121 research outputs found

    Soil Chemistry Properties Under Two Different Management Practices: Clipped Saint Augustine Grass Lawn and Annually Burned Cajun Prairie

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    Prescribed burning every two or more years is the recommended management practice to remove unnecessary invasive plants and to enhance the regrowth of desirable plants for the development of a fire-dependent plant community native to southwestern Louisiana. A portion of Saint Augustine grass lawn at Louisiana State University at Eunice (LSUE) was converted into a Cajun Prairie restoration plot in 1989. Since 1991, the adjacent lawn has been clipped weekly, whereas the prairie has been burned every January. The objective of this study was to determine the soil chemical properties of clipped lawn and burned prairie plots. Each plot (12 m x 104 m) had four blocks (replications). Soil samples from the 0-10 cm depth were taken from each block for each plot in December 2002, March 2003, and June 2003. They were analyzed in the laboratory for soil chemical properties: pH, organic carbon (OC), electrical conductivity (EC) as a measure of soluble salts, phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), iron (Fe), zinc (Zn) and copper (Cu). Extractable soil P, Ca, Mg and Na were significantly greater in the burned prairie than in the clipped lawn. In the burned prairie from December to June, Fe increased, whereas pH, EC, P, K, Na, Cu, and Zn decreased. The results suggest that the annually burned restored Cajun Prairie provided greater nutrient deposition into the soil than the clipped Saint Augustine lawn

    Una revisión teórica sobre la adopción del comercio electrónico

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    El propósito de este trabajo es presentar un breve acercamiento teórico de la adopción del comercio electrónico. Este conceptualmente se desplazó de una noción de estrategia de rentabilidad para las empresas que brindan servicios y organizaciones comerciales. El modelo de Aceptación Tecnológica propone pronosticar un grupo u organización que adoptan de una nueva tecnología con la finalidad de predecir el futuro de su uso. Una definición concluyente considerada para el comercio electrónico es que se considera como un implemento necesario e instrumento que permite al consumidor realizar actividades de compraventa donde el alcance de disponibilidad de acceso es ilimitado que genera rentabilidad para la empresa a través de sus dimensiones: seguridad percibida entendido como control de seguridad que se brinda al consumidor; la lealtad del consumidor siendo las actitudes que toma según sus experiencias y la expectativa que tiene frente a la empresa y por último la satisfacción siendo las expectativas del cliente del servicio brindado.LIMAEscuela Profesional de AdministraciónMarketin

    Embodied Energy Consumption in the Residential Sector: A Case Study of Affordable Housing

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    Embodied energy has a significant effect on the total environmental impact of a project. However, emphasis is often placed primarily on operational energy, resulting in a knowledge gap about the current state of embodied energy use in affordable housing. To address this, the study investigates the level of embodied energy consumption in affordable housing, as well as the drivers, barriers, and techniques to reduce embodied energy. Based on a single embedded case study covering the period from cradle to end of construction, data were collected using embodied energy calculations of three affordable housing units in the project, semi-structured interviews with five design team members, and a cross-examination of findings with contract documents. The results were analysed using sensitivity analysis and thematic analysis. The findings revealed that all three house units fulfilled the baseline embodied carbon target of 800 kg CO2/m2 and both detached properties fell within the LETI (2020) target of 500 kg CO2/m2. However, all three properties would fail to meet the RIBA or 2030 LETI target of 300 kg CO2/m2. This suggests that improvements are necessary to achieve future targets. The results show that financial capabilities and operational energy prioritisation act as the main enabler and barrier for reducing embodied energy. Local contractors/suppliers, minimising material use or intensity, and modular construction were highlighted as the key reduction techniques that can be used to help achieve future targets concerning embodied carbon in residential developments. The study contributes significantly to understanding the current state of embodied energy use in affordable housing and provides new insights on how to deal with embodied energy if we are to meet future energy targets

    A global database for metacommunity ecology, integrating species, traits, environment and space

