180 research outputs found

    Turning light into a liquid via atomic coherence

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    We study a four level atomic system with electromagnetically induced transparency with giant χ(3)\chi^{(3)} and χ(5)\chi^{(5)} susceptibilities of opposite signs. This system would allow to obtain multidimensional solitons and light condensates with surface tension properties analogous to those of usual liquids

    Effect of different protein sources on satiation and short-term satiety when consumed as a starter

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    <p>Abstract</p> <p>Background</p> <p>Because the source of protein may play a role in its satiating effect, we investigated the effect of different proteins on satiation and short-term satiety.</p> <p>Methods</p> <p>Two randomized single-blind cross-over studies were completed. In the first study, we investigated the effect of a preload containing 20 g of casein, whey, pea protein, egg albumin or maltodextrin vs. water control on food intake 30 min later in 32 male volunteers (25 ± 4 yrs, BMI 24 ± 0.4 kg/m<sup>2</sup>). Subjective appetite was assessed using visual analogue scales at 10 min intervals after the preload. Capillary blood glucose was measured every 30 min during 2 hrs before and after the ad libitum meal. In the second study, we compared the effect of 20 g of casein, pea protein or whey vs. water control on satiation in 32 male volunteers (25 ± 0.6 yrs, BMI 24 ± 0.5 kg/m<sup>2</sup>). The preload was consumed as a starter during an ad libitum meal and food intake was measured. The preloads in both studies were in the form of a beverage.</p> <p>Results</p> <p>In the first study, food intake was significantly lower only after casein and pea protein compared to water control (P = 0.02; 0.04 respectively). Caloric compensation was 110, 103, 62, 56 and 51% after casein, pea protein, whey, albumin and maltodextrin, respectively. Feelings of satiety were significantly higher after casein and pea protein compared to other preloads (P < 0.05). Blood glucose response to the meal was significantly lower when whey protein was consumed as a preload compared to other groups (P < 0.001). In the second study, results showed no difference between preloads on ad libitum intake. Total intake was significantly higher after caloric preloads compared to water control (P < 0.05).</p> <p>Conclusion</p> <p>Casein and pea protein showed a stronger effect on food intake compared to whey when consumed as a preload. However, consuming the protein preload as a starter of a meal decreased its impact on food intake as opposed to consuming it 30 min before the meal.</p

    Predicting Weight Outcomes in Preadolescence: The Role of Toddlers? Self-regulation Skills and the Temperament Dimension of Pleasure

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    Objective To investigate the role of toddlers? self-regulation skills and temperament in predicting weight outcomes in preadolescence. Method Participants for this study included 195 children (114 girls) obtained from three different cohorts participating in a larger ongoing longitudinal study. At 2 years of age, participants participated in several laboratory tasks designed to assess their self-regulation abilities, including emotion regulation, sustained attention, and delay of gratification, while parents filled out a temperament questionnaire to assess toddlers? pleasure expression. Height and weight measures were collected when children were 4, 5, 7, and 10 years of age. Children also filled out a body image and eating questionnaire at the 10 year visit. Results Self-regulation skills in toddlers were associated with both BMI development, pediatric obesity, and body image/eating concerns. The temperament dimension of pleasure was also associated with BMI development and pediatric obesity but not body image/eating concerns. Conclusion Self-regulation difficulties across domains as well as temperament based pleasure in toddlers represented significant individual risk factors for the development of pediatric obesity eight years later. Early self-regulation difficulties also contributed to body image and eating concerns that typically accompanied overweight children. The mechanisms by which early self-regulation skills and temperament based pleasure may contribute to the development of pediatric obesity and associated weight concerns are discussed

    Animal Perception of Seasonal Thresholds: Changes in Elephant Movement in Relation to Rainfall Patterns

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    Background: The identification of temporal thresholds or shifts in animal movement informs ecologists of changes in an animal\u2019s behaviour, which contributes to an understanding of species\u2019 responses in different environments. In African savannas, rainfall, temperature and primary productivity influence the movements of large herbivores and drive changes at different scales. Here, we developed a novel approach to define seasonal shifts in movement behaviour by examining the movements of a highly mobile herbivore (elephant; Loxodonta africana), in relation to local and regional rainfall patterns. Methodology/Principal Findings: We used speed to determine movement changes of between 8 and 14 GPS-collared elephant cows, grouped into five spatial clusters, in Kruger National Park, South Africa. To detect broad-scale patterns of movement, we ran a three-year daily time-series model for each individual (2007\u20132009). Piecewise regression models provided the best fit for elephant movement, which exhibited a segmented, waveform pattern over time. Major breakpoints in speed occurred at the end of the dry and wet seasons of each year. During the dry season, female elephant are constrained by limited forage and thus the distances they cover are shorter and less variable. Despite the inter-annual variability of rainfall, speed breakpoints were strongly correlated with both local and regional rainfall breakpoints across all three years. Thus, at a multi-year scale, rainfall patterns significantly affect the movements of elephant. The variability of both speed and rainfall breakpoints across different years highlights the need for an objective definition of seasonal boundaries. Conclusions/Significance: By using objective criteria to determine behavioural shifts, we identified a biologically meaningful indicator of major changes in animal behaviour in different years. We recommend the use of such criteria, from an animal\u2019s perspective, for delineating seasons or other extrinsic shifts in ecological studies, rather than arbitrarily fixed definitions based on convention or common practice

