1,354 research outputs found

    Discrete wavelet analysis of the influence of the North Atlantic Oscillation on Baltic Sea level

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    Mean sea level (MSL) in the Baltic Sea is influenced by several factors and therefore presents a complex behaviour over a wide range of time-scales. This work performs a multi-scale analysis of MSL variability in the Baltic Sea using discrete wavelet analysis. The North Atlantic Oscillation (NAO) is well known for having a strong influence in MSL variability over the Baltic; however, the relationship between MSL and NAO at different time-scales is still little understood. In this work a comparison of MSL and NAO variability is performed for a wide range of temporal scales, uncovering distinct relationships in high-frequency and long-term temporal variability. The annual and sub-annual scales are found to account for more than 50% of the total MSL variability. The MSL annual cycle is analysed and a shift from low to high amplitude values is identified in the 1970s for most stations. MSL is found to be anti-correlated to NAO at short time-scales while on the long-term NAO and MSL appear to be positively correlated for most stations. The physical mechanisms behind these distinct relationships deserve deeper study

    Comparing the impacts of 2003 and 2010 heatwaves in NPP over Europe

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    In the last decade, Europe was stricken by two outstanding heatwaves, the 2003 event in Western Europe and the recent 2010 episode over Russia. Both extreme events were characterised by record-breaking temperatures, and widespread socio-economic impacts, including significant increments on mortality rates, decreases in crop production and in hydroelectric production. This work aims to assess the influence of both mega-heatwaves on vegetation carbon uptake, using yearly Net Primary Production (NPP) and monthly Net Photosynthesis (PsN) data derived from satellite imagery obtained from MODIS for the period 2000–2011. <br><br> In 2010, markedly low productivity was observed over a very large area in Russia, at monthly, seasonal and yearly scales, falling below 50% of average NPP. This decrease in NPP in 2010 was far more intense than the one affecting Western Europe in 2003, which corresponded to 20–30% of the average, and affected a~much larger extent. Total NPP anomalies reached −19 Tg C for the selected regions in France during 2003 and −94 Tg C for western Russia in 2010, which corresponds almost to the magnitude of total NPP anomaly during 2010 for the whole Europe. <br><br> Overall, the widespread negative PsN anomalies in both regions match the patterns of very high temperature values preceded by a long period of below-average precipitation, leading to strong soil moisture deficits, stressing the role of soil-atmosphere coupling. In the case of 2003 heatwave, results indicate a strong influence of moisture deficits coupled with high temperatures in the response of vegetation, while for the 2010 event very high temperatures appear to be the main driver of very low NPP

    Drought impacts on vegetation in the pre- and post-fire events over Iberian Peninsula

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    The present work aims to study the combined effect of drought and large wildfires in the Iberian Peninsula relying on remotely sensed data of vegetation dynamics and leaf moisture content, in particular monthly NDVI, NDWI and NDDI time series from 1999–2009, derived from VEGETATION dataset. The impact of the exceptional 2004/2005 drought on vegetation was assessed for vegetation recovering from the extraordinary fire season of 2003 and on the conditions that contributed to the onsetting of the fire season of 2005. Drought severity was estimated by the cumulative negative effect on photosynthetic activity (NDVI) and vegetation dryness (NDDI), with about 2/3 of Iberian Peninsula presenting vegetative stress and low water availability conditions, in spring and early summer of 2005. Furthermore, NDDI has shown to be very useful to assess drought, since it combines information on vegetation and water conditions. Moreover, we show that besides looking at the inter-annual variability of NDVI and NDDI, it is useful to evaluate intra-annual changes (δNDVI and δNDDI), as indicators of change in vegetation greenness, allowing a detailed picture of the ability of the different land-cover types to resist to short-term dry conditions. In order to assess drought impact on post-fire regeneration, recovery times were evaluated by a mono-parametric model based on NDVI data and values corresponding to drought months were set to no value. Drought has shown to delay recovery times for several months in all the selected scars from 2003. The analysis of vegetation dynamics and fire selectivity in 2005 suggests that fires tended to occur in pixels presenting lower vegetative and water stress conditions during spring and early summer months. Additionally, pre-fire vegetation dynamics, in particular vegetation density and water availability during spring and early summer, has shown to influence significantly the levels of fire damage. These results stress the role of fuel availability in fire occurrence and impact on the Iberian Peninsula

