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Distribution by Scientific Domains

Medical Sciences	54%
Information Science and Computing	15%
Business, Economics, Finance and Accounting	8%
Life Sciences	6%
Humanities and Social Sciences	6%
Chemistry	3%
Engineering	2%

Distribution within Medical Sciences

Gastroenterology & Hepatology	16%
Hepatology	9%
Transplantation	7%
Radiology & Imaging	5%
General & Internal Medicine	3%
18 Other Subdomains	54%

Terms modified by Portal

portal hypertensive rat

portal vein blood flow

portal vein embolization

portal vein thrombosis

portal vein tumor thrombus

portal venous

portal venous blood flow

portal venous flow

portal venous gas

portal venule

Selected Abstracts

Portal-based Knowledge Environment for Collaborative Science

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 12 2007
Karen Schuchardt
Abstract The Knowledge Environment for Collaborative Science (KnECS) is an open-source informatics toolkit designed to enable knowledge Grids that interconnect science communities, unique facilities, data, and tools. KnECS features a Web portal with team and data collaboration tools, lightweight federation of data, provenance tracking, and multi-level support for application integration. We identify the capabilities of KnECS and discuss extensions from the Collaboratory for Multi-Scale Chemical Sciences (CMCS) which enable diverse combustion science communities to create and share verified, documented data sets and reference data, thereby demonstrating new methods of community interaction and data interoperability required by systems science approaches. Finally, we summarize the challenges we encountered and foresee for knowledge environments. Copyright © 2007 John Wiley & Sons, Ltd. [source]

The LEAD Portal: a TeraGrid gateway and application service architecture

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 6 2007
Marcus Christie
Abstract The Linked Environments for Atmospheric Discovery (LEAD) Portal is a science application portal designed to enable effective use of Grid resources in exploring mesoscale meteorological phenomena. The aim of the LEAD Portal is to provide a more productive interface for doing experimental work by the meteorological research community, as well as bringing weather research to a wider class of users, meaning pre-college students in grades 6,12 and undergraduate college students. In this paper, we give an overview of the LEAD project and the role that LEAD portal is playing in reaching its goals. We then describe the various technologies we are using to bring powerful and complex scientific tools to educational and research users. These technologies,a fine-grained capability based authorization framework, an application service factory toolkit, and a Web services-based workflow execution engine and supporting tools,enable our team to deploy these once inaccessible, stovepipe scientific codes onto a Grid where they can be collectively utilized. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Personalization versus Customization: The Importance of Agency, Privacy, and Power Usage

