534 research outputs found

    No-Sense: Sense with Dormant Sensors

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    Wireless sensor networks (WSNs) have enabled continuous monitoring of an area of interest (body, room, region, etc.) while eliminating expensive wired infrastructure. Typically in such applications, wireless sensor nodes report the sensed values to a sink node, where the information is required for the end-user. WSNs also provide the flexibility to the end-user for choosing several parameters for the monitoring application. For example, placement of sensors, frequency of sensing and transmission of those sensed data. Over the years, the advancement in embedded technology has led to increased processing power and memory capacity of these battery powered devices. However, batteries can only supply limited energy, thus limiting the lifetime of the network. In order to prolong the lifetime of the deployment, various efforts have been made to improve the battery technologies and also reduce the energy consumption of the sensor node at various layers in the networking stack. Of all the operations in the network stack, wireless data transmission and reception have found to consume most of the energy. Hence many proposals found in the literature target reducing them through intelligent schemes like power control, reducing retransmissions, etc. In this article we propose a new framework called Virtual Sensing Framework (VSF), which aims to sufficiently satisfy application requirements while conserving energy at the sensor nodes.Comment: Accepted for publication in IEEE Twentieth National Conference on Communications (NCC-2014

    Planning and Control of Mobile Robots in Image Space from Overhead Cameras

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    In this work, we present a framework for the development of a planar mobile robot controller based on image plane feedback. We show that the design of such a motion controller can be accomplished in the image plane by making use of a subset of the parameters that relate the image plane to the ground plane, while still leveraging the simplifications offered by modeling the system as a differentially flat system. Our method relies on a waypoint-based trajectory generator, with all the waypoints specified in the image, as seen by an overhead observer. We present some results from simulation as well as from experiments that validate the ideas presented in this work and discuss some ideas for future wor

    Why IT Managers Don\u27t Go for Cyber-Insurance Products

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    Despite positive expectations, cyber-insurance products have failed to take center stage in the management of IT security risk. Market inexperience, leading to conservatism in pricing cyber-insurance instruments, is often cited as the primary reason for the limited growth of the cyber-insurance market. In contrast, here we provide a demand-side explanation for why cyber-insurance products have not lived up to their initial expectations. We highlight the presence of information asymmetry between customers and providers, showing how it leads to overpricing cyber-insurance contracts and helps explain why cyber insurance might have failed to deliver its promise as a cornerstone of IT security-management programs

    A Game Theoretic Software Test-bed for Cyber Security Analysis of Critical Infrastructure

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    National critical infrastructures are vital to the functioning of modern societies and economies. The dependence on these infrastructures is so succinct that their incapacitation or destruction has a debilitating and cascading effect on national security. Critical infrastructure sectors ranging from financial services to power and transportation to communications and health care, all depend on massive information communication technology networks. Cyberspace is composed of numerous interconnected computers, servers and databases that hold critical data and allow critical infrastructures to function. Securing critical data in a cyberspace that holds against growing and evolving cyber threats is an important focus area for most countries across the world. A novel approach is proposed to assess the vulnerabilities of own networks against adversarial attackers, where the adversary’s perception of strengths and vulnerabilities are modelled using game theoretic techniques. The proposed game theoretic framework models the uncertainties of information with the players (attackers and defenders) in terms of their information sets and their behaviour is modelled and assessed using a probability and belief function framework. The attack-defence scenarios are exercised on a virtual cyber warfare test-bed to assess and evaluate vulnerability of cyber systems. Optimal strategies for attack and defence are computed for the players which are validated using simulation experiments on the cyber war-games testbed, the results of which are used for security analyses

    Friend Turns Foe: Transformation of Anti-Inflammatory HDL to Proinflammatory HDL during Acute-Phase Response

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    High-density lipoprotein (HDL) is a major carrier of cholesterol in the blood. Unlike other lipoproteins, physiological functions of HDL influence the cardiovascular system in favorable ways except when HDL is modified pathologically. The cardioprotective mechanism of HDL is mainly based on reverse cholesterol transport, but there has been an emerging interest in the anti-inflammatory and antioxidant roles of HDL. These latter activities of HDL are compromised in many pathological states associated with inflammation. Further, abnormal HDL can become proinflammatory contributing to oxidative damage. In this paper, we discuss the functional heterogeneity of HDL, how alterations in these particles in inflammatory states result in loss of both antioxidant activity and reverse cholesterol transport in relation to atherosclerosis, and the need for assays to predict its functionality

