The Geometric Phase and Gravitational Precession of D-Branes

We study Berry's phase in the D0-D4-brane system. When a D0-brane moves in the background of D4-branes, the first excited states undergo a holonomy described by a non-Abelian Berry connection. At weak coupling this is an SU(2) connection over R^5, known as the Yang monopole. At strong coupling, the holonomy is recast as the classical gravitational precession of a spinning particle. The Berry connection is the spin connection of the near-horizon limit of the D4-branes, which is a continuous deformation of the Yang and anti-Yang monopole.Comment: 23 pages; v3: typos correcte

The role of self-care interventions on men’s health-seeking behaviours to advance their sexual and reproductive health and rights

Background: Self-care interventions are influencing people’s access to, expectation and understanding of healthcare beyond formal health delivery systems. In doing so, self-care interventions could potentially improve health-seeking behaviours. While many men proactively engage in maintaining and promoting their health, the focus on men’s health comes from the recognition, at least partially, that male socialization and social norms can induce men and boys to have a lower engagement in institutionalized public health entities and systems around their sexual and reproductive health and rights, that could impact negatively on themselves, their partners and children. Main text: A research agenda could consider the ways that public health messaging and information on self care practices for sexual and reproductive health and rights could be tailored to reflect men’s lived realities and experiences. Three examples of evidence-based self-care interventions related to sexual and reproductive health and rights that men can, and many do, engage in are briefly discussed: condom use, HIV self-testing and use of telemedicine and digital platforms for sexual health. We apply four core elements that contribute to health, including men’s health (people-centred approaches, quality health systems, a safe and supportive enabling environment, and behaviour-change communication) to each intervention where further research can inform normative guidance. Conclusion: Engaging men and boys and facilitating their participation in self care can be an important policy intervention to advance global sexual and reproductive health and rights goals. The longstanding model of men neglecting or even sabotaging their wellbeing needs to be replaced by healthier lifestyles, which requires understanding how factors related to social support, social norms, power, academic performance or employability conditions, among others, influence men’s engagement with health services and with their own self care practices

Affine extension of noncrystallographic Coxeter groups and quasicrystals

Unique affine extensions H^{\aff}_2, H^{\aff}_3 and H^{\aff}_4 are determined for the noncrystallographic Coxeter groups $H_2$, $H_3$ and $H_4$. They are used for the construction of new mathematical models for quasicrystal fragments with 10-fold symmetry. The case of H^{\aff}_2 corresponding to planar point sets is discussed in detail. In contrast to the cut-and-project scheme we obtain by construction finite point sets, which grow with a model specific growth parameter.Comment: (27 pages, to appear in J. Phys. A

HYPOGLYCEMIC EFFECT OF TRECULIA AFRICANA DECNE ROOT BARK IN NORMAL AND ALLOXAN-INDUCED DIABETIC RATS.

The solvent partitioned purified fractions of the hydro-acetone root bark extract of the African breadfruit (Treculia africana Decne) were evaluated for hypoglycemic activities in normal and diabetic albino rats. Fasting blood glucose levels were estimated by the use of a glucometer at pre-determined intervals after oral administration of the test extracts/fractions. Results revealed that the test fractions have only a slight effect on blood sugar level of normal rats. On short term and chronic administration in diabetic rats however, diethyl ether-soluble (DEF) and the water-soluble (WSF) fractions significantly reduced the fasting blood sugar levels (

Characterization of the series 1000 camera system

The National Ignition Facility requires a compact network addressable scientific grade CCD camera for use in diagnostics ranging from streak cameras to gated x-ray imaging cameras. Due to the limited space inside the diagnostic, an analog and digital input/output option in the camera controller permits control of both the camera and the diagnostic by a single Ethernet link. The system consists of a Spectral Instruments Series 1000 camera, a PC104+ controller, and power supply. The 4k by 4k CCD camera has a dynamic range of 70 dB with less than 14 electron read noise at a 1MHz readout rate. The PC104+ controller includes 16 analog inputs, 4 analog outputs and 16 digital input/output lines for interfacing to diagnostic instrumentation. A description of the system and performance characterization is reported

Flow climatology for physicochemical properties of dichotomous aerosol over the western North Atlantic Ocean at Bermuda

Dichotomous aerosols (nominal super- and sub-μm-diameter size fractions) in sectored on-shore flow were sampled daily from July 2006 through June 2009, at the Tudor Hill Atmospheric Observatory (THAO) on the western coast of Bermuda (32.27° N, 64.87° W) and analyzed for major chemical and physical properties. FLEXPART retroplumes were calculated for each sampling period and aerosol properties were stratified accordingly based on transport from different regions. Transport from the northeastern United States (NEUS) was associated with significantly higher (factors of 2 to 3 based on median values) concentrations of bulk particulate non-sea-salt (nss) SO42-, NO3-, and NH4+ and associated scattering and absorption at 530 nm, relative to transport from Africa (AFR) and the oceanic background. These differences were driven primarily by higher values associated with the sub-μm size fraction under NEUS flow. We estimate that 75(±3)% of the NEUS nss SO42- was anthropogenic in origin, while only 25(±9)% of the AFR nss SO42- was anthropogenic. Integrating over all transport patterns, the contribution of anthropogenic sulfate has dropped 14.6% from the early 1990s. Bulk scattering was highly correlated with bulk nss SO42- in all flow regimes but the corresponding regression slopes varied significantly reflecting differential contributions to total scattering by associated aerosol components. Absorption by super-μm aerosol in transport from the NEUS versus AFR was similar although the super-μm aerosol size fraction accounted for a relatively greater contribution to total absorption in AFR flow. Significantly greater absorption Ångström exponents (AAEs) for AFR flow reflects the wavelength dependence of absorption by mineral aerosols; lower AAEs for NEUS flow is consistent with the dominance of absorption by combustion-derived aerosols. Higher AOD associated with transport from both the NEUS and AFR relative to oceanic background flow results in a top of atmosphere direct radiative forcing on the order of −1.6 to −2.5 W m−2, respectively, showing these aerosols drive cooling. The dominance of transport from the NEUS on an annual basis coupled with the corresponding decreases in anthropogenic nss SO42- aerosols since the early 1990s implies that emission reductions in the US account for a decline in atmospheric cooling over the western North Atlantic Ocean during this period

Berry's Phase in the Presence of a Stochastically Evolving Environment: A Geometric Mechanism for Energy-Level Broadening

The generic Berry phase scenario in which a two-level system is coupled to a second system whose dynamical coordinate is slowly-varying is generalized to allow for stochastic evolution of the slow system. The stochastic behavior is produced by coupling the slow system to a heat resevoir which is modeled by a bath of harmonic oscillators initially in equilibrium at temperature T, and whose spectral density has a bandwidth which is small compared to the energy-level spacing of the fast system. The well-known energy-level shifts produced by Berry's phase in the fast system, in conjunction with the stochastic motion of the slow system, leads to a broadening of the fast system energy-levels. In the limit of strong damping and sufficiently low temperature, we determine the degree of level-broadening analytically, and show that the slow system dynamics satisfies a Langevin equation in which Lorentz-like and electric-like forces appear as a consequence of geometrical effects. We also determine the average energy-level shift produced in the fast system by this mechanism.Comment: 29 pages, RevTex, submitted to Phys. Rev.