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1.
Weiss RA 《Cell》2005,123(4):539-542
This year marks the centenary of Robert Koch's Nobel Prize for discovering the cause of tuberculosis. Koch was also the first scientist to isolate the anthrax and cholera microbes. Yet perhaps one of his greatest contributions to biology is the least appreciated: his method for propagating individual colonies of bacteria on plates, a technique that came to be called cloning.  相似文献   

2.
《Zoologica scripta》2009,38(S1):17-24
Linnaeus expressed his fascination for microscopy in his work Mundum Invisibilem 1767 (the invisible world), which was one of the very first attempts to bring light and order to the microscopic discoveries of the time. Linnaeus wrote about his only microscopic experiment in the same publication. He wanted to know where to place the fungi in his grand 'Systema Naturae', but misinterpreted the results of the experiment completely. This is perhaps one of Linnaeus' greatest and least known mistakes, but one that somehow boosted development anyway.
We took the original microscope models used by Linnaeus, took photos, and compared them with images obtained with modern instruments. Our experiments revealed several new findings, and let us understand why Linnaeus made his mistake. One other finding is that Linnaeus must have used the most modern and advanced compound microscope of his time, a large Cuff microscope in his experiment. Only two large microscopes by Cuff were available in Sweden by the time. A large Cuff microscope was found in Sweden lately. This microscope is probably the actual instrument that Linnaeus used.  相似文献   

3.
Jell Peter A 《古生物学报》2014,(4):前插7-前插8
Although the times through which he lived were uncertain,at times cruel and predominantly harsh,the life of Zhang Wentang was one of pure scientific endeavour.The many obstacles which presented themselves during his lifetime would have discouraged and defeated most good men.It is the ultimate tribute to the man that he overcame so much hardship in his pursuit of knowledge and yet remained steadfastly focussed on his predetermined aims.While many good strong men deliver outstanding lifetime contributions from well supported positions it is often those who struggle most during their lives and rise above the drawbacks who deserve our greatest admiration — one such man was Zhang Wentang.  相似文献   

4.
Henryk Fryderyk Hoyer (1834--1907) is rightly considered to be the father of Polish histology. Despite his major scientific achievements his work has undeservedly been overlooked in the medical historical literature outside Poland. Apart from the fact that Hoyer was the first to have conclusively proved on the basis of successful histological methods the existence of arteriovenous anastomoses, his innovations in the area of histological technique were of the greatest importance for histological research. Here the most important publications of Hoyer in German scientific journals are considered. Until now there has been no critical historical analysis of Hoyer's German works. This is the first attempt at such an analysis.  相似文献   

5.
On December 11, 2005, Shoichiro Tsukita died at the young age of 52, after 14 months of treatment for cancer. Early in his career, Tsukita succeeded in isolating and purifying the adherens junction with his wife Sachiko, an accomplishment that he followed up with an impressive series of discoveries of cell adhesion and cytoskeletal molecules, including what may have been his greatest contribution to the field, the identification of occludin and the claudin family of molecules, which were watershed discoveries in the study of the molecular nature of tight junctions.  相似文献   

6.
A previously unknown group of flies is described whose males exhibit directional asymmetry, in that the left wing is larger than, and of a different shape from, the right wing. To our knowledge, wing asymmetry of this degree has not previously been reported in an animal capable of flight. Such consistent asymmetry must result from a left-right axis during development, a level of differentiation whose existence has been questioned for insects. Wing asymmetry of this magnitude has implications for questions in areas of development, natural selection, flight, mate selection and communication in insects. The 'handicap principle' provides a possible explanation: females will choose a mate with the greatest handicap because his survival, in spite of his handicap, is a measure of his genetic superiority.  相似文献   

