'Friendship' for fitness in chimpanzees?

It has been repeatedly suggested that primates trade social services for fitness benefits in their relationships with the opposite sex. We tested this proposal in a colony of captive chimpanzees, Pan troglodytes, by examining behavioural data on grooming, agonistic support and food sharing in relation to genetically established paternity. We found no support for the notion of trade. First, males did not sire more offspring with females that they actively groomed more frequently, that they supported more often or with which they shared food more frequently. Correspondingly, females did not give birth to more offspring sired by males from which they received more services. Second, males that showed more affiliative behaviour towards females in general did not sire more progeny. Furthermore, females did not bear more offspring sired by males to which they themselves directed more sociopositive behaviour. Results from this captive colony are compatible with those reported for chimpanzees under natural conditions. Copyright 1999 The Association for the Study of Animal Behaviour.     

Ethylene Production by Root Nodules and Effect of Ethylene on Nodulation in Glycine max

Nodulated soybean roots produced more ethylene and contained more 1-aminocyclopropane-1-carboxylic acid than uninoculated roots. Nodules produced more ethylene and contained more 1-aminocyclopropane-1-carboxylic acid per gram of material than roots. Almost all of the ethylene produced by the nodules was produced by the plant fractions of the nodules. Ethylene, at physiological concentrations, did not inhibit nodulation in soybeans.     

Contributions to infant care in captive cotton-top tamarins (Saguinus oedipus): The influence of age,sex, and reproductive status

Marmosets and tamarins are characterized by a reproductive strategy that includes twinning, and a communal rearing system in which infant care is shared among all group members, both breeders and nonbreeding helpers (often older offspring). In order to test some predictions about the extent to which different age-sex classes should invest in infants, contributions to infant carrying and food-sharing by all family members were measured in captive groups of cotton-top tamarins (Saquinus oedipus) ranging in size from 2 to 12 independent individuals. Fourteen litters were observed from birth to 12 weeks. Carrying by mothers decreased steadily over the study period, while carrying by fathers and other offspring increased for 3–5 weeks, then declined. Infants spent more time carried by siblings than by either parent, but parents did more carrying than individual siblings and, also, shared more food with infants. Older siblings contributed more care than younger siblings did. Adult sons carried infants more than adult daughters did, but immature daughters carried more than immature sons did. However, adult daughters actively offered food to infants more than any other class of helper did. These results were interpreted in the light of hypotheses concerning the reproductive and dispersal strategies of callitrichid species.     

Response of larch species to climate changes

Global warming has changed the distributions of forests of northeastern China. Larix are very important species in this area. Predicting the potential distributions of Larix species and their responses to climate change would attract more and more attention.This paper predicted the potential distributions of three Larix species based on 'climatic-topographic' relationships by logistic regression. The results showed that L. gmelinii is predicted to retreat northwestward by 220 km by 2050 and by 270 km more by 2100; L. olgensis var. changpaiensis is predicted to retreat northwestward by 200 km by 2050 and by 190 to 300 km more by 2100; L. principis-rupprechtii is predicted to retreat northeastward by 200 km by 2050 and by 250 to 400 km more by 2100. This indicated that L. gmelinii could have its optimum latitude moved into Russia, L. olgensis var. changpaiensis could move to the Small Xing'an Mountains and L. principis-rupprechtii would move to the middle part of the Great Xing'an Mountains.     

L’évaluation de l’industrie bifaciale chinoise d’un point de vue global

If Acheulean industry exists in China is a controversial issue for a long time. After the 1980, accompanying more surveys and excavations engaged in the Paleolithic Archaeology and more and more communication with western academic circles, Chinese researchers participate in the discussion and inquiry on Acheulean actively. This paper attempts to study the bifacial industry in China in global perspective by the theory of relativity between universality and particularity. We try to gather more sites, which are similar to those in China, and review the Acheulean assemblages in China by intersite comparisons.     

Excessive use of psychiatric services by suicidal patients.

