Darwin after 100 years. 1983.]

The triumph of Darwinism, together with the rise of Genetics, produced the virtual abandonment of the problem of form in Biology. The statement that any adaptive theory is tautological is however poor, the adaptation concept having an evident intuitive content. As in Geometrical Optics, a ray of light is, among the crowd of continuous curves uniting two points, the one requiring the minimum time for the light to go from one point to the other, so actual evolution, among the crowd of virtual evolutions between two forms, is the one best fitted to face 'selective pressure' in a given environment. The effect of selective pressure on the genome is unfortunately a merely theoretical not quantifiable concept. Most biological forms are forced by their internal stability to an essential fixity, so that the leap from one type-form to another should be abrupt-catastrophic. A good theory of evolution depends on a proper understanding of specific form stability. Biology must eventually return to the concept of ideal structure, the Goethian 'Urbild'.     

Toxoplasma: the next 100years

It has been 100 years since Toxoplasma gondii was initially described in Tunis by Nicolle and Manceaux (1908) in the tissues of the gundi (Ctenodoactylus gundi) and in Brazil by Splendore (1908) in the tissues of a rabbit. T. gondii is a ubiquitous, Apicomplexan parasite of warm-blooded animals that can cause several clinical syndromes including encephalitis, chorioretinitis and congenital infection. Due to the extensive repertoire of applicable experimental techniques available for this pathogen it has become a model organism for the study of intracellular pathogens. Data obtained from genome-wide expression studies, including ChIP on chip and proteomics surveys, are refining our understanding of the genetic networks involved in the developmental biology of this pathogen as well as the interactions of the parasite with its host. This review addresses recent advances in our understanding of the developmental biology and host-pathogen relationships of T. gondii.     

Tsetse control: the next 100 years

An international meeting on tsetse control was held 9–10 September 2002, in Edinburgh, UK.     

Bacteriophages,revitalized after 100 years in the shadow of antibiotics

<正>The year 2015 marks 100 years since Dr.Frederick Twort discovered thefilterable lytic factor,which was later independently discovered and named bacteriophage by Dr.Felix d'Herelle.On this memorable centennial,it is exciting to see a special issue published by Virologica Sinica on Phages and Therapy.In this issue,readers will not only fi nd that bacteriophage research is a     

100 years on: a century of genetics

In 2006 we celebrated the centenary of a remarkable year that saw the birth of genetics as a scientific discipline. This birth had its origins in horticulture and was supervised by a remarkable Cambridge academic, accompanied by a loyal group of female colleagues who worked together in underfunded conditions with little institutional support. Despite this deprivation, they established the foundations of an ongoing revolution, with huge academic and commercial consequences that we can recognize today in the shape of genomics and its application to biomedicine.     

Drug delivery: an odyssey of 100 years

Drug delivery has metamorphosed from the concept of a pill to molecular medicine in the past 100 years. Better appreciation and integration of pharmacokinetic and pharmacodynamic principles in design of drug delivery systems has led to improved therapeutic efficacy. A greater understanding of the molecular transport in relation to physico-chemical properties has led to the evolution of a biopharmaceutics classification system, which should be a future road map, governing drug design, development and delivery. While drugs belonging to class I and II will be delivered by established platform technologies, novel delivery strategies will evolve and mature to realize the potential of 'new generation' biotech and non biotech drugs belonging to class III and IV, respectively.     

近100年植被破坏侵蚀环境下土壤质量退化过程的定量评价

以黄土高原子午岭地区近100a不同开垦年限位于墚坡的农地为研究对象,通过相关分析并结合所选指标的有效性、全面性和敏感性分析,从6个土壤物理指标、6个土壤化学指标、8个土壤生物指标,共20个土壤性质指标中,筛选出有机碳、真菌数量、碱性磷酸酶活性、蔗糖酶活性、毛管孔隙度、物理性粘粒、粗粉粒和水稳性团聚体平均重量直径(MWD)等8个土壤性质指标,作为土壤质量退化评价指标体系。通过主成分分析,计算土壤质量综合指数(SQI),定量评价近100a植被破坏侵蚀环境下的土壤质量退化过程。结果表明,林地SQI在0—20和20—40cm土层分别为0.909和0.427;林地开垦耕种100a期间,SQI随开垦年限的增加呈快速下降的趋势,尤其是在开垦耕种初期4a内,SQI年均下降速率在0—20和20—40cm土层分别达0.073和0.028;同林地相比,SQI分别下降了32.3%和26.2%。此后随着开垦耕种年限的增加下降速率逐渐减小。开垦耕种12a后,0—20和20—40cm土层的SQI分别为0.549和0.235,分别下降39.6%和45.0%;4—12a期间的SQI下降速率分别为开垦初期的10.9%和35.7%。开垦耕种43a后,SQI在0—20和20—40cm土层分别为0.333和0.144,分别较林地下降64.4%和66.3%,12—43a期间的SQI下降速率分别为开垦初期的9.6%和10.7%;开垦耕种100a期间,SQI在0—20和20—40cm土层分别为0.140和0.068,分别下降84.6%和84.1%;43—100a期间的SQI下降速率分别为开垦初期的4.1%和3.6%。同时,SQI年均下降幅度在0—20cm土层高于在20—40cm土层;且随开垦耕种年限的增加,SQI在0—20cm和20—40cm上下两土层之间的差异趋于减少,说明加速侵蚀是研究区土壤质量下降的主要原因。     

盐度对红树植物海莲幼苗的生长和某些生理生态特性的影响

本文主要探讨了不同盐度海水砂培的海莲幼苗生长量和某些生理生态特性与盐度的相关效应。结果表明,生长基盐度20‰以上,海莲繁殖体的萌苗时间推迟,成活率降低;随着盐度的提高,幼苗高生长量降低,叶片变小;叶片叶绿素含量随盐度提高而提高,相反的叶片可溶性糖含量则降低,而叶片可溶性蛋白质含量变化不明显;叶片组织内氯含量随盐度提高而提高;随着盐度的提高,叶片蒸腾作用减弱,气孔导度降低。由此表明,海莲幼苗适宜生长的盐度范围在15‰以下,更高的盐度表现为生态抗盐适应性生长。