205 research outputs found

    First Records of the Yellow Bullhead, Ameiurus natalis, a Loricariid Catfish, Panaque suttonorum, and a Silver Pacu, Piaractus cf. P. brachypomus, in British Columbia

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    In Canada, there are no native catfish west of the continental divide and until recently, the list of extant exotic catfishes in British Columbia only included introduced Black Bullhead (Ameiurus melas) and Brown Bullhead (Ameiurus nebulosus). We report that a single Yellow Bullhead (Ameiurus natalis) was collected from Silvermere Lake in the Lower Fraser River drainage. This represents the first record of the Yellow Bullhead in western Canada, and its introduction likely was accidental with a shipment of Largemouth Bass (Micropterus salmoides) rather than dispersal from Washington. Warm, eutrophic, weedy habitat in the Fraser Delta provides ample habitat for Yellow Bullheads and other exotic fishes. A Blue-eyed Panaque (Panaque suttonorum), a loricariid catfish found in 1995 in Shawnigan Lake, Vancouver Island, probably represents a single, illegally released aquarium fish, as does a large Silver Pacu (Piaractus cf. P. brachypomus), which was found in Green Lake on Vancouver Island in 2004

    The chemomechanics of crystallization during rewetting of limestone impregnated with sodium sulfate

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    Breakdown of porous materials by salts occurs when growing crystals exert pressure on the pore walls, inducing stress in the material that exceeds its tensile strength. In this work, we quantify the mechanical stresses caused by a particularly destructive mechanism: the dissolution of an anhydrate (thenardite, Na2SO4) followed by precipitation of a hydrated salt (mirabilite, Na2SO4·10H2O). Stresses are measured using a composite specimen consisting of a plate of glass bonded to a plate of limestone (CaCO3) whose pores are impregnated with thenardite. As water wicks into the limestone, thenardite dissolves and mirabilite precipitates. The limestone expands from the pressure exerted by the salt resulting in deflection of the composite, and the stresses can be obtained from an elastic analysis. Synchrotron x-ray diffraction reveals the dissolution-crystallization rate. Numerical modeling shows that the stresses are affected by the kinetics of crystallization and dissolution, permeability, and mechanical properties of the stone, allowing us to determine the amount of salt that causes material fractur

    Defining success in community-university partnerships: lessons learned from Flint

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    The success of responsible research and innovation (RRI) work is as much about the process of partnership as it is about the products and outcomes. In this paper, we present lessons learned from the first three years of a participatory modeling (PM) research project based on RRI principles and focused on the transformation of the food system in Flint, Michigan through identification of leverage points. Participatory modeling is a type of community engaged research that seeks to build representations of a system collaboratively between researchers, decision-makers, and community members. We discuss the challenges, opportunities, and lessons learned from the Flint Leverage Points Project (FLPP) using the four ‘Ps’ framework–purpose, processes, partnerships and products. We argue a carefully designed participatory modeling process can serve to build lasting partnerships across community-university boundaries

    A cross-national study on the antecedents of work–life balance from the fit and balance perspective

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    Drawing on the perceived work–family fit and balance perspective, this study investigates demands and resources as antecedents of work–life balance (WLB) across four countries (New Zealand, France, Italy and Spain), so as to provide empirical cross-national evidence. Using structural equation modelling analysis on a sample of 870 full time employees, we found that work demands, hours worked and family demands were negatively related to WLB, while job autonomy and supervisor support were positively related to WLB. We also found evidence that resources (job autonomy and supervisor support) moderated the relationships between demands and work–life balance, with high resources consistently buffering any detrimental influence of demands on WLB. Furthermore, our study identified additional predictors of WLB that were unique to some national contexts. For example, in France and Italy, overtime hours worked were negatively associated with WLB, while parental status was positively associated with WLB. Overall, the implications for theory and practice are discussed.Peer ReviewedPostprint (author's final draft

    Comparative Proteomic Analysis of Aedes aegypti Larval Midgut after Intoxication with Cry11Aa Toxin from Bacillus thuringiensis

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    Cry toxins produced by Bacillus thuringiensis bacteria are environmentally safe alternatives to control insect pests. They are pore-forming toxins that specifically affect cell permeability and cellular integrity of insect-midgut cells. In this work we analyzed the defensive response of Aedes aegypti larva to Cry11Aa toxin intoxication by proteomic and functional genomic analyses. Two dimensional differential in-gel electrophoresis (2D-DIGE) was utilized to analyze proteomic differences among A. aegypti larvae intoxicated with different doses of Cry11Aa toxin compared to a buffer treatment. Spots with significant differential expression (p<0.05) were then identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS), revealing 18 up-regulated and seven down-regulated proteins. The most abundant subcategories of differentially expressed proteins were proteins involved in protein turnover and folding, energy production, and cytoskeleton maintenance. We selected three candidate proteins based on their differential expression as representatives of the different functional categories to perform gene silencing by RNA interference and analyze their functional role. The heat shock protein HSP90 was selected from the proteins involved in protein turnover and chaperones; actin, was selected as representative of the cytoskeleton protein group, and ATP synthase subunit beta was selected from the group of proteins involved in energy production. When we affected the expression of ATP synthase subunit beta and actin by silencing with RNAi the larvae became hypersensitive to toxin action. In addition, we found that mosquito larvae displayed a resistant phenotype when the heat shock protein was silenced. These results provide insight into the molecular components influencing the defense to Cry toxin intoxication and facilitate further studies on the roles of identified genes

