1,234 research outputs found

    Early symbiotic responses induced by Sinorhizobium meliloti ilvC mutants in alfalfa

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    A mutation in the ilvC gene of Sinorhizobium meliloti 1021 determines a symbiotically defective phenotype, ilvC mutants obtained from different S. meliloti wild-type strains are able to induce root hair deformation on alfalfa roots and show variable activation of the common nodulation genes nodABC. All of these mutants are noninfective. The presence of extra copies of nodD3-syrM in an IlvC‒ background does not promote nod expression but allows the detection of low levels of Nod factor production. The sulphation of the Nod factor metabolites, however, is not affected. Furthermore, IlvC‒ strains induce a specific pattern of starch accumulation on alfalfa roots as well as of early nodulin expression. Hence, the pleiotropic action of the ilvC gene in S. meliloti may reveal novel complexities involved in the symbiotic interaction.Instituto de Biotecnologia y Biologia MolecularFacultad de Ciencias Exacta

    Effectiveness of a program of physical activity in people with serious mental disorder

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    En el presente estudio se analiza el impacto que ha tenido un Programa de actividad física y deporte en un grupo de 28 personas con Trastorno Mental Grave (TMG). Se realizó una evaluación antes del comienzo del Programa y otra a los cuatro meses, tomando medidas antropométricas, de capacidad física funcional, equilibrio y coordinación, así como del funcionamiento social y las actividades de la vida cotidiana. Los resultados mostraron mejorías estadísticamente significativas en aquellas personas que asistieron a más del 50% de las sesiones en todas las variables antropométricas, y de condición física funcional y cualidades motrices, así como en la Escala de Funcionamiento Personal y Social (PSP).Por otro lado, la asistencia al programa fue alta, manteniéndose en el mismo el 80% de las personas que lo iniciaron. Se discute la relevancia de los resultados y la necesidad de implantar este tipo de intervenciones en el TMGIn this paper the effectiveness of a physical activity and sport program is analyzed in a group of 28 people with Severe Mental Illness (SMI). An assessment was made before the start of the program and again after four months, measuring anthropometric variables, physical functional ability, balance and coordination, and social functioning and activities of daily life. The results showed statistically significant improvements in those who attended more than 50% of the sessions in all anthropometric variables, and functional fitness and motor skills, as well as the Personal and Social Performance Scale (PSP). Moreover, assistance to the program was high, keeping the same 80% of people who started it. The relevance of the results and the need to implement such interventions in the SMI is discusse

    On the use of continuous spectrum and discrete-mode differential models to predict contraction-flow pressure drops for Boger fluids

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    Over recent years, there has been slow but steady progress towards the qualitative numerical prediction of observed behaviour when highly elastic Boger fluids flow in contraction geometries. This has led to an obvious desire to seek quantitative agreement between prediction and experiment, a subject which is addressed in the current paper. We conclude that constitutive models of non-trivial complexity are required to make headway in this regard. However, we suggest that the desire to move from qualitative to quantitative agreement between theory and experiment is making real progress. In the present case with differential models, this has involved the introduction of a generalized continuous spectrum model. This is based on direct data input from material functions and rheometrical measurements. The class of such models assumes functional separability across shear and extensional deformation, through two master functions, governing independently material-time and viscous-response. The consequences of such a continuous spectrum representation are compared and contrasted against discrete-mode alternatives, via an averaged single-mode approximation and a multi-modal approximation. The effectiveness of each chosen form is gauged by the quality of match to complex flow response and experimental measurement. Here, this is interpreted in circular contraction-type flows with Boger fluids, where large experimental pressure-drop data are available and wide disparity between different fluid responses has been recorded in the past. Findings are then back-correlated to base-material response from ideal viscometric flow

    Single top-quark production by strong and electroweak supersymmetric flavor-changing interactions at the LHC

