Dissociation energy of the hydrogen molecule at 10−9^{-9} accuracy

The ionization energy of ortho-H$_2$ has been determined to be $E^\mathrm{o}_\mathrm{I}(\mathrm{H}_2)/(hc)=124\,357.238\,062(25)$ cm$^{-1}$ from measurements of the GK(1,1)--X(0,1) interval by Doppler-free two-photon spectroscopy using a narrow band 179-nm laser source and the ionization energy of the GK(1,1) state by continuous-wave near-infrared laser spectroscopy. $E^\mathrm{o}_\mathrm{I}$(H$_2$) was used to derive the dissociation energy of H$_2$, $D^{N=1}_{0}$(H$_2$), at $35\,999.582\,894(25)$ cm$^{-1}$ with a precision that is more than one order of magnitude better than all previous results. The new result challenges calculations of this quantity and represents a benchmark value for future relativistic and QED calculations of molecular energies.Comment: 6 pages, 5 figure

Rifampin pharmacokinetics in children, with and without human immunodeficiency virus infection, hospitalized for the management of severe forms of tuberculosis

<p>Abstract</p> <p>Background</p> <p>Rifampin is a key drug in antituberculosis chemotherapy because it rapidly kills the majority of bacilli in tuberculosis lesions, prevents relapse and thus enables 6-month short-course chemotherapy. Little is known about the pharmacokinetics of rifampin in children. The objective of this study was to evaluate the pharmacokinetics of rifampin in children with tuberculosis, both human immunodeficiency virus type-1-infected and human immunodeficiency virus-uninfected.</p> <p>Methods</p> <p>Fifty-four children, 21 human immunodeficiency virus-infected and 33 human immunodeficiency virus-uninfected, mean ages 3.73 and 4.05 years (<it>P </it>= 0.68), respectively, admitted to a tuberculosis hospital in Cape Town, South Africa with severe forms of tuberculosis were studied approximately 1 month and 4 months after commencing antituberculosis treatment. Blood specimens for analysis were drawn in the morning, 45 minutes, 1.5, 3.0, 4.0 and 6.0 hours after dosing. Rifampin concentrations were determined by liquid chromatography tandem mass spectrometry. For two sample comparisons of means, the Welch version of the t-test was used; associations between variables were examined by Pearson correlation and by multiple linear regression.</p> <p>Results</p> <p>The children received a mean rifampin dosage of 9.61 mg/kg (6.47 to 15.58) body weight at 1 month and 9.63 mg/kg (4.63 to 17.8) at 4 months after commencing treatment administered as part of a fixed-dose formulation designed for paediatric use. The mean rifampin area under the curve 0 to 6 hours after dosing was 14.9 and 18.1 μg/hour/ml (<it>P </it>= 0.25) 1 month after starting treatment in human immunodeficiency virus-infected and human immunodeficiency virus-uninfected children, respectively, and 16.52 and 17.94 μg/hour/ml (<it>P </it>= 0.59) after 4 months of treatment. The mean calculated 2-hour rifampin concentrations in these human immunodeficiency virus-infected and human immunodeficiency virus-uninfected children were 3.9 and 4.8 μg/ml (<it>P </it>= 0.20) at 1 month after the start of treatment and 4.0 and 4.6 μg/ml (<it>P </it>= 0.33) after 4 months of treatment. These values are considerably less than the suggested lower limit for 2-hour rifampin concentrations in adults of 8.0 μg/ml and even 4 μg/ml</p> <p>Conclusion</p> <p>Both human immunodeficiency virus-infected and human immunodeficiency virus-uninfected children with tuberculosis have very low rifampin serum concentrations after receiving standard rifampin dosages similar to those used in adults. Pharmacokinetic studies of higher dosages of rifampin are urgently needed in children to assist in placing the dosage of rifampin used in childhood on a more scientific foundation.</p

Peer effects and intentional entrepreneurial behaviour: a systematic literature review and research agenda

What role peers play in individuals’ decisions to become entrepreneurs and to what extent peer effects play a role in influencing behaviours at the various stages of business venturing are important questions for scholars and policymakers. This systematic review takes stock of the recent additions to the literature around the phenomena of peer influence in entrepreneurship. The review identified 2,894 documents which were then narrowed down through three consecutive filtering stages. We thematically analysed the final sample of 27 empirical studies that shed light on how individuals’ peers influence the process and outcomes of these individuals’ entrepreneurial intentions and behaviour, allowing for critical analysis. We propose a conceptual schema of social influence that occurs in interactions among entrepreneurial individuals within business venturing and across the three stages of pre-formation, formation, and growth. Our framework reconciles the conceptual classification around discovering, evaluating and exploiting entrepreneurial opportunities with the mechanisms of social influence affecting entrepreneurial behaviours. Grounded in the findings of the literature review, this framework synthesizes peer influence in entrepreneurship with the tripartite distinction of the behavioural motives recognised in contemporary theories of social influence. We suggest promising directions for further research on how interactions with peers might affect individuals’ entrepreneurial behaviours

Stimulating the demand for insurance

The definitive version of this article is available from www.blackwell-synergy.comThis article acts as a review and also a guide to policymakers who are interested in understanding the determinants of insurance demand and how it affects general economic development. By providing a synopsis and evaluation of existing empirical research on the development of insurance markets, this article provides a discussion of the factors that promote insurance market development. This article then highlights certain issues that both insurance companies and policymakers can utilize further in their own markets to design future policies that can be geared to promote insurance market development.Stephanie Hussels, Damian Ward, Ralf Zurbrueg

South and East Asian insurance market growth and development

Stephanie Hussels, Claire Sherman, Damian Ward, and Ralf Zurbruegghttp://www.springer.com/business/book/978-0-387-34162-0?cm_mmc=Google-_-Book%20Search-_-Springer-_-