Sterile Neutrino Hot, Warm, and Cold Dark Matter

We calculate the incoherent resonant and non-resonant scattering production of sterile neutrinos in the early universe. We find ranges of sterile neutrino masses, vacuum mixing angles, and initial lepton numbers which allow these species to constitute viable hot, warm, and cold dark matter (HDM, WDM, CDM) candidates which meet observational constraints. The constraints considered here include energy loss in core collapse supernovae, energy density limits at big bang nucleosynthesis, and those stemming from sterile neutrino decay: limits from observed cosmic microwave background anisotropies, diffuse extragalactic background radiation, and Li-6/D overproduction. Our calculations explicitly include matter effects, both effective mixing angle suppression and enhancement (MSW resonance), as well as quantum damping. We for the first time properly include all finite temperature effects, dilution resulting from the annihilation or disappearance of relativistic degrees of freedom, and the scattering-rate-enhancing effects of particle-antiparticle pairs (muons, tauons, quarks) at high temperature in the early universe.Comment: 24 pages, including 8 figures. v3: to match version in PRD, added references and numerous minor changes. High resolution color figures available at http://superbeast.ucsd.edu/~kev/nucd

Microscopic two-fluid theory of rotational constants of the OCS-H2_2 complex in 4^4He droplets

We present a microscopic quantum analysis for rotational constants of the OCS-H$_2$ complex in helium droplets using the local two-fluid theory in conjunction with path integral Monte Carlo simulations. Rotational constants are derived from effective moments of inertia calculated assuming that motion of the H$_2$ molecule and the local non-superfluid helium density is rigidly coupled to the molecular rotation of OCS and employing path integral methods to sample the corresponding H$_2$ and helium densities. The rigid coupling assumption for H$_2$-OCS is calibrated by comparison with exact calculations of the free OCS-H$_2$ complex. The presence of the H$_2$ molecule is found to induce a small local non-superfluid helium density in the second solvation shell which makes a non-negligible contribution to the moment of inertia of the complex in helium. The resulting moments of inertia for the OCS-H$_2$ complex embedded in a cluster of 63 helium atoms are found to be in good agreement with experimentally measured values in large helium droplets. Implications for analysis of rotational constants of larger complexes of OCS with multiple H$_2$ molecules in helium are discussed.Comment: 11 pages, 5 figures, accepted for publication in J. Chem. Phy

Singularity Free Inhomogeneous Models with Heat Flow

We present a class of singularity free exact cosmological solutions of Einstein's equations describing a perfect fluid with heat flow. It is obtained as generalization of the Senovilla class [1] corresponding to incoherent radiation field. The spacetime is cylindrically symmetric and globally regular.Comment: 6 pages, TeX, to appear in Class.Quant.Gra

Productivity of key informants for identifying blind children: evidence from a pilot study in Malawi.

OBJECTIVES: To determine the productivity of village-based 'key informants' (KIs) in identifying blind children. MATERIALS AND METHODS: Ngabu subdistrict (population 101,000) of Chikwawa district was divided into KI catchment areas. KIs, selected by local village leaders, were trained to register children reported to be blind or with severe visual impairment. These children were clinically assessed at designated centres. RESULTS: In total, 44 KIs were selected and trained to cover 196 villages in Ngabu. They identified and referred 151 children, 37 of whom were blind (presenting vision <3/60 best eye). Overall, village leaders tended to choose female KIs (80%) compared to male KIs (20%); however, male KIs tended to be more productive, identifying 4.22 children each (compared to 3.23 for female KIs). Male KIs were 2.7 times more likely to identify blind children compared to female KIs. Only 25% of all identified blind children of school going age were in school. CONCLUSIONS: KIs may be effective in identifying blind children in the community; however, additional work is needed to determine who will be the most effective KI in a community and whether gender roles will limit interpretation of findings from KIs activities

Sacred groves in conservation of plant biodiversity in Banaskantha district, Gujarat, India.

Nature conservation practices are very ancient tradition in India. Useful biodiversity species have much reverence in culture of our country. Sacred groves are seen through out Gujarat, having varied forms, cultural practices and belief systems. The vegetation in the groves is highly varied viz. mangroves, fresh water swamps, or other tropical forest types. Sacred&nbsp; groves represent long&nbsp;&nbsp; tradition of environmental conservation based on indigenous knowledge by the tribal communities of Banaskantha District, Gujarat, India. The study deals with the role of sacred groves in conservation of plant biodiversity in Banaskantha District, Gujarat, India. Among the 11 sacred groves surveyed, over 25 different plant species are reported. In the sacred groves surveyed, only a few are well protected while most are partially threatened due to anthropogenic pressure.&nbsp; Considering all the dimensions of sacred groves, it is clear that these groves are considered as one of the most species-rich areas for plants, birds and mammals

Type I seesaw mechanism for quasi degenerate neutrinos

We discuss symmetries and scenarios leading to quasi-degenerate neutrinos in type-I seesaw models. The existence of degeneracy in the present approach is not linked to any specific structure for the Dirac neutrino Yukawa coupling matrix $y_D$ and holds in general. Basic input is the application of the minimal flavour violation principle to the leptonic sector. Generalizing this principle, we assume that the structure of the right handed neutrino mass matrix is determined by $y_D$ and the charged lepton Yukawa coupling matrix $y_l$ in an effective theory invariant under specific groups ${\cal G}_F$ contained in the full symmetry group of the kinetic energy terms. ${\cal G}_F$ invariance also leads to specific structure for the departure from degeneracy. The neutrino mass matrix (with degenerate mass $m_0$) resulting after seesaw mechanism has a simple form ${\cal M}_\nu\approx m_0(I-p y_ly_l^T)$ in one particular scenario based on supersymmetry. This form is shown to lead to correct description of neutrino masses and mixing angles. The thermal leptogenesis after inclusion of flavour effects can account for the observed baryon asymmetry of the universe within the present scenario. Rates for lepton flavour violating processes can occur at observable levels in the supersymmetric version of the scenario.Comment: 14 pages; two figure

Indirect Searches of the Degenerate MSSM

A degenerate sfermionic particle spectrum can escape constraints from flavor physics, and at the same time evade the limits from the direct searches if the degeneracy extends to the gaugino-higgsino sector. Inspired by this, we consider a scenario where all the soft terms have an approximately common mass scale at $M_{\text{SUSY}}$, with splittings $\lesssim \mathcal{O}(10\%)$. As a result, the third generation sfermions have large to maximal (left-right) mixing, the same being the case with charginos and some sectors of the neutralino mass matrix. We study this scenario in the light of discovery of the Higgs boson with mass $\sim$ 125 GeV. We consider constraints from $B$-physics, the anomalous magnetic moment of the muon and the dark matter relic density. We find that a supersymmetric spectrum as light as 600 GeV could be consistent with all current data and also account for the observed anomalous magnetic moment of the muon within $2\sigma$. The neutralino relic density is generally too small to saturate the measured cold dark matter relic density. Direct detection limits from XENON100 and LUX put severe constraints on this scenario which will be conclusively probed by XENONnT experiment.Comment: 27 pages, 8 figures; Comments welcom

The use of Sodium Taurocholate and Crystal Violet in the Isolation of Bact. tumefaciens Sm. & Town.

In the isolation of Bacterium tumefaciens from overgrowths on apple, one of the greatest sources of contamination is that of soil organisms. These are lodged in the soil within the crevices of the convoluted gall surface. In addition the crown gall organisms frequently occur in only small numbers, making it necessary to use large amounts of tissue for isolation purposes