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    The use of functional information in the form of species traits plays an important role in explaining biodiversity patterns and responses to environmental changes. Although relationships between species composition, their traits, and the environment have been extensively studied on a case-by-case basis, results are variable, and it remains unclear how generalizable these relationships are across ecosystems, taxa and spatial scales. To address this gap, we collated 80 datasets from trait-based studies into a global database for metaCommunity Ecology: Species, Traits, Environment and Space; “CESTES”. Each dataset includes four matrices: species community abundances or presences/absences across multiple sites, species trait information, environmental variables and spatial coordinates of the sampling sites. The CESTES database is a live database: it will be maintained and expanded in the future as new datasets become available. By its harmonized structure, and the diversity of ecosystem types, taxonomic groups, and spatial scales it covers, the CESTES database provides an important opportunity for synthetic trait-based research in community ecology

    Machine learning based prediction of COVID-19 mortality suggests repositioning of anticancer drug for treating severe cases

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    Despite available vaccinations COVID-19 case numbers around the world are still growing, and effective medications against severe cases are lacking. In this work, we developed a machine learning model which predicts mortality for COVID-19 patients using data from the multi-center ‘Lean European Open Survey on SARS-CoV-2-infected patients’ (LEOSS) observational study (>100 active sites in Europe, primarily in Germany), resulting into an AUC of almost 80%. We showed that molecular mechanisms related to dementia, one of the relevant predictors in our model, intersect with those associated to COVID-19. Most notably, among these molecules was tyrosine kinase 2 (TYK2), a protein that has been patented as drug target in Alzheimer's Disease but also genetically associated with severe COVID-19 outcomes. We experimentally verified that anti-cancer drugs Sorafenib and Regorafenib showed a clear anti-cytopathic effect in Caco2 and VERO-E6 cells and can thus be regarded as potential treatments against COVID-19. Altogether, our work demonstrates that interpretation of machine learning based risk models can point towards drug targets and new treatment options, which are strongly needed for COVID-19

    Ancient genomes in South Patagonia reveal population movements associated with technological shifts and geography

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    Archaeological research documents major technological shifts among people who have lived in the southern tip of South America (South Patagonia) during the last thirteen millennia, including the development of marine-based economies and changes in tools and raw materials. It has been proposed that movements of people spreading culture and technology propelled some of these shifts, but these hypotheses have not been tested with ancient DNA. Here we report genome-wide data from 20 ancient individuals, and co-analyze it with previously reported data. We reveal that immigration does not explain the appearance of marine adaptations in South Patagonia. We describe partial genetic continuity since ~6600 BP and two later gene flows correlated with technological changes: one between 4700–2000 BP that affected primarily marine-based groups, and a later one impacting all <2000 BP groups. From ~2200–1200 BP, mixture among neighbors resulted in a cline correlated to geographic ordering along the coast.Fil: Nakatsuka, Nathan. Harvard Medical School; Estados UnidosFil: Luisi, Pierre. Universidad Nacional de Córdoba. Facultad de Filosofía y Humanidades; ArgentinaFil: Motti, Josefina María Brenda. Universidad Nacional del Centro de la Provincia de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Salemme, Monica Cira. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina. Universidad Nacional de Tierra del Fuego; ArgentinaFil: Santiago, Fernando Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: D'angelo del Campo, Manuel Domingo. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Sociales. Grupo de Estudios Interdisciplinarios sobre Poblaciones Humanas de Patagonia Austral; Argentina. Universidad Autónoma de Madrid; EspañaFil: Vecchi, Rodrigo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur; ArgentinaFil: Espinosa Parrilla, Yolanda. Consejo Superior de Investigaciones Científicas; EspañaFil: Prieto, Alfredo. Universidad de Magallanes; ChileFil: Adamski, Nicole. Harvard Medical School; Estados UnidosFil: Lawson, Ann Marie. Harvard Medical School; Estados UnidosFil: Harper, Thomas K.. University of Pennsylvania; Estados UnidosFil: Culleton, Brendan J.. University of Pennsylvania; Estados UnidosFil: Kennett, Douglas J.. University of California; Estados UnidosFil: Lalueza Fox, Carles. Consejo Superior de Investigaciones Científicas; EspañaFil: Mallick, Swapan. Harvard Medical School; Estados UnidosFil: Rohland, Nadin. Harvard Medical School; Estados UnidosFil: Guichón, Ricardo A.. Universidad Nacional del Centro de la Provincia de Buenos Aires; ArgentinaFil: Cabana, Graciela S.. University of Tennessee; Estados UnidosFil: Nores, Rodrigo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Antropología de Córdoba. Universidad Nacional de Córdoba. Facultad de Filosofía y Humanidades. Instituto de Antropología de Córdoba; ArgentinaFil: Reich, David. Harvard Medical School. Department Of Medicine; Estados Unido

