318 research outputs found

    Initial physic nut nutrition and potassium balance in the soil-plant system

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    A B S T R A C T The objectives of this study were to evaluate the mineral nutrition and the response of physic nut to potassium fertilization as well as to assess whether the species can absorb K from the non-exchangeable soil fraction. The study was conducted in a greenhouse, in randomized blocks, and with four repetitions. Physic nut plants were cultivated in plastic recipients filled with 50 dm 3 of a Dark Red Latosol fertilized with rates of 0, 40, 80, 120 and 160 mg K dm -3 of soil. One hundred and fifty days after planting, the height, stem diameter and leaf area of the plants were measured, and the dry mass, concentration in leaf and total accumulation of macro and micronutrients were determined, as well as the soil contents of exchangeable and non-exchangeable K. The K balance in the soil-plant system was also calculated. The increase of potassium fertilization resulted in a greater uptake of K, Ca and Mn but did not alter the total dry mass production of physic nut. The species can release and absorb K from the non-exchangeable soil fraction. Nutrição inicial do pinhĂŁo-manso e balanço de potĂĄssio no sistema solo-planta R E S U M O Objetivou-se, neste trabalho, avaliar a nutrição mineral e a resposta do pinhĂŁo-manso Ă  adubação potĂĄssica, bem como se a espĂ©cie pode absorver K da fração nĂŁo-trocĂĄvel do solo. O estudo foi conduzido em estufa plĂĄstica, em blocos casualizados com quatro repetiçÔes. Plantas de pinhĂŁo-manso foram cultivadas em vasos plĂĄsticos preenchidos com 50 dm 3 de um Latossolo Vermelho Escuro testando-se as doses de 0, 40, 80, 120 e 160 mg K dm -3 do solo; apĂłs 150 dias do plantio foram mensurados altura, diĂąmetro de colo e ĂĄrea foliar das plantas e se determinou massa seca, teores foliares e acĂșmulo total de macro e micronutrientes, alĂ©m dos teores de K trocĂĄvel e K nĂŁo-trocĂĄvel do solo. O balanço do K no sistema solo-planta tambĂ©m foi calculado. O aumento da adubação potĂĄssica resulta em maior absorção de K, Ca e Mn mas nĂŁo altera a produção de massa seca total do pinhĂŁo-manso. A espĂ©cie Ă© capaz de disponibilizar e absorver K da fração nĂŁo-trocĂĄvel do solo. Key words: Jatropha curcas dynamic of nutrient uptake non-exchangeable K Palavras-chave: Jatropha curcas dinĂąmica de absorção K nĂŁo-trocĂĄvel Revista Brasileira de Engenharia AgrĂ­cola e Ambienta

    Self-homodyne tomography of a twin-beam state

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    A self-homodyne detection scheme is proposed to perform two-mode tomography on a twin-beam state at the output of a nondegenerate optical parametric amplifier. This scheme has been devised to improve the matching between the local oscillator and the signal modes, which is the main limitation to the overall quantum efficiency in conventional homodyning. The feasibility of the measurement is analyzed on the basis of Monte-Carlo simulations, studying the effect of non-unit quantum efficiency on detection of the correlation and the total photon-number oscillations of the twin-beam state.Comment: 13 pages (two-column ReVTeX) including 21 postscript figures; to appear on Phys. Rev.

    Does Sea Spray Aerosol Contribute Significantly To Aerosol Trace Element Loading? A Case Study From the U.S. GEOTRACES Pacific Meridional Transect (GP15)

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    Atmospheric deposition represents a major input for micronutrient trace elements (TEs) to the surface ocean and is often quantified indirectly through measurements of aerosol TE concentrations. Sea spray aerosol (SSA) dominates aerosol mass concentration over much of the global ocean, but few studies have assessed its contribution to aerosol TE loading, which could result in overestimates of “new” TE inputs. Low-mineral aerosol concentrations measured during the U.S. GEOTRACES Pacific Meridional Transect (GP15; 152°W, 56°N to 20°S), along with concurrent towfish sampling of surface seawater, provided an opportunity to investigate this aspect of TE biogeochemical cycling. Central Pacific Ocean surface seawater Al, V, Mn, Fe, Co, Ni, Cu, Zn, and Pb concentrations were combined with aerosol Na data to calculate a “recycled” SSA contribution to aerosol TE loading. Only vanadium was calculated to have a SSA contribution averaging \u3e1% along the transect (mean of 1.5%). We derive scaling factors from previous studies on TE enrichments in the sea surface microlayer and in freshly produced SSA to assess the broader potential for SSA contributions to aerosol TE loading. Maximum applied scaling factors suggest that SSA could contribute significantly to the aerosol loading of some elements (notably V, Cu, and Pb), while for others (e.g., Fe and Al), SSA contributions largely remaine

