2,303 research outputs found

    Skills of different mesoscale models over Indian region during monsoon season: Forecast errors

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    Performance of four mesoscale models namely, the MM5, ETA, RSM and WRF, run at NCMRWF for short range weather forecasting has been examined during monsoon-2006. Evaluation is carried out based upon comparisons between observations and day-1 and day-3 forecasts of wind, temperature, speci.c humidity, geopotential height, rainfall, systematic errors, root mean square errors and specific events like the monsoon depressions. It is very difficult to address the question of which model performs best over the Indian region? An honest answer is 'none'. Perhaps an ensemble approach would be the best. However, if we must make a final verdict, it can be stated that in general, (i) the WRF is able to produce best All India rainfall prediction compared to observations in the day-1 forecast and, the MM5 is able to produce best All India rainfall forecasts in day-3, but ETA and RSM are able to depict the best distribution of rainfall maxima along the west coast of India, (ii) the MM5 is able to produce least RMSE of wind and geopotential fields at most of the time, and (iii) the RSM is able to produce least errors in the day-1 forecasts of the tracks, while the ETA model produces least errors in the day-3 forecasts

    Moduli and electromagnetic black brane holography

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    We investigate the thermodynamic and hydrodynamic properties of 4-dimensional gauge theories with finite electric charge density in the presence of a constant magnetic field. Their gravity duals are planar magnetically and electrically charged AdS black holes in theories that contain a gauge Chern-Simons term. We present a careful analysis of the near horizon geometry of these black branes at finite and zero temperature for the case of a scalar field non-minimally coupled to the electromagnetic field. With the knowledge of the near horizon data, we obtain analytic expressions for the shear viscosity coefficient and entropy density, and also study the effect of a generic set of four derivative interactions on their ratio. We also comment on the attractor flows of the extremal solutions.Comment: 39 pages, no figures; v2: minor changes, refs. added; v3: typo fixed; v4: a proof for decoupling of the viscosity mode added in appendix, matches the published versio

    A randomized, parallel study of the safety and efficacy of 45 mg primaquine versus 75 mg bulaquine as gametocytocidal agents in adults with blood schizonticide-responsive uncomplicated falciparum malaria [ISCRTN50134587]

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    BACKGROUND: The WHO recommends that adults with uncomplicated P. falciparum successfully treated with a blood schizonticide receive a single dose of primaquine (PQ) 45 mg as a gametocytocidal agent. An earlier pilot study suggested that 75 mg of bulaquine (BQ), of which PQ is a major metabolite, may be a useful alternate to PQ. METHODS: In a randomized, partial blind study, 90 hospitalized adults with Plasmodium falciparum malaria that was blood schizonticide-responsive and a gametocytemia of > 55/μl within 3 days of diagnosis were randomized to receive single doses of either PQ 45 mg or BQ 75 mg on day 4. We assessed gametocytemia on days 8, 15, 22 and 29 and gametocyte viability as determined by exflagellation (2° end point) on day 8. RESULTS: On day 8, 20/31 (65%) primaquine recipients versus 19/59 (32%) bulaquine recipients showed persistence of gametocytes (P = 0.002). At day 15 and beyond, all patients were gametocyte free. On day 8, 16/31 PQ and 7/59 BQ volunteers showed gametocyte viability (p = 0.000065). CONCLUSION: BQ is a safe, useful alternate to PQ as a Plasmodium falciparum gametocytocidal agent and may clear gametocytemia faster than PQ

    LES-based Study of the Roughness Effects on the Wake of a Circular Cylinder from Subcritical to Transcritical Reynolds Numbers

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    This paper investigates the effects of surface roughness on the flow past a circular cylinder at subcritical to transcritical Reynolds numbers. Large eddy simulations of the flow for sand grain roughness of size k/D = 0.02 are performed (D is the cylinder diameter). Results show that surface roughness triggers the transition to turbulence in the boundary layer at all Reynolds numbers, thus leading to an early separation caused by the increased momentum deficit, especially at transcritical Reynolds numbers. Even at subcritical Reynolds numbers, boundary layer instabilities are triggered in the roughness sublayer and eventually lead to the transition to turbulence. The early separation at transcritical Reynolds numbers leads to a wake topology similar to that of the subcritical regime, resulting in an increased drag coefficient and lower Strouhal number. Turbulent statistics in the wake are also affected by roughness; the Reynolds stresses are larger due to the increased turbulent kinetic energy production in the boundary layer and separated shear layers close to the cylinder shoulders.We acknowledge “Red Española de Surpercomputación” (RES) for awarding us access to the MareNostrum III machine based in Barcelona, Spain (Ref. FI-2015-2-0026 and FI-2015-3-0011). We also acknowledge PRACE for awarding us access to Fermi and Marconi Supercomputers at Cineca, Italy (Ref. 2015133120). Oriol Lehmkuhl acknowledges a PDJ 2014 Grant by AGAUR (Generalitat de Catalunya). Ugo Piomelli acknowledges the support of the Natural Sciences and Engineering Research Council (NSERC) of Canada under the Discovery Grant Programme (Grant No. RGPIN-2016-04391). Ricard Borrell acknowledges a Juan de la Cierva postdoctoral grant (IJCI-2014-21034). Ivette Rodriguez, Oriol Lehmkuhl, Ricard Borrell and Assensi Oliva acknowledge Ministerio de Economía y Competitividad, Secretaría de Estado de Investigación, Desarrollo e Innovación, Spain (ref. ENE2014-60577-R).Peer ReviewedPostprint (author's final draft

