ATP
step
-2
priming glycolysis
+4
substrate level phosphorylation (glycolysis)
+6
2 NADH produced (glycolysis)
-2
transportation of two NADH into mitochondria
+6
2 NADH produced in conversion of pyruvate to acetyl-CoA
+18
6 NADH produced during Kreb's cycle
+4
2 FADH2 produced during Kreb's cycle
+2
substrate level phosphorylation (Kreb's cycle)
+36
total ATPs produced from one glucose from aerobic respiration in eucaryotes. Compare with total from glycolysis alone (i.e., 2 ATP).
Source(s):
http://www.mansfield.ohio-state.edu/~sab…
Read more...
The Art of Teaching Science
Wednesday, February 1, 2012
Sunday, January 29, 2012
Critic Paper: The Value of History of Science as a Medium for the Integral and Specific Education of the Individual
Translation of Antoni Quintana-Mari’s Valor de la Historia de la Ciencia como media de Edicacion Integral y Especifica del Individuo (1935)
By Antoni Roca-Rosell and Hans Schneider
Science and Education (2010) 19:919-923
DOI 10.007/s11191-010-9245-2
Springer Science + Business Media B.V. 2010
Published online: 30 March 2010
SUMMARY
The article answers the question: “What is the value of teaching history of science?” Following the works of Sarton , the value of HOS was distinguished across three components: scientific, psycho-sociological and pedagogical. Among them, pedagogical value was thoroughly explained giving readers a glimpse of Spain’s science education, 75 years past. Pedagogical issues on HOS were also raised but suggestions were forwarded to address concerns like the appropriate educational level for HOS introduction, teaching methodology, coverage, treatment as single or integrated subject, and topic selection for the specific and integral education of man.
CRITIC
The original version of the translated article was published in 1935 in Spanish. Fast forward to 2012, it still makes a lot of sense in the context of science education in the Philippines particularly here in Romblon.
The article may be mistaken as a speech. But for me it is a prophecy, a work of art, a classic, a masterpiece.
I feel the author talking to me while I was reading the article. Flashed before me were scenes of my science encounters, my misconceptions, my limited understandings, my evolution as a biology teacher, my readings, my realizations and my desire to become a better biology teacher. The article caused me to probe deep into what I have gone through to be what I am today. I literally listed random thoughts on the striking points of the article, plus the totality of the experiences I am getting so far in my HPS class, specially lately that I read Gribbin’s and Birch’s books. I beg your indulgence for making this piece longer, but I really want these thoughts to be shared because I have never been moved this way before.
Anyone who is aware of the development of HOS would be able to appreciate it more fully and more independently the significance of the current scientific movement than a person who is subject to the limitation of his time with the result that he can only base his assumptions on the local direction of this movement (E. Mach).
Prior to my exposure to HPS materials, my view of science was fragmented; it was like pieces of a jigsaw puzzle. Finding connections was difficult. It was when I took hold of Gribbin’s book that light came to me. The book enriched my imagination that I began to develop personal pictures of the characters in there. Simply put it, it was like reading a novel. And more often, I find myself getting along with these revered scientists. Now, I have developed a conceptual understanding of how science began… why there are science societies, scientific conferences and others. These are deeply rooted in history: research findings are presented to an august body of scientists; scientific knowledge is generated; and the discoverer or inventor’s name is carved in history.
I was really thinking that the Philippines, although a third world country, is not really lagging behind when it comes to scientific literacy because it constantly boasts of having one of the highest literacy rates in Asia. But to my chagrin, while I was reading Gribbin, I realized that we are not only lagging but we are actually left miles behind. During the scientific revolution, young men at the age of 20 or so were already using mathematics to explain various physical phenomena which I think at present very few Filipino of the same age can do. Truly, knowledge of HOS has broadened my perspectives about science and history.
HOS in a humanistic sense should be introduced at the primary level and should be continued until higher education. Its exposition should be based on legends and anecdotes because it is not difficult to enthrall children with historical anecdotes about science.
For the sake of pedagogy, science must be popularized. One of the best means of doing it is to humanize it. Upon reading the above lines, I empathized with the author because I was actually doing it but without really the intention of incorporating HOS. It just came out deliberately. For example, this blog entry on Sept. 3, 2009 was a proof when I used HOS as a potential tool in teaching how to prepare science investigatory projects:
“My purpose was to make SIP preparation a not so very scientific task; to make them believe that simple and ordinary kids can come up with an extraordinary project.
Here is what I did. I showed them a picture of Isaac Newton and the falling apple and below it was written: "Millions saw the apple fall but only Isaac Newton was the first to ask why." Then I showed them a news clip from GMA 7's Unang Hirit by Igan about the janitor fish problem in Marikina River. Then, I related to them the story of Emong (Raymund Joseph Amurao), "A Fishy Story: Emong and the Janitor Fish". And how such serendipitous discovery of fish oil turn into a bio-diesel that brought him to international INTEL competition. Then I introduced them to Joseph Farman and his discovery of the Ozone Hole.
After all these, I asked them what an SIP means. Responses were overwhelming. I made the concept so simple by presenting real life situations convincing them that science investigation is a part of everyday living. Then I presented them the framework of how scientists think and reason and how it was used by Newton, Emong and Farman to unfold scientific truths.”
My exposure to HPS resources this semester enabled me to meet the scientists up close and personal through my readings and realized that they were not really untouchables and exclusively special as they were stereotyped. They were also humans like me, fallible. The following are some collections of trivia based from my readings of Gribbin’s first book that would interest young and adult learners alike which could be used as springboards in integrating HOS in the subject:
Galen was an obnoxious self-publicist and plagiarist (p.20).
The fallopian tube was named after its discoverer Gabriele Fallopio and the
Eustachian tube from Bartolomeo Eustachio (p.26)
In 16th century Denmark, the law said that if a woman openly lived with a man, kept his keys and ate at his table, after three years she was his wife. This happened to Tycho Brahe and his wife Christine (p.43).
Johannes Kepler came from a very poor family. He trained for the priesthood because during his time, it was the obvious and traditional route out of poverty for an intelligent young man (p.51).
Rene Descartes was a late riser. He never married like Galileo (p.112)
Christian Huygens would have been the greatest scientist of his generation if he had not the misfortune to be active in science at almost exactly the same time as Isaac Newton (pp.118).
Robert Boyle was charitable. He was religious. He refused honors and presidency of the Royal Society (p.141).
Robert Hooke was very sickly (p.151) and had sexual relationships with his maidservants and niece (p.159).
Newton was arrogant and always harbored grudges. The famous phrase: “If I have seen farther, it is by standing on the shoulders of Giants,” is currently taken out of context. It was actually a phrase lifted from his letter to Hooke as they were major nemesis. Why should Newton choose to emphasize this word? Surely, because Hooke was a little man with a twisted back. The message Newton intends to convey is that although he may have borrowed from the Ancients, he has no need to steal ideas from a little man like Hooke, with the added implication that Hooke is a mental pygmy and a small man physically (p. 164).
Edmund Halley was handsome with a track record of sexual indiscretion and was allegedly linked to Newton. (p.170).
It is not true that Newton was born the very day or even year that Galileo died. The coincidences were hoaxes – using dates from two different calendar systems (p.175).
It was quite likely that Newton was a homosexual due to his secretive nature (p.178).
Gribbin cannot rule out the veracity of Newton’s apple story (p. 181).
In the secondary level, HOS must subsist as something as alive in each syllabus without becoming a body of doctrine.
I very well remember when my teacher in General Chemistry back in the master’s level assigned us to role play the discovery of the atom and its sub-particles. My group mates assigned me to prepare the script. All I did was to research into the character of the major players and the countries from which they came so that I could come up with a sci-fi script. Well, it worked. Our professor appreciated it. This must be how HOS must find its place in the secondary science syllabus. It must be vibrant that would enable students to actively engage, do further readings and interpret their understandings.
From the teacher’s engagement, it could be done that the teacher dresses and behaves like Gregor Mendel and explains the laws of heredity based from his investigations.
Recommended readings like well-written scientific biographies… complemented by the repetition of original experiments could tell our students much more than the entire chapters of a specific course.
I am handling a graduate course in biological sciences here in our university. Students are teachers of elementary and secondary high schools. I often heard them complain about the complacency of today’s learners, shorter attention span and loss of focus. They want everything served before them. Until I discover that most of them (my graduate students) too, have problems with concepts and pedagogy. The blame game starts to roll. So I am starting now to download original experiments, like the discovery of meiosis… and require them to summarize the manuscript and give their comments and critics. It sounds like a chain reaction has begun. Yes, it has. And I am part and will be part of that critical mass.
In the tertiary level, we believe that each faculty should insist that the history of their subject form part of the syllabus. This is the only way in which the students could obtain a synthetic view of the subject, be able to assess its present state and value it accordingly. Biographical studies and comments on the papers from the classics should be considerably increased at this level of study.
I must admit that I only became confident of my discipline when I was able to completely read the second part of Gribbin’s fifth book (529-571). Somehow, all the facts, names and events have fallen into proper places. I am handling cell biology in the undergraduate now and although I am really wanting in content, knowing the totality of the history of the discipline I am teaching gives me a little comfort. So far, I have been starting where my students are. I believe that gradually, I could send them out from their shells of complacency and replace it with passion, enthusiasm and interest in reading. Reading is still one of the best ways of acquiring knowledge because when one reads, the imagination is boundless, and when one imagines, the neural capacities are maximized.
It is only through HOS that we will be able to experience the relative and provisional character of all our knowledge.
Without studying HOS, one might think that everything came to exist as it is, similar to the ex nihilo doctrine. But, it was not. Scientists invested a lot of time to hold on to their claim whether the prevailing historical truth and philosophy would accept their discoveries or not. But as cited, the errors of today are the truths of tomorrow. This attests that our scientific knowledge is provisional. It evolves with time.
For example, Mendel was way advance of his time that was why his works were not recognized immediately. And who would, it was just the time of the discovery of the nucleus but Mendel was already dealing with hereditary ‘factors’ (now genes and DNA). During that point in history, nobody recognized his works. But today, he is revered for laying the foundation of genetics. I overhear the weather anchor saying: “Always remember, life is seasonal.” (Laging tandaan, ang buhay ay weather weather lang.)