    Systematic literature review of determinants of sedentary behaviour in older adults:a DEDIPAC study

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    BACKGROUND: Older adults are the most sedentary segment of society and high sedentary time is associated with poor health and wellbeing outcomes in this population. Identifying determinants of sedentary behaviour is a necessary step to develop interventions to reduce sedentary time. METHODS: A systematic literature review was conducted to identify factors associated with sedentary behaviour in older adults. Pubmed, Embase, CINAHL, PsycINFO and Web of Science were searched for articles published between 2000 and May 2014. The search strategy was based on four key elements: (a) sedentary behaviour and its synonyms; (b) determinants and its synonyms (e.g. correlates, factors); (c) types of sedentary behaviour (e.g. TV viewing, sitting, gaming) and (d) types of determinants (e.g. environmental, behavioural). Articles were included in the review if specific information about sedentary behaviour in older adults was reported. Studies on samples identified by disease were excluded. Study quality was rated by means of QUALSYST. The full review protocol is available from PROSPERO (PROSPERO 2014: CRD42014009823). The analysis was guided by the socio-ecological model framework. RESULTS: Twenty-two original studies were identified out of 4472 returned by the systematic search. These included 19 cross-sectional, 2 longitudinal and 1 qualitative studies, all published after 2011. Half of the studies were European. The study quality was generally high with a median of 82 % (IQR 69-96 %) using Qualsyst tool. Personal factors were the most frequently investigated with consistent positive association for age, negative for retirement, obesity and health status. Only four studies considered environmental determinants suggesting possible association with mode of transport, type of housing, cultural opportunities and neighbourhood safety and availability of places to rest. Only two studies investigated mediating factors. Very limited information was available on contexts and sub-domains of sedentary behaviours. CONCLUSION: Few studies have investigated determinants of sedentary behaviour in older adults and these have to date mostly focussed on personal factors, and qualitative studies were mostly lacking. More longitudinal studies are needed as well as inclusion of a broader range of personal and contextual potential determinants towards a systems-based approach, and future studies should be more informed by qualitative work

    An interdisciplinary intervention to prevent falls in community-dwelling elderly persons: protocol of a cluster-randomized trial [PreFalls]

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    <p>Abstract</p> <p>Background</p> <p>Prevention of falls in the elderly is a public health target in many countries around the world. While a large number of trials have investigated the effectiveness of fall prevention programs, few focussed on interventions embedded in the general practice setting and its related network. In the Prevent Falls (PreFalls) trial we aim to investigate the effectiveness of a pre-tested multi-modal intervention compared to usual care in this setting.</p> <p>Methods/Design</p> <p>PreFalls is a controlled multicenter prospective study with cluster-randomized allocation of about 40 general practices to an experimental or a control group. We aim to include 382 community dwelling persons aged 65 and older with an increased risk of falling. All participating general practitioners are trained to systematically assess the risk of falls using a set of validated tests. Patients from intervention practices are invited to participate in a 16-weeks exercise program with focus on fall prevention delivered by specifically trained local physiotherapists. Patients from practices allocated to the control group receive usual care. Main outcome measure is the number of falls per individual in the first 12 months (analysis by negative binomial regression). Secondary outcomes include falls in the second year, the proportion of participants falling in the first and the second year, falls associated with injury, risk of falls, fear of falling, physical activity and quality of life.</p> <p>Discussion</p> <p>Reducing falls in the elderly remains a major challenge. We believe that with its strong focus on a both systematic and realistic fall prevention strategy adapted to primary care setting PreFalls will be a valuable addition to the scientific literature in the field.</p> <p>Trial registration</p> <p><a href="http://www.clinicaltrials.gov/ct2/show/NCT01032252">NCT01032252</a></p

