298 research outputs found

    Towards a neural hierarchy of time scales for motor control

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    Animals show remarkable rich motion skills which are still far from realizable with robots. Inspired by the neural circuits which generate rhythmic motion patterns in the spinal cord of all vertebrates, one main research direction points towards the use of central pattern generators in robots. On of the key advantages of this, is that the dimensionality of the control problem is reduced. In this work we investigate this further by introducing a multi-timescale control hierarchy with at its core a hierarchy of recurrent neural networks. By means of some robot experiments, we demonstrate that this hierarchy can embed any rhythmic motor signal by imitation learning. Furthermore, the proposed hierarchy allows the tracking of several high level motion properties (e.g.: amplitude and offset), which are usually observed at a slower rate than the generated motion. Although these experiments are preliminary, the results are promising and have the potential to open the door for rich motor skills and advanced control

    Advocacy for an improved training in clinical nutrition during the medical cursus.

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    editorial reviewedThe knowledge of physicians regarding nutrition is often far below the expectations of patients, and does not comply with official recommendations. However, poor-quality nutrition and diet represent the first cause of mortality worldwide. As a result of an insufficient training and awareness, many physicians cannot meet patients' expectations. Moreover, nutrition is sometimes felt as a field of low scientific level, thereby opening the area to pseudo-scientific drifts. We advocate an improvement in the training in nutrition during the medical cursus, namely by the transversal integration of nutritional insights into medical courses, and the recognition of post-university training validated by the academic authorities. A clarification of the roles and the recognition of the competency are urgently required to promote the professionalism of nutritional counselling.Les connaissances des médecins en matière d’alimentation et de nutrition sont souvent en-deçà des attentes des patients et en décalage par rapport aux recommandations officielles. Pourtant, la mauvaise alimentation constitue la première cause de mortalité à l’échelle planétaire. Les attentes des patients sont importantes en matière de nutrition et le médecin y est mal préparé en raison d’une formation insuffisante. De plus, la nutrition est parfois perçue comme une matière peu scientifique, et la reconnaissance des compétences en nutrition est insuffisante, ouvrant le champ à des dérives pseudo-scientifiques. Nous plaidons pour une meilleure formation en nutrition dans le cursus des études médicales, notamment en intégrant les aspects nutritionnels de manière transversale au cours de la formation des futurs médecins, et pour la reconnaissance des cursus de formation post-universitaires validés par les autorités académiques. Une clarification des rôles et une reconnaissance des compétences sont urgentes afin de professionnaliser les conseils nutritionnels

    Determination of iodine value of palm oil based on triglyceride composition

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    The triglyceride (TG) composition of palm oil is normally determined by high-performance liquid chromatography (HPLC). The HPLC chromatograms indicated a good separation of most of the TG components in the oil. The TG can be classified based on either the TG groups, i.e., triunsaturated, monosaturated, disaturated, or trisaturated, or the number of double bonds, i.e., zero, one, two, three, or four double bonds. The more unsaturated the fatty acid, the greater the iodine value (IV). Therefore, it is hypothesized that the IV of an oil can be determined based upon the TG composition of the oil. Based on the TG groups, stepwise regression analysis showed that the areas of the disaturated, trisaturated, and triunsaturated TG peaks could predict the IV with a coefficient of determination (R2) of 0.990. The regression based on the number of double bonds yielded a good regression equation with R2=0.992. The important variables were the peak area of the fatty acids that contained zero, one, two, and three double bonds. This study concludes that the TG composition can be used to predict the IV of palm oil. The best prediction model is obtained by using the number of double bonds in the TG as the independent variable

    Insulin resistance causes inflammation in adipose tissue

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    Obesity is a major risk factor for insulin resistance and type 2 diabetes. In adipose tissue, obesity-mediated insulin resistance correlates with the accumulation of proinflammatory macrophages and inflammation. However, the causal relationship of these events is unclear. Here, we report that obesity-induced insulin resistance in mice precedes macrophage accumulation and inflammation in adipose tissue. Using a mouse model that combines genetically induced, adipose-specific insulin resistance (mTORC2-knockout) and diet-induced obesity, we found that insulin resistance causes local accumulation of proinflammatory macrophages. Mechanistically, insulin resistance in adipocytes results in production of the chemokine monocyte chemoattractant protein 1 (MCP1), which recruits monocytes and activates proinflammatory macrophages. Finally, insulin resistance (high homeostatic model assessment of insulin resistance [HOMA-IR]) correlated with reduced insulin/mTORC2 signaling and elevated MCP1 production in visceral adipose tissue from obese human subjects. Our findings suggest that insulin resistance in adipose tissue leads to inflammation rather than vice versa

