196 research outputs found

    Fast Authentication in Heterogeneous Wireless Networks

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    The growing diffusion of wireless devices is leading to an increasing demand for mobility and security. At the same time, most applications can only tolerate short breaks in the data flow, so that it is a challenge to find out mobility and authentication methods able to cope with these constraints. This paper aims to propose an authentication scheme which significantly shortens the authentication latency and that can be deployed in a variety of wireless environments ranging from common Wireless LANs (WLANs) to satellite-based access networks

    MOON: a New Overlay Network Architecture for Mobility and QoS Support

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    The continuously increasing diffusion of mobile devices such as laptops, PDAs and smartphones, all equipped with enhanced functionalities, has led to numerous studies about mobility and to the definition of new network architectures capable to support it. Problems related to mobility have been addressed mostly operating on the network or transport layers of the Internet protocol stack. As a result, most of these solutions generally require modifying the TCP and/or the IP protocol. Although this approach is well suited to handle mobility, it lacks in compatibility with the Internet Protocol Suite. This consideration led us to study a fully TCP compatible and flexible approach we dubbed MOON, for MObile Overlay Network. This network architecture is currently under design at LIPAR, the Internet, Protocols and Network Architecture Lab of Politecnico di Torino

    Fast Authentication in Heterogeneous Wireless Networks

    Get PDF
    The growing diffusion of wireless devices is leading to an increasing demand for mobility and security. At the same time, most applications can only tolerate short breaks in the data flow, so that it is a challenge to find out mobility and authentication methods able to cope with these constraints. This paper aims to propose an authentication scheme which significantly shortens the authentication latency and that can be deployed in a variety of wireless environments ranging from common Wireless LANs (WLANs) to satellite-based access networks

    Crucial role of α4 and α6 nicotinic acetylcholine receptor subunits from ventral tegmental area in systemic nicotine self-administration

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    The identification of the molecular mechanisms involved in nicotine addiction and its cognitive consequences is a worldwide priority for public health. Novel in vivo paradigms were developed to match this aim. Although the beta2 subunit of the neuronal nicotinic acetylcholine receptor (nAChR) has been shown to play a crucial role in mediating the reinforcement properties of nicotine, little is known about the contribution of the different alpha subunit partners of beta2 (i.e., alpha4 and alpha6), the homo-pentameric alpha7, and the brain areas other than the ventral tegmental area (VTA) involved in nicotine reinforcement. In this study, nicotine (8.7-52.6 microg free base/kg/inf) self-administration was investigated with drug-naive mice deleted (KO) for the beta2, alpha4, alpha6 and alpha7 subunit genes, their wild-type (WT) controls, and KO mice in which the corresponding nAChR subunit was selectively re-expressed using a lentiviral vector (VEC mice). We show that WT mice, beta2-VEC mice with the beta2 subunit re-expressed exclusively in the VTA, alpha4-VEC mice with selective alpha4 re-expression in the VTA, alpha6-VEC mice with selective alpha6 re-expression in the VTA, and alpha7-KO mice promptly self-administer nicotine intravenously, whereas beta2-KO, beta2-VEC in the substantia nigra, alpha4-KO and alpha6-KO mice do not respond to nicotine. We thus define the necessary and sufficient role of alpha4beta2- and alpha6beta2-subunit containing nicotinic receptors (alpha4beta2*- and alpha6beta2*-nAChRs), but not alpha7*-nAChRs, present in cell bodies of the VTA, and their axons, for systemic nicotine reinforcement in drug-naive mic

    Videovoice diaries to understand the perspectives of community health volunteers in Ethiopia: insights from collaborative qualitative research

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    Background: Audio-visual diary to collect data on daily routines of study participants is relatively new in health systems research. The concept uses participatory research techniques to elicit participants' views, priorities and empower them to take action. Methods: We discuss a collaborative qualitative study conducted by university researchers, rural communities and health managers (Southwest Ethiopia). We used Videovoice to understand the role of community health volunteers as mediators of accessible and responsive Primary Health Care in Ethiopia. Footage is obtained from 30 Health Development Army leaders in 3 diverse districts, over 3–4 months. Following community engagement and training, participants received an encrypted phone with recording capability. They are supported by researchers through regular contacts, to establish trust, support, and reduce social desirability. A co-production workshop with participants and researchers to interpret the findings will be held. Results: Employing Videovoice diaries demonstrates that collaborations involving academic researchers, community members and volunteers (as lay researchers) and managers have considerable benefits as well as challenges. Videovoice shifts power to the participants: they determine what to capture, what is important and how to convey their views and activities. Data is enriched by participant-generated insights into the reasons behind their decisions. Intensive engagement, effective communication and trust are essential in understanding constraints and preferences of their role, and interpreting findings. A multi-disciplinary research team will enhance the analytical process. Discussion: Videovoice can be a useful tool in enabling lay researchers to describe their daily life, better understand their needs, and identify mechanisms for change. The approach can strengthen the immediacy of the research, capturing perceptions within context. Co-production will involve a significant shift in power and emergence of new directions

    Readiness of primary health care facilities in Jimma zone to provide diabetic services for diabetic clients, Jimma zone, southwest Ethiopia, March 2013

