6,247 research outputs found

    The municipal solid waste landfill as a source of ozone-depleting substances in the United States and United Kingdom

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    This study provides observation-based national estimates of CFC-11, CFC-12, CFC-113, and 1,1,1-trichloroethane emissions for the United States (US) and United Kingdom (UK) from municipal solid waste (MSW) landfills. The scarcity of national estimates has lead to the assumption that a significant fraction of the lingering ozone-depleting substance (ODS) emissions, which have been detected in industrialized countries, could be emitted from landfills. Spatial coverage was achieved through sampling at seven landfills in Massachusetts and through data provided by nine UK landfills. Linear least square regressions of recovered ODS vs. CH4 were used in combination with national estimates of landfill CH4 emissions to estimate 2006 national US and UK ODS landfill emissions. The ODS landfill emission estimates were then compared to recent estimates of total US and UK ODS emissions. US ODS landfill emissions are 0.4%-1% (0.006-0.09 Gg/year) of total US emissions. UK ODS landfill emission estimates are 1% (0.008 Gg/year) and 6% (0.03 Gg/year) of total UK CFC-11 and CFC-12 emissions, respectively. This indicates that landfills are only a minor source of lingering ODS emissions in the US, but may be more significant for CFC-12 emissions in the UK. The implication is that the majority of current ODS emissions in industrialized countries is likely coming from equipment still in use.United States. National Aeronautics and Space Administration (Grant NNX07AE89G)United States. National Aeronautics and Space Administration (Grant NAG512669)National Science Foundation (U.S.) (Grant ATM-0120468

    The Next 50 Years: Considering Gender as a Context for Understanding Young Children’s Peer Relationships

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    The study of children’s peer relationships has been well represented within the pages of Merrill-Palmer Quarterly. Particularly over the last decade, the pace of publishing studies on peer relationships has increased. Despite this upswing in interest in peer relationships, significant gaps remain. In this article, we focus on a particularly overlooked and significant area of peer relationships, namely, the role of sex-segregated peer interactions and how these relate to development in early childhood. We review why this topic is important for researchers to consider and highlight promising directions for research that we hope will appear in future volumes of Merrill-Palmer Quarterly

    Mejoramiento de los procesos en el quirófano mediante la aplicación de la metodología Lean de Toyota

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    ResumenEl sector de la atención en salud está necesitando un cambio fundamental a fin de mejorar significativamente los resultados y limitar al mismo tiempo los costos. Los métodos Lean desarrollados inicialmente en la industria manufacturera han demostrado mejorar realmente la calidad, la productividad y la seguridad, a la vez que permiten utilizar menos recursos en la gestión de la salud. Estas herramientas, prácticas gerenciales y filosofías se han adaptado con éxito en los servicios de cirugía del SC. Pueden transformar el sistema y la cultura mediante el compromiso del personal de asistencia para el desarrollo de un servicio que mejora continuamente y permite obtener mejores resultados clínicos duraderos.AbstractHealthcare is in need of fundamental change if we are going to make significant improvements in outcomes while limiting costs. Lean methods, initially developed in the manufacturing industry, have been shown to deliver real improvements in quality, productivity, and safety while using fewer resources in healthcare service settings. These tools, management practices and philosophies have been successfully adapted in operative services at SC. They can transform your system and culture through engagement of frontline staff into a continuously improving service with real and sustainable enhancements in clinical outcomes

    HI and CO in the circumstellar environment of the S-type star RS Cnc

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    This paper presents interferometric and single-dish CO observations along with HI data obtained for the oxygen-rich semi-regular variable RS Cnc, in order to probe its circumstellar environment at different scales. With the Plateau de Bure Interferometer and the IRAM 30-m telescope, we detect both the CO(1-0) and the CO(2-1) rotational lines from RS Cnc. The line profiles are composite, with two components of half-width ~2 km/s and ~8 km/s respectively. Whereas the narrow velocity component seems to originate from an equatorial disk in the central part of the CO envelope, the broad component reveals a bipolar structure, with a north-south velocity gradient. In addition, we obtain new HI data on the source and around it in a field of almost 1 square degree. The HI line is centered at v_LSR = 7 km/s in agreement with CO observations. A new reduction process reveals a complex extended structure in the northwest direction, of estimated size ~18 arcmin, with a PA (~310 degrees) opposite to the direction of the stellar proper motion (~140 degrees). We derive an HI mass of ~3 10^-2 M_sun for this structure. Based on a non-spherical simulation, we find that this structure is consistent with arising from the interaction of the star undergoing mass loss at an average rate of ~10^-7 M_sun.yr^-1 over ~2-3 10^5 years with the interstellar medium. This work illustrates the powerful complementarity of CO and HI observations with regard to a more complete description of circumstellar environments around AGB stars.Comment: accepted for publication in A&

