62 research outputs found

    Short Lag Times for Invasive Tropical Plants: Evidence from Experimental Plantings in Hawai'i

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    Background: The lag time of an invasion is the delay between arrival of an introduced species and its successful spread in a new area. To date, most estimates of lag times for plants have been indirect or anecdotal, and these estimates suggest that plant invasions are often characterized by lag times of 50 years or more. No general estimates are available of lag times for tropical plant invasions. Historical plantings and documentation were used to directly estimate lag times for tropical plant invasions in Hawai’i. Methodology/Principal Findings: Historical planting records for the Lyon Arboretum dating back to 1920 were examined to identify plants that have since become invasive pests in the Hawaiian Islands. Annual reports describing escape from plantings were then used to determine the lag times between initial plantings and earliest recorded spread of the successful invaders. Among 23 species that eventually became invasive pests, the average lag time between introduction and first evidence of spread was 14 years for woody plants and 5 years for herbaceous plants. Conclusions/Significance: These direct estimates of lag times are as much as an order of magnitude shorter than previous, indirect estimates, which were mainly based on temperate plants. Tropical invaders may have much shorter lag times than temperate species. A lack of direct and deliberate observations may have also inflated many previous lag time estimates. Although there have been documented cases of long lag times due to delayed arrival of a mutualist or environmenta

    Hand washing with soap and water together with behavioural recommendations prevents infections in common work environment: an open cluster-randomized trial

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    <p>Abstract</p> <p>Background</p> <p>Hand hygiene is considered as an important means of infection control. We explored whether guided hand hygiene together with transmission-limiting behaviour reduces infection episodes and lost days of work in a common work environment in an open cluster-randomized 3-arm intervention trial.</p> <p>Methods</p> <p>A total of 21 clusters (683 persons) were randomized to implement hand hygiene with soap and water (257 persons), with alcohol-based hand rub (202 persons), or to serve as a control (224 persons). Participants in both intervention arms also received standardized instructions on how to limit the transmission of infections. The intervention period (16 months) included the emergence of the 2009 influenza pandemic and the subsequent national hand hygiene campaign influencing also the control arm.</p> <p>Results</p> <p>In the total follow-up period there was a 6.7% reduction of infection episodes in the soap-and water arm (p = 0.04). Before the onset of the anti-pandemic campaign, a statistically significant (p = 0.002) difference in the mean occurrence of infection episodes was observed between the control (6.0 per year) and the soap-and-water arm (5.0 per year) but not between the control and the alcohol-rub arm (5.6 per year). Neither intervention had a decreasing effect on absence from work.</p> <p>Conclusions</p> <p>We conclude that intensified hand hygiene using water and soap together with behavioural recommendations can reduce the occurrence of self-reported acute illnesses in common work environment. Surprisingly, the occurrence of reported sick leaves also increased in the soap-and water-arm.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00981877">NCT00981877</a></p> <p>Source of funding</p> <p>The Finnish Work Environment Fund and the National Institute for Health and Welfare.</p

    Glutathione Transferase from Trichoderma virens Enhances Cadmium Tolerance without Enhancing Its Accumulation in Transgenic Nicotiana tabacum

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    BACKGROUND: Cadmium (Cd) is a major heavy metal pollutant which is highly toxic to plants and animals. Vast agricultural areas worldwide are contaminated with Cd. Plants take up Cd and through the food chain it reaches humans and causes toxicity. It is ideal to develop plants tolerant to Cd, without enhanced accumulation in the edible parts for human consumption. Glutathione transferases (GST) are a family of multifunctional enzymes known to have important roles in combating oxidative stresses induced by various heavy metals including Cd. Some GSTs are also known to function as glutathione peroxidases. Overexpression/heterologous expression of GSTs is expected to result in plants tolerant to heavy metals such as Cd. RESULTS: Here, we report cloning of a glutathione transferase gene from Trichoderma virens, a biocontrol fungus and introducing it into Nicotiana tabacum plants by Agrobacterium-mediated gene transfer. Transgenic nature of the plants was confirmed by Southern blot hybridization and expression by reverse transcription PCR. Transgene (TvGST) showed single gene Mendelian inheritance. When transgenic plants expressing TvGST gene were exposed to different concentrations of Cd, they were found to be more tolerant compared to wild type plants, with transgenic plants showing lower levels of lipid peroxidation. Levels of different antioxidant enzymes such as glutathione transferase, superoxide dismutase, ascorbate peroxidase, guiacol peroxidase and catalase showed enhanced levels in transgenic plants expressing TvGST compared to control plants, when exposed to Cd. Cadmium accumulation in the plant biomass in transgenic plants were similar or lower than wild-type plants. CONCLUSION: The results of the present study suggest that transgenic tobacco plants expressing a Trichoderma virens GST are more tolerant to Cd, without enhancing its accumulation in the plant biomass. It should be possible to extend the present results to crop plants for developing Cd tolerance and in limiting Cd availability in the food chain