    Methamphetamine and Viagra Use: Relationship to Sexual Risk Behaviors

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    Recent studies show that Viagra and methamphetamine use are associated with unprotected anal intercourse among men who have sex with men (MSM). In Long Beach, California, we have reported on an association between Viagra use and the use of amphetamines during sex. The current research investigated the use of both Viagra and amphetamine in men in Long Beach, California. Data on 1,839 men recruited into HIV prevention and testing programs were collected using the Risk Behavior Assessment. A generalized logit model was constructed comparing ever having used both amphetamine and Viagra together and separately, as compared to never having used either (referent). Men who used both methamphetamine and Viagra showed a significantly higher prevalence of hepatitis B, syphilis, and HIV compared to those who used only one or neither drug. Of the 1,794 complete cases, 11.1% (199/1794) had used both amphetamine and Viagra. Of 20 potential risk and protective factors for use of amphetamine and Viagra, 12 were significant predictors: ever used gamma-hydroxybutyrate (GHB), ever used cocaine, ever used ecstasy, being infected with HIV, race = White compared to other, ever having hepatitis B, ever using crack, ever given money to have sex, living in a hotel, ever been in drug treatment, and ever using heroin. The protective factor was being heterosexual. Viagra use was associated with insertive, and methamphetamine was associated with receptive, anal intercourse. GHB use appears to play a more important role than previously thought

    The use of an implementation science theoretical framework to inform the development of a region wide Positive Behavioural Support Workforce Development approach

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    Background: Concern about the poor care of some people with an intellectual disability has highlighted the need for systemic, large scale interventions to develop a skilled workforce. Method: We outline how an implementation science theoretical model informed the development of a region wide Positive Behavioural Support (PBS) Workforce Development (WFD) approach. Results: We provide an example of the application of the model in practice and demonstrate how this enabled us to: understand the competencies and development needs of the workforce; engage effectively with stakeholders; and develop, deliver, and evaluate a PBS WFD model. Conclusion: The application of the model helped us to identify, prioritise, and address the multiple and complex factors that were relevant to the implementation of the PBS WFD approach

    Exploring the Midgut Transcriptome and Brush Border Membrane Vesicle Proteome of the Rice Stem Borer, Chilo suppressalis (Walker)

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    The rice stem borer, Chilo suppressalis (Walker) (Lepidoptera: Pyralidae), is one of the most detrimental pests affecting rice crops. The use of Bacillus thuringiensis (Bt) toxins has been explored as a means to control this pest, but the potential for C. suppressalis to develop resistance to Bt toxins makes this approach problematic. Few C. suppressalis gene sequences are known, which makes in-depth study of gene function difficult. Herein, we sequenced the midgut transcriptome of the rice stem borer. In total, 37,040 contigs were obtained, with a mean size of 497 bp. As expected, the transcripts of C. suppressalis shared high similarity with arthropod genes. Gene ontology and KEGG analysis were used to classify the gene functions in C. suppressalis. Using the midgut transcriptome data, we conducted a proteome analysis to identify proteins expressed abundantly in the brush border membrane vesicles (BBMV). Of the 100 top abundant proteins that were excised and subjected to mass spectrometry analysis, 74 share high similarity with known proteins. Among these proteins, Western blot analysis showed that Aminopeptidase N and EH domain-containing protein have the binding activities with Bt-toxin Cry1Ac. These data provide invaluable information about the gene sequences of C. suppressalis and the proteins that bind with Cry1Ac

    Consumers’ values and behaviour in the Brazilian coffee-in-capsules market: Promoting circular economy

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    Coffee consumption is changing. Monodose, flavoured coffee capsules provide new experiences beyond the traditional custom of brewing coffee. While these pods mean access to a selection of premium coffee worldwide, they create huge quantities of plastic-aluminium packaging waste. This paper examines the novelty of coffee capsule consumption in Brazil in terms of consumers’ perspectives about ethical enterprise and environmental stewardship. We argue for ‘waste to resource’ management and applying reverse logistics to the coffee production supply chain. Based on Circular Economy principles and fuelled by the ‘green’ awareness of Brazilian coffee consumers themselves, we propose a conceptual framework to support business decision-making by adopting a systemic intervention from the consumer viewpoint. To structure and scope the problematic situation, we conducted over 40 interviews, using purposive sampling. Analytic Hierarchy Process (AHP), Value Focused Thinking (VFT) and Rich Picture Technique also informed our problem structuring approach. Findings illustrate that the ambition for a reverse supply chain in coffee capsule manufacturing presents real challenges to achieving circular practice. Yet, the eco-values of Brazilian coffee enthusiasts may be partly considered a ‘wealth of information flow’ and a potential driving force for change. This paper should be of interest to researchers and practitioners exploring how consumers may contribute to behavioural change, towards more circular business
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