145 research outputs found

    Studies on Viruses in Water

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    A new procedure for the detection of viral antigens in fecal material was developed. The test is performed by first diluting a fecal sample with phosphate buffered saline to give a liquid consistency. The pH is then adjusted to 8.5-9.0 and the solids are allowed to settle for five minutes. Supernatant fluid from above the fecal sediment is placed on the upper surface of a well of an inverted Immulon microtiter plate and incubated for one hour at 37 degrees C to allow virus to adsorb to the plastic. The Immulon plate is then washed three times with a Tween 20 solution and dried. Adsorbed virus is stained with fluorescein labled antiviral antibody containing Evan\u27s Blue dye. The stained preparations are examined by epi-fluorescence microsopy for the presence of viral aggregates and virus-containing cellular membranes. The test is applied in a continuous water monitoring procedure that can be used to upplement methods in which infectious viruses are isolated from water. In another study a protamine sulfate procedure for concentrating and an immunofluorescent cell procedure for assaying infectious virus (IV, reovirus that is infectious without proteolytic enzyme treatment), and potentially infectious virus (PIV, enzyme enhanceable reovirus) from polluted waters have been developed. The presence of PIV inthe environment had not previously been investigated. In following these procedures, protamine sulfate concentratiosn of 0.005 percent for the first precipitation of the sample, and 0.0025 percent for the second were used. With these protamine concentrations and 0.25 percent fetal bovine serum, IV and PIV are concentrations over 500-fold from river water inoculated with virus. Virus recoveries are between 80 and 100 percent. The IV and PIV fractions are assayed respectively before and after treatment with 200 ug fo chymotrypsin per millileter. When PIV is precipitated from river water, and the precipitate is dissolved and stored at 20 degrees C as a protamine-virus concentrate, only 5 percent of the viral infectivity is lost after 14 days. Therefore, reovirus can be precipitated from water at the sampling site, and only the protamine concentrate needs to be taken to the laboratory to be examined for virus content. When reoviruses are treated with chlorine, PIV is more resistant to inactivation thatn IV, and PIV appears to be at least as resistant to chlorination as poliovirus and coxsackievirus A-2. Granular media filtration systems (i.e., sand, anthracite coal and sand; anthracite coal; sand and garnet) are ineffectual in the removal of the acteriophage MS 2 from water when used as in-line direct filters. Batch assays have indicated a 93 percent reduction of MS 2 can occur when polyelectrolytes are added to the water. In addition, alum concentrations of 20, 30, 40, and 50 mg/1 remove 80 to 98 percent of the virus by precipitation. No reduction of MS 2 was observed at alum concentrations from 1 to 10 mg/1

    Evaluation of Leaf Spot Resistance in Wild \u3ci\u3eArachis\u3c/i\u3e Species of Section \u3ci\u3eArachis\u3c/i\u3e

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    Wild diploid Arachis species are potential sources of resistance to early (ELS) and late (LLS) leaf spot diseases caused by Passalora arachidicola (syn. Cercospora arachidicola Hori), and Nothopassalora personata (syn. Cercosporidium personatum (Berk. & Curt.) Deighton), respectively. Within section Arachis, limited information is available on the extent of genetic variation for resistance to these fungal pathogens. A collection of 78 accessions representing 15 wild species of Arachis section Arachis from the U.S peanut germplasm collection was evaluated for resistance to leaf spots. Screening was conducted under field (natural inoculum) conditions in Dawson, Georgia, during 2017 and 2018. Accessions differed significantly (P , 0.01) for all three disease variables evaluated, which included final defoliation rating, ELS lesion counts, and LLS lesion counts. Relatively high levels of resistance were identified for both diseases, with LLS being the predominant pathogen during the two years of evaluation. This research documents new sources of resistance to leaf spot diseases selected from an environment with high inoculum pressure. The presence of ELS and LLS enabled the selection of resistant germplasm for further introgression and pre-breeding

