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51.
Food and Environmental Virology - Berries have been implicated as the probable vehicle of infection in multiple outbreaks of norovirus and hepatitis A virus (HAV). These foods often receive minimal...  相似文献   
52.
Interactions with fisheries are believed to be a major cause of mortality for adult leatherback turtles (Dermochelys coriacea), which is of particular concern in the Pacific Ocean, where they have been rapidly declining. In order to identify where these interactions are occurring and how they may be reduced, it is essential first to understand the movements and behavior of leatherback turtles. There are two regional nesting populations in the East Pacific (EP) and West Pacific (WP), comprising multiple nesting sites. We synthesized tracking data from the two populations and compared their movement patterns. A switching state-space model was applied to 135 Argos satellite tracks to account for observation error, and to distinguish between migratory and area-restricted search behaviors. The tracking data, from the largest leatherback data set ever assembled, indicated that there was a high degree of spatial segregation between EP and WP leatherbacks. Area-restricted search behavior mainly occurred in the southeast Pacific for the EP leatherbacks, whereas the WP leatherbacks had several different search areas in the California Current, central North Pacific, South China Sea, off eastern Indonesia, and off southeastern Australia. We also extracted remotely sensed oceanographic data and applied a generalized linear mixed model to determine if leatherbacks exhibited different behavior in relation to environmental variables. For the WP population, the probability of area-restricted search behavior was positively correlated with chlorophyll-a concentration. This response was less strong in the EP population, but these turtles had a higher probability of search behavior where there was greater Ekman upwelling, which may increase the transport of nutrients and consequently prey availability. These divergent responses to oceanographic conditions have implications for leatherback vulnerability to fisheries interactions and to the effects of climate change. The occurrence of leatherback turtles within both coastal and pelagic areas means they have a high risk of exposure to many different fisheries, which may be very distant from their nesting sites. The EP leatherbacks have more limited foraging grounds than the WP leatherbacks, which could make them more susceptible to any temperature or prey changes that occur in response to climate change.  相似文献   
53.
We present three studies providing an increased understanding of the interdependence between perceived organizational support (POS) and leader–member exchange (LMX). Using employees from a social service agency and new hires from a variety of organizations, we report evidence for a relational chain leading from supervisors' perceptions of support by the organization (supervisor POS) to the formation of high‐quality LMX relationships with their subordinates (first link), who interpret high‐quality LMX as support from the organization (subordinate POS, second link) and, ultimately, repay the organization with increased dedication and effort (examined here in terms of reduced withdrawal behavior). The relationship between supervisor POS and LMX with subordinates was strongly moderated by supervisor fear of exploitation in exchange relationships (reciprocation wariness), holding only for supervisors with low reciprocation wariness. Consistent with the view that employees perceive the organization as partly responsible for treatment received from supervisors, LMX was found to be more strongly related to POS when employees highly identified their supervisors with the organization (supervisor's organizational embodiment), and this interaction extended to reduced withdrawal behavior. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
54.
ABSTRACT

Recently, calls have increased for a paradigm shift or transition towards resource recovery and a circular economy in the Dutch wastewater system. However, we have observed diverging interpretations on the nature of the transition. This reflects the political environment of sustainability transitions: political struggle emerges over the definition of problems, futures and strategies to be used. In order to help clarify the emerging debate and identify political choices, we conducted a discourse analysis. We identified three discourses that reveal some of the political choices to be made. One discourse is becoming dominant and focusses on optimising the large-scale infrastructure, market development and legislative changes. The discourse draws on the existing infrastructure and current political-economic institutions, which gives it an advantage in becoming dominant. Our findings also suggest that this discourse shapes a transition pathway that is characterised by lock-in effects and, at most, incremental changes instead of a fundamental shift in the established Dutch wastewater system.  相似文献   
55.
Life-Cycle Assessment (LCA) is an analytical tool that evaluates the environmental consequences of a product, process, or activity across its entire life cycle. LCA is used internationally by government and industry to obtain a comprehensive perspective of the interactions between an activity and the environment and provides a method to systematically identify opportunities for improvement. The framework is integrated into environmental management programs motivated by market awareness, public perception, and cost savings. The use of LCA is driven by external forces such as eco-labels and the recent development of the ISO 14000 standards. However, LCA has many shortcomings that need to be addressed. The concerns of poor data quality, data availability, high implementation costs, subjectivity, and lack of standardization have sent LCA into a state of flux. In light of the recent surge of interest in LCA, the authors of this article have conducted a corporate survey that targets the implementation of LCA. Their goal is to determine the level of activity of LCA among known practitioners and to elucidate common themes. This article presents their findings from responses by 34 companies that were known to be actively involved in LCA or contemplating its future use.  相似文献   
56.
