47 research outputs found

    On Generalized Fractional Kinetic Equations

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    In a recent paper, Saxena et al. [1] developed the solutions of three generalized fractional kinetic equations in terms of Mittag-Leffler functions. The object of the present paper is to further derive the solution of further generalized fractional kinetic equations. The results are obtained in a compact form in terms of generalized Mittag-Leffler functions. Their relation to fundamental laws of physics is briefly discussed.Comment: 10 pages, LaTe

    Imaginary Potential as a Counter of Delay Time for Wave Reflection from a 1D Random Potential

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    We show that the delay time distribution for wave reflection from a one-dimensional random potential is related directly to that of the reflection coefficient, derived with an arbitrarily small but uniform imaginary part added to the random potential. Physically, the reflection coefficient, being exponential in the time dwelt in the presence of the imaginary part, provides a natural counter for it. The delay time distribution then follows straightforwardly from our earlier results for the reflection coefficient, and coincides with the distribution obtained recently by Texier and Comtet [C.Texier and A. Comtet, Phys.Rev.Lett. {\bf 82}, 4220 (1999)],with all moments infinite. Delay time distribution for a random amplifying medium is then derived . In this case, however, all moments work out to be finite.Comment: 4 pages, RevTeX, replaced with added proof, figure and references. To appear in Phys. Rev. B Jan01 200

    Up the ante: Electronic word of mouth and its effects on firm reputation and performance

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    Prior management research on firm reputation has acknowledged the importance of word of mouth (WOM) in influencing key choices made by businesses, as well as by individuals. In recent developments, Internet-based WOM forums aggregate vast amounts of information relevant to firm strategy and operations. For example, online social media communities aggregate information generated by both the firm (i.e. firm-generated content FGC) and users (i.e. user-generated content UGC). We theorize that FGC and UGC generate reputation benefits for a company in the form of two intermediate information mechanisms: information diversity and valence. We first undertake a qualitative content analysis to investigate the extent to which FGC and UGC generate information diversity and valence. We then test the hypothesis that both information diversity and valence increase a firm’s financial performance. Our findings show that electronic WOM as transmitted through social media communities enhances a firm’s reputation and thereby its performance through both these effects (i.e. embedded information and valence). We thus fully delineate the determinants of ‘good reputation’ in these social environments. As part of our robustness checks, we also consider the impact of price and quality, the two specific FGC components, on firm performance. Our findings further confirm these relationships

    Perceptions Regarding the SARS-CoV-2 Pandemic's Impact on Neurocritical Care Delivery: Results From a Global Survey

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    BACKGROUND: The SARS-CoV-2 (COVID-19) pandemic has impacted many facets of critical care delivery. METHODS: An electronic survey was distributed to explore the pandemic's perceived impact on neurocritical care delivery between June 2020 and March 2021. Variables were stratified by World Bank country income level, presence of a dedicated neurocritical care unit (NCCU) and experiencing a COVID-19 patient surge. RESULTS: Respondents from 253 hospitals (78.3% response rate) from 47 countries (45.5% low/middle income countries; 54.5% with a dedicated NCCU; 78.6% experienced a first surge) participated in the study. Independent of country income level, NCCU and surge status, participants reported reductions in NCCU admissions (67%), critical care drug shortages (69%), reduction in ancillary services (43%) and routine diagnostic testing (61%), and temporary cancellation of didactic teaching (44%) and clinical/basic science research (70%). Respondents from low/middle income countries were more likely to report lack of surge preparedness (odds ratio [OR], 3.2; 95% confidence interval [CI], 1.8-5.8) and struggling to return to prepandemic standards of care (OR, 12.2; 95% CI, 4.4-34) compared with respondents from high-income countries. Respondents experiencing a surge were more likely to report conversion of NCCUs and general-mixed intensive care units (ICUs) to a COVID-ICU (OR 3.7; 95% CI, 1.9-7.3), conversion of non-ICU beds to ICU beds (OR, 3.4; 95% CI, 1.8-6.5), and deviations in critical care and pharmaceutical practices (OR, 4.2; 95% CI 2.1-8.2). Respondents from hospitals with a dedicated NCCU were less likely to report conversion to a COVID-ICU (OR, 0.5; 95% CI, 0.3-0.9) or conversion of non-ICU to ICU beds (OR, 0.5; 95% CI, 0.3-0.9). CONCLUSION: This study reports the perceived impact of the COVID-19 pandemic on global neurocritical care delivery, and highlights shortcomings of health care infrastructures and the importance of pandemic preparedness
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