    Podofilox-Induced Regression of Shope Papillomas May Be Independent of Host Immunity

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    We tested the hypothesis that infiltrating leukocytes might contribute to papilloma destruction following podofilox treatment. New Zealand White (NZW) rabbits were inoculated with cottontail rabbit papillomavirus (CRPV) onto abraded areas of the dorsal skin. At 21 d after viral inoculation, 5.0% podofilox solution was applied to some papillomas, whereas others were used as controls. Three rabbits were sacrificed at each of three different periods after treatment initiation (1, 4, and 7 d). Four monoclonal antibodies (MoAbs), RG-16 (for B cells), L11/135 (specific for T cells), 2C4 (specific for class II antigen), and Ki67 (specific for proliferating cells), were used in an immunohistochemical study. All positive cells and total cells in the field were counted with an ocular grid. After 1 d of treatment, proliferation of papilloma cells was strongly suppressed in treated papillomas, but leukocytic infiltration was not altered. At 4 d and 7 d of treatment, there were substantial increases (about two to three times) in the numbers of B and T cells and class II – expressing leukocytes. The upper layers of the papillomas were highly necrotic and cell proliferation was absent in an layers. These data support the view that podofilox has a direct toxic effect on papilloma tissue. Leukocyte infiltration is not strongly associated with papilloma tissue and may not contribute to papilloma destruction

    Analysis of Nausea in Clinical Studies of Lubiprostone for the Treatment of Constipation Disorders

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    BACKGROUND: Lubiprostone is a ClC-2 chloride channel activator approved for the treatment of chronic idiopathic constipation (CIC) and opioid-induced constipation (OIC) in adults and irritable bowel syndrome with constipation (IBS-C) in women. Lubiprostone is generally well tolerated, with nausea being the most common adverse event. AIMS: To characterize nausea with lubiprostone using pooled results from clinical studies in patients with CIC, OIC, or IBS-C. METHODS: Data from three 3- and 4-week placebo-controlled studies and three long-term open-label studies were pooled for the CIC analysis. The OIC and IBS-C analyses each used pooled data from three 12-week placebo-controlled studies and one 36-week open-label extension study. RESULTS: The populations included the following numbers of patients: CIC, 316 (placebo) and 1113 (lubiprostone 24 mcg twice daily [BID]); OIC, 652 (placebo) and 889 (lubiprostone 24 mcg BID); and IBS-C, 435 (placebo) and 1011 (lubiprostone 8 mcg BID). The incidence of nausea in lubiprostone-treated patients ranged from 11.4 to 31.1%, with the highest incidence in patients with CIC. Among patients with any nausea, most reported only mild or moderate severity (96.5-99.1% across indications) and only one event (83.6-88.7%); most events occurred within the first 5 days of treatment. CONCLUSIONS: Nausea was the most common adverse event following the treatment with lubiprostone. Event rates varied by indication and dose, and the majority of nausea adverse events were mild to moderate in severity. Nausea events predominantly occurred early in the treatment period in all of the pooled study populations

    Relationships Among IL-6, TNF-α, Adipokines, Vitamin D and Chronic Periodontitis

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    Objectives to explore relationships among serum adipokines, vitamin D, clinical and microbial parameters of chronic periodontitis before and after treatment. Methods weight, height and smoking status were recorded for 56 patients with chronic periodontitis. Plaque, gingivitis, bleeding on probing (BOP), suppuration, pocket depth (PD) and attachment level (AL) were measured at all teeth present. Subgingival biofilm samples from each tooth were analyzed for levels of 40 bacterial species using checkerboard DNA-DNA hybridization. Serum levels of interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), adiponectin, leptin, resistin and vitamin D were measured at baseline. Sample collection was then performed in a subset of the population 6 months post-therapy (n=17). Serum samples were analyzed using ELISA and immunoassays. Differences in clinical, microbial and serum factors among groups were sought using the Mann-Whitney test. Correlations among factors were evaluated using regression analysis. Effects of therapy were sought using the Wilcoxon signed ranks test Results There were positive correlations between adiponectin/vitamin D and between IL-6/leptin; negative correlations between IL-6/vitamin D, and leptin/vitamin D, but no associations between serum analytes and clinical or microbial parameters. Gender and BMI were associated with levels of adipokines. Periodontal therapy improved clinical and microbiological parameters, but did not influence the levels of serum analytes. Conclusions Adipokines and IL-6 levels were affected by gender and BMI. Serum analytes were not influenced by periodontal therapy