It is impossible to conceive an integral man leaving out HOS from his intellectual education.
What must happen to the the 21st century man sans knowledge about HOS? In society, history matters because this is where the social foundations are rooted. Ignorance of history is like being lost in an ocean of uncertainty. No identity. No cultural pride. Remove HOS from the intellectual education of an integral man and he will be no different from an ordinary man. He would be lost. He won’t know where to begin and where to stop. He will be ungrateful. And if all men henceforth, be stripped of HOS education, that will be the end of a scientific culture sustained for about five centuries; that would mean the extinction of science and the resurrection of dark ages.
Teachers lack reference books. They may be able to collect a few well-known legends that are already very popular. A collection of such would surely constitute one of the finest facets of the history of our culture.
The author suggested this, 75 years back when the word ‘internet’ was not yet coined. But I think this is already addressed by the various websites that contain anecdotal accounts of our famous scientists.
But I found this point interesting because at present majority of the areas in Romblon are still unreached by internet services. It could be considered for a good research project or term paper: translation of anecdotal accounts of ten most cited scientists in elementary or secondary school textbooks.
As a final note, I would borrow John Gribbin’s words (2001) for those who are studying HOS:
“Science is one of the greatest achievements of the human mind, and the fact that progress has actually been made, in the most part, by ordinarily clever people building step by step from the work of their predecessors makes the story more remarkable, not less. Almost any of you (readers of his book) had you been in the right place at the right time, could have made the great discoveries described here. And since the progress of science has by no means come to a halt, some of you may yet be involved in the next step in the story.”
Hopefully, if not me, my students or my children may.
Read more...
By Antoni Roca-Rosell and Hans Schneider
Science and Education (2010) 19:919-923
DOI 10.007/s11191-010-9245-2
Springer Science + Business Media B.V. 2010
Published online: 30 March 2010
SUMMARY
The article answers the question: “What is the value of teaching history of science?” Following the works of Sarton , the value of HOS was distinguished across three components: scientific, psycho-sociological and pedagogical. Among them, pedagogical value was thoroughly explained giving readers a glimpse of Spain’s science education, 75 years past. Pedagogical issues on HOS were also raised but suggestions were forwarded to address concerns like the appropriate educational level for HOS introduction, teaching methodology, coverage, treatment as single or integrated subject, and topic selection for the specific and integral education of man.
CRITIC
The original version of the translated article was published in 1935 in Spanish. Fast forward to 2012, it still makes a lot of sense in the context of science education in the Philippines particularly here in Romblon.
The article may be mistaken as a speech. But for me it is a prophecy, a work of art, a classic, a masterpiece.
I feel the author talking to me while I was reading the article. Flashed before me were scenes of my science encounters, my misconceptions, my limited understandings, my evolution as a biology teacher, my readings, my realizations and my desire to become a better biology teacher. The article caused me to probe deep into what I have gone through to be what I am today. I literally listed random thoughts on the striking points of the article, plus the totality of the experiences I am getting so far in my HPS class, specially lately that I read Gribbin’s and Birch’s books. I beg your indulgence for making this piece longer, but I really want these thoughts to be shared because I have never been moved this way before.
Anyone who is aware of the development of HOS would be able to appreciate it more fully and more independently the significance of the current scientific movement than a person who is subject to the limitation of his time with the result that he can only base his assumptions on the local direction of this movement (E. Mach).
Prior to my exposure to HPS materials, my view of science was fragmented; it was like pieces of a jigsaw puzzle. Finding connections was difficult. It was when I took hold of Gribbin’s book that light came to me. The book enriched my imagination that I began to develop personal pictures of the characters in there. Simply put it, it was like reading a novel. And more often, I find myself getting along with these revered scientists. Now, I have developed a conceptual understanding of how science began… why there are science societies, scientific conferences and others. These are deeply rooted in history: research findings are presented to an august body of scientists; scientific knowledge is generated; and the discoverer or inventor’s name is carved in history.
I was really thinking that the Philippines, although a third world country, is not really lagging behind when it comes to scientific literacy because it constantly boasts of having one of the highest literacy rates in Asia. But to my chagrin, while I was reading Gribbin, I realized that we are not only lagging but we are actually left miles behind. During the scientific revolution, young men at the age of 20 or so were already using mathematics to explain various physical phenomena which I think at present very few Filipino of the same age can do. Truly, knowledge of HOS has broadened my perspectives about science and history.
HOS in a humanistic sense should be introduced at the primary level and should be continued until higher education. Its exposition should be based on legends and anecdotes because it is not difficult to enthrall children with historical anecdotes about science.
For the sake of pedagogy, science must be popularized. One of the best means of doing it is to humanize it. Upon reading the above lines, I empathized with the author because I was actually doing it but without really the intention of incorporating HOS. It just came out deliberately. For example, this blog entry on Sept. 3, 2009 was a proof when I used HOS as a potential tool in teaching how to prepare science investigatory projects:
“My purpose was to make SIP preparation a not so very scientific task; to make them believe that simple and ordinary kids can come up with an extraordinary project.
Here is what I did. I showed them a picture of Isaac Newton and the falling apple and below it was written: "Millions saw the apple fall but only Isaac Newton was the first to ask why." Then I showed them a news clip from GMA 7's Unang Hirit by Igan about the janitor fish problem in Marikina River. Then, I related to them the story of Emong (Raymund Joseph Amurao), "A Fishy Story: Emong and the Janitor Fish". And how such serendipitous discovery of fish oil turn into a bio-diesel that brought him to international INTEL competition. Then I introduced them to Joseph Farman and his discovery of the Ozone Hole.
After all these, I asked them what an SIP means. Responses were overwhelming. I made the concept so simple by presenting real life situations convincing them that science investigation is a part of everyday living. Then I presented them the framework of how scientists think and reason and how it was used by Newton, Emong and Farman to unfold scientific truths.”
My exposure to HPS resources this semester enabled me to meet the scientists up close and personal through my readings and realized that they were not really untouchables and exclusively special as they were stereotyped. They were also humans like me, fallible. The following are some collections of trivia based from my readings of Gribbin’s first book that would interest young and adult learners alike which could be used as springboards in integrating HOS in the subject:
Galen was an obnoxious self-publicist and plagiarist (p.20).
The fallopian tube was named after its discoverer Gabriele Fallopio and the
Eustachian tube from Bartolomeo Eustachio (p.26)
In 16th century Denmark, the law said that if a woman openly lived with a man, kept his keys and ate at his table, after three years she was his wife. This happened to Tycho Brahe and his wife Christine (p.43).
Johannes Kepler came from a very poor family. He trained for the priesthood because during his time, it was the obvious and traditional route out of poverty for an intelligent young man (p.51).
Rene Descartes was a late riser. He never married like Galileo (p.112)
Christian Huygens would have been the greatest scientist of his generation if he had not the misfortune to be active in science at almost exactly the same time as Isaac Newton (pp.118).
Robert Boyle was charitable. He was religious. He refused honors and presidency of the Royal Society (p.141).
Robert Hooke was very sickly (p.151) and had sexual relationships with his maidservants and niece (p.159).
Newton was arrogant and always harbored grudges. The famous phrase: “If I have seen farther, it is by standing on the shoulders of Giants,” is currently taken out of context. It was actually a phrase lifted from his letter to Hooke as they were major nemesis. Why should Newton choose to emphasize this word? Surely, because Hooke was a little man with a twisted back. The message Newton intends to convey is that although he may have borrowed from the Ancients, he has no need to steal ideas from a little man like Hooke, with the added implication that Hooke is a mental pygmy and a small man physically (p. 164).
Edmund Halley was handsome with a track record of sexual indiscretion and was allegedly linked to Newton. (p.170).
It is not true that Newton was born the very day or even year that Galileo died. The coincidences were hoaxes – using dates from two different calendar systems (p.175).
It was quite likely that Newton was a homosexual due to his secretive nature (p.178).
Gribbin cannot rule out the veracity of Newton’s apple story (p. 181).
In the secondary level, HOS must subsist as something as alive in each syllabus without becoming a body of doctrine.
I very well remember when my teacher in General Chemistry back in the master’s level assigned us to role play the discovery of the atom and its sub-particles. My group mates assigned me to prepare the script. All I did was to research into the character of the major players and the countries from which they came so that I could come up with a sci-fi script. Well, it worked. Our professor appreciated it. This must be how HOS must find its place in the secondary science syllabus. It must be vibrant that would enable students to actively engage, do further readings and interpret their understandings.
From the teacher’s engagement, it could be done that the teacher dresses and behaves like Gregor Mendel and explains the laws of heredity based from his investigations.
Recommended readings like well-written scientific biographies… complemented by the repetition of original experiments could tell our students much more than the entire chapters of a specific course.
I am handling a graduate course in biological sciences here in our university. Students are teachers of elementary and secondary high schools. I often heard them complain about the complacency of today’s learners, shorter attention span and loss of focus. They want everything served before them. Until I discover that most of them (my graduate students) too, have problems with concepts and pedagogy. The blame game starts to roll. So I am starting now to download original experiments, like the discovery of meiosis… and require them to summarize the manuscript and give their comments and critics. It sounds like a chain reaction has begun. Yes, it has. And I am part and will be part of that critical mass.
In the tertiary level, we believe that each faculty should insist that the history of their subject form part of the syllabus. This is the only way in which the students could obtain a synthetic view of the subject, be able to assess its present state and value it accordingly. Biographical studies and comments on the papers from the classics should be considerably increased at this level of study.
I must admit that I only became confident of my discipline when I was able to completely read the second part of Gribbin’s fifth book (529-571). Somehow, all the facts, names and events have fallen into proper places. I am handling cell biology in the undergraduate now and although I am really wanting in content, knowing the totality of the history of the discipline I am teaching gives me a little comfort. So far, I have been starting where my students are. I believe that gradually, I could send them out from their shells of complacency and replace it with passion, enthusiasm and interest in reading. Reading is still one of the best ways of acquiring knowledge because when one reads, the imagination is boundless, and when one imagines, the neural capacities are maximized.
