135 research outputs found

    Ultrastructure of the rat gut following small bowel resection

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    969-100 Changing Profile of the Cardiac Donor

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    AbstractAs the demand for organs for cardiac transplantation has increased, donor criteria have evolved. We reviewed the characteristics of 190 cardiac donors from 1983 to 1993 to identify trends in donor profile and to determine if recipient outcome were affected. Donors were divided into early(1983–1987; n=86) and late (1988-1993; n=104) groups according to operative era, While mean donor age has not changed significantly (24 ± 0.9 to 26 ± 1.3 years), the proportion of donors older than 40 years has increased from 1% (1/86) to 15% (16/104) (p<0.001). Trauma was the cause of death in 93% (80/86) of the early group and 65% of the late group (68/104) (p<0.001); in the total series, donors older than 40 years were less likely to have died from trauma 131%; 5/16) than younger donors (83%; 143/173) (p=0.001). The proportion of out-of-state donors has fallen from 71% (61/86) to 27% (28/104) (p<0.001), while the proportion of ethnic minorities increased from 10% (9/86) to 25% (26/1041 (p<0.001). There have been no significant changes in gender profile; males constituted 78% (67/86) of the early group and 72% (75/104) of the late group. Five year survival after transplant was not predicted by donor age, mode of donor death, recipient age, or recipient UNOS status. In summary, donors in the current era are more likely (1) to be older, (2) to be within the state, (3) to come from an ethnic minority, and (4) to have died from causes other than trauma when compared to donors from the earlier era

    Aortic root replacement Risk factor analysis of a seventeen-year experience with 270 patients

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    AbstractBetween September 1976 and September 1993, 270 patients underwent aortic root replacement at our institution. Two hundred fifty-two patients underwent a Bentall composite graft repair and 18 patients received a cryopreserved homograft aortic root. One hundred eighty-seven patients had a Marfan aneurysm of the ascending aorta (41 with dissection) and 53 patients had an aneurysm resulting from nonspecific medial degeneration (17 with dissection). These 240 patients were considered to have annuloaortic ectasia. Thirty patients were operated on for miscellaneous lesions of the aortic root. Thirty-day mortality for the overall series of 270 patients was 4.8% (13/270). There was no 30-day mortality among 182 patients undergoing elective root replacement for annuloaortic ectasia without dissection. Thirty-six of the 270 patients having root replacement also had mitral valve operations. There was no hospital mortality for aortic root replacement in these 36 patients, but there were seven late deaths. Twenty-two replacements and four were repeat root replacements for late endocarditis. One early death and two late deaths occurred in this group. Actuarial survival for the overall group of 270 patients was 73% at 10 years. In a multivariate analysis, only poor New Year Heart Association class (III and IV), non-Marfan status, preoperative dissection, and male gender emerged as significant predictors of early or late death. Endocarditis was the most common late complication (14 of 256 hospital survivors) and was optimally treated by root replacement with a cryopreserved aortic homograft. Late problems with the part of the aorta not operated on occur with moderate frequency; careful follow-up of the distal aorta is critical to long-term survival. (J THORAC CARDIOVASC SURG 1995; 109: 536-45

    Burn injury leads to increased long-term susceptibility to respiratory infection in both mouse models and population studies

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    Background: Burn injury initiates an acute inflammatory response that subsequently drives wound repair. However, acute disruption to the immune response is also common, leading to susceptibility to sepsis and increased morbidity and mortality. Despite increased understanding of the impact of burn injury on the immune system in the acute phase, little is known about longterm consequences of burn injury on immune function. This study was established to determine whether burn injury has long-term clinical impacts on patients' immune responses. Methods: Using a population-based retrospective longitudinal study and linked hospital morbidity and death data from Western Australia, comparative rates of hospitalisation for respiratory infections in burn patients and a non-injured comparator cohort were assessed. In addition, a mouse model of non-severe burn injury was also used in which viral respiratory infection was induced at 4 weeks post-injury using a mouse modified version of the Influenza A virus (H3NN; A/mem/71-a). Results and conclusions: The burn injured cohort contained 14893 adult patients from 1980-2012 after removal of those patients with evidence of smoke inhalation or injury to the respiratory tract. During the study follow-up study a total of 2,884 and 2,625 respiratory infection hospital admissions for the burn and uninjured cohorts, respectively, were identified. After adjusting for covariates, the burn cohort experienced significantly elevated admission rates for influenza and viral pneumonia (IRR, 95%CI: 1.73, 1.27-2.36), bacterial pneumonia (IRR, 95%CI: 2.05, 1.85-2.27) and for other types of upper and lower respiratory infections (IRR, 95% CI: 2.38, 2.09-2.71). In the mouse study an increased viral titre was observed after burn injury, accompanied by a reduced CD8 response and increased NK and NKT cells in the draining lymph nodes. This data suggests burn patients are at long-term increased risk of infection due to sustained modulation of the immune response

    Discovery of very high energy gamma rays from PKS 1424+240 and multiwavelength constraints on its redshift

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    We report the first detection of very-high-energy (VHE) gamma-ray emission above 140 GeV from PKS 1424+240, a BL Lac object with an unknown redshift. The photon spectrum above 140 GeV measured by VERITAS is well described by a power law with a photon index of 3.8 +- 0.5_stat +- 0.3_syst and a flux normalization at 200 GeV of (5.1 +- 0.9_stat +- 0.5_syst) x 10^{-11} TeV^-1 cm^-2 s^-1, where stat and syst denote the statistical and systematical uncertainty, respectively. The VHE flux is steady over the observation period between MJD 54881 and 55003 (2009 February 19 to June 21). Flux variability is also not observed in contemporaneous high energy observations with the Fermi Large Area Telescope (LAT). Contemporaneous X-ray and optical data were also obtained from the Swift XRT and MDM observatory, respectively. The broadband spectral energy distribution (SED) is well described by a one-zone synchrotron self-Compton (SSC) model favoring a redshift of less than 0.1. Using the photon index measured with Fermi in combination with recent extragalactic background light (EBL) absorption models it can be concluded from the VERITAS data that the redshift of PKS 1424+240 is less than 0.66.Comment: accepted for publication, Ap

