of infrared (thermography). Ultrasound is sound pitched so high that the human ear cannot hear sounds well beyond our ability. Bats in fact emit these sounds and then pick up the echoes from the walls of caves and they are thus able to roam pitch black corridors of underground caverns at top speed; while dogs can hear whistles that we cannot. Ultrasound is used to diagnose brain tumors and blood clots, check blood flow in veins and the heart, even observe the development of the fetus in the mother's womb. A process called ultrasonography has been used to differentiate benign from malignant tumors and to find foreign bodies imbedded in the eye, even to spot gallstones.
In thermography, on the other hand, the medical physicist takes advantage of the fact heat waves are given off by the body's tissues in certain disease processes. By devising scanning instruments that can measure the variations in the surface temperature of the skin, these scientists have made it possible to detect breast cancers so small that they were not found by other techniques, and even to give warning of a stroke to come. In fact this giving off of heat by the human skin is being used by the military for reconnaissance.
Requirements and Costs of Training
Although this is a very young field, there are already a number of university programs being offered. You may become a medical physicist with only a bachelor's degree and one or two years of additional specialized training.
To get into college, you'll need whatever level of high school grades the college of your choice wants, and this may vary considerably. In any case, the better your grades are, the easier your real entry into this field, starting a master's or doctoral program, nobody will pay much attention to your high school grades. They will, however, pay close attention to what you did in college. You should by able to show better than a B average.
Salaries, Satisfaction and Opportunities
Salaries start in the low five figures in academic life, somewhat higher in industry. The very newness of the field makes it exciting.
The opportunities in this field are vast, for the work on the scientific side of medicine has really only just begun. There is no foreseeable limit to what has to be done, both in the study of diseases and their treatment, and in the further understanding for medical physicists far exceeds the supply, nor is there any likelihood of sufficient numbers entering this field in the foreseeable future.
Medical physics is actually part of the larger field of biophysics, but it has become so important that those who work in it have formed their own society. Like so many new and growing fields, the boundaries of the field are far from sharp or decisive. The parent field, biophysics, itself is relatively new.
The original biophysicists were usually people involved with electronics, but today's biophysicist utilizes all the physical sciences, including a heavy dose of mathematics. This challenging profession, on the frontiers of modern science, applies the most modern and sophisticated techniques to the solution of problems in biology, which until recently was largely a descriptive science. The field of study and research is sometimes called molecular biology.
A great deal of overlapping and confusion exists about what is included in the fields of molecular biology, biophysics, medical physics, and even biochemistry. In which field a particular scientist belongs depends more on what he's doing than on his degree or the title of his job: For example, a man with a degree in biology can be in any of these fields, as can a physicist.
There are a number of specialized fields in medical physics and their names indicate pretty clearly what they involve. Hospital physicists and radiation physicists, health physicists and radiation safety physicists are found in hospitals and other installations where any form of ionizing radiation is used, and they are also needed to check on the safety of any facility that may be a source of radioactivity or a radiation hazard. Space travel, for example, presents a problem of the possible effects of high energy particles on the astronauts and so medical physicists have been involved in space medicine also.
The medical physicists is also needed to teach and to train radiobiologists and medical students and doctors. It's not surprising that with so many demands, many jobs are now going begging because there are just not enough people to fill them.
What Does the Medical Physicist Do?
Essentially the medical physicist is involved with patients and so is a key member of the health care team. All of his work, in the last analysis, revolves around diseases and disorders regardless of whether he is studying them, or the basic physical mechanisms of the life processes, or working on the measurement of various vital functions. For even his study of these normal body mechanisms is done with the ultimate aim of understanding and treating diseases or the disturbances producing various disorders.
Medical physicists are especially active in the field of ionizing radiation. This ionization is capable of destroying living cells and so it has been used to attack and destroy cancer cells.
But the medical physicist is engaged in several other areas in addition to radiation. He can be found working on bioelectrical investigations of the heart and brain. Your heart is about the size of your clenched fist. The muscles start their contraction at the top. As this contraction sweeps down from the top to the bottom of your heart there is a changing electrical potential. This is picked up by the electrocardiograph and used to diagnose the condition of your heart. In the brain, electrical changes also take place and these too can be picked up, by a machine called an electroencephalograph. These machines are used for diagnosis and for further research into what goes on in the heart and the brain in both normal and diseased states.
The medical physicist is also involved in the medical uses of ultrasound and of infrared (thermography). Ultrasound is sound pitched so high that the human ear cannot hear sounds well beyond our ability. Bats in fact emit these sounds and then pick up the echoes from the walls of caves and they are thus able to roam pitch black corridors of underground caverns at top speed; while dogs can hear whistles that we cannot. Ultrasound is used to diagnose brain tumors and blood clots, check blood flow in veins and the heart, even observe the development of the fetus in the mother's womb. A process called ultrasonography has been used to differentiate benign from malignant tumors and to find foreign bodies imbedded in the eye, even to spot gallstones.
In thermography, on the other hand, the medical physicist takes advantage of the fact heat waves are given off by the body's tissues in certain disease processes. By devising scanning instruments that can measure the variations in the surface temperature of the skin, these scientists have made it possible to detect breast cancers so small that they were not found by other techniques, and even to give warning of a stroke to come. In fact this giving off of heat by the human skin is being used by the military for reconnaissance.
Requirements and Costs of Training
Although this is a very young field, there are already a number of university programs being offered. You may become a medical physicist with only a bachelor's degree and one or two years of additional specialized training.
To get into college, you'll need whatever level of high school grades the college of your choice wants, and this may vary considerably. In any case, the better your grades are, the easier your real entry into this field, starting a master's or doctoral program, nobody will pay much attention to your high school grades. They will, however, pay close attention to what you did in college. You should by able to show better than a B average.
Salaries, Satisfaction and Opportunities
Salaries start in the low five figures in academic life, somewhat higher in industry. The very newness of the field makes it exciting.
The opportunities in this field are vast, for the work on the scientific side of medicine has really only just begun. There is no foreseeable limit to what has to be done, both in the study of diseases and their treatment, and in the further understanding for medical physicists far exceeds the supply, nor is there any likelihood of sufficient numbers entering this field in the foreseeable future.
Schooling...
Education
From Wikipedia, the free encyclopedia
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Jump to: navigation, search
This article is about institutionalized education. For broader context of the term, see learning.
A kindergarten classroom in Afghanistan.
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Education encompasses teaching and learning specific skills, and also something less tangible but more profound: the imparting of knowledge, positive judgment and well-developed wisdom. Education has as one of its fundamental aspects the imparting of culture from generation to generation (see socialization). Education means 'to draw out', facilitating realisation of self-potential and latent talents of an individual. It is an application of pedagogy, a body of theoretical and applied research relating to teaching and learning and draws on many disciplines such as psychology, philosophy, computer science, linguistics, neuroscience, sociology and anthropology. [1]
The education of an individual human begins at birth and continues throughout life. (Some believe that education begins even before birth, as evidenced by some parents' playing music or reading to the baby in the womb in the hope it will influence the child's development.) For some, the struggles and triumphs of daily life provide far more instruction than does formal schooling (thus Mark Twain's admonition to "never let school interfere with your education"). Family members may have a profound educational effect — often more profound than they realize — though family teaching may function very informally.
Contents[hide]
1 Etymology
2 Education systems
2.1 Primary education
2.2 Secondary education
2.3 Higher education
2.4 Adult education
2.5 Alternative education
3 Education curriculum
4 Education process
4.1 Learning modalities
4.2 Teaching
4.3 Parental involvement
4.4 Education technology
5 Education history
6 Education philosophy
7 Education psychology
8 Education economics
9 Education sociology
10 See also
11 References
12 External links
//
[edit] Etymology
The word "education" derives from the Latin educare, meaning "to nourish" or "to raise".
[edit] Education systems
Schooling occurs when society or a group or an individual designs a curriculum to educate people, usually the young. Schooling can become systematic and thorough. Sometimes education systems can be used to promote doctrines or ideals as well as knowledge, which is known as social engineering. This can lead to political abuse of the system, particularly in totalitarian states.
[edit] Primary education
Main article: Primary education
Primary school in open air. Teacher (priest) with class from the outskirts of Bucharest, around 1842.
Primary or elementary education consists of the first years of formal, structured education that occur during childhood. In most countries, it is compulsory for children to receive primary education (though in many jurisdictions it is permissible for parents to provide it). Primary education generally begins when children are four to eight years of age. The division between primary and secondary education is somewhat arbitrary, but it generally occurs at about eleven or twelve years of age (adolescence); some educational systems have separate middle schools with the transition to the final stage of secondary education taking place at around the age of fourteen. In the United Kingdom, Ireland, New Zealand, Australia, South Africa, etc., schools which provide primary education are referred to as primary schools. Primary schools in these countries are often subdivided into infant schools and junior schools.
[edit] Secondary education
Main article: Secondary education
In most contemporary educational systems of the world, secondary education consists of the second years of formal education that occur during adolescence. It is characterised by transition from the typically compulsory, comprehensive primary education for minors to the optional, selective tertiary, "post-secondary", or "higher" education (e.g., university, vocational school) for adults. Depending on the system, schools for this period or a part of it may be called secondary or high schools, gymnasiums, lyceums, middle schools, colleges, or vocational schools. The exact meaning of any of these varies between the systems. The exact boundary between primary and secondary education varies from country to country and even within them, but is generally around the seventh to the tenth year of education. Secondary education occurs mainly during the teenage years. In the United States and Canada primary and secondary education together are sometimes referred to as K-12 education. The purpose of secondary education can be to give common knowledge, to prepare for either higher education or vocational education, or to train directly to a profession.
