Voice Communications over 802.11 Ad Hoc Networks: Modeling, Optimization and Call Admission Control

Science.gov (United States)

Xu, Changchun; Xu, Yanyi; Liu, Gan; Liu, Kezhong

Supporting quality-of-service (QoS) of multimedia communications over IEEE 802.11 based ad hoc networks is a challenging task. This paper develops a simple 3-D Markov chain model for queuing analysis of IEEE 802.11 MAC layer. The model is applied for performance analysis of voice communications over IEEE 802.11 single-hop ad hoc networks. By using the model, we finish the performance optimization of IEEE MAC layer and obtain the maximum number of voice calls in IEEE 802.11 ad hoc networks as well as the statistical performance bounds. Furthermore, we design a fully distributed call admission control (CAC) algorithm which can provide strict statistical QoS guarantee for voice communications over IEEE 802.11 ad hoc networks. Extensive simulations indicate the accuracy of the analytical model and the CAC scheme.

Reliability analysis of cluster-based ad-hoc networks

International Nuclear Information System (INIS)

Cook, Jason L.; Ramirez-Marquez, Jose Emmanuel

2008-01-01

The mobile ad-hoc wireless network (MAWN) is a new and emerging network scheme that is being employed in a variety of applications. The MAWN varies from traditional networks because it is a self-forming and dynamic network. The MAWN is free of infrastructure and, as such, only the mobile nodes comprise the network. Pairs of nodes communicate either directly or through other nodes. To do so, each node acts, in turn, as a source, destination, and relay of messages. The virtue of a MAWN is the flexibility this provides; however, the challenge for reliability analyses is also brought about by this unique feature. The variability and volatility of the MAWN configuration makes typical reliability methods (e.g. reliability block diagram) inappropriate because no single structure or configuration represents all manifestations of a MAWN. For this reason, new methods are being developed to analyze the reliability of this new networking technology. New published methods adapt to this feature by treating the configuration probabilistically or by inclusion of embedded mobility models. This paper joins both methods together and expands upon these works by modifying the problem formulation to address the reliability analysis of a cluster-based MAWN. The cluster-based MAWN is deployed in applications with constraints on networking resources such as bandwidth and energy. This paper presents the problem's formulation, a discussion of applicable reliability metrics for the MAWN, and illustration of a Monte Carlo simulation method through the analysis of several example networks

Intrusion detection in wireless ad-hoc networks

CERN Document Server

Chaki, Nabendu

2014-01-01

Presenting cutting-edge research, Intrusion Detection in Wireless Ad-Hoc Networks explores the security aspects of the basic categories of wireless ad-hoc networks and related application areas. Focusing on intrusion detection systems (IDSs), it explains how to establish security solutions for the range of wireless networks, including mobile ad-hoc networks, hybrid wireless networks, and sensor networks.This edited volume reviews and analyzes state-of-the-art IDSs for various wireless ad-hoc networks. It includes case studies on honesty-based intrusion detection systems, cluster oriented-based

Ad Hoc Access Gateway Selection Algorithm

Science.gov (United States)

Jie, Liu

With the continuous development of mobile communication technology, Ad Hoc access network has become a hot research, Ad Hoc access network nodes can be used to expand capacity of multi-hop communication range of mobile communication system, even business adjacent to the community, improve edge data rates. For mobile nodes in Ad Hoc network to internet, internet communications in the peer nodes must be achieved through the gateway. Therefore, the key Ad Hoc Access Networks will focus on the discovery gateway, as well as gateway selection in the case of multi-gateway and handover problems between different gateways. This paper considers the mobile node and the gateway, based on the average number of hops from an average access time and the stability of routes, improved gateway selection algorithm were proposed. An improved gateway selection algorithm, which mainly considers the algorithm can improve the access time of Ad Hoc nodes and the continuity of communication between the gateways, were proposed. This can improve the quality of communication across the network.

Energy-Aware Routing Protocol for Ad Hoc Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Mann Raminder P

2005-01-01

Full Text Available Wireless ad hoc sensor networks differ from wireless ad hoc networks from the following perspectives: low energy, lightweight routing protocols, and adaptive communication patterns. This paper proposes an energy-aware routing protocol (EARP suitable for ad hoc wireless sensor networks and presents an analysis for its energy consumption in various phases of route discovery and maintenance. Based on the energy consumption associated with route request processing, EARP advocates the minimization of route requests by allocating dynamic route expiry times. This paper introduces a unique mechanism for estimation of route expiry time based on the probability of route validity, which is a function of time, number of hops, and mobility parameters. In contrast to AODV, EARP reduces the repeated flooding of route requests by maintaining valid routes for longer durations.

[Causal analysis approaches in epidemiology].

Science.gov (United States)

Dumas, O; Siroux, V; Le Moual, N; Varraso, R

2014-02-01

Epidemiological research is mostly based on observational studies. Whether such studies can provide evidence of causation remains discussed. Several causal analysis methods have been developed in epidemiology. This paper aims at presenting an overview of these methods: graphical models, path analysis and its extensions, and models based on the counterfactual approach, with a special emphasis on marginal structural models. Graphical approaches have been developed to allow synthetic representations of supposed causal relationships in a given problem. They serve as qualitative support in the study of causal relationships. The sufficient-component cause model has been developed to deal with the issue of multicausality raised by the emergence of chronic multifactorial diseases. Directed acyclic graphs are mostly used as a visual tool to identify possible confounding sources in a study. Structural equations models, the main extension of path analysis, combine a system of equations and a path diagram, representing a set of possible causal relationships. They allow quantifying direct and indirect effects in a general model in which several relationships can be tested simultaneously. Dynamic path analysis further takes into account the role of time. The counterfactual approach defines causality by comparing the observed event and the counterfactual event (the event that would have been observed if, contrary to the fact, the subject had received a different exposure than the one he actually received). This theoretical approach has shown limits of traditional methods to address some causality questions. In particular, in longitudinal studies, when there is time-varying confounding, classical methods (regressions) may be biased. Marginal structural models have been developed to address this issue. In conclusion, "causal models", though they were developed partly independently, are based on equivalent logical foundations. A crucial step in the application of these models is the

Dynamic ad hoc networks

CERN Document Server

Rashvand, Habib

2013-01-01

Motivated by the exciting new application paradigm of using amalgamated technologies of the Internet and wireless, the next generation communication networks (also called 'ubiquitous', 'complex' and 'unstructured' networking) are changing the way we develop and apply our future systems and services at home and on local, national and global scales. Whatever the interconnection - a WiMAX enabled networked mobile vehicle, MEMS or nanotechnology enabled distributed sensor systems, Vehicular Ad hoc Networking (VANET) or Mobile Ad hoc Networking (MANET) - all can be classified under new networking s

LAMAN: Load Adaptable MAC for Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Realp Marc

2005-01-01

Full Text Available In mobile ad hoc radio networks, mechanisms on how to access the radio channel are extremely important in order to improve network efficiency. In this paper, the load adaptable medium access control for ad hoc networks (LAMAN protocol is described. LAMAN is a novel decentralized multipacket MAC protocol designed following a cross-layer approach. Basically, this protocol is a hybrid CDMA-TDMA-based protocol that aims at throughput maximization in multipacket communication environments by efficiently combining contention and conflict-free protocol components. Such combination of components is used to adapt the nodes' access priority to changes on the traffic load while, at the same time, accounting for the multipacket reception (MPR capability of the receivers. A theoretical analysis of the system is developed presenting closed expressions of network throughput and packet delay. By simulations the validity of our analysis is shown and the performances of a LAMAN-based system and an Aloha-CDMA-based one are compared.

Context discovery in ad-hoc networks

NARCIS (Netherlands)

Liu, F.

2011-01-01

With the rapid development of wireless technology and portable devices, mobile ad-hoc networks (MANETs) are more and more present in our daily life. Ad-hoc networks are often composed of mobile and battery-supplied devices, like laptops, mobile phones, and PDAs. With no requirement for

Receiver-Based Ad Hoc On Demand Multipath Routing Protocol for Mobile Ad Hoc Networks.

Science.gov (United States)

Al-Nahari, Abdulaziz; Mohamad, Mohd Murtadha

2016-01-01

Decreasing the route rediscovery time process in reactive routing protocols is challenging in mobile ad hoc networks. Links between nodes are continuously established and broken because of the characteristics of the network. Finding multiple routes to increase the reliability is also important but requires a fast update, especially in high traffic load and high mobility where paths can be broken as well. The sender node keeps re-establishing path discovery to find new paths, which makes for long time delay. In this paper we propose an improved multipath routing protocol, called Receiver-based ad hoc on demand multipath routing protocol (RB-AOMDV), which takes advantage of the reliability of the state of the art ad hoc on demand multipath distance vector (AOMDV) protocol with less re-established discovery time. The receiver node assumes the role of discovering paths when finding data packets that have not been received after a period of time. Simulation results show the delay and delivery ratio performances are improved compared with AOMDV.

Research of Ad Hoc Networks Access Algorithm

Science.gov (United States)

Xiang, Ma

With the continuous development of mobile communication technology, Ad Hoc access network has become a hot research, Ad Hoc access network nodes can be used to expand capacity of multi-hop communication range of mobile communication system, even business adjacent to the community, improve edge data rates. When the ad hoc network is the access network of the internet, the gateway discovery protocol is very important to choose the most appropriate gateway to guarantee the connectivity between ad hoc network and IP based fixed networks. The paper proposes a QoS gateway discovery protocol which uses the time delay and stable route to the gateway selection conditions. And according to the gateway discovery protocol, it also proposes a fast handover scheme which can decrease the handover time and improve the handover efficiency.

VMQL: A Visual Language for Ad-Hoc Model Querying

DEFF Research Database (Denmark)

Störrle, Harald

2011-01-01

In large scale model based development, analysis level models are more like knowledge bases than engineering artifacts. Their effectiveness depends, to a large degree, on the ability of domain experts to retrieve information from them ad hoc. For large scale models, however, existing query...

Ad hoc supervision of general practice registrars as a 'community of practice': analysis, interpretation and re-presentation.

Science.gov (United States)

Clement, T; Brown, J; Morrison, J; Nestel, D

2016-05-01

General practice registrars in Australia undertake most of their vocational training in accredited general practices. They typically see patients alone from the start of their community-based training and are expected to seek timely ad hoc support from their supervisor. Such ad hoc encounters are a mechanism for ensuring patient safety, but also provide an opportunity for learning and teaching. Wenger's (Communities of practice: learning, meaning, and identity. Cambridge University Press, New York, 1998) social theory of learning ('communities of practice') guided a secondary analysis of audio-recordings of ad hoc encounters. Data from one encounter is re-presented as an extended sequence to maintain congruence with the theoretical perspective and enhance vicariousness. An interpretive commentary communicates key features of Wenger's theory and highlights the researchers' interpretations. We argue that one encounter can reveal universal understandings of clinical supervision and that the process of naturalistic generalisation allows readers to transfer others' experiences to their own contexts. The paper raises significant analytic, interpretive, and representational issues. We highlight that report writing is an important, but infrequently discussed, part of research design. We discuss the challenges of supporting the learning and teaching that arises from adopting a socio-cultural lens and argue that such a perspective importantly captures the complex range of issues that work-based practitioners have to grapple with. This offers a challenge to how we research and seek to influence work-based learning and teaching in health care settings.

Ad hoc public disclosure obligations of public companies on the capital market

Directory of Open Access Journals (Sweden)

Marjanski Vladimir

2012-01-01

Full Text Available The author gives a comprehensive analysis of the obligations of public companies regarding the provision of periodical (ad hoc information to the public on the capital market. Ad hoc disclosure is to achieve a number of aims. It is one of the devices to secure the market's functional abilities. By means of regularly fulfilling this obligation, the market is provided with all the relevant information necessary to form adequate prices of market materials - i.e. securities and other financial instruments (the function of market protection. Investors are thus being able to aptly respond to modified circumstances and deliver investment decisions whether to buy or sell market materials the price of which are being changed (the function of investor protection. Due to the fact that the duty of ad hoc disclosure encompasses the obligation to reveal insider information directly affecting the emitter, ad hoc disclosure serves as a preventive measure, i.e. as a protection against illicit trade with insider information (the function of prevention against the abuse of insider information.

AD HOC TEAMWORK BEHAVIORS FOR INFLUENCING A FLOCK

Directory of Open Access Journals (Sweden)

Katie Genter

2016-02-01

Full Text Available Ad hoc teamwork refers to the challenge of designing agents that can influence the behavior of a team, without prior coordination with its teammates. This paper considers influencing a flock of simple robotic agents to adopt a desired behavior within the context of ad hoc teamwork. Specifically, we examine how the ad hoc agents should behave in order to orient a flock towards a target heading as quickly as possible when given knowledge of, but no direct control over, the behavior of the flock. We introduce three algorithms which the ad hoc agents can use to influence the flock, and we examine the relative importance of coordinating the ad hoc agents versus planning farther ahead when given fixed computational resources. We present detailed experimental results for each of these algorithms, concluding that in this setting, inter-agent coordination and deeper lookahead planning are no more beneficial than short-term lookahead planning.

Routing Protocol for Mobile Ad-hoc Wireless Networks

Directory of Open Access Journals (Sweden)

I. M. B. Nogales

2007-09-01

Full Text Available Bluetooth is a cutting-edge technology used for implementing wireless ad hoc networks. In order to provide an overall scheme for mobile ad hoc networks, this paper deals with scatternet topology formation and routing algorithm to form larger ad hoc wireless Networks. Scatternet topology starts by forming a robust network, which is less susceptible to the problems posed by node mobility. Mobile topology relies on the presence of free nodes that create multiple connections with the network and on their subsequently rejoining the network. Our routing protocol is a proactive routing protocol, which is tailor made for the Bluetooth ad hoc network. The connection establishment connects nodes in a structure that simplifies packet routing and scheduling. The design allows nodes to arrive and leave arbitrarily, incrementally building the topology and healing partitions when they occur. We present simulation results that show that the algorithm presents low formation latency and also generates an efficient topology for forwarding packets along ad-hoc wireless networks.

Extending Service Area of IEEE 802.11 Ad Hoc Networks

Science.gov (United States)

Choi, Woo-Yong

2012-06-01

According to the current IEEE 802.11 wireless LAN standards, IEEE 802.11 ad hoc networks have the limitation that all STAs (Stations) are in the one-hop transmission range of each other. In this paper, to alleviate the limitation of IEEE 802.11 ad hoc networks we propose the efficient method for selecting the most appropriate pseudo AP (Access Point) from among the set of ad hoc STAs and extending the service area of IEEE 802.11 ad hoc networks by the pseudo AP's relaying the internal traffic of IEEE 802.11 ad hoc networks. Numerical examples show that the proposed method significantly extends the service area of IEEE 802.11 ad hoc networks.

Assured Resource Sharing in Ad-Hoc Collaboration

Energy Technology Data Exchange (ETDEWEB)

Ahn, Gail-Joon [Arizona State Univ., Tempe, AZ (United States)

2015-12-19

The project seeks an innovative framework to enable users to access and selectively share resources in distributed environments, enhancing the scalability of information sharing. We have investigated secure sharing & assurance approaches for ad-hoc collaboration, focused on Grids, Clouds, and ad-hoc network environments.

Ad-hoc Content-based Queries and Data Analysis for Virtual Observatories, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Aquilent, Inc. proposes to support ad-hoc, content-based query and data retrieval from virtual observatories (VxO) by developing 1) Higher Order Query Services that...

Game Theory in Wireless Ad-Hoc Opportunistic Radios

OpenAIRE

Mumtaz, Shahid; Gameiro, Atilio

2010-01-01

Emerging research in game theory based power control applied to ad hoc opportunist networks shows much promise to help understand the complex interactions between OR nodes in this highly dynamic and distributed environment. Also, the employment of game theory in modeling dynamic situations for opportunist ad hoc networks where OR nodes have incomplete information has led to the application of largely unexplored games such as games of imperfect monitoring. Ad hoc security using game theory is ...

The Ex hoc Architecture

DEFF Research Database (Denmark)

2006-01-01

Developed in the LIWAS project which develops technology for measuring road surfaces and communicating this data in an ad hoc environment. The communication part is built upon OOVM Resilient technology....

Innovative research of AD HOC network mobility model

Science.gov (United States)

Chen, Xin

2017-08-01

It is difficult for researchers of AD HOC network to conduct actual deployment during experimental stage as the network topology is changeable and location of nodes is unfixed. Thus simulation still remains the main research method of the network. Mobility model is an important component of AD HOC network simulation. It is used to describe the movement pattern of nodes in AD HOC network (including location and velocity, etc.) and decides the movement trail of nodes, playing as the abstraction of the movement modes of nodes. Therefore, mobility model which simulates node movement is an important foundation for simulation research. In AD HOC network research, mobility model shall reflect the movement law of nodes as truly as possible. In this paper, node generally refers to the wireless equipment people carry. The main research contents include how nodes avoid obstacles during movement process and the impacts of obstacles on the mutual relation among nodes, based on which a Node Self Avoiding Obstacle, i.e. NASO model is established in AD HOC network.

A tandem queueing model for delay analysis in disconnected ad hoc networks

NARCIS (Netherlands)

Al Hanbali, Ahmad; de Haan, Roland; Boucherie, Richardus J.; van Ommeren, Jan C.W.

2007-01-01

Ad hoc network routing protocols may fail to operate in the absence of an end-to-end connection from source to destination. This deficiency can be resolved by so-called opportunistic networking which exploits the mobility of the nodes by letting them operate as relays according to the

Protective effect of yerba mate intake on the cardiovascular system: a post hoc analysis study in postmenopausal women

OpenAIRE

da Veiga, D.T.A.; Bringhenti, R.; Copes, R.; Tatsch, E.; Moresco, R.N.; Comim, F.V.; Premaor, M.O.

2018-01-01

The prevalence of cardiovascular and metabolic diseases is increased in postmenopausal women, which contributes to the burden of illnesses in this period of life. Yerba mate (Ilex paraguariensis) is a native bush from Southern South America. Its leaves are rich in phenolic components, which may have antioxidant, vasodilating, hypocholesterolemic, and hypoglycemic proprieties. This post hoc analysis of the case-control study nested in the Obesity and Bone Fracture Cohort evaluated the consumpt...

Performance analysis of differentiated resource-sharing in a wireless ad-hoc network

NARCIS (Netherlands)

Roijers, F.; van den Berg, H.; Mandjes, M.

2010-01-01

In this paper we model and analyze a relay node in a wireless ad-hoc network; the capacity available at this node is used to both transmit traffic from the source nodes (towards the relay node), and to serve traffic at the relay node (so that it can be forwarded to successor nodes). Clearly, a

Decentralized position verification in geographic ad hoc routing

NARCIS (Netherlands)

Leinmüller, Tim; Schoch, Elmar; Kargl, Frank; Maihöfer, Christian

Inter-vehicle communication is regarded as one of the major applications of mobile ad hoc networks (MANETs). Compared to MANETs or wireless sensor networks (WSNs), these so-called vehicular ad hoc networks (VANETs) have unique requirements on network protocols. The requirements result mainly from

[Eco-epidemiology: towards epidemiology of complexity].

Science.gov (United States)

Bizouarn, Philippe

2016-05-01

In order to solve public health problems posed by the epidemiology of risk factors centered on the individual and neglecting the causal processes linking the risk factors with the health outcomes, Mervyn Susser proposed a multilevel epidemiology called eco-epidemiology, addressing the interdependence of individuals and their connection with molecular, individual, societal, environmental levels of organization participating in the causal disease processes. The aim of this epidemiology is to integrate more than a level of organization in design, analysis and interpretation of health problems. After presenting the main criticisms of risk-factor epidemiology focused on the individual, we will try to show how eco-epidemiology and its development could help to understand the need for a broader and integrative epidemiology, in which studies designed to identify risk factors would be balanced by studies designed to answer other questions equally vital to public health. © 2016 médecine/sciences – Inserm.

Enhanced WWTP effluent organic matter removal in hybrid ozonation-coagulation (HOC) process catalyzed by Al-based coagulant

Energy Technology Data Exchange (ETDEWEB)

Jin, Xin [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi Province, 710055 (China); Jin, Pengkang, E-mail: pkjin@hotmail.com [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi Province, 710055 (China); Hou, Rui [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi Province, 710055 (China); Yang, Lei [Department of Materials Science and Engineering, Monash University, Clayton, VIC, 3800 (Australia); Wang, Xiaochang C., E-mail: xcwang@xauat.edu.cn [School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an, Shaanxi Province, 710055 (China)

2017-04-05

Highlights: • A novel HOC process was firstly put forward to apply in wastewater reclamation. • Interactions between ozone and Al-based coagulants was found in the HOC process. • Ozonation can be catalyzed and enhanced by Al-based coagulants in the HOC process. • HOC process showed better organics removal than pre-ozonation-coagulation process. - Abstract: A novel hybrid ozonation-coagulation (HOC) process was developed for application in wastewater reclamation. In this process, ozonation and coagulation occurred simultaneously within a single unit. Compared with the conventional pre-ozonation-coagulation process, the HOC process exhibited much better performance in removing dissolved organic matters. In particular, the maximal organic matters removal efficiency was obtained at the ozone dosage of 1 mgO{sub 3}/mg DOC at each pH value (pH 5, 7 and 9). In order to interpret the mechanism of the HOC process, ozone decomposition was monitored. The results indicated that ozone decomposed much faster in the HOC process. Moreover, by using the reagent of O{sub 3}-resistant hydroxyl radical (·OH) probe compound, para-chlorobenzoic acid (pCBA), and electron paramagnetic resonance (EPR) analysis, it was observed that the HOC process generated higher content of ·OH compared with pre-ozonation process. This indicates that the ·OH oxidation reaction as the key step can be catalyzed and enhanced by Al-based coagulants and their hydrolyzed products in this developed process. Thus, based on the catalytic effects of Al-based coagulants on ozonation, the HOC process provides a promising alternative to the conventional technology for wastewater reclamation in terms of higher efficiency.

Post hoc analysis of Japanese patients from the placebo-controlled PREVAIL trial of enzalutamide in patients with chemotherapy-naive, metastatic castration-resistant prostate cancer—updated results

Science.gov (United States)

Ueda, Takeshi

2017-01-01

Abstract A post hoc analysis of interim results from PREVAIL, a Phase III, double-blind, placebo-controlled trial of men with metastatic castration-resistant prostate cancer, demonstrated that the treatment effects, safety and pharmacokinetics of enzalutamide in Japanese patients were generally consistent with those of the overall population. A recent longer term analysis of PREVAIL demonstrated continued benefit of enzalutamide treatment over placebo. Here, we report results from a post hoc analysis of Japanese patients enrolled in PREVAIL at the prespecified number of deaths for the final analysis. In Japanese patients, enzalutamide reduced the risk of death by 35% (hazard ratio, 0.65; 95% confidence interval, 0.28–1.51) and the risk of investigator-assessed radiographic progression or death by 60% (hazard ratio, 0.40; 95% confidence interval, 0.18–0.90). These results show that treatment effects and safety in Japanese patients in the final analysis of PREVAIL continued to be generally consistent with those of the overall population. PMID:28003320

Lenient vs. strict rate control in patients with atrial fibrillation and heart failure: a post-hoc analysis of the RACE II study

NARCIS (Netherlands)

Mulder, Bart A.; van Veldhuisen, Dirk J.; Crijns, Harry J. G. M.; Tijssen, Jan G. P.; Hillege, Hans L.; Alings, Marco; Rienstra, Michiel; Groenveld, Hessel F.; van den Berg, Maarten P.; van Gelder, Isabelle C.

2013-01-01

It is unknown whether lenient rate control is an acceptable strategy in patients with AF and heart failure. We evaluated differences in outcome in patients with AF and heart failure treated with lenient or strict rate control. This post-hoc analysis of the RACE II trial included patients with an

Ad hoc mobile wireless networks principles, protocols and applications

CERN Document Server

Sarkar, Subir Kumar; Puttamadappa, C

2007-01-01

Ad hoc mobile wireless networks have seen increased adaptation in a variety of disciplines because they can be deployed with simple infrastructures and virtually no central administration. In particular, the development of ad hoc wireless and sensor networks provides tremendous opportunities in areas including disaster recovery, defense, health care, and industrial environments. Ad Hoc Mobile Wireless Networks: Principles, Protocols and Applications explains the concepts, mechanisms, design, and performance of these systems. It presents in-depth explanations of the latest wireless technologies

Ad hoc mobile wireless networks principles, protocols, and applications

CERN Document Server

Sarkar, Subir Kumar

2013-01-01

The military, the research community, emergency services, and industrial environments all rely on ad hoc mobile wireless networks because of their simple infrastructure and minimal central administration. Now in its second edition, Ad Hoc Mobile Wireless Networks: Principles, Protocols, and Applications explains the concepts, mechanism, design, and performance of these highly valued systems. Following an overview of wireless network fundamentals, the book explores MAC layer, routing, multicast, and transport layer protocols for ad hoc mobile wireless networks. Next, it examines quality of serv

Outcome when adrenaline (epinephrine) was actually given vs. not given - post hoc analysis of a randomized clinical trial.

Science.gov (United States)

Olasveengen, Theresa M; Wik, Lars; Sunde, Kjetil; Steen, Petter A

2012-03-01

IV line insertion and drugs did not affect long-term survival in an out-of-hospital cardiac arrest (OHCA) randomized clinical trial (RCT). In a previous large registry study adrenaline was negatively associated with survival from OHCA. The present post hoc analysis on the RCT data compares outcomes for patients actually receiving adrenaline to those not receiving adrenaline. Patients from a RCT performed May 2003 to April 2008 were included. Three patients from the original intention-to-treat analysis were excluded due to insufficient documentation of adrenaline administration. Quality of cardiopulmonary resuscitation (CPR) and clinical outcomes were compared. Clinical characteristics were similar and CPR quality comparable and within guideline recommendations for 367 patients receiving adrenaline and 481 patients not receiving adrenaline. Odds ratio (OR) for being admitted to hospital, being discharged from hospital and surviving with favourable neurological outcome for the adrenaline vs. no-adrenaline group was 2.5 (CI 1.9, 3.4), 0.5 (CI 0.3, 0.8) and 0.4 (CI 0.2, 0.7), respectively. Ventricular fibrillation, response interval, witnessed arrest, gender, age and endotracheal intubation were confounders in multivariate logistic regression analysis. OR for survival for adrenaline vs. no-adrenaline adjusted for confounders was 0.52 (95% CI: 0.29, 0.92). Receiving adrenaline was associated with improved short-term survival, but decreased survival to hospital discharge and survival with favourable neurological outcome after OHCA. This post hoc survival analysis is in contrast to the previous intention-to-treat analysis of the same data, but agrees with previous non-randomized registry data. This shows limitations of non-randomized or non-intention-to-treat analyses. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Protecting Privacy of Shared Epidemiologic Data without Compromising Analysis Potential

Directory of Open Access Journals (Sweden)

John Cologne

2012-01-01

Full Text Available Objective. Ensuring privacy of research subjects when epidemiologic data are shared with outside collaborators involves masking (modifying the data, but overmasking can compromise utility (analysis potential. Methods of statistical disclosure control for protecting privacy may be impractical for individual researchers involved in small-scale collaborations. Methods. We investigated a simple approach based on measures of disclosure risk and analytical utility that are straightforward for epidemiologic researchers to derive. The method is illustrated using data from the Japanese Atomic-bomb Survivor population. Results. Masking by modest rounding did not adequately enhance security but rounding to remove several digits of relative accuracy effectively reduced the risk of identification without substantially reducing utility. Grouping or adding random noise led to noticeable bias. Conclusions. When sharing epidemiologic data, it is recommended that masking be performed using rounding. Specific treatment should be determined separately in individual situations after consideration of the disclosure risks and analysis needs.

Protecting Privacy of Shared Epidemiologic Data without Compromising Analysis Potential

International Nuclear Information System (INIS)

Cologne, J.; Nakashima, E.; Funamoto, S.; Grant, E.J.; Chen, Y.; Hiroaki Katayama, H.

2012-01-01

Objective. Ensuring privacy of research subjects when epidemiologic data are shared with outside collaborators involves masking (modifying) the data, but over masking can compromise utility (analysis potential). Methods of statistical disclosure control for protecting privacy may be impractical for individual researchers involved in small-scale collaborations. Methods. We investigated a simple approach based on measures of disclosure risk and analytical utility that are straightforward for epidemiologic researchers to derive. The method is illustrated using data from the Japanese Atomic-bomb Survivor population. Results. Masking by modest rounding did not adequately enhance security but rounding to remove several digits of relative accuracy effectively reduced the risk of identification without substantially reducing utility. Grouping or adding random noise led to noticeable bias. Conclusions. When sharing epidemiologic data, it is recommended that masking be performed using rounding. Specific treatment should be determined separately in individual situations after consideration of the disclosure risks and analysis needs

Performance Analysis of Routing Protocols in Ad-hoc and Sensor Networking Environments

Directory of Open Access Journals (Sweden)

L. Gavrilovska

2009-06-01

Full Text Available Ad-hoc and sensor networks are becoming an increasingly popular wireless networking concepts lately. This paper analyzes and compares prominent routing schemes in these networking environments. The knowledge obtained can serve users to better understand short range wireless network solutions thus leading to options for implementation in various scenarios. In addition, it should aid researchers develop protocol improvements reliable for the technologies of interest.

Reduced sick leave in multiple sclerosis after one year of natalizumab treatment. A prospective ad hoc analysis of the TYNERGY trial.

Science.gov (United States)

Wickström, Anne; Dahle, Charlotte; Vrethem, Magnus; Svenningsson, Anders

2014-07-01

In a retrospective study, we have previously shown that work ability was improved after the initiation of natalizumab treatment in relapsing-remitting multiple sclerosis (RRMS). In another prospective trial (TYNERGY) the effect on MS-related fatigue was evaluated after 12 months of treatment with natalizumab. A comprehensive Capacity for Work Questionnaire (CWQ) was used to collect data regarding number of working hours and sickness absence. The predefined intention-to-treat analysis regarding work ability did not, however, show significant results. The objective of this paper is to assess the amount of sick leave in RRMS before and after one year of natalizumab treatment and correlate it to fatigue and walking ability. This is a post-hoc analysis of the complete data from the CWQ used in the TYNERGY trial. MS patients receiving sickness benefit before start of treatment reduced their sickness benefit by an absolute change of 33% after one year of natalizumab treatment. Younger age and improvement of walking ability correlated significantly with reduction of sick leave. This ad-hoc analysis of prospectively collected data supported our previous retrospective study and thus indicates a positive relationship between natalizumab treatment and improvement in work ability. © The Author(s) 2013.

Epidemiologic research topics in Germany: a keyword network analysis of 2014 DGEpi conference presentations.

Science.gov (United States)

Peter, Raphael Simon; Brehme, Torben; Völzke, Henry; Muche, Rainer; Rothenbacher, Dietrich; Büchele, Gisela

2016-06-01

Knowledge of epidemiologic research topics as well as trends is useful for scientific societies, researchers and funding agencies. In recent years researchers recognized the usefulness of keyword network analysis for visualizing and analyzing scientific research topics. Therefore, we applied keyword network analysis to present an overview of current epidemiologic research topics in Germany. Accepted submissions to the 9th annual congress of the German Society for Epidemiology (DGEpi) in 2014 were used as data source. Submitters had to choose one of 19 subject areas, and were ask to provide a title, structured abstract, names of authors along with their affiliations, and a list of freely selectable keywords. Keywords had been provided for 262 (82 %) submissions, 1030 keywords in total. Overall the most common keywords were: "migration" (18 times), "prevention" (15 times), followed by "children", "cohort study", "physical activity", and "secondary data analysis" (11 times each). Some keywords showed a certain concentration under one specific subject area, e.g. "migration" with 8 of 18 in social epidemiology or "breast cancer" with 4 of 7 in cancer epidemiology. While others like "physical activity" were equally distributed over multiple subject areas (cardiovascular & metabolic diseases, ageing, methods, paediatrics, prevention & health service research). This keyword network analysis demonstrated the high diversity of epidemiologic research topics with a large number of distinct keywords as presented at the annual conference of the DGEpi.

Performance Analysis of Mobile Ad Hoc Unmanned Aerial Vehicle Communication Networks with Directional Antennas

Directory of Open Access Journals (Sweden)

Abdel Ilah Alshbatat

2010-01-01

Full Text Available Unmanned aerial vehicles (UAVs have the potential of creating an ad hoc communication network in the air. Most UAVs used in communication networks are equipped with wireless transceivers using omnidirectional antennas. In this paper, we consider a collection of UAVs that communicate through wireless links as a mobile ad-hoc network using directional antennas. The network design goal is to maximize the throughput and minimize the end-to-end delay. In this respect, we propose a new medium access control protocol for a network of UAVs with directional antennas. We analyze the communication channel between the UAVs and the effect of aircraft attitude on the network performance. Using the optimized network engineering tool (OPNET, we compare our protocol with the IEEE 802.11 protocol for omnidirectional antennas. The simulation results show performance improvement in end-to-end delay as well as throughput.

On Throughput Improvement of Wireless Ad Hoc Networks with Hidden Nodes

Science.gov (United States)

Choi, Hong-Seok; Lim, Jong-Tae

In this letter, we present the throughput analysis of the wireless ad hoc networks based on the IEEE 802.11 MAC (Medium Access Control). Especially, our analysis includes the case with the hidden node problem so that it can be applied to the multi-hop networks. In addition, we suggest a new channel access control algorithm to maximize the network throughput and show the usefulness of the proposed algorithm through simulations.

Post hoc analysis of Japanese patients from the placebo-controlled PREVAIL trial of enzalutamide in patients with chemotherapy-naive, metastatic castration-resistant prostate cancer-updated results.

Science.gov (United States)

Kimura, Go; Ueda, Takeshi

2017-03-01

A post hoc analysis of interim results from PREVAIL, a Phase III, double-blind, placebo-controlled trial of men with metastatic castration-resistant prostate cancer, demonstrated that the treatment effects, safety and pharmacokinetics of enzalutamide in Japanese patients were generally consistent with those of the overall population. A recent longer term analysis of PREVAIL demonstrated continued benefit of enzalutamide treatment over placebo. Here, we report results from a post hoc analysis of Japanese patients enrolled in PREVAIL at the prespecified number of deaths for the final analysis. In Japanese patients, enzalutamide reduced the risk of death by 35% (hazard ratio, 0.65; 95% confidence interval, 0.28-1.51) and the risk of investigator-assessed radiographic progression or death by 60% (hazard ratio, 0.40; 95% confidence interval, 0.18-0.90). These results show that treatment effects and safety in Japanese patients in the final analysis of PREVAIL continued to be generally consistent with those of the overall population. © The Author 2016. Published by Oxford University Press.

Epidemiology of RBC Transfusions in Patients With Severe Acute Kidney Injury: Analysis From the Randomized Evaluation of Normal Versus Augmented Level Study.

Science.gov (United States)

Bellomo, Rinaldo; Mårtensson, Johan; Kaukonen, Kirsi-Maija; Lo, Serigne; Gallagher, Martin; Cass, Alan; Myburgh, John; Finfer, Simon

2016-05-01

To assess the epidemiology and outcomes associated with RBC transfusion in patients with severe acute kidney injury requiring continuous renal replacement therapy. Post hoc analysis of data from a multicenter, randomized, controlled trial. Thirty-five ICUs in Australia and New Zealand. Cohort of 1,465 patients enrolled in the Randomized Evaluation of Normal versus Augmented Level replacement therapy study. Daily information on morning hemoglobin level and amount of RBC transfused were prospectively collected in the Randomized Evaluation of Normal versus Augmented Level study. We analyzed the epidemiology of such transfusions and their association with clinical outcomes. Overall, 977 patients(66.7%) received a total of 1,192 RBC units. By day 5, 785 of 977 transfused patients (80.4%) had received at least one RBC transfusion. Hemoglobin at randomization was lower in transfused than in nontransfused patients (94 vs 111 g/L; p regression analysis, RBC transfusion was independently associated with lower 90-day mortality (hazard ratio, 0.55; 95% CI, 0.38-0.79). However, we found no independent association between RBC transfusions and mortality when the analyses were restricted to patients surviving at least 5 days (hazard ratio, 1.29; 95% CI, 0.90-1.85). We found no independent association between RBC transfusion and renal replacement therapy-free days, mechanical ventilator-free days, or length of stay in ICU or hospital. In patients with severe acute kidney injury treated with continuous renal replacement therapy, we found no association of RBC transfusion with 90-day mortality or other patient-centered outcomes. The optimal hemoglobin threshold for RBC transfusion in such patients needs to be determined in future randomized controlled trials.

AD HOC Networks for the Autonomous Car

Science.gov (United States)

Ron, Davidescu; Negrus, Eugen

2017-10-01

The future of the vehicle is made of cars, roads and infrastructures connected in a two way automated communication in a holistic system. It is a mandatory to use Encryption to maintain Confidentiality, Integrity and Availability in an ad hoc vehicle network. Vehicle to Vehicle communication, requires multichannel interaction between mobile, moving and changing parties to insure the full benefit from data sharing and real time decision making, a network of such users referred as mobile ad hoc network (MANET), however as ad hoc networks were not implemented in such a scale, it is not clear what is the best method and protocol to apply. Furthermore the visibility of secure preferred asymmetric encrypted ad hoc networks in a real time environment of dense moving autonomous vehicles has to be demonstrated, In order to evaluate the performance of Ad Hoc networks in changing conditions a simulation of multiple protocols was performed on large number of mobile nodes. The following common routing protocols were tested, DSDV is a proactive protocol, every mobile station maintains a routing table with all available destinations, DSR is a reactive routing protocol which allows nodes in the MANET to dynamically discover a source route across multiple network hops, AODV is a reactive routing protocol Instead of being proactive. It minimizes the number of broadcasts by creating routes based on demand, SAODV is a secure version of AODV, requires heavyweight asymmetric cryptographic, ARIANDE is a routing protocol that relies on highly efficient symmetric cryptography the concept is primarily based on DSR. A methodical evolution was performed in a various density of transportation, based on known communication bench mark parameters including, Throughput Vs. time, Routing Load per packets and bytes. Out of the none encrypted protocols, It is clear that in terms of performance of throughput and routing load DSR protocol has a clear advantage the high node number mode. The encrypted

Research on Propagation Model of Malicious Programs in Ad Hoc Wireless Network

Directory of Open Access Journals (Sweden)

Weimin GAO

2014-01-01

Full Text Available Ad Hoc wireless network faces more security threats than traditional network due to its P2P system structure and the limited node resources. In recent years, malicious program has become one of the most important researches on international network security and information security. The research of malicious programs on wireless network has become a new research hotspot in the field of malicious programs. This paper first analyzed the Ad Hoc network system structure, security threats, the common classification of malicious programs and the bionic propagation model. Then starting from the differential equations of the SEIR virus propagation model, the question caused by introducing the SEIR virus propagation model in Ad Hoc wireless network was analyzed. This paper improved the malicious program propagation model through introducing the network topology features and concepts such as immunization delay, and designed an improved algorithm combined with the dynamic evolution of malware propagation process. Considering of the network virus propagation characteristics, network characteristics and immunization strategy to improve simulation model experiment analysis, the experimental results show that both the immunization strategy and the degrees of node can affect the propagation of malicious program.

Importance and pitfalls of molecular analysis to parasite epidemiology.

Science.gov (United States)

Constantine, Clare C

2003-08-01

Molecular tools are increasingly being used to address questions about parasite epidemiology. Parasites represent a diverse group and they might not fit traditional population genetic models. Testing hypotheses depends equally on correct sampling, appropriate tool and/or marker choice, appropriate analysis and careful interpretation. All methods of analysis make assumptions which, if violated, make the results invalid. Some guidelines to avoid common pitfalls are offered here.

Interference in wireless ad hoc networks with smart antennas

KAUST Repository

Alabdulmohsin, Ibrahim

2014-08-01

In this paper, we show that the use of directional antennas in wireless ad hoc networks can actually increase interference due to limitations of virtual carrier sensing. We derive a simple mathematical expression for interference in both physical and virtual carrier sense networks, which reveals counter-intuitively that receivers in large dense networks with directional antennas can experience larger interference than in omnidirectional networks unless the beamwidth is sufficiently small. Validity of mathematical analysis is confirmed using simulations.

agradecimento aos consultores ad hoc

Directory of Open Access Journals (Sweden)

REA Editor

2012-02-01

Full Text Available Agradecemos aos professores Nildo Viana (UFG e Flavio Sofiati (UFG, organizadores do DOSSIÊ JUVENTUDE & SOCIEDADE, e aos Consultores Ad hoc pela leitura e apreciação crítica dos artigos submetidos e publicados nesta edição.

Ad hoc networks telecommunications and game theory

CERN Document Server

Benslama, Malek; Batatia, Hadj

2015-01-01

Random SALOHA and CSMA protocols that are used to access MAC in ad hoc networks are very small compared to the multiple and spontaneous use of the transmission channel. So they have low immunity to the problems of packet collisions. Indeed, the transmission time is the critical factor in the operation of such networks. The simulations demonstrate the positive impact of erasure codes on the throughput of the transmission in ad hoc networks. However, the network still suffers from the intermittency and volatility of its efficiency throughout its operation, and it switches quickly to the satura

Vehicular ad hoc network security and privacy

CERN Document Server

Lin, X

2015-01-01

Unlike any other book in this area, this book provides innovative solutions to security issues, making this book a must read for anyone working with or studying security measures. Vehicular Ad Hoc Network Security and Privacy mainly focuses on security and privacy issues related to vehicular communication systems. It begins with a comprehensive introduction to vehicular ad hoc network and its unique security threats and privacy concerns and then illustrates how to address those challenges in highly dynamic and large size wireless network environments from multiple perspectives. This book is richly illustrated with detailed designs and results for approaching security and privacy threats.

Optimal channel choice for collaborative ad-hoc dissemination

DEFF Research Database (Denmark)

Hu, Liang; Boudec, J-Y. L.; Vojnovic, M.

2010-01-01

Collaborative ad-hoc dissemination of information has been proposed as an efficient means to disseminate information among devices in a wireless ad-hoc network. Devices help in forwarding the information channels to the entire network, by disseminating the channels they subscribe to, plus others...... by a Metropolis-Hastings sampling algorithm. We also give a variant that accounts for battery level. This leads to a practical channel selection and re-selection algorithm that can be implemented without any central control....

Les Protocoles de routage dans les réseaux mobiles Ad Hoc ...

African Journals Online (AJOL)

Dans cet article nous présentons un état de l'art sur les protocoles de routage dans les réseaux mobiles Ad hoc. Mots clés : Réseaux mobiles ad hoc/, Protocoles de routage. Routing protocols in wireless mobile ad hoc networks. Abstract:The communication between users with handheld computers interconnected through ...

A SAS(®) macro implementation of a multiple comparison post hoc test for a Kruskal-Wallis analysis.

Science.gov (United States)

Elliott, Alan C; Hynan, Linda S

2011-04-01

The Kruskal-Wallis (KW) nonparametric analysis of variance is often used instead of a standard one-way ANOVA when data are from a suspected non-normal population. The KW omnibus procedure tests for some differences between groups, but provides no specific post hoc pair wise comparisons. This paper provides a SAS(®) macro implementation of a multiple comparison test based on significant Kruskal-Wallis results from the SAS NPAR1WAY procedure. The implementation is designed for up to 20 groups at a user-specified alpha significance level. A Monte-Carlo simulation compared this nonparametric procedure to commonly used parametric multiple comparison tests. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Auto-Configuration Protocols in Mobile Ad Hoc Networks

Science.gov (United States)

Villalba, Luis Javier García; Matesanz, Julián García; Orozco, Ana Lucila Sandoval; Díaz, José Duván Márquez

2011-01-01

The TCP/IP protocol allows the different nodes in a network to communicate by associating a different IP address to each node. In wired or wireless networks with infrastructure, we have a server or node acting as such which correctly assigns IP addresses, but in mobile ad hoc networks there is no such centralized entity capable of carrying out this function. Therefore, a protocol is needed to perform the network configuration automatically and in a dynamic way, which will use all nodes in the network (or part thereof) as if they were servers that manage IP addresses. This article reviews the major proposed auto-configuration protocols for mobile ad hoc networks, with particular emphasis on one of the most recent: D2HCP. This work also includes a comparison of auto-configuration protocols for mobile ad hoc networks by specifying the most relevant metrics, such as a guarantee of uniqueness, overhead, latency, dependency on the routing protocol and uniformity. PMID:22163814

Auto-configuration protocols in mobile ad hoc networks.

Science.gov (United States)

Villalba, Luis Javier García; Matesanz, Julián García; Orozco, Ana Lucila Sandoval; Díaz, José Duván Márquez

2011-01-01

The TCP/IP protocol allows the different nodes in a network to communicate by associating a different IP address to each node. In wired or wireless networks with infrastructure, we have a server or node acting as such which correctly assigns IP addresses, but in mobile ad hoc networks there is no such centralized entity capable of carrying out this function. Therefore, a protocol is needed to perform the network configuration automatically and in a dynamic way, which will use all nodes in the network (or part thereof) as if they were servers that manage IP addresses. This article reviews the major proposed auto-configuration protocols for mobile ad hoc networks, with particular emphasis on one of the most recent: D2HCP. This work also includes a comparison of auto-configuration protocols for mobile ad hoc networks by specifying the most relevant metrics, such as a guarantee of uniqueness, overhead, latency, dependency on the routing protocol and uniformity.

SURVEI TEKNIK CLUSTERING ROUTING BERDASARKAN MOBILITAS PADA WIRELESS AD-HOC NETWORK

Directory of Open Access Journals (Sweden)

I Nyoman Trisna Wirawan

2016-01-01

Full Text Available Wireless ad-hoc merupakan sebuah skema jaringan yang didesain supaya mampu beroperasi tanpa membutuhkan infrastruktur tetap serta bersifat otonom. Teknik flooding pada proses path discovery dalam kasus wireless ad-hoc network dapat menimbulkan masalah beban jaringan yang berlebihan. Oleh karena itu, sebuah skema clustering diusulkan untuk mengurangi adanya flooding paket yang berlebihan dengan membagi node-node dalam jaringan menjadi beberapa bagian berdasarkan parameter tertentu. Teknik ini efektifuntuk mengurangi paket yang harus dilewatkan dalam jaringan. Namun masalah muncul ketika sebuah jaringan wireless ad-hoc harus membentuk sebuah cluster dengan mempertimbangkan beberapa parameter khusus. Parameter tersebut harus disesuaikan dengan kasus yang dihadapi. Pada tulisan ini akan dibahas secara khusus mengenai penerapan skema clustering dalam lingkungan wireless ad-hoc network, baik pada MANETdan penyesuaian skema clustering yang harus dilakukan pada VANET berdasarkan mobilitasnya.

New grid based test bed environment for carrying out ad-hoc networking experiments

CSIR Research Space (South Africa)

Johnson, D

2006-09-01

Full Text Available and the third is to do analysis on a real test bed network which has implemented the ad-hoc networking protocol. This paper concerns the third option. Most researchers who have done work on test bed environments have used either indoor Wifi inter-office links...

Maximization of Energy Efficiency in Wireless ad hoc and Sensor Networks With SERENA

Directory of Open Access Journals (Sweden)

Saoucene Mahfoudh

2009-01-01

Full Text Available In wireless ad hoc and sensor networks, an analysis of the node energy consumption distribution shows that the largest part is due to the time spent in the idle state. This result is at the origin of SERENA, an algorithm to SchEdule RoutEr Nodes Activity. SERENA allows router nodes to sleep, while ensuring end-to-end communication in the wireless network. It is a localized and decentralized algorithm assigning time slots to nodes. Any node stays awake only during its slot and the slots assigned to its neighbors, it sleeps the remaining time. Simulation results show that SERENA enables us to maximize network lifetime while increasing the number of user messages delivered. SERENA is based on a two-hop coloring algorithm, whose complexity in terms of colors and rounds is evaluated. We then quantify the slot reuse. Finally, we show how SERENA improves the node energy consumption distribution and maximizes the energy efficiency of wireless ad hoc and sensor networks. We compare SERENA with classical TDMA and optimized variants such as USAP in wireless ad hoc and sensor networks.

Effects of Data Replication on Data Exfiltration in Mobile Ad Hoc Networks Utilizing Reactive Protocols

Science.gov (United States)

2015-03-01

aerial vehicle VANET vehicular ad hoc network VoIP Voice over Internet Protocol VRR Virtual Ring Routing xiii EFFECTS OF DATA REPLICATION ON DATA...ad hoc networks in mobile ad hoc networks (MANETs), vehicular ad hoc networks (VANETs), and flying ad hoc net- works (FANETs). Much of the research...metric, such as capacity, congestion , power, or combinations thereof. Caro refers to two different types of ants, FANTs and BANTs which are analogous to

Atomoxetine treatment outcomes in adolescents and young adults with attention-deficit/hyperactivity disorder: results from a post hoc, pooled analysis.

Science.gov (United States)

Adler, Lenard A; Wilens, Timothy; Zhang, Shuyu; Dittmann, Ralf W; D'Souza, Deborah N; Schuh, Leslie; Durell, Todd M

2012-02-01

Many children with attention-deficit/hyperactivity disorder (ADHD) continue to experience this disorder as adults, which may, in part, be due to the discontinuity of health care that often occurs during the transition period between late adolescence and young adulthood. Although atomoxetine is reported to be efficacious in both adolescents and young adults, no longitudinal studies have been designed to assess directly the effects of atomoxetine treatment during this transition period. As a first step, we present the results of a post hoc, pooled analysis that compared the efficacy and safety profile of atomoxetine in these 2 patient populations. The aim of the present study was to assess the efficacy and safety profile of atomoxetine treatment in adolescents and young adults with ADHD. A post hoc, pooled analysis was conducted by combining data from 6 double-blind trials (6-9 weeks in duration) that studied adolescents (12-17 years of age; atomoxetine, n = 154; placebo, n = 88; mean final dose = 1.38 mg/kg) and 3 trials (10 weeks in duration) that studied young adults (18-30 years of age; atomoxetine, n = 117; placebo, n = 125; mean final dose = 1.21 mg/kg). Efficacy measures used in these analyses were ADHD Rating Scale (ADHDRS) for adolescents, Conners' Adult ADHD Rating Scale (CAARS) for young adults, and Clinical Global Impressions-ADHD-Severity (CGI-ADHD-S) for both age groups. Treatment response was defined as ≥30% reduction from baseline in total ADHD symptom score. In adolescents (mean age, 13.4 years), atomoxetine improved ADHD significantly compared with placebo (ADHDRS total score change, -12.9 vs -7.5; P young adults (mean age, 24.7 years), atomoxetine improved ADHD significantly (CAARS total score change, -13.6 vs -7.7; P young adults (13.7% vs 4.8%, respectively; P = 0.024); in adolescents no statistically significant differences were observed in frequency of nausea between atomoxetine and placebo treatment (4.5% vs 10.2%, respectively; P = 0

Australasian disasters of national significance: an epidemiological analysis, 1900-2012.

Science.gov (United States)

Bradt, David A; Bartley, Bruce; Hibble, Belinda A; Varshney, Kavita

2015-04-01

A regional epidemiological analysis of Australasian disasters in the 20th century to present was undertaken to examine trends in disaster epidemiology; to characterise the impacts on civil society through disaster policy, practice and legislation; and to consider future potential limitations in national disaster resilience. A surveillance definition of disaster was developed conforming to the Centre for Research on the Epidemiology of Disasters (CRED) criteria (≥10 deaths, ≥100 affected, or declaration of state emergency or appeal for international assistance). The authors then applied economic and legislative inclusion criteria to identify additional disasters of national significance. The surveillance definition yielded 165 disasters in the period, from which 65 emerged as disasters of national significance. There were 38 natural disasters, 22 technological disasters, three offshore terrorist attacks and two domestic mass shootings. Geographic analysis revealed that states with major population centres experienced the vast majority of disasters of national significance. Timeline analysis revealed an increasing incidence of disasters since the 1980s, which peaked in the period 2005-2009. Recent seasonal bushfires and floods have incurred the highest death toll and economic losses in Australasian history. Reactive hazard-specific legislation emerged after all terrorist acts and after most disasters of national significance. Timeline analysis reveals an increasing incidence in natural disasters over the past 15 years, with the most lethal and costly disasters occurring in the past 3 years. Vulnerability to disaster in Australasia appears to be increasing. Reactive legislation is a recurrent feature of Australasian disaster response that suggests legislative shortsightedness and a need for comprehensive all-hazards model legislation in the future. © 2015 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

Sensor and ad-hoc networks theoretical and algorithmic aspects

CERN Document Server

Makki, S Kami; Pissinou, Niki; Makki, Shamila; Karimi, Masoumeh; Makki, Kia

2008-01-01

This book brings together leading researchers and developers in the field of wireless sensor networks to explain the special problems and challenges of the algorithmic aspects of sensor and ad-hoc networks. The book also fosters communication not only between the different sensor and ad-hoc communities, but also between those communities and the distributed systems and information systems communities. The topics addressed pertain to the sensors and mobile environment.

Energy Efficient Probabilistic Broadcasting for Mobile Ad-Hoc Network

Science.gov (United States)

Kumar, Sumit; Mehfuz, Shabana

2017-06-01

In mobile ad-hoc network (MANETs) flooding method is used for broadcasting route request (RREQ) packet from one node to another node for route discovery. This is the simplest method of broadcasting of RREQ packets but it often results in broadcast storm problem, originating collisions and congestion of packets in the network. A probabilistic broadcasting is one of the widely used broadcasting scheme for route discovery in MANETs and provides solution for broadcasting storm problem. But it does not consider limited energy of the battery of the nodes. In this paper, a new energy efficient probabilistic broadcasting (EEPB) is proposed in which probability of broadcasting RREQs is calculated with respect to remaining energy of nodes. The analysis of simulation results clearly indicate that an EEPB route discovery scheme in ad-hoc on demand distance vector (AODV) can increase the network lifetime with a decrease in the average power consumption and RREQ packet overhead. It also decreases the number of dropped packets in the network, in comparison to other EEPB schemes like energy constraint gossip (ECG), energy aware gossip (EAG), energy based gossip (EBG) and network lifetime through energy efficient broadcast gossip (NEBG).

PERFORMANCE ANALYSIS OF DSR ROUTING PROTOCOL UNDER ENERGY BASED SELFISH ATTACK IN MOBILE AD HOC NETWORKS

Directory of Open Access Journals (Sweden)

T.V.P.Sundararajan

2010-06-01

Full Text Available Mobile Ad hoc Networks (MANETs rely on the cooperation of all participating nodes to provide the fundamental operations such as routing and data forwarding. However, due to the open structure and scarcely available battery-based energy, node misbehaviors may exist.[1]. One such routing misbehavior is that some selfish nodes will participate in the route discovery and maintenance processes but refuse to forward data packets. This paper pointed out Energy based selfish nodes (EBSN where these selfish nodes tend to use the network but do not cooperate, saving battery life for their own communications [2],[3]. We present a simulation study of the effects of Energy based selfish nodes (EBSN on DSR routing protocol and its impact over network performance in terms of throughput and delay of a mobile ad hoc network where a defined percentage of nodes were misbehaving.

Multichannel MAC Layer In Mobile Ad—Hoc Network

Science.gov (United States)

Logesh, K.; Rao, Samba Siva

2010-11-01

This paper we presented the design objectives and technical challenges in Multichannel MAC protocols in Mobile Ad-hoc Network. In IEEE 802.11 a/b/g standards allow use of multiple channels, only a single channel is popularly used, due to the lack of efficient protocols that enable use of Multiple Channels. Even though complex environments in ad hoc networks require a combined control of physical (PHY) and medium access control (MAC) layers resources in order to optimize performance. And also we discuss the characteristics of cross-layer frame and give a multichannel MAC approach.

Sustained disease-activity-free status in patients with relapsing-remitting multiple sclerosis treated with cladribine tablets in the CLARITY study: a post-hoc and subgroup analysis

DEFF Research Database (Denmark)

Giovannoni, Gavin; Cook, Stuart; Rammohan, Kottil

2011-01-01

/kg over 96 weeks was more effective than placebo. Achieving sustained freedom from disease activity is becoming a viable treatment goal in RRMS; we therefore aimed to assess the effects of cladribine on this composite outcome measure by doing a post-hoc analysis of data from the CLARITY study....

Securing DSR with mobile agents in wireless ad hoc networks

Directory of Open Access Journals (Sweden)

Ahmed Abosamra

2011-03-01

Full Text Available Ad hoc wireless network consists of a set of wireless nodes communicating with each other without a pre-defined infrastructure. They communicate by forwarding packets which can reach wireless nodes that do not exist in the range of the direct radio transmission. Designing ad hoc network routing protocols is a challenging task because of its decentralized infrastructure which makes securing ad hoc networks more and more challenging. Dynamic Source Routing (DSR protocol is a popular routing protocol designed for use in wireless ad hoc networks. Mobile agent is a promising technology used in diverse fields of network applications. In this paper, we try to implement DSR using mobile agents for securing this type of wireless network. Hybrid encryption technique (symmetric key encryption/public key encryption is used to improve performance; where symmetric keys are used to encrypt routing data to authenticate and authorize node sending data, while, public keys are used for the exchange of symmetric keys between nodes. We found that DSR may be secured using mobile agents with competitive performance.

