93 research outputs found

    Pentaquark Masses in Chiral Perturbation Theory

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    Heavy baryon chiral perturbation theory for pentaquarks is applied beyond leading order. The mass splitting in the pentaquark anti-decuplet is calculated up to NNLO. An expansion in the coupling of pentaquarks to non-exotic baryons simplifies calculations and makes the pentaquark masses insensitive to the pentaquark-nucleon mass difference. The possibility of determining coupling constants in the chiral Lagrangian on the lattice is discussed. Both positive and negative parities are considered.Comment: 11 pages; reference added, minor changes in wordin

    Chiral Soliton Model vs Pentaquark Structure for \Theta (1540)

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    The exotic baryon Θ+\Theta^+ (1540 MeV)isvisualisedasanexpected(iso)rotationalexcitationintheChiralSolitonModel.ItisalsoarguedasaPentaquarkbaryonstateinaconstituentquarkmodelwithstrongdiquarkcorrelations.Icontrastthetwopointsofview;thesimilaritiesanddifferencesbetweenthetwopictures.Collectiveexcitation,characteristicofChiralSolitonModelpointstowardsmallmixingofrepresentationsinthewakeofSU(3)breaking.Incontrast,ConstituentquarkModelsprefernearidealmixing,similarto is visualised as an expected (iso) rotational excitation in the Chiral Soliton Model. It is also argued as a Pentaquark baryon state in a constituent quark model with strong diquark correlations. I contrast the two points of view; the similarities and differences between the two pictures. Collective excitation, characteristic of Chiral Soliton Model points toward small mixing of representations in the wake of SU(3) breaking. In contrast, Constituent quark Models prefer near ``ideal'' mixing, similar to \omega - \phi$ mixing.Comment: 11 pages, references added, final published versio

    DWT based Compression of X-Ray Images using Fuzzy C - Means

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    People, Hospitals and many other organizations manage to store a large amount of files inside their storage devices. Once the storage reaches its limit then the organizations try to minimize the files size by using different compression techniques. In this paper, we focus on lossless image compression for DICOM images using clustering approach. Cluster of data point is formed by Fuzzy C-mean clustering approach. An automatic threshold is selected by this clustering approach and the data point whose pixel intensity is greater than threshold is grouped into one cluster and the data point whose pixel intensity is less than threshold is grouped into another cluster. Hence we obtain region of interest (ROI) and Non-region of interest (N-ROI). Discrete wavelet transform (DWT) is used to compress the image and inverse DWT is used to regenerate the image

    Technical Report: Anytime Computation and Control for Autonomous Systems

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    The correct and timely completion of the sensing and action loop is of utmost importance in safety critical autonomous systems. A crucial part of the performance of this feedback control loop are the computation time and accuracy of the estimator which produces state estimates used by the controller. These state estimators, especially those used for localization, often use computationally expensive perception algorithms like visual object tracking. With on-board computers on autonomous robots being computationally limited, the computation time of a perception-based estimation algorithm can at times be high enough to result in poor control performance. In this work, we develop a framework for co-design of anytime estimation and robust control algorithms while taking into account computation delays and estimation inaccuracies. This is achieved by constructing a perception-based anytime estimator from an off-the-shelf perception-based estimation algorithm, and in the process we obtain a trade-off curve for its computation time versus estimation error. This information is used in the design of a robust predictive control algorithm that at run-time decides a contract for the estimator, or the mode of operation of estimator, in addition to trying to achieve its control objectives at a reduced computation energy cost. In cases where the estimation delay can result in possibly degraded control performance, we provide an optimal manner in which the controller can use this trade-off curve to reduce estimation delay at the cost of higher inaccuracy, all the while guaranteeing that control objectives are robustly satisfied. Through experiments on a hexrotor platform running a visual odometry algorithm for state estimation, we show how our method results in upto a 10% improvement in control performance while saving 5-6% in computation energy as compared to a method that does not leverage the co-design

    Problem-Based Learning Research in Anesthesia Teaching: Current Status and Future Perspective

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    The teaching curriculum in anesthesia involves traditional teaching methods like topic-based didactic lectures, seminars, and journal clubs; intraoperative apprenticeship; and problem-based learning (PBL) and simulation. The advantages of incorporating PBL in anesthesia teaching include development of skills like clinical reasoning, critical thinking, and self-directed learning; in addition it also helps in developing a broader perspective of case scenarios. The present paper discusses the characteristics, key elements, and goals of PBL; various PBL methods available; lacunae in the existing knowledge of PBL research; its current status and future perspectives in anesthesia teaching

    Indirect inguinal hernia masquerading as a Spigelian hernia

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    Inguinal hernia usually developed and descended into scrotum. The clinical presentation is inguinal or inguino-scrotal swelling. Abdominal wall weakness as it is frequently seen in African tropical zones produces often rare clinical case. We report a case of inguinal hernia presented as an abdominal wall swelling clinically suggestive of a Spigelian hernia and discuss the mechanism

