991 resultados para burrow counting


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Dummett (1997) notes particular difficulties with single transferable vote (STV) and proposes an alternative vote counting system called "Quota/Borda system" (QBS) to remedy specific difficulties. I propose an alternative system, structurally related to QBS, which accomplishes similar solutions but has some significant differences. This alternative system is identical to STV in all aspects except one. It eliminates candidates in reverse order of their Borda scores rather than by their current ranking of first-place votes. I designate this system STV with Borda elimination (STV-B). STV-B and QBS share general features. They retain proportional representation from STV. However, they differ from STV is two critical manners. First, both permit some influence on candidate selection to occur between voting blocks. Second, they are much more stable than STV when subjected to small changes in voter preferences. Outcomes from STV-B differ from QBS outcomes in two ways. Under STV-B, a minority that shares some preferences may elect a candidate even if the minority is not a solid coalition, as is required for minorities under QBS. Further, QBS always selects Borda winners, either for a minority or overall. STV-B may reject a Borda winner through emphasis on each voter's most preferred candidates.

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Integrated optical detection is considered to be an important operation in lab-on-a-chips. This paper presents an optical fiber-based micro-sensor that is capable of detecting food substance particles in a lab-on-a-chip. The system consists of a microcontroller and associated circuitry, a laser emitter, a laser receiver, fiber optic cables, a microfluidics chip, and the food substance samples to be tested. When the particles flow through the microfluidic channel in the chip, the receiver’s output voltage varies due to the particles blocking the passage of the laser ray. The changes in the collected signals are analyzed to count the number of particles. Experiments are conducted on several food substance samples including talcum powder, ground ginger, and soy sauce. The experimental results are presented and discussed.

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Despite Australia having a high diversity of freshwater crayfish species, the ecology of many of these species remains poorly known, particularly burrowing crayfish of the genus Engaeus. Biological information on colour, behaviour, burrow structure, associated burrow fauna and habitat of the East Gippsland Burrowing Crayfish Engaeus orientalis obtained during incidental observations in 2007 and 2008 is provided. The burrow structure took the form of radiating runways under a rock slab, while the burrow location was in a semi-disturbed site away from water. Both are atypical for this species.

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Regular monitoring of seabird populations is necessary to improve our understanding of their responses to environmental change and inform conservation management. However, given the difficulty in accessing remote breeding sites and the limited resources typically available to land managers, conducting regular, extensive surveys of seabird populations is often not feasible. Our objective was to determine the minimum survey effort required to obtain accurate and precise population estimates of Short-tailed Shearwaters (Ardenna tenuirostris) and Little Penguins (Eudyptula minor), two abundant burrowing seabird species in southeastern Australia, by comparing bootstrapped means and confidence intervals under different sampling regimes on four islands. We found that, in many cases, survey effort (the proportion of transects and quadrats along transects surveyed) could be reduced. For Short-tailed Shearwaters, reducing the number of transects resulted in a maximum difference of 15% between the means at full survey effort and two levels of reduced survey effort. Means differed by <3% when we halved the number of quadrats. For Little Penguins, reducing the number of transects and quadrats by 50% resulted in differences of 7-40% and 4-34%, respectively, between the full and reduced survey effort means. Confidence intervals generally increased with decreasing survey effort for both species. Differences in required survey effort between the two species in our study may have been due to differences in burrow distribution on islands, with Short-tailed Shearwater burrows generally uniformly distributed on each island and Little Penguin burrows typically occurring in patches. These would be influenced by island-specific characteristics in concert with habitat preferences, population size, and seasonal variation in seabird abundance. Stratified sampling did not increase survey accuracy and simulations showed that large reductions in survey effort could be made under a pseudo-random sampling regime, with mean abundance estimates similar at most levels of survey effort. For both species, reducing the proportion of pseudo-random quadrats to 50% and 25% of the full survey effort produced confidence intervals of 12% and 21%, respectively, of the maximum, whereas a survey effort of 10% produced confidence intervals of up to 36% of the maximum for both species. A pseudo-random sampling regime would maximize survey efficiency because considerably fewer quadrats would be required and allow development of more efficient sampling protocols and regimes.