The use of psychiatric services by patients with a suicidal history was examined to see if they placed a greater long-term burden on these services than other types of patient. Suicidal patients spent significantly more days in hospital and made more outpatient attendances; suicide attemptors in particular not only needed more emergency consultations but also spent more days in hospital. A more economical yet more effective treatment policy for the suicidal patient is needed.     

Size-dependent reproduction in Australian alpine Ranunculus

Abstract The effect of plant size on reproduction in four species of alpine Ranunculus (R. muelleri, R. dissectifolius, R. graniticola and R. niphophilus) was investigated in two sites over two seasons in the field on a total of 190 plants. The effects of plant size (number of leaves) and number of flowers on the number of anthers, ovules and seed per flower and per plant were determined. There was a positive relationship between several measures of reproduction and plant size in all four species, indicating that reproduction is size-dependent. All the results indicate that the main factor controlling the amount of seed produced by alpine Ranunculus is the size of the plant. Specifically, bigger plants produced more seed by producing more flowers, not by producing more ovules per flower, or higher seed set per flower. Correspondingly, bigger plants produced more anthers by producing more flowers, rather than by producing flowers with more anthers. The total number of seeds produced by a plant was directly proportional to plant size in the four species. Therefore, reproductive effort should not vary with plant size in the four species.     

Colonization and extinction of ant communities in a fragmented landscape

Abstract In this paper we tested the assumption that smaller and more isolated remnants receive fewer ant colonizers and lose more species. We also tested hypotheses to explain such a pattern. We sampled ants in Brazil for 3 years in 18 forest remnants and in 10 grasslands between them. We tested the influence of remnant area and isolation on colonization rate, as well as the effect of remnant area on extinction rate. We tested the correlation between remnant area and isolation to verify the landscape design. Colonization rate was not affected by remnant area or isolation. Extinction rate, however, was smaller in larger remnants. Remnant area and isolation were negatively correlated. We tested two hypotheses related to the decrease in ant species extinction rate with increased remnant area: (i) small remnants support smaller and more extinction‐prone populations; and (ii) small remnants are more often invaded by generalist species, which suffer higher extinction inside remnants. The density of ant populations significantly increased with area. Generalist species presented a lower colonization rate in larger remnants, contrary to the pattern observed in forest species. Generalist species suffered more extinction than expected inside remnants. The lack of response of colonization rate to remnant area can be explained by the differential colonization by generalist and forest species. The decrease of ant population density in smaller remnants could be related to loss of habitat quality or quantity. The higher colonization by generalist ant species in the smaller remnants could be related to landscape design, because smaller remnants are more similar to the matrix than larger ones. Our results have important implications for conservation strategies because small remnants seem to be more affected by secondary effects of fragmentation, losing more forest species and being invaded more often by generalist species. Studies that compare only species richness between remnants cannot detect such patterns in species composition.     

A new hypothesis on cell provisioning in solitary wasps

Like many other eumenid wasps, Pachodynerus nasidens (Latr.) generally stores more provisions in female–producing cells than in male–producing cells. According to the proposed hypothesis the provisioning of more or less food is determined by the variation in the time available for storing; this in turn, is caused by the slower or more rapid development respectively of female or male eggs.     

Raising grateful children one day at a time

ABSTRACT

We examined micro developmental processes related to the socialization of children's gratitude by testing whether parents who engage in more frequent daily socialization practices targeting children's gratitude reported more frequent gratitude displays by their children after controlling for potential confounds. 101 parent-child dyads completed a baseline lab visit followed by a seven-day diary study. Using multi-level modeling, we found that parents who engaged in more frequent gratitude socialization acts reported more frequent displays of gratitude by their children across the seven-days (between-dyad effect) and that on days when a parent engaged in more socialization acts than usual parents reported relative increases in gratitude displays by their children (within-dyad effect). These findings show that parent socialization acts are associated with children’s displayed gratitude and point to the need for future work to explore reactive and proactive parent-child interactions that may underlie these associations as well as associations between micro-developmental and macro-developmental processes.     