    The genomic history of the Iberian Peninsula over the past 8000 years

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    We assembled genome-wide data from 271 ancient Iberians, of whom 176 are from the largely unsampled period after 2000 BCE, thereby providing a high-resolution time transect of the Iberian Peninsula.We document high genetic substructure between northwestern and southeastern hunter-gatherers before the spread of farming.We reveal sporadic contacts between Iberia and North Africa by ~2500 BCE and, by ~2000 BCE, the replacement of 40% of Iberia's ancestry and nearly 100% of its Y-chromosomes by people with Steppe ancestry.We show that, in the Iron Age, Steppe ancestry had spread not only into Indo-European-speaking regions but also into non-Indo-European-speaking ones, and we reveal that present-day Basques are best described as a typical Iron Age population without the admixture events that later affected the rest of Iberia. Additionally, we document how, beginning at least in the Roman period, the ancestry of the peninsula was transformed by gene flow from North Africa and the eastern Mediterranean

    Psychometric characteristics of the Spanish version of instruments to measure neck pain disability

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    [EN] Background. The NDI, COM and NPQ are evaluation instruments for disability due to NP. There was no Spanish version of NDI or COM for which psychometric characteristics were known. The objectives of this study were to translate and culturally adapt the Spanish version of the Neck Disability Index Questionnaire (NDI), and the Core Outcome Measure (COM), to validate its use in Spanish speaking patients with non-specific neck pain (NP), and to compare their psychometric characteristics with those of the Spanish version of the Northwick Pain Questionnaire (NPQ). Methods. Translation/re-translation of the English versions of the NDI and the COM was done blindly and independently by a multidisciplinary team. The study was done in 9 primary care Centers and 12 specialty services from 9 regions in Spain, with 221 acute, subacute and chronic patients who visited their physician for NP: 54 in the pilot phase and 167 in the validation phase. Neck pain (VAS), referred pain (VAS), disability (NDI, COM and NPQ), catastrophizing (CSQ) and quality of life (SF-12) were measured on their first visit and 14 days later. Patients' self-assessment was used as the external criterion for pain and disability. In the pilot phase, patients' understanding of each item in the NDI and COM was assessed, and on day 1 test-retest reliability was estimated by giving a second NDI and COM in which the name of the questionnaires and the order of the items had been changed. Results. Comprehensibility of NDI and COM were good. Minutes needed to fill out the questionnaires [median, (P25, P75)]: NDI. 4 (2.2, 10.0), COM: 2.1 (1.0, 4.9). Reliability: [ICC, (95%CI)]: NDI: 0.88 (0.80, 0.93). COM: 0.85 (0.75,0.91). Sensitivity to change: Effect size for patients having worsened, not changed and improved between days 1 and 15, according to the external criterion for disability: NDI: -0.24, 0.15, 0.66; NPQ: -0.14, 0.06, 0.67; COM: 0.05, 0.19, 0.92. Validity: Results of NDI, NPQ and COM were consistent with the external criterion for disability, whereas only those from NDI were consistent with the one for pain. Correlations with VAS, CSQ and SF-12 were similar for NDI and NPQ (absolute values between 0.36 and 0.50 on day 1, between 0.38 and 0.70 on day 15), and slightly lower for COM (between 0.36 and 0.48 on day 1, and between 0.33 and 0.61 on day 15). Correlation between NDI and NPQ: r = 0.84 on day 1, r = 0.91 on day 15. Correlation between COM and NPQ: r = 0.63 on day 1, r = 0.71 on day 15. Conclusion. Although most psychometric characteristics of NDI, NPQ and COM are similar, those from the latter one are worse and its use may lead to patients' evolution seeming more positive than it actually is. NDI seems to be the best instrument for measuring NP-related disability, since its results are the most consistent with patient's assessment of their own clinical status and evolution. It takes two more minutes to answer the NDI than to answer the COM, but it can be reliably filled out by the patient without assistanceS

