Genetic analysis of human immunodeficiency virus type 1 envelope V3 region isolates from mothers and infants after perinatal transmission.

The human immunodeficiency virus type 1 (HIV-1) sequences from variable region 3 (V3) of the envelope gene were analyzed from seven infected mother-infant pairs following perinatal transmission. The V3 region sequences directly derived from the DNA of the uncultured peripheral blood mononuclear cells from infected mothers displayed a heterogeneous population. In contrast, the infants' sequences were less diverse than those of their mothers. In addition, the sequences from the younger infants' peripheral blood mononuclear cell DNA were more homogeneous than the older infants' sequences. All infants' sequences were different but displayed patterns similar to those seen in their mothers. In the mother-infant pair sequences analyzed, a minor genotype or subtype found in the mothers predominated in their infants. The conserved N-linked glycosylation site proximal to the first cysteine of the V3 loop was absent only in one infant's sequence set and in some variants of two other infants' sequences. Furthermore, the HIV-1 sequences of the epidemiologically linked mother-infant pairs were closer than the sequences of epidemiologically unlinked individuals, suggesting that the sequence comparison of mother-infant pairs done in order to identify genetic variants transmitted from mother to infant could be performed even in older infants. There was no evidence for transmission of a major genotype or multiple genotypes from mother to infant. In conclusion, a minor genotype of maternal virus is transmitted to the infants, and this finding could be useful in developing strategies to prevent maternal transmission of HIV-1 by means of perinatal interventions.     

Effects of nonmaternal restraint on the vocalizations of infant rhesus monkeys (Macaca mulatta)

This study explored the effects of restraint by females other than the mother on the vocalizations of infant rhesus macaques (Macaca mulatta) in a captive social setting. In this species, females are very attracted to young infants and will frequently approach, groom, and hold the infant. Incompetent handling, abusive behavior, or extended periods away from the mother that prevent the infants from nursing represent potentially significant risks for infants. Vocal responses to such risky conditions appear to be the infants' only means to promote a return to their mothers. We examined the association between the severity of the threat posed to the infant and the nature of its vocal response to restraint, and whether the infants' calls influenced the behavior of their mothers or captors. The results suggest that situations posing greater risks for the infants, i.e., longer periods of restraint, were associated with a greater use of noisy screams. Furthermore, mothers' responding was associated with a greater use of noisy screams as well. The mothers' reactions, however, could be described as cautious, and consisted mostly of closer monitoring; such tempered response might be related to the risk of injury to the infant that could result from a more forceful and direct attempt at retrieval.     

Age differences in spatial positioning of males in a chimpanzee unit-group at the mahale mountains National Park,Tanzania

Proximity partner choice by male chimpanzees of various age classes was analyzed in relation to their spatial positioning. Field work was carried out twice at the Mahale Mountains National Park, Tanzania. Proximity data were recorded at 3 and 10m from the focal animal. The data for the proximity between the focal male and other individuals allowed the males to be classified into two categories according to both criteria: early adolescence to young adult, and prime to old age. Between the males, the 3m proximity data permitted a classification into two categories as above, but those for 10m did not. These two spatial distances thus probably have different meanings for the males. The numbers of male proximity partners and proximity with the alpha male also allowed the males to be classified into two categories: early and late adolescence, and young adult to old age. Together, the above results support the classification of males into three age-graded categories: (1) early and late adolescence, (2) young adult, and (3) prime to old age. This does not arise because the males of each category form an age group. Prime or older males are most frequently in proximity, while their juniors consistently attempt to approach them. However, even prime or older males are not equally in proximity with one another. Their proximity partners change as time passes. Probably recognizing such changes, they form coalitions or are in rivalry. The sexual interest of adolescent males is probably a factor stimulating them to separate from their mothers, and to approach older males. Young adult males, even though physically mature, do not have equal proximity relations with older males. They are not yet sufficiently qualified to join the coalitions formed by their seniors.     

The development of range of action in infant cynomolgus monkeys (Macaca fascicularis) reared by restrained mothers

In order to study the effects of the mothers' range of action on the development of their infants' range of action during the first year of life, mother cynomolgus monkeys were restrained in their range of action by penning them in a separation cage within the large cage of the harem group they belonged to. The infants, however, could leave their mothers' separation cage. The control group consisted of infants growing up with unrestrained mothers in the same group. It appeared that infants of restrained mothers were initially retarded in the development of their range of action but at the end of the first year they did not differ anymore from infants of unrestrained mothers. It is concluded that the maternal range of action only temporarily affects the development of the infant's range of action.     