    Spin Dynamics of the Magnetoresistive Pyrochlore Tl_2Mn_2O_7

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    Neutron scattering has been used to study the magnetic order and spin dynamics of the colossal magnetoresistive pyrochlore Tl_2Mn_2O_7. On cooling from the paramagnetic state, magnetic correlations develop and appear to diverge at T_C (123 K). In the ferromagnetic phase well defined spin waves are observed, with a gapless (Δ<0.04\Delta <0.04 meV) dispersion relation E=Dq^{2} as expected for an ideal isotropic ferromagnet. As T approaches T_C from low T, the spin waves renormalize, but no significant central diffusive component to the fluctuation spectrum is observed in stark contrast to the La1x_{1-x}(Ca,Ba,Sr)x_xMnO3_3 system. These results argue strongly that the mechanism responsible for the magnetoresistive effect has a different origin in these two classes of materials.Comment: 4 pages (RevTex), 4 figures (encapsulated postscript), to be published in Phys. Rev. Let

    Introduced and Native Congeners Use Different Resource Allocation Strategies to Maintain Performance During Infection

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    Hosts can manage parasitic infections using an array of tactics, which are likely to vary contingent on coevolutionary history between the host and the parasite. Here we asked whether coping ability of congeners that differ in host-parasite coevolutionary history differed in response to experimental infections with a coccidian parasite. House sparrows (Passer domesticus) and gray-headed sparrows (Passer griseus) are sympatric and ecologically similar, but house sparrows are recent colonizers of Kenya, the site of our comparison, whereas gray-headed sparrows are native. We evaluated three variables as barometers of infection coping ability: vertical flight, pectoral muscle size, and fat score. We also measured routing of a dose of 13C-labeled leucine, an essential amino acid, among tissues to compare resource allocation strategies in response to infection. We found that burden effects on performance were minimal in both species, but house sparrows maintained considerably higher burdens than gray-headed sparrows regardless of exposure. House sparrows also had more exogeneous leucine tracer in all tissues after 24 h, demonstrating a difference in the way the two species allocate or distribute resources. We argue that house sparrows may be maintaining larger resource reserves to mitigate costs associated with exposure and infection. Additionally, in response to increased parasite exposure, gray-headed sparrows had less leucine tracer in their spleens and more in their gonads, whereas house sparrows did not change allocation, perhaps indicating a trade-off that is not experienced by the introduced species

    Ares I-X Ground Diagnostic Prototype

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    The automation of pre-launch diagnostics for launch vehicles offers three potential benefits: improving safety, reducing cost, and reducing launch delays. The Ares I-X Ground Diagnostic Prototype demonstrated anomaly detection, fault detection, fault isolation, and diagnostics for the Ares I-X first-stage Thrust Vector Control and for the associated ground hydraulics while the vehicle was in the Vehicle Assembly Building at Kennedy Space Center (KSC) and while it was on the launch pad. The prototype combines three existing tools. The first tool, TEAMS (Testability Engineering and Maintenance System), is a model-based tool from Qualtech Systems Inc. for fault isolation and diagnostics. The second tool, SHINE (Spacecraft Health Inference Engine), is a rule-based expert system that was developed at the NASA Jet Propulsion Laboratory. We developed SHINE rules for fault detection and mode identification, and used the outputs of SHINE as inputs to TEAMS. The third tool, IMS (Inductive Monitoring System), is an anomaly detection tool that was developed at NASA Ames Research Center. The three tools were integrated and deployed to KSC, where they were interfaced with live data. This paper describes how the prototype performed during the period of time before the launch, including accuracy and computer resource usage. The paper concludes with some of the lessons that we learned from the experience of developing and deploying the prototype
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