313 research outputs found

    Three birds with one stone: Tidal wetland restoration, carbon sequestration, and enhancing resilience to rising sea levels in the Snohomish River Estuary, Washington

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    Recent attention has focused on exploring the carbon storage and sequestration values of tidal wetlands to mitigate greenhouse gas emissions. Efforts are now underway to develop the tools and refine the science needed to bring carbon markets to bear on tidal wetland restoration activities. Effective restoration not only maximizes carbon storage in former tidal wetlands but also, through the accumulation of organic and mineral matter, enhances these systems’ resilience to rising sea levels. To this end, this project focuses on the Snohomish River estuary of the Puget Sound, Washington, which offers a continuum of diked and un-diked wetlands including seasonal floodplains, open mudflats, mature and tidal forests, and salt marsh habitats. In addition, there is strong restoration potential in a suite of ongoing and proposed projects. We report here on the carbon storage pools, long-term sediment accretion rates (100 years), and estimated rates of carbon storage, derived from sediment cores collected at representative sites within the Snohomish estuary during the spring and summer of 2013. We found that natural wetlands (open to tidal exchange and riverine inputs) were accreting at rates that equaled or exceeded current rates of eustatic sea level rise, while formerly, or currently diked wetlands (closed to such exchanges and inputs) revealed marked evidence of subsidence. Restored sites showed evidence of both high rates of sediment accretion (1.61 cm/year) and carbon storage (352 g C/m2/year)

    Evaluation of azlocillin in-vitro and in discriminative animal models of infection

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    Azlocillin was more active in vitro than ticarcillin or carbenicillin against 561 aminoglycoside-resistant strains of Pseudomonas aeruginosa collected from 74 hospitals distributed over a wide geographic area in the eastern United States. Azlocillin was compared with various other antimicrobial agents in discriminative animal models of Ps. aeruginosa pyelonephritis, osteomyelitis, endocarditis, and meningitis in a variety of mammalian species. Cefsulodin was more effective than azlocillin in reducing Ps. aeruginosa kidney concentrations in rat pyelonephritis induced by intrarenal inoculation. The mean±s.d. logl0 cfu/g kidney after three days of therapy were as follows: controls = 5.4±1.5, azlocillin = 4.4±1.8, cefsulodin = 2.6±0.9 (P < 0.01) but the MBC for the test strain was eight-fold higher for azlocillin (8 vs. 1 mg/l) and effective concentrations were maintained longer in rat serum for cefsulodin as against azlocillin. In addition, ticarcillin reduced kidney bacterial concentrations faster than azlocillin in a mouse pyelonephritis model induced by intravenous Ps. aeruginosa inoculation with subsequent iron loading. Azlocillin was less effective than tobramycin in experimental chronic Ps. aeruginosa osteomyelitis induced in rabbits by direct injection into the tibia. An azlocillin-tobramycin regimen was not more effective than tobramycin alone. After 28 days of therapy, the percentages of positive bone cultures after death were as follows: no antibiotic (controls) = 92%, azlocillin = 95%, tobramycin = 76%, azlocillin plus tobramycin = 60%. Both ticarcillin and azlocillin were less active than tobramycin in experimental Ps. aeruginosa endocarditis induced in rabbits by intravenous inoculation of 108 cfu following 1 h of catheter induced aortic valve trauma. The best results were noted with an azlocillin-tobramycin regimen. The mean±s.d. log10 cfu Ps. aeruginosa/g vegetation after five days of therapy were as follows: no antibiotic controls = 8.1 ± 1.1, tobramycin = 4.5 ±0.8, ticarcillin = 6.9 ± 0.8, azlocillin = 5.7 ± 1.5, ticarcillin phis tobramycin = 4.9 ± 1.0, azlocillin plus tobramycin = 3.3 ± 1.6. Sterile vegetations were rarely attained with any regimen. The mean percentage penetration into purulent cerebrospinal fluid (CSF) in experimental Ps. aeruginosa meningitis for azlocillin was 13.3%, comparable to many other ÎČ-lactam antibiotics. Azlocillin was the single most active (P < 0.01) agent evaluated after 8 h intravenous infusions in this model. An azlocillin-amikacin regimen was more rapidly bactericidal (P < 0.01) than either agent alone in vivo. None of the agents evaluated alone or in combination, however, produced a sterile CSF after 8 h of therapy in any anima

