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The effect of stress to the pregnant mother on hormonal responses of the offspring to stressful events was investigated in juvenile rhesus monkeys. Six pregnant monkeys were repeatedly removed from their home cages and exposed to unpredictable noise during mid- to late gestation (Days 90-145 postconception), while six undisturbed pregnant mothers served as controls. Blood samples were collected from the juvenile offspring under anesthesia on four occasions and assayed for ACTH and cortisol. In a second experiment, blood samples were collected from the awake offspring under a baseline and four progressively stressful conditions. Offspring of stressed mothers showed higher ACTH and cortisol levels than control offspring at all four anesthesia samples and at a nonanesthesized home cage baseline. Prenatally stressed offspring also showed higher ACTH values in all four stress conditions. Cortisol values were similar for the two groups under the stress conditions. The disparity between the two groups in the relationship between ACTH and cortisol was greatest in the most stressful condition, suggesting regulatory differences between the two groups. These results indicate that offspring of primate mothers stressed during pregnancy show enhanced HPA axis responsivity to stressors later in life, and concur with rodent findings indicating that prenatal stress may have long-term effects on HPA axis regulation.

Formerly applied to studies of responsivity in children, in more recent years the concept of temperament has been applied to nonhuman primates at the individual, species, and now population levels. While the concepts of temperament and personality have been less distinguished in nonhuman primate studies than in the human literature, temperamental and personality differences have now been identified among individual primates and among primate species in a number of studies. At the individual level, certain temperamental characteristics have been associated with age, sex, and most frequently rank. At the species level, temperamental profiles have been linked to intraspecific differences in social systems, sociodemographics, and features of life history and ecology. In this report we discuss the application of the temperament concept to nonhuman primates and review findings from studies of primate temperament at the individual, population, and species level. We also cite evidence for genetic and experiential influences on temperament in primates, outline concepts related to possible evolutionary influences on temperament, and discuss the possible relation of temperamental characteristics to social behavior and ecology in selected species. o 1995 Wiley-Liss, Inc.Key words: temperament, personality, behavioral traits, reactivity, individual differences, species differences INTRODUCTION: THE CONCEPT OF TEMPERAMENTThe concept of temperament originated from studies of infants and young children, in which consistent response styles in novel situations could be identified in a certain proportion of children at an early age. Such terms as bold vs. shy, inhibited vs. uninhibited, highly reactive vs. unreactive, highly fearful vs. unfearful, and emotional vs. unemotional have been used to characterize the behavioral styles of young children in response to novel and/or challenging situations. The similarity among terms indicates the primary dimension by which children are characterized-that is, whether they tend to approach or avoid novel stimuli and to what extent they show negative emotional and heightened physiological responses to 104 I Clarke and Boinski novelty. While the precise definitions vary in the literature, the term temperament refers to behavioral styles or tendencies (rather than discrete behavioral acts) that show continuity over time and can be identified in early infancy. Such characteristic styles are reflected in the degree and nature (i.e., approach vs. avoidance [Kagan et al., 19921) of responsivity to novel or stressful stimuli, and nearly all temperamental frameworks include a dimension of intensity, distress, or emotionality [Lewis et al., 19891. In addition to behavioral responsivity, physiological reactivity to challenge is considered an important component of temperament, since it is believed that temperamental response styles are based on biological underpinnings that are reflected in physiological responsiveness [Fox, 1989; Goldsmith et al., 1987; Gunnar, 1988; Healy, 1989; Kagan, 1989; Kagan ...

Previous studies have found evidence of behavioral and psychophysiological differences between nonhuman primates reared in different social environments, however, few of these have employed longitudinal study of the animals over early development. In this study, HPA axis activity was assessed via measurement of ACTH and cortisol values over the first 6 months of life and in response to two stressful housing transitions in 48 infant rhesus monkeys that were either mother- or peer-reared. ACTH and cortisol values declined over the first 6 months in both rearing groups. Peer-reared monkeys showed lower levels of ACTH over the first 6 months of life than mother-reared, but the rearing groups did not differ in basal cortisol values over this period. Mother-reared animals showed a greater ACTH response to the mild stress of being moved to a new cage, and male monkeys showed higher values than females. Mother-reared animals showed the largest cortisol increase in response to the caging transition. Both groups showed increases in ACTH and cortisol in response to the more severe stress of separation from their rearing partners and housing with unfamiliar age-mates. Mother-reared animals again showed the largest increase in ACTH in response to these events, but increases in cortisol were similar among both sexes and rearing groups. These results suggest an interaction of sex and rearing history in response to stressful events.

