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1.
P Sullivan 《CMAJ》1995,153(3):337-338
Dr. Ronald Stewart admits that there are negative aspects to becoming a politician, but when he addressed a recent national meeting of Canada''s emergency physicians he pleaded for more physician involvement in the political process. Stewart, an emergency physician who serves as Nova Scotia''s health minister, thinks work as a politician can be both frustrating and fulfilling.  相似文献   

2.
N Robb 《CMAJ》1997,156(1):67-68
When Robert Johnson graduates from medical school in 1998, he will become Canada''s first Micmac physician. For him, going to medical school is a major responsibility because he is a role model for an entire community. He hopes he is only the first of many Micmacs to make this career choice.  相似文献   

3.
English Chemist Harold Kroto shared the 1996 Nobel Prize in Chemistry with Robert Curl and Richard Smalley for their discovery of Fullerenes (C60), molecules composed completely of carbon (C60) that form hollow spheres (also known as Buckyballs), tubes, or ellipsoids. These structures hold the potential for use in future technologies ranging from drug development and antimicrobial agents, to armor and superconductors.Harold Kroto was born in Wisbech, Cambridgeshire in 1939 and grew up in Bolton. Educated at Bolton School, he entered Sheffield University in 1958 to study Chemistry. During his time there he played tennis for the university team, illustrated the university''s magazine covers, and played folk music with other students. Enjoying his time at Sheffield very much, he chose to stay on and complete a Ph.D. in Chemistry under Richard Dixon.Following graduation in 1964, Kroto went on to post doc at the National Research Council (NRC) in Ottowa, Canada where microwave spectroscopy became his specialty. After two years of study at the NRC he spent a year at Bell Laboratories. He then accepted a position as a tutorial fellow at the University of Sussex, where he was soon offered a permanent position. There, he applied his expertise in microwave spectroscopy to the field of astronomy and spent several fruitful years detecting long carbon chains in the interstellar medium.Upon hearing of the work of Richard Smalley at Rice, who developed a laser that could vaporize graphite, Kroto thought they could use Smalley''s instrument to see carbon chains similar to those they had observed in interstellar matter. He suggested his idea for an experiment to Bob Curl, also at Rice. In 1985 he traveled to Rice to perform the experiment (and also to visit a half-price bookstore he''d heard about in Houston).Although he felt certain that the apparatus would create the carbon chains, the experiment revealed a totally unexpected result: the spontaneous formation of spherical shapes, which they called Buckminster Fullerenes in honor of the architect who popularized the geodesic dome.Though he is pleased to have received the Nobel Prize, Kroto does not believe in prizes or competition as a motivator for scientific (or athletic) progress. Rather, he believes that the pursuit of science or athletics should be simply for the enjoyment or interest in the subject matter, and he prefers to investigate subjects that other people aren''t working on.Kroto has mixed feelings about the effect the prize has had on his life. On the one hand, he would like to be able to spend more time pursuing graphic design, something he has always deeply enjoyed. On the other hand, he now enjoys a sense of responsibility for supporting the scientific community.As an atheist, Kroto feels that science is, in itself, atheistic. He doesn''t accept anything without evidence. Kroto expresses concern about people holding positions of power who do not use evidence as a basis for decision-making. "When they are prepared to accept one of 20-30 stories from thousands of years ago, I wonder what else they are prepared to accept when it comes to decisions which affect me?"Kroto is particularly worried about the effect of policies that require the teaching of non-scientific ideas, to the detriment of evidence-based scientific education. He points to the forced teaching of creationism in public schools and the existence of a "creation museum" in the United States as sources of misinformation that have given rise to "a whole generation of school children who''ve been abused."Download video file.(80M, mp4)  相似文献   

4.
Revisiting Metchnikoff''s work in light of the COVID-19 pandemic illustrates how much this amazing scientist was a polymath, and one could speculate how much he would have been fascinated and most interested in following the course of the pandemic. Since he coined the word “gerontology”, he would have been intrigued by the high mortality among the elderly, and by the concepts of immunosenescence and inflammaging that characterize the SARS-CoV-2 infection. While Metchnikoff''s work is mainly associated with the discovery of the phagocytes and the birth of cellular innate immunity, he regularly invited his closest collaborators to investigate humoral immunity, and it was in his laboratory that Jules Bordet made his major discovery of the complement system. While Metchnikoff and his team investigated many infectious diseases, he also contributed to studies linked to vaccination, such as those on typhoid fever performed in chimpanzees, illustrating that non-human primates can provide animal models which are potentially helpful for understanding the pathophysiology of the COVID-19 virus. In the present review, we illustrate how much his own work and the investigations of his trainees were pertinent to this new disease.  相似文献   