    Combined alkali and hydrothermal pretreatments for oat straw valorization within a biorefinery concept

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    The aim of this work was the evaluation of lime pretreatment combined or not with previous step of autohydrolysis for oat straw valorization. Under selected conditions of lime pretreatment, 96% of glucan and 77% of xylan were recovered and 42% of delignification was achieved. Xylose fermentation to ethanol by metabolic engineered Saccharomyces cerevisiae (MEC1133) strain improved the ethanol production by 22% achieving 41 g/L. Alternatively, first step of autohydrolysis (S0=4.22) allowed a high oligosaccharides recovery (68%) and subsequent lime pretreatment attained a 57% of delignification and 99% of glucan to glucose conversion. Oat straw processed by autohydrolysis and lime pretreatment reached the maximal ethanol concentration (50 g/L). Both strategies led to oat straw valorization into bioethanol, oligosaccharides and lignin indicating that these pretreatments are adequate as a first stage within an oat straw biorefinery.The authors thank the financial support from the Strategic Project of UID/BIO/04469/2013 CEB Unit (Funding agency for Science and Technology, FCT, Portugal) and for the Project CTQ2012-30855 of the Spanish "Ministry of Science and Innovation", partially funded by the FEDER program of the European Union. A Romani thanks her post-doctoral grant funded by Xunta of Galicia (Plan I2C, 2014)

    Valorization of eucalyptus wood by glycerol-organosolv pretreatment within the biorefinery concept: an integrated and intensified approach

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    The efficient utilization of lignocellulosic biomass and the reduction of production cost are mandatory to attain a cost-effective lignocellulose-to-ethanol process. The selection of suitable pretreatment that allows an effective fractionation of biomass and the use of pretreated material at high-solid loadings on saccharification and fermentation (SSF) processes are considered promising strategies for that purpose. Eucalyptus globulus wood was fractionated by organosolv process at 200 C for 69 min using 56% of glycerol-water. A 99% of cellulose remained in pretreated biomass and 65% of lignin was solubilized. Precipitated lignin was characterized for chemical composition and thermal behavior, showing similar features to commercial lignin. In order to produce lignocellulosic ethanol at high-gravity, a full factory design was carried to assess the liquid to solid ratio (3e9 g/g) and enzyme to solid ratio (8e16 FPU/g) on SSF of delignified Eucalyptus. High ethanol concentration (94 g/L) corresponding to 77% of conversion at 16FPU/g and LSR ¼ 3 g/g using an industrial and thermotolerant Saccharomyces cerevisiae strain was successfully produced from pretreated biomass. Process integration of a suitable pretreatment, which allows for whole biomass valorization, with intensified saccharification-fermentation stages was shown to be feasible strategy for the co-production of high ethanol titers, oligosaccharides and lignin paving the way for cost-effective Eucalyptus biorefinery.Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684). The authors also thank the FCT for finacial support under the scope of the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462). AR was supported by Postdoctoral Fellowship PlanI2C/2014 funded by Xunta of Galicia (Spain

    Fractionation of eucalyptus globulus wood by glycerol-water pretreatment: optimization and modeling

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    A glycerol-organosolv process can be a good alternative for Eucalyptus wood fractionation into its main compounds, improving the enzymatic saccharification of the cellulose. A study of process variables - glycerol−water percent content, temperature, and process time - was carried out using a Box-Behnken experimental design. The cellulose obtained from pretreated solids was recovered almost quantitatively, leading to a solid with a high percentage of cellulose (77 g/100 g of pretreated solid), low lignin content (9 g/100 g of pretreated solid), and 18% of residual hemicellulose in the solid at 200 °C, 56% of glycerol−water and 69 min. The enzymatic saccharification was enhanced achieving 98% cellulose-to-glucose conversion (under conditions: liquid to solid ratio 20 g/g and enzyme loading 20 FPU/g of solid). This study contributes to the improvement of biomass fractionation by exploring an eco-friendly treatment which allows for almost complete wood fractionation into constituents and high levels of glucose recovery available for subsequent yeast fermentation to bioethanol.The authors A. Romani and F. B. Pereira thank to the Portuguese Foundation for Science and Technology (FCT, Portugal) for their fellowships (grant number: SFRH/BPD/77995/2011 and SFRH/BD/64776/2009, respectively)