Sigsearch: a new term for post hoc unplanned search for statistically significant relationships with the intent to create publishable findings.

Science.gov (United States)

Hashim, Muhammad Jawad

2010-09-01

Post-hoc secondary data analysis with no prespecified hypotheses has been discouraged by textbook authors and journal editors alike. Unfortunately no single term describes this phenomenon succinctly. I would like to coin the term "sigsearch" to define this practice and bring it within the teaching lexicon of statistics courses. Sigsearch would include any unplanned, post-hoc search for statistical significance using multiple comparisons of subgroups. It would also include data analysis with outcomes other than the prespecified primary outcome measure of a study as well as secondary data analyses of earlier research.

Post-hoc analysis of randomised, placebo-controlled, double-blind study (MCI186-19) of edaravone (MCI-186) in amyotrophic lateral sclerosis.

Science.gov (United States)

Takei, Koji; Takahashi, Fumihiro; Liu, Shawn; Tsuda, Kikumi; Palumbo, Joseph

2017-10-01

Post-hoc analyses of the ALS Functional Rating Scale-Revised (ALSFRS-R) score data, the primary endpoint in the 24-week double-blind placebo-controlled study of edaravone (MCI186-19, NCT01492686), were performed to confirm statistical robustness of the result. The previously reported original analysis had used a last observation carried forward (LOCF) method and also excluded patients with fewer than three completed treatment cycles. The post-hoc sensitivity analyses used different statistical methods as follows: 1) including all patients regardless of treatment cycles received (ALL LOCF); 2) a mixed model for repeated measurements (MMRM) analysis; and 3) the Combined Assessment of Function and Survival (CAFS) endpoint. Findings were consistent with the original primary analysis in showing superiority of edaravone over placebo. We also investigated the distribution of change in ALSFRS-R total score across all patients in the study as well as which ALSFRS-R items and domains may have contributed to the overall efficacy findings. The distribution of changes in ALSFRS-R total score from baseline to the end of cycle 6 (ALL LOCF) shifted in favour of edaravone compared to placebo. Edaravone was descriptively favoured for each ALSFRS-R item and each of the four ALSFRS-R domains at the end of cycle 6 (ALL LOCF), suggesting a generalised effect of edaravone in slowing functional decline across all anatomical regions. The effect of edaravone appeared to be similar in patients with bulbar onset and limb onset. Together, these observations would be consistent with its putative neuroprotective effects against the development of oxidative damage unspecific to anatomical regions.

A post-hoc subgroup analysis of outcomes in the first phase III clinical study of edaravone (MCI-186) in amyotrophic lateral sclerosis.

Science.gov (United States)

2017-10-01

Our first phase III study failed to demonstrate efficacy of edaravone for amyotrophic lateral sclerosis (ALS) compared to placebo. Here, we performed post-hoc subgroup analysis to identify a subgroup in which edaravone might be expected to show efficacy. We focussed on two newly defined subgroups, EESP and dpEESP2y. The EESP was defined as the efficacy-expected subpopulation with % forced vital capacity of ≥80%, and ≥2 points for all item scores in the revised ALS functional rating scale (ALSFRS-R) score before treatment. The dpEESP2y was defined as the greater-efficacy-expected subpopulation within EESP having a diagnosis of 'definite' or 'probable' ALS according to the El Escorial revised Airlie House diagnostic criteria and onset of disease within two years. The primary endpoint of the post-hoc analysis was the change in the ALSFRS-R score during the 24-week treatment period. The intergroup differences of the least-squares mean change in the ALSFRS-R score ± standard error during treatment were 0.65 ± 0.78 (p = 0.4108) in the full analysis set, 2.20 ± 1.03 (p = 0.0360) in the EESP, and 3.01 ± 1.33 (p = 0.0270) in the dpEESP2y. Edaravone exhibited efficacy in the dpEESP2y subgroup. A further clinical study in patients meeting dpEESP2y criteria is warranted.

Model checking mobile ad hoc networks

NARCIS (Netherlands)

Ghassemi, Fatemeh; Fokkink, Wan

2016-01-01

Modeling arbitrary connectivity changes within mobile ad hoc networks (MANETs) makes application of automated formal verification challenging. We use constrained labeled transition systems as a semantic model to represent mobility. To model check MANET protocols with respect to the underlying

MWAHCA: a multimedia wireless ad hoc cluster architecture.

Science.gov (United States)

Diaz, Juan R; Lloret, Jaime; Jimenez, Jose M; Sendra, Sandra

2014-01-01

Wireless Ad hoc networks provide a flexible and adaptable infrastructure to transport data over a great variety of environments. Recently, real-time audio and video data transmission has been increased due to the appearance of many multimedia applications. One of the major challenges is to ensure the quality of multimedia streams when they have passed through a wireless ad hoc network. It requires adapting the network architecture to the multimedia QoS requirements. In this paper we propose a new architecture to organize and manage cluster-based ad hoc networks in order to provide multimedia streams. Proposed architecture adapts the network wireless topology in order to improve the quality of audio and video transmissions. In order to achieve this goal, the architecture uses some information such as each node's capacity and the QoS parameters (bandwidth, delay, jitter, and packet loss). The architecture splits the network into clusters which are specialized in specific multimedia traffic. The real system performance study provided at the end of the paper will demonstrate the feasibility of the proposal.

MWAHCA: A Multimedia Wireless Ad Hoc Cluster Architecture

Directory of Open Access Journals (Sweden)

Juan R. Diaz

2014-01-01

Full Text Available Wireless Ad hoc networks provide a flexible and adaptable infrastructure to transport data over a great variety of environments. Recently, real-time audio and video data transmission has been increased due to the appearance of many multimedia applications. One of the major challenges is to ensure the quality of multimedia streams when they have passed through a wireless ad hoc network. It requires adapting the network architecture to the multimedia QoS requirements. In this paper we propose a new architecture to organize and manage cluster-based ad hoc networks in order to provide multimedia streams. Proposed architecture adapts the network wireless topology in order to improve the quality of audio and video transmissions. In order to achieve this goal, the architecture uses some information such as each node’s capacity and the QoS parameters (bandwidth, delay, jitter, and packet loss. The architecture splits the network into clusters which are specialized in specific multimedia traffic. The real system performance study provided at the end of the paper will demonstrate the feasibility of the proposal.

Algorithmic, LOCS and HOCS (chemistry) exam questions: performance and attitudes of college students

Science.gov (United States)

Zoller, Uri

2002-02-01

The performance of freshmen biology and physics-mathematics majors and chemistry majors as well as pre- and in-service chemistry teachers in two Israeli universities on algorithmic (ALG), lower-order cognitive skills (LOCS), and higher-order cognitive skills (HOCS) chemistry exam questions were studied. The driving force for the study was an interest in moving science and chemistry instruction from an algorithmic and factual recall orientation dominated by LOCS, to a decision-making, problem-solving and critical system thinking approach, dominated by HOCS. College students' responses to the specially designed ALG, LOCS and HOCS chemistry exam questions were scored and analysed for differences and correlation between the performance means within and across universities by the questions' category. This was followed by a combined student interview - 'speaking aloud' problem solving session for assessing the thinking processes involved in solving these types of questions and the students' attitudes towards them. The main findings were: (1) students in both universities performed consistently in each of the three categories in the order of ALG > LOCS > HOCS; their 'ideological' preference, was HOCS > algorithmic/LOCS, - referred to as 'computational questions', but their pragmatic preference was the reverse; (2) success on algorithmic/LOCS does not imply success on HOCS questions; algorithmic questions constitute a category on its own as far as students success in solving them is concerned. Our study and its results support the effort being made, worldwide, to integrate HOCS-fostering teaching and assessment strategies and, to develop HOCS-oriented science-technology-environment-society (STES)-type curricula within science and chemistry education.

Neuromathematical Trichotomous Mixed Methods Analysis: Using the Neuroscientific Tri-Squared Test Statistical Metric as a Post Hoc Analytic to Determine North Carolina School of Science and Mathematics Leadership Efficacy

Science.gov (United States)

Osler, James Edward, II; Mason, Letita R.

2016-01-01

This study examines the leadership efficacy amongst graduates of The North Carolina School of Science and Mathematics (NCSSM) for the classes of 2000 through 2007 from a neuroscientific and neuromathematic perspective. NCSSM alumni (as the primary unit of analysis) were examined using a novel neuromathematic post hoc method of analysis. This study…

Internet-Based Mobile Ad Hoc Networking (Preprint)

National Research Council Canada - National Science Library

Corson, M. S; Macker, Joseph P; Cirincione, Gregory H

1999-01-01

Internet-based Mobile Ad Hoc Networking is an emerging technology that supports self-organizing, mobile networking infrastructures, and is one which appears well-suited for use in future commercial...

A Clustering Routing Protocol for Mobile Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Jinke Huang

2016-01-01

Full Text Available The dynamic topology of a mobile ad hoc network poses a real challenge in the design of hierarchical routing protocol, which combines proactive with reactive routing protocols and takes advantages of both. And as an essential technique of hierarchical routing protocol, clustering of nodes provides an efficient method of establishing a hierarchical structure in mobile ad hoc networks. In this paper, we designed a novel clustering algorithm and a corresponding hierarchical routing protocol for large-scale mobile ad hoc networks. Each cluster is composed of a cluster head, several cluster gateway nodes, several cluster guest nodes, and other cluster members. The proposed routing protocol uses proactive protocol between nodes within individual clusters and reactive protocol between clusters. Simulation results show that the proposed clustering algorithm and hierarchical routing protocol provide superior performance with several advantages over existing clustering algorithm and routing protocol, respectively.

Multiagent Based Information Dissemination in Vehicular Ad Hoc Networks

Directory of Open Access Journals (Sweden)

S.S. Manvi

2009-01-01

Full Text Available Vehicular Ad hoc Networks (VANETs are a compelling application of ad hoc networks, because of the potential to access specific context information (e.g. traffic conditions, service updates, route planning and deliver multimedia services (Voice over IP, in-car entertainment, instant messaging, etc.. This paper proposes an agent based information dissemination model for VANETs. A two-tier agent architecture is employed comprising of the following: 1 'lightweight', network-facing, mobile agents; 2 'heavyweight', application-facing, norm-aware agents. The limitations of VANETs lead us to consider a hybrid wireless network architecture that includes Wireless LAN/Cellular and ad hoc networking for analyzing the proposed model. The proposed model provides flexibility, adaptability and maintainability for traffic information dissemination in VANETs as well as supports robust and agile network management. The proposed model has been simulated in various network scenarios to evaluate the effectiveness of the approach.

Formal reconstruction of attack scenarios in mobile ad hoc and sensor networks

Directory of Open Access Journals (Sweden)

Rekhis Slim

2011-01-01

Full Text Available Abstract Several techniques of theoretical digital investigation are presented in the literature but most of them are unsuitable to cope with attacks in wireless networks, especially in Mobile Ad hoc and Sensor Networks (MASNets. In this article, we propose a formal approach for digital investigation of security attacks in wireless networks. We provide a model for describing attack scenarios in a wireless environment, and system and network evidence generated consequently. The use of formal approaches is motivated by the need to avoid ad hoc generation of results that impedes the accuracy of analysis and integrity of investigation. We develop an inference system that integrates the two types of evidence, handles incompleteness and duplication of information in them, and allows possible and provable actions and attack scenarios to be generated. To illustrate the proposal, we consider a case study dealing with the investigation of a remote buffer overflow attack.

DESAIN ALGORITMA DAN SIMULASI ROUTING UNTUK GATEWAY AD HOC WIRELESS NETWORKS

Directory of Open Access Journals (Sweden)

Nixson Meok

2009-12-01

Full Text Available   Routing protocol to the wireless ad hoc networks is very needed in the communication process between some terminals, to send the data packet through one or several node(s to the destination address where the network typology is always changing. Many previous works that discussed about routing ad hoc both for manet (mobile ad hoc networks and wireless networks, but the emphasis have more focus on comparing the performance of several routing ad hoc. While in this work, there is a bulding of routing algorithm model to gateway in land to the nodes that analogized as a boat that move on the sea. With the assumption that the communication inter terminals to radio band of Very High Frequency, thus algorithm that built in the simulation based on the range gap of the HF frequency. The result of this simulation will be developed as the platform to implement the service development of multiuser communication

Student Self-Assessment in HOCS Science Examinations: Is There a Problem?

Science.gov (United States)

Zoller, Uri; Ben-Chaim, David

1998-06-01

A specially-designed self-assessment questionnaire (SAQHOCS), containing higher-order cognitive skills (HOCS)-type questions, was administered to 71 biology majors, enrolled in a four-year college program. The gap between students' self-assessment marking, and that of their HOCS-biased teachers (the authors), is accounted for by the prevailing LOCS-orientation and the "testing culture"—a total separation between testing and learning—in contemporary science teaching. The majority of the students in the study evaluated themselves as capable of self-assessment, and felt reasonably confident in doing so. They were quite reserved as far as the applicability of the self-assessment method to nonalgorithmic ("correct/incorrect") questions is concerned. The results of this study suggest that the potential for student self-assessment within college science teaching and learning exists. However, still a great purposed effort in HOCS-oriented teaching and learning is required in order for the student self-assessment practice to become a routine integral component of HOCS science examinations.

Quantum load balancing in ad hoc networks

Science.gov (United States)

Hasanpour, M.; Shariat, S.; Barnaghi, P.; Hoseinitabatabaei, S. A.; Vahid, S.; Tafazolli, R.

2017-06-01

This paper presents a novel approach in targeting load balancing in ad hoc networks utilizing the properties of quantum game theory. This approach benefits from the instantaneous and information-less capability of entangled particles to synchronize the load balancing strategies in ad hoc networks. The quantum load balancing (QLB) algorithm proposed by this work is implemented on top of OLSR as the baseline routing protocol; its performance is analyzed against the baseline OLSR, and considerable gain is reported regarding some of the main QoS metrics such as delay and jitter. Furthermore, it is shown that QLB algorithm supports a solid stability gain in terms of throughput which stands a proof of concept for the load balancing properties of the proposed theory.

Two-terminal reliability analyses for a mobile ad hoc wireless network

International Nuclear Information System (INIS)

Cook, Jason L.; Ramirez-Marquez, Jose Emmanuel

2007-01-01

Reliability is one of the most important performance measures for emerging technologies. For these systems, shortcomings are often overlooked in early releases as the cutting edge technology overshadows a fragile design. Currently, the proliferation of the mobile ad hoc wireless networks (MAWN) is moving from cutting edge to commodity and thus, reliable performance will be expected. Generally, ad hoc networking is applied for the flexibility and mobility it provides. As a result, military and first responders employ this network scheme and the reliability of the network becomes paramount. To ensure reliability is achieved, one must first be able to analyze and calculate the reliability of the MAWN. This work describes the unique attributes of the MAWN and how the classical analysis of network reliability, where the network configuration is known a priori, can be adjusted to model and analyze this type of network. The methods developed acknowledge the dynamic and scalable nature of the MAWN along with its absence of infrastructure. Thus, the methods rely on a modeling approach that considers the probabilistic formation of different network configurations in a MAWN. Hence, this paper proposes reliability analysis methods that consider the effect of node mobility and the continuous changes in the network's connectivity

Global foot-and-mouth disease research update and gap analysis: 2 - epidemiology, wildlife and economics

Science.gov (United States)

In 2014, the Global Foot-and-mouth disease Research ings in the fields of (i) epidemiology, (ii) wildlife and (iii) Alliance (GFRA) conducted a gap analysis of foot-and- economics. Although the three sections, epidemiology, wildlife and economics are presented as separate entities, the fields are ...

Recent development in wireless sensor and ad-hoc networks

CERN Document Server

Li, Xiaolong; Yang, Yeon-Mo

2015-01-01

Wireless Sensor Network (WSN) consists of numerous physically distributed autonomous devices used for sensing and monitoring the physical and/or environmental conditions. A WSN uses a gateway that provides wireless connectivity to the wired world as well as distributed networks. There are many open problems related to Ad-Hoc networks and its applications. Looking at the expansion of the cellular infrastructure, Ad-Hoc network may be acting as the basis of the 4th generation wireless technology with the new paradigm of ‘anytime, anywhere communications’. To realize this, the real challenge would be the security, authorization and management issues of the large scale WSNs. This book is an edited volume in the broad area of WSNs. The book covers various chapters like Multi-Channel Wireless Sensor Networks, its Coverage, Connectivity as well as Deployment. It covers comparison of various communication protocols and algorithms such as MANNET, ODMRP and ADMR Protocols for Ad hoc Multicasting, Location Based C...

A flow level model for wireless multihop ad hoc network throughput

NARCIS (Netherlands)

Coenen, Tom Johannes Maria; van den Berg, Hans Leo; Boucherie, Richardus J.

2005-01-01

A flow level model for multihop wireless ad hoc networks is presented in this paper. Using a flow level view, we show the main properties and modeling challenges for ad hoc networks. Considering different scenarios, a multihop WLAN and a serial network with a TCP-like flow control protocol, we

Supporting Dynamic Ad hoc Collaboration Capabilities

CERN Document Server

Agarwal, D

2003-01-01

Modern HENP experiments such as CMS and Atlas involve as many as 2000 collaborators around the world. Collaborations this large will be unable to meet often enough to support working closely together. Many of the tools currently available for collaboration focus on heavy-weight applications such as videoconferencing tools. While these are important, there is a more basic need for tools that support connecting physicists to work together on an ad hoc or continuous basis. Tools that support the day-to-day connectivity and underlying needs of a group of collaborators are important for providing light-weight, non-intrusive, and flexible ways to work collaboratively. Some example tools include messaging, file-sharing, and shared plot viewers. An important component of the environment is a scalable underlying communication framework. In this paper we will describe our current progress on building a dynamic and ad hoc collaboration environment and our vision for its evolution into a HENP collaboration environment.

Supporting Dynamic Ad hoc Collaboration Capabilities

International Nuclear Information System (INIS)

Agarwal, Deborah A.; Berket, Karlo

2003-01-01

Modern HENP experiments such as CMS and Atlas involve as many as 2000 collaborators around the world. Collaborations this large will be unable to meet often enough to support working closely together. Many of the tools currently available for collaboration focus on heavy-weight applications such as videoconferencing tools. While these are important, there is a more basic need for tools that support connecting physicists to work together on an ad hoc or continuous basis. Tools that support the day-to-day connectivity and underlying needs of a group of collaborators are important for providing light-weight, non-intrusive, and flexible ways to work collaboratively. Some example tools include messaging, file-sharing, and shared plot viewers. An important component of the environment is a scalable underlying communication framework. In this paper we will describe our current progress on building a dynamic and ad hoc collaboration environment and our vision for its evolution into a HENP collaboration environment

Does the effect of one-day simulation team training in obstetric emergencies decline within one year? A post-hoc analysis of a multicentre cluster randomised controlled trial

NARCIS (Netherlands)

van de Ven, J.; Fransen, A F; Schuit, E.; van Runnard Heimel, P.J.; Mol, Ben W.; Oei, Swan G.

2017-01-01

Does the effect of one-day simulation team training in obstetric emergencies decline within one year? A post-hoc analysis of a multicentre cluster randomised controlled trial. J van de Ven, AF Fransen, E Schuit, PJ van Runnard Heimel, BW Mol, SG Oei Objective To investigate whether the effect of a

Twenty-One at TREC-7: ad-hoc and cross-language track

NARCIS (Netherlands)

Hiemstra, Djoerd; Kraaij, Wessel; Voorhees, E.M; Harman, D.K.

1999-01-01

This paper describes the official runs of the Twenty-One group for TREC-7. The Twenty-One group participated in the ad-hoc and the cross-language track and made the following accomplishments: We developed a new weighting algorithm, which outperforms the popular Cornell version of BM25 on the ad-hoc

Wireless ad hoc and sensor networks management, performance, and applications

CERN Document Server

He, Jing

2013-01-01

Although wireless sensor networks (WSNs) have been employed across a wide range of applications, there are very few books that emphasize the algorithm description, performance analysis, and applications of network management techniques in WSNs. Filling this need, Wireless Ad Hoc and Sensor Networks: Management, Performance, and Applications summarizes not only traditional and classical network management techniques, but also state-of-the-art techniques in this area. The articles presented are expository, but scholarly in nature, including the appropriate history background, a review of current

Regressive research: The pitfalls of post hoc data selection in the study of unconscious mental processes.

Science.gov (United States)

Shanks, David R

2017-06-01

Many studies of unconscious processing involve comparing a performance measure (e.g., some assessment of perception or memory) with an awareness measure (such as a verbal report or a forced-choice response) taken either concurrently or separately. Unconscious processing is inferred when above-chance performance is combined with null awareness. Often, however, aggregate awareness is better than chance, and data analysis therefore employs a form of extreme group analysis focusing post hoc on participants, trials, or items where awareness is absent or at chance. The pitfalls of this analytic approach are described with particular reference to recent research on implicit learning and subliminal perception. Because of regression to the mean, the approach can mislead researchers into erroneous conclusions concerning unconscious influences on behavior. Recommendations are made about future use of post hoc selection in research on unconscious cognition.

Performance analysis and implementation of proposed mechanism for detection and prevention of security attacks in routing protocols of vehicular ad-hoc network (VANET

Directory of Open Access Journals (Sweden)

Parul Tyagi

2017-07-01

Full Text Available Next-generation communication networks have become widely popular as ad-hoc networks, broadly categorized as the mobile nodes based on mobile ad-hoc networks (MANET and the vehicular nodes based vehicular ad-hoc networks (VANET. VANET is aimed at maintaining safety to vehicle drivers by begin autonomous communication with the nearby vehicles. Each vehicle in the ad-hoc network performs as an intelligent mobile node characterized by high mobility and formation of dynamic networks. The ad-hoc networks are decentralized dynamic networks that need efficient and secure communication requirements due to the vehicles being persistently in motion. These networks are more susceptible to various attacks like Warm Hole attacks, denial of service attacks and Black Hole Attacks. The paper is a novel attempt to examine and investigate the security features of the routing protocols in VANET, applicability of AODV (Ad hoc On Demand protocol to detect and tackle a particular category of network attacks, known as the Black Hole Attacks. A new algorithm is proposed to enhance the security mechanism of AODV protocol and to introduce a mechanism to detect Black Hole Attacks and to prevent the network from such attacks in which source node stores all route replies in a look up table. This table stores the sequences of all route reply, arranged in ascending order using PUSH and POP operations. The priority is calculated based on sequence number and discard the RREP having presumably very high destination sequence number. The result show that proposed algorithm for detection and prevention of Black Hole Attack increases security in Intelligent Transportation System (ITS and reduces the effect of malicious node in the VANET. NCTUNs simulator is used in this research work.

NDN-CRAHNs: Named Data Networking for Cognitive Radio Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Rana Asif Rehman

2015-01-01

Full Text Available Named data networking (NDN is a newly proposed paradigm for future Internet, in which communication among nodes is based on data names, decoupling from their locations. In dynamic and self-organized cognitive radio ad hoc networks (CRAHNs, it is difficult to maintain end-to-end connectivity between ad hoc nodes especially in the presence of licensed users and intermittent wireless channels. Moreover, IP-based CRAHNs have several issues like scalability, inefficient-mapping, poor resource utilization, and location dependence. By leveraging the advantages of NDN, in this paper, we propose a new cross layer fine-grained architecture called named data networking for cognitive radio ad hoc networks (NDN-CRAHNs. The proposed architecture provides distinct features such as in-networking caching, security, scalability, and multipath routing. The performances of the proposed scheme are evaluated comparing to IP-based scheme in terms of average end-to-end delay and packet delivery ratio. Simulation results show that the proposed scheme is effective in terms of average contents download time and packet delivery ratios comparing to conventional cognitive radio ad hoc networks.

[Bibliometric analysis of scientific articles on epidemiological study of burns in China].

Science.gov (United States)

Cheng, W F; Shen, Z A; Zhao, D X; Li, D W; Shang, Y R

2017-04-20

Objective: To analyze the current status of epidemiological study of burns in China, and to explore the related strategies. Methods: Retrospective or cross-sectional scientific articles in Chinese or English on epidemiological study of burns in China published from January 2005 to December 2015 were systemically retrieved from 4 databases. The databases include PubMed, Embase, China Biology Medicine disc, and Chinese Journals Full - text Database . From the results retrieved, data with regard to publication year, journal distribution, number of institutions participated in the study, affiliation of the first author and its location, and admission time span and age of patients in all the scientific articles were collected. Furthermore, the definition of age range and the grouping method of age of pediatric patients in English articles on epidemiological study of pediatric burns of China were recorded. Data were processed with descriptive statistical analysis. Results: A total of 256 scientific articles conforming to the study criteria were retrieved, among which 214 (83.59%) articles were in Chinese, and 42 (16.41%) articles were in English; 242 (94.53%) articles were retrospective studies, and 14 (5.47%) articles were cross-sectional studies. During the 11 years, the number of the relevant articles was fluctuant on the whole. The scientific articles were published in 130 journals, with 42 English articles in source journals for SCIENCE CITATION INDEX EXPANDED - JOURNAL LIST, accounting for 16.41%, and 116 Chinese articles in Source Journal for Chinese Scientific and Technical Papers, accounting for 45.31%. Totally 215 (83.98%) articles were single-center studies, and 29 (11.33%) articles were multicenter studies which were conducted by three or more centers. The number of affiliations of the first author of articles was 161 in total. The top 10 institutions regarding the article publishing number published 58 articles, accounting for 22.66%. Scientific articles on

Packets Distributing Evolutionary Algorithm Based on PSO for Ad Hoc Network

Science.gov (United States)

Xu, Xiao-Feng

2018-03-01

Wireless communication network has such features as limited bandwidth, changeful channel and dynamic topology, etc. Ad hoc network has lots of difficulties in accessing control, bandwidth distribution, resource assign and congestion control. Therefore, a wireless packets distributing Evolutionary algorithm based on PSO (DPSO)for Ad Hoc Network is proposed. Firstly, parameters impact on performance of network are analyzed and researched to obtain network performance effective function. Secondly, the improved PSO Evolutionary Algorithm is used to solve the optimization problem from local to global in the process of network packets distributing. The simulation results show that the algorithm can ensure fairness and timeliness of network transmission, as well as improve ad hoc network resource integrated utilization efficiency.

The post hoc use of randomised controlled trials to explore drug associated cancer outcomes

DEFF Research Database (Denmark)

Stefansdottir, Gudrun; Zoungas, Sophia; Chalmers, John

2013-01-01

on public health before proper regulatory action can be taken. This paper aims to discuss challenges of exploring drug-associated cancer outcomes by post-hoc analyses of Randomised controlled trials (RCTs) designed for other purposes. METHODOLOGICAL CHALLENGES TO CONSIDER: We set out to perform a post......-hoc nested case-control analysis in the ADVANCE trial in order to examine the association between insulin use and cancer. We encountered several methodological challenges that made the results difficult to interpret, including short duration of exposure of interest, lack of power, and correlation between...... exposure and potential confounders. Considering these challenges, we concluded that using the data would not enlighten the discussion about insulin use and cancer risk and only serve to further complicate any understanding. Therefore, we decided to use our experience to illustrate methodological challenges...

A Framework for Speech Enhancement with Ad Hoc Microphone Arrays

DEFF Research Database (Denmark)

Tavakoli, Vincent Mohammad; Jensen, Jesper Rindom; Christensen, Mads Græsbøll

2016-01-01

Speech enhancement is vital for improved listening practices. Ad hoc microphone arrays are promising assets for this purpose. Most well-established enhancement techniques with conventional arrays can be adapted into ad hoc scenarios. Despite recent efforts to introduce various ad hoc speech...... enhancement apparatus, a common framework for integration of conventional methods into this new scheme is still missing. This paper establishes such an abstraction based on inter and intra sub-array speech coherencies. Along with measures for signal quality at the input of sub-arrays, a measure of coherency...... is proposed both for sub-array selection in local enhancement approaches, and also for selecting a proper global reference when more than one sub-array are used. Proposed methods within this framework are evaluated with regard to quantitative and qualitative measures, including array gains, the speech...

Dynamic Path Analysis in Life-Course Epidemiology

DEFF Research Database (Denmark)

Gamborg, Michael Orland; Boje Jensen, Gorm; Sørensen, Thorkild I.A.

2011-01-01

it works through other risk factors. In this paper, the dynamic path analysis model is presented as a tool to analyze these dynamic mechanisms in life-course epidemiology. A key feature of dynamic path analysis is its ability to decompose the total effect of a risk factor into a direct effect (not mediated...... by other variables) and indirect effects (mediated through other variables). This is illustrated by examining the associations between repeated measurements of body mass index (BMI) and systolic blood pressure (SBP) and the risk of CHD in a sample of Danish men between 1976 and 2006. The effect of baseline...... BMI on the risk of CHD is decomposed into a direct effect and indirect effects going through later BMI, concurrent SBP, or later SBP. In conclusion, dynamic path analysis is a flexible tool that by the decomposition of effects can be used to increase the understanding of mechanisms that underlie...

Illustrating, Quantifying, and Correcting for Bias in Post-hoc Analysis of Gene-Based Rare Variant Tests of Association

Directory of Open Access Journals (Sweden)

Kelsey E. Grinde

2017-09-01

Full Text Available To date, gene-based rare variant testing approaches have focused on aggregating information across sets of variants to maximize statistical power in identifying genes showing significant association with diseases. Beyond identifying genes that are associated with diseases, the identification of causal variant(s in those genes and estimation of their effect is crucial for planning replication studies and characterizing the genetic architecture of the locus. However, we illustrate that straightforward single-marker association statistics can suffer from substantial bias introduced by conditioning on gene-based test significance, due to the phenomenon often referred to as “winner's curse.” We illustrate the ramifications of this bias on variant effect size estimation and variant prioritization/ranking approaches, outline parameters of genetic architecture that affect this bias, and propose a bootstrap resampling method to correct for this bias. We find that our correction method significantly reduces the bias due to winner's curse (average two-fold decrease in bias, p < 2.2 × 10−6 and, consequently, substantially improves mean squared error and variant prioritization/ranking. The method is particularly helpful in adjustment for winner's curse effects when the initial gene-based test has low power and for relatively more common, non-causal variants. Adjustment for winner's curse is recommended for all post-hoc estimation and ranking of variants after a gene-based test. Further work is necessary to continue seeking ways to reduce bias and improve inference in post-hoc analysis of gene-based tests under a wide variety of genetic architectures.

A Multivariant Stream Analysis Approach to Detect and Mitigate DDoS Attacks in Vehicular Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Raenu Kolandaisamy

2018-01-01

Full Text Available Vehicular Ad Hoc Networks (VANETs are rapidly gaining attention due to the diversity of services that they can potentially offer. However, VANET communication is vulnerable to numerous security threats such as Distributed Denial of Service (DDoS attacks. Dealing with these attacks in VANET is a challenging problem. Most of the existing DDoS detection techniques suffer from poor accuracy and high computational overhead. To cope with these problems, we present a novel Multivariant Stream Analysis (MVSA approach. The proposed MVSA approach maintains the multiple stages for detection DDoS attack in network. The Multivariant Stream Analysis gives unique result based on the Vehicle-to-Vehicle communication through Road Side Unit. The approach observes the traffic in different situations and time frames and maintains different rules for various traffic classes in various time windows. The performance of the MVSA is evaluated using an NS2 simulator. Simulation results demonstrate the effectiveness and efficiency of the MVSA regarding detection accuracy and reducing the impact on VANET communication.

Global stability analysis of epidemiological models based on Volterra–Lyapunov stable matrices

International Nuclear Information System (INIS)

Liao Shu; Wang Jin

2012-01-01

Highlights: ► Global dynamics of high dimensional dynamical systems. ► A systematic approach for global stability analysis. ► Epidemiological models of environment-dependent diseases. - Abstract: In this paper, we study the global dynamics of a class of mathematical epidemiological models formulated by systems of differential equations. These models involve both human population and environmental component(s) and constitute high-dimensional nonlinear autonomous systems, for which the global asymptotic stability of the endemic equilibria has been a major challenge in analyzing the dynamics. By incorporating the theory of Volterra–Lyapunov stable matrices into the classical method of Lyapunov functions, we present an approach for global stability analysis and obtain new results on some three- and four-dimensional model systems. In addition, we conduct numerical simulation to verify the analytical results.

Handbook on theoretical and algorithmic aspects of sensor, ad hoc wireless, and peer-to-peer networks

CERN Document Server

Wu, Jie

2005-01-01

PrefaceAD HOC WIRELESS NETWORKSA Modular Cross Layer Architecture for Ad Hoc Networks, M. Conti, J. Crowcroft, G. Maselli, and G. TuriRouting Scalability in MANETs, J. Eriksson, S. Krishnamurthy and M. FaloutsosUniformly Distributed Algorithm for Virtual Backbone Routing in Ad Hoc Wireless Networks, D.S. KimMaximum Necessary Hop Count for Packet Routing in MANET, X. Chen and J. ShenEfficient Strategyproof Multicast in Selfish Wireless Networks, X.-Yang LiGeocasting in Ad Hoc and Sensor Networks, I. StojmenovicTopology Control for Ad hoc Networks: Present Solutions and Open Issues, C.-C. Shen a

Assessment of direct analgesic effect of duloxetine for chronic low back pain: post hoc path analysis of double-blind, placebo-controlled studies

Directory of Open Access Journals (Sweden)

Enomoto H

2017-06-01

Full Text Available Hiroyuki Enomoto,1 Shinji Fujikoshi,2 Jumpei Funai,3 Nao Sasaki,4 Michael H Ossipov,5 Toshinaga Tsuji,6 Levent Alev,7 Takahiro Ushida8 1Medical Science, Eli Lilly Japan K.K., Tokyo, 2Statistical Science, 3Science Communications, 4Medical Science, Eli Lilly Japan K.K., Kobe, Japan; 5Clinical Division, inVentiv Health, LLC, Blue Bell, PA, USA; 6Medical Affairs Department, Shionogi & Co., Ltd., Osaka, Japan; 7Medical Department, Lilly Turkey, Istanbul, Turkey; 8Multidisciplinary Pain Center, Aichi Medical University, Nagakute, Aichi, Japan Background: Comorbid depression and depressive symptoms are common in patients with chronic low back pain (CLBP. Duloxetine is clinically effective in major depressive disorder and several chronic pain states, including CLBP. The objective of this post hoc meta-analysis was to assess direct and indirect analgesic efficacy of duloxetine for patients with CLBP in previous clinical trials. Methods: Post hoc path analyses were conducted of 3 randomized, double-blind, clinical studies of patients receiving duloxetine or placebo for CLBP. The primary outcome measure for pain was the Brief Pain Inventory, average pain score. A secondary outcome measure, the Beck Depression Inventory-II, was used for depressive symptoms. The changes in score from baseline to endpoint were determined for each index. Path analyses were employed to calculate the proportion of analgesia that may be attributed to a direct effect of duloxetine on pain.Results: A total of 851 patients (400 duloxetine and 451 placebo were included in this analysis. Duloxetine significantly improved pain scores compared with placebo (p<0.001. It also significantly improved depressive scores compared with placebo (p=0.015. Path analyses showed that 91.1% of the analgesic effect of duloxetine could be attributed to a direct analgesic effect, and 8.9% to its antidepressant effect. Similar results were obtained when data were evaluated at weeks 4 and 7, and when

Análisis de la aplicación de un sistema de actividad ad hoc para la promoción de habilidades metacognitivas de alfabetización académica Analysis Of Results Of Application Of System Of Activity Ad Hoc For The Promotion Of Abilities Metacognition Of Academic Alphabetization

Directory of Open Access Journals (Sweden)

María Elena Colombo

2008-12-01

Full Text Available Nuestro proyecto de investigación aborda una de las problemáticas de la enseñanza universitaria: la promoción de habilidades metacognitivas de alfabetización académica (PHMAA. El marco teórico adoptado corresponde a la Psicología Histórico-Cultural. Es una investigación cualitativa, según el modelo de investigación "estudio evolutivo del trabajo"que se realizó en contextos naturales de interacción áulica universitaria con un diseño longitudinal que abordó el estudio de los mismos grupos de alumnos en un lapso cuatrimestral para la misma cohorte 2006. La unidad de análisis escogida fue el "sistema de actividad áulico universitario". Se trabajó con dos muestras: una para el sistema de actividad artificial ad hoc y otra para el sistema de actividad tradicional, las que fueron analizadas y comparadas. Se utilizaron artefactos mediadores dentro del sistema ad hoc para la PHMAA. En el presente artículo se exponen los resultados del análisis y la comparación de evaluaciones escritas de los alumnos de ambos grupos.In our research project we examine one of the main issues on university level teaching: the promotion of metacognitive skills in academic literacy process (PHMAA in Spanish. The theoretical framework used is Historical - Cultural Psychology. It is a qualitative research, along the lines of investigation "evolutionary study of work" that took place in contexts of natural interaction classroom university with a design that addressed the longitudinal study of the same groups of students within four months for the same cohort 2006. The unit of analysis is chosen the "system activity classroom university." We worked with two samples: one for the system of artificial ad hoc activity and one for the traditional system, which were analyzed and compared. Mediators devices were used within the ad hoc system for PHMAA. In this article outlines the results of the analysis and comparison of written assessments of students in both

Traffic Agents for Improving QoS in Mixed Infrastructure and Ad Hoc Modes Wireless LAN

Directory of Open Access Journals (Sweden)

Yuan Hai-Feng

2006-01-01

Full Text Available As an important complement to infrastructured wireless networks, mobile ad hoc networks (MANET are more flexible in providing wireless access services, but more difficult in meeting different quality of service (QoS requirements for mobile customers. Both infrastructure and ad hoc network structures are supported in wireless local area networks (WLAN, which can offer high data-rate wireless multimedia services to the mobile stations (MSs in a limited geographical area. For those out-of-coverage MSs, how to effectively connect them to the access point (AP and provide QoS support is a challenging issue. By mixing the infrastructure and the ad hoc modes in WLAN, we propose in this paper a new coverage improvement scheme that can identify suitable idle MSs in good service zones as traffic agents (TAs to relay traffic from those out-of-coverage MSs to the AP. The service coverage area of WLAN is then expanded. The QoS requirements (e.g., bandwidth of those MSs are considered in the selection process of corresponding TAs. Mathematical analysis, verified by computer simulations, shows that the proposed TA scheme can effectively reduce blocking probability when traffic load is light.

A Group Based Key Sharing and Management Algorithm for Vehicular Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Zeeshan Shafi Khan

2014-01-01

Full Text Available Vehicular ad hoc networks (VANETs are one special type of ad hoc networks that involves vehicles on roads. Typically like ad hoc networks, broadcast approach is used for data dissemination. Blind broadcast to each and every node results in exchange of useless and irrelevant messages and hence creates an overhead. Unicasting is not preferred in ad-hoc networks due to the dynamic topology and the resource requirements as compared to broadcasting. Simple broadcasting techniques create several problems on privacy, disturbance, and resource utilization. In this paper, we propose media mixing algorithm to decide what information should be provided to each user and how to provide such information. Results obtained through simulation show that fewer number of keys are needed to share compared to simple broadcasting. Privacy is also enhanced through this approach.

INDEPENDENSI HAKIM AD-HOC PADA LINGKUNGAN PERADILAN HUBUNGAN INDUSTRIAL / THE JUDICIAL INDEPENDENCE OF AD-HOC JUDGES IN INDUSTRIAL RELATION COURT

Directory of Open Access Journals (Sweden)

Muhammad Ishar Helmi

2017-08-01

Full Text Available Undang-Undang PPHI mengatur asas penyelesaian perselisihan hubungan industrial dilakukan secara musyawarah mufakat, dengan berprinsip jika terjadi perselisihan antara pekerja/buruh dan pengusaha maka tahap pertama penyelesaian perselisihan tersebut diserahkan pada pihak yang berselisih (bipartit. Ketentuan Pasal 63 ayat (2 dan Pasal 67 ayat (1 huruf f Undang-Undang tersebut mengakibatkan hakim ad-hoc Pengadilan Hubungan Industrial, dalam menjalankan tugas dan tanggung jawabnya memeriksa dan memutus suatu perkara harus mandiri dan lepas dari segala bentuk intervensi lembaga/instansi manapun menjadi terbatasi dan tidak optimal. Hakim ad-hoc Peradilan Hubungan Industrial merupakan hakim yang diusulkan oleh serikat pekerja/serikat buruh, organisasi pengusaha, juga diberhentikan secara hormat oleh serikat pekerja/serikat buruh, organisasi pengusaha tersebut. Hal ini tentunya akan menciderai sistem peradilan yang bebas, tidak memihak dan bersih yang diimpikan karena para hakim akan dikuasai oleh para pihak yang berperkara, karena keberadaan hakim diangkat dan diberhentikan oleh pihak yang akan disidangkan di peradilan hubungan industrial tersebut. PPHI (Industrial Relations Disputes Settlement Act regulates the principle of settlement of industrial relations disputes by consensus, if there is a dispute between employee/workers and employers, the first stage of dispute settlement shall be submitted to disputing party (bipartite settlement. The provisions of Article 63 paragraph (2 and Article 67 paragraph (1 sub-paragraph f of the Act shall result in the ad-hoc judges of the Industrial Relations Court, in carrying out their duties and responsibilities to examine and decide a case shall be independent and kept away from any intervention of any institution. The ad-hoc judges of the Industrial Relations Court is a judge proposed by a trade union, employers organization, also dismissed respectfully by the trade union and the employers organization. This

Evolutionary algorithms for mobile ad hoc networks

CERN Document Server

Dorronsoro, Bernabé; Danoy, Grégoire; Pigné, Yoann; Bouvry, Pascal

2014-01-01

Describes how evolutionary algorithms (EAs) can be used to identify, model, and minimize day-to-day problems that arise for researchers in optimization and mobile networking. Mobile ad hoc networks (MANETs), vehicular networks (VANETs), sensor networks (SNs), and hybrid networks—each of these require a designer’s keen sense and knowledge of evolutionary algorithms in order to help with the common issues that plague professionals involved in optimization and mobile networking. This book introduces readers to both mobile ad hoc networks and evolutionary algorithms, presenting basic concepts as well as detailed descriptions of each. It demonstrates how metaheuristics and evolutionary algorithms (EAs) can be used to help provide low-cost operations in the optimization process—allowing designers to put some “intelligence” or sophistication into the design. It also offers efficient and accurate information on dissemination algorithms topology management, and mobility models to address challenges in the ...

Participatory epidemiology: the contribution of participatory research to epidemiology

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Mario Bach

2017-02-01

Full Text Available Abstract Background Epidemiology has contributed in many ways to identifying various risk factors for disease and to promoting population health. However, there is a continuing debate about the ability of epidemiology not only to describe, but also to provide results which can be better translated into public health practice. It has been proposed that participatory research approaches be applied to epidemiology as a way to bridge this gap between description and action. A systematic account of what constitutes participatory epidemiology practice has, however, been lacking. Methods A scoping review was carried out focused on the question of what constitutes participatory approaches to epidemiology for the purpose of demonstrating their potential for advancing epidemiologic research. Relevant databases were searched, including both the published and non-published (grey literature. The 102 identified sources were analyzed in terms of comparing common epidemiologic approaches to participatory counterparts regarding central aspects of the research process. Exemplary studies applying participatory approaches were examined more closely. Results A highly diverse, interdisciplinary body of literature was synthesized, resulting in a framework comprised of seven aspects of the research process: research goal, research question, population, context, data synthesis, research management, and dissemination of findings. The framework specifies how participatory approaches not only differ from, but also how they can enhance common approaches in epidemiology. Finally, recommendations for the further development of participatory approaches are given. These include: enhancing data collection, data analysis, and data validation; advancing capacity building for research at the local level; and developing data synthesis. Conclusion The proposed framework provides a basis for systematically developing the emergent science of participatory epidemiology.

Decentralized session initiation protocol solution in ad hoc networks

Science.gov (United States)

Han, Lu; Jin, Zhigang; Shu, Yantai; Dong, Linfang

2006-10-01

With the fast development of ad hoc networks, SIP has attracted more and more attention in multimedia service. This paper proposes a new architecture to provide SIP service for ad hoc users, although there is no centralized SIP server deployed. In this solution, we provide the SIP service by the introduction of two nodes: Designated SIP Server (DS) and its Backup Server (BDS). The nodes of ad hoc network designate DS and BDS when they join the session nodes set and when some pre-defined events occur. A new sip message type called REGISTRAR is presented so nodes can send others REGISTRAR message to declare they want to be DS. According to the IP information taken in the message, an algorithm works like the election of DR and BDR in OSPF protocol is used to vote DS and BDS SIP servers. Naturally, the DS will be replaced by BDS when the DS is down for predicable or unpredictable reasons. To facilitate this, the DS should register to the BDS and transfer a backup of the SIP users' database. Considering the possibility DS or BDS may abruptly go down, a special policy is given. When there is no DS and BDS, a new election procedure is triggered just like the startup phase. The paper also describes how SIP works normally in the decentralized model as well as the evaluation of its performance. All sessions based on SIP in ad hoc such as DS voting have been tested in the real experiments within a 500m*500m square area where about 30 random nodes are placed.

Assessment of intercentre reproducibility and epidemiological concordance of Legionella pneumophila serogroup 1 genotyping by amplified fragment length polymorphism analysis

DEFF Research Database (Denmark)

Fry, N K; Bangsborg, Jette Marie; Bernander, S

2000-01-01

The aims of this work were to assess (i) the intercentre reproducibility and epidemiological concordance of amplified fragment length polymorphism analysis for epidemiological typing of Legionella pneumophila serogroup 1, and (ii) the suitability of the method for standardisation and implementation...... by members of the European Working Group on Legionella Infections. Fifty coded isolates comprising two panels of well-characterised strains, a "reproducibility" panel (n=20) and an "epidemiologically related" panel (n=30), were sent to 13 centres in 12 European countries. Analysis was undertaken in each...... using gel analysis software yielded R=1.00 and E=1.00, with 12, 13 or 14 types. This method can be used as a simple, rapid screening tool for epidemiological typing of isolates of Legionella pneumophila serogroup 1. Results demonstrate that the method can be highly reproducible (R=1...

Nausea and Vomiting following Balanced Xenon Anesthesia Compared to Sevoflurane: A Post-Hoc Explorative Analysis of a Randomized Controlled Trial.

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Astrid V Fahlenkamp

Full Text Available Like other inhalational anesthetics xenon seems to be associated with post-operative nausea and vomiting (PONV. We assessed nausea incidence following balanced xenon anesthesia compared to sevoflurane, and dexamethasone for its prophylaxis in a randomized controlled trial with post-hoc explorative analysis.220 subjects with elevated PONV risk (Apfel score ≥2 undergoing elective abdominal surgery were randomized to receive xenon or sevoflurane anesthesia and dexamethasone or placebo after written informed consent. 93 subjects in the xenon group and 94 subjects in the sevoflurane group completed the trial. General anesthesia was maintained with 60% xenon or 2.0% sevoflurane. Dexamethasone 4mg or placebo was administered in the first hour. Subjects were analyzed for nausea and vomiting in predefined intervals during a 24h post-anesthesia follow-up.Logistic regression, controlled for dexamethasone and anesthesia/dexamethasone interaction, showed a significant risk to develop nausea following xenon anesthesia (OR 2.30, 95% CI 1.02-5.19, p = 0.044. Early-onset nausea incidence was 46% after xenon and 35% after sevoflurane anesthesia (p = 0.138. After xenon, nausea occurred significantly earlier (p = 0.014, was more frequent and rated worse in the beginning. Dexamethasone did not markedly reduce nausea occurrence in both groups. Late-onset nausea showed no considerable difference between the groups.In our study setting, xenon anesthesia was associated with an elevated risk to develop nausea in sensitive subjects. Dexamethasone 4mg was not effective preventing nausea in our study. Group size or dosage might have been too small, and change of statistical analysis parameters in the post-hoc evaluation might have further contributed to a limitation of our results. Further trials will be needed to address prophylaxis of xenon-induced nausea.EU Clinical Trials EudraCT-2008-004132-20 ClinicalTrials.gov NCT00793663.

Node counting in wireless ad-hoc networks

NARCIS (Netherlands)

Evers, J.H.M.; Kiss, D.; Kowalczyk, W.; Navilarekallu, T.; Renger, D.R.M.; Sella, L.; Timperio, V.; Viorel, A.; Wijk, van A.C.C.; Yzelman, A.J.; Planqué, B.; Bhulai, S.; Hulshof, J.; Kager, W.; Rot, T.

2012-01-01

We study wireless ad-hoc networks consisting of small microprocessors with limited memory, where the wireless communication between the processors can be highly unreliable. For this setting, we propose a number of algorithms to estimate the number of nodes in the network, and the number of direct

Information Sharing Modalities for Mobile Ad-Hoc Networks

Science.gov (United States)

de Spindler, Alexandre; Grossniklaus, Michael; Lins, Christoph; Norrie, Moira C.

Current mobile phone technologies have fostered the emergence of a new generation of mobile applications. Such applications allow users to interact and share information opportunistically when their mobile devices are in physical proximity or close to fixed installations. It has been shown how mobile applications such as collaborative filtering and location-based services can take advantage of ad-hoc connectivity to use physical proximity as a filter mechanism inherent to the application logic. We discuss the different modes of information sharing that arise in such settings based on the models of persistence and synchronisation. We present a platform that supports the development of applications that can exploit these modes of ad-hoc information sharing and, by means of an example, show how such an application can be realised based on the supported event model.

An implementation of traffic light system using multi-hop Ad hoc networks

KAUST Repository

Ansari, Imran Shafique

2009-08-01

In ad hoc networks nodes cooperate with each other to form a temporary network without the aid of any centralized administration. No wired base station or infrastructure is supported, and each host communicates via radio packets. Each host must act as a router, since routes are mostly multi-hop, due to the limited power transmission set by government agencies, (e.g. the Federal Communication Commission (FCC), which is 1 Watt in Industrial Scientific and Medical (ISM) band. The natures of wireless mobile ad hoc networks depend on batteries or other fatiguing means for their energy. A limited energy capacity may be the most significant performance constraint. Therefore, radio resource and power management is an important issue of any wireless network. In this paper, a design for traffic light system employing ad hoc networks is proposed. The traffic light system runs automatically based on signals sent through a multi-hop ad hoc network of \\'n\\' number of nodes utilizing the Token Ring protocol, which is efficient for this application from the energy prospective. The experiment consists of a graphical user interface that simulates the traffic lights and laptops (which have wireless network adapters) are used to run the graphical user interface and are responsible for setting up the ad hoc network between them. The traffic light system has been implemented utilizing A Mesh Driver (which allows for more than one wireless device to be connected simultaneously) and Java-based client-server programs. © 2009 IEEE.

16 CFR 1000.26 - Directorate for Epidemiology.

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Directorate for Epidemiology. 1000.26... AND FUNCTIONS § 1000.26 Directorate for Epidemiology. The Directorate for Epidemiology, managed by the Associate Executive Director for Epidemiology, is responsible for the collection and analysis of data on...

Ad Hoc on-Demand Distance Vector (AODV Routing Protocol Performance Evaluation on Hybrid Ad Hoc Network: Comparison of Result of Ns-2 Simulation and Implementation on Testbed using PDA

Directory of Open Access Journals (Sweden)

Riri Sari

2010-10-01

Full Text Available In Mobile Ad hoc NETwork (MANET, node supplemented with wireless equipment has the capacity to manage and organise autonomously, without the presence of network infrastructures. Hybrid ad hoc network, enable several nodes to move freely (mobile to create instant communication. Independent from infrastructure. They could access the Local Area Network (LAN or the Internet. Functionalities of ad hoc network very much dependent on the routing protocol that determines the routing around node. Ad hoc On-demand Distance Vector (AODV is one of routing protocols in ad hoc network which has a reactive characteristic. This protocol is the most common protocol being researched and used. In this Research, AODV protocol investigation was conducted by developing a testbed using Personal Computer, several Laptops (the Linux Red Hat operation system 9.0 and Fedora Core 2, and Personal Digital Assistant (PDA. This research also made a complete package by mean of cross compilation for PDA iPAQ. In general, results obtained from the simulation of AODV protocol using Network Simulator NS-2 are packet delivery ratio 99.89%, end-to-end delay of 0.14 seconds and routing overhead of 1,756.61 byte per second. Afterwards results from simulation were compared to results from testbed. Results obtained from testbed are as follows: the packet delivery ratio is 99.57%, the end-to-end delay is 1.004 seconds and the routing overhead is 1,360.36 byte per second.

Contribution to design a communication framework for vehicular ad hoc networks in urban scenarios

OpenAIRE

Tripp Barba, Carolina

2013-01-01

The constant mobility of people, the growing need to be always connected, the large number of vehicles that nowadays can be found in the roads and the advances in technology make Vehicular Ad hoc Networks (VANETs) be a major area of research. Vehicular Ad hoc Networks are a special type of wireless Mobile Ad hoc Networks (MANETs), which allow a group of mobile nodes configure a temporary network and maintain it without the need of a fixed infrastructure. A vehicular network presents some spec...

Proposal of interference reduction routing for ad-hoc networks

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Katsuhiro Naito

2010-10-01

Full Text Available In this paper, we propose an interference reduction routing protocol for ad-hoc networks. The interference is one of the degradation factors in wireless communications. In the ad-hoc network, some nodes communicate simultaneously. Therefore, these communications cause interference each other, and some packets are corrupted due to interference from another node. In the proposed protocol, each node estimates required transmission power according to hello messages. Therefore, the node can transmit a data packet with minimum required transmission power. Consequently, the interference against neighbor nodes can be reduced. From simulation results, we can find that the proposed protocol can reduce the number of control messages and can improve the throughput performance.

History of early abuse as a predictor of treatment response in patients with fibromyalgia : A post-hoc analysis of a 12-week, randomized, double-blind, placebo-controlled trial of paroxetine controlled release

NARCIS (Netherlands)

Pae, Chi-Un; Masand, Prakash S.; Marks, David M.; Krulewicz, Stan; Han, Changsu; Peindl, Kathleen; Mannelli, Paolo; Patkar, Ashwin A.

2009-01-01

Objectives. We conducted a post-hoc analysis to determine whether a history of physical or sexual abuse was associated with response to treatment in a double-blind, randomized, placebo-controlled trial of paroxetine controlled release (CR) in fibromyalgia. Methods. A randomized, double-blind,

Implementation and reporting of causal mediation analysis in 2015: a systematic review in epidemiological studies.

Science.gov (United States)

Liu, Shao-Hsien; Ulbricht, Christine M; Chrysanthopoulou, Stavroula A; Lapane, Kate L

2016-07-20

Causal mediation analysis is often used to understand the impact of variables along the causal pathway of an occurrence relation. How well studies apply and report the elements of causal mediation analysis remains unknown. We systematically reviewed epidemiological studies published in 2015 that employed causal mediation analysis to estimate direct and indirect effects of observed associations between an exposure on an outcome. We identified potential epidemiological studies through conducting a citation search within Web of Science and a keyword search within PubMed. Two reviewers independently screened studies for eligibility. For eligible studies, one reviewer performed data extraction, and a senior epidemiologist confirmed the extracted information. Empirical application and methodological details of the technique were extracted and summarized. Thirteen studies were eligible for data extraction. While the majority of studies reported and identified the effects of measures, most studies lacked sufficient details on the extent to which identifiability assumptions were satisfied. Although most studies addressed issues of unmeasured confounders either from empirical approaches or sensitivity analyses, the majority did not examine the potential bias arising from the measurement error of the mediator. Some studies allowed for exposure-mediator interaction and only a few presented results from models both with and without interactions. Power calculations were scarce. Reporting of causal mediation analysis is varied and suboptimal. Given that the application of causal mediation analysis will likely continue to increase, developing standards of reporting of causal mediation analysis in epidemiological research would be prudent.

Ad Hoc Wireless Networking and Shared Computation for Autonomous Multirobot Systems

OpenAIRE

Bevilacqua, Riccardo; Hall, Jason S.; Horning, James; Romano, Marcello

2009-01-01

The article of record as published may be located at http://dx.doi.org/10.2514/1.40734 A wireless ad hoc network is introduced that enables inter-robot communication and shared computation among multiple robots with PC/104-based single board computers running the real-time application interface patched Linux operating system. Through the use of IEEE 802.11 ad hoc technology and User Datagram Protocol, each robot is able to exchange data without the need of a centralized router ...

The Ex Hoc Infrastructure - Enhancing Traffic Safety through LIfe WArning Systems

DEFF Research Database (Denmark)

Hansen, Klaus Marius; Kristensen, Lars Michael; Eskildsen, Toke

2004-01-01

New pervasive computing technologies for sensing and communication open up novel possibilities for enhancing traffic safety. We are currently designing and implementing the Ex Hoc infrastructure framework for communication among mobile and stationary units including vehicles. The infrastructure...... will connect sensing devices on vehicles with sensing devices on other vehicles and with stationary communication units placed alongside roads. The current application of Ex Hoc is to enable the collection and dissemination of information on road condition through LIfe Warning Systems (LIWAS) units....

A multihop key agreement scheme for wireless ad hoc networks based on channel characteristics.

