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This research explores the ability of 60 mm thick reinforced concrete (RC) plates to resist impacts from ogive-nosed hard steel projectiles. The projectiles used in the present study have a diameter of 19 mm, a length of 200 mm, and a mass of 0.4 kg impacted on the RC plates with incident velocities ranging from 92 m/s to 161 m/s. Numerical simulations were conducted using ABAQUS/Explicit finite element software to validate the experimental results. The Holmquist–Johnson–Cook (HJC) material model was employed to simulate the constitutive behavior of concrete, while the Johnson–Cook (JC) material model was used to simulate the material response of reinforcing steel bars. The residual velocities obtained from the simulations closely matched the actual experimental results, showing a polynomial correlation with the incidence velocities of the projectiles. Moreover, the experimentally and numerically determined ballistic limit for the 60 mm thick RC plate was found to be 108 m/s and 109.5 m/s, respectively. In contrast, the ballistic limit calculated using empirical mathematical expressions was 107.4 m/s. This alignment between predicted, calculated, and actual ballistic limits underscores the reliability and accuracy of both numerical and empirical approaches. [ABSTRACT FROM AUTHOR]

Background: Dementia with Lewy bodies (DLB) can be difficult to distinguish from Alzheimer's disease (AD) and Parkinson's disease dementia (PDD) at different stages of its progression due to some overlaps in the clinical and neuropathological presentation of these conditions compared with DLB. Metallomic changes have already been observed in the AD and PDD brain--including widespread decreases in Cu levels and more localised alterations in Na, K, Mn, Fe, Zn, and Se. This study aimed to determine whether these metallomic changes appear in the DLB brain, and how the metallomic profile of the DLB brain appears in comparison to the AD and PDD brain. Methods: Brain tissues from ten regions of 20 DLB cases and 19 controls were obtained. The concentrations of Na, Mg, K, Ca, Zn, Fe, Mn, Cu, and Se were determined using inductively coupled plasma-mass spectrometry (ICPMS). Case-control differences were evaluated using Mann-Whitney U tests. Results were compared with those previously obtained from AD and PDD brain tissue, and principal component analysis (PCA) plots were created to determine whether cerebral metallomic profiles could distinguish DLB from AD or PDD metallomic profiles. Results: Na was increased and Cu decreased in four and five DLB brain regions, respectively. More localised alterations in Mn, Ca, Fe, and Se were also identified. Despite similarities in Cu changes between all three diseases, PCA plots showed that DLB cases could be readily distinguished from AD cases using data from the middle temporal gyrus, primary visual cortex, and cingulate gyrus, whereas DLB and PDD cases could be clearly separated using data from the primary visual cortex alone. Conclusion: Despite shared alterations in Cu levels, the post-mortem DLB brain shows very few other similarities with the metallomic profile of the AD or PDD brain. These findings suggest that while Cu deficiencies appear common to all three conditions, metal alterations otherwise differ between DLB and PDD/AD. These findings can contribute to our understanding of the underlying pathogenesis of these three diseases; if these changes can be observed in the living human brain, they may also contribute to the differential diagnosis of DLB from AD and/or PDD. [ABSTRACT FROM AUTHOR]

Understanding how and why menopause has evolved is a long-standing challenge across disciplines. Females can typically maximize their reproductive success by reproducing for the whole of their adult life. In humans, however, women cease reproduction several decades before the end of their natural lifespan1,2. Although progress has been made in understanding the adaptive value of menopause in humans3,4, the generality of these findings remains unclear. Toothed whales are the only mammal taxon in which menopause has evolved several times5, providing a unique opportunity to test the theories of how and why menopause evolves in a comparative context. Here, we assemble and analyse a comparative database to test competing evolutionary hypotheses. We find that menopause evolved in toothed whales by females extending their lifespan without increasing their reproductive lifespan, as predicted by the ‘live-long’ hypotheses. We further show that menopause results in females increasing their opportunity for intergenerational help by increasing their lifespan overlap with their grandoffspring and offspring without increasing their reproductive overlap with their daughters. Our results provide an informative comparison for the evolution of human life history and demonstrate that the same pathway that led to menopause in humans can also explain the evolution of menopause in toothed whales.A comparative analysis tests competing evolutionary hypotheses in toothed whales in which menopause has evolved many times as females extended their overall lifespan but not their reproductive lifespan, increasing their opportunity for intergenerational help without increasing intergenerational reproductive competition. [ABSTRACT FROM AUTHOR]

