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Comparison of reflux esophagitis and its complications between African Americans and non-Hispanic whites

World journal of Gastroenterology 2009年第23期15卷 2878-2881页

作者： Kenneth j Vega Sian Chisholm M Mazen jamal Divisions of Gastroenterology and General Internal Medicine University of Florida Health Sciences Center Jacksonville Florida 32207 United States Gastroenterology Section Veterans Affairs Medical Center 5901 E. 7th St. Long Beach CA 90822 United States

AIM: To determine the effect of ethnicity on the severity of reflux esophagitis (RE) and its complications. METHODS: A retrospective search of the endoscopy database at the University of Florida Health Science Center/jacksonville for all cases of reflux esophagitis and its complications from january 1 to March 31, 2001 was performed. Inclusion criteria were endoscopic evidence of esophagitis using the LA classif ication, reflux related complications and self-reported ethnicity. The data obtained included esophagitis grade, presence of a hiatal hernia, esophageal ulcer, stricture and Barrett's esophagus, and endoscopy indication. RESULTS: The search identified 259 patients with RE or its complications, of which 171 were non-Hispanic whites and 88 were African Americans. The mean ages and male/female ratios were similar in the two groups. RE grade, esophageal ulcer, stricture and hiatal hernia frequency were likewise similar in the groups. Barrett's esophagus was present more often in non-Hispanic whites than in African Americans (15.8% vs 4.5%; P < 0.01). Heartburn was a more frequent indication for endoscopy in non-Hispanic whites with erosive esophagitis than in African Americans (28.1% vs 7.9%; P < 0.001). CONCLUSION: Distribution of RE grade and frequency of reflux-related esophageal ulcer, stricture andhiatal hernia are similar in non-Hispanic whites and African Americans. Heartburn was more frequently and nausea/vomiting less frequently reported as the primary endoscopic indication in non-Hispanic whites compared with African Americans with erosive esophagitis or its complications. African Americans have a decreased prevalence of Barrett's esophagus compared with non-Hispanic whites.

关键词：西班牙美国人并发症食管

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Tandem pore TWIK-related potassium channels and neuroprotection

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Neural Regeneration Research 2019年第8期14卷 1293-1308页

作者： j.Antonio Lamas Diego Fernández-Fernández Laboratory of Neuroscience Biomedical Research Center (CINBIO) University of Vigo

TWIK-related potassium channels (TREK) belong to a subfamily of the two-pore domain potassium channels family with three members, TREK1, TREK2 and TWIK-related arachidonic acid-activated potassium channels. The two-pore domain potassium channels is the last big family of channels being discovered, therefore it is not surprising that most of the information we know about TREK channels predominantly comes from the study of heterologously expressed channels. Notw让hstanding, in this review we pay special attention to the limited amount of information available on native TREK-like channels and real neurons in relation to neuroprotection. Mainly we focus on the role of free fatty acids, lysophospholipids and other neuroprotective agents like riluzole in the modulation of TREK channels, emphasizing on how important this modulation may be for the development of new therapies against neuropathic pain, depression, schizophrenia, epilepsy, ischemia and cardiac complications.

关键词： TREK channels TREK-1 TREK-2 TRAAK neuroprotection free fatty acids lysophospholipids riluzole

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Do mowing regimes affect plant and soil biological activity in the mountain meadows of Southern Poland?

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journal of Mountain Science 2018年第11期15卷 2409-2421页

作者： jóZEFOWSKA Agnieszka ZALESKI Tomasz ZARZYCKI jan FRACZEK Krzysztof Institute of Soil Science and Agrophysics Department of Soil Science and Soil Protection University of Agriculture in Krakow Department of Ecology Climatology and Air Protection University of Agriculture in Krakow Department of Microbiology University of Agriculture in Krakow

