Agreement among surgical pathologists evaluating routine histologic sections of digits amputated from cats and dogs.

Agreement among pathologists interpreting histologic specimens is an area of interest within human pathology, but little work in this area has been reported in the veterinary literature. Agreement among pathologists evaluating routine histologic sections of amputated digits from cats and dogs submitted to multiple diagnostic centers was examined. Histologic sections from surgical specimens were reviewed in a blinded fashion by two pathologists, and a comparison to the original diagnosis, as stated in the diagnostic report, was recorded. A total of 513 cases were reviewed, and complete agreement was reached in 409 (79.7%). Of the 104 instances of disagreement, 77 (74.0%) were considered to be of clinical significance. The diagnosis of keratoacanthoma was disagreed with in 19 of 21 diagnoses (90.4%). No other individual diagnosis was similarly disputed. The overall level of disagreement is large and is similar to that reported in human pathology and suggests that further study of this issue would be useful in veterinary pathology.     

Major gene resistance in Brassica napus (oilseed rape) is overcome by changes in virulence of populations of Leptosphaeria maculans in France and Australia

Resistance of Brassica napus (oilseed rape, canola) conferred by three different major resistance genes has been overcome by changes in virulence of Leptosphaeria maculans populations in France and Australia. In South Australia where B. napus cultivars with major gene resistance derived from Brassica rapa ssp. sylvestris were grown extensively, resistance was rendered ineffective within 3 years of commercial release of the cultivar. Disease severity was higher on cultivars with sylvestris-derived resistance than cultivars with polygenic resistance. This Australian situation is compared to that in France, where resistance conferred by the Rlm1 gene was overcome nation-wide in 5 years under commercial cropping practices, and also where a source of resistance introgressed into B. napus from B. juncea was rendered inefficient in 3 years in experimental field plots near Rennes.     

Seasonality in ocean microbial communities

Ocean warming occurs every year in seasonal cycles that can help us to understand long-term responses of plankton to climate change. Rhythmic seasonal patterns of microbial community turnover are revealed when high-resolution measurements of microbial plankton diversity are applied to samples collected in lengthy time series. Seasonal cycles in microbial plankton are complex, but the expansion of fixed ocean stations monitoring long-term change and the development of automated instrumentation are providing the time-series data needed to understand how these cycles vary across broad geographical scales. By accumulating data and using predictive modeling, we gain insights into changes that will occur as the ocean surface continues to warm and as the extent and duration of ocean stratification increase. These developments will enable marine scientists to predict changes in geochemical cycles mediated by microbial communities and to gauge their broader impacts.     

A case study from the post-new deal state agricultural experiment station system: a life of mixed signals in southern Illinois

A wide literature in the sociology of agriculture has depicted the development of agricultural experiment stations at land grant colleges as part of a development project to improve agricultural productivity in particular commodities. Some experiment stations developed regional agricultural centers or stations to improve productivity and address local concerns, recognizing the importance of context in rural development. Through analysis of one such station, the Dixon Springs Agricultural Center in Southern Illinois, this paper describes how regional agricultural stations played a key role in the often conflicting agricultural programs of and following the New Deal. Changes in university structure from the 1970s to present and the current national recession have led to financial crises that have put these stations in a precarious position. Still, we argue that these institutions ought to be recognized as regional resources for a new era of agricultural development, and we suggest approaching that new era by building on the existing literature of community–university partnerships.     

Leptin regulates striatal regions and human eating behavior

Studies of the fat-derived hormone leptin have provided key insights into the molecular and neural components of feeding behavior and body weight regulation. An important challenge lies in understanding how the rewarding properties of food interact with, and can override, physiological satiety signals and promote overeating. We used functional magnetic resonance imaging to measure brain responses in two human patients with congenital leptin deficiency who were shown images of food before and after 7 days of leptin replacement therapy. Leptin was found to modulate neural activation in key striatal regions, suggesting that the hormone acts on neural circuits governing food intake to diminish the perception of food reward while enhancing the response to satiety signals generated during food consumption.     

Fungi as potential factors limiting natural regeneration of pedunculate oak (Quercus robur) in mixed-species forest stands in Poland

Dieback of young Quercus robur seedlings can limit natural regeneration in mixed-species forest stands in Poland. The aim of this study was to examine the role of fungi in the dieback of oak seedlings in central Europe. Fungi were isolated from the stems and roots of Q. robur, from both healthy seedlings and seedlings with symptoms, that were sampled from four stands in Poland. In total, 111 distinct taxa were identified. Ascomycota was dominant, representing 95.6% of the isolates. Among the taxa identified, Alternaria alternata, Colletotrichum fioriniae, Colletotrichum godetiae, Coniella quercicola, Diaporthe eres, Gnomoniopsis paraclavulata, Ilyonectria rufa, Mucor genevensis, Penicillium glandicola, Tubakia dryina, and Umbelopsis changbaiensis were most frequently isolated, and were consistently found in stems and roots of both healthy and diseased plants. The community compositions of fungi in healthy and diseased stems were similar, although Fusarium species, especially Fusarium sp. 1 (FTSC 5) and F. sporotrichioides, were found mainly in seedlings with symptoms. The pathogenicity of the most consistently isolated species from stems and roots of diseased seedlings was tested on Q. robur seedlings. F. sporotrichioides caused the largest lesions on inoculated seedlings. Six weeks after inoculation, D. eres, C. fioriniae, G. paraclavulata, T. dryina, and F. sporotrichioides killed 0%–18.8% of seedlings, while I. rufa and Ilyonectria pseudodestructans did not cause any lesions or other symptoms. This study is the first comprehensive report suggesting that massive fungal attack can lead to oak seedling dieback in mixed-species forest stands in central Europe.     

Modulation of postendocytic sorting of G protein-coupled receptors

Recycling of the mu opioid receptor to the plasma membrane after endocytosis promotes rapid resensitization of signal transduction, whereas targeting of the delta opioid receptor (DOR) to lysosomes causes proteolytic down-regulation. We identified a protein that binds preferentially to the cytoplasmic tail of the DOR as a candidate heterotrimeric GTP-binding protein (G protein)-coupled receptor-associated sorting protein (GASP). Disruption of the DOR-GASP interaction through receptor mutation or overexpression of a dominant negative fragment of GASP inhibited receptor trafficking to lysosomes and promoted recycling. The GASP family of proteins may modulate lysosomal sorting and functional down-regulation of a variety of G protein-coupled receptors.