Science.gov (United States)

Hao, Zhuo; Zhong, Sheng; Yu, Nenghai

2013-01-01

A number of key agreement schemes based on wireless channel characteristics have been proposed recently. However, previous key agreement schemes require that two nodes which need to agree on a key are within the communication range of each other. Hence, they are not suitable for multihop wireless networks, in which nodes do not always have direct connections with each other. In this paper, we first propose a basic multihop key agreement scheme for wireless ad hoc networks. The proposed basic scheme is resistant to external eavesdroppers. Nevertheless, this basic scheme is not secure when there exist internal eavesdroppers or Man-in-the-Middle (MITM) adversaries. In order to cope with these adversaries, we propose an improved multihop key agreement scheme. We show that the improved scheme is secure against internal eavesdroppers and MITM adversaries in a single path. Both performance analysis and simulation results demonstrate that the improved scheme is efficient. Consequently, the improved key agreement scheme is suitable for multihop wireless ad hoc networks.

Investigating the Reliability and Factor Structure of Kalichman's "Survey 2: Research Misconduct" Questionnaire: A Post Hoc Analysis Among Biomedical Doctoral Students in Scandinavia.

Science.gov (United States)

Holm, Søren; Hofmann, Bjørn

2017-10-01

A precondition for reducing scientific misconduct is evidence about scientists' attitudes. We need reliable survey instruments, and this study investigates the reliability of Kalichman's "Survey 2: research misconduct" questionnaire. The study is a post hoc analysis of data from three surveys among biomedical doctoral students in Scandinavia (2010-2015). We perform reliability analysis, and exploratory and confirmatory factor analysis using a split-sample design as a partial validation. The results indicate that a reliable 13-item scale can be formed (Cronbach's α = .705), and factor analysis indicates that there are four reliable subscales each tapping a different construct: (a) general attitude to misconduct (α = .768), (b) attitude to personal misconduct (α = .784), (c) attitude to whistleblowing (α = .841), and (d) attitude to blameworthiness/punishment (α = .877). A full validation of the questionnaire requires further research. We, nevertheless, hope that the results will facilitate the increased use of the questionnaire in research.

A Novel Medium Access Control for Ad hoc Networks Based on OFDM System

Institute of Scientific and Technical Information of China (English)

YU Yi-fan; YIN Chang-chuan; YUE Guang-xin

2005-01-01

Recently, hosts of Medium Access Control (MAC) protocols for Ad hoc radio networks have been proposed to solve the hidden terminal problem and exposed terminal problem. However most of them take into no account the interactions between physical (PHY) system and MAC protocol. Therefore, the current MAC protocols are either inefficient in the networks with mobile nodes and fading channel or difficult in hardware implementation. In this paper, we present a novel media access control for Ad hoc networks that integrates a media access control protocol termed as Dual Busy Tone Multiple Access (DBTMA) into Orthogonal Frequency Division Multiplexing (OFDM) system proposed in IEEE 802.11a standard. The analysis presented in the paper indicates that the proposed MAC scheme achieves performance improvement over IEEE 802.11 protocol about 25%～80% especially in the environment with high mobility and deep fading. The complexity of the proposed scheme is also lower than other implementation of similar busy tone solution. Furthermore, it is compatible with IEEE 802.11a networks.

Insight and Treatment Outcomes in Schizophrenia: Post-hoc Analysis of a Long-term, Double-blind Study Comparing Lurasidone and Quetiapine XR.

Science.gov (United States)

Harvey, Philip D; Siu, Cynthia O; Loebel, Antony D

2017-12-01

Objective: The objective of this post-hoc analysis was to evaluate the effect of lurasidone and quetiapine extended-release (XR) on insight and judgment and assess the longitudinal relationships between improvement in insight and cognitive performance, functional capacity, quality of well-being, and depressive symptoms in patients with schizophrenia. Design: Clinically unstable patients with schizophrenia (N=488) were randomized to once-daily, fixed-dose treatment with lurasidone 80mg, lurasidone 160mg, quetiapine XR 600mg, or placebo, followed by a long-term, double-blind, flexible-dose continuation study involving these agents. Results: Significantly greater improvement in insight and judgment (assessed by the Positive and Negative Syndrome Scale G12 item) for the lurasidone and quetiapine XR groups, compared to the placebo group, was observed at Week 6. Over a subsequent six-month continuation period, the flexible dose lurasidone group showed significantly greater improvement in insight from acute phase baseline compared to the flexible-dose quetiapine XR group (QXR-QXR) (p=0.032). Improvement in insight was significantly correlated with improvement in cognition ( p =0.014), functional capacity (p=0.006, UPSA-B), quality of well-being ( p =0.033, QWB), and depressive symptoms ( p =0.05, Montgomery-Åsberg Depression Rating Scale [MADRS] score) across treatment groups and study periods. Conclusion: In this post-hoc analysis, flexibly dosed lurasidone 40 to 160mg/d was found to be associated with significantly greater improvement in insight compared to flexibly dosed quetiapine XR 200 to 800mg/d over long-term treatment in patients with schizophrenia. Across treatment groups, improvement in insight and judgment was significantly associated with improvement in cognition, functional capacity, quality of well-being, and depressive symptoms over time.

Cognitive radio application for vehicular ad hoc networks (VANETS

Directory of Open Access Journals (Sweden)

Miladić Suzana D.

2016-01-01

Full Text Available This paper presents the application of cognitive radio technology in vehicular ad-hoc networks aimed to improve the communications between vehicles themselves as well as between vehicles and roadside infrastructure. Due to dynamic approach of spectrum access, cognitive radio is a technology that enables more efficient usage of radio-frequency spectrum. We review actual approaches and discuss research challenges related to the use of cognitive radio technology in vehicular ad hoc networks with emphasis on architecture, spectrum management as well as QoS optimization. The researching on cognitive radio application in vehicular networks is still developing and there are not many experimental platforms due to their complex setups. Some related research projects and cognitive radio realizations are provided in this paper.

Ad Hoc Physical Hilbert Spaces in Quantum Mechanics

Czech Academy of Sciences Publication Activity Database

Fernandez, F. M.; Garcia, J.; Semorádová, Iveta; Znojil, Miloslav

2015-01-01

Roč. 54, č. 12 (2015), s. 4187-4203 ISSN 0020-7748 Institutional support: RVO:61389005 Keywords : quantum mechanics * physical Hilbert spaces * ad hoc inner product * singular potentials regularized * low lying energies Subject RIV: BE - Theoretical Physics Impact factor: 1.041, year: 2015

Wireless Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Hong-Chuan Yang

2007-01-01

Full Text Available We study the energy-efficient configuration of multihop paths with automatic repeat request (ARQ mechanism in wireless ad hoc networks. We adopt a cross-layer design approach and take both the quality of each radio hop and the battery capacity of each transmitting node into consideration. Under certain constraints on the maximum tolerable transmission delay and the required packet delivery ratio, we solve optimization problems to jointly schedule the transmitting power of each transmitting node and the retransmission limit over each hop. Numerical results demonstrate that the path configuration methods can either significantly reduce the average energy consumption per packet delivery or considerably extend the average lifetime of the multihop route.

Molecular Infectious Disease Epidemiology: Survival Analysis and Algorithms Linking Phylogenies to Transmission Trees

Science.gov (United States)

Kenah, Eben; Britton, Tom; Halloran, M. Elizabeth; Longini, Ira M.

2016-01-01

Recent work has attempted to use whole-genome sequence data from pathogens to reconstruct the transmission trees linking infectors and infectees in outbreaks. However, transmission trees from one outbreak do not generalize to future outbreaks. Reconstruction of transmission trees is most useful to public health if it leads to generalizable scientific insights about disease transmission. In a survival analysis framework, estimation of transmission parameters is based on sums or averages over the possible transmission trees. A phylogeny can increase the precision of these estimates by providing partial information about who infected whom. The leaves of the phylogeny represent sampled pathogens, which have known hosts. The interior nodes represent common ancestors of sampled pathogens, which have unknown hosts. Starting from assumptions about disease biology and epidemiologic study design, we prove that there is a one-to-one correspondence between the possible assignments of interior node hosts and the transmission trees simultaneously consistent with the phylogeny and the epidemiologic data on person, place, and time. We develop algorithms to enumerate these transmission trees and show these can be used to calculate likelihoods that incorporate both epidemiologic data and a phylogeny. A simulation study confirms that this leads to more efficient estimates of hazard ratios for infectiousness and baseline hazards of infectious contact, and we use these methods to analyze data from a foot-and-mouth disease virus outbreak in the United Kingdom in 2001. These results demonstrate the importance of data on individuals who escape infection, which is often overlooked. The combination of survival analysis and algorithms linking phylogenies to transmission trees is a rigorous but flexible statistical foundation for molecular infectious disease epidemiology. PMID:27070316

Contribution to design a communication framework for vehicular ad hoc networks in urban scenarios

OpenAIRE

Tripp Barba, Carolina

2013-01-01

La movilidad constante de las personas y la creciente necesidad de estar conectados en todo momento ha hecho de las redes vehiculares un área cuyo interés ha ido en aumento. La gran cantidad de vehículos que hay en la actualidad, y los avances tecnológicos han hecho de las redes vehiculares (VANETS, Vehicular Ad hoc Networks) un gran campo de investigación. Las redes vehiculares son un tipo especial de redes móviles ad hoc inalámbricas, las cuales, al igual que las redes MANET (Mobile Ad hoc ...

MAC Protocol for Ad Hoc Networks Using a Genetic Algorithm

Science.gov (United States)

Elizarraras, Omar; Panduro, Marco; Méndez, Aldo L.

2014-01-01

The problem of obtaining the transmission rate in an ad hoc network consists in adjusting the power of each node to ensure the signal to interference ratio (SIR) and the energy required to transmit from one node to another is obtained at the same time. Therefore, an optimal transmission rate for each node in a medium access control (MAC) protocol based on CSMA-CDMA (carrier sense multiple access-code division multiple access) for ad hoc networks can be obtained using evolutionary optimization. This work proposes a genetic algorithm for the transmission rate election considering a perfect power control, and our proposition achieves improvement of 10% compared with the scheme that handles the handshaking phase to adjust the transmission rate. Furthermore, this paper proposes a genetic algorithm that solves the problem of power combining, interference, data rate, and energy ensuring the signal to interference ratio in an ad hoc network. The result of the proposed genetic algorithm has a better performance (15%) compared to the CSMA-CDMA protocol without optimizing. Therefore, we show by simulation the effectiveness of the proposed protocol in terms of the throughput. PMID:25140339

MAC Protocol for Ad Hoc Networks Using a Genetic Algorithm

Directory of Open Access Journals (Sweden)

Omar Elizarraras

2014-01-01

Full Text Available The problem of obtaining the transmission rate in an ad hoc network consists in adjusting the power of each node to ensure the signal to interference ratio (SIR and the energy required to transmit from one node to another is obtained at the same time. Therefore, an optimal transmission rate for each node in a medium access control (MAC protocol based on CSMA-CDMA (carrier sense multiple access-code division multiple access for ad hoc networks can be obtained using evolutionary optimization. This work proposes a genetic algorithm for the transmission rate election considering a perfect power control, and our proposition achieves improvement of 10% compared with the scheme that handles the handshaking phase to adjust the transmission rate. Furthermore, this paper proposes a genetic algorithm that solves the problem of power combining, interference, data rate, and energy ensuring the signal to interference ratio in an ad hoc network. The result of the proposed genetic algorithm has a better performance (15% compared to the CSMA-CDMA protocol without optimizing. Therefore, we show by simulation the effectiveness of the proposed protocol in terms of the throughput.

Source Authentication for Multicast in Mobile Ad Hoc Networks

National Research Council Canada - National Science Library

Ramachandran, Prabha

2003-01-01

Recent emergence and popularity of mobile ad hoc networks in a host of current-day applications has instigated a suite of research challenges, primarily in routing and security issues for such networks...

A Multi-User Game-Theoretical Multipath Routing Protocol to Send Video-Warning Messages over Mobile Ad Hoc Networks.

Science.gov (United States)

Mezher, Ahmad Mohamad; Igartua, Mónica Aguilar; de la Cruz Llopis, Luis J; Pallarès Segarra, Esteve; Tripp-Barba, Carolina; Urquiza-Aguiar, Luis; Forné, Jordi; Sanvicente Gargallo, Emilio

2015-04-17

The prevention of accidents is one of the most important goals of ad hoc networks in smart cities. When an accident happens, dynamic sensors (e.g., citizens with smart phones or tablets, smart vehicles and buses, etc.) could shoot a video clip of the accident and send it through the ad hoc network. With a video message, the level of seriousness of the accident could be much better evaluated by the authorities (e.g., health care units, police and ambulance drivers) rather than with just a simple text message. Besides, other citizens would be rapidly aware of the incident. In this way, smart dynamic sensors could participate in reporting a situation in the city using the ad hoc network so it would be possible to have a quick reaction warning citizens and emergency units. The deployment of an efficient routing protocol to manage video-warning messages in mobile Ad hoc Networks (MANETs) has important benefits by allowing a fast warning of the incident, which potentially can save lives. To contribute with this goal, we propose a multipath routing protocol to provide video-warning messages in MANETs using a novel game-theoretical approach. As a base for our work, we start from our previous work, where a 2-players game-theoretical routing protocol was proposed to provide video-streaming services over MANETs. In this article, we further generalize the analysis made for a general number of N players in the MANET. Simulations have been carried out to show the benefits of our proposal, taking into account the mobility of the nodes and the presence of interfering traffic. Finally, we also have tested our approach in a vehicular ad hoc network as an incipient start point to develop a novel proposal specifically designed for VANETs.

A Multi-User Game-Theoretical Multipath Routing Protocol to Send Video-Warning Messages over Mobile Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Ahmad Mohamad Mezher

2015-04-01

Full Text Available The prevention of accidents is one of the most important goals of ad hoc networks in smart cities. When an accident happens, dynamic sensors (e.g., citizens with smart phones or tablets, smart vehicles and buses, etc. could shoot a video clip of the accident and send it through the ad hoc network. With a video message, the level of seriousness of the accident could be much better evaluated by the authorities (e.g., health care units, police and ambulance drivers rather than with just a simple text message. Besides, other citizens would be rapidly aware of the incident. In this way, smart dynamic sensors could participate in reporting a situation in the city using the ad hoc network so it would be possible to have a quick reaction warning citizens and emergency units. The deployment of an efficient routing protocol to manage video-warning messages in mobile Ad hoc Networks (MANETs has important benefits by allowing a fast warning of the incident, which potentially can save lives. To contribute with this goal, we propose a multipath routing protocol to provide video-warning messages in MANETs using a novel game-theoretical approach. As a base for our work, we start from our previous work, where a 2-players game-theoretical routing protocol was proposed to provide video-streaming services over MANETs. In this article, we further generalize the analysis made for a general number of N players in the MANET. Simulations have been carried out to show the benefits of our proposal, taking into account the mobility of the nodes and the presence of interfering traffic. Finally, we also have tested our approach in a vehicular ad hoc network as an incipient start point to develop a novel proposal specifically designed for VANETs.

A peer-to-peer file search and download protocol for wireless ad-hoc networks

NARCIS (Netherlands)

Sözer, Hasan; Tekkalmaz, M.; Korpeoglu, I.

Deployment of traditional peer-to-peer file sharing systems on a wireless ad-hoc network introduces several challenges. Information and workload distribution as well as routing are major problems for members of a wireless ad-hoc network, which are only aware of their immediate neighborhood. In this

User-centred and context-aware identity management in mobile ad-hoc networks

CERN Document Server

Arabo, Abdullahi

2013-01-01

The emergent notion of ubiquitous computing makes it possible for mobile devices to communicate and provide services via networks connected in an ad-hoc manner. These have resulted in the proliferation of wireless technologies such as Mobile Ad-hoc Networks (MANets), which offer attractive solutions for services that need flexible setup as well as dynamic and low cost wireless connectivity. However, the growing trend outlined above also raises serious concerns over Identity Management (IM) du...

EEG Spectral Analysis in Serious Gaming: An Ad Hoc Experimental Application

Directory of Open Access Journals (Sweden)

Minchev Z.

2009-12-01

Full Text Available The application of serious gaming technology in different areas of human knowledge for learning is raising the question of quantitative measurement of the training process quality. In the present paper a pilot study of 10 healthy volunteers' EEG spectra is performed for ad hoc selected game events ('win' and 'lose' via continuous wavelet transform (real and complex on the basis of the Morlet mother wavelet function and S-transformation. The results have shown a general decrease of the alpha rhythms power spectra frequencies for the 'lose' events and increase for the 'win' events. This fact corresponds to an opposite behaviour of the theta rhythm of the players for the same 'win' and 'lose' events. Additionally, the frequency changes in the alpha1 (8-10.5 Hz, alpha2 (10.5-13 Hz and theta2 rhythms (6-8 Hz were supposed to be a phenomena related to positive and negative emotions appearance in the EEG activity of the players regarding the selected 'win' and 'lose' states.

Centralized cooperative spectrum sensing for ad-hoc disaster relief network clusters

DEFF Research Database (Denmark)

Pratas, Nuno; Marchetti, Nicola; Prasad, Neeli R.

2010-01-01

Disaster relief networks have to be highly adaptable and resilient. Cognitive radio enhanced ad-hoc architecture have been put forward as a candidate to enable such networks. Spectrum sensing is the cornerstone of the cognitive radio paradigm, and it has been the target of intensive research....... The main common conclusion was that the achievable spectrum sensing accuracy can be greatly enhanced through the use of cooperative sensing schemes. When considering applying Cognitive Radio to ad-hoc disaster relief networks, spectrum sensing cooperative schemes are paramount. A centralized cluster...

Dynamic fair node spectrum allocation for ad hoc networks using random matrices

Science.gov (United States)

Rahmes, Mark; Lemieux, George; Chester, Dave; Sonnenberg, Jerry

2015-05-01

Dynamic Spectrum Access (DSA) is widely seen as a solution to the problem of limited spectrum, because of its ability to adapt the operating frequency of a radio. Mobile Ad Hoc Networks (MANETs) can extend high-capacity mobile communications over large areas where fixed and tethered-mobile systems are not available. In one use case with high potential impact, cognitive radio employs spectrum sensing to facilitate the identification of allocated frequencies not currently accessed by their primary users. Primary users own the rights to radiate at a specific frequency and geographic location, while secondary users opportunistically attempt to radiate at a specific frequency when the primary user is not using it. We populate a spatial radio environment map (REM) database with known information that can be leveraged in an ad hoc network to facilitate fair path use of the DSA-discovered links. Utilization of high-resolution geospatial data layers in RF propagation analysis is directly applicable. Random matrix theory (RMT) is useful in simulating network layer usage in nodes by a Wishart adjacency matrix. We use the Dijkstra algorithm for discovering ad hoc network node connection patterns. We present a method for analysts to dynamically allocate node-node path and link resources using fair division. User allocation of limited resources as a function of time must be dynamic and based on system fairness policies. The context of fair means that first available request for an asset is not envied as long as it is not yet allocated or tasked in order to prevent cycling of the system. This solution may also save money by offering a Pareto efficient repeatable process. We use a water fill queue algorithm to include Shapley value marginal contributions for allocation.

Typicality Mediates Performance during Category Verification in Both Ad-Hoc and Well-Defined Categories

Science.gov (United States)

Sandberg, Chaleece; Sebastian, Rajani; Kiran, Swathi

2012-01-01

Background: The typicality effect is present in neurologically intact populations for natural, ad-hoc, and well-defined categories. Although sparse, there is evidence of typicality effects in persons with chronic stroke aphasia for natural and ad-hoc categories. However, it is unknown exactly what influences the typicality effect in this…

On the impact of network dynamics on a discovery protocol for ad-hoc networks

NARCIS (Netherlands)

Liu, F.; Heijenk, Geert

A very promising approach to discovering services and context information in ad-hoc networks is based on the use of Attenuated Bloom filters. In this paper we analyze the impact of changes in the connectivity of an ad-hoc network on this approach. We evaluate the performance of the discovery

What Is the Problem of Ad Hoc Hypotheses?

Science.gov (United States)

Bamford, Greg

1999-01-01

Philosophers' attempts to convincingly explicate the received view of an ad hoc hypothesis--that it accounts for only the observations it was designed to account for--have been unsuccessful. Familiar and firmer criteria for evaluating the hypotheses or modified theories so classified are characteristically available. Contains 41 references.…

Identification of dietary patterns using factor analysis in an epidemiological study in São Paulo

Directory of Open Access Journals (Sweden)

Dirce Maria Lobo Marchioni

Full Text Available CONTEXT AND OBJECTIVE: Diet and nutrition are environmental factors in health/disease relationships. From the epidemiological viewpoint, diet represents a complex set of highly correlated exposures. Our objective was to identify patterns of food intake in a group of individuals living in São Paulo, and to develop objective dietary measurements for epidemiological purposes. DESIGN AND LOCAL: Exploratory factor analysis of data in a case-control study in seven teaching hospitals in São Paulo. METHODS: The participants were 517 patients (260 oral cancer cases and 257 controls admitted to the study hospitals between November 1998 and March 2001. The weekly intake frequencies for dairy products, cereals, meat, processed meat, vegetables, pulses, fruits and sweets were assessed by means of a semi-quantitative food frequency questionnaire. Dietary patterns were identified by factor analysis, based on the intake of the eight food groups, using principal component analysis as an extraction method followed by varimax rotation. RESULTS: Factor analysis identified three patterns that accounted for 55% of the total variability within the sample. The first pattern ("prudent" was characterized by vegetable, fruit and meat intake; the second ("traditional" by cereals (mainly rice and pulses (mainly beans; and the third ("snacks" by dairy products and processed meat. CONCLUSION: This study identified food intake patterns through an a posteriori approach. Such analysis may be useful for nutritional intervention programs and, after computing scores for each individual according to the patterns identified, for establishing a relationship between diet and other epidemiological measurements of interest.

Deny-by-Default Distributed Security Policy Enforcement in Mobile Ad Hoc Networks

Science.gov (United States)

Alicherry, Mansoor; Keromytis, Angelos D.; Stavrou, Angelos

Mobile Ad-hoc Networks (MANETs) are increasingly employed in tactical military and civil rapid-deployment networks, including emergency rescue operations and ad hoc disaster-relief networks. However, this flexibility of MANETs comes at a price, when compared to wired and base station-based wireless networks: MANETs are susceptible to both insider and outsider attacks. This is mainly because of the lack of a well-defined defense perimeter preventing the effective use of wired defenses including firewalls and intrusion detection systems.

Multiplayer Game for DDoS Attacks Resilience in Ad Hoc Networks

DEFF Research Database (Denmark)

Mikalas, Antonis; Komninos, Nikos; Prasad, Neeli R.

2011-01-01

This paper proposes a multiplayer game to prevent Distributed Denial of Service attack (DDoS) in ad hoc networks. The multiplayer game is based on game theory and cryptographic puzzles. We divide requests from nodes into separate groups which decreases the ability of malicious nodes to cooperate...... with one another in order to effectively make a DDoS attack. Finally, through our experiments we have shown that the total overhead of the multiplayer game as well as the the total time that each node needs to be served is affordable for devices that have limited resources and for environments like ad hoc...

Recreating the seawater mixture composition of HOCs in toxicity tests with Artemia franciscana by passive dosing

Energy Technology Data Exchange (ETDEWEB)

Rojo-Nieto, E., E-mail: elisa.rojo@uca.es [Andalusian Centre of Marine Science and Technology (CACYTMAR), Department of Environmental Technologies, University of Cadiz, 11510 Puerto Real (Spain); Smith, K.E.C. [Department of Environmental Science, Aarhus University, DK-4000 Roskilde (Denmark); Perales, J.A. [Andalusian Centre of Marine Science and Technology (CACYTMAR), Department of Environmental Technologies, University of Cadiz, 11510 Puerto Real (Spain); Mayer, P. [Department of Environmental Science, Aarhus University, DK-4000 Roskilde (Denmark)

2012-09-15

The toxicity testing of hydrophobic organic compounds (HOCs) in aquatic media is generally challenging, and this is even more problematic for mixtures. The hydrophobic properties of these compounds make them difficult to dissolve, and subsequently to maintain constant exposure concentrations. Evaporative and sorptive losses are highly compound-specific, which can alter not only total concentrations, but also the proportions between the compounds in the mixture. Therefore, the general aim of this study was to explore the potential of passive dosing for testing the toxicity of a PAH mixture that recreates the mixture composition found in seawater from a coastal area of Spain, the Bay of Algeciras. First, solvent spiking and passive dosing were compared for their suitability to determine the acute toxicity to Artemia franciscana nauplii of several PAHs at their respective solubility limits. Second, passive dosing was applied to recreate the seawater mixture composition of PAHs measured in a Spanish monitoring program, to test the toxicity of this mixture at different levels. HPLC analysis was used to confirm the reproducibility of the dissolved exposure concentrations for the individual PAHs and mixtures. This study shows that passive dosing has some important benefits in comparison with solvent spiking for testing HOCs in aquatic media. These include maintaining constant exposure concentrations, leading to higher reproducibility and a relative increase in toxicity. Passive dosing is also able to faithfully reproduce real mixtures of HOCs such as PAHs, in toxicity tests, reproducing both the levels and proportions of the different compounds. This provides a useful approach for studying the toxicity of environmental mixtures of HOCs, both with a view to investigating their toxicity but also for determining safety factors before such mixtures result in detrimental effects.

Interference in wireless ad hoc networks with smart antennas

KAUST Repository

Alabdulmohsin, Ibrahim

2014-01-01

In this paper, we show that the use of directional antennas in wireless ad hoc networks can actually increase interference due to limitations of virtual carrier sensing. We derive a simple mathematical expression for interference in both physical

Ad Hoc Human Information Nets for Asymmetric Threat Surveillance

National Research Council Canada - National Science Library

Thiruvathukal, George

2003-01-01

...: Hybrid-Hierarchical Micro-Databases, Query Optimization, and XML for Embedded Systems. After meeting with the program manager, Tom Armour, in Washington, DC, we were able to get a better perspective on the ad hoc nature of the solicitation...

Modelling Mobility in Mobile AD-HOC Network Environments ...

African Journals Online (AJOL)

In the simulation of mobile ad-hoc networks (MANETs), the probability distribution governing the movement of nodes typically varies over time and converges to a steady state distribution, known as the stationary distribution. This paper presents and evaluates the stationary distribution for location, speed and pause time of a ...

Dynamic Mobile IP routers in ad hoc networks

NARCIS (Netherlands)

Kock, B.A.; Schmidt, J.R.

2005-01-01

This paper describes a concept combining mobile IP and ad hoc routing to create a robust mobile network. In this network all nodes are mobile and globally and locally reachable under the same IP address. Essential for implementing this network are the dynamic mobile IP routers. They act as gateways

Ad Hoc Categories and False Memories: Memory Illusions for Categories Created On-The-Spot

Science.gov (United States)

Soro, Jerônimo C.; Ferreira, Mário B.; Semin, Gün R.; Mata, André; Carneiro, Paula

2017-01-01

Three experiments were designed to test whether experimentally created ad hoc associative networks evoke false memories. We used the DRM (Deese, Roediger, McDermott) paradigm with lists of ad hoc categories composed of exemplars aggregated toward specific goals (e.g., going for a picnic) that do not share any consistent set of features. Experiment…

Energy management in wireless cellular and ad-hoc networks

CERN Document Server

Imran, Muhammad; Qaraqe, Khalid; Alouini, Mohamed-Slim; Vasilakos, Athanasios

2016-01-01

This book investigates energy management approaches for energy efficient or energy-centric system design and architecture and presents end-to-end energy management in the recent heterogeneous-type wireless network medium. It also considers energy management in wireless sensor and mesh networks by exploiting energy efficient transmission techniques and protocols. and explores energy management in emerging applications, services and engineering to be facilitated with 5G networks such as WBANs, VANETS and Cognitive networks. A special focus of the book is on the examination of the energy management practices in emerging wireless cellular and ad hoc networks. Considering the broad scope of energy management in wireless cellular and ad hoc networks, this book is organized into six sections covering range of Energy efficient systems and architectures; Energy efficient transmission and techniques; Energy efficient applications and services. .

Power-Controlled MAC Protocols with Dynamic Neighbor Prediction for Ad hoc Networks

Institute of Scientific and Technical Information of China (English)

LI Meng; ZHANG Lin; XIAO Yong-kang; SHAN Xiu-ming

2004-01-01

Energy and bandwidth are the scarce resources in ad hoc networks because most of the mobile nodes are battery-supplied and share the exclusive wireless medium. Integrating the power control into MAC protocol is a promising technique to fully exploit these precious resources of ad hoc wireless networks. In this paper, a new intelligent power-controlled Medium Access Control (MAC) (iMAC) protocol with dynamic neighbor prediction is proposed. Through the elaborate design of the distributed transmit-receive strategy of mobile nodes, iMAC greatly outperforms the prevailing IEEE 802.11 MAC protocols in not only energy conservation but also network throughput. Using the Dynamic Neighbor Prediction (DNP), iMAC performs well in mobile scenes. To the best of our knowledge, iMAC is the first protocol that considers the performance deterioration of power-controlled MAC protocols in mobile scenes and then proposes a solution. Simulation results indicate that DNP is important and necessary for power-controlled MAC protocols in mobile ad hoc networks.

Impulse control disorder related behaviours during long-term rotigotine treatment: a post hoc analysis.

Science.gov (United States)

Antonini, A; Chaudhuri, K R; Boroojerdi, B; Asgharnejad, M; Bauer, L; Grieger, F; Weintraub, D

2016-10-01

Dopamine agonists in Parkinson's disease (PD) are associated with impulse control disorders (ICDs) and other compulsive behaviours (together called ICD behaviours). The frequency of ICD behaviours reported as adverse events (AEs) in long-term studies of rotigotine transdermal patch in PD was evaluated. This was a post hoc analysis of six open-label extension studies up to 6 years in duration. Analyses included patients treated with rotigotine for at least 6 months and administered the modified Minnesota Impulse Disorders Interview. ICD behaviours reported as AEs were identified and categorized. For 786 patients, the mean (±SD) exposure to rotigotine was 49.4 ± 17.6 months. 71 (9.0%) patients reported 106 ICD AEs cumulatively. Occurrence was similar across categories: 2.5% patients reported 'compulsive sexual behaviour', 2.3% 'buying disorder', 2.0% 'compulsive gambling', 1.7% 'compulsive eating' and 1.7% 'punding behaviour'. Examining at 6-month intervals, the incidence was relatively low during the first 30 months; it was higher over the next 30 months, peaking in the 54-60-month period. No ICD AEs were serious, and 97% were mild or moderate in intensity. Study discontinuation occurred in seven (9.9%) patients with ICD AEs; these then resolved in five patients. Dose reduction occurred for 23 AEs, with the majority (73.9%) resolving. In this analysis of >750 patients with PD treated with rotigotine, the frequency of ICD behaviour AEs was 9.0%, with a specific incidence timeline observed. Active surveillance as duration of treatment increases may help early identification and management; once ICD behaviours are present rotigotine dose reduction may be considered. © 2016 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.

Epidemiology and statistics at the Nordic School of Public Health: Teaching and research 1979-2014.

Science.gov (United States)

Eriksson, Bo

2015-08-01

The Nordic School of Public Health (NHV) was jointly founded in 1953 by the Nordic countries. Until 1979, the school provided ad hoc courses on public health topics, using external teachers drawn mainly from the Nordic countries. At the time, the permanent staff of the school was small. In 1979, it began a Master's degree programme and a few academic positions were established and filled, to support these courses. The programme included four main areas: Epidemiology, Social Medicine, Environmental Health and Health Services Administration. Epidemiology was compulsory in all Master of Public Health (MPH) exams, but there were a handful of optional courses that could be substituted for the other subjects.This paper tells the story of Epidemiology at NHV from about 1980, up until closure of the school in 2014. The original MPH model ran until 1995. Nursing Science entered NHV from about 1985 and worked mainly with qualitative research that often focused on individual patients. The new methods attracted nurses, midwives, psychologists and other groups that previously had been less represented in NHV. Being quantitative and population oriented, Epidemiology lost its unique position as a mandatory subject for the MPH examination. In addition the 'New Public Health' proposed by the World Health Organisation (WHO) that advocated health promotion and the philosophy of salutogenesis became a challenge for the programme in epidemiology: pathogenesis no longer was of primary interest. From 1995, the MPH format changed repeatedly and a DrPH programme was begun. For the last 8 years of its existence, NHV offered a reasonably comprehensive, basic course in Epidemiology.Throughout the years, epidemiology training and research at NHV were very traditional. In being a relatively free institution in terms of academic choices, NHV should have contributed to the development and innovation of epidemiology in public health. For several reasons, this did not happen. © 2015 the Nordic

Mitigate DoS and DDoS attacks in Mobile Ad Hoc Networks

DEFF Research Database (Denmark)

Michalas, Antonis; Komninos, Nikos; Prasad, Neeli R.

2011-01-01

This paper proposes a technique to defeat Denial of Service (DoS) and Distributed Denial of Service (DDoS) attacks in Ad Hoc Networks. The technique is divided into two main parts and with game theory and cryptographic puzzles. Introduced first is a new client puzzle to prevent DoS attacks...... in DoS and DDoS attacks. Experimental results show the effectiveness of the approach for devices with limited resources and for environments like ad hoc networks where nodes must exchange information quickly....

Snippets from the past: the evolution of Wade Hampton Frost's epidemiology as viewed from the American Journal of Hygiene/Epidemiology.

Science.gov (United States)

Morabia, Alfredo

2013-10-01

Wade Hampton Frost, who was a Professor of Epidemiology at Johns Hopkins University from 1919 to 1938, spurred the development of epidemiologic methods. His 6 publications in the American Journal of Hygiene, which later became the American Journal of Epidemiology, comprise a 1928 Cutter lecture on a theory of epidemics, a survey-based study of tonsillectomy and immunity to Corynebacterium diphtheriae (1931), 2 papers from a longitudinal study of the incidence of minor respiratory diseases (1933 and 1935), an attack rate ratio analysis of the decline of diphtheria in Baltimore (1936), and a 1936 lecture on the age, time, and cohort analysis of tuberculosis mortality. These 6 American Journal of Hygiene /American Journal of Epidemiology papers attest that Frost's personal evolution mirrored that of the emerging "early" epidemiology: The scope of epidemiology extended beyond the study of epidemics of acute infectious diseases, and rigorous comparative study designs and their associated quantitative methods came to light.

Secure Geographic Routing in Ad Hoc and Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Zahariadis Theodore

2010-01-01

Full Text Available Security in sensor networks is one of the most relevant research topics in resource constrained wireless devices and networks. Several attacks can be suffered in ad hoc and wireless sensor networks (WSN, which are highly susceptible to attacks, due to the limited resources of the nodes. In this paper, we propose innovative and lightweight localization techniques that allow for intrusion identification and isolation schemes and provide accurate location information. This information is used by our routing protocol which additionally incorporates a distributed trust model to prevent several routing attacks to the network. We finally evaluate our algorithms for accurate localization and for secure routing which have been implemented and tested in real ad hoc and wireless sensor networks.

Distributed generation of shared RSA keys in mobile ad hoc networks

Science.gov (United States)

Liu, Yi-Liang; Huang, Qin; Shen, Ying

2005-12-01

Mobile Ad Hoc Networks is a totally new concept in which mobile nodes are able to communicate together over wireless links in an independent manner, independent of fixed physical infrastructure and centralized administrative infrastructure. However, the nature of Ad Hoc Networks makes them very vulnerable to security threats. Generation and distribution of shared keys for CA (Certification Authority) is challenging for security solution based on distributed PKI(Public-Key Infrastructure)/CA. The solutions that have been proposed in the literature and some related issues are discussed in this paper. The solution of a distributed generation of shared threshold RSA keys for CA is proposed in the present paper. During the process of creating an RSA private key share, every CA node only has its own private security. Distributed arithmetic is used to create the CA's private share locally, and that the requirement of centralized management institution is eliminated. Based on fully considering the Mobile Ad Hoc network's characteristic of self-organization, it avoids the security hidden trouble that comes by holding an all private security share of CA, with which the security and robustness of system is enhanced.

Fluoxetine-clonazepam cotherapy for anxious depression: an exploratory, post-hoc analysis of a randomized, double blind study.

Science.gov (United States)

Papakostas, George I; Clain, Alisabet; Ameral, Victoria E; Baer, Lee; Brintz, Carrie; Smith, Ward T; Londborg, Peter D; Glaudin, Vincent; Painter, John R; Fava, Maurizio

2010-01-01

Anxious depression, defined as major depressive disorder (MDD) accompanied by high levels of anxiety, seems to be both common and difficult to treat, with antidepressant monotherapy often yielding modest results. We sought to examine the relative benefits of antidepressant-anxiolytic cotherapy versus antidepressant monotherapy for patients with anxious depression versus without anxious depression. We conducted a post-hoc analysis of an existing dataset (N=80), from a 3-week, randomized, double-blind trial which demonstrated cotherapy with fluoxetine and clonazepam to result in superior efficacy than fluoxetine monotherapy in MDD. The present analysis involved examining whether anxious depression status served as a predictor and moderator of symptom improvement. Anxious depression status was not found to predict symptom improvement, or serve as a moderator of clinical improvement to cotherapy versus monotherapy. However, the advantage in remission rates in favor of cotherapy versus monotherapy was, numerically, much larger for patients with anxious depression (32.2%) than it was for patients without anxious MDD (9.7%). The respective number needed to treat statistic for these two differences in response rates were, approximately, one in three for patients with anxious depression versus one in 10 for patients without anxious depression. The efficacy of fluoxetine-clonazepam cotherapy compared with fluoxetine monotherapy was numerically but not statistically enhanced for patients with anxious depression than those without anxious depression.

Verification of mobile ad hoc networks : an algebraic approach

NARCIS (Netherlands)

Ghassemi, F.; Fokkink, W.J.; Movaghar, A.

2011-01-01

We introduced Computed Network Process Theory to reason about protocols for mobile ad hoc networks (MANETs). Here we explore the applicability of our framework in two regards: model checking and equational reasoning. The operational semantics of our framework is based on constrained labeled

Authentication and consensus overhead in vehicular ad hoc networks

NARCIS (Netherlands)

Petit, Jonathan; Mammeri, Zoubir

Vehicular ad hoc networks aim at increasing passenger safety by exchanging warning messages between vehicles wirelessly. A main challenge is to resist to various malicious abuses and security attacks. However, any security mechanism comes with overhead. We analyze how the authentication algorithm

Challenges of evidence acquisition in wireless ad-hoc networks

CSIR Research Space (South Africa)

Mutanga, MB

2010-05-01

Full Text Available a big challenge. Thus, the aim of this paper is to explore the challenges of acquiring live evidence in wireless ad-hoc networks. We also give some legal requirements of evidence admissibility as outlined in the Communications and Transactions Act...

A New Hybrid Channel Access Scheme for Ad Hoc Networks

National Research Council Canada - National Science Library

Wang, Yu; Garcia-Luna-Aceves, J. J

2002-01-01

Many contention-based channel access schemes have been proposed for multi-hop ad hoc networks in the recent past, and they can be divided into two categories, sender-initiated and receiver-initiated...

Statistical methods for the time-to-event analysis of individual participant data from multiple epidemiological studies

DEFF Research Database (Denmark)

Thompson, Simon; Kaptoge, Stephen; White, Ian

2010-01-01

Meta-analysis of individual participant time-to-event data from multiple prospective epidemiological studies enables detailed investigation of exposure-risk relationships, but involves a number of analytical challenges....

History of the research ad hoc committee on 'dissemination of information' and the special ad hoc committee on 'dissemination of information' of the Atomic Energy Society of Japan

Energy Technology Data Exchange (ETDEWEB)

Itabashi, Keizo [Japan Atomic Energy Agency, Intellectual Resources Department, Tokai, Ibaraki (Japan)

2010-06-15

The Research ad hoc committee on 'Dissemination of information' of the Atomic Energy Society of Japan was held 15 times from Oct. 1970 to Mar 1973. After that, The Special ad hoc committee on 'Dissemination of information' of the Atomic Energy Society of Japan was held 115 times from Apr. 1973 to Mar 2009. The history of these two committees is described. Activity report is arranged including the information on change of the member and topics of the meeting, and the minutes. Furthermore, the document list on International Nuclear Information System (INIS) from Japan is included. (author)

History of the research ad hoc committee on 'dissemination of information' and the special ad hoc committee on 'dissemination of information' of the Atomic Energy Society of Japan

International Nuclear Information System (INIS)

Itabashi, Keizo

2010-06-01

The Research ad hoc committee on 'Dissemination of information' of the Atomic Energy Society of Japan was held 15 times from Oct. 1970 to Mar 1973. After that, The Special ad hoc committee on 'Dissemination of information' of the Atomic Energy Society of Japan was held 115 times from Apr. 1973 to Mar 2009. The history of these two committees is described. Activity report is arranged including the information on change of the member and topics of the meeting, and the minutes. Furthermore, the document list on International Nuclear Information System (INIS) from Japan is included. (author)

On the Geometrical Characteristics of Three-Dimensional Wireless Ad Hoc Networks and Their Applications

Directory of Open Access Journals (Sweden)

2006-01-01

Full Text Available In a wireless ad hoc network, messages are transmitted, received, and forwarded in a finite geometrical region and the transmission of messages is highly dependent on the locations of the nodes. Therefore the study of geometrical relationship between nodes in wireless ad hoc networks is of fundamental importance in the network architecture design and performance evaluation. However, most previous works concentrated on the networks deployed in the two-dimensional region or in the infinite three-dimensional space, while in many cases wireless ad hoc networks are deployed in the finite three-dimensional space. In this paper, we analyze the geometrical characteristics of the three-dimensional wireless ad hoc network in a finite space in the framework of random graph and deduce an expression to calculate the distance probability distribution between network nodes that are independently and uniformly distributed in a finite cuboid space. Based on the theoretical result, we present some meaningful results on the finite three-dimensional network performance, including the node degree and the max-flow capacity. Furthermore, we investigate some approximation properties of the distance probability distribution function derived in the paper.

Access Point Security Service for wireless ad-hoc communication

NARCIS (Netherlands)

Scholten, Johan; Nijdam, M.

2006-01-01

This paper describes the design and implementation of a security solution for ad-hoc peer-to-peer communication. The security solution is based on a scenario where two wireless devices require secure communication, but share no security relationship a priori. The necessary requirements for the

Subsequent Chemotherapy and Treatment Patterns After Abiraterone Acetate in Patients with Metastatic Castration-resistant Prostate Cancer: Post Hoc Analysis of COU-AA-302.

Science.gov (United States)

de Bono, Johann S; Smith, Matthew R; Saad, Fred; Rathkopf, Dana E; Mulders, Peter F A; Small, Eric J; Shore, Neal D; Fizazi, Karim; De Porre, Peter; Kheoh, Thian; Li, Jinhui; Todd, Mary B; Ryan, Charles J; Flaig, Thomas W

2017-04-01

Treatment patterns for metastatic castration-resistant prostate cancer (mCRPC) have changed substantially in the last few years. In trial COU-AA-302 (chemotherapy-naïve men with mCRPC), abiraterone acetate plus prednisone (AA) significantly improved radiographic progression-free survival and overall survival (OS) when compared to placebo plus prednisone (P). This post hoc analysis investigated clinical responses to docetaxel as first subsequent therapy (FST) among patients who progressed following protocol-specified treatment with AA, and characterized subsequent treatment patterns among older (≥75 yr) and younger (AA arm received subsequent treatment with one or more agents approved for mCRPC. Efficacy analysis was performed for patients for whom baseline and at least one post-baseline prostate-specific antigen (PSA) values were available. Baseline and at least one post-baseline PSA values were available for 100 AA patients who received docetaxel as FST. While acknowledging the limitations of post hoc analyses, 40% (40/100) of these patients had an unconfirmed ≥50% PSA decline with first subsequent docetaxel therapy, and 27% (27/100) had a confirmed ≥50% PSA decline. The median docetaxel treatment duration among these 100 patients was 4.2 mo. Docetaxel was the most common FST among older and younger patients from each treatment arm. However, 43% (79/185) of older patients who progressed on AA received no subsequent therapy for mCRPC, compared with 17% (60/361) of younger patients. Patients with mCRPC who progress with AA treatment may still derive benefit from subsequent docetaxel therapy. These data support further assessment of treatment patterns following AA treatment for mCRPC, particularly among older patients. ClinicalTrials.gov NCT00887198. Treatment patterns for advanced prostate cancer have changed substantially in the last few years. This additional analysis provides evidence of clinical benefit for subsequent chemotherapy in men with advanced

FRAMEWORK FOR AD HOC NETWORK COMMUNICATION IN MULTI-ROBOT SYSTEMS

Directory of Open Access Journals (Sweden)

Khilda Slyusar

2016-11-01

Full Text Available Assume a team of mobile robots operating in environments where no communication infrastructure like routers or access points is available. The robots have to create a mobile ad hoc network, in that case, it provides communication on peer-to-peer basis. The paper gives an overview of existing solutions how to route messages in such ad hoc networks between robots that are not directly connected and introduces a design of a software framework for realization of such communication. Feasibility of the proposed framework is shown on the example of distributed multi-robot exploration of an a priori unknown environment. Testing of developed functionality in an exploration scenario is based on results of several experiments with various input conditions of the exploration process and various sizes of a team and is described herein.

Asymptotic Delay Analysis for Cross-Layer Delay-Based Routing in Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Philippe Jacquet

2007-01-01

Full Text Available This paper addresses the problem of the evaluation of the delay distribution via analytical means in IEEE 802.11 wireless ad hoc networks. We show that the asymptotic delay distribution can be expressed as a power law. Based on the latter result, we present a cross-layer delay estimation protocol and we derive new delay-distribution-based routing algorithms, which are well adapted to the QoS requirements of real-time multimedia applications. In fact, multimedia services are not sensitive to average delays, but rather to the asymptotic delay distributions. Indeed, video streaming applications drop frames when they are received beyond a delay threshold, determined by the buffer size. Although delay-distribution-based routing is an NP-hard problem, we show that it can be solved in polynomial time when the delay threshold is large, because of the asymptotic power law distribution of the link delays.

Preventive Ceftriaxone in Patients with Stroke Treated with Intravenous Thrombolysis: Post Hoc Analysis of the Preventive Antibiotics in Stroke Study

NARCIS (Netherlands)

Vermeij, Jan-Dirk; Westendorp, Willeke F.; Roos, Yvo B.; Brouwer, Matthijs C.; van de Beek, Diederik; Nederkoorn, Paul J.

2016-01-01

The Preventive Antibiotics in Stroke Study (PASS), a randomized open-label masked endpoint trial, showed that preventive ceftriaxone did not improve functional outcome at 3 months in patients with acute stroke (adjusted common OR 0.95; 95% CI 0.82-1.09). Post-hoc analyses showed that among patients

A Novel Routing Algorithm for Vehicular Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Raúl Aquino Santos

2008-01-01

Full Text Available Este trabajo examina la importancia de las redes inalámbricas ad hoc y el algoritmo de enrutamiento con inundación basada en grupos (LORA-CBF para la comunicación inter-vehicular con la finalidad de optimizar el flujo de tráfico e incrementar la seguridad en las autopistas. Se discute el algoritmo de enrutamiento LORA-CBF y se presentan los resultados de simulaciones realizadas en OPNET de una autopista con alta movilidad vehicular. Primero, el modelo de simulación propuesto se valida a pequeña escala con resultados experimentales. Posteriormente, se emplean simulaciones de nuestro modelo comparándolos con Ad Hoc On-Demand Distance Vector (AODV y Dynamic Source Routing (DSR. Finalmente, se emplea un modelo de tráfico microscópico desarrollado en OPNET para simular la movilidad de 250 vehículos en una autopista y se aplica el algoritmo de enrutamiento LORA-CBF en un escenario vehicular.

Profesi Epidemiologi

Directory of Open Access Journals (Sweden)

Buchari Lapau

2011-01-01

Full Text Available Makalah ini pertama kali menjelaskan perlu adanya profesi kesehatan masyarakat dalam rangka pembangunan kesehatan. Lalu dijelaskan apa profesi itu dan standar keberadaan profesi, atas dasar mana dapat ditetapkan bahwa pelayanan epidemiologi merupakan salah satu profesi. Dalam rangka pembinaan profesi kesehatan masyarakat, IAKMI dan APTKMI telah membentuk Majelis Kolegium Kesehatan Masyarakat Indonesia (MKKMI yang terdiri atas 8 kolegium antara lain Kolegium Epidemiologi, yang telah menyusun Standar Profesi Epidemiologi yang terdiri atas beberapa standar. Masing-masing standar dijelaskan mulai dari kurikulum, standar pelayanan epidmiologi, profil epidemiolog kesehatan, peran epidemiolog kesehatan, fungsi epidemiolog kesehatan, standar kompetensi epidemiologi, dan standar pendidikan profesi epidemiologi.

simulate_CAT: A Computer Program for Post-Hoc Simulation for Computerized Adaptive Testing

Directory of Open Access Journals (Sweden)

İlker Kalender

2015-06-01

Full Text Available This paper presents a computer software developed by the author. The software conducts post-hoc simulations for computerized adaptive testing based on real responses of examinees to paper and pencil tests under different parameters that can be defined by user. In this paper, short information is given about post-hoc simulations. After that, the working principle of the software is provided and a sample simulation with required input files is shown. And last, output files are described

Performance Analysis of the IEEE 802.11p Multichannel MAC Protocol in Vehicular Ad Hoc Networks.

Science.gov (United States)

Song, Caixia

2017-12-12

Vehicular Ad Hoc Networks (VANETs) employ multichannel to provide a variety of safety and non-safety applications, based on the IEEE 802.11p and IEEE 1609.4 protocols. The safety applications require timely and reliable transmissions, while the non-safety applications require efficient and high throughput. In the IEEE 1609.4 protocol, operating interval is divided into alternating Control Channel (CCH) interval and Service Channel (SCH) interval with an identical length. During the CCH interval, nodes transmit safety-related messages and control messages, and Enhanced Distributed Channel Access (EDCA) mechanism is employed to allow four Access Categories (ACs) within a station with different priorities according to their criticality for the vehicle's safety. During the SCH interval, the non-safety massages are transmitted. An analytical model is proposed in this paper to evaluate performance, reliability and efficiency of the IEEE 802.11p and IEEE 1609.4 protocols. The proposed model improves the existing work by taking serval aspects and the character of multichannel switching into design consideration. Extensive performance evaluations based on analysis and simulation help to validate the accuracy of the proposed model and analyze the capabilities and limitations of the IEEE 802.11p and IEEE 1609.4 protocols, and enhancement suggestions are given.

Illustrating, Quantifying, and Correcting for Bias in Post-hoc Analysis of Gene-Based Rare Variant Tests of Association

Science.gov (United States)

Grinde, Kelsey E.; Arbet, Jaron; Green, Alden; O'Connell, Michael; Valcarcel, Alessandra; Westra, Jason; Tintle, Nathan

2017-01-01

To date, gene-based rare variant testing approaches have focused on aggregating information across sets of variants to maximize statistical power in identifying genes showing significant association with diseases. Beyond identifying genes that are associated with diseases, the identification of causal variant(s) in those genes and estimation of their effect is crucial for planning replication studies and characterizing the genetic architecture of the locus. However, we illustrate that straightforward single-marker association statistics can suffer from substantial bias introduced by conditioning on gene-based test significance, due to the phenomenon often referred to as “winner's curse.” We illustrate the ramifications of this bias on variant effect size estimation and variant prioritization/ranking approaches, outline parameters of genetic architecture that affect this bias, and propose a bootstrap resampling method to correct for this bias. We find that our correction method significantly reduces the bias due to winner's curse (average two-fold decrease in bias, p bias and improve inference in post-hoc analysis of gene-based tests under a wide variety of genetic architectures. PMID:28959274

Epidemiology of Zygomycosis: Analysis of National Data from Pathological Autopsy Cases in Japan.

Science.gov (United States)

Suzuki, Yuhko; Kume, Hikaru; Togano, Tomiteru; Ohto, Hitoshi

2017-01-01

To identify recent trends in the frequency of zygomycosis in autopsy cases, we conducted epidemiological analysis every four years from 1989 to 2009 using national data reported in the "Annual of Pathological Autopsy Cases in Japan." 153,615 cases were autopsied, of which 6622 (4.3%) were found to have had mycosis. Among these, there were 243 cases (3.7%) of zygomycosis, which was the fourth most predominant causative agent of mycoses among the monopathogen mycoses. Of the complicated mycoses, zygomycosis accounted for 56 cases. A total of 299 cases with zygomycoses were observed. The frequency of zygomycosis appeared to be generally stable over the twenty-year period from 1989 to 2009, at around 4% of autopsy cases having mycosis. Younger patients tended to have severe and complicated infections that were characteristic of zygomycosis, compared with non-zygomycosis. The pulmonary and gastrointestinal (GI) systems were the most common foci in our analysis, reflecting the severity of zygomycosis in these sites. Hematological disease was the most frequent underlying disease, but there was a peak of neonatal infections in 2009, which was the first time that this was observed in our studies. These results of the epidemiological analysis of autopsy cases with mycosis demonstrate that clinicians should promptly recognize and treat zygomycosis.

UMDR: Multi-Path Routing Protocol for Underwater Ad Hoc Networks with Directional Antenna

Science.gov (United States)

Yang, Jianmin; Liu, Songzuo; Liu, Qipei; Qiao, Gang

2018-01-01

This paper presents a new routing scheme for underwater ad hoc networks based on directional antennas. Ad hoc networks with directional antennas have become a hot research topic because of space reuse may increase networks capacity. At present, researchers have applied traditional self-organizing routing protocols (such as DSR, AODV) [1] [2] on this type of networks, and the routing scheme is based on the shortest path metric. However, such routing schemes often suffer from long transmission delays and frequent link fragmentation along the intermediate nodes of the selected route. This is caused by a unique feature of directional transmission, often called as “deafness”. In this paper, we take a different approach to explore the advantages of space reuse through multipath routing. This paper introduces the validity of the conventional routing scheme in underwater ad hoc networks with directional antennas, and presents a special design of multipath routing algorithm for directional transmission. The experimental results show a significant performance improvement in throughput and latency.

Improving VANETs Connectivity with a Totally Ad Hoc Living Mobile Backbone

Directory of Open Access Journals (Sweden)

Joilson Alves Junior

2015-01-01

Full Text Available The vehicular ad hoc network (VANET for intelligent transportation systems is an emerging concept to improve transportation security, reliability, and management. The network behavior can be totally different in topological aspects because of the mobility of vehicular nodes. The topology can be fully connected when the flow of vehicles is high and may have low connectivity or be invalid when the flow of vehicles is low or unbalanced. In big cities, the metropolitan buses that travel on exclusive lanes may be used to set up a metropolitan vehicular data network (backbone, raising the connectivity among the vehicles. Therefore, this paper proposes the implementation of a living mobile backbone, totally ad hoc (MOB-NET, which will provide infrastructure and raise the network connectivity. In order to show the viability of MOB-NET, statistical analyses were made with real data of express buses that travel through exclusive lanes, besides evaluations through simulations and analytic models. The statistic, analytic, and simulation results prove that the buses that travel through exclusive lanes can be used to build a communication network totally ad hoc and provide connectivity in more than 99% of the time, besides raising the delivery rate up to 95%.

Collaboration Layer for Robots in Mobile Ad-hoc Networks

DEFF Research Database (Denmark)

Borch, Ole; Madsen, Per Printz; Broberg, Jacob Honor´e

2009-01-01

In many applications multiple robots in Mobile Ad-hoc Networks are required to collaborate in order to solve a task. This paper shows by proof of concept that a Collaboration Layer can be modelled and designed to handle the collaborative communication, which enables robots in small to medium size...

Distributed optimization of a multisubchannel Ad Hoc cognitive radio network

KAUST Repository

Leith, Alex

2012-05-01

In this paper, we study the distributed-duality-based optimization of a multisubchannel ad hoc cognitive radio network (CRN) that coexists with a multicell primary radio network (PRN). For radio resource allocation in multiuser orthogonal frequency-division multiplexing (MU-OFDM) systems, the orthogonal-access-based exclusive subchannel assignment (ESA) technique has been a popular method, but it is suboptimal in ad hoc networks, because nonorthogonal access between multiple secondary-user links by using shared subchannel assignment (SSA) can bring a higher weighted sum rate. We utilize the Lagrangian dual composition tool and design low-complexity near-optimal SSA resource allocation methods, assuming practical discrete-rate modulation and that the CRN-to-PRN interference constraint has to strictly be satisfied. However, available SSA methods for CRNs are either suboptimal or involve high complexity and suffer from slow convergence. To address this problem, we design fast-convergence SSA duality schemes and introduce several novel methods to increase the speed of convergence and to satisfy various system constraints with low complexity. For practical implementation in ad hoc CRNs, we design distributed-duality schemes that involve only a small number of CRN local information exchanges for dual update. The effects of many system parameters are presented through simulation results, which show that the near-optimal SSA duality scheme can perform significantly better than the suboptimal ESA duality and SSA-iterative waterfilling schemes and that the performance loss of the distributed schemes is small, compared with their centralized counterparts. © 2012 IEEE.

