1,558 research outputs found

    Three point SUSY Ward identities without Ghosts

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    We utilise a non-local gauge transform which renders the entire action of SUSY QED invariant and respects the SUSY algebra modulo the gauge-fixing condition, to derive two- and three-point ghost-free SUSY Ward identities in SUSY QED. We use the cluster decomposition principle to find the Green's function Ward identities and then takes linear combinations of the latter to derive identities for the proper functions.Comment: 20 pages, no figures, typos correcte

    On the episodic nature of derecho-producing convective systems in the United States

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    Convectively generated windstorms occur over broad temporal and spatial scales; however, one of the larger-scale and most intense of these windstorms has been given the name ‘derecho’. This study illustrates the tendency for derechoproducing mesoscale convective systems to group together across the United States – forming a derecho series. The derecho series is recognized as any succession of derechos that develop within a similar synoptic environment with no more than 72 h separating individual events. A derecho dataset for the period 1994–2003 was assembled to investigate the groupings of these extremely damaging convective wind events. Results indicate that over 62% of the derechos in the dataset were members of a derecho series. On average, nearly six series affected the United States annually. Most derecho series consisted of two or three events; though, 14 series during the period of record contained four or more events. Two separate series involved nine derechos within a period of nine days. Analyses reveal that derecho series largely frequent regions of the Midwest, Ohio Valley, and the south–central Great Plains during May, June, and July. Results suggest that once a derecho occurred during May, June, or July, there was a 58% chance that this event was the first of a series of two or more, and about a 46% chance that this was the first of a derecho series consisting of three or more events. The derecho series climatology reveals that forecasters in regions frequented by derechos should be prepared for the probable regeneration of a derecho-producing convective system after an initial event occurs

    Climatological Radar Delineation of Urban Convection for Atlanta, Georgia

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    The distribution of warm season (June through August) thunderstorm activity surrounding Atlanta, Georgia from 1997 to 2006 was determined utilizing composite reflectivity data obtained from the network of National Weather Service radars. The radar data, at 2 km and 5 min spatial and temporal resolutions, allows for high resolution analyses of urban convective trends when grid averaged over a 10-year period. Maxima of medium- to high-reflectivity episodes were identified to the north of and within downtown Atlanta and immediately east of the primary urban expansion of the central business district (CBD). Additional enhanced, high-reflectivity areas are found in southern Fulton and Clayton counties, located south of downtown Atlanta. These regions are also collocated with high-density urban expansion south of the Atlanta CBD. The research presented is the most comprehensive spatial and temporal analysis of grid averaged composite reflectivity data for urban convection conducted to date

    Reproductive biology and parasite (Perkinsus marinus) prevalence in the eastern oyster, Crassostrea virginica, within a Georgia tidal river

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    Peer-reviewed. © F.X. O'Beirn et al., 1997. Reproduced with the permission of the executive editor of the JNCAS.Recruitment, in 1992, of the eastern oyster, Crassostrea virginica, at one site (Flume Dock) within the Sapelo Island National Estuarine Research Reserve (SINERR) was lower than other sampling sites. Recruitment allied with gametogenesis and parasite (Perkinsus marinus) prevalence within the oysters was examined in 1993, in an attempt to explain the differences observed the previous year. Sampling occurred at three sites (Marsh Landing, Jack Hammock, and Flume Dock) along the Duplin River within the SINERR. Oyster recruitment in 1993 was reduced in all sites within the SINERR. No oyster recruitment was recorded at the Flume Dock site during any monthly collections or on collectors deployed for the duration of the sampling study. Oysters developed gametogenically and spawned at the Marsh Landing site two weeks prior to their occurrence at the Jack Hammock site. Gametogenic development in oysters at the Flume Dock site was retarded a further two weeks where the males appeared to spawn six weeks after the females, which could account for reduced recruitment levels at this site. Approximately, twice as many females as males occurred in all sites. Monthly sampling of prevalence and intensity of Perkinsus marinus (Dermo) revealed high levels of both parameters. Smaller oysters did display lower prevalences of Dermo than larger forms

    Implementation of a novel antimicrobial stewardship strategy for rural facilities utilising telehealth