    Outcomes of Mechanical Circulatory Support in STEMI Patients with Cardiogenic Shock: Insights from the National Inpatient Sample

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    Background Cardiogenic shock has been associated with a high mortality rate despite advances in mechanical circulatory support. Data is inconsistent as the majority of patients in the current trials are SCAI stage E, or data is combined with heart failure and STEMI cardiogenic shock. Methods Data was extracted from the 2020 United States National Inpatient data set. The diagnosis criteria were “STEMI” and “Cardiogenic shock”. The primary outcome of interest was comparing mortality in those patients who received mechanical circulatory support vs. those who did not in STEMI Cardiogenic shock. Results There were 4,302 patients with STEMI and cardiogenic shock, and 65.3% were males. The mean age was 66.7 years (SD 12.3), and the mean length of hospital stay was 7.9 days (SD 10.03). 36% of the patients died during hospital admission. 29% received an intra-aortic balloon pump (IABP), 15.5% had Impella left ventricular support, 3.2% had veno-arterial extracorporeal membrane oxygenation (ECMO), 2.2% had both IABP and Impella, 1.3% had both Impella and ECMO and 1.0% had both IABP and ECMO. The Kaplan-Meier analysis showed that IABP use was associated with decreased in-hospital mortality (p\u3c0.001). In the multivariate analysis, age (OR 1.034, 95% CI 1.028-1.04, p\u3c0.001), female (OR 1.26, 95% CI 1.1-1.45, p\u3c0.001), acute kidney injury (OR 1.96, 95% CI 1.71-2.25, p\u3c0.001), ECMO (OR 1.74, 95% CI 1.22-2.50, p=0.003), and Impella (OR 1.72, 95% CI 1.45-2.06, p\u3c0.001) were associated with increased in-hospital mortality. Conversely, using IABP (OR 0.65, 95% CI 0.56-0.76, p\u3c0.001) was associated with decreased in-hospital mortality. Conclusions Mechanical circulatory support devices are used individually and in combination with each other in patients with cardiogenic shock, with IABP being the most commonly used. However, in-hospital mortality remains high, but using IABP was associated with decreased in-hospital mortality. The patients with IABP were more likely SCAI stage C rather than SCAI stage E; therefore, this could have contributed to the decrease in-hospital mortality

    Experiences with chest trauma: where do we stand today

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    Background and Aims: Chest trauma is a major public health problem in India, but only few studies have been conducted to analyze its magnitude and management. The present study was carried out to determine the epidemiological profile of chest trauma cases and to analyze the management strategies with an aim to identify the scope of improvement in our set-up. Materials and Methods: It is a retrospective study of cases admitted with chest trauma, to a tertiary care hospital. Records of the patients admitted to the hospital with chest trauma over a period of one year were analyzed for the patients′ demographic profile; mechanism, nature and severity of injuries; associated injuries; management and outcome of cases. Results: Out of a total of 105 patients, most were males, belonged to age group of 21-40 years and suffered blunt trauma. Motor vehicle accident was the commonest mechanism of injury. The interval from injury to admission ranged from one hour, to more than 24 hours. Eight patients were admitted to the ICU, out of which 5 required ventilatory support. The most frequently used analgesics in the wards were non-steroidal anti-inflammatory drugs (NSAID). Ninety one patients improved, while seven patients died in the hospital. Conclusions: Chest trauma due to blunt injury is an important cause of morbidity and mortality in young males. Despite limitations of resources and manpower, attempts are being made to manage patients successfully. However, creation of dedicated trauma teams with well-designed management protocols in hospitals can further improve the outcome

    Experiences with chest trauma: where do we stand today

    No full text
    Background and Aims: Chest trauma is a major public health problem in India, but only few studies have been conducted to analyze its magnitude and management. The present study was carried out to determine the epidemiological profile of chest trauma cases and to analyze the management strategies with an aim to identify the scope of improvement in our set-up. Materials and Methods: It is a retrospective study of cases admitted with chest trauma, to a tertiary care hospital. Records of the patients admitted to the hospital with chest trauma over a period of one year were analyzed for the patients′ demographic profile; mechanism, nature and severity of injuries; associated injuries; management and outcome of cases. Results: Out of a total of 105 patients, most were males, belonged to age group of 21-40 years and suffered blunt trauma. Motor vehicle accident was the commonest mechanism of injury. The interval from injury to admission ranged from one hour, to more than 24 hours. Eight patients were admitted to the ICU, out of which 5 required ventilatory support. The most frequently used analgesics in the wards were non-steroidal anti-inflammatory drugs (NSAID). Ninety one patients improved, while seven patients died in the hospital. Conclusions: Chest trauma due to blunt injury is an important cause of morbidity and mortality in young males. Despite limitations of resources and manpower, attempts are being made to manage patients successfully. However, creation of dedicated trauma teams with well-designed management protocols in hospitals can further improve the outcome
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