It is only through HOS that we will be able to experience the relative and provisional character of all our knowledge.
Without studying HOS, one might think that everything came to exist as it is, similar to the ex nihilo doctrine. But, it was not. Scientists invested a lot of time to hold on to their claim whether the prevailing historical truth and philosophy would accept their discoveries or not. But as cited, the errors of today are the truths of tomorrow. This attests that our scientific knowledge is provisional. It evolves with time.
For example, Mendel was way advance of his time that was why his works were not recognized immediately. And who would, it was just the time of the discovery of the nucleus but Mendel was already dealing with hereditary ‘factors’ (now genes and DNA). During that point in history, nobody recognized his works. But today, he is revered for laying the foundation of genetics. I overhear the weather anchor saying: “Always remember, life is seasonal.” (Laging tandaan, ang buhay ay weather weather lang.)
It is impossible to conceive an integral man leaving out HOS from his intellectual education.
What must happen to the the 21st century man sans knowledge about HOS? In society, history matters because this is where the social foundations are rooted. Ignorance of history is like being lost in an ocean of uncertainty. No identity. No cultural pride. Remove HOS from the intellectual education of an integral man and he will be no different from an ordinary man. He would be lost. He won’t know where to begin and where to stop. He will be ungrateful. And if all men henceforth, be stripped of HOS education, that will be the end of a scientific culture sustained for about five centuries; that would mean the extinction of science and the resurrection of dark ages.
Teachers lack reference books. They may be able to collect a few well-known legends that are already very popular. A collection of such would surely constitute one of the finest facets of the history of our culture.
The author suggested this, 75 years back when the word ‘internet’ was not yet coined. But I think this is already addressed by the various websites that contain anecdotal accounts of our famous scientists.
But I found this point interesting because at present majority of the areas in Romblon are still unreached by internet services. It could be considered for a good research project or term paper: translation of anecdotal accounts of ten most cited scientists in elementary or secondary school textbooks.
As a final note, I would borrow John Gribbin’s words (2001) for those who are studying HOS:
“Science is one of the greatest achievements of the human mind, and the fact that progress has actually been made, in the most part, by ordinarily clever people building step by step from the work of their predecessors makes the story more remarkable, not less. Almost any of you (readers of his book) had you been in the right place at the right time, could have made the great discoveries described here. And since the progress of science has by no means come to a halt, some of you may yet be involved in the next step in the story.”
Hopefully, if not me, my students or my children may.
Read more...
Critic Paper: The Contribution of Ethnobiology to the Construction of a Dialogue Between Ways of Knowing: A Case Study
By Geilsa Costa Santos Baptista and Charbel Niño El-Hani
Springer Science + Business Media B.V. 2008
Science and Education (2009) 18:503-520
Published online: 25 February 2009
SUMMARY
This case study investigated the role of ethnobiological research in relating science education to traditional knowledge in a multicultural classroom in Brazil. It focused on the efficacy test of the didactic material and learning sequence designed to promote discussion between scientific and traditional knowledge in the context of biology teaching. The material was based on interviews from farmer students and was internally validated by biology teachers. Seventy-two high school students were the subjects of the two-phase intervention composing of a group work surveying their previous knowledge on local crops, and construction of the ‘table of comparative cognition’ grounded from the didactic material. The intervention was reported to have created possibilities of discussing in the classroom the similarities and differences between scientific and traditional knowledge and their specific applications. However, challenges on multicultural science education were identified like lack of teacher training and students’ prejudices to cultural differences, among others.
CRITIC
Ethnography, as a qualitative method of research, has been conceptually discussed in various research books but this is the first time that I was able to review such an investigation.
There are three things that caught my attention in the article: the way multicultural environment is defined; the role of traditional knowledge in understanding science; and the importance of observing research ethics.
According to the article, each and every science classroom can be regarded as a multicultural setting regardless of geographical location and class composition. This is explained by the authors in the context of students who do not share the cultural backgrounds needed to understand a scientific concept. They would fall beyond the assumptions of the Western Modern Science about the universal understanding of the universe as opposed to their cultural impressions of reality. I subscribe to this concept of multicultural setting because I believe that before there was science, the influence of culture in understanding reality and establishing knowledge was already on work.
In my experience as a college instructor of biology, I’ve met students who had provided culturally-based explanations in some of the concepts discussed in the class which enabled me to realize the vital role of traditional knowledge in understanding science. Coincidentally, most of my encounters were also concepts in botany.
For instance, a student asked if whether or not peanut is a root crop. Acknowledging my own misconception as a science generalist, I threw the question back to the class. And here’s one working student who insisted that it is NOT, instead he muttered, “It’s a fruit!” The class burst into laughter. Then I asked him to substantiate his answer. He said that his family was cultivating a peanut farm. He observed that when peanut flowers grew into fruits, the stems bent to the ground and the fruits touched the soil. Eventually, the fruits would penetrate into the soil which is why peanuts are mistaken as root crops. He even drew on the board the process. The class was caught in half-belief waiting for my confirmation. To mediate that information with science, I immediately googled how peanut is classified and posted it on my blog . I shared it with them the following meeting. I noticed that because of that incident, the student earned the respect of his classmates. He became confident with his ideas and manifested more interest in the subject.
There are still other entries in my blog that are based on the traditional knowledge students brought in my class which I used as springboards to initiate discourses between traditional and scientific information such as the reproduction of onion, coconut embryo and the like .
What has been presented in the fifth paragraph is a characteristic typical of a teacher with sound pedagogical content knowledge (PCK) posited by Shulman (1986) . It is important that teachers should consider the learners’ cultural background to effectively translate a concept within their social and cultural milieu. I think this is what we need in the country right now. Agri-technicians are coming to the field full of scientific knowledge but failed to translate it into consumable information losing the essential connection with the farmers. Likewise, academicians are missing the mark by using conceptual terms so abstract to be contained by an ordinary teacher or student. Context must be factored into the equation of generating knowledge.
On top of these, what really grabbed my attention was the authors’ observance of research ethics evidenced by the informed consent given by the school administration, teacher collaborator, each student participant and in case of minors, their parents. In my exposure to various research activities for the last five years, I seldom observe such a stringent adherence to research ethics, despite the presence of many a legal provision. I must also say that several researches in the country would fall short of this requirement as about 50 percent of research institutions in the country have functional Institutional Research Ethics Review Committee. That’s why I admired the patience and efficiency of the first author in keeping a field diary to take notes of the event that happened during the intervention as courtesy to the teacher who refused to be recorded with a video camera or a tape recorder.
Although the findings of the study are limited to the subjects investigated, I appreciated the research method used in determining the role of students’ cultural background in science teaching and discovering the challenges that go with it.
Read more...
Springer Science + Business Media B.V. 2008
Science and Education (2009) 18:503-520
Published online: 25 February 2009
SUMMARY
This case study investigated the role of ethnobiological research in relating science education to traditional knowledge in a multicultural classroom in Brazil. It focused on the efficacy test of the didactic material and learning sequence designed to promote discussion between scientific and traditional knowledge in the context of biology teaching. The material was based on interviews from farmer students and was internally validated by biology teachers. Seventy-two high school students were the subjects of the two-phase intervention composing of a group work surveying their previous knowledge on local crops, and construction of the ‘table of comparative cognition’ grounded from the didactic material. The intervention was reported to have created possibilities of discussing in the classroom the similarities and differences between scientific and traditional knowledge and their specific applications. However, challenges on multicultural science education were identified like lack of teacher training and students’ prejudices to cultural differences, among others.
CRITIC
Ethnography, as a qualitative method of research, has been conceptually discussed in various research books but this is the first time that I was able to review such an investigation.
There are three things that caught my attention in the article: the way multicultural environment is defined; the role of traditional knowledge in understanding science; and the importance of observing research ethics.
According to the article, each and every science classroom can be regarded as a multicultural setting regardless of geographical location and class composition. This is explained by the authors in the context of students who do not share the cultural backgrounds needed to understand a scientific concept. They would fall beyond the assumptions of the Western Modern Science about the universal understanding of the universe as opposed to their cultural impressions of reality. I subscribe to this concept of multicultural setting because I believe that before there was science, the influence of culture in understanding reality and establishing knowledge was already on work.
In my experience as a college instructor of biology, I’ve met students who had provided culturally-based explanations in some of the concepts discussed in the class which enabled me to realize the vital role of traditional knowledge in understanding science. Coincidentally, most of my encounters were also concepts in botany.
For instance, a student asked if whether or not peanut is a root crop. Acknowledging my own misconception as a science generalist, I threw the question back to the class. And here’s one working student who insisted that it is NOT, instead he muttered, “It’s a fruit!” The class burst into laughter. Then I asked him to substantiate his answer. He said that his family was cultivating a peanut farm. He observed that when peanut flowers grew into fruits, the stems bent to the ground and the fruits touched the soil. Eventually, the fruits would penetrate into the soil which is why peanuts are mistaken as root crops. He even drew on the board the process. The class was caught in half-belief waiting for my confirmation. To mediate that information with science, I immediately googled how peanut is classified and posted it on my blog . I shared it with them the following meeting. I noticed that because of that incident, the student earned the respect of his classmates. He became confident with his ideas and manifested more interest in the subject.
There are still other entries in my blog that are based on the traditional knowledge students brought in my class which I used as springboards to initiate discourses between traditional and scientific information such as the reproduction of onion, coconut embryo and the like .
What has been presented in the fifth paragraph is a characteristic typical of a teacher with sound pedagogical content knowledge (PCK) posited by Shulman (1986) . It is important that teachers should consider the learners’ cultural background to effectively translate a concept within their social and cultural milieu. I think this is what we need in the country right now. Agri-technicians are coming to the field full of scientific knowledge but failed to translate it into consumable information losing the essential connection with the farmers. Likewise, academicians are missing the mark by using conceptual terms so abstract to be contained by an ordinary teacher or student. Context must be factored into the equation of generating knowledge.