5.
Katja Werthmann 《Ethnos》2013,78(1):95-111
The article provides an example of how 'formal' and 'informal' modes of power and legitimacy, as well as material and symbolic leadership resources, may intersect and interrelate. It analyses the sources of power that a Big Man in West Africa mobilised in order to appropriate mining rights and to establish leadership in a gold mining camp. As an entrepreneur in an economic field directly regulated by state laws and authorities, he has to operate within these structures while at the same time subverting them by creating a 'system of personal power' that resembles Sahlins' classic model of the Big Man in Melanesia. Although he is elected to represent the gold diggers, his leadership position rests not so much on a formal vote as on wealth, violence, and charisma. These attributes are underscored in performances that draw on symbols of power and prestige, linking commonly held ideas about traditional rule and conspicuous consumption to personal legitimacy.  相似文献   

6.
T Spears 《CMAJ》1996,155(1):101-102
A recently published study discussed the trauma-related death toll that plagues northeastern Ontario, which has a much higher death rate from nonintentional trauma than the rest of the province Dr. Gary Bota, one of the study authors hates calling these tragedies accidents because that implies a random, act-of-God nature that he does not accept. "They''re not accidents," he maintains. "They''re patterns, just like infectious diseases."  相似文献   

7.
Trent 《CMAJ》1996,154(7):1089-1091
Retired prison psychiatrist George Scott recalls his career working in Canada''s penal system, including his peacemaking role in a hostage-taking incident and his work with Steven Truscott. Life "inside" is dangerous for guards, inmates, staff and psychiatrists, he says, but he never regretted his decision to devote his career to studying criminal behaviour.  相似文献   