    Deflated GMRES for Systems with Multiple Shifts and Multiple Right-Hand Sides

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    We consider solution of multiply shifted systems of nonsymmetric linear equations, possibly also with multiple right-hand sides. First, for a single right-hand side, the matrix is shifted by several multiples of the identity. Such problems arise in a number of applications, including lattice quantum chromodynamics where the matrices are complex and non-Hermitian. Some Krylov iterative methods such as GMRES and BiCGStab have been used to solve multiply shifted systems for about the cost of solving just one system. Restarted GMRES can be improved by deflating eigenvalues for matrices that have a few small eigenvalues. We show that a particular deflated method, GMRES-DR, can be applied to multiply shifted systems. In quantum chromodynamics, it is common to have multiple right-hand sides with multiple shifts for each right-hand side. We develop a method that efficiently solves the multiple right-hand sides by using a deflated version of GMRES and yet keeps costs for all of the multiply shifted systems close to those for one shift. An example is given showing this can be extremely effective with a quantum chromodynamics matrix.Comment: 19 pages, 9 figure

    Neurodevelopmental Outcome of Young Children with Biliary Atresia and Native Liver: Results from the ChiLDReN Study

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    OBJECTIVES: To assess neurodevelopmental outcomes among participants with biliary atresia with their native liver at ages 12 months (group 1) and 24 months (group 2), and to evaluate variables predictive of neurodevelopmental impairment. STUDY DESIGN: Participants enrolled in a prospective, longitudinal, multicenter study underwent neurodevelopmental testing with either the Bayley Scales of Infant Development, 2nd edition, or Bayley Scales of Infant and Toddler Development, 3rd edition. Scores (normative mean = 100 ± 15) were categorized as ≥100, 85-99, and <85 for χ2 analysis. Risk for neurodevelopmental impairment (defined as ≥1 score of <85 on the Bayley Scales of Infant Development, 2nd edition, or Bayley Scales of Infant and Toddler Development, 3rd edition, scales) was analyzed using logistic regression. RESULTS: There were 148 children who completed 217 Bayley Scales of Infant and Toddler Development, 3rd edition, examinations (group 1, n = 132; group 2, n = 85). Neurodevelopmental score distributions significantly shifted downward compared with test norms at 1 and 2 years of age. Multivariate analysis identified ascites (OR, 3.17; P = .01) and low length z-scores at time of testing (OR, 0.70; P < .04) as risk factors for physical/motor impairment; low weight z-score (OR, 0.57; P = .001) and ascites (OR, 2.89; P = .01) for mental/cognitive/language impairment at 1 year of age. An unsuccessful hepatoportoenterostomy was predictive of both physical/motor (OR, 4.88; P < .02) and mental/cognitive/language impairment (OR, 4.76; P = .02) at 2 years of age. CONCLUSION: Participants with biliary atresia surviving with native livers after hepatoportoenterostomy are at increased risk for neurodevelopmental delays at 12 and 24 months of age. Those with unsuccessful hepatoportoenterostomy are >4 times more likely to have neurodevelopmental impairment compared with those with successful hepatoportoenterostomy. Growth delays and/or complications indicating advanced liver disease should alert clinicians to the risk for neurodevelopmental delays, and expedite appropriate interventions

    Cleareye In-Ground and In-Concrete DIV Inspections: FY11 Final Report

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    This report summarizes the results of a series of feasibility testing studies for in-ground and in-concrete imaging/detection technologies including radar imaging and acoustic time-of flight method. The objectives of this project are: (1) Design Information Verification (DIV) Tools for In-Concrete Inspections - To determine the feasibility of using holographic radar imaging (HRI), radar imaging, and acoustic time-of-flight (TOF) non-destructive evaluation technologies to detect, locate and identify pipes and voids embedded in standard-density and high-density concrete walls that typify those the IAEA will need to verify during field inspections; (2) DIV Tools for In-Ground Inspections - To determine the feasibility of using HRI and radar imaging non-destructive evaluation technologies to detect, locate, and identify objects buried at various depths made of various materials (metal, plastic, wood, and concrete) and representing geometries that typify those the IAEA will need to verify during field inspections; and (3) Based on the results of the studies, recommend the next steps needed to realize fieldable tools for in-concrete and in-ground inspections (including detection of deeply buried polyvinyl chloride [PVC] pipes) that employ the technologies shown to be feasible

    Clinical trial to assess the effect of physical exercise on endothelial function and insulin resistance in pregnant women

