138 research outputs found

    Self-Perceived Readiness of Haitian Agricultural University Students to enter the Workforce: A Call for Curriculum Reform

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    The country of Haiti has faced chronic food insecurity for decades. Increasing domestic food production has been identified as a key part of the solution, but this requires building human capacity, especially related to agricultural extension and research. Haiti’s agricultural universities can be key players in this process. The purpose of this study was to explore the selfperceived readiness of Haitian agricultural university students to enter the workforce. Results revealed students had a wide variety of career aspirations and appreciated the breadth of the agronomy engineer degree. Students also expressed favorable opinions about their preparedness for the job market but felt pessimistic about finding a job. Students valued the importance of research and felt prepared to lead a research project. Finally, students thought all 17 Global Forum for Rural Advisory Services (GFRAS) New Extensionist competency areas were important. Recommendations for additional research and practice are provided

    Occurrence and specificity of glucose oxidase (E.C: 1.1.3.4) in botrytized sweet white wine. Comparison with laccase (E.C: 1.10.3.2), considered as the main responsible factor for oxidation in this type of wine

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    Two types of oxidizing enzymes are present in botrytized white grapes and wines: laccase (PPO) and glucose oxidase (GOX). The evolution of these two enzymes is similar both during the over-ripening of grapes and during wine making. Yet, PPO is severely inhibited by the addition of SO2 following the alcoholic fermentation, and shows a marked instability in both the must and wine environments. GOX, however, remains free and active in solution and helps develop the main characteristics of the wine. In particular, as is to be expected from its activity, GOX oxidizes tartaric acid, ethanol and glycerol, the major components of must and wine, respectively to glyoxylic acid, acetaldehyde and glyceraldehyde. And then, by nucleophilic additions under acidic conditions, these products react with catechins and proanthocyanidins to form several new compounds, some of which appear in a colored form. These reactions can have an impact on the visual quality of the wine.

    Haitian Agricultural Faculty Preparation for Their Academic Roles

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    Food insecurity is widespread in Haiti. The tertiary agricultureinstitutionshave the great challenge of educatingthe future professionals who will help in meeting the growth needs of the Haitian agriculturesector.The extent that faculty are prepared for the teaching roles is unknown. This study examined this topic using a basic qualitative study that consisted of interviews with 37 lecturers working at five leading agricultural universitiesin Haiti. Data were analyzed using a basic thematic analysis. Results revealed the majority of participants generally felt well-prepared for their academic roles. The institutional climate for professional development is variable across the universities represented by the participants of this study. Incentives for participating in professional development were primarily intrinsic. There were 56 specific topics suggested by participants for professional development trainings

    Formation of Flavanol-aldehyde Adducts in Barrel-aged White Wine – Possible Contribution of These Products to Colour

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    This paper describes the formation and diversity of new compounds resulting from the polymerisation of furanic andphenolic flavanol-aldehydes with HPLC‑DAD and LC‑ES/MS analysis. Polymerisation, resulting from nucleophilicreactions, formed dimers, trimers, soluble and insoluble polymers. Reactions in hydroalcoholic solution with purealdehydes (phenolic and furanic) and flavanols (catechin) were studied. The study was repeated with differentaldehydes in white wine. This research focused particularly on the colour properties of the released products and theirpotential impact on the colour of white wine. Some products were purified and isolated; these were mainly catechinfurfuraldehyde,catechin-methyl-5-furfuraldehyde, catechin-hydroxymethyl-furfuraldehyde,catechin-vanillin, andcatechin-syringaldehyde dimers. The most powerful coloured products resulted from furanic aldehydes. Over thecourse of the experiment, the reaction produced dimers, trimers and oligomers. After 50 to 60 days, the colour of thesolution was mainly due to soluble polymeric forms. In addition, the role of SO2, generally used during vinificationand ageing, was studied. The influence of SO2 on the kinetics of the reaction was limited

    Formation of Flavanol-aldehyde Adducts in Barrel-aged White Wine - Possible Contribution of These Products to Colour

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    [EN] This paper describes the formation and diversity of new compounds resulting from the polymerisation of furanic and phenolic flavanol-aldehydes with HPLC¿DAD and LC¿ES/MS analysis. Polymerisation, resulting from nucleophilic reactions, formed dimers, trimers, soluble and insoluble polymers. Reactions in hydroalcoholic solution with pure aldehydes (phenolic and furanic) and flavanols (catechin) were studied. The study was repeated with different aldehydes in white wine. This research focused particularly on the colour properties of the released products and their potential impact on the colour of white wine. Some products were purified and isolated; these were mainly catechinfurfuraldehyde, catechin-methyl-5-furfuraldehyde, catechin-hydroxymethyl-furfuraldehyde, catechin-vanillin, and catechin-syringaldehyde dimers. The most powerful coloured products resulted from furanic aldehydes. Over the course of the experiment, the reaction produced dimers, trimers and oligomers. After 50 to 60 days, the colour of the solution was mainly due to soluble polymeric forms. In addition, the role of SO2 , generally used during vinification and ageing, was studied. The influence of SO2 on the kinetics of the reaction was limited.Vivas, N.; Nonier, MFB.; Absalon, C.; Lizama Abad, V.; Jamet, F.; De Gaulejac, NV.; Vitry, C.... (2008). Formation of Flavanol-aldehyde Adducts in Barrel-aged White Wine - Possible Contribution of These Products to Colour. South African journal of enology and viticulture. 29(2):98-108. http://hdl.handle.net/10251/105310S9810829

