[Show abstract][Hide abstract] ABSTRACT: Upon evaporation, ZnO nanorods in a nanofluid droplet undergo rapid and spontaneous chemical and morphological transformation into centimetre-long Zn(OH)2 fibres, via a mechanism very different from that for coffee rings. We show that the detailed nanostructure and micromorphology in the residual thin film depend intricately on the ambient moisture, nanofluid solvent composition and substrate surface chemistry. Upon thermal annealing, these Zn(OH)2 fibres readily undergo further chemical and morphological transformation, forming nanoporous fibres with the pore size tuneable by temperature. Our results point to a simple route for generating a self-assembled 3D structure with ultralong and nanoporous ZnO/Zn(OH)2 fibres/belts, and may also be of interest to the fields of evaporation controlled dynamic self-assembly, non-equilibrium crystallisation, and flow and fingering instabilities in nanofluids.
[Show abstract][Hide abstract] ABSTRACT: Increasing interests in a global environment and climate change have led to studies focused on the changes in the multinational Arctic region. To facilitate Arctic research, a spatial data infrastructure (SDI), where Arctic data, information, and services are shared and integrated in a seamless manner, particularly in light of today's climate change scenarios, is urgently needed. In this paper, we utilize the knowledge-based approach and the spatial web portal technology to prototype an Arctic SDI (ASDI) by proposing (1) a hybrid approach for efficient service discovery from distributed web catalogs and the dynamic Internet; (2) a domain knowledge base to model the latent semantic relationships among scientific data and services; and (3) an intelligent logic reasoning mechanism for (semi-)automatic service selection and chaining. A study of the influence of solid water dynamics to the bio-habitat of the Arctic region is used as an example to demonstrate the prototype.
[Show abstract][Hide abstract] ABSTRACT: Web services are key enabling technology for information interoperability and serve as the foundation for spatial Web portal. However, the quality of web services is different and becomes one of the challenges for deploying a spatial web portal. We conducted initial research and developed a spatial web service evaluator to assess the qualities of web services taken Open Geospatial Consortium (OGC) web services as an example. A two-level evaluation mechanism is proposed: 1) analyzing the validity of OGC web services by examining the corresponding service specifications, 2) comparing the performances of different services of the same type through calculating the time spent on responding, parsing, and transmitting the services. By focusing on existing web services, our evaluator has the following features: 1) Supporting the most frequently used services such as WMS, WFS and WCS and catalog service such as CSW; 2) Periodically checking performances and records into the database; 3) Showing all services and their overall performances graphically; 4) Deploying as a component which can be integrated into spatial web portal. The spatial web service evaluator suggests a new way to assess and visualize service quality.
[Show abstract][Hide abstract] ABSTRACT: The Global Earth Observation System of Systems (GEOSS) is established to support the study of the Earth system in a global community. It provides services for social management, quick response, academic research, and education. The purpose of GEOSS is to achieve comprehensive, coordinated and sustained observations of the Earth system, improve monitoring of the state of the Earth, increase understanding of Earth processes, and enhance prediction of the behavior of the Earth system. In 2009, GEO called for a competition for an official GEOSS clearinghouse to be selected as a source to consolidating catalogs for Earth observations. The Joint Center for Intelligent Spatial Computing at George Mason University worked with USGS to submit a solution based on the open-source platform - GeoNetwork. In the spring of 2010, the solution is selected as the product for GEOSS clearinghouse. The GEOSS Clearinghouse is a common search facility for the Intergovernmental Group on Ea rth Observation (GEO). By providing a list of harvesting functions in Business Logic, GEOSS clearinghouse can collect metadata from distributed catalogs including other GeoNetwork native nodes, webDAV/sitemap/WAF, catalog services for the web (CSW)2.0, GEOSS Component and Service Registry (http://geossregistries.info/), OGC Web Services (WCS, WFS, WMS and WPS), OAI Protocol for Metadata Harvesting 2.0, ArcSDE Server and Local File System. Metadata in GEOSS clearinghouse are managed in a database (MySQL, Postgresql, Oracle, or MckoiDB) and an index of the metadata is maintained through Lucene engine. Thus, EO data, services, and related resources can be discovered and accessed. It supports a variety of geospatial standards including CSW and SRU for search, FGDC and ISO metadata, and WMS related OGC standards for data access and visualization, as linked from the metadata.