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The size and growth of seabird populations are believed to be regulated, in part, by the availability and quality of suitable breeding habitat. Global climate change is predicted to affect coastal habitats and may, therefore, have important consequences for the terrestrial breeding habitat of seabirds and hence seabird populations. The present study assessed use of breeding habitat in the four most abundant species of seabird breeding in south-eastern Australia using a generalised additive mixed-modelling approach. Habitat characteristics were measured on 13 islands in winter and summer, 2008-11. Burrows of the four species were associated with one or more habitat parameters, potentially explained by predator avoidance, physical requirements and possibly by interspecific competition. Whereas the habitat characteristics used by each species showed broad interspecific overlap, there was strong divergence, and the four species typically occupied different nesting sites within breeding areas. Information on the proportion of available habitat used and the influence of breeding habitat on reproductive success would enhance current understanding of what constitutes optimal breeding habitat as well as the role of interspecific competition in this assemblage of seabirds.

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This article uses the case of the Nubians in Kenya as an ethnic minority, and the 2009 Kenyan census as a particular form of recognition, to engage in a particular aspect of the debates surrounding the politics of recognition: the perceived competitive nature of the relationship between national and subnational groups, in this case ethnic groups. Using data obtained during a 6-month qualitative study conducted over the census period, this paper evaluates the response of some members of the Nubian community to their participation in the census, focusing on its most controversial question, ‘What tribe are you?’ The article concludes that the dynamic between ethnic and national identities and allegiances, when the former are recognized, can be the site of agency, participatory citizenship, and therefore also democratic equality, action and interaction.

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This article discusses an important panel held at ICIS 2011 in Shanghai to mark over thirty years of an ICIS institution, the ICIS Women’s Breakfast. The panel addressed the controversial question—is there still a need for the ICIS Women’s Breakfast? Panelists were asked if the ICIS Women’s Breakfast could be seen as divisive, and if, women’s issues are different from issues of diversity such as race or sexual  orientation. They were also asked why they thought women were still  underrepresented in our academic community, and if the lack of women at senior levels was a concern for the community. Finally, the panelists were asked what practices the community would need to adopt to combat what could be seen as structural discrimination in our community, which we believe reflects the wider world we live in. We frame the debate and the ensuing discussion in the literature about women in academia, and conclude with some practical and constructive  recommendations for the community as a whole.

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Prior studies on academic performance predominantly concentrated on ranking universities and geographical regions using publications in selected journals. Despite general agreement on journal rankings based on the number of citations, no extant articles analyze universities or countries on the basis of citations from publications in leading hospitality and tourism journals. This paper examined the number of citations that published articles from six leading journals in hospitality and tourism received during the 10-year period from 1996 to 2005. The affiliated universities, countries/regions, and geographical continents were then ranked to determine their level of academic performance. This paper provides an alternative insight into academic performance of research universities and countries.© 2014 The Authors.

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Egg predation is a major cause of reproductive failure among birds, and can compromise the viability of affected populations. Some egg predators aggregate near colonially breeding birds to exploit the seasonal increase of prey resources. We investigated spatial and temporal variations in the abundance of an egg predator (little raven Corvus mellori; Corvidae) to identify whether ravens aggregate spatially or temporally to coincide with any of three potential prey species: burrow-nesting little penguin (Eudyptula minor; Spheniscidae), short-tailed shearwater (Ardenna tenuirostris; Procellariidae), and surface-nesting silver gull (Chroicocephalus novaehollandiae; Laridae). We derived spatially explicit density estimates of little ravens using distance sampling along line transects throughout a calendar year, which encompassed little penguin, short-tailed shearwater and silver gull breeding and non-breeding seasons. High raven abundance coincided temporally with penguin and gull egg laying periods but not with that of shearwaters. The spatial distribution of raven density corresponded with the little penguin colony but not with shearwater or gull colonies. Thus, the presence of little penguin eggs in burrows correlated strongly with little raven activity, and this implies that little ravens may have learnt to exploit the plentiful subsurface food resource of little penguin eggs. Corvid management may be required to maintain the viability of this socially and economically important penguin colony.

