489 research outputs found
Impact of a 2-year intervention program on cardiometabolic profile according to the number of goals achieved
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: ≥5% weight loss; ≥150 min/week physical activities; <10% saturated fat intake/day; ≥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 ≥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 μU/L vs none: 5.7 ± 4.0 μU/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
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
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: CuCoCl-FeCl graphite bi-intercalation compound
Static and dynamic behavior of short-range Ising-spin glass
CuCoCl-FeCl graphite bi-intercalation compounds
(GBIC) has been studied with SQUID DC and AC magnetic susceptibility. The
dependence of the zero-field relaxation time above a spin-freezing
temperature (= 3.92 0.11 K) is well described by critical slowing
down. The absorption below decreases with
increasing angular frequency , which is in contrast to the case of 3D
Ising spin glass. The dynamic freezing temperature at which
dd, is determined as a function of
frequency (0.01 Hz 1 kHz) and magnetic field (0 5 kOe). The dynamic scaling analysis of the relaxation time
defined as at suggests the absence of
SG phase in the presence of (at least above 100 Oe). Dynamic scaling
analysis of and near
leads to the critical exponents ( = 0.36 0.03, = 3.5
0.4, = 1.4 0.2, = 6.6 1.2, = 0.24
0.02, and = 0.13 0.02). The aging phenomenon is studied through
the absorption below . It obeys a
power-law decay with an exponent . 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
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
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
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, . Three
quantities, the difference , the effective waiting time,
, and the difference are examined in our
analysis. Three regimes of spin-glass behavior are observed as
increases. Lines in the 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
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 is {\it unstable} to RSB.
The susceptibility associated to infinitesimal RSB perturbation in the
high-temperature phase is found to diverge as
when . 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
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
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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