Higher vitamin D dietary intake is associated with lower risk of alzheimer's disease: a 7-year follow-up

BACKGROUND: Hypovitaminosis D is associated with cognitive decline among older adults. The relationship between vitamin D intakes and cognitive decline is not well understood. Our objective was to determine whether the dietary intake of vitamin D was an independent predictor of the onset of dementia within 7 years among women aged 75 years and older.METHODS: Four hundred and ninety-eight community-dwelling women (mean, 79.8 3.8 years) free of vitamin D supplements from the EPIDemiology of OSteoporosis Toulouse cohort study were divided into three groups according to the onset of dementia within 7 years (ie, no dementia, Alzheimer\u27s disease [AD], or other dementias). Baseline vitamin D dietary intakes were estimated from self-administered food frequency questionnaire. Age, body mass index, initial cognitive performance, education level, physical activity, sun exposure, disability, number of chronic diseases, hypertension, depression, use of psychoactive drugs, and baseline season were considered as potential confounders. RESULTS: Women who developed AD (n = 70) had lower baseline vitamin D intakes (mean, 50.3 19.3 mug/wk) than nondemented (n = 361; mean intake = 59.0 29.9 mug/wk, p = .027) or those who developed other dementias (n = 67; mean intake = 63.6 38.1 mug/wk, p = .010). There was no difference between other dementias and no dementia (p = .247). Baseline vitamin D dietary intakes were associated with the onset of AD (adjusted odds ratio = 0.99 [95% confidence interval = 0.98-0.99], p = .041) but not with other dementias (p = .071). Being in the highest quintile of vitamin D dietary intakes was associated with a lower risk of AD compared with the lower 4 quintiles combined (adjusted odds ratio = 0.23 [95% confidence interval = 0.08-0.67], p = .007). CONCLUSIONS: Higher vitamin D dietary intake was associated with a lower risk of developing AD among older women

Efficient and perfect state transfer in quantum chains

We present a communication protocol for chains of permanently coupled qubits which achieves perfect quantum state transfer and which is efficient with respect to the number chains employed in the scheme. The system consists of $M$ uncoupled identical quantum chains. Local control (gates, measurements) is only allowed at the sending/receiving end of the chains. Under a quite general hypothesis on the interaction Hamiltonian of the qubits a theorem is proved which shows that the receiver is able to asymptotically recover the messages by repetitive monitoring of his qubits.Comment: 6 pages, 2 figures; new material adde

The Trans-Pacific Partnership Agreement: Looking Ahead to the Next Steps

Pressure has been building for the conclusion of the 12-country Trans-Pacific Partnership (TPP) negotiations. Getting the deal done is important, but the TPP is not just another free trade agreement (FTA). It represents the chance to set a trade agenda for the future across a wide range of topics for countries throughout the Asia-Pacific region. This means that the agreement should not be settled in haste. More importantly, it also means that key decisions need to be reached about broader issues related to the institutional structure of the TPP. These decisions must be made now, before the deal is closed, on issues such as how to create the TPP as a living agreement, the formation of a TPP Secretariat, and the clarification of entry conditions for future members such as the People’s Republic of China (PRC). These choices must be made deliberately and carefully even while officials are struggling with reaching closure on the most highly sensitive issues still remaining in the agreement. It will not be easy, but wise decisions are necessary now to ensure the long-term success of the TPP

Dietary Vitamin D Intake and Muscle Mass in Older Women. Results from a Cross-Sectional Analysis of the Epidos Study

Objectives: Vitamin D intake may prevent physical performance decline through prevention of muscle mass loss. Our objective was to determine whether low dietary intakes were associated with low muscle mass (MM). Design and participants: Cross-sectional analysis of 1989 community-dwelling women (mean age 80.5 +/- 3.8years) from the EPIDemiologie de l\u27OSteoporose (EPIDOS) study were assessed at baseline. Measurements: Low intakes of vitamin D (<70 mu g/week) were estimated from the weekly dietary vitamin D intakes (self-administered food frequency questionnaire). Low MM was defined according to the appendicular skeletal muscle mass index assessed using Dual Energy X-ray Absorptiometry, divided by square height of less than 5.45 kg/m(2). Usual gait speed defined physical performance. Age, sun exposure, co-morbidities, education level, living arrangements, recreational physical activity, dietary protein and calcium intakes, bone mineral density, handgrip strength, and body mass index were considered as potential confounders. Multivariate logistic regression analyses assessed the association between low vitamin D intakes and low MM. Results: Two-hundred and nine (10.5%) women with low MM were compared to 1,780 women with normal MM. In final model, obesity/overweight (Adjusted Odds Ratios, aOR=0.09; 95%CI [0.05-0.17]), malnutrition (aOR=3.90; 95%CI [2.74-5.54]) and low handgrip strength (aOR=2.33; 95%CI [1.44-3.77]; p<0.001) were statistically associated with a low MM status. Conclusion: No association with low MM has been reported regarding low dietary intakes of vitamin D

