485 research outputs found

    Impact of a 2-year intervention program on cardiometabolic profile according to the number of goals achieved

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    We investigated the impact of lifestyle goal achievement on cardiovascular risk factors after a 2-year behavioral intervention program applied to 394 adults (113 with diabetes, mean age 60.2 ± 11.4 years, 56% women) and targeting four goals: &#8805;5% weight loss; &#8805;150 min/week physical activities; <10% saturated fat intake/day; &#8805;400 g fruit and vegetable intake/day. Baseline characteristics and changes in variables after intervention among the four categories of number of goals achieved (none, 1, 2, and &#8805;3) were compared by independent ANOVA or the Kruskal-Wallis test. Individuals without diabetes achieving a higher number of goals were more likely to be older (3 or 4 goals: 61.8 ± 12.6 years vs none: 53.3 ± 10.3 years, P < 0.05) and to have a lower mean BMI (3 or 4 goals: 21.7 ± 2.6 kg/m² vs none: 29.0 ± 4.8 kg/m², P < 0.05), diastolic blood pressure (3 or 4 goals: 77.3 ± 2.1 mmHg vs none: 85.4 ± 9.6 mmHg, P < 0.05), triglyceride (3 or 4 goals: 116.1 ± 95.1 mg/dL vs none: 144.8 ± 65.5 mg/dL, P < 0.05) and insulin levels (3 or 4 goals: 3.6 ± 2.4 &#956;U/L vs none: 5.7 ± 4.0 &#956;U/L, P < 0.05) than those achieving fewer goals. The absolute changes in cardiovascular risk factors tended to be more pronounced with increasing number of goals achieved in individuals without diabetes. The intervention had a beneficial impact on the cardiometabolic profile of individuals with normal or altered glucose metabolism. The number of goals achieved in this lifestyle intervention was associated with the magnitude of improvement of cardiovascular risk factors in individuals without diabetes. Participants with a better cardiometabolic profile seemed to be more likely to have a healthy lifestyle

    Slowly synchronizing automata and digraphs

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    We present several infinite series of synchronizing automata for which the minimum length of reset words is close to the square of the number of states. These automata are closely related to primitive digraphs with large exponent.Comment: 13 pages, 5 figure

    Spin glass transition in a magnetic field: a renormalization group study

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    We study the transition of short range Ising spin glasses in a magnetic field, within a general replica symmetric field theory, which contains three masses and eight cubic couplings, that is defined in terms of the fields representing the replicon, anomalous and longitudinal modes. We discuss the symmetry of the theory in the limit of replica number n to 0, and consider the regular case where the longitudinal and anomalous masses remain degenerate. The spin glass transitions in zero and non-zero field are analyzed in a common framework. The mean field treatment shows the usual results, that is a transition in zero field, where all the modes become critical, and a transition in non-zero field, at the de Almeida-Thouless (AT) line, with only the replicon mode critical. Renormalization group methods are used to study the critical behavior, to order epsilon = 6-d. In the general theory we find a stable fixed-point associated to the spin glass transition in zero field. This fixed-point becomes unstable in the presence of a small magnetic field, and we calculate crossover exponents, which we relate to zero-field critical exponents. In a finite magnetic field, we find no physical stable fixed-point to describe the AT transition, in agreement with previous results of other authors.Comment: 36 pages with 4 tables. To be published in Phys. Rev.

    Dynamic scaling and aging phenomena in short-range Ising spin glass: Cu0.5_{0.5}Co0.5_{0.5}Cl2_{2}-FeCl3_{3} graphite bi-intercalation compound

