2,888 research outputs found
“It’s Making Memories”: A Qualitative Investigation of Family Mealtime Cognitions, Barriers and Strategies for Success of Parents and School-aged Kids
Objective: Family meals, particularly those occurring in calm environments, are associated with numerous health benefits for both children and parents. However, families often struggle to share meals, with the frequency declining as kids get older. This qualitative research study aimed to explore the factors influencing family meal behaviors.
Methods: Parents (n=38) and school-age children (n=37) participated in focus group discussions guided by Social Cognitive Theory.
Results: Content analysis results indicate that parents and children believed family meals were important, promoted communication, and strengthened family bonds. Parents and children reported that a calm, enjoyable, conflict-free mealtime environment bolstered mealtime enjoyment and increased the likelihood of regular family meals. Busy schedules were the greatest barrier to family meals identified by children and parents. Strategies for overcoming barriers to family meals identified by parents were similar to those shared by kids and included keeping mealtime conversations positive, altering schedules to accommodate family mealtime, planning ahead, using time saving strategies and recruiting kids to help with meal preparation.
Conclusion: This qualitative research study provides novel insights into parents’ and school-age children’s cognitions (e.g., beliefs, attitudes), barriers, and facilitators related to family meals. Consideration of these insights during the development of nutrition education interventions has the potential to improve intervention effectiveness in increasing family meal frequency
Neutron induced background in the COMPTEL detector on the Gamma Ray Observatory
Interactions of neutrons in a prototype of the Compton imaging telescope (COMPTEL) gamma ray detector for the Gamma Ray Observatory were studied to determine COMPTEL's sensitivity as a neutron telescope and to estimate the gamma ray background resulting from neutron interactions. The IUCF provided a pulsed neutron beam at five different energies between 18 and 120 MeV. These measurements showed that the gamma ray background from neutron interactions is greater than previously expected. It was thought that most such events would be due to interactions in the upper detector modules of COMPTEL and could be distinguished by pulse shape discrimination. Rather, the bulk of the gamma ray background appears to be due to interactions in passive material, primarily aluminum, surrounding the D1 modules. In a considerable fraction of these interactions, two or more gamma rays are produced simultaneously, with one interacting in the D1 module and the other interacting in the module of the lower (D2) detector. If the neutron interacts near the D1 module, the D1 D2 time of flight cannot distinguish such an event from a true gamma ray event. In order to assess the significance of this background, the flux of neutrons in orbit has been estimated based on observed events with neutron pulse shape signature in D1. The strength of this neutron induced background is estimated. This is compared with the rate expected from the isotropic cosmic gamma ray flux
Comparisons of the Metabolic Intensities at Heart Rate, Gas Exchange, and Ventilatory Thresholds
International Journal of Exercise Science 13(2): 455-469, 2020. PURPOSE: This study compared the O2corresponding to the critical heart rate (CHRO2) and the physical working capacity at the heart rate fatigue threshold (PWChrtO2) to the gas exchange threshold (GET), ventilatory threshold (VT), and respiratory compensation point (RCP). METHODS: Nine runners (mean ±SD, age 23 ±3 years) completed an incremental test on a treadmill to determine O2peak, GET, VT, and RCP. The CHRO2and PWChrtO2were determined from 4 separate constant velocity treadmill runs to exhaustion and HR and time to exhaustion were recorded. Differences among the thresholds were examined with a one-way repeated measures ANOVA (p≤ 0.05). RESULTS: The GET (38.44 mL×kg-1×min-1, 78%O2peak), VT (37.36 mL×kg-1×min-1, 76%O2peak), and PWChrtO2 (38.26 mL×kg-1×min-1, 77%O2peak) were not different, but were lower than the RCP (44.70 mL×kg-1×min-1, 90%O2peak;p= 0.010, p\u3c 0.001,p= 0.001, respectively). The CHRO2(40.09 mL×kg-1×min-1, 81%O2peak) was not different from the GET (p= 1.000), VT (p= 0.647), PWChrtO2(p =1.000), or RCP (p= 0.116). CONCLUSIONS: These results indicated that the initial metabolic intensities at CHR and PWChrtlie within the heavy and moderate intensity domains, respectively. Therefore, the PWChrtmay provide a relative intensity more appropriate for untrained populations, while the CHR may be more appropriate for more trained populations
Colour superconductivity in finite systems
In this paper we study the effect of finite size on the two-flavour colour
superconducting state. As well as restricting the quarks to a box, we project
onto states of good baryon number and onto colour singlets, these being
necessary restrictions on any observable ``quark nuggets''. We find that
whereas finite size alone has a significant effect for very small boxes, with
the superconducting state often being destroyed, the effect of projection is to
restore it again. The infinite-volume limit is a good approximation even for
quite small systems.Comment: 14 pages RevTeX4, 12 eps figure
A Parametrization of Bipartite Systems Based on SU(4) Euler Angles
In this paper we give an explicit parametrization for all two qubit density
matrices. This is important for calculations involving entanglement and many
other types of quantum information processing. To accomplish this we present a
generalized Euler angle parametrization for SU(4) and all possible two qubit
density matrices. The important group-theoretical properties of such a
description are then manifest. We thus obtain the correct Haar (Hurwitz)
measure and volume element for SU(4) which follows from this parametrization.
