Home About us Contact
|
Home About us Contact | ||
|
|
||
Various Sites (various + site)
Selected AbstractsEfficient sampling and data reduction techniques for probabilistic seismic lifeline risk assessmentEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 10 2010Nirmal Jayaram Abstract Probabilistic seismic risk assessment for spatially distributed lifelines is less straightforward than for individual structures. While procedures such as the ,PEER framework' have been developed for risk assessment of individual structures, these are not easily applicable to distributed lifeline systems, due to difficulties in describing ground-motion intensity (e.g. spectral acceleration) over a region (in contrast to ground-motion intensity at a single site, which is easily quantified using Probabilistic Seismic Hazard Analysis), and since the link between the ground-motion intensities and lifeline performance is usually not available in closed form. As a result, Monte Carlo simulation (MCS) and its variants are well suited for characterizing ground motions and computing resulting losses to lifelines. This paper proposes a simulation-based framework for developing a small but stochastically representative catalog of earthquake ground-motion intensity maps that can be used for lifeline risk assessment. In this framework, Importance Sampling is used to preferentially sample ,important' ground-motion intensity maps, and K -Means Clustering is used to identify and combine redundant maps in order to obtain a small catalog. The effects of sampling and clustering are accounted for through a weighting on each remaining map, so that the resulting catalog is still a probabilistically correct representation. The feasibility of the proposed simulation framework is illustrated by using it to assess the seismic risk of a simplified model of the San Francisco Bay Area transportation network. A catalog of just 150 intensity maps is generated to represent hazard at 1038 sites from 10 regional fault segments causing earthquakes with magnitudes between five and eight. The risk estimates obtained using these maps are consistent with those obtained using conventional MCS utilizing many orders of magnitudes more ground-motion intensity maps. Therefore, the proposed technique can be used to drastically reduce the computational expense of a simulation-based risk assessment, without compromising the accuracy of the risk estimates. This will facilitate computationally intensive risk analysis of systems such as transportation networks. Finally, the study shows that the uncertainties in the ground-motion intensities and the spatial correlations between ground-motion intensities at various sites must be modeled in order to obtain unbiased estimates of lifeline risk. Copyright © 2010 John Wiley & Sons, Ltd. [source] The effects of fluvial processes and habitat heterogeneity on distribution, growth and densities of juvenile Atlantic salmon (Salmo salar L.), with consequences on abundance of the adult fishECOLOGY OF FRESHWATER FISH, Issue 4 2002R. J. Gibson Abstract,,,The required freshwater habitats of juvenile Atlantic salmon (Salmo salar) are, in general, well known, but vary in quality, related to interacting effects of several variables, which may depend on different parts of a river system. Examples are given of ranges of densities and growth that can be found at various sites in eastern Canada, illustrating the biological and physico-chemical factors affecting production of juvenile salmon. Relative growth rates can indicate habitat quality and population densities. Salmon parr have negative effects on brook trout in riffle habitats. The effects of migrations within the river and of changes with stream succession on juvenile salmon production are illustrated with examples from a Newfoundland river. Migration of age-classes can be quantified from ,self-thinning' curves. Lakes have enhancing effects on downstream fluvial habitats, and, at least in Newfoundland, and probably in many boreal areas, the lacustrine proportion of the basin can be used as an index for deriving estimates of required spawning escapement. The factors described should be taken into account for more refined estimates of river production and management of the salmon resource. [source] Use of laboratory toxicity tests with bivalve and echinoderm embryos to evaluate the bioavailability of copper in San Diego Bay, California, USAENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2005Gunther Rosen Abstract Copper concentrations in parts of San Diego Bay (CA, USA) exceed ambient water quality criteria (WQC; currently 3.1 ,g/L dissolved, U.S. Environmental Protection Agency [U.S. EPA]). In order to better understand the bioavailability of copper to water-column organisms in the bay, toxicity tests were performed with copper added to surface water collected from various sites in the estuary over a three-year period. The species and endpoints used, bivalve and echinoderm embryo-larval development, are among the most sensitive in the U.S. EPA's national toxicity dataset, which is used to derive WQC. No toxicity was observed in ambient bay water samples, as indicated by high proportions of normally developed larvae in control treatments, averaging 93 ± 5% across all sites and all sampling events. Median effects concentrations (EC50), obtained by copper spiking of ambient water samples, ranged from 1.7 to 3.4 times lower at sites located near the mouth compared to sites near the back of the bay. These data indicate a gradient in complexation capacity