Simulation modeling and preliminary analysis of TIMS data from the Carlin area and the northern Grapevine Mountains, Nevada

A theoretical radiance model was employed together with laboratory data on a suite of igneous rock to evaluate various algorithms for processing Thermal Infrared Multispectral Scanner (TIMS) data. Two aspects of the general problem were examined: extraction of emissivity information from the observed TIMS radiance data, and how to use emissivity data in a way that is geologically meaningful. The four algorithms were evaluated for appropriate band combinations of TIMS data acquired on both day and night overflights of the Tuscarora Mountains, including the Carlin gold deposit, in north-central Nevada. Analysis of a color composited PC decorrelated image (Bands 3, 4, 5--blue/green/red) of the Northern Grapevine Mountains, Nevada, area showed some useful correlation with the regional geology. The thermal infrared region provides fundamental spectral information that can be used to discriminate the major rock types occurring on the Earth's surface

Parabolic differential equations with Hölder continuous and unbounded coefficients

We consider one-dimensional linear parabolic differential equations with Hölder continuous, unbounded drifts. We first extend the classical parametrix method of E. Levi to prove existence of fundamental solutions. From this we derive existence and uniqueness of solutions for the corresponding Cauchy problem. Our results extend to equations in higher dimensions with additional unbounded potential

Accommodating Employees With and Without Disabilities

Efforts to recruit and retain employees with disabilities are often tempered by employers’ concerns over potential workplace accommodation costs. This study reports on accommodations requested and granted in intensive case studies of eight companies, based on more than 5,000 employee and manager surveys, and interviews and focus groups with 128 managers and employees with disabilities. Two unique contributions are that we analyze accommodations for employees without disabilities as well as for those with disabilities, and compare perspectives on accommodation costs and benefits among employees, their coworkers, and their managers. We find people with disabilities are more likely than those without disabilities to request accommodations, but the types of accommodations requested and the reported costs and benefits are similar for disability and non-disability accommodations. In particular, fears of high accommodation costs and negative reactions of coworkers are not realized; all groups tend to report generally positive coworker reactions. Multilevel models indicate granting accommodations has positive spillover effects on attitudes of coworkers, as well as a positive effect on attitudes of requesting employees, but only when coworkers are supportive. Consistent with recent theorizing and other studies, our results suggest the benefits from a corporate culture of flexibility and attention to the individualized needs of employees

GPD-linked Bonds as a Financing Tool for Developing Countries and Emerging Markets

The paper examines the applicability of GDP-linked bonds for the financing of developing countries and emerging markets. GDP-linked bonds are bonds of which the coupon and/or redemption payments are tied to the GDP of the issuing country. The study encompasses a detailed empirical analysis of their pricing behaviour, the pricing sensitivities to changes in GDP, and of their behaviour in a portfolio context is conducted. A survey amongst potential investors as well as issuing-side capital market participants assesses the prospects of success of this new type of bond. Finally, the usefulness of a partial public guarantee of payments is examined. The paper provides evidence under which circumstances, for which investors and for which countries GDP-linked bonds might be an appropriate investment vehicle

Paroxysmales Vorhofflimmern bei Schrittmacherpatienten : Einfluss präventiver Stimulationsalgorithmen auf das Verteilungsmuster der Induktionsszenarien

