Mate compatibility,parental allocation and fitness consequences of mate choice in the sand goby <Emphasis Type="Italic">Pomatoschistus minutus</Emphasis>

Recent theory and empirical work suggests that there may be variation among females in mate preferences that is adaptive. One of the possible mechanisms maintaining variability in preferences and preferred traits is that the benefits of mate choice may depend on compatibility with potential mating partners. We examined fitness consequences of mate choice in a species of fish, the sand goby, Pomatoschistus minutus with a special focus on mate compatibility. Females were given the opportunity to establish their mate preferences in a dichotomous mate choice experiment. This information was then applied by mating the focal or control female with either the preferred or the non-preferred male. The parental performance of the males of these four mating combinations was then measured. In a separate experiment, we assessed the female differential allocation by determining the residual gonad weight of spawned females as a measure of the proportion of eggs spawned. We also estimated the amount of filial cannibalism separately for both sexes. Our results show that preferred males provided benefits in the form of an increased number of hatching eggs. This benefit was the same when the male was mated with a focal or a control female. Hence, we found no support for benefits that depend on mate compatibility. Neither did we find support for the hypothesis that females would lay a different number of eggs depending on the male status. The results also indicate that male filial cannibalism has a strong role in determining hatching success in this species.     

Extra-pair paternity in alpine marmots, <Emphasis Type="Italic">Marmota marmota</Emphasis>: genetic quality and genetic diversity effects

Assuming that a male’s genetic characteristics affect those of his offspring, extra-pair copulation has been hypothesized to increase heterozygosity of the progeny—the “genetic compatibility” hypothesis—and the genetic diversity within litters—the “genetic diversity” hypothesis. We tested these two hypotheses in the alpine marmot (Marmota marmota), a socially monogamous mammal showing a high rate of extra-pair paternity (EPP). In a first step, we tested the assumption that a male’s genetic characteristics (heterozygosity and genetic similarity to the female) affect those of his offspring. Genetic similarity between parents influenced offspring heterozygosity, offspring genetic similarity to their mother, and litter genetic diversity. The father’s heterozygosity also influenced litter genetic diversity but did not affect offspring heterozygosity. Hence, heterozygosity seems not to be heritable in the alpine marmot. In a second step, we compared genetic characteristics of extra-pair young (EPY) and within-pair young (WPY). EPY were less genetically similar to their mother but not more heterozygous than WPY. EPY siblings were also less genetically similar than their WPY half siblings. Finally, the presence of EPY promoted genetic diversity within the litter. Thus, our data support both the “genetic compatibility” and the “genetic diversity” hypotheses. We discuss further investigations needed to determine the primary causes of EPP in this species.     

Brood sex ratio and male UV ornamentation in blue tits (<Emphasis Type="Italic">Cyanistes caeruleus</Emphasis>): correlational evidence and an experimental test

Sex-allocation theory predicts that females paired to attractive males should bias the brood sex ratio towards male offspring, as these would inherit the attractiveness of their father. We studied sex allocation based on male ornamentation in blue tits. Brood sex ratios varied with male UV coloration in an age-dependent manner. For juvenile males, the proportion of sons increased with increasing UV ornamentation, which is in agreement with previous findings from a Swedish population. However, the relationship between UV ornamentation and brood sex ratio was reversed for adult males, with females paired to less UV-ornamented adult males producing more sons. This pattern fits with the observation that, in our population, less UV-ornamented adult males sire the majority of extra-pair young. To test the causality of the association between brood sex ratio and male coloration, we experimentally manipulated crown colour largely within the natural range. We created two groups of males: one with higher and one with lower UV reflectance, UV(+) and UV(−), respectively. Contrary to our expectations, there was no significant treatment effect. However, in UV(−), but not UV(+) males, the proportion of sons was negatively correlated with male coloration before manipulation. This suggests that the UV(−) treatment caused males that were more UV ornamented to decline more in attractiveness, as shown in a similar experiment in Sweden. However, given that correlational patterns differ between these populations, similarities in experimental results should not be taken as evidence for consistent patterns of adaptive sex allocation in this species.     