HUMAN COMMUNICATION RESEARCH, Issue 3 2010
S. Shyam Sundar
What makes customization so appealing? Is it because the content is tailored or because the user feels greater agency? Study 1 tested these propositions with a news-aggregator Website that was either personalized (system-tailored), customized (user-tailored), or neither. Power users rated content quality higher when it had a customizable interface, whereas nonpower users preferred personalized content. In Study 2, half the participants were told that their browsing information may be used for providing requested services while the other half was told that it would not be used. The interaction found in Study 1 was observed only under conditions of low privacy, with the pattern being reversed under high privacy. Significant three-way interactions were found for sense of control and perceived convenience. Personalisierung vs. Kundenorientierung: Die Rolle von Agentschaft, Privatheit und Machtausübung Dieser Artikel dokumentiert zwei Studien. Studie 1 setzte Vielnutzer und Normalnutzer einer Nachrichtenaggregationswebseite aus, welche entweder personalisiert (system-zugeschnitten), kundenorientiert (nutzerzugeschnitten) oder keines von beiden war. Die Ergebnisse zeigen eine Kreuzinteraktion dahingehend, dass Vielnutzer die Qualität des Inhalts höher einstuften, wenn sie die kundenorientierte Oberfläche nutzten, während Normalnutzer den personalisierten Inhalt bevorzugten. In Studie 2 wurde der Hälfte der Teilnehmer erzählt, dass ihre Surfinformationen möglicherweise genutzt werden, um die abgefragten Angebote bereitzustellen. Der anderen Hälfte wurde gesagt, dass dies nicht geschehe. Die Ergebnisse duplizieren das Kreuzmuster der ersten Studie, allerdings nur für die Niedrige-Privatheit-Bedingung. Das Muster kehrt sich für die Hohe-Privatheit-Kondition um. Signifikante 3-Wege-Interaktionen wurden für Wahrnehmung von Kontrolle und wahrgenommene Verbraucherfreundlichkeit gefunden. Schlüsselbegriffe: Kundenorientierung, Personalisierung, Agentschaft, Vielnutzung, Privatheit, wahrgenommene Kontrolle, wahrgenommene Verbraucherfreundlichkeit, Online-Nachrichten, Gatekeeping, Portal Adaptation ou personnalisation : L'importance de l'agentivité, de la confidentialité et de l'intensité de l'utilisation Résumé Cet article fait état de deux études. La première a présentéà de grands utilisateurs et à des utilisateurs réguliers un site web agrégateur de nouvelles qui était adaptéà l'utilisateur (conçu par le système), personnalisé (façonné par l'utilisateur lui-même) ou qui n'était ni l'un ni l'autre. Les résultats révèlent une interaction asymétrique en ce que les grands utilisateurs notaient plus favorablement la qualité du contenu lorsque le site avait une interface personnalisée, alors que les utilisateurs réguliers préféraient le contenu adapté. Dans la seconde étude, la moitié des participants ont été avisés que l'information sur leur navigation pourrait être utilisée afin de leur offrir les services demandés, alors que l'autre moitié a été avisée que cette information ne serait pas utilisée. Les résultats montrent que le modèle asymétrique révélé dans la première étude ne s'observait que sous les conditions de faible confidentialité, alors que le rapport s'inversait dans le contexte de forte confidentialité. Des interactions triangulaires significatives ont été démontrées pour le sentiment de contrôle et pour le sentiment de commodité. Mots clés : adaptation, personnalisation, agentivité, grands utilisateurs, vie privée, sentiment de contrôle, sentiment de commodité, nouvelles en ligne, portail La Personalización versus la Adaptación al Cliente La Importancia de la Agencia, la Privacidad, y el Uso del Poder Resumen Este manuscrito presenta dos estudios. El estudio 1 expuso a los usuarios de poder, así como a los usuarios regulares a una página agregada de noticias de Internet que estuvo ó personalizada (adaptada al sistema), ó adaptada al cliente (adaptada al usuario), ó a ninguna de las dos. Los hallazgos revelaron una interacción de cruce tal que los usuarios con poder estimaron al contenido como de mayor calidad cuando tenían una interfaz adaptada al usuario, mientras que los usuarios sin poder prefirieron el contenido personalizado. En el estudio 2, se les dijo a la mitad de los participantes que la forma en la que buscaban información podría ser usada para proveer los servicios solicitados mientras que a la otra mitad se le dijo que no sería usada. Los resultados revelaron que la pauta de cruzamiento encontrada en el estudio 1 fue observada solo en condiciones de privacidad baja, mientras que la pauta fue reversa bajo las condiciones de privacidad alta. Las interacciones significativas de 3 partes fueron encontradas para el sentido del control y la percepción de la conveniencia. Palabras Claves: Adaptado al cliente, personalización, agencia, poder de uso, privacidad, control percibido, percepción de conveniencia, noticias online, guardián, portal. [source]

The application of change management theory to HR portal implementation in subsidiaries of multinational corporations

HUMAN RESOURCE MANAGEMENT, Issue 1 2005
Cataldo Dino Ruta
HR portals are complex information technology (IT) applications that can be accessed by all employees of a given organization. By placing more applications and information online, HR portals reduce the reliance employees have on HR personnel. Given this relational change, from human to computer, the HR portal implementation process must take into account the challenges of both change management and technology acceptance. By integrating change management theories with IT user acceptance models, this article adds to HR's collective knowledge of ways to effectively implement HR portals. In addition, this article describes the cross-national challenges that exist when a global firm attempts to implement an HR portal around the world. Thus, this article will present a model that (1) integrates change management theories and IT user acceptance models and (2) illustrates the ways in which change management plans may need to be adapted to be effective in various subsidiaries. A case study of Hewlett-Packard's (HP's) worldwide implementation of their @HP Employee Portal in the Italian subsidiary of HP illustrates the key issues of these theories. © 2005 Wiley Periodicals, Inc. [source]

A knowledge management perspective to evaluation of enterprise information portals

KNOWLEDGE AND PROCESS MANAGEMENT: THE JOURNAL OF CORPORATE TRANSFORMATION, Issue 2 2002
Yong Jin Kim
The paper develops conceptual criteria for evaluating Enterprise Information Portal (EIP) systems in the context of knowledge management activities such as knowledge integration and application. The criteria have been drawn from an Activity theory perspective consisting of actors, community, object, tools, rules, and division of labor. It then discusses the characteristics of several commercial EIPs and evaluates one major commercial EIP in the context of the framework. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Rodents, plants, and precipitation: spatial and temporal dynamics of consumers and resources