    Gender differences in sexual behaviors, sexual partnerships, and HIV among drug users in New York City

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/48789/1/absalon_gender differences in sexual behaviors_2006.pd

    A Comparison of HIV Seropositive and Seronegative Young Adult Heroin- and Cocaine- Using Men Who Have Sex with Men in New York City, 2000-2003

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    The purpose of this analysis was to determine the prevalence and correlates of HIV infection among a street-recruited sample of heroin- and cocaine-using men who have sex with men (MSM). Injection (injecting â¤3 years) and non-injection drug users (heroin, crack, and/or cocaine use <10 years) between 18 and 40 years of age were simultaneously street-recruited into two cohort studies in New York City, 2000â2003, by using identical recruitment techniques. Baseline data collected among young adult men who either identified as gay/bisexual or reported ever having sex with a man were used for this analysis. Nonparametric statistics guided interpretation. Of 95 heroin/ cocaine-using MSM, 25.3% tested HIV seropositive with 75% reporting a previous HIV diagnosis. The majority was black (46%) or Hispanic (44%), and the median age was 28 years (range 18â40). HIV-seropositive MSM were more likely than seronegatives to be older and to have an HIV-seropositive partner but less likely to report current homelessness, illegal income, heterosexual identity, multiple sex partners, female partners, and sex for money/drug partners than seronegatives. These data indicate high HIV prevalence among street-recruited, drug-using MSM compared with other injection drug use (IDU) subgroups and drug-using MSM; however, lower risk behaviors were found among HIV seropositives compared with seronegatives. Large-scale studies among illicit drug-using MSM from more marginalized neighborhoods are warranted.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/40372/2/Fuller_A Comparison of HIV Seropositive and Seronegative_2005.pd

    Basal Body Positioning Is Controlled by Flagellum Formation in Trypanosoma brucei

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    To perform their multiple functions, cilia and flagella are precisely positioned at the cell surface by mechanisms that remain poorly understood. The protist Trypanosoma brucei possesses a single flagellum that adheres to the cell body where a specific cytoskeletal structure is localised, the flagellum attachment zone (FAZ). Trypanosomes build a new flagellum whose distal tip is connected to the side of the old flagellum by a discrete structure, the flagella connector. During this process, the basal body of the new flagellum migrates towards the posterior end of the cell. We show that separate inhibition of flagellum assembly, base-to-tip motility or flagella connection leads to reduced basal body migration, demonstrating that the flagellum contributes to its own positioning. We propose a model where pressure applied by movements of the growing new flagellum on the flagella connector leads to a reacting force that in turn contributes to migration of the basal body at the proximal end of the flagellum

    A Communal Bacterial Adhesin Anchors Biofilm and Bystander Cells to Surfaces

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    While the exopolysaccharide component of the biofilm matrix has been intensively studied, much less is known about matrix-associated proteins. To better understand the role of these proteins, we undertook a proteomic analysis of the V. cholerae biofilm matrix. Here we show that the two matrix-associated proteins, Bap1 and RbmA, perform distinct roles in the biofilm matrix. RbmA strengthens intercellular attachments. In contrast, Bap1 is concentrated on surfaces where it serves to anchor the biofilm and recruit cells not yet committed to the sessile lifestyle. This is the first example of a biofilm-derived, communally synthesized conditioning film that stabilizes the association of multilayer biofilms with a surface and facilitates recruitment of planktonic bystanders to the substratum. These studies define a novel paradigm for spatial and functional differentiation of proteins in the biofilm matrix and provide evidence for bacterial cooperation in maintenance and expansion of the multilayer biofilm

    The immunological synapse: a focal point for endocytosis and exocytosis

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    There are many different cells in the immune system. To mount an effective immune response, they need to communicate with each other. One way in which this is done is by the formation of immunological synapses between cells. Recent developments show that the immune synapse serves as a focal point for exocytosis and endocytosis, directed by centrosomal docking at the plasma membrane. In this respect, formation of the immunological synapse bears striking similarities to cilia formation and cytokinesis. These intriguing observations suggest that the centrosome may play a conserved role in designating a specialized area of membrane for localized endocytosis and exocytosis
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