检索结果-南通市图书馆

Different canopy openings affect underground traits in herbaceous plants of a southern forest in Patagonia

journal of Plant Ecology 2016年第5期9卷 542-552页

作者： Luciano j.Selzer carlos A.Busso CADIC-CONICET Houssay 200(9410)UshuaiaTierra del FuegoArgentina.Instituto de Ciencias PolaresAmbiente y Recursos Naturales.Universidad Nacional de Tierra del FuegoAlem 1036(9410)UshuaiaTierra del FuegoArgentina CERZOS-CONICET San Andrés 800(8000)Bahía BlancaBuenos AiresArgentina.Depto.de Agronomía-Universidad Nacional del SurSan Andrés 800(8000)Bahía BlancaBuenos AiresArgentina

Aims Forest canopy openings modify the natural environment,producing changes in light quality and intensity,precipitation and *** turn,these changes promote the acclimation of understory ***,little work has been done on underground responses to those environmental *** objective of this work was to determine how Osmorhiza depauperata,Phleum alpinum and Poa pratensis change its root length density and root colonization by mycorrhiza as a function of light availability in a Nothofagus pumilio(***)forest harvested following the variable retention *** We selected three microenvironments in an old growth forest harvested by the variable retention prescription:aggregated retention,dispersed retention with influence of aggregated retention and dispersed retention.A non-harvested primary forest(PF),similar to the harvested one,was used as a *** 2 months,from October 2008 to April 2009,we took soil cores from randomly selected *** these soil cores,root length density and colonization percentage(CP)by arbuscular mycorrhizae were *** Findings Light availability changed significantly among the *** general,root length density was significantly greater in *** than in *** and both species greater than in *** availability increased root length density in all species,although the magnitude of these increases difference among *** length density was 187%greater in ***,101%in *** and 94%in *** in the disperse retention system than in the *** CP was higher in *** than in *** and ***,it was lower in the PF than in the harvested *** were very low.

关键词： root length density mycorrhizal colonization light shade understory Tierra del Fuego

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Role of ABCC2 common variants in intrahepatic cholestasis of pregnancy

引用

World journal of Gastroenterology 2008年第13期14卷 2126-2127页

作者： Silvia Sookoian Gustavo Castao carlos j Pirola Department of Molecular Genetics and Biology of Complex Diseases Institute of Medical Research A. Lanari University of Buenos Aires-CONICET Buenos Aires 1427 Argentina Research Council of GCBA Buenos Aires 1427 Argentina

The pathogenesis of intrahepatic cholestasis of pregnancy (ICP), a disorder that adversely affects maternal wellbeing and fetal outcome, is unclear. However, multiple factors probably interact along with a genetic predisposition. We would like to add some comments on a paper recently published concerning the role of ABCB11 and ABCC2 polymorphisms in both ICP and contraceptive-induced cholestasis, especially in the light of our recently published findings about a positive association between ICP and ABCC2 common variants.

关键词： Intrahepatic cholestasis of pregnancy ABCC2 MRP2 Gene variants

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Hyperpycnal (over density) flows and deposits

引用

journal of Palaeogeography 2020年第3期9卷 267-287页

作者： carlos Zavala Departamento de Geologia Universidad Nacional del SurSan Juan 6708000 Bahia BlancaArgentina GCS Argentina 5RL Molina Campos 1508000 Bahia BlancaArgentina

A hyperpycnal flow forms when a relatively dense land-derived gravity flow enters into a marine or lacustrine water reservoir. As a consequence of its excess of density, the incoming flow plunges in coastal areas, generating a highly dynamic and often long-lived dense underflow. Depending on the characteristics of the parent flow(flow duration and flow rheology) and basin salinity, the resulting deposits(hyperpycnites) can be very *** to flow duration, land-derived gravity flows can be classified into short-lived or long-lived flows. Shortlived gravity flows last for minutes or hours, and are mostly related to small mountainous river discharges, alluvial fans, collapse of natural dams, landslides, volcanic eruptions, j?kulhlaups, etc. Long-lived gravity flows last for days,weeks or even months, and are mostly associated with medium-to large-size river *** the rheology of the incoming flow, hyperpycnal flows can be initiated by non-Newtonian(cohesive debris flows), Newtonian supercritical(lahars, hyperconcentrated flows, and concentrated flows) or Newtonian subcritical flows(pebbly, sandy or muddy sediment-laden turbulent flows). Once plunged, non-Newtonian and Newtonian supercritical flows require steep slopes to accelerate, allow the incorporation of ambient water and develop flow transformations in order to evolve into a turbidity current and travel further basinward. Their resulting deposits are difficult to differentiate from those related to intrabasinal turbidites. On the contrary, long-lived Newtonian subcritical flows are capable of transferring huge volumes of sediment, freshwater and organic matter far from the coast even along gentle or flat slopes. In marine settings, the buoyant effect of interstitial freshwater in pebbly and sandy hyperpycnal flows can result in lofting due to flow density reversal. Since the excess of density in muddy hyperpycnal flows is provided by silt-clay sediments in turbulent suspension, lofting