On top of these, what really grabbed my attention was the authors’ observance of research ethics evidenced by the informed consent given by the school administration, teacher collaborator, each student participant and in case of minors, their parents. In my exposure to various research activities for the last five years, I seldom observe such a stringent adherence to research ethics, despite the presence of many a legal provision. I must also say that several researches in the country would fall short of this requirement as about 50 percent of research institutions in the country have functional Institutional Research Ethics Review Committee. That’s why I admired the patience and efficiency of the first author in keeping a field diary to take notes of the event that happened during the intervention as courtesy to the teacher who refused to be recorded with a video camera or a tape recorder.
Although the findings of the study are limited to the subjects investigated, I appreciated the research method used in determining the role of students’ cultural background in science teaching and discovering the challenges that go with it.
Read more...
Critic Paper: Historical Science, Over and Underdetermined: A Study of Darwin's Inference of Origins
By Aviezer Tucker
The British Journal for the Philosophy of Science
July 18, 2011
SUMMARY
Tucker analyzes the method of how Darwin inferred the origin of species from his major works. Two philosophical theses are highlighted: overdetermination and undetermination. Tucker discloses Darwin’s three-consecutive-stage-approach in inferring origins. First, Darwin inferred that homologies have common cause rather than separate cause, a case of overdetermination. Next, he developed possible causal nets to infer the origin of species sharing common cause, but acknowledged this approach to be an interplay between over and underdetermination depending upon the causal models. Third, Darwin avoided overdetermination in inferring the character traits of the ancestor species implying that some information might have been lost overtime such that the current evidences are insufficient to characterize the traits of the origin. Based on this case, Tucker concludes that inferences in historical sciences proceed from overdetermination to underdetermination, an approach that is also true in the inference of ancestral languages.
CRITIC
Debates about the process of how knowledge is grounded in science did not bother me until I went in the graduate school and was asked to write a critic paper. In fact, all I know is that science is ‘science’, without distinguishing between historical and experimental. I have assumed that evolution has come to develop as a body of knowledge because of evidences supporting it. No more, no less. At first, I hardly comprehend what’s the debate about the truthfulness of scientific information generated by historical scientists. After all, they are doing science.
Tucker’s paper enabled me to discriminate between ‘what is’ from ‘what is not’ in science. I realized that experimental scientists are the ones doing the Baconian scientific method reliant on hardcore empiricism. I did not have any idea that historical scientists are waiving this time-honored method in favor of observations, evidences available and rational thinking in order to infer the origin of a certain thing . Now, it has been made clear to me why historical scientists are always placed on a hot seat.
Let me make Darwin’s inferential analysis simpler, at least in the context I am familiar with. It is easy to claim that we have some semblance because we are relatives by blood (overdetermination), let alone the look-alikes. The next question would be ‘how in the world have we become relatives?’ So we trace our genealogies. Depending on the availability of information, we speculate (interplay of over and underdetermination). Granting that our common ancestor has been traced based on the most plausible model, we may infer phenotypic traits but to determine the character traits of our common ancestor is another story (underdetermination).
That is how I understand Darwin’s experience in inferring the origin of species. It is obvious that as the process of inference goes deeper, tracing the common ancestor is becoming unlikely overdetermined .
That the past is overdetermined by its effects may sound an overstatement. But that is how we usually reason, ‘like begets like.’ We tend to imply correlation with causation, which should not always be. However, I have some problem with Cleland’s attempt to connect overdetermination with ‘radiative asymmetry’ like waves spreading outwards than inwards as time progresses. There may be the spreading away of waves, but we have learned in Physics that overtime these waves will lose energy.
It is on this premise that Turner’s thesis of underdetermination of the past due to information decay appealed to me. He cited the law of entropy as supporting evidence to his thesis. Indeed the amount of disorder in the universe tends to increase. The fossils may provide clues to the past or even preserve some important information as Cleland would argue, but still they are not excluded from the action of entropy.
It was interesting to note that Darwin’s approach has been found to be also workable in the inference of ancestral languages. But my comments are rather trivial. I understand better what Tucker pointed out as homologies with common cause when I came across with some typos like “pronounciation” and “undertermined” in the paper. I am certain that these unlikely occurrences have common cause: ‘error in coding’, and that’s an overdetermination, as with the mutations that occur in our genes.
Given the merits of these two theses in the historical sciences, I cannot settle for Tucker’s cliché that ‘the truth lies somewhere in the middle.’ I want the debate to keep going.
REFERENCES
Cleland, Carol E. (2002). "Methodological and Epistemic Differences Between Historical Science and Experimental Science," Philosophy of Science 69, pp. 474-496. Retrieved November 30, 3011, Available at http://spot.colorado.edu/~cleland/articles/Cleland.PS.Pdf
Psillos, Stathis (2008). “Review of Derek Turner’s Making Prehistory: Historical Science and the Scientific Realism Debate” Notre Dame Philosophical Reviews. Retrieved December 1, 2011 at http://ndpr.nd.edu/news/23501-making-prehistory-historical-science-and-the-scientific-realism-debate/
Read more...
The British Journal for the Philosophy of Science
July 18, 2011
SUMMARY
Tucker analyzes the method of how Darwin inferred the origin of species from his major works. Two philosophical theses are highlighted: overdetermination and undetermination. Tucker discloses Darwin’s three-consecutive-stage-approach in inferring origins. First, Darwin inferred that homologies have common cause rather than separate cause, a case of overdetermination. Next, he developed possible causal nets to infer the origin of species sharing common cause, but acknowledged this approach to be an interplay between over and underdetermination depending upon the causal models. Third, Darwin avoided overdetermination in inferring the character traits of the ancestor species implying that some information might have been lost overtime such that the current evidences are insufficient to characterize the traits of the origin. Based on this case, Tucker concludes that inferences in historical sciences proceed from overdetermination to underdetermination, an approach that is also true in the inference of ancestral languages.
CRITIC
Debates about the process of how knowledge is grounded in science did not bother me until I went in the graduate school and was asked to write a critic paper. In fact, all I know is that science is ‘science’, without distinguishing between historical and experimental. I have assumed that evolution has come to develop as a body of knowledge because of evidences supporting it. No more, no less. At first, I hardly comprehend what’s the debate about the truthfulness of scientific information generated by historical scientists. After all, they are doing science.
Tucker’s paper enabled me to discriminate between ‘what is’ from ‘what is not’ in science. I realized that experimental scientists are the ones doing the Baconian scientific method reliant on hardcore empiricism. I did not have any idea that historical scientists are waiving this time-honored method in favor of observations, evidences available and rational thinking in order to infer the origin of a certain thing . Now, it has been made clear to me why historical scientists are always placed on a hot seat.
Let me make Darwin’s inferential analysis simpler, at least in the context I am familiar with. It is easy to claim that we have some semblance because we are relatives by blood (overdetermination), let alone the look-alikes. The next question would be ‘how in the world have we become relatives?’ So we trace our genealogies. Depending on the availability of information, we speculate (interplay of over and underdetermination). Granting that our common ancestor has been traced based on the most plausible model, we may infer phenotypic traits but to determine the character traits of our common ancestor is another story (underdetermination).
That is how I understand Darwin’s experience in inferring the origin of species. It is obvious that as the process of inference goes deeper, tracing the common ancestor is becoming unlikely overdetermined .
That the past is overdetermined by its effects may sound an overstatement. But that is how we usually reason, ‘like begets like.’ We tend to imply correlation with causation, which should not always be. However, I have some problem with Cleland’s attempt to connect overdetermination with ‘radiative asymmetry’ like waves spreading outwards than inwards as time progresses. There may be the spreading away of waves, but we have learned in Physics that overtime these waves will lose energy.
It is on this premise that Turner’s thesis of underdetermination of the past due to information decay appealed to me. He cited the law of entropy as supporting evidence to his thesis. Indeed the amount of disorder in the universe tends to increase. The fossils may provide clues to the past or even preserve some important information as Cleland would argue, but still they are not excluded from the action of entropy.
It was interesting to note that Darwin’s approach has been found to be also workable in the inference of ancestral languages. But my comments are rather trivial. I understand better what Tucker pointed out as homologies with common cause when I came across with some typos like “pronounciation” and “undertermined” in the paper. I am certain that these unlikely occurrences have common cause: ‘error in coding’, and that’s an overdetermination, as with the mutations that occur in our genes.
Given the merits of these two theses in the historical sciences, I cannot settle for Tucker’s cliché that ‘the truth lies somewhere in the middle.’ I want the debate to keep going.
REFERENCES
Cleland, Carol E. (2002). "Methodological and Epistemic Differences Between Historical Science and Experimental Science," Philosophy of Science 69, pp. 474-496. Retrieved November 30, 3011, Available at http://spot.colorado.edu/~cleland/articles/Cleland.PS.Pdf
Psillos, Stathis (2008). “Review of Derek Turner’s Making Prehistory: Historical Science and the Scientific Realism Debate” Notre Dame Philosophical Reviews. Retrieved December 1, 2011 at http://ndpr.nd.edu/news/23501-making-prehistory-historical-science-and-the-scientific-realism-debate/
Read more...
Article Review: PreClinical and Clinical Safety Studies on DNA Vaccines
Pre-Clinical and Clinical Safety Studies on DNA Vaccines
Johanna A.C. Schalk, Frits R. Mooi, Guy A.M. Berbers, Leon A.G.J.M. Van Aerts, Hans Ovelgonne and Tjeerd G. Kimman
Human Vaccines 2:2 45-53, March/April 2006; Landes Bioscience
The topic under review is the safety issues on the use of DNA vaccines. There are a number of studies cited by the authors. Findings from these were used in organizing the paper based on the major safety issues (genetic, immune-mediated and environmental) surrounding the preclinical and clinical use of DNA vaccines both in animal models and humans.
GENERAL SAFETY
The use of DNA vaccines in mice, rabbits and rats administered either intravenously, intramuscularly or intradermally were well tolerated by the subjects regardless of the doses applied. This was based on the experiments done by Parker et al (1999); Hanke et al (2002) and Tuomela et al (2005.) Based on the reports of McGergor et al. (1998), Moorthy et al. (2003), Mwau et al (2004) and Rottinghaus et al. (2003), all DNA vaccines used so far in humans are well tolerated with no local or systemic serious adverse effects.
GENETIC ISSUES
The authors raised three major genetic concerns on the use of DNA vaccines.
