Developmental trajectories of body mass index and emotional-behavioral functioning of underweight children. A longitudinal study

Although several studies have addressed developmental trajectories from childhood to adolescence of internalizing/externalizing problems, limited attention has been given to underweight children. Two groups were recruited for this study from a community sample: underweight (Ug, N = 80, 50% female) and normal weight (NWg, N = 80, 50% female) to examine the developmental trajectories of body mass index and emotional-behavioral functioning of underweight children from the age two years, and their risk of eating disorder at early adolescence. The study was organized over four waves, each of three years. Pediatricians measured BMI, parents completed the Child Behavior Checklist (CBCL) and the Eating Disorders Inventory-Referral Form (EDI-3-RF). Our results showed that children in the two groups recorded different BMI trajectories over time. In NWg, male and female subjects started from a higher BMI at T1 than their peers. In Ug, internalizing and externalizing problems in males and females remained higher than their peers at all points of assessment. Males and females in Ug scored higher than those in NWg on EDI-3-RF total score. Our results indicate a need for effective physical and psychological assessment of underweight children in community samples to prevent psychological difficulties and eating disorders in adolescenc

Trajectories of aggressive and depressive symptoms in male and female overweight children. Do they share a common path or do they follow different routes?

The prevalence of childhood overweight is a major social and public health issue, and primary assessment should focus on early and middle childhood, because weight gain in these phases constitutes a strong predictor of subsequent negative outcomes. Studies on community samples have shown that growth curves may follow linear or non-linear trajectories from early to middle childhood, and can differ based on sex. Overweight children may exhibit a combination of physiological and psychosocial issues, and several studies have demonstrated an association between overweight and internalizing/externalizing behavior. Nevertheless, there is a dearth of longitudinal studies on depressive and aggressive symptoms in children with high BMI. This study adopted a growth curve modeling over three phases to: (1) describe BMI trajectories in two groups of children aged 2–8 (overweight and normal weight) from a community sample; (2) describe the developmental trajectories of children’s aggressive and depressive symptoms from 2 to 8 years of age. Results indicate higher BMI in 2-year-old girls, with males catching up with them by age 8. While overweight females’ BMIs were consistently high, males’ increased at 5 and 8 years. The mean scores for aggressive symptoms at T1 (2 years of age) were the same in all subjects, but a significant deviation occurred from T1 to T2 in both samples, in divergent directions. With regards to children’s depressive symptoms, the two groups had different starting points, with normal weight children scoring lower than overweight youths. Overweight females showed lower depressive scores than overweight males at T1, but they surpassed boys before T2, and showed more maladaptive symptoms at T3. This study solicits professionals working in pediatric settings to consider overweight children’s psychopathological risk, and to be aware that even when children’s BMI does not increase from 2 to 8 years, their psychopathological symptoms may grow in intensit

Quantum cavitation in liquid helium

Using a functional-integral approach, we have determined the temperature below which cavitation in liquid helium is driven by thermally assisted quantum tunneling. For both helium isotopes, we have obtained the crossover temperature in the whole range of allowed negative p essures. Our results are compatible with recent experimental results on 4He.Comment: Typeset using Revtex, 10 pages and 2 figures, Phys. Rev B (1996

Experimental test of strongly non-classical character of a noisy squeezed single-photon state

We experimentally verify the quantum non-Gaussian character of a conditionally generated noisy squeezed single-photon state with positive Wigner function. Employing an optimized witness based on probabilities of squeezed vacuum and squeezed single-photon states we prove that the state cannot be expressed as a mixture of Gaussian states. In our experiment, the non-Gaussian state is generated by conditional subtraction of a single photon from squeezed vacuum state. The state is probed with a homodyne detector and the witness is determined by averaging a suitable pattern function over the measured homodyne data. Our experimental results are in good agreement with a theoretical fit obtained from a simple yet realistic model of the experimental setup.Comment: 10 pages, 8 figures, REVTeX