increasing from the mouth to the back of the bay, which is consistent with similar trends in dissolved organic carbon and total suspended solids. For the bay as a whole, estimates for total recoverable and dissolved water-effect ratios (WER) ranged from 2.07 to 2.27 and 1.54 to 1.67, respectively. Water-effect ratios of this magnitude suggest that adoption of a somewhat higher site-specific WQC for San Diego Bay still would achieve the level of protection that is intended by the WQC guidelines. [source] Trans fatty acids and cancers: AFSSA recommendationsEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 9 2007Mariette Gerber Abstract The results of epidemiological studies were too few and inconsistent to enable a conclusion to be drawn as to whether dietary trans fatty acids (TFA) including conjugated linoleic acids (CLA) were beneficial or detrimental to the various sites of cancer studied. The effect of CLA isomers has only been studied in animal models, and mainly on mammary tumours. CLA , particularly the 9c,11t CLA , exerted an inhibitory effect on the initiation and development of these tumours, whereas a similar effect has not been observed in humans, whose intake level is much lower than the threshold required for an antitumour effect to be detectable in rodents. The aforementioned effect has been obtained in animal models at prolonged and high intakes, from 0.5 to 2% of the total energy intake, which corresponds approximately to 5,10,g/day in humans. The underlying mechanisms have not been identified and are probably indirect and multiple. [source] The crystal structure of a xyloglucan-specific endo-,-1,4-glucanase from Geotrichum sp.FEBS JOURNAL, Issue 18 2009M128 xyloglucanase reveals a key amino acid residue for substrate specificity Geotrichum sp. M128 possesses two xyloglucan-specific glycoside hydrolases belonging to family 74, xyloglucan-specific endo-,-1,4-glucanase (XEG) and oligoxyloglucan reducing-end-specific cellobiohydrolase (OXG-RCBH). Despite their similar amino acid sequences (48% identity), their modes of action and substrate specificities are distinct. XEG catalyzes the hydrolysis of xyloglucan polysaccharides in endo mode, while OXG-RCBH acts on xyloglucan oligosaccharides at the reducing end in exo mode. Here, we determined the crystal structure of XEG at 2.5 Å resolution, and compared it to a previously determined structure of OXG-RCBH. For the most part, the amino acid residues that interact with substrate are conserved between the two enzymes. However, there are notable differences at subsite positions ,1 and +2. OXG-RCBH has a loop around the +2 site that blocks one end of the active site cleft, which accounts for its exo mode of action. In contrast, XEG lacks a corresponding loop at this site, thereby allowing binding to the middle of the main chain of the substrate. At the ,1 site in OXG-RCBH, Asn488 interacts with the xylose side chain of the substrate, whereas the ,1 site is occupied by Tyr457 in XEG. To confirm the contribution of this residue to substrate specificity, Tyr457 was substituted by Gly in XEG. The wild-type XEG cleaved the oligoxyloglucan at a specific site; the Y457G variant cleaved the same substrate, but at various sites. Together, the absence of a loop in the cleft and the presence of bulky Tyr457 determine the substrate specificity of XEG. [source] CULTURAL ECONOMY AND THE CREATIVE FIELD OF THE CITYGEOGRAFISKA ANNALER SERIES B: HUMAN GEOGRAPHY, Issue 2 2010Allen J. Scott ABSTRACT. I begin with a rough sketch of the incidence of the cultural economy in US cities today. I then offer a brief review of some theoretical approaches to the question of creativity, with special reference to issues of social and geographic context. The city is a powerful fountainhead of creativity, and an attempt is made to show how this can be understood in terms of a series of localized field effects. The creative field of the city is broken down (relative to the cultural economy) into four major components, namely, (a) intra-urban webs of specialized and complementary producers, (b) the local labour market and the social networks that bind workers together in urban space, (c) the wider urban environment, including various sites of memory, leisure, and social reproduction, and (d) institutions of governance and collective action. I also briefly describe some of the path-dependent dynamics of the creative field. The article ends with a reference to some issues of geographic scale. Here, I argue that the urban is but one (albeit important) spatial articulation of an overall creative field whose extent is ultimately nothing less than global. [source] Current status of ectopic varices in Japan: Results of a survey by the Japan Society for Portal HypertensionHEPATOLOGY RESEARCH, Issue 8 2010Norihito Watanabe Aim:, The Clinical Research Committee of the Japan Society for Portal Hypertension has conducted a nationwide questionnaire survey to clarify the current status of ectopic varices in Japan. Methods:, A total of 173 cases of ectopic varices were collected. Results:, Duodenal varices were found in 57 cases, and most of them were located in the descending to transverse parts. There were 11 cases of small intestinal varices and 6 cases of colonic varices, whereas 77 patients had rectal varices, accounting for the greatest proportion (44.5%). Other sites of varices were the biliary tract, anastomotic sites, the stoma, and the diaphragm. Liver cirrhosis was the most frequent diseases (80.3%) underlying ectopic varices. It was noted that patients with