7.
The majority of tropical marine families demonstrate their greatest concentration of species within the relatively small East Indies Triangle. In every direction, the species diversity decreases with distance from the East Indies. Other patterns suggest that the East Indies is where the average generic age is youngest, where some historical routes of dispersal originate, where the most apomorphic species occur, where genetic diversity is the greatest, and where extinctions are likely to originate. These coincident patterns provide support for the hypothesis that the East Indies has been operating as a center of evolutionary radiation. The driving force for this dynamic system is apparently the predominance of successful speciation involving relatively large populations with higher genetic diversity. This mechanism fits the centrifugal speciation model that was proposed more than 50 years ago.  相似文献   

8.
在今天,我们的生存环境面临着诸多挑战,包括气候变化,生物多样性减少,可用于发展的土地资源接近上限等等。面对这些问题,前荷兰首席国家风景园林师德克·西蒙斯认为我们必须关注那些能够改变景观的力量,不管它们是水利工程、旅游业、农业还是新能源。西蒙斯在文中介绍了他的过程导向方法论的思想起点,并通过几个获奖项目阐释了他如何运用这一方法。同时特别强调对生态系统的保护和修复是这个时代最重要的议题之一,也是我们这一代人最重要的使命之一。作为风景园林师,设计结合研究是我们的有力武器。我们不能仅关注眼前工作,还需要用长远的眼光批判地看待整个城市化进程。  相似文献   

9.
The uses and actions of a few of the large number of new drugs that have been introduced to the medical profession in recent years are reviewed herein. The greatest number of drugs introduced are those affecting the autonomic nervous system. Their usefulness often depends upon the individual patient''s own response. A knowledge of the type of drug he is administering and a comparison with others that are related better enables a physician to appraise the results of his treatment.  相似文献   

10.
This article describes the scientific legacy of Dr. Leon Wolfe, with illustrations from his contributions to insect physiology, glycolipid, and eicosanoid biochemistry as well as to our understanding of neuronal ceroid lipofuscinoses and lysosomal storage diseases. In addition to the written record, Wolfe inspired all who knew him with his boundless imagination and enthusiasm for science and his ability to see the promise and potential of every experiment.  相似文献   

11.
Michael Banton's paper provides fascinating insights into his long-running intellectual disagreements with John Rex, the other major post-war figure in the sociology of ‘race relations’. Published work and personal recollections are supplemented by a series of communications by letter to flesh out the precise nature of these debates. They reveal differing views on the ontological status of ‘race’, race relations and racism, as well as a number of criticisms of Rex's work. He argues that Rex was wrong to put so much faith in the ability of classical sociology to address these concerns, and that there was a disjuncture between theory, methods and substance in his empirical work. There is also a suggestion that Rex played down the significance of racism. The greatest difference between them, however, lay in their divergent views on the role of sociology and the sociologist.  相似文献   

12.
Synopsis Eel samples from Lake Ellesmere, a brackish water lake in the South Island, New Zealand, were taken at approximately monthly intervals from January 1974 to April 1976. Nets were set for 24 h and emptied every three hours. Total lengths and stomach fullness values of 498 eels were recorded. Analysis using the non-parametric Kruskal-Wallis test showed that eels ⩽40 cm and 40.1–50 cm in length increased in fullness through the night with greatest fullness values at 0300 and 0600 h. Seasonal analyses revealed greatest eel activity in spring, summer and autumn. There was little eel activity in winter.  相似文献   

13.
The composer Gaetano Donizetti, who died in a state of mental derangement due to neurosyphilis, created some of opera's greatest scenes of psychosis. His letters reveal the clinical progression of his neurobiological illness, which was confirmed by autopsy. One can hypothesize that the composer's brain disease, which led to his psychosis and death, may have had an influence on his ability to create the powerful and unforgettable scenes of psychosis in his operas. In Anna Bolena, he captured in musical and dramatic terms Anne Boleyn's historically corroborated mental disorder during her imprisonment in the Tower of London. Sixteen years after having composed Anna Bolena, Donizetti himself would be locked up, against his will, in a mental institution. In Lucia di Lammermoor, Donizetti portrayed a girl given to hallucinations who, in her unforgettable "mad" scene, comes on stage, a pathetic embodiment of a human being in the throes of psychosis. Thirteen years after Lucia's première, Donizetti would die, psychotic and paralyzed, of untreated neurosyphilis. Studying Donizetti's neurosyphilis and the portrayals of psychosis in his operas can help one to appreciate the pain of human beings trapped in the prison of a brain subjected to the devastation of mental derangement.  相似文献   

