Sexual Maturation of Female Japanese Macaques Under Poor Nutritional Conditions and Food-Enhanced Perineal Swelling in the Koshima Troop

Provisioned food was severely restricted for 5 years, from 1972 until June 1977, in the insular Koshima troop of Japanese macaques. The monkeys experienced very poor nutritional conditions during this period. The feeding policy was changed in 1977 and food conditions improved, but only in summer. A remarkable consequence of intensive provisioning in summer was the occurrence of perineal swelling in many young females outside of the mating season. Females that matured during the period of poor food conditions showed an extraordinary delay in primiparity and exhibited conspicuous perineal swelling in the summer of 1977. Researchers studied the development of perineal swelling under standard conditions of constant provisioning from 1990 to 1995. First perineal swelling appeared at 5 years of age under standard conditions but appeared at 8 years of age under poor food conditions. The extraordinary delay in primiparity did not occur among females that were 6 years old when food conditions were improved in summer. We deduced that female Japanese macaques have a critical age of 5 to 6 years for sexual maturation. If the critical age is exceeded under poor food conditions, sexual maturation is hard to achieve even with improvements in food conditions. Seasonal changes in the incidence of perineal swelling were related to the period of high body weight. Rapid improvements in food conditions probably caused perineal swelling and activated sex hormones in female Koshima Japanese macaques.     

Rank and age related feeding strategy observed through field experiments in the Koshima group of Japanese macaques

The feeding process of Japanese monkeys on soy beans which were scattered over a sandy beach on Koshima islet was studied. Younger monkeys were able to pick up more beans when 8 kg of beans were divided and given two times (“two times feeding”) than when the whole amount (8 kg) of beans was given at one time (“one time feeding”). The effect of saturation of the food intake capacity in younger monkeys at the first feeding in “two times feeding” did not appear at the second feeding one hour later. The minutely intake of soy beans (feeding speed) for each age class was analyzed. The decline of feeding speed in adult females after the peak in “one time feeding” was not related to the decline in density of beans on the ground, and this decline was caused by saturation of their food intake capacity. Adult females were divided into four classes according to their dominance rank order: high, lower-high, higher-low, and low classes. The total amount of intake in “one time feeding” was far larger in the high class than in any of the other classes. The total amount of feeding in the first feeding of “two times feeding” increased in accordance with rise in the dominance rank class, and there was no relation to rank and total feeding amount in the second feeding of “two times feeding.” Differences existed in the process of feeding between the rank classes. The feeding speed of the low class was as high as that of the high class on the curve of minutely intake, while the low class stopped feeding much earlier than the high class. The lower-high class displayed a low feeding speed, and stopped feeding the latest. The order of the duration to stay and to feed in the feeding area was lower-high > high > higher-low > low, and this order did not change under the three different feeding conditions, “one time feeding,” and the first and second feedings of “two times feeding.” Adolescent females tended to stay the longest duration in the feeding area among all age classes. Both the lower-high class females and adolescent females had an unstable social status in the Koshima group, and their social status affected their feeding behaviors. The feeding behaviors were similar in attitude depending on social status, and are considered to be maintained for a fairly long time. The feeding strategy of the lower-high class, in staying a longer duration in the artificial feeding area, and departing later, may be effective under the artificial feeding conditions, but it may be a bad strategy in a natural habitat where the food is not so clumped as in artificial feeding, and where choice of other food patches is possible. The above results agree well with previous reports for the Koshima group, indicating that the rank of the lower-high class females was unstable (Mori et al., 1989), and that their reproductive success was low (Watanabe et al., 1992).     

Intra-troop spacing mechanism of the wild Japanese monkeys of the Koshima troop

The average frequencies of communicative behavior, social behavior, and social encounters (inter-individual proximity within three meters) per hour for a monkey were obtained in their natural habitat by tracing several adult males and females of a Japanese monkey troop living in the Koshima islet. The spatial distribution patterns and the density of troop members within the expanse of the troop at any moment were investigated by tracing several adult femals. Frequency distributions of the monkeys found within five and 10 meters were compared with a Poisson distribution. The frequencies of social encounters and of social interactions of Japanese monkeys were distinctly low, except between mothers and their offspring. The density of monkeys within the expanse of the troop at any moment was very low. Both aggressive behavior and inter-individual proximity (within three meters) were distinctly low when monkeys were foraging for natural food. An avoiding mechanism among troop members plays an important role in maintaining the social structure of these Japanese monkeys. This mechanism works in two ways: each individual does not approach others too closely; the density of monkeys within the expanse of the troop is low at all times.     