rectal varices frequently had a history of esophageal varices (94.8%) and received endoscopic treatment (87.0%). The treatments for ectopic varices were as an emergency in 46.5%, elective in 35.4% and prophylactic in 18.2%. In emergency cases, endoscopic therapy was most frequent (67.4%), followed by interventional radiology (IVR; 15.2%), and endoscopy-IVR combination (6.5%). Elective treatment was performed by endoscopy in 34.3%, IVR in 28.6%, combined endoscopy-IVR in 5.7%, and surgical operation in 25.7%. The prophylactic treatment was endoscopic in 50.0%, IVR in 33.3%, combined treatments in 11.1%, and prophylactic surgery in none. The change of ectopic varices after treatment was disappearance in 54.9%, remnant in 35.4% and recurrence in 9.7%. The rate of disappearance was significantly lower in rectal varices (40.8%) than in duodenal varices (73.4%). The patient outcome did not differ among the various sites of the lesion. Conslusions:, Current status of ectopic varices in Japan has been clarified by a nationwide questionnaire survey. The authors expect that the pathophysiology of ectopic varices will be further elucidated, and that improved diagnostic modalities and treatment methods are established in the future. [source] Estimating the snow water equivalent on the Gatineau catchment using hierarchical Bayesian modellingHYDROLOGICAL PROCESSES, Issue 4 2006Ousmane Seidou Abstract One of the most important parameters for spring runoff forecasting is the snow water equivalent on the watershed, often estimated by kriging using in situ measurements, and in some cases by remote sensing. It is known that kriging techniques provide little information on uncertainty, aside from the kriging variance. In this paper, two approaches using Bayesian hierarchical modelling are compared with ordinary kriging; Bayesian hierarchical modelling is a flexible and general statistical approach that uses observations and prior knowledge to make inferences on both unobserved data (snow water equivalent on the watershed where there is no measurements) and on the parameters (influence of the covariables, spatial interactions between the values of the process at various sites). The first approach models snow water equivalent as a Gaussian spatial process, for which the mean varies in space, and the other uses the theory of Markov random fields. Although kriging and the Bayesian models give similar point estimates, the latter provide more information on the distribution of the snow water equivalent. Furthermore, kriging may considerably underestimate interpolation error. Copyright © 2006 Environment Canada. Published by John Wiley & Sons, Ltd. [source] Social Citizenship in the European Union: Nested MembershipJCMS: JOURNAL OF COMMON MARKET STUDIES, Issue 1 2001Thomas Faist The ,European social dimension' offers a strategic entry point for analysing the development of citizenship in the European Union (EU). The first part of this contribution discusses the functions of social citizenship in this emerging multi-level governance network. Second, the analysis deals with two prominent and stylized paradigms that have sought to grasp the new multiple-level quality of social citizenship in the EU: residual and post-national concepts of membership in liberal democracies and advanced welfare states. Although each of these approaches captures selected elements of social citizenship, they are unable to deal with rights and duties in multiple governance levels in a satisfactory way. Therefore, the discussion moves to an alternative concept,nested citizenship. This means that European citizenship is nested in various sites: regional, state and supra-state forms of citizenship function in complementary ways,while the associated norms, rules and institutions are subject to constant revision and further development on all governance levels. Third, the analysis shows that the concept of nested citizenship can help to overcome the fruitless dichotomy of Euro-optimism and Euro-pessimism concerning social policy and citizenship. This discussion suggests a conception of European social citizenship as a common project, evolving towards common present- and future-oriented understandings of substantial rights and democratic principles in the EU. [source] Characterization of enterococci populations collected from a subsurface flow constructed wetlandJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2010A.K. Graves Abstract Aims:, The aim of this study was to identify and characterize the population of Enterococcus sp. in domestic wastewater as it flows through a constructed wetland. Methods and Results:, Four hundred and eighty-four Enterococcus isolates were collected from the inlet, various sites within and from the outlet of a plastic lined constructed wetland in College Station, TX. The wetland treated septic tank effluent that passed sequentially through two 1·89 m3 septic tanks and a 1·89 m3 pump tank allowing 48 l doses at a 24 l min,1 rate. The Enterococcus isolates were identified to species using the commercial Biolog system. The 484 Enterococcus isolates were comprised of ten different species, including Enterococcus faecalis (30·6%), Enterococcus pseudoavium (24·0%), Enterococcus casseliflavus (12·8%), Enterococcus faecium (11·2%), Enterococcus mundtii (7·9%), Enterococcus gallinarum (6·2%), Enterococcus dispar (3·7%), Enterococcus hirae (2·1%), Enterococcus durans and Enterococcus flavescens both 0·8%. Of the 88 isolates collected from the inlet, only 9·1% of the isolates were identified as Ent. faecalis and