Social responses to abnormal infant monkeys

Experimental modification of an individual's behavior can be used to evaluate the range of group social reactions to him. This principle is used in evaluating the degree to which macaque groups compensate for an infant's clumsiness, consequent on reduced visual acuity from an experimental cataract. Evidence is presented to support the following propositions: Defective infants are not killed by the group even in crowded conditions; compensatory care is given during the first year, primarily by the mother and to a certain extent by other animals in the group; isolation of the infant begins in the second year; social responses to the defective infant reflect normal social responses. Compensatory care of chronically defective individuals is a consequence of evolution of social behaviors adapted to nurture young individuals over a long period of dependence and to protect other group members during temporary periods of weakness.     

Confidence intervals for uncommon but dramatic responses to treatment

A small literature discusses locally most powerful rank tests when only a fraction of treated subjects respond to treatment. The ranks used in these tests are very different from conventional ranks, being relatively flat for low responses and then rising steeply, and the associated tests are much more powerful than conventional rank tests when, indeed, only a small fraction of treated subjects exhibit dramatic responses. Because the tests are derived from considerations of local power, they do not yield a plausible family of models for effect, and therefore they do not yield confidence intervals for the magnitude of effect formed by inverting the tests. There is a similarity between these tests and another family of tests, originally motivated by different considerations involving peak performance in small subsets. Exploiting this similarity, a method for obtaining confidence statements is proposed. In the case of observational studies, sensitivity to unobserved bias from nonrandom assignment of treatments is also examined. Two examples are used as illustrations: (i) a study of smoking during pregnancy and its effects on birth weight, in which smokers are matched to six controls, and (ii) a matched pair study of damage to DNA among workers at aluminum production plants.     

Fear responses of Japanese monkeys to scale models

This study investigated fear responses of Japanese monkeys (Macaca fuscata) to scale models. Fear responses of participants were assessed using rating scores assigned by judges. In Experiment 1, participants were presented with scale models of objects in furniture, vehicle, and mammal categories. Overall, the participants expressed stronger fear responses to mammal objects as compared to the other two kinds. In Experiment 2, participants were presented with scale models of furniture, new mammals, and animals composed of insects, birds, fish, and reptiles. As a whole, the participants showed stronger fear responses to the new mammal and animal objects than to furniture objects. Fear responses to mammal and animal objects were comparable. These results suggest that Japanese monkeys show stronger fear responses to objects possessing perceptual properties of animals, as opposed to objects that do not possess such properties.     

Changes in the latencies of motor responses to visual stimuli presented with musical accompaniment

The effects of music with specific intensity on the latencies of the left or right hand motor responses to visual stimuli have been studied. When the latency of the initial motor response is more than 400 ms, the music accompaniment decreases the latency of the motor response of the left hand. It is supposed that the decrease in the mean latency of the left hand response in subjects who are not professional musicians is related to the activation effect of music on the right hemisphere. Music has no effect when the initial motor responses have shorter latencies.     

Structural analysis of potential barriers to bulk-flow exchanges between uvea and sclera in eyes of Macaque monkeys

Summary The uveal tract of the eyes of monkeys was examined by electron microscopy using both thin sections and freeze-fracture replicas. The ultrastructural features of the lamina fusca in the monkey resembled those previously described for rabbit. The lamina fusca was composed of numerous interleaved processes of fibroblastic and pigmented cells and contained tight junctions between fibroblastic cell processes that were predominantly discontinuous, as well as numerous fenestrations through the attenuated cell processes. There was no regional compaction of cellular processes traversing the entire uvea at the level of the ora serrata as reported previously in hamster eyes.     

Women with an avoidant attachment style show attenuated estradiol responses to emotionally intimate stimuli

The current study examined neuroendocrine processes associated with emotional intimacy in humans. Despite the importance of this aspect of close relationships, emotional intimacy has received much less attention in neuroendocrine research compared to other aspects of close relationships. In this study, participants viewed movie clips depicting an emotionally intimate parent-child interaction or other, non-intimate themes, and we assessed whether depictions of emotional intimacy increased levels of estradiol, a steroid hormone associated with attachment and caregiving processes. We also examined whether estradiol responses were moderated by individual differences in attachment avoidance, or people's discomfort with closeness and intimacy. Our findings revealed that, among single participants, estradiol levels increased in response to the emotionally intimate clip, but this effect was not observed among currently partnered participants. Moreover, the effects of emotional intimacy were moderated by gender and attachment avoidance, such that highly avoidant women showed smaller increases in estradiol after watching the emotionally intimate clip. Women's avoidance was unrelated to estradiol responses in the non-intimate control conditions, however, suggesting that the effects of avoidance were specific to intimate contexts. Taken together, the current findings contribute to our understanding of the biological bases of attachment and caregiving processes. They also highlight the potential role of estradiol in avoidant individuals' regulation of closeness and intimacy.     