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Context Egg depredation is a major cause of reproductive failure among birds and can drive population declines. In this study we investigate predatory behaviour of a corvid (little raven; Corvus mellori) that has only recently emerged, leading to widespread and intense depredation of eggs of a burrow-nesting seabird (little penguin; Eudyptula minor). Aims The main objective of this study was to measure the rate of penguin egg depredation by ravens to determine potential threat severity. We also examined whether penguin burrow characteristics were associated with the risk of egg depredation. Ravens generally employ two modes of predatory behaviour when attacking penguin nests; thus we examined whether burrow characteristics were associated with these modes of attack. Methods Remote-sensing cameras were deployed on penguin burrows to determine egg predation rates. Burrow measurements, including burrow entrance and tunnel characteristics, were measured at the time of camera deployment. Key results Overall, clutches in 61% of monitored burrows (n≤203) were depredated by ravens, the only predator detected by camera traps. Analysis of burrow characteristics revealed two distinct types of burrows, only one of which was associated with egg depredation by ravens. Clutches depredated by ravens had burrows with wider and higher entrances, thinner soil or vegetation layer above the egg chamber, shorter and curved tunnels and greater areas of bare ground and whitewash near entrances. In addition, 86% were covered by bower spinach (Tetragonia implexicoma), through which ravens could excavate. Ravens used two modes to access the eggs: they attacked through the entrance (25% of burrow attacks, n≤124); or dug a hole through the burrow roof (75% of attacks, n≤124). Burrows that were subject to attack through the entrance had significantly shorter tunnels than burrows accessed through the roof. Conclusions The high rates of clutch loss recorded here highlight the need for population viability analysis of penguins to assess the effect of egg predation on population growth rates. Implications The subterranean foraging niche of a corvid described here may have implications for burrow-nesting species worldwide because many corvid populations are increasing, and they exhibit great capacity to adopt new foraging strategies to exploit novel prey. Journal compilation

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The authors discuss the change in cinema ticket price and its effect on audience perception on cinema attendance in Australia. Topics discussed include the comparison of ticket prices in Australia to countries such as the U.S., Japan, and New Zealand, the reason of high ticket prices in Australia such as high wages in theatre operation and piracy, and the drop of cinema admission as result of high ticket prices. They mention the social equity issues raised by the high cost of cinema tickets.

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What gives legitimacy to the numbers that constitute the measurement techniques of the audit culture? We argue that the audit culture’s blind application of numbers to people as if there was no moral or ethical dimension to the calculation rests on a military discourse resi-dent in mathematics. This argument is based on the genealogy presented in this paper, which uncovers a regime of measurement-by-number, sedimented as legitimate through an associa-tion with military power. We claim that this military measurement-by-number is a dubious technique of government on which the audit culture relies for its highly questionable authori-ty.

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Most ecological studies require knowledge of animal abundance, but it can be challenging and destructive of habitat to obtain accurate density estimates for cryptic species, such as crustaceans that tunnel deeply into the seafloor, beaches, or mudflats. Such fossorial species are, however, widely used in environmental impact assessments, requiring sampling techniques that are reliable, efficient, and environmentally benign for these species and environments.2.Counting and measuring the entrances of burrows made by cryptic species is commonly employed to index population and body sizes of individuals. The fundamental premise is that burrow metrics consistently predict density and size. Here we review the evidence for this premise. We also review criteria for selecting among sampling methods: burrow counts, visual censuses, and physical collections.3.A simple 1:1 correspondence between the number of holes and population size cannot be assumed. Occupancy rates, indexed by the slope of regression models, vary widely between species and among sites for the same species. Thus, 'average' or 'typical' occupancy rates should not be extrapolated from site- or species specific field validations and then be used as conversion factors in other situations.4.Predictions of organism density made from burrow counts often have large uncertainty, being double to half of the predicted mean value. Whether such prediction uncertainty is 'acceptable' depends on investigators' judgements regarding the desired detectable effect sizes.5.Regression models predicting body size from burrow entrance dimensions are more precise, but parameter estimates of most models are specific to species and subject to site-to-site variation within species.6.These results emphasise the need to undertake thorough field validations of indirect census techniques that include tests of how sensitive predictive models are to changes in habitat conditions or human impacts. In addition, new technologies (e.g. drones, thermal-, acoustic- or chemical sensors) should be used to enhance visual census techniques of burrows and surface-active animals.