8.
The scientific process requires a critical attitude towards existing hypotheses and obvious explanations. Teaching this mindset to students is both important and challenging.People who read about scientific discoveries might get the misleading impression that scientific research produces a few rare breakthroughs—once or twice per century—and a large body of ‘merely incremental'' studies. In reality, however, breakthrough discoveries are reported on a weekly basis, and one can cite many fields just in biology—brain imaging, non-coding RNAs and stem cell biology, to name a few—that have undergone paradigm shifts within the past decade.The truly surprising thing about discovery is not just that it happens at a regular pace, but that most significant discoveries occurred only after the scientific community had already accepted another explanation. It is not merely the accrual of new data that leads to a breakthrough, but a willingness to acknowledge that a problem that is already ‘solved'' might require an entirely different explanation. In the case of breakthroughs or paradigm shifts, this new explanation might seem far-fetched or nonsensical and not even worthy of serious consideration. It is as if new ideas are sitting right in front of everyone, but in their blind spots so that only those who use their peripheral vision can see them.Scientists do not all share any single method or way of working. Yet they tend to share certain prevalent attitudes: they accept ‘facts'' and ‘obvious'' explanations only provisionally, at arm''s length, as it were; they not only imagine alternatives, but—almost as a reflex—ask themselves what alternative explanations are possible.When teaching students, it is a challenge to convey this critical attitude towards seemingly obvious explanations. In the spring semester of 2009, I offered a seminar entitled The Process of Scientific Discovery to Honours undergraduate students at the University of Illinois-Chicago in the USA. I originally planned to cover aspects of discovery such as the impact of funding agencies, the importance of mentoring and hypothesis-driven as opposed to data-driven research. As the semester progressed, however, my sessions moved towards ‘teaching moments'' drawn from everyday life, which forced the students to look at familiar things in unfamiliar ways. These served as metaphors for certain aspects of the process by which scientists discover new paradigms.For the first seven weeks of the spring semester, the class read Everyday Practice of Science by Frederick Grinnell [1]. During the discussion of the first chapter, one of the students noted that Grinnell referred to a scientist generically as ‘she'' rather than ‘he'' or the neutral ‘he or she''. This use is unusual and made her vaguely uneasy: she wondered whether the author was making a sexist point. Before considering her hypothesis, I asked the class to make a list of assumptions that they took for granted when reading the chapter, together with the possible explanations for the use of ‘she'' in the first chapter, no matter how far-fetched or unlikely they might seem.For example, one might assume that Frederick Grinnell or ‘Fred'' is from a culture similar to our own. How would we interpret his behaviour and outlook if we knew that Fred came from an exotic foreign land? Another assumption is that Fred is male; how would we view the remark if we discover that Frederick is short for Fredericka? We have equally assumed that Fred, as with most humans, wants us to like him. Instead, perhaps he is being intentionally provocative in order to get our attention or move us out of our comfort zone. Perhaps he planted ‘she'' as a deliberate example for us to discuss, as he does later in the second chapter, in which he deliberately hides a strange item in plain sight within one of the illustrations in order to make a point about observing anomalies. Perhaps the book was written not by Fred but by a ghost writer? Perhaps the ‘she'' was a typo?The truly surprising thing about discovery is […] that most significant discoveries occurred only after the scientific community had already accepted another explanationLooking for patterns throughout the book, and in Fred''s other writing, might persuade us to discard some of the possible explanations: does ‘she'' appear just once? Does Fred use other unusual or provocative turns of phrase? Does Fred discuss gender bias or sexism explicitly? Has anyone written or complained about him? Of course, one could ask Fred directly what he meant, although without knowing him personally, it would be difficult to know how to interpret his answer or whether to take his remarks at face value. Notwithstanding the answer, the exercise is an important lesson about considering and weighing all possible explanations.Arguably, the most prominent term used in science studies is the notion of a ‘paradigm''. I use this term with reluctance, as it is extraordinarily ambiguous. For example, it could simply refer to a specific type of experimental design: a randomized, placebo-controlled clinical trial could be considered a paradigm. In the context of science studies, however, it most often refers to the idea of large-scale leaps in scientific world views, as promoted by Thomas Kuhn in The Structure of Scientific Revolutions [2]. Kuhn''s notion of a paradigm can lead one to believe—erroneously in my opinion—that paradigm shifts are the opposite of practical, everyday scientific problem-solving.A paradigm is recognized by the set of assumptions that an observer might not realize he or she is making…Instead, I propose here a definition of ‘paradigm'' that emphasizes not the nature of the problem, the type of discovery or the scope of its implications, but rather the psychology of the scientist. A scientist viewing a problem or phenomenon resides within a paradigm when he or she does not notice, and cannot imagine, that an alternative way of looking at things needs to be considered seriously. Importantly, a paradigm is not a viewpoint, model, interpretation, hypothesis or conclusion. A paradigm is not the object that is viewed but the lenses through which it is viewed. A paradigm is recognized by the set of assumptions that an observer might not realize he or she is making, but which imply many automatic expectations and simultaneously prevent the observer from seeing the issue in any other fashion.For example, the teacher–student paradigm feels natural and obvious, yet it is merely set up by habit and tradition. It implies lectures, assignments, grades, ways of addressing the professor and so on, all of which could be done differently, if we had merely thought to consider alternatives. What feels most natural in a paradigm is often the most arbitrary. When we have a birthday, we expect to have a cake with candles, yet there is no natural relationship at all between birthdays, cakes and candles. In fact, when something is arbitrary or conventional yet feels entirely natural, that is an important clue that a paradigm is present.It is certainly natural for people to colour their observations according to their expectations: “To a man with a hammer, everything looks like a nail,” as Mark Twain put it. However, this is a pitfall that scientists (and doctors) must try hard to avoid. When I was a first-year medical student at Albert Einstein College of Medicine in New York City, we took a class on how to approach patients. As part of this course, we attended a session in which a psychiatrist interviewed a ‘normal, healthy old person'' in order to understand better the lives and perspectives of the elderly.A man came in, and the psychiatrist began to ask him some benign questions. After about 10 minutes, however, the man began to pause before answering; then his answers became terse; then he said he did not feel well, excused himself and abruptly left the room. The psychiatrist continued to lecture to the students for another half-hour, analysing and interpreting the halting responses in terms of the emotional conflicts that the man was experiencing. ‘Repression'', ‘emotional blocks'', and ‘reaction formation'' were some of the terms bandied about.However, unbeknown to the class, the man had collapsed just on the other side of the classroom door. Two cardiologists happened to be walking by and instantly realized the man was having an acute heart attack. They instituted CPR on the spot, but the man died within a few minutes.The psychiatrist had been told that the man was healthy, and thus interpreted everything that he saw in psychological terms. It never entered his mind that the man might have been dying in front of his eyes. The cardiologists saw a man having a heart attack, and it never entered their minds that the man might have had psychological issues.The movie The Sixth Sense [3] resonated particularly well with my students and served as a platform for discussing attitudes that are helpful for scientific investigation, such as “keep an open mind”, “reality is much stranger than you can imagine” and “our conclusions are always provisional at best”. Best of all, The Sixth Sense demonstrates the tension that exists between different scientific paradigms in a clear and beautiful way. When Haley Joel Osment says, “I see dead people,” does he actually see ghosts? Or is he hallucinating?