[edit] Higher education
Main article: Higher education
The University of Cambridge is an institute of higher learning.
Higher education, also called tertiary, third stage or post secondary education, often known as academia, is the non-compulsory educational level following the completion of a school providing a secondary education, such as a high school, secondary school, or gymnasium. Tertiary education is normally taken to include undergraduate and postgraduate education, as well as vocational education and training. Colleges and universities are the main institutions that provide tertiary education. Collectively, these are sometimes known as tertiary institutions. Examples of institutions that provide post-secondary education are vocational schools, community colleges and universities in the United States, the TAFEs in Australia, CEGEPs in Quebec,and the IEKs in Greece. Tertiary education generally results in the receipt of certificates, diplomas, or academic degrees. Higher education includes teaching, research and social services activities of universities, and within the realm of teaching, it includes both the undergraduate level (sometimes referred to as tertiary education) and the graduate (or postgraduate) level (sometimes referred to as graduate school). In the United Kingdom post-secondary education below the level of higher education is referred to as further education. Higher education in that country generally involves work towards a degree-level or foundation degree qualification. In most developed countries a high proportion of the population (up to 50%) now enter higher education at some time in their lives. Higher education is therefore very important to national economies, both as a significant industry in its own right, and as a source of trained and educated personnel for the rest of the economy.
[edit] Adult education
Lifelong, or adult, education has become widespread in many countries. However, education is still seen by many as something aimed at children, and adult education is often branded as adult learning or lifelong learning. Adult education takes on many forms, from formal class-based learning to self-directed learning. Lending libraries provide inexpensive informal access to books and other self-instructional materials. The rise in computer ownership and internet access has given both adults and children greater access to both formal and informal education. In Scandinavia a unique approach to learning termed folkbildning has long been recognised as contributing to adult education through the use of learning circles.
[edit] Alternative education
Main article: Alternative education
Alternative education, also known as non-traditional education or educational alternative, is a broad term which may be used to refer to all forms of education outside of traditional education (for all age groups and levels of education). This may include both forms of education designed for students with special needs (ranging from teenage pregnancy to intellectual disability) and forms of education designed for a general audience which employ alternative educational philosophies and/or methods.
Alternatives of the latter type are often the result of education reform and are rooted in various philosophies that are commonly fundamentally different from those of traditional compulsory education. While some have strong political, scholarly, or philosophical orientations, others are more informal associations of teachers and students dissatisfied with certain aspects of traditional education. These alternatives, which include charter schools, alternative schools, independent schools, and home-based learning vary widely, but often emphasize the value of small class size, close relationships between students and teachers, and a sense of community.
In certain places, especially in the United States, the term alternative may largely refer to forms of education catering to "at risk" students, as it is, for example, in this definition drafted by the Massachusetts Department of Education. [1]
[edit] Education curriculum
Main articles: Curriculum and List of academic disciplines
An academic discipline is a branch of knowledge which is formally taught, either at the university, or via some other such method. Functionally, disciplines are usually defined and recognized by the academic journals in which research is published, and by the learned societies to which their practitioners belong. Professors say schooling is 80% psychological, 20% physical effort.
Each discipline usually has several sub-disciplines or branches, and distinguishing lines are often both arbitrary and ambiguous. Examples of broad areas of academic disciplines include the natural sciences, mathematics, computer science, social sciences, humanities and applied sciences. [2]
[edit] Education process
[edit] Learning modalities
There has been a great deal of work on learning styles over the last two decades. Dunn and Dunn[3] focused on identifying relevant stimuli that may influence learning and manipulating the school environment, at about the same time as Joseph Renzulli[4] recommended varying teaching strategies. Howard Gardner[5] identified individual talents or aptitudes in his Multiple Intelligences theories. Based on the works of Jung, the Myers-Briggs Type Indicator and Keirsey Temperament Sorter[6] focused on understanding how people's personality affects the way they interact personally, and how this affects the way individuals respond to each other within the learning environment. The work of David Kolb and Anthony Gregorc's Type Delineator[7] follows a similar but more simplified approach.
Education can be physically divided into many different learning "modes" but the learning modalities[8] are probably the most common:[9]
Kinesthetic learning based on hands-on work and engaging in activities.
Visual learning based on observation and seeing what is being learned.
Auditory learning based on listening to instructions/information.
Depending on their preferred learning modality, different teaching techniques have different levels of effectiveness.[10] Effective teaching requires a variety of teaching methods which cover all three learning modalities. No matter what their preference, students should have equal opportunities to learn in a way that is effective for them.[11]
[edit] Teaching
Teachers need the ability to understand a subject well enough to convey its essence to a new generation of students. The goal is to establish a sound knowledge base on which students will be able to build as they are exposed to different life experiences. The passing of knowledge from generation to generation allows students to grow into useful members of society. Good teachers can translate information, good judgment, experience and wisdom into relevant knowledge that a student can understand and retain. As a profession, teaching has very high levels of Work-Related Stress (WRS)[12] which are listed as amongst the highest of any profession in some countries, such as the United Kingdom. The degree of this problem is becoming increasingly recognized and support systems are put into place.[13]
[edit] Parental involvement
Parental involvement is an important element in a child's educational development. Early and consistent parental involvement in the child's life is critical. Examples include reading to children at an early age, teaching patterns, interpersonal communication skills, getting them involved in their community, exposing them to diverse cultures and educating them about a healthy lifestyle. The socialization and academic education of a child are aided by the involvement of the student, parent(s), extended family, teachers and others in the community. Parent involvement is more than the parent being the field trip helper or the lunch lady. Parents need to be asked about how their child learns best. They need to share their career expertise with the children. Today's educators need to remember that parents are the child's first and foremost teacher; parents, too, are experts, and teachers should learn from them.
Academic achievement and parental involvement are strongly linked in the research. Many schools are now beginning parental involvement programs in a more organized fashion. In the US this has been led in part by the No Child Left Behind legislation from the US Department of Education.
Parental involvement in education does not end at high school graduation. College parents play a vital role in supporting their children's post-secondary education emotionally, intellectually and financially.
[edit] Education technology
Main article: Educational technology
Technology is an increasingly influential factor in education. Computers and mobile phones are being widely used in developed countries both to complement established education practices and develop new ways of learning such as online education (a type of distance education). This gives students the opportunity to choose what they are interested in learning. The proliferation of computers also means the increase of programming and blogging. Technology offers powerful learning tools that demand new skills and understandings of students, including Multimedia literacy, and provides new ways to engage students, such as classroom management software. Technology is being used more not only in administrative duties in education but also in the instruction of students. The use of technologies such as PowerPoint and interactive whiteboard is capturing the attention of students in the classroom. Technology is also being used in the assessment of students. One example is the Audience Response System (ARS), which allows immediate feedback tests and classroom discussions.
Information and communication technologies (ICTs) are a “diverse set of tools and resources used to communicate, create, disseminate, store, and manage information.”[14] These technologies include computers, the Internet, broadcasting technologies (radio and television), and telephony. There is increasing interest in how computers and the Internet can improve education at all levels, in both formal and non-formal settings.[15] Older ICT technologies, such as radio and television, have for over forty years been used for open and distance learning, although print remains the cheapest, most accessible and therefore most dominant delivery mechanism in both developed and developing countries.[16] The use of computers and the Internet is still in its infancy in developing countries, if these are used at all, due to limited infrastructure and the attendant high costs of access. Usually, various technologies are used in combination rather than as the sole delivery mechanism. For example, the Kothmale Community Radio Internet uses both radio broadcasts and computer and Internet technologies to facilitate the sharing of information and provide educational opportunities in a rural community in Sri Lanka.[17] The Open University of the United Kingdom (UKOU), established in 1969 as the first educational institution in the world wholly dedicated to open and distance learning, still relies heavily on print-based materials supplemented by radio, television and, in recent years, online programming.[18] Similarly, the Indira Gandhi National Open University in India combines the use of print, recorded audio and video, broadcast radio and television, and audioconferencing technologies.[19]
Computer assisted learning (CAL), CAL has been increasingly used to describe the use of technology in teaching.
[edit] Education history
Main article: History of education
A depiction of the University of Bologna, Italy
The history of education according to Dieter Lenzen, president of the Freie Universität Berlin 1994 "began either millions of years ago or at the end of 1770". Education as a science cannot be separated from the educational traditions that existed before. Education was the natural response of early civilizations to the struggle of surviving and thriving as a culture. Adults trained the young of their society in the knowledge and skills they would need to master and eventually pass on. The evolution of culture, and human beings as a species depended on this practice of transmitting knowledge. In pre-literate societies this was achieved orally and through imitation. Story-telling continued from one generation to the next. Oral language developed into written symbols and letters. The depth and breadth of knowledge that could be preserved and passed soon increased exponentially. When cultures began to extend their knowledge beyond the basic skills of communicating, trading, gathering food, religious practices, etc, formal education, and schooling, eventually followed. Schooling in this sense was already in place in Egypt between 3000 and 500BC.
