1,571 research outputs found
Epidemiology of chronic hepatitis B and C in Victoria, Australia: insights and impacts from enhanced surveillance
Objective: To assess the impact of an enhanced viral hepatitis surveillance program on datacompleteness and on epidemiological assessment of affected populations.Methods: Notified cases of non-acute hepatitis B and C were analysed to determinedemographic characteristics and risk factors during the period prior to July 2015–June 2016,and during enhanced surveillance of the period July 2016–June 2017, during which timedoctors were contacted for information about new diagnoses.Results: During the enhanced period, completeness for country of birth and Indigenous statusdoubled for both hepatitis B and hepatitis C, from 18–37% to 48–65%. The incidence ratio ofhepatitis C among Aboriginal and Torres Strait Islander people increased from eight-fold to 11.4-fold, and the proportion of hepatitis B cases reported as born in China and Vietnam relative toother countries increased. New data fields identified that 12% of hepatitis C diagnoses occurredin a correctional facility, and 2% of hepatitis B cases were healthcare workers.Conclusions: Improved data completeness highlighted the underlying epidemiology ofchronic viral hepatitis, demonstrating the increased burden of infection among specific prioritypopulations.Implications for public health: Enhanced surveillance provides greater insight into theepidemiology of chronic viral hepatitis, identifying groups at risk and opportunities for publichealth action
Association of a Bovine Prion Gene Haplotype with Atypical BSE
Background: Atypical bovine spongiform encephalopathies (BSEs) are recently recognized prion diseases of cattle. Atypical BSEs are rare; approximately 30 cases have been identified worldwide. We tested prion gene (PRNP) haplotypes for an association with atypical BSE.
Methodology/Principle Findings: Haplotype tagging polymorphisms that characterize PRNP haplotypes from the promoter region through the three prime untranslated region of exon 3 (25.2 kb) were used to determine PRNP haplotypes of six available atypical BSE cases from Canada, France and the United States. One or two copies of a distinct PRNP haplotype were identified in five of the six cases (p = 1.36×10-4, two-tailed Fisher’s exact test; CI95% 0.263–0.901, difference between proportions). The haplotype spans a portion of PRNP that includes part of intron 2, the entire coding region of exon 3 and part of the three prime untranslated region of exon 3 (13 kb).
Conclusions/Significance: This result suggests that a genetic determinant in or near PRNP may influence susceptibility of cattle to atypical BSE
Dimensionality and dynamics in the behavior of C. elegans
A major challenge in analyzing animal behavior is to discover some underlying
simplicity in complex motor actions. Here we show that the space of shapes
adopted by the nematode C. elegans is surprisingly low dimensional, with just
four dimensions accounting for 95% of the shape variance, and we partially
reconstruct "equations of motion" for the dynamics in this space. These
dynamics have multiple attractors, and we find that the worm visits these in a
rapid and almost completely deterministic response to weak thermal stimuli.
Stimulus-dependent correlations among the different modes suggest that one can
generate more reliable behaviors by synchronizing stimuli to the state of the
worm in shape space. We confirm this prediction, effectively "steering" the
worm in real time.Comment: 9 pages, 6 figures, minor correction
Prognostic impact of urokinase-type plasminogen activator receptor (uPAR) in cytosols and pellet extracts derived from primary breast tumours
Using a previously developed enzyme-linked immunosorbent assay (ELISA), the levels of the receptor for urokinase-type plasminogen activator (uPAR) were determined in cytosols and corresponding membrane pellets derived from 878 primary breast tumours. The levels of uPAR in the pellet extracts were more than 3-fold higher than those measured in the cytosols (P< 0.001). Moreover, the uPAR levels in the two types of extracts were weakly, though significantly, correlated with each other (rS= 0.20, P< 0.001). In Cox univariate analysis, high cytosolic levels of uPAR were significantly associated with reduced overall survival (OS) and relapse-free survival (RFS). The levels of uPAR in pellet extracts appeared not to be related with patient survival. In multivariate analysis, elevated levels of uPAR measured in cytosols and pellet extracts were found to be independent predictors of poor OS, not RFS. The prediction of poor prognosis on the basis of high uPAR levels emphasizes its important role in plasmin-mediated degradation of extracellular matrix proteins during cancer invasion and metastasis. © 2001 Cancer Research Campaign http://www.bjcancer.co
Natural images from the birthplace of the human eye
Here we introduce a database of calibrated natural images publicly available
through an easy-to-use web interface. Using a Nikon D70 digital SLR camera, we
acquired about 5000 six-megapixel images of Okavango Delta of Botswana, a
tropical savanna habitat similar to where the human eye is thought to have
evolved. Some sequences of images were captured unsystematically while
following a baboon troop, while others were designed to vary a single parameter
such as aperture, object distance, time of day or position on the horizon.