OIKOS, Issue 3 2000
S. K. Morgan Ernest
Resource/consumer dynamics are potentially mediated by both limiting resources and biotic interactions. We examined temporal correlations between precipitation, plant cover, and rodent density, with varying time lags using long-term data from two sites in the Chihuahuan desert of North America: the Sevilleta Long-term Ecological Research site (LTER), New Mexico, USA and a site near Portal, Arizona, USA. We also calculated the spatial correlations in precipitation, plant cover, and rodent dynamics among six sites, five at Sevilleta and one at Portal. At Sevilleta, all three variables were temporally correlated, with plant cover responding to precipitation during the same growing season and rodent populations lagging at least one season behind. At Portal, plant stem count was also correlated with precipitation during the same growing season, but there was no significant correlation between rodents and either precipitation or plant growth. Spatial correlations in plant cover and rodent populations between sites reflected the localized nature of summer rainfall, so that sites with highly correlated summer precipitation exhibited higher correlations in plant cover and rodent populations. In general, our results indicate that limiting resources influence consumer dynamics, but these dynamics also depend crucially on the biotic interactions in the system. [source]

Two-dimensional reference map for the basic proteome of the human dorsolateral prefrontal cortex (dlPFC) of the prefrontal lobe region of the brain

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 13 2010
Ciara A. McManus
Abstract We describe a 2-DE proteomic reference map containing 227 basic proteins in the dorsolateral prefrontal cortex region of the human brain. Proteins were separated in the first dimension on pH 6,11 IPG strips using paper-bridge loading and on 12% SDS-PAGE in the second dimension. Proteins were subsequently identified by MS and spectra were analyzed using an in-house proteomics data analysis platform, Proline. The 2-DE reference map is available via the UCD 2-DE Proteome Database (http://proteomics-portal.ucd.ie:8082) and can also be accessed via the WORLD-2DPAGE Portal (http://www.expasy.ch/world-2dpage/). The associated protein identification data have been submitted to the PRIDE database (accession numbers 10018,10033). Separation of proteins in the basic region resolves more membrane associated proteins relevant to the synaptic pathology central to many neurological disorders. The 2-DE reference map will aid with further characterisation of neurological disorders such as bipolar and schizophrenia. [source]

Space on Earth: A Virtual Portal Between the Earth and Outer Space

ARCHITECTURAL DESIGN, Issue 3 2008
Valentina Croci
Abstract Every time you text or call from your mobile phone, you may be unknowingly providing essential data that is being captured for public or commercial research. Valentina Croci describes how The Senseable City Lab at MIT and the Estonian group Positium LBS with the Department of Geography at the University of Tartu have been developing projects that enable us to sense the city, dynamically mapping social movement. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Inventing the Gothic Portal: Suger, Hugh of Saint Victor, and the Construction of a New Public Art at Saint-Denis

ART HISTORY, Issue 4 2010
Conrad Rudolph
First page of article [source]

Manipulation of the small intestine as a cause of the increased inflammatory response after open compared with laparoscopic surgery,,

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 2 2006
N. Hiki
Background: Laparoscopic surgery of the gastrointestinal tract involves a reduced immune response compared with open surgery. The aim of this study was to assess manual handling of the gut in open procedures as the principal cause of the enhanced immune response. Methods: Eighteen Landrace pigs underwent gastrectomy by three different methods: conventional open wound with bowel manipulation, laparoscopically assisted gastrectomy, and gastrectomy without manipulation using a combination of open wound and laparoscopic surgical devices. Local inflammatory changes were assessed by ascites formation, intestinal adhesion development and intestinal inflammatory gene expression. Associated systemic inflammatory changes were determined by measuring portal and systemic plasma endotoxin levels, plasma inflammatory cytokine levels, liver inflammatory gene expression and transaminase levels. Results: Significantly more postoperative intra-abdominal fluid and adhesions were seen in the open group. The expression of inflammatory cytokines was significantly greater in the intestine and liver in the open group. Portal and systemic levels of endotoxin, inflammatory cytokines and transaminases were also higher. Conclusion: Manual handling of organs during gastrectomy is an important contributor to the molecular and humoral inflammatory response to surgery, supporting the use of minimally invasive techniques in gastrointestinal surgery. Copyright © 2005 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source]

Can MR fluoroscopic triggering technique and slow rate injection provide appropriate arterial phase images with reducing artifacts on gadoxetic acid-DTPA (Gd-EOB-DTPA)-enhanced hepatic MR imaging?