关键词： Hyperpycnal flows Hyperpycnites Turbidites Sediment gravity flows

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Remark on "An Efficient Real Space Method for Orbital-Free Density-Functional Theory"

引用

Communications in Computational Physics 2008年第4期3卷 968-972页

作者： carlos j.Garcia-Cervera Mathematics Department University of CaliforniaSanta BarbaraCA 93106USA

In this short note we clarify some issues regarding the existence of minimizers for the Thomas-Fermi-von Weiszacker energy functional in orbital-free density functional theory,when the Wang-Teter corrections are inclu... 详细信息

关键词： Density functional theory Thomas-Fermi constrained optimization

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

MULTIGRID METHOD FOR A MODIFIED CURVATURE DRIVEN DIFFUSION MODEL FOR IMAGE INPAINTING

引用

journal of Computational Mathematics 2008年第6期26卷 856-875页

作者： carlos Brito-Loeza Department of Mathematical Sciences University of Liverpool

Digital inpainting is a fundamental problem in image processing and many variational models for this problem have appeared recently in the literature. Among them are the very successfully Total Variation （TV） model [11] designed for local inpainting and its improved version for large scale inpainting： the Curvature-Driven Diffusion （CDD） model [10]. For the above two models, their associated Euler Lagrange equations are highly nonlinear partial differential equations. For the TV model there exists a relatively fast and easy to implement fixed point method, so adapting the multigrid method of [24] to here is immediate. For the CDD model however, so far only the well known but usually very slow explicit time marching method has been reported and we explain why the implementation of a fixed point method for the CDD model is not straightforward. Consequently the multigrid method as in [Savage and Chen, Int. j. Comput. Math., 82 （2005）, pp. 1001-1015] will not work here. This fact represents a strong limitation to the range of applications of this model since usually fast solutions are expected. In this paper, we introduce a modification designed to enable a fixed point method to work and to preserve the features of the original CDD model. As a result, a fast and efficient multigrid method is developed for the modified model. Numerical experiments are presented to show the very good performance of the fast algorithm.

关键词： Image inpainting Variational models Regularization Multilevel methods.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Liver tissue microbiota in nonalcoholic liver disease:a change in the paradigm of host-bacterial interactions

引用

Hepatobiliary Surgery and Nutrition 2021年第3期10卷 337-349页

作者： Silvia Sookoian carlos j.Pirola School of Medicine Institute of Medical Research A LanariUniversity of Buenos AiresCiudad Autónoma de Buenos AiresArgentina Department of Clinical and Molecular Hepatology Institute of Medical Research(IDIM)National Scientific and Technical Research Council(CONICET)University of Buenos AiresCiudad Autónoma de Buenos AiresArgentina Department of Molecular Genetics and Biology of Complex Diseases Institute of Medical Research(IDIM)National Scientific and Technical Research Council(CONICET)University of Buenos AiresCiudad Autónoma de Buenos AiresArgentina

Nonalcoholic fatty liver disease(NAFLD)pathogenesis is explained by the complex relationship among diet and lifestyle-predisposing factors,the genetic variance of the nuclear and mitochondrial genome,associated phenotypic traits,and the yet not fully explored interactions with epigenetic and other environmental factors,including the *** the wealth of knowledge gained from molecular and genome-wide investigations in patients with NAFLD,the precise mechanisms that explain the variability of the histological phenotypes are not fully *** studies of the gut microbiota in patients with NAFLD and nonalcoholic steatohepatitis(NASH)provided clues on the role of the fecal microbiome in the disease ***,the composition of the gut microbiota does not fully explain tissue-specific mechanisms associated with the degree of disease severity,including liver inflammation,ballooning of hepatocytes,and *** liver acts as a key filtration system of the whole body by receiving blood from the hepatic artery and the portal ***,not only microbes would become entrapped in the complex liver anatomy but,more importantly,bacterial derived products that are likely to be potentially powerful stimuli for initiating the inflammatory ***,the study of liver tissue microbiota offers the opportunity of changing the paradigm of host-NAFLD-microbial interactions from a“gut-centric”to a“liver-centric”***,we highlight the evidence on the role of liver tissue bacterial DNA in the biology of NAFLD and ***,we provide evidence of metagenomic findings that can serve as the seed of further hypothesis-raising studies as well as can be leveraged to discover novel therapeutic targets.