    Lowe Syndrome Protein OCRL1 Supports Maturation of Polarized Epithelial Cells

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    Mutations in the inositol polyphosphate 5-phosphatase OCRL1 cause Lowe Syndrome, leading to cataracts, mental retardation and renal failure. We noted that cell types affected in Lowe Syndrome are highly polarized, and therefore we studied OCRL1 in epithelial cells as they mature from isolated individual cells into polarized sheets and cysts with extensive communication between neighbouring cells. We show that a proportion of OCRL1 targets intercellular junctions at the early stages of their formation, co-localizing both with adherens junctional components and with tight junctional components. Correlating with this distribution, OCRL1 forms complexes with junctional components α-catenin and zonula occludens (ZO)-1/2/3. Depletion of OCRL1 in epithelial cells growing as a sheet inhibits maturation; cells remain flat, fail to polarize apical markers and also show reduced proliferation. The effect on shape is reverted by re-expressed OCRL1 and requires the 5′-phosphatase domain, indicating that down-regulation of 5-phosphorylated inositides is necessary for epithelial development. The effect of OCRL1 in epithelial maturation is seen more strongly in 3-dimensional cultures, where epithelial cells lacking OCRL1 not only fail to form a central lumen, but also do not have the correct intracellular distribution of ZO-1, suggesting that OCRL1 functions early in the maturation of intercellular junctions when cells grow as cysts. A role of OCRL1 in junctions of polarized cells may explain the pattern of organs affected in Lowe Syndrome

    Exploring the Professional Identity Formation of Student Pharmacists through Self-Authorship: An Interpretative Phenomenological Analysis

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    The purpose of this study was to explore how student pharmacists at a top ten school of pharmacy in the Pacific Northwest conceive and experience the process of professional identity formation. Using the theoretical framework of self-authorship, final-year student pharmacists participated in semi-structured interviews covering their expectations and experiences while enrolled in the Doctor of Pharmacy program. Analysis of interview transcripts led to the identification of four superordinate themes. The first three superordinate themes that emerged represent domains of professional identity formation: Defining the Profession, Building Confidence & Competence, and Discerning Values. Development in each domain occurred across three stages that align with the self-authorship framework, which emphasizes the transition between defining one’s experiences based on external factors to relying on an internalized sense of understanding. A fourth superordinate theme, Significant Experiences, illustrated factors that helped to support participants in the professional identity formation process: Early & Sustained Practice Opportunities, Exposure to Multiple Practice Models/Settings, and a Supportive Learning Environment. The results of this study emphasize important considerations for professional training programs in the health professions that may extend to other higher education disciplines

    Impact of Pre-Advanced Pharmacy Practice Experience (APPE) Curriculum on Student Pharmacists\u27 Professional Identity Formation.

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    OBJECTIVE: To (1) evaluate changes in student pharmacists\u27 professional identity during a curriculum prior to advanced pharmacy practice experiences (APPEs) and (2) describe the components of a pre-APPE curriculum that positively and negatively influenced students\u27 professional identity formation (PIF). METHODS: The University of Washington School of Pharmacy launched a new curriculum in 2019 featuring components intentionally designed to support students\u27 PIF. The Macleod-Clark Professional Identity Scale (MCPIS) was administered to the class of 2023 before starting pharmacy school (pre) and upon completion of the pre-APPE curriculum (post). The postsurvey also contained 2 open-response questions asking students to identify the most positive and negative influences on their PIF. Mean pre- and post-responses were calculated for all MCPIS items and each MCPIS item and compared using paired t tests. Responses to the open-ended questions were sorted into categories using inductive thematic analysis and frequencies were calculated. RESULTS: A total of 99 students (96%) completed both surveys. Mean MCPIS pre-scores and post-scores were both 3.3, indicating no statistically significant change in professional identity. The most frequently reported positive influences on PIF were didactic coursework (40%), experiential learning (30%), and student organizations (27%). The most frequently reported negative influences were didactic coursework (27%), none (25%), and perceptions of the pharmacy profession (22%). CONCLUSION: Students\u27 overall professional identity, as measured by the MCPIS, did not change during the pre-APPE curriculum. Didactic coursework had the most common positive and negative influence on professional identity prior to APPEs
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