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Life-history theory suggests that individuals should reproduce until death, yet females of a small number of mammals live for a significant period after ceasing reproduction, a phenomenon known as post-reproductive lifespan. It is thought that the evolution of this trait is facilitated by increasing local relatedness throughout a female's lifetime. This allows older females to gain inclusive fitness through helping their offspring (known as a mother effect) and/or grandoffspring (known as a grandmother effect), rather than gaining direct fitness through reproducing. However, older females may only benefit from stopping reproducing when their direct offspring compete with those of their daughters. Here, we investigate whether a lack of post-reproductive lifespan in long-finned pilot whales (Globicephala melas) results from minimal benefits incurred from the presence of older females, or from a lack of costs resulting from mother–daughter co-reproduction. Using microsatellite data, we conducted parentage analysis on individuals from 25 pods and find that younger females were more likely to have offspring if their mother was present in their pod, indicating that mothers may assist inexperienced daughters to reproduce. However, we found no evidence of reproductive conflict between co-reproducing mothers and daughters, indicating that females may be able to reproduce into old age while simultaneously aiding their daughters in reproduction. This highlights the importance of reproductive conflict in the evolution of a post-reproductive lifespan and demonstrates that mother and grandmother effects alone do not result in the evolution of a post-reproductive lifespan. [ABSTRACT FROM AUTHOR]

The NanChang Spherical Tokamak (NCST) is a new compact tokamak (with an aspect ratio of R/a = 1.67) for exploring the merging compression by which the plasma start-up is highly efficient. In this paper, a magnetic diagnostic system is designed, calibrated, and constructed on the NCST to meet the requirements of measurements. Based on detailed testing and analysis, the reliability of the sensors is guaranteed by optimizing the support structure and installation process. In addition, high-precision positioning equipment is utilized to ensure the installation accuracy of the sensors. During the start-up phase of the NCST, plasma currents on the order of a few kiloamperes were measured despite that the commensurate signal of eddy current is also found in the conducting structure. The magnetic diagnostic system is now completely operational and meets the requirements of the physical analysis on the NCST. [ABSTRACT FROM AUTHOR]

The acoustic environment can serve as a niche axis, structuring animal behaviour by providing or obscuring salient information. Meadow katydid choruses occupy the ultrasonic, less studied, realm of this acoustic milieu, form dense populations in some habitats and present a potential sensory challenge to co-occurring ultrasonic-hearing animals. Aerial-hawking insectivorous bats foraging immediately over vegetation must listen for echoes of their prey and other cues amidst the chorus din. 2. We experimentally created the cacophony of a katydid chorus in a katydid-free rice paddy using an aggregation of 100 ultrasonic speakers in a 25 × 25 m grid to test the hypothesis that aerially hawking bats are averse to this noise source. We alternated between chorus-on and chorus-off hourly, and acoustically monitored bat activity and arthropod prey abundance. 3. We found that our phantom katydid chorus reduced bat activity nearest the sound source by 39.3% (95% CI: 7.8%-60.0%) for species whose call spectrum fully overlapped with the chorus, and elicited marginal reductions in activity in species with only partial spectral overlap. 4. Our study suggests that ultrasonic insect choruses degrade foraging habitat, potentially suppressing bats' ecosystem services as consumers of pests; and, given the global distribution of meadow katydids, may provide an underappreciated force modifying animal behaviour in other grassland habitats. [ABSTRACT FROM AUTHOR]

In a handful of mammals, females show an extended postreproductive lifespan (PRLS), leading to questions over why they spend a substantial portion of their lifespan nonreproductive. Theoretical and empirical studies suggest that PRLS may evolve when 1) demographic patterns lead to increasing local relatedness as females age, and 2) females come into reproductive competition with their daughters, as these conditions lead to high relative benefits of helping kin versus reproducing in later life. However, evolutionary pathways to PRLS are poorly understood and empirical studies are scarce. Here, we use a dataset of 1522 individuals comprising 22 pods to investigate patterns of reproduction and relatedness in long-finned pilot whales Globicephala melas ; a toothed whale without species-wide PRLS. We find a similar relatedness structure to whales with PRLS: pods appear composed of related matrilines, and relatedness of females to their pod increases with age, suggesting that this species could benefit from late-life help. Furthermore, females with a large number of philopatric adult daughters are less likely to reproduce, implying intergenerational reproductive competition between females. This suggests that individuals may display a plastic cessation of reproduction, switching to investing in existing offspring when they come into competition with their daughters. To the best of our knowledge, this is the first time such a relationship has been described in relation to PRLS, and it raises questions about whether this represents a step towards evolving PRLS or is a stable alternative strategy to widespread postreproductive periods. [ABSTRACT FROM AUTHOR]