Benefits to Female Helpers in Wild Rhinopithecus roxellana

To assess what female Sichuan snub-nosed monkeys (Rhinopithecus roxellana) gain from allowing others to care for their infants, we collected behavioral data on 12 mother-infant dyads at Zhouzhi National Nature Reserve in the Qinling Mountains, China. Mothers’ feeding time significantly increased when infants were cared for by other group members versus when they were cared for by the mothers themselves. The time mothers spent autogrooming and receiving grooming also increased when they were temporarily relieved of maternal duties; however, mothers did not groom other individuals more when they were not encumbered by infants. There are several benefits that mothers gain from having helpers care for their infants: They gain more time to feed and thus increase their feeding efficiency. Mothers have more time to engage in hygienic and maintenance activities because they autogroom and receive allogrooming more. Lastly, mothers save energy when their infants are with helpers. Wild Sichuan snub-nosed monkey mothers meet their basic survival and maintenance needs because of helping behavior.     

Association partners of young chimpanzees in the Mahale Mountains National Park,Tanzania

Association partners of young chimpanzees at the Mahale Mountains National Park were analyzed. Juvenile and adolescent chimpanzees associated frequently with their mothers, although mother-offspring association decreased as the offspring grew up. Males tended to leave their mothers and associate with adult males, while females remained frequently associating with their mothers in early adolescence. In late adolescence and young adulthood, males usually associated with adult males and cycling adult females. Females may transfer into neighboring unit-groups in this stage. Although an immigrant female tended to be alone when her estrous cycle stopped, she associated with many individuals, in particular with adult males, when she resumed cycling. Some orphans were observed to associate frequently with particular adults. The findings were discussed in relation to the unique characteristics of chimpanzee social system.     

Emergence of individual recognition in young macaques

Few studies have addressed the development of nonhuman primate infants' responses to conspecific vocalizations. Previous studies showed that the appropriate response to alarm, intergroup and long-distance contact calls emerged at about 6 months of age. It remained unclear whether this age constitutes a watershed in terms of infants' sociocognitive development or whether it was due to the types of stimuli used in the experiments. I therefore examined the development of infant Barbary macaque, Macaca sylvanus, responses to maternal calls, under the assumption that recognition of the mother is one of the tasks that infants should master as early as possible. I presented infants of different age categories with short bouts of screams recorded from their mothers or another female of the same social group. Experiments on yearlings confirmed the suitability of the experimental approach: yearlings responded significantly more strongly to maternal calls than to calls from unrelated females. Infants were tested at 4, 10 and 16 weeks of age. In the youngest age group, they failed to respond to the playbacks, whereas from 10 weeks of age on they responded significantly more strongly to maternal calls, suggesting that by this age they recognized their mothers by voice. These results suggest that the developmental trajectories in the domain of comprehension learning may be flexible, in the sense that infant responses may depend on the salience of, and the exposure to, the call type under study. The experiments also show that screams may transmit individual-specific characteristics that are perceptually salient to the listeners.     

基于灰色关联分析方法评价13种野生兜兰的迁地保护适应性

由于过度收集和对原生境地的破坏,我国野生兜兰已濒临灭绝,对其进行迁地保护十分必要。通过对引种的13种40份野生兜兰资源进行迁地栽培,并观测兜兰种质在迁移地的各种生长性状指标等,本研究利用灰色关联分析方法评价13种兜兰的迁地适应性,分析影响其迁地保护的关键因素。结果表明:(1)带叶兜兰、同色兜兰、长瓣兜兰、文山兜兰适应性较强,与理想种的关联度均在0.8以上;巨瓣兜兰、白花兜兰、小叶兜兰、紫纹兜兰、紫毛兜兰、硬叶兜兰适应性一般,与理想种的关联度在0.7~0.8之间;麻栗坡兜兰、杏黄兜兰、红旗兜兰适应性较差,与理想种的关联度均在0.6以下;(2)不同兜兰种类、同一种类不同产地兜兰种质的迁地生长适应性不同,来源地和栽培温度可能是影响其迁地保护的关键因子。     

Discrimination of mother by infant among Japanese Macaques (Macaca fuscata)

Experiments on five mother-infant pairs of Japanese monkeys (Macaca fuscata)living together in a captive group were conducted during the first 12 weeks after birth in order to assess the time at which infants begin to discriminate their own mothers from other adult females. After removal from their social group, infants exposed to their mothers and three unfamiliar adult females at a distance of 150 cm failed to orient visually toward their mothers. However, when the infants were allowed to approach the four females, they responded preferentially to their mothers during the third month of life. We concluded that by 8–12 weeks of age, infant Japanese macaques are able to discriminate between their mothers and other adult females.     

