989 research outputs found
sj-pdf-1-jmx-10.1177_00222429221114317 - Supplemental material for Innovation Imprinting: Why Some Firms Beat the Post-IPO Innovation Slump
No full textSupplemental material, sj-pdf-1-jmx-10.1177_00222429221114317 for Innovation Imprinting: Why Some Firms Beat the Post-IPO Innovation Slump by Simone Wies, Christine Moorman and Rajesh K. Chandy in Journal of Marketing</p
10201 Executive Summary and Manifesto – Event Processing
No full textThe second Dagstuhl seminar on event processing took place in May 2010. This five-day meeting was oriented to work toward a comprehensive document that would explain event processing and how it relates to other technologies and suggest future work in terms of standards, challenges, and shorter-term research projects.
The 45 participants came from academia and industry, some of them out of the event processing field. The teams continued the work after the conference and have summarized their findings in this document. The chapters were written by different teams and then edited for consistency
HAM: the heuristic aggregation method for solving general closed queueing network models of computer systems
No full textAn approximate analytical method for estimating performance statistics of general closed queueing network models of computing systems is presented. These networks may include queues with priority scheduling disciplines and non-exponential servers and several classes of jobs. The method is based on the aggregation theorem (Norton's theorem) of Chandy, Herzog and Woo
Mitogen induction of ion channels in murine T lymphocytes.
No full textUsing gigohm-seal recording, we studied ion channel expression in resting and activated T lymphocytes from mice. Both the number of channels per cell and the predominant type of K+ channel depend upon the state of activation of the cell. Unstimulated T cells express small numbers of K+ channels, typically a dozen per cell, and are heterogeneous, usually expressing either type n or type l K+ channels (see DeCoursey, T. E., K. G. Chandy, S. Gupta, and M. D. Cahalan. 1987. Journal of General Physiology. 89:379-404). 1 d after stimulation by the murine T cell mitogen concanavalin A, large numbers of type n K+ channels appear in enlarged, activated cells. Type n channels appear in activated cells with a time course consistent with that reported for mitogen-induced enhancement of protein synthesis. Voltage-gated tetrodotoxin-sensitive Na+ channels present in about one-third of unstimulated cells from the MRL-n strain are increased approximately 10-fold after activation
Programming Parallel Computers
No full textThis paper is from a keynote address to the IEEE International Conference on Computer Languages, October 9, 1988. Keynote addresses are expected to be provocative (and perhaps even entertaining), but not necessarily scholarly. The reader should be warned that this talk was prepared with these expectations in mind.Parallel computers offer the potential of great speed at low cost. The promise of parallelism is limited by the ability to program parallel machines effectively. This paper explores the opportunities and the problems of parallel computing. Technological and economic trends are studied with a view towards determining where the field of parallel computing is going. An approach to parallel programming, called UNITY, is described. UNITY was developed by Jay Misra and myself, and is described in [Chandy]. Extensions to UNITY are discussed; these extensions were motivated by discussions with Chuck Seit
Practice Prize Reports
No full textThe Practice Prize Reports consist of one article with two parts as follows: “Sinha, Ashish, J. Jeffrey Inman, Yantao Wang, Joonwook Park. Attribute drivers: A factor analytic choice map approach for understanding choices among SKUs” and “Tellis, Gerard J., Rajesh K. Chandy, Deborah MacInnis, Pattana Thaivanich. “Modeling the microeffects of television advertising: Which ad works, when, where, for how long, and why?”product management, choice models, assortment, advertising response, wear-in, wear-out, carry-over effect, long-term effect, ad creative, ad cues
Antibiotic use and resistance : patterns, perceptions, policy and the price to pay