Using evolutionary theory to predict the dynamics of populations is one of the aims of evolutionary conservation. In endangered species, with geographic range extending over continuous areas, the predictive capacity of evolutionary-based conservation measures greatly depends on the accurate identification of reproductive units. The endangered European eel ( Anguilla anguilla) is a highly migratory fish species with declining population due to a steep recruitment collapse in the beginning of the 1980s. Despite punctual observations of genetic structure, the population is viewed as a single panmictic reproductive unit. To understand the possible origin of the detected structure in this species, we used a combination of mitochondrial and nuclear loci to indirectly evaluate the possible existence of cryptic demes. For that, 403 glass eels from three successive cohorts arriving at a single location were screened for phenotypic and genetic diversity, while controlling for possible geographic variation. Over the 3 years of sampling, we consistently identified three major matrilines which we hypothesized to represent demes. Interestingly, not only we found that population genetic models support the existence of those matriline-driven demes over a completely panmictic mode of reproduction, but also we found evidence for asymmetric gene flow amongst those demes. We uphold the suggestion that the detection of demes related to those matrilines reflect a fragmented spawning ground, a conceptually plausible consequence of the low abundance that the European eel has been experiencing for three decades. Furthermore, we suggest that this cryptic organization may contribute to the maintenance of the adaptive potential of the species. [ABSTRACT FROM AUTHOR]

Abstract: Sexual selection through female mate choice for genetic characteristics has been suggested to be an important evolutionary force maintaining genetic variation in animal populations. However, the genetic targets of female mate choice are not clearly identified and whether female mate choice is based on neutral genetic characteristics or on particular functional loci remains an open question. Here, we investigated the genetic targets of female mate choice in Alpine marmots (Marmota marmota), a socially monogamous mammal where extra‐pair paternity (EPP) occurs. We used 16 microsatellites to describe neutral genetic characteristics and two MHC loci belonging to MHC class I and II as functional genetic characteristics. Our results reveal that (1) neutral and MHC genetic characteristics convey different information in this species, (2) social pairs show a higher MHC class II dissimilarity than expected under random mate choice, and (3) the occurrence of EPP increases when social pairs present a high neutral genetic similarity or dissimilarity but also when they present low MHC class II dissimilarity. Thus, female mate choice is based on both neutral and MHC genetic characteristics, and the genetic characteristics targeted seem to be context dependent (i.e., the genes involved in social mate choice and genetic mate choice differ). We emphasize the need for empirical studies of mate choice in the wild using both neutral and MHC genetic characteristics because whether neutral and functional genetic characteristics convey similar information is not universal. [ABSTRACT FROM AUTHOR]

HFCs (heterozygosity-fitness correlations) measure the direct relationship between an individual's genetic diversity and fitness. The effects of parental heterozygosity and the environment on HFCs are currently under-researched. We investigated these in a high-density U.K. population of European badgers ( Meles meles), using a multimodel capture-mark-recapture framework and 35 microsatellite loci. We detected interannual variation in first-year, but not adult, survival probability. Adult females had higher annual survival probabilities than adult males. Cubs with more heterozygous fathers had higher first-year survival, but only in wetter summers; there was no relationship with individual or maternal heterozygosity. Moist soil conditions enhance badger food supply (earthworms), improving survival. In dryer years, higher indiscriminate mortality rates appear to mask differential heterozygosity-related survival effects. This paternal interaction was significant in the most supported model; however, the model-averaged estimate had a relative importance of 0.50 and overlapped zero slightly. First-year survival probabilities were not correlated with the inbreeding coefficient ( f); however, small sample sizes limited the power to detect inbreeding depression. Correlations between individual heterozygosity and inbreeding were weak, in line with published meta-analyses showing that HFCs tend to be weak. We found support for general rather than local heterozygosity effects on first-year survival probability, and g2 indicated that our markers had power to detect inbreeding. We emphasize the importance of assessing how environmental stressors can influence the magnitude and direction of HFCs and of considering how parental genetic diversity can affect fitness-related traits, which could play an important role in the evolution of mate choice. [ABSTRACT FROM AUTHOR]