[Show abstract][Hide abstract] ABSTRACT: This study reports the preliminary experience of dual grafts living donor liver transplantation (LDLT) for patients with acute-on-chronic liver failure (AoCLF) caused by hepatitis B.
Two patients who demonstrated acute-on-chronic hepatitis B liver failure and portal hypertension with Model for End-Stage Liver Disease (MELD) scores of 42 and 37, respectively, underwent dual LDLT grafts including one right lobe without a middle hepatic vein and one left lobe because the graft-to-recipient body weight ratio of the right lobe grafts were 0.53% and 0.66%. The donors and the recipients have been followed for over 1 year.
Mortality and operative complications were not observed in the donors or recipients. At present, the donors and recipients have returned to their daily routine. No prisoners or organs from prisoners were used to obtain these data.
Dual LDLT grafts including one right lobe without the middle hepatic vein and one left lobe may be a possible therapeutic option for subjects with acute-on-chronic hepatitis B-induced liver failure.
[Show abstract][Hide abstract] ABSTRACT: Our planet is facing great environmental challenges including global climate change, environmental vulnerability, extreme poverty, and a shortage of clean cheap energy. To address these problems, scientists are developing various models to analysis, forecast, simulate various geospatial phenomena to support critical decision making. These models not only challenge our computing technology, but also challenge us to feed huge demands of earth observation data. Through various policies and programs, open and free sharing of earth observation data are advocated in earth science. Currently, thousands of data sources are freely available online through open standards such as Web Map Service (WMS), Web Feature Service (WFS) and Web Coverage Service (WCS). Seamless sharing and access to these resources call for a spatial Cyberinfrastructure (CI) to enable the use of spatial data for the advancement of related applied sciences including environmental research. Based on Microsoft Bing Search Engine and Bing Map, a seamlessly integrated and visual tool is under development to bridge the gap between researchers/educators and earth observation data providers. With this tool, earth science researchers/educators can easily and visually find the best data sets for their research and education. The tool includes a registry and its related supporting module at server-side and an integrated portal as its client. The proposed portal, Bing Earth Observation (BingEO), is based on Bing Search and Bing Map to: 1) Use Bing Search to discover Web Map Services (WMS) resources available over the internet; 2) Develop and maintain a registry to manage all the available WMS resources and constantly monitor their service quality; 3) Allow users to manually register data services; 4) Provide a Bing Maps-based Web application to visualize the data on a high-quality and easy-to-manipulate map platform and enable users to select the best data layers online. Given the amount of observation data accumulated already and still growing, BingEO will allow these resources to be utilized more widely, intensively, efficiently and economically in earth science applications.
[Show abstract][Hide abstract] ABSTRACT: In order to effectively tackle many scientific challenges that we are facing today, we have to depend on collaborations among distributed computer systems as well as the synergy among multiple disciplines. We see cloud computing as a promising technology to support such collaborations. In this paper, cloud computing concept is described and a cloud computing framework is proposed. The proposed cloud computing infrastructure enables users to request and manage scalable and virtualized computing resources on demand through a client interface. It supports large-scale scientific applications through offering unparalleled compute capability and storage. Within this infrastructure, Open nebula is used as a cloud computing middleware. In order to test the feasibility of the cloud computing platform for supporting geospatial computing, we deployed a dust storm simulation model on the cloud computing platform. Based on the analysis of performance results of dust storm simulation, we conclude that the cloud computing is emerging as a credible solution for supporting responsive on-demand, data-intensive and memory-intensive geospatial applications.
[Show abstract][Hide abstract] ABSTRACT: This cross-sectional study investigated potential factors impacting quality of life in 125 recipients after living-donor liver transplantation (LDLT). Health-related quality of life (HRQoL) was measured by using the Chinese version of Medical Outcomes Study Short Form-36 (SF-36), and psychologic symptoms by using the Symptom Checklist-90-Revised (SCL-90-R). Clinical and demographic data were collected from the records of the Chinese Liver Transplant Registry and via questionnaire. A total of 102 recipients (81.6%) completed the questionnaires. All SF-36 domain scores (except the mental health score) were lower in the study than in the general population of Sichuan. The mental quality of life was significantly lower in female than in male subjects (P = .000). Regarding the role-physical (P = .016), social functioning (P = .000), and role-emotional (P = .004) domains, recipients >1 year after transplantation scored higher than those <1 year. Bodily pain scores were lower in recipients with prior acute liver failure than those with hepatic carcinoma or hepatic cirrhosis (P = .032). Social functioning was poorer in recipients with than in those without complications (P = .039). Mental component summary scale (MCS) scores and some of physical component summary scale (PCS) significantly correlated with symptom dimension scores of the SCL-90-R (P < .05). In conclusion, gender, time since transplant, etiology of disease, complications, occupation, and some psychologic symptoms were possible factors influencing postoperative HRQoL of LDLT recipients.
