1,094 research outputs found

    Ecological research in the Large Scale Biosphere Atmosphere Experiment in Amazonia: A discussion of early results

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    The Large-scale Biosphere–Atmosphere Experiment in Amazonia (LBA) is a multinational, interdisciplinary research program led by Brazil. Ecological studies in LBA focus on how tropical forest conversion, regrowth, and selective logging influence carbon storage, nutrient dynamics, trace gas fluxes, and the prospect for sustainable land use in the Amazon region. Early results from ecological studies within LBA emphasize the variability within the vast Amazon region and the profound effects that land-use and land-cover changes are having on that landscape. The predominant land cover of the Amazon region is evergreen forest; nonetheless, LBA studies have observed strong seasonal patterns in gross primary production, ecosystem respiration, and net ecosystem exchange, as well as phenology and tree growth. The seasonal patterns vary spatially and interannually and evidence suggests that these patterns are driven not only by variations in weather but also by innate biological rhythms of the forest species. Rapid rates of deforestation have marked the forests of the Amazon region over the past three decades. Evidence from ground-based surveys and remote sensing show that substantial areas of forest are being degraded by logging activities and through the collapse of forest edges. Because forest edges and logged forests are susceptible to fire, positive feedback cycles of forest degradation may be initiated by land-use-change events. LBA studies indicate that cleared lands in the Amazon, once released from cultivation or pasture usage, regenerate biomass rapidly. However, the pace of biomass accumulation is dependent upon past land use and the depletion of nutrients by unsustainable land-management practices. The challenge for ongoing research within LBA is to integrate the recognition of diverse patterns and processes into general models for prediction of regional ecosystem function

    How Does the Level of Physical Activity Influence Eating Behavior? A Self-Determination Theory Approach

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    Physical activity and diet are two predominant determinants of population health status that may influence each other. Physical activity has been identified as a behavior that may lead to a healthier diet and regulates eating behaviors. This research aimed to investigate how the level of physical activity is associated with the motivation related to eating behaviors and, consequently, the eating style individuals have on a daily basis. This was a cross-sectional study in which participants completed an online questionnaire that assessed the following variables: the level of physical activity, the motivation toward eating behavior, and the type of eating behavior. In total, 440 individuals (180 men and 260 women) who regularly exercised in gyms and fitness centers aged between 19 and 64 years (M = 33.84; SD = 10.09) took part in the study. The data were collected following the Declaration of Helsinki and with the approval of the Ethics Committee of the Polytechnic of Leiria. For the statistical analysis, mean and standard deviations were first calculated, as well as bivariate correlations between all the variables of interest. Then, structural equation model analyses were performed considering the levels of physical activity as the independent variable, motivations toward eating behavior as the mediators, and eating styles as the dependent variables. It was concluded that a greater level of physical activity leads to a more self-determined type of eating regulation, which in turn results in less constricted eating behaviors that are influenced by external factors and emotional factors.info:eu-repo/semantics/publishedVersio

    Flexible random lasers in dye-doped bio-degradable cellulose nanocrystalline needles

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    M-ERA-NET2/0007/2016 POCI-01-0145-FEDER-007688 PTDC/CTM-BIO/6178/2014 PTDC/CTM-REF/30529/2017 UID/CTM/50025In this work, we developed and investigated a random laser based on rhodamine6G (Rh6G) in ethylene glycol (EG) solution with varying cellulose nanocrystalline (CNC) needles as scatterers in the lasing media. Besides the suspension-in-cuvette scheme, an alternative configuration was also employed: a dye-CNC flexible self-supported thick-film (70 µm) random laser made by drop casting of the CNCs + Rh6G + hydroxypropyl cellulose suspension. In relation to conventional scatterers, the biodegradable cellulose nanocompounds showed a comparable reduction in both the spectral full width at half-maximum and the energy threshold values, with an optimal concentration of 5 mg [CNC]/ml[EG] in suspension. Its performance was also compared with other cellulose-based random lasers, presenting advantages for some parameters. The flexible film configuration showed similar results, but contained 10% less Rh6G than the suspension.authorsversionpublishe

    Pericardial Fat Is Associated with Coronary Artery Calcification in Non-Dialysis Dependent Chronic Kidney Disease Patients

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    Pericardial fat (PF) a component of visceral adipose tissue has been consistently related to coronary atherosclerosis in the general population. This study evaluated the association between PF and coronary artery calcification (CAC) in non-dialysis dependent chronic kidney disease (CKD) patients. This is a post-hoc cross sectional analysis of the baseline of a prospective cohort of 117 outward CKD patients without manifest coronary artery disease (age, 56.9 +/- 11.0 years, 64.1% males, 95.1% hypertensives, 25.2% diabetics, 15.5% ever smokers, CKD stage 2 to 5 with estimated glomerular filtration rate 36.8 +/- 18.1 ml/min). CAC scores, PF volume and abdominal visceral fat (AVF) areas were measured by computed tomography. the association of PF as a continuous variable with the presence of CAC was analyzed by multivariate logistic regression. CAC (calcium score >0) was present in 59.2% patients. Those presenting CAC were on average 10 years older, had a higher proportion of male gender (78.7% vs. 42.9%, p<0.001), and had higher values of waist circumference (95.9 +/- 10.7 vs. 90.2 +/- 13.2 cm, p=0.02), PF volumes (224.8 +/- 107.6 vs. 139.1 +/- 85.0 cm(3), p<0.01) and AVF areas (109.2 +/- 81.5 vs. 70.2 +/- 62.9 cm(2), p=0.01). in the multivariate analysis, adjusting for age, gender, diabetes, smoking and, left ventricular concentric hypertrophy, PF was significantly associated with the presence of CAC (OR: 1.88 95% CI: 1.03-3.43 per standard deviation). PF remained associated with CAC even with additional adjustments for estimated glomerular filtration rate or serum phosphorus (OR: 1.85 95% CI: 1.00-3.42, p=0.05). PF is independently associated with CAC in non-dialysis dependent CKD patients.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ São Paulo, Sch Med, Lipid Clin Heart Inst InCor, São Paulo, BrazilUniversidade Federal de São Paulo, Div Nephrol, São Paulo, BrazilUniv São Paulo, Sch Med, Cardiovasc Magnet Resonance & Computed Tomog Sect, Heart Inst InCor, São Paulo, BrazilUniversidade Federal de São Paulo, Div Nephrol, São Paulo, BrazilFAPESP: 2011/14201-2Web of Scienc

