Development and validation of a one-tube, nested real-time PCR method suitable for routine detection of Mycobacterium bovis in animal tissue.

AIMS: Development and validation of a real-time PCR test for high-throughput routine screening of animal tissue for Mycobacterium bovis and other Mycobacterium tuberculosis complex (MTBC) members. METHODS AND RESULTS: A preliminary study compared the results of a combination of five tissue preparation/DNA extraction methods and nine PCR assays on a panel of 92 cattle tissue samples of known M. bovis culture status (55 positive and 37 negative). The combination of DNA extraction and PCR was found to be important in achieving optimal detection of M. bovis. The optimal combination of a simple tissue preparation/DNA extraction method and a one-tube, nested real-time PCR to maximize the sensitivity of detection of an M. bovis-specific RD4 deletion and an IS1081 MTBC-specific target was selected for further evaluation. In total, tissue samples collected from 981 cattle and 366 non-bovine animals and submitted for routine TB culture were parallel tested with the selected method, as well as tissue samples obtained from 156 animals in certified TB-free cattle herds. CONCLUSION: For cattle, the optimized RD4-IS1081 PCR test exhibited a diagnostic sensitivity of 96% (95% CI: 94-97%) and specificity of 97% (95% CI: 95-98%) compared to culture. Specificity was 100% when testing the 156 samples from known TB-free cattle. For non-bovine species, the PCR had a diagnostic sensitivity of 93% (95% CI: 83-98%) and a specificity of 99% (95% CI: 97-100%).

Acute kidney injury in the critical care setting.

Acute kidney injury is a sudden reduction in renal function which impairs the kidneys' ability to maintain fluid, electrolyte and acid-base balance. The syndrome often develops secondary to severe illness and is associated with a significant increase in morbidity and mortality rate in critically ill patients. This article gives an overview of the pathophysiology and aetiology of acute kidney injury, as well as the associated complications and clinical diagnostic signs. The authors also describe some common causes of the syndrome in critically ill patients, specifically sepsis, liver failure and cardiac failure, and discuss patient management in the critical care setting, with a focus on haemodynamic support and continuous renal replacement therapy.

Measuring the outcome and impact of research capacity strengthening initiatives: A review of indicators used or described in the published and grey literature.

Background: Development partners and research councils are increasingly investing in research capacity strengthening initiatives in low- and middle-income countries to support sustainable research systems. However, there are few reported evaluations of research capacity strengthening initiatives and no agreed evaluation metrics. Methods: To advance progress towards a standardised set of outcome and impact indicators, this paper presents a structured review of research capacity strengthening indicators described in the published and grey literature. Results: We identified a total of 668 indicators of which 40% measured output, 59.5% outcome and 0.5% impact. Only 1% of outcome and impact indicators met all four quality criteria applied. A majority (63%) of reported outcome indicators clustered in four focal areas, including: research management and support (97/400), the attainment and application of new research skills and knowledge (62/400), research collaboration (53/400), and knowledge transfer (39/400). Conclusions: Whilst this review identified few examples of quality research capacity strengthening indicators, it has identified priority focal areas in which outcome and impact indicators could be developed as well as a small set of 'candidate' indicators that could form the basis of development efforts.

Improved camouflage through ontogenetic colour change confers reduced detection risk in shore crabs.

Animals from many taxa, from snakes and crabs to caterpillars and lobsters, change appearance with age, but the reasons why this occurs are rarely tested.We show the importance that ontogenetic changes in coloration have on the camouflage of the green shore crabs (Carcinus maenas), known for their remarkable phenotypic variation and plasticity in colour and pattern.In controlled conditions, we reared juvenile crabs of two shades, pale or dark, on two background types simulating different habitats for 10 weeks.In contrast to expectations for reversible colour change, crabs did not tune their background match to specific microhabitats, but instead, and regardless of treatment, all developed a uniform dark green phenotype. This parallels changes in shore crab appearance with age observed in the field.Next, we undertook a citizen science experiment at the Natural History Museum London, where human subjects ("predators") searched for crabs representing natural colour variation from different habitats, simulating predator vision.In concert, crabs were not hardest to find against their original habitat, but instead, the dark green phenotype was hardest to detect against all backgrounds.The evolution of camouflage can be better understood by acknowledging that the optimal phenotype to hide from predators may change over the life history of many animals, including the utilization of a generalist camouflage strategy. A plain language summary is available for this article.

Background matching and disruptive coloration as habitat-specific strategies for camouflage.

Camouflage is a key defence across taxa and frequently critical to survival. A common strategy is background matching, resembling the colour and pattern of the environment. This approach, however, may be ineffective in complex habitats where matching one patch may lead to increased visibility in other patches. In contrast, disruptive coloration, which disguises body outlines, may be effective against complex backgrounds. These ideas have rarely been tested and previous work focuses on artificial systems. Here, we test the camouflage strategies of the shore crab (Carcinus maenas) in two habitats, being a species that is highly variable, capable of plastic changes in appearance, and lives in multiple environments. Using predator (bird and fish) vision modelling and image analysis, we quantified background matching and disruption in crabs from rock pools and mudflats, predicting that disruption would dominate in visually complex rock pools but background matching in more uniform mudflats. As expected, rock pool individuals had significantly higher edge disruption than mudflat crabs, whereas mudflat crabs more closely matched the substrate than rock pool crabs for colour, luminance, and pattern. Our study demonstrates facultative expression of camouflage strategies dependent on the visual environment, with implications for the evolution and interrelatedness of defensive strategies.