762 research outputs found

    Short communication: In vitro screening of Sonneratia alba extract against the oomycete fish pathogen, Aphanomyces invadans

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    Epizootic ulcerative syndrome (EUS), caused by the aquatic oomycete fish pathogen, Aphanomyces invadans (David and Kirk, 1997) is one of the OIE-listed diseases that leads to huge economic losses in the fish industry in the world. Traditional disease management strategies relying on chemotherapy continue to cause undesirable effects such as antibiotic resistance, environmental pollution and food security issues (Pandey et al., 2012). In addition, there has been no vaccine available to prevent the outbreak of EUS according to the Office International des Epizooties (OIE) (2015). Therefore, many current research focuses on alternative strategies such as using plants for EUS treatments (Fairweather, 1999; Campbell et al., 2001; Chowdhury and Rahman, 2013; Alam et al., 2014; Uthayakumar et al., 2014; Kumar et al., 2015; Yogeshwari et al., 2015)

    Asymptotic Expansions for the Conditional Sojourn Time Distribution in the M/M/1M/M/1-PS Queue

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    We consider the M/M/1M/M/1 queue with processor sharing. We study the conditional sojourn time distribution, conditioned on the customer's service requirement, in various asymptotic limits. These include large time and/or large service request, and heavy traffic, where the arrival rate is only slightly less than the service rate. The asymptotic formulas relate to, and extend, some results of Morrison \cite{MO} and Flatto \cite{FL}.Comment: 30 pages, 3 figures and 1 tabl

    Wintertime CO2 Emission from Soils of Northeastern Siberia

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    The emission of C02 from northeastern Siberian soil was estimated for the period December 1989 to February 1990. Concentrations of air CO2 near the ground and 1 m above the snow cover were measured by an infrared gas analyzer. Fluxes of CO2 across the snow cover were calculated from the differences of these two values and the predetermined CO2 transfer coefficients at various flux rates through a layer of snow. Temperature and moisture content of the soil profiles were also observed simultaneously. The average transfer coefficient of CO2 for packed snow measured in the winter of 1989/90 was about 0.28 sq. cm/s. This value was used to estimate the average CO2 flux from soil: 0.26 g C/sq. m/day in December 1989, 0.13 g C/sq. m/day in January 1990 and 0.07 g C/sq. m/day in February 1990. Thus a minimal total of about 13.8 g C/sq. m had been released from the tundra soil during the 90 days from December 1989 to February 1990. Using the study by Kelley et al. (1968) and assuming that the minimal CO2 transfer coefficient is also applicable for the entire tundra and Northern Taiga zones between September and June, the total emission from this region would amount to 0.23 x 10**15 g of carbon. The main source of this CO2 probably originated from microbial oxidation of soil organic matter. This assertion is supported by the existence of a relatively warm layer in the frozen soil at 40-120 cm depth. This warm layer was about 10-40 C higher than the ambient air, or about 5-10 C higher than the soil surface, and its moisture content was also higher than the surrounding layers.Key words: CO2 flux, Siberian tundra, soil temperature, moisture contentOn a évalué l'émission de CO2 provenant du sol dans le nord-est sibérien, durant la période allant de décembre 1989 à février 1990. On a mesuré les concentrations du CO2 ambiant près du sol et à 1 m de la couverture de neige, à l'aide d'un analyseur de gaz infrarouge. On a calculé les flux du CO2 à travers le couvert nival à partir des différences de ces deux valeurs et des coefficients de transfert du CO2 prédéterminés pour divers taux de flux à travers une couche de neige. On a aussi observé simultanément la température et la teneur en humidité des profils pédologiques. Le coefficient de transfert moyen du CO2 pour la neige tassée mesuré durant l'hiver de 1989-90 était d'environ 0,28 cm²/s. Cette valeur a servi à estimer le flux moyen du CO2 provenant du sol: 0,26 g C/m²/jour en décembre 1989, 0,13 g C/m²/jour en janvier 1990 et 0,07 g C/m²/jour en février 1990. Par conséquent, un total minimal d'environ 13,8 g C/m² a été libéré du sol de la toundra au cours des 90 jours allant de décembre à février 1990. En nous servant de l'étude menée précédemment par Kelley et al. (1968) et en supposant que le coefficient minimal de transfert du CO2 s'applique aussi à l'ensemble des zones de toundra et de taïga septentrionale entre septembre et juin, l'émission totale provenant de cette région se monterait à 0,23 x 10**15 g de carbone. La source principale de ce CO2 venait probablement de l'oxydation microbienne de la matière organique contenue dans le sol. Cette assertion est soutenue par l'existence d'une couche de température relativement élevée dans le sol gelé, qui se trouve de 40 à 120 cm de profondeur. La température de cette couche était de 10 à 40 °C plus élevée que l'air ambiant, ou environ de 5 à 10 °C plus élevée que la surface du sol, et sa teneur en eau était aussi plus élevée que les couches adjacentes.Mots clés : flux de CO2, toundra sibérienne, temperature du sol, teneur en ea