ABSTRACT: The production of videotape as a product of a water resources seminar is an innovative approach to graduate education. The research effort required builds upon the traditional graduate seminar approach. The videotape production requires research effort to be focused into a coherent body of information which may be widely disseminated and effectively communicates information to the public. The use of outside speakers and field trips blends very well into the preparation of a videotape. The requriement to present the many sides of a complex water resource issue in a fair and equitable manner requires maturity and professional capability on the part of the students. The research effort requires the students to meet their professional obligation to present an objective, factual, and accurate statement of the issues studies.  相似文献   
57.
58.
Genogroup II.4 norovirus (NoV) remains the predominant NoV strain in food- and water-borne outbreaks. Capsid integrity as well as viral RNA persistence were determined for GII.4 NoV by real-time RT-PCR after 1?C14 freeze/thaw (F/T) cycles (?80?°C/+22?°C) or after ?80?°C storage for up to 120?days. In both cases, capsid integrity and viral RNA titers remained stable. RNase was exogenously added after 1?C14 F/T cycles, but did not alter the amount of genomic NoV RNA detected, indicating that capsids remained intact. Presumptive NoV infectivity was evaluated in functional studies by a porcine gastric mucin binding assay. Viruses frozen and thawed up to 14× bound similarly to porcine mucin, suggesting no reduction in virus infectivity. Overall, this study shows that a) NoV particles retain their integrity for at least 14 F/T cycles, b) long-term (120?day) frozen storage does not decrease NoV RNA titers, and c) capsid binding to receptor-like glycoprotein moieties remains unaltered after 14 F/T cycles. This work indicates that freezing and thawing of foods or beverages would not be a practical processing intervention to reduce NoV contamination. Likewise, repeated freezing and thawing, as might be encountered during winter months, is not expected to inactivate NoV in the environment. Results do show that laboratory samples destined for molecular biological analyses or for use as positive controls may be repeatedly frozen and thawed without any anticipated reduction in NoV RNA titers. This study documents the cryostability of NoV capsids and RNA to freezing and thawing and to the possible retention of virus infectivity.  相似文献   
59.
Herein, we report evidence of an envenomation apparatus (EA) in two different species of extinct “giant” shrews, Beremendia and an indeterminate soricine (Mammalia, Eulipotyphla, Soricidae), documented by very well preserved fossil specimens recovered from two Early Pleistocene cave deposits of the Sierra de Atapuerca in Burgos, Spain. The two soricine taxa from Atapuerca have evolved specialized teeth as EAs, which differ from those of recently reported mammals of the Paleocene age, being more similar to the ones described in the modern Solenodon. This discovery reveals the first instance of shrews possessing what appears to be an EA, an evolutionary adaptation that, in these species, was probably related to an increase in body mass and hunting of a larger-sized prey. The Atapuerca specimens would have a highly specialized EA, one of the very few reported for an extinct or living mammal of any time. In addition to the presence of a gutter-like groove along the medial side of the crown of the lower incisors, these two species also present stout jaws and a modified mandibular symphysis with a conspicuous cavity, which in life would likely contain large amounts of connective tissue. The strong mandible architecture of these large shrews would be, in this way, reinforced by a more immovable symphysis, increasing the bite force exerted over a potential prey. This adaptation, together with the grooved incisors, would ensure a rapid and efficient transmission of the poisonous saliva to paralyze relatively large-sized prey.  相似文献   
60.
Previous historic trends analyses on 21st Century hydrologic data in the United States generally focus on annual flow statistics and have continued to use USGS hydro‐climatic data network (HCDN) stations, although post‐1988 diversions and runoff regulations are not reflected in the HCDN. Using a more recent dataset, Geospatial Attributes of Gages for Evaluating Streamflow, version II (GAGES II), compiled by Falcone (2012), which includes more watersheds with reference conditions, a comprehensive analysis of changes in seasonal, and annual streamflow in Wisconsin watersheds is demonstrated. Given the pronounced influence of seasonal hydrology in Wisconsin watersheds, the objective of this study is to elucidate the nature of temporal (annual, seasonal, and monthly) changes in runoff. Considerable temporal and regional variability was found in annual and seasonal streamflow changes between the two historic periods 1951‐1980 and 1981‐2010 considered in the study. For example, the northern watersheds show relatively small changes in streamflow discharge ranging from ?6.0 to 4.2%, while the southern watersheds show relatively large increases in streamflow discharge ranging from 13.1 to 18.2%. To apportion streamflow changes to climate and nonclimatic factors, a method based on potential evapotranspiration changes is demonstrated. Results show that nonclimatic factors account for more than 60% of changes in annual runoff in Wisconsin watersheds considered in the study.  相似文献   
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