1,261,654 research outputs found
Transport properties of the heavy fermion superconductor PrOsSb
We have measured the electrical resistivity, thermoelectric power, Hall
coefficient, and magnetoresistance (MR) on single crystals of
PrOsSb, LaOsSb and NdOsSb. All the
transport properties in PrOsSb are similar to those in
LaOsSb and NdOsSb at high temperatures, indicating
the localized character of 4-electrons. The transverse MR both in
LaOsSb and PrOsSb tends to saturate for wide field
directions, indicating these compounds to be uncompensated metals with no open
orbit. We have determined the phase diagram of the field induced ordered phase
by the MR measurement for all the principle field directions, which indicates
an unambiguous evidence for the singlet crystalline electric
field ground state.Comment: 7 pages, 10 figures, to appear in Physical Review
The ergogenic effect of beta-alanine combined with sodium bicarbonate on high-intensity swimming performance
We investigated the effect of beta-alanine (BA) alone (study A) and in combination with sodium bicarbonate (SB) (study B) on 100- and 200-m swimming performance. In study A, 16 swimmers were assigned to receive either BA (3.2 g·day−1 for 1 week and 6.4 g·day−1 for 4 weeks) or placebo (PL; dextrose). At baseline and after 5 weeks of supplementation, 100- and 200-m races were completed. In study B, 14 were assigned to receive either BA (3.2 g·day−1 for 1 week and 6.4 g·day−1 for 3 weeks) or PL. Time trials were performed once before and twice after supplementation (with PL and SB), in a crossover fashion, providing 4 conditions: PL-PL, PL-SB, BA-PL, and BA-SB. In study A, BA supplementation improved 100- and 200-m time-trial performance by 2.1% (p = 0.029) and 2.0% (p = 0.0008), respectively. In study B, 200-m time-trial performance improved in all conditions, compared with presupplementation, except the PL-PL condition (PL-SB, +2.3%; BA-PL, +1.5%; BA-SB, +2.13% (p < 0.05)). BA-SB was not different from BA-PL (p = 0.21), but the probability of a positive effect was 78.5%. In the 100-m time-trial, only a within-group effect for SB was observed in the PL-SB (p = 0.022) and BA-SB (p = 0.051) conditions. However, 6 of 7 athletes swam faster after BA supplementation. The probability of BA having a positive effect was 65.2%; when SB was added to BA, the probability was 71.8%. BA and SB supplementation improved 100- and 200-m swimming performance. The coingestion of BA and SB induced a further nonsignificant improvement in performance
Is urinary incontinence associated with sedentary behaviour in older women? Analysis of data from the National Health and Nutrition Examination Survey
BACKGROUND: Urinary incontinence (UI) is a common geriatric syndrome associated with physical and cognitive impairments. The association between type of UI and sedentary behaviour (SB) has not been explored.
AIM: To determine association between moderate-severe UI, or any stress UI (SUI) or any urgency UI (UUI) and SB in community-dwelling older women.
METHODS: Women aged 60 and over from the 2005-2006 cycle of the National Health and Nutrition Examination Survey (NHANES) with objectively measured (accelerometer) and self-reported SB and UI data were selected. Multivariate models exploring association between moderate-severe UI and SB, or SUI and SB, or UUI and SB were analysed using logistic regression adjusted for factors associated with UI.
RESULTS: In the overall sample of 459 older women, 23.5% reported moderate-severe UI, 50.5% reported any SUI and 41.4% reported any UUI. In bivariate analysis objectively measured proportion of time in SB was associated with moderate-severe UI and UUI (p = 0.014 and p = 0.047) but not SUI. Average duration of SB bouts in those with moderate-severe UI or any SUI was no longer than older women reporting no continence issues, but it was significantly (19%) longer in older women with any UUI (mean difference 3.2 minutes; p = 0.001). Self-reported SB variables were not associated with any type of UI. Multivariate analysis showed an association between UUI and a longer average duration of SB bouts (OR = 1.05, 95% CI = 1.01-1.09, p = 0.006) but no association with moderate-severe UI or SUI.