    Collagen membrane from bovine pericardium for treatment of long bone defect

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    The treatment of bone regeneration failures has been constantly improved with the study of new biomaterials. Techgraft® is a collagen membrane derived from bovine pericardium, which has been shown to have biocompatibility and effectiveness in tissue repair. However, its use in orthopedics has not yet been evaluated. Therefore, the purpose of this study was to characterize a bovine pericardium collagen membrane and evaluate the effects of its use in the regeneration of a bone defect in rat tibia. Scanning electron microscopy, atomic force microscopy, weight lost and water uptake tests, and mechanical test were performed. Afterwards, the membrane was tested in an experimental study, using 12 male Sprague Dawley rats. A bone defect was surgically made in tibiae of animals, which were assigned to two groups (n = 6): bone defect treated with collagen membrane (TG) and bone defect without treatment (CONT). Then, tibiae were submitted to micro-CT. The membranes preserved their natural collagen characteristics, presenting great strength, high water absorption, hydrophilicity, and almost complete dissolution in 30 days. In the experimental study, the membrane enhanced the growth of bone tissue in contact with its surface. A higher bone volume and trabeculae number and less trabecular space was observed in bone defects of the membrane group compared to the control group at 21 days. In conclusion, the Techgraft membrane seems to have favorable characteristics for treatment of long bone repair.The authors gratefully acknowledge the financial support from the São Paulo Research Foundation (reference 2017/20051-0) and the scholarship from the Coordination for the Improvement of Higher Education Personnel

    Testagem anti-HIV em mulheres grávidas no Brasil: taxas e preditores

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    OBJETIVO: Estimar las tasas de oferta y realización de la prueba anti-HIV y sus predictivos entre mujeres que recibieron atención prenatal. MÉTODOS: Se realizó un estudio transversal, de base poblacional, con 2.234 puérperas en 12 ciudades de Brasil. Las muestras probabilísticas fueron seleccionadas independientemente por ciudad, entre puérperas que asistieron a por lo menos una visita prenatal. Se colectaron datos sociodemográficos, informaciones sobre cuidado prenatal y acceso a intervenciones de prevención del HIV durante el embarazo, con la utilización de una encuesta. Se realizaron análisis bivariadas y multivariadas para verificar los efectos independientes de las co-variables en la oferta y realización de la prueba anti-HIV. Los datos fueron colectados en el período de noviembre de 1999 a abril de 2000. RESULTADOS: La realización de la prueba anti-HIV durante el embarazo fue realizada por el 77,5% de las encuestadas. La oferta de la prueba fue positivamente asociada con: el conocimiento previo sobre la prevención de la transmisión materno-infantil del HIV; mayor número de visitas prenatal; mayor nivel de escolaridad y presencia de color blanco de piel. La tasa de aceptación de la prueba anti-HIV fue de 92,5%. CONCLUSIONES: Los resultados indican que La diseminación de la información sobre prevención de la transmisión materno-infantil del HIV puede contribuir para aumentar la cobertura de la evaluación anti-HIV durante el embarazo. Las mujeres no-blancas con menores niveles de educación deben ser priorizadas. La estrategias para aumentar la participación de poblaciones vulnerables al cuidado prenatal y la sensibilización de trabajadores de la salud son de gran importancia.OBJETIVO: Estimar as taxas de oferta e realização do teste anti-HIV e seus preditores entre mulheres que receberam atendimento pré-natal. MÉTODOS: Foi conduzido estudo transversal, de base populacional, com 2.234 puérperas em 12 cidades do Brasil. Amostras probabilísticas foram selecionadas independentemente por cidade, entre puérperas que compareceram a pelo menos uma visita pré-natal. Foram coletados dados sociodemográficos, informações sobre cuidado pré-natal e acesso a intervenções de prevenção do HIV durante a gravidez corrente, com a utilização de um questionário. Foram realizadas análises bivariadas e multivariadas para verificar os efeitos independentes das covariáveis na oferta e realização do teste anti-HIV. Os dados foram coletados no período de novembro de 1999 a abril de 2000. RESULTADOS: A realização do teste na gravidez foi relatada por 77,5% das entrevistadas. A oferta do teste anti-HIV foi positivamente associada a: conhecimento prévio sobre a prevenção da transmissão materno-infantil do HIV; maior número de visitas pré-natal; maior nível de escolaridade e ter cor da pele branca. A taxa de aceitação do teste anti-HIV foi de 92,5%. CONCLUSÕES: Os resultados indicam que a disseminação da informação sobre prevenção da transmissão materno-infantil do HIV pode contribuir para aumentar a cobertura da testagem anti-HIV durante a gravidez. Mulheres não-brancas com menores níveis educacionais devem ser priorizadas. Estratégias para aumentar a participação de populações vulneráveis ao cuidado pré-natal e a sensibilização de trabalhadores de saúde são de grande importância.OBJECTIVE: To assess rates of offering and uptake of HIV testing and their predictors among women who attended prenatal care. METHODS: A population-based cross-sectional study was conducted among postpartum women (N=2,234) who attended at least one prenatal care visit in 12 cities. Independent and probabilistic samples were selected in the cities studied. Sociodemographic data, information about prenatal care and access to HIV prevention interventions during the current pregnancy were collected. Bivariate and multivariate analyses were carried out to assess independent effects of the covariates on offering and uptake of HIV testing. Data collection took place between November 1999 and April 2000. RESULTS: Overall, 77.5% of the women reported undergoing HIV testing during the current pregnancy. Offering of HIV testing was positively associated with: previous knowledge about prevention of mother-to-child transmission of HIV; higher number of prenatal care visits; higher level of education and being white. HIV testing acceptance rate was 92.5%. CONCLUSIONS: The study results indicate that dissemination of information about prevention of mother-to-child transmission among women may contribute to increasing HIV testing coverage during pregnancy. Non-white women with lower level of education should be prioritized. Strategies to increase attendance of vulnerable women to prenatal care and to raise awareness among health care workers are of utmost importance