    Psychometric characteristics of the Spanish version of instruments to measure neck pain disability

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    Background: The NDI, COM and NPQ are evaluation instruments for disability due to NP. There was no Spanish version of NDI or COM for which psychometric characteristics were known. The objectives of this study were to translate and culturally adapt the Spanish version of the Neck Disability Index Questionnaire (NDI), and the Core Outcome Measure (COM), to validate its use in Spanish speaking patients with non-specific neck pain (NP), and to compare their psychometric characteristics with those of the Spanish version of the Northwick Pain Questionnaire (NPQ). Methods: Translation/re-translation of the English versions of the NDI and the COM was done blindly and independently by a multidisciplinary team. The study was done in 9 primary care Centers and 12 specialty services from 9 regions in Spain, with 221 acute, subacute and chronic patients who visited their physician for NP: 54 in the pilot phase and 167 in the validation phase. Neck pain (VAS), referred pain (VAS), disability (NDI, COM and NPQ), catastrophizing (CSQ) and quality of life (SF-12) were measured on their first visit and 14 days later. Patients' self-assessment was used as the external criterion for pain and disability. In the pilot phase, patients' understanding of each item in the NDI and COM was assessed, and on day 1 test-retest reliability was estimated by giving a second NDI and COM in which the name of the questionnaires and the order of the items had been changed. Results: Comprehensibility of NDI and COM were good. Minutes needed to fill out the questionnaires [median, (P25, P75)]: NDI. 4 (2.2, 10.0), COM: 2.1 (1.0, 4.9). Reliability: [ICC, (95%CI)]: NDI: 0.88 (0.80, 0.93). COM: 0.85 (0.75,0.91). Sensitivity to change: Effect size for patients having worsened, not changed and improved between days 1 and 15, according to the external criterion for disability: NDI: -0.24, 0.15, 0.66; NPQ: -0.14, 0.06, 0.67; COM: 0.05, 0.19, 0.92. Validity: Results of NDI, NPQ and COM were consistent with the external criterion for disability, whereas only those from NDI were consistent with the one for pain. Correlations with VAS, CSQ and SF-12 were similar for NDI and NPQ (absolute values between 0.36 and 0.50 on day 1, between 0.38 and 0.70 on day 15), and slightly lower for COM (between 0.36 and 0.48 on day 1, and between 0.33 and 0.61 on day 15). Correlation between NDI and NPQ: r = 0.84 on day 1, r = 0.91 on day 15. Correlation between COM and NPQ: r = 0.63 on day 1, r = 0.71 on day 15. Conclusion: Although most psychometric characteristics of NDI, NPQ and COM are similar, those from the latter one are worse and its use may lead to patients' evolution seeming more positive than it actually is. NDI seems to be the best instrument for measuring NP-related disability, since its results are the most consistent with patient's assessment of their own clinical status and evolution. It takes two more minutes to answer the NDI than to answer the COM, but it can be reliably filled out by the patient without assistance
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