[edit] Education philosophy
Main articles: Philosophy of education and Epistemology
John Locke's work Some Thoughts Concerning Education was written in 1693 and still reflects traditional education priorities
The philosophy of education is the study of the purpose, nature and ideal content of education. Related topics include knowledge itself, the nature of the knowing mind and the human subject, problems of authority, and the relationship between education and society. At least since Locke's time, the philosophy of education has been linked to theories of developmental psychology and human development.
Fundamental purposes that have been proposed for education include:
The enterprise of civil society depends on educating young people to become responsible, thoughtful and enterprising citizens. This is an intricate, challenging task requiring deep understanding of ethical principles, moral values, political theory, aesthetics, and economics, not to mention an understanding of who children are, in themselves and in society.
Progress in every practical field depends on having capacities that schooling can educate. Education is thus a means to foster the individual's, society's, and even humanity's future development and prosperity. Emphasis is often put on economic success in this regard.
One's individual development and the capacity to fulfill one's own purposes can depend on an adequate preparation in childhood. Education can thus attempt to give a firm foundation for the achievement of personal fulfillment. The better the foundation that is built, the more successful the child will be. Simple basics in education can carry a child far.
A central tenet of education typically includes “the imparting of knowledge.” At a very basic level, this purpose ultimately deals with the nature, origin and scope of knowledge. The branch of philosophy that addresses these and related issues is known as epistemology. This area of study often focuses on analyzing the nature and variety of knowledge and how it relates to similar notions such as truth and belief.
While the term, knowledge, is often used to convey this general purpose of education, it can also be viewed as part of a continuum of knowing that ranges from very specific data to the highest levels. Seen in this light, the continuum may be thought to consist of a general hierarchy of overlapping levels of knowing. Students must be able to connect new information to a piece of old information to be better able to learn, understand, and retain information. This continuum may include notions such as data, information, knowledge, wisdom, and realization.
[edit] Education psychology
Main article: Educational psychology
A class size experiment in the United States found that attending small classes for 3 or more years in the early grades increased high school graduation of students from low income families.[20]
Educational psychology is the study of how humans learn in educational settings, the effectiveness of educational interventions, the psychology of teaching, and the social psychology of schools as organizations. Although the terms "educational psychology" and "school psychology" are often used interchangeably, researchers and theorists are likely to be identified as educational psychologists, whereas practitioners in schools or school-related settings are identified as school psychologists. Educational psychology is concerned with the processes of educational attainment in the general population and in sub-populations such as gifted children and those with specific disabilities.
Educational psychology can in part be understood through its relationship with other disciplines. It is informed primarily by psychology, bearing a relationship to that discipline analogous to the relationship between medicine and biology. Educational psychology in turn informs a wide range of specialities within educational studies, including instructional design, educational technology, curriculum development, organizational learning, special education and classroom management. Educational psychology both draws from and contributes to cognitive science and the learning sciences. In universities, departments of educational psychology are usually housed within faculties of education, possibly accounting for the lack of representation of educational psychology content in introductory psychology textbooks (Lucas, Blazek, & Raley, 2006).
[edit] Education economics
If we look at a sorted list of nations with the highest level of secondary schooling we notice these are the richest countries in the world, based on GDP per capita. High rates of education are essential for countries to achieve high levels of economic growth. In theory poor countries should grow faster than rich countries because they can adopt cutting edge technologies already tried and tested by rich countries. But economists argue that if the gap in education between a rich and a poor nation is too large, as is the case between the poorest and the richest nations in the world, the transfer of these technologies that drive economic growth becomes difficult, thus the economies of the world's poorest nations stagnate.
[edit] Education sociology
Main article: Sociology of education
The sociology of education is the study of how social institutions and forces affect educational processes and outcomes, and vice versa. By many, education is understood to be a means of overcoming handicaps, achieving greater equality and acquiring wealth and status for all (Sargent 1994). Learners may be motivated by aspirations for progress and betterment. Education is perceived as a place where children can develop according to their unique needs and potentialities (Schofield 1999). The purpose of education can be to develop every individual to their full potential. However, according to some sociologists, a key problem is that the educational needs of individuals and marginalized groups may be at odds with existing social processes, such as maintaining social stability through the reproduction of inequality. The understanding of the goals and means of educational socialization processes differs according to the sociological paradigm used.
Developing countries
Russia has more academic graduates than any other country in Europe.
In developing countries, the number and seriousness of the problems faced are naturally greater. People are sometimes unaware of the importance of education, and there is economic pressure from those parents who prioritize their children's making money in the short term over any long-term benefits of education. Recent studies on child labor and poverty have suggested that when poor families reach a certain economic threshold where families are able to provide for their basic needs, parents return their children to school. This has been found to be true, once the threshold has been breached, even if the potential economic value of the children's work has increased since their return to school. Teachers are often paid less than other similar professions.
A lack of good universities, and a low acceptance rate for good universities, is evident in countries with a relatively high population density. In some countries, there are uniform, overstructured, inflexible centralized programs from a central agency that regulates all aspects of education.
Due to globalization, increased pressure on students in curricular activities
Removal of a certain percentage of students for improvisation of academics (usually practised in schools, after 10th grade)
India is now developing technologies that will skip land based phone and internet lines. Instead, India launched EDUSAT, an education satellite that can reach more of the country at a greatly reduced cost. There is also an initiative started by a group out of MIT and supported by several major corporations to develop a $100 laptop. The laptops should be available by late 2006 or 2007. The laptops, sold at cost, will enable developing countries to give their children a digital education, and to close the digital divide across the world.
In Africa, NEPAD has launched an "e-school programme" to provide all 600,000 primary and high schools with computer equipment, learning materials and internet access within 10 years. Private groups, like The Church of Jesus Christ of Latter-day Saints, are working to give more individuals opportunities to receive education in developing countries through such programs as the Perpetual Education Fund. An International Development Agency project called nabuur.com, started with the support of American President Bill Clinton, uses the internet to allow co-operation by individuals on issues of social development.
Internationalisation
Education is becoming increasingly international. Not only are the materials becoming more influenced by the rich international environment, but exchanges among students at all levels are also playing an increasingly important role. In Europe, for example, the Socrates-Erasmus Programme stimulates exchanges across European universities. Also, the Soros Foundation provides many opportunities for students from central Asia and eastern Europe. Some scholars argue that, regardless of whether one system is considered better or worse than another, experiencing a different way of education can often be considered to be the most important, enriching element of an international learning experience (Dubois et al. 2006).
Challenges
The goal of education is fourfold: the social purpose, intellectual purpose, economic purpose, and political/civic purpose. Current education issues include which teaching method(s) are most effective, how to determine what knowledge should be taught, which knowledge is most relevant, and how well the pupil will retain incoming knowledge. Educators such as George Counts and Paulo Freire identified education as an inherently political process with inherently political outcomes. The challenge of identifying whose ideas are transferred and what goals they serve has always stood in the face of formal and informal education.
In addition to the "Three R's", reading, writing, and arithmetic, Western primary and secondary schools attempt to teach the basic knowledge of history, geography, mathematics (usually including calculus and algebra), physics, chemistry and sometimes politics, in the hope that students will retain and use this knowledge as they age or that the skills acquired will be transferable. The current education system measures competency with tests and assignments and then assigns each student a corresponding grade. The grades, usually a letter grade or a percentage, are intended to represent the amount of all material presented in class that the student understood. Pre- and post-tests may be used to measure how much was learned.
Educational progressives or advocates of unschooling often believe that grades do not necessarily reveal the strengths and weaknesses of a student, and that there is an unfortunate lack of youth voice in the educational process. Some feel the current grading system lowers students' self-confidence, as students may receive poor marks due to factors outside their control. Such factors include poverty, child abuse, and prejudiced or incompetent teachers.
By contrast, many advocates of a more traditional or "back to basics" approach believe that the direction of reform needs to be the opposite. Students are not inspired or challenged to achieve success because of the dumbing down of the curriculum and the replacement of the "canon" with inferior material. They believe that self-confidence arises not from removing hurdles such as grading, but by making them fair and encouraging students to gain pride from knowing they can jump over these hurdles. On the one hand, Albert Einstein, the most famous physicist of the twentieth century, who is credited with helping us understand the universe better, was not a model school student. He was uninterested in what was being taught, and he did not attend classes all the time. On the other hand, his gifts eventually shone through and added to the sum of human knowledge.
There are a number of highly controversial issues in education. Should some knowledge be forgotten? Should classes be segregated by gender? What should be taught? There are also some philosophies, for example Transcendentalism, that would probably reject conventional education in the belief that knowledge should be gained through more direct personal experience. A recent book argues that children are being expected to learn too much. "There is an ongoing tendency to increase the length of textbooks. There are various reasons why people want to add to the education of children. People who work on education often believe, nobly enough, that the most important contribution is to get children to learn more. Publishers want to sell new books and adding new material is an important aspect of an effective sales pitch".[21] Also, the cost of higher education in developed countries is increasingly becoming an issue.
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This article is about institutionalized education. For broader context of the term, see learning.
A kindergarten classroom in Afghanistan.