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 2 2010
Hiroki Haradome MD
Abstract Purpose: To evaluate whether using MR fluoroscopic triggering technique and slow rate injection improves the quality of arterial phase images in gadoxetic acid-DTPA-enhanced (Gd-EOB-DTPA) MR imaging because of proper acquisition timing and reduction of artifacts. Materials and Methods: Two hundred sixteen patients undergoing examination for liver diseases were retrospectively reviewed. All MR images were obtained with two Gd-EOB-DTPA injection protocols: (i) a combination protocol, in which the MR fluoroscopic triggering technique and slow rate injection (1 mL/s) were used; and for comparison, (ii) a conventional protocol, in which adjusted fixed scan delay and ordinary rate injection (2 mL/s) were adopted. Signal-to-noise ratio (SNR) of aorta, portal vein, and liver parenchyma on arterial phase images were calculated. Two blinded readers independently evaluated the obtained arterial phase images in terms of acquisition timing and degree of artifacts. Results: The SNRs of aorta and portal vein on arterial phase images were significantly higher in the combination protocol group (aorta/portal: 221.9 ± 91.9/197.1 ± 89.8) than that in the conventional protocol group (aorta/portal: 169.8 ± 97.4/92.7 ± 48.5) (P < 0.05). The acquisition timing for arterial phase images with the combination protocol was significantly better than that with the conventional protocol (P < 0.01). The image quality of the combination protocol was significantly higher than that of the conventional protocol (P < 0.01). The occurrence rate of moderate or severe degree of artifacts in the conventional protocol (38.0%) was more prominent than that in the combination protocol (18.5%). Conclusion: The combination of the MR fluoroscopic triggering technique and slow rate injection provides proper arterial phase images and reduces the artifacts in Gd-EOB-DTPA MR imaging. J. Magn. Reson. Imaging 2010;32:334,340. © 2010 Wiley-Liss, Inc. [source]

BUILDING A DATA-MINING GRID FOR MULTIPLE HUMAN BRAIN DATA ANALYSIS

COMPUTATIONAL INTELLIGENCE, Issue 2 2005
Ning Zhong
E-science is about global collaboration in key areas of science such as cognitive science and brain science, and the next generation of infrastructure such as the Wisdom Web and Knowledge Grids. As a case study, we investigate human multiperception mechanism by cooperatively using various psychological experiments, physiological measurements, and data mining techniques for developing artificial systems which match human ability in specific aspects. In particular, we observe fMRI (functional magnetic resonance imaging) and EEG (electroencephalogram) brain activations from the viewpoint of peculiarity oriented mining and propose a way of peculiarity oriented mining for knowledge discovery in multiple human brain data. Based on such experience and needs, we concentrate on the architectural aspect of a brain-informatics portal from the perspective of the Wisdom Web and Knowledge Grids. We describe how to build a data-mining grid on the Wisdom Web for multiaspect human brain data analysis. The proposed methodology attempts to change the perspective of cognitive scientists from a single type of experimental data analysis toward a holistic view at a long-term, global field of vision. [source]

A Grid-enabled problem-solving environment for advanced reservoir uncertainty analysis

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 18 2008
Zhou Lei
Abstract Uncertainty analysis is critical for conducting reservoir performance prediction. However, it is challenging because it relies on (1) massive modeling-related, geographically distributed, terabyte, or even petabyte scale data sets (geoscience and engineering data), (2) needs to rapidly perform hundreds or thousands of flow simulations, being identical runs with different models calculating the impacts of various uncertainty factors, (3) an integrated, secure, and easy-to-use problem-solving toolkit to assist uncertainty analysis. We leverage Grid computing technologies to address these challenges. We design and implement an integrated problem-solving environment ResGrid to effectively improve reservoir uncertainty analysis. The ResGrid consists of data management, execution management, and a Grid portal. Data Grid tools, such as metadata, replica, and transfer services, are used to meet massive size and geographically distributed characteristics of data sets. Workflow, task farming, and resource allocation are used to support large-scale computation. A Grid portal integrates the data management and the computation solution into a unified easy-to-use interface, enabling reservoir engineers to specify uncertainty factors of interest and perform large-scale reservoir studies through a web browser. The ResGrid has been used in petroleum engineering. Copyright © 2008 John Wiley & Sons, Ltd. [source]

An application portal for collaborative coastal modeling

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 12 2007
Chongjie Zhang
Abstract We describe the background, architecture and implementation of a user portal for the SCOOP coastal ocean observing and modeling community. SCOOP is engaged in the real-time prediction of severe weather events, including tropical storms and hurricanes, and provides operational information including wind, storm surge and resulting inundation, which are important for emergency management. The SCOOP portal, built with the GridSphere Framework, currently integrates customized Grid portlet components for data access, job submission, resource management and notification. Copyright © 2007 John Wiley & Sons, Ltd. [source]

