Dendritic cell stimulation by mycobacterial Hsp70 is mediated through CCR5

An effective host immune response to mycobacterial infection must control pathogen dissemination without inducing immunopathology. Constitutive overexpression of mycobacterial heat shock protein (myHsp70) is associated with impaired bacterial persistence, but the immune-mediated mechanisms are unknown. We found that myHsp70, in addition to enhancing antigen delivery to human dendritic cells, signaled through the CCR5 chemokine receptor, promoting dendritic cell aggregation, immune synapse formation between dendritic cells and T cells, and the generation of effector immune responses. Thus, CCR5 acts as a pattern-recognition receptor for myHsp70, which may have implications for both the pathophysiology of tuberculosis and the use of myHsps in tumor-directed immunotherapy.     

The emergence and framing of farm-to-school initiatives: civic engagement, health and local agriculture

Interest in and initiation of farm-to-school (FTS) programs have increased in recent years, spurred on by converging public concerns about child obesity trends and risks associated with industrialization and distancing in the modern food system. A civic agriculture framework that more specifically considers civic engagement and problem solving offers insights about variations in the development and prospects for FTS programs. Drawing on comparative case studies of two emerging FTS initiatives in Pennsylvania—one in a rural setting and one in an urban setting—this article examines the role of internal and external “champions” in launching FTS programs and fostering civic engagement. Farm-to-school community stakeholders across the two cases framed FTS in broadly similar terms of (1) redressing poor food environments; (2) improving student nutrition, health and well-being; and (3) revitalizing rural community through support of local agriculture. However, specific concerns and emphases differed across the rural and urban cases, illustrating the significance of local context for such programs. The article concludes by discussing the importance of frame bridging and frame extension as strategies for expanding the FTS movement, and also ensuring programs that correspond to the specific circumstances and possibilities of their social and geographic settings.     

Triple-bond reactivity of diphosphorus molecules

We report a mild method for generating the diphosphorus molecule or its synthetic equivalent in homogeneous solution; the P2 allotrope of the element phosphorus is normally obtained only under extreme conditions (for example, from P4 at 1100 kelvin). Diphosphorus is extruded from a niobium complex designed for this purpose and can be trapped efficiently by two equivalents of an organic diene to produce an organodiphosphorus compound. Diphosphorus stabilized by coordination to tungsten pentacarbonyl can be generated similarly at 25 degrees C, and in this stabilized form it still efficiently consumes two organic diene molecules for every diphosphorus unit.     

Functional links between Aβ toxicity, endocytic trafficking, and Alzheimer's disease risk factors in yeast

Aβ (beta-amyloid peptide) is an important contributor to Alzheimer's disease (AD). We modeled Aβ toxicity in yeast by directing the peptide to the secretory pathway. A genome-wide screen for toxicity modifiers identified the yeast homolog of phosphatidylinositol binding clathrin assembly protein (PICALM) and other endocytic factors connected to AD whose relationship to Aβ was previously unknown. The factors identified in yeast modified Aβ toxicity in glutamatergic neurons of Caenorhabditis elegans and in primary rat cortical neurons. In yeast, Aβ impaired the endocytic trafficking of a plasma membrane receptor, which was ameliorated by endocytic pathway factors identified in the yeast screen. Thus, links between Aβ, endocytosis, and human AD risk factors can be ascertained with yeast as a model system.     

品种和栽培条件对草莓果实中水杨酸含量的影响

为了明确草莓内源SA(Salicylic acid,简称SA)含量与其抗病性的关系,并探索人们从草莓等植物性食物中摄取SA的总量,用HPLC分析比较了露地与设施栽培条件下五个对白粉病抗性不同的草莓品种果实的SA含量.结果表明,所测五种草莓红熟期果实内源总SA含量差别明显,露地栽培条件下为1.904～5.023 μg/g,设施栽培条件下为1.068～4.201 μg/g,与各品种的抗白粉病能力无明显相关性.草莓果实中SA均以结合态为主,五个品种结合态SA含量是游离态SA的4～20倍.游离态SA和结合态SA含量都随着果实的成熟而逐渐下降.说明草莓果实中内源SA含量不仅受基因型的影响,并且受栽培环境和成熟度的影响.     

Pre‐Columbian fisheries catch reconstruction for a subtropical estuary in South America

Small‐scale fisheries provide food and livelihoods for thousands of people along the Brazilian coastline. However, considerable uncertainties still surround the extent to which artisanal and subsistence fisheries contribute to the total of national landings and their historical ecological significance. Fisheries monitoring is deficient in Brazil, and historical records are limited to irregular accounts spanning the last few decades, while this coastline has supported human populations for at least 6,000 years. Here, we estimate pre‐Columbian subsistence catches for a large subtropical estuary in southern Brazil. Our results suggest that prehistoric populations may have extracted volumes of fish biomass higher than or comparable with historical subsistence fisheries in the region, and that the latter is likely underestimated. If a long‐term perspective is required to evaluate the current economic value and status of fisheries in subtropical and tropical South America, this should go beyond the historical time interval and integrate the contribution of pre‐Columbian archaeology.     

Energy dynamics of subyearling Chinook salmon reveal the importance of piscivory to short‐term growth during early marine residence

Variation in prey quantity and quality can influence growth and survival of marine predators, including anadromous fish that migrate from freshwater systems. The objective of this study was to examine the energy dynamics of subyearling Chinook salmon (Oncorhynchus tshawytscha) following freshwater emigration. To address this objective, a population of Chinook salmon and their marine prey were repeatedly sampled from June to September over 2 years in coastal waters off Oregon and Washington. Subyearlings from the same population were also reared under laboratory conditions. Using a bioenergetics model evaluated in the laboratory, we found that growth rate variability in the field was associated more with differences in northern anchovy (Engraulis mordax) consumption and less with variation in diet energy density or ocean temperature. Highest growth rates (2.43–3.22% body weight/day) occurred in months when anchovy biomass peaked, and the timing of peak anchovy biomass varied by year. Our results support a general pattern among subyearling Chinook salmon occurring from Alaska to California that feeding rates contribute most to growth rate variability during early marine residence, although dominant prey types can differ seasonally, annually, or by ecosystem. In the northern California Current, faster growth appears to be associated with the availability of age‐0 anchovy. Identifying factors that influence the seasonal development of the prey field and regulate prey quantity and quality will improve understanding of salmon growth and survival during early marine residence.     

Bonamia in Ostrea angasi: Diagnostic performance,field prevalence and intensity

Bonamia spp. parasites threaten flat oyster (Ostrea spp.) farming worldwide. Understanding test performance is important for designing surveillance and interpreting diagnostic results. Following a pilot survey which found low Bonamia sp. intensity in farmed Ostrea angasi, we tested further oysters (n = 100–150) from each of three farms for Bonamia sp. using heart smear, histology and qPCR. We used a Bayesian Latent Class Model to assess diagnostic sensitivity (DSe) and specificity (DSp) of these tests individually or in combination, and to assess prevalence. Histology was the best individual test (DSe 0.76, DSp 0.93) compared to quantitative polymerase chain reaction (qPCR) (DSe 0.69, DSp 0.93) and heart smear (DSe 0.61, DSp 0.60). Histology combined with qPCR and defining a positive from either test as an infected case maximized test performance (DSe 0.91, DSp 0.88). Prevalence was higher at two farms in a high‐density oyster growing region than at a farm cultivating oysters at lower density. Parasite intensities were lower than in New Zealand and European studies, and this is probably contributed to differences in the performance of test when compared to other studies. Understanding diagnostic test performance in different populations can support the development of improved Bonamia surveillance programs.