Minimizing Broadcast Expenses in Clustered Ad-hoc Networks

Directory of Open Access Journals (Sweden)

S. Zeeshan Hussain

2018-01-01

Full Text Available One way to minimize the broadcast expenses of routing protocols is to cluster the network. In clustered ad-hoc networks, all resources can be managed easily by resolving scalability issues. However, blind query broadcast is a major issue that leads to the broadcast storm problem in clustered ad-hoc networks. This query broadcast is done to carry out the route-search task that leads to the unnecessary propagation of route-query even after route has been found. Hence, this query propagation poses the problem of congestion in the network. In particular this motivates us to propose a query-control technique in such networks which works based on broadcast repealing. A huge amount of work has been devoted to propose the query control broadcasting techniques. However, such techniques used in traditional broadcasting mechanisms need to be properly extended for use in the cluster based routing architecture. In this paper, query-control technique is proposed for cluster based routing technique to reduce the broadcast expenses. Finally, we report some experiments which compare the proposed technique to other commonly used techniques including standard one-class AODV that follows TTL-sequence based broadcasting technique.

Applied immuno-epidemiological research: an approach for integrating existing knowledge into the statistical analysis of multiple immune markers.

Science.gov (United States)

Genser, Bernd; Fischer, Joachim E; Figueiredo, Camila A; Alcântara-Neves, Neuza; Barreto, Mauricio L; Cooper, Philip J; Amorim, Leila D; Saemann, Marcus D; Weichhart, Thomas; Rodrigues, Laura C

2016-05-20

Immunologists often measure several correlated immunological markers, such as concentrations of different cytokines produced by different immune cells and/or measured under different conditions, to draw insights from complex immunological mechanisms. Although there have been recent methodological efforts to improve the statistical analysis of immunological data, a framework is still needed for the simultaneous analysis of multiple, often correlated, immune markers. This framework would allow the immunologists' hypotheses about the underlying biological mechanisms to be integrated. We present an analytical approach for statistical analysis of correlated immune markers, such as those commonly collected in modern immuno-epidemiological studies. We demonstrate i) how to deal with interdependencies among multiple measurements of the same immune marker, ii) how to analyse association patterns among different markers, iii) how to aggregate different measures and/or markers to immunological summary scores, iv) how to model the inter-relationships among these scores, and v) how to use these scores in epidemiological association analyses. We illustrate the application of our approach to multiple cytokine measurements from 818 children enrolled in a large immuno-epidemiological study (SCAALA Salvador), which aimed to quantify the major immunological mechanisms underlying atopic diseases or asthma. We demonstrate how to aggregate systematically the information captured in multiple cytokine measurements to immunological summary scores aimed at reflecting the presumed underlying immunological mechanisms (Th1/Th2 balance and immune regulatory network). We show how these aggregated immune scores can be used as predictors in regression models with outcomes of immunological studies (e.g. specific IgE) and compare the results to those obtained by a traditional multivariate regression approach. The proposed analytical approach may be especially useful to quantify complex immune

Service for fault tolerance in the Ad Hoc Networks based on Multi Agent Systems

Directory of Open Access Journals (Sweden)

Ghalem Belalem

2011-02-01

Full Text Available The Ad hoc networks are distributed networks, self-organized and does not require infrastructure. In such network, mobile infrastructures are subject of disconnections. This situation may concern a voluntary or involuntary disconnection of nodes caused by the high mobility in the Ad hoc network. In these problems we are trying through this work to contribute to solving these problems in order to ensure continuous service by proposing our service for faults tolerance based on Multi Agent Systems (MAS, which predict a problem and decision making in relation to critical nodes. Our work contributes to study the prediction of voluntary and involuntary disconnections in the Ad hoc network; therefore we propose our service for faults tolerance that allows for effective distribution of information in the Network by selecting some objects of the network to be duplicates of information.

Capacity, delay and mobility in wireless ad-hoc networks

NARCIS (Netherlands)

Bansal, N.; Liu, Z.

2003-01-01

Network throughput and packet delay are two important parameters in the design and the evaluation of routing protocols for ad-hoc networks. While mobility has been shown to increase the capacity of a network, it is not clear whether the delay can be kept low without trading off the throughput. We

Quality control in the neutron activation analysis of biological markers for selenium in epidemiological investigations

International Nuclear Information System (INIS)

Morris, J.S.; Ngwenyama, R.A.; Guthrie, J.M.; Brockman, J.D.; Spate, V.L.; Robertson, J.D.

2008-01-01

Instrumental neutron activation analysis is routinely used at the MURR to quantify selenium in prospectively-collected biologic markers including blood serum and toenails. These specimens are typically collected from well-defined cohort populations participating in investigations assessing selenium intake and incidence of chronic disease endpoints. These epidemiological investigations, whether observational (case-control) or clinical (intervention), typically generate thousands of samples. The purpose of this paper is to assess, through evaluation of quality control results, if the achievable accuracy and precision in the measurement of selenium using NAA is adequate to determine a relative risk of 1.2 at high confidence in epidemiological studies. (author)

On-Demand Routing in Multi-hop Wireless Mobile Ad Hoc Networks

National Research Council Canada - National Science Library

Maltz, David A

2001-01-01

.... Routing protocols used in ad hoc networks must automatically adjust to environments that can vary between the extremes of high mobility with low bandwidth, and low mobility with high bandwidth...

Throughput and Fairness of Collision Avoidance Protocols in Ad Hoc Networks

National Research Council Canada - National Science Library

Garcia-Luna-Aceves, J. J; Wang, Yu

2004-01-01

.... In Section 1, The authors present an analytical modeling to derive the saturation throughput of these sender-initiated collision avoidance protocols in multi-hop ad hoc networks with nodes randomly...

Whole genome sequencing options for bacterial strain typing and epidemiologic analysis based on single nucleotide polymorphism versus gene-by-gene-based approaches.

Science.gov (United States)

Schürch, A C; Arredondo-Alonso, S; Willems, R J L; Goering, R V

2018-04-01

Whole genome sequence (WGS)-based strain typing finds increasing use in the epidemiologic analysis of bacterial pathogens in both public health as well as more localized infection control settings. This minireview describes methodologic approaches that have been explored for WGS-based epidemiologic analysis and considers the challenges and pitfalls of data interpretation. Personal collection of relevant publications. When applying WGS to study the molecular epidemiology of bacterial pathogens, genomic variability between strains is translated into measures of distance by determining single nucleotide polymorphisms in core genome alignments or by indexing allelic variation in hundreds to thousands of core genes, assigning types to unique allelic profiles. Interpreting isolate relatedness from these distances is highly organism specific, and attempts to establish species-specific cutoffs are unlikely to be generally applicable. In cases where single nucleotide polymorphism or core gene typing do not provide the resolution necessary for accurate assessment of the epidemiology of bacterial pathogens, inclusion of accessory gene or plasmid sequences may provide the additional required discrimination. As with all epidemiologic analysis, realizing the full potential of the revolutionary advances in WGS-based approaches requires understanding and dealing with issues related to the fundamental steps of data generation and interpretation. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

PNNI routing support for ad hoc mobile networking: The multilevel case

Energy Technology Data Exchange (ETDEWEB)

Martinez, L.; Sholander, P.; Tolendino, L.

1998-01-01

This contribution extends the Outside Nodal Hierarchy List (ONHL) procedures described in ATM Forum Contributions 97-0766 and 97-0933. These extensions allow multiple mobile networks to form either an ad hoc network or an extension of a fixed PNNI infrastructure. A previous contribution (97-1073) covered the simplest case where the top-most Logical Group Nodes (LGNs), in those mobile networks, all resided at the same level in a PNNI hierarchy. This contribution covers the more general case wherein those top-most LGNs may reside at different PNNI hierarchy levels. Both of the SNL contributions consider flat ad hoc network architectures in the sense that each mobile network always participates in the PNNI hierarchy at the pre-configured level of its top-most LGN.

Intelligent routing protocol for ad hoc wireless network

Science.gov (United States)

Peng, Chaorong; Chen, Chang Wen

2006-05-01

A novel routing scheme for mobile ad hoc networks (MANETs), which combines hybrid and multi-inter-routing path properties with a distributed topology discovery route mechanism using control agents is proposed in this paper. In recent years, a variety of hybrid routing protocols for Mobile Ad hoc wireless networks (MANETs) have been developed. Which is proactively maintains routing information for a local neighborhood, while reactively acquiring routes to destinations beyond the global. The hybrid protocol reduces routing discovery latency and the end-to-end delay by providing high connectivity without requiring much of the scarce network capacity. On the other side the hybrid routing protocols in MANETs likes Zone Routing Protocol still need route "re-discover" time when a route between zones link break. Sine the topology update information needs to be broadcast routing request on local zone. Due to this delay, the routing protocol may not be applicable for real-time data and multimedia communication. We utilize the advantages of a clustering organization and multi-routing path in routing protocol to achieve several goals at the same time. Firstly, IRP efficiently saves network bandwidth and reduces route reconstruction time when a routing path fails. The IRP protocol does not require global periodic routing advertisements, local control agents will automatically monitor and repair broke links. Secondly, it efficiently reduces congestion and traffic "bottlenecks" for ClusterHeads in clustering network. Thirdly, it reduces significant overheads associated with maintaining clusters. Fourthly, it improves clusters stability due to dynamic topology changing frequently. In this paper, we present the Intelligent Routing Protocol. First, we discuss the problem of routing in ad hoc networks and the motivation of IRP. We describe the hierarchical architecture of IRP. We describe the routing process and illustrate it with an example. Further, we describe the control manage

ENERGY EFFICIENT ROUTING PROTOCOLS FOR WIRELESS AD HOC NETWORKS – A SURVEY

Directory of Open Access Journals (Sweden)

K. Sankar

2012-06-01

Full Text Available Reducing energy consumption, primarily with the goal of extending the lifetime of battery-powered devices, has emerged as a fundamental challenge in wireless communication. The performance of the medium access control (MAC scheme not only has a fairly significant end-result on the behaviour of the routing approach employed, but also on the energy consumption of the wireless network interface card (NIC. We investigate the inadequacies of the MAC schemes designed for ad hoc wireless networks in the context of power awareness herein. The topology changes due to uncontrollable factors such as node mobility, weather, interference, noise, as well as on controllable parameters such as transmission power and antenna direction results in significant amount of energy loss. Controlling rapid topology changes by minimizing the maximum transmission power used in ad hoc wireless networks, while still maintaining networks connectivity can prolong battery life and hence network lifetime considerably. In addition, we systematically explore the potential energy consumption pitfalls of non–power-based and power based routing schemes. We suggest a thorough energy-based performance survey of energy aware routing protocols for wireless mobile ad-hoc networks. We also present the statistical performance metrics measured by our simulations.

Exploiting Mobile Ad Hoc Networking and Knowledge Generation to Achieve Ambient Intelligence

Directory of Open Access Journals (Sweden)

Anna Lekova

2012-01-01

Full Text Available Ambient Intelligence (AmI joins together the fields of ubiquitous computing and communications, context awareness, and intelligent user interfaces. Energy, fault-tolerance, and mobility are newly added dimensions of AmI. Within the context of AmI the concept of mobile ad hoc networks (MANETs for “anytime and anywhere” is likely to play larger roles in the future in which people are surrounded and supported by small context-aware, cooperative, and nonobtrusive devices that will aid our everyday life. The connection between knowledge generation and communication ad hoc networking is symbiotic—knowledge generation utilizes ad hoc networking to perform their communication needs, and MANETs will utilize the knowledge generation to enhance their network services. The contribution of the present study is a distributed evolving fuzzy modeling framework (EFMF to observe and categorize relationships and activities in the user and application level and based on that social context to take intelligent decisions about MANETs service management. EFMF employs unsupervised online one-pass fuzzy clustering method to recognize nodes' mobility context from social scenario traces and ubiquitously learn “friends” and “strangers” indirectly and anonymously.

Inherent Risk Factors for Nosocomial Infection in the Long Stay Critically Ill Child Without Known Baseline Immunocompromise: A Post Hoc Analysis of the CRISIS Trial.

Science.gov (United States)

Carcillo, Joseph A; Dean, J Michael; Holubkov, Richard; Berger, John; Meert, Kathleen L; Anand, Kanwaljeet J S; Zimmerman, Jerry; Newth, Christopher J; Harrison, Rick; Burr, Jeri; Willson, Douglas F; Nicholson, Carol; Bell, Michael J; Berg, Robert A; Shanley, Thomas P; Heidemann, Sabrina M; Dalton, Heidi; Jenkins, Tammara L; Doctor, Allan; Webster, Angie

2016-11-01

Nosocomial infection remains an important health problem in long stay (>3 days) pediatric intensive care unit (PICU) patients. Admission risk factors related to the development of nosocomial infection in long stay immune competent patients in particular are not known. Post-hoc analysis of the previously published Critical Illness Stress induced Immune Suppression (CRISIS) prevention trial database, to identify baseline risk factors for nosocomial infection. Because there was no difference between treatment arms of that study in nosocomial infection in the population without known baseline immunocompromise, both arms were combined and the cohort that developed nosocomial infection was compared with the cohort that did not. There were 254 long stay PICU patients without known baseline immunocompromise. Ninety (35%) developed nosocomial infection, and 164 (65%) did not. Admission characteristics associated with increased nosocomial infection risk were increased age, higher Pediatric Risk of Mortality version III score, the diagnoses of trauma or cardiac arrest and lymphopenia (P risk of developing nosocomial infection (P risk factors (P < 0.05); whereas trauma tended to be related to nosocomial infection development (P = 0.07). These data suggest that increasing age, cardiac arrest and lymphopenia predispose long stay PICU patients without known baseline immunocompromise to nosocomial infection. These findings may inform pre-hoc stratification randomization strategies for prospective studies designed to prevent nosocomial infection in this population.

How to use sequence analysis for life course epidemiology? An example on HIV-positive Sub-Saharan migrants in France.

Science.gov (United States)

Gosselin, Anne; Desgrées du Loû, Annabel; Lelièvre, Eva

2018-06-01

Life course epidemiology is now an established field in social epidemiology; in sociodemography, the quantitative analysis of biographies recently experienced significant trend from event history analysis to sequence analysis. The purpose of this article is to introduce and adapt this methodology to a social epidemiology question, taking the example of the impact of HIV diagnosis on Sub-Saharan migrants' residential trajectories in the Paris region. The sample consists of 640 migrants born in Sub-Saharan Africa receiving HIV care. They were interviewed in healthcare facilities in the Paris region within the PARCOURS project, conducted from 2012 to 2013, using life event history calendars, which recorded year by year their health, family and residential histories. We introduce a two-step methodological approach consisting of (1) sequence analysis by optimal matching to build a typology of migrants' residential pathways before and after diagnosis, and (2) a Cox model of the probability to experience changes in the residential situation. The seven-clusters typology shows that for a majority, the HIV diagnosis did not entail changes in residential situation. However 30% of the migrants experienced a change in their residential situation at time of diagnosis. The Cox model analysis reveals that this residential change was in fact moving in with one's partner (HR 2.99, P<0.000) rather than network rejection. This original combination of sequence analysis and Cox models is a powerful process that could be applied to other themes and constitutes a new approach in the life course epidemiology toolbox. NCT02566148. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

QoS Routing in Ad-Hoc Networks Using GA and Multi-Objective Optimization

Directory of Open Access Journals (Sweden)

Admir Barolli

2011-01-01

Full Text Available Much work has been done on routing in Ad-hoc networks, but the proposed routing solutions only deal with the best effort data traffic. Connections with Quality of Service (QoS requirements, such as voice channels with delay and bandwidth constraints, are not supported. The QoS routing has been receiving increasingly intensive attention, but searching for the shortest path with many metrics is an NP-complete problem. For this reason, approximated solutions and heuristic algorithms should be developed for multi-path constraints QoS routing. Also, the routing methods should be adaptive, flexible, and intelligent. In this paper, we use Genetic Algorithms (GAs and multi-objective optimization for QoS routing in Ad-hoc Networks. In order to reduce the search space of GA, we implemented a search space reduction algorithm, which reduces the search space for GAMAN (GA-based routing algorithm for Mobile Ad-hoc Networks to find a new route. We evaluate the performance of GAMAN by computer simulations and show that GAMAN has better behaviour than GLBR (Genetic Load Balancing Routing.

Car-to-Pedestrian Communication Safety System Based on the Vehicular Ad-Hoc Network Environment: A Systematic Review

Directory of Open Access Journals (Sweden)

Peng Jing

2017-10-01

Full Text Available With the unparalleled growth of motor vehicles, traffic accident between pedestrians and vehicles is one of the most serious issues in the word-wild. Plenty of injuries and fatalities are caused by the traffic accidents and crashes. The connected vehicular ad hoc network as an emerging approach which has the potential to reduce and even avoid accidents have been focused on by many researchers. A large number of car-to-pedestrian communication safety systems based on the vehicular ad hoc network are researching and developing. However, to our limited knowledge, a systematic review about the car-to-pedestrian communication safety system based on the vehicular ad-hoc network has not be written. The purpose and goal of this review is to systematically evaluate and access the reliability of car-to-pedestrian communication safety system based on the vehicular ad-hoc network environment and provide some recommendations for the future works according to throwing some light on the previous literatures. A quality evaluation was developed through established items and instruments tailored to this review. Future works are needed to focus on developing a valid as well as effective communication safety system based on the vehicular ad hoc network to protect the vulnerable road users.

Studies on urban vehicular ad-hoc networks

CERN Document Server

Zhu, Hongzi

2013-01-01

With the advancement of wireless technology, vehicular ad hoc networks (VANETs) are emerging as a promising approach to realizing 'smart cities' and addressing many important transportation problems such as road safety, efficiency, and convenience.This brief provides an introduction to the large trace data set collected from thousands of taxis and buses in Shanghai, the largest metropolis in China. It also presents the challenges, design issues, performance modeling and evaluation of a wide spectrum of VANET research topics, ranging from realistic vehicular mobility models and opportunistic ro

Analysis of those national analytic epidemiological studies that by obtention the exposure-response functions

International Nuclear Information System (INIS)

Molina, E.; Meneses, E.

2003-01-01

The Impact Pathway methodology, developed in the frame of Extern E project for estimating of the external costs or externalities of the energy use, has as one of their main steps the health impact evaluation. This evaluation is carried out through exposure-response functions. In previous estimates of the external costs of power generation in Cuba, functions obtained in international studies were used. The main objective of this work was to carry out a summarized critical analysis of those national analytic epidemiological studies that, according the exposed methodology, consider the main aspects specialized with views to the possible preliminary proposal of functions exposure-response (FER) based own in epidemiologic evidences. In agreement with the analysis, the results show that the great majority of the studies are not useful for the FER establishment, at least in their present form. A minority studies exists that contributes limited evidence and their reanalysis could increase their contribution to the propose purpose. Finally the main problems found in the studies are enumerated revision object

TMAP ad hoc Working Group Fish Progress report 2007

NARCIS (Netherlands)

Bolle, L.J.; Damm, U.; Diederichs, B.; Jager, Z.; Overzee, van H.M.J.

2007-01-01

Building on previous work done by the TMAP ad hoc Working Group Fish, a meeting and a workshop were held in Hamburg in June and October 2007. The most important aim of both was to come to an agreement on how to proceed with the data preparations and analyses, and to facilitate the exchange of data

Optimal design of cluster-based ad-hoc networks using probabilistic solution discovery

International Nuclear Information System (INIS)

Cook, Jason L.; Ramirez-Marquez, Jose Emmanuel

2009-01-01

The reliability of ad-hoc networks is gaining popularity in two areas: as a topic of academic interest and as a key performance parameter for defense systems employing this type of network. The ad-hoc network is dynamic and scalable and these descriptions are what attract its users. However, these descriptions are also synonymous for undefined and unpredictable when considering the impacts to the reliability of the system. The configuration of an ad-hoc network changes continuously and this fact implies that no single mathematical expression or graphical depiction can describe the system reliability-wise. Previous research has used mobility and stochastic models to address this challenge successfully. In this paper, the authors leverage the stochastic approach and build upon it a probabilistic solution discovery (PSD) algorithm to optimize the topology for a cluster-based mobile ad-hoc wireless network (MAWN). Specifically, the membership of nodes within the back-bone network or networks will be assigned in such as way as to maximize reliability subject to a constraint on cost. The constraint may also be considered as a non-monetary cost, such as weight, volume, power, or the like. When a cost is assigned to each component, a maximum cost threshold is assigned to the network, and the method is run; the result is an optimized allocation of the radios enabling back-bone network(s) to provide the most reliable network possible without exceeding the allowable cost. The method is intended for use directly as part of the architectural design process of a cluster-based MAWN to efficiently determine an optimal or near-optimal design solution. It is capable of optimizing the topology based upon all-terminal reliability (ATR), all-operating terminal reliability (AoTR), or two-terminal reliability (2TR)

Local level epidemiological analysis of TB in people from a high incidence country of birth

OpenAIRE

Massey Peter D; Durrheim David N; Stephens Nicola; Christensen Amanda

2013-01-01

Abstract Background The setting for this analysis is the low tuberculosis (TB) incidence state of New South Wales (NSW), Australia. Local level analysis of TB epidemiology in people from high incidence countries-of-birth (HIC) in a low incidence setting has not been conducted in Australia and has not been widely reported. Local level analysis could inform measures such as active case finding and targeted earlier diagnosis. The aim of this study was to use a novel approach to identify local ar...

A-priori and post-hoc segmentation in the design of healthy eating campaigns

DEFF Research Database (Denmark)

Kazbare, Laura; van Trijp, Hans C. M.; Eskildsen, Jacob Kjær

2010-01-01

. Although such practice may be justifiable from the practical point of view, it is unclear how effective these implicit segmentations are. In this study the authors argue that  it is important to transcend demographic boundaries and to further segment demographic groups. A study with 13-15-year-old...... and a post-hoc segmentation. The results of the study show that it is useful and also ethical to differentiate people using segmentation methods, since it facilitates reaching more vulnerable segments of society that in general resist change. It also demonstrates that post-hoc segmentation is more helpful...

An Ad-Hoc Adaptive Pilot Model for Pitch Axis Gross Acquisition Tasks

Science.gov (United States)

Hanson, Curtis E.

2012-01-01

An ad-hoc algorithm is presented for real-time adaptation of the well-known crossover pilot model and applied to pitch axis gross acquisition tasks in a generic fighter aircraft. Off-line tuning of the crossover model to human pilot data gathered in a fixed-based high fidelity simulation is first accomplished for a series of changes in aircraft dynamics to provide expected values for model parameters. It is shown that in most cases, for this application, the traditional crossover model can be reduced to a gain and a time delay. The ad-hoc adaptive pilot gain algorithm is shown to have desirable convergence properties for most types of changes in aircraft dynamics.

The Ad Hoc process to strengthen the framework convention on climate change

Energy Technology Data Exchange (ETDEWEB)

Ramakrishna, K.; Deutz, A.M.; Jacobsen, L.A. [eds.

1995-11-01

The Woods Hole Research Center convened an International Conference on The Ad Hoc Process to Strengthen the Framework Convention on Climate Change in Woods Hole, MA, on October 7-9, 1995. The conference was conducted to examine the prospects for successful adoption of a protocol to the Framework Convention on Climate Change by 1997. In preparation for the Second session of the Ad Hoc Group on the Berlin Mandate, several governmental and nongovernmental representatives met in Woods Hole to discuss the process and possible outcome of the Berlin Mandate negotiations for a protocol or other legal instrument to strengthen the Convention. The conference was by invitation and all participants attended in their personal capacities.

Simulating Nationwide Pandemics: Applying the Multi-scale Epidemiologic Simulation and Analysis System to Human Infectious Diseases

Energy Technology Data Exchange (ETDEWEB)

Dombroski, M; Melius, C; Edmunds, T; Banks, L E; Bates, T; Wheeler, R

2008-09-24

This study uses the Multi-scale Epidemiologic Simulation and Analysis (MESA) system developed for foreign animal diseases to assess consequences of nationwide human infectious disease outbreaks. A literature review identified the state of the art in both small-scale regional models and large-scale nationwide models and characterized key aspects of a nationwide epidemiological model. The MESA system offers computational advantages over existing epidemiological models and enables a broader array of stochastic analyses of model runs to be conducted because of those computational advantages. However, it has only been demonstrated on foreign animal diseases. This paper applied the MESA modeling methodology to human epidemiology. The methodology divided 2000 US Census data at the census tract level into school-bound children, work-bound workers, elderly, and stay at home individuals. The model simulated mixing among these groups by incorporating schools, workplaces, households, and long-distance travel via airports. A baseline scenario with fixed input parameters was run for a nationwide influenza outbreak using relatively simple social distancing countermeasures. Analysis from the baseline scenario showed one of three possible results: (1) the outbreak burned itself out before it had a chance to spread regionally, (2) the outbreak spread regionally and lasted a relatively long time, although constrained geography enabled it to eventually be contained without affecting a disproportionately large number of people, or (3) the outbreak spread through air travel and lasted a long time with unconstrained geography, becoming a nationwide pandemic. These results are consistent with empirical influenza outbreak data. The results showed that simply scaling up a regional small-scale model is unlikely to account for all the complex variables and their interactions involved in a nationwide outbreak. There are several limitations of the methodology that should be explored in future

ON SECURE FULL DUPLEX COMMUNICATION IN MOBILE AD HOC NETWORK

OpenAIRE

S. C. Dutta; Sudha Singh; D. K. Singh

2013-01-01

This paper is to establish Ad Hoc network in mobile phones and start fully secured full duplex communication in any situation. This type of communication will be cost effective and it will be fastest way of communication in case of any server failure or server error.

An Economic Framework for Resource Allocation in Ad-hoc Grids

NARCIS (Netherlands)

Pourebrahimi, B.

2009-01-01

In this dissertation, we present an economic framework to study and develop different market-based mechanisms for resource allocation in an ad-hoc Grid. Such an economic framework helps to understand the impact of certain choices and explores what are the suitable mechanisms from Grid user/owner

A Tool for Visualizing Mobile Ad-Hoc Network Topology Definitions Files

National Research Council Canada - National Science Library

Nguyen, Binh Q

2006-01-01

This report documents a research and development effort that the U.S. Army Research Laboratory conducted in FY05 in support of the building of an emulated tactical mobile ad hoc network (MANET) research test bed...

Capacity of Wireless Ad Hoc Networks with Opportunistic Collaborative Communications

Directory of Open Access Journals (Sweden)

Simeone O

2007-01-01

Full Text Available Optimal multihop routing in ad hoc networks requires the exchange of control messages at the MAC and network layer in order to set up the (centralized optimization problem. Distributed opportunistic space-time collaboration (OST is a valid alternative that avoids this drawback by enabling opportunistic cooperation with the source at the physical layer. In this paper, the performance of OST is investigated. It is shown analytically that opportunistic collaboration outperforms (centralized optimal multihop in case spatial reuse (i.e., the simultaneous transmission of more than one data stream is not allowed by the transmission protocol. Conversely, in case spatial reuse is possible, the relative performance between the two protocols has to be studied case by case in terms of the corresponding capacity regions, given the topology and the physical parameters of network at hand. Simulation results confirm that opportunistic collaborative communication is a promising paradigm for wireless ad hoc networks that deserves further investigation.

Capacity of Wireless Ad Hoc Networks with Opportunistic Collaborative Communications

Directory of Open Access Journals (Sweden)

O. Simeone

2007-03-01

Full Text Available Optimal multihop routing in ad hoc networks requires the exchange of control messages at the MAC and network layer in order to set up the (centralized optimization problem. Distributed opportunistic space-time collaboration (OST is a valid alternative that avoids this drawback by enabling opportunistic cooperation with the source at the physical layer. In this paper, the performance of OST is investigated. It is shown analytically that opportunistic collaboration outperforms (centralized optimal multihop in case spatial reuse (i.e., the simultaneous transmission of more than one data stream is not allowed by the transmission protocol. Conversely, in case spatial reuse is possible, the relative performance between the two protocols has to be studied case by case in terms of the corresponding capacity regions, given the topology and the physical parameters of network at hand. Simulation results confirm that opportunistic collaborative communication is a promising paradigm for wireless ad hoc networks that deserves further investigation.

An Effective Approach for Mobile ad hoc Network via I-Watchdog Protocol

Directory of Open Access Journals (Sweden)

Nidhi Lal

2014-12-01

Full Text Available Mobile ad hoc network (MANET is now days become very famous due to their fixed infrastructure-less quality and dynamic nature. They contain a large number of nodes which are connected and communicated to each other in wireless nature. Mobile ad hoc network is a wireless technology that contains high mobility of nodes and does not depend on the background administrator for central authority, because they do not contain any infrastructure. Nodes of the MANET use radio wave for communication and having limited resources and limited computational power. The Topology of this network is changing very frequently because they are distributed in nature and self-configurable. Due to its wireless nature and lack of any central authority in the background, Mobile ad hoc networks are always vulnerable to some security issues and performance issues. The security imposes a huge impact on the performance of any network. Some of the security issues are black hole attack, flooding, wormhole attack etc. In this paper, we will discuss issues regarding low performance of Watchdog protocol used in the MANET and proposed an improved Watchdog mechanism, which is called by I-Watchdog protocol that overcomes the limitations of Watchdog protocol and gives high performance in terms of throughput, delay.

Epidemiología de campo y epidemiología social Field epidemiology and social epidemiology

Directory of Open Access Journals (Sweden)

Javier Segura del Pozo

2006-03-01

Full Text Available Mediante la comparación de la epidemiología de campo y la epidemiología social, se pretende reflexionar sobre los imaginarios no explícitos que operan en ambos ámbitos, necesariamente convergentes, sobre los obstáculos de la práctica epidemiológica actual para alcanzar su función social y sobre la necesidad de cambiar las bases epistemológicas, metodológicas y prácticas que operan en la epidemiología, empezando por la formación del epidemiólogo de campo. La epidemiología de campo tiende a la acción sin marco teórico. La epidemiología social, por el contrario, tiende a los desarrollos teóricos (reflexión e investigación sobre los determinantes sociales alejados de la acción, debido a los limitantes para cambiar las políticas públicas. Otras diferencias se sitúan en el nivel de intervención (micro/macroespacios, el objeto de intervención (control del brote frente a control de las desigualdades y en la forma de articular la comunicación con la sociedad. Se asemejan en la preocupación por el método, la predominancia de una orientación positivista y condicionada por la estadística, aunque en proceso de cierta apertura epistemológica, la tensión experimentada entre relacionarse con un mundo virtual de bases de datos o con la sociedad real, su situación en la periferia del sistema político-social-institucional-profesional y por estar abocadas a la frustración profesional. Finalmente, se formulan 10 interrogantes a los epidemiólogos de campo sobre su práctica actual, a través de los cuales se podría evaluar si están realizando una epidemiología social, y se sugieren cambios para introducir en la formación y práctica del epidemiólogo.Comparing field epidemiology and social epidemiology, we pretend to think about the no explicit images and meanings operating in both necessary convergent fields, about the obstacles present in epidemiological practice to fulfil its social function and about the necessity of

Anti-hypertensive drug treatment of patients with and the metabolic syndrome and obesity: a review of evidence, meta-analysis, post hoc and guidelines publications.

Science.gov (United States)

Owen, Jonathan G; Reisin, Efrain

2015-06-01

Epidemiological studies have shown an increasing prevalence of obesity and the metabolic syndrome worldwide. Lifestyle modifications that include dietary changes, weight reduction, and exercise are the cornerstones in the treatment of this pathology. However, adherence to this approach often meets with failure in clinical practice; therefore, drug therapy should not be delayed. The ideal pharmacological antihypertensive regimen should target the underlying mechanisms involved in this syndrome, including sympathetic activation, increased renal tubular sodium reabsorption, and overexpression of the renin-angiotensin-aldosterone system by the adipocyte. Few prospective trials have been conducted in the search of the ideal antihypertensive regimen in patients with obesity and the metabolic syndrome. We summarize previously published ad hoc studies, prospective studies, and guideline publications regarding the treatment of hypertension in patients with obesity and the metabolic syndrome. We conclude that the optimal antihypertensive drug therapy in these patients has not been defined. Though caution exists regarding the use of thiazide diuretics due to potential metabolic derangements, there is insufficient data to show worsened cardiovascular or renal outcomes in patients treated with these drugs. In regard to beta blockers, the risk of accelerating conversion to diabetes and worsening of inflammatory mediators described in patients treated with traditional beta blockers appears much less pronounced or absent when using the vasodilating beta blockers. Renin-angiotensin-aldosterone system (RAAS) inhibition with an ACE or an ARB and treatment with calcium channel blockers appears safe and well tolerated in obesity-related hypertension and in patients with metabolic syndrome. Future prospective pharmacological studies in this population are needed.

Archeological Echocardiography: Digitization and Speckle-Tracking Analysis of Archival Echocardiograms in the HyperGEN Study

Science.gov (United States)

Aguilar, Frank G.; Selvaraj, Senthil; Martinez, Eva E.; Katz, Daniel H.; Beussink, Lauren; Kim, Kwang-Youn A.; Ping, Jie; Rasmussen-Torvik, Laura; Goyal, Amita; Sha, Jin; Irvin, Marguerite R.; Arnett, Donna K.; Shah, Sanjiv J.

2015-01-01

Background Several large epidemiologic studies and clinical trials have included echocardiography, but images were stored in analog format and these studies predated tissue Doppler imaging (TDI) and speckle-tracking echocardiography (STE). We hypothesized that digitization of analog echocardiograms, with subsequent quantification of cardiac mechanics using STE, is feasible, reproducible, accurate, and produces clinically valid results. Methods In the NHLBI HyperGEN study (N=2234), archived analog echocardiograms were digitized and subsequently analyzed using STE to obtain tissue velocities/strain. Echocardiograms were assigned quality scores and inter/intraobserver agreement was calculated. Accuracy was evaluated in (1) a separate second study (N=50) comparing prospective digital strain vs. post-hoc analog-to-digital strain; and (2) in a third study (N=95) comparing prospectively-obtained TDI e′ velocities with post-hoc STE e′ velocities. Finally, we replicated previously known associations between tissue velocities/strain, conventional echocardiographic measurements, and clinical data. Results Of the 2234 HyperGEN echocardiograms, 2150 (96.2%) underwent successful digitization and STE analysis. Inter/intraobserver agreement was high for all STE parameters, especially longitudinal strain (LS). In accuracy studies, LS performed best when comparing post-hoc STE to prospective digital STE for strain analysis. STE-derived e′ velocities correlated with, but systematically underestimated, TDI e′ velocity. Several known associations between clinical variables and cardiac mechanics were replicated in HyperGEN. We also found a novel independent inverse association between fasting glucose and LS (adjusted β =−2.4 [95% CI −3.6,−1.2]% per 1-SD increase in fasting glucose; Pechocardiography, the digitization and speckle-tracking analysis of archival echocardiograms, is feasible and generates parameters of cardiac mechanics similar to contemporary studies. PMID

Archeological Echocardiography: Digitization and Speckle Tracking Analysis of Archival Echocardiograms in the HyperGEN Study.

Science.gov (United States)

Aguilar, Frank G; Selvaraj, Senthil; Martinez, Eva E; Katz, Daniel H; Beussink, Lauren; Kim, Kwang-Youn A; Ping, Jie; Rasmussen-Torvik, Laura; Goyal, Amita; Sha, Jin; Irvin, Marguerite R; Arnett, Donna K; Shah, Sanjiv J

2016-03-01

Several large epidemiologic studies and clinical trials have included echocardiography, but images were stored in analog format and these studies predated tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE). We hypothesized that digitization of analog echocardiograms, with subsequent quantification of cardiac mechanics using STE, is feasible, reproducible, accurate, and produces clinically valid results. In the NHLBI HyperGEN study (N = 2234), archived analog echocardiograms were digitized and subsequently analyzed using STE to obtain tissue velocities/strain. Echocardiograms were assigned quality scores and inter-/intra-observer agreement was calculated. Accuracy was evaluated in: (1) a separate second study (N = 50) comparing prospective digital strain versus post hoc analog-to-digital strain, and (2) in a third study (N = 95) comparing prospectively obtained TDI e' velocities with post hoc STE e' velocities. Finally, we replicated previously known associations between tissue velocities/strain, conventional echocardiographic measurements, and clinical data. Of the 2234 HyperGEN echocardiograms, 2150 (96.2%) underwent successful digitization and STE analysis. Inter/intra-observer agreement was high for all STE parameters, especially longitudinal strain (LS). In accuracy studies, LS performed best when comparing post hoc STE to prospective digital STE for strain analysis. STE-derived e' velocities correlated with, but systematically underestimated, TDI e' velocity. Several known associations between clinical variables and cardiac mechanics were replicated in HyperGEN. We also found a novel independent inverse association between fasting glucose and LS (adjusted β = -2.4 [95% CI -3.6, -1.2]% per 1-SD increase in fasting glucose; P echocardiography, the digitization and speckle tracking analysis of archival echocardiograms, is feasible and generates indices of cardiac mechanics similar to contemporary studies. © 2015, Wiley Periodicals, Inc.

A fault-tolerant small world topology control model in ad hoc networks for search and rescue

Science.gov (United States)

Tan, Mian; Fang, Ling; Wu, Yue; Zhang, Bo; Chang, Bowen; Holme, Petter; Zhao, Jing

2018-02-01

Due to their self-organized, multi-hop and distributed characteristics, ad hoc networks are useful in search and rescue. Topology control models need to be designed for energy-efficient, robust and fast communication in ad hoc networks. This paper proposes a topology control model which specializes for search and rescue-Compensation Small World-Repeated Game (CSWRG)-which integrates mobility models, constructing small world networks and a game-theoretic approach to the allocation of resources. Simulation results show that our mobility models can enhance the communication performance of the constructed small-world networks. Our strategy, based on repeated game, can suppress selfish behavior and compensate agents that encounter selfish or faulty neighbors. This model could be useful for the design of ad hoc communication networks.

Epidemiologic analysis: Prophylaxis and multidrug-resistance in surgery.

Science.gov (United States)

Solís-Téllez, H; Mondragón-Pinzón, E E; Ramírez-Marino, M; Espinoza-López, F R; Domínguez-Sosa, F; Rubio-Suarez, J F; Romero-Morelos, R D

Surgical site infection is defined as an infection related to the surgical procedure in the area of manipulation occurring within the first 30 postoperative days. The diagnostic criteria include: purulent drainage, isolation of microorganisms, and signs of infection. To describe the epidemiologic characteristics and differences among the types of prophylactic regimens associated with hospital-acquired infections at the general surgery service of a tertiary care hospital. The electronic case records of patients that underwent general surgery at a tertiary care hospital within the time frame of January 1, 2013 and December 31, 2014 were reviewed. A convenience sample of 728 patients was established and divided into the following groups: Group 1: n=728 for the epidemiologic study; Group 2: n=638 for the evaluation of antimicrobial prophylaxis; and Group 3: n=50 for the evaluation of multidrug-resistant bacterial strains in the intensive care unit. The statistical analysis was carried out with the SPSS 19 program, using the Mann-Whitney U test and the chi-square test. A total of 728 procedures were performed (65.9% were elective surgeries). Three hundred twelve of the patients were males and 416 were females. Only 3.98% of the patients complied with the recommended antimicrobial prophylaxis, and multidrug-resistant bacterial strains were found in the intensive care unit. A single prophylactic dose is effective, but adherence to this recommendation was not adequate. The prophylactic guidelines are not strictly adhered to in our environment. There was a significant association between the development of nosocomial infections from multidrug-resistant germs and admission to the intensive care unit. Copyright © 2016 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.

Report of the evaluation by the Ad Hoc Review Committee on Health Physics. Result evaluation in fiscal year 2000

International Nuclear Information System (INIS)

2001-06-01

The Research Evaluation Committee, which consisted of 14 members from outside of the Japan Atomic Energy Research Institute (JAERI), set up an Ad Hoc Review Committee on Health Physics in accordance with the 'Fundamental Guideline for the Evaluation of Research and Development (R and D) at JAERI' and its subsidiary regulations in order to evaluate the R and D accomplishments achieved for five years from Fiscal Year 1995 to Fiscal Year 1999 at Department of Health Physics in Tokai Research Establishment and at related departments in other Establishments of JAERI. The Ad Hoc Review Committee consisted of six specialists from outside of JAERI. The Ad Hoc Review Committee conducted its activities from October 2000 to January 2001. The evaluation was performed on the basis of the materials submitted in advance and of the oral presentations made at the Ad Hoc Review Committee meeting which was held on October 10, 2000, in line with the items, viewpoints, and criteria for the evaluation specified by the Research Evaluation Committee. The result of the evaluation by the Ad Hoc Review Committee was submitted to the Research Evaluation Committee, and was judged to be appropriate at its meeting held on March 16, 2001. This report describes the result of the evaluation by the Ad Hoc Review Committee on Health Physics. (author)

Ad Hoc Transient Groups: Instruments for Awareness in Learning Networks

NARCIS (Netherlands)

Fetter, Sibren; Rajagopal, Kamakshi; Berlanga, Adriana; Sloep, Peter

2011-01-01

Fetter, S., Rajagopal, K., Berlanga, A. J., & Sloep, P. B. (2011). Ad Hoc Transient Groups: Instruments for Awareness in Learning Networks. In W. Reinhardt, T. D. Ullmann, P. Scott, V. Pammer, O. Conlan, & A. J. Berlanga (Eds.), Proceedings of the 1st European Workshop on Awareness and Reflection in

Probabilistic Modelling of Information Propagation in Wireless Mobile Ad-Hoc Network

DEFF Research Database (Denmark)

Schiøler, Henrik; Hansen, Martin Bøgsted; Schwefel, Hans-Peter

2005-01-01

In this paper the dynamics of broadcasting wireless ad-hoc networks is studied through probabilistic modelling. A randomized transmission discipline is assumed in accordance with existing MAC definitions such as WLAN with Decentralized Coordination or IEEE-802.15.4. Message reception is assumed...... to be governed by node power-down policies and is equivalently assumed to be randomized. Altogether randomization facilitates a probabilistic model in the shape of an integro-differential equation governing the propagation of information, where brownian node mobility may be accounted for by including an extra...... diffusion term. The established model is analyzed for transient behaviour and a travelling wave solution facilitates expressions for propagation speed as well as parametrized analysis of network reliability and node power consumption. Applications of the developed models for node localization and network...

Premium adjustment: actuarial analysis on epidemiological models ...

African Journals Online (AJOL)

In this paper, we analyse insurance premium adjustment in the context of an epidemiological model where the insurer's future financial liability is greater than the premium from patients. In this situation, it becomes extremely difficult for the insurer since a negative reserve would severely increase its risk of insolvency, ...

Analysis of epidemiological indicators: Bovine brucellosis on the Atlantic coast and Antioquia - Colombia, 2005-2013

Directory of Open Access Journals (Sweden)

Misael Oviedo-Pastrana

2017-05-01

Full Text Available Objective. Describe the situation of the bovine brucellosis in the Atlantic Coast and Antioquia (CAA by analysis of epidemiological indicators during 2005-2013. Materials and methods. The data was obtained from epidemiological reports of the Colombian Agricultural Institute and the National Agricultural Census 2014. The annual departmental average of the variables studied was compared and it was performed a temporal analysis through graphical representation. Results. 44% of the positive farms were focused on the CAA; the positivity rate of farms in the CAA (27.9% was higher and statistically significant when related to the average rate in the country (24.8% being promoted by the least producing departments. Regarding to the cattle population, the CAA concentrated 47.0% of positive cattle in the country; however, the bovine positivity rate (5.8% was statistically equal to the national average (5.3%; yet, the departments with lower cattle population had the highest rates. The best surveillance for bovine brucellosis was observed between 2005 and 2009, in contrast, during 2010, 2011 and 2013 there was a considerable reduction in the number of diagnoses, in both farms and cattle. In the least producing departments the temporary distribution of epidemiological indicators favored more the presence of the disease. Conclusions. The National Prevention Control and Eradication Program of Bovine Brucellosis in the CAA presented promising results, however, the lack of continuity in the diagnostic surveillance during some years and mainly in the least producing departments affected negatively their development.

Association between exposure to noise and risk of hypertension: a meta-analysis of observational epidemiological studies.

Science.gov (United States)

Fu, Wenning; Wang, Chao; Zou, Li; Liu, Qiaoyan; Gan, Yong; Yan, Shijiao; Song, Fujian; Wang, Zhihong; Lu, Zuxun; Cao, Shiyi

2017-12-01

An increasing amount of original studies suggested that exposure to noise could be associated with the risk of hypertension, but the results remain inconsistent and inconclusive. We aimed to synthesize available epidemiological evidence about the relationship between various types of noise and hypertension, and to explore the potential dose-response relationship between them in an up-to-date meta-analysis. We conducted a literature search of PubMed and Embase from these databases' inception through December 2016 to identify observational epidemiological studies examining the association between noise and risk of hypertension. A random effects model was used to combine the results of included studies. Dose-response meta-analysis was conducted to examine the potential dose-response relationship. In total, 32 studies (five cohort studies, one case-control study, and 26 cross-section studies) involving 264 678 participants were eligible for inclusion. Pooled result showed that living or working in environment with noise exposure was significantly associated with increased risk of hypertension (odds ratio 1.62; 95% confidence interval: 1.40-1.88). We found no evidence of a curve linear association between noise and risk of hypertension. A dose-response analysis suggested that, for an increment of per 10 dB(A) of noise, the combined odds ratio of hypertension was 1.06 (95% confidence interval: 1.04-1.08). Integrated epidemiological evidence supports the hypothesis that exposure to noise may be a risk factor of hypertension, and there is a positive dose-response association between them.

Signaling-Free Max-Min Airtime Fairness in IEEE 802.11 Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Youngsoo Lee

2016-01-01

Full Text Available We propose a novel media access control (MAC protocol, referred to as signaling-free max-min airtime fair (SMAF MAC, to improve fairness and channel utilization in ad hoc networks based on IEEE 802.11 wireless local area networks (WLANs. We introduce busy time ratio (BTR as a measure for max-min airtime fairness. Each node estimates its BTR and adjusts the transmission duration by means of frame aggregation and fragmentation, so that it can implicitly announce the BTR to neighbor nodes. Based on the announced BTR, each of the neighbor nodes controls its contention window. In this way, the SMAF MAC works in a distributed manner without the need to know the max-min fair share of airtime, and it does not require exchanging explicit control messages among nodes to attain fairness. Moreover, we successfully incorporate the hidden node detection and resolution mechanisms into the SMAF MAC to deal with the hidden node problem in ad hoc networks. The simulation results confirm that the SMAF MAC enhances airtime fairness without degrading channel utilization, and it effectively resolves several serious problems in ad hoc networks such as the starvation, performance anomaly, and hidden node problems.

Power control algorithms for mobile ad hoc networks

Directory of Open Access Journals (Sweden)

Nuraj L. Pradhan

2011-07-01

We will also focus on an adaptive distributed power management (DISPOW algorithm as an example of the multi-parameter optimization approach which manages the transmit power of nodes in a wireless ad hoc network to preserve network connectivity and cooperatively reduce interference. We will show that the algorithm in a distributed manner builds a unique stable network topology tailored to its surrounding node density and propagation environment over random topologies in a dynamic mobile wireless channel.

Multicasting in Wireless Communications (Ad-Hoc Networks): Comparison against a Tree-Based Approach

Science.gov (United States)

Rizos, G. E.; Vasiliadis, D. C.

2007-12-01

We examine on-demand multicasting in ad hoc networks. The Core Assisted Mesh Protocol (CAMP) is a well-known protocol for multicast routing in ad-hoc networks, generalizing the notion of core-based trees employed for internet multicasting into multicast meshes that have much richer connectivity than trees. On the other hand, wireless tree-based multicast routing protocols use much simpler structures for determining route paths, using only parent-child relationships. In this work, we compare the performance of the CAMP protocol against the performance of wireless tree-based multicast routing protocols, in terms of two important factors, namely packet delay and ratio of dropped packets.

A Spontaneous Ad Hoc Network to Share WWW Access

Directory of Open Access Journals (Sweden)

Lloret Jaime

2010-01-01

Full Text Available In this paper, we propose a secure spontaneous ad-hoc network, based on direct peer-to-peer interaction, to grant a quick, easy, and secure access to the users to surf the Web. The paper shows the description of our proposal, the procedure of the nodes involved in the system, the security algorithms implemented, and the designed messages. We have taken into account the security and its performance. Although some people have defined and described the main features of spontaneous ad-hoc networks, nobody has published any design and simulation until today. Spontaneous networking will enable a more natural form of wireless computing when people physically meet in the real world. We also validate the success of our proposal through several simulations and comparisons with a regular architecture, taking into account the optimization of the resources of the devices. Finally, we compare our proposal with other caching techniques published in the related literature. The proposal has been developed with the main objective of improving the communication and integration between different study centers of low-resource communities. That is, it lets communicate spontaneous networks, which are working collaboratively and which have been created on different physical places.

Epidemiological analysis of Salmonella clusters identified by whole genome sequencing, England and Wales 2014.

Science.gov (United States)

Waldram, Alison; Dolan, Gayle; Ashton, Philip M; Jenkins, Claire; Dallman, Timothy J

2018-05-01

The unprecedented level of bacterial strain discrimination provided by whole genome sequencing (WGS) presents new challenges with respect to the utility and interpretation of the data. Whole genome sequences from 1445 isolates of Salmonella belonging to the most commonly identified serotypes in England and Wales isolated between April and August 2014 were analysed. Single linkage single nucleotide polymorphism thresholds at the 10, 5 and 0 level were explored for evidence of epidemiological links between clustered cases. Analysis of the WGS data organised 566 of the 1445 isolates into 32 clusters of five or more. A statistically significant epidemiological link was identified for 17 clusters. The clusters were associated with foreign travel (n = 8), consumption of Chinese takeaways (n = 4), chicken eaten at home (n = 2), and one each of the following; eating out, contact with another case in the home and contact with reptiles. In the same time frame, one cluster was detected using traditional outbreak detection methods. WGS can be used for the highly specific and highly sensitive detection of biologically related isolates when epidemiological links are obscured. Improvements in the collection of detailed, standardised exposure information would enhance cluster investigations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Clinical Outcomes from Androgen Signaling-directed Therapy after Treatment with Abiraterone Acetate and Prednisone in Patients with Metastatic Castration-resistant Prostate Cancer: Post Hoc Analysis of COU-AA-302.

Science.gov (United States)

Smith, Matthew R; Saad, Fred; Rathkopf, Dana E; Mulders, Peter F A; de Bono, Johann S; Small, Eric J; Shore, Neal D; Fizazi, Karim; Kheoh, Thian; Li, Jinhui; De Porre, Peter; Todd, Mary B; Yu, Margaret K; Ryan, Charles J

2017-07-01

In the COU-AA-302 trial, abiraterone acetate plus prednisone significantly increased overall survival for patients with chemotherapy-naïve metastatic castration-resistant prostate cancer (mCRPC). Limited information exists regarding response to subsequent androgen signaling-directed therapies following abiraterone acetate plus prednisone in patients with mCRPC. We investigated clinical outcomes associated with subsequent abiraterone acetate plus prednisone (55 patients) and enzalutamide (33 patients) in a post hoc analysis of COU-AA-302. Prostate-specific antigen (PSA) response was assessed. Median time to PSA progression was estimated using the Kaplan-Meier method. The PSA response rate (≥50% PSA decline, unconfirmed) was 44% and 67%, respectively. The median time to PSA progression was 3.9 mo (range 2.6-not estimable) for subsequent abiraterone acetate plus prednisone and 2.8 mo (range 1.8-not estimable) for subsequent enzalutamide. The majority of patients (68%) received intervening chemotherapy before subsequent abiraterone acetate plus prednisone or enzalutamide. While acknowledging the limitations of post hoc analyses and high censoring (>75%) in both treatment groups, these results suggest that subsequent therapy with abiraterone acetate plus prednisone or enzalutamide for patients who progressed on abiraterone acetate is associated with limited clinical benefit. This analysis showed limited clinical benefit for subsequent abiraterone acetate plus prednisone or enzalutamide in patients with metastatic castration-resistant prostate cancer following initial treatment with abiraterone acetate plus prednisone. This analysis does not support prioritization of subsequent abiraterone acetate plus prednisone or enzalutamide following initial therapy with abiraterone acetate plus prednisone. Copyright © 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Ad hoc Sensor Networks to Support Maritime Interdiction Operations

OpenAIRE

Osmundson, John; Bordetsky, Alex

2014-01-01

Networking sensors, decision centers, and boarding parties supports success in Maritime Interdiction Operations. Led by a team from Naval Post-graduate School (NPS), experiments were conducted in 2012 to test the use of ad-hoc, self-forming communication networks to link sensors, people, and decision centers. The experiments involved international participants and successfully shared valuable biometric and radiological sensor data between boarding parties and decis...

Peer-to-peer over mobile ad hoc networks (Chapter 11)

NARCIS (Netherlands)

Qadri, N.N.; Liotta, A.; Pierre, S.

2010-01-01

In this chapter we review various approaches for the convergence of Peer-to-Peer (P2P) and Mobile Ad hoc Networks (MANETs), identifying strengths and weaknesses, and putting things in perspective. P2P and MANETs are among the most active research topics in pervasive computing. The convergence of P2P

Intelligent Stale-Frame Discards for Real-Time Video Streaming over Wireless Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Sheu Tsang-Ling

2009-01-01

Full Text Available Abstract This paper presents intelligent early packet discards (I-EPD for real-time video streaming over a multihop wireless ad hoc network. In a multihop wireless ad hoc network, the quality of transferring real-time video streams could be seriously degraded, since every intermediate node (IN functionally like relay device does not possess large buffer and sufficient bandwidth. Even worse, a selected relay node could leave or power off unexpectedly, which breaks the route to destination. Thus, a stale video frame is useless even if it can reach destination after network traffic becomes smooth or failed route is reconfigured. In the proposed I-EPD, an IN can intelligently determine whether a buffered video packet should be early discarded. For the purpose of validation, we implement the I-EPD on Linux-based embedded systems. Via the comparisons of performance metrics (packet/frame discards ratios, PSNR, etc., we demonstrate that video quality over a wireless ad hoc network can be substantially improved and unnecessary bandwidth wastage is greatly reduced.

Are we drawing the right conclusions from randomised placebo-controlled trials? A post-hoc analysis of data from a randomised controlled trial

Directory of Open Access Journals (Sweden)

Bone Kerry M

2009-06-01

Full Text Available Abstract Background Assumptions underlying placebo controlled trials include that the placebo effect impacts on all study arms equally, and that treatment effects are additional to the placebo effect. However, these assumptions have recently been challenged, and different mechanisms may potentially be operating in the placebo and treatment arms. The objective of the current study was to explore the nature of placebo versus pharmacological effects by comparing predictors of the placebo response with predictors of the treatment response in a randomised, placebo-controlled trial of a phytotherapeutic combination for the treatment of menopausal symptoms. A substantial placebo response was observed but no significant difference in efficacy between the two arms. Methods A post hoc analysis was conducted on data from 93 participants who completed this previously published study. Variables at baseline were investigated as potential predictors of the response on any of the endpoints of flushing, overall menopausal symptoms and depression. Focused tests were conducted using hierarchical linear regression analyses. Based on these findings, analyses were conducted for both groups separately. These findings are discussed in relation to existing literature on placebo effects. Results Distinct differences in predictors were observed between the placebo and active groups. A significant difference was found for study entry anxiety, and Greene Climacteric Scale (GCS scores, on all three endpoints. Attitude to menopause was found to differ significantly between the two groups for GCS scores. Examination of the individual arms found anxiety at study entry to predict placebo response on all three outcome measures individually. In contrast, low anxiety was significantly associated with improvement in the active treatment group. None of the variables found to predict the placebo response was relevant to the treatment arm. Conclusion This study was a post hoc analysis

Cross-Layer Service Discovery Mechanism for OLSRv2 Mobile Ad Hoc Networks

Directory of Open Access Journals (Sweden)

M. Isabel Vara

2015-07-01

Full Text Available Service discovery plays an important role in mobile ad hoc networks (MANETs. The lack of central infrastructure, limited resources and high mobility make service discovery a challenging issue for this kind of network. This article proposes a new service discovery mechanism for discovering and advertising services integrated into the Optimized Link State Routing Protocol Version 2 (OLSRv2. In previous studies, we demonstrated the validity of a similar service discovery mechanism integrated into the previous version of OLSR (OLSRv1. In order to advertise services, we have added a new type-length-value structure (TLV to the OLSRv2 protocol, called service discovery message (SDM, according to the Generalized MANET Packet/Message Format defined in Request For Comments (RFC 5444. Each node in the ad hoc network only advertises its own services. The advertisement frequency is a user-configurable parameter, so that it can be modified depending on the user requirements. Each node maintains two service tables, one to store information about its own services and another one to store information about the services it discovers in the network. We present simulation results, that compare our service discovery integrated into OLSRv2 with the one defined for OLSRv1 and with the integration of service discovery in Ad hoc On-demand Distance Vector (AODV protocol, in terms of service discovery ratio, service latency and network overhead.

Cross-Layer Service Discovery Mechanism for OLSRv2 Mobile Ad Hoc Networks.

