152 research outputs found

    A description of the NSSL cases used for a simulated VAS retrieval study

    Get PDF
    A documentation of eight National Severe Storm Laboratory severe storm cases, which serve as a basis for a simulated VISSR Atmospheric Sounder retrieval study, is presented in this paper. Six of the selected cases provide a control data set to complete the statistical information needed for retrieval techniques based upon the use of regression matrices. The other two cases are to be used in the actual retrieval experiments. The selection was based upon the presence of moisture gradients in the analysis region, the availability of satellite images at the selected time periods, and the extent of cloud cover within the observing network

    Assessment of VAS soundings in the analysis of a preconvective environment

    Get PDF
    Retrievals from the VISSR Atmospheric Sounder (VAS) are combined with conventional data to assess the impact of geosynchronous satellite soundings upon the analysis of a preconvective environment. VAS retrievals of temperature, dewpoint, equivalent potential temperature, precipitable water, and lifted index are derived with 60 km resolution at 3 hour intervals. When VAS fields are combined with analyses from conventional data sources, mesoscale regions with convective instability are more clearly delineated prior to the rapid development of the thunderstorms. The retrievals differentiate isolated areas in which air extends throughout the lower troposphere from those regions where moisture is confined to a thin layer near the Earth's surface. The analyses of the VAS retrievals identify significant spatial gradients and temporal changes in the thermal and moisture fields, especially in the regions between radiosonde observations

    Improved VAS regression soundings of mesoscale temperature structure observed during the 1982 atmospheric variability experiment

    Get PDF
    An Atmospheric Variability Experiment (AVE) was conducted over the central U.S. in the spring of 1982, collecting radiosonde date to verify mesoscale soundings from the VISSR Atmospheric Sounder (VAS) on the GOES satellite. Previously published VAS/AVE comparisons for the 6 March 1982 case found that the satellite retrievals scarcely detected a low level temperature inversion or a mid-tropospheric cold pool over a special mesoscale radiosonde verification network in north central Texas. The previously published regression and physical retrieval algorithms did not fully utilize VAS' sensitivity to important subsynoptic thermal features. Therefore, the 6 March 1982 case was reprocessed adding two enhancements to the VAS regression retrieval algorithm: (1) the regression matrix was determined using AVE profile data obtained in the region at asynoptic times, and (2) more optimistic signal-to-noise statistical conditioning factors were applied to the VAS temperature sounding channels. The new VAS soundings resolve more of the low level temperature inversion and mid-level cold pool. Most of the improvements stems from the utilization of asynoptic radiosonde observations at NWS sites. This case suggests that VAS regression soundings may require a ground-based asynoptic profiler network to bridge the gap between the synoptic radiosonde network and the high resolution geosynchronous satellite observations during the day

    OPTN/SRTR 2015 Annual Data Report: Heart

    Full text link
    The number of heart transplant candidates and transplants performed continued to rise each year. In 2015, 2819 heart transplants were performed. In addition, the number of new adult candidates on the waiting list increased 51% since 2004. The number of adult heart transplant survivors continued to increase, and in 2015, 29,172 recipients were living with heart transplants. Patient mortality following transplant has declined. The number of pediatric candidates and transplants performed also increased. New listings for pediatric heart transplants increased from 451 in 2004 to 644 in 2015. The number of pediatric heart transplants performed each year increased from 297 in 2004 to 460 in 2015. Among pediatric patients who underwent transplant in 2014, death occurred in 7.2% at 6 months and 9.6% at 1 year.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135509/1/ajt14128.pd

    OPTN/SRTR 2017 Annual Data Report: Heart

    Full text link
    In 2017, 3273 heart transplants were performed in the United States. New listings continued to increase, and 3769 new adults were listed for heart transplant in 2017. Over the past decade, posttransplant mortality has declined. The number of new pediatric listings increased over the past decade, as did the number of pediatric heart transplants, although some fluctuation has occurred more recently. New listings for pediatric heart transplants increased from 481 in 2007 to 623 in 2017. The number of pediatric heart transplants performed each year increased from 330 in 2007 to 432 in 2017, slightly fewer than in 2016. Short‐term and long‐term mortality improved. Among pediatric patients who underwent transplant between 2015‐2016, 4.8% had died by 6 months and 6.2% by 1 year.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148229/1/ajt15278.pd

