1,724 research outputs found

    Variables associated with the tolerance to water deficit in forage grasses

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    Avaliou-se, sob condições de campo, a tolerância ao déficit hídrico de quatro gramíneas forrageiras. Determinaram-se o potencial hídrico da folha, a resistência estomática, a altura dos perfilhos e o comprimento do limbo foliar do capim-carimagua (Andropogon gayanus), capim-bufel (Cenchrus ciliaris) cvs. Gayndah e Biloela, e quicuio-da-amazônia (Brachiaria humidicola). Os capins carimagua, 'Gayndah' e 'Biloela' sob regime seco, não atingiram um valor crítico de potencial hídrico da folha para o fechamento estomático. O capim quicuio-da-amazônia atingiu mais baixo potencial hídrico da folha (-21 bares) e mais alta resistência estomática (20 seg.cm-1) em relação aos demais capins estudados neste trabalho. Com relação a altura do perfilho e comprimento do limbo foliar, os capins carimagua, 'Gayndah' e 'Biloela' também se comportaram como mais tolerantes ao déficit hídrico. Dessa forma, os capins carimagua, 'Gayndah' e 'Biloela' são opções mais seguras para as áreas onde ocorrem estiagens de mais de 120 dias.The tolerance to water deficit of four tropical grasses was evaluated under field conditions. The leaf water potential, stomatal resistance, sprout height and leaf blade length were determined for Carimagua grass (Andropogon gayanus) buffel grass (Cenchrus ciliaris) cvs. Gayndah and Biloela, and Brachiaria Amazonian kikuyo grass (Brachiaria humidicola). The carimagua, 'Gayndah' and Biloela' grasses, under water deficit conditions, did not attain the critical level of leaf water potential for stomatal closing. The Amazonian kikuyo grass attained the lowest leaf water potential (-21 bars) and greatest diffusive stomatal resistance (20 seg. Cm-1) of the grasses studied here. The carimagua 'Gayndah' and 'Biloela' grasses also demonstrated, in relation to sprout height and leaf blade length, greater tolerance to water deficit than Amazonian kikuyo grass. Hence, the carimagua, 'Gayandah' and Biloela' grasses are a choice for areas where drought occurs for more than 120 days

    TGF-b2 induction regulates invasiveness of theileria-transformed leukocytes and disease susceptibility

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    Theileria parasites invade and transform bovine leukocytes causing either East Coast fever (T. parva), or tropical theileriosis (T. annulata). Susceptible animals usually die within weeks of infection, but indigenous infected cattle show markedly reduced pathology, suggesting that host genetic factors may cause disease susceptibility. Attenuated live vaccines are widely used to control tropical theileriosis and attenuation is associated with reduced invasiveness of infected macrophages in vitro. Disease pathogenesis is therefore linked to aggressive invasiveness, rather than uncontrolled proliferation of Theileria-infected leukocytes. We show that the invasive potential of Theileria-transformed leukocytes involves TGF-b signalling. Attenuated live vaccine lines express reduced TGF-b2 and their invasiveness can be rescued with exogenous TGF-b. Importantly, infected macrophages from disease susceptible Holstein-Friesian (HF) cows express more TGF-b2 and traverse Matrigel with great efficiency compared to those from disease-resistant Sahiwal cattle. Thus, TGF-b2 levels correlate with disease susceptibility. Using fluorescence and time-lapse video microscopy we show that Theileria-infected, disease-susceptible HF macrophages exhibit increased actin dynamics in their lamellipodia and podosomal adhesion structures and develop more membrane blebs. TGF-b2-associated invasiveness in HF macrophages has a transcription-independent element that relies on cytoskeleton remodelling via activation of Rho kinase (ROCK). We propose that a TGF-b autocrine loop confers an amoeboid-like motility on Theileria-infected leukocytes, which combines with MMP-dependent motility to drive invasiveness and virulence

    Cross-sectional and longitudinal associations between psychosocial well-being and sleep in European children and adolescents

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    Research on associations of positive mental health, in contrast to mental ill-health, with sleep duration and sleep disturbances in young populations is scarce. In particular, longitudinal studies focussing on the influence of positive mental health on sleep characteristics are lacking. Therefore, we investigated cross-sectional and longitudinal associations of psychosocial well-being with sleep duration and sleep disturbances. For the cross-sectional analysis, we used data of 3-15-year-old children and adolescents participating in the 2013/14 examination of the European IDEFICS/I.Family cohort study (N = 6,336). The longitudinal analysis was restricted to children who also participated in the 2009/10 examination (N = 3,379). Associations between a psychosocial well-being score created from 16 items of the KINDLR Health-Related Quality of Life Questionnaire covering emotional well-being, self-esteem and social relationships, an age-standardized nocturnal sleep duration z-score and two sleep disturbance indicators ("trouble getting up in the morning", "difficulties falling asleep") were estimated using linear and logistic mixed-effects models. Cross-sectionally, a higher well-being score was associated with longer sleep duration and lower odds of sleep disturbances. A positive change in the well-being score over the 4-year period was associated with longer sleep duration and lower odds of sleep disturbances at follow-up. However, there was only weak evidence that higher psychosocial well-being at baseline was associated with better sleep 4 years later. Thus, our results suggest that increases in well-being are associated with improvements in both sleep duration and sleep disturbances, but that well-being measured at one point in time does not predict sleep characteristics several years later.Peer reviewe

