762 research outputs found

    On the Two-point Correlation of Potential Vorticity in Rotating and Stratified Turbulence

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    A framework is developed to describe the two-point statistics of potential vorticity in rotating and stratified turbulence as described by the Boussinesq equations. The Karman-Howarth equation for the dynamics of the two-point correlation function of potential vorticity reveals the possibility of inertial-range dynamics in certain regimes in the Rossby, Froude, Prandtl and Reynolds number parameters. For the case of large Rossby and Froude numbers, and for the case of quasi-geostrophic dynamics, a linear scaling law with 2/3 prefactor is derived for the third-order mixed correlation between potential vorticity and velocity, a result that is analogous to the Kolmogorov 4/5-law for the third-order velocity structure function in turbulence theory.Comment: 10 pages, to appear in Journal of Fluid Mechanics (2006

    To PEG or not to PEG that is the question

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    Nutrition support involves the use of oral supplements, enteral tube feeding or parenteral nutrition. These interventions are considered when oral intake alone fails to meet nutritional requirements. Special diets and oral supplements are usually the first approach to managing malnutrition; however, their role becomes limited when oral intake is restricted or if swallowing is unsafe. Enteral tube feeding or parenteral nutrition are alternative means of providing nutrition support for this select group of patients. Percutaneous endoscopic gastrostomy (PEG) feeding was introduced into clinical practice in 1980. It describes a feeding tube placed directly into the stomach under endoscopic guidance. It is an established means of providing enteral nutrition to those who have functionally normal gastrointestinal tracts, but who cannot meet their nutritional requirements due to inadequate oral intake. The intervention is usually reserved when nutritional intake is likely to be inadequate for more than 4–6 weeks. Although the benefits of PEG have been shown for a select group of patients, there currently exists concerns about the increasing frequency of this intervention, and also uncertainty about the long-term benefits for certain patients. The 2004 UK National Confidential Enquiry into Patient Outcome and Death report emphasised this concern, with almost a fifth of PEG being undertaken for futile indications that negatively influenced morbidity and mortality. The present review paper discusses the indications for, controversies surrounding and complications of gastrostomy feeding and provides practical advice on optimising patient selection for this intervention

    Sign-symmetry of temperature structure functions

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    New scalar structure functions with different sign-symmetry properties are defined. These structure functions possess different scaling exponents even when their order is the same. Their scaling properties are investigated for second and third orders, using data from high-Reynolds-number atmospheric boundary layer. It is only when structure functions with disparate sign-symmetry properties are compared can the extended self-similarity detect two different scaling ranges that may exist, as in the example of convective turbulence.Comment: 18 pages, 5 figures, accepted for publication in Physical Review

    PTU-112 Incidence and predictors of buried bumper syndrome following gastrostomy insertion: a systematic review

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    Introduction Gastrostomies are widely used to provide enteral nutrition support. Buried Bumper Syndrome (BBS) is a recognised complication seen following gastrostomy insertion, describing the migration of the internal bumper along the stoma tract towards the skin. The consequences of BBS can be fatal. Currently, there is a paucity of knowledge about the incidence and predictors of BBS, which is addressed in this study by systematically reviewing the medical literature. Method A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Guidelines (PRISMA). Four databases (EMBASE, MEDLINE, CINHAL, Web of Science) were utilised, and studies identified by searching for key terms relating to gastrostomy and BBS (Jan 1980 -Dec 2016). Unpublished studies were identified from conference abstract booklets. Two independent reviewers screened studies to identify those that included description of adult patients with BBS. Data was extracted relating to patient demographics, incidence, time to presentation and factors associated with BBS. Results 434 studies were initially identified (database search and grey literature). Of these, 299 (68.9%) were excluded following screening review of title and abstract (Kappa coefficient of reviewers=0.753). Of the remaining 135 studies, 85 met inclusion criteria (35 case studies, 11 case series and 39 cohort studies). No controlled trials were retrieved. In total, 16 627 patients were described post gastrostomy placement. 473 cases of BBS were reported in the literature, giving a pooled estimate incidence of 2.8% (0.46%–8.80%). The median age of presentation was 66 years, with 59.1% being in males. BBS was most frequently associated with gastrostomy tubes with thinner internal bumpers (40.7% of all reported cases), however reporting bias may have heavily influenced this outcome. The time to BBS presentation ranged from 3 days to 7 years. Common predictors of BBS reported in the literature include tight external bumpers and increased external traction made directly by the patient or during gastrostomy care. Conclusion This is the first study to systematically review the incidence of Buried Bumper syndrome and assess factors predicting its development. The paucity of high quality studies identified in this systematic review, provides the impetus to develop a national gastrostomy registry accurately assessing gastrostomy outcomes. Healthcare professionals, patients and their caregivers need to be appropriately educated about BBS, considering factors such as tightness of external bumpers and minimising external traction

    EVALUATION OF THE ANTIBACTERIAL ACTIVITY OF CALCIUM ALGINATE BEADS MODIFIED WITH ETHANOLIC EXTRACT OF ADHATODA VASICA LEAF EXTRACT ON STAPHYLOCOCCUS AUREUS AND ESCHERICHIA COLI

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     Objective: The objective of the present study was to investigate the antibacterial activity of calcium alginate (Ca-ALG) loaded with ethanolic extract of Adhatoda vasica (A. vasica) leaves against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli).Methods: Ca-ALG beads containing ethanolic extract of A. vasica leaves were developed by ionic gelation technique. The prepared Ca-ALG beads were characterized by Fourier-transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The antibacterial effect of A. vasica leaf extract loaded Ca-ALG beads was examined against S. aureus and E. coli. Results: FT-IR studies revealed the cross-linking of ALG and calcium ions. The spherical morphology of the beads was designated by SEM. The prepared beads were found to display distinctive growth inhibition against S. aureus and E. coli.Conclusion: The antibacterial activity analysis indicated that the prepared beads have good activity against S. aureus and E. coli. The present study proposes a strategy to enhance antibacterial properties of ALG which are widely used in biomedical applications

    Supply Chain Performance Measurement Practices of Indian Industries

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    In any Industry the Supply chain performance plays a crucial role and it is vital in growth of the industry. Through this study an attempt is made to find some insight to the supply chain performance measurement practices of Indian industries through an exploratory survey. The study reveals almost all the respondents (84%) felt that supply chain performance measurement system employed in their organisation has a clear purpose. Also the study reveals that most supply chain performance measurement system provides high importance to quality measurements and includes both financial and non-financial indicators. The study gave clarity in understanding the objectives of implementing supply chain performance measurement systems and metrics (measures) used in supply chain performance measurement systems The Multivariate analysis revealed three factors emerged from this study are ‘Strategic Orientation’ followed by ‘Internal Focus’ and ‘Motivation and Control’
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