Viviparity and K-selected life history in a Mesozoic marine plesiosaur (Reptilia, Sauropterygia)

Viviparity is known in several clades of Mesozoic aquatic reptiles, but evidence for it is lacking in the Plesiosauria. Here, we report a Late Cretaceous plesiosaur fossil consisting of a fetus preserved within an adult of the same taxon. We interpret this occurrence as a gravid female and unborn young and hence as definitive evidence for plesiosaur viviparity. Quantitative analysis indicates that plesiosaurs gave birth to large, probably single progeny. The combination of viviparity, large offspring size, and small brood number differs markedly from the pattern seen in other marine reptiles but does resemble the K-selected strategy of all extant marine mammals and a few extant lizards. Plesiosaurs may have shared other life history traits with these clades, such as sociality and maternal care.     

Social bonds of female baboons enhance infant survival

Among nonhuman primates, females often form strong bonds with kin and other group members. These relationships are thought to have adaptive value for females, but direct effects of sociality on fitness have never been demonstrated. We present 16 years of behavioral data from a well-studied population of wild baboons, which demonstrate that sociality of adult females is positively associated with infant survival, an important component of variation in female lifetime fitness. The effects of sociality on infant survival are independent of the effects of dominance rank, group membership, and environmental conditions. Our results are consistent with the evidence that social support has beneficial effects on human health and well-being across the life span. For humans and other primates, sociality has adaptive value.     

大型猪场基于RFID的信息平台研究与应用

大型猪场由于缺乏统一的信息平台而造成部门之间难以共享数据,从而影响了企业的管理效率.RFID技术可以应用于生猪的个体标识,在养猪业具有较好的应用前景.基于RFID的信息平台能够实现各个部门之间数据和业务的共享,可以给企业带来较好的经济效益和社会效益.     

论自然灾害的社会属性及防灾减灾对策——兼论发展防灾减灾农业

本文对自然灾害发生背后潜在的社会性因素进行了深入系统地剖析。分析了自然灾害社会属性的具体表现,包括致灾原因的社会性、灾害影响的社会性和防灾减灾的社会性;以及认识自然灾害社会属性的现实意义,即有利于帮助人们全面、客观地分析灾害发生的原因,有利于规范人类的生产生活行为,实现人与自然的和谐,有利于增强相关部门防灾减灾的责任意识,有利于化灾为利、造福人类;提出了发挥社会力量增强防灾减灾成效的思路。     

Social components of fitness in primate groups

There is much interest in the evolutionary forces that favored the evolution of large brains in the primate order. The social brain hypothesis posits that selection has favored larger brains and more complex cognitive capacities as a means to cope with the challenges of social life. The hypothesis is supported by evidence that shows that group size is linked to various measures of brain size. But it has not been clear how cognitive complexity confers fitness advantages on individuals. Research in the field and laboratory shows that sophisticated social cognition underlies social behavior in primate groups. Moreover, a growing body of evidence suggests that the quality of social relationships has measurable fitness consequences for individuals.     

公平正义与社会主义和谐社会

社会和谐意味着社会成员、社会群体之间的友好相处与和平共处，其中，“公平正义”构成和谐社会的首要价值规范和前提保障，对社会的和谐起着重要的协调和维系作用。然而，伴随着我国经济速度的不断加快，现实社会生活的不和谐性也已经发展到相当严重的程度，真正做到“公平正义”成为我国能够更好的构建社会主义和谐社会的重要步骤，坚持并实现公平正义，是和谐社会的重保证之一，同时也是和谐社会的重要特征。     

Interleukin-1 stimulation of astroglial proliferation after brain injury

The interleukins, which have a regulatory role in immune function, may also mediate inflammation associated with injury to the brain. In experiments to determine the effect of these peptide hormones on glial cell proliferation in culture, interleukin-1 was a potent mitogen for astroglia but had no effect on oligodendroglia. Interleukin-2 did not alter the growth of either type of glial cell. Activity similar to that of interleukin-1 was detected in brains of adult rats 10 days after the brains had been injured. These findings suggest that interleukin-1, released by inflammatory cells, may promote the formation of scars by astroglia in the damaged mammalian brain.     