    Associations between body mass index, weight control concerns and behaviors, and eating disorder symptoms among non-clinical Chinese adolescents

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    <p>Abstract</p> <p>Background</p> <p>Previous research with adolescents has shown associations of body weight, weight control concerns and behaviors with eating disorder symptoms, but it is unclear whether these associations are direct or whether a mediating effect exists. This study was conducted to investigate the prevalence of overweight and obesity, weight control concerns and behaviors, and eating disorder symptoms and to examine the mediating function of weight control concerns and behaviors on the relationship between body mass index (BMI) and eating disorder symptoms among non-clinical adolescents in China.</p> <p>Methods</p> <p>A cross-sectional survey among 2019 adolescent girls and 1525 adolescent boys in the 7th, 8th, 10th and 11th grades from seven cities in China was conducted. Information on weight control concerns and behaviors, and eating disorder symptoms (Eating Disorder Inventory-3) were collected from the adolescents using a self-administrated questionnaire.</p> <p>Results</p> <p>Weight control concerns and behaviors, and eating disorder symptoms were prevalent among the study population. A high proportion of adolescents scored at or above the threshold on the eating disorder inventory (EDI) subscale such as bulimia, interoceptive deficits, perfectionism, and maturity fears, which indicated eating disorder symptoms. High BMI was significantly associated with high score of drive for thinness, body dissatisfaction, bulimia, low self-esteem, interceptive deficits and maturity fears, so do perceived body weight status. Almost all weight control concerns and behaviors we investigated were significantly associated with high EDI subscale scores. When weight control concerns were added to the model, as shown in the model, the association between BMI and tendency of drive to thinness and bulimia was attenuated but still kept significant. The association between BMI and body dissatisfaction were no further significant. The association of BMI and drive for thinness, body dissatisfaction and bulimia was considerably weaker than when weight control behaviors were not included.</p> <p>Conclusions</p> <p>Weight control concerns and behaviors may be mediators of the association between BMI and eating disorder symptoms. Interpretation of these weight control problems is crucial to develop culturally appropriate educational and intervention programs for adolescents.</p

    Thermal Decomposition of Co-Doped Calcium Tartrate and Use of the Products for Catalytic Chemical Vapor Deposition Synthesis of Carbon Nanotubes.

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    Thermal decomposition of Co-doped calcium tartrate in an inert atmosphere or air was studied using thermogravimetric analysis and X-ray absorption fine structure (XAFS) spectroscopy. It was shown that the powder substance containing 4 at.% of cobalt completely decomposes within 650-730 °C, depending on the environment, and the formation of Co clusters does not proceed before 470 °C. The products of decomposition were characterized by transmission electron microscopy, XAFS, and X-ray photoelectron spectroscopy. Surfaceoxidized Co metal nanoparticles as large as ∼5.6 ( 1.2 nm were found to form in an inert atmosphere, while the annealing in air led to a wide distribution of diameters of the nanoparticles, with the largest nanoparticles (30-50 nm) mainly present as a Co3O4 phase. It was found that the former nanoparticles catalyze the growth of CNTs from alcohol while a reducing atmosphere is required for activation of the latter nanoparticles. We propose the scheme of formation of CaO-supported catalyst from Co-doped tartrate, depending on the thermal decomposition conditions

    Interactions between four species in a complex wildlife: livestock disease community : implications for Mycobacterium bovis maintenance and transmission

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    Livestock diseases such as bovine tuberculosis can have considerable negative effects on human health and economic activity. Wildlife reservoirs often hinder disease eradication in sympatric livestock populations. Therefore, quantifying interactions between wildlife and livestock is an important aspect of understanding disease persistence. This study was conducted on an extensive cattle farm in southwest Spain, where cattle, domestic pigs, wild boar and red deer are considered to be part of a tuberculosis host community. We tested the hypothesis that the frequency of both types of interactions would be greater at food and water sites, due to the aggregation of individuals from multiple species at these locations. We measured direct and indirect interactions between individuals using GPS and proximity loggers. Over 57,000 direct interactions were recorded over a 2-year period, of which 875 (1.5 %) occurred between different species and 216 (0.38 %) occurred between wildlife and livestock. Most direct and indirect interactions occurred at water sites. Over 90 % of indirect interactions between wildlife and livestock took place within the estimated 3-day environmental survival time of Mycobacterium bovis in this habitat. Red deer home ranges and daily activity patterns revealed significant spatial and temporal overlaps with cattle, particularly in autumn. Suids and red deer also cross the farm boundary regularly, introducing a between-farm interaction risk. The infrequent occurrence of direct interactions between individuals from different species suggests that they are unlikely to be the sole mode of disease transmission and that indirect interactions may play an important role
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