Ent. pseudoavium (36·4%) was identified as the predominant species. Whereas of the 74 isolates collected from the outlet, the predominant species were identified as Ent. faecalis (29·7%). Species identification varied among sites within the wetland, but often Ent. faecalis was the predominant species. Conclusions:, Our data suggest that while Ent. faecalis is the predominant species of Enterococcus found in domestic wastewater, the populations may shift during treatment as the wastewater flows through the constructed wetland. Significance and Impact of the Study:, We found that shifts in Enterococcus species composition occurred during domestic wastewater treatment. This has implications for the identification of faecal pollution based on the presence of specific bacterial types associated with domestic wastewater. [source] The effect of ionic interaction on the miscibility and crystallization behaviors of poly(ethylene glycol)/poly(L -lactic acid) blendsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2008Wei-Chi Lai Abstract The effect of end groups (2NH2) of poly(ethylene glycol) (PEG) on the miscibility and crystallization behaviors of binary crystalline blends of PEG/poly(L -lactic acid) (PLLA) were investigated. The results of conductivity meter and dielectric analyzer (DEA) implied the existence of ions, which could be explained by the amine groups of PEG gaining the protons from the carboxylic acid groups of PLLA. The miscibility of PEG(2NH2)/PLLA blends was the best because of the ionic interaction as compared with PEG(2OH, 1OH-1CH3, and 2CH3)/PLLA blends. Since the ionic interaction formed only at the chain ends of PEG(2NH2) and PLLA, unlike hydrogen bonds forming at various sites along the chains in the other PEG/PLLA blend systems, the folding of PLLA blended with PEG(2NH2) was affected in a different manner. Thus the fold surface free energy played an important role on the crystallization rate of PLLA for the PEG(2NH2)/PLLA blend system. PLLA had the least fold surface free energy and the fast crystallization rate in the PEG(2NH2)/PLLA blend system, among all the PEG/PLLA systems studied. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Fatal HHV6 infection in an immunocompromised patient presenting with skin involvementJOURNAL OF CUTANEOUS PATHOLOGY, Issue 2 2010Anjela Galan Infection with human herpesvirus-6 (HHV6) has a broad distribution in the human population, with a seroprevalence approaching 100% worldwide. Primary infection takes place during childhood, after which the virus remains latent mostly in lymphocytes and monocytes at various sites. Immunosuppression can result in viral reactivation, associated with clinical sequelae and even death. We report a case of a disseminated HHV6 infection in a 53-year-old patient, who was immunocompromised after allogeneic bone marrow transplant treatment for acute lymphocytic leukemia. Initially, he presented with a macular eruption of the skin, followed by involvement of other sites. Histopathologic analysis of skin biopsies revealed superficial perivascular large atypical mononuclear cells with intranuclear and intracytoplasmic inclusions. Most affected cells labeled with antibodies to CD3 and CD43 as lymphocytes, and some labeled with CD68 as macrophages. Polymerase chain reaction (PCR) studies of the blood, skin, liver, colon, cerebrospinal fluid and brain were positive for HHV6 virus. Additionally, the serologic titers for HHV6 were high. Viral particles were also detected by electron microscopy (EM) in the colon. Although rare, HHV6 virus may be an important pathogen in immunocompromised patients, and may present initially in the skin. Awareness of this infection is critical to diagnosis in acute settings. Galan A, McNiff JM, Nam Choi J and Lazova R. Fatal HHV6 infection in an immunocompromised patient presenting with skin involvement. [source] A multidegree-of-freedom manipulator for curtain-wall installationJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 5 2006Chang Soo Han Recently, the trend in architectural forms has been towards larger and taller buildings. Building materials are, therefore, also becoming larger and heavier. Typical construction machineries are not adequate for handling such materials, and most construction works are still managed by a human operator. Construction processes are, therefore, fraught with a number of problems, including frequent accidents, high construction cost, and heterogeneous construction quality depending on the experience of the workers. Automation has been introduced at various sites to address these construction problems. In this paper, the process of a curtain-wall installation in a skyscraper is analyzed, and the prototype of a construction robot for curtain-wall installation (CRCWI) is proposed. Use of the proposed CRCWI can reduce the need for manpower and the construction period and cost, and can assure safety in the curtain-wall construction site. The performance of the proposed CRCWI was verified with a real application test in a skyscraper construction site. © 2006 Wiley Periodicals, Inc. [source] Intrapopulational polymorphism of nucleolus organizer regions in Serrapinnus notomelas (Characidae, Cheirodontinae) from the Paraná RiverJOURNAL OF FISH BIOLOGY, Issue 5 2008A. P. Santi-Rampazzo Analysis of the nucleolus organizer regions by silver nitrate (AgNOR), fluorescent in situ hybridization (FISH) and C-banding of Serrapinnus notomelas from the Paraná River, PR, Brazil revealed intrapopulational polymorphisms that could be classified into six patterns (I,VI). Pattern I consisted of a single nucleolus organizer region (NOR) on chromosome pair 26 with at least one active homologue, indicating that it was a preferential NO. This NOR was also present in all the other patterns. In addition, seven other variable pairs appeared in patterns II,VI. These polymorphisms may indicate transpositions of rDNA genes, located on pair 26, to various sites in the genome. These transpositions may be due to transpose mechanisms or reinsertion into sites that have sequences homologous with the inserts. C-band analysis also reflected this variability and confirmed the various patterns described here. [source] Naturally occurring bacteraemia in American lobsters, Homarus americanus Milne-Edwards, in Long Island SoundJOURNAL OF FISH DISEASES, Issue 1 2008S L Bartlett Abstract The health status of the American lobster, Homarus americanus Milne-Edwards, in Long Island Sound (LIS) has been in decline, with seasonal mortality events occurring since 1998. In order to assess the potential effects of environmental conditions on lobster health via haemolymph analysis, lobsters collected from various sites in LIS were examined and sampled while concurrent environmental data (water temperature, salinity and dissolved oxygen) were recorded. The pH of the haemolymph of each lobster was tested, followed by a collection of haemolymph for serum biochemistry analysis and bacterial culture. This report focuses on the results of the bacterial sampling. The majority of bacteria cultured were opportunistic pathogens commonly found in the environment, including some that are associated with sewage and pollution. The prevalence of bacteraemia was correlated with the site of collection, the month in which the lobsters were sampled, and water temperature. [source] Biopsy site for detecting Helicobacter pylori infection in patients with gastric cancerJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 3 2009Chan Gyoo Kim Abstract Background:,Helicobacter pylori eradication is recommended in post-gastric cancer resection, but premalignant changes may prevent the detection of H. pylori. The aim of this study was to determine appropriate biopsy site for detecting H. pylori in gastric cancer patients. Materials and Methods:, Consecutive patients (194) with gastric adenocarcinoma were prospectively enrolled. Helicobacter pylori was evaluated by serology, histology and rapid urease test. Biopsy sites included antrum lesser curvature, upper body lesser curvature (UBLC) and upper body greater curvature (UBGC). Two biopsy specimens were obtained from each site for histological examination. One additional specimen was obtained from UBGC for the rapid urease test. Results:, The overall infection rate of H. pylori was 84.0% (95% CI 78.9,89.2). The sensitivity of histology for detecting H. pylori at various sites was: antrum (54.9%; 95% CI 45.7,63.9), UBLC (80.3%; 95% CI 72.2,87.0) and UBGC (95.1%; 95% CI 89.6,98.2). Specificities of all three biopsy sites were more than 95%. Sensitivity and specificity of the rapid urease test performed at UBGC were 96% and 100%, respectively. Sensitivities of histology decreased in correlation with increasing severity of atrophy and intestinal metaplasia (both P < 0.001 using the chi-square test for trend). The proportions of moderate to marked atrophy/intestinal metaplasia at UBGC (12.8%/14.7%) were significantly lower than those at antrum (50.0%/57.8%, P < 0.001 respectively) or UBLC (40.0%/48.9%, P < 0.001 respectively). Conclusions:, The UBGC side is the most sensitive and specific biopsy site to detect H. pylori in gastric cancer patients due to less frequent atrophy and intestinal metaplasia than at the antrum or UBLC side. [source] Incidence, spectrum and antibiotic sensitivity pattern of bacterial infections among patients with acute pancreatitisJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 9 2001Pramod Kumar Garg Abstract Background and Aim: Secondary infection of pancreatic necrotic tissue and peripancreatic fluid is a serious complication of acute pancreatitis resulting in significant morbidity and mortality. The aim of this study was to find out the spectrum of bacterial infections, and their antibiotic sensitivity pattern in patients with acute pancreatitis. Methods: All consecutive patients with acute pancreatitis were studied prospectively. Detailed investigations were carried out to identify bacterial infections and their antibiotic sensitivities in patients with suspected infection. These investigations included cultures of various body fluids, throat swabs, indwelling cannula and catheter tips. Pancreatic tissue was obtained by using needle aspiration or at surgery for Gram's stain, culture and sensitivity. All cultures were repeated until the presence of infection was confirmed or excluded. Results: A total of 169 patients with acute pancreatitis were studied during the period between January 1997 and June 2000 (mean age 41.3 years; 116 males and 53 females). Of the 169 patients, 63 had infections at various sites. A total of 80 cultures were positive, and 12 different bacterial isolates were cultured from samples taken from these 63 patients. Polymicrobial infection was seen in 32% of patients. Twenty-four patients had a confirmed pancreatic infection. Blood cultures had a growth of organisms in 19 patients, with evidence of ongoing or worsening pancreatitis, thus raising a strong suspicion of infected necrosis in them. The commonest organisms were Escherichia coli from 20 cultures and Pseudomonas aeruginosa from 18 