Conserved Cdk inhibitors show unique structural responses to tyrosine phosphorylation

Balanced proliferation-quiescence decisions are vital during normal development and in tissue homeostasis, and their dysregulation underlies tumorigenesis. Entry into proliferative cycles is driven by Cyclin/Cyclin-dependent kinases (Cdks). Conserved Cdk inhibitors (CKIs) p21^Cip1/Waf1, p27^Kip1, and p57^Kip2 bind to Cyclin/Cdks and inhibit Cdk activity. p27 tyrosine phosphorylation, in response to mitogenic signaling, promotes activation of CyclinD/Cdk4 and CyclinA/Cdk2. Tyrosine phosphorylation is conserved in p21 and p57, although the number of sites differs. We use molecular-dynamics simulations to compare the structural changes in Cyclin/Cdk/CKI trimers induced by single and multiple tyrosine phosphorylation in CKIs and their impact on CyclinD/Cdk4 and CyclinA/Cdk2 activity. Despite shared structural features, CKI binding induces distinct structural responses in Cyclin/Cdks and the predicted effects of CKI tyrosine phosphorylation on Cdk activity are not conserved across CKIs. Our analyses suggest how CKIs may have evolved to be sensitive to different inputs to give context-dependent control of Cdk activity.     

Induction of immunodeficiency virus-specific immune responses in rhesus monkeys following gene gun-mediated DNA vaccination

Abstract: The Accell® gene delivery system (gene gun) was used to deliver gold particles coated with HIV-1_LAI and SIV_mac239 expression constructs into the epidermis of rhesus macaques, resulting in the elicitation of env- and gag-specific humoral responses. One microgram of vector DNA per dose was sufficient to induce immune responses in monkeys using SIV_mac239 gp160 and gp120 vectors driven by the CMV-intron A promoter. Several parameters, including the identity of the vector, the length of the rest period between immunizations, the number of immunizations, and the amount of DNA per immunization, are all important in designing an optimal DNA immunization regimen. In addition, gene gun-based DNA immunization using low efficiency expression vectors is an effective means of priming for the induction of vigorous antibody responses in macaques following boosting with recombinant subunits.     

Behavioral responses of free-ranging rhesus monkeys to food shortage

During early July 1968, a severe food shortage occurred on Cayo Santiago, an island colony of free-ranging rhesus monkeys (Macaca mulatta). The food shortage produced striking changes in the behavior of the monkeys. Within the one social group intensively studied, the total frequencies of grooming, play and fights decreased significantly; the frequency of matings also dropped; body contact, displacements by other groups, and non-displacement movements decreased, but not in statistically significant amounts. Changes in the percentage of total grooming attributable to related and unrelated monkeys reflected the stability of the rhesus matriline. Comparisons made between Cayo Santiago and other primate groups under analogous situations reveal similar responses to food shortage.     

Enhanced chronotropic and inotropic responses of rat myocardium to cholinergic stimulus with aging.

The ability of the heart to respond to adrenergic stimulation diminishes with aging, and this may be one of the factors contributing to the age-associated decline in cardiac stress responsiveness. On the other hand, little is known about the impact of aging on the responsiveness of the heart to cholinergic stimulation. In this study, we determined the chronotropic and inotropic responses of the isolated, Langendorff-perfused hearts from adult (6-8 months) and aged (28-30 months) rats to cholinergic agonists so as to assess age-related alterations in postsynaptic cholinergic control of heart function. The results showed the following. (i) In isolated perfused spontaneously bearing rat hearts, the negative chronotropic response to acetylcholine (10(-9)-10(-5) M) was up to 4-fold greater in the aged compared with adult hearts; this age-related difference was less marked (2-fold) but not abolished in the presence of a maximally effective concentration (5 microM) of the cholinesterase inhibitor eserine. (ii) The cholinesterase-resistant agonist carbachol (10(-9)-2.5 x 10(-6) M) elicited a 2- to 3-fold greater negative chronotropic response in the aged compared with adult hearts. (iii) In isolated perfused, electrically paced (4 Hz) rat hearts, carbachol (10(-9)-10(-5) M) elicited a concentration-dependent negative inotropic response, which was 2-fold greater in the aged compared with adult heart at all carbachol concentrations. (iv) Acetylcholinesterase activities (micromoles per gram per hour) were 50-60% lower in the aged atria (83 +/- 21) and ventricles (24 +/- 6) than in adult atria (210 +/- 20) and ventricles (47 +/- 7).(ABSTRACT TRUNCATED AT 250 WORDS)     

Habitat associations of species show consistent but weak responses to climate

Different vegetation types can generate variation in microclimates at local scales, potentially buffering species from adverse climates. To determine if species could respond to such microclimates under climatic warming, we evaluated whether ectothermic species (butterflies) can exploit favourable microclimates and alter their use of different habitats in response to year-to-year variation in climate. In both relatively cold (Britain) and warm (Catalonia) regions of their geographical ranges, most species shifted into cooler, closed habitats (e.g. woodland) in hot years, and into warmer, open habitats (e.g. grassland) in cooler years. Additionally, three-quarters of species occurred in closed habitats more frequently in the warm region than in the cool region. Thus, species shift their local distributions and alter their habitat associations to exploit favourable microclimates, although the magnitude of the shift (approx. 1.3% of individuals from open to shade, per degree Celsius) is unlikely to buffer species from impacts of regional climate warming.