A workflow portal supporting multi-language interoperation and optimization

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 12 2007
Lican Huang
Abstract In this paper we present a workflow portal for Grid applications, which supports different workflow languages and workflow optimization. We present an XSLT converter that converts from one workflow language to another and enables the interoperation between different workflow languages. We discuss strategies for choosing the optimal service from several semantically equivalent Web services in a Grid application. The dynamic selection of Web services involves discovering a set of semantically equivalent services by filtering the available services based on metadata, and selecting an optimal service based on real-time data and/or historical data recorded during prior executions. Finally, we describe the framework and implementation of the workflow portal which aggregates different components of the project using Java portlets. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Portal-based Knowledge Environment for Collaborative Science

The LEAD Portal: a TeraGrid gateway and application service architecture

An EasyGrid portal for scheduling system-aware applications on computational Grids

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 6 2006
C. Boeres
Abstract One of the objectives of computational Grids is to offer applications the collective computational power of distributed but typically shared heterogeneous resources. Unfortunately, efficiently harnessing the performance potential of such systems (i.e. how and where applications should execute on the Grid) is a challenging endeavor due principally to the very distributed, shared and heterogeneous nature of the resources involved. A crucial step towards solving this problem is the need to identify both an appropriate scheduling model and scheduling algorithm(s). This paper presents a tool to aid the design and evaluation of scheduling policies suitable for efficient execution of system-aware parallel applications on computational Grids. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Analysis of gene expression patterns in the developing chick liver

DEVELOPMENTAL DYNAMICS, Issue 3 2005
Masaaki Yanai
Abstract The chick embryo has been used widely for studying liver development. However, in the past 30 years, the usage has decreased markedly due to lack of appropriate marker genes for differentiation in the developing chick liver. To use the chick embryo for analyzing the molecular mechanism of liver development, we surveyed marker genes in the developing chick liver by examining the expression pattern of genes that are well-characterized in the developing mammalian liver. By whole-mount in situ hybridization, Fibrinogen - gamma (FIB) expression was first detected at stage 12, specifically in the anterior intestinal portal, and its liver-specific expression persisted in the later stages. Albumin (ALB) expression was first detected at stage 30, when the liver starts maturing. Cytokeratin 19 (CK19) was first detected at stage 37 in the ductal plate of the liver, and its expression continued in the intrahepatic bile ducts derived from the ductal plate. Hex, a transcription factor, is an additional marker of bile duct differentiation. Hence, FIB, ALB, and CK19 expression can be used to trace hepatic induction, maturation, and bile duct differentiation, respectively. Developmental Dynamics 233:1116,1122, 2005. © 2005 Wiley-Liss, Inc. [source]

A correlation study on diagnostic endoscopic ultrasound-guided fine-needle aspiration of lymph nodes with histological and clinical diagnoses, the UCLA Medical Center experience

DIAGNOSTIC CYTOPATHOLOGY, Issue 7 2008
Bita V. Naini M.D.
Abstract Endoscopic ultrasound guided (EUS) FNA procedure has two aspects, the endoscopic sampling and the FNA interpretation. The two aspects of the procedure are performed in two different disciplines; gastroenterology (EUS) and pathology (FNA). The aim of this study was to evaluate the concordance, sensitivity, specificity, positive predictive (PPV), and negative predictive values (NPV). Sixty-one EUS-FNA procedures of the lymph nodes were analyzed by correlating the FNA results with histological or clinical diagnoses. The lymph nodes were divided in five groups; mediastinal, gastrohepatic, peripancreatic, portal, and perirectal. The study showed a concordance of 92% in mediastinal, 80% in gastrohepatic, 81% in peripancreatic, 95% in portal, and 100% in perirectal lymph nodes with an overall sensitivity of 84%, specificity of 92%, PPV of 88%, and NPV of 89%. In conclusion, EUS-FNA offers an invaluable approach for diagnostic examination of the internal lymph nodes where percutaneous FNA is either difficult or impossible. impossible. Diagn. Cytopathol. 2008;36:460,466. © 2008 Wiley-Liss, Inc. [source]

Proximity to the US,Mexico border: a key to explaining geographic variation in US methamphetamine, cocaine and heroin purity