First, is the possible long-term persistence of the DNA vaccines which might facilitate the integration of plasmid DNA into the host’s genome and could cause long term skewing of the immune system influencing future immunizations and infections. Although current studies reported that the amount of plasmid DNA dissipates from the introduction site few minutes shortly after injection (Parker et al., 1999; Hoblwerg et al., 2001; Manam et al., 2000; Kim et al., 2003; and Bureau et al., 2004), it was also found out that DNA vaccines could be stably expressed for about 19 months (Wolf et al., 1992) and could even persist up to two years (Armengol et al., 2004). However in both cases, no integration was detected and the amount discovered was low, but at significant level.
Second, is the probable integration of plasmid DNA into the host’s genome. Integration could lead to activation of oncogenes, inactivation of tumor suppressor genes or to vertical transmission when integrated into the chromosomal DNA of germ line cells. Nevertheless, current studies show that the risk of mutation to plasmid integration is negligible as demonstrated by the experiments of Nichols et al. (1995) and Ledwith et al. (2000). Several studies also support the claim that various plasmid DNA vaccines did not demonstrate any integration event in rat (Kang et al., 2003; Yang et al., 2003), in fish (Kanellos et al., 1999) and in mice (Martin et.al, 1999 and Manam et.al, 2000). As to the manner of delivery, it was found out that even if the use of biojector increases the plasmid uptake of host cells as compared with needle injection, it did not still result in a detectable increase in integration frequency, likewise, in the use of aluminum phosphate adjuvant (Manam et al,2000).
However, in the study of Wang et al. (2004), they found out that subjecting the cell to electroporation results in increased plasmid frequency. That’s why integration events even at a very low frequency should not be neglected. It is for this reason that suicide vectors are now being developed to induce the apoptotic cell death of transfected cells (Xiao et al., 2004; Kohno et al.,1998; Chattergon et al, 2000; Sasaki et al.,2001; Kim et al.,2004) and alleviate the concerns of potential integration and cell transformation.
Third, is the issue on germ line integration and vertical transmission. The study of Parker et al. (1999) and Manam et al. (2000) revealed that plasmid DNA can be detected in gonads shortly after upon injection. However, its integration into chromosomal germ line DNA has not yet been observed so far. This raises some concerns because when plasmid is transmitted to the gonads, there is a possibility that germ line chromosomal integration and transmission could occur. However, it was reported that this will just be very minimal.
IMMUNE MEDIATED ISSUES
Four concerns related to immunity on the use of DNA vaccines were drawn by the reviewers.
First, is the possible induction of auto-immunity which is a general concern. In the experiment on knockout mice (normal and with lupus), it was confirmed that DNA vaccines can really induce the formation of anti-DNA antibodies, however, no evidence was found that they induce systemic auto-immune diseases. In another four separate experiments, it was found out that no anti-DNA antibodies at all were observed after DNA vaccination of mice, rat, rabbits, fish and non-human primates. However Donnely et al. (1997), Gurunthan et al. (2000)and Kreig et al. (2002) raised the immunostimulatory activity issue of the unmethylated CpG motifs in plasmid backbone because these can lead to the formation of anti-DNA antibodies which might accelerate the development of auto-immune diseases. It was also raised that introduction of other immunomodulatory molecules, the attachment of peptides to the DNA vectors and destruction of the injected muscle cells as a result of DNA vaccination may induce auto-immunity. Nevertheless, the authors believe that it is unlikely that DNA vaccines would pose any greater risk than conventional vaccines.
Second concern is on the induction of immunological tolerance particularly among infants and children. Given their immature immune system, there is a fear that vaccination may develop tolerance rather than immunity. This was confirmed by the studies of Ichino et al. (1999) and Mor et al. (1996) who found out that vaccination of 2-6 month old mice resulted in immunity but those younger than 7 days old did not develop an antibody response and remained unresponsive when revaccinated as adults. This tolerance was not induced by early vaccination which was antigen specific.
The third concern is about the altered immune responsiveness to other vaccines and infections. Plasmids that encode cytokines affect the immune capacity of the host cell. The coadministration of these immunostimulatory molecules can result in their release in the circulation causing undesirable systemic effects like enhanced susceptibility to infections and mortality rates that may range from substantial to high. However, in the experiment of Ishi et al. (1999), they found out that some plasmids that encode specific protein boosted immunity against a coadministered vaccine without unwanted side effects.
The fourth issue is on the toxicity and immunotoxicity of the DNA vaccines. Taylor et al. (2003) discovered that vaccination against TB in mice caused pulmonary necrosis. They manifested pyrogenic responses suggestive of a lung damage. This is not the case however in some other animals where plasmid DNA vaccines provided protection against lethal type. For example, immunization of mice with DNA plasmid, protected the mice against lethal challenges with tetanus toxin.
ENVIRONMENTAL ISSUES
Several studies reported that DNA vaccines can be spread in the environment by shedding or by consumption of vaccinated animals. They can also recombine with viruses, bacteria or parasites outside the vaccinated host after shedding or inside the vaccinated host and consequently generate the spread of genetically modified organism. And they can also spread via integration in the genome of germ line cells.
At first this is really a matter of great concern. We do not want more stress in our environment. However the study of Comerota et al. (2002), the only paper so far that addresses the environmental issues surrounding the use of DNA vaccines revealed that once shed in the environment, DNA will be degraded. This was proven by an experiment in humans that after intramuscular administration of a naked plasmid DNA, none was detectable in the urine.
Chances on recombination events particularly in resident microorganisms and subsequent shedding and long term transmission are extremely low especially when DNA vaccines are introduced intramuscularly. This is because DNA vaccines do not replicate in mammalian cells in contrast to live vaccines.
Thus release of plasmid DNA into the environment is not likely to have any direct impact on other organisms. Much more, the consumption of vaccinated animals may not pose greater risk as this would just be likened to the consumption of natural DNA.
REFLECTIONS
The use of DNA vaccines has been found so far to be safe in preclinical and clinical trials and holds a lot of promise for the improved well-being of humanity, particularly those in the third world countries.
The risks according to various studies are minimal, but there is no need to be complacent. I am so much concerned of the genetic effects of using DNA vaccines particularly their potential to turn on the oncogenes and shutting off the tumor suppressor genes. If this will not be addressed properly, we are going to create problem than solution. The development of suicide vectors must be given attention and focus as this would reduce the fears and worries of the possible integration of the plasmid to the patient’s genome. The process must be perfected in order to ensure the safety of the vaccine users.
The world has erstwhile bet on the live and weakened vaccines and has saved lives and I think to take another risk to something that is in the form of a molecule, handy, freezer free and which has the potential to create long term immunity is more than worth it.
Who knows one day…
… DNA vaccines against infectious diseases such as AIDS, rabies, malaria will be made available in the market already;
….scientists would be able to isolate plasmid DNA with multiple genes that could provide immunity against many diseases in one booster;
Then, this world will surely appreciate more what science and technology is all about!
Read more...
Johanna A.C. Schalk, Frits R. Mooi, Guy A.M. Berbers, Leon A.G.J.M. Van Aerts, Hans Ovelgonne and Tjeerd G. Kimman
Human Vaccines 2:2 45-53, March/April 2006; Landes Bioscience
The topic under review is the safety issues on the use of DNA vaccines. There are a number of studies cited by the authors. Findings from these were used in organizing the paper based on the major safety issues (genetic, immune-mediated and environmental) surrounding the preclinical and clinical use of DNA vaccines both in animal models and humans.
GENERAL SAFETY
The use of DNA vaccines in mice, rabbits and rats administered either intravenously, intramuscularly or intradermally were well tolerated by the subjects regardless of the doses applied. This was based on the experiments done by Parker et al (1999); Hanke et al (2002) and Tuomela et al (2005.) Based on the reports of McGergor et al. (1998), Moorthy et al. (2003), Mwau et al (2004) and Rottinghaus et al. (2003), all DNA vaccines used so far in humans are well tolerated with no local or systemic serious adverse effects.
GENETIC ISSUES
The authors raised three major genetic concerns on the use of DNA vaccines.
First, is the possible long-term persistence of the DNA vaccines which might facilitate the integration of plasmid DNA into the host’s genome and could cause long term skewing of the immune system influencing future immunizations and infections. Although current studies reported that the amount of plasmid DNA dissipates from the introduction site few minutes shortly after injection (Parker et al., 1999; Hoblwerg et al., 2001; Manam et al., 2000; Kim et al., 2003; and Bureau et al., 2004), it was also found out that DNA vaccines could be stably expressed for about 19 months (Wolf et al., 1992) and could even persist up to two years (Armengol et al., 2004). However in both cases, no integration was detected and the amount discovered was low, but at significant level.
Second, is the probable integration of plasmid DNA into the host’s genome. Integration could lead to activation of oncogenes, inactivation of tumor suppressor genes or to vertical transmission when integrated into the chromosomal DNA of germ line cells. Nevertheless, current studies show that the risk of mutation to plasmid integration is negligible as demonstrated by the experiments of Nichols et al. (1995) and Ledwith et al. (2000). Several studies also support the claim that various plasmid DNA vaccines did not demonstrate any integration event in rat (Kang et al., 2003; Yang et al., 2003), in fish (Kanellos et al., 1999) and in mice (Martin et.al, 1999 and Manam et.al, 2000). As to the manner of delivery, it was found out that even if the use of biojector increases the plasmid uptake of host cells as compared with needle injection, it did not still result in a detectable increase in integration frequency, likewise, in the use of aluminum phosphate adjuvant (Manam et al,2000).
However, in the study of Wang et al. (2004), they found out that subjecting the cell to electroporation results in increased plasmid frequency. That’s why integration events even at a very low frequency should not be neglected. It is for this reason that suicide vectors are now being developed to induce the apoptotic cell death of transfected cells (Xiao et al., 2004; Kohno et al.,1998; Chattergon et al, 2000; Sasaki et al.,2001; Kim et al.,2004) and alleviate the concerns of potential integration and cell transformation.
Third, is the issue on germ line integration and vertical transmission. The study of Parker et al. (1999) and Manam et al. (2000) revealed that plasmid DNA can be detected in gonads shortly after upon injection. However, its integration into chromosomal germ line DNA has not yet been observed so far. This raises some concerns because when plasmid is transmitted to the gonads, there is a possibility that germ line chromosomal integration and transmission could occur. However, it was reported that this will just be very minimal.