The scaling of animal space use

Space used by animals increases with increasing body size. Energy requirements alone can explain how population density decreases, but not the steep rate at which home range area increases. We present a general mechanistic model that predicts the frequency of interaction, spatial overlap, and loss of resources to neighbors. Extensive empirical evidence supports the model, demonstrating that spatial constraints on defense cause exclusivity of home range use to decrease with increasing body size. In large mammals, over 90% of available resources may be lost to neighbors. Our model offers a general framework to understand animal space use and sociality.     

Autoradiographic localization of radioactivity in rat brain after injection of tritiated sex hormones

Radioactivity was found in cell bodies of neurons and glial cells throughout brains of male and female rats that had been injected with either testosterone-H(3) or estradiol-H(3). Uptake by limbic and hypothalamic structures was higher and longer lasting than that in nonlimbic structures. In all brains, the preoptic area, prepiriform cortex, olfactory tubercle, and septum had particularly high, long-lasting uptake of both hormones.     

Parkinson's disease: activity of L-dopa decarboxylase in discrete brain regions

The activity of L-dopa decarboxylase was greatly reduced in the striatum, less so in the hypothalamus, and unchanged in the cortex of brains of patients with Parkinson's disease. However, it appears that even in the striatum enough activity remained to allow for the formation of dopamine from L-dopa in patients treated with large doses of L-dopa.     

Discovery of a basaltic asteroid in the outer main belt

Visible and near-infrared spectroscopic observations of the asteroid 1459 Magnya indicate that it has a basaltic surface. Magnya is at 3. 15 astronomical units (AU) from the sun and has no known dynamical link to any family, to any nearby large asteroid, or to asteroid 4 Vesta at 2.36 AU, which is the only other known large basaltic asteroid. We show that the region of the belt around Magnya is densely filled by mean-motion resonances, generating slow orbital diffusion processes and providing a potential mechanism for removing other basaltic fragments that may have been created on the same parent body as Magnya. Magnya may represent a rare surviving fragment from a larger, differentiated planetesimal that was disrupted long ago.     

农民生态与经济需求关系的实证考察——以贵州省H乡和C镇为例

通过对贵州省H乡和C镇的农村进行抽样调查,发现生态环境保护的需求已经融入到了农民的基本生活需求中,为此要求政府采取有效措施回应广大农民的需求,有效地加强农村的生态建设。     

茉莉花茶抗抑郁的效果

通过观察茉莉花茶对小鼠的体征状态、行为学指标及全脑中去甲肾上腺素（NA）、多巴胺（DA）和5-羟色胺（5-HT）含量的影响,研究茉莉花茶对抑郁模型小鼠的防治作用及其相关机制．首先,对小鼠先后各进行21d的第1次造模和灌胃治疗及第2次造模和灌胃治疗,检测小鼠在第1、2次造模前后的体重、摄食量和糖水偏好程度,发现茉莉花茶对小鼠的体征状态有改善作用（P〈0．05）;其次,在第2次造模前后对小鼠进行悬尾和强迫游泳试验,发现连续使用茶汤灌胃和茶香气处理均能明显缩短小鼠的不动时间（P〈O．01）;最后,检测小鼠全脑中NA、DA和5-HT的含量,发现茉莉花茶能够明显提高NA和DA的含量（P〈O．05）．结果显示,茉莉花茶具有抗抑郁的作用,机制可能与提高NA和DA的含量有关．     

Infection-specific particle from the unconventional slow virus diseases

Scrapie-associated fibrils, first observed in brains of scrapie-infected mice, were also observed in scrapie-infected hamsters and monkeys, in humans with Creutzfeldt-Jakob disease, and in kuru-infected monkeys. These fibrils were not found in a comprehensive series of control brains from humans and animals affected with central nervous system disorders resulting in histopathologies, ultrastructural features, or disease symptoms similar to those of scrapie, kuru, and Creutzfeldt-Jakob disease. These fibrils are also found in preclinical scrapie and in the spleens of scrapie-infected mice; they are a specific marker for the "unconventional" slow virus diseases, and may be the etiological agent.     

