Gun Ownership and Firearm-related Deaths

BACKGROUND: A variety of claims about possible associations between gun ownership rates, mental illness burden, and the risk of fi rearm-related deaths have been put forward. However, systematic data on this issue among various countries remain scant. Our objective was to assess whether the popular notion "guns make a nation safer" has any merits.METHODS: Data on gun ownership were obtained from the Small Arms Survey, and for fi rearm-related deaths from a European detailed mortality database (World Health Organization), the National Center for Health Statistics, and others. Crime rate was used as an indicator of safety of the nation and was obtained from the United Nations Surveys of Crime Trends. Age-standardized disability-adjusted life- year rates due to major depressive disorder per 100,000 inhabitants with data obtained from the World Health Organization database were used as a putative indicator for mental illness burden in a given country.RESULTS: Among the 27 developed countries, there was a significant positive correlation between guns per capita per country and the rate of fi rearm-related deaths ( r ¼ 0.80; P < .0001). In addition, there was a positive correlation (r ¼ 0.52; P ¼ .005) between mental illness burden in a country and fi rearm-related deaths. However, there was no significant correlation (P ¼ .10) between guns per capita per country and crime rate ( r ¼ .33), or between mental illness and crime rate ( r ¼ 0.32; P ¼ .11). In a linear regression model with fi rearm-related deaths as the dependent variable with gun ownership and mental illness as independent covariates, gun ownership was a significant predictor ( P < .0001) of fi rearm-related deaths, whereas mental illness was of borderline significance ( P ¼ .05) only.CONCLUSION: The number of guns per capita per country was a strong and independent predictor of fi rearm-related death in a given country, whereas the predictive power of the mental illness burden was of borderline significance in a multivariable model. Regardless of exact cause and effect, however, the current study debunks the widely quoted hypothesis that guns make a nation safer

Overlap properties and adsorption transition of two Hamiltonian paths

We consider a model of two (fully) compact polymer chains, coupled through an attractive interaction. These compact chains are represented by Hamiltonian paths (HP), and the coupling favors the existence of common bonds between the chains. Using a ($n=0$ component) spin representation for these paths, we show the existence of a phase transition for strong coupling (i.e. at low temperature) towards a ``frozen'' phase where one chain is completely adsorbed onto the other. By performing a Legendre transform, we obtain the probability distribution of overlaps. The fraction of common bonds between two HP, i.e. their overlap $q$, has both lower ($q_m$) and upper ($q_M$) bounds. This means in particuliar that two HP with overlap greater than $q_M$ coincide. These results may be of interest in (bio)polymers and in optimization problems.Comment: 13 pages, 2 figure

Connexin 40 promoter-based enrichment of embryonic stem cell-derived cardiovascular progenitor cells

Background: Pluripotent embryonic stem (ES) cells that can differentiate into functional cardiomyocytes as well as vascular cells in cell culture may open the door to cardiovascular cell transplantation. However, the percentage of ES cells in embryoid bodies (EBs) which spontaneously undergo cardiovascular differentiation is low (< 10%), making strategies for their specific labeling and purification indispensable. Methods: The human connexin 40 (Cx40) promoter was isolated and cloned in the vector pEGFP. The specificity of the construct was initially assessed in Xenopus embryos injected with Cx40-EGFP plasmid DNA. Stable Cx40-EGFP ES cell clones were differentiated and fluorescent cells were enriched manually as well as via fluorescence-activated cell sorting. Characterization of these cells was performed with respect to spontaneous beating as well as via RT-PCRs and immunofluorescent stainings. Results: Cx40-EGFP reporter plasmid injection led to EGFP fluorescence specifically in the abdominal aorta of frog tadpoles. After crude manual enrichment of highly Cx40-EGFP- positive EBs, the appearance of cardiac and vascular structures was increased approximately 3-fold. Immuno fluorescent stainings showed EGFP expression exclusively in vascular-like structures simultaneously expressing von Willebrand factor and in formerly beating areas expressing alpha-actinin. Cx40-EGFP-expressing EBs revealed significantly higher numbers of beating cardiomyocytes and vascular-like structures. Semiquantitative RT-PCRs confirmed an enhanced cardiovascular differentiation as shown for the cardiac markers Nkx2.5 and MLC2v, as well as the endothelial marker vascular endothelial cadherin. Conclusions: Our work shows the feasibility of specific labeling and purification of cardiovascular progenitor cells from differentiating EBs based on the Cx40 promoter. We provide proof of principle that the deleted CD4 (Delta CD4) surface marker-based method for magnetic cell sorting developed by our group will be ideally suitable for transference to this promoter. Copyright (c) 2008 S. Karger AG, Basel

Theory of quasiparticle interference on the surface of a strong topological insulator

Electrons on the surface of a strong topological insulator, such as Bi2Te3 or Bi1-xSnx, form a topologically protected helical liquid whose excitation spectrum contains an odd number of massless Dirac fermions. A theoretical survey and classification is given of the universal features, observable by the ordinary and spin-polarized scanning tunneling spectroscopy, in the interference patterns resulting from the quasiparticle scattering by magnetic and non-magnetic impurities in such a helical liquid. Our results confirm the absence of backscattering from non-magnetic impurities observed in recent experiments and predict new interference features, uniquely characteristic of the helical liquid, when the scatterers are magnetic.Comment: 4 pages, 2 figures, 1 table. Version to appear in PRB/RC; Typos correcte

Status Seeking in the Small Open Economy

In our modified version of the small open economy Ramsey model, we assume that agents have preferences over consumption and status which, in turn, is determined by relative wealth. This extension potentially eliminates the standard model's counterfactual result that an impatient country over time mortgages all of its capital and labor income. We show that the steady-state values of net assets and consumption, the speed of convergence and, in particular, the direction of adjustment during the transition depend crucially upon the degree of status consciousness. The latter also influences the economy's response to macro-economic shocks.Status seeking, Relative wealth, Open economy dynamics

Conspicious Consumption, Economic Growth, and Taxation: A Generalization

This paper studies the infuence of consumption externalities in the Ramsey model. In contrast to the recent literature, a quite general specification of preferences is used and the concept of the effective intertemporal elasticity of substitution is introduced. We give conditions for the observational equivalence between economies with consumption externalities and externality-free economies. An additional key result is that there exist several types of instantaneous utility functions in which the decentralized solution coincides with the socially planned one in spite of the presence of consumption externalities. The conditions for optimal taxation are also derived.Social status, Conspicuous consumption, Economic growth

Relative Consumption and Endogenous Labour Supply in the Ramsey Model: Do Status-Conscious People Work Too Much?

This paper introduces consumption externalities into a Ramsey-type model with endogenous labour supply and homogeneous agents. The instantaneous utility of any consumer is assumed to depend on work effort, own consumption and relative consumption, where the latter determines the individual's status in the society. Appropriate normality conditions with respect to consumption and leisure ensure that at least in the long run status-conscious individuals consume and work too much, compared to the social optimum, and that the capital stock is too high. Public policy can, however, induce the private sector to attain the social optimum by designing an optimal consumption tax policy.Status, Relative consumption, Work effort

Generalized London free energy for high-TcT_c vortex lattices

We generalize the London free energy to include four-fold anisotropies which could arise from d-wave pairing or other sources in a tetragonal material. We use this simple model to study vortex lattice structure and discuss neutron scattering, STM, Bitter decoration and $\mu$SR experiments.Comment: REVTeX, 4 pages, 2 .ps figures included, submitted to PR