Mode-coupling theory for multiple-time correlation functions of tagged particle densities and dynamical filters designed for glassy systems

The theoretical framework for higher-order correlation functions involving multiple times and multiple points in a classical, many-body system developed by Van Zon and Schofield [Phys. Rev. E 65, 011106 (2002)] is extended here to include tagged particle densities. Such densities have found an intriguing application as proposed measures of dynamical heterogeneities in structural glasses. The theoretical formalism is based upon projection operator techniques which are used to isolate the slow time evolution of dynamical variables by expanding the slowly-evolving component of arbitrary variables in an infinite basis composed of the products of slow variables of the system. The resulting formally exact mode-coupling expressions for multiple-point and multiple-time correlation functions are made tractable by applying the so-called N-ordering method. This theory is used to derive for moderate densities the leading mode coupling expressions for indicators of relaxation type and domain relaxation, which use dynamical filters that lead to multiple-time correlations of a tagged particle density. The mode coupling expressions for higher order correlation functions are also succesfully tested against simulations of a hard sphere fluid at relatively low density.Comment: 15 pages, 2 figure

Changes in mean-squared charge radii and magnetic moments of Tl 179-184 measured by in-source laser spectroscopy

Hyperfine structure and isotope shifts have been measured for the ground and isomeric states in the neutron-deficient isotopes Tl179-184 using the 276.9-nm transition. The experiment has been performed at the CERN-Isotope Separator On-Line facility using the in-source resonance-ionization laser spectroscopy technique. Spins for the ground states in Tl179,181,183 have been determined as I=1/2. Magnetic moments and changes in the nuclear mean-square charge radii have been deduced. By applying the additivity relation for magnetic moments of the odd-odd Tl nuclei the leading configuration assignments were confirmed. A deviation of magnetic moments for isomeric states in Tl182,184 from the trend of the heavier Tl nuclei is observed. The charge radii of the ground states of the isotopes Tl179-184 follow the trend for isotonic (spherical) lead nuclei. The noticeable difference in charge radii for ground and isomeric states of Tl183,184 has been observed, suggesting a larger deformation for the intruder-based 9/2- and 10- states compared to the ground states. An unexpected growth of the isomer shift for Tl183 has been found

Extensive Copy-Number Variation of Young Genes across Stickleback Populations

MM received funding from the Max Planck innovation funds for this project. PGDF was supported by a Marie Curie European Reintegration Grant (proposal nr 270891). CE was supported by German Science Foundation grants (DFG, EI 841/4-1 and EI 841/6-1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

β-delayed fission and α decay of At196

A nuclear-decay spectroscopy study of the neutron-deficient isotope At196 is reported where an isotopically pure beam was produced using the selective Resonance Ionization Laser Ion Source and On-Line Isotope Mass Separator (CERN). The fine-structure α decay of At196 allowed the low-energy excited states in the daughter nucleus Bi192 to be investigated. A β-delayed fission study of At196 was also performed. A mixture of symmetric and asymmetric fission-fragment mass distributions of the daughter isotope Po196 (populated by β decay of At196) was deduced based on the measured fission-fragment energies. A βDF probability PβDF(At196)=9(1)×10−5 was determined

Exposure to p,p′-DDE: A Risk Factor for Type 2 Diabetes

BACKGROUND: Persistent organic pollutants (POPs), such as PCBs, DDT and dioxins have in several cross-sectional studies shown strong associations with type 2 diabetes mellitus. Reversed causality can however not be excluded. The aim of this case-control study was to evaluate whether POPs concentration is a risk factor for type 2 diabetes. METHODOLOGY/PRINCIPAL FINDINGS: A case-control study was performed within a well-defined cohort of women, age 50-59 years, from the Southern part of Sweden. Biomarkers for POP exposure, 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE) were analyzed in stored serum samples, which were collected at the baseline examination when the cohort was established. For 107 out of the 371 cases, serum samples were stored at least three years before their type 2 diabetes was diagnosed. In this data set, CB-153 and p,p'-DDE were not associated with an increased risk to develop type 2 diabetes. However, when only the cases (n = 39) that were diagnosed more than six years after the baseline examination and their controls were studied, the women in the highest exposed quartile showed an increased risk to develop type 2 diabetes (OR of 1.6 [95% 0.61, 4.0] for CB-153 and 5.5 [95% CI 1.2, 25] for p,p'-DDE). CONCLUSIONS/SIGNIFICANCE: The results from the present case-control study, including a follow-up design, confirms that p,p'-DDE exposure can be a risk factor for type 2 diabetes