Retardation of bone development in the Koshima troop of Japanese macaques

Retardation of bone development was observed in the Koshima troop of free ranging Japanese macaques. In the control group, epiphyseal unions of appendicular long bones generally started to close at about 4 yrs of age and were completed at about 8 or 9 yrs of age. Limb bone unions of the Koshima troop, however, started to close at about 9 yrs of age and completely closed at about 15 yrs of age. In the epiphyseal unions of trunk and girdle bones, the Koshima troop again showed a retardation of closure compared with the control group. Until long bones reached their full length, that is, until about 15 yrs of age, their size was small in the Koshima troop compared with the control group, though the sample size of the Koshima troop was small. After 15 yrs of age, however, many osteometrical measurements of the Koshima troop were nearly the same as controls. A prolonged growing duration compensated for the slow growth and allowed them to become as large as controls. This prolongation may be an adaptation in response to small size during the developmental period. In some parts of the body, however, Koshima macaques failed to reach the adult size of controls. Males were less likely than females to reach full size. Causes of the retardation and small size in the Koshima troop are discussed, but they remain open to further studies.     

An electrostatic mechanism closely reproducing observed behavior in the bacterial flagellar motor

A mechanism coupling the transmembrane flow of protons to the rotation of the bacterial flagellum is studied. The coupling is accomplished by means of an array of tilted rows of positive and negative charges around the circumference of the rotor, which interacts with a linear array of proton binding sites in channels. We present a rigorous treatment of the electrostatic interactions using minimal assumptions. Interactions with the transition states are included, as well as proton-proton interactions in and between channels. In assigning values to the parameters of the model, experimentally determined structural characteristics of the motor have been used. According to the model, switching and pausing occur as a consequence of modest conformational changes in the rotor. In contrast to similar approaches developed earlier, this model closely reproduces a large number of experimental findings from different laboratories, including the nonlinear behavior of the torque-frequency relation in Escherichia coli, the stoichiometry of the system in Streptococcus, and the pH-dependence of swimming speed in Bacillus subtilis.     

Catching function in action

A major interest of Jörg is the establishment and sensible use of high-throughput analysis processes — with some emphasis on array-based assays — for the understanding and evaluation of the complex molecular interactions in living organisms.     

Quasispecies-like behavior observed in catalytic RNA populations evolving in a test tube

Background  

During the RNA World, molecular populations were probably very small and highly susceptible to the force of strong random drift. In conjunction with Muller's Ratchet, this would have imposed difficulties for the preservation of the genetic information and the survival of the populations. Mechanisms that allowed these nascent populations to overcome this problem must have been advantageous.     

冲击生物技术第三次浪潮

工业生物催化是继医药、农业之后的生物技术第三次浪潮。从21世纪化学工业发展的前沿特点,介绍生物催化加工过程及生产方式,主要解决传统产业改造和新的应用领域的开拓,提出发展生物催化产业的策略和加强支持力度的建设。     

A study of reliability and its hierarchical structure in observed chimpanzee behavior

The overall excellence of the reliability of a system of behavioral observations based onGoodall's glossary of chimpanzee behavior is demonstrated, as well as the reliability of the majority of individual behaviors in the system. Non-random misclassifications are systematically analyzed to yield information on the structure of observed behavior. These findings are applied (1) to improving the system further, and (2) to assessing factors which apparently obscure distinctions between observable patterns of behavior for use in future development of observational systems.     

Catching bird flu in a droplet

It is assumed that a timely mass administration of antiviral drugs, backed by quarantines and social distancing, could contain a nascent influenza epidemic at its source, provided that the first clusters of cases were localized within a short time. However, effective routine surveillance may be impossible in countries lacking basic public health resources. For a global containment strategy to be successful, low-cost, easy-to-use handheld units that permit decentralized testing would be vital. Here we present a microfluidic platform that can detect the highly pathogenic avian influenza virus H5N1 in a throat swab sample by using magnetic forces to manipulate a free droplet containing superparamagnetic particles. In a sequential process, the viral RNA is isolated, purified, preconcentrated by 50,000% and subjected to ultrafast real-time RT-PCR. Compared to commercially available tests, the bioassay is equally sensitive and is 440% faster and 2,000-5,000% cheaper.