Beim Vorhofflimmern handelt es sich um die häufigste anhaltende Rhythmusstörung des Herzens. Ziel vieler Studien war es, Vorhofflimmern durch präventive Stimulation mittels Schrittmacher zu verhindern. Folgende Fragen sollen mit dieser Dissertation beantwortet werden: Welchen Einfluss haben präventive Stimulationsalgorithmen eines DDD-Schrittmachers auf das Verteilungsmuster der Vorhofflimmer-Induktionsszenarien und verändern sich die Charakteristika der unterschiedlichen Flimmertypen? Es bestätigte sich, dass in der Diagnostikphase 53,6 % der Patienten Triggerflimmerer und die übrigen 46,4 % Substratflimmerer waren. In der Therapiephase blieb das Verhältnis zwar gleich, allerdings wechselten ca. 26 % den Flimmertyp. So bestand ein signifikanter Zusammenhang zum einen zwischen der Aktivierung der SVES(Supraventrikuläre Extrasystole)-Unterdrückung und der Post-SVES-Adaption und dem Wechsel der Trigger- zu den Substratflimmerern und zum anderen zwischen der Aktivierung der Stimulationskonditionierung und dem Wechsel der Substrat- zu den Triggerflimmerern. Die Häufigkeit bzw. Gesamtdauer des Vorhofflimmerns wurde jedoch nicht signifikant beeinflusst. Insgesamt bestätigte sich eine große Streubreite der verschiedenen Induktionsszenarien von Vorhofflimmern. Betrachtet für das Gesamtkollektiv wird durch die Aktivierung der Präventionsalgorithmen im Gegensatz zur Diagnostikphase der „Sudden Onset“ als häufigster Induktor nachgewiesen und die in der Diagnostik häufigsten „SVES-abhängigen“ Onsets von 58 auf 45 % reduziert. In der Subgruppe der Triggerflimmerer bestätigte sich mit 68,8 % in der Diagnostik- und 59,7 % in der Therapiephase ein deutliches Überwiegen der „SVES-abhängigen“ Induktionsmechanismen. Bei den Substratflimmerern liegt der Schwerpunkt der Onset-Szenarien eindeutig beim „Sudden Onset“, nämlich 51,6 % in der Diagnostik- und 70,1 % in der Therapiephase. Unabhängig davon, ob das Gesamtkollektiv oder die Subgruppen angesehen wurden, fiel eine breite Varianz der Induktionsmechanismen für den einzelnen Patienten auf. Es gelang durch Aktivierung der Präventionsalgorithmen eine signifikante Reduktion der im Mittel vier (maximal 6) verschiedenen Onsets in der Diagnostikphase auf im Mittel zwei (maximal 4). Zusammenfassend können folgende Aussagen getroffen werden: Durch die verwendete diagnostische Schrittmacher-Software konnten in diffiziler Weise die Induktionsszenarien für Vorhofflimmern dokumentiert werden. Durch das Einschalten der Präventionsmechanismen änderte sich bei einem Viertel der Patienten der ursprüngliche Flimmertyp und es wurde eine signifikante Homogenisierung der Onset-Mechanismen bei dem einzelnen Patienten erreicht

Evidence for a regulatory role of Cullin-RING E3 ubiquitin ligase 7 in insulin signalling

Dysfunctional regulation of signalling pathways downstream of the insulin receptor plays a pivotal role in the pathogenesis of insulin resistance and type 2 diabetes. In this study we report both in vitro and in vivo experimental evidence for a role of Cullin-RING E3 ubiquitin ligase 7 (CRL7) in the regulation of insulin signalling and glucose homeostasis. We show that Cul7−/− mouse embryonic fibroblasts displayed enhanced AKT and Erk MAP kinase phosphorylation upon insulin stimulation. Depletion of CUL7 by RNA interference in C2C12 myotubes led to increased activation of insulin signalling pathways and cellular glucose uptake, as well as a reduced capacity of these cells to execute insulin-induced degradation of insulin receptor substrate 1 (IRS1). In vivo, heterozygosity of either Cul7 or Fbxw8, both key components of CRL7, resulted in elevated PI3 kinase / AKT activation in skeletal muscle tissue upon insulin stimulation when compared to wild-type controls. Finally, Cul7+/− or Fbxw8+/− mice exhibited enhanced insulin sensitivity and plasma glucose clearance. Collectively, our findings point to a yet unrecognized role of CRL7 in insulin-mediated control of glucose homeostasis by restraining PI3 kinase / AKT activities in skeletal muscle cells

A Gene for Universal Congenital Alopecia Maps to Chromosome 8p21-22

SummaryComplete or partial congenital absence of hair (congenital alopecia) may occur either in isolation or with associated defects. The majority of families with isolated congenital alopecia has been reported to follow an autosomal-recessive mode of inheritance (MIM 203655). As yet, no gene has been linked to isolated congenital alopecia, nor has linkage been established to a specific region of the genome. In an attempt to map the gene for the autosomal recessive form of the disorder, we have performed genetic linkage analysis on a large inbred Pakistani family in which affected persons show complete absence of hair development (universal congenital alopecia). We have analyzed individuals of this family, using >175 microsatellite polymorphic markers of the human genome. A maximum LOD score of 7.90 at a recombination fraction of 0 has been obtained with locus D8S258. Haplotype analysis of recombination events localized the disease to a 15-cM region between marker loci D8S261 and D8S1771. We have thus mapped the gene for this hereditary form of isolated congenital alopecia to a locus on chromosome 8p21-22 (ALUNC [alopecia universalis congenitalis]). This will aid future identification of the responsible gene, which will be extremely useful for the understanding of the biochemistry of hair development