    ANTIULCER ACTIVITY OF AGNIMUKHA CHURNA

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    Background: Agnimukha Churna is a popular Ayurvedic formulation, composed of herbs and spices, used for treatment of gastrointestinal disorders by traditional healers. Objectives: In present study, we have to subject the pharmacognostic, phytochemical test and to evaluate the anti-ulcer activity of Agnimukha Churna. Material and Methods: Study was carried out, by using two methods i.e., ethanol induced ulcers (5ml/kg, Absolute ethanol) and aspirin induced ulcers (200mg/kg) in rats pretreated with the doses of, Alcoholic Extract of Churna (AEC) (200mg/kg), Hydro-alcoholic Extract of Churna (HAEC) (200mg/kg), Ranitidine (20mg/kg). After 1 hour in ethanol induced method and 4 hour in aspirin induced method rat was sacrificed and stomach was removed for observation of ulcer scores, ulcer index and percentage of inhibition. Results: The AEC and HAEC maintain the integrity of gastric mucosa by virtue of its effect on offensive and defensive gastric mucosal factors. AEC and HAEC significantly (P<0.0001) decreased ulcer index in ethanol induced and aspirin induced model. Conclusions: Cyto-protective action may be the major mechanism responsible for the present study, which cause the generation of prostaglandins promoting inhibition of ulcer. Our study shows that Agnimukha churna and their fractions have the potential to be used as an anti-ulcer

    An evaluation of risk factors for major adverse cardiovascular events during tocilizumab therapy

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    Objective: To evaluate associations between lipid levels, inflammation, and rheumatoid arthritis (RA) disease activity, at baseline and during treatment, with the risk of major adverse cardiovascular events (MACE) in tocilizumab‐treated patients with RA. Methods: In retrospective post hoc analyses, data were pooled for 3,986 adult patients with moderate to severe RA who received ≥1 dose of tocilizumab (4 mg/kg or 8 mg/kg) intravenously every 4 weeks in randomized controlled trials and extension studies. Cox proportional hazards modeling was used to evaluate associations between baseline characteristics and posttreatment changes in laboratory and disease characteristics (week 24) and change in disease activity and laboratory values from baseline to week 24 with the risk of future MACE during extended followup. Results: We identified 50 independently adjudicated cases of MACE during 14,683 patient‐years of followup (0.34 MACE cases/100 patient‐years). At baseline, age, a history of cardiac disorders, the Disease Activity Score in 28 joints (DAS28), and the total cholesterol:high‐density lipoprotein cholesterol ratio were independently associated with MACE in multivariable models (P < 0.05 for all). During treatment, a higher DAS28 and higher swollen and tender joint counts at week 24 were associated with future MACE. In separate models, greater reductions in the DAS28 and joint counts from baseline to week 24 were inversely associated with future MACE; changes in lipid parameters were not statistically significantly associated with the risk of MACE. Conclusion: In this population of patients treated with tocilizumab, an association was observed between the baseline total cholesterol:high‐density lipoprotein cholesterol ratio and an increased risk of MACE. The risk of MACE while receiving treatment, however, was associated with control of disease activity but not lipid changes. Larger studies are needed to confirm these findings

    EFFECT OF NICORANDIL ON PENTYLENETETRAZOLE (PTZ) INDUCED CONVULSIONS IN MICE

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    Aims & Objectives: To evaluate or screen the anticonvulsant effect of Nicorandil a potassium channel opener in Pentylenetetrazole(PTZ) induced convusions in albino mice. Materials & Methods: Mice of either sex weighing 20-25gms were selected for the present study. The animals were divided into 6 groups with each group consisting of 6 albino mice. Group 1 mice received placebo (0.2ml of distilled water) intraperitoneally (i.p), group 2 received sodium valproate 200 mg/kg/i.p. as positive control, while groups 3,4, 5 and 6 were administered Nicorandil 5, 10, 20 and 40 mg/kg i.p respectively. Pentylenetetrazole (PTZ) was administered in the dose of 100mg/kg i.p, 30mins after Nicorandil/ control drug pre-treatment. Onset and duration of clonic convulsion were recorded. Results: Nicorandil pretreatment in the dose of 5mg/kg increased onset time and significantly decreased the duration of convulsions,while the doses of 10, 20, 40mg/kg prevented the convulsions. Conclusion: Nicorandil possesses significant anticonvulsant activity comparable to sodium valproate on PTZ induced seizure in albino mice. KEYWORDS: Pentylenetetrazole; Sodium valproate; Nicorandil; Anticonvulsant activity
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