A genetic component to size in queens of the ant,<Emphasis Type="Italic"> Formica truncorum</Emphasis>

The genetic basis of morphological traits in social insects remains largely unexplored. This is even true for individual body size, a key life-history trait. In the social insects, the size of reproductive individuals affects dispersal decisions, so that small size in queens is often associated with reduced dispersal, and large size with long-range dispersal and independent colony founding. Worker size is connected to division of labour when workers specialize in certain tasks according to their size. In many species, variation in worker size has been shown to increase colony performance. In this study, we present the first evidence of an additive genetic component to queen size in ants, using maternal half sib analysis. We also compared intra-colony size variation in colonies with high (queen doubly mated) versus low (queen singly mated) genetic variability. We found a high and significant heritability (h²=0.51) for queen size in one of the two study years, but not in the other. Size variation among queens was greater in colonies headed by a doubly mated queen in one of the study years, but not in the other. This indicates that genetic factors can influence queen size, but that environmental factors may override these under some circumstances. The heritability for worker size was low (h²=0.09) and non-significant. Increased genetic diversity did not increase worker size variation in the colonies. Worker size appeared largely environmentally determined, potentially allowing colonies to adjust worker size ratios to current conditions.Communicated by J. Heinze     

First trimester chorionic villus sampling versus mid-trimester genetic amniocentesis-preliminary results of a controlled prospective trial

This controlled prospective study assesses the relative risks of first trimester chorionic villus sampling (CVS) versus mid-trimester gentic amniocentesis (GA). CVS subjects and amnio-centesis controls were comparable with regard to several confounding variables which might influence the risk of pregnancy loss including maternal age, smoking, alcohol consumption, gestational age at study entry, and history of vaginal bleeding or poor prior reproductive outcome. The most common indication for prenatal diagnosis was advanced maternal age (n = 511). In this subgroup, spontaneous abortion (<24 weeks) occurred in 2·9 per cent of CVS subjects versus 4−3 per cent of amniocentesis controls. The sum of spontaneous and therapeutic abortions (<24 weeks) was identical (5·3 per cent) in both groups. Therefore, intervention in the CVS group (i.e., therapeutic abortion for cytogenetic abnormalities) did not influence the observed risk of pregnancy loss. Overall perinatal mortality rates were also similar in both groups. No significant differences were identified for a number of pregnancy outcome parameters including 5 min Apgar score, birth weight, body length, head circumference, gestational age at delivery, preterm delivery, fetal growth retardation, congenital malformations, and neonatal complications. Preliminary results of this controlled prospective study suggest that chorionic villus sampling carries a low and acceptable risk.     

大气边界层中起尘、降尘过程的模拟实验的相似性原则

风洞模拟实验是研究起、降尘过程最有效的手段。前人只研究了低湍流度气流中,平坦表面的实际起尘过程。作者提出一组扩展的相似性原则,用于模拟大气边界层湍流及复杂地形对趋、降尘过程的影响及防尘风障在此条件下的减尘效率,并得到一系列有意义的结果。      

Effects of Recent Volcanic Eruptions on Aquatic Habitat in the Drift River, Alaska, USA: Implications at Other Cook Inlet Region Volcanoes

/ Numerous drainages supporting productive salmon habitat are surrounded by active volcanoes on the west side of Cook Inlet in south-central Alaska. Eruptions have caused massive quantities of flowing water and sediment to enter the river channels emanating from glaciers and snowfields on these volcanoes. Extensive damage to riparian and aquatic habitat has commonly resulted, and benthic macroinvertebrate and salmonid communities can be affected. Because of the economic importance of Alaska's fisheries, detrimental effects on salmonid habitat can have significant economic implications. The Drift River drains glaciers on the northern and eastern flanks of Redoubt Volcano. During and following eruptions in 1989-1990, severe physical disturbances to the habitat features of the river adversely affected the fishery. Frequent eruptions at other Cook Inlet region volcanoes exemplify the potential effects of volcanic activity on Alaska's important commercial, sport, and subsistence fisheries. Few studies have documented the recovery of aquatic habitat following volcanic eruptions. The eruptions of Redoubt Volcano in 1989-1990 offered an opportunity to examine the recovery of the macroinvertebrate community. Macroinvertebrate community composition and structure in the Drift River were similar in both undisturbed and recently disturbed sites. Additionally, macroinvertebrate samples from sites in nearby undisturbed streams were highly similar to those from some Drift River sites. This similarity and the agreement between the Drift River macroinvertebrate community composition and that predicted by a qualitative model of typical macroinvertebrate communities in glacier-fed rivers indicate that the Drift River macroinvertebrate community is recovering five years after the disturbances associated with the most recent eruptions of Redoubt Volcano. KEY WORDS: Aquatic habitat; Volcanoes; Lahars; Lahar-runout flows; Macroinvertebrates; Community structure; Community composition; Taxonomic similarity     

