3,997 research outputs found

    A fine-tuned global distribution dataset of marine forests

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    Species distribution records are a prerequisite to follow climate-induced range shifts across space and time. However, synthesizing information from various sources such as peer-reviewed literature, herbaria, digital repositories and citizen science initiatives is not only costly and time consuming, but also challenging, as data may contain thematic and taxonomic errors and generally lack standardized formats. We address this gap for important marine ecosystem-structuring species of large brown algae and seagrasses. We gathered distribution records from various sources and provide a fine-tuned dataset with ~2.8 million dereplicated records, taxonomically standardized for 682 species, and considering important physiological and biogeographical traits. Specifically, a flagging system was implemented to signal potentially incorrect records reported on land, in regions with limiting light conditions for photosynthesis, and outside the known distribution of species, as inferred from the most recent published literature. We document the procedure and provide a dataset in tabular format based on Darwin Core Standard (DwC), alongside with a set of functions in R language for data management and visualization.FCT: (SFRH/BPD/111003/2015) / (SFRH/BSAB/150485/2019) / (SFRH/BD/144878/2019)(PTDC/MAREST/6053/2014) / MARFOR (BIODIVERSA/004/2015) / UIDB/04326/2020info:eu-repo/semantics/publishedVersio

    Expanding EAL expertise: Taking a multilingual stance

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    English as an Additional Language (EAL) students are increasingly taught by non-specialist, mainstream teachers. This trend calls for a reconceptualization of teacher education to explicitly and purposefully include linguistically and culturally responsive pedagogy in their curriculum. In the United States, several frameworks have been proposed to address this need, although much still needs to be learned about actual practice in preservice teacher preparation programs. In this article, I caution against the monolingual bias in preservice teacher preparation and argue for the mandate for developing a multilingual stance for all teachers of EAL students

    An Investigation into the Communication Needs and Concerns of Asian Students in Speech Communication Performance Classes

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    The University of Nebraska is one of the many institutions of higher education in the United States with a growing foreign student enrollment. Consequently, the numbers of foreign students enrolled in speech communication classes has been increasing. There, however, is currently a lack of systematic investigation into the needs and concerns of foreign students in speech performance classes. This study investigates the needs and concerns of Asian students in speech performance classes. The study uses three methods to determine the needs of Asian students: (1) participant observation, (2) survey and (3) focus group interviews. The findings show that Asian students are extremely anxious about speaking in public. Their anxiety it appears stems from two sources: (1) an insecurity about their linguistic fluency and (2) their instructor\u27s expectations of them. Guidelines are suggested for instructors of Asian students

    Mosquito Larvicidal Constituents from Lantana Viburnoides SP Viburnoides Var Kisi (A. rich) Verdc (Verbenaceae).

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    \ud \ud Lantana viburnoides sp viburnoides var kisi is used in Tanzania ethnobotanically to repel mosquitoes as well as in traditional medicine for stomach ache relief. Bioassay-guided fractionation and subtraction bioassays of the dichloromethane extract of the root barks were carried out in order to identify the bioactive components for controlling Anopheles gambiae s.s. mosquito larvae. Twenty late III or early IV instar larvae of An. gambiae s.s. were exposed to various concentrations of the plant extracts, fractions, blends and pure compounds, and were assayed in the laboratory by using the protocol of WHO 1996. Mean mortalities were compared using Dunnett's test (p < 0.05) and lethal concentration calculated by Lackfit Inversel of the SAS programme. The crude extract (LC50 = 7.70 ppm in 72 h) and fractions exhibited different level of mosquito larvicidal activity with subtraction of some fractions resulting in activity enhancement. The active fractions contained furanonaphthaquinones regio-isomers (LC50 = 5.48-5.70 ppm in 72 h) and the lantadene triterpenoid camaric acid (LC50 = 6.19 ppm in 72 h) as active principles while the lupane triterpenoid betulinic acid (LC50 < 10 ppm in 72 h) was obtained from the least active fraction. Crude extracts and some fractions had higher or comparable larvicidal activity to the pure compounds. These results demonstrate that L. viburnoides sp viburnoides var kisi extracts may serve as larvicides for managing various mosquito habitats even in their semi-purified form. The isolated compounds can be used as distinct markers in the active extracts or plant materials belonging to the genus Lantana

    Envelliment: el pas del temps

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