    The use of curved vs. straight instruments in single port access surgery, on standardized box trainer tasks

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    BACKGROUND: Single-port access (SPA) surgery is a novel surgical technique to create nearly "scarless" surgery. SPA surgery appears to be safe and feasible, but the exposure and handling of tissue may not be optimal. Therefore, the performance of SPA surgery with different instruments used and conventional laparoscopy is compared. METHODS: Fifteen participants (>50 laparoscopic procedures) performed three basic tasks (translocation, clip & cut, and tissue dissection, based on the fundamentals of laparoscopic surgery) in the box trainer in laparoscopy and SPA settings with both (conventional) crossed and curved instruments. All participants completed a questionnaire, which asked their opinion on the use of instruments and preference. RESULTS: Translocation was performed significantly faster in both laparoscopy and SPA crossed than SPA curved (means, 130.3 and 137.7 vs. 170.7 sec; p < 0.001 and p = 0.005). The errors also were less in laparoscopy and SPA crossed (means, 0.9 and 1.2 vs. 1.6), but not significant. The time to complete the dissection was almost equal between laparoscopy and SPA curved settings, but took longer for SPA crossed, although not significantly (148.1 and 150.8 vs. 179.5 sec). The errors only differed significantly between laparoscopy and SPA crossed (means, 0.5 vs. 1.27; p = 0.044). Fourteen participants still favored conventional laparoscopy and one SPA curved. They also thought SPA curved was better than crossed (means, 3.6 vs. 2.47; p = 0.003) and that exposure is superior in curved (means, 3.4 vs. 2.27; p = 0.002). CONCLUSIONS: Although conventional laparoscopy may appear most effective for proper dissection and exposure of tissue, single-port access surgery shows potential. Especially in the tissue dissection task, there is no significant difference in time or errors between conventional laparoscopy and SPA surgery, using specially designed curved instruments. Although the participants favor conventional laparoscopy, this could evolve to a more accepting mind when SPA surgery becomes more available and used in the clinical setting

    Protective effect of stromal Dickkopf-3 in prostate cancer: opposing roles for TGFBI and ECM-1

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    Aberrant transforming growth factor–β (TGF-β) signaling is a hallmark of the stromal microenvironment in cancer. Dickkopf-3 (Dkk-3), shown to inhibit TGF-β signaling, is downregulated in prostate cancer and upregulated in the stroma in benign prostatic hyperplasia, but the function of stromal Dkk-3 is unclear. Here we show that DKK3 silencing in WPMY-1 prostate stromal cells increases TGF-β signaling activity and that stromal cellconditioned media inhibit prostate cancer cell invasion in a Dkk-3-dependent manner. DKK3 silencing increased the level of the cell-adhesion regulator TGF-β–induced protein (TGFBI) in stromal and epithelial cell-conditioned media, and recombinant TGFBI increased prostate cancer cell invasion. Reduced expression of Dkk-3 in patient tumors was associated with increased expression of TGFBI. DKK3 silencing reduced the level of extracellular matrix protein-1 (ECM-1) in prostate stromal cell-conditioned media but increased it in epithelial cell-conditioned media, and recombinant ECM-1 inhibited TGFBI-induced prostate cancer cell invasion. Increased ECM1 and DKK3 mRNA expression in prostate tumors was associated with increased relapse-free survival. These observations are consistent with a model in which the loss of Dkk-3 in prostate cancer leads to increased secretion of TGFBI and ECM-1, which have tumor-promoting and tumor-protective roles, respectively. Determining how the balance between the opposing roles of extracellular factors influences prostate carcinogenesis will be key to developing therapies that target the tumor microenvironment