IMMUNE MEDIATED ISSUES
Four concerns related to immunity on the use of DNA vaccines were drawn by the reviewers.
First, is the possible induction of auto-immunity which is a general concern. In the experiment on knockout mice (normal and with lupus), it was confirmed that DNA vaccines can really induce the formation of anti-DNA antibodies, however, no evidence was found that they induce systemic auto-immune diseases. In another four separate experiments, it was found out that no anti-DNA antibodies at all were observed after DNA vaccination of mice, rat, rabbits, fish and non-human primates. However Donnely et al. (1997), Gurunthan et al. (2000)and Kreig et al. (2002) raised the immunostimulatory activity issue of the unmethylated CpG motifs in plasmid backbone because these can lead to the formation of anti-DNA antibodies which might accelerate the development of auto-immune diseases. It was also raised that introduction of other immunomodulatory molecules, the attachment of peptides to the DNA vectors and destruction of the injected muscle cells as a result of DNA vaccination may induce auto-immunity. Nevertheless, the authors believe that it is unlikely that DNA vaccines would pose any greater risk than conventional vaccines.
Second concern is on the induction of immunological tolerance particularly among infants and children. Given their immature immune system, there is a fear that vaccination may develop tolerance rather than immunity. This was confirmed by the studies of Ichino et al. (1999) and Mor et al. (1996) who found out that vaccination of 2-6 month old mice resulted in immunity but those younger than 7 days old did not develop an antibody response and remained unresponsive when revaccinated as adults. This tolerance was not induced by early vaccination which was antigen specific.
The third concern is about the altered immune responsiveness to other vaccines and infections. Plasmids that encode cytokines affect the immune capacity of the host cell. The coadministration of these immunostimulatory molecules can result in their release in the circulation causing undesirable systemic effects like enhanced susceptibility to infections and mortality rates that may range from substantial to high. However, in the experiment of Ishi et al. (1999), they found out that some plasmids that encode specific protein boosted immunity against a coadministered vaccine without unwanted side effects.
The fourth issue is on the toxicity and immunotoxicity of the DNA vaccines. Taylor et al. (2003) discovered that vaccination against TB in mice caused pulmonary necrosis. They manifested pyrogenic responses suggestive of a lung damage. This is not the case however in some other animals where plasmid DNA vaccines provided protection against lethal type. For example, immunization of mice with DNA plasmid, protected the mice against lethal challenges with tetanus toxin.
ENVIRONMENTAL ISSUES
Several studies reported that DNA vaccines can be spread in the environment by shedding or by consumption of vaccinated animals. They can also recombine with viruses, bacteria or parasites outside the vaccinated host after shedding or inside the vaccinated host and consequently generate the spread of genetically modified organism. And they can also spread via integration in the genome of germ line cells.
At first this is really a matter of great concern. We do not want more stress in our environment. However the study of Comerota et al. (2002), the only paper so far that addresses the environmental issues surrounding the use of DNA vaccines revealed that once shed in the environment, DNA will be degraded. This was proven by an experiment in humans that after intramuscular administration of a naked plasmid DNA, none was detectable in the urine.
Chances on recombination events particularly in resident microorganisms and subsequent shedding and long term transmission are extremely low especially when DNA vaccines are introduced intramuscularly. This is because DNA vaccines do not replicate in mammalian cells in contrast to live vaccines.
Thus release of plasmid DNA into the environment is not likely to have any direct impact on other organisms. Much more, the consumption of vaccinated animals may not pose greater risk as this would just be likened to the consumption of natural DNA.
REFLECTIONS
The use of DNA vaccines has been found so far to be safe in preclinical and clinical trials and holds a lot of promise for the improved well-being of humanity, particularly those in the third world countries.
The risks according to various studies are minimal, but there is no need to be complacent. I am so much concerned of the genetic effects of using DNA vaccines particularly their potential to turn on the oncogenes and shutting off the tumor suppressor genes. If this will not be addressed properly, we are going to create problem than solution. The development of suicide vectors must be given attention and focus as this would reduce the fears and worries of the possible integration of the plasmid to the patient’s genome. The process must be perfected in order to ensure the safety of the vaccine users.
The world has erstwhile bet on the live and weakened vaccines and has saved lives and I think to take another risk to something that is in the form of a molecule, handy, freezer free and which has the potential to create long term immunity is more than worth it.
Who knows one day…
… DNA vaccines against infectious diseases such as AIDS, rabies, malaria will be made available in the market already;
….scientists would be able to isolate plasmid DNA with multiple genes that could provide immunity against many diseases in one booster;
Then, this world will surely appreciate more what science and technology is all about!
Read more...
Article Review: The importance of plasma membrane coenzyme Q in aging and stress response
Article Review: The importance of plasma membrane coenzyme Q in aging and stress response
Placido Navas, Jose Manuel Villalba and Rafael de Cabo
Elsevier B.V. and Mitochondria Research Society
February 3, 2007
The article is a review of different studies that focus on the importance of coenzyme Q in cell aging and stress response. Coenzyme Q is the only lipid antioxidant in the mammalian cell characterized by its ability to exchange two electrons simultaneously or sequentially in a redox cycle between its oxidized and reduced forms. It also acts as a cofactor for uncoupling proteins and enhances the survival of cells subjected to chemotherapy. In the mitochondrial respiratory chain complexes, CoQ acts as an electron carrier.
Together, CoQ and its reductases constitute an antioxidant system spanning the plasma membrane and are responsible for its stabilization, regeneration of antioxidants and regulation of the apoptosis pathway.
However, the regulation of CoQ biosynthesis pathway remains largely unknown. What is known is that, its biosynthesis is completed in the mitochondrion (in the case of yeast), and is driven to the plasma membrane by the brefeldin A-sensitive endomembrane pathway. It has also been posited that the biosynthesis of this compound involves the participation of about nine gene products, making the delineation of its metabolic pathway a challenge.
In order to fully understand the issue, the researchers reviewed various scientific studies about coenzyme Q focusing on its functions in the plasma membrane along with its reductases; its regulation under aging and stress conditions; and its role in the regulation of stress-induced apoptosis.
Review Highlights
Antioxidant System is CoQ Dependent
The antioxidant system of the plasma membrane shelters the cell from various environmental stress. The antioxidant ascorbate protects the hydrophilic cell surface while both CoQ and α-tocopherol protect the hydrophobic phospholipid bilayer.
It has been reported that the oxidized and reduced forms of CoQ in the plasma membrane as well as its free radicals can be detected. This is because CoQ interchanges electrons with other redox compounds as well as superoxides. These exchanges lead to the regeneration of CoQH2, a reduced form that recycles other antioxidants. Among the four CoQ reductases, only NADH-cytochrome b5 reductase and NQO1 were demonstrated to act at the plasma membrane. The former displays maximal activity with CoQ0, while the latter catalyzes the reduction of CoQ to CoQH2 and maintains its reduced state. These two enzymes contribute to the trans-plasma membrane redox system providing the electrons that are required to maintain CoQ’s antioxidant properties.
Based on these findings, the authors developed a scheme of a plasma membrane with a trans-membrane electron transport system that drives electron either from NADH-ascorbate free radical reductase, NQO1, or both, to CoQ which follows a cycle to CoQH2, through the semiquinone radical. This compound is then able to recycle other antioxidants such as ascorbate and α-tocopherol. CoQH2 and α-tocopherol both prevent the oxidative degradation of lipids.
Antioxidant System is Oxidative Stress Modulated
The reviewers pointed out that the actual mechanisms involved in regulating the changes in CoQ concentration in the plasma membrane and the accumulation of its reductases still remain elusive but, evidences are pointing to the activation of a stress signaling pathway.
Scientists found out that the eukaryotic cell has developed an adaptation which can be considered as a general response to impaired mitochondrial function in order to regulate NAD+/NADH levels. This impairment induces an increase of CoQ levels at the plasma membrane resulting in enhanced trans-membrane redox activity. These responses are likely evoked by cells for protection against oxidative stress. The more the oxidative stress, the more biosynthesis of CoQ and its reductases are observed. This increase in biosynthesis is not actually stress-related but an adaptive response to prevent cell death.
In the same manner, oxidative stress can be provoked by feeding on diet deficient with Vitamin E and Selenium, as findings on rat experiment show. This in turn results in increased CoQ biosysynthesis.
Generally, the enhanced amount of CoQ in the plasma membrane may be attributed to the enhanced biosynthesis, translocation of CoQ to the plasma membrane from the ER or mitochondria, or nutrient deficiency. These results support the authors’ findings in their own laboratory that the plasma membrane redox system is at least in part, responsible for the maintenance of the anti-oxidant capacity during oxidative stress induced by diet and aging.
Antioxidant System is Related with Age
Findings from various studies show that the level of antioxidant decreases with age. In the same way, oxidative damage to plasma membrane increases with age. However, this can be retarded by caloric restriction.
In rats, it was observed that aging is associated with increased level of lipid peroxidation, decreased fluidity of the plasma membrane and decreased ratio between good and bad fatty acids. It was also found out that those fed with polyunsaturated fatty acids and supplemented with CoQ10 had longer life span than those without CoQ10 supplements.
CoQ and Apoptosis
A plasma membrane that is supplemented with CoQ demonstrates an increased cell growth. With the increased CoQ concentration, its reductases likewise increase. This makes the plasma membrane more resistant to serum removal oxidative stress mediated apoptosis and accumulates lower levels of ceramide, a chemical signal that regulates programmed cell death and apoptosis.
When growth factors are withdrawn, the neutral sphingomyelinase (n-SMase) is activated in the plasma membrane. The activation of this compound is one of the signals for apoptosis to take place resulting in ceramide production which will eventually activate caspases, the general executioners of apoptosis.
However, CoQ10 can directly inhibit the n-SMase through a non-competitive mechanism at the initiation phase of apoptosis. This was proven in the experiment of pig liver. By preventing the activation of n-SMase in the plasma membrane, the activation of caspase is inhibited, thus the apoptosis pathway is shut down.
