Women and Human Development.

Women and Human Development. Martha C. Nussbaum. New York: Cambridge University Press, 2000, 303 pp.     

全球变化与可持续发展

全球变化与可持续发展彭少麟（中国科学院华南植物研究所,广州５１０６５０）ＧｌｏｂａｌＣｈａｎｇｅａｎｄＳｕｓｔａｉｎａｂｌｅＤｅｖｅｌｏｐｍｅｎｔ．ＰｅｎｇＳｈａｏｌｉｎ（ＳｏｕｔｈＣｈｉｎａＩｎｓｔｉｔｕｔｅｏｆＢｏｔａｎｙ,ＡｃａｄｅｍｉａＳｉ...     

生物防治稻田与普通稻田水体中浮游植物的生态特征研究

通过对大沙镇生物防治稻田及普通稻田水体中浮游植物的调查研究,共检出藻类112种,其中生物防治稻田中82种,普通稻田中89种.稻田水体中的浮游植物以硅藻、裸藻和绿藻占优势.在普通稻田中,硅藻种类数超过生物防治稻田,其优势度最高的5种藻类中除双对栅藻外,其余4种均为硅藻;而在生物防治稻田中,裸藻种类数高于普通稻田,且其优势度最高的5种藻类中有两种为裸藻.通过比较发现,生物防治稻田水体中浮游生物的密度明显高于普通稻田.对水体浮游植物多样性及均匀度的分析表明,稻田水体中的浮游植物自秧苗插上至干田期间,多样性指数略有上升(主要是由于种类数的增加引起的),而均匀度呈下降趋势.     

Rural Settlement Structure and African Development.

Rural Settlement Structure and African Development. Marilyn Silberfein. ed. Dunmore, PA: Harper Collins, 1998. 338 pp.     

进化生态学的产生与发展

进化论、遗传学与生态学是在不同时期发展起来的独立学科,然而,随着科学的发展,们越来越认识到它们之间存在着密切的关系。Petrusewicz(1959)(见Shvarts,1977)曾写过《达尔文进化论是一种生态理论》一书,强调进化在本质上是一生态过程。Hutchinson(1965)写了一部题名为《生态学舞台和进化节目》一书,认为生态的布景可以作为进化过程的舞台。但是,最早提出进化生态学这一概念的则是Orians(1962)。进化生态学从产生到现在虽然只有20多年的历史,但已成为生态学研究的重要领域。下面从几个方面谈谈进化生态学的产生与发展。     

Development and evolution of lateral line placodes in amphibians I. Development

Lateral line placodes are specialized regions of the ectoderm that give rise to the receptor organs of the lateral line system as well as to the sensory neurons innervating them. The development of lateral line placodes has been studied in amphibians since the early 1900s. This paper reviews these older studies and tries to integrate them with more recent findings. Lateral line placodes are probably induced in a multistep process from a panplacodal area surrounding the neural plate. The time schedule of these inductive processes has begun to be unravelled, but little is known yet about their molecular basis. Subsequent pattern formation, morphogenesis and differentiation of lateral line placodes proceeds in most respects relatively autonomously: Onset and polarity of migration of lateral line primordia, the type, spacing, size and number of receptor organs formed, as well as the patterned differentiation of different cell types occur normally even in ectopic locations. Only the pathways for migration of lateral line primordia depend on external cues. Thus, lateral line placodes act as integrated and relatively context-insensitive developmental modules.