Science.gov (United States)

Vara, M Isabel; Campo, Celeste

2015-07-20

Service discovery plays an important role in mobile ad hoc networks (MANETs). The lack of central infrastructure, limited resources and high mobility make service discovery a challenging issue for this kind of network. This article proposes a new service discovery mechanism for discovering and advertising services integrated into the Optimized Link State Routing Protocol Version 2 (OLSRv2). In previous studies, we demonstrated the validity of a similar service discovery mechanism integrated into the previous version of OLSR (OLSRv1). In order to advertise services, we have added a new type-length-value structure (TLV) to the OLSRv2 protocol, called service discovery message (SDM), according to the Generalized MANET Packet/Message Format defined in Request For Comments (RFC) 5444. Each node in the ad hoc network only advertises its own services. The advertisement frequency is a user-configurable parameter, so that it can be modified depending on the user requirements. Each node maintains two service tables, one to store information about its own services and another one to store information about the services it discovers in the network. We present simulation results, that compare our service discovery integrated into OLSRv2 with the one defined for OLSRv1 and with the integration of service discovery in Ad hoc On-demand Distance Vector (AODV) protocol, in terms of service discovery ratio, service latency and network overhead.

Applications of artificial intelligence systems in the analysis of epidemiological data.

Science.gov (United States)

Flouris, Andreas D; Duffy, Jack

2006-01-01

A brief review of the germane literature suggests that the use of artificial intelligence (AI) statistical algorithms in epidemiology has been limited. We discuss the advantages and disadvantages of using AI systems in large-scale sets of epidemiological data to extract inherent, formerly unidentified, and potentially valuable patterns that human-driven deductive models may miss.

Spatial epidemiological techniques in cholera mapping and analysis towards a local scale predictive modelling

Science.gov (United States)

Rasam, A. R. A.; Ghazali, R.; Noor, A. M. M.; Mohd, W. M. N. W.; Hamid, J. R. A.; Bazlan, M. J.; Ahmad, N.

2014-02-01

Cholera spatial epidemiology is the study of the spread and control of the disease spatial pattern and epidemics. Previous studies have shown that multi-factorial causation such as human behaviour, ecology and other infectious risk factors influence the disease outbreaks. Thus, understanding spatial pattern and possible interrelationship factors of the outbreaks are crucial to be explored an in-depth study. This study focuses on the integration of geographical information system (GIS) and epidemiological techniques in exploratory analyzing the cholera spatial pattern and distribution in the selected district of Sabah. Spatial Statistic and Pattern tools in ArcGIS and Microsoft Excel software were utilized to map and analyze the reported cholera cases and other data used. Meanwhile, cohort study in epidemiological technique was applied to investigate multiple outcomes of the disease exposure. The general spatial pattern of cholera was highly clustered showed the disease spread easily at a place or person to others especially 1500 meters from the infected person and locations. Although the cholera outbreaks in the districts are not critical, it could be endemic at the crowded areas, unhygienic environment, and close to contaminated water. It was also strongly believed that the coastal water of the study areas has possible relationship with the cholera transmission and phytoplankton bloom since the areas recorded higher cases. GIS demonstrates a vital spatial epidemiological technique in determining the distribution pattern and elucidating the hypotheses generating of the disease. The next research would be applying some advanced geo-analysis methods and other disease risk factors for producing a significant a local scale predictive risk model of the disease in Malaysia.

Spatial epidemiological techniques in cholera mapping and analysis towards a local scale predictive modelling

International Nuclear Information System (INIS)

Rasam, A R A; Ghazali, R; Noor, A M M; Mohd, W M N W; Hamid, J R A; Bazlan, M J; Ahmad, N

2014-01-01

Cholera spatial epidemiology is the study of the spread and control of the disease spatial pattern and epidemics. Previous studies have shown that multi-factorial causation such as human behaviour, ecology and other infectious risk factors influence the disease outbreaks. Thus, understanding spatial pattern and possible interrelationship factors of the outbreaks are crucial to be explored an in-depth study. This study focuses on the integration of geographical information system (GIS) and epidemiological techniques in exploratory analyzing the cholera spatial pattern and distribution in the selected district of Sabah. Spatial Statistic and Pattern tools in ArcGIS and Microsoft Excel software were utilized to map and analyze the reported cholera cases and other data used. Meanwhile, cohort study in epidemiological technique was applied to investigate multiple outcomes of the disease exposure. The general spatial pattern of cholera was highly clustered showed the disease spread easily at a place or person to others especially 1500 meters from the infected person and locations. Although the cholera outbreaks in the districts are not critical, it could be endemic at the crowded areas, unhygienic environment, and close to contaminated water. It was also strongly believed that the coastal water of the study areas has possible relationship with the cholera transmission and phytoplankton bloom since the areas recorded higher cases. GIS demonstrates a vital spatial epidemiological technique in determining the distribution pattern and elucidating the hypotheses generating of the disease. The next research would be applying some advanced geo-analysis methods and other disease risk factors for producing a significant a local scale predictive risk model of the disease in Malaysia

Molecular epidemiology of human rhinoviruses

OpenAIRE

Savolainen-Kopra, Carita

2006-01-01

The first part of this work investigates the molecular epidemiology of a human enterovirus (HEV), echovirus 30 (E-30). This project is part of a series of studies performed in our research team analyzing the molecular epidemiology of HEV-B viruses. A total of 129 virus strains had been isolated in different parts of Europe. The sequence analysis was performed in three different genomic regions: 420 nucleotides (nt) in the VP4/VP2 capsid protein coding region, the entire VP1 capsid protein cod...

Improvement in 24-hour bronchodilation and symptom control with aclidinium bromide versus tiotropium and placebo in symptomatic patients with COPD: post hoc analysis of a Phase IIIb study

Directory of Open Access Journals (Sweden)

Beier J

2017-06-01

Full Text Available Jutta Beier,1 Robert Mroz,2,3 Anne-Marie Kirsten,4 Ferran Chuecos,5 Esther Garcia Gil5 1insaf Respiratory Research Institute, Wiesbaden, Germany; 2Centrum Medycyny Oddechowej, 3Medical University of Białystok, Białystok, Poland; 4Pulmonary Research Institute at LungenClinic Grosshansdorf, Airway Research Center North, German Center for Lung Research, Grosshansdorf, Germany; 5AstraZeneca PLC, Barcelona, Spain Background: A previous Phase IIIb study (NCT01462929 in patients with moderate to severe COPD demonstrated that 6 weeks of treatment with aclidinium led to improvements in 24-hour bronchodilation comparable to those with tiotropium, and improvement of symptoms versus placebo. This post hoc analysis was performed to assess the effect of treatment in the symptomatic patient group participating in the study. Methods: Symptomatic patients (defined as those with Evaluating Respiratory Symptoms [E-RS™] in COPD baseline score ≥10 units received aclidinium bromide 400 µg twice daily (BID, tiotropium 18 µg once daily (QD, or placebo, for 6 weeks. Lung function, COPD respiratory symptoms, and incidence of adverse events (AEs were assessed. Results: In all, 277 symptomatic patients were included in this post hoc analysis. Aclidinium and tiotropium treatment improved forced expiratory volume in 1 second (FEV1 from baseline to week 6 at all time points over 24 hours versus placebo. In addition, improvements in FEV1 from baseline during the nighttime period were observed for aclidinium versus tiotropium on day 1 (aclidinium 157 mL, tiotropium 67 mL; P<0.001 and week 6 (aclidinium 153 mL, tiotropium 90 mL; P<0.05. Aclidinium improved trough FEV1 from baseline versus placebo and tiotropium at day 1 (aclidinium 136 mL, tiotropium 68 mL; P<0.05 and week 6 (aclidinium 137 mL, tiotropium 71 mL; P<0.05. Aclidinium also improved early-morning and nighttime symptom severity, limitation of early-morning activities, and E-RS Total and domain scores versus

The accuracy of interpreting key psychiatric terms by ad hoc ...

African Journals Online (AJOL)

MacFarlane et al.15 note that a greater number of people have a preference for working with ad hoc interpreters in comparison to professional interpreters ... As part of a larger study, a cross-sectional qualitative interview design was used to ..... obstacle they would face if they would receive training. They had concerns over ...

An enhanced performance through agent-based secure approach for mobile ad hoc networks

Science.gov (United States)

Bisen, Dhananjay; Sharma, Sanjeev

2018-01-01

This paper proposes an agent-based secure enhanced performance approach (AB-SEP) for mobile ad hoc network. In this approach, agent nodes are selected through optimal node reliability as a factor. This factor is calculated on the basis of node performance features such as degree difference, normalised distance value, energy level, mobility and optimal hello interval of node. After selection of agent nodes, a procedure of malicious behaviour detection is performed using fuzzy-based secure architecture (FBSA). To evaluate the performance of the proposed approach, comparative analysis is done with conventional schemes using performance parameters such as packet delivery ratio, throughput, total packet forwarding, network overhead, end-to-end delay and percentage of malicious detection.

Taxonomic and ad hoc categorization within the two cerebral hemispheres.

Science.gov (United States)

Shen, Yeshayahu; Aharoni, Bat-El; Mashal, Nira

2015-01-01

A typicality effect refers to categorization which is performed more quickly or more accurately for typical than for atypical members of a given category. Previous studies reported a typicality effect for category members presented in the left visual field/right hemisphere (RH), suggesting that the RH applies a similarity-based categorization strategy. However, findings regarding the typicality effect within the left hemisphere (LH) are less conclusive. The current study tested the pattern of typicality effects within each hemisphere for both taxonomic and ad hoc categories, using words presented to the left or right visual fields. Experiment 1 tested typical and atypical members of taxonomic categories as well as non-members, and Experiment 2 tested typical and atypical members of ad hoc categories as well as non-members. The results revealed a typicality effect in both hemispheres and in both types of categories. Furthermore, the RH categorized atypical stimuli more accurately than did the LH. Our findings suggest that both hemispheres rely on a similarity-based categorization strategy, but the coarse semantic coding of the RH seems to facilitate the categorization of atypical members.

Autonomous Power Control MAC Protocol for Mobile Ad Hoc Networks

Directory of Open Access Journals (Sweden)

2006-01-01

Full Text Available Battery energy limitation has become a performance bottleneck for mobile ad hoc networks. IEEE 802.11 has been adopted as the current standard MAC protocol for ad hoc networks. However, it was developed without considering energy efficiency. To solve this problem, many modifications on IEEE 802.11 to incorporate power control have been proposed in the literature. The main idea of these power control schemes is to use a maximum possible power level for transmitting RTS/CTS and the lowest acceptable power for sending DATA/ACK. However, these schemes may degrade network throughput and reduce the overall energy efficiency of the network. This paper proposes autonomous power control MAC protocol (APCMP, which allows mobile nodes dynamically adjusting power level for transmitting DATA/ACK according to the distances between the transmitter and its neighbors. In addition, the power level for transmitting RTS/CTS is also adjustable according to the power level for DATA/ACK packets. In this paper, the performance of APCMP protocol is evaluated by simulation and is compared with that of other protocols.

Report of the evaluation by the Ad Hoc Review Committee on Information Technology. In-advance evaluation in fiscal year 2000

International Nuclear Information System (INIS)

2001-06-01

The Research Evaluation Committee, which consisted of 14 members from outside of the Japan Atomic Energy Research Institute (JAERI), set up an Ad Hoc Review Committee on Information Technology in accordance with the Fundamental Guideline for the Evaluation of Research and Development (R and D) at JAERI' and its subsidiary regulations in order to evaluate the adequacy of the R and D programs pertaining to the establishment and utilization of the Information Technology Based Laboratory (ITBL) to be implemented for five years starting in Fiscal Year 2001 at Center for Promotion of Computational Science and Engineering and Department of Environmental Sciences of JAERI. The Ad Hoc Review Committee consisted of eight specialists from outside of JAERI. The Ad Hoc Review Committee conducted its activities from February to March 2001. The evaluation was performed on the basis of the materials submitted in advance and of the oral presentations made at the Ad Hoc Review Committee meeting which was held on February 9, 2001, in line with the items, viewpoints, and criteria for the evaluation specified by the Research Evaluation Committee. The result of the evaluation by the Ad Hoc Review Committee was submitted to the Research Evaluation Committee, and was judged to be appropriate at its meeting held on March 16, 2001. This report describes the result of the evaluation by the Ad Hoc Review Committee on Information Technology. (author)

Report of the evaluation by the Ad Hoc Review Committee on Nuclear Safety Research. Result evaluation in fiscal year 2000

International Nuclear Information System (INIS)

2001-06-01

The Research Evaluation Committee, which consisted of 14 members from outside of the Japan Atomic Energy Research Institute (JAERI), set up an Ad Hoc Review Committee on Nuclear Safety Research in accordance with the Fundamental Guideline for the Evaluation of Research and Development (R and D) at JAERI' and its subsidiary regulations in order to evaluate the R and D accomplishments achieved for five years from Fiscal Year 1995 to Fiscal Year 1999 at Department of Reactor Safety Research, Department of Fuel Cycle Safety Research, Department of Environmental Safety Research and Department of Safety Research Technical Support in Tokai Research Establishment at JAERI. The Ad Hoc Review Committee consisted of 11 specialists from outside of JAERI. The Ad Hoc Review Committee conducted its activities from December 2000 to February 2001. The evaluation was performed on the basis of the materials submitted in advance and of the oral presentations made at the Ad Hoc Review Committee meeting which was held on December 11, 2000, in line with the items, viewpoints, and criteria for the evaluation specified by the Research Evaluation Committee. The result of the evaluation by the Ad Hoc Review Committee was submitted to the Research Evaluation Committee, and was judged to be appropriate at its meeting held on March 16, 2001. This report describes the result of the evaluation by the Ad Hoc Review Committee on Nuclear Safety Research. (author)

Cross-Layer Design Approach for Power Control in Mobile Ad Hoc Networks

Directory of Open Access Journals (Sweden)

A. Sarfaraz Ahmed

2015-03-01

Full Text Available In mobile ad hoc networks, communication among mobile nodes occurs through wireless medium The design of ad hoc network protocol, generally based on a traditional “layered approach”, has been found ineffective to deal with receiving signal strength (RSS-related problems, affecting the physical layer, the network layer and transport layer. This paper proposes a design approach, deviating from the traditional network design, toward enhancing the cross-layer interaction among different layers, namely physical, MAC and network. The Cross-Layer design approach for Power control (CLPC would help to enhance the transmission power by averaging the RSS values and to find an effective route between the source and the destination. This cross-layer design approach was tested by simulation (NS2 simulator and its performance over AODV was found to be better.

Broadcast Expenses Controlling Techniques in Mobile Ad-hoc Networks: A Survey

Directory of Open Access Journals (Sweden)

Naeem Ahmad

2016-07-01

Full Text Available The blind flooding of query packets in route discovery more often characterizes the broadcast storm problem, exponentially increases energy consumption of intermediate nodes and congests the entire network. In such a congested network, the task of establishing the path between resources may become very complex and unwieldy. An extensive research work has been done in this area to improve the route discovery phase of routing protocols by reducing broadcast expenses. The purpose of this study is to provide a comparative analysis of existing broadcasting techniques for the route discovery phase, in order to bring about an efficient broadcasting technique for determining the route with minimum conveying nodes in ad-hoc networks. The study is designed to highlight the collective merits and demerits of such broadcasting techniques along with certain conclusions that would contribute to the choice of broadcasting techniques.

Cognitive radio network in vehicular ad-hoc network (VANET: A survey

Directory of Open Access Journals (Sweden)

Joanne Mun-Yee Lim

2016-05-01

Full Text Available Cognitive radio network and Vehicular Ad hoc Network (VANET are recent emerging concepts in wireless networking. Cognitive radio network obtains knowledge of its operational geographical environment to manage sharing of spectrum between primary and secondary users, while VANET shares emergency safety messages among vehicles to ensure safety of users on the road. Cognitive radio network is employed in VANET to ensure the efficient use of spectrum, as well as to support VANET’s deployment. Random increase and decrease of spectrum users, unpredictable nature of VANET, high mobility, varying interference, security, packet scheduling and priority assignment are the challenges encountered in a typical cognitive VANET environment. This paper provides survey and critical analysis on different challenges of cognitive radio VANET, with discussion on the open issues, challenges and performance metrics, for different cognitive radio VANET applications.

Correctness-by-construction and post-hoc verification : a marriage of convenience?

NARCIS (Netherlands)

Watson, B.W.; Kourie, D.G.; Schaefer, I.; Cleophas, L.G.W.A.; Margaria, T.; Steffen, B.

2016-01-01

Correctness-by-construction (CbC), traditionally based on weakest precondition semantics, and post-hoc verification (PhV) aspire to ensure functional correctness. We argue for a lightweight approach to CbC where lack of formal rigour increases productivity. In order to mitigate the risk of

Illustration, detection and prevention of sleep deprivation anomaly in mobile ad hoc networks

International Nuclear Information System (INIS)

Nadeem, A.; Ahsan, K.; Sarim, M.

2017-01-01

MANETs (Mobile Ad Hoc Networks) have applications in various walks of life from rescue operations to battle field operations, personal and commercial. However, routing operations in MANETs are still vulnerable to anomalies and DoS (Denial of Service) attacks such as sleep deprivation. In SD (Sleep Deprivation) attack malicious node exploits the vulnerability in the route discovery function of the reactive routing protocol for example AODV (Ad Hoc On-Demand Distance Vector). In this paper, we first illustrate the SD anomaly in MANETs and then propose a SD detection and prevention algorithm which efficiently deals with this attack. We assess the performance of our proposed approach through simulation, evaluating its successfulness using different network scenarios. (author)

Position-Based Packet Forwarding for Vehicular Ad-Hoc Networks

OpenAIRE

Füßler, Holger

2007-01-01

Mobile Ad-Hoc Networks, or MANETs, are data communication networks between (potentially) mobile computer systems equipped with wireless communication devices and — in their purest form — in complete absence of communication infrastructure. Usage scenarios for these systems include communication during disaster recovery or battlefield communications. One of the great research challenges concerning MANETs is the Packet Forwarding Problem, i.e., the question to which neighbor node a data packet ...

Protocols for Detection and Removal of Wormholes for Secure Routing and Neighborhood Creation in Wireless Ad Hoc Networks

Science.gov (United States)

Hayajneh, Thaier Saleh

2009-01-01

Wireless ad hoc networks are suitable and sometimes the only solution for several applications. Many applications, particularly those in military and critical civilian domains (such as battlefield surveillance and emergency rescue) require that ad hoc networks be secure and stable. In fact, security is one of the main barriers to the extensive use…

Unmanned Aerial ad Hoc Networks: Simulation-Based Evaluation of Entity Mobility Models’ Impact on Routing Performance

Directory of Open Access Journals (Sweden)

Jean-Daniel Medjo Me Biomo

2015-06-01

Full Text Available An unmanned aerial ad hoc network (UAANET is a special type of mobile ad hoc network (MANET. For these networks, researchers rely mostly on simulations to evaluate their proposed networking protocols. Hence, it is of great importance that the simulation environment of a UAANET replicates as much as possible the reality of UAVs. One major component of that environment is the movement pattern of the UAVs. This means that the mobility model used in simulations has to be thoroughly understood in terms of its impact on the performance of the network. In this paper, we investigate how mobility models affect the performance of UAANET in simulations in order to come up with conclusions/recommendations that provide a benchmark for future UAANET simulations. To that end, we first propose a few metrics to evaluate the mobility models. Then, we present five random entity mobility models that allow nodes to move almost freely and independently from one another and evaluate four carefully-chosen MANET/UAANET routing protocols: ad hoc on-demand distance vector (AODV, optimized link state routing (OLSR, reactive-geographic hybrid routing (RGR and geographic routing protocol (GRP. In addition, flooding is also evaluated. The results show a wide variation of the protocol performance over different mobility models. These performance differences can be explained by the mobility model characteristics, and we discuss these effects. The results of our analysis show that: (i the enhanced Gauss–Markov (EGM mobility model is best suited for UAANET; (ii OLSR, a table-driven proactive routing protocol, and GRP, a position-based geographic protocol, are the protocols most sensitive to the change of mobility models; (iii RGR, a reactive-geographic hybrid routing protocol, is best suited for UAANET.

ANALYSIS OF THE INCIDENCE OF LYMPHOMAS IN THE REPUBLIC OF KHAKASSIA FOR 2014 AND ITS EPIDEMIOLOGICAL FEATURES

Directory of Open Access Journals (Sweden)

Olga Valentinovna Smirnova

2016-05-01

Full Text Available The aim of the study was to study patterns in the incidence of lymphomas and its epidemiological characteristics in the Republic of Khakassia for 2014. The research was conducted by retrospective analysis. The following epidemiological features are revealed: NHL is more common; LGM often ill persons young and middle age, and the NHL people in the older age groups; incidence among men is higher than women’s; among refined morphological variants LGM disseminated sclerosis and nodular lymphoid predominance, among the NHL is most prevalent diffuse non-Hodgkin’s lymphoma; it is noted that the NHL is more common in urban populations.

Stability analysis on an economic epidemiological model with vaccination Pages : - , and.

Science.gov (United States)

Avusuglo, Wisdom S; Abdella, Kenzu; Feng, Wenying

2017-08-01

In this paper, an economic epidemiological model with vaccination is studied. The stability of the endemic steady-state is analyzed and some bifurcation properties of the system are investigated. It is established that the system exhibits saddle-point and period-doubling bifurcations when adult susceptible individuals are vaccinated. Furthermore, it is shown that susceptible individuals also have the tendency of opting for more number of contacts even if the vaccine is inefficacious and thus causes the disease endemic to increase in the long run. Results from sensitivity analysis with specific disease parameters are also presented. Finally, it is shown that the qualitative behaviour of the system is affected by contact levels.

Report of the evaluation by the Ad Hoc Review Committee on Materials Science Research. Ex-post evaluation in fiscal year 2003

International Nuclear Information System (INIS)

2004-06-01

The Research Evaluation Committee, which consisted of 13 members from outside of the Japan Atomic Energy Research Institute (JAERI), set up an Ad Hoc Review Committee on Materials Science Research in accordance with the Fundamental Guideline for the Evaluation of Research and Development (R and D) at JAERI' and its subsidiary regulations in order to evaluate the adequacy of the R and D results achieved for five years until Fiscal Year 2002 at Department of Materials Science in Tokai Research Establishment of JAERI. The Ad Hoc Review Committee consisted of eight specialists from outside of JAERI. The Ad Hoc Review Committee conducted its activities from October 2003 to February 2004. The evaluation was performed on the basis of the materials submitted in advance and of the oral presentations made at the Ad Hoc Review Committee meeting which was held on November 14, 2003, in line with the items, viewpoints, and criteria for the evaluation specified by the Research Evaluation Committee. The result of the evaluation by the Ad Hoc Review Committee was submitted to the Research Evaluation Committee, and was judged to be appropriate at its meeting held on March 8, 2004. This report describes the result of the evaluation by the Ad Hoc Review Committee on Materials Science Research. (author)

Report of the evaluation by the Ad Hoc Review Committee on Computational Science and Engineering. Result evaluation in fiscal year 2000

International Nuclear Information System (INIS)

2001-06-01

The Research Evaluation Committee, which consisted of 14 members from outside of the Japan Atomic Energy Research Institute (JAERI), set up an Ad Hoc Review Committee on Computational Science and Engineering in accordance with the 'Fundamental Guideline for the Evaluation of Research and Development (R and D) at JAERI' and its subsidiary regulations in order to evaluate the R and D accomplishments achieved for five years from Fiscal Year 1995 to Fiscal Year 1999 at Center for Promotion of Computational Science and Engineering of JAERI. The Ad Hoc Review Committee consisted of seven specialists from outside of JAERI. The Ad Hoc Review Committee conducted its activities from December 2000 to March 2001. The evaluation was performed on the basis of the materials submitted in advance and of the oral presentations made at the Ad Hoc Review Committee meeting which was held on December 27, 2000, in line with the items, viewpoints, and criteria for the evaluation specified by the Research Evaluation Committee. The result of the evaluation by the Ad Hoc Review Committee was submitted to the Research Evaluation Committee, and was judged to be appropriate at its meeting held on March 16, 2001. This report describes the result of the evaluation by the Ad Hoc Review Committee on Computational Science and Engineering. (author)

A communication theoretical analysis of FRET-based mobile ad hoc molecular nanonetworks.

Science.gov (United States)

Kuscu, Murat; Akan, Ozgur B

2014-09-01

Nanonetworks refer to a group of nanosized machines with very basic operational capabilities communicating to each other in order to accomplish more complex tasks such as in-body drug delivery, or chemical defense. Realizing reliable and high-rate communication between these nanomachines is a fundamental problem for the practicality of these nanonetworks. Recently, we have proposed a molecular communication method based on Förster Resonance Energy Transfer (FRET) which is a nonradiative excited state energy transfer phenomenon observed among fluorescent molecules, i.e., fluorophores. We have modeled the FRET-based communication channel considering the fluorophores as single-molecular immobile nanomachines, and shown its reliability at high rates, and practicality at the current stage of nanotechnology. In this study, for the first time in the literature, we investigate the network of mobile nanomachines communicating through FRET. We introduce two novel mobile molecular nanonetworks: FRET-based mobile molecular sensor/actor nanonetwork (FRET-MSAN) which is a distributed system of mobile fluorophores acting as sensor or actor node; and FRET-based mobile ad hoc molecular nanonetwork (FRET-MAMNET) which consists of fluorophore-based nanotransmitter, nanoreceivers and nanorelays. We model the single message propagation based on birth-death processes with continuous time Markov chains. We evaluate the performance of FRET-MSAN and FRET-MAMNET in terms of successful transmission probability and mean extinction time of the messages, system throughput, channel capacity and achievable communication rates.

Structural effects of sprifermin in knee osteoarthritis: a post-hoc analysis on cartilage and non-cartilaginous tissue alterations in a randomized controlled trial.

Science.gov (United States)

Roemer, Frank W; Aydemir, Aida; Lohmander, Stefan; Crema, Michel D; Marra, Monica Dias; Muurahainen, Norma; Felson, David T; Eckstein, Felix; Guermazi, Ali

2016-07-09

A recent publication on efficacy of Sprifermin for knee osteoarthritis (OA) using quantitatively MRI-defined central medial tibio-femoral compartment cartilage thickness as the structural primary endpoint reported no statistically significant dose response. However, Sprifermin was associated with statistically significant, dose-dependent reductions in loss of total and lateral tibio-femoral cartilage thickness. Based on these preliminary promising data a post-hoc analysis of secondary assessment and endpoints was performed to evaluate potential effects of Sprifermin on semi-quantitatively evaluated structural MRI parameters. Aim of the present analysis was to determine effects of sprifermin on several knee joint tissues over a 12 month period. 1.5 T or 3 T MRIs were acquired at baseline and 12 months follow-up using a standard protocol. MRIs were read according to the Whole-Organ Magnetic Resonance Imaging Score (WORMS) scoring system (in 14 articular subregions) by four muskuloskeletal radiologists independently. Analyses focused on semiquantitative changes in the 100 μg subgroup and matching placebo of multiple MRI-defined structural alterations. Analyses included a delta-subregional and delta-sum approach for the whole knee and the medial and lateral tibio-femoral (MTFJ, LTFJ), and patello-femoral (PFJ) compartments, taking into account number of subregions showing no change, improvement or worsening and changes in the sum of subregional scores. Mann-Whitney - Wilcoxon tests assessed differences between groups. Fifty-seven and 18 patients were included in the treatment and matched placebo subgroups. Less worsening of cartilage damage was observed from baseline to 12 months in the PFJ (0.02, 95 % confidence interval (CI) (-0.04, 0.08) vs. placebo 0.22, 95 % CI (-0.05, 0.49), p = 0.046). For bone marrow lesions (BMLs), more improvement was observed from 6 to 12 months for whole knee analyses (-0.14, 95 % CI (-0.48, 0.19) vs. placebo 0.44, 95�

The association of the effect of lithium in the maintenance treatment of bipolar disorder with lithium plasma levels : a post hoc analysis of a double-blind study comparing switching to lithium or placebo in patients who responded to quetiapine (Trial 144)

NARCIS (Netherlands)

Nolen, Willem A.; Weisler, Richard H.

Nolen WA, Weisler RH. The association of the effect of lithium in the maintenance treatment of bipolar disorder with lithium plasma levels: a post hoc analysis of a double-blind study comparing switching to lithium or placebo in patients who responded to quetiapine (Trial 144). Bipolar Disord 2012:

An Ad-Hoc Opportunistic Dissemination Protocol for Smartphone-based Participatory Traffic Monitoring

NARCIS (Netherlands)

Türkes, Okan; Seraj, Fatjon; Scholten, Johan; Meratnia, Nirvana; Havinga, Paul J.M.

2015-01-01

This study introduces an ad-hoc opportunistic data dissemination protocol, called VADISS, that facilitates participatory traffic monitoring applications with smartphones. As a ubiquitous alternative to existing vehicular networking methods, VADISS uses the default WiFi interfaces universally adopted

Report of the evaluation by the Ad Hoc Review Committee on Nuclear Safety Research. Result evaluation in fiscal year 2000

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-06-01

The Research Evaluation Committee, which consisted of 14 members from outside of the Japan Atomic Energy Research Institute (JAERI), set up an Ad Hoc Review Committee on Nuclear Safety Research in accordance with the Fundamental Guideline for the Evaluation of Research and Development (R and D) at JAERI' and its subsidiary regulations in order to evaluate the R and D accomplishments achieved for five years from Fiscal Year 1995 to Fiscal Year 1999 at Department of Reactor Safety Research, Department of Fuel Cycle Safety Research, Department of Environmental Safety Research and Department of Safety Research Technical Support in Tokai Research Establishment at JAERI. The Ad Hoc Review Committee consisted of 11 specialists from outside of JAERI. The Ad Hoc Review Committee conducted its activities from December 2000 to February 2001. The evaluation was performed on the basis of the materials submitted in advance and of the oral presentations made at the Ad Hoc Review Committee meeting which was held on December 11, 2000, in line with the items, viewpoints, and criteria for the evaluation specified by the Research Evaluation Committee. The result of the evaluation by the Ad Hoc Review Committee was submitted to the Research Evaluation Committee, and was judged to be appropriate at its meeting held on March 16, 2001. This report describes the result of the evaluation by the Ad Hoc Review Committee on Nuclear Safety Research. (author)

Conflict Management in "Ad Hoc" Problem-Solving Groups: A Preliminary Investigation.

Science.gov (United States)

Wallace, Les; Baxter, Leslie

Full study of small group communication must include consideration of task and socio-emotional dimensions, especially in relation to group problem solving. Thirty small groups were tested for their reactions in various "ad hoc" conflict resolution situations. Instructions to the groups were (1) no problem-solving instructions (control),…

A multi-protocol framework for ad-hoc service discovery

OpenAIRE

Flores-Cortes, C.; Blair, Gordon S.; Grace, P.

2006-01-01

Discovering the appropriate services in ad-hoc computing environments where a great number of devices and software components collaborate discreetly and provide numerous services is an important challenge. Service discovery protocols make it possible for participating nodes in a network to locate and advertise services with minimum user intervention. However, because it is not possible to predict at design time which protocols will be used to advertise services in a given context/environment,...

mec-associated dru typing in the epidemiological analysis of ST239 MRSA in Malaysia.

Science.gov (United States)

Ghaznavi-Rad, E; Goering, R V; Nor Shamsudin, M; Weng, P L; Sekawi, Z; Tavakol, M; van Belkum, A; Neela, V

2011-11-01

The usefulness of mec-associated dru typing in the epidemiological analysis of methicillin-resistant Staphylococcus aureus (MRSA) isolated in Malaysia was investigated and compared with pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and spa and SCCmec typing. The isolates studied included all MRSA types in Malaysia. Multilocus sequence type ST188 and ST1 isolates were highly clonal by all typing methods. However, the dru typing of ST239 isolates produced the clearest discrimination between SCCmec IIIa and III isolates, yielding more subtypes than any other method. Evaluation of the discriminatory power for each method identified dru typing and PFGE as the most discriminatory, with Simpson's index of diversity (SID) values over 89%, including an isolate which was non-typeable by spa, but dru-typed as dt13j. The discriminatory ability of dru typing, especially with closely related MRSA ST239 strains (e.g., Brazilian and Hungarian), underscores its utility as a tool for the epidemiological investigation of MRSA.

A LOOP-BASED APPROACH IN CLUSTERING AND ROUTING IN MOBILE AD HOC NETWORKS

Institute of Scientific and Technical Information of China (English)

Li Yanping; Wang Xin; Xue Xiangyang; C.K. Toh

2006-01-01

Although clustering is a convenient framework to enable traffic control and service support in Mobile Ad hoc NETworks (MANETs), it is seldom adopted in practice due to the additional traffic overhead it leads to for the resource limited ad hoc network. In order to address this problem, we proposed a loop-based approach to combine clustering and routing. By employing loop topologies, topology information is disseminated with a loop instead of a single node, which provides better robustness, and the nature of a loop that there are two paths between each pair of nodes within a loop suggests smart route recovery strategy. Our approach is composed of setup procedure, regular procedure and recovery procedure to achieve clustering, routing and emergent route recovering.

Mobile ad hoc networking the cutting edge directions

CERN Document Server

Basagni, Stefano; Giordano, Silvia; Stojmenovic, Ivan

2013-01-01

""An excellent book for those who are interested in learning the current status of research and development . . . [and] who want to get a comprehensive overview of the current state-of-the-art.""-E-Streams This book provides up-to-date information on research and development in the rapidly growing area of networks based on the multihop ad hoc networking paradigm. It reviews all classes of networks that have successfully adopted this paradigm, pointing out how they penetrated the mass market and sparked breakthrough research. Covering both physical issues and applica

The Complex Epidemiology of Carbapenem-Resistant Enterobacter Infections: A Multicenter Descriptive Analysis.

Science.gov (United States)

Lazarovitch, Tsilia; Amity, Keren; Coyle, Joseph R; Ackerman, Benjamin; Tal-Jasper, Ruthy; Ofer-Friedman, Hadas; Hayakawa, Kayoko; Bogan, Christopher; Lephart, Paul R; Kaplansky, Tamir; Maskit, Moran; Azouri, Tal; Zaidenstein, Ronit; Perez, Federico; Bonomo, Robert A; Kaye, Keith S; Marchaim, Dror

2015-11-01

The pandemic of carbapenem-resistant Enterobacteriaceae (CRE) was primarily due to clonal spread of bla KPC producing Klebsiella pneumoniae. Thus, thoroughly studied CRE cohorts have consisted mostly of K. pneumoniae. To conduct an extensive epidemiologic analysis of carbapenem-resistant Enterobacter spp. (CREn) from 2 endemic and geographically distinct centers. CREn were investigated at an Israeli center (Assaf Harofeh Medical Center, January 2007 to July 2012) and at a US center (Detroit Medical Center, September 2008 to September 2009). bla KPC genes were queried by polymerase chain reaction. Repetitive extragenic palindromic polymerase chain reaction and pulsed-field gel electrophoresis were used to determine genetic relatedness. In this analysis, 68 unique patients with CREn were enrolled. Sixteen isolates (24%) were from wounds, and 33 (48%) represented colonization only. All isolates exhibited a positive Modified Hodge Test, but only 93% (27 of 29) contained bla KPC. Forty-three isolates (63%) were from elderly adults, and 5 (7.4%) were from neonates. Twenty-seven patients died in hospital (40.3% of infected patients). Enterobacter strains consisted of 4 separate clones from Assaf Harofeh Medical Center and of 4 distinct clones from Detroit Medical Center. In this study conducted at 2 distinct CRE endemic regions, there were unique epidemiologic features to CREn: (i) polyclonality, (ii) neonates accounting for more than 7% of cohort, and (iii) high rate of colonization (almost one-half of all cases represented colonization). Since false-positive Modified Hodge Tests in Enterobacter spp. are common, close monitoring of carbapenem resistance mechanisms (particularly carbapenemase production) among Enterobacter spp. is important.

Post hoc support vector machine learning for impedimetric biosensors based on weak protein-ligand interactions.

Science.gov (United States)

Rong, Y; Padron, A V; Hagerty, K J; Nelson, N; Chi, S; Keyhani, N O; Katz, J; Datta, S P A; Gomes, C; McLamore, E S

2018-04-30

Impedimetric biosensors for measuring small molecules based on weak/transient interactions between bioreceptors and target analytes are a challenge for detection electronics, particularly in field studies or in the analysis of complex matrices. Protein-ligand binding sensors have enormous potential for biosensing, but achieving accuracy in complex solutions is a major challenge. There is a need for simple post hoc analytical tools that are not computationally expensive, yet provide near real time feedback on data derived from impedance spectra. Here, we show the use of a simple, open source support vector machine learning algorithm for analyzing impedimetric data in lieu of using equivalent circuit analysis. We demonstrate two different protein-based biosensors to show that the tool can be used for various applications. We conclude with a mobile phone-based demonstration focused on the measurement of acetone, an important biomarker related to the onset of diabetic ketoacidosis. In all conditions tested, the open source classifier was capable of performing as well as, or better, than the equivalent circuit analysis for characterizing weak/transient interactions between a model ligand (acetone) and a small chemosensory protein derived from the tsetse fly. In addition, the tool has a low computational requirement, facilitating use for mobile acquisition systems such as mobile phones. The protocol is deployed through Jupyter notebook (an open source computing environment available for mobile phone, tablet or computer use) and the code was written in Python. For each of the applications, we provide step-by-step instructions in English, Spanish, Mandarin and Portuguese to facilitate widespread use. All codes were based on scikit-learn, an open source software machine learning library in the Python language, and were processed in Jupyter notebook, an open-source web application for Python. The tool can easily be integrated with the mobile biosensor equipment for rapid

A Cross Layer Solution to Address TCP Intra-flow Performance Degradation in Multihop Ad hoc Networks

OpenAIRE

Rakocevic, V.; Hamadani, E.

2008-01-01

Incorporating the concept of TCP end-to-end congestion control for wireless networks is one of the primary concerns in designing ad hoc networks since TCP was primarily designed and optimized based on the assumptions for wired networks. In this study, our interest lies on tackling the TCP instability and in particular intra-flow instability problem since due to the nature of applications in multihop ad hoc networks, connection instability or starvation even for a short period of time can have...

Adaptive Demand-Driven Multicast Routing in Multi-Hop Wireless Ad Hoc Networks

National Research Council Canada - National Science Library

Jetcheva, Jorjeta G

2004-01-01

...) nodes that wish to communicate. Each node in the ad hoc network acts as a router and forwards packets on behalf of other nodes, allowing nodes that are not within wireless range of each other to communicate over multi-hop paths...

Report of the evaluation by the Ad Hoc Review Committee on Materials Science Research. In-advance evaluation in fiscal year 2002

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-11-01

The Research Evaluation Committee, which consisted of 13 members from outside of the Japan Atomic Energy Research Institute (JAERI), set up an Ad Hoc Review Committee on Materials Science Research in accordance with the Fundamental Guideline for the Evaluation of Research and Development (R and D) at JAERI' and its subsidiary regulations in order to evaluate the adequacy of the R and D programs to be implemented for five years starting in Fiscal Year 2003 at Department of Materials Science in Tokai Research Establishment of JAERI. The Ad Hoc Review Committee consisted of eight specialists from outside of JAERI. The Ad Hoc Review Committee conducted its activities from April 2002 to August 2002. The evaluation was performed on the basis of the materials submitted in advance and of the oral presentations made at the Ad Hoc Review Committee meeting which was held on June 5th, 2002, in line with the items, viewpoints, and criteria for the evaluation specified by the Research Evaluation Committee. The result of the evaluation by the Ad Hoc Review Committee was submitted to the Research Evaluation Committee, and was judged to be appropriate at its meeting held on August 5th, 2002. This report describes the result of the evaluation by the Ad Hoc Review Committee on Materials Science Research. (author)

Report of the evaluation by the Ad Hoc Review Committee on Materials Science Research. In-advance evaluation in fiscal year 2002

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-11-01

The Research Evaluation Committee, which consisted of 13 members from outside of the Japan Atomic Energy Research Institute (JAERI), set up an Ad Hoc Review Committee on Materials Science Research in accordance with the Fundamental Guideline for the Evaluation of Research and Development (R and D) at JAERI' and its subsidiary regulations in order to evaluate the adequacy of the R and D programs to be implemented for five years starting in Fiscal Year 2003 at Department of Materials Science in Tokai Research Establishment of JAERI. The Ad Hoc Review Committee consisted of eight specialists from outside of JAERI. The Ad Hoc Review Committee conducted its activities from April 2002 to August 2002. The evaluation was performed on the basis of the materials submitted in advance and of the oral presentations made at the Ad Hoc Review Committee meeting which was held on June 5th, 2002, in line with the items, viewpoints, and criteria for the evaluation specified by the Research Evaluation Committee. The result of the evaluation by the Ad Hoc Review Committee was submitted to the Research Evaluation Committee, and was judged to be appropriate at its meeting held on August 5th, 2002. This report describes the result of the evaluation by the Ad Hoc Review Committee on Materials Science Research. (author)

Report of the evaluation by the ad hoc review committee on radiation application research. In-advance evaluation in fiscal year 2001

International Nuclear Information System (INIS)

2001-11-01

The Research Evaluation Committee, which consisted of 13 members from outside of the Japan Atomic Energy Research Institute (JAERI), set up an Ad Hoc Review Committee on Radiation Application Research in accordance with the Fundamental Guideline for the Evaluation of Research and Development (R and D) at JAERI' and its subsidiary regulations in order to evaluate the adequacy of the R and D programs to be implemented for five years starting in Fiscal Year 2002 at Department of Material Development, at Department of Ion-Beam-Applied Biology and at Advanced Radiation Technology Center in Takasaki Radiation Chemistry Research Establishment of JAERI. The Ad Hoc Review Committee consisted of ten specialists from outside of JAERI. The Ad Hoc Review Committee conducted its activities from May to July 2001. The evaluation was performed on the basis of the materials submitted in advance and of the oral presentations made at the Ad Hoc Review Committee meeting which was held on June 25, 2001, in line with the items, viewpoints, and criteria for the evaluation specified by the Research Evaluation Committee. The result of the evaluation by the Ad Hoc Review Committee was submitted to the Research Evaluation Committee, and was judged to be appropriate at its meeting held on July 12, 2001. This report describes the result of the evaluation by the Ad Hoc Review Committee on Radiation Application Research. (author)

Safety of natural radiation exposure. A meta-analysis of epidemiological studies on natural radiation

International Nuclear Information System (INIS)

Osaki, S.

2000-01-01

. Furthermore, the combine of these studies, a meta-analysis, is expected to decrease the confidence limit and to countervail the confounding factors. This study reviewed the epidemiological studies on natural radiation exposure and tried to combine their results to prove the safety of natural radiation exposure. (author)

Sistem Verifikasi Tanda Tangan Off-Line Berdasar Ciri Histogram Of Oriented Gradient (HOG Dan Histogram Of Curvature (HoC

Directory of Open Access Journals (Sweden)

Agus Wahyu Widodo

2015-08-01

Full Text Available Abstrak Tanda tangan dengan sifat uniknya merupakan salah satu dari sekian banyak atribut personal yang diterima secara luas untuk verifikasi indentitas seseorang, alat pembuktian kepemilikan berbagai transaksi atau dokumen di dalam masyarakat. Keberhasilan penggunaan ciri gradien dan curvature dalam bidang-bidang penelitian pengenalan pola dan bahwa tanda tangan dapat dikatakan merupakan hasil tulisan tangan yang tersusun atas beragam garis dan lengkungan (curve yang memiliki arah atau orientasi merupakan alasan bahwa kedua ciri tersebut digunakan sebagai metoda verifikasi tanda tangan offline di penelitian ini. Berbagai implementasi dari pre-processing, ekstraksi dan representasi ciri, dan pembelajaran SVM serta usaha perbaikan yang telah dilakukan dalam penelitian ini menunjukkan hasil bahwa ciri HOG dan HoC mampu dimanfaatkan dalam proses verifikasi tanda tangan secara offline.  Pada basis data GPDS960Signature, HOG dan HoC yang dihitung pada ukuran sel 30 x 30 piksel memberikan dengan nilai %FRR terbaik 26,90 dan %FAR 37,56.  Sedangkan pada basis data FUM-PHSDB, HOG dn HoC yang dihitung pada ukuran 60 x 60 piksel memberikan nilai %FRR terbaik 4 dan %FAR 57. Kata kunci: verifikasi tanda tangan, curvature, orientation, gradient, histogram of curvature (HoC, histogram of oriented gradient (HOG Abstract Signature with unique properties is one of the many personal attributes that are widely accepted to verify a person's identity, proof of ownership transactions instrument or document in the community. The successful use of gradient and curvature feature in the research fields of pattern recognition is the reason that both of these features are used as an offline signature verification method in this study. Various implementations of preprocessing, feature extraction and representation, and SVM learning has been done in the study showed results that HOG and HoC feature can be utilized in the process of offline signature verification.  HOG and

Chondrosarcoma of the Osseous Spine: An Analysis of Epidemiology, Patient Outcomes, and Prognostic Factors Using the SEER Registry From 1973 to 2012.

Science.gov (United States)

Arshi, Armin; Sharim, Justin; Park, Don Y; Park, Howard Y; Bernthal, Nicholas M; Yazdanshenas, Hamed; Shamie, Arya N

2017-05-01

Retrospective analysis. To determine the epidemiology and prognostic indicators in patients with chondrosarcoma of the osseous spine. Chondrosarcoma of the spine is rare, with limited data on its epidemiology, clinicopathologic features, and treatment outcomes. Therapy centers on complete en bloc resection with radiotherapy reserved for subtotal resection or advanced disease. The Surveillance, Epidemiology, and End Results Registry was queried for patients with chondrosarcoma of the osseous spine from 1973 to 2012. Study variables included age, sex, race, year of diagnosis, size, grade, extent of disease, and treatment modality. The search identified 973 cases of spinal chondrosarcoma. Mean age at diagnosis was 51.6 years, and 627% of patients were males. Surgical resection and radiotherapy were performed in 75.2% and 21.3% of cases, respectively. Kaplan-Meier analysis demonstrated overall survival (OS) and disease-specific survival (DSS) of 53% and 64%, respectively, at 5 years. Multivariate Cox regression analysis showed that age (OS, P chondrosarcoma of the spine independent of extent of disease. Radiotherapy improves survival in patients with metastatic disease and worsens outcomes in patients with confined and locally invasive disease. 4.

[Occupational epidemiology: some methodological considerations].

Science.gov (United States)

Alvear-Galindo, María Guadalupe; del Pilar Paz-Román, María

2006-01-01

During the last decade, occupational epidemiology has gained a great importance, not only because of the increase of pollutants and their noxiousness, but also because it has gone from the descriptive to the analytic level. The purpose of this work is to present what has been reported on epidemiological studies, different ways of characterizing and measuring occupational exposure, by emphasizing slants of exposure and selection measurement. In the reviewed studies, an interest in improving the exposure evaluation has been shown. The mainly reported measurement slants are the ways of measuring and classifying the exposure. The main designs were transversal with the use of matrixes to improve the evaluation of exposure. Conditions of hygiene and security were considered in order to control the quality of the information. This information was analyzed with different criteria. Some of the elements that hinder the research on occupational epidemiology are a mixed exposure, small populations, lack of exposure data, low levels of exposure and long periods of illness latency. Some breakthroughs in the strategies of epidemiological analysis and some other areas of knowledge have made possible a better understanding of work and health conditions of workers.

Multicollinearity in Regression Analyses Conducted in Epidemiologic Studies.

Science.gov (United States)

Vatcheva, Kristina P; Lee, MinJae; McCormick, Joseph B; Rahbar, Mohammad H

2016-04-01

The adverse impact of ignoring multicollinearity on findings and data interpretation in regression analysis is very well documented in the statistical literature. The failure to identify and report multicollinearity could result in misleading interpretations of the results. A review of epidemiological literature in PubMed from January 2004 to December 2013, illustrated the need for a greater attention to identifying and minimizing the effect of multicollinearity in analysis of data from epidemiologic studies. We used simulated datasets and real life data from the Cameron County Hispanic Cohort to demonstrate the adverse effects of multicollinearity in the regression analysis and encourage researchers to consider the diagnostic for multicollinearity as one of the steps in regression analysis.

An evidence-based analysis of epidemiologic associations between lymphatic and hematopoietic cancers and occupational exposure to gasoline.

Science.gov (United States)

Keenan, J J; Gaffney, S; Gross, S A; Ronk, C J; Paustenbach, D J; Galbraith, D; Kerger, B D

2013-10-01

The presence of benzene in motor gasoline has been a health concern for potential increased risk of acute myelogenous leukemia and perhaps other lymphatic/hematopoietic cancers for approximately 40 years. Because of the widespread and increasing use of gasoline by consumers and the high exposure potential of occupational cohorts, a thorough understanding of this issue is important. The current study utilizes an evidence-based approach to examine whether or not the available epidemiologic studies demonstrate a strong and consistent association between occupational exposure to gasoline and lymphatic/hematopoietic cancers. Among 67 epidemiologic studies initially identified, 54 were ranked according to specific criteria relating to the relevance and robustness of each study for answering the research question. The 30 highest-ranked studies were sorted into three tiers of evidence and were analyzed for strength, specificity, consistency, temporality, dose-response trends and coherence. Meta statistics were also calculated for each general and specific lymphatic/hematopoietic cancer category with adequate data. The evidence-based analysis did not confirm any strong and consistent association between occupational exposure to gasoline and lymphatic/hematopoietic cancers based on the epidemiologic studies available to date. These epidemiologic findings, combined with the evidence showing relatively low occupational benzene vapor exposures associated with gasoline formulations during the last three decades, suggest that current motor gasoline formulations are not associated with increased lymphatic/hematopoietic cancer risks related to benzene.

Methodological exploratory study applied to occupational epidemiology

Energy Technology Data Exchange (ETDEWEB)

Carneiro, Janete C.G. Gaburo; Vasques, MOnica Heloisa B.; Fontinele, Ricardo S.; Sordi, Gian Maria A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: janetegc@ipen.br

2007-07-01

The utilization of epidemiologic methods and techniques has been object of practical experimentation and theoretical-methodological reflection in health planning and programming process. Occupational Epidemiology is the study of the causes and prevention of diseases and injuries from exposition and risks in the work environment. In this context, there is no intention to deplete such a complex theme but to deal with basic concepts of Occupational Epidemiology, presenting the main characteristics of the analysis methods used in epidemiology, as investigate the possible determinants of exposition (chemical, physical and biological agents). For this study, the social-demographic profile of the IPEN-CNEN/SP work force was used. The knowledge of this reference population composition is based on sex, age, educational level, marital status and different occupations, aiming to know the relation between the health aggravating factors and these variables. The methodology used refers to a non-experimental research based on a theoretical methodological practice. The work performed has an exploratory character, aiming a later survey of indicators in the health area in order to analyze possible correlations related to epidemiologic issues. (author)

Methodological exploratory study applied to occupational epidemiology

International Nuclear Information System (INIS)

Carneiro, Janete C.G. Gaburo; Vasques, MOnica Heloisa B.; Fontinele, Ricardo S.; Sordi, Gian Maria A.

2007-01-01

The utilization of epidemiologic methods and techniques has been object of practical experimentation and theoretical-methodological reflection in health planning and programming process. Occupational Epidemiology is the study of the causes and prevention of diseases and injuries from exposition and risks in the work environment. In this context, there is no intention to deplete such a complex theme but to deal with basic concepts of Occupational Epidemiology, presenting the main characteristics of the analysis methods used in epidemiology, as investigate the possible determinants of exposition (chemical, physical and biological agents). For this study, the social-demographic profile of the IPEN-CNEN/SP work force was used. The knowledge of this reference population composition is based on sex, age, educational level, marital status and different occupations, aiming to know the relation between the health aggravating factors and these variables. The methodology used refers to a non-experimental research based on a theoretical methodological practice. The work performed has an exploratory character, aiming a later survey of indicators in the health area in order to analyze possible correlations related to epidemiologic issues. (author)

Causal diagrams in systems epidemiology

Directory of Open Access Journals (Sweden)

Joffe Michael

2012-03-01

Full Text Available Abstract Methods of diagrammatic modelling have been greatly developed in the past two decades. Outside the context of infectious diseases, systematic use of diagrams in epidemiology has been mainly confined to the analysis of a single link: that between a disease outcome and its proximal determinant(s. Transmitted causes ("causes of causes" tend not to be systematically analysed. The infectious disease epidemiology modelling tradition models the human population in its environment, typically with the exposure-health relationship and the determinants of exposure being considered at individual and group/ecological levels, respectively. Some properties of the resulting systems are quite general, and are seen in unrelated contexts such as biochemical pathways. Confining analysis to a single link misses the opportunity to discover such properties. The structure of a causal diagram is derived from knowledge about how the world works, as well as from statistical evidence. A single diagram can be used to characterise a whole research area, not just a single analysis - although this depends on the degree of consistency of the causal relationships between different populations - and can therefore be used to integrate multiple datasets. Additional advantages of system-wide models include: the use of instrumental variables - now emerging as an important technique in epidemiology in the context of mendelian randomisation, but under-used in the exploitation of "natural experiments"; the explicit use of change models, which have advantages with respect to inferring causation; and in the detection and elucidation of feedback.

Causal diagrams in systems epidemiology.

Science.gov (United States)

Joffe, Michael; Gambhir, Manoj; Chadeau-Hyam, Marc; Vineis, Paolo

2012-03-19

Methods of diagrammatic modelling have been greatly developed in the past two decades. Outside the context of infectious diseases, systematic use of diagrams in epidemiology has been mainly confined to the analysis of a single link: that between a disease outcome and its proximal determinant(s). Transmitted causes ("causes of causes") tend not to be systematically analysed.The infectious disease epidemiology modelling tradition models the human population in its environment, typically with the exposure-health relationship and the determinants of exposure being considered at individual and group/ecological levels, respectively. Some properties of the resulting systems are quite general, and are seen in unrelated contexts such as biochemical pathways. Confining analysis to a single link misses the opportunity to discover such properties.The structure of a causal diagram is derived from knowledge about how the world works, as well as from statistical evidence. A single diagram can be used to characterise a whole research area, not just a single analysis - although this depends on the degree of consistency of the causal relationships between different populations - and can therefore be used to integrate multiple datasets.Additional advantages of system-wide models include: the use of instrumental variables - now emerging as an important technique in epidemiology in the context of mendelian randomisation, but under-used in the exploitation of "natural experiments"; the explicit use of change models, which have advantages with respect to inferring causation; and in the detection and elucidation of feedback.

Using Social Media Sentiment Analysis to Understand Audiences

DEFF Research Database (Denmark)

McGuire, Mark; Kampf, Constance Elizabeth

2015-01-01

approach for contextually understanding social media posts. The human interaction step in ad-hoc corpus analysis is central to this methodology as it provides a means to ask critical questions of the content curated through the ad-hoc corpus directly. Results of ad-hoc corpus analysis from this critical......Social media communication is changing the opportunities for technical communicators to really understand audiences when these audiences are active about issues on social media platforms. Through applying ad-hoc corpus building processes to create word lists relevant to specific organizational...... projects, technical communicators can listen to their external users and identify areas of importance with greater accuracy. While other methods of sentiment analysis look for a solution that leads to artificial intelligence in the program, this paper identifies the present needs of a human interaction...

Protective effect of yerba mate intake on the cardiovascular system: a post hoc analysis study in postmenopausal women.

Science.gov (United States)

da Veiga, D T A; Bringhenti, R; Copes, R; Tatsch, E; Moresco, R N; Comim, F V; Premaor, M O

2018-01-01

The prevalence of cardiovascular and metabolic diseases is increased in postmenopausal women, which contributes to the burden of illnesses in this period of life. Yerba mate (Ilex paraguariensis) is a native bush from Southern South America. Its leaves are rich in phenolic components, which may have antioxidant, vasodilating, hypocholesterolemic, and hypoglycemic proprieties. This post hoc analysis of the case-control study nested in the Obesity and Bone Fracture Cohort evaluated the consumption of yerba mate and the prevalence of hypertension, dyslipidemia, and coronary diseases in postmenopausal women. Ninety-five postmenopausal women were included in this analysis. A questionnaire was applied to evaluate the risk factors and diagnosis of cardiovascular diseases and consumption of yerba mate infusion. Student's t-test and chi-square test were used to assess significant differences between groups. The group that consumed more than 1 L/day of mate infusion had significantly fewer diagnoses of coronary disease, dyslipidemia, and hypertension (P<0.049, P<0.048, and P<0.016, respectively). Furthermore, the serum levels of glucose were lower in the group with a higher consumption of yerba mate infusion (P<0.013). The serum levels of total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglycerides were similar between the groups. This pragmatic study points out the benefits of yerba mate consumption for the cardiovascular and metabolic systems. The ingestion of more than 1 L/day of mate infusion was associated with fewer self-reported cardiovascular diseases and lower serum levels of glucose. Longitudinal studies are needed to evaluate the association between yerba mate infusion and reduction of cardiovascular diseases in postmenopausal women.

