Genetics of Focal Segmental Glomerulosclerosis in African American Children

Focal segmental glomerulosclerosis (FSGS) is a histologic diagnosis based on kidney biopsy findings of focal and segmental scarring of the glomeruli, with minimal immune deposits. Patients with FSGS present clinically with progressive proteinuric chronic kidney disease (CKD). The International Study of Kidney Disease in Children described FSGS in 6.9% of children with nephrotic syndrome, but more recent estimates of the disease are higher. This group has been understudied in Africa. As in adults, FSGS is more common in Black and Hispanic children. Compared to non-Black children, Black children are older at disease presentation, have increased rates of progression to kidney failure requiring therapy and, among kidney transplant recipients, have significantly shorter kidney allograft lifespan and higher rates of delayed graft function. As genetic factors are more likely to underlie diseases with pediatric onset and greater severity, characterizing genetic susceptibility to FSGS in Black children may provide insights into disease mechanisms and potential treatment

Stabilizing chaotic vortex trajectories: an example of high-dimensional control

A chaos control algorithm is developed to actively stabilize unstable periodic orbits of higher-dimensional systems. The method assumes knowledge of the model equations and a small number of experimentally accessible parameters. General conditions for controllability are discussed. The algorithm is applied to the Hamiltonian problem of point vortices inside a circular cylinder with applications to an experimental plasma system.Comment: 15 LaTex pages, 4 Postscript figures adde

Second Harmonic Generation for a Dilute Suspension of Coated Particles

We derive an expression for the effective second-harmonic coefficient of a dilute suspension of coated spherical particles. It is assumed that the coating material, but not the core or the host, has a nonlinear susceptibility for second-harmonic generation (SHG). The resulting compact expression shows the various factors affecting the effective SHG coefficient. The effective SHG per unit volume of nonlinear coating material is found to be greatly enhanced at certain frequencies, corresponding to the surface plasmon resonance of the coated particles. Similar expression is also derived for a dilute suspension of coated discs. For coating materials with third-harmonic (THG) coefficient, results for the effective THG coefficients are given for the cases of coated particles and coated discs.Comment: 11 pages, 3 figures; accepted for publication in Phys. Rev.

Three disks in a row: A two-dimensional scattering analog of the double-well problem

We investigate the scattering off three nonoverlapping disks equidistantly spaced along a line in the two-dimensional plane with the radii of the outer disks equal and the radius of the inner disk varied. This system is a two-dimensional scattering analog to the double-well-potential (bound state) problem in one dimension. In both systems the symmetry splittings between symmetric and antisymmetric states or resonances, respectively, have to be traced back to tunneling effects, as semiclassically the geometrical periodic orbits have no contact with the vertical symmetry axis. We construct the leading semiclassical ``creeping'' orbits that are responsible for the symmetry splitting of the resonances in this system. The collinear three-disk-system is not only one of the simplest but also one of the most effective systems for detecting creeping phenomena. While in symmetrically placed n-disk systems creeping corrections affect the subleading resonances, they here alone determine the symmetry splitting of the 3-disk resonances in the semiclassical calculation. It should therefore be considered as a paradigm for the study of creeping effects. PACS numbers: 03.65.Sq, 03.20.+i, 05.45.+bComment: replaced with published version (minor misprints corrected and references updated); 23 pages, LaTeX plus 8 Postscript figures, uses epsfig.sty, espf.sty, and epsf.te

Comparative study of density functional theories of the exchange-correlation hole and energy in silicon

We present a detailed study of the exchange-correlation hole and exchange-correlation energy per particle in the Si crystal as calculated by the Variational Monte Carlo method and predicted by various density functional models. Nonlocal density averaging methods prove to be successful in correcting severe errors in the local density approximation (LDA) at low densities where the density changes dramatically over the correlation length of the LDA hole, but fail to provide systematic improvements at higher densities where the effects of density inhomogeneity are more subtle. Exchange and correlation considered separately show a sensitivity to the nonlocal semiconductor crystal environment, particularly within the Si bond, which is not predicted by the nonlocal approaches based on density averaging. The exchange hole is well described by a bonding orbital picture, while the correlation hole has a significant component due to the polarization of the nearby bonds, which partially screens out the anisotropy in the exchange hole.Comment: 16 pages, 5 figures, RevTeX, added conten

A Monitor of Beam Polarization Profiles for the TRIUMF Parity Experiment

TRIUMF experiment E497 is a study of parity violation in pp scattering at an energy where the leading term in the analyzing power is expected to vanish, thus measuring a unique combination of weak-interaction flavour conserving terms. It is desired to reach a level of sensitivity of 2x10^-8 in both statistical and systematic errors. The leading systematic errors depend on transverse polarization components and, at least, the first moment of transverse polarization. A novel polarimeter that measures profiles of both transverse components of polarization as a function of position is described.Comment: 19 pages LaTeX, 10 PostScript figures. To appear in Nuclear Instruments and Methods in Physics Research, Section

Integromic analysis of genetic variation and gene expression identifies networks for cardiovascular disease phenotypes