Sex-differential herbivory in androdioecious Mercurialis annua

Males of plants with separate sexes are often more prone to attack by herbivores than females. A common explanation for this pattern is that individuals with a greater male function suffer more from herbivory because they grow more quickly, drawing more heavily on resources for growth that might otherwise be allocated to defence. Here, we test this 'faster-sex' hypothesis in a species in which males in fact grow more slowly than hermaphrodites, the wind-pollinated annual herb Mercurialis annua. We expected greater herbivory in the faster-growing hermaphrodites. In contrast, we found that males, the slower sex, were significantly more heavily eaten by snails than hermaphrodites. Our results thus reject the faster-sex hypothesis and point to the importance of a trade-off between defence and reproduction rather than growth.     

Duet function in the yellow-naped amazon, Amazona auropalliata: evidence from playbacks of duets and solos

The question of why animals participate in duets is an intriguing one, as many such displays appear to be more costly to produce than individual signals. Mated pairs of yellow-naped amazons, Amazona auropalliata, give duets on their nesting territories. We investigated the function of those duets with a playback experiment. We tested two hypotheses for the function of those duets: the joint territory defense hypothesis and the mate-guarding hypothesis, by presenting territorial pairs with three types of playback treatments: duets, male solos, and female solos. The joint territory defense hypothesis suggests that individuals engage in duets because they appear more threatening than solos and are thus more effective for the establishment, maintenance and/or defense of territories. It predicts that pairs will be coordinated in their response (pair members approach speakers and vocalize together) and will either respond more strongly (more calls and/or more movement) to duet treatments than to solo treatments, or respond equally to all treatments. Alternatively, the mate-guarding hypothesis suggests that individuals participate in duets because they allow them to acoustically guard their mate, and predicts uncoordinated responses by pairs, with weak responses to duet treatments and stronger responses by individuals to solos produced by the same sex. Yellow-naped amazon pairs responded to all treatments in an equivalently aggressive and coordinated manner by rapidly approaching speakers and vocalizing more. These responses generally support the joint territory defense hypothesis and further suggest that all intruders are viewed as a threat by resident pairs.     

Flock feeding and time budgets in the house sparrow (Passer domesticus L.)

A winter population of house sparrows at a farm fed on barley seed in two distinct types of habitat: cattlesheds and open fields. The risk of predation was apparently higher in the fields where birds scanned more frequently than in the cattlesheds and where scanning was negatively influenced by flock size but positively influenced by distance from cover. Individual time budgets were more influenced by flock size than by seed density in the fields but more influenced by seed density than by flock size in the cattlesheds. Higher rates of scanning resulted in greater flock vigilance and longer flight distances in the fields but flight distance was negatively influenced by the density of seeds on which birds were feeding.     

Dominance and dispersal between feeding sites in the herring gull (Larus argentatus)

The feeding behaviour and movements of individually marked herring gulls at refuse tips were observed during the winters of 1973–1976. Refuse tips were used more by adult than by immature gulls. Adult female and immature gulls were more transient than adult males, changed their feeding sites more often, and used the secondary rather than the main feeding area of a tip more than the adult males. Individuals feeding in the main area fed at a higher rate and were involved in more aggressive encounters than those in the secondary area. Competition between adults and immatures, and a tendency for adult males to be the most dominant, brings about the dispersal between feeding sites of the adult females and the immatures.     

Polygyny and nest site selection in the pied flycatcher

Nest site choice, and its influence on mating and breeding success were studied in a population of individually marked pied flycatchers (Ficedula hypoleuca) for 7 years. Some nest boxes were used more frequently than expected from random choice of nest site. Flycatchers bred more successfully in such attractive boxes, irrespective of whether the brood was attended by the male or not. Arriving males and females settled at boxes in descending order of attractiveness. Boxes accepted by females were more attractive than alternative boxes advertised simultaneously by males. Secondary nest boxes of polygynous males tended to be more attractive than boxes at which monogamous males displayed, without success, for secondary mates. Returning males with local breeding experience started to sing at nest boxes earlier in spring than first season males, settled at more attractive boxes, and mated polygynously more often. The results indicate that male mating success should be closely dependent on the male's ability to monopolize attractive nest sites.     