Education Portal
University Portal
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Education encompasses teaching and learning specific skills, and also something less tangible but more profound: the imparting of knowledge, positive judgment and well-developed wisdom. Education has as one of its fundamental aspects the imparting of culture from generation to generation (see socialization). Education means 'to draw out', facilitating realisation of self-potential and latent talents of an individual. It is an application of pedagogy, a body of theoretical and applied research relating to teaching and learning and draws on many disciplines such as psychology, philosophy, computer science, linguistics, neuroscience, sociology and anthropology. [1]
The education of an individual human begins at birth and continues throughout life. (Some believe that education begins even before birth, as evidenced by some parents' playing music or reading to the baby in the womb in the hope it will influence the child's development.) For some, the struggles and triumphs of daily life provide far more instruction than does formal schooling (thus Mark Twain's admonition to "never let school interfere with your education"). Family members may have a profound educational effect — often more profound than they realize — though family teaching may function very informally.
Contents[hide]
1 Etymology
2 Education systems
2.1 Primary education
2.2 Secondary education
2.3 Higher education
2.4 Adult education
2.5 Alternative education
3 Education curriculum
4 Education process
4.1 Learning modalities
4.2 Teaching
4.3 Parental involvement
4.4 Education technology
5 Education history
6 Education philosophy
7 Education psychology
8 Education economics
9 Education sociology
10 See also
11 References
12 External links
//
[edit] Etymology
The word "education" derives from the Latin educare, meaning "to nourish" or "to raise".
[edit] Education systems
Schooling occurs when society or a group or an individual designs a curriculum to educate people, usually the young. Schooling can become systematic and thorough. Sometimes education systems can be used to promote doctrines or ideals as well as knowledge, which is known as social engineering. This can lead to political abuse of the system, particularly in totalitarian states.
[edit] Primary education
Main article: Primary education
Primary school in open air. Teacher (priest) with class from the outskirts of Bucharest, around 1842.
Primary or elementary education consists of the first years of formal, structured education that occur during childhood. In most countries, it is compulsory for children to receive primary education (though in many jurisdictions it is permissible for parents to provide it). Primary education generally begins when children are four to eight years of age. The division between primary and secondary education is somewhat arbitrary, but it generally occurs at about eleven or twelve years of age (adolescence); some educational systems have separate middle schools with the transition to the final stage of secondary education taking place at around the age of fourteen. In the United Kingdom, Ireland, New Zealand, Australia, South Africa, etc., schools which provide primary education are referred to as primary schools. Primary schools in these countries are often subdivided into infant schools and junior schools.
[edit] Secondary education
Main article: Secondary education
In most contemporary educational systems of the world, secondary education consists of the second years of formal education that occur during adolescence. It is characterised by transition from the typically compulsory, comprehensive primary education for minors to the optional, selective tertiary, "post-secondary", or "higher" education (e.g., university, vocational school) for adults. Depending on the system, schools for this period or a part of it may be called secondary or high schools, gymnasiums, lyceums, middle schools, colleges, or vocational schools. The exact meaning of any of these varies between the systems. The exact boundary between primary and secondary education varies from country to country and even within them, but is generally around the seventh to the tenth year of education. Secondary education occurs mainly during the teenage years. In the United States and Canada primary and secondary education together are sometimes referred to as K-12 education. The purpose of secondary education can be to give common knowledge, to prepare for either higher education or vocational education, or to train directly to a profession.
[edit] Higher education
Main article: Higher education
The University of Cambridge is an institute of higher learning.
Higher education, also called tertiary, third stage or post secondary education, often known as academia, is the non-compulsory educational level following the completion of a school providing a secondary education, such as a high school, secondary school, or gymnasium. Tertiary education is normally taken to include undergraduate and postgraduate education, as well as vocational education and training. Colleges and universities are the main institutions that provide tertiary education. Collectively, these are sometimes known as tertiary institutions. Examples of institutions that provide post-secondary education are vocational schools, community colleges and universities in the United States, the TAFEs in Australia, CEGEPs in Quebec,and the IEKs in Greece. Tertiary education generally results in the receipt of certificates, diplomas, or academic degrees. Higher education includes teaching, research and social services activities of universities, and within the realm of teaching, it includes both the undergraduate level (sometimes referred to as tertiary education) and the graduate (or postgraduate) level (sometimes referred to as graduate school). In the United Kingdom post-secondary education below the level of higher education is referred to as further education. Higher education in that country generally involves work towards a degree-level or foundation degree qualification. In most developed countries a high proportion of the population (up to 50%) now enter higher education at some time in their lives. Higher education is therefore very important to national economies, both as a significant industry in its own right, and as a source of trained and educated personnel for the rest of the economy.
[edit] Adult education
Lifelong, or adult, education has become widespread in many countries. However, education is still seen by many as something aimed at children, and adult education is often branded as adult learning or lifelong learning. Adult education takes on many forms, from formal class-based learning to self-directed learning. Lending libraries provide inexpensive informal access to books and other self-instructional materials. The rise in computer ownership and internet access has given both adults and children greater access to both formal and informal education. In Scandinavia a unique approach to learning termed folkbildning has long been recognised as contributing to adult education through the use of learning circles.
[edit] Alternative education
Main article: Alternative education
Alternative education, also known as non-traditional education or educational alternative, is a broad term which may be used to refer to all forms of education outside of traditional education (for all age groups and levels of education). This may include both forms of education designed for students with special needs (ranging from teenage pregnancy to intellectual disability) and forms of education designed for a general audience which employ alternative educational philosophies and/or methods.
Alternatives of the latter type are often the result of education reform and are rooted in various philosophies that are commonly fundamentally different from those of traditional compulsory education. While some have strong political, scholarly, or philosophical orientations, others are more informal associations of teachers and students dissatisfied with certain aspects of traditional education. These alternatives, which include charter schools, alternative schools, independent schools, and home-based learning vary widely, but often emphasize the value of small class size, close relationships between students and teachers, and a sense of community.
In certain places, especially in the United States, the term alternative may largely refer to forms of education catering to "at risk" students, as it is, for example, in this definition drafted by the Massachusetts Department of Education. [1]
[edit] Education curriculum
Main articles: Curriculum and List of academic disciplines
An academic discipline is a branch of knowledge which is formally taught, either at the university, or via some other such method. Functionally, disciplines are usually defined and recognized by the academic journals in which research is published, and by the learned societies to which their practitioners belong. Professors say schooling is 80% psychological, 20% physical effort.
Each discipline usually has several sub-disciplines or branches, and distinguishing lines are often both arbitrary and ambiguous. Examples of broad areas of academic disciplines include the natural sciences, mathematics, computer science, social sciences, humanities and applied sciences. [2]
[edit] Education process
[edit] Learning modalities
There has been a great deal of work on learning styles over the last two decades. Dunn and Dunn[3] focused on identifying relevant stimuli that may influence learning and manipulating the school environment, at about the same time as Joseph Renzulli[4] recommended varying teaching strategies. Howard Gardner[5] identified individual talents or aptitudes in his Multiple Intelligences theories. Based on the works of Jung, the Myers-Briggs Type Indicator and Keirsey Temperament Sorter[6] focused on understanding how people's personality affects the way they interact personally, and how this affects the way individuals respond to each other within the learning environment. The work of David Kolb and Anthony Gregorc's Type Delineator[7] follows a similar but more simplified approach.
Education can be physically divided into many different learning "modes" but the learning modalities[8] are probably the most common:[9]
Kinesthetic learning based on hands-on work and engaging in activities.
Visual learning based on observation and seeing what is being learned.
Auditory learning based on listening to instructions/information.
Depending on their preferred learning modality, different teaching techniques have different levels of effectiveness.[10] Effective teaching requires a variety of teaching methods which cover all three learning modalities. No matter what their preference, students should have equal opportunities to learn in a way that is effective for them.[11]
[edit] Teaching
Teachers need the ability to understand a subject well enough to convey its essence to a new generation of students. The goal is to establish a sound knowledge base on which students will be able to build as they are exposed to different life experiences. The passing of knowledge from generation to generation allows students to grow into useful members of society. Good teachers can translate information, good judgment, experience and wisdom into relevant knowledge that a student can understand and retain. As a profession, teaching has very high levels of Work-Related Stress (WRS)[12] which are listed as amongst the highest of any profession in some countries, such as the United Kingdom. The degree of this problem is becoming increasingly recognized and support systems are put into place.[13]
[edit] Parental involvement
Parental involvement is an important element in a child's educational development. Early and consistent parental involvement in the child's life is critical. Examples include reading to children at an early age, teaching patterns, interpersonal communication skills, getting them involved in their community, exposing them to diverse cultures and educating them about a healthy lifestyle. The socialization and academic education of a child are aided by the involvement of the student, parent(s), extended family, teachers and others in the community. Parent involvement is more than the parent being the field trip helper or the lunch lady. Parents need to be asked about how their child learns best. They need to share their career expertise with the children. Today's educators need to remember that parents are the child's first and foremost teacher; parents, too, are experts, and teachers should learn from them.
Academic achievement and parental involvement are strongly linked in the research. Many schools are now beginning parental involvement programs in a more organized fashion. In the US this has been led in part by the No Child Left Behind legislation from the US Department of Education.
Parental involvement in education does not end at high school graduation. College parents play a vital role in supporting their children's post-secondary education emotionally, intellectually and financially.