Maternal discrimination of offspring vocalizations in Barbary macaques (Macaca sylvanus)

The response of Barbary macaque (Macaca sylvanus) females to vocalizations of their offspring was studied in a semi-free ranging population. The results of both facal observations and playback experiments demonstrated that mothers preferentially turned to their offspring's vocalizations over those of other young, providing evidence that mothers are able to recognize their offspring by acoustic signals alone. We assume that they may use this ability to monitor their infants' activities.     

A mother’s legacy: the strength of maternal effects in animal populations

Although mothers influence the traits of their offspring in many ways beyond the transmission of genes, it remains unclear how important such ‘maternal effects’ are to phenotypic differences among individuals. Synthesizing estimates derived from detailed pedigrees, we evaluated the amount of phenotypic variation determined by maternal effects in animal populations. Maternal effects account for half as much phenotypic variation within populations as do additive genetic effects. Maternal effects most greatly affect morphology and phenology but, surprisingly, are not stronger in species with prolonged maternal care than in species without. While maternal effects influence juvenile traits more than adult traits on average, they do not decline across ontogeny for behaviour or physiology, and they do not weaken across the life cycle in species without maternal care. These findings underscore maternal effects as an important source of phenotypic variation and emphasise their potential to affect many ecological and evolutionary processes.     

Infant-caregiver interactions in common marmosets (Callithrix jacchus): Consequences of rejections and rub-offs of infants by caregivers

Interactions between common marmoset infants (Callithrix jacchus) and their fathers, mothers, older siblings and twins were examined in captive family groups. The aim was to record infants' behaviour after being rejected in their attempts to get on to caregivers and after being rubbed off by caregivers who had been carrying them. The results showed that infants' behaviour differed according to which caregiver was involved and that behaviours following rejections differed from those following rub-offs. These differences in infants' behaviour had been predicted from previous work which showed that caregivers have a limit to the amount of time they are prepared to devote to infants and that different caregivers give different amounts of care to infants of specific ages.     

Social Dependence of Infant Slow Lorises to Learn Diet

Nocturnal lorises and pottos (Lorisinae) are among the least gregarious of primates. Mothers start to leave their infants alone during the night as early as the day of birth. However, captive studies also indicate that weaning young lorisines closely follow their mothers nearly all the time and obtain their first solid food via scrounging. Accordingly, it has been suggested that young lorisines depend on their mothers to obtain dietary information and to achieve dietary independence by watching their mothers feeding or interacting directly with their mothers over food. We tested for a social dependence on dietary learning by infants in a social network of wild slow lorises (Nycticebus coucang). The social network included one male infant, his mother, and two subadult females. The infant only took to mouth food items that were also part of the females' diet and showed concordance in the frequency of use of food patches with the females. These results contradict dietary learning by trial and error. They indicate that dietary learning by infants depends on information obtained from older conspecifics. However, the infant was never involved in direct interactions with conspecifics over food and fed mostly alone. He was not within a distance where he could see the females feeding more often than expected from the configuration and utilization of home ranges. The infant never looked at conspecifics feeding in his vicinity, which suggests that visual observation or direct interaction over food may not be the mechanisms by which information about food resources is passed from older individuals to young, but that other ways of obtaining such information are used.     

Likeability of Garden Birds: Importance of Species Knowledge & Richness in Connecting People to Nature

Interacting with nature is widely recognised as providing many health and well-being benefits. As people live increasingly urbanised lifestyles, the provision of food for garden birds may create a vital link for connecting people to nature and enabling them to access these benefits. However, it is not clear which factors determine the pleasure that people receive from watching birds at their feeders. These may be dependent on the species that are present, the abundance of individuals and the species richness of birds around the feeders. We quantitatively surveyed urban households from towns in southern England to determine the factors that influence the likeability of 14 common garden bird species, and to assess whether people prefer to see a greater abundance of individuals or increased species richness at their feeders. There was substantial variation in likeability across species, with songbirds being preferred over non-songbirds. Species likeability increased for people who fed birds regularly and who could name the species. We found a strong correlation between the number of species that a person could correctly identify and how connected to nature they felt when they watched garden birds. Species richness was preferred over a greater number of individuals of the same species. Although we do not show causation this study suggests that it is possible to increase the well-being benefits that people gain from watching birds at their feeders. This could be done first through a human to bird approach by encouraging regular interactions between people and their garden birds, such as through learning the species names and providing food. Second, it could be achieved through a bird to human approach by increasing garden songbird diversity because the pleasure that a person receives from watching an individual bird at a feeder is dependent not only on its species but also on the diversity of birds at the feeder.     

