On smoothed probability density estimation for stationary processes

Aspects of estimation of the (marginal) probability density for a stationary sequence or continuous parameter process, are considered in this paper. Consistency and asymptotic distributional results are obtained using a class of smoothed function estimators including those of kernel type, under various decay of dependence conditions for the process. Some of the consistency results contain convergence rates which appear to be more delicate than those previously available, even for i.i.d. sequences

Association of a homozygous GCK missense mutation with mild diabetes

Background: Homozygous inactivating GCK mutations have been repeatedly reported to cause severe hyperglycemia, presenting as permanent neonatal diabetes mellitus (PNDM). Conversely, only two cases of GCK homozygous mutations causing mild hyperglycemia have been so far described. We here report a novel GCK mutation (c.1116G>C, p.E372D), in a family with one homozygous member showing mild hyperglycemia. Methods: GCK mutational screening was carried out by Sanger sequencing. Computational analyses to investigate pathogenicity and molecular dynamics (MD) were performed for GCK-E372D and for previously described homozygous mutations associated with mild (n = 2) or severe (n = 1) hyperglycemia, used as references. Results: Of four mildly hyperglycemic family-members, three were heterozygous and one, diagnosed in the adulthood, was homozygous for GCK-E372D. Two nondiabetic family members carried no mutations. Fasting glucose (p = 0.016) and HbA1c (p = 0.035) correlated with the number of mutated alleles (0–2). In-silico predicted pathogenicity was not correlated with the four mutations’ severity. At MD, GCK-E372D conferred protein structure flexibility intermediate between mild and severe GCK mutations. Conclusions: We present the third case of homozygous GCK mutations associated with mild hyperglycemia, rather than PNDM. Our in-silico analyses support previous evidences suggesting that protein stability plays a role in determining clinical severity of GCK mutations

Shelf slope convection: A note for antarctic regions

Some basic processes associated with buoyancy-driven convection in the presence of coastal upwellingcurren ts were investigated in a 2.5D framework near the Adelie Coast of Antarctica. The surface buoyancy forcingw as derived from coolingand brine deposition due to ice formation, and was specified over a persistent off-shore polynya maintained by the off-shore katabatic winds. Rotational effects and the formation of a turbulent surface mixed layer were included in the model. The representation of topography was done via the VBM (virtual Boundary Method) that utilizes equivalent body forces in the momentum equation, thus enabling the use of very efficient Poisson solvers for the pressure, based on FFTs. The simulations were carried out near longitude 143E, between latitude 68S and 65S, over the nearshore shelf region. The hydrography was initialized with the 1/4 deg Levitus annual climatology. Two cases of idealized meteorological forcing were considered: constant winds blowingalong -shore and off-shore. The resultant motions in each case were characterized by interaction between the wind-driven upwellingmotions and the downward movingdense convection plumes, but with marked differences: a) the formation of a strongfron t under the open sea edge of the polynya only by off-shore winds; b) the periodic suppression of the surface off-shore currents and of the coastal upwelling only by the along-shore winds; c) the formation of deep upwelling currents along the slope between 400 and 200 meters only for along-shore winds, and d) the rapid filling of the surface layers (depths < 100m) with high salinities under the whole polynya by the off-shore forcing, vs. the delayed fillingof a narrow region near the downwellingplume with intermediate salinity values by the along-shore forcing

Superconductor-semiconductor magnetic microswitch

A hybrid superconductor--two-dimensional electron gas microdevice is presented. Its working principle is based on the suppression of Andreev reflection at the superconductor-semiconductor interface caused by a magnetic barrier generated by a ferromagnetic strip placed on top of the structure. Device switching is predicted with fields up to some mT and working frequencies of several GHz, making it promising for applications ranging from microswitches and storage cells to magnetic field discriminators.Comment: 4 pages, 3 figures, minor changes to tex

Role of the Tracy-Widom distribution in the finite-size fluctuations of the critical temperature of the Sherrington-Kirkpatrick spin glass

We investigate the finite-size fluctuations due to quenched disorder of the critical temperature of the Sherrington-Kirkpatrick spin glass. In order to accomplish this task, we perform a finite-size analysis of the spectrum of the susceptibility matrix obtained via the Plefka expansion. By exploiting results from random matrix theory, we obtain that the fluctuations of the critical temperature are described by the Tracy-Widom distribution with a non-trivial scaling exponent 2/3

A family history of type 2 diabetes as a predictor of fatty liver disease in diabetes-free individuals with excessive body weight

Comprehensive screening for non-alcoholic fatty liver disease (NAFLD) may help prompt clinical management of fatty liver disease. A family history, especially of diabetes, has been little studied as a predictor for NAFLD. We characterized the cross-sectional relationship between a family history of type 2 diabetes (FHT2D) and NAFLD probability in 1185 diabetes-free Apulian (Southern-Italy) subjects aged &gt; 20&nbsp;years with overweight or obesity not receiving any drug or supplementation. Clinical data and routine biochemistry were analysed. NAFLD probability was defined using the fatty liver index (FLI). A first-degree FHT2D was assessed by interviewing subjects and assigning a score of 0, 1, or 2 if none, only one, or both parents were affected by type 2 diabetes mellitus (T2DM). Our study population featured most females (70.9%, N = 840), and 48.4% (N = 574) of the sample had first-degree FHT2D. After dividing the sample by a FHT2D, we found a higher BMI, Waist Circumference (WC), and diastolic blood pressure shared by FHT2D subjects; they also showed altered key markers of glucose homeostasis, higher triglyceride levels, and worse liver function. FLI scores were significantly lower in subjects without a first-degree FHT2D. After running logistic regression models, a FHT2D was significantly associated with the NAFLD probability, even adjusting for major confounders and stratifying by age (under and over 40&nbsp;years of age). A FHT2D led to an almost twofold higher probability of NAFLD, regardless of confounding factors (OR 2.17, 95% CI 1.63 to 2.89). A first-degree FHT2D acts as an independent determinant of NAFLD in excess weight phenotypes, regardless of the age group (younger or older than 40&nbsp;years). A NAFLD risk assessment within multidimensional screening might be useful in excess weight subjects reporting FHT2D even in the absence of diabetes