    Genetic and Environmental Determinants of Immune Response to Cutaneous Melanoma

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    The immune response to melanoma improves the survival in untreated patients and predicts the response to immune checkpoint blockade. Here, we report genetic and environmental predictors of the immune response in a large primary cutaneous melanoma cohort. Bioinformatic analysis of 703 tumor transcriptomes was used to infer immune cell infiltration and to categorize tumors into immune subgroups, which were then investigated for association with biological pathways, clinicopathologic factors, and copy number alterations. Three subgroups, with “low”, “intermediate”, and “high” immune signals, were identified in primary tumors and replicated in metastatic tumors. Genes in the low subgroup were enriched for cell-cycle and metabolic pathways, whereas genes in the high subgroup were enriched for IFN and NF-ÎșB signaling. We identified high MYC expression partially driven by amplification, HLA-B downregulation, and deletion of IFNÎł and NF-ÎșB pathway genes as the regulators of immune suppression. Furthermore, we showed that cigarette smoking, a globally detrimental environmental factor, modulates immunity, reducing the survival primarily in patients with a strong immune response. Together, these analyses identify a set of factors that can be easily assessed that may serve as predictors of response to immunotherapy in patients with melanoma. Significance: These findings identify novel genetic and environmental modulators of the immune response against primary cutaneous melanoma and predict their impact on patient survival

    The Clinical Genome Resource (ClinGen) Familial Hypercholesterolemia Variant Curation Expert Panel consensus guidelines for LDLR variant classification

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    PURPOSE: In 2015, the American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP) published consensus standardized guidelines for sequence-level variant classification in Mendelian disorders. To increase accuracy and consistency, the Clinical Genome Resource Familial Hypercholesterolemia (FH) Variant Curation Expert Panel was tasked with optimizing the existing ACMG/AMP framework for disease-specific classification in FH. In this study, we provide consensus recommendations for the most common FH-associated gene, LDLR, where >2300 unique FH-associated variants have been identified. METHODS: The multidisciplinary FH Variant Curation Expert Panel met in person and through frequent emails and conference calls to develop LDLR-specific modifications of ACMG/AMP guidelines. Through iteration, pilot testing, debate, and commentary, consensus among experts was reached. RESULTS: The consensus LDLR variant modifications to existing ACMG/AMP guidelines include (1) alteration of population frequency thresholds, (2) delineation of loss-of-function variant types, (3) functional study criteria specifications, (4) cosegregation criteria specifications, and (5) specific use and thresholds for in silico prediction tools, among others. CONCLUSION: Establishment of these guidelines as the new standard in the clinical laboratory setting will result in a more evidence-based, harmonized method for LDLR variant classification worldwide, thereby improving the care of patients with FH

    Comparison of the characteristics at diagnosis and treatment of children with heterozygous familial hypercholesterolaemia (FH) from eight European countries

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    Background and aims: For children with heterozygous familial hypercholesterolaemia (HeFH), European guidelines recommend consideration of statin therapy by age 8–10 years for those with a low density lipoprotein cholesterol (LDL-C) >3.5 mmol/l, and dietary and lifestyle advice. Here we compare the characteristics and lipid levels in HeFH children from Norway, UK, Netherlands, Belgium, Czech Republic, Austria, Portugal and Greece. Methods: Fully-anonymized data were analysed at the London centre. Differences in registration and on treatment characteristics were compared by standard statistical tests. Results: Data was obtained from 3064 children. The median age at diagnosis differed significantly between countries (range 3–11 years) reflecting differences in diagnostic strategies. Mean (SD) LDL-C at diagnosis was 5.70 (±1.4) mmol/l, with 88% having LDL-C>4.0 mmol/l. The proportion of children older than 10 years at follow-up who were receiving statins varied significantly (99% in Greece, 56% in UK), as did the proportion taking Ezetimibe (0% in UK, 78% in Greece). Overall, treatment reduced LDL-C by between 28 and 57%, however, in those >10 years, 23% of on-treatment children still had LDL-C>3.5 mmol/l and 66% of those not on a statin had LDL-C>3.5 mmol/l. Conclusions: The age of HeFH diagnosis in children varies significantly across 8 countries, as does the proportion of those >10 years being treated with statin and/or ezetimibe. Approximately a quarter of the treated children and almost three quarters of the untreated children older than 10 years still have LDL-C concentrations over 3.5 mmol/l. These data suggest that many children with FH are not receiving the full potential benefit of early identification and appropriate lipid-lowering treatment according to recommendations
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