No full textBackground: Antibiotic resistance is a major health challenge especially in low and middle income countries such as India. Inappropriate antibiotic use is one important factor contributing to resistance. Strategies to improve use would help contain resistance. In order to develop strategies that are feasible and appropriate, knowledge is needed about patterns and perceptions of antibiotic use, the consequences of resistance and impact of policy guidelines. Current knowledge and evidence is limited in India.Aim: To improve knowledge on the patterns and perceptions of antibiotic use in the community, the consequences of resistance in individual patients, and the impact of policy guidelines on hospital antibiotic use, so as to identify potential interventional targets, generate key messages and subsequently develop appropriate strategies towards improving use and containing resistance. The specific objectives were:1. To determine patterns of antibiotic use through a surveillance system in the community and challenges faced while developing the system. (I)2. To ascertain the perceptions of stakeholders in antibiotic use and resistance and highlight the challenges to changing practice. (II)3. To assess the impact of antibiotic resistance on cost burden and health consequences in patients with suspected sepsis. (III)4. To determine patterns of inpatient antibiotic use over a decade and evaluate the impact of policy guidelines and modes of dissemination on antibiotic use. (IV)Methods: The first two studies (Paper I & II) for this thesis were done in urban and rural areas of Vellore district, south India and the two other studies (Paper III & IV) at Christian Medical College, Vellore (CMC), a not for profit, university teaching hospital with 2140 beds. Surveillance of antibiotic use patterns (prescriptions and dispensations) in thirty community healthcare facilities for 2 years was conducted with a repeated cross-sectional design (I). A qualitative study with eight focus group discussions among doctors, pharmacists and public explored perceptions about resistance, antibiotic use practices, factors driving use, and strategies for appropriate use (II). A one year observational study on inpatients with a preliminary diagnosis of suspected sepsis and a positive blood culture report analysed costs and health consequences in two groups, ‘resistant’ and ‘susceptible’ based on susceptibility of causative bacteria to the empiric antibiotic given (III). A time series segmented regression analysis of antibiotic use across a decade revealed the patterns of use over time segments and the impact of differing modes of policy guideline development and implementation (IV).Findings: Surveillance in community healthcare facilities (I) revealed that among 52,788 patients, 40.9% were prescribed or dispensed antibiotics (antibiotic encounters). There were significant differences among facilities types and areas. Fluoroquinolones and penicillins were widely used, co-trimoxazole more in rural hospitals and cephalosporins in urban private hospitals. 41.1% of antibiotics were for respiratory infections. Focus group discussions (II) revealed that the public had limited awareness of infection, antibiotics and resistance and wanted quick relief through antibiotics. Doctors prescribed antibiotics for perceived patient expectations and quick recovery. Business concerns promoted antibiotic sales by pharmacists. Improving public awareness, provider communication, diagnostic support, and strict regulatory implementation were suggested strategies. Among 220 patients admitted into the hospital with suspected sepsis (III), the median difference between ‘resistant’ and ‘susceptible’ groups in overall costs, antibiotic costs and pharmacy costs was Rs. 41,993 (p = 0.001), 8,315 (p Conclusion: The level of antibiotic use is significant in the community, especially for respiratory infections and fluoroquinolone use. Patterns of antibiotic use varied among healthcare facilities and stakeholders. Knowledge and understanding of resistance was limited. Patient demand and competitive pressures were some of the main challenges expressed in changing practice. Antibiotic resistance had significant impact on cost and health consequences in patients. Containment of rising inpatient antibiotic use was possible with guideline dissemination through intranet computer network.List of scientific papersI. Chandy SJ, Thomas K, Mathai E, Antonisamy B, Holloway KA, Stalsby Lundborg C. Patterns of antibiotic use in the community and challenges of antibiotic surveillance in a lower-middle-income country setting: a repeated cross-sectional study in Vellore, south India. J Antimicrob Chemother. 2013 Jan;68(1):229-36. https://doi.org/10.1093/jac/dks355 II. Chandy SJ, Mathai E, Thomas K, Faruqui AR, Holloway K, Stalsby Lundborg C. Antibiotic Use and Resistance: perceptions and ethical challenges among doctors, pharmacists and the public in Vellore, South India. Indian J Medical Ethics. 2013 Jan-Mar;10(1):20-27. https://pubmed.ncbi.nlm.nih.gov/23439193III. Chandy SJ, Naik GS, Balaji V, Jeyaseelan V, Thomas K, Stalsby Lundborg C. High Cost Burden and Health Consequences of Antibiotic Resistance – The Price to Pay. [Submitted]IV. Chandy SJ, Naik GS, Charles R, Jeyaseelan V, Naumova EN, Thomas K, Stalsby Lundborg C. The Impact of Policy Guidelines on Hospital Antibiotic Use over a Decade: A Segmented Time Series Analysis. PLoS One. 2014 Mar 19;9(3):e92206. https://doi.org/10.1371/journal.pone.0092206 </p
Inhibitors of mitochondrial Kv1.3 channels induce Bax/Bak-independent death of cancer cells