    Characterisation of a Platinum-based Electrochemical Biosensor for Real-time Neurochemical Analysis of Choline

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    A choline biosensor was characterised in detail to determine the effects of physiologically relevant parameters on the ability of the sensor to reliably detect neurochemical changes in choline. This first generation Pt-based polymer enzyme composite sensor displayed excellent shelf-life and biocompatibility with no significant decrease in choline sensitivity observed following 14 days of storage dry, or in ex-vivo rodent brain tissue. However, subjecting the sensor to repeated calibrations and storage over the same period resulted in significant decreases (20–70 %) due to enzyme denaturation associated with the repeated calibration and storage cycles. Potential interference signals generated by the principal electroactive interferents present in the brain were minimal; typically <1 % of the choline current response at in vivo levels. Additionally, changing temperature over the physiologically relevant range of 34–40 °C had no effect on sensitivity, while increasing pH between 7.2 and 7.6 produced only a 5 % increase in signal. The limit of detection of the sensor was in the low ÎŒM range (0.11±0.02 ΌM), while the in vitro response time was determined to be less than the solution mixing time and within ca. 5 s, suggesting potential sub-second in vivo response characteristics. Finally, the sensor was implanted in the striatum of freely moving rats and demonstrated reliable detection of physiological changes in choline in response to movement, and pharmacological manipulation by injection of choline chloride

    Shockwave lithotripsy compared with ureteroscopic stone treatment for adults with ureteric stones : the TISU non-inferiority RCT

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    Acknowledgements The authors wish to thank the patients who participated in the TISU trial.We also thank Stanley Coutts (patient representative) and Charles Clark (patient representative and co-applicant) for their contribution to the design of the participant-facing documents (patient information sheet and questionnaires); Sharon Wren for her secretarial support and data management; previous data co-ordinators, Jessica Wood and Margery Heath, for their data and trial management support; the CHaRT programming team led by Gladys McPherson (to 2016) and Mark Forrest (2016–present); other staff within CHaRT and the HSRU for their assistance with the trial (Cynthia Fraser); members of the PMG for their ongoing advice and support of the trial, plus the independent members of the TSC and DMC; and the staff at the recruitment sites who facilitated the recruitment, treatment and follow-up of trial participants (all listed below); and, finally, we would like to thank the National Institute for Health Research and the Health Technology Assessment programme for funding the TISU trial. Funding This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 19. See the NIHR Journals Library website for further project information.Peer reviewedPublisher PD

    ‘Triple wins’ or ‘triple faults’? Analysing the equity implications of policy discourses on climate-smart agriculture (CSA)

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    This paper analyses contrasting discourses of ‘climate-smart agriculture’ (CSA) for their implications on control over and access to changing resources in agriculture. One of the principal areas of contestation around CSA relates to equity, including who wins and who loses, who is able to participate, and whose knowledge and perspectives count in the process. Yet to date, the equity implications of CSA remain an under-researched area. We apply an equity framework centred on procedure, distribution and recognition, to four different discourses. Depending on which discourses are mobilised, the analysis helps to illuminate: (1) how CSA may transfer the burden of responsibility for climate change mitigation to marginalised producers and resource managers (distributive equity); (2) how CSA discourses generally fail to confront entrenched power relations that may constrain or block the emergence of more ‘pro-poor’ forms of agricultural development, adaptation to climate change, or carbon sequestration and storage (procedural equity); (3) how CSA discourses can have tangible implications for the bargaining power of the poorest and most vulnerable groups (recognition). The paper contributes to work showing the need for deeper acknowledgement of the political nature of the transformations necessary to address the challenges caused by a changing climate for the agricultural sector