RISA、DGGE和2D-PAGE技术对大豆根际土壤细菌多样性分析的比较

采用基于PCR扩增的核糖体间隔区分析(RISA)、变性梯度凝胶电泳(DGGE)和双向电泳(2D-PAGE)3种分子生态学技术对大豆根际土壤细菌多样性比对分析.结果表明:2D-PAGE技术得到的土壤细菌多样性(基因点)最丰富,其次为DGGE技术(基因片段),RISA技术(基因片段)最低.RISA技术得到的条带数最少,但结...     

Do man‐made structures and water depth affect the diel rhythms in click recordings of harbor porpoises (Phocoena phocoena)?

The construction of industrial offshore structures may lead to colonization by a variety of marine organisms resulting in locally enhanced biodiversity and biomass, which may then affect the habitat use and behavior of marine predators. For harbor porpoises high nocturnal echolocation activity was demonstrated near industrial structures and it was hypothesized that this was caused by increased feeding opportunities at night. Here we tested the hypothesis that bridge pillars will lead to more nocturnal echolocation activity by porpoises near them than at positions further away. The daily rhythms in porpoise detections near bridge pillars tended to be slightly more pronounced and a greater proportion of clicks occurred during the night. However, water depth had a greater impact on these rhythms, with more nocturnal porpoise echolocation activity and more pronounced daily rhythms in deeper waters. This may be related to different feeding techniques and prey choice by porpoises in deep and shallow water. In deeper water porpoises may be feeding pelagically on herring and cod, which show more activity and are easier to catch at night. In shallow water they may be targeting mainly gobies using a bottom feeding technique and this may not be more efficient at night.     

Interaction between dry starch and plasticisers glycerol or ethylene glycol, measured by differential scanning calorimetry and solid state NMR spectroscopy

The interaction of crystalline amylose and of crystalline and amorphous amylopectin with the plasticisers glycerol or ethylene glycol in the absence of water was studied, by using differential scanning calorimetry (DSC) and solid state nuclear magnetic resonance (NMR) spectroscopy. Upon heating starch freshly mixed with plasticisers, a strong exothermal interaction enthalpy of ΔH−35 J/g was detected by DSC. At room temperature glycerol interacts mainly with the amorphous starch regions, the interaction taking 8 days to reach equilibrium. For ethylene glycol the interaction is faster, taking four days to reach equilibrium, and the rate is not affected by crystallinity. Ethylene glycol interacts in a more ordered manner with amorphous than with crystalline material, resulting in a narrower ethylene glycol cross-polarisation magic angle spinning (CP/MAS) signal when equilibrium is reached at room temperature. Upon heating, more glycerol or ethylene glycol is immobilised, but in a less ordered manner than upon storage at room temperature. This results in a more intense, but broader plasticiser CP/MAS signal upon heating. Interaction in a more ordered manner probably implies interaction with more of the hydroxy groups of the plasticiser. The polysaccharide mobility is increased more when the plasticiser interacts in a more ordered manner, as observed by small starch signals in HP/DEC spectra.     

THE FOOD OF RED GROUSE CHICKS LAGOPUS L. SCOTICUS

The diet of young Red Grouse was studied from the crop contents of 211 chicks caught on a moor in northeast Scotland. The food was more varied than that of adults, but shoot tips of heather usually formed at least 75% (by dry weight) of their diet, as in adults. Arthropods, particularly Diptera, were taken frequently by chicks up to three weeks old, but they formed less than 5% (by dry weight) of the diet then. The chicks ate more invertebrates when more were available. There was no evidence that chick survival was related to the abundance of invertebrates. The chicks ate heather containing more nitrogen and phosphorus than that eaten by adults at the same time of year.     

Role of viral isolate in the etiopathogenetic determinism of HCV infection: diagnostic and epidemiological evaluation.

HCV genotyping by nucleic acid sequencing emphasizes the difficulties involved in carrying out a more precise determination of the infectant viral population, probably due in part to the finding of still unknown isolates. Signs of heterogeneity in the genotype composition of the viral quasi-species and its evolutionary dynamism over time, together with the role played by some, more potentially aggressive, isolates in causing hepatic damage, encourage a more in-depth study of such topics.