Duodenal ulcer is a multifactorial disorder the role of pepsinogen I

Serum pepsinogen I (PGI) levels were measured in 231 duodenal ulcer (DU) patients and 100 sex and age-comparable healthy controls. Significantly higher mean serum PGI levels were found in DU patients than in controls (124,7 ± 3,4 ng/ml v. 92,9 ± 2,3 ng/ml; P < 0,001) (mean ± SE). These levels were higher in male DU patients than in female DU patients (128,5 ± 3,9 ng/IDl v. 107,4 ± 6,4 ng/ml; P < 0,05). Smoking was associated with elevated serum PGI levels in DU patients (145,3 ± 5,1 ng/ml v. 109,0 ± 4,2 ngl/ml; P < 0,001). Healed DUs were associated with lower mean serum PGI levels than active ulcers (110,9 ± 7,6 ng/ml v. 129,4 ± 3,8 ng/ml, P < 0,05). Whether patients were positive or negative for Helicobacter pylori, infection did not affect mean serum PGI levels. All the risk factors for DU may not affect serum PGI levels and DU may therefore be considered a multifactorial disease

The application of componentised modelling techniques to catastrophe model generation

In this paper we show that integrated environmental modelling (IEM) techniques can be used to generate a catastrophe model for groundwater flooding. Catastrophe models are probabilistic models based upon sets of events representing the hazard and weights their likelihood with the impact of such an event happening which is then used to estimate future financial losses. These probabilistic loss estimates often underpin re-insurance transactions. Modelled loss estimates can vary significantly, because of the assumptions used within the models. A rudimentary insurance-style catastrophe model for groundwater flooding has been created by linking seven individual components together. Each component is linked to the next using an open modelling framework (i.e. an implementation of OpenMI). Finally, we discuss how a flexible model integration methodology, such as described in this paper, facilitates a better understanding of the assumptions used within the catastrophe model by enabling the interchange of model components created using different, yet appropriate, assumptions

Equilibrium clumped-isotope effects in doubly substituted isotopologues of ethane

We combine path-integral Monte Carlo methods with a new intramolecular potential energy surface to quantify the equilibrium enrichment of doubly substituted ethane isotopologues due to clumped-isotope effects. Ethane represents the simplest molecule to simultaneously exhibit 13C–13C, 13C–D, and D–D clumped-isotope effects, and the analysis of corresponding signatures may provide useful geochemical and biogeochemical proxies of formation temperatures or reaction pathways. Utilizing path-integral statistical mechanics, we predict equilibrium fractionation factors that fully incorporate nuclear quantum effects, such as anharmonicity and rotational-vibrational coupling which are typically neglected by the widely used Urey model. The magnitude of the calculated fractionation factors for the doubly substituted ethane isotopologues indicates that isotopic clumping can be observed if rare-isotope substitutions are separated by up to three chemical bonds, but the diminishing strength of these effects suggests that enrichment at further separations will be negligible. The Urey model systematically underestimates enrichment due to 13C–D and D–D clumped-isotope effects in ethane, leading to small relative errors in the apparent equilibrium temperature, ranging from 5 K at 273.15 K to 30 K at 873.15 K. We additionally note that the rotameric dependence of isotopologue enrichment must be carefully considered when using the Urey model, whereas the path-integral calculations automatically account for such effects due to configurational sampling. These findings are of direct relevance to future clumped-isotope studies of ethane, as well as studies of 13C–13C, 13C–D, and D–D clumped-isotope effects in other hydrocarbons

An analytical approximation of urban heat and dry islands and their impact on convection triggering

It is well known that cities increase air and surface temperatures compared to their rural surroundings, the so-called urban heat island (UHI) effect. However, the associated changes in atmospheric humidity (also known as urban dry island, UDI) and convection triggering remain largely unexplored and it is still unclear how urban modifications of the surface energy budget influence the diurnal evolution of temperature and humidity in the Atmospheric Boundary Layer (ABL) and ultimately control the initiation of convective clouds. Here we quantify the impact of different urban settings and free atmospheric conditions on UHI, UDI, and convection triggers by means of a zero-order model of the ABL. Specifically, we derive an approximate solution for urban-rural changes in surface energy fluxes and ABL potential temperature and humidity and we investigate the crossing between the ABL height and the lifting condensation level (LCL) which is a proxy for the triggering of convective clouds. We show that urban areas are generally warmer and drier, thus causing an increase in both ABL and LCL heights. However, the response of the ABL-LCL crossing to surface conditions is non-linear and there exists a range of free atmosphere conditions for which changes in imperviousness can impact convective clouds

Genome-wide scan using DArT markers for selection footprints in six-rowed naked barley from the Tibetan Plateau

As one of the world’s earliest domesticated crops, barley is a model species for the study of evolution and domestication. Domestication is an evolutionary process whereby a population adapts, through selection; to new environments created by human cultivation. We describe the genome-scanning of molecular diversity to assess the evolution of barley in the Tibetan Plateau. We used 667 Diversity Arrays Technology (DArT) markers to genotype 185 barley landraces and wild barley accessions from the Tibetan Plateau. Genetic diversity in wild barley was greater than in landraces at both genome and chromosome levels, except for chromosome 3H. Landraces and wild barley accessions were clearly differentiated genetically, but a limited degree of introgression was still evident. Significant differences in diversity between barley subspecies at the chromosome level were observed for genes known to be related to physiological and phenotypical traits, disease resistance, abiotic stress tolerance, malting quality and agronomic traits. Selection on the genome of six-rowed naked barley has shown clear multiple targets related to both its specific end-use and the extreme environment in Tibet. Our data provide a platform to identify the genes and genetic mechanisms that underlie phenotypic changes, and provide lists of candidate domestication genes for modified breeding strategies

Search for sharp lines in e+-e- coincidences from positrons on Th

Two mini-orange spectrometers were used to view e+-e- pairs from a positron source and a Th scatterer from opposite directions, 180° apart. No statistically significant evidence for peaks previously reported was found in the coincidence spectra

Electron-capture branching ratio of Krm81

The branching ratio of the electron-capture decay of Krm81 (13 s) has been measured in order to obtain the rate of the neutrino capture reaction Br81(,re-)81Kr(190.6 keV). This quantity is needed to determine the properties of an Br81 solar neutrino detector. A branching ratio of (3.140.58)×10-5 was obtained, leading to a logft of 5.10-0.07+0.06 for this transition

Hot Extrusion Effect on the Microstructure and Mechanical Properties of a Mg–Y–Nd–Zr Alloy

A Mg–Y–Nd–Zr alloy was prepared by casting and hot extrusion. The microstructure and mechanical properties of OM, SEM, XRD, TEM, and tensile tests were investigated with casting and hot extruded alloys. The results demonstrate that in a casting Mg–Y–Nd–Zr alloy, the α-Mg matrix is separated into the cell structure by a discontinuously distributed coarse Mg₂₄Y₅/α-Mg eutectic structure and fine Mg₁₂Nd particles.Сплав Mg-Y-Nd-Zr получен литьем и горячей экструзией. Исследованы микроструктура и механические свойства литейного и экструзионного сплавов с помощью оптической, сканирующей электронной, просвечивающей электронной микроскопии, рентгенографии и испытаний на растяжение. Показано, что матрица α-Mg в литейном сплаве превращается в ячеистую структуру за счет образования дискретно распределенной крупной эвтектики Mg₂₄Y₅ и мелких частиц Mg₁₂Nd/α-Mg