My Take
If the introduction of CoQ among rats resulted in longer life span, is it possible that it could also be introduced to humans and produce the same results? What foods are rich in CoQ? What role will CoQ play in the development of carcinomas?
Read more...
Placido Navas, Jose Manuel Villalba and Rafael de Cabo
Elsevier B.V. and Mitochondria Research Society
February 3, 2007
The article is a review of different studies that focus on the importance of coenzyme Q in cell aging and stress response. Coenzyme Q is the only lipid antioxidant in the mammalian cell characterized by its ability to exchange two electrons simultaneously or sequentially in a redox cycle between its oxidized and reduced forms. It also acts as a cofactor for uncoupling proteins and enhances the survival of cells subjected to chemotherapy. In the mitochondrial respiratory chain complexes, CoQ acts as an electron carrier.
Together, CoQ and its reductases constitute an antioxidant system spanning the plasma membrane and are responsible for its stabilization, regeneration of antioxidants and regulation of the apoptosis pathway.
However, the regulation of CoQ biosynthesis pathway remains largely unknown. What is known is that, its biosynthesis is completed in the mitochondrion (in the case of yeast), and is driven to the plasma membrane by the brefeldin A-sensitive endomembrane pathway. It has also been posited that the biosynthesis of this compound involves the participation of about nine gene products, making the delineation of its metabolic pathway a challenge.
In order to fully understand the issue, the researchers reviewed various scientific studies about coenzyme Q focusing on its functions in the plasma membrane along with its reductases; its regulation under aging and stress conditions; and its role in the regulation of stress-induced apoptosis.
Review Highlights
Antioxidant System is CoQ Dependent
The antioxidant system of the plasma membrane shelters the cell from various environmental stress. The antioxidant ascorbate protects the hydrophilic cell surface while both CoQ and α-tocopherol protect the hydrophobic phospholipid bilayer.
It has been reported that the oxidized and reduced forms of CoQ in the plasma membrane as well as its free radicals can be detected. This is because CoQ interchanges electrons with other redox compounds as well as superoxides. These exchanges lead to the regeneration of CoQH2, a reduced form that recycles other antioxidants. Among the four CoQ reductases, only NADH-cytochrome b5 reductase and NQO1 were demonstrated to act at the plasma membrane. The former displays maximal activity with CoQ0, while the latter catalyzes the reduction of CoQ to CoQH2 and maintains its reduced state. These two enzymes contribute to the trans-plasma membrane redox system providing the electrons that are required to maintain CoQ’s antioxidant properties.
Based on these findings, the authors developed a scheme of a plasma membrane with a trans-membrane electron transport system that drives electron either from NADH-ascorbate free radical reductase, NQO1, or both, to CoQ which follows a cycle to CoQH2, through the semiquinone radical. This compound is then able to recycle other antioxidants such as ascorbate and α-tocopherol. CoQH2 and α-tocopherol both prevent the oxidative degradation of lipids.
Antioxidant System is Oxidative Stress Modulated
The reviewers pointed out that the actual mechanisms involved in regulating the changes in CoQ concentration in the plasma membrane and the accumulation of its reductases still remain elusive but, evidences are pointing to the activation of a stress signaling pathway.
Scientists found out that the eukaryotic cell has developed an adaptation which can be considered as a general response to impaired mitochondrial function in order to regulate NAD+/NADH levels. This impairment induces an increase of CoQ levels at the plasma membrane resulting in enhanced trans-membrane redox activity. These responses are likely evoked by cells for protection against oxidative stress. The more the oxidative stress, the more biosynthesis of CoQ and its reductases are observed. This increase in biosynthesis is not actually stress-related but an adaptive response to prevent cell death.
In the same manner, oxidative stress can be provoked by feeding on diet deficient with Vitamin E and Selenium, as findings on rat experiment show. This in turn results in increased CoQ biosysynthesis.
Generally, the enhanced amount of CoQ in the plasma membrane may be attributed to the enhanced biosynthesis, translocation of CoQ to the plasma membrane from the ER or mitochondria, or nutrient deficiency. These results support the authors’ findings in their own laboratory that the plasma membrane redox system is at least in part, responsible for the maintenance of the anti-oxidant capacity during oxidative stress induced by diet and aging.
Antioxidant System is Related with Age
Findings from various studies show that the level of antioxidant decreases with age. In the same way, oxidative damage to plasma membrane increases with age. However, this can be retarded by caloric restriction.
In rats, it was observed that aging is associated with increased level of lipid peroxidation, decreased fluidity of the plasma membrane and decreased ratio between good and bad fatty acids. It was also found out that those fed with polyunsaturated fatty acids and supplemented with CoQ10 had longer life span than those without CoQ10 supplements.
CoQ and Apoptosis
A plasma membrane that is supplemented with CoQ demonstrates an increased cell growth. With the increased CoQ concentration, its reductases likewise increase. This makes the plasma membrane more resistant to serum removal oxidative stress mediated apoptosis and accumulates lower levels of ceramide, a chemical signal that regulates programmed cell death and apoptosis.
When growth factors are withdrawn, the neutral sphingomyelinase (n-SMase) is activated in the plasma membrane. The activation of this compound is one of the signals for apoptosis to take place resulting in ceramide production which will eventually activate caspases, the general executioners of apoptosis.
However, CoQ10 can directly inhibit the n-SMase through a non-competitive mechanism at the initiation phase of apoptosis. This was proven in the experiment of pig liver. By preventing the activation of n-SMase in the plasma membrane, the activation of caspase is inhibited, thus the apoptosis pathway is shut down.
My Take
If the introduction of CoQ among rats resulted in longer life span, is it possible that it could also be introduced to humans and produce the same results? What foods are rich in CoQ? What role will CoQ play in the development of carcinomas?
Read more...
Thursday, January 26, 2012
Evolution and Plant Diversity
NOTE: :Lifted from Sir Baggy
Evolutionary Highlights and Plant Diversity
Plant evolutionary process leads to the diversification and increasing complexity of plant species. As what has been commonly accepted, the process started with the earliest form of algal mats and ended up with the recent angiosperms. Moreover, the new grade of organization of plants were believed to have become successful than its predecessors. Though a continuing debate, most scientists accepted that all forms of plants begun with an algal scum formed on land around 1,200 million years ago. Through the years (i.e. about millions of years), this scum has evolved into the first land plants. These plants then evolved and diversified further producing more new structures, as evidenced in fossil assemblages. Currently, there were several aspects in plant life that have become the focus of investigation to come up further evidences of the process of its evolution.
In this module, you will study how plants evolved through time, and how the process has led to the diversification of plants.
Below is the list of topics that will be discussed in this module. You can click on each topic to access or download the learning materials.
1.The Origin and Early Evolution of Plants on Land - this topic discusses the evolutionary process of plants and the highlights of the process in each evolutionary period; the discussion is based on paleobotanical discoveries and advances in systematics.
2.The Evolution of Plant Development - this topic dissects the evolution of major developmental transitions among land plants, including those associated with apical meristems, the origins of the root/shoot dichotomy, diversification of leaves, and origin and subsequent modification of flower structure.
3.The Evolution of Plant Sexual Diversity - this topic discusses sexual evolution and diversification of plants with inputs from the integration of phylogenetic, ecological and population-genetic studies. These studies have provided new insights into the selective mechanisms that are responsible for major evolutionary transitions between reproductive modes.
4.The Evolution of Leaf Venation - this discusses the evolution of different leaf venation patterns and possible
interrelationships between form and function of leaf venation systems.
5.Factors that Effect Evolution
■ Atmospheric Carbon Dioxide
■ Recombination
■ Gravity
6.Plant Diversity
Learning Activity
Listed above are the factors that influenced the evolution of plants. Some studies such as Niklas (1999) indicate that wind also plays an important role in plant evolution. You have to surf the net and find out how wind effects evolution on plants. Then, write a simple scientific paper that shows the role/s of wind in plant evolution. Be sure to cite your references. Your simple scientific paper should consist of about 2,500 words, and should have a title, abstract, introduction, objective/s of the paper, discussion, conclusion, and literature cited. Use APA style in citing the literature that you review. Post your simple scientific paper in the discussion forum intended for this purpose. You can click on this link to access the forum.
Watch the video clip below. The video is about the diversity of plant structures among various groups of plants. This is uploaded by Critters Inc last September 5, 2008 in you tube.
Video
Read more...
Evolutionary Highlights and Plant Diversity
Plant evolutionary process leads to the diversification and increasing complexity of plant species. As what has been commonly accepted, the process started with the earliest form of algal mats and ended up with the recent angiosperms. Moreover, the new grade of organization of plants were believed to have become successful than its predecessors. Though a continuing debate, most scientists accepted that all forms of plants begun with an algal scum formed on land around 1,200 million years ago. Through the years (i.e. about millions of years), this scum has evolved into the first land plants. These plants then evolved and diversified further producing more new structures, as evidenced in fossil assemblages. Currently, there were several aspects in plant life that have become the focus of investigation to come up further evidences of the process of its evolution.
In this module, you will study how plants evolved through time, and how the process has led to the diversification of plants.
Below is the list of topics that will be discussed in this module. You can click on each topic to access or download the learning materials.
1.The Origin and Early Evolution of Plants on Land - this topic discusses the evolutionary process of plants and the highlights of the process in each evolutionary period; the discussion is based on paleobotanical discoveries and advances in systematics.
2.The Evolution of Plant Development - this topic dissects the evolution of major developmental transitions among land plants, including those associated with apical meristems, the origins of the root/shoot dichotomy, diversification of leaves, and origin and subsequent modification of flower structure.
3.The Evolution of Plant Sexual Diversity - this topic discusses sexual evolution and diversification of plants with inputs from the integration of phylogenetic, ecological and population-genetic studies. These studies have provided new insights into the selective mechanisms that are responsible for major evolutionary transitions between reproductive modes.
4.The Evolution of Leaf Venation - this discusses the evolution of different leaf venation patterns and possible
interrelationships between form and function of leaf venation systems.