The soil biological activity of mountain meadows is a significant factor that determines the health and utility of these regions. The climax stage of this area is forest, but to maintain semi-natural grassland, which is characterised by high biodiversity,low-intensity land use(mowing or grazing) is necessarily required. To understand the effect of various mowing regimes on the soil biological activity and plants, the soil microbial activity(microbial biomass carbon, dehydrogenase activity and number of the cultivable fraction of soil microbial community),annelids community(density and species composition earthworms and enchytraeids) and plant species composition were investigated. The study area was located in the Pieniny National Park in the Carpathian Mountains, in a meadow belonging to the association Dactylis glomerata-Poa trivialis. The investigated variants were divided according to mowing regime:traditional scything – hand mowing(HM), mechanical mowing(MM), or the abandonment of mowing – nonmowing(NM). The microbial activities(expressed by,e.g. microbial biomass carbon and the number of phosphorus bacteria) were affected by the mowing regime. The density of earthworms was higher in the HM and MM than in the NM variants. The largest changes in plant species composition were caused by the abandonment of mowing(NM). The mean number of plant species was positively correlated with soil moisture, earthworm density, and microbial activity(expressed indirectly by dehydrogenases activity). The soil microbial community, such as vegetative bacteria forms and ammonifying bacteria,were positively associated with pH value, and the microbial and total organic carbon content. The results presented here indicate that there is no single form of optimal management for all living *** about mowing regimes, or abandonment of use, should be preceded by multi-aspect studies,including plants and soil biota.

关键词： Mowing techniques Grassland management Earthworms Enchytraeids Microorganisms Biodiversity

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AtGGM2014, an Arabidopsis gene co-expression network for functional studies

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Science China(Life Sciences) 2015年第3期58卷 276-286页

作者： MA ShiSong BOHNERT Hans j DINESH-KUMAR Savithramma P Department of Plant Biology and the Genome Center College of Biological Sciences University of California Departments of Plant Biology and of Crop Sciences University of Illinois at Urbana-Champaign

Gene co-expression networks provide an important tool for systems biology studies. Using microarray data from the Array Express database, we constructed an Arabidopsis gene co-expression network, termed At GGM2014, based on the graphical Gaussian model, which contains 102,644 co-expression gene pairs among 18,068 genes. The network was grouped into 622 gene co-expression modules. These modules function in diverse house-keeping, cell cycle, development, hormone response, metabolism, and stress response pathways. We developed a tool to facilitate easy visualization of the expression patterns of these modules either in a tissue context or their regulation under different treatment conditions. The results indicate that at least six modules with tissue-specific expression pattern failed to record modular regulation under various stress conditions. This discrepancy could be best explained by the fact that experiments to study plant stress responses focused mainly on leaves and less on roots, and thus failed to recover specific regulation pattern in other tissues. Overall, the modular structures revealed by our network provide extensive information to generate testable hypotheses about diverse plant signaling pathways. At GGM2014 offers a constructive tool for plant systems biology studies.

关键词：拟南芥属共表达基因网络模块化结构组织特异性 Express 系统生物学

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Variable retention harvesting in Great Lakes mixed-pine forests: emulating a natural model in managed ecosystems

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Ecological Processes 2019年第1期8卷 210-224页

作者： Brian j.Palik Anthony W.D’Amato USDA Forest Service Northern Research StationGrand RapidsMN 55744USA Rubenstein School of Environment and Natural Resources University of VermontBurlingtonVT 05095USA.

Variable retention harvesting(VRH)systems have gained wide use in many different forest types across the globe,but largely have been implemented in forests characterized by severe,infrequent disturbance *** has been less attention given to developing VRH approaches in forests that are characterized as having a mixed-severity disturbance regime that often results in only partial mortality of canopy trees in spatially heterogeneous *** example of such a forest type is red pine(Pinus resinosa Ait.)-dominated ecosystem of the western Great Lakes region of North *** purpose of this review is to provide a conceptual foundation for developing VRH approaches in red pine ecosystems that are based on a mixed-severity disturbance *** contention is that red pine forests managed following a natural model are more resilient to disturbances and external threats such as climate *** the red pine ecosystem,VRH application should reflect the often severe,but partial canopy removal from natural disturbance that is characteristic of this ecosystem and that results in more than trivial numbers of surviving overstory trees across a range of spatial configurations in regenerating *** live trees should span a range of diameters,but favor the larger end of the diameter distribution,as this reflects the likely pattern of survival after natural disturbance and is often a key structural element lacking from managed *** should be applied in ways that vary the spatial pattern of legacy trees in and among stands,but largely in ways that reflect the pattern of spatially patchy canopy structure,with large openings surrounded by a less disturbed matrix,as occurs with a natural disturbance *** trees and deadwood structures should reflect the composition of the pre-disturbance forest,including species in addition to dominant red ***,retained structures should be viewed as dynamic entities that grow,die,and decay and that need

