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We examined the impact of winner and loser effects on dominance hierarchy formation when individuals are capable of estimating their opponent's resource holding power (RHP). The accuracy of such estimates was a variable in our simulations, and we considered cases in which all individuals err within the same bounds, as well as cases in which some individuals consistently overestimate, while others consistently underestimate their opponent's fighting RHP. In all cases, we found a clearly defined linear hierarchy. In most simulations, the vast majority of interactions were 'attack-retreats', and the remainder of interactions were almost all 'fights'. Error rates had no effect on the linearity of the hierarchy or the basic attack-retreat nature of interactions, and consistent over and underestimation did not affect the ultimate position of an individual in a hierarchy.  相似文献   

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Mono- and sesqui-terpenes of individual oil glands of Citrus latipes fruits were analyzed for their homogeneity. The effect of oleocellosis, desiccation, Penicillium and Phytophthora infection upon the individual terpene components was investigated and expressed in a discriminant analysis and in canonical variables. Each oil gland contained the entire spectrum of terpenes specific for each species, and the biggest difference in affected glands was due to Penicillium infection.  相似文献   

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Keast RS  Roper J 《Chemical senses》2007,32(3):245-253
Detection thresholds and psychophysical curves were established for caffeine, quinine-HCl (QHCl), and propylthiouracil (PROP) in a sample of 33 subjects (28 female mean age 24 +/- 4). The mean detection threshold (+/-standard error) for caffeine, QHCl, and PROP was 1.2 +/- 0.12, 0.0083 +/- 0.001, and 0.088 +/- 0.07 mM, respectively. Pearson product-moment analysis revealed no significant correlations between detection thresholds of the compounds. Psychophysical curves were constructed for each bitter compound over 6 concentrations. There were significant correlations between incremental points of the individual psychophysical curves for QHCl and PROP. Regarding caffeine, there was a specific concentration (6 mM) below and above which the incremental steps in bitterness were correlated. Between compounds, analysis of psychophysical curves revealed no correlations with PROP, but there were significant correlations between the bitterness of caffeine and QHCl at higher concentrations on the psychophysical curve (P<0.05). Correlation analysis of detection threshold and suprathreshold intensity within a compound revealed a significant correlation between PROP threshold and suprathreshold intensity (r=0.46-0.4, P<0.05), a significant negative correlation for QHCl (r=-0.33 to -0.4, P<0.05), and no correlation for caffeine. The results suggest a complex relationship between chemical concentration, detection threshold, and suprathreshold intensity.  相似文献   

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Bioinformatics is a new field of study whose ethical implications involve a combination of bioethics, computer ethics and information ethics. This paper is an attempt to view some of these implications from the perspective of Buddhism. Privacy is a central concern in both computer/information ethics and bioethics, and with information technology being increasingly utilized to process biological and genetic data, the issue has become even more pronounced. Traditionally, privacy presupposes the individual self but as Buddhism does away with the ultimate conception of an individual self, it has to find a way to analyse and justify privacy that does not presuppose such a self. It does this through a pragmatic conception that does not depend on a positing of the substantial self, which is then found to be unnecessary for an effective protection of privacy. As it may be possible one day to link genetic data to individuals, the Buddhist conception perhaps offers a more flexible approach, as what is considered to be integral to an individual person is not fixed in objectivity but depends on convention.  相似文献   

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Variation between individuals is an essential component of natural selection and evolutionary change, but it is only recently that the consequences of persistent differences between individuals on population dynamics have been considered. In particular, few authors have addressed whether interactions exist between individual quality and environmental variation. In part, this is due to the difficulties of collecting sufficient data, but also the challenge of defining individual quality. Using a long-established study population of red deer, Cervus elaphus, inhabiting the North Block of the Isle of Rum, and three quality measures, this paper investigates how differences in maternal quality affect variation in birth body mass and date, as population density varies, and how this differs depending on the sex of the offspring and the maternal quality measure used. Significant interactions between maternal quality, measured as a hind's total contribution to population growth, and population density are reported for birth mass, but only for male calves. Analyses using dominance or age at primiparity to define maternal quality showed no significant interactions with population density, highlighting the difficulties of defining a consistent measure of individual quality.  相似文献   