14.
Leon Athanase Gosselin was one of the greatest French surgeons of the 19th century. He successfully directed many university surgical departments and excelled in orthopaedics, anatomy, physiology and urology. Thanks to his advanced research into testicular, scrotal and spermatic cord diseases and their effects on fertilisation and virility, Gosselin is rightly considered to have been a great andrologist before this branch of medical science had been recognised.  相似文献   

15.
A 48-year-old man presented with an itchy rash that resembled superficial burns or cane marks on his left forearm; similar lesions had appeared every summer for 5 years. Poison ivy dermatitis had been the initial diagnosis, but the patient knew that this plant was absent from his well tended garden. A visit to the garden revealed the gas plant Dictamnus albus, and occlusive patch testing with leaf cuttings produced a reaction after the skin was exposed to sunlight. Gas plant phytophotodermatitis was diagnosed.  相似文献   

16.
基于持续高产的近海渔业双寡头捕捞策略   总被引:1,自引:0,他引:1  
海洋鱼类是人类一种重要的生活物质资料,当代人在进行渔业捕捞满足自身生活需求时,应合理确定捕捞努力量以实现渔业资源的可持续利用,不危及后代人的需求,假定存在两个捕捞主体,分别就Cournot模型和Stackelbeerg模型分析了两个主体为了自身获得最大持续产量而投入的捕捞努力量,研究表明,与只有一个捕捞主体相比,当存在两个捕捞主体时,每个捕捞主体都将投入更多的捕捞努力量,但最大持续产量不随之增加,甚至还会减少,产生这种后果的原因在于每个主体只考虑自己投入的捕捞 努力量对自己产出量的影响,而不考虑对对方或社会产生的负面影响,对渔业捕捞进行全面规划,综合管理是消除这种后果所必要的。  相似文献   

17.
Bibliometric studies have found that male researchers have their greatest productivity around the age of 40, that female researchers produce less than their male colleagues, that incentives for collaboration are slow to affect productivity and that, just like humans, research institutes become larger, less productive, more expensive to maintain and less able to raise money as they grow old. Almost invariably, these conclusions come from statistical studies of large numbers of European and American scientists, and there are practically no studies about tropical researchers. We present an in-depth analysis of the productivity of an internationally recognized tropical botanist and conservationist, Luis Diego Gómez Pignataro, based on the totality of his published work and on our own knowledge, as co-workers and friends, of the life frame in which that scientific output was produced. His life output departs from the expected pattern in that he had the highest productivity before reaching the expected peak productivity age, and that when he reached it his productivity fell and never recovered. Furthermore, marriage did not produce the expected fall in productivity. A close analysis of his life indicates that in the middle of his career he switched to intense teaching and conservation activities, and this better explains why his output of scientific research articles was low afterwards. This switch may occur in other tropical scientists.  相似文献   

18.
19.
As long ago as 1914, Theodor Boveri suggested that there is an inhibitory mechanism in every normal cell that prevents the process of cell division until the inhibition has been overcome by a special stimulus. From his work on abnormal mitoses in the eggs of echinoderms, Boveri also suggested that the inhibitor resided in the chromosomes. The relevance of Boveri's ideas to modern cancer research is discussed in this Retrospective article.  相似文献   

20.
Summary Madura foot incited by a new species ofCephalosporium is presented. Case history, clinical symptoms and morphological features of the new pathogen are discussed. Comparative studies with the previously reported species indicate that the species isolated is an undescribed one and the nameCephalosporium madurae is proposed for it. Dedicated to Professor Tibor Benedek,one of our greatest living Medical Mycologists, on the occasion of his 70th birthday.  相似文献   

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