Enhancing On-Demand Multicast Routing Protocols using Mobility Prediction in Mobile Ad-hoc Network

Directory of Open Access Journals (Sweden)

Nermin Makhlouf

2014-08-01

Full Text Available A Mobile Ad hoc Network (MANET is a self-organizing wireless communication network in which mobile devices are based on no infrastructure like base stations or access points. Minimal configuration and quick deployment make ad hoc networks suitable for emergency situations like disaster recovery or military conflict. Since node mobility may cause links to be broken frequently, a very important issue for routing in MANETs is how to set reliable paths which can last as long as possible. To solve this problem, non-random behaviors for the mobility patterns that mobile users exhibit are exploited. This paper introduces a scheme to improve On-Demand Multicast Routing Protocol (ODMRP performances by using mobility prediction. 

Design of free patterns of nanocrystals with ad hoc features via templated dewetting

Energy Technology Data Exchange (ETDEWEB)

Aouassa, M.; Berbezier, I.; Favre, L.; Ronda, A. [IM2NP, CNRS, AMU, Marseille (France); Bollani, M.; Sordan, R. [LNES, Como (Italy); Delobbe, A.; Sudraud, P. [Orsay Physics, Fuveau (France)

2012-07-02

Design of monodisperse ultra-small nanocrystals (NCs) into large scale patterns with ad hoc features is demonstrated. The process makes use of solid state dewetting of a thin film templated through alloy liquid metal ion source focused ion beam (LMIS-FIB) nanopatterning. The solid state dewetting initiated at the edges of the patterns controllably creates the ordering of NCs with ad hoc placement and periodicity. The NC size is tuned by varying the nominal thickness of the film while their position results from the association of film retraction from the edges of the lay out and Rayleigh-like instability. The use of ultra-high resolution LMIS-FIB enables to produce monocrystalline NCs with size, periodicity, and placement tunable as well. It provides routes for the free design of nanostructures for generic applications in nanoelectronics.

Analysis of epidemiological indices of type 2 diabetes mellitus in the adult population of Moscow

Directory of Open Access Journals (Sweden)

Marina Fedorovna Kalashnikova

2014-07-01

Full Text Available Diabetes mellitus is a disease that presents a global medical problem. It is necessary to implement an in-depth analysis of the epidemiological situation of type 2 diabetes mellitus for planning and organizing specialized medical help to patients with type 2 diabetes mellitus.AimTo rate the basic epidemiological indices of type 2 diabetes mellitus in actual clinical practice using the informational database of national registry of diabetic patients.Materials and methodsEpidemiological analyses were performed in two administrative districts of Moscow. From 1999 to 2011 48978 adult patients with type 2 diabetes mellitus who were aged 18 years and older were registered. We used methods of clinical, analytical and statistical epidemiology with elements of descriptive research.ResultsThe prevalence rate of type 2 diabetes mellitus was 1590 per hundred thousand, most patients were in the 60–64 and 70–74 age groups, and approximately 80% of patients were older than 55 years. The morbidity rate of type 2 diabetes mellitus was 138,72 per hundred thousand and was found to be higher in women at 1,89. The mortality rate of adult patients with diabetes mellitus was 0,83, mostly in men of all ages. Cardiovascular diseases accounted for most of the registered cases of deaths (34,4%. The average life expectancy appeared to be 75,24±0,45 years, although women lived 6 years longer than men. The average duration of the disease was 10,04±0,34 years. A total of 0,4% of patients underwent hospital treatment and the average length of treatment was 17–18 days. The total number of days of disablement was an average of 307,33±30,13 days (80% of patients were older than 55 years. In the study group, a mean grade of НbА1c <7% was observed in 56,6% of patients. The prevalence rate of detected chronic complications was considerably lower compared to other epidemiological studies.ConclusionsOur epidemiological analyses revealed a number of features and consistent

A User Authentication Scheme Based on Elliptic Curves Cryptography for Wireless Ad Hoc Networks.

Science.gov (United States)

Chen, Huifang; Ge, Linlin; Xie, Lei

2015-07-14

The feature of non-infrastructure support in a wireless ad hoc network (WANET) makes it suffer from various attacks. Moreover, user authentication is the first safety barrier in a network. A mutual trust is achieved by a protocol which enables communicating parties to authenticate each other at the same time and to exchange session keys. For the resource-constrained WANET, an efficient and lightweight user authentication scheme is necessary. In this paper, we propose a user authentication scheme based on the self-certified public key system and elliptic curves cryptography for a WANET. Using the proposed scheme, an efficient two-way user authentication and secure session key agreement can be achieved. Security analysis shows that our proposed scheme is resilient to common known attacks. In addition, the performance analysis shows that our proposed scheme performs similar or better compared with some existing user authentication schemes.

The impact of brief team communication, leadership and team behavior training on ad hoc team performance in trauma care settings.

Science.gov (United States)

Roberts, Nicole K; Williams, Reed G; Schwind, Cathy J; Sutyak, John A; McDowell, Christopher; Griffen, David; Wall, Jarrod; Sanfey, Hilary; Chestnut, Audra; Meier, Andreas H; Wohltmann, Christopher; Clark, Ted R; Wetter, Nathan

2014-02-01

Communication breakdowns and care coordination problems often cause preventable adverse patient care events, which can be especially acute in the trauma setting, in which ad hoc teams have little time for advanced planning. Existing teamwork curricula do not address the particular issues associated with ad hoc emergency teams providing trauma care. Ad hoc trauma teams completed a preinstruction simulated trauma encounter and were provided with instruction on appropriate team behaviors and team communication. Teams completed a postinstruction simulated trauma encounter immediately afterward and 3 weeks later, then completed a questionnaire. Blinded raters rated videotapes of the simulations. Participants expressed high levels of satisfaction and intent to change practice after the intervention. Participants changed teamwork and communication behavior on the posttest, and changes were sustained after a 3-week interval, though there was some loss of retention. Brief training exercises can change teamwork and communication behaviors on ad hoc trauma teams. Copyright © 2014 Elsevier Inc. All rights reserved.

Report of the Ad Hoc Committee on SSC physics

International Nuclear Information System (INIS)

1990-04-01

The Ad Hoc Committee on SSC Physics has reexamined the relationship between beam energy, machine luminosity, and physics capability. In the next section, the physics motivation for the SSC is reviewed in general terms. This is followed by a discussion of the ability to detect a number of specific processes as a function of the SSC energy and luminosity. The viability of various detector technologies is then assessed as a function of luminosity. The report ends with a brief summary and some conclusions

TFOS DEWS II Epidemiology Report

NARCIS (Netherlands)

Stapleton, Fiona; Alves, Monica; Bunya, Vatinee Y.; Jalbert, Isabelle; Lekhanont, Kaevalin; Malet, Florence; Na, Kyung-Sun; Schaumberg, Debra; Uchino, Miki; Vehof, Jelle; Viso, Eloy; Vitale, Susan; Jones, Lyndon

The subcommittee reviewed the prevalence, incidence, risk factors, natural history, morbidity and questionnaires reported in epidemiological studies of dry eye disease (DED). A meta-analysis of published prevalence data estimated the impact of age and sex. Global mapping of prevalence was

Report of the evaluation by the Ad Hoc Review Committee on High-Temperature Engineering and Research. Result evaluation in fiscal year 2000

International Nuclear Information System (INIS)

2001-06-01

The Research Evaluation Committee, which consisted of 14 members from outside of the Japan Atomic Energy Research Institute (JAERI), set up an Ad Hoc Review Committee on High-Temperature Engineering and Research in accordance with the 'Fundamental Guideline for the Evaluation of Research and Development (R and D) at JAERI' and its subsidiary regulations in order to evaluate the R and D accomplishments achieved for five years from Fiscal Year 1995 to Fiscal Year 1999 at Department of HTTR Project and Department of Advanced Nuclear Heat Technology in Oarai Research Establishment of JAERI. The Ad Hoc Review Committee consisted of nine specialists from outside of JAERI. The Ad Hoc Review Committee conducted its activities from December 2000 to February 2001. The evaluation was performed on the basis of the materials submitted in advanced and of the oral presentations made at the Ad Hoc Review Committee meeting which was held on December 8, 2000, in line with the items, viewpoints, and criteria for the evaluation specified by the Research Evaluation Committee. The result of the evaluation by the Ad Hoc Review Committee was submitted to the Research Evaluation Committee, and was judged to be appropriate at its meeting held on March 16, 2001. This report describes the result of the evaluation by the Ad Hoc Review Committee on High-Temperature Engineering and Research. (author)

Coffee consumption and risk of esophageal cancer incidence: A meta-analysis of epidemiologic studies.

Science.gov (United States)

Zhang, Juan; Zhou, Bin; Hao, Chuanzheng

2018-04-01

In epidemiologic studies, association between coffee consumption and esophageal cancer risk is inconsistent. The aim of tjis study was to evaluate the effect of coffee on esophageal cancer by combining several similar studies. We conducted a meta-analysis for association of coffee intake and esophageal cancer incidence. Eleven studies, including 457,010 participants and 2628 incident cases, were identified. A relative risk (RR, for cohort study) or odds ratio (OR, for case-control study) of heavy coffee drinkers was calculated, compared with light coffee drinkers or non-drinkers. The analysis was also stratified by cancer types (esophageal squamous cell carcinoma and esophageal adenocarcinoma), sex, and geographic region. The summarized OR of having esophageal cancer in heavy coffee drinkers was 0.93 (95% confidence interval [CI]: 0.73-1.12), compared with light coffee drinkers. When stratified by sex, pathologic type of esophageal cancer, and type of epidemiologic study, we did not find any association of coffee consumption and esophageal cancer incidence. However, an inverse association between coffee consumption and incidence of esophageal cancer was found in East Asia participants with OR of 0.64 (95% CI: 0.44-0.83), but not in Euro-America participants (OR = 1.05; 95% CI: 0.81-1.29). There is a protective role of coffee consumption against esophageal cancer in East Asians, but not in Euro-Americans.

Ad Hoc Transient Communities to Enhance Social Interaction and Spread Tutor Responsibilities

NARCIS (Netherlands)

Sloep, Peter; Kester, Liesbeth; Brouns, Francis; Van Rosmalen, Peter; De Vries, Fred; De Croock, Marcel; Koper, Rob

2007-01-01

Sloep, P.B., Kester, L., Brouns, F., Van Rosmalen, P., De Vries, F., De Croock, M., Koper, R. (2007). Ad Hoc Transient Communities to Enhance Social Interaction and Spread Tutor Responsibilities. Presentation given at the Sixth IASTED International Conference on Web-based Education, 14-16 March,

A Survey on Trust Management for Mobile Ad Hoc Networks

Science.gov (United States)

2011-11-01

expects, trust is dangerous implying the possible betrayal of trust. In his comments on Lagerspetz’s book titled Trust: The Tacit Demand, Lahno [24...AODV Zouridaki et al. (2005 ) [79] (2006) [80] Secure routing Direct observation [79][80] Reputation by secondhand information [80] Packet dropping...areas of signal processing, wireless communications, sensor and mobile ad hoc networks. He is co-editor of the book Wireless Sensor Networks: Signal

On knowledge transfer management as a learning process for ad hoc teams

Science.gov (United States)

Iliescu, D.

2017-08-01

Knowledge management represents an emerging domain becoming more and more important. Concepts like knowledge codification and personalisation, knowledge life-cycle, social and technological dimensions, knowledge transfer and learning management are integral parts. Focus goes here in the process of knowledge transfer for the case of ad hoc teams. The social dimension of knowledge transfer plays an important role. No single individual actors involved in the process, but a collective one, representing the organisation. It is critically important for knowledge to be managed from the life-cycle point of view. A complex communication network needs to be in place to supports the process of knowledge transfer. Two particular concepts, the bridge tie and transactive memory, would eventually enhance the communication. The paper focuses on an informational communication platform supporting the collaborative work on knowledge transfer. The platform facilitates the creation of a topic language to be used in knowledge modelling, storage and reuse, by the ad hoc teams.

Perioperative hyperoxia - Long-term impact on cardiovascular complications after abdominal surgery, a post hoc analysis of the PROXI trial

DEFF Research Database (Denmark)

Fonnes, Siv; Gogenur, Ismail; Sondergaard, Edith Smed

2016-01-01

BACKGROUND: Increased long-term mortality was found in patients exposed to perioperative hyperoxia in the PROXI trial, where patients undergoing laparotomy were randomised to 80% versus 30% oxygen during and after surgery. This post hoc follow-up study assessed the impact of perioperative hyperoxia...... included myocardial infarction, other heart disease, and acute coronary syndrome or death. Data were analysed in the Cox proportional hazards model. RESULTS: The primary outcome, acute coronary syndrome, occurred in 2.5% versus 1.3% in the 80% versus 30% oxygen group; HR 2.15 (95% CI 0.96-4.84). Patients...

Analysis of epidemiological indices of type 2 diabetes mellitus in the adult population of Moscow

Directory of Open Access Journals (Sweden)

Marina Fedorovna Kalashnikova

2014-07-01

Full Text Available Diabetes mellitus is a disease that presents a global medical problem. It is necessary to implement an in-depth analysis of the epidemiological situation of type 2 diabetes mellitus for planning and organizing specialized medical help to patients with type 2 diabetes mellitus. Aim. To rate the basic epidemiological indices of type 2 diabetes mellitus in actual clinical practice using the informational database of national registry of diabetic patients. Materials and methods. Epidemiological analyses were performed in two administrative districts of Moscow. From 1999 to 2011 48978 adult patients with type 2 diabetes mellitus who were aged 18 years and older were registered. We used methods of clinical, analytical and statistical epidemiology with elements of descriptive research. Results. The prevalence rate of type 2 diabetes mellitus was 1590 per hundred thousand, most patients were in the 60?64 and 70?74 age groups, and approximately 80% of patients were older than 55 years. The morbidity rate of type 2 diabetes mellitus was 138,72 per hundred thousand and was found to be higher in women at 1,89. The mortality rate of adult patients with diabetes mellitus was 0,83, mostly in men of all ages. Cardiovascular diseases accounted for most of the registered cases of deaths (34,4%. The average life expectancy appeared to be 75,24?0,45 years, although women lived 6 years longer than men. The average duration of the disease was 10,04?0,34 years. A total of 0,4% of patients underwent hospital treatment and the average length of treatment was 17?18 days. The total number of days of disablement was an average of 307,33?30,13 days (80% of patients were older than 55 years. In the study group, a mean grade of НbА1c

Analysis of epidemiological situation of iodine deficiency in Tomsk region from 1998 to 2014

Science.gov (United States)

Samoilova, Y. G.; Oleynik, O. A.; Yurchenko, E. V.; Zinchuk, S. F.; Sivolobova, T. V.; Rotkank, M. A.; Mazhitova, D. S.

2017-08-01

The purpose of the present research is the comparative analysis of the epidemiological situation of iodine deficiency in the Tomsk region from 1998 to 2014. There were examined 9901 and 15174 children of the school age including within the medical examination of the children’s population in 1998 and 2014 in Tomsk. At all school pupils there were analyzed anamnestic data and carried out anthropometrical measurements, ultrasonography of the thyroid gland was carried out using the portable scanner "Aloka SSD 500" with the linear sensor of 7,5 MHz frequency in the real time, the thyroid volume was evaluated according to Delange (1997). The excretion of inorganic iodine was determined at 264 in 1998 and at 120 children in 2014, respectively, in a one-time portion of urine by the cerium-arsenic method. There was additionally carried out the analysis of results of determination of TSH at 10717 in 1998, and at 15091 in 2014 in a spot of the whole blood at newborn children on the 4-5 day after birth at full-term and on the 7-14 day at prematurely born children. Neonatal TSH in the dried-up samples of capillary blood was determined by the method of the fluorometric immune-ferment analysis with the use of sets of TSH-Neonatal: Delfia, Finland. Statistical processing of the data obtained was carried out with the use of the applied software package pspp. The descriptive analysis included calculation of the median for the quantitative and the calculation of frequencies for qualitative data. The comparative analysis included calculation of distinctions reliability by the Mann-Whitney criterion for independent and to Wilcoxon’s criterion for dependent data. The comparative analysis of epidemiological situation of iodine deficiency in Tomsk and the Tomsk region in 1998 and 2014 specifies decreasing the iodine deficiency diseases in the Tomsk region, increasing the iodine provision of the population within 15 years by 27%, decreasing neonatal hyperthyroidism by 1.5 times.

Epidemiological Distribution and Subtype Analysis of Premenstrual Dysphoric Disorder Syndromes and Symptoms Based on TCM Theories

Directory of Open Access Journals (Sweden)

Mingqi Qiao

2017-01-01

Full Text Available We performed an epidemiological investigation of subjects with premenstrual dysphoric disorder (PMDD to identify the clinical distribution of the major syndromes and symptoms. The pathogenesis of PMDD mainly involves the dysfunction of liver conveyance and dispersion. Excessive liver conveyance and dispersion are associated with liver-qi invasion syndrome, while insufficient liver conveyance and dispersion are expressed as liver-qi depression syndrome. Additionally, a nonconditional logistic regression was performed to analyze the symptomatic features of liver-qi invasion and liver-qi depression. As a result of this analysis, two subtypes of PMDD are proposed, namely, excessive liver conveyance and dispersion (liver-qi invasion syndrome and insufficient liver conveyance and dispersion (liver-qi depression syndrome. Our findings provide an epidemiological foundation for the clinical diagnosis and treatment of PMDD based on the identification of different types.

Post-hoc principal component analysis on a largely illiterate elderly population from North-west India to identify important elements of mini-mental state examination.

Science.gov (United States)

Raina, Sunil Kumar; Chander, Vishav; Raina, Sujeet; Grover, Ashoo

2016-01-01

Mini-mental state examination (MMSE) scale measures cognition using specific elements that can be isolated, defined, and subsequently measured. This study was conducted with the aim to analyze the factorial structure of MMSE in a largely, illiterate, elderly population in India and to reduce the number of variables to a few meaningful and interpretable combinations. Principal component analysis (PCA) was performed post-hoc on the data generated by a research project conducted to estimate the prevalence of dementia in four geographically defined habitations in Himachal Pradesh state of India. Questions on orientation and registration account for high percentage of cumulative variance in comparison to other questions. The PCA conducted on the data derived from a largely, illiterate population reveals that the most important components to consider for the estimation of cognitive impairment in illiterate Indian population are temporal orientation, spatial orientation, and immediate memory.

Post-hoc principal component analysis on a largely illiterate elderly population from North-west India to identify important elements of mini-mental state examination

Directory of Open Access Journals (Sweden)

Sunil Kumar Raina

2016-01-01

Full Text Available Background: Mini-mental state examination (MMSE scale measures cognition using specific elements that can be isolated, defined, and subsequently measured. This study was conducted with the aim to analyze the factorial structure of MMSE in a largely, illiterate, elderly population in India and to reduce the number of variables to a few meaningful and interpretable combinations. Methodology: Principal component analysis (PCA was performed post-hoc on the data generated by a research project conducted to estimate the prevalence of dementia in four geographically defined habitations in Himachal Pradesh state of India. Results: Questions on orientation and registration account for high percentage of cumulative variance in comparison to other questions. Discussion: The PCA conducted on the data derived from a largely, illiterate population reveals that the most important components to consider for the estimation of cognitive impairment in illiterate Indian population are temporal orientation, spatial orientation, and immediate memory.

Ad Hoc Transient Communities to Enhance Social Interaction and Spread Tutor Responsibilities

NARCIS (Netherlands)

Sloep, Peter; Kester, Liesbeth; Brouns, Francis; Van Rosmalen, Peter; De Vries, Fred; De Croock, Marcel; Koper, Rob

2007-01-01

Sloep, P.B., Kester, L. Brouns, F., Van Rosmalen, P., De Vries, F., De Croock, M., Koper, R. (2007) Ad Hoc Transient Communities to Enhance Social Interaction and Spread Tutor Responsibilities. In V. Uskov (Ed.) The Sixth IASTED International Conference on Web-based Education WBE 2007, March 14-16,

Model-based prototyping of an interoperability protocol for mobile ad-hoc networks

NARCIS (Netherlands)

Kristensen, L.M.; Westergaard, M.; Norgaard, P.C.; Romijn, J.; Smith, G.; Pol, van de J.

2005-01-01

We present an industrial project conducted at Ericsson Danmark A/S, Telebit where formal methods in the form of Coloured Petri Nets (CP-nets or CPNs) have been used for the specification of an interoperability protocol for routing packets between fixed core networks and mobile ad-hoc networks. The

Energy-aware architecture for multi-rate ad hoc networks

Directory of Open Access Journals (Sweden)

Ahmed Yahya

2010-06-01

Full Text Available The backbone of ad hoc network design is energy performance and bandwidth resources limitations. Multi-rate adaptation architectures have been proposed to reduce the control overhead and to increase bandwidth utilization efficiency. In this paper, we propose a multi-rate protocol to provide the highest network performance under very low control overhead. The efficiency of the proposed auto multi-rate protocol is validated extensive simulations using QualNet network simulator. The simulation results demonstrate that our solution significantly improves the overall network performance.

Adjusting Sensing Range to Maximize Throughput on Ad-Hoc Multi-Hop Wireless Networks

National Research Council Canada - National Science Library

Roberts, Christopher

2003-01-01

.... Such a network is referred to as a multi-hop ad-hoc network, or simply a multi-hop network. Most multi-hop network protocols use some form of carrier sensing to determine if the wireless channel is in use...

Molecular epidemiology of Mycobacterium tuberculosis complex in Brussels, 2010-2013.

Directory of Open Access Journals (Sweden)

Christelle Vluggen

Full Text Available The tuberculosis (TB incidence rate in Brussels-Capital Region is 3-fold higher than in Belgium as a whole. Eight years after the realization of initial prospective population-based molecular epidemiology investigations in this Region, a similar study over the period 2010-2013 was conducted. TB strains isolated from 945 patients were submitted to genotyping by standardized 24-locus-MIRU-VNTR typing and spoligotyping. The phylogenetic analysis showed that the LAM (16.7% and Haarlem (15.7% branches are the two most prevalent TB lineages circulating in Brussels. Analysis of the MDR subgroup showed an association with Beijing strains (39.9% and patients native of Eastern Europe (40.7%. Genotyping detected 113 clusters involving 321 patients, giving a recent transmission index of 22.9%. Molecular-guided epidemiological investigations and routine surveillance activities revealed family transmission or social contact for patients distributed over 34 clusters. Most of the patients were foreign-born (75.7%. However, cluster analysis revealed only limited trans-national transmission. Comparison with the previous study shows a stable epidemiological situation except for the mean age difference between Belgian-born and foreign-born patients which has disappeared. This study confirms that molecular epidemiology has become an important determinant for TB control programs. However, sufficient financial means need to be available to perform all required epidemiological investigations.

Energy-Aware Broadcasting and Multicasting in Wireless Ad Hoc Networks: A Cross-Layering Approach

National Research Council Canada - National Science Library

Wieselthier, Jeffrey E; Nguyen, Gam D; Ephremides, Anthony

2004-01-01

...) problems, especially when energy-aware operation is required. To address the specific problem of energy-aware tree construction in wireless ad hoc networks, we have developed the Broadcast Incremental Power (BIP...

Demographic and epidemiological characteristics of HIV ...

African Journals Online (AJOL)

Department of Epidemiology and Medical Statistics, College of Medicine, University of Ibadan, Ibadan, Nigeria ... Methods: Analysis of data extracted from electronic records of 17, 312 .... system for the purpose of privacy and confidentiality of.

Recruitment and Participation of Recreational Runners in a Large Epidemiological and Genetic Research Study: Retrospective Data Analysis.

Science.gov (United States)

Manzanero, Silvia; Kozlovskaia, Maria; Vlahovich, Nicole; Hughes, David C

2018-05-23

With the increasing capacity for remote collection of both data and samples for medical research, a thorough assessment is needed to determine the association of population characteristics and recruitment methodologies with response rates. The aim of this research was to assess population representativeness in a two-stage study of health and injury in recreational runners, which consisted of an epidemiological arm and genetic analysis. The cost and success of various classical and internet-based methods were analyzed, and demographic representativeness was assessed for recruitment to the epidemiological survey, reported willingness to participate in the genetic arm of the study, actual participation, sample return, and approval for biobank storage. A total of 4965 valid responses were received, of which 1664 were deemed eligible for genetic analysis. Younger age showed a negative association with initial recruitment rate, expressed willingness to participate in genetic analysis, and actual participation. Additionally, female sex was associated with higher initial recruitment rates, and ethnic origin impacted willingness to participate in the genetic analysis (all P<.001). The sharp decline in retention through the different stages of the study in young respondents suggests the necessity to develop specific recruitment and retention strategies when investigating a young, physically active population. ©Silvia Manzanero, Maria Kozlovskaia, Nicole Vlahovich, David C Hughes. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 23.05.2018.

Built-In Device Orientation Sensors for Ad-Hoc Pairing and Spatial Awareness

DEFF Research Database (Denmark)

Grønbæk, Jens Emil; O'Hara, Kenton

Mobile devices are equipped with multiple sensors. The ubiquity of these sensors is key in their ability to support in-the-wild application and use. Building on the ubiquity we look at how we can use this existing sensing infrastructure combined with user mediation to support ad-hoc sharing with ...

Impact of Mobility on the Performance of Relaying in Ad Hoc Networks

NARCIS (Netherlands)

Al Hanbali, Ahmad; Kherani, A.A.; Groenevelt, R.; Nain, P.; Altman, E

2006-01-01

We consider a mobile ad hoc network consisting of three types of nodes: source, destination, and relay nodes. All the nodes are moving over a bounded region with possibly different mobility patterns. We introduce and study the notion of relay throughput, i.e. the maximum rate at which a node can

Improving the Usability of OCL as an Ad-hoc Model Querying Language

DEFF Research Database (Denmark)

Störrle, Harald

2013-01-01

from our research and make it accessible to the OCL community, we propose the OCL Query API (OQAPI), a library of query-predicates to improve the user-friendliness of OCL for ad-hoc querying. The usability of OQAPI is studied using controlled experiments. We nd considerable evidence to support our...

Tiotropium and Salmeterol in COPD Patients at Risk of Exacerbations: A Post Hoc Analysis from POET-COPD(®).

Science.gov (United States)

Vogelmeier, Claus F; Asijee, Guus M; Kupas, Katrin; Beeh, Kai M

2015-06-01

Among patients with chronic obstructive pulmonary disease (COPD), the frequency and severity of past exacerbations potentiates future events. The impact of current therapies on exacerbation frequency and severity in patients with different exacerbation risks is not well known. A post hoc analysis of patients at low (≤1 exacerbation [oral steroids/antibiotics requirement] and no COPD-related hospitalization in the year preceding trial entry) or high (≥2 exacerbations [oral steroids/antibiotics requirement] or ≥1 COPD-related hospitalization[s] in the year preceding trial entry) exacerbation risk, from the Prevention of Exacerbations with Tiotropium in Chronic Obstructive Pulmonary Disease (POET-COPD(®)) database. Compared with salmeterol, tiotropium significantly increased time to first COPD exacerbation (hazard ratio 0.84; 95% confidence interval [CI] 0.76-0.92; p = 0.0002) and reduced the number of COPD exacerbations (rate ratio 0.90; 95% CI 0.81-0.99; p = 0.0383) in patients at high exacerbation risk. With treatment, the risk of remaining in the high-risk exacerbator subgroup was statistically lower with tiotropium versus salmeterol (risk ratio [RR] 0.89; 95% CI 0.80-1.00; p = 0.0478). For low-risk patients, time to first COPD exacerbation and number of COPD exacerbations were numerically lower with tiotropium versus salmeterol. With treatment, the risk of transitioning from a low to a high exacerbation risk was lower with tiotropium versus salmeterol (RR 0.87; 95% CI 0.71-1.07; p = 0.1968). This analysis confirms the higher efficacy of tiotropium versus salmeterol in prolonging time to first COPD exacerbation and reducing number of exacerbations in patients both at low and high exacerbation risk. Boehringer Ingelheim and Pfizer. ClinicalTrials.gov NCT00563381.

Epidemiological analysis of data for scrapie in Great Britain

NARCIS (Netherlands)

Hagenaars, T.H.J.; Donnelly, C.; Ferguson, N.M.

2006-01-01

In recent years, the control or eradication of scrapie and any other transmissible spongiform encephalopathies (TSEs) possibly circulating in the sheep population has become a priority in Britain and elsewhere in Europe. A better understanding of the epidemiology of scrapie would greatly aid the

Red and processed meat intake and risk of colorectal adenomas: a systematic review and meta-analysis of epidemiological studies

NARCIS (Netherlands)

Aune, D.; Chan, D.S.M.; Vieira, A.; Navarro Rosenblatt, D.; Vieira, R.; Greenwood, D.C.; Kampman, E.; Norat, T.

2013-01-01

Background Current evidence indicates that red and processed meat intake increases the risk of colorectal cancer; however, the association with colorectal adenomas is unclear. Objective To conduct a systematic review and meta-analysis of epidemiological studies of red and processed meat intake and

Power-Aware Intrusion Detection in Mobile Ad Hoc Networks

Science.gov (United States)

Şen, Sevil; Clark, John A.; Tapiador, Juan E.

Mobile ad hoc networks (MANETs) are a highly promising new form of networking. However they are more vulnerable to attacks than wired networks. In addition, conventional intrusion detection systems (IDS) are ineffective and inefficient for highly dynamic and resource-constrained environments. Achieving an effective operational MANET requires tradeoffs to be made between functional and non-functional criteria. In this paper we show how Genetic Programming (GP) together with a Multi-Objective Evolutionary Algorithm (MOEA) can be used to synthesise intrusion detection programs that make optimal tradeoffs between security criteria and the power they consume.

RAILWAY INFRASTRUCTURE CAPACITY MANAGEMENT FOR AD-HOC TRAINS ON THE SŽDC NETWORK

Directory of Open Access Journals (Sweden)

Petr Nachtigall

2016-09-01

Full Text Available The paper describes basic principles of ad-hoc routes assignment. Each carrier has its own interface called information system KADR with SŽDC for capacity requests management. The paper describes all steps which must be done before train departure.

An Approach to Ad-hoc Messaging Networks Using Time Shifted Propagation

Directory of Open Access Journals (Sweden)

Christoph Fuchß

2007-10-01

Full Text Available Many communication devices, like mobile phones and PDAs, are enabled for near field communication by using Bluetooth. Many approaches dealt so far with the attempt to transfer mobile ad-hoc networks (MANET to the mechanism of the “fixed internet” to mobile networks. In order to achieve liability and robustness of common TCP connections routing algorithm in near field communication based networks become more sophisticated and complex. These mechanisms often do not reflect on the application’s particularities.Our approach of an ad-hoc messaging network (AMNET uses simple store-and-forward message passing to spread data asynchronously. We do not aim at the reliability of common internet networks but focus on application specific needs that can be covered by simple message passing mechanism. In this paper we will portray a powerful network by using simple devices and communication protocols on the basis of AMNETs. Simulation results of our AMNET approach provide insights towards speeding up the network setup process and to enable the use of AMNETs even with few participants by introducing a hybrid structure of infrastructure and mobile nodes.

Selective epidemic broadcast algorithm to suppress broadcast storm in vehicular ad hoc networks

Directory of Open Access Journals (Sweden)

M. Chitra

2018-03-01

Full Text Available Broadcasting in Vehicular Ad Hoc Networks is the best way to spread emergency messages all over the network. With the dynamic nature of vehicular ad hoc networks, simple broadcast or flooding faces the problem called as Broadcast Storm Problem (BSP. The issue of the BSP will degrade the performance of a message broadcasting process like increased overhead, collision and dissemination delay. The paper is motivated to solve the problems in the existing Broadcast Strom Suppression Algorithms (BSSAs like p-Persistence, TLO, VSPB, G-SAB and SIR. This paper proposes to suppress the Broadcast Storm Problem and to improve the Emergency Safety message dissemination rate through a new BSSA based on Selective Epidemic Broadcast Algorithm (SEB. The simulation results clearly show that the SEB outperforms the existing algorithms in terms of ESM Delivery Ratio, Message Overhead, Collision Ratio, Broadcast Storm Ratio and Redundant Rebroadcast Ratio with decreased Dissemination Delay.

Spatial evolutionary epidemiology of spreading epidemics.

Science.gov (United States)

Lion, S; Gandon, S

2016-10-26

Most spatial models of host-parasite interactions either neglect the possibility of pathogen evolution or consider that this process is slow enough for epidemiological dynamics to reach an equilibrium on a fast timescale. Here, we propose a novel approach to jointly model the epidemiological and evolutionary dynamics of spatially structured host and pathogen populations. Starting from a multi-strain epidemiological model, we use a combination of spatial moment equations and quantitative genetics to analyse the dynamics of mean transmission and virulence in the population. A key insight of our approach is that, even in the absence of long-term evolutionary consequences, spatial structure can affect the short-term evolution of pathogens because of the build-up of spatial differentiation in mean virulence. We show that spatial differentiation is driven by a balance between epidemiological and genetic effects, and this quantity is related to the effect of kin competition discussed in previous studies of parasite evolution in spatially structured host populations. Our analysis can be used to understand and predict the transient evolutionary dynamics of pathogens and the emergence of spatial patterns of phenotypic variation. © 2016 The Author(s).

Post-hoc analysis of MCI186-17, the extension study to MCI186-16, the confirmatory double-blind, parallel-group, placebo-controlled study of edaravone in amyotrophic lateral sclerosis.

Science.gov (United States)

Takahashi, Fumihiro; Takei, Koji; Tsuda, Kikumi; Palumbo, Joseph

2017-10-01

In the 24-week double-blind study of edaravone in ALS (MCI186-16), edaravone did not show a statistically significant difference versus placebo for the primary efficacy endpoint. For post-hoc analyses, two subpopulations were identified in which edaravone might be expected to show efficacy: the efficacy-expected subpopulation (EESP), defined by scores of ≥2 points on all 12 items of the ALS Functional Rating Scale-Revised (ALSFRS-R) and a percent predicted forced vital capacity (%FVC) ≥80% at baseline; and the definite/probable EESP 2 years (dpEESP2y) subpopulation which, in addition to EESP criteria, had definite or probable ALS diagnosed by El Escorial revised criteria, and disease duration of ≤2 years. In the 36-week extension study of MCI186-16, a 24-week double-blind comparison followed by 12 weeks of open-label edaravone (MCI186-17; NCT00424463), analyses of ALSFRS-R scores of the edaravone-edaravone group and edaravone-placebo group for the full analysis set (FAS) and EESP, as prospectively defined, were reported in a previous article. Here we additionally report results in patients who met dpEESP2y criteria at the baseline of MCI186-16. In the dpEESP2y, the difference in ALSFRS-R changes from 24 to 48 weeks between the edaravone-edaravone and edaravone-placebo groups was 2.79 (p = 0.0719), which was greater than the differences previously reported for the EESP and the FAS. The pattern of adverse events in the dpEESP2y did not show any additional safety findings to those from the earlier prospective study. In conclusion, this post-hoc analysis suggests a potential effect of edaravone between 24 and 48 weeks in patients meeting dpEESP2y criteria at baseline.

Cross-layer model design in wireless ad hoc networks for the Internet of Things.

Science.gov (United States)

Yang, Xin; Wang, Ling; Xie, Jian; Zhang, Zhaolin

2018-01-01

Wireless ad hoc networks can experience extreme fluctuations in transmission traffic in the Internet of Things, which is widely used today. Currently, the most crucial issues requiring attention for wireless ad hoc networks are making the best use of low traffic periods, reducing congestion during high traffic periods, and improving transmission performance. To solve these problems, the present paper proposes a novel cross-layer transmission model based on decentralized coded caching in the physical layer and a content division multiplexing scheme in the media access control layer. Simulation results demonstrate that the proposed model effectively addresses these issues by substantially increasing the throughput and successful transmission rate compared to existing protocols without a negative influence on delay, particularly for large scale networks under conditions of highly contrasting high and low traffic periods.

Cross-layer model design in wireless ad hoc networks for the Internet of Things.

Directory of Open Access Journals (Sweden)

Xin Yang

Full Text Available Wireless ad hoc networks can experience extreme fluctuations in transmission traffic in the Internet of Things, which is widely used today. Currently, the most crucial issues requiring attention for wireless ad hoc networks are making the best use of low traffic periods, reducing congestion during high traffic periods, and improving transmission performance. To solve these problems, the present paper proposes a novel cross-layer transmission model based on decentralized coded caching in the physical layer and a content division multiplexing scheme in the media access control layer. Simulation results demonstrate that the proposed model effectively addresses these issues by substantially increasing the throughput and successful transmission rate compared to existing protocols without a negative influence on delay, particularly for large scale networks under conditions of highly contrasting high and low traffic periods.

A game-theoretic approach to optimize ad hoc networks inspired by small-world network topology

Science.gov (United States)

Tan, Mian; Yang, Tinghong; Chen, Xing; Yang, Gang; Zhu, Guoqing; Holme, Petter; Zhao, Jing

2018-03-01

Nodes in ad hoc networks are connected in a self-organized manner. Limited communication radius makes information transmit in multi-hop mode, and each forwarding needs to consume the energy of nodes. Insufficient communication radius or exhaustion of energy may cause the absence of some relay nodes and links, further breaking network connectivity. On the other hand, nodes in the network may refuse to cooperate due to objective faulty or personal selfish, hindering regular communication in the network. This paper proposes a model called Repeated Game in Small World Networks (RGSWN). In this model, we first construct ad hoc networks with small-world feature by forming "communication shortcuts" between multiple-radio nodes. Small characteristic path length reduces average forwarding times in networks; meanwhile high clustering coefficient enhances network robustness. Such networks still maintain relative low global power consumption, which is beneficial to extend the network survival time. Then we use MTTFT strategy (Mend-Tolerance Tit-for-Tat) for repeated game as a rule for the interactions between neighbors in the small-world networks. Compared with other five strategies of repeated game, this strategy not only punishes the nodes' selfishness more reasonably, but also has the best tolerance to the network failure. This work is insightful for designing an efficient and robust ad hoc network.

Accurate 3D Localization Method for Public Safety Applications in Vehicular Ad-hoc Networks

KAUST Repository

Ansari, Abdul Rahim; Saeed, Nasir; Haq, Mian Imtiaz Ul; Cho, Sunghyun

2018-01-01

Vehicular ad hoc networks (VANETs) represent a very promising research area because of their ever increasing demand, especially for public safety applications. In VANETs vehicles communicate with each other to exchange road maps and traffic

A framework for reactive optimization in mobile ad hoc networks

DEFF Research Database (Denmark)

McClary, Dan; Syrotiuk, Violet; Kulahci, Murat

2008-01-01

We present a framework to optimize the performance of a mobile ad hoc network over a wide range of operating conditions. It includes screening experiments to quantify the parameters and interactions among parameters influential to throughput. Profile-driven regression is applied to obtain a model....... The predictive accuracy of the model is monitored and used to update the model dynamically. The results indicate the framework may be useful for the optimization of dynamic systems of high dimension....

Epidemiology of pediatric functional abdominal pain disorders: a meta-analysis.

Science.gov (United States)

Korterink, Judith J; Diederen, Kay; Benninga, Marc A; Tabbers, Merit M

2015-01-01

We aimed to review the literature regarding epidemiology of functional abdominal pain disorders in children and to assess its geographic, gender and age distribution including associated risk factors of developing functional abdominal pain. The Cochrane Library, MEDLINE, EMBASE, CINAHL and PsychInfo databases were systematically searched up to February 2014. Study selection criteria included: (1) studies of birth cohort, school based or general population samples (2) containing data concerning epidemiology, prevalence or incidence (3) of children aged 4-18 years (4) suffering from functional abdominal pain. Quality of studies was rated by a self-made assessment tool. A random-effect meta-analysis model was used to estimate the prevalence of functional abdominal pain in childhood. A total of 58 articles, including 196,472 children were included. Worldwide pooled prevalence for functional abdominal pain disorders was 13.5% (95% CI 11.8-15.3), of which irritable bowel syndrome was reported most frequently (8.8%, 95% CI 6.2-11.9). The prevalence across studies ranged widely from 1.6% to 41.2%. Higher pooled prevalence rates were reported in South America (16.8%) and Asia (16.5%) compared to Europe (10.5%). And a higher pooled prevalence was reported when using the Rome III criteria (16.4%, 95% CI 13.5-19.4). Functional abdominal pain disorders are shown to occur significantly more in girls (15.9% vs. 11.5%, pooled OR 1.5) and is associated with the presence of anxiety and depressive disorders, stress and traumatic life events. Functional abdominal pain disorders are a common problem worldwide with irritable bowel syndrome as most encountered abdominal pain-related functional gastrointestinal disorder. Female gender, psychological disorders, stress and traumatic life events affect prevalence.

Epidemiology of pediatric functional abdominal pain disorders: a meta-analysis.

Directory of Open Access Journals (Sweden)

Judith J Korterink

Full Text Available We aimed to review the literature regarding epidemiology of functional abdominal pain disorders in children and to assess its geographic, gender and age distribution including associated risk factors of developing functional abdominal pain.The Cochrane Library, MEDLINE, EMBASE, CINAHL and PsychInfo databases were systematically searched up to February 2014. Study selection criteria included: (1 studies of birth cohort, school based or general population samples (2 containing data concerning epidemiology, prevalence or incidence (3 of children aged 4-18 years (4 suffering from functional abdominal pain. Quality of studies was rated by a self-made assessment tool. A random-effect meta-analysis model was used to estimate the prevalence of functional abdominal pain in childhood.A total of 58 articles, including 196,472 children were included. Worldwide pooled prevalence for functional abdominal pain disorders was 13.5% (95% CI 11.8-15.3, of which irritable bowel syndrome was reported most frequently (8.8%, 95% CI 6.2-11.9. The prevalence across studies ranged widely from 1.6% to 41.2%. Higher pooled prevalence rates were reported in South America (16.8% and Asia (16.5% compared to Europe (10.5%. And a higher pooled prevalence was reported when using the Rome III criteria (16.4%, 95% CI 13.5-19.4. Functional abdominal pain disorders are shown to occur significantly more in girls (15.9% vs. 11.5%, pooled OR 1.5 and is associated with the presence of anxiety and depressive disorders, stress and traumatic life events.Functional abdominal pain disorders are a common problem worldwide with irritable bowel syndrome as most encountered abdominal pain-related functional gastrointestinal disorder. Female gender, psychological disorders, stress and traumatic life events affect prevalence.

Risk reductions for cardiovascular disease with pravastatin treatment by dyslipidemia phenotype: a post hoc analysis of the MEGA Study.

Science.gov (United States)

Nishiwaki, Masato; Ikewaki, Katsunori; Ayaori, Makoto; Mizuno, Kyoichi; Ohashi, Yasuo; Ohsuzu, Fumitaka; Ishikawa, Toshitsugu; Nakamura, Haruo

2013-03-01

The beneficial effect of statins for cardiovascular disease (CVD) prevention has been well established. However, the effectiveness among different phenotypes of dyslipidemia has not been confirmed. We evaluated the effect of pravastatin on the incidence of CVD in relation to the phenotype of dyslipidemia. The MEGA Study evaluated the effect of low-dose pravastatin on primary prevention of CVD in 7832 Japanese patients, who were randomized to diet alone or diet plus pravastatin and followed for more than 5 years. These patients were classified into phenotype IIa (n=5589) and IIb (n=2041) based on the electrophoretic pattern for this post hoc analysis. In the diet group there was no significant difference in the incidence of coronary heart disease (CHD), stroke, CVD, and total mortality between the two phenotypes. Phenotype IIb patients, compared to phenotype IIa, had lower levels of high-density lipoprotein cholesterol (HDL-C) and a significantly higher incidence of CVD in relation to a low HDL-C level (dyslipidemia. Significant risk reductions were observed for CHD by 38% (p=0.04) and CVD by 31% (p=0.02) in type IIa dyslipidemia but not in phenotype IIb. Pravastatin therapy provided significant risk reductions for CHD and CVD in patients with phenotype IIa dyslipidemia, but not in those with phenotype IIb dyslipidemia. Copyright © 2012 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Does the effect of one-day simulation team training in obstetric emergencies decline within one year? A post-hoc analysis of a multicentre cluster randomised controlled trial.

Science.gov (United States)

van de Ven, J; Fransen, A F; Schuit, E; van Runnard Heimel, P J; Mol, B W; Oei, S G

2017-09-01

Does the effect of one-day simulation team training in obstetric emergencies decline within one year? A post-hoc analysis of a multicentre cluster randomised controlled trial. J van de Ven, AF Fransen, E Schuit, PJ van Runnard Heimel, BW Mol, SG Oei OBJECTIVE: To investigate whether the effect of a one-day simulation-based obstetric team training on patient outcome changes over time. Post-hoc analysis of a multicentre, open, randomised controlled trial that evaluated team training in obstetrics (TOSTI study).We studied women with a singleton pregnancy beyond 24 weeks of gestation in 24 obstetric units. Included obstetric units were randomised to either a one-day, multi-professional simulation-based team training focusing on crew resource management in a medical simulation centre (12 units) or to no team training (12 units). We assessed whether outcomes differed between both groups in each of the first four quarters following the team training and compared the effect of team training over quarters. Primary outcome was a composite outcome of low Apgar score, severe postpartum haemorrhage, trauma due to shoulder dystocia, eclampsia and hypoxic-ischemic encephalopathy. During a one year period after the team training the rate of obstetric complications, both on the composite level and the individual component level, did not differ between any of the quarters. For trauma due to shoulder dystocia team training led to a significant decrease in the first quarter (0.06% versus 0.26%, OR 0.19, 95% CI 0.03 to 0.98) but in the subsequent quarters no significant reductions were observed. Similar results were found for invasive treatment for severe postpartum haemorrhage where a significant increase was only seen in the first quarter (0.4% versus 0.03%, OR 19, 95% CI 2.5-147), and not thereafter. The beneficial effect of a one-day, simulation-based, multiprofessional, obstetric team training seems to decline after three months. If team training is further evaluated or

Fault Tolerant Mechanism for Multimedia Flows in Wireless Ad Hoc Networks Based on Fast Switching Paths

Directory of Open Access Journals (Sweden)

Juan R. Diaz

2014-01-01

Full Text Available Multimedia traffic can be forwarded through a wireless ad hoc network using the available resources of the nodes. Several models and protocols have been designed in order to organize and arrange the nodes to improve transmissions along the network. We use a cluster-based framework, called MWAHCA architecture, which optimizes multimedia transmissions over a wireless ad hoc network. It was proposed by us in a previous research work. This architecture is focused on decreasing quality of service (QoS parameters like latency, jitter, and packet loss, but other network features were not developed, like load balance or fault tolerance. In this paper, we propose a new fault tolerance mechanism, using as a base the MWAHCA architecture, in order to recover any multimedia flow crossing the wireless ad hoc network when there is a node failure. The algorithm can run independently for each multimedia flow. The main objective is to keep the QoS parameters as low as possible. To achieve this goal, the convergence time must be controlled and reduced. This paper provides the designed protocol, the analytical model of the algorithm, and a software application developed to test its performance in a real laboratory.

[Epidemiological data for uterine fibroids in France in 2010-2012 in medical center--analysis from the French DRG-based information system (PMSI)].

Science.gov (United States)

Fernandez, H; Chabbert-Buffet, N; Koskas, M; Nazac, A

2014-10-01

Uterine fibroids are a common disorder, responsible for menorrhagia/metrorrhagia and pelvic pain and remain the leading reason for hysterectomy in France. Although it is common disorder, French epidemiological data are locking. The objective of this study was to realize an epidemiological analysis from the medicalized information system program (PMSI). The diagnosis codes were selected from 10th version of the International Classification Disease. The medical procedures concerning uterine fibroids were selected (so called: procedures listed). A descriptive analysis was performed from hospitals stays, patients' characteristics and medical procedures (mean, standard distribution, median, range, quartile). In 2012, 46,126 patients (median age: 46 years old) were admitted in hospital (public or private hospitals) due to uterine fibroid corresponding to 47,690 hospital stays (hospital stays for surgery: 32,397). Diagnosis of anemia was reported in approximately 8% of patients and 7.1% of patients hospitalized in 2012 had already been hospitalized between 2004-2012. The median length of hospital stay was 4 days. In 2012, 16,070 hospital stays were reported for total or subtotal hysterectomy, 16,384 hospitals stays for myomectomy and 1376 hospital stays for embolization. In terms of management care, among 46,126 patients with uterine fibroids (principal or related diagnosis), 31,846 patients received a procedure listed in a surgical diagnostic related groups (DRG). To conclude, the study permits to update the epidemiological data concerning uterine fibroid management between 2010-2011-2012 in final. Because the PMSI collects partially information regarding epidemiological data, a clear epidemiological study is needed either with database from health insurance or with dedicated study. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Report of the independent Ad Hoc Group for the Davis-Besse incident

International Nuclear Information System (INIS)

1986-06-01

The Nuclear Regulatory Commission established an independent Ad Hoc Group in January 1986 to review issues subsequent to a complete loss of feedwater event at Davis-Besse Nuclear Power Station on June 9, 1985, including the NRC Incident Investigation Team (IIT) investigation of that event. The Commission asked the Group to identify additional lessons that might be learned and from these to make recommendations to improve NRC oversight of reactor licensees. To fulfill its charter, the Ad Hoc Group examined the following: (1) pre-event interactions between the licensee and NRC concerning reliability of the auxiliary feedwater system and associated systems; (2) pre-event probabilistic assessments of the reliability of plant safety systems, NRC's review of them, and their use in regulatory decisionmaking; (3) licensee management, operation and maintenance programs as they may have contributed to equipment failures and NRC oversight of such programs; and (4) the mandate, capabilities of members, operation, and results of the NRC Davis-Besse IIT, and the use to which its report was put by the regulatory staff

Ad Hoc Transient Communities to Enhance Social Interaction and Spread Tutor Responsibilities

OpenAIRE

Sloep, Peter; Kester, Liesbeth; Brouns, Francis; Van Rosmalen, Peter; De Vries, Fred; De Croock, Marcel; Koper, Rob

2007-01-01

Sloep, P.B., Kester, L. Brouns, F., Van Rosmalen, P., De Vries, F., De Croock, M., Koper, R. (2007) Ad Hoc Transient Communities to Enhance Social Interaction and Spread Tutor Responsibilities. In V. Uskov (Ed.) The Sixth IASTED International Conference on Web-based Education WBE 2007, March 14-16, Chamonix, France (pp. 549-554). Calgary, Canada: Acta Press.

Forming an ad-hoc nearby storage, based on IKAROS and social networking services

International Nuclear Information System (INIS)

Filippidis, Christos; Cotronis, Yiannis; Markou, Christos

2014-01-01

We present an ad-hoc 'nearby' storage, based on IKAROS and social networking services, such as Facebook. By design, IKAROS is capable to increase or decrease the number of nodes of the I/O system instance on the fly, without bringing everything down or losing data. IKAROS is capable to decide the file partition distribution schema, by taking on account requests from the user or an application, as well as a domain or a Virtual Organization policy. In this way, it is possible to form multiple instances of smaller capacity higher bandwidth storage utilities capable to respond in an ad-hoc manner. This approach, focusing on flexibility, can scale both up and down and so can provide more cost effective infrastructures for both large scale and smaller size systems. A set of experiments is performed comparing IKAROS with PVFS2 by using multiple clients requests under HPC IOR benchmark and MPICH2.

An Agent-Based Approach To Nodes Misbehaviour Detection In Mobile Ad-Hoc Networks

Directory of Open Access Journals (Sweden)

Otor Samera U.

2017-02-01

Full Text Available Existing Misbehaviour Detection Systems in Mobile Ad-hoc Networks MANETs are challenged with routing overhead and high latency resulting from complexity and failure to isolate and block misbehaving nodes for the reason that it is difficult to detect them as they participate fully in route finding. In this work a Mobile Agent-Based Acknowledgement scheme MAACK was formulated to address this problem using an object oriented algorithm deployed to report misbehaving nodes to the source and destination by registering the Internet Protocol IP address of misbehaving nodes in their header. The scheme was simulated using Network Simulator-3 NS-3 and results benchmarked with an existing scheme the Enhanced Adaptive Acknowledgment EAACK using packet delivery ratio routing overhead and latency as performance metrics in the two scenarios. The results showed that the MAACK paradigm guaranteed a higher packet delivery ratio lower latency and routing overhead than the EAACK scheme. The model can be adapted by Ad-Hoc network protocol developers.

Forming an ad-hoc nearby storage, based on IKAROS and social networking services

Science.gov (United States)

Filippidis, Christos; Cotronis, Yiannis; Markou, Christos

2014-06-01

We present an ad-hoc "nearby" storage, based on IKAROS and social networking services, such as Facebook. By design, IKAROS is capable to increase or decrease the number of nodes of the I/O system instance on the fly, without bringing everything down or losing data. IKAROS is capable to decide the file partition distribution schema, by taking on account requests from the user or an application, as well as a domain or a Virtual Organization policy. In this way, it is possible to form multiple instances of smaller capacity higher bandwidth storage utilities capable to respond in an ad-hoc manner. This approach, focusing on flexibility, can scale both up and down and so can provide more cost effective infrastructures for both large scale and smaller size systems. A set of experiments is performed comparing IKAROS with PVFS2 by using multiple clients requests under HPC IOR benchmark and MPICH2.

The effect of DAD timeout period on address autoconfiguration in wireless ad-hoc networks

CSIR Research Space (South Africa)

Mutanga, MB

2011-09-01

Full Text Available Lack of manual management mechanisms in wireless ad-hoc networks means that automatic configuration of IP addresses and other related network parameters are very crucial. Many IP address autoconfiguration mechanisms have been proposed in literature...

Clinical Factors Associated with Dose of Loop Diuretics After Pediatric Cardiac Surgery: Post Hoc Analysis.

Science.gov (United States)

Haiberger, Roberta; Favia, Isabella; Romagnoli, Stefano; Cogo, Paola; Ricci, Zaccaria

2016-06-01

A post hoc analysis of a randomized controlled trial comparing the clinical effects of furosemide and ethacrynic acid was conducted. Infants undergoing cardiac surgery with cardiopulmonary bypass were included in order to explore which clinical factors are associated with diuretic dose in infants with congenital heart disease. Overall, 67 patients with median (interquartile range) age of 48 (13-139) days were enrolled. Median diuretic dose was 0.34 (0.25-0.4) mg/kg/h at the end of postoperative day (POD) 0 and it significantly decreased (p = 0.04) over the following PODs; during this period, the ratio between urine output and diuretic dose increased significantly (p = 0.04). Age (r -0.26, p = 0.02), weight (r -0.28, p = 0.01), cross-clamp time (r 0.27, p = 0.03), administration of ethacrynic acid (OR 0.01, p = 0.03), and, at the end of POD0, creatinine levels (r 0.3, p = 0.009), renal near-infrared spectroscopy saturation (-0.44, p = 0.008), whole-blood neutrophil gelatinase-associated lipocalin levels (r 0.30, p = 0.01), pH (r -0.26, p = 0.02), urinary volume (r -0.2755, p = 0.03), and fluid balance (r 0.2577, p = 0.0266) showed a significant association with diuretic dose. At multivariable logistic regression cross-clamp time (OR 1.007, p = 0.04), use of ethacrynic acid (OR 0.2, p = 0.01) and blood pH at the end of POD0 (OR 0.0001, p = 0.03) was independently associated with diuretic dose. Early resistance to loop diuretics continuous infusion is evident in post-cardiac surgery infants: Higher doses are administered to patients with lower urinary output. Independently associated variables with diuretic dose in our population appeared to be cross-clamping time, the administration of ethacrynic acid, and blood pH.

An Economic Framework for Resource Allocation in Ad-hoc Grids

OpenAIRE

Pourebrahimi, B.

2009-01-01

In this dissertation, we present an economic framework to study and develop different market-based mechanisms for resource allocation in an ad-hoc Grid. Such an economic framework helps to understand the impact of certain choices and explores what are the suitable mechanisms from Grid user/owner perspectives under given circumstances. We focus on resource allocation in a Grid-based environment in the case where some resources are lying idle and could be linked with overloaded nodes in a netwo...

Report of the evaluation by the ad hoc review committee on advanced photon and synchrotron radiation research. In-advance evaluation in fiscal year 2001

International Nuclear Information System (INIS)

2001-11-01

The Research Evaluation Committee, which consisted of 13 members from outside of the Japan Atomic Energy Research Institute (JAERI), set up an Ad Hoc Review Committee on Advanced Photon and Synchrotron Radiation Research in accordance with the 'Fundamental Guideline for the Evaluation of Research and Development (R and D) at JAERI' and its subsidiary regulations in order to evaluate the adequacy of the R and D programs to be implemented for five years starting in Fiscal Year 2002 at Advanced Photon Research Center and at Synchrotron Radiation Research Center in Kansai Research Establishment of JAERI. The Ad Hoc Review Committee consisted of ten specialists from outside of JAERI. The Ad Hoc Review Committee conducted its activities from May to July 2001. The evaluation was performed on the basis of the materials submitted in advanced and of the oral presentations made at the Ad Hoc Review Committee meeting which was held on June 21, 2001, in line with the items, viewpoints, and criteria for the evaluation specified by the Research Evaluation Committee. The result of the evaluation by the Ad Hoc Review Committee was submitted to the Research Evaluation Committee, and was judged to be appropriate at its meeting held on July 12, 2001. This report describes the result of the evaluation by the Ad Hoc Review Committee on Advanced Photon and Synchrotron Radiation Research. (author)

Clustering of Mobile Ad Hoc Networks: An Adaptive Broadcast Period Approach

OpenAIRE

Gavalas, Damianos; Pantziou, Grammati; Konstantopoulos, Charalampos; Mamalis, Basilis

2011-01-01

Organization, scalability and routing have been identified as key problems hindering viability and commercial success of mobile ad hoc networks. Clustering of mobile nodes among separate domains has been proposed as an efficient approach to address those issues. In this work, we introduce an efficient distributed clustering algorithm that uses both location and energy metrics for cluster formation. Our proposed solution mainly addresses cluster stability, manageability and energy efficiency i...