[Show abstract][Hide abstract] ABSTRACT: Untranslated regions (UTRs) of eukaryotic mRNAs play crucial roles in post-transcriptional regulation of gene expression via the modulation of nucleocytoplasmic mRNA transport, translation efficiency, subcellular localization, and message stability. Single-nucleotide polymorphisms (SNPs) in UTRs of a candidate gene may also change the post-transcriptional regulation of a gene or function by nucleotide mutation. For species that have not been entirely sequenced genomically, new methods need to be devised to discover SNPs in noncoding regions of candidate genes. In this study, based on the expressed sequence tag (EST) of Pinus radiata (Monterey pine), we obtained all the sequences of UTRs of the actin gene by using a chromosome walking method. We also detected all the SNPs in and around the coding region of the actin gene. In this way, the full genomic sequence (2154 bp) of the actin gene was identified, including the 5’UTR, introns, the coding sequence, and the 3’UTR. PCR amplification and DNA fragment sequencing from 200 unrelated P. radiata trees revealed a total of 21 SNPs in the actin gene, of which 3 were located in the 5’UTR, 3 in the introns, 10 in the coding sequence, and 5 in the 3’UTR. We show that chromosome walking can be used for obtaining the sequence of UTRs, and then, based on this sequence, to discover SNPs in the noncoding regions of candidate genes from this species without an entire genomic sequence.
[Show abstract][Hide abstract] ABSTRACT: Two heterocyclic compounds, 1-ethylhexyl-ethyl ester-thiomethyl-2-sulphur-benzo-thiazole (referred to as MBES) and 1-(dibutylamine-sulphur-methyl)-thiomethyl-2-sulphur-benzothiazole (referred to as MBON), as lubricating oil additives, were synthesized to replace or partially replace zincdialkyldithiophosphates (ZDDP). It was found that two heterocyclic compounds added in base oil at a proper concentration showed rather good anti-wear behaviour; there was a pronounced synergism between MBES and 1.0 wt% ZDDP in terms of the anti-wear properties and load-carrying capacities, whereas there was no synergism between MBON and 1.0 wt% ZDDP. X-ray photoelectron spectroscope analytical results showed that the tribofilms generated from the base oil-1.5 wt% MBON mainly contained pyrite, sulphite, and sulphate, whereas the films from the base oil-1.5 wt% MBES only contain sulphate; for the films from the complexes of the additive with 1.0 wt% ZDDP, S-containing compounds in the films are mainly in the form of sulphate and sulphite, and there are some N-containing organic compounds adsorbed on the worn surfaces.
ARCHIVE Proceedings of the Institution of Mechanical Engineers Part J Journal of Engineering Tribology 1994-1996 (vols 208-210) 01/2010; 224(1):65-72. DOI:10.1243/13506501JET615 · 0.66 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Recent advancements of scientific modeling allow high resolution simulation of natural phenomena, such as metrological parameters. And the simulation results are offered online in increasing data volume. In the Internet arena, a distributed visualization approach for representing the resulting data is critical for data sharing and understanding. Our objective is to utilize spatial computing to develop a distributed visualization system, which provides three visualization modes for Earth Scientists to analyze spatial data. The system involves the data server, the application server, Internet and the visualization client. At the server side, the data are preprocessed to generate visualization results, such as images, models and geometries. When large volume data are involved, parallel computing is invoked to accelerate the processing. At the client side, NASA World Wind and enhanced development are deployed to display the results from the server. Using our dust storm simulation data as an example, this system can visualize the metrological parameters associated with dust storm events produced by the Weather Research and Forecasting (WRF) model. Current visualization modes include 2D images, 3D volume rendering, and time enabled animation. With the distributed visualization approach, the research featured with multi-dimensional view of Earth phenomena interactively. Acknowledgements: Research reported is sponsored by a NASA project (NNX07AD99G).