Testis size variation in the greenfinch Carduelis chloris : relevance for some recent models of sexual selection

Interspecific evidence that testis size responds to selection caused by sperm competition has been obtained from many taxa. However, little is known about the sources of intraspecific variation in testis size, although such variation may have functional significance. Variation in testis size and asymmetry was studied within and between eight geographically separated (and genetically differentiated) populations of greenfinches Carduelis chloris. The relationships between testis size and plumage brightness (degree of yellowness) and the prevalence of haematozoan infections were also investigated in three of these populations, as they related to the predictions of the immunocompetence handicap hypothesis, and Møller's hypothesis relating directional testis asymmetry to phenotypic quality. There were large differences between populations in testis size, with males from northern populations having larger testes than those from southern populations. Within populations, large testes were associated with larger body size and greater age. When the influence of these factors was removed statistically, males with large testes were more likely to be infected with haematozoan parasites, and had brighter yellow plumage. No evidence was found that directional asymmetry in testis size was related to either of these measures of phenotypic quality. These results are consistent with the hypothesis that males with large testes, while signalling higher phenotypic quality as revealed by increased plumage brightness, also pay a cost in terms of reduced immunocompetence, revealed by the increased probability of infection in these males. That these patterns were similar in three different populations adds further strength to these conclusions. Our results suggest that studying the sources of variation in testis size among individuals can reveal interesting processes in sexual selection.     

不同电子受体除磷污泥相似性与菌群结构研究

分别以硝酸盐、亚硝酸盐、氧气为电子受体,采用3组SBR反应器培养除磷污泥,连续126d的稳定运行表明:以硝酸盐、亚硝酸盐、氧气为电子受体除磷污泥对TP平均去除率分别为84.8%, 78.7%, 87.4%,出水TP平均浓度分别为0.758, 0.931, 0.632mg/L.采用高通量测序技术对不同电子受体除磷污泥的相似性与菌群结构进行了研究,结果表明,以硝酸盐,亚硝酸盐为电子受体的反硝化除磷污泥具有近似的菌群结构,与好氧除磷污泥菌群结构差异较大.基于各样品主导OTUs序列的系统发育关系及其比例的分布,主导微生物主要可以分为5个簇.通过序列比对,在97%的序列相似度条件下,种泥中聚磷菌与聚糖菌序列比例为0.716%与0.368%,以硝酸盐、亚硝酸盐、氧气为电子受体除磷污泥中聚磷菌与聚糖菌序列比例分别为1.78%, 2.53%, 4.80%与1.44%, 1.32%, 30.9%,厌氧-缺氧条件有利于抑制聚糖菌.亚硝酸盐为反硝化除磷污泥电子受体时潜在公共卫生安全隐患.     

Simulation-based fault propagation analysis—Application on hydrogen production plant

Recently production of hydrogen from water through the Cu–Cl thermochemical cycle is developed as a new technology. The main advantages of this technology over existing ones are higher efficiency, lower costs, lower environmental impact and reduced greenhouse gas emissions. Considering these advantages, the usage of this technology in new industries such as nuclear and oil is increasingly developed. Due to hazards involved in hydrogen production, design and implementation of hydrogen plants require provisions for safety, reliability and risk assessment. However, very little research is done from safety point of view. This paper introduces fault semantic network (FSN) as a novel method for fault diagnosis and fault propagation analysis by using evolutionary techniques like genetic programming (GP) and neural networks (NN), to uncover process variables’ interactions. The effectiveness, feasibility and robustness of the proposed method are demonstrated on simulated data obtained from the simulation of hydrogen production process in Aspen HYSYS^®. The proposed method has successfully achieved reasonable detection and prediction of non-linear interaction patterns among process variables.