256 research outputs found
Salmonella in free-ranging quokkas (Setonix brachyurus) from Rottnest Island and the mainland of Western Australia
Salmonella is a genus of Gram-negative, motile, and facultative anaerobic bacteria with a worldwide distribution that contaminates multiple substrates (vegetation, food, soil, and water) and inhabits the gastrointestinal tract of birds, reptiles, and mammals, including humans. Rottnest Island is a popular tourist destination and is abundantly inhabited by quokkas (Setonix brachyurus), a charismatic small wallaby. Current data on the association between Salmonella and quokkas on Rottnest Island are outdated by approximately 30 years. Additionally, previous studies on quokkas on this island and mainland Western Australia did not perform physical examinations or any diagnostic tests. The aim of the project was to assess the prevalence of Salmonella spp. in quokkas from Rottnest Island and mainland Western Australia and correlate the presence of the bacterium with the health of the animal. Ninety-two quokkas from Rottnest Island (n = 71) and populations on the mainland (n = 21) were screened for Salmonella, and a prevalence of 47.9% and 4.8%, respectively, was determined. A total of 16 serovars were identified from 37 isolates; five of these serovars had previously not been described in the quokka. Salmonella appeared to have an effect on the haematology and blood chemistry of quokkas on Rottnest Island consistent with subclinical salmonellosis. The health of Rottnest Island quokkas, and their potential impact on the health of the visitors to the island, should continue to be monitored carefully
Qualitative Behavioural Assessment of Bos indicus cattle after surgical castration
There are various methods to perform castration of cattle, but surgical castration is the most common. Although it is well documented that surgical procedures inflict pain, analgesic use is usually omitted for surgical castration of production animals in Australia. This study compares the behavioural responses of castrated cattle (C) with non-castrated (NC) controls, and C with those castrated and given lignocaine and meloxicam (CLM) for analgesia. Brahman bull calves (n = 8 for each treatment) were filmed in the morning pre- (day -1) and post- (day +1) castration in the paddock and feed yard (‘context’ of observation). Over four sessions, volunteer observers viewed the video footage for Qualitative Behaviour Analysis (QBA) using the Free Choice Profiling methodology comparing C and NC cattle, and C and CLM cattle under both contexts. The QBA consensus profiles explained 37.4% (C vs. NC) and 40.6% (C vs. CLM) of variation among observers for paddock sessions and 34.7% (C vs. NC) and 38.7% (C vs. CLM) for feed yard sessions. Significant treatment x day interaction effects were recorded in the paddock (P = 0.007 and P < 0.001) and yard (P = 0.004 and P = 0.025) contexts for comparisons between NC vs C, and C vs CLM respectively. Compared to NC, post-castration C cattle were described as more ‘bored’/’lethargic’ and ‘alone’ (paddock) and were more ‘calm’/’relaxed’ and ‘relaxed’/’lonely’ (yard). Similarly, compared to CLM, post-castration C cattle were described as more ‘docile’/’chilled’ and ‘curious’/’aware’ (paddock) and were less ‘hungry’/’alert’ (yard). There was only one correlation between qualitative and quantitative behaviour scoring; ruminating showed significant correlation with one dimension in each context, that reflected a positive emotion (‘calm, relaxed’). The comparison between C vs. NC suggest that C were less active and less engaged with their environment compared to the NC group following castration. The C vs. CLM comparison suggests a more subtle response whereby analgesia was associated with more positive valence (higher scores on ‘calm/comfortable’, and ‘hungry/alert’ dimensions) following castration. The interpretation of findings requires careful consideration of the emotional responses given these calves were unhabituated and reactive to their surroundings. These results suggest the body language of Bos indicus cattle may reveal indicators of pain, and that the administration of analgesia may be beneficial at the time of castration. The study highlights the complexities and challenges of identifying pain responses in Brahman cattle
Heavy quarkonium: progress, puzzles, and opportunities
A golden age for heavy quarkonium physics dawned a decade ago, initiated by
the confluence of exciting advances in quantum chromodynamics (QCD) and an
explosion of related experimental activity. The early years of this period were
chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in
2004, which presented a comprehensive review of the status of the field at that
time and provided specific recommendations for further progress. However, the
broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles
could only be partially anticipated. Since the release of the YR, the BESII
program concluded only to give birth to BESIII; the -factories and CLEO-c
flourished; quarkonium production and polarization measurements at HERA and the
Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the
deconfinement regime. All these experiments leave legacies of quality,
precision, and unsolved mysteries for quarkonium physics, and therefore beg for
continuing investigations. The plethora of newly-found quarkonium-like states
unleashed a flood of theoretical investigations into new forms of matter such
as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the
spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b},
and b\bar{c} bound states have been shown to validate some theoretical
approaches to QCD and highlight lack of quantitative success for others. The
intriguing details of quarkonium suppression in heavy-ion collisions that have
emerged from RHIC have elevated the importance of separating hot- and
cold-nuclear-matter effects in quark-gluon plasma studies. This review
systematically addresses all these matters and concludes by prioritizing
directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K.
Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D.
Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A.