Effects of high-rise living on physical and mental development of children

Effects of high-rise living on infants' development were investigated in 1987-1988 in a high-rise residential area in Tokyo, using questionnaires on the daily behaviors of a total of 1,045 infants, completed by mothers and kindergarten teachers. Infants of high-rise living showed a delayed independence in fundamental daily customs compared with those of low-rise living. This could be ascribed to an over-attachment of mothers of high-rise living with their infants resulting from a reduced number of outings.     

A hybrid design for studying genetic influences on risk of diseases with onset early in life

Studies of genetic contributions to risk can be family-based, such as the case-parents design, or population-based, such as the case-control design. Both provide powerful inference regarding associations between genetic variants and risks, but both have limitations. The case-control design requires identifying and recruiting appropriate controls, but it has the advantage that nongenetic risk factors like exposures can be assessed. For a condition with an onset early in life, such as a birth defect, one should also genotype the mothers of cases and the mothers of controls to avoid potential confounding due to maternally mediated genetic effects acting on the fetus during gestation. The case-parents approach is less vulnerable than the case-mother/control-mother approach to biases due to population structure and self-selection. The case-parents approach also allows access to epigenetic phenomena like imprinting, but it cannot evaluate the role of nongenetic cofactors like exposures. We propose a hybrid design based on augmenting a set of affected individuals and their parents with a set of unaffected, unrelated individuals and their parents. The affected individuals and their parents are all genotyped, whereas only the parents of unaffected individuals are genotyped, although exposures are ascertained for both affected and unaffected offspring. The proposed hybrid design, through log-linear, likelihood-based analysis, allows estimation of the relative risk parameters, can provide more power than either the case-parents approach or the case-mother/control-mother approach, permits straightforward likelihood-ratio tests for bias due to mating asymmetry or population stratification, and admits valid alternative analyses when mating is asymmetric or when population stratification is detected.     

Maternal responses to dead and dying infants in wild troops of ring-tailed lemurs at the Berenty Reserve,Madagascar

We describe responses of seven mothers and other troop members to dead and dying infants in several troops of ring-tailed lemurs(Lemur catta) at the Berenty Reserve, Madagascar. In contrast to mothers in simian species, ring-tailed lemur mothers rarely carried their dying, immobile or dead infants. However, they sniffed, licked, and touched them even after they had died. While the dying infants were still peeping, their mothers remained near them, and 15 to 76 min after the infants ceased to peep, they were left by their mothers. Six of the seven mothers returned to their dead infants several times within the first few hours after they had left them. All seven mothers gave repeated calls, such as “mew” and “pyaa,” when they were separated from either their dead infants or other troop members or both. Thus, each mother exhibited some form of maternal behavior toward her dead infant for hours after its death. These results indicate that there may not be a great gap in terms of maternal affection between simian and prosimian mothers. We also discuss visuospatial memory ability in ring-tailed lemurs and the causes of the infants’ deaths.     

Early maternal recognition of offspring vocalizations in rhesus macaques (Macaca mulatta)

This study investigated the development of maternal recognition of infant calls in rhesus macaques (Macaca mulatta). Fifteen mothers and their offspring, of age ranging from several hours to 28 days, served as subjects of an experiment in which the offspring's distress vocalizations were recorded and then played back to their mothers simultaneously with those of an age-matched control infant. The proportion of time looking at, but not the proportion of orientations to the speaker playing the offspring's vocalizations increased significantly as a function of infant age. Specifically, mothers of infants older than 1 week of age responded longer to the playback of their own infant's calls than did mothers of younger infants. These findings provide the firt evidence that offspring recognition in macaques develops between the first and second week of the infant's life and are consistent with the hypothesis that mothers need to be exposed to their infants' calls in order to learn their acoustic characteristics.     

Food availability affects the maternal transfer of androgens and antibodies into eggs of a colonial seabird

Mothers can improve the quality of their offspring by increasing the level of certain components in their eggs. To examine whether or not mothers increase deposition of such components in eggs as a function of food availability, we food-supplemented black-legged kittiwake females (Rissa tridactyla) before and during egg laying and compared deposition of androgens and antibodies into eggs of first and experimentally induced replacement clutches. Food-supplemented females transferred lower amounts of androgens and antibodies into eggs of induced replacement clutches than did non-food-supplemented mothers, whereas first clutches presented no differences between treatments. Our results suggest that when females are in lower condition, they transfer more androgens and antibodies into eggs to facilitate chick development despite potential long-term costs for juveniles. Females in prime condition may avoid these potential long-term costs because they can provide their chicks with more and higher quality resources.