The CI lines as tracers of molecular gas, and their prospects at high redshifts

We examine the fine structure lines $^{3}P_{1}\to$$^{3}P_{0}$ (492 GHz) and $^{3}P_2\to$$^{3}P_1$ (809 GHz) of neutral atomic carbon as bulk molecular gas mass tracers and find that they can be good and on many occasions better than $^{12}$CO transitions, especially at high redshifts. The notion of CI emission as an H$_2$ gas mass tracer challenges the long-held view of its distribution over only a relatively narrow layer in the CII/CI/CO transition zone in FUV-illuminated molecular clouds. Past observations have indeed consistently pointed towards a more extended CI distribution but it was only recently, with the advent of large scale imaging of its $^{3}P_{1}\to$$^{3}P_{0}$ transition, that its surprising ubiquity in molecular clouds has been fully revealed. In the present work we show that under {\it typical} ISM conditions such an ubiquity is inevitable because of well known dynamic and non-equilibrium chemistry processes maintaining a significant [C]/[$^{12}$CO] abundance throughout Giant Molecular Clouds during their lifetime. These processes are more intense in star-forming environments where a larger ambient cosmic ray flux will also play an important role in boosting [C]/[$^{12}$CO]. The resulting CI lines can be bright and effective H$_2$ mass tracers especially for diffuse ($\sim 10^2-10^3\rm cm^{-3}$) gas while in UV-intense and/or metal-poor environments their H$_2$-tracing capability diminishes because of large scale CII production but nevertheless remains superior to that of $^{12}$CO. The best place to take full advantage of CI's capacity to trace H$_2$ is not in the low-$z$ Universe, where large atmospheric absorption at 492 and 809 GHz precludes routine observations, but at high redshifts (\rm z\ga 1).Comment: Accepted for publication at the Monthly Notices of the Royal Astronomical Society (29 pages, 5 figures

Enhancement of Immune Response Against Bordetella spp. by Disrupting Immunomodulation

Well-adapted pathogens must evade clearance by the host immune system and the study of how they do this has revealed myriad complex strategies and mechanisms. Classical bordetellae are very closely related subspecies that are known to modulate adaptive immunity in a variety of ways, permitting them to either persist for life or repeatedly infect the same host. Exploring the hypothesis that exposure to immune cells would cause bordetellae to induce expression of important immunomodulatory mechanisms, we identified a putative regulator of an immunomodulatory pathway. The deletion of btrS in B. bronchiseptica did not affect colonization or initial growth in the respiratory tract of mice, its natural host, but did increase activation of the inflammasome pathway, and recruitment of inflammatory cells. The mutant lacking btrS recruited many more B and T cells into the lungs, where they rapidly formed highly organized and distinctive Bronchial Associated Lymphoid Tissue (BALT) not induced by any wild type Bordetella species, and a much more rapid and strong antibody response than observed with any of these species. Immunity induced by the mutant was measurably more robust in all respiratory organs, providing completely sterilizing immunity that protected against challenge infections for many months. Moreover, the mutant induced sterilizing immunity against infection with other classical bordetellae, including B. pertussis and B. parapertussis, something the current vaccines do not provide. These findings reveal profound immunomodulation by bordetellae and demonstrate that by disrupting it much more robust protective immunity can be generated, providing a pathway to greatly improve vaccines and preventive treatments against these important pathogens

The molecular gas in Luminous Infrared Galaxies II: extreme physical conditions, and their effects on the X_{co} factor

In this work we conclude the analysis of our CO line survey of Luminous Infrared Galaxies (LIRGs: L_{IR}>=10^{11}L_{sol}) in the local Universe (Paper\,I), by focusing on the influence of their average ISM properties on the total molecular gas mass estimates via the so-called X_{co}=M(H_2)/L_{co,1-0} factor. One-phase radiative transfer models of the global CO Spectral Line Energy Distributions (SLEDs) yield an X_{co} distribution with: \sim(0.6+/-0.2) M_{sol}(K km s^{-1} pc^2)^{-1} over a significant range of average gas densities, temperatures and dynamical states. The latter emerges as the most important parameter in determining X_{co}, with unbound states yielding low values and self-gravitating states the highest ones. Nevertheless in many (U)LIRGs where available higher-J CO lines (J=3--2, 4--3, and/or J=6--5) or HCN line data from the literature allow a separate assessment of the gas mass at high densities (>=10^{4} cm^{-3}) rather than a simple one-phase analysis we find that {\it near-Galactic X_{co} (3-6)\, M_sol\,(K\,km^{-1}\,pc^2)^{-1} values become possible.} We further show that in the highly turbulent molecular gas in ULIRGs a high-density component will be common and can be massive enough for its high X_{co} to dominate the average value for the entire galaxy. ......... ...this may have thus resulted to systematic underestimates of molecular gas mass in ULIRGs.Comment: 77 pages, 6 figures, one Table, accepted for publication at The Astrophysical Journa

Cloning, sequencing, and overexpression of gene 16 of salmonella bacteriophage P22