No full textOvercoming the resistance of tumours to chemotherapy, often due to downregulation of Bax and Bak, represents a significant clinical challenge. It is therefore important to identify novel apoptosis inducers that bypass Bax and Bak. Potassium channels are emerging as oncological targets and a crucial role of mitochondrial Kv1.3 in apoptosis has been demonstrated. Here we report for the first time that Psora-4, PAP-1 and clofazimine, three distinct membrane-permeant inhibitors of Kv1.3, induce death by directly targeting the mitochondrial channel in multiple human and mouse cancer cell lines. Importantly, these drugs activated the intrinsic apoptotic pathway also in the absence of Bax and Bak, a result in agreement with the current mechanistic model for mitochondrial Kv1.3 action. Genetic deficiency or short interfering RNA (siRNA)-mediated downregulation of Kv1.3 abrogated the effects of the drugs. Intraperitoneal injection of clofazimine reduced tumour size by 90% in an orthotopic melanoma B16F10 mouse model in vivo, while no adverse effects were observed in several healthy tissues. The study indicates that inhibition of mitochondrial Kv1.3 might be a novel therapeutic option for the induction of cancer cell death independent of Bax and Bak. © 2012 EMBO Molecular Medicine
Balancing pairs of interfering elements
No full textMany decisions in different fields of application have to take into account the joined effects of two elements that can interfere with each other. For example, in Industrial Economics the demand of an asset can be influenced by the supply of another asset, with synergic or antagonistic effects. The same happens in Public Economics, where two differing economic policies can create mutual interference. Analogously in Medicine and Life Sciences with drugs whose combined administration can produce extra damages or synergies. Other examples occur in Agriculture, Zootechnics and so on. When it is necessary to intervene in such elements, there is sometimes a primary interest for one effect rather than another. For example, if the importance of the effect of an element is ten times greater than the importance of the effect of another, then it is convenient to take this importance into consideration in deciding to what extent it should be employed. With this in mind, the model proposed here allows the optimal quantities of two elements that interfere with each other to be calculated, taking into account the minimum quantities to be allocated. Algorithms for determining solutions for continuous effects' functions are given, together with software specifically for the case of bilinear functions. It concludes with the presentation of applications particularly to economical problems.Antagonist Elements; Interfering Elements; Optimal dosage; Combinations of interfering strategies; Synergies
Sensor Networks for Geospatial Event Detection - Theory and Applications
No full textThis thesis presents theories, analyses, and algorithms for detecting and estimating parameters of geospatial events with today's large, noisy sensor networks. A geospatial event is initiated by a significant change in the state of points in a region in a 3-D space over an interval of time. After the event is initiated it may change the state of points over larger regions and longer periods of time.
Networked sensing is a typical approach for geospatial event detection. In contrast to traditional sensor networks comprised of a small number of high quality (and expensive) sensors, trends in personal computing devices and consumer electronics have made it possible to build large, dense networks at a low cost. The changes in sensor capability, network composition, and system constraints call for new models and algorithms suited to the opportunities and challenges of the new generation of sensor networks.
This thesis offers a single unifying model and a Bayesian framework for analyzing different types of geospatial events in such noisy sensor networks. It presents algorithms and theories for estimating the speed and accuracy of detecting geospatial events as a function of parameters from both the underlying geospatial system and the sensor network. Furthermore, the thesis addresses network scalability issues by presenting rigorous scalable algorithms for data aggregation for detection. These studies provide insights to the design of networked sensing systems for detecting geospatial events.
In addition to providing an overarching framework, this thesis presents theories and experimental results for two very different geospatial problems: detecting earthquakes and hazardous radiation. The general framework is applied to these specific problems, and predictions based on the theories are validated against measurements of systems in the laboratory and in the field.</p
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