Androdioecy (the coexistence of males and hermaphrodites) is considered a transitional state derived from pure hermaphroditism or dioecy, but the processes selecting for this rare breeding system are unclear, particularly in animals. In androdioecious species, the proportion of males in relation to hermaphrodites is usually so reduced that it is not known whether there is scope for mate choice, particularly when simultaneous hermaphrodites can self-fertilize. We investigated the potential role of male mate choice in the persistence of androdioecy in animals using a self-fertilizing androdioecious fish (Kryptolebias marmoratus) as a model. Hermaphrodites preferred to associate with males but showed no preference based on genetic similarity. In contrast, males displayed a strong preference for genetically dissimilar hermaphrodites, based, apparently, on olfactory cues. We suggest that disassortative male mate choice could be a critical factor in stabilizing androdioecy in cases where high selfing rates are associated with inbreeding depression. [ABSTRACT FROM AUTHOR]

A scan involving 1134 single-nucleotide polymorphisms (SNPs) from 709 expressed genes was used to assess the potential impact of artificial selection for height growth on the genetic diversity of white spruce. Two case populations of different sizes simulating different family selection intensities (K = 13% and 5%, respectively) were delineated from the Quebec breeding program. Their genetic diversity and allele frequencies were compared with those of control populations of the same size and geographic origin to assess the effect of increasing the selection intensity. The two control populations were also compared to assess the effect of reducing the sampling size. On one hand, in all pairwise comparisons, genetic diversity parameters were comparable and no alleles were lost in the case populations compared with the control ones, except for few rare alleles in the large case population. Also, the distribution of allele frequencies did not change significantly (P ≤ 0.05) between the populations compared, but ten and nine SNPs (0.8%) exhibited significant differences in frequency (P ≤ 0.01) between case and control populations of large and small sizes, respectively. Results of association tests between breeding values for height at 15 years of age and these SNPs supported the hypothesis of a potential effect of selection on the genes harboring these SNPs. On the other hand, contrary to expectations, there was no evidence that selection induced an increase in linkage disequilibrium in genes potentially affected by selection. These results indicate that neither the reduction in the sampling size nor the increase in selection intensity was sufficient to induce a significant change in the genetic diversity of the selected populations. Apparently, no loci were under strong selection pressure, confirming that the genetic control of height growth in white spruce involves many genes with small effects. Hence, selection for height growth at the present intensities did not appear to compromise background genetic diversity but, as predicted by theory, effects were detected at a few gene SNPs harboring intermediate allele frequencies. [ABSTRACT FROM AUTHOR]

The article presents a study that investigated the genetic mating system of Upland Sandpiper at Konza Prairie Biological Station in northeastern Kansas and the effect of spatial patterns of philopatry and nest placement on opportunities for extra-pair mating. It states that researchers found high levels of heterozygosity through six microsatellite markers. It notes that these markers were also used to estimate the rates of extra-pair paternity in 58 family groups.

This paper presents the multiple set of requirements for the ITER magnetic diagnostic systems and the current status of the various R&D activities performed by the EU partners. [ABSTRACT FROM AUTHOR]

The idea that extrapair paternity (EPP) in birds is part of a mixed reproductive strategy driven primarily by females is controversial. In cooperatively breeding American crows, we compared predictions of four female benefits hypotheses-the genetic diversity, good genes, genetic compatibility, and direct benefits hypotheses- to our predictions if EPP was primarily male driven. We found that genetically diverse broods were not more successful, extrapair young were not in better condition and did not have a higher survival probability, and, contrary to prediction, offspring sired by withingroup extrapair males were more inbred than within-pair offspring. There was evidence of direct benefits, however: provisioning rate and number of surviving offspring were higher in groups containing within-group extrapair sires. Females therefore derived no apparent benefits from extragroup extrapair males but both direct benefits and genetic costs from within-group extrapair males. We suggest that males and females both influence the distribution of EPP in this system. [ABSTRACT FROM AUTHOR]

The article presents the study conducted regarding the use of microsatellite loci in determining extra-pair paternity and compatible alleles of the socially monogamous bird species. The study aims to understand the benefits of the extra-pair mating activities of female birds present in the socially monogamous environment and their possibility of increasing offspring heterozygosity. The scheme has produced mixed result indicating that outcome relies on the microsatellite loci employed by the researchers.