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    Static and dynamic behavior of short-range Ising-spin glass Cu0.5_{0.5}Co0.5_{0.5}Cl2_{2}-FeCl3_{3} graphite bi-intercalation compounds (GBIC) has been studied with SQUID DC and AC magnetic susceptibility. The TT dependence of the zero-field relaxation time τ\tau above a spin-freezing temperature TgT_{g} (= 3.92 ±\pm 0.11 K) is well described by critical slowing down. The absorption χ\chi^{\prime\prime} below TgT_{g} decreases with increasing angular frequency ω\omega, which is in contrast to the case of 3D Ising spin glass. The dynamic freezing temperature Tf(H,ω)T_{f}(H,\omega) at which dMFC(T,H)/M_{FC}(T,H)/dH=χ(T,H=0,ω)H=\chi^{\prime}(T,H=0,\omega), is determined as a function of frequency (0.01 Hz ω/2π\leq \omega/2\pi \leq 1 kHz) and magnetic field (0 H\leq H \leq 5 kOe). The dynamic scaling analysis of the relaxation time τ(T,H)\tau(T,H) defined as τ=1/ω\tau = 1/\omega at T=Tf(H,ω)T = T_{f}(H,\omega) suggests the absence of SG phase in the presence of HH (at least above 100 Oe). Dynamic scaling analysis of χ(T,ω)\chi^{\prime \prime}(T, \omega) and τ(T,H)\tau(T,H) near TgT_{g} leads to the critical exponents (β\beta = 0.36 ±\pm 0.03, γ\gamma = 3.5 ±\pm 0.4, ν\nu = 1.4 ±\pm 0.2, zz = 6.6 ±\pm 1.2, ψ\psi = 0.24 ±\pm 0.02, and θ\theta = 0.13 ±\pm 0.02). The aging phenomenon is studied through the absorption χ(ω,t)\chi^{\prime \prime}(\omega, t) below TgT_{g}. It obeys a (ωt)b(\omega t)^{-b^{\prime \prime}} power-law decay with an exponent b0.150.2b^{\prime \prime}\approx 0.15 - 0.2. The rejuvenation effect is also observed under sufficiently large (temperature and magnetic-field) perturbations.Comment: 14 pages, 19 figures; to be published in Phys. Rev. B (September 1, 2003

    Morphophysiological Plasticity Of Plagiotropic Branches In Response To Change In The Coffee Plant Spacing Within Rows

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    Changes in spacing within rows may alter the morphology of the coffee plant by affecting the physiological constituents of its productivity. Even though some common plant responses to crop spacing variation are known, there is yet no scientific evidence that elucidates the effects of decreased spacing on the sourcesink relation in plagiotropic branches and, its association with both productivity and eco-physiological aspects of coffee leaves, mainly for new coffee cultivars in the Brazilian savannah. The aim of this work was to characterize the morphophysiological responses of Coffea arabica L. cultivars subjected to different spacing between plants within rows. Four Arabica coffee cultivars (Catuaí Vermelho IAC 144, Catuaí Amarelo IAC 62, Catuaí Amarelo IAC 32, and Tupi RN IAC 1669-13) were transplanted in January 2010. A row spacing of 0.40, 0.50, 0.60, 0.70, and 0.80 m was adopted between plants, maintaining a 3.80-m constant between rows. A randomized block design with four replicates was applied. During the experimental period, several morphophysiological characteristics of plagiotropic fruiting branches were evaluated in the months of April and December in 2013 and, in April 2014. The evaluation was conducted based on two canopy positions; canopy toward the rows, representing low exposure to light or toward the inter-row spacing, representing high light exposure. Leaf gas exchange, chlorophyll fluorescence, and photosynthetic pigments levels were minimally or not at all affected by changing either the coffee cultivars or plant spacing. During the first evaluation, the leaf-to-fruitratio linearly increased, regardless of the cultivar. Light-exposed branches showed higher content of carotenoids and chlorophyll a in leaves and lower leaf-to-fruit-ratio as compared to those within the plant canopy. A major reduction in the number of fruits per branch was observed which was closely related to a parallel decrease in the number of fruits per node but not in the number of fruiting nodes per branch. Although this response was largely cultivar-dependent, it also changed according to the branch position in the hedgerow. Our results suggest that all tested cultivars exhibit high morphophysiological plasticity and have the potential to grow under different plant spacing within rows.3763819383

    Experimental characterization of combustion in recirculation zone of double-stage swirl chamber