    OPTN/SRTR 2018 Annual Data Report: Heart

    Full text link
    The new adult heart allocation policy was approved in 2016 and implemented in October 2018, so its effect was not yet evident in 2018 data. However, the more granular data being collected are anticipated to allow for improved analyses. In 2018, new listings continued to increase; 3883 new adult and 685 new pediatric candidates were added. In 2018, 3440 heart transplants were performed, an increase of 167 over 2017; 473 transplants occurred in pediatric recipients and 2967 in adult recipients. Short‐term and long‐term posttransplant mortality improved. Overall 1‐year survival for adults who underwent heart transplant in 2011‐2013 was 90.3%, 3‐year survival was 84.7%, and 5‐year survival was 79.6%. Mortality rates for pediatric recipients were 4.5% at 6 months and in 5.9% at 1 year posttransplant, 12.5% at 3 years for transplants in 2014‐2015, 14.8% at 5 years for transplants in 2012‐2013, and 29.8% at 10 years for transplants performed in 2008‐2009.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153233/1/ajt15676.pd

    OPTN/SRTR 2016 Annual Data Report: Heart

    Full text link
    In 2016, 3209 heart transplants were performed in the United States. New, active listings increased 57% since 2005. The number of adult heart transplant survivors continued to increase, and in 2016, 30,622 recipients were living with heart transplants. Patient mortality following transplant has declined. The number of pediatric candidates and transplants performed also increased. New listings for pediatric heart transplants increased from 454 in 2005 to 624 in 2016. The number of pediatric heart transplants performed each year increased from 319 in 2005 to 445 in 2016. Among pediatric patients who underwent transplant in 2015, death occurred in 5.9% at 6 months and 7.2% at 1 year.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141946/1/ajt14561.pd

    Melanoma NOS1 expression promotes dysfunctional IFN signaling.

    Get PDF
    In multiple forms of cancer, constitutive activation of type I IFN signaling is a critical consequence of immune surveillance against cancer; however, PBMCs isolated from cancer patients exhibit depressed STAT1 phosphorylation in response to IFN-α, suggesting IFN signaling dysfunction. Here, we demonstrated in a coculture system that melanoma cells differentially impairs the IFN-α response in PBMCs and that the inhibitory potential of a particular melanoma cell correlates with NOS1 expression. Comparison of gene transcription and array comparative genomic hybridization (aCGH) between melanoma cells from different patients indicated that suppression of IFN-α signaling correlates with an amplification of the NOS1 locus within segment 12q22-24. Evaluation of NOS1 levels in melanomas and IFN responsiveness of purified PBMCs from patients indicated a negative correlation between NOS1 expression in melanomas and the responsiveness of PBMCs to IFN-α. Furthermore, in an explorative study, NOS1 expression in melanoma metastases was negatively associated with patient response to adoptive T cell therapy. This study provides a link between cancer cell phenotype and IFN signal dysfunction in circulating immune cells

    An Earth-system prediction initiative for the twenty-first century

    Get PDF
    International audienceSome scientists have proposed the Earth-System Prediction Initiative (EPI) at the 2007 GEO Summit in Cape Town, South Africa. EPI will draw upon coordination between international programs for Earth system observations, prediction, and warning, such as the WCRP, WWRP, GCOS, and hence contribute to GEO and the GEOSS. It will link with international organizations, such as the International Council for Science (ICSU), Intergovernmental Oceanographic Commission (IOC), UNEP, WMO, and World Health Organization (WHO). The proposed initiative will provide high-resolution climate models that capture the properties of regional high-impact weather events, such as tropical cyclones, heat wave, and sand and dust storms associated within multi-decadal climate projections of climate variability and change. Unprecedented international collaboration and goodwill are necessary for the success of EPI

    Wavelet analysis of stratosphere gravity wave packets over Macquarie Island 1. Wave parameters

    Get PDF
    We describe a technique to detect gravity wave packets in high-resolution radiosonde soundings of horizontal wind and temperature. The vertical profiles of meridional and zonal wind speeds are transformed using the Morlet wavelet, and regions of high wind variance in height-wavenumber space are identified as gravity wave packets. Application of the Stokes parameter analysis to horizontal wind and temperature profiles of the reconstructed wave packets yields the wave parameters. The technique was applied to twice-daily radiosonde launches at Macquarie Island (55°S, 159°E) between 1993 and 1995. A strong seasonal cycle in the total wave variance was found, with a maximum in winter. The amount of wave energy propagating downward from the upper stratosphere also maximized in winter. Waves propagated predominately toward the southwest in winter, but in summer propagation directions were approximately isotropic. The intrinsic frequencies were close to the inertial frequency, and the waves had inferred horizontal wavelengths of several hundred kilometers.Florian Zink and Robert A. Vincen
    • 

    corecore