…when scientists reach a conclusion, it is merely a place to pause and rest for a moment, not a final destinationIt is important to emphasize that these are not merely different viewpoints, or different ways of defining terms. If we argued about which mountain is higher, Everest or K2, we might disagree about which kind of evidence is more reliable, but we would fundamentally agree on the notion of measurement. By contrast, in The Sixth Sense, the same evidence used by one paradigm to support its assertion is used with equal strength by the other paradigm as evidence in its favour. In the movie, Bruce Willis plays a psychologist who assumes that Osment must be a troubled youth. However, the fact that he says he sees ghosts is also evidence in favour of the existence of ghosts, if you do not reject out of hand the possibility of their existence. These two explanations are incommensurate. One cannot simply weigh all of the evidence because each side rejects the type of evidence that the other side accepts, and regards the alternative explanation not merely as wrong but as ridiculous or nonsensical. It is in this sense that a paradigm represents a failure of imagination—each side cannot imagine that the other explanation could possibly be true, or at least, plausible enough to warrant serious consideration.The failure of imagination means that each side fails to notice or to seek ‘objective'' evidence that would favour one explanation over the other. For example, during the episodes when Osment saw ghosts, the thermostat in the room fell precipitously and he could see his own breath. This certainly would seem to constitute objective evidence to favour the ghost explanation, and the fact that his mother had noticed that the heating in her apartment was erratic suggests that the temperature change was not simply another imagined symptom. But the mother assumed that the problem was in the heating system and did not even conceive that this might be linked to ghosts—so the ‘objective'' evidence certainly was not compelling or even suggestive on its own.Osment did succeed eventually in convincing his mother that he saw ghosts, and he did it in the same way that any scientist would convince his colleagues: namely, he produced evidence that made perfect sense in the context of one, and only one, explanation. First, he told his mother a secret that he said her dead mother had told him. This secret was about an incident that had occurred before he was born, and presumably she had never spoken of it, so there was no obvious way that he could have learned about it. Next, he told her that the grandmother had heard her say “every day” when standing near her grave. Again, the mother had presumably visited the grave alone and had not told anyone about the visit or about what was said. So, the mother was eventually convinced that Osment must have spoken with the dead grandmother after all. No other explanation seemed to fit all the facts.Is this the end of the story? We, the audience, realize that it is possible that Osment had merely guessed about the incidents, heard them second-hand from another relative or (as with professional psychics) might have retold his anecdotes whilst looking for validation from his mother. The evidence seems compelling only because these alternatives seem even less likely. It is in this same sense that when scientists reach a conclusion, it is merely a place to pause and rest for a moment, not a final destination.Near the end of the course, I gave a pop-quiz asking each student to give a ‘yes'' or ‘no'' answer, plus a short one-sentence explanation, to the following question: Donald Trump seems to be a wealthy businessman. He dresses like one, he has a TV show in which he acts like one, he gives seminars on wealth building and so on. Everything we know about him says that he is wealthy as a direct result of his business activities. On the basis of this evidence, are we justified in concluding that he is, in fact, a wealthy businessman?About half the class said that yes, if all the evidence points in one direction, that suffices. About half the class said ‘no'', the stated evidence is circumstantial and we do not know, for example, what his bank balance is or whether he has more debt than equity. All the evidence we know about points in one direction, but we might not know all the facts.Even when looked at carefully, not every anomaly is attractive enough or ‘ripe'' enough to be pursued when first noticedHow do we know whether or not we know all the facts? Again, it is a matter of imagination. Let us review a few possible alternatives. Maybe his wealth comes from inheritance rather than business acumen; or from silent partners; or from drug running. Maybe he is dangerously over-extended and living on borrowed money; maybe his wealth is more apparent than real. Maybe Trump Casinos made up the role of Donald Trump as its symbol, the way McDonald''s made up the role of Ronald McDonald?Several students complained that this was a ridiculous question. Yet I had posed this just after Bernard Madoff''s arrest was blanketing the news. Madoff was known as a billionaire investor genius for decades and had even served as the head of the Securities and Exchange Commission. As it turned out, his money was obtained by a massive Ponzi scheme. Why was Madoff able to succeed for so long? Because it was inconceivable that such a famous public figure could be a common con man and the people around him could not imagine the possibility that his livelihood needed to be scrutinized.To this point, I have emphasized the benefits of paying attention to anomalous, strange or unwelcome observations. Yet paradoxically, scientists often make progress by (provisionally) putting aside anomalous or apparently negative findings that seem to invalidate or distract from their hypothesis. When Rita Levi-Montalcini was assaying the neurite-promoting effects of tumour tissue, she had predicted that this was a property of tumours and was devastated to find that normal tissue had the same effects. Only by ‘ignoring'' this apparent failure could she move forward to characterize nerve growth factor and eventually understand its biology [4].Another classic example is Huntington disease—a genetic disorder in which an inherited alteration in the gene that encodes a protein, huntingtin, leads to toxicity within certain types of neuron and causes a progressive movement disorder associated with cognitive decline and psychiatric symptoms. Clinicians observed that the offspring of Huntington disease patients sometimes showed symptoms at an earlier age than their parents, and this phenomenon, called ‘genetic anticipation'', could affect successive generations at earlier and earlier ages of onset. This observation was met with scepticism and sometimes ridicule, as everything that was known about genetics at the time indicated that genes do not change across generations. Ascertainment bias was suggested as a much more probable explanation; in other words, once a patient is diagnosed with Huntington disease, their doctors will look at their offspring much more closely and will thus tend to identify the onset of symptoms at an earlier age. Eventually, once the detailed genetics of the disease were understood at the molecular level, it was shown that the structure of the altered huntingtin gene does change. Genetic anticipation is now an accepted phenomenon.…in fact, schools teach a lot about how to test hypotheses but little about how to find good hypotheses in the first placeWhat does this teach us about discovery? Even when looked at carefully, not every anomaly is attractive enough or ‘ripe'' enough to be pursued when first noticed. The biologists who identified the structure of the abnormal huntingtin gene did eventually explain genetic anticipation, although they set aside the puzzling clinical observations and proceeded pragmatically according to their (wrong) initial best-guess as to the genetics. The important thing is to move forward.Finally, let us consider the case of Grigori Perelman, an outstanding mathematician who solved the Poincaré Conjecture a few years ago. He did not tell anyone he was working on the problem, lest their ‘helpful advice'' discourage him; he posted his historic proof online, bypassing peer-reviewed journals altogether; he turned down both the Fields Medal and a million dollar prize; and he has refused professorial posts at prestigious universities. Having made a deliberate decision to eschew the external incentives associated with science as a career, his choices have been written off as examples of eccentric anti-social behaviour. I suggest, however, that he might have simply recognized that the usual rules for success and the usual reward structure of the scientific community can create roadblocks, which had to be avoided if he was to solve a supposedly unsolvable problem.If we cannot imagine new paradigms, then how can they ever be perceived, much less tested? It should be clear by now that the ‘process of scientific discovery'' can proceed by many different paths. However, here is one cognitive exercise that can be applied to almost any situation. (i) Notice a phenomenon, even if (especially if) it is familiar and regarded as a solved problem; regard it as if it is new and strange. In particular, look hard for anomalous and strange aspects of the phenomenon that are ignored by scientists in the field. (ii) Look for the hidden assumptions that guide scientists'' thinking about the phenomenon, and ask what kinds of explanation would be possible if the assumptions were false (or reversed). (iii) Make a list of possible alternative explanations, no matter how unlikely they seem to be. (iv) Ask if one of these explanations has particular appeal (for example, if it is the most elegant theoretically; if it can generalize to new domains; and if it would have great practical impact). (v) Ask what kind of evidence would allow one to favour that hypothesis over the others, and carry out experiments to test the hypothesis.The process just outlined is not something that is taught in graduate school; in fact, schools teach a lot about how to test hypotheses but little about how to find good hypotheses in the first place. Consequently, this cognitive exercise is not often carried out within the brain of an individual scientist. Yet this creative tension happens naturally when investigators from two different fields, who have different assumptions, methods and ways of working, meet to discuss a particular problem. This is one reason why new paradigms so often emerge in the cross-fertilization of different disciplines.There are of course other, more systematic ways of searching for hypotheses by bringing together seemingly unrelated evidence. The Arrowsmith two-node search strategy [5], for instance, is based on distinct searches of the biomedical literature to retrieve articles on two different areas of science that have not been studied in relation to each other, but that the investigator suspects might be related in some fashion. The software identifies common words or phrases, which might point to meaningful links between them. This is but one example of ‘literature-based discovery'' as a heuristic technique [6], and in turn, is part of the larger data-driven approach of ‘text mining'' or ‘data mining'', which looks for unusual, new or unexpected patterns within large amounts of observational data. Regardless of whether one follows hypothesis-driven or data-driven models of investigation, let us teach our students to repeat the mantra: ‘odd is good''!? Open in a separate windowNeil R Smalheiser  相似文献   