Umlauf B, Dreiseikelmann B. Cloning, sequencing, and overexpression of gene 16 of salmonella bacteriophage P22. Virology. 1992;188(2):495-501.It has been suggested that gene product 16 of bacteriophage P22 forms a pore for DNA transfer and/or that it functions as a pilot protein guiding the DNA across the membrane. We have cloned gene 16 and determined the nucleotide sequence. Within the sequenced region there is an open reading frame that could encode a protein of 609 amino acids having a molecular weight of 64,366. The hydropathic plot of this protein does not reveal putative membrane-spanning regions as expected for a protein forming a membrane pore. Overproduction of gene product 16 in Escherichia coli was successful only in a mutant in which the La protease was inactivated. Gene 16 mutants of phage P22 were not able to infect recBCD mutants of Salmonella typhimurium nor was protein 16, synthesized in E. colifrom a plasmid, able to substitute for the pilot protein of phage T4. It seems that gene product 16 is not a pilot protein in the meaning of binding to the ends of linear DNA, thus protecting it from degradation by nucleases

Heterotic Black Horizons

We show that the supersymmetric near horizon geometry of heterotic black holes is either an AdS_3 fibration over a 7-dimensional manifold which admits a G_2 structure compatible with a connection with skew-symmetric torsion, or it is a product R^{1,1} * S^8, where S^8 is a holonomy Spin(7) manifold, preserving 2 and 1 supersymmetries respectively. Moreover, we demonstrate that the AdS_3 class of heterotic horizons can preserve 4, 6 and 8 supersymmetries provided that the geometry of the base space is further restricted. Similarly R^{1,1} * S^8 horizons with extended supersymmetry are products of R^{1,1} with special holonomy manifolds. We have also found that the heterotic horizons with 8 supersymmetries are locally isometric to AdS_3 * S^3 * T^4, AdS_3 * S^3 * K_3 or R^{1,1} * T^4 * K_3, where the radii of AdS_3 and S^3 are equal and the dilaton is constant.Comment: 35 pages, latex. Minor alterations to equation (3.11) and section 4.1, the conclusions are not affecte

Are 12^{12}CO lines good indicators of the star formation rate in galaxies?

In this paper, we investigate the relevance of using the $^{12}$CO line emissions as indicators of star formation rates (SFR). For the first time, we present this study for a relatively large number of $^{12}$CO transitions (12) as well as over a large interval in redshift (from z$\sim$0 to z$\sim$6). For the nearby sources (D$\leq$10 Mpc), we have used homogeneous sample of $^{12}$CO data provided by Bayet et al. (2004, 2006), mixing observational and modelled line intensities. For higher-z sources (z $\geq$ 1), we have collected $^{12}$CO observations from various papers and have completed the data set of line intensities with model predictions which we also present in this paper. Finally, for increasing the statistics, we have included recent $^{12}$CO(1-0) and $^{12}$CO(3-2) observations of intermediate-z sources. Linear regressions have been calculated for identifying the tightest SFR-$^{12}$CO line luminosity relationships. We show that the \emph{total} $^{12}$CO, the $^{12}$CO(5-4), the $^{12}$CO(6-5) and the $^{12}$CO(7-6) luminosities are the best indicators of SFR (as measured by the far-infrared luminosity). Comparisons with theoretical approaches from Krumholz and Thompson (2007) and Narayanan et al. (2008) are also performed in this paper. Although in general agreement, the predictions made by these authors and the observational results we present here show small and interesting discrepancies. In particular, the slope of the linear regressions, for J$_{upper}\geq$ 4 $^{12}$CO lines are not similar between theoretical studies and observations. On one hand, a larger high-J $^{12}$CO data set of observations might help to better agree with models, increasing the statistics. On the other hand, theoretical studies extended to high redshift sources might also reduce such discrepancies.Comment: 10 pages, 3 figures and 4 tables, Accepted in MNRA

Pathways to Prevention: Improving Nonresident African American Fathers' Parenting Skills and Behaviors to Reduce Sons' Aggression

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102680/1/cdev12127.pd

Detroit's East Side Village Health Worker Partnership: Community-Based Lay Health Advisor Intervention in an Urban Area

In recent years, there have been few reports in the literature of interventions using a lay health advisor approach in an urban area. Consequently, little is known about how implementation of this type of community health worker model, which has been used extensively in rural areas, may differ in an urban area. This article describes the implementation of the East Side Village Health Worker Partnership, a lay health advisor intervention, in Detroit, Michigan, and notes how participatory action research methods and principles for community-based partnership research are being used to guide the intervention. Findings are presented on how the urban context is affecting the design and implementation of this intervention. Implications of the findings for health educators are also presented and include the utility of a participatory action research approach, the importance of considering the context and history of a community in designing a health education intervention, and the importance of recognizing and considering the differences between rural and urban settings when designing a health education intervention.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67390/2/10.1177_109019819802500104.pd

Ordered Incidence geometry and the geometric foundations of convexity theory

An Ordered Incidence Geometry, that is a geometry with certain axioms of incidence and order, is proposed as a minimal setting for the fundamental convexity theorems, which usually appear in the context of a linear vector space, but require only incidence, order (and for separation, completeness), and none of the linear structure of a vector space.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42995/1/22_2005_Article_BF01227810.pd