166 resultados para paternity success


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Context : Designing an appropriate survey protocol requires understanding of how capture rates of target species may be influenced by factors other than on-ground abundance, such as weather conditions or seasonality. This is particularly relevant for ectotherms such as reptiles, as activity can be affected by environmental conditions such as ambient temperature.
Aims : The present study examines factors affecting capture success of reptiles in semi-arid environments of southern Australia, and addresses the following two main questions: (1) what is the influence of weather and seasonal factors on capture rates of reptiles, and (2) what are the implications for developing an effective protocol for reptile surveys?
Methods : We surveyed reptiles using pitfall traps in spring and summer of 2006/07 and 2007/08 at sites (n = 280) throughout the Murray Mallee region of south-eastern Australia. We used mixed-effect regression models to investigate the influence of seasonal and weather-related variables on species’ capture success.
Key results : Total captures of reptiles, and the likelihood of capture of 15 reptile species, increased with rising daily temperature. Greater numbers of individual species were captured during spring than in summer, even though temperatures were cooler. This probably reflects greater levels of activity associated with breeding. Several species were more likely to be captured when maximum or minimum daily temperatures exceeded a certain level (e.g. Lerista labialis, Delma australis, Nephrurus levis). Other factors, such as rainfall and moon phase, also influenced capture success of some species.
Conclusions : Surveys for reptiles in semi-arid environments are likely to capture the greatest diversity of species on warm days in late spring months, although surveys on hot days in summer will enhance detection of particular species (e.g. Morethia boulengeri, Varanus gouldii). We recommend trapping during periods with maximum temperatures exceeding 25–30C and minimum overnight temperatures of 15C. Finally, trapping during rainfall and full-moon events will maximise chances of encountering species sensitive to these variables (blind snakes and geckoes).
Implications : Selecting the most favourable seasonal and weather conditions will help ensure that reptile surveys maximise the likelihood of capturing the greatest diversity of reptiles, while minimising trap-effort required.

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The implementation of a business intelligence (BI) system is a complex undertaking requiring considerable resources. Yet there is a limited authoritative set of critical success factors (CSFs) for management reference because the BI market has been driven mainly by the IT industry and vendors. This research seeks to bridge the gap that exists between academia and practitioners by investigating the CSFs influencing BI systems success. The study followed a two-stage qualitative approach. Firstly, the authors utilised the Delphi method to conduct three rounds of studies. The study develops a CSFs framework crucial for BI systems implementation. Next, the framework and the associated CSFs are delineated through a series of case studies. The empirical findings substantiate the construct and applicability of the framework. More significantly, the research further reveals that those organisations which address the CSFs from a business orientation approach will be more likely to achieve better results.

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Background: Studies of mate choice in anuran amphibians have shown female preference for a wide range of male traits despite females gaining no direct resources from males (i.e. non-resource based mating system). Nevertheless, theoretical and empirical studies have shown that females may still gain indirect genetic benefits from choosing males of higher genetic quality and thereby increase their reproductive success.
Methodology/Principal Findings: We investigated two components of sexual selection in the Moor frog (Rana arvalis), precopulatory female choice between two males of different size (‘large’ vs. ‘small’), and their fertilization success in sperm competition and in isolation. Females’ showed no significant preference for male size (13 small and six large male preferences) but associated preferentially with the male that subsequently was the most successful at fertilizing her eggs in isolation. Siring success of males in competitive fertilizations was unrelated to genetic similarity with the female and we detected no effect of sperm viability on fertilization success. There was, however, a strong positive association between a male’s innate fertilization ability with a female and his siring success in sperm competition. We also detected a strong negative effect of a male’s thumb length on his competitive siring success.
Conclusions/Significance: Our results show that females show no preference for male size but are still able to choose males which have greater fertilization success. Genetic similarity and differences in the proportion of viable sperm within a males ejaculate do not appear to affect siring success. These results could be explained through pre- and/or postcopulatory choice for genetic benefits and suggest that females are able to perceive the genetic quality of males, possibly basing their choice on multiple phenotypic male traits.

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Artificial chick shelters might improve productivity of beach-nesting birds threatened by anthropogenic disturbance. We investigated the efficacy of three different chick shelter designs against four criteria: accessibility to chicks over time, thermal insulation, conspicuousness to beach-goers, and practicality (cost and ease of transport). One design (‘A-frame’) was selected because it offered the greatest thermal insulation, was the least conspicuous, most cost effective, and performed equally well in terms of accessibility. We deployed these artificial shelters on Hooded Plover Thinornis rubricollis territories where broods were present (n 5 11), and compared the behaviour and survival rate of chicks to that at control sites (n 5 10). We were unable to discern any difference in the behaviour of broods when artificial shelters were available. However, the survival rate of chicks to fledging was 71.8% higher where an artificial shelter was provided (n 5 21 broods). This was validated by analysing data from a larger sample of broods monitored as part of an active volunteer-based management programme; shelters conferred a 42.8%increase in survival to fledging (n 5 81 broods). Thus, artificial shelters have the potential to increase survival rates of threatened shorebird chicks, though the mechanisms through which survival is increased require further investigation.