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    (Abridged) We report on a complete study of the single top-quark production by direct supersymmetric flavor-changing neutral-current (FCNC) processes at the LHC. The total cross section for pp(gg)->t\bar{c}+\bar{t}c is computed at the 1-loop order within the unconstrained Minimal Supersymmetric Standard Model (MSSM). The present study extends the results of the supersymmetric strong effects (SUSY-QCD), which were advanced by some of us in a previous work, and includes the computation of the full supersymmetric electroweak corrections (SUSY-EW). Our analysis of pp(gg)->t\bar{c}+\bar{t}c in the MSSM has been performed in correspondence with the stringent low-energy constraints from b->s gamma. In the most favorable scenarios, the SUSY-QCD contribution can give rise to production rates of around 10^5 events per 100 fb^{-1} of integrated luminosity. Furthermore, we show that there exist regions of the MSSM parameter space where the SUSY-EW correction becomes sizeable. In the SUSY-EW favored regions, one obtains lower, but still appreciable, event production rates that can reach the 10^3 level for the same range of integrated luminosity. We study also the possible reduction in the maximum event rate obtained from the full MSSM contribution if we additionally include the constraints from B^0_s-\bar{B}^0_s. In view of the fact that the FCNC production of heavy quark pairs of different flavors is extremely suppressed in the SM, the detection of a significant number of these events could lead to evidence of new physics -- of likely supersymmetric origin.Comment: LaTex, 35 pages, typos corrected. Version accepted in JHE

    Biopesticide of Neem Obtained by Enzyme-Assisted Extraction: An Alternative to Improve the Pest Control

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    The indiscriminate use of chemical pesticides to control pests and diseases without technical assistance instead of solving the pest problems has caused environmental damage, agriculture productivity, and human health. Pesticides can remain for several years in the soil, being able to contaminate rivers and lagoons, animals of shepherding and foods. Besides, in recent years, pests have shown an alarmingly resistance over several pesticides. This makes necessary the use of other natural sources of pesticides that could be degraded avoiding the resistance problem. One of the main sources analyzed is the neem (Azadirachta indica) due to its complex content of bioactive triterpenoids. However, cellulosic structures of cell wall conditioned the extraction of these components, acting as physical barrier and avoiding its complete extraction. This chapter included a review of the consequences of the use of chemical pesticides to control pests spread in plant and animals and its repercussions on the environment. Moreover, the advantages of the use of food-grade enzyme preparations as an alternative to elaborate an extract of neem without organic solvents are exposed. The results are promissory and could improve the acaricide and repellent effects of the neem extracts over pests, reducing the negative effect caused by chemical pesticides

    Monolithic stirrer reactors for the sustainable production of dihydroxybenzenes over 3D printed Fe/γ-Al2O3 monoliths: kinetic modeling and CFD simulation

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    The aim of this work is to evaluate the performance of the stirring 3D Fe/Al2O3 monolithic reactor in batch operation applied to the liquid-phase hydroxylation of phenol by hydrogen peroxide (H2O2 ). An experimental and numerical investigation was carried out at the following operating conditions: CPHENOL,0 = 0.33 M, CH2O2,0 = 0.33 M, T = 75–95◦C, P = 1 atm, ω = 200–500 rpm and WCAT ~ 1.1 g. The kinetic model described the consumption of the H2O2 by a zero-order power-law equation, while the phenol hydroxylation and catechol and hydroquinone production by Eley–Rideal model; the rate determining step was the reaction between the adsorbed H2O2, phenol in solution with two active sites involved. The 3D CFD model, coupling the conservation of mass, momentum and species together with the reaction kinetic equations, was experimentally validated. It demonstrated a laminar flow characterized by the presence of an annular zone located inside and surrounding the monoliths (u = 40–80 mm s−1 ) and a central vortex with very low velocities (u = 3.5–8 mm s−1 ). The simulation study showed the increasing phenol selectivity to dihydroxybenzenes by the reaction temperature, while the initial H2O2 concentration mainly affects the phenol conversio