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We assess life history from birth to death in male mandrills (Mandrillus sphinx) living in a semifree-ranging colony in Gabon, using data collected for 82 males that attained at least the age of puberty, including 33 that reached adulthood and 25 that died, yielding data for their entire lifespan. We describe patterns of mortality and injuries, dominance rank, group association, growth and stature, and secondary sexual character expression across the male lifespan. We examine relationships among these variables and investigate potential influences on male life history, including differences in the social environment (maternal rank and group demography) and early development, with the aim of identifying characteristics of successful males. Sons of higher-ranking females were more likely to survive to adulthood than sons of low-ranking females. Adolescent males varied consistently in the rate at which they developed, and this variation was related to a male's own dominance rank. Males with fewer peers and sons of higher-ranking and heavier mothers also matured faster. However, maternal variables were not significantly related to dominance rank during adolescence, the age at which males attained adult dominance rank, or whether a male became alpha male. Among adult males, behavior and morphological development were related to a male's own dominance rank, and sons of high-ranking females were larger than sons of low-ranking females. Alpha males were always the most social, and the most brightly colored males, but were not necessarily the largest males present. Finally, alpha male tenure was related to group demography, with larger numbers of rival adult males and maturing adolescent males reducing the time a male spent as alpha male. Tenure did not appear to be related to characteristics of the alpha male himself.  相似文献   

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Respiration rate, heart rate, and body temperature values were obtained from 14 cynomolgus monkeys (Macaca fascicularis) during neurosurgery under barbiturate anesthesia. Vital sign values markedly declined below baseline during the early stages of surgery, steadily increased as surgery progressed and neared completion, and finally returned to baseline by the end of the postsurgical recovery period. There was considerable variability among the 14 monkeys, but the ranking of each monkey relative to the others remained constant across the period of observation. The findings suggested that the cynomolgus monkey may be more sensitive to barbiturates than the rhesus monkey, and cynomolgus monkeys may exhibit considerable individual differences in their sensitivity to barbiturates.  相似文献   

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ABSTRACT Carotenoid‐based coloration of skin and plumage has been found to be correlated with individual quality in many species of birds during the breeding season. However, less is known about the possible role of these signals during the nonbreeding season, particularly among nonpasserines that defend winter territories. American Kestrels (Falco sparverius) are sexually dimorphic raptors that defend winter territories and possess carotenoid‐based morphological features known to be correlated with individual quality. Much is known about winter territory use and habitat segregation by male and female kestrels, but possible relationships among morphological features, individual quality, and habitat quality have not been examined. Our objective was to examine possible relationships between morphology, territory quality, and skin color of American Kestrels. Male kestrels had brighter skin than females, and the skin color of male kestrels was positively correlated with size (wing chord and tail length) and territorial quality (hunting territories with less canopy and more grass cover). No such relationships were found for female kestrels. Skin color appears to be an honest indicator of quality for male American Kestrels and may serve both intersexual (territory acquisition) and intersexual (mate choice) functions during the breeding and nonbreeding seasons.  相似文献   

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A novel cross river, self cleansing system for the remote monitoring of downstream and upstream migration of PIT tagged fishes past a fixed point in deep, fast flowing rivers is described.  相似文献   

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Mechanisms affecting consistent interindividual behavioral variation (i.e., animal personality) are of wide scientific interest. In poikilotherms, ambient temperature is one of the most important environmental factors with a direct link to a variety of fitness‐related traits. Recent empirical evidence suggests that individual differences in boldness are linked to behavioral thermoregulation strategy in heliothermic species, as individuals are regularly exposed to predators during basking. Here, we tested for links between behavioral thermoregulation strategy, boldness, and individual state in adult males of the high‐mountain Carpetan rock lizard (Iberolacerta cyreni). Principal component analysis revealed the following latent links in our data: (i) a positive relationship of activity with relative limb length and color brightness (PC1, 23% variation explained), (ii) a negative relationship of thermoregulatory precision with parasite load and risk‐taking (PC2, 20.98% variation explained), and (iii) a negative relationship between preferred body temperature and relative limb length (PC3, 19.23% variation explained). We conclude that differences in boldness and behavioral thermoregulatory strategy could be explained by both stable and labile state variables. The moderate link between behavioral thermoregulatory strategy and risk‐taking personality in our system is plausibly the result of differences in reproductive state of individuals or variation in ecological conditions during the breeding season.  相似文献   

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Although schooling behaviour is an important antipredator response of guppies ( Poecilia reticulata ) in Trinidad it is not known whether fish elect to school with particular individuals. Familiarity is a simple mechanism that could lead to non-random associations within schools. In this paper we test the idea that prior experience of particular individuals influences the choice of partners during schooling. We show (in a laboratory study) that female guppies prefer to associate with familiar individuals. However, we are unable to detect any schooling preference for unfamiliar females from the same population.  相似文献   