[Show abstract][Hide abstract] ABSTRACT: The past decade achievement in geospatial interoperability includes
thousands of map layers deployed on the Internet and are persistently
served for the community through standard interfaces, such as WMS, WFS,
and WCS. Our empirical study reveals that the status of the services is
not satisfactory and it is often true that a predefined map application
is unable to compose because some published map servers simply do not
work. When a map composes several layers from different servers, it
becomes a serious problem. The request of each map layer takes time and
even in the most optimistic expectation, the total time for composing a
map is longer than the longest response time. While these services are
geographically distributed and maintained by various hosts, it is not
possible to solve this problem by improving these services at the host
sides. We propose an approach to solve this problem by providing a
mechanism that allows map composition to select the best map layers in
run time based on real-time monitoring of the quality of services.
Service Oriented Architecture (SOA) is extended in this approach to
include quality elements in the process of registration, search and
binding. OGC capability document is extended to describe quality of
service. Techniques, such as online and automatic substitution of
second-best layer, local cache, and virtual tile system, are designed
and implemented in this approach to enable map composition by requesting
map layers from various service providers. A prototype system based on
this approach will be demonstrated in our presentation to prove that
this approach significantly improves users’ experience of web map
composition and is one of the most desired method to make service
suitable for decision support.
[Show abstract][Hide abstract] ABSTRACT: Knowledge Base (KB) is an essential component for capturing, structuring and defining the meanings of domain knowledge. It's important in enabling the sharing and interoperability of scientific data and services in a smart manner. It's also the foundation for most the research in semantic field, such as semantic reasoning and ranking. In collaborating with ESIP, GMU is developing an online interface and supporting infrastructure to allow semantic registration of datasets and other web resources. The semantic description of data, services, and scientific content will be collected and transformed to the KB. As a case study, the harvest of web map services from by Nordic mapping agencies to build a virtual Arctic spatial data infrastructure will be used as the domain example. To automate the process, a controlled vocabulary of certain subjects, such as solid water, is created to filter from existing data and service repositories to obtain a collection of closely related document. Then latent semantic indexing is utilized to analyze semantic relationship among concepts that appears in service document. At last, semantic structure in plain text will be mapped and automatically populated to the specific presentation of knowledge in the KB.
[Show abstract][Hide abstract] ABSTRACT: Web-based spatial data services are essential building blocks for Spatial Data Infrastructure (SDI). WMS, WFS and WCS are adopted increasingly to provide interoperable access to facilitate the integration of different web applications with a large number of data from various scientific domains. However, these services are widely dispersed and hard to be found, accessed, and utilized, this is especially true when we want to develop an application to mashing up multiple layers from multiple servers. To tackle this problem, we proposed a layer-based service oriented integration framework, focusing on the integration of distributed WMS resources, including 1) a Service Capabilities Clearing House (SCCH) to preprocess and store the services' capability information of WMS, WFS and WCS. 2) a layer-based search engine with spatial, temporal and performance criteria to find more accurate records. 3) API and layer-based metadata to make the framework open and interoperable. 4) Customized 2-D, 3-D, and 4-D visualization interface for application integration. Acknowledgement: The research is supported by FGDC 2009 CAP program (project # G09AC00103, http://www.cisc.gmu.edu/projects/portal4gos.htm)
[Show abstract][Hide abstract] ABSTRACT: The simulations of dust storm and potential forecasting are of significant interest to public health, environment sciences, and global Earth observation system of systems (GEOSS). To support improved decision making of public health with higher resolution of dust storm forecasting. Model interoperability and high performance computing need to be leveraged to increase the resolution to the zip code level. This poses significant computational challenge for dust storm simulations. This presentation reports our research in utilizing interoperability technologies and high performance computing to enhance dust storm forecasting by facilitating model integration, data discovery, data access, and data utilization in a HPC (High performance computing) environment for a) reducing the computing time, b)lengthening the period of forecast, and c) ingesting large amount of geospatial datasets.DREAM-eta-8p and NMM-dust dust storm simulation models are utilized for the exploration of utilizing Model Interoperability and High Performance Computing to Enhance Dust Storm Forecasting. In our approach, the coarse model (DREAM-eta 8p) is used to identify hotspots of higher predicted dust concentration, and the output results are served as the input for the fine-grain model (NMM-dust) on the hotspot areas. After ingesting the DREAM-eta output the NMM-dust can start simulation. Experimental results demonstrates promising towards a forecasting system of dust storm forecasting. Acknowledgements: We would like to thank Drs. Karl Benedict, Bill Hudspeth of Univ. from New Mexico, Drs. William Sprigg, Goran Pejanovic, Slobodan Nickovic from UofArizona, and Dr. John D. Evans, and Ms. Myra J. Bambacus from NASA GSFC for the collaboration
