1,252 research outputs found

    Impacto de un programa de ejercicio sobre la Autoeficacia en mujeres con sobrepeso y obesidad

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    Introducción: En México la prevalencia combinada de sobrepeso y obesidad en muje- res es de 73%, problema de salud pública que se relaciona con las principales causas de muerte. Las principales estrategias se realizan a través de la práctica de ejercicio y alimentación saludable; sin embargo, no se ha tenido el impacto deseado; es necesario obtener indicadores cognitivos para fortalecer las estrategias de salud.Objetivo: Analizar el impacto de un programa de entrenamiento físico aeróbico gradual sobre el nivel de Autoeficacia (AE) para practicar ejercicio y dieta saludable en mujeres con sobrepeso y obesidad.Material y métodos: Se trató de un experimento en el que se incluyeron mujeres de 18 a 24 años con un IMC≥27. La muestra se conformó por 34 mujeres divididas en los grupos control y experimental (17 mujeres respectivamente), seleccionadas y asignadas median- te muestreo aleatorio. Las mediciones se realizaron mediante un inventario valido y con- fiable que mide la AE en dieta y ejercicio. La dosis de ejercicio fue calculada por la fórmula de Karvonen durante diez semanas de manera gradual y controlada. El estadístico utiliza- do fue un MANOVA de mediciones repetidas, se consideró un nivel de significancia <.05. Resultados: Posterior a la intervención se apreciaron cambios estadísticamente signi- ficativos, AE en ejercicio 40.3±4.0 vs. 35.8±5.4; y AE en dieta 85.8±10.5 vs. 78.8±10.7 (p<.05).Conclusiones: El ejercicio a la dosis establecida mejoró la condición de AE que favoreció la práctica de ejercicio y la dieta saludable en mujeres con sobrepeso y obesidad

    Impacto de un programa de ejercicio sobre la Autoeficacia en mujeres con sobrepeso y obesidad

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    Introducción: En México la prevalencia combinada de sobrepeso y obesidad en muje- res es de 73%, problema de salud pública que se relaciona con las principales causas de muerte. Las principales estrategias se realizan a través de la práctica de ejercicio y alimentación saludable; sin embargo, no se ha tenido el impacto deseado; es necesario obtener indicadores cognitivos para fortalecer las estrategias de salud.Objetivo: Analizar el impacto de un programa de entrenamiento físico aeróbico gradual sobre el nivel de Autoeficacia (AE) para practicar ejercicio y dieta saludable en mujeres con sobrepeso y obesidad.Material y métodos: Se trató de un experimento en el que se incluyeron mujeres de 18 a 24 años con un IMC≥27. La muestra se conformó por 34 mujeres divididas en los grupos control y experimental (17 mujeres respectivamente), seleccionadas y asignadas median- te muestreo aleatorio. Las mediciones se realizaron mediante un inventario valido y con- fiable que mide la AE en dieta y ejercicio. La dosis de ejercicio fue calculada por la fórmula de Karvonen durante diez semanas de manera gradual y controlada. El estadístico utiliza- do fue un MANOVA de mediciones repetidas, se consideró un nivel de significancia <.05. Resultados: Posterior a la intervención se apreciaron cambios estadísticamente signi- ficativos, AE en ejercicio 40.3±4.0 vs. 35.8±5.4; y AE en dieta 85.8±10.5 vs. 78.8±10.7 (p<.05).Conclusiones: El ejercicio a la dosis establecida mejoró la condición de AE que favoreció la práctica de ejercicio y la dieta saludable en mujeres con sobrepeso y obesidad

    Stochastic Gravity: Theory and Applications

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    Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein-Langevin equation, which has in addition sources due to the noise kernel. In the first part, we describe the fundamentals of this new theory via two approaches: the axiomatic and the functional. In the second part, we describe three applications of stochastic gravity theory. First, we consider metric perturbations in a Minkowski spacetime, compute the two-point correlation functions of these perturbations and prove that Minkowski spacetime is a stable solution of semiclassical gravity. Second, we discuss structure formation from the stochastic gravity viewpoint. Third, we discuss the backreaction of Hawking radiation in the gravitational background of a black hole and describe the metric fluctuations near the event horizon of an evaporating black holeComment: 100 pages, no figures; an update of the 2003 review in Living Reviews in Relativity gr-qc/0307032 ; it includes new sections on the Validity of Semiclassical Gravity, the Stability of Minkowski Spacetime, and the Metric Fluctuations of an Evaporating Black Hol

    Nonlinear vortex light beams supported and stabilized by dissipation

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    We describe nonlinear Bessel vortex beams as localized and stationary solutions with embedded vorticity to the nonlinear Schr\"odinger equation with a dissipative term that accounts for the multi-photon absorption processes taking place at high enough powers in common optical media. In these beams, power and orbital angular momentum are permanently transferred to matter in the inner, nonlinear rings, at the same time that they are refueled by spiral inward currents of energy and angular momentum coming from the outer linear rings, acting as an intrinsic reservoir. Unlike vortex solitons and dissipative vortex solitons, the existence of these vortex beams does not critically depend on the precise form of the dispersive nonlinearities, as Kerr self-focusing or self-defocusing, and do not require a balancing gain. They have been shown to play a prominent role in "tubular" filamentation experiments with powerful, vortex-carrying Bessel beams, where they act as attractors in the beam propagation dynamics. Nonlinear Bessel vortex beams provide indeed a new solution to the problem of the stable propagation of ring-shaped vortex light beams in homogeneous self-focusing Kerr media. A stability analysis demonstrates that there exist nonlinear Bessel vortex beams with single or multiple vorticity that are stable against azimuthal breakup and collapse, and that the mechanism that renders these vortexes stable is dissipation. The stability properties of nonlinear Bessel vortex beams explain the experimental observations in the tubular filamentation experiments.Comment: Chapter of boo

