The changing social environment for adolescents in Kassena-Nankana District of northern Ghana: Implications for reproductive behavior

This study reports on a primarily qualitative investigation of adolescent reproductive behavior in the Kassena-Nankana District, a rural isolated area in northern Ghana, where traditional patterns of marriage, family formation, and social organization persist. The study is based on in-depth interviews and focus groups with adolescents, parents, chiefs and traditional leaders, teachers, youth leaders, and health workers, supplemented by quantitative data from the 1996 wave of a panel survey of reproductive-aged women conducted by the Navrongo Health Research Centre. The social environment faced by adolescent boys and girls in the Kassena-Nankana District and its links to reproductive behavior are described. The principal question is whether even in this remote, rural area, the environment has been altered in ways that have undermined traditional sexual and reproductive patterns. The survey data indicate a considerable increase in educational attainment among younger women. In addition, it appears that the incidence of early marriage has begun to decline. The qualitative data suggest that social institutions, systems, and practices such as female circumcision, which previously structured the lives of adolescent boys and girls, have eroded, leading to an apparent increase in premarital sexual activity. The implications of these developments for adolescent health and well-being in the District are discussed

Interferon Alpha in Systemic Lupus Erythematosus

The pleiotropic cytokine interferon alpha is involved in multiple aspects of lupus etiology and pathogenesis. Interferon alpha is important under normal circumstances for antiviral responses and immune activation. However, heightened levels of serum interferon alpha and expression of interferon response genes are common in lupus patients. Lupus-associated autoantibodies can drive the production of interferon alpha and heightened levels of interferon interfere with immune regulation. Several genes in the pathways leading to interferon production or signaling are associated with risk for lupus. Clinical and cellular manifestations of excess interferon alpha in lupus combined with the genetic risk factors associated with interferon make this cytokine a rare bridge between genetic risk and phenotypic effects. Interferon alpha influences the clinical picture of lupus and may represent a therapeutic target. This paper provides an overview of the cellular, genetic, and clinical aspects of interferon alpha in lupus

Multiple modalities converge on a common gate to control K2P channel function

K2P potassium channels play important roles in the regulation of neuronal excitability. K2P channels are gated chemical, thermal, and mechanical stimuli, and the present study identifies and characterizes a common molecular gate that responds to all different stimuli, both activating and inhibitory ones

Characterization of herpes simplex virus clinical isolate Y3369 as a glycoprotein G variant and its bearing on virus typing

<p>Abstract</p> <p>Background</p> <p>Herpes simplex viruses exist as two major serotypes, type 1 (HSV-1) and type 2 (HSV-2). Determination of type, either HSV-1 or HSV-2, is important in accurate diagnosis and clinical control of transmission. Several tests are available for typing HSV, including a monoclonal antibody specific for glycoprotein G and several PCR assays.</p> <p>Findings</p> <p>A clinical isolate was identified as herpes simplex virus, but tested negative for both HSV-1 and HSV-2 antigens using type-specific monoclonal antibody assays. The isolate was determined to be HSV-1 by PCR analysis. A mutation which likely caused the monoclonal antibody non-reactivity was found in glycoprotein G. Phylogenetic analysis revealed two groups of HSV, one with the mutation and one without. Three population studies examining mutations in HSV-1 glycoprotein G were analyzed by chi-squared test. To this point, the epitope which the monoclonal antibody recognizes was only found in HSV-1 isolates from human European populations (<it>p </it>< 0.0001).</p> <p>Conclusions</p> <p>These findings suggest that the PCR-based methods for HSV typing may be more useful than the standard monoclonal antibody test in areas of the world where the variant in glycoprotein G is more prevalent.</p

Mercury Orbiter: Report of the Science Working Team

The results are presented of the Mercury Orbiter Science Working Team which held three workshops in 1988 to 1989 under the auspices of the Space Physics and Planetary Exploration Divisions of NASA Headquarters. Spacecraft engineering and mission design studies at the Jet Propulsion Lab were conducted in parallel with this effort and are detailed elsewhere. The findings of the engineering study, summarized herein, indicate that spin stabilized spacecraft carrying comprehensive particles and fields experiments and key planetology instruments in high elliptical orbits can survive and function in Mercury orbit without costly sun shields and active cooling systems

Multiple scattering of polarized radiation by non-spherical grains: first results

We present the first numerical radiative transfer simulation of multiple light scattering in dust configurations containing aligned non-spherical (spheroidal) dust grains. Such models are especially important if one wants to explain the circular polarization of light, observed in a variety of astronomical objects. The radiative transfer problem is solved on the basis of the Monte Carlo method. Test simulations, confirming the correct numerical implementation of the scattering mechanism, are presented. As a first application, we investigate the linear and circular polarization of light coming from a spherical circumstellar shell. This shell contains perfectly aligned prolate or oblate spheroidal grains. The most remarkable features of the simulated linear polarization maps are so-called polarization null points where the reversal of polarization occurs. They appear in the case when the grain alignment axis is perpendicular to the line of sight. The maps of circular polarization have a sector-like structure with maxima at the ends of lines inclined to the grain alignment axis by \pm 45\degr.Comment: 13 pages, 14 figures, accepted by A&

Enzymatic engineering of the porcine genome with transposons and recombinases

<p>Abstract</p> <p>Background</p> <p>Swine is an important agricultural commodity and biomedical model. Manipulation of the pig genome provides opportunity to improve production efficiency, enhance disease resistance, and add value to swine products. Genetic engineering can also expand the utility of pigs for modeling human disease, developing clinical treatment methodologies, or donating tissues for xenotransplantation. Realizing the full potential of pig genetic engineering requires translation of the complete repertoire of genetic tools currently employed in smaller model organisms to practical use in pigs.</p> <p>Results</p> <p>Application of transposon and recombinase technologies for manipulation of the swine genome requires characterization of their activity in pig cells. We tested four transposon systems- <it>Sleeping Beauty</it>, <it>Tol2</it>, <it>piggyBac</it>, and <it>Passport </it>in cultured porcine cells. Transposons increased the efficiency of DNA integration up to 28-fold above background and provided for precise delivery of 1 to 15 transgenes per cell. Both Cre and Flp recombinase were functional in pig cells as measured by their ability to remove a positive-negative selection cassette from 16 independent clones and over 20 independent genomic locations. We also demonstrated a Cre-dependent genetic switch capable of eliminating an intervening positive-negative selection cassette and activating GFP expression from episomal and genome-resident transposons.</p> <p>Conclusion</p> <p>We have demonstrated for the first time that transposons and recombinases are capable of mobilizing DNA into and out of the porcine genome in a precise and efficient manner. This study provides the basis for developing transposon and recombinase based tools for genetic engineering of the swine genome.</p

Nonparametric estimation of age-at-onset distributions from censored kin-cohort data

SUMMARY We present a nonparametric estimator of genotype-specific age-at-onset distributions from kin-cohort data. Standard error calculations are derived and the methodology is illustrated through an analysis of the influence of mutations of the Parkin gene on Parkinson&apos;s disease. Semiparametric efficiency considerations are briefly discussed