关键词： Red pine Mixed-severity Variable retention Natural disturbance

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TANGENT UNIT-VECTOR FIELDS:NONABELIAN HOMOTOPY INVARIANTS AND THE DIRICHLET ENERGY

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Acta Mathematica Scientia 2010年第5期30卷 1357-1399页

作者： A.Majumdar j.M.Robbins M.Zyskin Mathematical Institute University of Oxford24-29 St.GilesOxford OX1 3LBUK School of Mathematics University of BristolUniversity WalkBristol BS8 1TWUK Department of Mathematics SETB 2.454-80 Fort BrownBrownsvilleTX 78520USA

Let O be a closed geodesic polygon in S2. Maps from O into S2 are said to satisfy tangent boundary conditions if the edges of O are mapped into the geodesics which contain them. Taking O to be an octant of S2, we compute the infimum Dirichlet energy 6（H） for continuous maps satisfying tangent boundary conditions of arbitrary homotopy type H. The expression for C（H） involves a topological invariant - the spelling length - associated with the （non-abelian） fundamental group of the n-times punctured two-sphere, π1（S2 - {s1,..., sn}, ＊）. The lower bound for C（H） is obtained from combinatorial group theory arguments, while the upper bound is obtained by constructing explicit representatives which, on all but an arbitrarily small subset of O, are alternatively locally conformal or anticonformal. For conformal and anticonformal classes （classes containing wholly conformal and anticonformal representatives respectively）, the expression for C（H） reduces to a previous result involving the degrees of a set of regular values sl,…… sn in the target 82 space. These degrees may be viewed as invariants associated with the abelianization of vr1（S2 - {s1,..., sn}, ＊）. For nonconformal classes, however, ε（H） may be strictly greater than the abelian bound. This stems from the fact that, for nonconformal maps, the number of preimages of certain regular values may necessarily be strictly greater than the absolute value of their degrees. This work is motivated by the theoretical modelling of nematic liquid crystals in confined polyhedral geometries. The results imply new lower and upper bounds for the Dirichlet energy （one-constant Oseen-Frank energy） of reflection-symmetric tangent unitvector fields in a rectangular prism.

关键词： harmonic maps conformal maps algebraic topology non-abelian homotopy invariants eombinatorics liquid crystals

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Short-Term Response of Soil Respiration to Addition of Chars:Impact of Fermentation Post-Processing and Mineral Nitrogen

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Pedosphere 2015年第5期25卷 761-769页

作者： Giacomo LANZA Stephan WIRTH Arthur GESSLER jrgen KERN Leibniz Institute for Agricultural Engineering Leibniz Centre for Agricultural Landscape Research (ZALF) Swiss Federal Institute for Forest Snow and Landscape Research WSL

The biodegradability of chars derived from pyrolysis and hydrothermal carbonisation(HTC) was studied in short-term dynamic incubation experiments under controlled conditions. Carbon dioxide C(CO2) emissions from soil-char mixtures in combination with solid digestate or mineral nitrogen(N) fertiliser were measured in dynamic chambers for 10 d. Compared to the original material(maize straw), pyrolysis and HTC chars showed significantly lower CO2 emissions and slower decay dynamics; and compared to the soil control, HTC char increased soil respiration to a significant extent, while pyrolysis char did not. The addition of mineral N resulted in a delayed respiration dynamics for HTC char, while the addition of digestate resulted in an increase in the respired CO2 for pyrolysis char and a decrease for HTC char. For the first time, a peculiar two-stage decay kinetics was observed for HTC char,indicating a highly inhomogeneous substrate consisting at least of two C pools.

关键词：土壤呼吸字符短期矿质氮后处理 CO2排放衰减动力学发酵

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On the radiogenic heat production of metamorphic,igneous,and sedimentary rocks

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Geoscience Frontiers 2018年第6期9卷 1777-1794页

作者： D.Hasterok M.Gard j.Webb Department of Earth Sciences University of AdelaideNorth TerraceSA5005Australia Centre for Tectonics Research and Exploration(TRaX) University of AdelaideNorth TerraceSA5005Australia Ramelius Resources Ltd. East PerthWA 6005Australia