cultures. The antibiotic sensitivity pattern showed that most bacteria were sensitive to third generation cephalosporins and quinolones; notably among them were cefotaxime, ceftazidime, and ciprofloxacin. Conclusion: Bacterial infections were seen in 37% of patients with acute pancreatitis. The commonest organisms were Pseudomonas aeruginosa and Escherichia coli. Most bacterial isolates were sensitive to third generation cephalosporins and quinolones. [source] CT appearances of hydatid disease at various locationsJOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 4 2006K Taori Summary Hydatid disease has characteristic imaging features on CT, which allow accurate preoperative diagnosis in most cases. However, when it occurs at unusual locations the diagnosis is often difficult, especially as the imaging appearance varies at different sites. In this article we have presented a pictorial review of the CT features of disease due to Echinococcus granulosus at various sites in the human body. [source] Hydrogen storage properties of B- and N-doped microporous carbonAICHE JOURNAL, Issue 7 2009Lifeng Wang Abstract A B- and N-doped microporous carbon has been synthesized via a substitution reaction. The obtained carbon exhibited much higher surface area than the previously reported B- and N-doped carbon. The hydrogen storage measurements indicated that the B- and N-doped microporous carbon had a 53% higher storage capacity than the carbon materials with similar surface areas. Furthermore, hydrogen storage via spillover was studied on Ru-supported B- and N-doped microporous carbon and a storage capacity of 1.2 wt % at 298 K and 10 MPa was obtained, showing an enhancement factor of 2.2. Ab initio molecular orbital calculations were also performed for the binding energies between the spiltover hydrogen atom and various sites on the doped carbon. The theoretical calculations can explain the experimental results well, which also shed light on the most favorable and possible sites with which the spiltover hydrogen atoms bind. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] Who Should Be Screened for Asymptomatic Carotid Artery Stenosis?JOURNAL OF NEUROIMAGING, Issue 2 2001Experience From the Western New York Stroke Screening Program ABSTRACT Objective. Identification of significant asymptomatic carotid artery stenosis (ACAS) is important because of the stroke-risk reduction observed with carotid endarterectomy. The authors developed and validated a simple scoring system based on routinely available information to identify persons at high risk for ACAS using data collected during a community health screening program at various sites in western New York. A total of 1331 unselected volunteers without previous stroke, transient ischemic attack, or carotid artery surgery were evaluated by personal interview and duplex ultrasound. The main outcome measure was carotid artery stenosis >60% by duplex ultrasound. In the derivation set (n= 887), 4 variables were significantly associated with ACAS >60%: age >65 years (odds ratio [OR] = 4.1, 95% confidence interval [CI] = 2.6,6.7), current smoking (OR = 2.0, 95% CI = 1.2,3.5), coronary artery disease (OR = 2.4, 95% CI = 1.5,3.9), and hypercholesterolemia (OR = 1.9, 95% CI = 1.2,2.9). Three risk groups (low, intermediate, and high) were defined on the basis of total risk score assigned on the basis of the strength of association. The scheme effectively stratified the validation set (n= 444); the likelihood ratio and posttest probability for ACAS in the high-risk group were 3.0 and 35%, respectively, and in the intermediate and low-risk groups were 1.4 and 20% and 0.4 and 7%, respectively. Routinely available information can be used to identify persons in the community at high risk for ACAS. Doppler ultrasound screening in this subgroup may prove to be cost-effective and have an effect on stroke-free survival. [source] Detection of human papilloma virus subtypes 16 and P16ink4a in invasive squamous cell carcinoma of the fallopian tube and concomitant squamous cell carcinoma in situ of the cervixJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 2 2009Zhiqin Wang Abstract Squamous cell carcinoma (SCC) of the fallopian tube is rare and often diagnosed postoperatively. Cervical cancer is considered as a long-term sequaele, resulting from sexual transmitted infection with certain common high-risk human papilloma virus (HPV) types. The role of human papilloma virus in the development of the tubal SCC is unknown. We report an unusual case of SCC of the fallopian tube, synchronously occurring with cervical SCC in situ in a 49-year-old patient. Histological examination of the entire endometrium revealed no involvement. Both tubal and cervical lesions showed the presence of high risk HPV 16 by PCR and increased expression of p16INK4a protein. Both SCC of the fallopian tube and cervical SCC in situ were positive for p63, while the non-involved tubal epithelium was positive for WT-1, but negative for p63. In conclusion, the concomitant occurrence of fallopian tube and cervical SCC can be explained by: (i) the ,field effect' of HPV infection resulting in the concomitant development of primary SCC in various sites of the female genital tract; (ii) the primary fallopian tube SSC metastasizing to the uterine cervix; or (iii) primary cervical SCC metastasizing to the fallopian tube. The detection of HPV 16 and p16INK4a in both the fallopian tube and cervical SCCs strengthens the hypothesis of the ,field effect' of HPV infection. [source] Ab Initio Calculations