In addition, we study the role of this parametrization in the Peres-Horodecki
criteria for separability and its corresponding usefulness in calculating
entangled two qubit states as represented through the parametrization.Comment: 23 pages, no figures; changed title and abstract and rewrote certain
areas in line with referee comments. To be published in J. Phys. A: Math. and
Ge
Hilbert--Schmidt volume of the set of mixed quantum states
We compute the volume of the convex N^2-1 dimensional set M_N of density
matrices of size N with respect to the Hilbert-Schmidt measure. The hyper--area
of the boundary of this set is also found and its ratio to the volume provides
an information about the complex structure of M_N. Similar investigations are
also performed for the smaller set of all real density matrices. As an
intermediate step we analyze volumes of the unitary and orthogonal groups and
of the flag manifolds.Comment: 13 revtex pages, ver 3: minor improvement
Quasi-doubly periodic solutions to a generalized Lame equation
We consider the algebraic form of a generalized Lame equation with five free
parameters. By introducing a generalization of Jacobi's elliptic functions we
transform this equation to a 1-dim time-independent Schroedinger equation with
(quasi-doubly) periodic potential. We show that only for a finite set of
integral values for the five parameters quasi-doubly periodic eigenfunctions
expressible in terms of generalized Jacobi functions exist. For this purpose we
also establish a relation to the generalized Ince equation.Comment: 15 pages,1 table, accepted for publication in Journal of Physics
Vegetation Type and Decomposition Priming Mediate Brackish Marsh Carbon Accumulation Under Interacting Facets of Global Change
Coastal wetland carbon pools are globally important, but their response to interacting facets of global change remain unclear. Numerical models neglect species-specific vegetation responses to sea level rise (SLR) and elevated CO2 (eCO2) that are observed in field experiments, while field experiments cannot address the long-term feedbacks between flooding and soil growth that models show are important. Here, we present a novel numerical model of marsh carbon accumulation parameterized with empirical observations from a long-running eCO2 experiment in an organic rich, brackish marsh. Model results indicate that eCO2 and SLR interact synergistically to increase soil carbon burial, driven by shifts in plant community composition and soil volume expansion. However, newly parameterized interactions between plant biomass and decomposition (i.e. soil priming) reduce the impact of eCO2 on marsh survival, and by inference, the impact of eCO2 on soil carbon accumulation
Muscular Performance and Neuromuscular Fatigue are not Sex-Dependent During Low-Load Fatiguing Bilateral Leg Extension Exercise
Purpose. This study examined the sex-related differences in muscular performance and neuromuscular (electromyographic [EMG] and mechanomyographic [MMG] amplitude [AMP] and mean power frequency [MPF]) responses during fatiguing leg extension repetitions performed at the critical load (CL). Methods. Eleven men and nine women completed one-repetition maximum (1RM) testing, repetitions to failure at 50, 60, 70, and 80% 1RM to determine CL, and repetitions to failure at CL, on separate days. The EMG and MMG, AMP and MPF signals and number of repetitions completed were recorded. Results. There were no sex-dependent responses in the %1RM that corresponded to, the number of repetitions completed at, or the neuromuscular responses during repetitions performed to failure at CL. There were time-dependent responses in EMG AMP from 25-100% of total repetitions completed, respectively. The EMG MPF and MMG MPF demonstrated fatigue-induced decreases from 50-100% and at 100% of total repetitions completed, respectively. There was no change over time for MMG AMP. Conclusions. These findings indicated men and women responded similarly to leg extension exercise performed at the CL. Further, sex-dependent responses to fatiguing exercise may be related to the amount of active muscle mass engaged in exercise and the corresponding afferent feedback that influences peripheral fatigue and central drive during fatiguing tasks
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