9.
Carl Woese developed a unique research program, based on rRNA, for discerning bacterial relationships and constructing a universal tree of life. Woese''s interest in the evolution of the genetic code led to him to investigate the deep roots of evolution, develop the concept of the progenote, and conceive of the Archaea. In so doing, he and his colleagues at the University of Illinois in Urbana revolutionized microbiology and brought the classification of microbes into an evolutionary framework. Woese also provided definitive evidence for the role of symbiosis in the evolution of the eukaryotic cell while underscoring the importance of lateral gene transfer in microbial evolution. Woese and colleagues'' proposal of three fundamental domains of life was brought forward in direct conflict with the prokaryote-eukaryote dichotomy. Together with several colleagues and associates, he brought together diverse evidence to support the rRNA evidence for the fundamentally tripartite nature of life. This paper aims to provide insight into his accomplishments, how he achieved them, and his place in the history of biology.  相似文献   

10.
Although only 21 of Sir William Osler''s 45 years in academic medicine were spent in US medical schools (1884 to 1905), he played a major role in shaping modern medical education in this country. The integration of scholarship with patient care, together with the science and art of medicine, was central to Osler''s teaching and writing throughout his career. A classic generalist and a charismatic clinical teacher, he taught by example and was as concerned with the ideals of medicine as with its science and knowledge.Many changes have reshaped the content, process and concerns of American medical education since Osler''s time. Subspecialization and balkanization of medical education and practice have become dominant. Many of the important issues in medicine today do not fit neatly into the domain of any of the established specialties or medical organizations. There is now an urgent need to promote generalist attitudes in medicine, and the Oslerian tradition has much to offer in approaching today''s problems in medical education and practice.  相似文献   