    Evaluation of Multi-Level Barriers and Facilitators in a Large Diabetic Retinopathy Screening Program in Federally Qualified Health Centers: A Qualitative Study

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    BACKGROUND: Recommended annual diabetic retinopathy (DR) screening for people with diabetes has low rates in the USA, especially in underserved populations. Telemedicine DR screening (TDRS) in primary care clinics could expand access and increase adherence. Despite this potential, studies have observed high variability in TDRS rates among clinics and over time, highlighting the need for implementation supports. Previous studies of determinants of TDRS focus on patients\u27 perspectives, with few studies targeting upstream multi-level barriers and facilitators. Addressing this gap, this qualitative study aimed to identify and evaluate multi-level perceived determinants of TDRS in Federally Qualified Health Centers (FQHCs), to inform the development of targeted implementation strategies. METHODS: We developed a theory-based semi-structured interview tool based on the Consolidated Framework for Implementation Research (CFIR). We conducted 22 key informant interviews with professionals involved in TDRS (administrators, clinicians, staff). The interviews were audio-recorded and transcribed verbatim. Reported barriers and facilitators were organized into emergent themes and classified according to CFIR constructs. Constructs influencing TDRS implementation were rated for each study site and compared across sites by the investigators. RESULTS: Professionals identified 21 main barriers and facilitators under twelve constructs of the five CFIR domains. Several identified themes were novel, whereas others corroborated previous findings in the literature (e.g., lack of time and human resources, presence of a champion). Of the 21 identified themes, 13 were classified under the CFIR’s Inner Setting domain, specifically under the constructs Compatibility and Available Resources. Themes under the Outer Setting domain (constructs External Incentives and Cost) were primarily perceived by administrators, whereas themes in other domains were perceived across all professional categories. Two Inner Setting (Leadership Engagement, Goals and Feedback) and two Process (Champion, Engaging) constructs were found to strongly distinguish sites with high versus low TDRS performance. CONCLUSIONS: This study classified barriers and facilitators to TDRS as perceived by administrators, clinicians, and staff in FQHCs, then identified CFIR constructs that distinguished high- and low-performance clinics. Implementation strategies such as academic detailing and collection and communication of program data and successes to leadership; engaging of stakeholders through involvement in implementation planning; and appointment of intervention champions may therefore improve TDRS implementation and sustainment in resource-constrained settings