CONCLUSION: UUI was significantly associated with increased average duration of SB bouts in community-dwelling older women. The importance of objective measurement of SB is highlighted and suggests that decreasing time in prolonged sitting may be a target intervention to reduce UUI. Future studies are required to further explore the association between SB and incontinence
Prevalence of Physical Activity and Sedentary Behavior among Chinese Children and Adolescents: Variations, Gaps, and Recommendations
Physical-activity (PA) and sedentary-behavior (SB) assessment is of particular importance in the promotion of health in young people. However, there is no comprehensive overview of PA and SB from national surveys among Chinese children and adolescents. Following a literature search for Chinese national health surveys, 11 papers from six national surveys were found. Of the included studies, the majority applied self-reported questionnaires to estimate the prevalence of PA and SB. Owing to different definitions of the prevalence of PA and SB and various measures, a large variation in prevalence of PA and SB was observed. Such variations were attributable to methodological and practical issues. This study highlights the current gaps in estimating the national prevalence of PA and SB among Chinese children and adolescents, which should be addressed. To improve the quality of PA and SB surveillance, standardized measurement protocols to estimate the prevalence of PA and SB more accurately among Chinese children and adolescents are urgently required
Joint effect of physical activity and sedentary behaviour on cardiovascular risk factors in Chilean adults
Background:
To investigate the associations between combined categories of moderate-to-vigorous physical activity (MVPA) and sedentary behaviour (SB) with markers of adiposity and cardiovascular risk in adults.
Methods:
Overall, 5040 participants (mean age 46.4 years and 59.3% women) from the cross-sectional Chilean National Health Survey 2009–2010 were included in this study. MVPA and SB were measured using the Global Physical Activity questionnaire. Four categories were computed using MVPA- and SB-specific cut-offs (‘High-SB & Active’, ‘Low-SB & Active’, ‘High-SB & Inactive’ and ‘Low-SB & Inactive’).
Results:
Compared to the reference group (‘High-SB & Inactive’), those in ‘High-SB & Active’ and ‘Low-SB & Active’ were less likely to have an obese BMI (OR: 0.67 [0.54; 0.85], P = 0.0001 and 0.74 [0.59; 0.92] P = 0.0007, respectively) and less likely to have metabolic syndrome (OR: 0.63 [0.49; 0.82], P < 0.0001 and 0.72 [0.57; 0.91], P = 0.007), central obesity (OR: 0.79 [0.65; 0.96], P = 0.016 and 0.71 [0.59; 0.84], P < 0.0001), diabetes (OR: 0.45 [0.35; 0.59], P < 0.0001 and 0.44 [0.34; 0.56], P < 0.0001) and hypertension (OR: 0.52 [0.43; 0.63], P < 0.0001 and 0.60 [0.50; 0.72], P < 0.0001), respectively.
Conclusions:
Being physically active and spending less time in SBs was associated with lower adiposity and improvements in cardiovascular risk factors
Distortion of boundary sets under inner functions and applications
10 pages, no figures.-- MSC2000 codes: 30C85, 30D50.MR#: MR1183352 (93k:30014)Zbl#: Zbl 0765.30011An inner function is a bounded holomorphic function from the unit disc of the complex plane such that the radial boundary values have modulus 1 a.e. . If is a Borel subset of we also define f(E)=\{e\sp{i\theta}/\lim\sb{r\to 1} f(re\sp{i\theta}) exists and belongs to . Let M\sb \alpha, \text{cap}\sb \alpha and dim denote respectively the -dimensional content, - dimensional capacity and the Hausdorff dimension. In relation to the available results the authors in this paper prove that if is inner, , and is a Borel subset of then M\sb \alpha(f\sp{-1}(E)) \geq C\sb \alpha M\sb \alpha(E) and for , \text{cap}\sb \alpha(f\sp{-1}(E)) \geq C\sb \alpha \text{cap}\sb \alpha(E). An immediate consequence of course is \dim(f\sp{-1}(E))\geq \dim E. They also give examples to show that the inequalities cannot be reversed [source: Zentralblatt MATH].The first author was supported in part by a grant from CICYT, Ministerio de Educación y Ciencia, Spain.Publicad
Theory of Adsorption and Surfactant Effect of Sb on Ag (111)
We present first-principles studies of the adsorption of Sb and Ag on clean
and Sb-covered Ag (111). For Sb, the {\it substitutional} adsorption site is
found to be greatly favored with respect to on-surface fcc sites and to
subsurface sites, so that a segregating surface alloy layer is formed. Adsorbed
silver adatoms are more strongly bound on clean Ag(111) than on Sb-covered Ag.
We propose that the experimentally reported surfactant effect of Sb is due to
Sb adsorbates reducing the Ag adatom mobility. This gives rise to a high
density of Ag islands which coalesce into regular layers.Comment: RevTeX 3.0, 11 pages, 0 figures] 13 July 199
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