5.Factors that Effect Evolution
■ Atmospheric Carbon Dioxide
■ Recombination
■ Gravity
6.Plant Diversity
Learning Activity
Listed above are the factors that influenced the evolution of plants. Some studies such as Niklas (1999) indicate that wind also plays an important role in plant evolution. You have to surf the net and find out how wind effects evolution on plants. Then, write a simple scientific paper that shows the role/s of wind in plant evolution. Be sure to cite your references. Your simple scientific paper should consist of about 2,500 words, and should have a title, abstract, introduction, objective/s of the paper, discussion, conclusion, and literature cited. Use APA style in citing the literature that you review. Post your simple scientific paper in the discussion forum intended for this purpose. You can click on this link to access the forum.
Watch the video clip below. The video is about the diversity of plant structures among various groups of plants. This is uploaded by Critters Inc last September 5, 2008 in you tube.
Video
Read more...
Biological Control
NOTE: Lifted from Sir Baggy
Biological Control
Aside from the principles of DNA, protein synthesis, or ecological interactions, some other biological concepts were utilized to improve production. One concept that is being applied is predation. The idea of predation has been used more particularly in controlling unwanted organisms in the production spectrum. The practitioners refer to this application as the Biological Pest Control (BPC) or simply Biological Control (BC). In general, BC has been widely used in agricultural production to limit the impacts of pests in yield. The idea is to produce or reproduce the natural predators of these pests so as to limit their population. The relationship could be stated simply as follows: "As the population of predators increases, the population of prey is reduced." But in the field, this is not simply a linear relationship. There are other factors that need to be considered in the implementation of this tecnology.
In this module, you will study how this technology can appropriately be implemented in a certain ecological context. Of course, you will have to study what this technology is all about before you will be able to understand the diversity of the ways it is implemented. Just like bioremediation, the primary player of this technology are living organisms. But unlike it, the organisms are multicellular; definitely, not a bacteria. In addition, the subject of its action is not to remedy contamination or eliminate pollutants from the environment; rather, its action is to eliminate or limit the population of "unwanted" organisms.
Furthermore, you will also look at some case studies where the implementation of biological control is being studied.
Below is a list of topic that you will study in this module. Click on each topic to access or download the resource materials.
1.Principles of Biological Control
2.Approaches and Applications of biological Control
3.Case Studies
■ Diamondback Moth and Its Parasitoids
■ Gypsy Moth
Activity
Were you able to encounter this concept "biological control" in your previous learning transactions? Or, this is your first time to encounter the term? If you have already acquired certain levels of knowledge regarding this topic, can you share what it was that you learned? If this is your first time, can you share how you might be able to include this in your teaching or research undertakings? Post your thoughts in the discussion forum intended for this topic. You can click on this link (for first timers) or this link (for those with prior knowledge) to access the forum.
Read more...
Biological Control
Aside from the principles of DNA, protein synthesis, or ecological interactions, some other biological concepts were utilized to improve production. One concept that is being applied is predation. The idea of predation has been used more particularly in controlling unwanted organisms in the production spectrum. The practitioners refer to this application as the Biological Pest Control (BPC) or simply Biological Control (BC). In general, BC has been widely used in agricultural production to limit the impacts of pests in yield. The idea is to produce or reproduce the natural predators of these pests so as to limit their population. The relationship could be stated simply as follows: "As the population of predators increases, the population of prey is reduced." But in the field, this is not simply a linear relationship. There are other factors that need to be considered in the implementation of this tecnology.
In this module, you will study how this technology can appropriately be implemented in a certain ecological context. Of course, you will have to study what this technology is all about before you will be able to understand the diversity of the ways it is implemented. Just like bioremediation, the primary player of this technology are living organisms. But unlike it, the organisms are multicellular; definitely, not a bacteria. In addition, the subject of its action is not to remedy contamination or eliminate pollutants from the environment; rather, its action is to eliminate or limit the population of "unwanted" organisms.
Furthermore, you will also look at some case studies where the implementation of biological control is being studied.
Below is a list of topic that you will study in this module. Click on each topic to access or download the resource materials.
1.Principles of Biological Control
2.Approaches and Applications of biological Control
3.Case Studies
■ Diamondback Moth and Its Parasitoids
■ Gypsy Moth
Activity
Were you able to encounter this concept "biological control" in your previous learning transactions? Or, this is your first time to encounter the term? If you have already acquired certain levels of knowledge regarding this topic, can you share what it was that you learned? If this is your first time, can you share how you might be able to include this in your teaching or research undertakings? Post your thoughts in the discussion forum intended for this topic. You can click on this link (for first timers) or this link (for those with prior knowledge) to access the forum.
Read more...
Bioremediation
NOTE: Lifted from Sir Baggy
Bioremediation
One approach to clean up a contaminated environment is the use of microbes, the technology now known as Bioremediation. Bioremediation is the use of microbes to clean up hazardous contaminants such as oils and gasoline. Certain microbes will completely digest these chemicals, and transform them in to harmless water and gases such as carbon dioxide. However, for these microbes to work efficiently, certain environmental conditions should be met. Factors like temperature, nutrients, oxygen, and other chemicals needed for their work must be present. These factors when present in right amount will allow rapid growth and reproduction of these microbes, and thus, rapid process of cleaning up the contaminants. But the process is more than this.
In this module, you will study the principles behind this technology, how it is currently practiced, and the factors that affect the process. To further your learning, a case study is presented to allow you to see how it is being implemented and studied in situ.
Below is a list of topics for this module. Click on each topic to access or download the resource materials.
1. Principles of Bioremediation
2. Current Practice of Bioremediation
3. Factors Affecting Bioremediation
4. Case Study
Activity
Watch the video clip below. This video shows research activities that led to the development of the bioremediation technology.
Video
Read more...
Bioremediation
One approach to clean up a contaminated environment is the use of microbes, the technology now known as Bioremediation. Bioremediation is the use of microbes to clean up hazardous contaminants such as oils and gasoline. Certain microbes will completely digest these chemicals, and transform them in to harmless water and gases such as carbon dioxide. However, for these microbes to work efficiently, certain environmental conditions should be met. Factors like temperature, nutrients, oxygen, and other chemicals needed for their work must be present. These factors when present in right amount will allow rapid growth and reproduction of these microbes, and thus, rapid process of cleaning up the contaminants. But the process is more than this.
In this module, you will study the principles behind this technology, how it is currently practiced, and the factors that affect the process. To further your learning, a case study is presented to allow you to see how it is being implemented and studied in situ.
Below is a list of topics for this module. Click on each topic to access or download the resource materials.
1. Principles of Bioremediation
2. Current Practice of Bioremediation
3. Factors Affecting Bioremediation
4. Case Study
Activity
Watch the video clip below. This video shows research activities that led to the development of the bioremediation technology.
Video
Read more...
Environmental Issues and Concerns
NOTE: Lifted from Sir Baggy
Environmental Issues and Concerns
Environmental and natural resources conservation and management have been the focus of efforts currently. Countries throughout the globe have developed international partnerships in dealing with the issue of environmental destruction, natural resources degradation, biodiversity loss, climate change, massive deforestation, and the like. The impacts of anthropogenic activities on ecosystem structure and functions call for a widespread environmental awareness campaign, and a deeper study on the issues and concerns that beset the environment.
This module will help you explain the ecological problems that beset our environment at present. You will study in this module some environmental problems and the strategies that were employed to address these problems. You will also review certain approaches in managing environmental and natural resources.
Below is a list of topics that you will study in this module. Click on each topic to access or download the resource materials.
1.Global Environmental Issues and Concerns
■ Loss of Biodiversity and Extinction
■ Climate Change and Global Warming
■ Coral Reef Destruction
■ Urban Sprawl
■ Transboundary Dumping of Hazardous Wastes
■ Water Pollution Disaster
2.Philippine Environmental Problems
■ Deforestation and Biodiversity Loss
■ Mining and Environmental Contamination
3.Strategies in Managing Environmental Problems
■ UNEP Agenda 21 - in this site, you will see the programs of action for each pressing global environmental issues. Click each link so that you will see the strategies that ought to be done to address these issues.
■ Philippine Agenda 21 - this is Philippine's equivalent of the UNEP Agenda 21 as it applies the strategies locally.
■ NIPAS - this is a system of managing biodiversity by proclaiming biodiversity or ecologically hotspot areas in the Philippines.
ACTIVITY
Can you share with the group how you might integrate environmental awareness in your course (for teachers) or help improve the environmental awareness in your immediate community (for non-teachers)? Post your thoughts in the discussion forum intended for this activity. Click on this link to access the forum.
Read more...
Environmental Issues and Concerns
Environmental and natural resources conservation and management have been the focus of efforts currently. Countries throughout the globe have developed international partnerships in dealing with the issue of environmental destruction, natural resources degradation, biodiversity loss, climate change, massive deforestation, and the like. The impacts of anthropogenic activities on ecosystem structure and functions call for a widespread environmental awareness campaign, and a deeper study on the issues and concerns that beset the environment.
This module will help you explain the ecological problems that beset our environment at present. You will study in this module some environmental problems and the strategies that were employed to address these problems. You will also review certain approaches in managing environmental and natural resources.
Below is a list of topics that you will study in this module. Click on each topic to access or download the resource materials.
1.Global Environmental Issues and Concerns
■ Loss of Biodiversity and Extinction
■ Climate Change and Global Warming
■ Coral Reef Destruction
■ Urban Sprawl
■ Transboundary Dumping of Hazardous Wastes
■ Water Pollution Disaster
2.Philippine Environmental Problems
■ Deforestation and Biodiversity Loss
■ Mining and Environmental Contamination
3.Strategies in Managing Environmental Problems
■ UNEP Agenda 21 - in this site, you will see the programs of action for each pressing global environmental issues. Click each link so that you will see the strategies that ought to be done to address these issues.
■ Philippine Agenda 21 - this is Philippine's equivalent of the UNEP Agenda 21 as it applies the strategies locally.
■ NIPAS - this is a system of managing biodiversity by proclaiming biodiversity or ecologically hotspot areas in the Philippines.
ACTIVITY
Can you share with the group how you might integrate environmental awareness in your course (for teachers) or help improve the environmental awareness in your immediate community (for non-teachers)? Post your thoughts in the discussion forum intended for this activity. Click on this link to access the forum.
Read more...
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