174 research outputs found

    A remark on "Study of a Leslie-Gower-type tritrophic population model" [Chaos, Solitons and Fractals 14 (2002) 1275-1293]

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    In [Aziz-Alaoui, 2002] a three species ODE model, based on a modified Leslie-Gower scheme is investigated. It is shown that under certain restrictions on the parameter space, the model has bounded solutions for all positive initial conditions, which eventually enter an invariant attracting set. We show that this is not true. To the contrary, solutions to the model can blow up in finite time, even under the restrictions derived in [Aziz-Alaoui, 2002], if the initial data is large enough. We also prove similar results for the spatially extended system. We validate all of our results via numerical simulations.Comment: 10 pages, 4 figure

    What is India speaking: The "Hinglish" invasion

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    While language competition models of diachronic language shift are increasingly sophisticated, drawing on sociolinguistic components like variable language prestige, distance from language centers and intermediate bilingual transitionary populations, in one significant way they fall short. They fail to consider contact-based outcomes resulting in mixed language practices, e.g. outcome scenarios such as creoles or unmarked code switching as an emergent communicative norm. On these lines something very interesting is uncovered in India, where traditionally there have been monolingual Hindi speakers and Hindi/English bilinguals, but virtually no monolingual English speakers. While the Indian census data reports a sharp increase in the proportion of Hindi/English bilinguals, we argue that the number of Hindi/English bilinguals in India is inaccurate, given a new class of urban individuals speaking a mixed lect of Hindi and English, popularly known as "Hinglish". Based on predator-prey, sociolinguistic theories, salient local ecological factors and the rural-urban divide in India, we propose a new mathematical model of interacting monolingual Hindi speakers, Hindi/English bilinguals and Hinglish speakers. The model yields globally asymptotic stable states of coexistence, as well as bilingual extinction. To validate our model, sociolinguistic data from different Indian classes are contrasted with census reports: We see that purported urban Hindi/English bilinguals are unable to maintain fluent Hindi speech and instead produce Hinglish, whereas rural speakers evidence monolingual Hindi. Thus we present evidence for the first time where an unrecognized mixed lect involving English but not "English", has possibly taken over a sizeable faction of a large global population.Comment: This paper has been withdrawan as the model has now been modified and the existing model has some error

    Retrospective Evaluation of the Epidemiology and Practice Variation of Dexmedetomidine Use in Invasively Ventilated Pediatric Intensive Care Admissions, 2007-2013

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    OBJECTIVES: The study assessed dexmedetomidine utilization and practice variation over time in ventilated pediatric intensive care unit (PICU) patients; and evaluated differences in hospital outcomes between high- and low-dexmedetomidine utilization hospitals. STUDY DESIGN: This serial cross-sectional analysis used administrative data from PICU admissions in the pediatric health information system (37 US tertiary care pediatric hospitals). Included admissions from 2007 to 2013 had simultaneous dexmedetomidine and invasive mechanical ventilation charges, <18 years of age, excluding neonates. Patient and hospital characteristics were compared as well as hospital-level severity-adjusted indexed length of stay (LOS), charges, and mortality. RESULTS: The utilization of dexmedetomidine increased from 6.2 to 38.2 per 100 ventilated PICU patients among pediatric hospitals. Utilization ranged from 3.8 to 62.8 per 100 in 2013. Few differences in patient demographics and no differences in hospital-level volume/severity of illness measures between high- and low-utilization hospitals occurred. No differences in hospital-level, severity-adjusted indexed outcomes (LOS, charges, and mortality) were found. CONCLUSION: Wide practice variation in utilization of dexmedetomidine for ventilated PICU patients existed even as use has increased sixfold. Higher utilization was not associated with increased hospital charges or reduced hospital LOS. Further work should define the expected outcome benefits of dexmedetomidine and its appropriate use

    Before the Flood: Impact of Coordination of Care and Direct Admissions on Emergency Department Volumes

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    Background: Transfers of pediatric patients occur to access specialty and subspecialty care, but incur risk, and consume resources. Direct admissions to medical and surgical wards may improve patient experience and mitigate resource utilization. Objective: We sought to identify common elements for direct admissions, as well as the pattern of disposition for patients referred to our emergency department (ED). Design: A retrospective qualitative analysis of patients transferred to our pediatric hospital for 12 months was performed. Different physician groups were evaluated for use of direct admissions or evaluation in the ED. Patients referred to the ED were additionally tracked to evaluate their eventual disposition. Results: A total of 3982 transfers occurred during the 12-month analysis period. Of those, 3463 resulted in admission, accounting for 32.55% of all admissions. Transfers accepted by nonsurgical services accounted for 82% of the transfers, whereas 18% were facilitated by one of the surgical services. Direct admissions accounted for 1707 (44.8%) of all referrals and were used more often by nonsurgical services. Of patients referred to the ED (2101 or 55.2% of all referrals), most patients were admitted and 343 (16% of those referred to the ED) were discharged home. Conclusions: The direct admission process helped avoid ED assessments for some patients; however, some patients referred to the ED were able to be evaluated, treated, and discharged. Consistent triage of the patients being transferred as direct admissions may improve ED throughput and potentially improve the patient's experience, reduce redundant services, and expedite care

    Study on the ameliorating effect of aqueous extract of Moringa oleifera on Ganga water

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    The quality of&nbsp; surface water is deteriorating day by day due to various anthropogenic activities. Ganga water is assumed polluted almost in the entire strech of river. The medicinal plants may be useful for amelioration of pollution. The present work deals with the study of several chemical characteristics as well as microbial examination of water samples taken from few sites of Ganga river namely Krishna Ghat, Kali Ghat and N.I.T Ghat (Gandhi Ghat) at Patna. The study was foccused on the evaluation of antimicrobial effect of Moringa oleifera (sahjan) leaves extract in the Ganga water. The aqueous leaves extract of different concentrations (0.1%, 0.16%, 0.23%, 0.3%) showed ameliorating results on pH and chloride content of water as well as microbial activity. Significant ameliorating results were observed on pH and chloride content of water. pH was reduced from 8.1 to 7.4 and chloride was reduced from 82.36 mg/l to 48.14 mg/l under plant extract treatment. Colony Forming Unit (CFU) was assessed by standard plate count (SPC) method and was found to be 468 CFU/ml for raw water, which was reduced to 143 CFU/ml when treated with plant extract. Similar decreasing trend was observed in case of MPN of coliform. So extract of Moringa oleifera may also be applied to purify drinking water. Morever it will be cheaper for the people in comparision to other purification devices
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