First Case of Systemic Coronavirus Infection in a Domestic Ferret (Mustela putorius furo) in Peru.

A domestic ferret from Lima, Peru, died after ten days of non-specific clinical signs. Based on pathology, immunohistochemistry and molecular analysis, ferret systemic coronavirus (FRSCV)-associated disease was diagnosed for the first time in South America. This report highlights the potential spread of pathogens by the international pet trade

Experimental pig-to-pig transmission dynamics for African swine fever virus, Georgia 2007/1 strain

African swine fever virus (ASFV) continues to cause outbreaks in domestic pigs and wild boar in Eastern European countries. To gain insights into its transmission dynamics, we estimated the pig-to-pig basic reproduction number (R 0) for the Georgia 2007/1 ASFV strain using a stochastic susceptible-exposed-infectious-recovered (SEIR) model with parameters estimated from transmission experiments. Models showed that R 0 is 2·8 [95% confidence interval (CI) 1·3–4·8] within a pen and 1·4 (95% CI 0·6–2·4) between pens. The results furthermore suggest that ASFV genome detection in oronasal samples is an effective diagnostic tool for early detection of infection. This study provides quantitative information on transmission parameters for ASFV in domestic pigs, which are required to more effectively assess the potential impact of strategies for the control of between-farm epidemic spread in European countries.ISSN:0950-2688ISSN:1469-440

AINFO - versão 5.0: manual on-line.

O AINFO é um sistema para automação de bibliotecas e recuperação de informação, desenvolvimento em padrão Windows, com arquitetura cliente/servidor baseada no sistema gerenciador de banco de dados relacional Firebird. Pemite o gerenciamento de informação técnico-científica, integrando bases de dados documentais, cadastrais e processos bibliográficos através do armazenamento, atualização, indexação e recuperação de informação de forma simples e rápida, utilizando não apenas recursos de um istema gerenciador de banco de dados, como controle de concorrência e manutenção de integridade das bases de dados, mas também oferecendo facilidades de recuperação de informação textual não disponíveis nesses sistemas.bitstream/CNPTIA/10207/1/doc40.pdfAcesso em: 29 maio 2008

Intrasexual competition facilitates the evolution of alternative mating strategies in a colour polymorphic fish

<p>Abstract</p> <p>Background</p> <p>Intense competition for access to females can lead to males exploiting different components of sexual selection, and result in the evolution of alternative mating strategies (AMSs). Males of <it>Poecilia parae</it>, a colour polymorphic fish, exhibit five distinct phenotypes: drab-coloured (immaculata), striped (parae), structural-coloured (blue) and carotenoid-based red and yellow morphs. Previous work indicates that immaculata males employ a sneaker strategy, whereas the red and yellow morphs exploit female preferences for carotenoid-based colours. Mating strategies favouring the maintenance of the other morphs remain to be determined. Here, we report the role of agonistic male-male interactions in influencing female mating preferences and male mating success, and in facilitating the evolution of AMSs.</p> <p>Results</p> <p>Our study reveals variation in aggressiveness among <it>P. parae </it>morphs during indirect and direct interactions with sexually receptive females. Two morphs, parae and yellow, use aggression to enhance their mating success (i.e., number of copulations) by 1) directly monopolizing access to females, and 2) modifying female preferences after winning agonistic encounters. Conversely, we found that the success of the drab-coloured immaculata morph, which specializes in a sneak copulation strategy, relies in its ability to circumvent both male aggression and female choice when facing all but yellow males.</p> <p>Conclusions</p> <p>Strong directional selection is expected to deplete genetic variation, yet many species show striking genetically-based polymorphisms. Most studies evoke frequency dependent selection to explain the persistence of such variation. Consistent with a growing body of evidence, our findings suggest that a complex form of balancing selection may alternatively explain the evolution and maintenance of AMSs in a colour polymorphic fish. In particular, this study demonstrates that intrasexual competition results in phenotypically distinct males exhibiting clear differences in their levels of aggression to exclude potential sexual rivals. By being dominant, the more aggressive males are able to circumvent female mating preferences for attractive males, whereas another male type incorporates subordinate behaviours that allow them to circumvent male aggression and female mating preferences. Together, these and previous results indicate that exploiting different aspects of social interactions may allow males to evolve distinct mating strategies and thus the long term maintenance of polymorphisms within populations.</p

Exact Histogram Specification Optimized for Structural Similarity

An exact histogram specification (EHS) method modifies its input image to have a specified histogram. Applications of EHS include image (contrast) enhancement (e.g., by histogram equalization) and histogram watermarking. Performing EHS on an image, however, reduces its visual quality. Starting from the output of a generic EHS method, we maximize the structural similarity index (SSIM) between the original image (before EHS) and the result of EHS iteratively. Essential in this process is the computationally simple and accurate formula we derive for SSIM gradient. As it is based on gradient ascent, the proposed EHS always converges. Experimental results confirm that while obtaining the histogram exactly as specified, the proposed method invariably outperforms the existing methods in terms of visual quality of the result. The computational complexity of the proposed method is shown to be of the same order as that of the existing methods. Index terms: histogram modification, histogram equalization, optimization for perceptual visual quality, structural similarity gradient ascent, histogram watermarking, contrast enhancement

Rodent Aβ Modulates the Solubility and Distribution of Amyloid Deposits in Transgenic Mice

The amino acid sequence of amyloid precursor protein (APP) is highly conserved, and age-related Abeta aggregates have been described in a variety of vertebrate animals, with the notable exception of mice and rats. Three amino acid substitutions distinguish mouse and human Abeta that might contribute to their differing properties in vivo. To examine the amyloidogenic potential of mouse Abeta, we studied several lines of transgenic mice overexpressing wild-type mouse amyloid precursor protein (moAPP) either alone or in conjunction with mutant PS1 (PS1dE9). Neither overexpression of moAPP alone nor co-expression with PS1dE9 caused mice to develop Alzheimer-type amyloid pathology by 24 months of age. We further tested whether mouse Abeta could accelerate the deposition of human Abeta by crossing the moAPP transgenic mice to a bigenic line expressing human APPswe with PS1dE9. The triple transgenic animals (moAPP x APPswe/PS1dE9) produced 20% more Abeta but formed amyloid deposits no faster and to no greater extent than APPswe/PS1dE9 siblings. Instead, the additional mouse Abeta increased the detergent solubility of accumulated amyloid and exacerbated amyloid deposition in the vasculature. These findings suggest that, although mouse Abeta does not influence the rate of amyloid formation, the incorporation of Abeta peptides with differing sequences alters the solubility and localization of the resulting aggregates