Experimental subacute spongiform virus encephalopathies in primates and other laboratory animals

The host range of subacute spongiform virus encephalopathies is described. The asymptomatic incubation period and the duration of the illnesses in various species of animal hosts is discussed along with information on additional species of Old World and New World monkeys and the domestic cat, which have been shown to be susceptible to subacute spongiform virus encephalopathies.     

Vocal tract limitations on the vowel repertoires of rhesus monkey and other nonhuman primates

The vowel repertoire of a rhesus monkey (Macaca mulatta) was explored by means of a computer program that calculated formant frequencies from the area function of the animal's supralaryngeal vocal tract, which was systematically varied within the limits imposed by anatomical constraints. The resulting vowels were compared with those of humans and with recorded vocalizations of nonhuman primates. The computer model indicates that the acoustic "vowel space" of a rhesus monkey is quite restricted compared to that of the human. This limitation results from the lack of a pharyngeal region that can change its cross-sectional area. These animals thus lack the output mechanism necessary for production of human speech. Man's speech output mechanism is apparently species-specific.     

Cellular senescence in aging primates

The aging of organisms is characterized by a gradual functional decline of all organ systems. Mammalian somatic cells in culture display a limited proliferative life span, at the end of which they undergo an irreversible cell cycle arrest known as replicative senescence. Whether cellular senescence contributes to organismal aging has been controversial. We investigated telomere dysfunction, a recently discovered biomarker of cellular senescence, and found that the number of senescent fibroblasts increases exponentially in the skin of aging baboons, reaching >15% of all cells in very old individuals. In addition, the same cells contain activated ataxia-telangiectasia mutated kinase and heterochromatinized nuclei, confirming their senescent status.     

非人灵长类性打搅行为研究进展

性打搅行为是指非人灵长类社群内非交配个体对正在发生性行为个体的干扰行为,该行为在非人灵长类中普遍存在,通过综述目前已知的36种非灵长类的性打搅行为的报道,探讨性打搅行为的功能和意义。性打搅行为具有更高度的种间和种内差异,种间的性打搅的方式不同、同时受到社会结构和婚配制度的影响;在种内受到性别、年龄、等级等因素的影响。结合川金丝猴性打搅的研究结果,从性打搅的类型、被打搅的反应、性打搅的功能以及相关假说等方面入手,对非人灵长类性打搅行为进行系统总结,旨在为我国相关领域的研究提供参考,为生殖行为学研究者启发思路,推动本领域的发展。     

Social relationships and social cognition in nonhuman primates

Complex social relationships among nonhuman primates appear to contribute to individual reproductive success. Experiments with and behavioral observations of natural populations suggest that sophisticated cognitive mechanisms may underlie primate social relationships. Similar capacities are usually less apparent in the nonsocial realm, supporting the view that at least some aspects of primate intelligence evolved to solve the challenges of interacting with conspecifics.     

Program clocks in small mammals

Complex patterns of time, direction, and speed of running by small nocturnal mammals in activity wheels sometimes are duplicated almost exactly from night to night. These activity pattern repetitions disclose: (i) previously unknown capabilities of biological clocks to act as sequence programmers for behavior; (ii) that animals can retain a record of the sequence and timing of their activities covering an entire night; and (iii) that the activities of one night can bias an animal toward similar behavior on subsequent nights.     

Microbial fermentation in certain mammals

The fermentation in the caecum and large intestine of ruminants is negligible compared with that in the rumen. In small ruminants the rate per unit contents is faster than in large ones, due to faster turnover. The cellulolytic bacteria of several ruminants are similar but differ in nutritional requirements.     

Insulin levels in primates by immunoassay

Only trace amounts of insulin were detected by an immunoassay system with guinea pig antibody to pork insulin in the New World primates Cebus and Saimiri. The system found insulin levels in the Old World primates rhesus and chimpanzee which were quite like those of human beings. The findings suggest important structural differences in the insulins of the two primate divisions.