    SARS Transmission among Hospital Workers in Hong Kong

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    Despite infection control measures, breakthrough transmission of severe acute respiratory syndrome (SARS) occurred for many hospital workers in Hong Kong. We conducted a case-control study of 72 hospital workers with SARS and 144 matched controls. Inconsistent use of goggles, gowns, gloves, and caps was associated with a higher risk for SARS infection (unadjusted odds ratio 2.42 to 20.54, p < 0.05). The likelihood of SARS infection was strongly associated with the amount of personal protection equipment perceived to be inadequate, having <2 hours of infection control training, and not understanding infection control procedures. No significant differences existed between the case and control groups in the proportion of workers who performed high-risk procedures, reported minor protection equipment problems, or had social contact with SARS-infected persons. Perceived inadequacy of personal protection equipment supply, infection control training <2 hours, and inconsistent use of personal protection equipment when in contact with SARS patients were significant independent risk factors for SARS infection

    Evidence for a persistent, major excess in all cause admissions to hospital in children with type-1 diabetes: results from a large Welsh national matched community cohort study

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    OBJECTIVES: To estimate the excess in admissions associated with type1 diabetes in childhood. DESIGN: Matched-cohort study using anonymously linked hospital admission data. SETTING: Brecon Group Register of new cases of childhood diabetes in Wales linked to hospital admissions data within the Secure Anonymised Information Linkage Databank. POPULATION: 1577 Welsh children (aged between 0 and 15 years) from the Brecon Group Register with newly-diagnosed type-1 diabetes between 1999–2009 and 7800 population controls matched on age, sex, county, and deprivation, randomly selected from the local population. MAIN OUTCOME MEASURES: Difference in all-cause hospital admission rates, 30-days post-diagnosis until 31 May 2012, between participants and controls. RESULTS: Children with type-1 diabetes were followed up for a total of 12 102 person years and were at 480% (incidence rate ratios, IRR 5.789, (95% CI 5.34 to 6.723), p<0.0001) increased risk of hospital admission in comparison to matched controls. The highest absolute excess of admission was in the age group of 0–5 years, with a 15.4% (IRR 0.846, (95% CI 0.744 to 0.965), p=0.0061) reduction in hospital admissions for every 5-year increase in age at diagnosis. A trend of increasing admission rates in lower socioeconomic status groups was also observed, but there was no evidence of a differential rate of admissions between men and women when adjusted for background risk. Those receiving outpatient care at large centres had a 16.1% (IRR 0.839, (95% CI 0.709 to 0.990), p=0.0189) reduction in hospital admissions compared with those treated at small centres. CONCLUSIONS: There is a large excess of hospital admissions in paediatric patients with type-1 diabetes. Rates are highest in the youngest children with low socioeconomic status. Factors influencing higher admission rates in smaller centres (eg, “out of hours resources”) need to be explored with the aim of targeting modifiable influences on admission rates

    Numerical Results for Ground States of Mean-Field Spin Glasses at low Connectivities

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    An extensive list of results for the ground state properties of spin glasses on random graphs is presented. These results provide a timely benchmark for currently developing theoretical techniques based on replica symmetry breaking that are being tested on mean-field models at low connectivity. Comparison with existing replica results for such models verifies the strength of those techniques. Yet, we find that spin glasses on fixed-connectivity graphs (Bethe lattices) exhibit a richer phenomenology than has been anticipated by theory. Our data prove to be sufficiently accurate to speculate about some exact results.Comment: 4 pages, RevTex4, 5 ps-figures included, related papers available at http://www.physics.emory.edu/faculty/boettcher

    Two-dimensional one-component plasma on a Flamm's paraboloid

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    We study the classical non-relativistic two-dimensional one-component plasma at Coulomb coupling Gamma=2 on the Riemannian surface known as Flamm's paraboloid which is obtained from the spatial part of the Schwarzschild metric. At this special value of the coupling constant, the statistical mechanics of the system are exactly solvable analytically. The Helmholtz free energy asymptotic expansion for the large system has been found. The density of the plasma, in the thermodynamic limit, has been carefully studied in various situations
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