关键词： Nonalcoholic fatty liver disease(NAFLD) nonalcoholic steatohepatitis(NASH) HSD17B13 microbiota microbiome proteobacteria lipopolysaccharide(LPS) drug prediction

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

MODELING HEADCUT DEVELOPMENT AND MIGRATION IN UPLAND CONCENTRATED FLOWS

引用

International journal of Sediment Research 2005年第4期20卷 281-294页

作者： Sean j. BENNETT carlos V. ALONSO Department of Geography University at Buffalo Buffalo NY 14261-0055 USA USDA-ARS National Sedimentation Laboratory P.O. Box 1157 Oxford MS 38655

On hillslopes and agricultural fields, discrete areas of intense, localized soil erosion commonly take place in the form of migrating headcuts. These erosional features significantly increase soil loss and landscape degradation, yet the unsteady, transient, and migratory habits of headcuts complicate their phenomenological and erosional characterization. Here a unique experimental facility was constructed to examine actively migrating headcuts typical of upland concentrated flows. Essential components of the facility include a deep soil cavity with external drainage, rainfall simulator, capacity for overland flow, and a video recording technique for data collection. Results from these experiments show that: (1) after a short period of adjustment, headcut migration attained a steady-state condition, where the rate of migration, scour hole geometry, and sediment discharge remain constant with time; (2) boundary conditions of higher rates of overland flow, steeper bed slopes, and larger initial headcut heights produced systematically larger scour holes with higher rates of soil erosion; and (3) during migration, the turbulent flow structure within the scour hole remained unchanged, consisting of an overfall nappe at the brink transitioning into a reattached wall jet with two recirculation eddies within the plunge pool. The systematic behavior of headcut development and migration enabled the application of modified jet impingement theory to predict with good success the characteristics of the impinging jet, the depth of maximum scour, the rate of headcut migration, and the rate of sediment erosion. These laboratory data and the analytical formulation can be used in conjunction with soil erosion prediction technology to improve the management of agricultural areas impacted by headcut development and ephemeral gully erosion.

关键词： Soil erosion Headcuts Rills Gullies jet impingement

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

The Rhyacian El Cortijo suture zone: Aeromagnetic signature and insights for the geodynamic evolution of the southwestern Rio de la Plata craton, Argentina

引用

Geoscience Frontiers 2014年第1期5卷 43-52页

作者： carlos j.Chernicoff Eduardo O.Zappettini javier Peroni Council for Scientifc and Technical Research (CONICET) Argentina Argentine Geological-Mining Survey (SEGEMAR) Argentina

The amalgamation of the southern Rio de la Plata craton involves two possibly coeval Rhyacian sutures associated with the Transamazonian orogeny, rather than a single one as previously envisaged, i.e. the El Cortijo suture zone and the Salado suture. We circumscribe the Tandilia terrane to the region between these two sutures. The E1 Cortijo suture zone runs along a roughly WNW oriented magnetic low aligned along the southern boundary of the Tandilia terrane, i.e. boundary between the Tandilia and Balcarce terranes. This extensive magnetic low, ca. 300 km long, and ca. 90 km wide, would be caused by demagnetization associated with shearing. At a more local scale, the trend of the El Cortijo suture zone often turns toward the E-W. At this scale, WNW trending tholeiitic dykes of Statherian age are seen to cut the Rhyacian E1 Cortijo suture zone. Spatially associated with the El Corti]o suture zone, there are small magnetic highs interpreted to be related to unexposed basic bodies of ophiolitic nature related to those forming part of the El Cortijo Formation. We envisage the pre-Neoproterozoic evolution of the Tandilia belt to have been initiated by the extension of Neoarchean （ - 2650 Ma） crust occurred during Siderian times （2500-2300 Ma）, causing the separation between the Balcarce, Tandilia and Buenos Aires terranes, and the development of narrow oceans at both north and south sides of the Tandilia terrane, accompanied by -2300-2200 Ma sedi- mentation over transitional -continental to oceanic- crust, and arc magmatism developed in the Tan- dilia terrane. The island arc represented by the El Cortijo Formation was also developed at this time. At late Rhyacian times, it occurred in both the closure of the narrow oceans developed previously, the entrapment of the El Cortijo island arc, as well as anatectic magmatism in the Balcarce terrane.