[Show abstract][Hide abstract] ABSTRACT: Most reported data on posttransplantation diabetes mellitus (PTDM) are from Western countries with patients who underwent deceased donor liver transplantation. A retrospective study was performed to assess the prevalence and predictive factors of PTDM in the context of living donor liver transplantation (LDLT) in the Chinese population using the definition of PTDM proposed in 2003 by the World Health Organization and the American Diabetes Association. The prevalence of DM after LDLT in our study was 25% (21/84), and the incidence of PTDM was 14.9% (11/74) with 64% of cases diagnosed within 3 months after LDLT; 9.5% were observed to show impaired fasting glucose postoperatively. Multivariate analysis identified body mass index >or= 25 kg/m(2) before LDLT as the only independent risk factor for developing PTDM. Only one patient was operated for hepatitis C virus (HCV) infection. Hepatitis B virus (HBV)-related diseases were common in our study population, accounting for 78.6% of all patients. Both HCV and HBV infection status were not independent risk factors for developing PTDM. In addition, a greater tacrolimus trough blood level in the PTDM group versus no-DM group was observed at 3 months post-LDLT (11.03 ng/mL vs 4.87 ng/mL). The mean tacrolimus dose was not significantly different between the two groups. In conclusion, PTDM was prevalent among Chinese LDLT recipients.
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to explore the indications for liver transplantation among patients with hepatolithiasis.
Data from 1,431 consecutive patients who underwent surgical treatment from January 2000 to December 2006 were retrospectively collected for analysis. Surgical procedures included T-tube insertion combined with intraoperative cholangioscopic removal of intrahepatic stones, hepatectomy, cholangiojejunostomy, and liver transplantation.
Nine hundred sixty-one patients who had a stone located in the left or right intrahepatic duct underwent hepatectomy or T-tube insertion combined with intraoperative cholangioscopic removal of intrahepatic stones. The rate of residual stones was 7.5%. Four hundred seventy patients who had a stone located in the bilateral intrahepatic ducts underwent surgical procedures other than liver transplantation; the rate of residual stones was 21.7%. Only 15 patients with hepatolithiasis underwent liver transplantation; they all survived. According to the degree of biliary cirrhosis, recipients were divided into 2 groups: a group with biliary decompensated cirrhosis (n = 7), or group with compensated cirrhosis or no cirrhosis (n = 8). There were significant differences in operative times, transfusion volumes, and blood losses between the 2 groups (P < .05). In the first group, 6 of 7 patients experienced surgical complications, and in the second, 8 recipients recovered smoothly with no complications. Health status, disability, and psychological wellness of all recipients (n = 15) were significantly improved at 1 year after transplantation compared with pretransplantation (P < .05).
Liver transplantation is a possible method to address hepatolithiasis and secondary decompensated biliary cirrhosis or difficult to remove, diffusely distributed intrahepatic duct stones unavailable by hepatectomy, cholangiojejunostomy, and choledochoscopy.
[Show abstract][Hide abstract] ABSTRACT: The antiwear properties of three S-containing triazine derivatives with different active groups, referred to as TOSS, HOT, and HOMA, as additives in mineral oil, were evaluated using a four-ball friction and wear tester. Their thermal stabilities were investigated and the results suggest that all the synthesized compounds have good thermal stability. It was found that all the three S-containing triazine compounds added to the mineral oil showed rather good tribological behaviour, and the synergism between HOMA and zinc dialkyldithiophosphate (ZDDP) is better than that between ZDDP and HOT/TOSS. The worn surfaces of the steel balls were observed using X-ray photoelectron spectroscope. It is supposed that the synthetic additives adsorb and react with the steel surface during the process and thus generate a surface protective film composed of sulphate, iron oxide, and N-, O-, and S-containing organic compounds, which accounts for the better tribological behaviours of the base stock containing the synthetic additives when compared with the base stock alone.
ARCHIVE Proceedings of the Institution of Mechanical Engineers Part J Journal of Engineering Tribology 1994-1996 (vols 208-210) 11/2008; 222(7):909-915. DOI:10.1243/13506501JET443 · 0.66 Impact Factor