[edit] Education technology
Main article: Educational technology
Technology is an increasingly influential factor in education. Computers and mobile phones are being widely used in developed countries both to complement established education practices and develop new ways of learning such as online education (a type of distance education). This gives students the opportunity to choose what they are interested in learning. The proliferation of computers also means the increase of programming and blogging. Technology offers powerful learning tools that demand new skills and understandings of students, including Multimedia literacy, and provides new ways to engage students, such as classroom management software. Technology is being used more not only in administrative duties in education but also in the instruction of students. The use of technologies such as PowerPoint and interactive whiteboard is capturing the attention of students in the classroom. Technology is also being used in the assessment of students. One example is the Audience Response System (ARS), which allows immediate feedback tests and classroom discussions.
Information and communication technologies (ICTs) are a “diverse set of tools and resources used to communicate, create, disseminate, store, and manage information.”[14] These technologies include computers, the Internet, broadcasting technologies (radio and television), and telephony. There is increasing interest in how computers and the Internet can improve education at all levels, in both formal and non-formal settings.[15] Older ICT technologies, such as radio and television, have for over forty years been used for open and distance learning, although print remains the cheapest, most accessible and therefore most dominant delivery mechanism in both developed and developing countries.[16] The use of computers and the Internet is still in its infancy in developing countries, if these are used at all, due to limited infrastructure and the attendant high costs of access. Usually, various technologies are used in combination rather than as the sole delivery mechanism. For example, the Kothmale Community Radio Internet uses both radio broadcasts and computer and Internet technologies to facilitate the sharing of information and provide educational opportunities in a rural community in Sri Lanka.[17] The Open University of the United Kingdom (UKOU), established in 1969 as the first educational institution in the world wholly dedicated to open and distance learning, still relies heavily on print-based materials supplemented by radio, television and, in recent years, online programming.[18] Similarly, the Indira Gandhi National Open University in India combines the use of print, recorded audio and video, broadcast radio and television, and audioconferencing technologies.[19]
Computer assisted learning (CAL), CAL has been increasingly used to describe the use of technology in teaching.
[edit] Education history
Main article: History of education
A depiction of the University of Bologna, Italy
The history of education according to Dieter Lenzen, president of the Freie Universität Berlin 1994 "began either millions of years ago or at the end of 1770". Education as a science cannot be separated from the educational traditions that existed before. Education was the natural response of early civilizations to the struggle of surviving and thriving as a culture. Adults trained the young of their society in the knowledge and skills they would need to master and eventually pass on. The evolution of culture, and human beings as a species depended on this practice of transmitting knowledge. In pre-literate societies this was achieved orally and through imitation. Story-telling continued from one generation to the next. Oral language developed into written symbols and letters. The depth and breadth of knowledge that could be preserved and passed soon increased exponentially. When cultures began to extend their knowledge beyond the basic skills of communicating, trading, gathering food, religious practices, etc, formal education, and schooling, eventually followed. Schooling in this sense was already in place in Egypt between 3000 and 500BC.
[edit] Education philosophy
Main articles: Philosophy of education and Epistemology
John Locke's work Some Thoughts Concerning Education was written in 1693 and still reflects traditional education priorities
The philosophy of education is the study of the purpose, nature and ideal content of education. Related topics include knowledge itself, the nature of the knowing mind and the human subject, problems of authority, and the relationship between education and society. At least since Locke's time, the philosophy of education has been linked to theories of developmental psychology and human development.
Fundamental purposes that have been proposed for education include:
The enterprise of civil society depends on educating young people to become responsible, thoughtful and enterprising citizens. This is an intricate, challenging task requiring deep understanding of ethical principles, moral values, political theory, aesthetics, and economics, not to mention an understanding of who children are, in themselves and in society.
Progress in every practical field depends on having capacities that schooling can educate. Education is thus a means to foster the individual's, society's, and even humanity's future development and prosperity. Emphasis is often put on economic success in this regard.
One's individual development and the capacity to fulfill one's own purposes can depend on an adequate preparation in childhood. Education can thus attempt to give a firm foundation for the achievement of personal fulfillment. The better the foundation that is built, the more successful the child will be. Simple basics in education can carry a child far.
A central tenet of education typically includes “the imparting of knowledge.” At a very basic level, this purpose ultimately deals with the nature, origin and scope of knowledge. The branch of philosophy that addresses these and related issues is known as epistemology. This area of study often focuses on analyzing the nature and variety of knowledge and how it relates to similar notions such as truth and belief.
While the term, knowledge, is often used to convey this general purpose of education, it can also be viewed as part of a continuum of knowing that ranges from very specific data to the highest levels. Seen in this light, the continuum may be thought to consist of a general hierarchy of overlapping levels of knowing. Students must be able to connect new information to a piece of old information to be better able to learn, understand, and retain information. This continuum may include notions such as data, information, knowledge, wisdom, and realization.
[edit] Education psychology
Main article: Educational psychology
A class size experiment in the United States found that attending small classes for 3 or more years in the early grades increased high school graduation of students from low income families.[20]
Educational psychology is the study of how humans learn in educational settings, the effectiveness of educational interventions, the psychology of teaching, and the social psychology of schools as organizations. Although the terms "educational psychology" and "school psychology" are often used interchangeably, researchers and theorists are likely to be identified as educational psychologists, whereas practitioners in schools or school-related settings are identified as school psychologists. Educational psychology is concerned with the processes of educational attainment in the general population and in sub-populations such as gifted children and those with specific disabilities.
Educational psychology can in part be understood through its relationship with other disciplines. It is informed primarily by psychology, bearing a relationship to that discipline analogous to the relationship between medicine and biology. Educational psychology in turn informs a wide range of specialities within educational studies, including instructional design, educational technology, curriculum development, organizational learning, special education and classroom management. Educational psychology both draws from and contributes to cognitive science and the learning sciences. In universities, departments of educational psychology are usually housed within faculties of education, possibly accounting for the lack of representation of educational psychology content in introductory psychology textbooks (Lucas, Blazek, & Raley, 2006).
[edit] Education economics
If we look at a sorted list of nations with the highest level of secondary schooling we notice these are the richest countries in the world, based on GDP per capita. High rates of education are essential for countries to achieve high levels of economic growth. In theory poor countries should grow faster than rich countries because they can adopt cutting edge technologies already tried and tested by rich countries. But economists argue that if the gap in education between a rich and a poor nation is too large, as is the case between the poorest and the richest nations in the world, the transfer of these technologies that drive economic growth becomes difficult, thus the economies of the world's poorest nations stagnate.
[edit] Education sociology
Main article: Sociology of education
The sociology of education is the study of how social institutions and forces affect educational processes and outcomes, and vice versa. By many, education is understood to be a means of overcoming handicaps, achieving greater equality and acquiring wealth and status for all (Sargent 1994). Learners may be motivated by aspirations for progress and betterment. Education is perceived as a place where children can develop according to their unique needs and potentialities (Schofield 1999). The purpose of education can be to develop every individual to their full potential. However, according to some sociologists, a key problem is that the educational needs of individuals and marginalized groups may be at odds with existing social processes, such as maintaining social stability through the reproduction of inequality. The understanding of the goals and means of educational socialization processes differs according to the sociological paradigm used.
Developing countries
Russia has more academic graduates than any other country in Europe.
In developing countries, the number and seriousness of the problems faced are naturally greater. People are sometimes unaware of the importance of education, and there is economic pressure from those parents who prioritize their children's making money in the short term over any long-term benefits of education. Recent studies on child labor and poverty have suggested that when poor families reach a certain economic threshold where families are able to provide for their basic needs, parents return their children to school. This has been found to be true, once the threshold has been breached, even if the potential economic value of the children's work has increased since their return to school. Teachers are often paid less than other similar professions.
A lack of good universities, and a low acceptance rate for good universities, is evident in countries with a relatively high population density. In some countries, there are uniform, overstructured, inflexible centralized programs from a central agency that regulates all aspects of education.
Due to globalization, increased pressure on students in curricular activities
Removal of a certain percentage of students for improvisation of academics (usually practised in schools, after 10th grade)
India is now developing technologies that will skip land based phone and internet lines. Instead, India launched EDUSAT, an education satellite that can reach more of the country at a greatly reduced cost. There is also an initiative started by a group out of MIT and supported by several major corporations to develop a $100 laptop. The laptops should be available by late 2006 or 2007. The laptops, sold at cost, will enable developing countries to give their children a digital education, and to close the digital divide across the world.
In Africa, NEPAD has launched an "e-school programme" to provide all 600,000 primary and high schools with computer equipment, learning materials and internet access within 10 years. Private groups, like The Church of Jesus Christ of Latter-day Saints, are working to give more individuals opportunities to receive education in developing countries through such programs as the Perpetual Education Fund. An International Development Agency project called nabuur.com, started with the support of American President Bill Clinton, uses the internet to allow co-operation by individuals on issues of social development.
Internationalisation
Education is becoming increasingly international. Not only are the materials becoming more influenced by the rich international environment, but exchanges among students at all levels are also playing an increasingly important role. In Europe, for example, the Socrates-Erasmus Programme stimulates exchanges across European universities. Also, the Soros Foundation provides many opportunities for students from central Asia and eastern Europe. Some scholars argue that, regardless of whether one system is considered better or worse than another, experiencing a different way of education can often be considered to be the most important, enriching element of an international learning experience (Dubois et al. 2006).