The effect of maternal psychological disturbance during pregnancy on postnatal responses of the offspring to stressful events was investigated in juvenile rhesus monkeys. Six pregnant monkeys were repeatedly removed from their home cages and briefly exposed to unpredictable noise during mid to late gestation (Days 90-145 postconception). Six undisturbed pregnant mothers served as controls. Behavioral data were later collected from the 18-month-old offspring under a baseline and four progressively stressful conditions. Social behaviors were considerably more affected by prenatal treatment than nonsocial behaviors. Prenatally stressed offspring showed more abnormal social behavior (mutual clinging) and less normal social behavior (proximity, contact) than controls. These results suggest that offspring of mothers stressed during pregnancy may show enhanced responsivity to stressors later in life, and concur with rodent findings indicating that prenatal stress may have long-term effects on behavioral reactivity.

A new algorithm for the construction of a dense random packing of a binary mixture of hard spheres is presented. The algorithm uses periodic boundary conditions and is capable of handling any binary composition with radius ratio between 1.0 and 2.0. Computed results are relatively insensitive to variations in program parameters. The resulting packings are extremely homogeneous and isotropic. The packing fraction, the radial distribution function, and the Voronoi-cell statistics are all calculated for equal spheres. The packing fraction is also calculated as a function of composition fraction and size ratio for unequal sphere mixtures. For all cases the packing fraction is between 0.64 and 0.68. This contradicts the popular notion that the packing fraction increases rapidly as a function of size ratio for a given composition fraction for dense random packings. Since the mass density scales linearly with packing fraction and amorphous metals have mass densities very close to those of the corresponding crystal, the dense random packing of hard spheres predicts mass densities that are 8 -14% lower than in the crystalline metal. The unlikelihood of this implies that the atoms in an amorphous metal cannot act like hard spheres. Rather they deform in such a way as to pack together more efficiently than a dense random packing of hard spheres.

Abstract-The science goals of space missions from the Hubble Space Telescope through to Gaia and Euclid require ultra-precise positional, photometric and shape measurement information. However, in the radiation environment of the space telescopes, damage to the focal plane detectors through high energy protons leads to the creation of traps, a loss of charge transfer efficiency and a consequent deterioration in measurement accuracy. An understanding of the traps produced and their properties in the CCD during operation is essential to allow optimisation of the devices and suitable modelling to correct the effect of the damage through the post-processing of images. The technique of "pumping single traps" has allowed the study of individual traps in high detail that cannot be achieved with other techniques, such as Deep Level Transient Spectroscopy, whilst also locating each trap to the sub-pixel level in the device. Outlining the principles used, we have demonstrated the technique for the Acentre, the most influential trap in serial read-out, giving results consistent with the more general theoretical values, but here showing new results indicating the spread in the emission times achieved and the variation in capture probability of individual traps with increasing signal levels. This technique can now be applied to other time and temperature regimes in the CCD to characterise individual traps in situ under standard operating conditions such that dramatic improvements can be made to optimisation processes and modelling techniques.

Summary A study of host‐parasite relationships has been made on the cestode Schistocephalus solidus Müller by examining conditions relating to the infection and growth of the plerocercoid in the stickleback, and‐ its transfer to other hosts for maturation; the infection of Cyclops by the coracidimn with its subsequent change to a procercoid; and the passage of the procercoid into the body cavity of the fish to become a plerocercoid. It has been possible, by establishing suitable techniques, to carry out the whole life cycle in the laboratory and so facilitate these studies. Eggs were obtained from plerocercoids and observations made on their development. The time of hatching of the coracidium varies considerably, both with temperature and with intrinsic factors. The average time is about three weeks but hatching may occur up to six months after the eggs have been shed. From such eggs, free coracidia and, subsequently, procercoids in Cyclops and nauplii, were secured and studied. The growth rate of procercoids was determined together with the effect of infection on the growth of nauplii. Infections in fish were secured from infected Cyclops but not in sufficient numbers to justify more than tentative conclusions about the growth rate of plerocercoids. The time required for penetration of the fish gut wall by the procercoid can be as short as two hours. Changes in morphology of the worm in its transformation from a coracidium to a plerocercoid were surveyed and it was shown how the formation of the musculature precedes the initiation of strobilation which occurs rapidly and completely, followed immediately by the formation of the genital rudiments. The excretory system of the plerocercoid could be displayed effectively by a method of embedding in transparent plastic. Infected fish from one source were collected throughout the year and the weights of the fish and of the worms within them were ascertained. It was found that in the autumn there was an increase in the number of large fish in the marginal zone–possibly related to an increase of plankton–but during the months from winter to summer the mean size of fish was less and remained relatively stable in this zone. The mean weights of plerocercoids however, increased during this period as did the temperature of the water. Some indications of the growth rate of the plerocercoid were observed from the collected data. An examination of the stomach contents of the fish showed a wide variety of diet with little or no change throughout the year and also indicated that Cyclops form an almost insignificant feature in this diet.