1,590 research outputs found
An experiment analysis of the impact of advertising and food packaging on women\u27s eating behavior
Obesity is considered a national epidemic and is associated with increased eating behavior and decreased physical activity. Research has demonstrated biological underpinnings, but the dramatic increase in prevalence rates in recent decades (Flegal et al., 2002) suggests that environmental influences also contribute (Hill et al., 2008). This led researchers to speculate about the impact of our purported “Toxic Environment,” in which high-calorie, energy-dense foods are readily available for consumption and technological advances have decreased physical activity (Wadden et al., 2002). Most of the literature examining the theory of the Toxic Environment is correlational in nature, limiting causal inference. A pilot study of five participants demonstrated that exposure to purported Toxic Environment cues elicited increased food consumption compared to exposure to Thin-Ideal or Neutral cues. Therefore, the present study aimed to explore the influence of two elements of the purported Toxic Environment on women’s eating behavior – advertising and food packaging size. Eighty-two participants were randomly assigned to a 2 (toxic vs. healthy food ad) x 2 (large vs. small package-size) design. Participants, deceived about the true aims of the study, were asked to find dots in the ad stimuli and were given food according to package-size condition to consume ad lib during the session. The next day participants were contacted to provide a 24- hour dietary recall. Results demonstrated that participants exposed to healthy ads and large package size consumed more calories in session than those in other conditions. There were no differences among conditions on caloric intake in the following 24 hours. When examining the pattern of consumption, it appears that participants may have regulated their food intake during the study. Results also suggest that overweight women may be more sensitive to Toxic Environment cues, whereas restrained eaters may be more sensitive to packaging size as opposed to advertising. Binge-eaters appear to be sensitive to food cues in general, regardless of condition, compared to non-binge eaters. Results may have treatment implications for various weight-related populations. If further research supports the impact of our potentially Toxic Environment on eating behavior, implications for developing public health policies addressing the obesity epidemic may be warranted
The relationship between body image and weight maintenance in community women enrolled in weight-loss programs
Research suggests that poor body image, low self-esteem, and depression may be associated with failure to maintain weight loss (Lean, 2000). However, definitive results are lacking, necessitating further research. Both successful and unsuccessful weight maintainers (N = 148) were recruited from weight-loss programs. Self-report measures on dimensions of body image, depression, and self-esteem were administered at baseline and a three-month follow-up. Results suggest that those with early-onset obesity have more body image dissatisfaction than those with late-onset obesity, which appears to be due to BMI differences between groups with the former having a higher BMI than the later. Other results indicate no differences between short-term and long-term weight maintainers on change in body image in three months. Furthermore, change in body image is not a significant predictor of successful weight maintenance. Further research will be necessary to clarify the relationship between body image and weight maintenance
Increases in the Irreversibility Field and the Upper Critical Field of Bulk MgB2 by ZrB2 Addition
In a study of the influence of ZrB2 additions on the irreversibility field,
Birr and the upper critical field Bc2, bulk samples with 7.5 at. % ZrB2
additions were made by a powder milling and compaction technique. These samples
were then heated to 700-900C for 0.5 hours. Resistive transitions were measured
at 4.2 K and Birr and Bc2 values were determined. An increase in Bc2 from 20.5
T to 28.6 T and enhancement of Birr from 16 T to 24 T were observed in the ZrB2
doped sample as compared to the binary sample at 4.2 K. Critical field
increases similar to those found with SiC doping were seen at 4.2 K. At higher
temperatures, increases in Birr were also determined by M-H loop extrapolation
and closure. Values of Birr which were enhanced with ZrB2 doping (as compared
to the binary) were seen at temperatures up to 34 K, with Birr values larger
than those for SiC doped samples at higher temperatures. The transition
temperature, Tc, was then measured using DC susceptibility and a 2.5 K drop of
the midpoint of Tc was observed. The critical current density was determined
using magnetic measurements and was found to increase at all temperatures
between 4.2 K and 35 K with ZrB2 doping.Comment: 15 pages, 5 figs, 1 tabl
Evaporation of ices near massive stars: models based on laboratory TPD data
