THE GENETICS OF INSULIN RESISTANCE IN FAMILIES WITH POLYCYSTIC OVARY SYNDROME

Polycystic ovary syndrome (PCOS) is a familial disorder characterized by major metabolic consequences related to insulin resistance (IR), including T2DM and metabolic syndrome (MS). There is mounting evidence, which supports association of each of G-174C variant in IL-6 and Pro12Ala variant in PPARλ genes with PCOS-associated biochemical or metabolic features in hyperandrogenic and PCOS adults/adolescents. The major aim of this study was to demonstrate the ability to enroll PCOS probands, who have one or more clinically PCOS-diagnosed woman, and their multigenerational family members for a total sample size of 100-125 to study IR and inflammation markers in such families. Additional important aims were to test for linkage between the IL6 and PPARλ genes' loci and for associations between the IL6G-174C SNP and the Pro12Ala PPARλ SNP with IR, MS and its components, serum inflammation levels (IL-6 and CRP) and testosterone in this special population of PCOS families. IR was defined by a HOMA-IR value > 3.9 in adults and HOMA-IR values which are age-gender specific in adolescents. MS was defined according to the ATP III diagnostic criteria in adults and the same criteria, modified for age in adolescents. In total, 101 individuals were recruited from 9 multigenerational extended families; eight of the families were Caucasian and the remaining was African American. No evidence for linkage of each of the IL6 and the PPARγ markers to any of the examined phenotypes was found. However, interesting significant SNP-phenotype associations were found in this population of PCOS families. The Ala12 allele was found to be negatively associated with diastolic blood pressure (DBP) and with fasting glucose. Moreover, the G allele of the IL6 SNP was found to be positively associated with DBP, serum IL6 and testosterone levels. These associations are particularly important because they were adjusted for covariates which are known or were found to be significantly associated with the outcome in our population and were the results of the variance components association test, a test which accounts for family relationships. The findings are of major public health significance, mainly because they are the first to be reported in PCOS extended families

High-order WENO scheme for Polymerization-type equations

Polymerization of proteins is a biochimical process involved in different diseases. Mathematically, it is generally modeled by aggregation-fragmentation-type equations. In this paper we consider a general polymerization model and propose a high-order numerical scheme to investigate the behavior of the solution. An important property of the equation is the mass conservation. The fifth-order WENO scheme is built to preserve the total mass of proteins along time

Interplay of Chemical Bonding and Magnetism in Fe_4N, Fe_3N, Fe_2N

Using spin density functional theory we have carried out a comparative study of chemical bonding and magnetism in Fe_4N, Fe_3N and Fe_2N. All of these compounds form close packed Fe lattices, while N occupies octahedral interstitial positions. High spin fcc Fe and hypothetical FeN with rock salt structure have been included in our study as reference systems. We find strong, covalent Fe-N bonds as a result of a substantial \sigma-type p-d hybridisation, with some charge transfer to N. Those Fe d orbitals which contribute to the p-d bonds, do no longer participate in the exchange splitting of the Fe d bands. Because of the large exchange fields, the majority spin d bands are always fully occupied, while the minority spin d bands are close to half-filling, thus optimizing the Fe d-d covalent bonding. As a consequence, in good approximation the individual Fe moments decrease in steps of 0.5 \mu_B from fcc iron (2.7 \mu_B) via Fe_4N (2.7 and 1.97 mu_B}), \chem{Fe_3N} (1.99 \mu_B) to \zeta - Fe_2N (1.43 \mu_B).Comment: 16 pages, 15 figure

Selmer groups and anticyclotomic Zp\mathbb{Z}_p-extensions

Let $E/\mathbb{Q}$ be an elliptic curve, $p$ a prime and $K_{\infty}/K$ the anticyclotomic $\mathbb{Z}_p$-extension of a quadratic imaginary field $K$ satisfying the Heegner hypothesis. In this paper we give a new proof to a theorem of Bertolini which determines the value of the $\Lambda$-corank of $\text{Sel}(E/K_{\infty})$ in the case where $E$ has ordinary reduction at $p$. In the case where $E$ has supersingular reduction at $p$ we make a conjecture about the structure of the module of Heegner points mod $p$. Assuming this conjecture we give a new proof to a theorem of Ciperiani which determines the value of the $\Lambda$-corank of $\text{Sel}(E/K_{\infty})$ in the case where $E$ has supersingular reduction at $p$.Comment: Made a slight change to the conjectur

Spreading of a surfactant monolayer on a thin liquid film: Onset and evolution of digitated structures

We describe the response of an insoluble surfactant monolayer spreading on the surface of a thin liquid film to small disturbances in the film thickness and surfactant concentration. The surface shear stress, which derives from variations in surfactant concentration at the air–liquid interface, rapidly drives liquid and surfactant from the source toward the distal region of higher surface tension. A previous linear stability analysis of a quasi-steady state solution describing the spreading of a finite strip of surfactant on a thin Newtonian film has predicted only stable modes. [Dynamics in Small Confining Systems III, Materials Research Society Symposium Proceedings, edited by J. M. Drake, J. Klafter, and E. R. Kopelman (Materials Research Society, Boston, 1996), Vol. 464, p. 237; Phys. Fluids A 9, 3645 (1997); O. K. Matar Ph.D. thesis, Princeton University, Princeton, NJ, 1998]. A perturbation analysis of the transient behavior, however, has revealed the possibility of significant amplification of disturbances in the film thickness within an order one shear time after the onset of flow [Phys. Fluids A 10, 1234 (1998); "Transient response of a surfactant monolayer spreading on a thin liquid film: Mechanism for amplification of disturbances," submitted to Phys. Fluids]. In this paper we describe the linearized transient behavior and interpret which physical parameters most strongly affect the disturbance amplification ratio. We show how the disturbances localize behind the moving front and how the inclusion of van der Waals forces further enhances their growth and lifetime. We also present numerical solutions to the fully nonlinear 2D governing equations. As time evolves, the nonlinear system sustains disturbances of longer and longer wavelength, consistent with the quasi-steady state and transient linearized descriptions. In addition, for the parameter set investigated, disturbances consisting of several harmonics of a fundamental wavenumber do not couple significantly. The system eventually singles out the smallest wavenumber disturbance in the chosen set. The summary of results to date seems to suggest that the fingering process may be a transient response which nonetheless has a dramatic influence on the spreading process since the digitated structures redirect the flux of liquid and surfactant to produce nonuniform surface coverage