ADDICTION, Issue 10 2010
James K. Cunningham
ABSTRACT Aims Although illicit drug purity is a widely discussed health risk, research explaining its geographic variation within a country is rare. This study examines whether proximity to the US,Mexico border, the United States' primary drug import portal, is associated with geographic variation in US methamphetamine, heroin and cocaine purity. Design Distances (proximity) between the US,Mexico border and locations of methamphetamine, cocaine and heroin seizures/acquisitions (n = 239 070) recorded in STRIDE (System to Retrieve Information from Drug Evidence) were calculated for the period of 1990,2004. The association of drug purity with these distances and other variables, including time and seizure/acquisition size, was examined using hierarchical multivariate linear modeling (HMLM). Setting Coterminous United States. Findings Methamphetamine, cocaine and heroin purity generally decreased with distance from the US,Mexico border. Heroin purity, however, after initially declining with distance, turned upwards,a U-shaped association. During 2000,04, methamphetamine purity also had a U-shaped association with distance. For each of the three drugs, temporal changes in the purity of small acquisitions (<10 g) were typically more dynamic in areas closer to the US,Mexico border. Conclusions Geographic variance in methamphetamine, cocaine and heroin purity throughout the coterminous United States was associated with US,Mexico border proximity. The U-shaped associations between border-distance and purity for heroin and methamphetamine may be due to imports of those drugs via the eastern United States and southeast Canada, respectively. That said, areas closer to the US,Mexico border generally had relatively high illicit drug purity, as well as more dynamic change in the purity of small (,retail level') drug amounts. [source]

Effects of endothelin-1 on portal-systemic collaterals of common bile duct-ligated cirrhotic rats

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 4 2004
C.-C. Chan
Abstract Background/Aims, Endothelin-1 (ET-1) may induce intrahepatic vasoconstriction and consequently increase portal pressure. Endothelin-1 has been shown to exert a direct vasoconstrictive effect on the collateral vessels in partially portal vein-ligated rats with a high degree of portal-systemic shunting. This study investigated the collateral vascular responses to ET-1, the receptors in mediation and the regulation of ET-1 action by nitric oxide and prostaglandin in cirrhotic rats with a relatively low degree of portal-systemic shunting. Methods, The portal-systemic collaterals of common bile duct-ligated (BDL) cirrhotic rats were tested by in situ perfusion. The concentration-response curves of collaterals to graded concentrations of ET-1 (10,10,10,7 m) with or without BQ-123 (ETA receptor antagonist, 2 × 10,6 m), BQ-788 (ETB receptor antagonist, 10,7 m) or both were recorded. In addition, the collateral responses to ET-1 with preincubation of N, -nitro-L-arginine (NNA, 10,4 M), indomethacin (INDO, 10,5 M) or in combination were assessed. Results, Endothelin-1 significantly increased the perfusion pressures of portal-systemic collaterals. The ET-1-induced constrictive effects were inhibited by BQ-123 or BQ-123 plus BQ-788 but not by BQ-788 alone. The inhibitory effect was greater in the combination group. Pretreatment of NNA or NNA plus INDO equivalently enhanced the response of ET-1 while pretreatment of INDO alone exerted no effect. Conclusion, Endothelin-1 has a direct vasoconstrictive effect on the collaterals of BDL cirrhotic rats, mainly mediated by ETA receptor. Endogenous nitric oxide may play an important role in modulating the effects of ET-1 in the portal-systemic collaterals of BDL cirrhotic rats. [source]

Inhibition of prostacyclin by indomethacin ameliorates the splanchnic hyposensitivity to glypressin in haemorrhage-transfused common bile duct-ligated rats

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 2 2001
F.-Y. Lee
Prostacyclin (PGI2) is an important contributor to the mediation of hyporeactivity to vasoconstrictors and the development of hyperdynamic circulation in portal hypertensive states. Inhibition of PGI2 synthesis in haemorrhage-transfused partially portal vein-ligated rats could ameliorate the splanchnic hyposensitivity to glypressin, a long-acting vasopressin analogue. This study investigated whether the hyposensitivity to glypressin also exists in rats with common bile duct ligation (BDL) and whether the inhibition of PGI2 synthesis by indomethacin could potentiate the portal-hypotensive effect of glypressin in bleeding BDL rats. Two series of BDL rats were used. Series 1 investigated the haemodynamic effects of low dose glypressin (0·07 mg kg,1) in BDL rats with or without bleeding by catheterization. In series 2, haemodynamic parameters were measured in stable or bleeding BDL rats that were receiving intravenously high dose glypressin (0·2 mg kg,1) or indomethacin (5 mg kg,1) followed by high dose glypressin. In rats with a hypotensive haemorrhage, 4·5 mL of blood was withdrawn and 50% of the withdrawn blood was reinfused before the administration of glypressin or indomethacin. Splanchnic hyposensitivity to glypressin was demonstrated in haemorrhage-transfused BDL rats receiving high, but not low, doses of glypressin. Indomethacin infusion did not cause significant systemic and portal haemodynamic changes in bleeding BDL rats (P > 0·05). The addition of indomethacin significantly enhanced the portal-hypotensive effects of glypressin (P < 0·05) and potentiated the increases in mean arterial pressure induced by glypressin infusion (P < 0·001) in bleeding BDL rats. Splanchnic hyposensitivity to glypressin observed in haemorrhage-transfused BDL rats could be ameliorated by the addition of indomethacin, suggesting a role of endogenous PGI2 in its pathophysiology. [source]