    Novel approach for a controlled delivery of essential Oils during long-term maize storage: clove bud and pennyroyal oils efficacy to control sitophilus zeamais, reducing grain damage and post-harvest losses

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    Maize grains represent a significant contribution for assuring food safety all over the globe. Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae), also known as the maize weevil, is one of the most destructive pests in stored maize, causing qualitative and quantitative losses. To control S. zeamais populations in maize storage sites, synthetical chemical insecticides are applied. However, these are often used wastefully, have environmental implications, and can induce the development of resistant populations. In this work, the insecticidal and grain protecting efficacy of an innovative macro-capsule delivery device, loaded with essential oils from Clove bud and Pennyroyal, as well as their combined solutions, was tested against naturally S. zeamais-infested maize grains. The blend of both compounds incorporated in a controlled release device reduced losses by more than 45% over a long storage period of twenty weeks, diminishing the survivability of maize weevils by over 90%. The usage of the blend at a concentration of 370 L L1 air with an antioxidant showed the best results, however, by halving the concentration 185 L L1 air , a significant control of S. zeamais populations was still achieved.info:eu-repo/semantics/publishedVersio

    Bio-based solar energy harvesting for onsite mobile optical temperature sensing in Smart Cities

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    The Internet of Things (IoT) fosters the development of smart city systems for sustainable living and increases comfort for people. One of the current challenges for sustainable buildings is the optimization of energy management. Temperature monitoring in buildings is of prime importance, as heating account for a great part of the total energy consumption. Here, a solar optical temperature sensor is presented with a thermal sensitivity of up to 1.23% °C-1 based on sustainable aqueous solutions of enhanced green fluorescent protein and C-phycocyanin from biological feedstocks. These photonic sensors are presented under the configuration of luminescent solar concentrators widely proposed as a solution to integrate energy-generating devices in buildings, as windows or façades. The developed mobile sensor is inserted in IoT context through the development of a self-powered system able to measure, record, and send data to a user-friendly website.publishe

    Pharmacological and Non-Pharmacological Agents versus Bovine Colostrum Supplementation for the Management of Bone Health Using an Osteoporosis-Induced Rat Model

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    Osteoporosis is defined by loss of bone mass and deteriorated bone microarchitecture. The present study compared the effects of available pharmacological and non-pharmacological agents for osteoporosis [alendronate (ALE) and concomitant supplementation of vitamin D (VD) and calcium (Ca)] with the effects of bovine colostrum (BC) supplementation in ovariectomized (OVX) and orchidectomized (ORX) rats. Seven-month-old rats were randomly allocated to: (1) placebo-control, (2) ALE group (7.5 μg/kg of body weight/day/5 times per week), (3) VD/Ca group (VD: 35 μg/kg of body weight/day/5 times per week; Ca: 13 mg/kg of body weight/day/3 times per week), and (4) BC supplementation (OVX: 1.5 g/day/5 times per week; ORX: 2 g/day/5 times per week). Following four months of supplementation, bone microarchitecture, strength and bone markers were evaluated. ALE group demonstrated significantly higher Ct.OV, Ct.BMC, Tb.Th, Tb.OV and Tb.BMC and significantly lower Ct.Pr, Tb.Pr, Tb.Sp, Ct.BMD and Tb.BMD, compared to placebo (p < 0.05). BC presented significantly higher Ct.Pr, Ct.BMD, Tb.Pr, Tb.Sp, and Tb.BMD and significantly lower Ct.OV, Ct.BMC, Tb.Th, Tb.OV and Tb.BMC compared to ALE in OVX rats (p < 0.05). OVX rats receiving BC experienced a significant increase in serum ALP and OC levels post-supplementation (p < 0.05). BC supplementation may induce positive effects on bone metabolism by stimulating bone formation, but appear not to be as effective as ALE
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