1,234 research outputs found

    The effect of handlebar height and bicycle frame length on muscular activity during cycling: a pilot study

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    The cycling literature is filled with reports of electromyography (EMG) analyses for a better understanding of muscle function during cycling. This research is not just limited to performance, as the cyclist’s goal may be rehabilitation, recreation, or competition, so a bicycle that meets the rider’s needs is essential for a more efficient muscular activity. Therefore, the purpose of this study was to understand the contribution of the activity of each of the following muscles: TD (trapezius descending), LD (latissimus dorsi), GM (gluteus maximus), and AD (anterior deltoid) in response to different bicycle-rider systems (handlebar height; bicycle frame length) and intensities in a bicycle equipped with a potentiometer. Surface EMG signals from muscles on the right side of the body were measured. A general linear model test was used to analyze the differences between muscle activation in the test conditions. Effect sizes were calculated using a partial Eta2 (η 2 ). The level of significance was set at 0.05. Muscle activation of different muscles differs, depending on the cycling condition (Pillai’s trace = 2.487; F (36.69) = 9.300; p < 0.001. η 2 = 0.958), mostly during low intensities. In high intensities, one specific pattern emerges, with a greater contribution of GM and TD and weaker participation of LD and AD, enhancing the cycling power output.info:eu-repo/semantics/publishedVersio

    Interaction of [(VO)-O-IV(acac)(2)] with Human Serum Transferrin and Albumin

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    VO(acac)(2)] is a remarkable vanadium compound and has potential as a therapeutic drug. It is important to clarify how it is transported in blood, but the reports addressing its binding to serum proteins have been contradictory. We use several spectroscopic and mass spectrometric techniques (ESI and MALDI-TOF), small-angle X-ray scattering and size exclusion chromatography (SEC) to characterize solutions containing [VO(acac)(2)] and either human serum apotransferrin (apoHTF) or albumin (HSA). DFT and modeling protein calculations are carried out to disclose the type of binding to apoHTF. The measured circular dichroism spectra, SEC and MALDI-TOF data clearly prove that at least two VOacac moieties may bind to apoHTF, most probably forming [(VO)-O-IV(acac)(apoHTF)] complexes with residues of the HTF binding sites. No indication of binding of [VO(acac)(2)] to HSA is obtained. We conclude that (VO)-O-IV-acac species may be transported in blood by transferrin. At very low complex concentrations speciation calculations suggest that [(VO)(apoHTF)] species form.Fundacao para a Ciencia e Tecnologia (FCT), Portugal [ RECI/QEQMED/0330/2012, PTDC/QEQ-MED/1902/2014]FCT [IF/00100/2013, IF/00007/2015]PROTEOMASS Scientific SocietyUCIBIO, Unidade de Ciencias Biomoleculares Aplicadas [UID/Multi/04378/2013]ERDF [POCI-01-0145-FEDER-007728, POCI-01-0145-FEDER-007265]info:eu-repo/semantics/publishedVersio

    Experimental supporting data on DIS3L2 over nonsense-mediated mRNA decay targets in human cells

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    In this article, we present supportive data related to the research article “A role for DIS3L2 over natural nonsense-mediated mRNA decay targets in human cells” [1], where interpretation of the data presented here is available. Indeed, here we analyze the impact of the DIS3L2 exoribonuclease over nonsense-mediated mRNA decay (NMD)-targets. Specifically, we present data on: a) the expression of various reporter human β-globin mRNAs, monitored by Northern blot and RT-qPCR, before and after altering DIS3L2 levels in HeLa cells, and b) the gene expression levels of deregulated transcripts generated by re-analyzing publicly available data from UPF1-depleted HeLa cells that were further cross-referenced with a dataset of transcripts upregulated in DIS3L2-depleted cells. These analyses revealed that DIS3L2 regulates the levels of a subset of NMD-targets. These data can be valuable for researchers interested in the NMD mechanism.This work was partially supported by Fundação para a Ciencia e a Tecnologia (FCT) (PTFC/BIM-MEC/3749/2014 to LR and UID/MULTI/04046/2013 to BioISI). PJdC, HAS and JFG-M are recipients of a fellowship from BioSys PhD programme (SFRH/BD/52495/2014, SFRH/BD/52492/2014, and PD/BD/ 142898/2018, respectively) and JM is a postdoctoral fellow (SFRH/BPD/98360/2013) from FCT. Work at ITQB-NOVA was financially supported by: Project LISBOA-01-0145-FEDER-007660 funded by the European Regional Development Fund (FEDER) through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI) and by FCT funds: PTDC/BIA-MIC/1399/2014 to CMA and PTFC/BIM-MEC/3749/2014 to SCV. SCV was financed by program IF of FCT (IF/00217/2015). MS was financed by an FCT contract according to DL57/2016 [SFRH/BPD/109464/2015]info:eu-repo/semantics/publishedVersio

    Comparação entre a suplementação com volumosos e a de concentrado na alimentação de equinos em crescimento