11.
Charles Darwin's empirical research in palaeontology, especially on fossil invertebrates, has been relatively neglected as a source of insight into his thinking, other than to note that he viewed the fossil record as very incomplete. During the Beagle voyage, Darwin gained extensive experience with a wide diversity of fossil taxa, and he thought deeply about the nature of the fossil record. That record was, for him, a major source of evidence for large-scale transmutation, but much less so for natural selection or single lineages. Darwin's interpretation of the fossil record has been criticised for its focus on incompleteness, but the record as he knew it was extremely incomplete. He was compelled to address this in arguing for descent with modification, which was likely his primary goal. Darwin's gradualism has been both misrepresented and exaggerated, and has distracted us from the importance of the fossil record in his thinking, which should be viewed in the context of the multiple, sometimes competing demands of the multifaceted argument he presented in the Origin of Species.  相似文献   

12.
H. J. Muller is best known for his Nobel Prize work on the induction of mutations by ionizing radiation. Geneticists are less familiar with his contributions to mutation and how he related the process of mutagenesis to the gene and distinguished gene mutations from other genetic and epigenetic events such as polyploidy, chromosome rearrangements, and position effects. The hallmark of Muller's contributions is his design of genetic stocks to solve genetic problems and allow experimentation to reveal new phenomena. In this review I relate Muller's personality to his teaching and research and present a history of Muller's ideas on mutation from his first days in Morgan's fly lab to his final thoughts on what became called “Muller's ratchet”, a term he did not get to enjoy because it was coined seven years after his death.  相似文献   

13.
W. F. Bowker 《CMAJ》1963,88(14):745
Scientists test new drugs by giving them to volunteers. In spite of every precaution, the drug may harm the volunteer. Under Canadian law, can he recover damages against any of the persons connected with the test? He cannot succeed against the scientist if the latter had made complete disclosure of the risks and had then obtained the volunteer''s free consent. Where the subject of a test is a child or one of unsound mind, the guardian''s consent probably does not protect the scientist from a possible claim by the subject. Where a married woman is a volunteer, her husband''s consent is unnecessary. The volunteer cannot succeed against his family physician who referred him to the scientist unless the physician took an active part in an experiment that was conducted negligently or without a proper consent. The volunteer cannot succeed against the maker unless he has negligently prepared the drug or given misleading information.  相似文献   