    Stochastic Gravity: Theory and Applications

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    Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein-Langevin equation, which has in addition sources due to the noise kernel.In the first part, we describe the fundamentals of this new theory via two approaches: the axiomatic and the functional. In the second part, we describe three applications of stochastic gravity theory. First, we consider metric perturbations in a Minkowski spacetime: we compute the two-point correlation functions for the linearized Einstein tensor and for the metric perturbations. Second, we discuss structure formation from the stochastic gravity viewpoint. Third, we discuss the backreaction of Hawking radiation in the gravitational background of a quasi-static black hole.Comment: 75 pages, no figures, submitted to Living Reviews in Relativit

    How Emotion Strengthens the Recollective Experience: A Time-Dependent Hippocampal Process

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    Emotion significantly strengthens the subjective recollective experience even when objective accuracy of the memory is not improved. Here, we examine if this modulation is related to the effect of emotion on hippocampal-dependent memory consolidation. Two critical predictions follow from this hypothesis. First, since consolidation is assumed to take time, the enhancement in the recollective experience for emotional compared to neutral memories should become more apparent following a delay. Second, if the emotion advantage is critically dependent on the hippocampus, then the effects should be reduced in amnesic patients with hippocampal damage. To test these predictions we examined the recollective experience for emotional and neutral photos at two retention intervals (Experiment 1), and in amnesics and controls (Experiment 2). Emotional memories were associated with an enhancement in the recollective experience that was greatest after a delay, whereas familiarity was not influenced by emotion. In amnesics with hippocampal damage the emotion effect on recollective experience was reduced. Surprisingly, however, these patients still showed a general memory advantage for emotional compared to neutral items, but this effect was manifest primarily as a facilitation of familiarity. The results support the consolidation hypothesis of recollective experience, but suggest that the effects of emotion on episodic memory are not exclusively hippocampally mediated. Rather, emotion may enhance recognition by facilitating familiarity when recollection is impaired due to hippocampal damage

    Optimal Timing of Insecticide Fogging to Minimize Dengue Cases: Modeling Dengue Transmission among Various Seasonalities and Transmission Intensities

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    Dengue virus infection is a serious infectious disease transmitted by Aedes mosquitoes in the tropics and sub-tropics. Disease control often involves the use of insecticide fogging against mosquito vectors. However, the effectiveness of this method for reducing dengue cases, in addition to appropriate application procedures, is still debated. The previous mathematical simulation study reported that insecticide fogging reduces dengue cases most effectively when applied soon after the epidemic peak; however, the model did not take into account seasonality and population immunity, which strongly affect the epidemic pattern of dengue infection. Considering these important factors, we used a mathematical simulation model to explore the most effective time for insecticide fogging and to evaluate its impact on reducing dengue cases. Simulations were conducted with various lengths of the wet season and population immunity levels. We found that insecticide fogging substantially reduces dengue cases if conducted at an appropriate time. In contrast to the previously suggested application time during the peak of disease prevalence, the optimal timing is relatively early: between the beginning of the dengue season and the prevalence peak

    Dominance relationships and coalitionary aggression against conspecifics in female carrion crows

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    Funding: European Research Council (ERCStG-336536 FuncSpecGen to J.W.), the Swedish Research Council Vetenskapsrådet (621-2013-4510 to J.W.), Knut and Alice Wallenberg Foundation (to J.W.) and Tovetorp fieldstation through Stockholm University.Cooperation is a prevailing feature of many animal systems. Coalitionary aggression, where a group of individuals engages in coordinated behaviour to the detriment of conspecific targets, is a form of cooperation involving complex social interactions. To date, evidence has been dominated by studies in humans and other primates with a clear bias towards studies of male-male coalitions. We here characterize coalitionary aggression behaviour in a group of female carrion crows consisting of recruitment, coordinated chase, and attack. The individual of highest social rank liaised with the second most dominant individual to engage in coordinated chase and attack of a lower ranked crow on several occasions. Despite active intervention by the third most highly ranked individual opposing the offenders, the attack finally resulted in the death of the victim. All individuals were unrelated, of the same sex, and naive to the behaviour excluding kinship, reproduction, and social learning as possible drivers. Instead, the coalition may reflect a strategy of the dominant individual to secure long-term social benefits. Overall, the study provides evidence that members of the crow family engage in coordinated alliances directed against conspecifics as a possible means to manipulate their social environment.Publisher PDFPeer reviewe

    Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

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    The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV

    Search for pair-produced long-lived neutral particles decaying to jets in the ATLAS hadronic calorimeter in ppcollisions at √s=8TeV

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    The ATLAS detector at the Large Hadron Collider at CERN is used to search for the decay of a scalar boson to a pair of long-lived particles, neutral under the Standard Model gauge group, in 20.3fb−1of data collected in proton–proton collisions at √s=8TeV. This search is sensitive to long-lived particles that decay to Standard Model particles producing jets at the outer edge of the ATLAS electromagnetic calorimeter or inside the hadronic calorimeter. No significant excess of events is observed. Limits are reported on the product of the scalar boson production cross section times branching ratio into long-lived neutral particles as a function of the proper lifetime of the particles. Limits are reported for boson masses from 100 GeVto 900 GeV, and a long-lived neutral particle mass from 10 GeVto 150 GeV
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