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    A significant portion of healthcare takes place in small hospitals, and many are located in rural and regional areas. Facilities in these regions frequently do not have adequate resources to implement an onsite antimicrobial stewardship programme and there are limited data relating to their implementation and effectiveness. We present an innovative model of providing a specialist telehealth antimicrobial stewardship service utilising a centralised service (Queensland Statewide Antimicrobial Stewardship Program) to a rural Hospital and Health Service. Results of a 2-year post-implementation follow-up showed an improvement in adherence to guidelines [33.7% (95% CI 27.0–40.4%) vs. 54.1% (95% CI 48.7–59.5%)] and appropriateness of antimicrobial prescribing [49.0% (95% CI 42.2–55.9%) vs. 67.5% (95% CI 62.7–72.4%) (P < 0.001). This finding was sustained after adjustment for hospitals, with improvement occurring sequentially across the years for adherence to guidelines [adjusted odds ratio (aOR) = 2.44, 95% CI 1.70–3.51] and appropriateness of prescribing (aOR = 2.48, 95% CI 1.70–3.61). There was a decrease in mean total antibiotic use (DDDs/1000 patient-days) between the years 2016 (52.82, 95% CI 44.09–61.54) and 2018 (39.74, 95% CI 32.76–46.73), however this did not reach statistical significance. Additionally, there was a decrease in mean hospital length of stay (days) from 2016 (3.74, 95% CI 3.08–4.41) to 2018 (2.55, 95% CI 1.98–3.12), although this was not statistically significant. New telehealth-based models of antimicrobial stewardship can be effective in improving prescribing in rural areas. Programmes similar to ours should be considered for rural facilities

    Active-duty military service members’ visual representations of PTSD and TBI in masks

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    Active-dutymilitary service members have a significant risk of sustaining physical and psychological trauma resulting in traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD). Within an interdisciplinary treatment approach at the National Intrepid Center of Excellence, servicemembers participated in mask making during art therapy sessions. This study presents an analysis of the mask-making experiences of service members (n = 370) with persistent symptoms from combatand mission-related TBI, PTSD, and other concurrent mood issues. Data sources included mask images and therapist notes collected over a five-year period. The data were coded and analyzed using grounded theory methods. Findings indicated that mask making offered visual representations of the self related to individual personhood, relationships, community, and society. Imagery themes referenced the injury, relational supports/losses, identity transitions/questions, cultural metaphors, existential reflections, and conflicted sense of self. These visual insights provided an increased understanding of the experiences of service members, facilitating their recovery

    Statistics of Coulomb blockade peak spacings for a partially open dot

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    We show that randomness of the electron wave functions in a quantum dot contributes to the fluctuations of the positions of the conductance peaks. This contribution grows with the conductance of the junctions connecting the dot to the leads. It becomes comparable with the fluctuations coming from the randomness of the single particle spectrum in the dot while the Coulomb blockade peaks are still well-defined. In addition, the fluctuations of the peak spacings are correlated with the fluctuations of the conductance peak heights.Comment: 13 pages, 1 figur

    Duration and Magnitude of Postoperative Risk of Venous Thromboembolism after Cholecystectomy: A Population-Based Cohort Study

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    Background: This study aimed to identify burden and risk of VTE associated with cholecystectomy in England. Methods: An historical cohort study of cholecystectomy patients from 2001-2011 was undertaken using linked primary (Clinical Practice Research Datalink) and secondary (Hospital Episode Statistics) care data. Crude rates and adjusted hazard ratios (HRs) were calculated for risk of VTE following cholecystectomy using Cox regression.Results: 24 677 patients were identified with a rate of VTE in the first year following cholecystectomy of 2.80 per 1000 person years (95% CI 2.18-3.59). Patients aged >/=70 vs aged 30 vs BMI less than 0 had 2.4-fold increase in risk (HR 2.42, 95% CI 1.40–4.18); open vs. laparoscopic operation had 3-fold increase in risk (HR 2.94, 95% CI 1.55–5.55). Compared to general population, VTE risk was the highest in the first 30 days post-operatively with 9.9-fold risk following emergency cholecystectomy and 4.5-fold risk after inpatient cholecystectomy (HR 9.90, 95% CI 4.42–22.21; HR 4.54, 95% CI 2.85–7.21). Conclusions: Cholecystectomy is associated with a low absolute risk of VTE and we have identified high risk groups including the elderly, obese and those having open surgery

    Quasi-particle Lifetimes in a d_{x^2-y^2} Superconductor

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    We consider the lifetime of quasi-particles in a d-wave superconductor due to scattering from antiferromagnetic spin-fluctuations, and explicitly separate the contribution from Umklapp processes which determines the electrical conductivity. Results for the temperature dependence of the total scattering rate and the Umklapp scattering rate are compared with relaxation rates obtained from thermal and microwave conductivity measurements, respectively.Comment: 14 pages, 4 figure
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