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    <p>Abstract</p> <p>Background</p> <p>Preeclampsia (PE) is a common maternal disease that complicates 5 to 10% of pregnancies and remains as the major cause of maternal and neonatal mortality. Cost-effective interventions aimed at preventing the development of preeclampsia are urgently needed. However, the pathogenesis of PE is not well known. Multiple mechanisms such as oxidative stress, endothelial dysfunction and insulin resistance may contribute to its development. Regular aerobic exercise recovers endothelial function; improves insulin resistance and decreases oxidative stress. Therefore the purpose of this clinical trial is to determine the effect of regular aerobic exercise on endothelial function, on insulin resistance and on pregnancy outcome.</p> <p>Methods and design</p> <p>64 pregnant women will be included in a blind, randomized clinical trial, and parallel assignment. The exercise group will do regular aerobic physical exercise: walking (10 minutes), aerobic exercise (30 minutes), stretching (10 minutes) and relaxation exercise (10 minutes) in three sessions per week. Control group will do the activities of daily living (bathing, dressing, eating, and walking) without counselling from a physical therapist.</p> <p>Trial registration</p> <p>NCT00741312.</p

    Summary Statement Novel Agents in the Treatment of Lung Cancer: Fifth Cambridge Conference Assessing Opportunities for Combination Therapy

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    The promise of effective targeted therapy for lung cancer requires rigorous identification of potential targets combined with intensive discovery and development efforts aimed at developing effective "drugs" for these targets. We now recognize that getting the right drug to the right target in the right patient is more complicated than one could have imagined a decade ago. As knowledge of targets and development of agents have proliferated and advanced, so too have data demonstrating the biologic heterogeneity of tumors. The finding that lung cancers are genetically diverse and can exhibit several pathways of resistance in response to targeted agents makes the prospect for curative therapy more daunting. It is becoming increasingly clear that single-agent treatment will be the exception rather than the rule. This information raises important new questions about the development and assessment of novel agents in lung cancer treatment: (1) How do we identify the most important drug targets for tumor initiation and maintenance? (2) What is the best way to assess drug candidates that may only be relevant in a small fraction of patients? (3) What models do we use to predict clinical response and identify effective combinations? And (4) how do we bring combination regimens to the clinic, particularly when the agents are not yet approved individually and may be under development from different companies? The Fifth Cambridge Conference on Novel Agents in the Treatment of Lung Cancer was held in Cambridge, Massachusetts, on October 1-2, 2007, to discuss these questions by reviewing recent progress in the field and advancing recommendations for research and patient care. New information, conclusions, and recommendations considered significant for the field by the program faculty are summarized here and presented at greater length in the individual articles and accompanying discussions that comprise the full conference proceedings. A CME activity based on this summary is also available at www.informedicalcme.com/cme

    Primed acclimation of cultivated peanut (Arachis hypogaea L.) through the use of deficit irrigation timed to crop developmental periods

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    Water-deficits and high temperatures are the predominant factors limiting peanut production across the U.S., either because of regional aridity or untimely rainfall events during crucial crop developmental periods. In the southern High Plains of west Texas and eastern New Mexico, low average annual rainfall (450. mm) and high evaporative demand necessitates the use of significant irrigation in production systems. In this west Texas study, the primary objective was to develop irrigation schemes that maximized peanut yield and grade while reducing overall water consumption. Therefore, a large-scale field experiment was established in 2005 and 2006 that utilized 15 treatment combinations of differing rates of irrigation (50, 75, and 100% of grower applied irrigation) applied at different periods of peanut development (early, middle, and late season). Precipitation patterns and ambient temperatures showed greater stress levels in 2006 which likely reduced yields across all treatments in comparison to 2005. Yields were reduced 26 (2005) and 10% (2006) in the lowest irrigation treatment (50% full season) compared with full irrigation (100% full season); but early-season water deficit (50 and 75% in the first 45. days after planting) followed by 100% irrigation in the mid- and late-seasons were successful at sustaining yield and/or crop value. Root growth was significantly enhanced at 50% irrigation compared with 100% irrigation, through greater root length, diameter, surface area, and depth, suggesting greater access to water during mid- and late-season periods. These results suggest that early to mid-season deficit irrigation has the potential to maintain peanut yield without altering quality, and to substantially reduce water use in this semi-arid environment

    Economic Analysis of Knowledge: The History of Thought and the Central Themes

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    Following the development of knowledge economies, there has been a rapid expansion of economic analysis of knowledge, both in the context of technological knowledge in particular and the decision theory in general. This paper surveys this literature by identifying the main themes and contributions and outlines the future prospects of the discipline. The wide scope of knowledge related questions in terms of applicability and alternative approaches has led to the fragmentation of research. Nevertheless, one can identify a continuing tradition which analyses various aspects of the generation, dissemination and use of knowledge in the economy
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