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    Published date: Oct 12, 2016Background: Diabetes is one of the commonest non-communicable diseases of the 21st century. Global burden of diabetes in 2010 was estimated at 285 million and projected to increase to 438 million by the year 2030, if no interventions are put in place. The primary health care facilities are the first level of contact for such rising cases of diabetes, despite of this fact there is no study done on the capabilities of primary health care facilities to accommodate diabetic services. Hence, the objective of this study is to assess the readiness of selected primary public hospitals and health centers to accommodate diabetic care in Jimma zone south west Ethiopia. Methods: Health facility based cross-sectional study design using quantitative and qualitative method of data collection was conducted from Feb 1-March 1, 2013. After checking the completeness, and coding of questionnaires, the quantitative data were entered into computer software and analyzed using SPSS version 20.0. Results: All of the facilities have at least some of the drugs and medical supplies and other resources required for the diagnosis and management of diabetes never the less there was no specific plan to deal with diabetic management at health facilities. Majority of patients were first diagnosed in other health facilities and referred to the current health institutions for follow up and there is no routine screening for diabetics in adult outpatient department in some health facilities. Conclusion and recommendation: Required drugs and medical supplies are not regularly fulfilled, health facilities have no plan for diabetic management, and health workers did not get training on management of diabetics. No routine screening at adult patients at outpatient departments. Hence the Woreda and the zone have to work on the capacity of the health workers and health facilities to handle diabetic care at health center level.Fikru Tafese, Elias Teferi, Beyene Wondafirash, Sintayehu Fekadu, Garumma Tolu and Gugsa Nemarr

    Low cadmium concentration in whole blood from residents of Northern Sardinia (Italy) with special reference to smoking habits

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    Introduction. The present study was initiated to investigate the cadmium concentrations in whole blood of Northern Sardinian, non-occupationally exposed adult subjects. Sardinia is a large Italian island which differs genetically and environmentally from other mainland Italian areas. Methods. Two hundred and forty-three adults (157 females and 86 males) were selected in the study area from subjects who were undergoing blood collection for laboratory analysis during the period January 2005-May 2005. Whole blood was analysed by graphite furnace atomic absorption spectrometer equipped with a Zeeman-effect background corrector (Perkin Elmer ZL5100) and an auto sampler. The adopted analytical procedure uses the Stabilized Platform Temperature Furnace (STPF) technique. Results. The mean value of Blood Cadmium Concentration (BCdC), expressed as Geometric Mean, was 0.32 mg/l (CI 95%: 0.31-0.34 mg/l) significantly ranging from 0.27 mg/l (CI 95%: 0.26-0.29 mg/l) in non-smokers to 0.34 mg/l (CI 95%: 0.30-0.39 mg/l) in ex-smokers up to 0.47 mg/l (CI 95%: 0.42-0.53 mg/l) in smokers (p inf. 0.0001). Discussion. The results show that BCdC levels in Northern Sar- dinian non-occupationally exposed adults are lower than levels found in many other regions, including those within Italy. Nev- ertheless, similar values have been detected in other European countries and cities. Conclusions. In relation to other reports in which data were analysed by strata for smoking habit and age, we found similar BCdC values among non smokers. However, Sardinian smokers seem to show lower levels of blood cadmium

    002 BP: VIDEOVOICE DIARIES TO UNDERSTAND THE PERSPECTIVES OF COMMUNITY HEALTH VOLUNTEERS IN ETHIOPIA: INSIGHTS FROM COLLABORATIVE QUALITATIVE RESEARCH

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    Background Audio-visual diary to collect data on daily routines of study participants is relatively new in health systems research. The concept uses participatory research techniques to elicit participants' views, priorities and empower them to take action. Methods We discuss a collaborative qualitative study conducted by university researchers, rural communities and health managers (Southwest Ethiopia). We used Videovoice to understand the role of community health volunteers as mediators of accessible and responsive Primary Health Care in Ethiopia. Footage is obtained from 30 Health Development Army leaders in 3 diverse districts, over 3–4 months. Following community engagement and training, participants received an encrypted phone with recording capability. They are supported by researchers through regular contacts, to establish trust, support, and reduce social desirability. A co-production workshop with participants and researchers to interpret the findings will be held. Results Employing Videovoice diaries demonstrates that collaborations involving academic researchers, community members and volunteers (as lay researchers) and managers have considerable benefits as well as challenges. Videovoice shifts power to the participants: they determine what to capture, what is important and how to convey their views and activities. Data is enriched by participant-generated insights into the reasons behind their decisions. Intensive engagement, effective communication and trust are essential in understanding constraints and preferences of their role, and interpreting findings. A multi-disciplinary research team will enhance the analytical process. Discussion Videovoice can be a useful tool in enabling lay researchers to describe their daily life, better understand their needs, and identify mechanisms for change. The approach can strengthen the immediacy of the research, capturing perceptions within context. Co-production will involve a significant shift in power and emergence of new directions

    Endogenous cholinergic inputs and local circuit mechanisms govern the phasic mesolimbic dopamine response to nicotine

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    Nicotine exerts its reinforcing action by stimulating nicotinic acetylcholine receptors (nAChRs) and boosting dopamine (DA) output from the ventral tegmental area (VTA). Recent data have led to a debate about the principal pathway of nicotine action: direct stimulation of the DAergic cells through nAChR activation, or disinhibition mediated through desensitization of nAChRs on GABAergic interneurons. We use a computational model of the VTA circuitry and nAChR function to shed light on this issue. Our model illustrates that the α4β2-containing nAChRs either on DA or GABA cells can mediate the acute effects of nicotine. We account for in vitro as well as in vivo data, and predict the conditions necessary for either direct stimulation or disinhibition to be at the origin of DA activity increases. We propose key experiments to disentangle the contribution of both mechanisms. We show that the rate of endogenous acetylcholine input crucially determines the evoked DA response for both mechanisms. Together our results delineate the mechanisms by which the VTA mediates the acute rewarding properties of nicotine and suggest an acetylcholine dependence hypothesis for nicotine reinforcement.Peer reviewe
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