Sweetened beverages, snacks and overweight: findings from the Young Lives cohort study in Peru

OBJECTIVE: To determine the association between consumption of snacks and sweetened beverages and risk of overweight among children. DESIGN: Secondary analysis of the Young Lives cohort study in Peru. SETTING: Twenty sentinel sites from a total of 1818 districts available in Peru. SUBJECTS: Children in the younger cohort of the Young Lives study in Peru, specifically those included in the third (2009) and the fourth (2013) rounds. RESULTS: A total of 1813 children were evaluated at baseline; 49·2 % girls and mean age 8·0 (sd 0·3) years. At baseline, 3·3 (95 % CI 2·5, 4·2) % reported daily sweetened beverage consumption, while this proportion was 3·9 (95 % CI 3·1, 4·9) % for snacks. Baseline prevalence of overweight was 22·0 (95 % CI 20·1, 23·9) %. Only 1414 children were followed for 4·0 (sd 0·1) years, with an overweight incidence of 3·6 (95 % CI 3·1, 4·1) per 100 person-years. In multivariable analysis, children who consumed sweetened beverages and snacks daily had an average weight increase of 2·29 (95 % CI 0·62, 3·96) and 2·04 (95 % CI 0·48, 3·60) kg more, respectively, than those who never consumed these products, in approximately 4 years of follow-up. Moreover, there was evidence of an association between daily consumption of sweetened beverages and risk of overweight (relative risk=2·12; 95 % CI 1·05, 4·28). CONCLUSIONS: Daily consumption of sweetened beverages and snacks was associated with increased weight gain v. never consuming these products; and in the case of sweetened beverages, with higher risk of developing overweight

Relaxation and Landau-Zener experiments down to 100 mK in ferritin

Temperature-independent magnetic viscosity in ferritin has been observed from 2 K down to 100 mK, proving that quantum tunneling plays the main role in these particles at low temperature. Magnetic relaxation has also been studied using the Landau-Zener method making the system crossing zero resonant field at different rates, alpha=dH/dt, ranging from 10^{-5} to 10^{-3} T/s, and at different temperatures, from 150 mK up to the blocking temperature. We propose a new Tln(Delta H_{eff}/tau_0 alpha) scaling law for the Landau-Zener probability in a system distributed in volumes, where Delta H_{eff} is the effective width of the zero field resonance.Comment: 13 pages, 4 postscript figure

Chronic hepatitis C and health-related quality of life in patients with cognitive impairment

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Non-monotonic field-dependence of the ZFC magnetization peak in some systems of magnetic nanoparticles

We have performed magnetic measurements on a diluted system of gamma-Fe2O3 nanoparticles (~7nm), and on a ferritin sample. In both cases, the ZFC-peak presents a non-monotonic field dependence, as has already been reported in some experiments,and discussed as a possible evidence of resonant tunneling. Within simple assumptions, we derive expressions for the magnetization obtained in the usual ZFC, FC, TRM procedures. We point out that the ZFC-peak position is extremely sensitive to the width of the particle size distribution, and give some numerical estimates of this effect. We propose to combine the FC magnetization with a modified TRM measurement, a procedure which allows a more direct access to the barrier distribution in a field. The typical barrier values which are obtained with this method show a monotonic decrease for increasing fields, as expected from the simple effect of anisotropy barrier lowering, in contrast with the ZFC results. From our measurements on gamma-Fe2O3 particles, we show that the width of the effective barrier distribution is slightly increasing with the field, an effect which is sufficient for causing the observed initial increase of the ZFC-peak temperatures.Comment: LaTeX file 19 pages, 9 postscript figures. To appear in Phys. Rev. B (tentative schedule: Dec.97

Normalization factors for magnetic relaxation of small particle systems in non-zero magnetic field

We critically discuss relaxation experiments in magnetic systems that can be characterized in terms of an energy barrier distribution, showing that proper normalization of the relaxation data is needed whenever curves corresponding to different temperatures are to be compared. We show how these normalization factors can be obtained from experimental data by using the $T \ln(t/\tau_0)$ scaling method without making any assumptions about the nature of the energy barrier distribution. The validity of the procedure is tested using a ferrofluid of Fe_3O_4 particles.Comment: 5 pages, 6 eps figures added in April 22, to be published in Phys. Rev. B 55 (1 April 1997

Ejercicio de negociación: una decisión de rutina

It shows an exercise whose objective is to get the students or participants to design the strategy they will follow during a negotiation process, taking into account the basic principles of a price negotiation. It simulates a typical negotiation between a buyer and a seller, each of whom has information that the other does not know. Each party must negotiate the price at which it will be willing to enter into the transaction. A second objective is to record the evolution of the negotiation process in order to measure the strength and sequence of the arguments, as well as the style of the negotiation. To this end, the instructor's guide suggests that the participant should define his strategy, prepare the arguments with which he will support it and define his negotiation style.Muestra un ejercicio cuyo objetivo es lograr que los estudiantes o participantes diseñen la estrategia que seguirán durante un proceso de negociación, teniendo en cuenta los principios básicos de una negociación de precios. Simula una negociación típica entre un comprador y un vendedor, cada uno de los cuales tiene información que el otro desconoce. Cada parte debe negociar el precio al que estará dispuesta a realizar la transacción. Un segundo objetivo es registrar la evolución del proceso de negociación para medir la fuerza y ​​secuencia de los argumentos, así como el estilo de la negociación. Para ello, la guía del instructor sugiere que el participante defina su estrategia, prepare los argumentos con los que la sustentará y defina su estilo de negociación

