24 research outputs found

    Noncommutative Geometry: Fuzzy Spaces, the Groenewold-Moyal Plane

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    In this talk, we review the basics concepts of fuzzy physics and quantum field theory on the Groenwald-Moyal Plane as examples of noncommutative spaces in physics. We introduce the basic ideas, and discuss some important results in these fields. In the end we outline some recent developments in the field.Comment: This is a contribution to the Proc. of the O'Raifeartaigh Symposium on Non-Perturbative and Symmetry Methods in Field Theory (June 2006, Budapest, Hungary), published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA

    Prevalence of diabetic retinopathy among individuals screened positive for diabetes in five community based eye camps in northern Karachi Pakistan

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    Background: Population-based data on the prevalence of diabetic retinopathy in Pakistan are lacking. We determined the prevalence of diabetic retinopathy among individuals screened positive for diabetes in five community-based eye camps in northern Karachi, Pakistan. Methods: In summer 2002, five community-based eye camps were set up in Karachi, Pakistan’s largest city. All individuals aged 30 years or older who visited the camps were requested to participate in the study. Those who agreed were screened for diabetes and those found to have the disease were referred to an eye hospital for diabetic retinopathy screening. Verbal informed consent was obtained from all participants at the examination site. Our main outcome measure was diabetic retinopathy, which was classified as non-proliferative diabetic retinopathy (NPDR), severe NPDR, and proliferative diabetic retinopathy (PDR). Our grading was based on clinical examination. Results: A total of 912 subjects were screened for diabetes mellitus. Of these, 160(17.5%) had diabetes- 1.8% had type I diabetes and 15.9% had type II diabetes. One hundred and eight individuals visited the hospital for ophthalmic examination. Of them, 15.7% had diabetic retinopathy. The prevalence of diabetic retinopathy was higher among individuals with type I diabetes, with greater duration of diabetes, and among women. The commonest form of diabetic retinopathy was non-proliferative (76.5% [mild: 35.3 %, moderate: 29.4 %, and severe: 11.8 %]), followed by maculopathy (17.6 %) and proliferative diabetic retinopathy (5.9 %). Conclusion: More systematic and population-based research is needed to estimate the prevalence of and identify risk factors for diabetic retinopathy in Pakista

    Enhancing the Hardened Properties of Recycled Concrete (RC) through Synergistic Incorporation of Fiber Reinforcement and Silica Fume

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    Portland cement concrete is fragile in tension and it has numerous negative impacts on the environment. To deal with these issues, both fiber reinforcement and recycled materials can be utilized to manufacture sustainable and ductile concrete. In this study, the synergistic effects of high-performance mineral admixture silica fume and glass fiber reinforcement were investigated on the hardened properties of RC. For this purpose, two concrete mix families, namely, NC and RC were prepared. To understand the benefits of synergistic utilization of glass fiber and silica fume, in both NC and RC, 0.5% glass fiber was incorporated with three different levels of silica fume. i.e., 0%, 5%, and 10%. Both strength and permeability-related durability properties were investigated. Results revealed that combined incorporation of 0.5% fiber and 10% silica fume can help in the production of RC having better mechanical and durability performance compared to reference “NC”. Simultaneous incorporation of silica fume and glass fiber produces a combined effect greater than their individual effects on both mechanical and permeability properties of concrete. Silica fume plays a very dominant and positive role in the development of CS, WA, and CIPR of RC, whereas glass fiber plays a vital role in upgrading STS and FS of RC and whereas, with the addition of 0.5% glass fiber, RC can yield 8–9 times higher flexural toughness than that of the plain NC

    Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

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    Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

    Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

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    This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

    Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

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    PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

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    PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    Symmetries in noncommutative physics

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    Quantum field theories on noncommutative spaces are an important area of research in high energy physics because of their importance as a tool to capture aspects of Planck scale physics, where one expects the spacetime to show noncommutative behavior, their emergence in string theory and also as a tool to regularize quantum field theories. An important issue in the study of noncommutative quantum field theories (NCQFT\u27s) is that of symmetries. Introduction of noncommutativity explicitly breaks Lorentz invariance. However, the classical actions of noncommutative field theories are invariant under a twisted action of the Poincaré group. In this thesis we study the consequences of such twisted symmetries at the quantum level. We give complete construction of quantum field theories covariant under the twisted Poincaré action including the explicit form of the twisted Poincaré generators. We find some striking results such as twisting of Bose and Fermi statistics and removal of UV-IR mixing in the non-gauge theories. We also apply the idea of twisting to gauge symmetries and construct gauge theories covariant under twisted action of gauge and Poincaré groups. Any gauge group can be treated using our formulation, unlike the ordinary noncommutative gauge theories where only U ( N ) groups admit direct treatment. We derive the Feynman rules for this theory and find interesting results such as violation of Pauli principle and violation of Lorentz invariance due to failure of a generalized form of locality. We also treat the twisted form of supersymmetry. Finally we study the formulation of supersymmetry on fuzzy sphere and construct fuzzy supersymmetric instanton. We find the zero modes in the instanton sector and study their index theory

    THE APPLICATION OF KANO’S MODEL IN THE AIRLINE INDUSTRY

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    This paper shows how airline passenger service necessities can be scrutinized by utilizing Kano's model of quality component and examines the potential advantages that can be accomplished by applying this way to deal with marketing strategy planning. As per Kano's model, quality components can be grouped into three classifications, to be specific must-be, One-dimensional and Attractive needs, contingent upon their capacity to make consumer satisfaction or dissatisfaction. Aftereffects of this review propose that airline passenger service components could be grouped comparable with Kano's model to recognize the most critical passenger service components. Effects of the service components highlights on passenger satisfaction or dissatisfaction have been likewise figured as estimation records for development

    Business Intelligence Systems in the Holistic Infrastructure Development Supporting Decision-Making in Organisations

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    The aim of this review is analysing Business Intelligence Systems with regards to opportunities for enhancing basic leadership and improving decision making power in a contemporary organization. We took specifics of basic decision making procedure together with heterogeneity and scattering of data sources into thought – introduce Business Intelligence Systems as some all-encompassing framework of decision making. It has been demonstrated that the Business Intelligence may contribute towards enhancing nature of decision making in any organization, better consumer service and consumer loyalty. The review is cantered around three essential segments of the BI frameworks, i.e. key information technologies, capability of key information technologies and BI applications that help various decision making in organization. This review is devoted not only to find out how BI is for decision making but how frequently these are applied in business practic
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