Throughput Capacity of Ad Hoc Networks with Route Discovery

Directory of Open Access Journals (Sweden)

Blum Rick S

2007-01-01

Full Text Available Throughput capacity of large ad hoc networks has been shown to scale adversely with the size of network . However the need for the nodes to find or repair routes has not been analyzed in this context. In this paper, we explicitly take route discovery into account and obtain the scaling law for the throughput capacity under general assumptions on the network environment, node behavior, and the quality of route discovery algorithms. We also discuss a number of possible scenarios and show that the need for route discovery may change the scaling for the throughput capacity.

Ad-Hoc vs. Standardized and Optimized Arthropod Diversity Sampling

Directory of Open Access Journals (Sweden)

Pedro Cardoso

2009-09-01

Full Text Available The use of standardized and optimized protocols has been recently advocated for different arthropod taxa instead of ad-hoc sampling or sampling with protocols defined on a case-by-case basis. We present a comparison of both sampling approaches applied for spiders in a natural area of Portugal. Tests were made to their efficiency, over-collection of common species, singletons proportions, species abundance distributions, average specimen size, average taxonomic distinctness and behavior of richness estimators. The standardized protocol revealed three main advantages: (1 higher efficiency; (2 more reliable estimations of true richness; and (3 meaningful comparisons between undersampled areas.

Evaluation of epidemiological studies

International Nuclear Information System (INIS)

Breckow, J.

1995-01-01

The publication is intended for readers with a professional background in radiation protection who are not experts in the field of epidemiology. The potentials and the limits of epidemiology are shown and concepts and terminology of radioepidemilogic studies as well as epidemiology in general are explained, in order to provide the necessary basis for understanding or performing evaluations of epidemiologic studies. (orig./VHE) [de

Perampanel with concomitant levetiracetam and topiramate: Post hoc analysis of adverse events related to hostility and aggression.

Science.gov (United States)

Chung, Steve; Williams, Betsy; Dobrinsky, Cindy; Patten, Anna; Yang, Haichen; Laurenza, Antonio

2017-10-01

In 4 Phase III registration trials (3 in patients with partial seizures, N=1480; 1 in patients with PGTCS, N=163), perampanel administered to patients already receiving 1-3 concomitant antiepileptic drugs (AEDs) demonstrated statistically superior efficacy compared to placebo in reducing seizure frequency. However, use of perampanel in these studies was associated with a risk of psychiatric and behavioral adverse reactions, including aggression, hostility, irritability, anger, and homicidal ideation and threats. The present study is a post hoc analysis of pooled data from these 4 trials to determine if concomitant treatment with levetiracetam and/or topiramate increased the risk of hostility- and aggression-related AEs. Treatment-emergent AEs (TEAEs) were determined using a "Narrow & Broad" search based on the Medical Dictionary for Regulatory Activities (MedDRA) standard MedDRA query (SMQ) for hostility- and aggression-related events. The rate of hostility- and aggression-related TEAEs was observed to be similar among perampanel-treated patients: a) receiving levetiracetam (N=340) compared to those not receiving levetiracetam (N=779); b) receiving topiramate (N=223) compared to those not receiving topiramate (N=896); and c) receiving both levetiracetam and topiramate (N=47) compared to those not receiving levetiracetam and topiramate (N=1072). Severe and serious TEAEs related to hostility and aggression were rare and occurred at a similar rate regardless of concomitant levetiracetam and/or topiramate therapy. Taken together, these results suggest that concomitant treatment with levetiracetam and/or topiramate has no appreciable effect on the occurrence of hostility- or aggression-related TEAEs in patients receiving perampanel. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Assessing Clinical Microbiology Practice Guidelines: American Society for Microbiology Ad Hoc Committee on Evidence-Based Laboratory Medicine Practice Guidelines Assessment.

Science.gov (United States)

Nachamkin, Irving; Kirn, Thomas J; Westblade, Lars F; Humphries, Romney

2017-11-01

As part of the American Society for Microbiology (ASM) Evidence-Based Laboratory Medicine Practice Guidelines Committee of the Professional Practice Committee, an ad hoc committee was formed in 2014 to assess guidelines published by the committee using an assessment tool, Appraisal of Guidelines for Research Evaluation II (AGREE II). The AGREE II assessment helps reviewers determine whether published guidelines are robust, transparent, and clear in presenting practice recommendations in a standardized manner. Identifying strengths and weaknesses of practice guidelines by ad hoc assessments helps with improving future guidelines through the participation of key stakeholders. This minireview describes the development of the ad hoc committee and results from their review of several ASM best practices guidelines and a non-ASM practice guideline from the Emergency Nurses Association. Copyright © 2017 American Society for Microbiology.

Worm epidemics in wireless ad hoc networks

Energy Technology Data Exchange (ETDEWEB)

Nekovee, Maziar [BT Research, Polaris 134, Adastral Park, Martlesham, Suffolk IP5 3RE (United Kingdom); Centre for Computational Science, University College London, 20 Gordon Street, London WC1H 0AJ (United Kingdom)

2007-06-15

A dramatic increase in the number of computing devices with wireless communication capability has resulted in the emergence of a new class of computer worms which specifically target such devices. The most striking feature of these worms is that they do not require Internet connectivity for their propagation but can spread directly from device to device using a short-range radio communication technology, such as WiFi or Bluetooth. In this paper, we develop a new model for epidemic spreading of these worms and investigate their spreading in wireless ad hoc networks via extensive Monte Carlo simulations. Our studies show that the threshold behaviour and dynamics of worm epidemics in these networks are greatly affected by a combination of spatial and temporal correlations which characterize these networks, and are significantly different from the previously studied epidemics in the Internet.

Worm epidemics in wireless ad hoc networks

Science.gov (United States)

Nekovee, Maziar

2007-06-01

A dramatic increase in the number of computing devices with wireless communication capability has resulted in the emergence of a new class of computer worms which specifically target such devices. The most striking feature of these worms is that they do not require Internet connectivity for their propagation but can spread directly from device to device using a short-range radio communication technology, such as WiFi or Bluetooth. In this paper, we develop a new model for epidemic spreading of these worms and investigate their spreading in wireless ad hoc networks via extensive Monte Carlo simulations. Our studies show that the threshold behaviour and dynamics of worm epidemics in these networks are greatly affected by a combination of spatial and temporal correlations which characterize these networks, and are significantly different from the previously studied epidemics in the Internet.

Worm epidemics in wireless ad hoc networks

International Nuclear Information System (INIS)

Nekovee, Maziar

2007-01-01

A dramatic increase in the number of computing devices with wireless communication capability has resulted in the emergence of a new class of computer worms which specifically target such devices. The most striking feature of these worms is that they do not require Internet connectivity for their propagation but can spread directly from device to device using a short-range radio communication technology, such as WiFi or Bluetooth. In this paper, we develop a new model for epidemic spreading of these worms and investigate their spreading in wireless ad hoc networks via extensive Monte Carlo simulations. Our studies show that the threshold behaviour and dynamics of worm epidemics in these networks are greatly affected by a combination of spatial and temporal correlations which characterize these networks, and are significantly different from the previously studied epidemics in the Internet

[Epidemiology of psoriasis in Germany--analysis of secondary health insurance data].

Science.gov (United States)

Schäfer, I; Rustenbach, S J; Radtke, M; Augustin, J; Glaeske, G; Augustin, M

2011-05-01

In Germany, population-based data on the epidemiology of psoriasis are still rare. This study aims to assess the prevalence of psoriasis in the total population as well as for subgroups relevant to health care. As further epidemiological parameters the severity and regional distribution of psoriasis were analysed. A secondary analysis of data collected routinely for the members of a nationwide statutory health insurance company was conducted. Prevalences were calculated for a closed cohort of continuously insured persons in 2005. Defined criteria for the existence of psoriasis were at least one diagnoses of psoriasis (ICD-10) relating to ambulatory or hospital treatment or disability. 33,981 of the 1,344,071 continuously insured persons in 2005 were diagnosed with psoriasis, thus the one-year-prevalence in this cohort was 2.53%. Up to the age of 80 years the prevalence rate was increasing with increasing age and highest for the age groups from 50 to 79 years (range: 3.99-4.18%). Insured persons up to 20 years had a prevalence of 0.73%. Regional differences showed up after stratification for broad categories (1 digit) of ZIP codes: Lowest prevalence rates were seen in the south (2.17%) and highest (2.78%) in the north and western regions of Germany. If the prevalence rate of 2.5% assessed in this study is applied to the total resident population, 2 million people are treated because of psoriasis in Germany. Routine data from health insurance companies are a relevant and suitable data source to assess the prevalence of chronic diseases (under medical treatment) in the population. © Georg Thieme Verlag KG Stuttgart · New York.

On Energy-Efficient Hierarchical Cross-Layer Design: Joint Power Control and Routing for Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Poor HVincent

2007-01-01

Full Text Available A hierarchical cross-layer design approach is proposed to increase energy efficiency in ad hoc networks through joint adaptation of nodes' transmitting powers and route selection. The design maintains the advantages of the classic OSI model, while accounting for the cross-coupling between layers, through information sharing. The proposed joint power control and routing algorithm is shown to increase significantly the overall energy efficiency of the network, at the expense of a moderate increase in complexity. Performance enhancement of the joint design using multiuser detection is also investigated, and it is shown that the use of multiuser detection can increase the capacity of the ad hoc network significantly for a given level of energy consumption.

On Energy-Efficient Hierarchical Cross-Layer Design: Joint Power Control and Routing for Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Cristina Comaniciu

2007-03-01

Full Text Available A hierarchical cross-layer design approach is proposed to increase energy efficiency in ad hoc networks through joint adaptation of nodes' transmitting powers and route selection. The design maintains the advantages of the classic OSI model, while accounting for the cross-coupling between layers, through information sharing. The proposed joint power control and routing algorithm is shown to increase significantly the overall energy efficiency of the network, at the expense of a moderate increase in complexity. Performance enhancement of the joint design using multiuser detection is also investigated, and it is shown that the use of multiuser detection can increase the capacity of the ad hoc network significantly for a given level of energy consumption.

Low dose epidemiology

International Nuclear Information System (INIS)

Tirmarche, M.; Hubert, P.

1992-01-01

Actually, epidemiological studies have to establish if the assessment of cancer risk can be verified at low chronic radiation doses. The population surveillance must be very long, the side effects and cancers of such radiation appearing much later. In France, this epidemiological study on nuclear workers have been decided recently. Before describing the experiment and french projects in epidemiology of nuclear workers, the authors present the main english and american studies

PUCA: A Pseudonym Scheme with User-Controlled Anonymity for Vehicular Ad-Hoc Networks (VANET)

NARCIS (Netherlands)

Förster, David; Kargl, Frank; Löhr, Hans

2014-01-01

Envisioned vehicular ad-hoc networks (VANET) standards use pseudonym certificates to provide secure and privacy-friendly message authentication. Revocation of long-term credentials is required to remove participants from the system, e.g. in case of vehicle theft. However, the current approach to

FRCA: A Fuzzy Relevance-Based Cluster Head Selection Algorithm for Wireless Mobile Ad-Hoc Sensor Networks

Directory of Open Access Journals (Sweden)

Taegwon Jeong

2011-05-01

Full Text Available Clustering is an important mechanism that efficiently provides information for mobile nodes and improves the processing capacity of routing, bandwidth allocation, and resource management and sharing. Clustering algorithms can be based on such criteria as the battery power of nodes, mobility, network size, distance, speed and direction. Above all, in order to achieve good clustering performance, overhead should be minimized, allowing mobile nodes to join and leave without perturbing the membership of the cluster while preserving current cluster structure as much as possible. This paper proposes a Fuzzy Relevance-based Cluster head selection Algorithm (FRCA to solve problems found in existing wireless mobile ad hoc sensor networks, such as the node distribution found in dynamic properties due to mobility and flat structures and disturbance of the cluster formation. The proposed mechanism uses fuzzy relevance to select the cluster head for clustering in wireless mobile ad hoc sensor networks. In the simulation implemented on the NS-2 simulator, the proposed FRCA is compared with algorithms such as the Cluster-based Routing Protocol (CBRP, the Weighted-based Adaptive Clustering Algorithm (WACA, and the Scenario-based Clustering Algorithm for Mobile ad hoc networks (SCAM. The simulation results showed that the proposed FRCA achieves better performance than that of the other existing mechanisms.

FRCA: a fuzzy relevance-based cluster head selection algorithm for wireless mobile ad-hoc sensor networks.

Science.gov (United States)

Lee, Chongdeuk; Jeong, Taegwon

2011-01-01

Clustering is an important mechanism that efficiently provides information for mobile nodes and improves the processing capacity of routing, bandwidth allocation, and resource management and sharing. Clustering algorithms can be based on such criteria as the battery power of nodes, mobility, network size, distance, speed and direction. Above all, in order to achieve good clustering performance, overhead should be minimized, allowing mobile nodes to join and leave without perturbing the membership of the cluster while preserving current cluster structure as much as possible. This paper proposes a Fuzzy Relevance-based Cluster head selection Algorithm (FRCA) to solve problems found in existing wireless mobile ad hoc sensor networks, such as the node distribution found in dynamic properties due to mobility and flat structures and disturbance of the cluster formation. The proposed mechanism uses fuzzy relevance to select the cluster head for clustering in wireless mobile ad hoc sensor networks. In the simulation implemented on the NS-2 simulator, the proposed FRCA is compared with algorithms such as the Cluster-based Routing Protocol (CBRP), the Weighted-based Adaptive Clustering Algorithm (WACA), and the Scenario-based Clustering Algorithm for Mobile ad hoc networks (SCAM). The simulation results showed that the proposed FRCA achieves better performance than that of the other existing mechanisms.

Should the history of epidemiology be taught in epidemiology training programs?

Science.gov (United States)

Laskaris, Zoey; Morabia, Alfredo

2015-01-01

Currently, there is no evidence concerning the presence of historical content in the epidemiology curricula of the United States and abroad. Similarly, it is not known how epidemiologists view this topic in the context of master's or doctoral level course work. We attempted to fill these knowledge gaps with data from 2 online surveys-Survey I administered to persons in charge of all epidemiology training programs in North America and Survey II to epidemiologists practicing around the world. A substantial minority (39%) of graduate programs in epidemiology in the United States teach a course on the history of the field. In both surveys, the most common reasons selected for teaching such a course were "To build a sense of identity as an epidemiologist" and "As a tool for achieving a deeper understanding into specific methods and concepts." The majority of respondents, from 63 countries, agreed that the history of epidemiology should be included in curricula for graduate students in epidemiology.

An epidemiological analysis of equine welfare data from regulatory inspections by the official competent authorities.

Science.gov (United States)

Hitchens, P L; Hultgren, J; Frössling, J; Emanuelson, U; Keeling, L J

2017-07-01

Determining welfare status in a population is the first step in efforts to improve welfare. The primary objective of this study was to explore a new epidemiological approach for analysis of data from official competent authorities that pertain to compliance with animal welfare legislation. We reviewed data already routinely collected as part of Swedish official animal welfare inspections for 2010-13, using a checklist containing 45 checkpoints (CPs). These covered animal-, resource- and management-based measures of equine welfare. The animal-based CPs were measures that directly related to the animal and included social contact, body condition, hoof condition and cleanliness. Non-compliance with one or more of the animal-based CPs was used as a binary outcome of poor equine welfare; 95% confidence intervals (CI) were estimated using the exact binomial distribution. Associations were determined using multivariable logistic regression, adjusting for clustering on premises. Resource- and management-based CPs (model inputs) were reduced by principal component analysis. Other input factors included premises characteristics (e.g. size, location) and inspection characteristics (e.g. type of inspection). There were 30 053 premises with horses from 21 counties registered by the Swedish Board of Agriculture. In total 13 321 inspections of premises were conducted at 28.4% (n=8532) of all registered premises. For random inspections, the premises-prevalence of poor equine welfare was 9.5% (95% CI 7.5, 11.9). Factors associated with poor equine welfare were non-compliance with requirements for supervision, care or feeding of horses, facility design, personnel, stable hygiene, pasture and exercise area maintenance, as well as the owner not being notified of the inspection, a previous complaint or deficiency, spring compared with autumn, and not operating as a professional equine business. Horses at premises compliant with stabling and shelter requirements had significantly better

Report of the evaluation by the Ad Hoc Review Committee on advance science research. Result evaluation, interim evaluation, in-advance evaluation in fiscal year 2003

International Nuclear Information System (INIS)

2003-11-01

The Research Evaluation Committee, which consisted of 13 members from outside of the Japan Atomic Energy Research Institute (JAERI), set up an Ad Hoc Review Committee on Advanced Science Research in accordance with the Fundamental Guideline for the Evaluation of Research and Development (R and D) at JAERI' and its subsidiary regulations in order to evaluate the accomplishments of the research completed in Fiscal Year 2002, the accomplishments of the research started in Fiscal Year 2001, and the adequacy of the programs of the research to be started in Fiscal Year 2004 at Advanced Science Research Center of JAERI. The Ad Hoc Review Committee consisted of nine specialists from outside of JAERI. The Ad Hoc Review Committee conducted its activities from May to July 2003. The evaluation was performed on the basis of the materials submitted in advance and of the oral presentations made at the Ad Hoc Review Committee meeting which was held on June 24, 2003, in line with the items, viewpoints, and criteria for the evaluation specified by the Research Evaluation Committee. The result of the evaluation by the Ad Hoc Review Committee was submitted to the Research Evaluation Committee, and was judged to be appropriate at its meeting held on August 4, 2003. This report describes the result of the evaluation by the Ad Hoc Review Committee on Advanced Science Research. (author)

Report of the evaluation by the Ad Hoc Review Committee on Advance Science Research. Result evaluation, interim evaluation, in-advance evaluation in fiscal year 2002

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-11-01

The Research Evaluation Committee, which consisted of 13 members from outside of the Japan Atomic Energy Research Institute (JAERI), set up an Ad Hoc Review Committee on Advanced Science Research in accordance with the Fundamental Guideline for the Evaluation of Research and Development (R and D) at JAERI' and its subsidiary regulations in order to evaluate the accomplishments of the research completed in Fiscal Year 2001, the accomplishments of the research started in Fiscal Year 2000, and the adequacy of the programs of the research to be started in Fiscal Year 2003 at Advanced Science Research Center of JAERI. The Ad Hoc Review Committee consisted of eight specialists from outside of JAERI. The Ad Hoc Review Committee conducted its activities from May to July 2002. The evaluation was performed on the basis of the materials submitted in advance and of the oral presentations made at the Ad Hoc Review Committee meeting which was held on June 4, 2002, in line with the items, viewpoints, and criteria for the evaluation specified by the Research Evaluation Committee. The result of the evaluation by the Ad Hoc Review Committee was submitted to the Research Evaluation Committee, and was judged to be appropriate at its meeting held on August 5, 2002. This report describes the result of the evaluation by the Ad Hoc Review Committee on Advanced Science Research. (author)

An Analysis of the Privacy Threat in Vehicular Ad Hoc Networks due to Radio Frequency Fingerprinting

Directory of Open Access Journals (Sweden)

Gianmarco Baldini

2017-01-01

Full Text Available In Vehicular Ad Hoc Networks (VANETs used in the road transportation sector, privacy risks may arise because vehicles could be tracked on the basis of the information transmitted by the Vehicle to Vehicle (V2V and Vehicle to Infrastructure (V2I communications implemented with the Dedicated Short Range Communications (DSRC standards operating at 5.9 GHz. Various techniques have been proposed in the literature to mitigate these privacy risks including the use of pseudonym schemes, but they are mostly focused on data anonymization at the network and application layer. At the physical layer, the capability to accurately identify and fingerprint wireless devices through their radio frequency (RF emissions has been demonstrated in the literature. This capability may generate a privacy threat because vehicles can be tracked using the RF emissions of their DSRC devices. This paper investigates the privacy risks related to RF fingerprinting to determine if privacy breaches are feasible in practice. In particular, this paper analyzes the tracking accuracy in challenging RF environments with high attenuation and fading.

Epidemiology of pediatric functional abdominal pain disorders: a meta-analysis

NARCIS (Netherlands)

Korterink, Judith J.; Diederen, Kay; Benninga, Marc A.; Tabbers, Merit M.

2015-01-01

We aimed to review the literature regarding epidemiology of functional abdominal pain disorders in children and to assess its geographic, gender and age distribution including associated risk factors of developing functional abdominal pain. The Cochrane Library, MEDLINE, EMBASE, CINAHL and PsychInfo

Epidemiology and moral philosophy.

OpenAIRE

Westrin, C G; Nilstun, T; Smedby, B; Haglund, B

1992-01-01

To an increasing extent ethical controversies affect and sometimes obstruct public health work and epidemiological research. In order to improve communication between the concerned parties a model for identification and analysis of ethical conflicts in individual-based research has been worked out in co-operation between epidemiologists and moral philosophers. The model has two dimensions. One dimension specifies relevant ethical principles (as beneficence, non-maleficence, autonomy and justi...

Real-Time Support on IEEE 802.11 Wireless Ad-Hoc Networks: Reality vs. Theory

Science.gov (United States)

Kang, Mikyung; Kang, Dong-In; Suh, Jinwoo

The usable throughput of an IEEE 802.11 system for an application is much less than the raw bandwidth. Although 802.11b has a theoretical maximum of 11Mbps, more than half of the bandwidth is consumed by overhead leaving at most 5Mbps of usable bandwidth. Considering this characteristic, this paper proposes and analyzes a real-time distributed scheduling scheme based on the existing IEEE 802.11 wireless ad-hoc networks, using USC/ISI's Power Aware Sensing Tracking and Analysis (PASTA) hardware platform. We compared the distributed real-time scheduling scheme with the real-time polling scheme to meet deadline, and compared a measured real bandwidth with a theoretical result. The theoretical and experimental results show that the distributed scheduling scheme can guarantee real-time traffic and enhances the performance up to 74% compared with polling scheme.

Relationship of Glucose Variability With Glycated Hemoglobin and Daily Mean Glucose: A Post Hoc Analysis of Data From 5 Phase 3 Studies.

Science.gov (United States)

Luo, Junxiang; Qu, Yongming; Zhang, Qianyi; Chang, Annette M; Jacober, Scott J

2018-03-01

The association of glucose variability (GV) with other glycemic measures is emerging as a topic of interest. The aim of this analysis is to study the correlation between GV and measures of glycemic control, such as glycated hemoglobin (HbA1c) and daily mean glucose (DMG). Data from 5 phase 3 trials were pooled into 3 analysis groups: type 2 diabetes (T2D) treated with basal insulin only, T2D treated with basal-bolus therapy, and type 1 diabetes (T1D). A generalized boosted model was used post hoc to assess the relationship of the following variables with glycemic control parameters (HbA1c and DMG): within-day GV, between-day GV (calculated using self-monitored blood glucose and fasting blood glucose [FBG]), hypoglycemia rate, and certain baseline characteristics. Within-day GV (calculated using standard deviation [SD]) was found to have a significant influence on endpoints HbA1c and DMG in all 3 patient groups. Between-day GV from FBG (calculated using SD), within-day GV (calculated using coefficient of variation), and hypoglycemia rate were found to significantly influence the endpoint HbA1c in the T2D basal-only group. Lower within-day GV was significantly associated with improvement in DMG and HbA1c. This finding suggests that GV could be a marker in the early phases of new antihyperglycemic therapy development for predicting clinical outcomes in terms of HbA1c and DMG.

Delay-dependent asymptotic stability of mobile ad-hoc networks: A descriptor system approach

International Nuclear Information System (INIS)

Yang Juan; Yang Dan; Zhang Xiao-Hong; Huang Bin; Luo Jian-Lu

2014-01-01

In order to analyze the capacity stability of the time-varying-propagation and delay-dependent of mobile ad-hoc networks (MANETs), in this paper, a novel approach is proposed to explore the capacity asymptotic stability for the delay-dependent of MANETs based on non-cooperative game theory, where the delay-dependent conditions are explicitly taken into consideration. This approach is based on the Lyapunov—Krasovskii stability theory for functional differential equations and the linear matrix inequality (LMI) technique. A corresponding Lyapunov—Krasovskii functional is introduced for the stability analysis of this system with use of the descriptor and “neutral-type” model transformation without producing any additional dynamics. The delay-dependent stability criteria are derived for this system. Conditions are given in terms of linear matrix inequalities, and for the first time referred to neutral systems with the time-varying propagation and delay-dependent stability for capacity analysis of MANETs. The proposed criteria are less conservative since they are based on an equivalent model transformation. Furthermore, we also provide an effective and efficient iterative algorithm to solve the constrained stability control model. Simulation experiments have verified the effectiveness and efficiency of our algorithm. (general)

Random Amplified Polymorphic DNA PCR in the Teaching of Molecular Epidemiology

Science.gov (United States)

Reinoso, Elina B.; Bettera, Susana G.

2016-01-01

In this article, we describe a basic practical laboratory designed for fifth-year undergraduate students of Microbiology as part of the Epidemiology course. This practice provides the students with the tools for molecular epidemiological analysis of pathogenic microorganisms using a rapid and simple PCR technique. The aim of this work was to assay…

Cross-Layer QoS Control for Video Communications over Wireless Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Pei Yong

2005-01-01

Full Text Available Assuming a wireless ad hoc network consisting of homogeneous video users with each of them also serving as a possible relay node for other users, we propose a cross-layer rate-control scheme based on an analytical study of how the effective video transmission rate is affected by the prevailing operating parameters, such as the interference environment, the number of transmission hops to a destination, and the packet loss rate. Furthermore, in order to provide error-resilient video delivery over such wireless ad hoc networks, a cross-layer joint source-channel coding (JSCC approach, to be used in conjunction with rate-control, is proposed and investigated. This approach attempts to optimally apply the appropriate channel coding rate given the constraints imposed by the effective transmission rate obtained from the proposed rate-control scheme, the allowable real-time video play-out delay, and the prevailing channel conditions. Simulation results are provided which demonstrate the effectiveness of the proposed cross-layer combined rate-control and JSCC approach.

Globally asymptotically stable analysis in a discrete time eco-epidemiological system

International Nuclear Information System (INIS)

Hu, Zengyun; Teng, Zhidong; Zhang, Tailei; Zhou, Qiming; Chen, Xi

2017-01-01

Highlights: • Dynamical behaviors of a discrete time eco-epidemiological system are discussed. • Global asymptotical stability of this system is obtained by an iteration scheme which can be expended to general dimensional discrete system. • More complex dynamical behaviors are obtained by numerical simulations. - Abstract: In this study, the dynamical behaviors of a discrete time eco-epidemiological system are discussed. The local stability, bifurcation and chaos are obtained. Moreover, the global asymptotical stability of this system is explored by an iteration scheme. The numerical simulations illustrate the theoretical results and exhibit the complex dynamical behaviors such as flip bifurcation, Hopf bifurcation and chaotic dynamical behaviors. Our main results provide an efficient method to analyze the global asymptotical stability for general three dimensional discrete systems.

1995 annual epidemiologic surveillance report for Hanford Site

International Nuclear Information System (INIS)

1995-01-01

The US Department of Energy's (DOE) commitment to assuring the health and safety of its workers includes the conduct of epidemiologic surveillance activities that provide an early warning system for health problems among workers. A number of DOE sites participate in the Epidemiologic Surveillance Program. This program monitors illnesses and health conditions that result in an absence of five or more consecutive workdays, occupational injuries and illnesses, disabilities and deaths among current workers. This report provides a summary of epidemiologic surveillance data collected from the Hanford Site from January 1, 1995 through December 31, 1995. The data were collected by a coordinator at Hanford and submitted to the Epidemiologic Surveillance Data Center, located at Oak Ridge Institute for Science and Education, where quality control procedures and data analyses were carried out. The information in the main body of the report provides a descriptive analysis of the data collected from the site, and the appendices provides additional detail. The report also contains an expanded Glossary and an Explanation of Diagnostic Categories which gives examples of health conditions in each of the diagnostic categories

1995 annual epidemiologic surveillance report for Hanford Site

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-31

The US Department of Energy`s (DOE) commitment to assuring the health and safety of its workers includes the conduct of epidemiologic surveillance activities that provide an early warning system for health problems among workers. A number of DOE sites participate in the Epidemiologic Surveillance Program. This program monitors illnesses and health conditions that result in an absence of five or more consecutive workdays, occupational injuries and illnesses, disabilities and deaths among current workers. This report provides a summary of epidemiologic surveillance data collected from the Hanford Site from January 1, 1995 through December 31, 1995. The data were collected by a coordinator at Hanford and submitted to the Epidemiologic Surveillance Data Center, located at Oak Ridge Institute for Science and Education, where quality control procedures and data analyses were carried out. The information in the main body of the report provides a descriptive analysis of the data collected from the site, and the appendices provides additional detail. The report also contains an expanded Glossary and an Explanation of Diagnostic Categories which gives examples of health conditions in each of the diagnostic categories.

Residual symptoms and functioning in depression, does the type of residual symptom matter? A post-hoc analysis

Directory of Open Access Journals (Sweden)

Romera Irene

2013-02-01

Full Text Available Abstract Background The degrees to which residual symptoms in major depressive disorder (MDD adversely affect patient functioning is not known. This post-hoc analysis explored the association between different residual symptoms and patient functioning. Methods Patients with MDD who responded (≥50% on the 17-item Hamilton Rating Scale for Depression; HAMD-17 after 3 months of treatment (624/930 were included. Residual core mood-symptoms (HAMD-17 core symptom subscale ≥1, residual insomnia-symptoms (HAMD-17 sleep subscale ≥1, residual anxiety-symptoms (HAMD-17-anxiety subscale ≥1, residual somatic-symptoms (HAMD-17 Item 13 ≥1, pain (Visual Analogue Scale ≥30, and functioning were assessed after 3 months treatment. A stepwise logistic regression model with normal functioning (Social and Occupational Functioning Assessment Scale ≥80 as the dependent variable was used. Results After 3 months, 59.5% of patients (371/624 achieved normal functioning and 66.0% (412/624 were in remission. Residual symptom prevalence was: core mood symptoms 72%; insomnia 63%; anxiety 78%; and somatic symptoms 41%. Pain reported in 18%. Factors associated with normal functioning were absence of core mood symptoms (odds ratio [OR] 8.7; 95% confidence interval [CI], 4.6–16.7, absence of insomnia symptoms (OR 1.8; 95% CI, 1.2–2.7, episode length (4–24 weeks vs. ≥24 weeks [OR 2.0; 95% CI, 1.1–3.6] and better baseline functioning (OR 1.0; 95% CI, 1.0–1.1. A significant interaction between residual anxiety symptoms and pain was found (p = 0.0080. Conclusions Different residual symptoms are associated to different degrees with patient functioning. To achieve normal functioning, specific residual symptoms domains might be targeted for treatment.

Topology Control with Anisotropic and Sector Turning Antennas in Ad-hoc and Sensor Networks

Directory of Open Access Journals (Sweden)

V. Černý

2011-01-01

Full Text Available During the last several years, technological advances have allowed the development of small, cheap, embedded, independent and rather powerful radio devices that can self-organise into data networks. Such networks are usually called ad-hoc networks or, sometimes, depending on the application field, sensor networks. One of the first standards for ad-hoc networks to impose itself as a fully industrial framework for data gathering and control over such devices is IEEE 802.15.4 and, on top of it, its pair network architecture: ZigBee. In the case of multiple radio devices clamped into a small geographical area, the lack of radio bandwidth becomes a major problem, leading to multiple data losses and unnecessary power drain from the batteries of these small devices. This problem is usually perceived as interference. The deployment of appropriate topology control mechanisms (TC can solve interference. All of these algorithms calculate TC on the basis of isotropic antenna radiation patterns in the horizontal plane.

Client-Server and Peer-to-Peer Ad-hoc Network for a Flexible Learning Environment

Directory of Open Access Journals (Sweden)

Ferial Khaddage

2011-01-01

Full Text Available Peer-to-Peer (P2P networking in a mobile learning environment has become a popular topic of research. One of the new emerging research ideas is on the ability to combine P2P network with server-based network to form a strong efficient portable and compatible network infrastructure. This paper describes a unique mobile network architecture, which reflects the on-campus students’ need for a mobile learning environment. This can be achieved by combining two different networks, client-server and peer-to-peer ad-hoc to form a sold and secure network. This is accomplished by employing one peer within the ad-hoc network to act as an agent-peer to facilitate communication and information sharing between the two networks. It can be implemented without any major changes to the current network technologies, and can combine any wireless protocols such as GPRS, Wi-Fi, Bluetooth, and 3G.

Adhoc: an R package to calculate ad hoc distance thresholds for DNA barcoding identification

Directory of Open Access Journals (Sweden)

Gontran Sonet

2013-12-01

Full Text Available Identification by DNA barcoding is more likely to be erroneous when it is based on a large distance between the query (the barcode sequence of the specimen to identify and its best match in a reference barcode library. The number of such false positive identifications can be decreased by setting a distance threshold above which identification has to be rejected. To this end, we proposed recently to use an ad hoc distance threshold producing identifications with an estimated relative error probability that can be fixed by the user (e.g. 5%. Here we introduce two R functions that automate the calculation of ad hoc distance thresholds for reference libraries of DNA barcodes. The scripts of both functions, a user manual and an example file are available on the JEMU website (http://jemu.myspecies.info/computer-programs as well as on the comprehensive R archive network (CRAN, http://cran.r-project.org.

Epidemiology of IBD

Science.gov (United States)

... IBD? Projects and Partners Data and Statistics Resources Epidemiology of the IBD Recommend on Facebook Tweet Share ... 5:1424-9. 2 Loftus EV, Jr. Clinical epidemiology of inflammatory bowel disease: Incidence, prevalence, and environmental ...

The New Epidemiology--A Challenge to Health Administration. Issues in Epidemiology for Administration.

Science.gov (United States)

Crichton, Anne, Ed.; Neuhauser, Duncan, Ed.

The role of epidemiology in health administration is considered in 11 articles, and three course descriptions and a bibliography are provided. Titles and authors include the following: "The Need for Creative Managerial Epidemiology" (Gary L. Filerman); "The Growing Role of Epidemiology in Health Administration" (Maureen M.…

Challenges and Opportunities for Occupational Epidemiology in the Twenty-first Century.

Science.gov (United States)

Stayner, L T; Collins, J J; Guo, Y L; Heederik, D; Kogevinas, M; Steenland, K; Wesseling, C; Demers, P A

2017-09-01

There are many opportunities and challenges for conducting occupational epidemiologic studies today. In this paper, we summarize the discussion of a symposium held at the Epidemiology in Occupational Health (EPICOH) conference, Chicago 2014, on challenges for occupational epidemiology in the twenty-first century. The increasing number of publications and attendance at our conferences suggests that worldwide interest in occupational epidemiology has been growing. There are clearly abundant opportunities for new research in occupational epidemiology. Areas ripe for further work include developing improved methods for exposure assessment, statistical analysis, studying migrant workers and other vulnerable populations, the use of biomarkers, and new hazards. Several major challenges are also discussed such as the rapidly changing nature and location of work, lack of funding, and political/legal conflicts. As long as work exists there will be occupational diseases that demand our attention, and a need for epidemiologic studies designed to characterize these risks and to support the development of preventive strategies. Despite the challenges and given the important past contribution in this field, we are optimistic about the importance and continued vitality of the research field of occupational epidemiology.

A Family of ACO Routing Protocols for Mobile Ad Hoc Networks

Science.gov (United States)

Rupérez Cañas, Delfín; Sandoval Orozco, Ana Lucila; García Villalba, Luis Javier; Kim, Tai-hoon

2017-01-01

In this work, an ACO routing protocol for mobile ad hoc networks based on AntHocNet is specified. As its predecessor, this new protocol, called AntOR, is hybrid in the sense that it contains elements from both reactive and proactive routing. Specifically, it combines a reactive route setup process with a proactive route maintenance and improvement process. Key aspects of the AntOR protocol are the disjoint-link and disjoint-node routes, separation between the regular pheromone and the virtual pheromone in the diffusion process and the exploration of routes, taking into consideration the number of hops in the best routes. In this work, a family of ACO routing protocols based on AntOR is also specified. These protocols are based on protocol successive refinements. In this work, we also present a parallelized version of AntOR that we call PAntOR. Using programming multiprocessor architectures based on the shared memory protocol, PAntOR allows running tasks in parallel using threads. This parallelization is applicable in the route setup phase, route local repair process and link failure notification. In addition, a variant of PAntOR that consists of having more than one interface, which we call PAntOR-MI (PAntOR-Multiple Interface), is specified. This approach parallelizes the sending of broadcast messages by interface through threads. PMID:28531159

A Family of ACO Routing Protocols for Mobile Ad Hoc Networks.

Science.gov (United States)

Rupérez Cañas, Delfín; Sandoval Orozco, Ana Lucila; García Villalba, Luis Javier; Kim, Tai-Hoon

2017-05-22

In this work, an ACO routing protocol for mobile ad hoc networks based on AntHocNet is specified. As its predecessor, this new protocol, called AntOR, is hybrid in the sense that it contains elements from both reactive and proactive routing. Specifically, it combines a reactive route setup process with a proactive route maintenance and improvement process. Key aspects of the AntOR protocol are the disjoint-link and disjoint-node routes, separation between the regular pheromone and the virtual pheromone in the diffusion process and the exploration of routes, taking into consideration the number of hops in the best routes. In this work, a family of ACO routing protocols based on AntOR is also specified. These protocols are based on protocol successive refinements. In this work, we also present a parallelized version of AntOR that we call PAntOR. Using programming multiprocessor architectures based on the shared memory protocol, PAntOR allows running tasks in parallel using threads. This parallelization is applicable in the route setup phase, route local repair process and link failure notification. In addition, a variant of PAntOR that consists of having more than one interface, which we call PAntOR-MI (PAntOR-Multiple Interface), is specified. This approach parallelizes the sending of broadcast messages by interface through threads.

移动Ad Hoc网络路由协议综述%A Survey of Routing Protocols for Mobile Ad Hoc Networks

Institute of Scientific and Technical Information of China (English)

张顺亮; 叶澄清; 李方敏

2003-01-01

A review of current research about routing protocols for mobile Ad Hoc networks is made. Based on classifying of them, the characteristic, the strength and the weakness of these protocols are evaluated respectively. Then some crucial strategies to improve the existing routing protocols are proposed. Besides, a frame of new routing protocol for Ad Hoc networks is put forward. Finally, open issues that still need investigation are listed.

An Automated Tool for the Creation of Desired Emulated Topologies of a Mobile Ad-Hoc Network

National Research Council Canada - National Science Library

Nguyen, Binh Q

2006-01-01

This report documents a research effort that the U.S. Army Research Laboratory conducted in FY 2005 in support of the development of advanced technologies for tactical mobile ad hoc networks (MANET...

An ad hoc wireless sensor network for tele medicine applications

International Nuclear Information System (INIS)

Sheltami, Tarek R.; Mahmoud, Ashraf S.; Abu-Amara, Marwan H.

2007-01-01

Recent advances in embedded computing systems have led to the emergence of wireless sensor networks (SNETs), consisting of small, battery-powered motes with limited computation and radio communication capabilities. SNETs permit data gathering and computation to be deeply embedded in the physical environment. Large scale ad hoc sensor networks (ASNET), when deployed among mobile patients, can provide dynamic data query architecture to allow medical specialists to monitor patients at any place via the web or cellular network. In case of an emergency, doctors and/or nurses will be contacted automatically through their handheld personal digital assistants (PDAs) or cellular phones. In specific, the proposed network consists of sensor nodes at the first layer whose responsibility is to measure, collect and communicate, via wired or wireless interface, readings to a microcontroller presenting the second layer of architecture. Deployed microcontrollers process incoming readings and report to a central system via a wireless interface. The implemented network distinguishes between periodic sensor readings and critical or event driven readings where higher priorities is given for the latter. In this paper we implement 3 special cases for tracking and monitoring patients and doctors using SNETs. In addition, the performance of a large scale of our implementation has been tested by means of mathematical analysis. (author)

The incidence and prevalence of ankle sprain injury: a systematic review and meta-analysis of prospective epidemiological studies.

Science.gov (United States)

Doherty, Cailbhe; Delahunt, Eamonn; Caulfield, Brian; Hertel, Jay; Ryan, John; Bleakley, Chris

2014-01-01

Ankle sprain is one of the most common musculoskeletal injuries, yet a contemporary review and meta-analysis of prospective epidemiological studies investigating ankle sprain does not exist. Our aim is to provide an up-to-date account of the incidence rate and prevalence period of ankle sprain injury unlimited by timeframe or context activity. We conducted a systematic review and meta-analyses of English articles using relevant computerised databases. Search terms included Medical Search Headings for the ankle joint, injury and epidemiology. The following inclusion criteria were used: the study must report epidemiology findings of injuries sustained in an observed sample; the study must report ankle sprain injury with either incidence rate or prevalence period among the surveyed sample, or provide sufficient data from which these figures could be calculated; the study design must be prospective. Independent extraction of articles was performed by two authors using pre-determined data fields. One-hundred and eighty-one prospective epidemiology studies from 144 separate papers were included. The average rating of all the included studies was 6.67/11, based on an adapted version of the STROBE (STrengthening the Reporting of OBservational studies in Epidemiology) guidelines for rating observational studies. 116 studies were considered high quality and 65 were considered low quality. The main findings of the meta-analysis demonstrated a higher incidence of ankle sprain in females compared with males (13.6 vs 6.94 per 1,000 exposures), in children compared with adolescents (2.85 vs 1.94 per 1,000 exposures) and adolescents compared with adults (1.94 vs 0.72 per 1,000 exposures). The sport category with the highest incidence of ankle sprain was indoor/court sports, with a cumulative incidence rate of 7 per 1,000 exposures or 1.37 per 1,000 athlete exposures and 4.9 per 1,000 h. Low-quality studies tended to underestimate the incidence of ankle sprain when compared with

Integrated Social and Quality of Service Trust Management of Mobile Groups in Ad Hoc Networks

Science.gov (United States)

2013-01-01

high resiliency to malicious attacks and misbehaving nodes. Keywords—trust management; mobile ad hoc networks; QoS trust; social trust; trust...paper we address an importance issue of trust management protocol design for MANETs: trust bias minimization despite misbehaving nodes performing

Web tools for molecular epidemiology of tuberculosis.

Science.gov (United States)

Shabbeer, Amina; Ozcaglar, Cagri; Yener, Bülent; Bennett, Kristin P

2012-06-01

In this study we explore publicly available web tools designed to use molecular epidemiological data to extract information that can be employed for the effective tracking and control of tuberculosis (TB). The application of molecular methods for the epidemiology of TB complement traditional approaches used in public health. DNA fingerprinting methods are now routinely employed in TB surveillance programs and are primarily used to detect recent transmissions and in outbreak investigations. Here we present web tools that facilitate systematic analysis of Mycobacterium tuberculosis complex (MTBC) genotype information and provide a view of the genetic diversity in the MTBC population. These tools help answer questions about the characteristics of MTBC strains, such as their pathogenicity, virulence, immunogenicity, transmissibility, drug-resistance profiles and host-pathogen associativity. They provide an integrated platform for researchers to use molecular epidemiological data to address current challenges in the understanding of TB dynamics and the characteristics of MTBC. Copyright © 2011. Published by Elsevier B.V.

Ad Hoc Microphone Array Beamforming Using the Primal-Dual Method of Multipliers

DEFF Research Database (Denmark)

Tavakoli, Vincent Mohammad; Jensen, Jesper Rindom; Heusdens, Richard

2016-01-01

In the recent years, there have been increasing amount of researches aiming at optimal beamforming with ad hoc microphone arrays, mostly with fusion-based schemes. However, huge amount of computational complexity and communication overhead impede many of these algorithms from being useful in prac...... the distributed linearly-constrained minimum variance beamformer using the the state of the art primal-dual method of multipliers. We study the proposed algorithm with an experiment....

The emergence of translational epidemiology: from scientific discovery to population health impact.

Science.gov (United States)

Khoury, Muin J; Gwinn, Marta; Ioannidis, John P A

2010-09-01

Recent emphasis on translational research (TR) is highlighting the role of epidemiology in translating scientific discoveries into population health impact. The authors present applications of epidemiology in TR through 4 phases designated T1-T4, illustrated by examples from human genomics. In T1, epidemiology explores the role of a basic scientific discovery (e.g., a disease risk factor or biomarker) in developing a "candidate application" for use in practice (e.g., a test used to guide interventions). In T2, epidemiology can help to evaluate the efficacy of a candidate application by using observational studies and randomized controlled trials. In T3, epidemiology can help to assess facilitators and barriers for uptake and implementation of candidate applications in practice. In T4, epidemiology can help to assess the impact of using candidate applications on population health outcomes. Epidemiology also has a leading role in knowledge synthesis, especially using quantitative methods (e.g., meta-analysis). To explore the emergence of TR in epidemiology, the authors compared articles published in selected issues of the Journal in 1999 and 2009. The proportion of articles identified as translational doubled from 16% (11/69) in 1999 to 33% (22/66) in 2009 (P = 0.02). Epidemiology is increasingly recognized as an important component of TR. By quantifying and integrating knowledge across disciplines, epidemiology provides crucial methods and tools for TR.

A Bioinspired Adaptive Congestion-Avoidance Routing for Mobile Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Huang Qiong

2014-01-01

Full Text Available Traditional mobile Ad Hoc network routing protocols are mainly based on the Shortest Path, which possibly results in many congestion nodes that incur routing instability and rerouting. To mitigate the side-efforts, this paper proposed a new bioinspired adaptive routing protocol (ATAR based on a mathematics biology model ARAS. This paper improved the ARAS by reducing the randomness and by introducing a new routing-decision metric “the next-hop fitness” which was denoted as the congestion level of node and the length of routing path. In the route maintenance, the nodes decide to forward the data to next node according to a threshold value of the fitness. In the recovery phase, the node will adopt random manner to select the neighbor as the next hop by calculation of the improved ARAS. With this route mechanism, the ATAR could adaptively circumvent the congestion nodes and the rerouting action is taken in advance. Theoretical analysis and numerical simulation results show that the ATAR protocol outperforms AODV and MARAS in terms of delivery ratio, ETE delay, and the complexity. In particular, ATAR can efficiently mitigate the congestion.

Further Development of Synchronous Array Method for Ad Hoc Wireless Networks

Directory of Open Access Journals (Sweden)

Yingbo Hua

2008-09-01

Full Text Available A further development of the synchronous array method (SAM as a medium access control scheme for large-scale ad hoc wireless networks is presented. Under SAM, all transmissions of data packets between adjacent nodes are synchronized on a frame-by-frame basis, and the spacing between concurrent cochannel transmissions of data packets is properly controlled. An opportunistic SAM (O-SAM is presented which allows concurrent cochannel transmissions to be locally adaptive to channel gain variations. A distributed SAM (D-SAM is discussed that schedules all concurrent cochannel transmissions in a distributed fashion. For networks of low mobility, the control overhead required by SAM can be made much smaller than the payload. By analysis and simulation, the intranetwork throughput of O-SAM and D-SAM is evaluated. The effects of traffic load and multiple antennas on the intranetwork throughput are studied. The throughput of ALOHA is also analyzed and compared with that of O-SAM and D-SAM. By a distance-weighted throughput, a comparison of long distance transmission versus short distance transmission is also presented. The study of D-SAM reveals an important insight into the MSH-DSCH protocol adopted in IEEE 802.16 standards.

Chromium VI and stomach cancer: a meta-analysis of the current epidemiological evidence.

Science.gov (United States)

Welling, Roberta; Beaumont, James J; Petersen, Scott J; Alexeeff, George V; Steinmaus, Craig

2015-02-01

Chromium VI (hexavalent chromium, Cr(VI)) is an established cause of lung cancer, but its association with gastrointestinal cancer is less clear. The goal of this study was to examine whether the current human epidemiological research on occupationally inhaled Cr(VI) supports the hypothesis that Cr(VI) is associated with human stomach cancer. Following a thorough literature search and review of individual studies, we used meta-analysis to summarise the current epidemiological literature on inhaled Cr(VI) and stomach cancer, explore major sources of heterogeneity, and assess other elements of causal inference. We identified 56 cohort and case-control studies and 74 individual relative risk (RR) estimates on stomach cancer and Cr(VI) exposure or work in an occupation associated with high Cr(VI) exposure including chromium production, chrome plating, leather work and work with Portland cement. The summary RR for all studies combined was 1.27 (95% CI 1.18 to 1.38). In analyses limited to only those studies identifying increased risks of lung cancer, the summary RR for stomach cancer was higher (RR=1.41, 95% CI 1.18 to 1.69). Overall, these results suggest that Cr(VI) is a stomach carcinogen in humans, which is consistent with the tumour results reported in rodent studies. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Protocolo W2LAN para transformar una red móvil 802.11 Ad-Hoc (MANET) en una LAN Ethernet

OpenAIRE

Burrull I Mestres, Francesco; García Haro, Juan; Malgosa Sanahuja, José María; Monzó Sánchez, Francisco Miguel

2005-01-01

Las redes MANET (Mobile Ad-Hoc Network) presentan el problema de la visibilidad parcial [1], por lo que hay que considerar protocolos de encaminamiento de nivel de enlace (capa 2 OSI) o superior. Algunos ejemplos de protocolos de encaminamiento en uso podrían ser el protocolo AODV (Ad Hoc On-demand Distance Vector[2]) -reactivo- y DSDV (Destination-Sequenced Distance Vector [3]) -proactivo-. En [4] se puede encontrar una comparativa extensa sobre protocolos de encaminamiento en redes MANET, o...

Clinical and epidemiological predictors of transmission in Severe Acute Respiratory Syndrome (SARS

Directory of Open Access Journals (Sweden)

Leong Hoe

2006-10-01

Full Text Available Abstract Background Only a minority of probable SARS cases caused transmission. We assess if any epidemiological or clinical factors in SARS index patients were associated with increased probability of transmission. Methods We used epidemiological and clinical data on probable SARS patients admitted to Tan Tock Seng Hospital. Using a case-control approach, index patients who had probable SARS who subsequently transmitted the disease to at least one other patient were analysed as "cases" against patients with no transmission as "controls", using multivariate logistic regression analysis. Results 98 index patients were available for analysis (22 with transmission, 76 with no transmission. Covariates positively associated with transmission in univariate analysis at p 650 IU/L (OR 6.4, 23.8 and 4.7 respectively. Conclusion Clinical and epidemiological factors can help us to explain why transmission was observed in some instances but not in others.

Social inequalities in health: a proper concern of epidemiology.

Science.gov (United States)

Marmot, Michael; Bell, Ruth

2016-04-01

Social inequalities are a proper concern of epidemiology. Epidemiological thinking and modes of analysis are central, but epidemiological research is one among many areas of study that provide the evidence for understanding the causes of social inequalities in health and what can be done to reduce them. Understanding the causes of health inequalities requires insights from social, behavioral and biological sciences, and a chain of reasoning that examines how the accumulation of positive and negative influences over the life course leads to health inequalities in adult life. Evidence that the social gradient in health can be reduced should make us optimistic that reducing health inequalities is a realistic goal for all societies. Copyright © 2016 Elsevier Inc. All rights reserved.

Spontaneous ad hoc mobile cloud computing network.

Science.gov (United States)

Lacuesta, Raquel; Lloret, Jaime; Sendra, Sandra; Peñalver, Lourdes

2014-01-01

Cloud computing helps users and companies to share computing resources instead of having local servers or personal devices to handle the applications. Smart devices are becoming one of the main information processing devices. Their computing features are reaching levels that let them create a mobile cloud computing network. But sometimes they are not able to create it and collaborate actively in the cloud because it is difficult for them to build easily a spontaneous network and configure its parameters. For this reason, in this paper, we are going to present the design and deployment of a spontaneous ad hoc mobile cloud computing network. In order to perform it, we have developed a trusted algorithm that is able to manage the activity of the nodes when they join and leave the network. The paper shows the network procedures and classes that have been designed. Our simulation results using Castalia show that our proposal presents a good efficiency and network performance even by using high number of nodes.

Ad hoc committee on reactor physics benchmarks

International Nuclear Information System (INIS)

Diamond, D.J.; Mosteller, R.D.; Gehin, J.C.

1996-01-01

In the spring of 1994, an ad hoc committee on reactor physics benchmarks was formed under the leadership of two American Nuclear Society (ANS) organizations. The ANS-19 Standards Subcommittee of the Reactor Physics Division and the Computational Benchmark Problem Committee of the Mathematics and Computation Division had both seen a need for additional benchmarks to help validate computer codes used for light water reactor (LWR) neutronics calculations. Although individual organizations had employed various means to validate the reactor physics methods that they used for fuel management, operations, and safety, additional work in code development and refinement is under way, and to increase accuracy, there is a need for a corresponding increase in validation. Both organizations thought that there was a need to promulgate benchmarks based on measured data to supplement the LWR computational benchmarks that have been published in the past. By having an organized benchmark activity, the participants also gain by being able to discuss their problems and achievements with others traveling the same route

Costs and health resources utilization following switching to pregabalin in individuals with gabapentin-refractory neuropathic pain: a post hoc analysis.

Science.gov (United States)

Navarro, Ana; Saldaña, María T; Pérez, Concepción; Masramón, Xavier; Rejas, Javier

2012-06-01

To analyze the changes in pain severity and associated costs resulting from resource utilization and reduced productivity in patients with gabapentin-refractory peripheral neuropathic pain who switched to pregabalin therapy in primary care settings in Spain. This is a post hoc analysis of a 12-week, multicentre, noninterventional cost-of-illness study. Patients were included in the study if they were over 18 years of age and had a diagnosis of chronic, treatment-refractory peripheral neuropathic pain. The analysis included all pregabalin-naïve patients who had previously shown an inadequate response to gabapentin and switched to pregabalin. Severity of pain before and after treatment with pregabalin, alone or as an add-on therapy, was assessed using the Short-Form McGill Pain Questionnaire (SF-MPQ) and its related visual analogue scale (VA). Healthcare resource utilization, productivity (including lost-workday equivalents [LWDE]), and related costs were assessed at baseline and after pregabalin treatment. A total of 174 patients switched to pregabalin had significant and clinically relevant reductions in pain severity (mean [SD] change on SF-MPQ VA scale, -31.9 [22.1]; P use [in pregabalin add-on group], ancillary tests, and unscheduled medical visits) were observed at the end of trial. Additionally, there were substantial improvements in productivity, including a reduction in the number of LWDE following pregabalin treatment (-18.9 [26.0]; P < 0.0001). These changes correlated with substantial reductions in both direct (-652.9 ± 1622.4 €; P < 0.0001) and indirect healthcare costs (-851.6 [1259.6] €; P < 0.0001). The cost of care in patients with gabapentin-refractory peripheral neuropathic pain appeared to be significantly reduced after switching to pregabalin treatment, alone or in combination with other analgesic drugs, in a real-life setting. © 2011 The Authors. Pain Practice © 2011 World Institute of Pain.

Specification and Validation of an Edge Router Discovery Protocol for Mobile Ad Hoc Networks

DEFF Research Database (Denmark)

Kristensen, Lars Michael; Jensen, Kurt

2004-01-01

We present an industrial project at Ericsson Telebit A/S where Coloured Petri Nets (CP-nets or CPNs) have been used for the design and specification of an edge router discovery protocol for mobile ad-hoc networks. The Edge Router Discovery Protocol (ERDP) supports an edge router in a stationary...

Impact of mobility on the performance of relaying in ad hoc networks (Extended version)

NARCIS (Netherlands)

Al Hanbali, A.; Kherani, A.A.; Groenevelt, R.; Nain, P.; Altman, E.

2007-01-01

We consider a mobile ad hoc network consisting of three types of nodes: source, destination, and relay nodes. All the nodes are moving over a bounded region with possibly different mobility patterns. We introduce and study the notion of relay throughput, i.e. the maximum rate at which a node can

BLESSED with Opportunistic Beacons: A Lightweight Data Dissemination Model for Smart Mobile Ad-Hoc Networks

NARCIS (Netherlands)

Türkes, Okan; Scholten, Johan; Havinga, Paul J.M.

2015-01-01

This paper introduces BLESSED, a universal opportunistic ad hoc networking model intended for smart mobile devices. It enables fast and lightweight data dissemination in wireless community networks through the complementary utilization of the IEEE 802.11 and Bluetooth Low Energy standards. As a

System optimization for peer-to-peer multi hop video broadcasting in wireless ad hoc networks

NARCIS (Netherlands)

Dedeoglu, V.; Atici, C.; Salman, F.S.; Sunay, M.O.