Challenges
The goal of education is fourfold: the social purpose, intellectual purpose, economic purpose, and political/civic purpose. Current education issues include which teaching method(s) are most effective, how to determine what knowledge should be taught, which knowledge is most relevant, and how well the pupil will retain incoming knowledge. Educators such as George Counts and Paulo Freire identified education as an inherently political process with inherently political outcomes. The challenge of identifying whose ideas are transferred and what goals they serve has always stood in the face of formal and informal education.
In addition to the "Three R's", reading, writing, and arithmetic, Western primary and secondary schools attempt to teach the basic knowledge of history, geography, mathematics (usually including calculus and algebra), physics, chemistry and sometimes politics, in the hope that students will retain and use this knowledge as they age or that the skills acquired will be transferable. The current education system measures competency with tests and assignments and then assigns each student a corresponding grade. The grades, usually a letter grade or a percentage, are intended to represent the amount of all material presented in class that the student understood. Pre- and post-tests may be used to measure how much was learned.
Educational progressives or advocates of unschooling often believe that grades do not necessarily reveal the strengths and weaknesses of a student, and that there is an unfortunate lack of youth voice in the educational process. Some feel the current grading system lowers students' self-confidence, as students may receive poor marks due to factors outside their control. Such factors include poverty, child abuse, and prejudiced or incompetent teachers.
By contrast, many advocates of a more traditional or "back to basics" approach believe that the direction of reform needs to be the opposite. Students are not inspired or challenged to achieve success because of the dumbing down of the curriculum and the replacement of the "canon" with inferior material. They believe that self-confidence arises not from removing hurdles such as grading, but by making them fair and encouraging students to gain pride from knowing they can jump over these hurdles. On the one hand, Albert Einstein, the most famous physicist of the twentieth century, who is credited with helping us understand the universe better, was not a model school student. He was uninterested in what was being taught, and he did not attend classes all the time. On the other hand, his gifts eventually shone through and added to the sum of human knowledge.
There are a number of highly controversial issues in education. Should some knowledge be forgotten? Should classes be segregated by gender? What should be taught? There are also some philosophies, for example Transcendentalism, that would probably reject conventional education in the belief that knowledge should be gained through more direct personal experience. A recent book argues that children are being expected to learn too much. "There is an ongoing tendency to increase the length of textbooks. There are various reasons why people want to add to the education of children. People who work on education often believe, nobly enough, that the most important contribution is to get children to learn more. Publishers want to sell new books and adding new material is an important aspect of an effective sales pitch".[21] Also, the cost of higher education in developed countries is increasingly becoming an issue.
Salary...
Salary of a Physicist
The Physics Factbook™Edited by Glenn Elert -- Written by his studentsAn educational, Fair Use website
topic index author index special index
Bibliographic Entry
Result(w/surrounding text)
StandardizedResult
Average Level I Physicist Salary. SalaryWizard. May 2006.
"The median expected salary for a typical Physicist I in the United States is $47,714. This basic market pricing report was prepared using our Certified Compensation Professionals' analysis of survey data collected from thousands of HR departments at employers of all sizes, industries and geographies"
$47,714
"Physicist." Occupational Outlook Handbook. NTC/Contemporary Publishing Group: 1998.
"According to a 1997 National association of colleges … doctoral degree candidates was $34,700."
$34,700
Milss, Michael, William J. Spano, Baby O. Jose, Beverly A. Kelly and James P. Brille. Preparing a cost analysis for the section of medical physics—guidelines and methods [pdf]. Journal of Applied Clinical Medical Physics. Vol. 1, No. 2: Spring 2000.
"According to the American Association of Physicists in Medicine Professional Information Survey Report, Calendar Year 1998,3 the average total income for a medical physicist in the United States was $99,000, while income at the 80th percentile was approximately 30% higher."
$99,000
Albert Einstein. Encyclopedia Fun Trivia. 2006.
"Einstein retained a faculty appointment at Princeton University. He was asked to name his salary. It ended up at $10,000 a year, but what had he requested?"
$10,000
Chu, Raymond. Salary growth slows for industrial physicists. May 2006.
"Overall, the typical salaries for industrial physicists, which represent the 25th and 75th percentiles of the wages reported, ranged from $85,000 to $127,000. The typical salary range covers the middle portion of earnings, that is, one-quarter of the salaries fall below and one-quarter are above this range. Physicists in industry who earned their Ph.D.'s within the past five years had typical salaries ranging from $72,000 to $95,000. This group of recent Ph.D.'s reported the same median salary, $82,000, as their counterparts did in 2002."
$85,000 to $127,000
Physicists are scientists who specialize in physics. They can specialize in many different areas, such as astronomy, subatomic particles, magnetism, electricity, mechanics, optics, heat-transfer, or acoustics. Becoming a physicists generally requires a doctoral degree, such as a Ph.D., which means many years of college. Once finishing college though there is no guarantee of employment. Physicists are generally employed by universities as professors, lecturers, and researchers, and by laboratories in industry unless of course they are using their skills to become an engineer, economist, or financier.
The salary of a physicist ranges tremendously based upon schooling, and as all areas of life over time salary has increased due to inflation. Albert Einstein would probably be considered the most well known physicist of his time made $10,000. In fact Einstein did not even ask Princeton University for $10,000 he asked for about $7,500. Now though an average physicist makes about $47,714, which isn't terrible considering that an average American salary is $20,000-$30,000. Through schooling that salary of $47,414 has the potential to go to $99,000 or even $127,000, — that is of course with a Ph.D.
Jamin Bennett -- 2006
The Physics Factbook™Edited by Glenn Elert -- Written by his studentsAn educational, Fair Use website
topic index author index special index
Bibliographic Entry
Result(w/surrounding text)
StandardizedResult
Average Level I Physicist Salary. SalaryWizard. May 2006.
"The median expected salary for a typical Physicist I in the United States is $47,714. This basic market pricing report was prepared using our Certified Compensation Professionals' analysis of survey data collected from thousands of HR departments at employers of all sizes, industries and geographies"
$47,714
"Physicist." Occupational Outlook Handbook. NTC/Contemporary Publishing Group: 1998.
"According to a 1997 National association of colleges … doctoral degree candidates was $34,700."
$34,700
Milss, Michael, William J. Spano, Baby O. Jose, Beverly A. Kelly and James P. Brille. Preparing a cost analysis for the section of medical physics—guidelines and methods [pdf]. Journal of Applied Clinical Medical Physics. Vol. 1, No. 2: Spring 2000.
"According to the American Association of Physicists in Medicine Professional Information Survey Report, Calendar Year 1998,3 the average total income for a medical physicist in the United States was $99,000, while income at the 80th percentile was approximately 30% higher."
$99,000
Albert Einstein. Encyclopedia Fun Trivia. 2006.
"Einstein retained a faculty appointment at Princeton University. He was asked to name his salary. It ended up at $10,000 a year, but what had he requested?"
$10,000
Chu, Raymond. Salary growth slows for industrial physicists. May 2006.
"Overall, the typical salaries for industrial physicists, which represent the 25th and 75th percentiles of the wages reported, ranged from $85,000 to $127,000. The typical salary range covers the middle portion of earnings, that is, one-quarter of the salaries fall below and one-quarter are above this range. Physicists in industry who earned their Ph.D.'s within the past five years had typical salaries ranging from $72,000 to $95,000. This group of recent Ph.D.'s reported the same median salary, $82,000, as their counterparts did in 2002."
$85,000 to $127,000
Physicists are scientists who specialize in physics. They can specialize in many different areas, such as astronomy, subatomic particles, magnetism, electricity, mechanics, optics, heat-transfer, or acoustics. Becoming a physicists generally requires a doctoral degree, such as a Ph.D., which means many years of college. Once finishing college though there is no guarantee of employment. Physicists are generally employed by universities as professors, lecturers, and researchers, and by laboratories in industry unless of course they are using their skills to become an engineer, economist, or financier.
The salary of a physicist ranges tremendously based upon schooling, and as all areas of life over time salary has increased due to inflation. Albert Einstein would probably be considered the most well known physicist of his time made $10,000. In fact Einstein did not even ask Princeton University for $10,000 he asked for about $7,500. Now though an average physicist makes about $47,714, which isn't terrible considering that an average American salary is $20,000-$30,000. Through schooling that salary of $47,414 has the potential to go to $99,000 or even $127,000, — that is of course with a Ph.D.
Jamin Bennett -- 2006
Friday, November 2, 2007
#1, Becky
Okay, so Becky and I are doing this project, so to speak... and we made a blog to keep track of our information. I think that about sums it up.
The things we think are important we'll highlight or something.
Here's some info that Becky found.
Introduction
Radiation oncology is a branch of medicine that uses various types of radiation to treat and control cancer. The foundation of radiation oncology is based on the interaction between matter and energy. Beginning with the discovery of x-rays in 1895 by Wilhelm Roentgen, the role of the physicist has been critical in understanding how radiation interacts with matter. With the discovery of radioactivity by Henri Becquerel in 1896 and the separation of radium by Marie and Pierre Curie in 1898, it became known that certain materials also emitted radiation. Almost immediately the hazards and biological effects of x-rays and radioactive materials became apparent. In 1903, Alexander Graham Bell was one of many who suggested that radiation might be used to treat malignancies. Since the turn of the 20th century, radiation has been a part of medicine. The medical application of x-rays and radioactivity has given rise to the discipline of Medical Physics.