    La compatibilidad entre estudios y deporte en estudiantes de secundaria

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    The purpose of this research was to analysethe difficulties thathigh school studentshadto balance outstudiesandsports. Following adescriptiveexploratorymethodandthroughthe application of atestquestionnaireandconductinga discussion group, informationwascollectedin relation to fourkey factors: the characteristicsof the sport, the conflicts of interestemergedinbalancingstudiesand sport, the support and resources theyhadto bring togetherthisdoubleactivityandthetrainingand professional expectationsthatwereahead of theirfuture. Theanalysis of the differentfactors involved inthe development of thisdouble activity, constitutes afundamentalelement of reference sothatschoolsimplementmeasuresand actions that allow these students to continue with theirsports training, without having to give upeducation. The results obtainedhighlightthe difficulties thathigh school students havetocombineboth processes, which requires them greateffort, good planning ofgoals, appropriate organization of time andpersistenceinachievingthe objectives.La finalidad de esta investigación fue analizar las dificultades que los estudiantes de secundaria tenían para compatibilizar estudios y deportes. Siguiendo un método descriptivo de carácter exploratorio y a través de la aplicación de una prueba de cuestionario y la realización de un grupo de discusión, se recogió información en relación a cuatro factores clave: las características propias de la práctica deportiva, el conflicto de intereses surgido a la hora de compatibilizar los estudios y el deporte, los apoyos y recursos con los que contaban para armonizar esta doble actividad y las expectativas formativas y profesionales que tenían de cara a su futuro. El análisis de los distintos factores que intervienen en el desarrollo de esta doble actividad, constituye un elemento de referencia fundamental para que los centros educativos implanten medidas y acciones que permitan a estos estudiantes continuar con su preparación deportiva, sin tener que renunciar a la formación. Los resultados obtenidos ponen de manifiesto las dificultades que tienen los estudiantes de secundaria para compaginar ambos procesos, lo que les exige un gran esfuerzo, una buena planificación de metas, una adecuada organización del tiempo y persistencia en el logro de los objetivos planteados

    Virtual reality-based early neurocognitive stimulation in critically ill patients: A pilot randomized clinical trial

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    This study focuses on the application of a non-immersive virtual reality (VR)-based neurocognitive intervention in critically ill patients. Our aim was to assess the feasibility of direct outcome measures to detect the impact of this digital therapy on patients’ cognitive and emotional outcomes. Seventy-two mechanically ventilated adult patients were randomly assigned to the “treatment as usual” (TAU, n = 38) or the “early neurocognitive stimulation” (ENRIC, n = 34) groups. All patients received standard intensive care unit (ICU) care. Patients in the ENRIC group also received adjuvant neurocognitive stimulation during the ICU stay. Outcome measures were a full neuropsychological battery and two mental health questionnaires. A total of 42 patients (21 ENRIC) completed assessment one month after ICU discharge, and 24 (10 ENRIC) one year later. At onemonth follow-up, ENRIC patients had better working memory scores (p = 0.009, d = 0.363) and showed up to 50% less non-specific anxiety (11.8% vs. 21.1%) and depression (5.9% vs. 10.5%) than TAU patients. A general linear model of repeated measures reported a main effect of group, but not of time or group–time interaction, on working memory, with ENRIC patients outperforming TAU patients (p = 0.008, ¿p2 = 0.282). Our results suggest that non-immersive VR-based neurocognitive stimulation may help improve short-term working memory outcomes in survivors of critical illness. Moreover, this advantage could be maintained in the long term. An efficacy trial in a larger sample of participants is feasible and must be conducted. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

    The reactivity of cyclopropyl cyanide in titan's atmosphere: a possible pre-biotic mechanism

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    Cyclopropyl cyanide and other simple nitriles detected in Titan's atmosphere could be precursors leading to the formation of organic macromolecules in the atmosphere of Saturn's largest satellite. Proposing a thermodynamically possible mechanism that explains their formation and supports experimental results represents a difficult challenge. Experiments done in the Atomic and Molecular Physics Laboratory at the University of Trento (AMPL) have studied the ion-molecule reaction between cyclopropyl cyanide and its protonated form, with reaction products being characterized by mass spectrometry. In addition to the expected ion-molecule adduct stabilized by non-covalent long-range interactions, in this work we prove that another distinct species having the same mass to charge ratio (m/z) of 135 is also produced. Moreover, from a previous study of the neutral cyclopropyl cyanide potential energy surface (PES) which shows a partial biradical character it has been possible to characterize the formation through the bimolecular reaction of a new covalent cyclic organic molecule. Calculations have been carried out at the ab initio Møller-Plesset (MP2) level of theory, ensuring the connectivity of the stationary points by using the intrinsic reaction coordinate (IRC) procedure. In order to characterize the reaction transition state, multireference calculations were done using a complete active space involving six electrons and six molecular orbitals [CAS (6 e, 6 m.o.)]. This study opens the possibility of exploring the formation of new organic molecules by gaseous phase ion-molecule interaction schemes, with such molecules having relevance in interstellar space and in astrobiology (and may be involved in prebiotic molecular evolution)
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