Sedimentary rocks cover-73% of the Earth's surface and metamorphic rocks account for approximately91% of the crust by volume. Understanding the average behavior and variability of heat production for these rock types are vitally important for developing accurate models of lithospheric temperature. We analyze the heat production of ～204,000 whole rock geochemical data to quantify how heat production of these rocks varies with respect to chemistry and their evolution during metamorphism. The heat production of metaigneous and metasedimentary rocks are similar to their respective protoliths. Igneous and metaigneous samples increase in heat production with increasing SiO_2 and K_2 O, but decrease with increasing FeO, MgO and CaO. Sedimentary and metasedimentary rocks increase in heat production with increasing Al_2 O_3, FeO, TiO_2, and K_2 O but decrease with increasing CaO. For both igneous and sedimentary rocks, the heat production variations are largely correlated with processes that affect K_2 O concentration and covary with other major oxides as a consequence. Among sedimentary rocks,aluminous shales are the highest heat producing(2.9 μW^(-3)) whereas more common iron shales are lower heat producing(1.7 μW m^(-3)). Pure quartzites and carbonates are the lowest heat producing sedimentary rocks. Globally, there is little definitive evidence for a decrease in heat production with increasing metamorphic grade. However, there remains the need for high resolution studies of heat production variations within individual protoliths that vary in metamorphic grade. These results improve estimates of heat production and natural variability of rocks that will allow for more accurate temperature models of the lithosphere.

关键词： Heat generation Density Metamorphic rocks Sedimentary rocks Igneous rocks Continental lithosphere

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CONVERGENCE OF ADAPTIVE EDGE ELEMENT METHODS FOR THE 3D EDDY CURRENTS EQUATIONS

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journal of Computational Mathematics 2009年第5期27卷 657-676页

作者： R.H.W.Hoppe j.Schberl Institut fur Mathematik Universitat AugsburgD-86159AugsburgGermanyand Department of MathematicsUniversity of HoustonHoustonTX 77204-3008USA Dept.for Mathematics CCES(Center for Computational Engineering Science) RWTH AachenD-52074 AachenGermany

We consider an Adaptive Edge Finite Element Method （AEFEM） for the 3D eddy currents equations with variable coefficients using a residual-type a posteriori error estimator. Both the components of the estimator and certain oscillation terms, due to the occurrence of the variable coefficients, have to be controlled properly within the adaptive loop which is taken care of by appropriate bulk criteria. Convergence of the AEFEM in terms of reductions of the energy norm of the discretization error and of the oscillations is shown. Numerical results are given to illustrate the performance of the AEFEM.

关键词： Adaptive edge elements 3D eddy currents equations Convergence analysis,Error and oscillation reduction Residual type a posteriori error estimates.

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Environmental Fate of Petroleum Hydrocarbons in Soil:Review of Multiphase Transport,Mass Transfer,and Natural Attenuation Processes

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Pedosphere 2018年第6期28卷 833-847页

作者： Maria BALSEIRO-ROMERO Carmen MONTERROSO juan j.CASARES Department of Chemical Engineering Centre for Research in Environmental Technologies (CRETUS)Universidade de Santiago de CompostelaSantiago de Compostela 15782(Spain) Department of Soil Science and Agricultural Chemistry Centre for Research in Environmental Technologies (CRETUS)Unzversidade de Santiago de CompostelaSantiago de Compostela 15782(Spain)

The increasing use of petroleum-derived fuels over the last few decades has subsequently augmented the risk of spills in the environment. Soil pollution with petroleum hydrocarbons(principally caused by leaks in pipelines and underground storage tanks) is one of the major sources of soil degradation. Once in soil, fuel hydrocarbons suffer from a wide variety of multiphase processes including transport(advection, diffusion, and dispersion) among and within phases(aqueous and non-aqueous liquid, gas, and soil solids), mass transfer among phases(volatilization, sorption, and solution), and other natural attenuation processes, such as biodegradation and plant uptake and metabolism. This review identifies and describes the major processes occurring in soil that have a significant influence on the environmental fate of petroleum hydrocarbons. The definition of the processes involved in pollutant migration and distribution in soil and the formulation of adequate equations using accurate parameters(e.g., diffusion coefficients, velocity of advective flows, and mass transfer coefficients) will allow prediction of the final fate of soil pollutants. In addition to transport and mass transfer processes,which are more widely studied, the incorporation of attenuation mechanisms driven by microorganisms and plants is essential to predict the final concentration of the pollutants in the whole multiphase scenario. This work underlines the importance of the determination of accurate parameters through the performance of laboratory and/or field-scale experiments to develop precise pollutant migration models.

关键词： degradation fuel-derived pollutants modelling multiphase non-aqueous phase liquid soil pollution soil processes sorption

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