关键词： El Cortijo suture zone Rhyacian Rio de la Plata craton Aeromagnetics

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Variations of OCT measurements corrected for the magnification effect according to axial length and refractive error in children

引用

journal of Innovative Optical Health Sciences 2018年第1期11卷 123-137页

作者： Inmaculada Bueno-Gimeno Enrique España-Gregori Andres Gene-Sampedro juan carlos Ondategui-Parra carlos j.Zapata-Rodriguez Department of Optics and Optometry and Vision Science University of Valencia Spain Department of Surgery University of Valencia University Hospital La FeSpain Faculty of Optics and Optometry University Vision Centre Polytechnic University of CataloniaSpain

Purpose:The aim of this paper was to examine the distribution of macular,retinal nerve fiber layer(RNFL)thickness and optic disc parameters of myopic and hyperopic eyes in comparison withemmetropic control eyes and to investigate their variation according to axial length(AL)andspherical equivalent(SE)in healthy ***:This study included 293 pairs of eyes of 293children(145 boys and 148 girks),ranging in age from 6 to 17 years,Subjects were dividedaccording to SE in control(emmetropia,99 children),myopia(100 children)and hyperopia(94children)groups and according to axial AL in 68 short(25.00 mm,36).Macular parameters,RNFL thickness and opticdisc morphology were assessed by the Cirrus^(TM) *** was measured using the ***'s formula was used for calculating the corrected AL-related ocular *** Mean age(±SD)was 10.84±3.05 years;mean(±SD)SE was+0.14±0.51 D(range from8.75 to+8.25 D)and mean AL(±SD)was 23.12±*** RNFL thickness,averagemacular thickness and macular volume decreased as AL and myopia *** correlationsbetween AL/SE and optic disc parameters were found after correcting for magnification ***:AL and refractive error affect measurements of macular and RNFL thickness inhealthy *** make a correct interpretation of ocT measurements,ocular magnificationeffect should be taken into account by clinicians or OCT manufacturers.

关键词： Axial length refractive error children OCT measurements magnification fect

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Muscle strength deficits are associated with low bone mineral density in young pediatric cancer survivors:The iBoneFIT project

引用

journal of Sport and Health Science 2024年第3期13卷 419-427页

作者： Andres Marmol-Perez jose j.Gil-Cosano Esther Ubago-Guisado Francisco j.Llorente-Cantarero juan Francisco Pascual-Gázquez Kirsten K.Ness Vicente Martinez-Vizcaino jonatan R.Ruiz Luis Gracia-Marco Department of Physical Education and Sports Faculty of Sport SciencesSport and Health University Research Institute(iMUDS)University of GranadaGranada 18011Spain Department of Epidemiology and Cancer Control St.Jude Children's Research HospitalMemphisTN 38105USA Department of Communication and Education Loyola University AndalusiaSeville 41704Spain Biosanitary Research Institute ibs.GranadaGranada 18012Spain Maimonides Biomedical Research Institute of Cordoba(IMIBIC) Cordoba 14004Spain CIBEROBN Biomedical Research Networking Center for Physiopathology of Obesity and NutritionCarlos III Health InstituteMadrid 28029Spain Department of Specific Didactics Faculty of EducationUniversity of CordobaCordoba 14071Spain Pediatric and adolescent hematology and oncology service Pediatrics and Pediatric Surgery Clinical Management UnitVirgen de las Nieves University HospitalGranada 18014Spain Health and Social Research Center Universidad de Castilla-La ManchaCuenca 13001Spain

Background Pediatric cancer survivors are at increased risk of muscle weakness and low areal bone mineral density(aBMD).However,the prevalence of muscle strength deficits is not well documented,and the associations of muscle strength with aBMD are unknown in this ***,this study aimed to investigate the prevalence of upper-and lower-body muscle strength deficits and to examine the associations of upper-and lower-body muscle strength with age-,sex,and race-specific aBMD Z-scores at the total body,total hip,femoral neck,and lumbar *** This cross-sectional study included 116 pediatric cancer survivors(12.1±3.3 years old,mean±SD;42.2%female).Upper-and lower-body muscle strength were assessed by handgrip and standing long jump test,***‑energy X‑ray absorptiometry was used to measure aBMD(g/cm2).Associations between muscle strength and aBMD were evaluated in multivariable linear regression *** regression was used to evaluate the contribution of muscle strength(1-decile lower)to the odds of having low aBMD(Z-score≤1.0).All analyses were adjusted for time from treatment completion,radiotherapy exposure,and body mass *** More than one-half of survivors were within the 2 lowest deciles for upper-(56.9%)and lower-body muscle strength(60.0%)in comparison to age-and sex-specific reference *** strength deficits were associated with lower aBMD Z-scores at all sites(B=0.133–0.258,p=0.001–0.032).Each 1-decile lower in upper-body muscle strength was associated with 30%–95%higher odds of having low aBMD Z-scores at all *** 1-decile lower in lower-body muscle strength was associated with 35%–70%higher odds of having low aBMD Z-scores at total body,total hip,and femoral *** Muscle strength deficits are prevalent in young pediatric cancer survivors,and such deficits are associated with lower aBMD Z-scores at all *** results suggest that interventions designed to improve muscle strength in t

关键词： Bone health Childhood cancer DXA Lean mass Resistance training

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：