14.
To mark A.R. Wallace's 200th birthday, we review the direct and indirect contributions he made to our understanding of the Indo-Australian Archipelago's biogeography. He is widely known for his field research (1854–1862) and his 1863 boundary line separating the Oriental and Australasian faunal realms (between Bali and Lombok, Borneo and Sulawesi, and the Philippines and the Moluccas). Notably, though, he never accepted Huxley's ‘Wallace Line’ proposal (1868), whose northern part runs between the main Philippine islands and the Palawan Group to the west. Furthermore, in 1910, which was 3 years prior to his demise, he transferred Sulawesi's fauna to the Oriental realm. In 1924, Merrill introduced the ‘Wallacea’ transition zone. Although the label is today widely used to denote a sub-region within the Indo-Australian Archipelago between Wallace's 1863 line and Lydekker's 1896 line (first presented by Darlington in 1957), the western boundary was originally based on Huxley's line, and thus included the Philippine islands minus the Palawan group. Most biogeographers appear to be unaware of Merrill and his intention. Finally, recent attempts to define the faunal break have not led to a consensus view, despite the huge increase in primary data plus the application of modern analytical techniques. This reflects the complexities and diversity of the region's faunal distribution patterns, plus the differences in the ways that researchers choose to process their data.  相似文献   

15.
German biologist Ernst Haeckel (1834–1919) is often considered the most renowned Darwinian in his country since, as early as 1862, he declared that he accepted the conclusions Darwin had reached three years before in On the Origin of Species, and afterwards, he continuously proclaimed himself a supporter of the English naturalist and championed the evolutionary theory. Nevertheless, if we examine carefully his books, in particular his General Morphology (1866), we can see that he carries on a tradition very far from Darwin's thoughts. In spite of his acceptance of the idea of natural selection, that he establishes as an argument for materialism, he adopts, indeed, a conception of evolution that is, in some respects, rather close to Lamarck's views. He is, thus, a good example of the ambiguities of the reception of Darwinism in Germany in the second part of the 19th century. To cite this article: S. Schmitt, C. R. Biologies 332 (2009).  相似文献   

16.
To get the best out of people the McGregor Theory ''Y'' manager will be supportive and collaborative rather than controlling. The aim will be to appoint staff to properly designed jobs and to motivate them by working with them and agreeing joint goals, by encouraging self development and appropriate training, and by being both firm and fair. In essence this manager will care about colleagues and see them as a resource to be nurtured rather than competitors to be undermined or costs to be cut. If the doctor in the case study had been treated in this way perhaps he might still be motivated and treating British patients instead of going to Saudi Arabia where he feels more greatly valued both as an individual and a professional.  相似文献   

17.
In this paper we explore two contrasting perspectives on individuals'' participation in associations. On the one hand, some have considered participation the byproduct of pre-existing friendship ties — the more friends one already has in the association, the more likely he or she is to participate. On the other hand, some have considered participation to be driven by the association''s capacity to form new identities — the more new friends one meets in the association, the more likely he or she is to participate. We use detailed temporal data from an online association to adjudicate between these two mechanisms and explore their interplay. Our results show a significant impact of new friendship ties on participation, compared to a negligible impact of pre-existing friends, defined here as ties to other members formed outside of the organization''s context. We relate this finding to the sociological literature on participation and we explore its implications in the discussion.  相似文献   

18.
Two ‘papers’ of Darwin's were read at the famous 1 July 1858 meeting of the Linnean Society: an excerpt from his 1844 essay and a summary of his theory, enclosed in an 1857 letter to Asa Gray. Quite apart from not selecting the essay excerpt, Darwin's letters appear to indicate that he definitely did not want, and hence did not expect, an excerpt from his 1844 essay to be included (and that he did not learn of its inclusion until some 2 weeks after the meeting). As a result, we refine Darwin's role in ‘the delicate arrangement’, as well as the basis for Hooker's and Lyell's. In particular, why did they choose an essay excerpt to be presented contrary to Darwin's wishes? In direct opposition to the popular view, the essay excerpt was the afterthought, the last‐minute add‐on, not the enclosure to the Gray letter.  相似文献   