Mate choice is often based on multiple signal traits and can be influenced by context-dependent factors. Understanding the importance of these signals and factors can be difficult because they are often correlated and might interact. Here, we experimentally disentangle the effects of familiarity, kinship, pattern rarity, and ornament patterns on mate choice in guppies. We estimate whether these factors alter sexual selection on six phenotypic traits known to influence male attractiveness. Rarity of the male's phenotype is the only context-dependent factor that significantly influenced female mating decisions, with common patterns being least attractive. This preference for rare male patterns is a source of negative frequency-dependent selection that may contribute to maintaining the extreme polymorphism in male guppy coloration. Neither visual familiarity nor relatedness between mating partners had any significant effect on mate choice decisions. There was significant linear and nonlinear sexual selection on ornamental traits, but this was not influenced by the context-dependent measures. Our approach highlights the complexity of female mate choice and sexual selection, as well as the value of combining multifactorial experiments with multivariate selection analyses. Our study shows that both negative frequency-dependent selection and disruptive selection contribute to the maintenance of extreme polymorphism in guppies. [ABSTRACT FROM AUTHOR]

From an evolutionary perspective, human facial attractiveness is proposed to signal mate quality. Using a novel approach to the study of the genetic basis of human preferences for facial features, we investigated whether attractiveness signals mate quality in terms of genetic diversity. Genetic diversity in general has been linked to fitness and reproductive success, and genetic diversity within the major histocompatibility complex (MHC) has been linked to immunocompetence and mate preferences. We asked whether any preference for genetic diversity is specific to MHC diversity or reflects a more general preference for overall genetic diversity. We photographed and genotyped 160 participants using microsatellite markers situated within and outside the MHC, and calculated two measures of genetic diversity: mean heterozygosity and standardized mean d2. Our results suggest a special role for the MHC in female preferences for male faces. MHC heterozygosity positively predicted male attractiveness, and specifically facial averageness, with averageness mediating the MHC-attractiveness relationship. For females, standardized mean d2 at non-MHC loci predicted facial symmetry. Thus, attractive facial characteristics appear to provide visual cues to genetic quality in both males and females, supporting the view that face preferences have been shaped by selection pressures to identify high-quality mates. [ABSTRACT FROM AUTHOR]

The adaptive function of female extrapair mating in socially monogamous passerines is currently debated. In the bluethroat ( Luscinia s. svecica), a previous study showed that offspring sired by extrapair males had a higher cell-mediated immunity than their within-pair half siblings, suggesting an immunogenetic benefit of extrapair mating in this species. Here, we expanded that dataset with two more years and investigated the association between extrapair paternity and microsatellite multilocus heterozygosity, in addition to cell-mediated immunity. We found that extrapair offspring were more heterozygous than their within-pair half siblings, and corroborated the previous finding of enhanced cellular immunity in extrapair offspring in this four-year dataset. The increased heterozygosity among extrapair offspring appeared to be a result of extrapair mates being less genetically similar than pair mates, and also less genetically similar than expected by random choice. Together with previous findings in this species, showing that the majority of females participate in extrapair copulations, our results indicate a postcopulatory cryptic female choice of genetically dissimilar males. The enhanced cellular immunity and increased heterozygosity were not related to each other, and hence our results indicate two independent genetic benefits of extrapair mating in the bluethroat. [ABSTRACT FROM AUTHOR]