    Hemobilia caused by a ruptured hepatic cyst: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Hemobilia is a rare cause of upper gastrointestinal bleeding. More than 50% of hemobilia cases are related to iatrogenic trauma from hepatobiliary procedures, and needle biopsy of the liver represents the most common cause. A minority of hemobilia cases are due to hepatobiliary disorders such as cholangitis, hepatobiliary cancers, choledocholithiasis, and vascular abnormalities in the liver. The classic presentation of hemobilia is the triad of right upper quadrant (biliary) pain, obstructive jaundice, and upper gastrointestinal bleeding. We report a rare case of hemobilia caused by a spontaneous hepatic cyst rupture, where our patient presented without the classical symptoms, in the absence of therapeutic or pathological coagulopathy, and in the absence of spontaneous or iatrogenic trauma.</p> <p>Case presentation</p> <p>A 91-year-old African-American woman was referred to our out-patient gastroenterology clinic for evaluation of mild epigastric pain and intermittent melena. An abdominal computed tomography scan was remarkable for multiple hepatic cysts. Esophagogastroduodenoscopy revealed multiple blood clots at the ampulla of Vater. Endoscopic retrograde cholangiopancreatography showed a single 18 mm-sized filling defect in the common hepatic duct wall at the junction of the right and left hepatic duct, adjacent to one of the hepatic cysts. The ruptured hepatic cyst communicated to the bile ducts and was the cause of hemobilia with an atypical clinical presentation.</p> <p>Conclusion</p> <p>Hemobilia is an infrequent cause of upper gastrointestinal bleeding and rarely occurs due to hepatic cyst rupture. To the best of our knowledge, this is only the second case report in the literature that describes hemobilia due to hepatic cyst rupture. However, it is the first case in the literature of hemobilia due to hepatic cyst rupture in the absence of iatrogenic or spontaneous trauma, and in the absence of a spontaneous or pathological coagulopathy.</p

    Canine respiratory coronavirus employs caveolin-1-mediated pathway for internalization to HRT-18G cells

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    Canine respiratory coronavirus (CRCoV), identified in 2003, is a member of the Coronaviridae family. The virus is a betacoronavirus and a close relative of human coronavirus OC43 and bovine coronavirus. Here, we examined entry of CRCoV into human rectal tumor cells (HRT-18G cell line) by analyzing co-localization of single virus particles with cellular markers in the presence or absence of chemical inhibitors of pathways potentially involved in virus entry. We also targeted these pathways using siRNA. The results show that the virus hijacks caveolin-dependent endocytosis to enter cells via endocytic internalization

    Quasar Sightline and Galaxy Evolution (QSAGE) - III. The mass-metallicity and fundamental metallicity relation of z ≈ 2.2 galaxies

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    We present analysis of the mass-metallicity relation (MZR) for a sample of 67 [O iii]-selected star-forming (SF) galaxies at a redshift range of z = 1.99-2.32 (zmed = 2.16) using Hubble Space Telescope Wide Field Camera 3 grism spectroscopy from the Quasar Sightline and Galaxy Evolution survey. Metallicities were determined using empirical gas-phase metallicity calibrations based on the strong emission lines [O ii]3727, 3729, [O iii]4959, 5007 and Hβ. SF galaxies were identified, and distinguished from active-galactic nuclei, via Mass-Excitation diagrams. Using z ∼0 metallicity calibrations, we observe a negative offset in the z = 2.2 MZR of ≈-0.51 dex in metallicity when compared to locally derived relationships, in agreement with previous literature analysis. A similar offset of ≈-0.46 dex in metallicity is found when using empirical metallicity calibrations that are suitable out to z ∼5, though our z = 2.2 MZR, in this case, has a shallower slope. We find agreement between our MZR and those predicted from various galaxy evolution models and simulations. Additionally, we explore the extended fundamental metallicity relation (FMR) which includes an additional dependence on star formation rate. Our results consistently support the existence of the FMR, as well as revealing an offset of 0.28 ± 0.04 dex in metallicity compared to locally derived relationships, consistent with previous studies at similar redshifts. We interpret the negative correlation with SFR at fixed mass, inferred from an FMR existing for our sample, as being caused by the efficient accretion of metal-poor gas fuelling SFR at cosmic noon

    Detection of virulence genes in Malaysian Shigella species by multiplex PCR assay

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    BACKGROUND: In Malaysia, Shigella spp. was reported to be the third commonest bacterial agent responsible for childhood diarrhoea. Currently, isolation of the bacterium and confirmation of the disease by microbiological and biochemical methods remain as the "gold standard". This study aimed to detect the prevalence of four Shigella virulence genes present concurrently, in randomly selected Malaysian strains via a rapid multiplex PCR (mPCR) assay. METHODS: A mPCR assay was designed for the simultaneous detection of chromosomal- and plasmid-encoded virulence genes (set1A, set1B, ial and ipaH) in Shigella spp. One hundred and ten Malaysian strains (1997–2000) isolated from patients from various government hospitals were used. Reproducibility and sensitivity of the assay were also evaluated. Applicability of the mPCR in clinical settings was tested with spiked faeces following preincubation in brain heart infusion (BHI) broth. RESULTS: The ipaH sequence was present in all the strains, while each of the set1A, set1B and ial gene was present in 40% of the strains tested. Reproducibility of the mPCR assay was 100% and none of the non-Shigella pathogens tested in this study were amplified. The mPCR could detect 100 colony-forming units (cfu) of shigellae per reaction mixture in spiked faeces following preincubation. CONCLUSIONS: The mPCR system is reproducible, sensitive and is able to identify pathogenic strains of shigellae irrespective of the locality of the virulence genes. It can be easily performed with a high throughput to give a presumptive identification of the causal pathogen
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