Long-term increases in clutch size in common snapping turtles (Chelydra serpentina) and diamondback terrapins (Malaclemys terrapin)

Clutch size (CS) is a well-studied life history characteristic, and optimal egg size theory predicts that CS should correlate positively with reproductive investment. Turtles are good subjects for studies of reproductive strategies because few turtle species exhibit parental care; therefore quantifying their short-term reproductive investment is mostly limited to measuring egg size and number. Clutch size is usually reported as an average value for each turtle population, and where CS variation is noted, it is usually attributable to variation in adult body size. In two long-term studies of ecologically dissimilar species we detected a dramatic increase in CS in a common snapping turtle (Chelydra serpentina) population and in a diamondback terrapin (Malaclemys terrapin) population. It is unknown whether these changes are due to either variation in adult body size or resource availability; but the temporal patterns we observed have apparently never been reported previously. These trends remain unexplained and should be explored further.     

论辅助生殖技术引发的伦理问题及其应对机制

简单介绍了辅助生殖技术,分析了辅助生殖技术引发的伦理问题,提出了应对这些伦理问题的机制。     

修正的Navier—Stokes方程的再生性质和周期解

本文证明了由提出的修正的Navier-Stokes方程在小外力的条件下对t_1∈(0,T]存在唯一的初始速度分布使得相应的初边值问题的广义解具再生性质:(t_1)=(0)=.从而当外力还是时间t的周期函数时,是周期解.进而证明此周期解以指数方式吸引相应于同一外力但初值可任意的其它解.上述结论的证明基于对广义解v的导数v在空间L~∞(0,T;L~2(Ω))中估计.     

Pharmacodynamic profile of CQP 201-403, a novel 8α-amino-ergoline

Summary The profile of action in animals of CQP 201-403, a novel 8-amino-ergoline, is in most aspects that of a very potent dopaminomimetic, both as a prolactin secretion inhibitor, and at the levels of the CNS and the cardiovascular system. Qualitatively CQP 201-403 differs slightly from bromocriptine and apomorphine in its effects on the CNS (no influence on serotonin metabolism in the rat cortex; induction of masculine mounting behavior in rats) and the cardiovascular system of the dog (reflex tachycardia in response to a blood-pressure fall). In man the new compound proved to be highly active in lowering prolactin serum levels and to be more potent than bromocriptine (Parlodel^®).In memory of Dr Annemarie Closse, who died 14 June 1987.     

Endorcine cells producing regulatory peptides

Summary Recent data on the immunologication of regulatory peptides and related propeptide sequences in endocrine cells and tumours of the gastrointestinal tract pancreas, lung, thyroid, pituitary (ACTH and opioids), adrenals and paraganglia have been revised and discussed. Gastrin, xenopsin, cholecystokinin (CCK), somatostatin, motilin, secretin, GIP (gastric inhibitory beenrevised and discussed. Gastrin, xenopsin, cholecystokinin (CCK), somatostatin, motilin, secretin, GIP (gastric inhibitory polypeptide), neurotensin, glicentin/glucagon-37 and PYY (peptide tyrosine tyrosine) are the main products of gastrointestinal endocrine cells; glucagon, CRF (corticotropin releasing factor), somatostatin, PP (pancreatic polypeptide) and GRF (growth hormone releasing factor), in addition to insulin, are produced in pancreatic islet cells; bombesin-related peptidesare the main markers of pulmonary endocrine cells; calcitonin and CGRP (calcitonin gene-related peptide) occur in thyroid and extrathyroid C cells; ACTH and endorphins in anterior and intermediate lobe pituitary cells, -MSH and CLIP (corticotropoin-like intermediate lobe peptide) in intermediate lobe cells; met- and leu-enkephalins and related peptides in adrenal medullary and paraganglionic cells as well as in some gut (enterochromaffin) cells; NPY (neuropeptide Y) in adrenalin-type adrenal medullary cells, etc.. Both tissue-appropriate and tissue-inappropriate regulatory peptides are produced by endocrine tumours, with inappropriate peptides mostly produced by malignant tumours.     

昆虫窝卵数：现象及其解释

自然界广泛存在生物体产卵成批（窝、块等）现象（如姐妹利间异同、频次分布、季节动态及年间变异）等昆虫系统发育和个体生长（如解剖学特征、个体大小、年龄（产卵顺序）等内因和环境资源（寄主植物、昆虫、温度、水分等）等外因对窝卵数（ｃｌｕｔｃｈｓｉｚｅ）均有一定影响,同一窝卵中的个体受捕食、被寄生、姐妹手足竞争、卵粒大小、个体大小、生殖力、性比等子代适合度因子也受窝卵数大小的影响,本文总结以上各现象提出一关系模型．以较为综合的“窝卵数与继续繁殖间的平衡”假说,从理论上阐述昆虫决定窝印数的机制,并讨论窝印数研究的实际意义。     

Nitric oxide-related pancreatic endocrine responses to hyperglycaemia in the conscious calf

Mean plasma insulin concentration was reduced and mean plasma glucose concentration increased following the administration of N-nitro-L-arginine methyl ester (L-NAME; 100 mol kg^–1 i.a.) in conscious calves given continuous infusions of exogenous glucose (30–60 mol min^–1 kg^–1 i.v.). It is concluded that the rise in plasma insulin concentration which occurs in these animals in response to glucose is mediated, at least in part, by a nitric oxide-related factor (NOx).     

福州陶江中国淡水蛏Novaculina chinensis生殖周期的研究

采用活体性腺观察和组织切片法对福建闵候尚干陶江中国淡水蛏的生殖腺进行了初步研究,淡水蛏的性腺发育分为５期,增殖期,生长期,成熟期,排放期和休止期,一年只有一个繁殖周期,繁殖期为３月下旬至４月,雌雄异体,有雄性早熟现象,较晚期的卵母细胞和成熟卵子有双质核仁现象。     

THYESS法结合QSAR分析对环境内分泌干扰性物质的筛检研究

利用THYESS法对几种典型的环境内分泌干扰物质的毒理活性进行了定量筛检，并进一步结合量子化学对被检物质作了QSAR分析．结果表明，用THYESS法筛检出的环境内分泌干扰物质存在着良好的毒活性．反应剂量关系．这种测定方法再结合量子化学的QSAR分析，有望成为获得大量环境样品中EDCs毒害数据的一种良好方法．     

环境内分泌干扰物对男(雄)性生殖系统的影响

动物实验和人群流行病学调查表明，环境内分泌干扰物对男(雄)性生殖系统的影响主要包括精子数量和质量、生殖器官发育、睾丸肿瘤以及子代生殖系统造成危害。文章就以上几方面国内外研究的现状进行综述。