    Stratosphere‐troposphere coupling and annular mode variability in chemistry‐climate models

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    The internal variability and coupling between the stratosphere and troposphere in CCMVal‐2 chemistry‐climate models are evaluated through analysis of the annular mode patterns of variability. Computation of the annular modes in long data sets with secular trends requires refinement of the standard definition of the annular mode, and a more robust procedure that allows for slowly varying trends is established and verified. The spatial and temporal structure of the models’ annular modes is then compared with that of reanalyses. As a whole, the models capture the key features of observed intraseasonal variability, including the sharp vertical gradients in structure between stratosphere and troposphere, the asymmetries in the seasonal cycle between the Northern and Southern hemispheres, and the coupling between the polar stratospheric vortices and tropospheric midlatitude jets. It is also found that the annular mode variability changes little in time throughout simulations of the 21st century. There are, however, both common biases and significant differences in performance in the models. In the troposphere, the annular mode in models is generally too persistent, particularly in the Southern Hemisphere summer, a bias similar to that found in CMIP3 coupled climate models. In the stratosphere, the periods of peak variance and coupling with the troposphere are delayed by about a month in both hemispheres. The relationship between increased variability of the stratosphere and increased persistence in the troposphere suggests that some tropospheric biases may be related to stratospheric biases and that a well‐simulated stratosphere can improve simulation of tropospheric intraseasonal variability

    Skeletonization of radial and gastroepiploic conduits in coronary artery bypass surgery

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    The use of a skeletonized internal thoracic artery in coronary artery bypass graft surgery has been shown to confer certain advantages over a traditional pedicled technique, particularly in certain patient groups. Recent reports indicate that radial and gastroepiploic arteries can also be harvested using a skeletonized technique. The aim of this study is to systematically review the available evidence regarding the use of skeletonized radial and gastroepiploic arteries within coronary artery bypass surgery, focusing specifically on it's effect on conduit length and flow, levels of endothelial damage, graft patency and clinical outcome. Four electronic databases were systematically searched for studies reporting the utilisation of the skeletonization technique within coronary revascularisation surgery in humans. Reference lists of all identified studies were checked for any missing publications. There appears to be some evidence that skeletonization may improve angiographic patency, when compared with pedicled vessels in the short to mid-term. We have found no suggestion of increased complication rates or increased operating time. Skeletonization may increase the length of the conduit, and the number of sequential graft sites, but no clear clinical benefits are apparent. Our study suggests that there is not enough high quality or consistent evidence to currently advocate the application of this technique to radial or gastroepiploic conduits ahead of a traditional pedicled technique

    The importance of left ventricular function for long-term outcome after primary percutaneous coronary intervention

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    <p>Abstract</p> <p>Background</p> <p>In the present study we sought to determine the long-term prognostic value of left ventricular ejection fraction (LVEF), assessed by planar radionuclide ventriculography (PRV), after ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PPCI).</p> <p>Methods</p> <p>In total 925 patients underwent PRV for LVEF assessment after PPCI for myocardial infarction before discharge from the hospital. PRV was performed with a standard dose of 500 Mbq of <sup>99m</sup>Tc-pertechnetate. Average follow-up time was 2.5 years.</p> <p>Results</p> <p>Mean (± SD) age was 60 ± 12 years. Mean (± SD) LVEF was 45.7 ± 12.2 %. 1 year survival was 97.3 % and 3 year survival was 94.2 %. Killip class, multi vessel-disease, previous cardiovascular events, peak creatin kinase and its MB fraction, age and LVEF proved to be univariate predictors of mortality. When entered in a forward conditional Cox regression model age and LVEF were independent predictors of 1 and 3 year mortality.</p> <p>Conclusion</p> <p>LVEF assessed by PRV is a powerful independent predictor of long term mortality after PPCI for STEMI.</p
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