The Emergency Medical Treatment and Labor Act as a Federal Health Care Safety Net Program

ACADEMIC EMERGENCY MEDICINE, Issue 11 2001
W. Wesley Fields MD
Abstract Despite the greatest economic expansion in history during the 1990s, the number of uninsured U.S. residents surpassed 44 million in 1998. Although this number declined for the first time in recent years in 1999, to 42.6 million, the current economic slow-down threatens once again to increase the ranks of the uninsured. Many uninsured patients use hospital emergency departments as a vital portal of entry into an access-improverished health care system. In 1986, Congress mandated access to emergency care when it passed the Emergency Medical Treatment and Labor Act (EMTALA). The EMTALA statute has prevented the unethical denial of emergency care based on inability to pay; however, the financial implications of EMTALA have not yet been adequately appreciated or addressed by Congress or the American public. Cuts in payments from public and private payers, as well as increasing demands from a larger uninsured population, have placed unprecedented financial strains on safety net providers. This paper reviews the financial implications of EMTALA, illustrating how the statute has evolved into a federal health care safety net program. Future actions are proposed, including the pressing need for greater public safety net funding and additional actions to preserve health care access for vulnerable populations. [source]

Calculations in the Field of Geotechnics

GEOMECHANICS AND TUNNELLING, Issue 4 2009
Article first published online: 5 AUG 200
The cover picture shows the Terfens portal of the main contract H5 of the Vomp-Terfens tunnel. The tunnel is 8,480 km long and was built between August 2003 and January 2009. Das Titelbild zeigt das Portal Terfens des Hauptbauloses H5 Tunnel Vomp-Terfens im Unterintal. Der Tunnel ist 8.480 m lang und wurde zwischen August 2003 und Januar 2009 errichtet. [source]

Rules of engagement in turbulent times: How Verizon Wireless uses a robust HR portal for employee communication

GLOBAL BUSINESS AND ORGANIZATIONAL EXCELLENCE, Issue 4 2009
Antonio Poglianich
Turbulent times such as these will test the resilience of many companies' communication capabilities, particularly for rapid response with consistent messaging to focus and engage a wary and distracted workforce on the many challenges ahead. The answer may be an HR portal like that at Verizon Wireless, where it is a core part of an engagement strategy that is the envy of the industry. The article discusses the importance of engagement for organizational and business performance; the role communication can play in driving engagement; and five principles for accomplishing this. The article goes on to explore how Verizon Wireless has developed and positioned its HR portal for rapid as well as sustained messaging, personalization, and self-service tools that all help define the employee experience. © 2009 Wiley Periodicals, Inc. [source]

Bone marrow and tumour stroma: an intimate relationship

HEMATOLOGICAL ONCOLOGY, Issue 4 2006
Natalie C Direkze
Abstract In recent years the bone marrow has become recognized as a potential source of cells for non-haematopoietic wound healing, in some instances demonstrating surprising plasticity in providing new epithelial cells. On the other hand, the contribution of bone marrow derived cells to fibrosis and blood vessel formation is more widely acknowledged. Tumour stroma has a vital role to play in determining cancer growth and spread, and there is a growing realization that the bone marrow has a significant input into this desmoplastic response. This review focuses on the contribution of bone marrow cells to tumour stroma, highlighting the bone marrow as a potential new portal through which to direct anti-tumour therapies. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Stereological measurement of porto-central gradients in gene expression in mouse liver