of Pristine and Doped Zirconia ,5 (310)/[001] Tilt Grain BoundariesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2002Zugang Mao The structure of the cubic-ZrO2 symmetrical tilt ,5 (310)/[001] grain boundary is examined using density functional theory within the local density and pseudopotential approximations. Several pristine stoichiometric grain-boundary structures are investigated and compared with Z-contrast scanning transmission electron microscopy and electron energy loss spectroscopy results. The lowest-energy grain-boundary structure is found to agree well with the experimental data. When Y3+ is substituted for Zr4+ at various sites in the lowest-energy grain-boundary structure, the calculations indicate that Y3+ segregation to the grain boundary is energetically preferred to bulk doping, in agreement with experimental results. [source] Cetirizine in horses: pharmacokinetics and effect of ivermectin pretreatmentJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 3 2007L. OLSÉN The pharmacokinetics of the histamine H1 -antagonist cetirizine and the effects of pretreatment with the antiparasitic macrocyclic lactone ivermectin on the pharmacokinetics of cetirizine were studied in horses. After oral administration of cetirizine at 0.2 mg/kg bw, the mean terminal half-life was 3.4 h (range 2.9,3.7 h) and the maximal plasma concentration 132 ng/mL (101,196 ng/mL). The time to reach maximal plasma concentration was 0.7 h (0.5,0.8 h). Ivermectin (0.2 mg/kg bw) given orally 1.5 h before cetirizine did not affect its pharmacokinetics. However, ivermectin pretreatment 12 h before cetirizine increased the area under the plasma concentration,time curve by 60%. The maximal plasma concentration, terminal half-life and mean residence time also increased significantly following the 12 h pretreatment. Ivermectin is an inhibitor of P-glycoprotein, which is a major drug efflux transporter in cellular membranes at various sites. The elevated plasma levels of cetirizine following the pretreatment with ivermectin may mainly be due to decreased renal secretion, related to inhibition of the P-glycoprotein in the proximal tubular cells of the kidney. The pharmacokinetic properties of cetirizine have characteristics which are suitable for an antihistamine, and this substance may be a useful drug in horses. [source] Regional daily maximum rainfall estimation for Cekerek Watershed by L-momentsMETEOROLOGICAL APPLICATIONS, Issue 4 2009Kadri Yurekli Abstract The estimation of maximum daily rainfall (PDmax) is usually required for the estimation of design flood (the maximum flood that any hydraulic structure can safely pass). However, PDmax estimation is usually required for watersheds where rainfall data are either not available or only available in short periods from various sites and so are unsuitable for maximum daily rainfall estimation. In this study, the regional PDmax of the Cekerek watershed in Turkey is estimated using the method of l-moments using 17 rainfall stations in the region. The discordant test for outlier stations showed no discordant station in the region. Applying the homogeneity measure, Hi, the homogeneous region was identified. To find the best regional distribution, the ZDIST goodness-of-fit test was applied. This test introduced two distributions as the candidates for regional parent distributions; Generalized Extreme Values (GEV) and 3-parameter Log Normal (LOGN3) distributions. The LOGN3 distribution was selected as the best regional distribution as it has the smaller absolute value of the statistics (ZDIST) based on the goodness-of-fit-test. Copyright © 2009 Royal Meteorological Society [source] Experimental evaluation of the diversity performance for a DVB-SH mobile terminalMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2010Benoit Poussot Abstract This article presents measurements performed with test infrastructures for digital TV broadcasting (DVB-SH standard). The objective is to determine the diversity performance of a mobile terminal integrating two orthogonally polarized antennas in various sites. The performance evaluation is based on a narrow band analysis of the propagation channel. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 2145,2148, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25361 [source] Social network coordination and graph routingNETWORKS: AN INTERNATIONAL JOURNAL, Issue 1 2003Shmuel Onn Abstract We consider the problem of coordinating robots moving on a network. Each robot is autonomous and needs to visit various sites of the network at various times. The sequence of destinations for each robot changes dynamically and unpredictably. Recently, Onn and Tennenholtz showed that the problem can be solved by introducing a social law on the network, which, once obeyed by all robots, enables each to move to any desired destination without collisions and regardless of the actions of other robots, needing neither central coordination nor mutual communication. This social law can be derived from a suitably defined routing of the graph underlying the network. Here, we study the complexity of routing. We provide an effective characterization of 2-routable graphs, and by establishing a correspondence between hypergraph coloring and graph routing, we show that computing or approximating an optimal routing is generally hard. We also discuss routing in planar graphs, which often underlie robotic networks and show that the correspondence between coloring and routing together with the Four Color Theorem guarantee the existence of small and