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    Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.The focus of the present work is a new Low-NOx combustor configuration to especial application in gas turbine. The combustion happens in two phases; the first one with oxidant deficiency, or fuel rich combustion, and the second one is a fuel lean combustion. This combustion structure allows the conciliation of low NOx emissions and partial oxidation combustion products, as carbon monoxide and unburned hydrocarbons. In the new concept proposed here, these unfavorable combustion conditions for NOx formation are reached through the dynamic control of reactants mixing process into the chamber. However, the success of this strategy depends on the formation of a strong recirculation zone in the secondary chamber and quick-mixing between air, reminiscent fuel and combustion products. So that the present work shows experimental results about the structure of the recirculation zone using Particle Image Velocimetry (PIV) and the combustion dynamics using Planar Laser Inducing Fluorescence (PLIF). Both techniques were applied in the secondary zone of combustion. The conclusion based on the results presented in this paper can be summarized according to the increase of the recirculation zone intensity: 1. the volume occupied by recirculation zone is greater, the transition to reverse flow is more abrupt and the magnitude of the reverse velocity is higher; 2. intensify the vortices formation; 3. the combustion reactions take place in the central region of recirculation zone.dc201

    From Linear to Nonlinear Response in Spin Glasses: Importance of Mean-Field-Theory Predictions

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    Deviations from spin-glass linear response in a single crystal Cu:Mn 1.5 at % are studied for a wide range of changes in magnetic field, ΔH\Delta H. Three quantities, the difference TRM(MFCZFC)TRM-(MFC-ZFC), the effective waiting time, twefft_{w}^{eff}, and the difference TRM(tw)TRM(tw=0)TRM(t_{w})-TRM(t_{w}=0) are examined in our analysis. Three regimes of spin-glass behavior are observed as ΔH\Delta H increases. Lines in the (T,ΔH)(T,\Delta H) plane, corresponding to ``weak'' and ``strong'' violations of linear response under a change in magnetic field, are shown to have the same functional form as the de Almeida-Thouless critical line. Our results demonstrate the existence of a fundamental link between static and dynamic properties of spin glasses, predicted by the mean-field theory of aging phenomena.Comment: 9 pages, 10 figure

    Replica Symmetry Breaking Instability in the 2D XY model in a random field

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    We study the 2D vortex-free XY model in a random field, a model for randomly pinned flux lines in a plane. We construct controlled RG recursion relations which allow for replica symmetry breaking (RSB). The fixed point previously found by Cardy and Ostlund in the glass phase T<TcT<T_c is {\it unstable} to RSB. The susceptibility χ\chi associated to infinitesimal RSB perturbation in the high-temperature phase is found to diverge as χ(TTc)γ\chi \propto (T-T_c)^{-\gamma} when TTc+T \rightarrow T_c^{+}. This provides analytical evidence that RSB occurs in finite dimensional models. The physical consequences for the glass phase are discussed.Comment: 8 pages, REVTeX, LPTENS-94/2

    Bounded version vectors

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    Version vectors play a central role in update tracking under optimistic distributed systems, allowing the detection of obsolete or inconsistent versions of replicated data. Version vectors do not have a bounded representation; they are based on integer counters that grow indefinitely as updates occur. Existing approaches to this problem are scarce; the mechanisms proposed are either unbounded or operate only under specific settings. This paper examines version vectors as a mechanism for data causality tracking and clarifies their role with respect to vector clocks. Then, it introduces bounded stamps and proves them to be a correct alternative to integer counters in version vectors. The resulting mechanism, bounded version vectors, represents the first bounded solution to data causality tracking between replicas subject to local updates and pairwise symmetrical synchronization.FCT project POSI/ICHS/44304/2002, FCT under grant BSAB/390/2003

    Scalable and accurate causality tracking for eventually consistent stores

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    Lecture Notes in Computer Science 8460, 2014In cloud computing environments, data storage systems often rely on optimistic replication to provide good performance and availability even in the presence of failures or network partitions. In this scenario, it is important to be able to accurately and efficiently identify updates executed concurrently. Current approaches to causality tracking in optimistic replication have problems with concurrent updates: they either (1) do not scale, as they require replicas to maintain information that grows linearly with the number of writes or unique clients; (2) lose information about causality, either by removing entries from client-id based version vectors or using server-id based version vectors, which cause false conflicts. We propose a new logical clock mechanism and a logical clock framework that together support a traditional key-value store API, while capturing causality in an accurate and scalable way, avoiding false conflicts. It maintains concise information per data replica, only linear on the number of replica servers, and allows data replicas to be compared and merged linear with the number of replica servers and versions.(undefined
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