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    Sixteen fillies aged 9.5 months were submitted during 112 days to the treatments: A - concentrate at the rate of 1% of body weight; B - Guinea grass (Panicum maximum Jacq.); C – Alfafa hay (Medicago sativa L.); and D - Rhodes hay (Chloris gayana Kunth.) offered ad libitum plus protein supplement. Considering the daily gain of body weight the best performance was obtained with the animals of treatment A, which presented gains as foreseen in the previsions of feedings in three experimental periods (0.84, 0.52 and 0.70 kg/day), while treatment B made possible satisfactory gain in two periods (0.50 and 0.48 kg/day) and treatment C in one period (0.59 kg/day). The highest gain in height at the withers/period was obtained with treatment A (1.85 cm), which was superior (P ≤ 0.05) to those having treatment C and D, nevertheless, not differing from treatment B. There were not any statistical differences among treatment B, C and D. The average hearth girth/period gain was 4.37 cm, there not being any significant differences (P ≥ 0.05) among the treatments. The intake of treatment C varied from 36.25 to 75.13 g/kg0.75, while, on the other hand, treatment D, even though it had a low nutritive value, presented an intake of 17.56 to 78.95 g/kg0.75.Dezesseis potrancas, com 9,5 meses de idade, foram submetidas, durante 112 dias, aos tratamentos: A - concentrado à razão de 1% do peso vivo; B - capim-colonião (Panicum maximum Jacq.); C - feno de alfafa (Medicago sativa L.) e D - feno de rhodes  (Chloris gayana Kunth.), oferecidos à vontade, mais fonte protéica. Considerando o ganho diário de peso vivo, o melhor desempenho foi obtido com os animais do tratamento A, que apresentaram ganhos compatíveis com o previsto nas normas de alimentação em três períodos experimentais (0,84, 0,52 e 0,70 kg/dia), enquanto o tratamento B possibilitou ganho satisfatório em dois períodos (0,50 e 0,48 kg/dia) e o tratamento C em um período (0,59 kg/dia). O maior aumento da altura na cernelha/período foi obtido com o tratamento A (1,85 cm) que superou (P ≤ 0,05) os obtidos com os tratamentos C e D, não diferindo, no entanto, do tratamento B. Não houve diferença estatística (P ≥ 0,05) entre os tratamentos B, C e D. O aumento médio no perímetro torácico/período foi de 4,37 cm, não havendo diferença significativa (P ≥ 0,05) entre os tratamentos. O tratamento C apresentou consumos variando de 36,25 a 75,13 g/kg0,75, enquanto o tratamento D, apesar do seu baixo valor nutritivo, apresentou consumos de 17,56 a 78,95 g/kg0,75.

    Molecular excitation in the Interstellar Medium: recent advances in collisional, radiative and chemical processes

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    We review the different excitation processes in the interstellar mediumComment: Accepted in Chem. Re

    The Intrinsic Resolution Limit in the Atomic Force Microscope: Implications for Heights of Nano-Scale Features

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    Background; Accurate mechanical characterization by the atomic force microscope at the highest spatial resolution requires that topography is deconvoluted from indentation. The measured height of nanoscale features in the atomic force microscope (AFM) is almost always smaller than the true value, which is often explained away as sample deformation, the formation of salt deposits and/or dehydration. We show that the real height of nano-objects cannot be obtained directly: a result arising as a consequence of the local probe-sample geometry. Methods and Findings; We have modeled the tip-surface-sample interaction as the sum of the interaction between the tip and the surface and the tip and the sample. We find that the dynamics of the AFM cannot differentiate between differences in force resulting from 1) the chemical and/or mechanical characteristics of the surface or 2) a step in topography due to the size of the sample; once the size of a feature becomes smaller than the effective area of interaction between the AFM tip and sample, the measured height is compromised. This general result is a major contributor to loss of height and can amount to up to ∼90% for nanoscale features. In particular, these very large values in height loss may occur even when there is no sample deformation, and, more generally, height loss does not correlate with sample deformation. DNA and IgG antibodies have been used as model samples where experimental height measurements are shown to closely match the predicted phenomena. Conclusions; Being able to measure the true height of single nanoscale features is paramount in many nanotechnology applications since phenomena and properties in the nanoscale critically depend on dimensions. Our approach allows accurate predictions for the true height of nanoscale objects and will lead to reliable mechanical characterization at the highest spatial resolution

    CHEMICAL CONSTITUENTS OF Amburana acreana Ducke A. C. Sm. LEAVES

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    This study aimed to isolate, purify and characterize secondary metabolites present in Amburana acreana leaves, native to the state of Rondônia, using classical chromatographic methods and 1D, 2D nuclear magnetic resonance spectroscopy. From the hydroethanolic leaves extract of A. acreana, p-hydroxybenzoic acid, vanillic acid, coumarin, campesterol 3-β-D-glucoside and amburoside B, all known compounds, were identified. To the best of our knowledge, this is the first report of isolation and chemical characterization of secondary metabolites in A. acreana. In addition, in vitro assays indicated that amburoside B does not have inhibitory potential on the growth of gram-negative bacteria. The presence of these compounds suggests that, thus far, amburosides (A and B) could be chemotaxonomic markers of the genus Amburana

    Solar Irradiance Forecasting Using Dynamic Ensemble Selection

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    Solar irradiance forecasting has been an essential topic in renewable energy generation. Forecasting is an important task because it can improve the planning and operation of photovoltaic systems, resulting in economic advantages. Traditionally, single models are employed in this task. However, issues regarding the selection of an inappropriate model, misspecification, or the presence of random fluctuations in the solar irradiance series can result in this approach underperforming. This paper proposes a heterogeneous ensemble dynamic selection model, named HetDS, to forecast solar irradiance. For each unseen test pattern, HetDS chooses the most suitable forecasting model based on a pool of seven well-known literature methods: ARIMA, support vector regression (SVR), multilayer perceptron neural network (MLP), extreme learning machine (ELM), deep belief network (DBN), random forest (RF), and gradient boosting (GB). The experimental evaluation was performed with four data sets of hourly solar irradiance measurements in Brazil. The proposed model attained an overall accuracy that is superior to the single models in terms of five well-known error metrics
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