NMDA receptor losses in putamen from patients with Huntington's disease

N-Methyl-D-aspartate (NMDA), phencyclidine (PCP), and quisqualate receptor binding were compared to benzodiazepine, gamma-aminobutyric acid (GABA), and muscarinic cholinergic receptor binding in the putamen and cerebral cortex of individuals with Huntington's disease (HD). NMDA receptor binding was reduced by 93 percent in putamen from HD brains compared to binding in normal brains. Quisqualate and PCP receptor binding were reduced by 67 percent, and the binding to other receptors was reduced by 55 percent or less. Binding to these receptors in the cerebral cortex was unchanged in HD brains. The results support the hypothesis that NMDA receptor-mediated neurotoxicity plays a role in the pathophysiology of Huntington's disease.     

Alterations in L-glutamate binding in Alzheimer's and Huntington's diseases

Brain sections from patients who had died with senile dementia of the Alzheimer's type (SDAT), Huntington's disease (HD), or no neurologic disease were studied by autoradiography to measure sodium-independent L-[3H]glutamate binding. In brain sections from SDAT patients, glutamate binding was normal in the caudate, putamen, and claustrum but was lower than normal in the cortex. The decreased cortical binding represented a reduction in numbers of binding sites, not a change in binding affinity, and appeared to be the result of a specific decrease in numbers of the low-affinity quisqualate binding site. No significant changes in cortical binding of other ligands were observed. In brains from Huntington's disease patients, glutamate binding was lower in the caudate and putamen than in the same regions of brains from control and SDAT patients but was normal in the cortex. It is possible that development of positron-emitting probes for glutamate receptors may permit diagnosis of SDAT in vivo by means of positron emission tomographic scanning.     

Costly punishment across human societies

Recent behavioral experiments aimed at understanding the evolutionary foundations of human cooperation have suggested that a willingness to engage in costly punishment, even in one-shot situations, may be part of human psychology and a key element in understanding our sociality. However, because most experiments have been confined to students in industrialized societies, generalizations of these insights to the species have necessarily been tentative. Here, experimental results from 15 diverse populations show that (i) all populations demonstrate some willingness to administer costly punishment as unequal behavior increases, (ii) the magnitude of this punishment varies substantially across populations, and (iii) costly punishment positively covaries with altruistic behavior across populations. These findings are consistent with models of the gene-culture coevolution of human altruism and further sharpen what any theory of human cooperation needs to explain.     

醴陵市土地生产潜力与人口承载力研究

采用限制因子修正法,估算了醴陵市的土地资源生产潜力,同时对土地资源人口承载力进行了研究.结果表明:醴陵市土地的开发空间和生产潜力较大,水稻、玉米、花生3种主要农作物的生产潜力指数分别为74.28%、86.52%、84.94%.尚有较大的土地生产潜力有待开发;在现有条件下,醴陵市的土地资源可以满足当地人口"小康型"的生活标准,但是醴陵市面对不断激增的人口和人民广泛的致富要求,还需不断挖掘土地的生产潜力,努力提高土地生产力;控制人口增长,缓解用地矛盾;切实保护耕地,确保总量动态平衡.     

The current situation in mexican immigration

By 1988, the Mexican-origin population of the United States had grown to 12.1 million, largely from recent, sharp increases in immigration. The policy concerns raised by this phenomenon have been influenced by some perceptions that available research contradicts. Today most Mexican immigrants come to stay, about half are female, and they have increasingly less schooling compared to the native-born population and other immigrants. Nationally, they do not cause adverse economic effects for native-born workers and, across generations, their language and political assimilation is proceeding well. They put greater demands on education than on other public services. However, the Mexican-origin population affects the economy and public services more and differently in the areas where it is concentrated, primarily in the western United States and large urban areas. Further, the recent legalization of 2.3 million Mexican immigrants can be expected to increase the demand on public services, especially in those areas.