    Association mapping of malting quality traits in UK spring and winter barley cultivar collections

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    Key Message: Historical malting quality data was collated from UK national and recommended list trial data and used in a GWAS. 25 QTL were identified, with the majority from spring barley cultivar sets. Abstract: In Europe, the most economically significant use of barley is the production of malt for use in the brewing and distilling industries. As such, selection for traits related to malting quality is of great commercial interest. In order to study the genetic basis of variation for malting quality traits in UK cultivars, a historical set of trial data was collated from national and recommended list trials from the period 1988 to 2016. This data was used to estimate variety means for 20 quality related traits in 451 spring barley cultivars, and 407 winter cultivars. Genotypes for these cultivars were generated using iSelect 9k and 50k genotyping platforms, and a genome wide association scan performed to identify malting quality quantitative trait loci (QTL). 24 QTL were identified in spring barley cultivars, and 2 from the winter set. A number of these correspond to known malting quality related genes but the remainder represents novel genetic variation that is accessible to breeders for the genetic improvement of new cultivars.Mark E. Looseley, Luke Ramsay, Hazel Bull, J. Stuart Swanston, Paul D. Shaw, Malcolm Macaulay, Allan Booth, Joanne R. Russell, Robbie Waugh, on behalf of the IMPROMALT Consortium, William T.B. Thoma

    Signatures of the post-hydration heating of highly aqueously altered CM carbonaceous chondrites and implications for interpreting asteroid sample returns

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    The CM carbonaceous chondrites have all been aqueously altered, and some of them were subsequently heated in a parent body environment. Here we have sought to understand the impact of short duration heating on a highly aqueously altered CM through laboratory experiments on Allan Hills (ALH) 83100. Unheated ALH 83100 contains 83 volume per cent serpentine within the fine-grained matrix and altered chondrules. The matrix also hosts grains of calcite and dolomite, which are often intergrown with tochilinite, Fe(Ni) sulphides (pyrrhotite, pentlandite), magnetite and organic matter. Some of the magnetite formed by replacement of Fe(Ni) sulphides that were accreted from the nebula. Laboratory heating to 400 °C has caused partial dehydroxylation of serpentine and loss of isotopically light oxygen leading to an increase in bulk δ18O and fall in Δ17O. Tochilinite has decomposed to magnetite, whereas carbonates have remained unaltered. With regards to infrared spectroscopy (4000–400 cm-1; 2.5–25 µm), heating to 400 °C has resulted in decreased emissivity (increased reflectance), a sharper and more symmetric OH band at 3684 cm-1 (2.71 µm), a broadening of the Si—O stretching band together with movement of its minimum to longer wavenumbers, and a decreasing depth of the Mg—OH band (625 cm-1; 16 µm). The Si—O bending band is unmodified by mild heating. With heating to 800 °C the serpentine has fully dehydroxylated and recrystallized to ∼Fo60/70 olivine. Bulk δ18O has further increased and Δ17O decreased. Troilite and pyrrhotite have formed, and recrystallization of pentlandite has produced Fe,Ni metal. Calcite and dolomite were calcined at ∼700 °C and in their place is an un-named Ca-Fe oxysulphide. Heating changes the structural order of organic matter so that Raman spectroscopy of carbon in the 800 °C sample shows an increased (D1 + D4) proportional area parameter. The infrared spectrum of the 800 °C sample confirms the abundance of Fe-bearing olivine and is very similar to the spectrum of naturally heated stage IV CM Pecora Escarpment 02010. The temperature-related mineralogical, chemical, isotopic and spectroscopic signatures defined in ALH 83100 will help to track the post-hydration thermal histories of carbonaceous chondrite meteorites, and samples returned from the primitive asteroids Ryugu and Bennu

    The Discovery of gamma-Ray Emission From The Blazar RGB J0710+591

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    The high-frequency-peaked BL Lacertae object RGB J0710+591 was observed in the very high-energy (VHE; E > 100 GeV) wave band by the VERITAS array of atmospheric Cherenkov telescopes. The observations, taken between 2008 December and 2009 March and totaling 22.1 hr, yield the discovery of VHE gamma rays from the source. RGB J0710+591 is detected at a statistical significance of 5.5 standard deviations (5.5{\sigma}) above the background, corresponding to an integral flux of (3.9 +/- 0.8) x 10-12 cm-2 s-1 (3% of the Crab Nebula's flux) above 300 GeV. The observed spectrum can be fit by a power law from 0.31 to 4.6 TeV with a photon spectral index of 2.69 +/- 0.26stat +/- 0.20sys. These data are complemented by contemporaneous multiwavelength data from the Fermi Large Area Telescope, the Swift X-ray Telescope, the Swift Ultra-Violet and Optical Telescope, and the Michigan-Dartmouth-MIT observatory. Modeling the broadband spectral energy distribution (SED) with an equilibrium synchrotron self-Compton model yields a good statistical fit to the data. The addition of an external-Compton component to the model does not improve the fit nor brings the system closer to equipartition. The combined Fermi and VERITAS data constrain the properties of the high-energy emission component of the source over 4 orders of magnitude and give measurements of the rising and falling sections of the SED

    Spatial dimensions of stated preference valuation in environmental and resource economics: methods, trends and challenges

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