Hot cores and their precursors contain an integrated record of the physics of
the collapse process in the chemistry of the ices deposited during that
collapse. In this paper, we present results from a new model of the chemistry
near high mass stars in which the desorption of each species in the ice mixture
is described as indicated by new experimental results obtained under conditions
similar to those hot cores. Our models show that provided there is a monotonic
increase in the temperature of the gas and dust surrounding the protostar, the
changes in the chemical evolution of each species due to differential
desorption are important. The species HS, SO, SO, OCS, HCS, CS, NS,
CHOH, HCOOCH, CHCO, CHOH show a strong time dependence that
may be a useful signature of time evolution in the warm-up phase as the star
moves on to the Main Sequence. This preliminary study demonstrates the
consequences of incorporating reliable TPD data into chemical models.Comment: 5 pages, accepted by MNRA
Analytical study of space processing of immiscible materials for superconductors and electrical contacts
The results of a study conducted to determine the role space processing or materials research in space plays in the superconductor and electrical contact industries are presented. Visits were made to manufacturers, users, and research organizations connected with these products to provide information about the potential benefits of the space environment and to exchange views on the utilization of space facilities for manufacture, process development, or research. In addition, space experiments were suggested which could result in improved terrestrial processes or products. Notable examples of these are, in the case of superconductors, the development of Nb-bronze alloys (Tsuei alloys) and, in the electrical contact field, the production of Ag-Ni or Ag-metal oxide alloys with controlled microstructure for research and development activities as well as for product development. A preliminary experimental effort to produce and evaluate rapidly cooled Pb-Zn and Cu-Nb-Sn alloys in order to understand the relationship between microstructure and superconducting properties and to simulate the fine structure potentially achievable by space processing was also described
Thermal Desorption of Water-Ice in the Interstellar Medium
Water (H2O) ice is an important solid constituent of many astrophysical
environments. To comprehend the role of such ices in the chemistry and
evolution of dense molecular clouds and comets, it is necessary to understand
the freeze-out, potential surface reactivity, and desorption mechanisms of such
molecular systems. Consequently, there is a real need from within the
astronomical modelling community for accurate empirical molecular data
pertaining to these processes. Here we give the first results of a laboratory
programme to provide such data. Measurements of the thermal desorption of H2O
ice, under interstellar conditions, are presented. For ice deposited under
conditions that realistically mimic those in a dense molecular cloud, the
thermal desorption of thin films (~50 molecular layers) is found to occur with
zero order kinetics characterised by a surface binding energy, E_{des}, of 5773
+/- 60 K, and a pre-exponential factor, A, of 10^(30 +/- 2) molecules cm^-2
s^-1. These results imply that, in the dense interstellar medium, thermal
desorption of H2O ice will occur at significantly higher temperatures than has
previously been assumed.Comment: 9 pages, 4 figures, accepted for publication in MNRA
Applying laboratory thermal desorption data in an interstellar context: sublimation of methanol thin films
Methods by which experimental measurements of thermal desorption can be applied in astrophysical environments have been developed, using the sublimation of solid methanol as an example. The temperature programmed desorption of methanol from graphitic, amorphous silica and polycrystalline gold substrates was compared, with the kinetic parameters of desorption extracted by either a leading edge analysis or by fitting using a stochastic integration method. At low coverages, the desorption shows a substrate-dependent fractional order. However, at higher coverages methanol desorption is zeroth order with kinetic parameters independent of substrate. Using a kinetic model based on the stochastic integration analyses, desorption under astrophysically relevant conditions can be simulated. We find that the chemical and morphological nature of the substrate has relatively little impact on the desorption temperature of solid methanol, and that the substrate independent zeroth-order kinetics can provide a satisfactory model for desorption in astrophysical environments. Uncertainties in the heating rate and the distribution of grain sizes will have the largest influence on the range of desorption temperature. These conclusions are likely to be generally applicable to all species in dust grain ice mantles
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