X-rays are a form of electromagnetic energy which are light rays of very high frequencies. Gamma rays, which originate in the nucleus of the atom, have even higher frequencies. Electromagnetic energy with high frequency also has short wavelength, which means that it’s small and passes through matter. Very early on it was discovered that the use of radiation in medicine was revolutionary due to the fact that it passed through matter. When radiation does interact with matter, it produces ionization. When a cell gets enough ionization, it dies. Since the emission and absorption of radiation takes place on the atomic scale, the interaction between radiation and matter must be well understood for clinical application to be possible. The medical physicist helps translate the science of radiation physics into the clinical treatment of cancer. Radiobiologists also help us understand the biological effects of radiation.
The Department of Radiation Oncology and Molecular Radiation Sciences derives the second part of it's name from our experts in medical physics and radiobiology. As modern medical technology allows for the precise creation and application of radiation therapy, the medical physicist is called upon for treatment planning, quality assurance and the advancement of clinical procedures. This in turn continues to translate into the Johns Hopkins philosophy of excellence in research, teaching and patient care.
The Role of the Medical PhysicistClinical medical physicists are a very important part of the radiation oncology team. Their primary role is to assure that the highest level of quality care is maintained. The medical physics group design and implement the quality assurance program in radiation oncology. They are responsible for selecting and specifying the types of equipment that are used in radiation therapy. After new equipment is installed, the medical physicist assures that the equipment meets or exceeds specifications.
Once the equipment is accepted, the physicist is responsible for commissioning the equipment, which involves taking enough measurements so that the equipment can be used clinically. Measurement data must also be transferred to other computer systems so that patient treatments can be planned. The medical physicist is frequently consulted by the radiation oncologist to help design a treatment that is difficult or unusual. A physicist is responsible for doing the quality assurance of every treatment plan before it starts. He or she checks that the planned information has been correctly transferred to the machine, that the plan agrees with the physicians prescription, that beam-on times are correct for each treatment field, and that all information is consistent, understandable, and well-documented.
The medical physicists also instructs radiation oncology residents, physics residents and graduate students, dosimetrists, nurses, and radiation therapists on the subject of radiation physics. Most of the physicists are also involved in specific areas of research, some basic research, others clinical or translational research.
Dosimetry
Dosimetry is the section of Medical Physics that specializes in developing patient treatment plans. To begin, a patient must have three dimensional pictures taken of their anatomy. These pictures are created using technologies such as computer tomography (CT) which uses low energy x-rays to create images of their internal organs. Once a patient has been imaged their anatomy is highlighted within a computer program. This allows for the definition of the cancer or gross tumor volume (GTV), and the "critical structures". The critical structures are the sensitive areas of the body that must be limited in their exposure. These include the eyes, kidneys, lungs, and spinal cord among other organs.
Having defined the cancer a radiation oncologist will decide how much radiation needs to be delivered. The physician will make a prescription for the amount of radiation to be used and a dosimetrist will begin treatment planning. In treatment planning, the angles of delivery of radiation, and how much radiation each part of the body is receiving (called the dose distribution) must be calculated. Sophisticated computer programs are used to show levels of radiation within the body, and there are also many other facets of the treatment plan that the dosimetrist is responsible for.
Once a treatment plan is complete the dosimetrist performs hand calculations to verify accuracy and will have a medical physicist review the plan. When the physician is satisfied with the treatment approach, the patient can begin undergoing therapy. During this time a dosimetrist will review their charts regularly to monitor treatment delivery and check for any changes in the treatment plan.
Medical Physics and Radiation Therapy
Medical Physics is based on the understanding of the scientific principles of the interaction between radiation and the human body. In the case of radiation oncology, cancer cells are acted upon by high energy x-rays. The x-rays deposit energy in tissue, which is called absorbed dose. This energy causes cancer cells to die, but the precise application of such energy must be exact so as to avoid damaging normal healthy cells. By treating a tumor from a number of different directions and avoiding normal tissue, we can destroy the tumor without causing serious side effects.
Types of External Beam Radiation Therapy
Conventional external beam radiation therapy - The science of radiation oncology and medical physics has developed standard approaches to dose delivery. In many cancer cases the treatment approach may be very similar and allows for conventional treatment.For example, many tumors can be treated with a single field from the front and a single field from the back or with two fields from the opposite sides. These are examples of parallel opposed fields. The combination of fields helps to uniformly deliver dose across the tumor. Sometimes 3 or 4 fields will be used. Occasionally, the gantry of the linear accelerator will rotate during treatment using what is called arc therapy.
3-D Conformal Radiation Therapy - Through the advancement of imaging technology enhanced images of the body allow for programming of treatment beams to conform better to the shape of a tumor. Hence treatment is more effective and side effects are reduced. By treating with large numbers of beams each shaped with a multileaf collimator (MLC) or cerrobend block, radiation dose is delivered uniformly and conformally to the tumor
Intensity Modulated Radiation Therapy (IMRT) - IMRT is one of the latest advancements in radiation therapy. This new approach to treatment allows for dose sculpting and even distribution of delivery to avoid critical structures while delivering precise uniform treatment. In this technique, the multileaf collimator (MLC) moves and modulates the radiation as the linac treats the patient.
Linear Accelerators for External Beam Radiation Therapy
The transmission of radiation in the clinical environment depends on very sophisticated technology. One of the primary types of treatment devices is called a linear accelerator. These linear accelerators, or Linacs, create the x-ray treatment beams. These beams consist of much higher energies then a standard x-ray machine and must be meticulously maintained in order to guarantee patient safety. Physicists are responsible for regular quality assurance measurements on all the equipment in the department that is used for patient treatment.
Linacs at Johns Hopkins:
600C -The 600C model is a lower energy (only 6 million volts effective energy, i.e. 6 MV) linear accelerator that is used mostly for treating areas of the head and neck, breasts, and lungs. The 600C has a 52 leaf MLC, which restricts the size of tumors that can be treated on this machine. The single X-ray energy also makes it less useful for treating the abdomen or pelvis. The 600C also has a special micro-multileaf collimator (mMLC) that can be used to treat small lesions in the brain.
6EX - This unit is also a single energy linac (6 MV) similar to the 600C, butnewer and more flexible for a variety of treatment plans The 6EX has an 80 leaf MLC allowing beam shaping for a larger range of beams. A special mMLC can also be attached to this linac and provides support for IMRT and stereotactic radiosurgery (see below). This linac is mostly used for brain, head and neck, and breast treatments.
2300 - This type of accelerator provides a dual energy system which allows for two X-ray energies (6MV and 15MV). In addition, this machine allows for treatment with electron beams of 6 different energies (from 4 MeV to 20 MeV) The higher energy X-ray beam can be used for treating larger regions of the body, such as the abdomen or the pelvis.
21EX - This linac is also a dual energy system (6MV and 15MV X-rays). It is capable of treating with electrons of 5 different energies. The 21EX is combined with a "BAT" ultrasound system. An ultrasound is used to align a patient properly for treatment of the prostate. In addition this unit incorporates a gating system used for lung cancer treatment. The gating system records the patient's respiratory pattern and treats according to their breathing position.
Films and Electronic Portal Imaging
Correct positioning is verified and documented regularly. On the 600C and 2300C, positioning is verified with X-ray film. On the 6EX and 21EX, films may be periodically taken, but most verification is done with electronic portal imaging (EPI).
Stereotactic Radiosurgery
This form of treatment is extremely precise and literally means to probe in three dimensions. It is most often referred to treatments of the brain as computer defined coordinates are used to precisely locate the target point.
Treatment modalities :
Stereotactic Radiosurgery (SRS) - Single treatment, high dose radiation, very accurate, patient's body position must be exact.
Stereotactic Radiotherapy (SRT) - Localized treatment using 3-d images, treatments will be repeated over time using lower dosages. The patient's position will be recorded using a stabilization device.
Fractionated Radio surgery (FSR) - Uses intermediate levels of radiation that are delivered over a small number of treatments.
Stereotactic treatment planning relies heavily on precise data acquisition and imaging technologies. Computer Tomography (CT Scannning), Magnetic Resonance Imaging (MRI), angiograms, and the fusion of CT and MRI scans are relied upon to provide the accuracy of anatomy necessary.
For more information please visit the Stereotactic Radiosurgery website and the Johns Hopkins Leksell Gamma Knife webpage.
Brachytherapy
Brachytherapy is a form of radiation therapy in which a radioactive source or radioactive seeds are placed very close to the tumor. This involves exposure of cancer cells to radioactive material rather than through external beam treatment. In brachytherapy the effective distance of the radiation source is small so effects on healthy tissue are reduced. Also this type of treatment requires a shorter exposure time and smaller number of treatments for dose delivery. In some cases, the seeds are permanently implanted and the patient is allowed to leave shortly after the procedure is completed.
The things we think are important we'll highlight or something.
Here's some info that Becky found.