Anisotropic Magnetoresistance in Ga1−x_{1-x}Mnx_xAs

We have measured the magnetoresistance in a series of Ga$_{1-x}$Mn$_x$As samples with 0.033$\le x \le$ 0.053 for three mutually orthogonal orientations of the applied magnetic field. The spontaneous resistivity anisotropy (SRA) in these materials is negative (i.e. the sample resistance is higher when its magnetization is perpendicular to the measuring current than when the two are parallel) and has a magnitude on the order of 5% at temperatures near 10K and below. This stands in contrast to the results for most conventional magnetic materials where the SRA is considerably smaller in magnitude for those few cases in which a negative sign is observed. The magnitude of the SRA drops from its maximum at low temperatures to zero at T$_C$ in a manner that is consistent with mean field theory. These results should provide a significant test for emerging theories of transport in this new class of materials.Comment: 4 pages with 4 figures. Submitted to Physical Review

Sarcopenia and cognitive impairment in elderly women: results from the EPIDOS cohort

BACKGROUND: common pathophysiological pathways are shared between age-related body composition changes and cognitive impairment. OBJECTIVE: evaluate whether current operative sarcopenia definitions are associated with cognition in community-dwelling older women. DESIGN: cross-sectional analyses. SUBJECTS: a total of 3,025 women aged 75 years and older. MEASUREMENTS: body composition (assessed by dual energy X-ray absorptiometry) and cognition (measured by short portable mental status questionnaire) were obtained in all participants. Multivariate logistic regression models assessed the association of six operative definitions of sarcopenia with cognitive impairment. Gait speed (GS, measured over a 6-meter track at usual pace) and handgrip strength (HG, measured by a hand-held dynamometer) were considered additional factors of interest. RESULTS: a total of 492 (16.3%) women were cognitively impaired. The prevalence of sarcopenia ranged from 3.3 to 18.8%. No sarcopenia definition was associated with cognitive impairment after controlling for potential confounders. To proof consistency, the analyses were performed using GS and HG, two well-established predictors of cognitive impairment. Low GS [odds ratio (OR) 2.42, 95% confidence interval (CI) 1.72-3.40] and low HG (OR: 1.81, 95% CI: 1.33-2.46) were associated with cognitive impairment. CONCLUSION: no significant association was evidenced between different operative sarcopenia definitions and cognitive impairment. The study suggests that the association between physical performance and cognitive impairment in not mediated by sarcopenia

Signatures of High-Intensity Compton Scattering

We review known and discuss new signatures of high-intensity Compton scattering assuming a scenario where a high-power laser is brought into collision with an electron beam. At high intensities one expects to see a substantial red-shift of the usual kinematic Compton edge of the photon spectrum caused by the large, intensity dependent, effective mass of the electrons within the laser beam. Emission rates acquire their global maximum at this edge while neighbouring smaller peaks signal higher harmonics. In addition, we find that the notion of the centre-of-mass frame for a given harmonic becomes intensity dependent. Tuning the intensity then effectively amounts to changing the frame of reference, going continuously from inverse to ordinary Compton scattering with the centre-of-mass kinematics defining the transition point between the two.Comment: 25 pages, 16 .eps figure

Polarized light bursts from kicked quantum rings

Non-equilibrium quantum rings emit circular polarized subterahertz radiation with a polarization degree controllable on nano- to picosecond time scales. This we conclude using a theory developed here for the time-dependent detection of the circular polarization of polychromatic radiations, valid for time scales comparable to the reciprocal of characteristic emission frequencies. The theory is applied to driven quantum rings whereby the influence of radiative and non-radiative processes on the properties of the emitted light is incorporated.Comment: 4 pages, 2 figures; submitted to Phys. Rev. Let