432 research outputs found

    Influence of shoot number and crop load on potted Chambourcin grapevines. 2. Whole-vine vs. single-leaf photosynthesis

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    Two-year-old potted Chambourcin grapevines were trained to one shoot with 0 or 1 cluster (1/0 and 1/1 respectively) or four shoots with 0 or 4 clusters (4/0 and 4/4 respectively) to determine the effects of canopy development rate, canopy morphology, and crop load on whole-vine photosynthesis. Significant differences in canopy development rate, canopy morphology and dry matter partitioning occurred among treatments but whole-vine net photosynthesis (Pn) and dry matter production were not affected. Photosynthetic compensation by leaves of severely pruned vines enabled them to produce quantities of dry matter similar to vines with greater leaf area. Vines bearing crop supported the development of berries by partitioning carbohydrate to fruit at the expense of vegetative tissues so overall vine dry weight was not different among cropped and non-cropped treatments. Whole-vine Pn determinations were linearly related to vine dry mass. By contrast, single leaf measurements used to estimate whole-vine Pn were not related to dry mass. If a similar relationship can be demonstrated in field vines, it may be possible to quantify the influence of biotic and abiotic stresses on vine biomass production and subsequent yields

    Ontogenetic loops in habitat use highlight the importance of littoral habitats for early life-stages of oceanic fishes in temperate waters

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    General concepts of larval fish ecology in temperate oceans predominantly associate dispersal and survival to exogenous mechanisms such as passive drift along ocean currents. However, for tropical reef fish larvae and species in inland freshwater systems behavioural aspects of habitat selection are evidently important components of dispersal. This study is focused on larval Atlantic herring (Clupea harengus) distribution in a Baltic Sea retention area, free of lunar tides and directed current regimes, considered as a natural mesocosm. A Lorenz curve originally applied in socio-economics to describe demographic income distribution was adapted to a 20 year time-series of weekly larval herring distribution, revealing size-dependent spatial homogeneity. Additional quantitative sampling of distinct larval development stages across pelagic and littoral areas uncovered a loop in habitat use during larval ontogeny, revealing a key role of shallow littoral waters. With increasing rates of coastal change, our findings emphasize the importance of the littoral zone when considering reproduction of pelagic, ocean-going fish species; highlighting a need for more sensitive management of regional coastal zones

    Asymmetric collisions in MadGraph5_aMC@NLO

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    We will gain unprecedented, high-accuracy insights into the internal structure of the atomic nucleus thanks to lepton-hadron collision studies in the coming years at the Electron-Ion-Collider (EIC) in the United States. A good control of radiative corrections is necessary for the EIC to be fully exploited and to extract valuable information from various measurements. We present our extension of photoproduction at fixed order in MadGraph5_aMC@NLO, a widely used framework for (next-to-)leading order calculations at the Large Hadron Collider (LHC). It applies to electron-hadron collisions, in which the quasi-real photon comes from an electron as well as to proton-nucleus and nucleus-nucleus collisions

    Reweighting the Sivers function with jet data from STAR

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    The reweighting procedure that using Bayesian statistics incorporates the information contained in a new data set, without the need of re-fitting, is applied to the quark Sivers function extracted from Semi-Inclusive Deep Inelastic Scattering (SIDIS) data. We exploit the recently published single spin asymmetry data for the inclusive jet production in polarized pppp collisions from the STAR Collaboration at RHIC, which cover a much wider xx region compared to SIDIS measurements. The reweighting method is extended to the case of asymmetric errors and the results show a remarkable improvement of the knowledge of the quark Sivers function.Comment: 9 pages, 5 figure

    EXPLORING STUDENTS’ ATTITUDES TOWARDS ONLINE-BASED LEARNING SYSTEM IN THE NEW NORMAL: AN EXPLORATORY FACTOR ANALYSIS

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    The implementation of online learning modality in the “New Normal Education” shifted the track of education institutions across the globe from conducting face-to-face classes to holding online-classes. The study presented in this paper aimed to explore students’ attitude towards online-based learning system in the “New Normal” education. Specifically, it investigated the factor structure and the level of attitudes of 200 students towards online-based learning system. This study utilized a mixed method of research utilizing in-depth interview and a dimension reduction technique through Principal Component Analysis. Results revealed that, attitudes toward online-based learning system is multidimensional exploring eight dimensions namely: Engagement, Convenience, Satisfaction, Technology Acceptance, Adaptability, Interaction, Self-Regulation and Control. Moreover, the level of attitudes of students revealed a high level of convenience, technology acceptance, adaptability, interaction, assessment satisfaction, self-regulation and control and a moderate level of student engagement. Thus, the researchers recommend a training proposal for teachers as well as recalibrating the result of the study utilizing Confirmatory Factor Analysis.   Article visualizations

    Prevalence of sustainable and unsustainable use of wild species inferred from the IUCN Red List of Threatened Species

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    Unsustainable exploitation of wild species represents a serious threat to biodiversity and to the livelihoods of local communities and Indigenous peoples. However, managed, sustainable use has the potential to forestall extinctions, aid recovery, and meet human needs. We analyzed species-level data for 30,923 species from 13 taxonomic groups on the International Union for Conservation of Nature Red List of Threatened Species to investigate patterns of intentional biological resource use. Forty percent of species (10,098 of 25,009 species from 10 data-sufficient taxonomic groups) were used. The main purposes of use were pets, display animals, horticulture, and human consumption. Intentional use is currently contributing to elevated extinction risk for 28–29% of threatened or near threatened (NT) species (2752–2848 of 9753 species). Intentional use also affected 16% of all species used (1597–1631 of 10,098). However, 72% of used species (7291 of 10,098) were least concern, of which nearly half (3469) also had stable or improving population trends. The remainder were not documented as threatened by biological resource use, including at least 172 threatened or NT species with stable or improving populations. About one-third of species that had use documented as a threat had no targeted species management actions to directly address this threat. To improve use-related red-list data, we suggest small amendments to the relevant classification schemes and required supporting documentation. Our findings on the prevalence of sustainable and unsustainable use, and variation across taxa, can inform international policy making, including the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, the Convention on Biological Diversity, and the Convention on International Trade in Endangered Species.Fil: Marsh, Sophie M. E.. Colegio Universitario de Londres; Reino UnidoFil: Hoffmann, Michael. The Zoological Society of London; Reino UnidoFil: Burgess, Neil D.. Universidad de Copenhagen; Dinamarca. United Nations Environment Programme World Conservation Monitoring Centre; DinamarcaFil: Brooks, Thomas M.. University of the Philippines; Filipinas. University of Tasmania; Australia. International Union for Conservation of Nature; SuizaFil: Challender, Daniel W. S.. University of Oxford; Reino UnidoFil: Cremona, Patricia J.. International Union for Conservation of Nature; Reino UnidoFil: Hilton Taylor, Craig. International Union for Conservation of Nature; Reino UnidoFil: de Micheaux, Flore Lafaye. Universite de Lausanne; Suiza. Institut Francais de Pondichery; India. International Union For Conservation Of Nature And Natural Resources; SuizaFil: Lichtenstein, Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Secretaría de Cultura de la Nación. Dirección Nacional de Cultura y Museos. Instituto Nacional de Antropología y Pensamiento Latinoamericano; ArgentinaFil: Roe, Dilys. International Institute For Environment And Development; Reino UnidoFil: Böhm, Monika. Zoological Society Of London Institute Of Zoology; Reino Unid
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