    Simultaneous saccharification and fermentation of hydrothermal pretreated lignocellulosic biomass: evaluation of process performance under multiple stress conditions

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    Industrial lignocellulosic bioethanol processes are exposed to different environmental stresses (such as inhibitor compounds, high temperature, and high solid loadings). In this study, a systematic approach was followed where the liquid and solid fractions were mixed to evaluate the influence of varied solid loadings, and different percentages of liquor were used as liquid fraction to determine inhibitor effect. Ethanol production by simultaneous saccharification and fermentation (SSF) of hydrothermally pretreated Eucalyptus globulus wood (EGW) was studied under combined diverse stress operating conditions (3038 °C, 6080 g of liquor from hydrothermal treatment or autohydrolysis (containing inhibitor compounds)/100 g of liquid and liquid to solid ratio between 4 and 6.4 g liquid in SSF/g unwashed pretreated EGW) using an industrial Saccharomyces cerevisiae strain supplemented with low-cost byproducts derived from agro-food industry. Evaluation of these variables revealed that the combination of temperature and higher solid loadings was the most significant variable affecting final ethanol concentration and cellulose to ethanol conversion, whereas solid and autohydrolysis liquor loadings had the most significant impact on ethanol productivity. After optimization, an ethanol concentration of 54 g/L (corresponding to 85 % of conversion and 0.51 g/Lh of productivity at 96 h) was obtained at 37 °C using 60 % of autohydrolysis liquor and 16 % solid loading (liquid to solid ratio of 6.4 g/g). The selection of a suitable strain along with nutritional supplementation enabled to produce noticeable ethanol titers in quite restrictive SSF operating conditions, which can reduce operating cost and boost the economic feasibility of lignocellulose-to-ethanol processes.The authors thank the financial support from the Strategic Project of UID/BIO/04469/2013 CEB Unit and A Romaní postdoctoral grant funded by Xunta of Galicia (Plan I2C, 2014)

    Lipid-lowering therapy and risk-based LDL-C goal attainment in Belgium: DA VINCI observational study

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    Background Cardiovascular disease (CVD) is one of the leading causes of death in Belgium. Current strategies for the prevention and management of CVD focus on reducing low-density lipoprotein cholesterol (LDL-C) levels. This analysis assessed whether LDL-C goals, recommended by the European Society of Cardiology (ESC)/European Atherosclerosis Society (EAS) guidelines, were being achieved in a Belgian study population. Methods The cross-sectional, observational, DA VINCI study enrolled patients prescribed lipid-lowering therapy (LLT) between 21 June 2017 and 20 November 2018. Data for patients from Belgium were extracted for this country-specific analysis. Primary endpoint was the proportion of patients who achieved 2016 ESC/EAS risk-based LDL-C goals; attainment of 2019 risk-based LDL-C goals was evaluated post hoc. Results Of 497 enrolled patients, 41% were female and mean age was 68 years. Among subjects with an LDL-C measurement on stabilised LLT, moderate-intensity statin monotherapy was the most prescribed LLT regimen (59%). Overall, 63% of patients achieved their risk-based LDL-C goals according to the 2016 ESC/EAS guidelines. Among patients with established ASCVD, risk-based LDL-C goal attainment was higher in patients with peripheral arterial disease (53%) than patients with coronary (37%) and cerebrovascular disease (42%). According to the updated 2019 ESC/EAS guidelines, less than half (41%) of patients achieved their risk-based LDL-C goal. The proportion of primary and secondary prevention patients who achieved 2019 risk-based LDL-C goals was 59% and 18%, respectively. Conclusion These findings reveal a large gap between the LDL-C goals advocated by the ESC/EAS and the levels achieved in routine clinical practice in Belgium
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