Images are available in the raw RGB format and in grayscale. Images are also
available in units relevant to the physiology of human cone photoreceptors,
where pixel values represent the expected number of photoisomerizations per
second for cones sensitive to long (L), medium (M) and short (S) wavelengths.
This database is distributed under a Creative Commons Attribution-Noncommercial
Unported license to facilitate research in computer vision, psychophysics of
perception, and visual neuroscience.Comment: Submitted to PLoS ON
Lineage Divergence and Historical Gene Flow in the Chinese Horseshoe Bat (Rhinolophus sinicus)
PMCID: PMC3581519This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Host Suitability of a Gregarious Parasitoid on Beetle Hosts: Flexibility between Fitness of Adult and Offspring
Behavioral tactics play a crucial role in the evolution of species and are likely to be found in host-parasitoid interactions where host quality may differ between host developmental stages. We investigated foraging decisions, parasitism and related fitness in a gregarious ectoparasitoid, Sclerodermus harmandi in relation to two distinct host developmental stages: larvae and pupae. Two colonies of parasitoids were reared on larvae of Monochamus alternatus and Saperda populnea (Cerambycidae: Lamiinae). Paired-choice and non-choice experiments were used to evaluate the preference and performance of S. harmandi on larvae and pupae of the two species. Foraging decisions and offspring fitness-related consequences of S. harmandi led to the selection of the most profitable host stage for parasitoid development. Adult females from the two colonies oviposited more quickly on pupae as compared to larvae of M. alternatus. Subsequently, their offspring development time was faster and they gained higher body weight on the pupal hosts. This study demonstrates optimal foraging of intraspecific détente that can occur during host-parasitoid interactions, of which the quality of the parasitism (highest fitness benefit and profitability) is related to the host developmental stage utilized. We conclude that S. harmandi is able to perfectly discriminate among host species or stages in a manner that maximizes its offspring fitness. The results indicated that foraging potential of adults may not be driven by its maternal effects, also induced flexibly with encountering prior host quality
Sex-biased parental care and sexual size dimorphism in a provisioning arthropod
The diverse selection pressures driving the evolution of sexual size dimorphism (SSD) have long been debated. While the balance between fecundity selection and sexual selection has received much attention, explanations based on sex-specific ecology have proven harder to test. In ectotherms, females are typically larger than males, and this is frequently thought to be because size constrains female fecundity more than it constrains male mating success. However, SSD could additionally reflect maternal care strategies. Under this hypothesis, females are relatively larger where reproduction requires greater maximum maternal effort – for example where mothers transport heavy provisions to nests.
To test this hypothesis we focussed on digger wasps (Hymenoptera: Ammophilini), a relatively homogeneous group in which only females provision offspring. In some species, a single large prey item, up to 10 times the mother’s weight, must be carried to each burrow on foot; other species provide many small prey, each flown individually to the nest.
We found more pronounced female-biased SSD in species where females carry single, heavy prey. More generally, SSD was negatively correlated with numbers of prey provided per offspring. Females provisioning multiple small items had longer wings and thoraxes, probably because smaller prey are carried in flight.
Despite much theorising, few empirical studies have tested how sex-biased parental care can affect SSD. Our study reveals that such costs can be associated with the evolution of dimorphism, and this should be investigated in other clades where parental care costs differ between sexes and species
Factors influencing research engagement: research interest, confidence and experience in an Australian speech-language pathology workforce
Background: Recent initiatives within an Australia public healthcare service have seen a focus on increasing the research capacity of their workforce. One of the key initiatives involves encouraging clinicians to be research generators rather than solely research consumers. As a result, baseline data of current research capacity are essential to determine whether initiatives encouraging clinicians to undertake research have been effective. Speech pathologists have previously been shown to be interested in conducting research within their clinical role; therefore they are well positioned to benefit from such initiatives. The present study examined the current research interest, confidence and experience of speech language pathologists (SLPs) in a public healthcare workforce, as well as factors that predicted clinician research engagement
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