Petrov, P. Robbe, A. Vair
Genetic algorithm based feature selection combined with dual classification for the automated detection of proliferative diabetic retinopathy
Proliferative diabetic retinopathy (PDR) is a condition that carries a high risk of severe visual impairment. The hallmark of PDR is the growth of abnormal new vessels. In this paper, an automated method for the detection of new vessels from retinal images is presented. This method is based on a dual classification approach. Two vessel segmentation approaches are applied to create two separate binary vessel map which each hold vital information. Local morphology features are measured from each binary vessel map to produce two separate 4-D feature vectors. Independent classification is performed for each feature vector using a support vector machine (SVM) classifier. The system then combines these individual outcomes to produce a final decision. This is followed by the creation of additional features to generate 21-D feature vectors, which feed into a genetic algorithm based feature selection approach with the objective of finding feature subsets that improve the performance of the classification. Sensitivity and specificity results using a dataset of 60 images are 0.9138 and 0.9600, respectively, on a per patch basis and 1.000 and 0.975, respectively, on a per image basis
Reproductive biology of Artibeus fimbriatus Gray 1838 (Chiroptera) at the southern limit of its geographic range
Comunidades de morcegos em hábitats de uma Mata Amazônica remanescente na Ilha de São Luís, Maranhão
Frugivoria por aves em um mosaico de Floresta Estacional Semidecidual e reflorestamento misto em Rio Claro, São Paulo, Brasil
Visando subsidiar futuros projetos de recuperação florestal com base nas interações animal-planta, foram avaliadas as espécies ornitocóricas e o consumo de frutos por aves em um mosaico de Floresta Estacional Semidecidual e um reflorestamento misto, em Rio Claro, São Paulo. Através do monitoramento da frutificação e avaliação dos eventos de frugivoria em sessões focais e ad libitum, foram registradas 31 espécies ornitocóricas fornecendo frutos para 38 espécies de aves consumidoras. No reflorestamento misto foram observadas 90,3% (n=28) das espécies ornitocóricas frutificando ao longo de todo ano, enquanto no fragmento florestal, somente 51,6% (n=16) delas foram registradas, com maiores variações temporais na oferta de frutos; 65,2% (n=1027) dos frutos foram consumidos no reflorestamento misto e 34,8% (n=547) no fragmento florestal. Tais resultados podem estar relacionados ao menor tamanho do fragmento de vegetação nativa, o que, proporcionalmente, poderia determinar uma menor riqueza de espécies vegetais no mesmo e/ou ao fato de a dispersão abiótica tender a predominar nos locais fragmentados e perturbados. O reflorestamento misto, embora apresente algumas espécies vegetais exóticas, está sendo ecologicamente mais funcional para a avifauna e, devido à proximidade com o fragmento, parece estar contribuindo para a manutenção das comunidades de aves residentes e visitantes deste último através dos recursos alimentares oferecidos.To support future forest recovery projects based on plant-animal interactions, this work aimed to evaluate the ornithochoric species and fruit consumption by birds in both a mosaic of seasonal semideciduous forest and a mixed reforested area in Rio Claro, Sao Paulo, Brazil. By monitoring and evaluating fruiting and frugivory events in focal and ad libitum sessions, 31 ornithochoric species were found that provide fruits to 38 species of frugivorous birds. In the mixed reforested area, 90.3% (n = 28) of the ornithochoric species had fruit throughout the year, while in the forest fragment this percentage was only 51.6% (n = 16), with higher temporal variations in the availability of the fruits; 65.2% (n = 1027) of fruits were consumed in the reforested area and 34.8% (n = 547) in the forest fragment. These results may be related to the smaller size of the forest fragment, which, proportionately, could determine a lower richness of plant species, and/or to the fact that abiotic dispersal tends to predominate in fragmented and disturbed sites. The mixed reforested area, although it has some exotic plant species, is ecologically more functional for birds and, due to its proximity to the fragment, apparently contributes to the maintenance of the resident and visiting bird communities of this region by providing food resources
Habitat structure and small mammals abundances in one semiarid landscape in the Brazilian Caatinga
Studies conducted under a major project sponsored by the Brazilian Academy of Sciences in the 1970's concluded that the small mammal fauna of the semiarid Caatinga region of Brazil is impoverished and highly restricted to mesic granite outcroppings due to the lack of water conserving physiological capabilities in its species. This work focuses the abundance of small mammals in five typical Caatinga habitats. Indirect gradient analysis shows that three theoretical environmental variables explain most of the variance present in the community abundance matrix. Direct analysis of gradients show that none of these variables is highly correlated to availability of granite outcroppings. Our data also suggest that the abundances in Caatinga are not particularly low when compared to neighbor biomes and that underlying factors of habitat use by Caatinga small mammals are more complex than previously supposed.<br>Estudos realizados dentro de um grande projeto financiado pela Academia Brasileira de Ciências na década de 1970 concluíram que a fauna de pequenos mamíferos da região semiárida da Caatinga do Brasil é empobrecida e altamente restrita a afloramentos graníticos mésicos devido à falta de capacidades fisiológicas para a conservação de água das suas espécies. Este trabalho enfoca a abundância de pequenos mamíferos em cinco habitats típicos da Caatinga. A análise indireta de gradiente mostra que três variáveis ambientais teóricas explicam a maior parte da variância presente na matriz de abundâncias da comunidade. A análise direta de gradiente mostra que nenhuma dessas variáveis está altamente correlacionada à disponibilidade de afloramentos graníticos. Nossos dados também sugerem que a abundância na Caatinga não é particularmente baixa quando comparada a biomas vizinhos e que os fatores subjacentes ao uso do habitat pelos pequenos mamíferos da Caatinga é mais complexo do que previamente suposto
Evolution and phylogeny of the New Zealand cicada genus Kikihia Dugdale (Homoptera: Auchenorrhyncha: Cicadidae) with special reference to the origin of the Kermadec and Norfolk Islands' species
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