Exercise training favors increased insulin-stimulated glucose uptake in skeletal muscle in contrast to adipose tissue: a randomized study using FDG PET imaging

Physical exercise increases peripheral insulin sensitivity, but regional differences are poorly elucidated in humans. We investigated the effect of aerobic exercise training on insulin-stimulated glucose uptake in five individual femoral muscle groups and four different adipose tissue regions, using dynamic (femoral region) and static (abdominal region) 2-deoxy-2-[18F]fluoro-d-glucose (FDG) PET/CT methodology during steady-state insulin infusion (40 mU·m−2·min−1). Body composition was measured by dual X-ray absorptiometry and MRI. Sixty-one healthy, sedentary [V̇o2max 36(5) ml·kg−1·min−1; mean(SD)], moderately overweight [BMI 28.1(1.8) kg/m2], young [age: 30(6) yr] men were randomized to sedentary living (CON; n = 17 completers) or moderate (MOD; 300 kcal/day, n = 18) or high (HIGH; 600 kcal/day, n = 18) dose physical exercise for 11 wk. At baseline, insulin-stimulated glucose uptake was highest in femoral skeletal muscle followed by intraperitoneal visceral adipose tissue (VAT), retroperitoneal VAT, abdominal (anterior + posterior) subcutaneous adipose tissue (SAT), and femoral SAT ( P &lt; 0.0001 between tissues). Metabolic rate of glucose increased similarly (∼30%) in the two exercise groups in femoral skeletal muscle (MOD 24[9, 39] μmol·kg−1·min−1, P = 0.004; HIGH 22[9, 35] μmol·kg−1·min−1, P = 0.003) (mean[95% CI]) and in five individual femoral muscle groups but not in femoral SAT. Standardized uptake value of FDG decreased ∼24% in anterior abdominal SAT and ∼20% in posterior abdominal SAT compared with CON but not in either intra- or retroperitoneal VAT. Total adipose tissue mass decreased in both exercise groups, and the decrease was distributed equally among subcutaneous and intra-abdominal depots. In conclusion, aerobic exercise training increases insulin-stimulated glucose uptake in skeletal muscle but not in adipose tissue, which demonstrates some interregional differences. </jats:p

Physical activity and fat-free mass during growth and in later life

Physical activity may be a way to increase and maintain fat-free mass (FFM) in later life, similar to the prevention of fractures by increasing peak bone mass.A study is presented of the association between FFM and physical activity in relation to age.In a cross-sectional study, FFM was analyzed in relation to physical activity in a large participant group as compiled in the International Atomic Energy Agency Doubly Labeled Water database. The database included 2000 participants, age 3–96 y, with measurements of total energy expenditure (TEE) and resting energy expenditure (REE) to allow calculation of physical activity level (PAL = TEE/REE), and calculation of FFM from isotope dilution.PAL was a main determinant of body composition at all ages. Models with age, fat mass (FM), and PAL explained 76\% and 85\% of the variation in FFM in females and males &lt; 18 y old, and 32\% and 47\% of the variation in FFM in females and males ≥ 18 y old, respectively. In participants &lt; 18 y old, mean FM-adjusted FFM was 1.7 kg (95\% CI: 0.1, 3.2 kg) and 3.4 kg (95\% CI: 1.0, 5.6 kg) higher in a very active participant with PAL = 2.0 than in a sedentary participant with PAL = 1.5, for females and males, respectively. At age 18 y, height and FM–adjusted FFM was 3.6 kg (95\% CI: 2.8, 4.4 kg) and 4.4 kg (95\% CI: 3.2, 5.7 kg) higher, and at age 80 y 0.7 kg (95\% CI: −0.2, 1.7 kg) and 1.0 kg (95\% CI: −0.1, 2.1 kg) higher, in a participant with PAL = 2.0 than in a participant with PAL = 1.5, for females and males, respectively.If these associations are causal, they suggest physical activity is a major determinant of body composition as reflected in peak FFM, and that a physically active lifestyle can only partly protect against loss of FFM in aging adults