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During four breeding seasons, 2003–2006, we studied the relationship between snow cover and nesting performance in pink-footed geese (Anser brachyrhynchus) in a key breeding site on Svalbard. Snow cover in late May, i.e., at the time of egg laying of geese, was derived from MODIS satellite images. Snow cover had a profound cascading effect on reproductive output via the number of nesting pairs and timing of nesting, which affected nest success, while there was only a tendency for a negative effect on clutch size. Hence, we estimated a five-fold difference in the number of young produced (to post-hatching) between years with little snow and years with high snow cover. The results from the study area correlated with whole-population productivity estimates recorded in autumn. Thus, snow cover derived from MODIS satellite images appears to provide a useful indicator of the breeding conditions in the Arctic.

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Engineering asset management organisations (EAMOs) are increasingly motivated to implement business intelligence (BI) systems in response to dispersed information environments and compliance requirements. However, the implementation of a business intelligence (BI) system is a complex undertaking requiring considerable resources. Yet, so far, there are few defined critical success factors (CSFs) to which management can refer. Drawing on the CSFs framework derived from a previous Delphi study, a multiple-case design was used to examine how these CSFs could be implemented by five EAMOs. The case studies substantiate the construct and applicability of the CSFs framework. These CSFs are: committed management support and sponsorship, a clear vision and well-established business case, business-centric championship and balanced team composition, a business-driven and iterative develop ment approach, user-oriented change management, a business-driven, scalable and flexible technical framework, and sustainable data quality and integrity. More significantly, the study further reveals that those organisations which address the CSFs from a business orientation approach will be more likely to achieve better results.

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This paper presents and discusses the critical success factors (CSFs) influencing the implementation of business intelligence (BI) systems. Based on a preliminary critical success factors (CSFs) framework, multiple case studies approach was applied to investigate the CSFs influencing BI systems implementation in seven large engineering enterprises. The empirical findings demonstrate a clear trend towards multidimensional challenges involved in such resourceful and complex undertaking. The CSFs exist in various dimensions composed of organisation, process, and technology perspectives. More significantly, the study reveals that a more fundamental issue concerning the business needs of BI systems may, in the end, impede BI systems success. That is, BI stakeholders are urged to apply a business-orientation approach in tackling implementation challenges and ensuring buy-in from business stakeholders.

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Background: A major question in behavioural ecology concerns the relationship between genetic mating systems and the strength of sexual selection. In this study, we investigated the genetic mating system of the two-spotted goby (Gobiusculus flavescens), a useful fish model for the study of sexual selection whose genetic mating system remains uncharacterized. We developed four polymorphic microsatellite markers and used them to conduct parentage analyses on 21 nests collected during the breeding season to examine the rates of multiple mating by males and to test for evidence of alternative mating strategies.

Results: Results of this study indicate that male G. flavescens mate with multiple females and enjoy confidence of paternity. We detected only one instance of sneaking, so cuckoldry contributed a very small percentage (~0.1%) of the total fertilizations in this population. Nests were nearly full and males that maintain larger nests have higher mating and reproductive success, irrespective of body size.

Conclusion: Overall, our investigation shows that G. flavescens is similar to other, related gobies in that the nests of care-giving males often contain eggs from multiple females. However, G. flavescens differs from other gobies in displaying an extremely low rate of cuckoldry. The study of ecological factors responsible for this important

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This paper introduces and analyses three broad discourses of academic achievement and failure, specifically those that speak of students' deficits, disadvantages and differences. It draws on interview data collected from teachers working in Australian primary (elementary) and secondary (high) schools and on academic literature that speaks to the field. The paper argues that 'deficit', 'disadvantage' and 'difference' represent discourses of considerable influence in determining how teachers, students and parents define what constitutes success or failure in schools, which respective approaches educators employ, and the beliefs we hold about students who fail and those who succeed. In this respect, the paper is concerned with matters of inclusion and exclusion in schooling. In particular, we seek to tease out the stories that these discourses tell about student diversity, as a way of unmasking how students are differently represented and how these representations serve to include some and exclude others from the benefits of schooling and society more broadly.

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Institutionally collected data identifying student demographics, course performance in both the precollege mathematics course and the college-level mathematics course, and 'stopping-out' time between the pre-college course and the college-level course were used to create a predictive model of academic success for 'high risk' college-level mathematics students. The two most significant factors were the pre-college mathematics course grade and the student's over-all college GPA.