    Associations between sleep duration and insulin resistance in European children and adolescents considering the mediating role of abdominal obesity

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    Background Short sleep duration has been suggested to lead to insulin resistance both directly by altering glucose metabolism and indirectly through obesity. This study aims to investigate associations between nocturnal sleep duration and insulin resistance considering abdominal obesity as a mediator. Methods We analysed data of 3 900 children aged 2-15 years participating in the second (2009/10) and third (2013/14) examination wave of the European IDEFICS/I.Family study (hereafter referred to as baseline and follow-up). Information on nocturnal sleep duration was collected by questionnaires and age-standardised (SLEEP z-score). The homeostasis model assessment (HOMA) was calculated from fasting insulin and fasting glucose obtained from blood samples; waist circumference (WAIST) was measured with an inelastic tape. HOMA and WAIST were used as indicators for insulin resistance and abdominal obesity, respectively, and transformed to age- and sex-specific z-scores. Cross-sectional and longitudinal associations between SLEEP z-score and HOMA z-score were investigated based on a path model considering WAIST z-score as a mediator adjusting for relevant confounders. Results Cross-sectionally, baseline SLEEP z-score was negatively associated with baseline WAIST z-score (unstandardised effect estimate -0.120, 95% confidence interval [-0.167; -0.073]). We observed no direct effect of baseline SLEEP z-score on baseline HOMA z-score but a negative indirect effect through baseline WAIST z-score (-0.042 [-0.058; -0.025]). Longitudinally, there was no direct effect of baseline SLEEP z-score on HOMA z-score at follow-up but a negative indirect effect through both baseline WAIST z-score and WAIST z-score at follow-up (-0.028 [-0.040; -0.016]). Conclusions Our results do not support the hypothesis of an association between short sleep duration and insulin resistance independent of abdominal obesity. However, longer sleep duration may exert short and long term beneficial effects on insulin resistance through its beneficial effects on abdominal obesity

    Physical and functional aspects of persons with multiple sclerosis practicing Tai-Geiko: randomized trial

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    OBJECTIVES: This study aimed to verify the influence of Tai-Geiko on the physical and functional aspects of people with multiple sclerosis (MS). METHODS: This was a parallel-group, randomized trial with two arms. People with MS were allocated to an experimental group (EG) (n=10) and control group (CG) (n=09). The participants received multidisciplinary care supervised by a physiotherapist in the Tai-Geiko exercise. Participants underwent the assessments after the intervention. The Expanded Disability Status Scale (EDSS-maximum score of 6.0), strength test (kgf) using a dynamometer, Timed Up and Go mobility test (TUG), and stabilometric balance test (Platform EMG systems) were evaluated. Demographic data were recorded, including age, sex, comorbidities, lifestyle and classification of MS. Clinical Trials (ReBeC): RBR-4sty47. RESULTS: The EG group improved in 12 variables, and the CG improved in 3 variables. The following values were obtained for pre/postintervention, respectively: EG: lumbar force (38/52 kgf), TUG (11/9 s), locomotion velocity (519/393 ms); double task two (53/39 s); platform stabilometric trajectory: traversed get up (39/26 s) and sit (45/29 s); anteroposterior (AP) amplitude rise (11/8 cm) and sit (12.40/9.94 cm) and anteroposterior frequency rise (1.00/1.56 Hz) and sit (0.8/1.25 Hz) (po0.05); CG: right-hand grip force (26/29 kgf); TUG (9.8 /8.7 s) and AP (11.84 /9.53 cm) stabilometric amplitude at the sitting moment (po0.05), (3.2/5.99 Hz, p=0.01) and sit (3.47/5.01 Hz, p=0.04). CONCLUSION: Tai-Geiko practice can be suggested as complementary exercise in the rehabilitation of persons with MS

    Inflammaging and blood pressure profiles in late life: the screening for CKD among older people across Europe (SCOPE) study

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    The neutrophil-to-lymphocyte ratio (NLR) is a marker for systemic inflammation. Since inflammation plays a relevant role in vascular aging, the aim of this study was to investigate whether NLR is associated with blood pressure profiles in older adults. This study was performed within the framework of the SCOPE study including 2461 outpatients aged 75 years and over. Mean blood pressure values, namely systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse pressure (PP) were investigated across tertiles of NLR. Change in blood pressure levels in 2 years of follow-up were compared across categories of baseline NLR. Data of 2397 individuals were used, of which 1854 individuals had hypertension. Mean values of blood pressure did not differ across categories of baseline NLR in individuals without hypertension. Individuals with hypertension with a high-range NLR had lower SBP and PP when compared to those in low-range NLR (mean difference SBP −2.94 mmHg, p = 0.032 and PP −2.55 mmHg, p = 0.030). Mean change in blood pressure in 2 years did only slightly differ in non-clinically relevant ranges, when compared across tertiles of baseline NLR. NLR as a marker of inflammaging was not associated with unfavorable blood pressure profiles in older individuals with or without hypertension

    TRY plant trait database - enhanced coverage and open access

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    Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    Vaccines for the Leishmaniases: Proposals for a Research Agenda

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    The International Symposium on Leishmaniasis Vaccines, held in Olinda, Brazil, on March 9–11, 2009, congregated international experts who conduct research on vaccines against the leishmaniases. The questions that were raised during that meeting and the ensuing discussions are compiled in this report and may assist in guiding a research agenda. A group to further discussion on issues raised in this policy platform has been set up at http://groups.google.com/group/leishvaccines-l
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