1,069 research outputs found
An Ongoing Shift in Mammalian Nest Predators of Yellow-billed Loons in Arctic Alaska
The Coastal Plain of northern Alaska is an important nesting area for a variety of avian species, where the productivity of ground-nesting species can be strongly influenced by nest predators. Recently, the density of red foxes (Vulpes vulpes) has increased in many areas of the Arctic, likely because of climate warming as well as the availability of anthropogenic food sources during winter. In areas where they occur sympatrically, red foxes can outcompete and kill the smaller Arctic fox (Vulpes lagopus). There is considerable dietary overlap between the fox species, but if the red fox is a more successful nest predator, this ongoing shift in canid species could have important implications for ground-nesting species like the Yellow-billed Loon (Gavia adamsii). We examined time-lapse photographs from 186 nests of Yellow-billed Loons in northern Alaska during the years 2008 â 15 and 2019 for the presence of foxes and other nest predators and quantified nest predation by species. Although both Arctic and red foxes were photographed near nests, we found that all successful predation of Yellow-billed Loon nests by foxes was attributable to red foxes, which were the second most frequent predator of Yellow-billed Loon nests after Glaucous Gulls (Larus hyperboreus). Arctic foxes photographed at Yellow-billed Loon nests were unsuccessful at displacing incubating loons. Several data sources suggest that the prevalence of red foxes has increased in Arctic Alaska over the last three decades, a change that is likely to have negative impacts on the nesting success of Yellow-billed Loons and possibly other large waterbirds. La plaine cĂŽtiĂšre du nord de lâAlaska est une aire de nidification importante pour une variĂ©tĂ© dâespĂšces aviaires, oĂč la productivitĂ© des espĂšces nichant au sol peut ĂȘtre grandement influencĂ©e par les prĂ©dateurs de nids. RĂ©cemment, la densitĂ© de renards roux (Vulpes vulpes) a augmentĂ© en maint endroit de lâArctique, vraisemblablement en raison du rĂ©chauffement climatique et de la disponibilitĂ© de sources alimentaires anthropiques en hiver. LĂ oĂč ils se retrouvent de maniĂšre sympatrique, les renards roux peuvent lâemporter sur les renards arctiques (Vulpes lagopus) plus petits et rĂ©ussir Ă les tuer. Il existe un chevauchement alimentaire considĂ©rable entre les espĂšces de renards, mais si le renard roux est un prĂ©dateur de nids plus prolifique, le virage caractĂ©risant les espĂšces de canidĂ©s pourrait avoir dâimportantes incidences sur les espĂšces nichant au sol, comme le plongeon Ă bec blanc (Gavia adamsii). Nous avons examinĂ© les photographies accĂ©lĂ©rĂ©es de 186 nids de plongeons Ă bec blanc du nord de lâAlaska prises entre les annĂ©es 2008 et 2015 ainsi quâen 2019 afin de repĂ©rer la prĂ©sence de renards et dâautres prĂ©dateurs de nids, en plus de quantifier la prĂ©dation des nids en fonction des espĂšces. MĂȘme sâil y a des photographies de renards roux et de renards arctiques Ă proximitĂ© de nids, nous avons pu constater que toutes les prĂ©dations rĂ©ussies de nids de plongeons Ă bec blanc Ă©taient attribuables au renard roux, le deuxiĂšme plus grand prĂ©dateur de nids de plongeons Ă bec blanc aprĂšs le goĂ©land bourgmestre (Larus hyperboreus). Les renards arctiques photographiĂ©s aux nids de plongeons Ă bec blanc nâont pas rĂ©ussi Ă dĂ©placer les plongeons en pĂ©riode dâincubation. Plusieurs sources de donnĂ©es suggĂšrent que la prĂ©dominance des renards roux a augmentĂ© dans lâArctique alaskien au cours des trois derniĂšres dĂ©cennies, un changement qui est susceptible dâavoir des incidences nĂ©gatives sur le succĂšs de la nidification des plongeons Ă bec blanc, voire dâautres oiseaux aquatiques plus volumineux.