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褐飞虱对抗性水稻品种Mudgo个体致害性指标   总被引:2,自引:1,他引:1  
周亦红  韩召军 《昆虫学报》2003,46(3):305-310
在28±1℃下,观测了褐飞虱Nilaparvata lugens羽化24?h内短翅型雌成虫在敏感水稻品种TN1及抗性品种Mudgo上的寿命及体重增量。结果表明,取食抗性品种时,试虫的平均增重与寿命之间表现出明显的正相关。寿命在7天内的个体,存活期间平均体重增量为负值,而存活7天以上的个体则平均增重明显。进一步研究了初羽化的褐飞虱长翅型雌成虫在TN1及Mudgo上取食第1~4天的体重增量、寿命及产卵量,结果发现试虫在Mudgo上的这3个生物学参数之间存在明显正相关。其中,寿命及体重增量较好地反映出害虫个体对抗性品种的致害能力,可作为个体致害性指标。根据研究结果,提出将羽化后在Mudgo上存活7天以上或最初4天内体重增量大于0.1mg的雌成虫定为能够致害该抗性品种的个体。  相似文献   

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Individual‐based, spatially explicit models provide a mechanism to understand distributions of individuals on the landscape; however, few models have been coupled with population genetics. The primary benefits of such a combination is to assess performance of population‐genetic estimators in realistic situations. kernelpop represents a flexible framework to implement almost any arbitrary population‐genetic and demographic model in a spatially explicit context using a variety of dispersal kernels. Estimates of type I error associated with genome scans in metapopulations are provided as an illustration of this software's utility.  相似文献   

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2010年5~9月从长江支流沱江收集性成熟宽体沙鳅个体,研究了其个体生殖力及其与多项生物学指标的关系。实验鱼共76尾,由2+、3、4龄鱼组成。其绝对生殖力(F)为414~9625粒,平均3230粒;体长相对生殖力(FL)为50~837粒/cm,平均324粒/cm;体重相对生殖力(FW)为21~789粒/g,平均227粒/g;绝对生殖力、体长相对生殖力和体重相对生殖力与成熟系数呈幂函数相关,回归方程为:F=177.99GSI0.9872,FL=20.315GSI0.9592,FW=13.957GSI0.9542;绝对生殖力和体长相对生殖力与体重呈幂函数相关,回归方程为:F=9.4876M1.9425,FL=2.2684M1.6597。  相似文献   

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Biobanks are increasingly being established to act as mediators between patient-donors and researchers. In practice, some of these will close. This paper details the experiences of one such bank. We report interviews with the bank's staff and oversight group during the period when the bank ceased biobanking activity, reconfigured as a disseminator of best practice, before then closing altogether. The paper makes three distinct contributions: (i) to provide a detailed account of the establishment, operational challenges, and eventual closure of the bank, which makes clear the rapid turnover in a cycle of promise and disappointment; (ii) to explore this in terms of a novel analytical focus upon field, institutional, and individual expectations; and (iii) to use this typology to demonstrate how, even after the bank's closure, aspects of its work were reconfigured and reused in new contexts. This provides a unique empirical analysis of the under-reported issue of biobank closure.  相似文献   

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Male leopard geckos that hatch from eggs incubated at a female‐biased temperature (Tf) behave differently when compared with males hatching at a temperature which produces a male‐biased sex ratio (Tm). We investigated the effect of incubation temperature and androgen implantation on aspects of the dopaminergic system of Tf and Tm males. Our data suggest that more dopamine (DA) is stored in the nucleus accumbens of naive Tf males compared with naïve Tm males when they encounter a receptive female conspecific across a barrier. No difference was measured in the preoptic area and the ventral tegmental area (VTA). This difference in intracellular DA levels in a motivation‐related brain nucleus might be correlated with differences in sociosexual behavior observed between the two morphs. There were no differences in tyrosine hydroxylase (TH) expressing cell numbers in the VTA of cholesterol (CH)‐implanted naive castrated Tf and Tm males. Only Tf males implanted with testosterone had significantly higher TH immunopositive cell numbers in the VTA compared with CH‐ and dihydrotestosterone‐implanted Tf males. These data indicate that both the embryonic environment as well as the circulating hormonal milieu can modulate neurochemistry, which might in turn be a basis for individual variation in behavior. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007  相似文献   

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