BACKGROUND - : Cardiovascular disease (CVD) reflects a highly coordinated complex of traits. Although genome-wide association studies have reported numerous single nucleotide polymorphisms (SNPs) to be associated with CVD, the role of most of these variants in disease processes remains unknown. METHODS AND RESULTS - : We built a CVD network using 1512 SNPs associated with 21 CVD traits in genome-wide association studies (at P≤5×10) and cross-linked different traits by virtue of their shared SNP associations. We then explored whole blood gene expression in relation to these SNPs in 5257 participants in the Framingham Heart Study. At a false discovery rate <0.05, we identified 370 cis-expression quantitative trait loci (eQTLs; SNPs associated with altered expression of nearby genes) and 44 trans-eQTLs (SNPs associated with altered expression of remote genes). The eQTL network revealed 13 CVD-related modules. Searching for association of eQTL genes with CVD risk factors (lipids, blood pressure, fasting blood glucose, and body mass index) in the same individuals, we found examples in which the expression of eQTL genes was significantly associated with these CVD phenotypes. In addition, mediation tests suggested that a subset of SNPs previously associated with CVD phenotypes in genome-wide association studies may exert their function by altering expression of eQTL genes (eg, LDLR and PCSK7), which in turn may promote interindividual variation in phenotypes. CONCLUSIONS - : Using a network approach to analyze CVD traits, we identified complex networks of SNP-phenotype and SNP-transcript connections. Integrating the CVD network with phenotypic data, we identified biological pathways that may provide insights into potential drug targets for treatment or prevention of CVD

Women, men and coronary heart disease: a review of the qualitative literature

Aim. This paper presents a review of the qualitative literature which examines the experiences of patients with coronary heart disease. The paper also assesses whether the experiences of both female and male patients are reflected in the literature and summarizes key themes. Background. Understanding patients' experiences of their illness is important for coronary heart disease prevention and education. Qualitative methods are particularly suited to eliciting patients' detailed understandings and perceptions of illness. As much previous research has been 'gender neutral', this review pays particular attention to gender. Methods. Published papers from 60 qualitative studies were identified for the review through searches in MEDLINE, EMBASE, CINAHL, PREMEDLINE, PsychINFO, Social Sciences Citation Index and Web of Science using keywords related to coronary heart disease. Findings. Early qualitative studies of patients with coronary heart disease were conducted almost exclusively with men, and tended to generalize from 'male' experience to 'human' experience. By the late 1990s this pattern had changed, with the majority of studies including women and many being conducted with solely female samples. However, many studies that include both male and female coronary heart disease patients still do not have a specific gender focus. Key themes in the literature include interpreting symptoms and seeking help, belief about coronary 'candidates' and relationships with health professionals. The influence of social roles is important: many female patients have difficulties reconciling family responsibilities and medical advice, while male patients worry about being absent from work. Conclusions. There is a need for studies that compare the experiences of men and women. There is also an urgent need for work that takes masculinity and gender roles into account when exploring the experiences of men with coronary heart disease

DCC dynamics with the SU(3) linear sigma model

The SU(3) extension of the linear sigma model is employed to elucidate the effect of including strangeness on the formation of disoriented chiral condensates. By means of a Hartree factorization, approximate dispersion relations for the 18 scalar and pseudoscalar meson species are derived and their self-consistent solution makes it possible to trace out the thermal path of the two order parameters as well as delineate the region of instability within which spontaneous pair creation becomes possible. The results depend significantly on the employed sigma mass, with the highest values yielding the largest regions of instability. An approximate solution of the equations of motion for the order parameter in scenarios emulating uniform scaling expansions show that even with a rapid quench only the pionic modes grow unstable. Nevertheless, the rapid and oscillatory relaxation of the order parameters leads to enhanced production of both pions and (to a lesser degree) kaons.Comment: 29 pages, RevTeX, 11 postscript figures, discussion about anomaly term adde

The New ‘Hidden Abode’: Reflections on Value and Labour in the New Economy

In a pivotal section of Capital, volume 1, Marx (1976: 279) notes that, in order to understand the capitalist production of value, we must descend into the ‘hidden abode of production’: the site of the labour process conducted within an employment relationship. In this paper we argue that by remaining wedded to an analysis of labour that is confined to the employment relationship, Labour Process Theory (LPT) has missed a fundamental shift in the location of value production in contemporary capitalism. We examine this shift through the work of Autonomist Marxists like Hardt and Negri, Lazaratto and Arvidsson, who offer theoretical leverage to prize open a new ‘hidden abode’ outside employment, for example in the ‘production of organization’ and in consumption. Although they can open up this new ‘hidden abode’, without LPT's fine-grained analysis of control/resistance, indeterminacy and structured antagonism, these theorists risk succumbing to empirically naive claims about the ‘new economy’. Through developing an expanded conception of a ‘new hidden abode’ of production, the paper demarcates an analytical space in which both LPT and Autonomist Marxism can expand and develop their understanding of labour and value production in today's economy. </jats:p