The complex interactions between genetic diversity and evolution have important implications in many biological areas including conservation, speciation, and mate choice. A common way to study these interactions is to look at heterozygosity-fitness correlations (HFCs). Until recently, HFCs based on noncoding markers were believed to result primarily from global inbreeding effects. However, accumulating theoretical and empirical evidence shows that HFCs may often result from genes being linked to the markers used (local effect). Moreover, local effect HFCs could differ from global inbreeding effects in their direction and occurrence. Consequently, the investigation of the structure and consequences of local HFCs is emerging as a new important goal in evolutionary biology. In this study of a wild threespine stickleback (Gasterosteus aculeatus) population, we first tested the presence of significant positive or negative local effects of heterozygosity at 30 microsatellites loci on rive fitness components: survival, mating success, territoriality, length, and body condition. Then, we evaluated the direction and shape of total impact of local HFCs, and estimated the magnitude of the impacts on fitness using regression coefficients and selection differentials. We found that multilocus heterozygosity was not a reliable estimator of individual inbreeding coefficient, which supported the relevance of single-locus based analyses. Highly significant and temporally stable local HFCs were observed. These were mainly positive, but negative effects of heterozygosity were also found. Strong and opposite effects of heterozygosity are probably present in many populations, but may be blurred in HFC analyses looking for global effects only. In this population, both negative and positive HFCs are apparently driving mate preference by females, which is likely to contribute to the maintenance of both additive and nonadditive genetic variance. [ABSTRACT FROM AUTHOR]

Avoidance of incestuous matings is widely reported across many animal taxa, and the adaptive value of such behavior is explained through inbreeding depression. However, an old and somewhat neglected theoretical result predicts that inbred matings offer another, positive effect on the inclusive fitness of parents: an individual who mates with a relative will help that relative to spread genes identical by descent. This benefit can be substantial, if the additional mating achieved by the relative does not harm his mating success otherwise, and in the context of selfing in plants the phenomenon is well known. Here, we develop a model that derives expected values of inbreeding tolerance, that is, the magnitude of inbreeding depression that is required to make individuals avoid inbreeding, for different animal life histories and parental investment patterns. We also distinguish between simultaneous and sequential mate choice, and show that inbreeding tolerance should often be remarkably high in the latter scenario in particular, although egalitarian parental care will lead to lower tolerance. There is a mismatch between theory and data: the almost complete lack of cases where individuals prefer to mate incestuously is at odds with a large overlap between the predicted range of inbreeding tolerance and estimates of inbreeding depression found in nature. We discuss four different solutions to this enigma, and suggest that inbreeding tolerance, where it is found, should not always be attributed to a simple constraint that has prevented finding any other mate. [ABSTRACT FROM AUTHOR]

The breeding system of an animal population is thought to depend on the ability of one sex (usually the male) to acquire mates, either directly through association with females or indirectly through defense of the resources desired by females. The sex that contributes most to infant care (usually the female) is constrained by parental involvement and thereby limits reproduction of the opposite sex. Accordingly, males, but not females, enhance their reproductive success by acquiring additional mates. This classical view has emphasized the role of male-male competition in sexual selection, at the expense of fully exploring the potential for female choice. A more recent shift in focus has revealed substantial variation in female reproductive success and increasingly accentuates the importance of female intrasexual competition and male mate choice. A comparative review of primate reproduction, therefore, challenges expectations of male control and female compliance, and calls for a comprehensive treatment of costs and benefits that extends beyond conventional mention of heavy female investment versus male negligence or absenteeism. For individuals that manipulate their social environment or reproductive output, consideration of more subtle, even cryptic, aspects of female behavior and physiology (e.g., social strategizing, sexual solicitation or rejection, sexual advertisement or concealed ovulation, multiple mating, and reproductive failure) raises the question of whether females can be effectively "monopolized." Widespread patterns that counter Bateman's paradigm call for a reexamination of the predictions generated by dichotomizing gametes into 'expensive eggs' and 'cheap sperm,' and encourage continued mechanistic research focused on conception quality rather than quantity. [ABSTRACT FROM AUTHOR]

Recent genetic studies of natural populations have shown that heterozygosity and other genetic estimates of parental relatedness correlate with a wide variety of fitness traits, from juvenile survival and parasite resistance to male reproductive success. Many of these traits involve health and survival, where the underlying mechanism may involve changes in the effectiveness of the immune system. However, for traits such as reproductive success, the likely mechanisms remain less obvious. In this paper, we examine the relationship between heterozygosity and a range of traits that contribute to male reproductive success, including time spent on territories and competitiveness. Our analysis is based on observational and genetic data from eight consecutive breeding seasons at a colony of the Antarctic fur seal, Arctocephalus gazella. Overall, male reproductive success was found to correlate strongly with internal relatedness (IR, a form of heterozygosity). When different components of success were analyzed, we found that IR correlates independently with reproductive longevity, time spent ashore, and competitive ability per unit mating opportunity on the study beach, with more heterozygous males being more successful. Behavioral observations were sufficiently detailed to allow examination of how daily mean IR values for males present on the beach varied within seasons and from year to year. Again, significant variation was found both among and within seasons, with more homozygous males appearing less able to hold territories in poor seasons when pup production is low and, within a season, at both the start of the season and to some extent around the peak of female estrus. Finally, we tested whether the benefits of high heterozygosity are due mainly to a genomewide effect (e.g. inbreeding depression) or to single locus heterosis by asking whether the relationship between IR and male success was robust to the removal of any single locus or to any pair of loci. Since the... [ABSTRACT FROM AUTHOR]