    Acupuncture at “Zusanli” (St.36) and “Sanyinjiao” (SP.6) Points on the Gastrointestinal Tract: A Study of the Bioavailability of 99mTc-Sodium Pertechnetate in Rats

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    The objective of this study is to investigate the differences of acupuncture effect between the Zusanli (St.36) and Sanyinjiao (SP.6) points on the gastrointestinal-tract (GIT) segment performed by the bioavailability of 99mTc-sodium-pertechnetate (Na99mTcO4) in rats. Male Wistar rats (n = 21) were allocated into three groups of seven each. Group 1 was treated by acupuncture bilaterally at St.36; Group 2 at SP.6; and Group 3 was untreated (control). After 10 min of needle insertion in anesthetized rats, 0.3 mL of Na99mTcO4 (7.4 MBq) was injected via ocular-plexus. After 20 min, the exitus of animals was induced by cervical-dislocation and GIT organs isolated. However, immediately before the exitus procedure, blood was collected by cardiac-puncture for blood radio-labeling (BRL). The radioactivity uptake of the blood constituents was calculated together with the GIT organs by a well gamma counter. The percentage of injected dose per gram of tissue (%ID/g) of Na99mTcO4 was calculated for each GIT organs, while BRL was calculated in %ID. According to the one-way ANOVA, the stomach, jejunum, ileum from the treated groups (Group 1 and Group 2) had significant differences compared to the controls (Group 3). However, between the treated groups (Group 1 and Group 2), there were significant differences (P < .05) in the stomach, jejunum, ileum, cecum, transverse and rectum. In BRL analysis, Group 2 showed significant increase and decrease of the insoluble and soluble fractions of the blood cells, respectively (P < .0001). The authors suggest that St.36 may have a tendency of up-regulation effect on GIT, whereas SP.6, down-regulation effect. However, further rigorous experimental studies to examine the effectiveness of acupuncture in either acupuncture points need to be carried out

    Convex central configurations of the 4-body problem with two pairs of equal masses

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    Agraïments: The first and third authors are partially supported by FAPEMIG grant APQ-001082/14. The third author is partially supported by CNPq grant 472321/2013-7 and by FAPEMIG grant PPM-00516-15. The second and third autors are supported by CAPES CSF-PVE grant 88881.030454/2013-01.MacMillan and Bartky in 1932 proved that there is a unique isosceles trapezoid central configuration of the 4--body problem when two pairs of equal masses are located at adjacent vertices. After this result the following conjecture was well known between people working on central configurations: The isosceles trapezoid is the unique convex central configuration of the planar 4--body problem when two pairs of equal masses are located at adjacent vertices. We prove this conjecture

    Uniparental Genetic Heritage of Belarusians: Encounter of Rare Middle Eastern Matrilineages with a Central European Mitochondrial DNA Pool

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    Ethnic Belarusians make up more than 80% of the nine and half million people inhabiting the Republic of Belarus. Belarusians together with Ukrainians and Russians represent the East Slavic linguistic group, largest both in numbers and territory, inhabiting East Europe alongside Baltic-, Finno-Permic- and Turkic-speaking people. Till date, only a limited number of low resolution genetic studies have been performed on this population. Therefore, with the phylogeographic analysis of 565 Y-chromosomes and 267 mitochondrial DNAs from six well covered geographic sub-regions of Belarus we strove to complement the existing genetic profile of eastern Europeans. Our results reveal that around 80% of the paternal Belarusian gene pool is composed of R1a, I2a and N1c Y-chromosome haplogroups – a profile which is very similar to the two other eastern European populations – Ukrainians and Russians. The maternal Belarusian gene pool encompasses a full range of West Eurasian haplogroups and agrees well with the genetic structure of central-east European populations. Our data attest that latitudinal gradients characterize the variation of the uniparentally transmitted gene pools of modern Belarusians. In particular, the Y-chromosome reflects movements of people in central-east Europe, starting probably as early as the beginning of the Holocene. Furthermore, the matrilineal legacy of Belarusians retains two rare mitochondrial DNA haplogroups, N1a3 and N3, whose phylogeographies were explored in detail after de novo sequencing of 20 and 13 complete mitogenomes, respectively, from all over Eurasia. Our phylogeographic analyses reveal that two mitochondrial DNA lineages, N3 and N1a3, both of Middle Eastern origin, might mark distinct events of matrilineal gene flow to Europe: during the mid-Holocene period and around the Pleistocene-Holocene transition, respectively

    Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

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    Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson
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