Introduction
Radiation oncology is a branch of medicine that uses various types of radiation to treat and control cancer. The foundation of radiation oncology is based on the interaction between matter and energy. Beginning with the discovery of x-rays in 1895 by Wilhelm Roentgen, the role of the physicist has been critical in understanding how radiation interacts with matter. With the discovery of radioactivity by Henri Becquerel in 1896 and the separation of radium by Marie and Pierre Curie in 1898, it became known that certain materials also emitted radiation. Almost immediately the hazards and biological effects of x-rays and radioactive materials became apparent. In 1903, Alexander Graham Bell was one of many who suggested that radiation might be used to treat malignancies. Since the turn of the 20th century, radiation has been a part of medicine. The medical application of x-rays and radioactivity has given rise to the discipline of Medical Physics.
X-rays are a form of electromagnetic energy which are light rays of very high frequencies. Gamma rays, which originate in the nucleus of the atom, have even higher frequencies. Electromagnetic energy with high frequency also has short wavelength, which means that it’s small and passes through matter. Very early on it was discovered that the use of radiation in medicine was revolutionary due to the fact that it passed through matter. When radiation does interact with matter, it produces ionization. When a cell gets enough ionization, it dies. Since the emission and absorption of radiation takes place on the atomic scale, the interaction between radiation and matter must be well understood for clinical application to be possible. The medical physicist helps translate the science of radiation physics into the clinical treatment of cancer. Radiobiologists also help us understand the biological effects of radiation.
The Department of Radiation Oncology and Molecular Radiation Sciences derives the second part of it's name from our experts in medical physics and radiobiology. As modern medical technology allows for the precise creation and application of radiation therapy, the medical physicist is called upon for treatment planning, quality assurance and the advancement of clinical procedures. This in turn continues to translate into the Johns Hopkins philosophy of excellence in research, teaching and patient care.
The Role of the Medical PhysicistClinical medical physicists are a very important part of the radiation oncology team. Their primary role is to assure that the highest level of quality care is maintained. The medical physics group design and implement the quality assurance program in radiation oncology. They are responsible for selecting and specifying the types of equipment that are used in radiation therapy. After new equipment is installed, the medical physicist assures that the equipment meets or exceeds specifications.
Once the equipment is accepted, the physicist is responsible for commissioning the equipment, which involves taking enough measurements so that the equipment can be used clinically. Measurement data must also be transferred to other computer systems so that patient treatments can be planned. The medical physicist is frequently consulted by the radiation oncologist to help design a treatment that is difficult or unusual. A physicist is responsible for doing the quality assurance of every treatment plan before it starts. He or she checks that the planned information has been correctly transferred to the machine, that the plan agrees with the physicians prescription, that beam-on times are correct for each treatment field, and that all information is consistent, understandable, and well-documented.
The medical physicists also instructs radiation oncology residents, physics residents and graduate students, dosimetrists, nurses, and radiation therapists on the subject of radiation physics. Most of the physicists are also involved in specific areas of research, some basic research, others clinical or translational research.
Dosimetry
Dosimetry is the section of Medical Physics that specializes in developing patient treatment plans. To begin, a patient must have three dimensional pictures taken of their anatomy. These pictures are created using technologies such as computer tomography (CT) which uses low energy x-rays to create images of their internal organs. Once a patient has been imaged their anatomy is highlighted within a computer program. This allows for the definition of the cancer or gross tumor volume (GTV), and the "critical structures". The critical structures are the sensitive areas of the body that must be limited in their exposure. These include the eyes, kidneys, lungs, and spinal cord among other organs.
Having defined the cancer a radiation oncologist will decide how much radiation needs to be delivered. The physician will make a prescription for the amount of radiation to be used and a dosimetrist will begin treatment planning. In treatment planning, the angles of delivery of radiation, and how much radiation each part of the body is receiving (called the dose distribution) must be calculated. Sophisticated computer programs are used to show levels of radiation within the body, and there are also many other facets of the treatment plan that the dosimetrist is responsible for.
Once a treatment plan is complete the dosimetrist performs hand calculations to verify accuracy and will have a medical physicist review the plan. When the physician is satisfied with the treatment approach, the patient can begin undergoing therapy. During this time a dosimetrist will review their charts regularly to monitor treatment delivery and check for any changes in the treatment plan.
Medical Physics and Radiation Therapy
Medical Physics is based on the understanding of the scientific principles of the interaction between radiation and the human body. In the case of radiation oncology, cancer cells are acted upon by high energy x-rays. The x-rays deposit energy in tissue, which is called absorbed dose. This energy causes cancer cells to die, but the precise application of such energy must be exact so as to avoid damaging normal healthy cells. By treating a tumor from a number of different directions and avoiding normal tissue, we can destroy the tumor without causing serious side effects.
Types of External Beam Radiation Therapy
Conventional external beam radiation therapy - The science of radiation oncology and medical physics has developed standard approaches to dose delivery. In many cancer cases the treatment approach may be very similar and allows for conventional treatment.For example, many tumors can be treated with a single field from the front and a single field from the back or with two fields from the opposite sides. These are examples of parallel opposed fields. The combination of fields helps to uniformly deliver dose across the tumor. Sometimes 3 or 4 fields will be used. Occasionally, the gantry of the linear accelerator will rotate during treatment using what is called arc therapy.
3-D Conformal Radiation Therapy - Through the advancement of imaging technology enhanced images of the body allow for programming of treatment beams to conform better to the shape of a tumor. Hence treatment is more effective and side effects are reduced. By treating with large numbers of beams each shaped with a multileaf collimator (MLC) or cerrobend block, radiation dose is delivered uniformly and conformally to the tumor
Intensity Modulated Radiation Therapy (IMRT) - IMRT is one of the latest advancements in radiation therapy. This new approach to treatment allows for dose sculpting and even distribution of delivery to avoid critical structures while delivering precise uniform treatment. In this technique, the multileaf collimator (MLC) moves and modulates the radiation as the linac treats the patient.
Linear Accelerators for External Beam Radiation Therapy
The transmission of radiation in the clinical environment depends on very sophisticated technology. One of the primary types of treatment devices is called a linear accelerator. These linear accelerators, or Linacs, create the x-ray treatment beams. These beams consist of much higher energies then a standard x-ray machine and must be meticulously maintained in order to guarantee patient safety. Physicists are responsible for regular quality assurance measurements on all the equipment in the department that is used for patient treatment.
Linacs at Johns Hopkins:
600C -The 600C model is a lower energy (only 6 million volts effective energy, i.e. 6 MV) linear accelerator that is used mostly for treating areas of the head and neck, breasts, and lungs. The 600C has a 52 leaf MLC, which restricts the size of tumors that can be treated on this machine. The single X-ray energy also makes it less useful for treating the abdomen or pelvis. The 600C also has a special micro-multileaf collimator (mMLC) that can be used to treat small lesions in the brain.
6EX - This unit is also a single energy linac (6 MV) similar to the 600C, butnewer and more flexible for a variety of treatment plans The 6EX has an 80 leaf MLC allowing beam shaping for a larger range of beams. A special mMLC can also be attached to this linac and provides support for IMRT and stereotactic radiosurgery (see below). This linac is mostly used for brain, head and neck, and breast treatments.
2300 - This type of accelerator provides a dual energy system which allows for two X-ray energies (6MV and 15MV). In addition, this machine allows for treatment with electron beams of 6 different energies (from 4 MeV to 20 MeV) The higher energy X-ray beam can be used for treating larger regions of the body, such as the abdomen or the pelvis.
21EX - This linac is also a dual energy system (6MV and 15MV X-rays). It is capable of treating with electrons of 5 different energies. The 21EX is combined with a "BAT" ultrasound system. An ultrasound is used to align a patient properly for treatment of the prostate. In addition this unit incorporates a gating system used for lung cancer treatment. The gating system records the patient's respiratory pattern and treats according to their breathing position.
Films and Electronic Portal Imaging
Correct positioning is verified and documented regularly. On the 600C and 2300C, positioning is verified with X-ray film. On the 6EX and 21EX, films may be periodically taken, but most verification is done with electronic portal imaging (EPI).
Stereotactic Radiosurgery
This form of treatment is extremely precise and literally means to probe in three dimensions. It is most often referred to treatments of the brain as computer defined coordinates are used to precisely locate the target point.
Treatment modalities :
Stereotactic Radiosurgery (SRS) - Single treatment, high dose radiation, very accurate, patient's body position must be exact.
Stereotactic Radiotherapy (SRT) - Localized treatment using 3-d images, treatments will be repeated over time using lower dosages. The patient's position will be recorded using a stabilization device.
Fractionated Radio surgery (FSR) - Uses intermediate levels of radiation that are delivered over a small number of treatments.
Stereotactic treatment planning relies heavily on precise data acquisition and imaging technologies. Computer Tomography (CT Scannning), Magnetic Resonance Imaging (MRI), angiograms, and the fusion of CT and MRI scans are relied upon to provide the accuracy of anatomy necessary.
For more information please visit the Stereotactic Radiosurgery website and the Johns Hopkins Leksell Gamma Knife webpage.
Brachytherapy
Brachytherapy is a form of radiation therapy in which a radioactive source or radioactive seeds are placed very close to the tumor. This involves exposure of cancer cells to radioactive material rather than through external beam treatment. In brachytherapy the effective distance of the radiation source is small so effects on healthy tissue are reduced. Also this type of treatment requires a shorter exposure time and smaller number of treatments for dose delivery. In some cases, the seeds are permanently implanted and the patient is allowed to leave shortly after the procedure is completed.
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