The deleterious effects of inbreeding can be substantial in wild populations and mechanisms to avoid such matings have evolved in many organisms. In situations where social mate choice is restricted, extrapair paternity may be a strategy used by females to avoid inbreeding and increase offspring heterozygosity. In the cooperatively breeding Seychelles warbler, Acrocephalus sechellensis, neither social nor extrapair mate choice was used to avoid inbreeding facultatively, and close inbreeding occurred in approximately 5% of matings. However, a higher frequency of extragroup paternity may be selected for in female subordinates because this did reduce the frequency of mating between close relatives. Inbreeding resulted in reduced individual heterozygosity, which, against expectation, had an almost significant (P = 0.052), positive effect on survival. Conversely, low heterozygosity in the genetic mother was linked to reduced offspring survival, and the magnitude of this intergenerational inbreeding depression effect was environmentdependent. Because we controlled for genetic effects and most environmental effects (through the experimental cross-fostering of nestlings), we conclude that the reduced survival was a result of maternal effects. Our results show that inbreeding can have complicated effects even within a genetic bottlenecked population where the "purging" of recessive alleles is expected to reduce the effects of inbreeding depression. [ABSTRACT FROM AUTHOR]

Presents a study which investigated the association between microsatellite measures of heterozygosity and trait variation. Materials and methods; Results; Discussion.

1. I present a stochastic simulation model that describes individual movements of Metrioptera bicolor Philippi in a heterogeneous landscape, consisting of patches of suitable habitat surrounded by a matrix of unprofitable habitats. Although the model is parameterized with information about daily movement behaviour, it can generate spatially explicit predictions about inter-patch dispersal rates for much longer periods, e.g. one generation. 2. Long-term dispersal experiments were conducted to evaluate model predictions. Patch-specific emigration rates and the total distance moved by individuals could be predicted with satisfactory precision. Because of the stochastic nature of the model, it failed to predict which recipient patches emigrating individuals actually chose in a particular situation. 3. Spatially explicit simulations of the movement model were made for the whole natural distribution area of M. bicolor. The results suggest that emigration rates are negatively correlated with patch size. Local populations occurring on small patches may be more prone to extinction than those on large patches, by losing more emigrants than are compensated for by immigration. [ABSTRACT FROM AUTHOR]

Currently, short tandem repeat (STR) loci are the genetic markers of choice for forensic DNA testing; however, not all STRs are suitable for forensic applications. D18S535 is an STR locus [...], Genetic characterization of one European and three aboriginal populations from northern Ontario was undertaken to assess the utility of the D18S535 short tandem repeat locus (STR) as a genetic marker for forensic DNA typing in the region. The D18S535 locus was amplified using monoplex polymerase chain reaction (PCR), separated by denaturing polyacrylamide gel electrophoresis (PAGE), and visualized using the silver-stain detection method. The generated population data demonstrated that the D18S535 locus is highly polymorphic with a heterozygosity of ≥0.75. The exact test showed violations of Hardy-Weinberg equilibrium in two of the aboriginal populations. Pairwise comparisons of allele-frequency distributions indicated that the four northern Ontario populations were significantly different from each other. This test also revealed that the northern Ontario populations differed significantly from ten European populations (from Germany, Spain, and Croatia) and one population from South America (from Argentina). Forensic parameters showed that the D18S535 locus is highly discriminating (power of discrimination ≥0.85, chance of exclusion ≥0.51); however, the lack of Hardy-Weinberg equilibrium in some of the populations must be taken into account in the application of these results to northern Ontario forensic casework. KEY WORDS: SHORT TANDEM REPEAT (STR), D18S535, NORTHERN ONTARIO (CANADA), POPULATION GENETICS, FORENSIC SCIENCE, OJIBWA.