Measuring turbulent large-eddy structures with an ADCP. 1. Vertical velocity variance

Two different turbulent flows, Langmuir supercells and unstable convection, have been sampled with a VADCP, an acoustic Doppler current profiler (ADCP) with an additional vertical (V) beam. Direct measurements of the profile of vertical velocity variance provided by the vertical beam are used to calculate observational response functions for algorithms used to derive vertical velocity from the 4 beams of a standard ADCP. A theoretical response function derived for the vertical velocity estimate from a single pair of opposed slant beams illustrates the importance of large-scale quasi-coherent flow structures, as well as effects of different angles of slant beams from vertical. Different large-eddy characteristics for Langmuir supercells and unstable convection yield different theoretical response: however in both cases, the theoretical response agrees qualitatively with that derived from observations. For Langmuir super-cells, there is additional agreement with numerical response functions generated by using the geometry of a VADCP to sample three-dimensional flow fields available from large eddy simulations (LES). The results from all three approaches show that there can be significant error in vertical velocity inferred from slant beam velocities. The error may be either over- or under-estimation, depending upon (usually unknown) features of the large eddies of the turbulent field, such as vertical/horizontal anisotropy, phase coherence, and orientation of horizontally anisotropic turbulent structures relative to the instrument. Given only a standard ADCP, the “best” estimate of vertical velocity variance is not the usual 4-beam estimate, but the larger of the two pair estimates

Measuring turbulent large-eddy structures with an ADCP. Part 2. Horizontal velocity variance

This paper considers the degree of accuracy with which observations from an acoustic Doppler current profiler (ADCP) can determine turbulent horizontal velocity variance. As in a previous paper addressing turbulent vertical velocity variance, we use a combination of techniques, deriving response functions from simple theory and from oceanic observations taken with a VADCP (an ADCP with an additional vertical (V) beam) in two different oceanic turbulent flows, Langmuir supercells (LSC) and unstable convection. In the case of LSC, we also determine response by sampling available Large-Eddy Simulations (LES) with specified beam geometry. In contrast with the previous investigation, where a direct measurement of vertical velocity variance was available from the vertical beam of the VADCP, we lack direct measurements of horizontal velocity variances. Thus the observational response reported here for horizontal variance is an estimate, taken as the ratio of first-order to the (assumed more accurate) second-order variance estimates made possible for the first time by the presence of a vertical beam.The theoretical response function is used to illustrate effects on response of horizontal scale, vertical/horizontal anisotropy and possible quasi-coherent phase structure of the large eddies of the turbulent field, and to predict the impact of changing θ, the angle of slant beams from vertical. Observational estimates show that convective turbulence is characterized by near-unity response throughout the water column for both horizontal velocity variances, in agreement with theoretical prediction. For Langmuir supercells, theoretical responses correctly predict qualitative behavior of the LES-derived response functions, specifically overestimation in the lower part of the water column shifting to underestimation toward the surface. LES-derived responses for different values of θ are also in agreement with theory: both approaches suggest that θ = 30° provides more accurate measurement of horizontal turbulent velocity variance than does θ = 20°, the present commercial standard.For all examined cases of unstable convection and most (normal) LSC cases, observationally estimated response functions generally agree with theoretical (and, where available, LES) predictions. However in a few (abnormal) LSC cases, record-averaged second-order variances are clearly underestimated (most obviously when they are actually negative). We have been unable to assign a cause to this underestimation and advise against use of second-order horizontal velocity variances until this unpredictable effect is understood. Normal LSC cases exhibit overestimation of horizontal variance by a maximum factor of 1.5 (observational estimates) to 3 (LES estimates), a degree of accuracy comparable to that associated with microscale-based estimates of turbulent large-eddy quantities. We suggest ways in which the parameters needed for theoretical prediction of the response function for horizontal velocity can be estimated directly from VADCP measurements

The role of temperature in the magnetic irreversibility of type-I Pb superconductors

Evidence of how temperature takes part in the magnetic irreversibility in the intermediate state of a cylinder and various disks of pure type-I superconducting lead is presented. Isothermal measurements of first magnetization curves and magnetic hysteresis cycles are analyzed in a reduced representation that defines an equilibrium state for flux penetration in all the samples and reveals that flux expulsion depends on temperature in the disks but not in the cylinder. The magnetic field at which irreversibility sets in along the descending branch of the hysteresis cycle and the remnant magnetization at zero field are found to decrease with temperature in the disks. The contributions to irreversibility of the geometrical barrier and the energy minima associated to stress defects that act as pinning centers on normal-superconductor interfaces are discussed. The differences observed among the disks are ascribed to the diverse nature of the stress defects in each sample. The pinning barriers are suggested to decrease with the magnetic field to account for these results