effectively computable routings in bipartite planar graphs of small radius. The complexity of routing arbitrary planar graphs remains open. © 2002 Wiley Periodicals, Inc. [source] A case of melanotic desmoplastic gangliogliomaNEUROPATHOLOGY, Issue 5 2009Manila Antonelli We describe a case of desmoplastic infantile ganglioglioma (DIG) in a 9-month-old boy located in the temporal lobe. Grossly the tumor was brown and superficially located. Histologically the tumor contained pigment in numerous neoplastic cells, shown to be melanosomal melanin by ultrastructural examination. Pigmented neoplasms have been reported at various sites in the central and peripheral nervous system. Previous reports on pigmented neuroepithelial tumors include neoplasms containing melanin, while others have contained neuromelanin and or lipofuscin. This case represents the first description of pigmented neoplastic cells in DIG, enlarging the spectrum of pigmented primary CNS tumors. [source] The impact of managed care on nurses' workplace learning and teaching,NURSING INQUIRY, Issue 2 2000Jerry P. White The impact of managed care on nurses' workplace learning and teaching This paper examines the impact of managed care on the informal learning process for nurses in a major US-based health organisation. Through the analysis of focus group data we report the nurses' view of the effect recent changes have had on the nurse/patient/care relationship. Managed care, our research indicates, has transformed the learning milieus for nurses with two effects. First, nurses have seen their need for informal learning increase while the time and context for that learning has diminished. Second, the process of teaching patients and families has also been adversely affected even as managed care creates the need for more patient education. We report the analysis of the data collected at group interviews involving nurses working in both hospital and community settings of a leading US-based HMO. All interviews took place during September of 1997 at various sites in California. This study is part of a larger Social Science Research Council of Canada funded investigation into managed care in the US and Canada. [source] Sunao Tawara: A Father of Modern CardiologyPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1 2001KOZO SUMA SUMA, K.: Sunao Tawara: A Father of Modern Cardiology. Knowledge of the conduction system of the heart was greatly advanced by Tawara's work carried out in Aschoff's laboratory in Marburg at the beginning of this century. In his monograph, The Conduction System of the Mammalian Heart, published in 1906, Tawara indicated that the treelike structure of specific muscle fibers comprising the atrioventricular node, His bundle, bundle branches, and Purkinje fibers served as the pathway for atrioventricular conduction of excitation in the mammalian heart. From his own anatomic and histological findings of the conduction system, he assumed precisely that the conduction velocity of excitation in the system, except in the atrioventricular node, would be fast and that contraction as the result of excitation would take place at the various sites of the ventricles almost simultaneously. According to Tawara, a long pathway to each contracting unit and a fast conduction velocity of excitation would be a prerequisite for the effective contraction of the ventricles. Tawara's findings and assumptions provided Einthoven the theoretical basis for interpreting the electrocardiogram, resulting in rapid popularization of electrocardiography. This century has witnessed the rapid progress of cardiology, including cardiac pacing and its related sciences. This progress has its roots in the discovery of the conduction system and the development of electrocardiography that took place almost in the same period at the beginning of this century. Tawara's pioneering work on the conduction system still serves as an invaluable reference for basic and clinical research. [source] Potential health effects from non-specific stimulation of the immune function in early age: The example of BCG vaccinationPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 5 2008Marie-Claude Rousseau There is increasing, but still inconsistent evidence that vaccinations and childhood infections may play a role in the normal maturation of the immune system, and in the development and balance of immune regulatory pathways, both of which might impact health later in life. This review covers the epidemiological evidence regarding the role of Bacillus Calmette,Guérin (BCG) vaccination on the following inflammatory or autoimmune diseases: asthma and allergic diseases, Crohn's disease (CD), insulin-dependent diabetes mellitus (IDDM), and specific cancers. The literature is more comprehensive for asthma and allergic diseases, with 16 studies reporting the absence of an association while seven rather suggest a protective effect of BCG. We found insufficient evidence on CD to conclude at this point. Overall, the evidence for IDDM based on four studies leans towards no association, although some effects were observed in population subsets. Five epidemiological investigations provide evidence on a possible link with cancer incidence or mortality at various sites, with indications of both increased and decreased risks. Given the potential public health implications, it is imperative to acquire a better understanding of how BCG vaccination could influence the development of such chronic health conditions in the population. [source] | |||||||||||||||||||||||||||||||||||||||||||