HEPATOLOGY, Issue 2 2004
Jan M. Ruijter
The liver is thought to consist of lobules, numerous repeating, randomly oriented units. Within these lobules, genes are expressed in gradients along the porto-central axis, which spans the distance between portal and central veins. We have developed a robust stereological method to map all points in an image to their position on this porto-central axis. This approach is based on the distribution of well-characterized periportal and pericentral enzymes, which are visualized on sections preceding and following the section of interest. Because expression of the model genes phosphoenolpyruvate carboxykinase and ornithine aminotransferase declines gradually with increasing distance from the portal vein and central vein, respectively, these genes can be used to prepare images with topographical information without any assumption about the shape of the hepatic unit, or about the direction or shape of the gradient to be determined. The "relative distance" image is a 2-dimensional image that accurately maps the relative position of hepatocytes on the porto-central axis in 3-dimensional space. It is superimposed on the serial section under investigation to relate local staining density to position on the porto-central axis and obtain the gene expression gradient. The method was used to determine the expression gradient of 2 periportal and 2 pericentral enzymes and their response to fasting. The "total distance" image was used to measure the length of the porto-central axis, which was approximately 210 ,m in mice and found to decrease 13% after 1 day of starvation. The method can be applied to any tissue component that can be stained quantitatively. (HEPATOLOGY 2004;39:343,352.) [source]

Interorgan ammonia and amino acid metabolism in metabolically stable patients with cirrhosis and a TIPSS

HEPATOLOGY, Issue 5 2002
Steven W. M. Olde Damink
Ammonia is central to the pathogenesis of hepatic encephalopathy. This study was designed to determine the quantitative dynamics of ammonia metabolism in patients with cirrhosis and previous treatment with a transjugular intrahepatic portosystemic stent shunt (TIPSS). We studied 24 patients with cirrhosis who underwent TIPSS portography. Blood was sampled and blood flows were measured across portal drained viscera, leg, kidney, and liver, and arteriovenous differences across the spleen and the inferior and superior mesenteric veins. The highest amount of ammonia was produced by the portal drained viscera. The kidneys also produced ammonia in amounts that equaled total hepatosplanchnic area production. Skeletal muscle removed more ammonia than the cirrhotic liver. The amount of nitrogen that was taken up by muscle in the form of ammonia was less than the glutamine that was released. The portal drained viscera consumed glutamine and produced ammonia, alanine, and citrulline. Urea was released in the splenic and superior mesenteric vein, contributing to whole-body ureagenesis in these cirrhotic patients. In conclusion, hyperammonemia in metabolically stable, overnight-fasted patients with cirrhosis of the liver and a TIPSS results from portosystemic shunting and renal ammonia production. Skeletal muscle removes more ammonia from the circulation than the cirrhotic liver. Muscle releases excessive amounts of the nontoxic nitrogen carrier glutamine, which can lead to ammonia production in the portal drained viscera (PDV) and kidneys. Urinary ammonia excretion and urea synthesis appear to be the only way to remove ammonia from the body. [source]

Improved diagnosis of well-differentiated hepatocellular carcinoma with gadolinium ethoxybenzyl diethylene triamine pentaacetic acid-enhanced magnetic resonance imaging and Sonazoid contrast-enhanced ultrasonography

HEPATOLOGY RESEARCH, Issue 9 2010
Natsuko Kawada
Aim:, Two new imaging modalities have been developed recently that are directed at the focal liver lesions: gadolinium ethoxybenzyl diethylene triamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and Sonazoid contrast-enhanced ultrasonography (CEUS). We investigated the usefulness of these modalities for the diagnosis of small (<2 cm), well-differentiated hepatocellular carcinoma (HCC). Methods:, A total of 15 nodules from 13 patients, which were histologically diagnosed as well-differentiated HCC, were subjected to this study. Lesions that showed hypervascularity in the arterial phase and washout in the portal or late non-hemodynamic phase were regarded as HCC in the dynamic studies of all imaging modalities. Results:, By multidetector computed tomography (MDCT), six of 15 (40%) nodules were diagnosed as HCC. Gd-EOB-DTPA-enhanced MRI diagnosed HCC in nine of the 15 (60%) nodules. Of the nine nodules that were not diagnosed by MDCT, four could be diagnosed by Gd-EOB-DTPA-enhanced MRI. In Sonazoid CEUS, 10 of 15 nodules (67%) were diagnosed as HCC. Four of nine nodules that could not be diagnosed as HCC by MDCT, were diagnosed by Sonazoid CEUS. A total of 11 of the 15 (73%) nodules were diagnosed as HCC by Gd-EOB-DTPA-enhanced MRI and Sonazoid CEUS in addition to MDCT. Conclusion:, Gd-EOB-DTPA-enhanced MRI and Sonazoid CEUS had greater diagnostic value for small, well-differentiated HCC than did conventional MDCT. [source]