3,819 research outputs found

    Biological Species Concepts in Eastern North American Populations of Lentinellus ursinus

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    As part of a biosystematic study of the Lentinellus ursinus species complex, field and herbarium specimens from North America, Central America, and Europe were examined. Single basidiospore isolates from basidiomata collected in Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, Tennessee, North Carolina, Wisconsin, Costa Rica, and Austria were crossed in all possible combinations to determine the mating system operating in each population. All populations exhibited bifactorial or tetrapolar mating systems. Tester strains were then crossed to identify intercompatible populations and to determine if morphological species in the L. ursinus species complex are congruent with biological species. Three biological species were recognized and identified as L. ursinus, L. angustifolius, and L. vulpinus. Polyspore isolates were subsequently used in culture mat and phenoloxidase analyses to facilitate identification of somatic cultures. The production of gloeocystidia and/or chlamydospores is taxonomically important for identifying somatic cultures of these species. All three taxa produced laccase, tyrosinase, and peroxidase in culture and were identified as white-rot fungi. This represents the first confirmed report of L. angustifolius from North America

    A short note on the presence of spurious states in finite basis approximations

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    The genesis of spurious solutions in finite basis approximations to operators which possess a continuum and a point spectrum is discussed and a simple solution for identifying these solutions is suggested

    New species of Capronia (Herpotrichiellaceae, Ascomycota) from Patagonian forests, Argentina

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    Three new species belonging to Capronia are described from plants native to the Andean Patagonian forests, Argentina. The first record of C. chlorospora in South America is also reported. The identity of the three new species is based on detailed morpho-anatomical observations as well as analyses of ITS and LSU nuclear rDNA. A key to the Capronia species present in Argentina is provided.Fil: Sanchez, Romina Magali. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Miller Andrew, N.. University of Illinois at Urbana; Estados UnidosFil: Bianchinotti, Maria Virginia. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentin

    Elastic constants of 3-, 4- and 6-connected chiral and anti-chiral honeycombs subject to uniaxial in-plane loading

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    Finite Element models are developed for the in-plane linear elastic constants of a family of honeycombs comprising arrays of cylinders connected by ligaments. Honeycombs having cylinders with 3, 4 and 6 ligaments attached to them are considered, with two possible configurations explored for each of the 3- (trichiral and anti-trichiral) and 4- (tetrachiral and anti-tetrachiral) connected systems. Honeycombs for each configuration have been manufactured using rapid prototyping and subsequently characterised for mechanical properties through in-plane uniaxial loading to verify the models. An interesting consequence of the family of 'chiral' honeycombs presented here is the ability to produce negative Poisson's ratio (auxetic) response. The deformation mechanisms responsible for auxetic functionality in such honeycombs are discussed

    Effect of bromoform and linseed oil on greenhouse gas emissions from stored beef manure

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    Emissions of carbon dioxide, methane, and nitrous oxide – potent greenhouse gases - from stored beef feedlot manure are a significant concern relative to climate change. Research on methane reduction strategies for enteric emissions has identified the application of organic additives, such as bromoform and linseed oil, to ruminant diets as potential solutions for reducing enteric emissions and pathogenic bacteria in excreted manure. The objective of this study was to determine the effect of bromoform and linseed oil on greenhouse gas emissions from beef feedlot manure, and on E. coli concentration in beef cattle manure, during a 5-week storage period. The experiment used a completely randomized block design (CRBD) with 4 replications of 5 treatments: 5.5 g/kg and 11 g/kg of linseed oil, 4.3 g/kg, and 8.6 g/kg of bromoform, and a control receiving no additives. Treatments were added to a 3-liter mix of 50% manure, 50% soil, mixed by hand, and stored in airtight columns (10-cm diameter x 40-cm tall) in a greenhouse maintained at 25 C during the storage period. Gas samples were collected 10 times during the 5-week test period using a 15 ml syringe and were analyzed using gas chromatography to determine concentrations of methane, carbon dioxide and nitrous oxide. A 1-cm diameter core of material was removed from the top 20 cm of each column 4 times during the sampling period to conduct bacterial enumerations. Quantification of E.coli in samples was determined by incubating serial dilutions for 24 hours at 36 C and manually counting colonies. Preliminary results of the study showed that through 5 weeks of observation, 11g/kg linseed oil reduced the average concentration of E. coli (p \u3c0.05) compared to all other treatments. Preliminary results also indicate that bromoform at 8.6g/kg decreased carbon dioxide emissions but neither bromoform concentration had any significant effect on methane or nitrous oxide emissions compared to control. Linseed oil at 11g/kg increased methane emissions compared to control but neither linseed oil concentrations significantly impacted the average flux of carbon dioxide, or nitrous oxide from manure storages when compared to control

    Bimodal release ondansetron for acute gastroenteritis among adolescents and adults: A randomized clinical trial

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    Importance: Vomiting resulting from acute gastroenteritis is commonly treated with intravenous antiemetics in acute care settings. If oral treatment were beneficial, patients might not need intravenous administered hydration or medication. Furthermore, a long-acting treatment could provide sustained relief from nausea and vomiting. Objective: To determine whether an experimental long-acting bimodal release ondansetron tablet decreases gastroenteritis-related vomiting and eliminates the need for intravenous therapy for 24 hours after administration. Design, Setting, and Participants: This placebo-controlled, double-blind, randomized clinical trial included patients from 19 emergency departments and 2 urgent care centers in the United States from December 8, 2014, to February 17, 2017. Patients 12 years and older with at least 2 vomiting episodes from presumed gastroenteritis in the previous 4 hours and symptoms with less than 36 hours\u27 duration were randomized using a 3:2 active to placebo ratio. Analyses were performed on an intent-to-treat basis and conducted from June 1, 2017, to November 1, 2017. Intervention: Bimodal release ondansetron tablet containing 6 mg of immediate release ondansetron and 18 mg of a 24-hour release matrix for a total of 24 mg of ondansetron. Main Outcomes and Measures: Treatment success was defined as no further vomiting, no need for rescue medication, and no intravenous hydration for 24 hours after bimodal release ondansetron administration. Results: Analysis included 321 patients (mean [SD] age, 29.0 [11.1] years; 195 [60.7%] women), with 192 patients in the bimodal release ondansetron group and 129 patients in the placebo group. Treatment successes were observed in 126 patients in the bimodal release ondansetron group (65.6%) compared with 70 patients in the placebo group (54.3%), with an 11.4% (95% CI, 0.3%-22.4%) absolute probability difference. The proportion of treatment success was 21% higher among patients who received bimodal release ondansetron compared with those who received a placebo (relative risk, 1.21; 95% CI, 1.00-1.46; P = .04). In an analysis including only patients with a discharge diagnosis of acute gastroenteritis and no major protocol violations, there were 123 treatment successes (69.5%) in the bimodal release ondansetron group compared with 67 treatment successes (54.9%) in the placebo group (relative risk, 1.27; 95% CI, 1.05-1.53; P = .01). Adverse effects were infrequent and similar to the known safety profile of ondansetron. Conclusions and Relevance: This randomized clinical trial found that a long-acting bimodal release oral ondansetron tablet was an effective antiemetic among adolescents and adults with moderate to severe vomiting from acute gastroenteritis. The drug benefits extended to 24 hours after administration. Bimodal release ondansetron may decrease the need for intravenous access and emergency department care to manage acute gastroenteritis. Trial Registration: ClinicalTrials.gov identifier: NCT02246439
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