Radar and Snow Structure Studies in the Percolation Zone of the Greenland Ice Sheet: A Data Report on the 1993 Field Season at Dye-2

From June 18 to July 12, 1993, a Byrd Polar Research Center team undertook radar and snow physical properties studies near Dye-2, in the percolation zone of Greenland's ice sheet. These studies were intended to advance our understanding of the microwave scattering properties of the ice sheet, in order to better interpret satellite remote sensing signals for mass balance and climate studies. This report summarizes the experiments performed and the data collected. Table I summarizes a list of our measurement objectives. In general terms, our work at Dye-2 consisted of making radar observations of the snow at Ku-band (13.5 GHz) and a variety of incidence angles. The radar frequency is the same as that of the radar altimeter aboard the ERS-1 satellite. In conjunction with the radar observations, we dug pits in the snow and recorded physical properties such as snow stratigraphy, density, and grain sizes. In section 2 we present a map of the camp and experiment sites. In sections 3 and 4 we describe the pit and radar studies in detail. Finally, section 5 is a detailed chronology of the field season

Quantum cavitation in liquid 3^3He: dissipation effects

We have investigated the effect that dissipation may have on the cavitation process in normal liquid $^3$He. Our results indicate that a rather small dissipation decreases sizeably the quantum-to-thermal crossover temperature $T^*$ for cavitation in normal liquid $^3$He. This is a possible explanation why recent experiments have not yet found clear evidence of quantum cavitation at temperatures below the $T^*$ predicted by calculations which neglect dissipation.Comment: To be published in Physical Review B6

Shear measurements across the northern margin of Whillans Ice Stream

This is the publisher's version, also available electronically from "http://www.ingentaconnect.com".Field measurements of surface deformation across the northern shear margin of Whillans Ice Stream, West Antarctica, were analyzed to better understand the processes controlling the position and migration of this margin. Four lines of poles extending ∼6 km from the interstream ridge into the shear margin were installed in November 1997 and resurveyed in January 2000, using GPS methods. A band of arcuate crevasses form where the surficial shear stress reaches ∼130 kPa, and a chaotic zone of crevassing occurs where this stress reaches a maximum of ∼270 kPa. Inspection of the RAMP mosaic indicates that the band of arcuate crevasses is separated from the chaotic zone by a narrow zone (∼250 m) with a relatively undisturbed surface morphology. A force-budget analysis suggests the transition from no basal sliding to full basal sliding must be restricted to a relatively narrow band, ∼1.5 km wide beneath the chaotic zone. On the ice stream, resistance from the bed is near zero and the driving stress is balanced by gradients in lateral shearing. Basal drag reaches a maximum close to the shear margin where basal conditions transition from well lubricated (beneath the ice stream) to no basal slip (beneath the ridge). The zone of elevated basal drag is ∼4 km wide. Within this zone, lateral drag is reduced and becomes increasingly restricted to upper layers. Localized meltwater production under the region of elevated basal drag is similar in magnitude to melting under the ice stream. The uniform bed morphology, inferred from radar sounding, excludes the presence of abundant basal water either in a water film at the glacier bed or in a thick saturated till layer. This suggests that most of the meltwater produced under the shear margin is diverted towards the ice stream, possibly playing a crucial role in maintaining lubricated conditions allowing streaming flow

Stability of vortex lines in liquid 3He-4He mixtures at zero temperature

At low temperatures and 3He concentrations below 6.6 %, there is experimental evidence about the existence in liquid helium mixtures, of stable vortices with 3He-rich cores. When the system is either supersaturated or submitted to a tensile strength, vortices lose stability becoming metastable and eventually completely unstable, so that their cores freely expand. Within a density functional approach, we have determined the pressure-3He concentration curve along which this instability appears at zero temperature.Comment: Typeset using Revtex, 9 pages and 5 Postscript figure