19.
American Biologist Martin Chalfie shared the 2008 Nobel Prize in Chemistry with Roger Tsien and Osamu Shimomura for their discovery and development of the Green Fluorescent Protein (GFP).Martin Chalfie was born in Chicago in 1947 and grew up in Skokie Illinois. Although he had an interest in science from a young age-- learning the names of the planets and reading books about dinosaurs-- his journey to a career in biological science was circuitous. In high school, Chalfie enjoyed his AP Chemistry course, but his other science courses did not make much of an impression on him, and he began his undergraduate studies at Harvard uncertain of what he wanted to study. Eventually he did choose to major in Biochemistry, and during the summer between his sophomore and junior years, he joined Klaus Weber''s lab and began his first real research project, studying the active site of the enzyme aspartate transcarbamylase. Unfortunately, none of the experiments he performed in Weber''s lab worked, and Chalfie came to the conclusion that research was not for him.Following graduation in 1969, he was hired as a teacher Hamden Hall Country Day School in Connecticut where he taught high school chemistry, algebra, and social sciences for 2 years. After his first year of teaching, he decided to give research another try. He took a summer job in Jose Zadunaisky''s lab at Yale, studying chloride transport in the frog retina. Chalfie enjoyed this experience a great deal, and having gained confidence in his own scientific abilities, he applied to graduate school at Harvard, where he joined the Physiology department in 1972 and studied norepinephrine synthesis and secretion under Bob Pearlman. His interest in working on C. elegans led him to post doc with Sydney Brenner, at the Medical Research Council Laboratory of Molecular Biology in Cambridge, England. In 1982 he was offered position at Columbia University.When Chalfie first heard about GFP at a research seminar given by Paul Brehm in 1989, his lab was studying genes involved in the development and function of touch-sensitive cells in C. elegans. He immediately became very excited about the idea of expressing the fluorescent protein in the nematode, hoping to figure out where the genes were expressed in the live organism. At the time, all methods of examining localization, such as antibody staining or in situ hybridization, required fixation of the tissue or cells, revealing the location of proteins only at fixed points in time.In September 1992, after obtaining GFP DNA from Douglas Prasher, Chalfie asked his rotation student, Ghia Euskirchen to express GFP in E. coli, unaware that several other labs were also trying to express the protein, without success. Chalfie and Euskirchen used PCR to amplify only the coding sequence of GFP, which they placed in an expression vector and expressed in E.coli. Because of her engineering background, Euskirchen knew that the microscope in the Chalfie lab was not good enough to use for this type of experiment, so she captured images of green bacteria using the microscope from her former engineering lab. This work demonstrated that GFP fluorescence requires no component other than GFP itself. In fact, the difficulty that other labs had encountered stemmed from their use of restriction enzyme digestions for subcloning, which brought along an extra sequence that prevented GFP''s fluorescent expression. Following Euskirchen''s successful expression in E. coli, Chalfie''s technician Yuan Tu went on to express GFP in C. elegans, and Chalfie published the findings in Science in 1994.Through the study of C. elegans and GFP, Chalfie feels there is an important lesson to be learned about the importance basic research. Though there has been a recent push for clinically-relevant or patent-producing (translational) research, Chalfie warns that taking this approach alone is a mistake, given how "woefully little" we know about biology. He points out the vast expanse of the unknowns in biology, noting that important discoveries such as GFP are very frequently made through basic research using a diverse set of model organisms. Indeed, the study of GFP bioluminescence did not originally have a direct application to human health. Our understanding of it, however, has led to a wide array of clinically-relevant discoveries and developments. Chalfie believes we should not limit ourselves: "We should be a little freer and investigate things in different directions, and be a little bit awed by what we''re going to find."Download video file.(152M, mp4)  相似文献   

20.
Van Wyhe and Rookmaaker (2012) postulate a set of events to support their claim that Wallace's ‘evolution’ letter, posted at Ternate in the Moluccas in the spring of 1858, arrived at Darwin's home on 18 June 1858. If their claim were to be proven, then evidence that Darwin probably received Wallace's letter 2 weeks earlier than he ever admitted would clearly be erroneous, and any charges that he plagiarized the ideas of Wallace from that letter would be shown to be wrong. Here, evidence against this interpretation is presented and it is argued that the letter did indeed arrive in the port of Southampton on 2 June 1858 and would have been at Darwin's home near London the following day. If this were true, then the 66 new pages of material on aspects of Divergence that Darwin entered into his ‘big’ species book in the weeks before admitting he had received the letter could be interpreted as an attempt to present Wallace's ideas as his own. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105 , 472–477.  相似文献   

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