Child sexual abuse material in child-centred institutions: situational crime prevention approaches
This paper focuses on the potential for child-centred institutions to use situational crime prevention (SCP) strategies to prevent or reduce child sexual abuse material (CSAM)1 offending as a distinct form of child sexual abuse (CSA). We discuss the failure of the Royal Commission into Institutional Responses to Child Sexual Abuse in Australia to address the potential for CSAM offending to occur in child-centred institutions. Our premise is that CSAM offending is markedly shaped by the situation in which it occurs, rather than by any pre-existing preparedness to offend sexually against children. In this context, SCP for CSAM offending must be considered as part of overall strategies to combat CSA in institutional settings. However, we acknowledge that effective implementation of SCP in this area is not straightforward. We consider some of the challenges in implementing SCP at an institutional level
Taxing the Informal Economy: The Current State of Knowledge and Agendas for Future Research
This paper reviews the literature on taxation of the informal economy, taking stock of key debates
and drawing attention to recent innovations. Conventionally, the debate on whether to tax has frequently focused
on the limited revenue potential, high cost of collection, and potentially adverse impact on small firms. Recent
arguments have increasingly emphasised the more indirect benefits of informal taxation in relation to economic
growth, broader tax compliance, and governance. More research is needed, we argue, into the relevant costs and
benefits for all, including quasi-voluntary compliance, political and administrative incentives for reform, and
citizen-state bargaining over taxation
Measuring Information Transfer
An information theoretic measure is derived that quantifies the statistical
coherence between systems evolving in time. The standard time delayed mutual
information fails to distinguish information that is actually exchanged from
shared information due to common history and input signals. In our new
approach, these influences are excluded by appropriate conditioning of
transition probabilities. The resulting transfer entropy is able to distinguish
driving and responding elements and to detect asymmetry in the coupling of
subsystems.Comment: 4 pages, 4 Figures, Revte
Test your surrogate data before you test for nonlinearity
The schemes for the generation of surrogate data in order to test the null
hypothesis of linear stochastic process undergoing nonlinear static transform
are investigated as to their consistency in representing the null hypothesis.
In particular, we pinpoint some important caveats of the prominent algorithm of
amplitude adjusted Fourier transform surrogates (AAFT) and compare it to the
iterated AAFT (IAAFT), which is more consistent in representing the null
hypothesis. It turns out that in many applications with real data the
inferences of nonlinearity after marginal rejection of the null hypothesis were
premature and have to be re-investigated taken into account the inaccuracies in
the AAFT algorithm, mainly concerning the mismatching of the linear
correlations. In order to deal with such inaccuracies we propose the use of
linear together with nonlinear polynomials as discriminating statistics. The
application of this setup to some well-known real data sets cautions against
the use of the AAFT algorithm.Comment: 14 pages, 15 figures, submitted to Physical Review
Assays to Detect ÎČ-Tubulin Codon 200 Polymorphism in Trichuris trichiura and Ascaris lumbricoides
The soil-transmitted helminths Ascaris lumbricoides and Trichuris trichiura are gastrointestinal nematodes causing many disabilities in tropical parts of the developing world. Control programs, such as âThe Focussing Resources on Effective School Healthâ (FRESH) Partnership, have been implemented to remove human soil-transmitted nematodes through large-scale use of benzimidazole anthelmintic drugs for school-aged children in developing countries. The benzimidazole drugs albendazole and mebendazole are commonly used as a single annual treatment in areas where the burden is high. In veterinary nematodes, repeated use of these anthelmintics has selected for resistant populations. Resistance to benzimidazoles is commonly associated with a single amino acid substitution from phenylalanine to tyrosine in the ÎČ-tubulin gene at position 200. In this study, we have developed pyrosequencing assays for codon 200 in A. lumbricoides and T. trichiura to screen for this single nucleotide polymorphism (SNP) in ÎČ-tubulin. The 200Tyr SNP was detected at low frequency in T. trichiura from non-treated people from Kenya and at high frequency in T. trichiura from treated people from Panama. The presence of the resistance-associated SNP may play a role in the sometimes low and variable efficacy of benzimidazole anthelmintics against T. trichiura
Non-Steroidal Anti-Inflammatory Drug Induced Upper Gastrointestinal Haemorrhage And Bleeding
Non-steroidal anti-inflammatory drugs are very widely used in our community. There has been much concern recently about the risks of NSAIDs-induced upper gastrointestinal haemorrhage and perforation. Many patients taking these drugs have become concerned about these matters and confused by contradictory statements appearing in the media. This paper seeks to address those issues
Implications of Debunking the "Critical Positivity Ratio" for Humanistic Psychology:Introduction to Special Issue
An extraordinary claim was made by one of the leading researchers within positive psychology, namely, there is a universal-invariant ratio between positive to negative emotions that serves as a unique tipping point between flourishing and languishing in individuals, marriages, organizations, and other human systems across all cultures and times. Known as the "critical positivity ratio," this finding was supposedly derived from the famous Lorenz equation in physics by using the mathematics of nonlinear dynamic systems, and was defined precisely as "2.9013." This exact number was widely touted as a great discovery by many leaders of positive psychology, had tremendous impact in various applied areas of psychology, and, more broadly, and was extensively cited in both the scientific literature and in the global popular media. However, this finding has been demonstrated to be bogus. Since its advent as a relatively new subdiscipline, positive psychology has claimed superiority to its precursor, the subdiscipline of humanistic psychology, in terms of supposedly both using more rigorous science and avoiding popularizing nonsense. The debunking of the critical positivity ratio demonstrates that positive psychology did not live up to these claims, and this has important implications, which are discussed in terms of "romantic scientism" and "voodoo science." In addition, articles in the special issue on the "Implications of Debunking the 'Critical Positivity Ratio' for Humanistic Psychology" are introduced, as they also delve into these concerns
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