2008-01-01

We consider peer-to-peer video broadcasting using cooperation among peers in an ad hoc wireless network. As opposed to the traditional single hop broadcasting, multiple hops cause an increase in broadcast video quality while creating interference and increasing transmission delay. We develop

Basic concepts of epidemiology

International Nuclear Information System (INIS)

Savitz, D.A.

1984-01-01

Epidemiology can be defined simply as the science of the distribution and determinants of disease in human populations. As a descriptive tool, epidemiology can aid health care service providers, for example, in allocation of resources. In its analytic capacity, the epidemiologic approach can help identify determinants of disease through the study of human populations. Epidemiology is primarily an observational rather than experimental methodology, with corresponding strengths and limitations. Relative to other approaches for assessing disease etiology and impacts of potential health hazards, epidemiology has a rather unique role that is complementary to, but independent of, both basic biologic sciences and clinical medicine. Experimental biologic sciences such as toxicology and physiology provide critical information on biologic mechanisms of disease required for causal inference. Clinical medicine often serves as the warning system that provides etiologic clues to be pursued through systematic investigation. The advantage of the epidemiologic approach is its reliance on human field experience, that is, the real world. While laboratory experimentation is uniquely well suited to defining potential hazards, it can neither determine whether human populations have actually been affected nor quantify that effect. Building all the complexities of human behavior and external factors into a laboratory study or mathematical model is impossible. By studying the world as it exists, epidemiology examines the integrated, summarized product of the myriad factors influencing health

WHO - IPHECA: Epidemiological aspects

International Nuclear Information System (INIS)

Souchkevitch, G.

1996-01-01

In May 1991 the World Health Assembly endorsed the establishment of the International Programme on the Health Effects of the Chernobyl Accident (IPHECA) under the auspices of WHO. Five pilot projects have been carried out within IPHECA in the study territories of Belarus, Russian Federation and Ukraine in a period from 1991 to 1994. This pilot projects dealt with the detection and treatment of leukaemia and related diseases (Haematology Project), thyroid disorders (Thyroid project), brain damage during exposure 'in-utero' (Brain Damage 'in-Utero' project) and with the development of the Chernobyl registries (Epidemiological Registry Project). A fifth pilot project on oral health was performed only in Belarus. Epidemiological investigations have been an important component of all IPHECA pilot projects. Within 'Epidemiological Registry' Project such investigations have been the principal activity. But with respect to other IPHECA projects it was carried out in addition to main objectives relating to medical monitoring, early diagnosis and treatment of specific diseases included in project protocols. To support the epidemiological investigations within IPHECA, WHO supplied 41 computers in Belarus, Russian Federation and Ukraine and provided training for specialists from these countries in internationally recognized centres. The training programmes and host countries were as follows: standardization of epidemiological investigations (United Kingdom), radiation epidemiology (Russia), development of software (United Kingdom), principles of epidemiological investigations (The Czech Republic), cohort investigations (Japan)

WHO - IPHECA: Epidemiological aspects

Energy Technology Data Exchange (ETDEWEB)

Souchkevitch, G [World Health Organization, Geneva (Swaziland)

1996-07-01

In May 1991 the World Health Assembly endorsed the establishment of the International Programme on the Health Effects of the Chernobyl Accident (IPHECA) under the auspices of WHO. Five pilot projects have been carried out within IPHECA in the study territories of Belarus, Russian Federation and Ukraine in a period from 1991 to 1994. This pilot projects dealt with the detection and treatment of leukaemia and related diseases (Haematology Project), thyroid disorders (Thyroid project), brain damage during exposure 'in-utero' (Brain Damage 'in-Utero' project) and with the development of the Chernobyl registries (Epidemiological Registry Project). A fifth pilot project on oral health was performed only in Belarus. Epidemiological investigations have been an important component of all IPHECA pilot projects. Within 'Epidemiological Registry' Project such investigations have been the principal activity. But with respect to other IPHECA projects it was carried out in addition to main objectives relating to medical monitoring, early diagnosis and treatment of specific diseases included in project protocols. To support the epidemiological investigations within IPHECA, WHO supplied 41 computers in Belarus, Russian Federation and Ukraine and provided training for specialists from these countries in internationally recognized centres. The training programmes and host countries were as follows: standardization of epidemiological investigations (United Kingdom), radiation epidemiology (Russia), development of software (United Kingdom), principles of epidemiological investigations (The Czech Republic), cohort investigations (Japan)

Mobile agents affect worm spreading in wireless ad hoc networks

International Nuclear Information System (INIS)

Huang, Zi-Gang; Sun, Jin-Tu; Wang, Ying-Hai; Wang, Sheng-Jun; Xu, Xin-Jian

2009-01-01

Considering the dynamic nature of portable computing devices with wireless communication capability, an extended model is introduced for worm spreading in the wireless ad hoc network, with a population of mobile agents in a planar distribution, starting from an initial infected seed. The effect of agents' mobility on worm spreading is investigated via extensive Monte Carlo simulations. The threshold behavior and the dynamics of worm epidemics in the wireless networks are greatly affected by both agents' mobility and spatial and temporal correlations. The medium access control mechanism for the wireless communication promotes the sensitivity of the spreading dynamics to agents' mobility

Enhanced Secure Trusted AODV (ESTA Protocol to Mitigate Blackhole Attack in Mobile Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Dilraj Singh

2015-09-01

Full Text Available The self-organizing nature of the Mobile Ad hoc Networks (MANETs provide a communication channel anywhere, anytime without any pre-existing network infrastructure. However, it is exposed to various vulnerabilities that may be exploited by the malicious nodes. One such malicious behavior is introduced by blackhole nodes, which can be easily introduced in the network and, in turn, such nodes try to crumble the working of the network by dropping the maximum data under transmission. In this paper, a new protocol is proposed which is based on the widely used Ad hoc On-Demand Distance Vector (AODV protocol, Enhanced Secure Trusted AODV (ESTA, which makes use of multiple paths along with use of trust and asymmetric cryptography to ensure data security. The results, based on NS-3 simulation, reveal that the proposed protocol is effectively able to counter the blackhole nodes in three different scenarios.

Methodologic frontiers in environmental epidemiology.

OpenAIRE

Rothman, K J

1993-01-01

Environmental epidemiology comprises the epidemiologic study of those environmental factors that are outside the immediate control of the individual. Exposures of interest to environmental epidemiologists include air pollution, water pollution, occupational exposure to physical and chemical agents, as well as psychosocial elements of environmental concern. The main methodologic problem in environmental epidemiology is exposure assessment, a problem that extends through all of epidemiologic re...

High-resolution minisatellite-based typing as a portable approach to global analysis of Mycobacterium tuberculosis molecular epidemiology

Science.gov (United States)

Mazars, Edith; Lesjean, Sarah; Banuls, Anne-Laure; Gilbert, Michèle; Vincent, Véronique; Gicquel, Brigitte; Tibayrenc, Michel; Locht, Camille; Supply, Philip

2001-01-01

The worldwide threat of tuberculosis to human health emphasizes the need to develop novel approaches to a global epidemiological surveillance. The current standard for Mycobacterium tuberculosis typing based on IS6110 restriction fragment length polymorphism (RFLP) suffers from the difficulty of comparing data between independent laboratories. Here, we propose a high-resolution typing method based on variable number tandem repeats (VNTRs) of genetic elements named mycobacterial interspersed repetitive units (MIRUs) in 12 human minisatellite-like regions of the M. tuberculosis genome. MIRU-VNTR profiles of 72 different M. tuberculosis isolates were established by PCR analysis of all 12 loci. From 2 to 8 MIRU-VNTR alleles were identified in the 12 regions in these strains, which corresponds to a potential of over 16 million different combinations, yielding a resolution power close to that of IS6110-RFLP. All epidemiologically related isolates tested were perfectly clustered by MIRU-VNTR typing, indicating that the stability of these MIRU-VNTRs is adequate to track outbreak episodes. The correlation between genetic relationships inferred from MIRU-VNTR and IS6110-RFLP typing was highly significant. Compared with IS6110-RFLP, high-resolution MIRU-VNTR typing has the considerable advantages of being fast, appropriate for all M. tuberculosis isolates, including strains that have a few IS6110 copies, and permitting easy and rapid comparison of results from independent laboratories. This typing method opens the way to the construction of digital global databases for molecular epidemiology studies of M. tuberculosis. PMID:11172048

Epidemiological studies of radiation workers in nuclear facilities

International Nuclear Information System (INIS)

Iwai, Satoshi; Semba, Tsuyoshi; Ishida, Kenji; Takagi, Syunji; Igari, Takafumi

2017-01-01

Regarding workers at nuclear facilities, this paper described INWORKS epidemiological research published in 2015, cooperative cohort epidemiological research of IARC 15 countries 10 years before that (15-country study), and the flow of radiation epidemiological research in the period from 15-country study to INWORKS. INWORKS is a retrospective cohort study to investigate the correlation between mortality due to solid cancer, blood cancer, and cardiovascular diseases in workers in three countries of France / the U.K. / the U.S. and low dose exposure through long-term photon external exposure. It obtained the data showing the statistical significance of increased cancer death rate. However, from the subjects of the analysis, no significant evaluation was made on neutron exposure and internal exposure. Statistically significant cancer mortality was confirmed in 15-country study at low dose, low dose rate, and prolonged exposure, but significant cancer mortality rate could not be confirmed excluding Canadian data, which had problems in dose evaluation. In the epidemiological studies of cancer mortality rates of radiation workers in nuclear power industries performed in France / the U.K. / the U.S. in the period ranging from 15-country study to INWORKS, significant difference was not recognized between cancer death rate and excessive relative risk (ERR) compared with LSS epidemiological research studies that handled acute exposure. Several tasks are still remaining. (A.O.)

An Incentivized Approach for Fair Participation in Wireless Ad hoc Networks

OpenAIRE

Choudhuri, Arka Rai; S, Kalyanasundaram; Sridhar, Shriyak; B, Annappa

2015-01-01

In Wireless Ad hoc networks (WANETs), nodes separated by considerable distance communicate with each other by relaying their messages through other nodes. However, it might not be in the best interests of a node to forward the message of another node due to power constraints. In addition, all nodes being rational, some nodes may be selfish, i.e. they might not relay data from other nodes so as to increase their lifetime. In this paper, we present a fair and incentivized approach for participa...

General statistical data structure for epidemiologic studies of DOE workers

International Nuclear Information System (INIS)

Frome, E.L.; Hudson, D.R.

1981-01-01

Epidemiologic studies to evaluate the occupational risks associated with employment in the nuclear industry are currently being conducted by the Department of Energy. Data that have potential value in evaluating any long-term health effects of occupational exposure to low levels of radiation are obtained for each individual at a given facility. We propose a general data structure for statistical analysis that is used to define transformations from the data management system into the data analysis system. Statistical methods of interest in epidemiologic studies include contingency table analysis and survival analysis procedures that can be used to evaluate potential associations between occupational radiation exposure and mortality. The purposes of this paper are to discuss (1) the adequacy of this data structure for single- and multiple-facility analysis and (2) the statistical computing problems encountered in dealing with large populations over extended periods of time

Epidemiological analysis of Leishmania tropica strains and giemsa-stained smears from Syrian and Turkish leishmaniasis patients using multilocus microsatellite typing (MLMT.

Directory of Open Access Journals (Sweden)

Mehmet Karakuş

2017-04-01

Full Text Available Turkey is located in an important geographical location, in terms of the epidemiology of vector-borne diseases, linking Asia and Europe. Cutaneous leishmaniasis (CL is one of the endemic diseases in a Turkey and according to the Ministry Health of Turkey, 45% of CL patients originate from Şanlıurfa province located in southeastern Turkey. Herein, the epidemiological status of CL, caused by L. tropica, in Turkey was examined using multilocus microsatellite typing (MLMT of strains obtained from Turkish and Syrian patients. A total of 38 cryopreserved strains and 20 Giemsa-stained smears were included in the present study. MLMT was performed using 12 highly specific microsatellite markers. Delta K (ΔK calculation and Bayesian statistics were used to determine the population structure. Three main populations (POP A, B and C were identified and further examination revealed the presence of three subpopulations for POP B and C. Combined analysis was performed using the data of previously typed L. tropica strains and Mediterranean and Şanlıurfa populations were identified. This finding suggests that the epidemiological status of L. tropica is more complicated than expected when compared to previous studies. A new population, comprised of Syrian L. tropica samples, was reported for the first time in Turkey, and the data presented here will provide new epidemiological information for further studies.

Epidemiological causality.

Science.gov (United States)

Morabia, Alfredo

2005-01-01

Epidemiological methods, which combine population thinking and group comparisons, can primarily identify causes of disease in populations. There is therefore a tension between our intuitive notion of a cause, which we want to be deterministic and invariant at the individual level, and the epidemiological notion of causes, which are invariant only at the population level. Epidemiologists have given heretofore a pragmatic solution to this tension. Causal inference in epidemiology consists in checking the logical coherence of a causality statement and determining whether what has been found grossly contradicts what we think we already know: how strong is the association? Is there a dose-response relationship? Does the cause precede the effect? Is the effect biologically plausible? Etc. This approach to causal inference can be traced back to the English philosophers David Hume and John Stuart Mill. On the other hand, the mode of establishing causality, devised by Jakob Henle and Robert Koch, which has been fruitful in bacteriology, requires that in every instance the effect invariably follows the cause (e.g., inoculation of Koch bacillus and tuberculosis). This is incompatible with epidemiological causality which has to deal with probabilistic effects (e.g., smoking and lung cancer), and is therefore invariant only for the population.

Optimal JPWL Forward Error Correction Rate Allocation for Robust JPEG 2000 Images and Video Streaming over Mobile Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Benoit Macq

2008-07-01

Full Text Available Based on the analysis of real mobile ad hoc network (MANET traces, we derive in this paper an optimal wireless JPEG 2000 compliant forward error correction (FEC rate allocation scheme for a robust streaming of images and videos over MANET. The packet-based proposed scheme has a low complexity and is compliant to JPWL, the 11th part of the JPEG 2000 standard. The effectiveness of the proposed method is evaluated using a wireless Motion JPEG 2000 client/server application; and the ability of the optimal scheme to guarantee quality of service (QoS to wireless clients is demonstrated.

Epidemiology: Then and Now.

Science.gov (United States)

Kuller, Lewis H

2016-03-01

Twenty-five years ago, on the 75th anniversary of the Johns Hopkins Bloomberg School of Public Health, I noted that epidemiologic research was moving away from the traditional approaches used to investigate "epidemics" and their close relationship with preventive medicine. Twenty-five years later, the role of epidemiology as an important contribution to human population research, preventive medicine, and public health is under substantial pressure because of the emphasis on "big data," phenomenology, and personalized medical therapies. Epidemiology is the study of epidemics. The primary role of epidemiology is to identify the epidemics and parameters of interest of host, agent, and environment and to generate and test hypotheses in search of causal pathways. Almost all diseases have a specific distribution in relation to time, place, and person and specific "causes" with high effect sizes. Epidemiology then uses such information to develop interventions and test (through clinical trials and natural experiments) their efficacy and effectiveness. Epidemiology is dependent on new technologies to evaluate improved measurements of host (genomics), epigenetics, identification of agents (metabolomics, proteomics), new technology to evaluate both physical and social environment, and modern methods of data collection. Epidemiology does poorly in studying anything other than epidemics and collections of numerators and denominators without specific hypotheses even with improved statistical methodologies. © The Author 2015. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Comparison of Efficacy and Safety of Liraglutide 3.0 mg in Individuals with BMI above and below 35 kg/m²: A Post-hoc Analysis

Science.gov (United States)

le Roux, Carel; Aroda, Vanita; Hemmingsson, Joanna; Cancino, Ana Paula; Christensen, Rune; Pi-Sunyer, Xavier

2018-01-01

Objective To investigate whether the efficacy and safety of liraglutide 3.0 mg differed between two subgroups, BMI 27 to 3.0 mg were evaluated by testing the interaction between treatment group and baseline BMI subgroup. Results Significantly greater weight loss (0–56 weeks) was observed with liraglutide 3.0 mg versus placebo in all patient groups while on treatment. There was no evidence that the weight-lowering effect of liraglutide 3.0 mg differed between BMI subgroups (interaction p > 0.05). Similarly, for most secondary endpoints significantly greater improvements were observed with liraglutide 3.0 mg versus placebo, with no indication treatment effects differing between subgroups. The safety profile of liraglutide 3.0 mg was broadly similar across BMI subgroups. Conclusion This post-hoc analysis did not indicate any differences in the treatment effects, or safety profile, of liraglutide 3.0 mg for individuals with BMI 27 to 3.0 mg can therefore be considered for individuals with a BMI of ≥35 as well as for those with a BMI of 27 to <35 kg/m². PMID:29145215

Epidemiology and the Tobacco Epidemic: How Research on Tobacco and Health Shaped Epidemiology.

Science.gov (United States)

Samet, Jonathan M

2016-03-01

In this article, I provide a perspective on the tobacco epidemic and epidemiology, describing the impact of the tobacco-caused disease epidemic on the field of epidemiology. Although there is an enormous body of epidemiologic evidence on the associations of smoking with health, little systematic attention has been given to how decades of research have affected epidemiology and its practice. I address the many advances that resulted from epidemiologic research on smoking and health, such as demonstration of the utility of observational designs and important parameters (the odds ratio and the population attributable risk), guidelines for causal inference, and systematic review approaches. I also cover unintended and adverse consequences for the field, including the strategy of doubt creation and the recruitment of epidemiologists by the tobacco industry to serve its mission. The paradigm of evidence-based action for addressing noncommunicable diseases began with the need to address the epidemic of tobacco-caused disease, an imperative for action documented by epidemiologic research. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Epidemiology applied to health physics

International Nuclear Information System (INIS)

1983-01-01

The technical program of the mid-year meeting of the Health Physics Society, entitled Epidemiology Applied to Health physics, was developed to meet three objectives: (1) give health physicists a deeper understanding of the basics of epidemiological methods and their use in developing standards, regulations, and criteria and in risk assessment; (2) present current reports on recently completed or on-going epidemiology studies; and (3) encourage greater interaction between the health physics and epidemiology disciplines. Included are studies relating methods in epidemiology to radiation protection standards, risk assessment from exposure to bone-seekers, from occupational exposures in mines, mills and nuclear facilities, and from radioactivity in building materials

Toxicology and Epidemiology: Improving the Science with a Framework for Combining Toxicological and Epidemiological Evidence to Establish Causal Inference

Science.gov (United States)

Adami, Hans-Olov; Berry, Sir Colin L.; Breckenridge, Charles B.; Smith, Lewis L.; Swenberg, James A.; Trichopoulos, Dimitrios; Weiss, Noel S.; Pastoor, Timothy P.

2011-01-01

Historically, toxicology has played a significant role in verifying conclusions drawn on the basis of epidemiological findings. Agents that were suggested to have a role in human diseases have been tested in animals to firmly establish a causative link. Bacterial pathogens are perhaps the oldest examples, and tobacco smoke and lung cancer and asbestos and mesothelioma provide two more recent examples. With the advent of toxicity testing guidelines and protocols, toxicology took on a role that was intended to anticipate or predict potential adverse effects in humans, and epidemiology, in many cases, served a role in verifying or negating these toxicological predictions. The coupled role of epidemiology and toxicology in discerning human health effects by environmental agents is obvious, but there is currently no systematic and transparent way to bring the data and analysis of the two disciplines together in a way that provides a unified view on an adverse causal relationship between an agent and a disease. In working to advance the interaction between the fields of toxicology and epidemiology, we propose here a five-step “Epid-Tox” process that would focus on: (1) collection of all relevant studies, (2) assessment of their quality, (3) evaluation of the weight of evidence, (4) assignment of a scalable conclusion, and (5) placement on a causal relationship grid. The causal relationship grid provides a clear view of how epidemiological and toxicological data intersect, permits straightforward conclusions with regard to a causal relationship between agent and effect, and can show how additional data can influence conclusions of causality. PMID:21561883

Post hoc subgroups in clinical trials: Anathema or analytics?

Science.gov (United States)

Weisberg, Herbert I; Pontes, Victor P

2015-08-01

There is currently much interest in generating more individualized estimates of treatment effects. However, traditional statistical methods are not well suited to this task. Post hoc subgroup analyses of clinical trials are fraught with methodological problems. We suggest that the alternative research paradigm of predictive analytics, widely used in many business contexts, can be adapted to help. We compare the statistical and analytics perspectives and suggest that predictive modeling should often replace subgroup analysis. We then introduce a new approach, cadit modeling, that can be useful to identify and test individualized causal effects. The cadit technique is particularly useful in the context of selecting from among a large number of potential predictors. We describe a new variable-selection algorithm that has been applied in conjunction with cadit. The cadit approach is illustrated through a reanalysis of data from the Randomized Aldactone Evaluation Study trial, which studied the efficacy of spironolactone in heart-failure patients. The trial was successful, but a serious adverse effect (hyperkalemia) was subsequently discovered. Our reanalysis suggests that it may be possible to predict the degree of hyperkalemia based on a logistic model and to identify a subgroup in which the effect is negligible. Cadit modeling is a promising alternative to subgroup analyses. Cadit regression is relatively straightforward to implement, generates results that are easy to present and explain, and can mesh straightforwardly with many variable-selection algorithms. © The Author(s) 2015.

[Analysis of projects of infectious disease epidemiology sponsored by National Natural Science Foundation of China].

Science.gov (United States)

Jian-Ming, Wang; Yan-Kai, Xia; Hui-Juan, Zhu; Feng, Chen; Hong-Bing, Shen

2016-05-10

To analyze the projects on the infectious disease epidemiology sponsored by the National Natural Science Foundation of China (NSFC), explore the hotspot and development trend, and offer a reference for researchers in this field. Based on the NSFC database, the projects on the infectious disease epidemiology (H2609) sponsored from 1987 to 2014 were analyzed. The changes of fund numbers, amounts and research fields were described. During the study period, NSFC sponsored 373 projects, including 228 general projects (61.1%), 78 youth projects (20.9%) and 67 other projects (18.0%). The average amount of the grant was 358.2 thousand Yuan (20 thousand-8 million). The main sponsored research fields were mechanisms of pathogen and immunity (36.2%) and population-based epidemiological studies (33.0%). The top three diseases were hepatitis, HIV/AIDS and tuberculosis. The amount of funding on researches of infectious disease epidemiology has increased continuously, which has played an important role in training scientific talents in the field of prevention and control of infectious diseases.

Transforming Epidemiology for 21st Century Medicine and Public Health

Science.gov (United States)

Khoury, Muin J.; Lam, Tram Kim; Ioannidis, John P.A.; Hartge, Patricia; Spitz, Margaret R.; Buring, Julie E.; Chanock, Stephen J.; Croyle, Robert T.; Goddard, Katrina A.; Ginsburg, Geoffrey S.; Herceg, Zdenko; Hiatt, Robert A.; Hoover, Robert N.; Hunter, David J.; Kramer, Barnet S.; Lauer, Michael S.; Meyerhardt, Jeffrey A.; Olopade, Olufunmilayo I.; Palmer, Julie R.; Sellers, Thomas A.; Seminara, Daniela; Ransohoff, David F.; Rebbeck, Timothy R.; Tourassi, Georgia; Winn, Deborah M.; Zauber, Ann; Schully, Sheri D.

2013-01-01

In 2012, the National Cancer Institute (NCI) engaged the scientific community to provide a vision for cancer epidemiology in the 21st century. Eight overarching thematic recommendations, with proposed corresponding actions for consideration by funding agencies, professional societies, and the research community emerged from the collective intellectual discourse. The themes are (i) extending the reach of epidemiology beyond discovery and etiologic research to include multilevel analysis, intervention evaluation, implementation, and outcomes research; (ii) transforming the practice of epidemiology by moving towards more access and sharing of protocols, data, metadata, and specimens to foster collaboration, to ensure reproducibility and replication, and accelerate translation; (iii) expanding cohort studies to collect exposure, clinical and other information across the life course and examining multiple health-related endpoints; (iv) developing and validating reliable methods and technologies to quantify exposures and outcomes on a massive scale, and to assess concomitantly the role of multiple factors in complex diseases; (v) integrating “big data” science into the practice of epidemiology; (vi) expanding knowledge integration to drive research, policy and practice; (vii) transforming training of 21st century epidemiologists to address interdisciplinary and translational research; and (viii) optimizing the use of resources and infrastructure for epidemiologic studies. These recommendations can transform cancer epidemiology and the field of epidemiology in general, by enhancing transparency, interdisciplinary collaboration, and strategic applications of new technologies. They should lay a strong scientific foundation for accelerated translation of scientific discoveries into individual and population health benefits. PMID:23462917

Perceptions of molecular epidemiology studies of HIV among stakeholders

Directory of Open Access Journals (Sweden)

Cynthia Schairer

2017-12-01

Full Text Available Background: Advances in viral sequence analysis make it possible to track the spread of infectious pathogens, such as HIV, within a population. When used to study HIV, these analyses (i.e., molecular epidemiology potentially allow inference of the identity of individual research subjects. Current privacy standards are likely insufficient for this type of public health research. To address this challenge, it will be important to understand how stakeholders feel about the benefits and risks of such research. Design and Methods: To better understand perceived benefits and risks of these research methods, in-depth qualitative interviews were conducted with HIV-infected individuals, individuals at high-risk for contracting HIV, and professionals in HIV care and prevention. To gather additional perspectives, attendees to a public lecture on molecular epidemiology were asked to complete an informal questionnaire. Results: Among those interviewed and polled, there was near unanimous support for using molecular epidemiology to study HIV. Questionnaires showed strong agreement about benefits of molecular epidemiology, but diverse attitudes regarding risks. Interviewees acknowledged several risks, including privacy breaches and provocation of anti-gay sentiment. The interviews also demonstrated a possibility that misunderstandings about molecular epidemiology may affect how risks and benefits are evaluated. Conclusions: While nearly all study participants agree that the benefits of HIV molecular epidemiology outweigh the risks, concerns about privacy must be addressed to ensure continued trust in research institutions and willingness to participate in research.

Deep vein thrombosis and the oestrogen content in oral contraceptives. An epidemiological analysis.

Science.gov (United States)

Kierkegaard, A

1985-01-01

Epidemiological studies have pointed to a correlation between the oestrogen content of oral contraceptives and the risk of deep vein thrombosis (DVT). The correlation has been strongest in studies which partially consisted of adverse drug reaction reports to the Swedish Adverse Drug Reaction Advisory Committee (SADRAC). The present study analyzes the epidemiological basis of the adverse drug reaction reports on DVT in women on oral contraceptives to SADRAC. It verifies the reported correlation between the oestrogen content of the pills and the risk of DVT but it also demonstrates that this correlation probably was secondary to differences in the diagnostic standard of DVT, to differences in reporting policies to SADRAC and to an age difference between women on low-oestrogen-pills and those on high-oestrogen pills and is thus due to bias. It is concluded that adverse drug reaction reporting on oral contraceptives has been very unreliable, for which reason it cannot support any epidemiological conclusion concerning the relative thrombogenicity of high-oestrogen pills compared with that of low-oestrogen pills.

PROTOCOLS FOR INCREASING THE LIFETIME OF NODES OF AD HOC WIRELESS NETWORKS

Directory of Open Access Journals (Sweden)

B.Malarkodi

2010-03-01

Full Text Available Power consumption of nodes in ad hoc networks is a critical issue as they predominantly operate on batteries. In order to improve the lifetime of an ad hoc network, all the nodes must be utilized evenly and the power required for connections must be minimized. Energy management deals with the process of managing energy resources by means of controlling the battery discharge, adjusting the transmission power and scheduling of power sources so as to increase the lifetime of the nodes of an ad hoc wireless network. In this paper, two protocols are proposed to improve the lifetime of the nodes. The first protocol assumes smart battery packages with L cells and uses dynamic programming (DP to optimally select the set of cells used to satisfy a request for power. The second one proposes a MAC layer protocol denoted as Power Aware medium Access Control (PAMAC protocol which enables the network layer to select a route with minimum total power requirement among the possible routes between a source and a destination provided all nodes in the routes have battery capacity above a threshold. The life time of the nodes using the DP based scheduling policy is found through simulation and compared with that obtained using the techniques reported in the literature. It is found that DP based policy increases the lifetime of the mobile nodes by a factor of 1.15 to 1.8. The life expectancy, the average power consumption and throughput of the network using PAMAC protocol are computed through simulation and compared with that of the other MAC layer protocols 802.11, MACA, and CSMA. Besides this, the life expectancy and average power consumption of the network for different values of threshold are also compared. From the simulation results, it is observed that PAMAC consumes the least power and provides the longest lifetime among the various MAC Layer protocols. Moreover, using PAMAC as the MAC layer protocol, the performance obtained using different routing layer

Comunicaciones seguras sobre redes móviles ad hoc

OpenAIRE

Rocabado Moreno, Sergio Hernán; Arias Figueroa, Daniel; Sánchez, Ernesto

2011-01-01

En este proyecto se ha planteado investigar diferentes mecanismos para realizar comunicaciones seguras utilizando redes móviles ad-hoc, esto permitirá aprovechar las características inherentes de este tipo de redes, para llevar información crítica de forma segura a lugares donde no se disponga de acceso a redes de infraestructura. El resultado final será una propuesta que servirá de base para el desarrollo e implementación de sistemas móviles para emergencias médicas y también como material d...

A Partitioned Approach to Signal Separation with Microphone Ad Hoc Arrays

DEFF Research Database (Denmark)

Tavakoli, Vincent Mohammad; Jensen, Jesper Rindom; Benesty, Jacob

2016-01-01

In this paper, a blind algorithm is proposed for speech enhancement in multi-speaker scenarios, in which interference rejection is the main objective. Here, the ad hoc array is broken into microphone duples which are used to partition the array into local sub-arrays. The core algorithm takes...... advantage of differences in signal structure in each duple. A geometric mean filter is then used to merge the output signals obtained with different duples, and to form a global broadband maximum signal-to-interference ratio (SIR) enhancement apparatus. The resulting filter outputs are enhanced acoustic...

Increased longevity of wireless Ad hoc network through fuzzy system

Directory of Open Access Journals (Sweden)

Fawzia Abdali Larki

2014-06-01

Full Text Available The Ad hoc network is one of the multistep-based self-organizing networks, which are dynamically changing and are taken more into account as the ways of connecting the terminals through the development of wireless communication terminals. We are faced with numerous challenges in designing a wireless network such as the dynamic topology, common and limited bandwidth, and the limited energy. The nodes are moving according to the continuous changes in the topology and the source-to-destination paths are completely broken. Therefore, the repeated route discovery enhances the delay and overload of routing. Thus, it is essential to consider the link stability while designing the path in order to choose the routing protocol. Providing the multiple paths may lead to the better performance than a path. The transmission energy control in the wireless Ad hoc networks is the option for the level of transmission energy in order to transmit each node packet in this system. Therefore, transmission energy control affects the wireless medium interface. Because of choosing the appropriate protocol, the routing operation can be improved and the energy consumption can be controlled properly as well as enhancing the durability and longevity of network. The main objective of this study is to enhance the network longevity. The proposed algorithm in this research considers the combination of 2 parameters including the rate of node energy and number of steps in Fuzzy System applied on AOMDV Protocol, which is a Multipath Routing Protocol. The results of simulation also indicate the improved performance of proposed algorithm (AOMDV-F compared to AODV and AOMDV Protocols in NS2 simulator.

A Systematic Bayesian Integration of Epidemiological and Genetic Data

Science.gov (United States)

Lau, Max S. Y.; Marion, Glenn; Streftaris, George; Gibson, Gavin

2015-01-01

Genetic sequence data on pathogens have great potential to inform inference of their transmission dynamics ultimately leading to better disease control. Where genetic change and disease transmission occur on comparable timescales additional information can be inferred via the joint analysis of such genetic sequence data and epidemiological observations based on clinical symptoms and diagnostic tests. Although recently introduced approaches represent substantial progress, for computational reasons they approximate genuine joint inference of disease dynamics and genetic change in the pathogen population, capturing partially the joint epidemiological-evolutionary dynamics. Improved methods are needed to fully integrate such genetic data with epidemiological observations, for achieving a more robust inference of the transmission tree and other key epidemiological parameters such as latent periods. Here, building on current literature, a novel Bayesian framework is proposed that infers simultaneously and explicitly the transmission tree and unobserved transmitted pathogen sequences. Our framework facilitates the use of realistic likelihood functions and enables systematic and genuine joint inference of the epidemiological-evolutionary process from partially observed outbreaks. Using simulated data it is shown that this approach is able to infer accurately joint epidemiological-evolutionary dynamics, even when pathogen sequences and epidemiological data are incomplete, and when sequences are available for only a fraction of exposures. These results also characterise and quantify the value of incomplete and partial sequence data, which has important implications for sampling design, and demonstrate the abilities of the introduced method to identify multiple clusters within an outbreak. The framework is used to analyse an outbreak of foot-and-mouth disease in the UK, enhancing current understanding of its transmission dynamics and evolutionary process. PMID:26599399

Epidemiological Characteristics and Space-Time Analysis of the 2015 Dengue Outbreak in the Metropolitan Region of Tainan City, Taiwan.

Science.gov (United States)

Chuang, Ting-Wu; Ng, Ka-Chon; Nguyen, Thi Luong; Chaves, Luis Fernando

2018-02-26

The metropolitan region of Tainan City in southern Taiwan experienced a dengue outbreak in 2015. This manuscript describes basic epidemiological features of this outbreak and uses spatial and temporal analysis tools to understand the spread of dengue during the outbreak. The analysis found that, independently of gender, dengue incidence rate increased with age, and proportionally affected more males below the age of 40 years but females above the age of 40 years. A spatial scan statistic was applied to detect clusters of disease transmission. The scan statistic found that dengue spread in a north-south diffusion direction, which is across the North, West-Central and South districts of Tainan City. Spatial regression models were used to quantify factors associated with transmission. This analysis indicated that neighborhoods with high proportions of residential area (or low wetland cover) were associated with dengue transmission. However, these association patterns were non-linear. The findings presented here can help Taiwanese public health agencies to understand the fundamental epidemiological characteristics and diffusion patterns of the 2015 dengue outbreak in Tainan City. This type of information is fundamental for policy making to prevent future uncontrolled dengue outbreaks, given that results from this study suggest that control interventions should be emphasized in the North and West-Central districts of Tainan city, in areas with a moderate percentage of residential land cover.

Molecular Epidemiology of Brucella abortus in Northern Ireland-1991 to 2012.

Directory of Open Access Journals (Sweden)

Adrian Allen

Full Text Available Brucellosis is the most common bacterial zoonoses worldwide. Bovine brucellosis caused by Brucella abortus has far reaching animal health and economic impacts at both the local and national levels. Alongside traditional veterinary epidemiology, the use of molecular typing has recently been applied to inform on bacterial population structure and identify epidemiologically-linked cases of infection. Multi-locus variable number tandem repeat VNTR analysis (MLVA was used to investigate the molecular epidemiology of a well-characterised Brucella abortus epidemic in Northern Ireland involving 387 herds between 1991 and 2012.MLVA identified 98 unique B. abortus genotypes from disclosing isolates in the 387 herds involved in the epidemic. Clustering algorithms revealed the relatedness of many of these genotypes. Combined with epidemiological information on chronology of infection and geographic location, these genotype data helped to identify 7 clonal complexes which underpinned the outbreak over the defined period. Hyper-variability of some VNTR loci both within herds and individual animals led to detection of multiple genotypes associated with single outbreaks. However with dense sampling, these genotypes could still be associated with specific clonal complexes thereby permitting inference of epidemiological links. MLVA- based epidemiological monitoring data were congruent with an independent classical veterinary epidemiology study carried out in the same territory.MLVA is a useful tool in ongoing disease surveillance of B. abortus outbreaks, especially when combined with accurate epidemiological information on disease tracings, geographical clustering of cases and chronology of infection.

"Schmallenberg" virus: Analysis of the Epidemiological Data and Assessment of Impact

DEFF Research Database (Denmark)

Balenghien, Thomas; Bødker, Rene; Bøtner, Anette

by laboratory testing across several Member States, mid May 2012. EFSA reviewed the epidemiological reports noting that SBV has been detected in cattle, sheep, goats and a bison. SBV antibodies have been detected in deer and no other species are known to be affected. EFSA also confirms that new studies support....... Currently there is no evidence of any other route of transmission other than transplacental or vector borne routes. EFSA coordinated the collation of SBV epidemiological data during 2011-2012 in order to obtain comparable data for Europe. The maximum proportion of reported sheep holdings with SBV confirmed...... hydranencephaly syndrome cases) three models were used. In regions with SBV confirmed holdings, assuming a high prevalence of infection and post infection immunity, impact in the 2012-2013 calving and lambing season should be low. However, assuming SBV survived the winter of 2011, the models suggest...

Undilatable Stent Neoatherosclerosis Treated with Ad Hoc Rotational Atherectomy

Directory of Open Access Journals (Sweden)

Michael Koutouzis

2017-01-01

Full Text Available A middle age woman with known ischemic heart disease and old stents in proximal left anterior descending coronary artery (LAD was admitted to Coronary Care Unit with acute coronary syndrome. The coronary angiography showed one vessel disease with significant restenosis within the previously implanted stents. The lesion was tough and remained undilatable despite high pressure balloon inflation. Eventually, the balloon ruptured creating a massive dissection of the LAD beginning immediately after the distal part of the undilatable lesion. We proceeded with a challenging ad hoc rotational atherectomy of the lesion and finally stenting of the lesion. In-stent restenosis many years after stent implantation is considered to be mainly due to neoatheromatosis compared to intimal hyperplasia, making lesion treatment more difficult and unpredictable.

Topology for efficient information dissemination in ad-hoc networking

Science.gov (United States)

Jennings, E.; Okino, C. M.

2002-01-01

In this paper, we explore the information dissemination problem in ad-hoc wirless networks. First, we analyze the probability of successful broadcast, assuming: the nodes are uniformly distributed, the available area has a lower bould relative to the total number of nodes, and there is zero knowledge of the overall topology of the network. By showing that the probability of such events is small, we are motivated to extract good graph topologies to minimize the overall transmissions. Three algorithms are used to generate topologies of the network with guaranteed connectivity. These are the minimum radius graph, the relative neighborhood graph and the minimum spanning tree. Our simulation shows that the relative neighborhood graph has certain good graph properties, which makes it suitable for efficient information dissemination.

CEDR: Comprehensive Epidemiologic Data Resource

Energy Technology Data Exchange (ETDEWEB)

1993-08-01

The Department of Energy (DOE) and its predecessor agencies have a long history of epidemiologic research programs. The main focus of these programs has been the Health and Mortality Study of the DOE work force. This epidemiologic study began in 1964 with a feasibility study of workers at the Hanford facility. Studies of other populations exposed to radiation have also been supported, including the classic epidemiologic study of radium dial painters and studies of atomic bomb survivors. From a scientific perspective, these epidemiologic research program have been productive, highly credible, and formed the bases for many radiological protection standards. Recently, there has been concern that, although research results were available, the data on which these results were based were not easily obtained by interested investigators outside DOE. Therefore, as part of an effort to integrate and broaden access to its epidemiologic information, the DOE has developed the Comprehensive Epidemiologic Data Resource (CEDR) Program. Included in this effort is the development of a computer information system for accessing the collection of CEDR data and its related descriptive information. The epidemiologic data currently available through the CEDAR Program consist of analytic data sets, working data sets, and their associated documentation files. In general, data sets are the result of epidemiologic studies that have been conducted on various groups of workers at different DOE facilities during the past 30 years.

Verifying Safety Messages Using Relative-Time and Zone Priority in Vehicular Ad Hoc Networks

Science.gov (United States)

Banani, Sam; Thiemjarus, Surapa; Kittipiyakul, Somsak

2018-01-01

In high-density road networks, with each vehicle broadcasting multiple messages per second, the arrival rate of safety messages can easily exceed the rate at which digital signatures can be verified. Since not all messages can be verified, algorithms for selecting which messages to verify are required to ensure that each vehicle receives appropriate awareness about neighbouring vehicles. This paper presents a novel scheme to select important safety messages for verification in vehicular ad hoc networks (VANETs). The proposed scheme uses location and direction of the sender, as well as proximity and relative-time between vehicles, to reduce the number of irrelevant messages verified (i.e., messages from vehicles that are unlikely to cause an accident). Compared with other existing schemes, the analysis results show that the proposed scheme can verify messages from nearby vehicles with lower inter-message delay and reduced packet loss and thus provides high level of awareness of the nearby vehicles. PMID:29652840

Epidemiology of invasive meningococcal disease in the Netherlands, 1960-2012: an analysis of national surveillance data

NARCIS (Netherlands)

Bijlsma, Merijn W.; Bekker, Vincent; Brouwer, Matthijs C.; Spanjaard, Lodewijk; van de Beek, Diederik; van der Ende, Arie

2014-01-01

Epidemiological data for invasive meningococcal disease is essential for public health policy and vaccine development. We analysed national surveillance data from the Netherlands for PorA coverage of two PorA-based meningococcal serogroup B vaccines to describe the epidemiology of invasive

International Lymphoma Epidemiology Consortium

Science.gov (United States)

The InterLymph Consortium, or formally the International Consortium of Investigators Working on Non-Hodgkin's Lymphoma Epidemiologic Studies, is an open scientific forum for epidemiologic research in non-Hodgkin's lymphoma.

An introduction to mathematical epidemiology

CERN Document Server

Martcheva, Maia

2015-01-01

The book is a comprehensive, self-contained introduction to the mathematical modeling and analysis of infectious diseases. It includes model building, fitting to data, local and global analysis techniques. Various types of deterministic dynamical models are considered: ordinary differential equation models, delay-differential equation models, difference equation models, age-structured PDE models and diffusion models. It includes various techniques for the computation of the basic reproduction number as well as approaches to the epidemiological interpretation of the reproduction number. MATLAB code is included to facilitate the data fitting and the simulation with age-structured models.

Ad-hoc Network of Smart Sensors for Mechanical Load Measurement

Directory of Open Access Journals (Sweden)

Manuel A. Vieira

2016-07-01

Full Text Available Strain gauges load cells are transducers devices capable of converting changes in applied mechanical load into an electrical analog signal. Those devices have a large spectrum of applications ranging from domestic to industrial or even medical appliances just to name a few. In this work, they are used in the electronic instrumentation of a force platform that will be used to carry out the analysis and characterization of human biomechanical walking. In this platform, four load cells are installed, each one capable of measuring forces along two different axis. A total of eight strain-gauges per load cell are employed. Hence, analog signal transmission, besides requiring a large number of connection wires, is prone to interference and noise. Moreover, with this solution, scalability requires severe changes in the connection topology. In order to circumvent those problems, an alternative in-situ signal conditioning and digital data transmission system was devised. This approach, as far as investigated, presents an innovative solution to signal conditioning and data transmission for load-cells. In particular, the presented solution allows the creation of an ad-hoc network of load cells, using the I²C protocol with a master interface that allows the users to interact and change the parameters of each load cell. This instrumentation structure has been successfully tested and the obtained results are documented in this article.

A bibliometric analysis in the fields of preventive medicine, occupational and environmental medicine, epidemiology, and public health

Directory of Open Access Journals (Sweden)

Soteriades Elpidoforos S

2006-12-01

Full Text Available Abstract Background Research in the fields of Preventive Medicine, Occupational/Environmental Medicine, Epidemiology and Public Health play an important role in the advancement of knowledge. In order to map the research production around the world we performed a bibliometric analysis in the above fields. Methods All articles published by different world regions in the above mentioned scientific fields and cited in the Journal Citation Reports (JCR database of the Institute for Scientific Information (ISI during the period 1995 and 2003, were evaluated. The research production of different world regions was adjusted for: a the gross domestic product in 1995 US dollars, and b the population size of each region. Results A total of 48,861 articles were retrieved and categorized. The USA led the research production in all three subcategories. The percentage of articles published by USA researchers was 43%, 44% and 61% in the Preventive Medicine, Epidemiology, and Public Health subcategories, respectively. Canada and Western Europe shared the second position in the first two subcategories, while Oceania researchers ranked second in the field of Public Health. Conclusion USA researchers maintain a leadership position in the production of scientific articles in the fields of Preventive Medicine, Occupational/Environmental Medicine and Epidemiology, at a level similar to other scientific disciplines, while USA contribution to science in the field of Public Health is by all means outstanding. Less developed regions would need to support their researchers in the above fields in order to improve scientific production and advancement of knowledge in their countries.

Analysis of dose record and epidemiology for radiation workers in Korea

International Nuclear Information System (INIS)

Choi, S.Y.; Kim, T.H.

2003-01-01

This study presents data on the externally received doses and preliminary results of epidemiological survey for radiation workers. The statistical analysis was carried out in order to understand better the occupational radiation doses in Korea. Records containing dose information from 1984 to 1999 for 64,518 persons were extracted from the National Dose Registry of Korea (Korea Radioisotope Association's personal dose record). The total number of workers registered from 1984 to 1999 was 64,518. The number of workers steadily increased and the accumulated dose somewhat increased. The proportion of radiation workers by occupation was 38.4% for nuclear power plant, 20.3% for industrial organization and 12.4% for non-destructive industry, respectively. The collective annual dose of radiation workers was 31.72 man Sv in 1999. The mean annual dose by sex was 1.49 mSv for male and 0.56 mSv for female. The mean annual dose for workers was 1.41 mSv with the highest mean dose being received by non-destructive industry (3.53 mSv). Very few workers(0.8%) received more than 20 mSv and only one more than 50 mSv, the legal limit for an annual dose. There has been a steady decline in the mean dose since 1984, showing a significant decrease in dose with time. The data showed that radiation protection in Korea was improving, though annual doses were still higher than other countries. Nevertheless, this finding brings to light the necessity of the workers to pay more careful attention to radiation protection procedures and practices, and suggest the need for continuous effort to implement procedures. We are carrying out epidemiological survey in order to evaluate radiation effects on Korean workers based on radiation dose data from the year of 2000. Follow-up is carrying out in order to detect and measure directly the risks of cancer using the Korean Mortality Data, Cancer Registry and individual investigation

ARSENAL: A Cross Layer Architecture for Secure Resilient Tactical Mobile AdHoc Networks

Science.gov (United States)

2016-01-21

stations separated by 0.5 to 1 km can be coherently measured to a single mobile subscriber using LTE signaling. These are the first measurements of...undertake three parallel but inter-coupled tasks geared towards a) performing measurements via real deployments and enhancing our understanding of layer...dependencies and vulnerabilities in mobile ad hoc networks; these measurements will be on existing testbeds at The views, opinions and/or findings

Estudio de la topología y protocolos de una red móvil ad-hoc

OpenAIRE

Albalat Montenegro, Bruno

2010-01-01

This project intends to describe how a basic messaging application that, using ad-hoc networks, supports delay tolerance, has been created. Its purpose is to serve as a basis for research groups to be able to work over it for their testing purposes.

MQARR-AODV: A NOVEL MULTIPATH QOS AWARE RELIABLE REVERSE ON-DEMAND DISTANCE VECTOR ROUTING PROTOCOL FOR MOBILE AD-HOC NETWORKS

Directory of Open Access Journals (Sweden)

K.G. Santhiya

2012-12-01

Full Text Available MANET (Mobile Ad-hoc Network is an infra structure less wireless ad-hoc network that does not require any basic central control. The topology of the network changes drastically due to very fast mobility of nodes. So an adaptive routing protocol is needed for routing in MANET. AODV (Ad-hoc On-demand Distance Vector routing is the effective and prominent on-demand Ad-hoc routing protocols. During route establishment phase in traditional AODV, only one route reply message will be sent in the reverse path to establish routing path. The high mobility of nodes may affect the reply messages which lead to the retransmission of route request message by the sender which in turn leads to higher communication delay, power consumption and the reduction in the ratio of packets delivered. Sending multiple route reply messages and establishing multiple paths in a single path discovery will reduce the routing overhead involved in maintaining the connection between source and destination nodes. Multipath routing can render high scalability, end-to-end throughput and provide load balancing in MANET. The new proposed novel Multipath QoS aware reliable routing protocol establishes two routes of maximum node disjoint paths and the data transfer is carried out in the two paths simultaneously. To select best paths, the new proposed protocol uses three parameters Link Eminence, MAC overhead and node residual energy. The experimental values prove that the MQARR-AODV protocol achieves high reliability, stability, low latency and outperforms AODV by the less energy consumption, overhead and delay.

Against Popperized epidemiology.

Science.gov (United States)

Jacobsen, M

1976-03-01

The recommendation of Popper's philosophy of science should be adopted by epidemiologists is disputed. Reference is made to other authors who have shown that the most constructive elements in Popper's ideas have been advocated by earlier philosophers and have been used in epidemiology without abandoning inductive reasoning. It is argued that Popper's denigration of inductive methods is particularly harmful to epidemiology. Inductive reasoning and statistical inference play a key role in the science; it is suggested that unfamiliarity with these ideas contributes to widespread misunderstanding of the function of epidemiology. Attention is drawn to a common fallacy involving correlations between three random variables. The prevalence of the fallacy may be related to confusion between deductive and inductive logic.

Development and application of Human Genome Epidemiology

Science.gov (United States)

Xu, Jingwen

2017-12-01

Epidemiology is a science that studies distribution of diseases and health in population and its influencing factors, it also studies how to prevent and cure disease and promote health strategies and measures. Epidemiology has developed rapidly in recent years and it is an intercross subject with various other disciplines to form a series of branch disciplines such as Genetic epidemiology, molecular epidemiology, drug epidemiology and tumor epidemiology. With the implementation and completion of Human Genome Project (HGP), Human Genome Epidemiology (HuGE) has emerged at this historic moment. In this review, the development of Human Genome Epidemiology, research content, the construction and structure of relevant network, research standards, as well as the existing results and problems are briefly outlined.

Molecular epidemiology of measles virus in Italy during 2008

Directory of Open Access Journals (Sweden)

Fabio Magurano

2013-03-01

Full Text Available INTRODUCTION. In view of the goal of measles elimination, it is of great importance to assess the circulation of wild-type measles virus (MV. Genetic analysis is indispensable to understand the epidemiology of measles. A large measles outbreak occurred in Italy in 2008, with over 4000 cases reported to the enhanced measles surveillance system introduced in 2007, 37% of which were laboratory confirmed. METHODS. Urine and saliva samples were collected during 2008. A phylogenetic analysis of measles sequences was performed in order to understand the epidemiological situation of wild-type (MV circulation in that period. RESULT AND DISCUSSION. Data showed predominant circulation of the genotype D4. Genotypes A, D8, D9 and H1 were also detected in a small number of samples, probably representing imported cases.

Automated Dental Epidemiology System. II. Systems Analysis and Functional Design,

Science.gov (United States)

1983-08-01

involvement or debilitating soft tissue pathology (e.g., pericoronitis or periodontal abscess ). Therefore it is desired that urgently needed treatment...through the naval population. Developing this kind of information requires extensive use of dental epidemiology. The incidence of caries and periodontal ...Navy Dental Corps efforts toward reducing the incidence and detrimental effects of caries and periodontal disease in the field and afloat. In this

Accidents, disasters and crisis: contribution of epidemiology in the nuclear field

International Nuclear Information System (INIS)

Verger, P.; Bard, D.; Hubert, P.

1995-01-01

The experience of the Chernobyl accident has shown the necessity of being prepared for epidemiological assessment of the health consequences of a nuclear or a radiological accident. We discuss the contribution of epidemiology in such situations, in addition to the existing tools designed to assess or manage radiological risks. From a decisional point of view, three issues are distinguished: the protection of the different population groups against ionizing radiations, the achievement of health care and the communication with the public and media. We discuss the input of epidemiological tools in both perspectives. Epidemiology may also contribute to the analysis of health events that may be observed after an accident, i.e. to assess whether these events are not statistical artifacts, whether they are an effect of the exposure to ionizing radiations or a non specific consequence of any accident. Finally, epidemiological studies should be carried out to improve our knowledge on ionizing radiations effects with a special consideration given to the dose-effect relationships. Examples of past nuclear accidents are used to discuss these issues. The last part of this paper is focused on different research issues that should be developed for preparing epidemiological plans for nuclear accidents. (Author). 48 refs., 1 fig., 3 tabs

Improving TCP Performance over Wireless Ad Hoc Networks with Busy Tone Assisted Scheme

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Cai Lin

2006-01-01

Full Text Available It is well known that transmission control protocol (TCP performance degrades severely in IEEE 802.11-based wireless ad hoc networks. We first identify two critical issues leading to the TCP performance degradation: (1 unreliable broadcast, since broadcast frames are transmitted without the request-to-send and clear-to-send (RTS/CTS dialog and Data/ACK handshake, so they are vulnerable to the hidden terminal problem; and (2 false link failure which occurs when a node cannot successfully transmit data temporarily due to medium contention. We then propose a scheme to use a narrow-bandwidth, out-of-band busy tone channel to make reservation for broadcast and link error detection frames only. The proposed scheme is simple and power efficient, because only the sender needs to transmit two short messages in the busy tone channel before sending broadcast or link error detection frames in the data channel. Analytical results show that the proposed scheme can dramatically reduce the collision probability of broadcast and link error detection frames. Extensive simulations with different network topologies further demonstrate that the proposed scheme can improve TCP throughput by 23% to 150%, depending on user mobility, and effectively enhance both short-term and long-term fairness among coexisting TCP flows in multihop wireless ad hoc networks.

Immune Status and Epidemiological Characteristics of Human Immunodeficiency Virus Seroconverters in Korea, 1999–2009

OpenAIRE

Wang, Jin-Sook; Kim, Na-young; Sim, Hyo Jung; Choi, Byeong-Sun; Kee, Mee-Kyung

2012-01-01

Objectives The detection of HIV seroconverters increased annually since HIV antigen/antibody testing kits have been available widely in South Korea. This study aimed to identify the epidemiological characteristics of HIV seroconverters and their immune level at HIV diagnosis. Method We analyzed the epidemiological and immunological characteristics of 341 HIV seroconverters among 6,008 HIV-diagnosed individuals from 1999 and 2009. The analysis of immune level and epidemiological factors of HIV...

Epidemiology and 'developing countries': writing pesticides, poverty and political engagement in Latin America.

Science.gov (United States)

Brisbois, Ben W

2014-08-01

The growth of the field of global health has prompted renewed interest in discursive aspects of North-South biomedical encounters, but analysis of the role of disciplinary identities and writing conventions remains scarce. In this article, I examine ways of framing pesticide problems in 88 peer-reviewed epidemiology papers produced by Northerners and their collaborators studying pesticide-related health impacts in Latin America. I identify prominent geographic frames in which truncated and selective histories of Latin America are used to justify research projects in specific research sites, which nevertheless function rhetorically as generic 'developing country' settings. These frames legitimize health sector interventions as solutions to pesticide-related health problems, largely avoiding more politically charged possibilities. In contrast, some epidemiologists appear to be actively pushing the bounds of epidemiology's traditional journal article genre by engaging with considerations of political power, especially that of the international pesticide industry. I therefore employ a finer-grained analysis to a subsample of 20 papers to explore how the writing conventions of epidemiology interact with portrayals of poverty and pesticides in Latin America. Through analysis of a minor scientific controversy, authorial presence in epidemiology articles, and variance of framing strategies across genres, I show how the tension between 'objectivity' and 'advocacy' observed in Northern epidemiology and public health is expressed in North-South interaction. I end by discussing implications for postcolonial and socially engaged approaches to science and technology studies, as well as their relevance to the actual practice of global health research. In particular, the complicated interaction of the conflicted traditions of Northern epidemiology with Latin American settings on paper hints at a far more complex interaction in the form of public health programming involving

Statistical significance of epidemiological data. Seminar: Evaluation of epidemiological studies

International Nuclear Information System (INIS)

Weber, K.H.

1993-01-01

In stochastic damages, the numbers of events, e.g. the persons who are affected by or have died of cancer, and thus the relative frequencies (incidence or mortality) are binomially distributed random variables. Their statistical fluctuations can be characterized by confidence intervals. For epidemiologic questions, especially for the analysis of stochastic damages in the low dose range, the following issues are interesting: - Is a sample (a group of persons) with a definite observed damage frequency part of the whole population? - Is an observed frequency difference between two groups of persons random or statistically significant? - Is an observed increase or decrease of the frequencies with increasing dose random or statistically significant and how large is the regression coefficient (= risk coefficient) in this case? These problems can be solved by sttistical tests. So-called distribution-free tests and tests which are not bound to the supposition of normal distribution are of particular interest, such as: - χ 2 -independence test (test in contingency tables); - Fisher-Yates-test; - trend test according to Cochran; - rank correlation test given by Spearman. These tests are explained in terms of selected epidemiologic data, e.g. of leukaemia clusters, of the cancer mortality of the Japanese A-bomb survivors especially in the low dose range as well as on the sample of the cancer mortality in the high background area in Yangjiang (China). (orig.) [de

Neuroprotection as initial therapy in acute stroke - Third report of an Ad Hoc Consensus Group Meeting

NARCIS (Netherlands)

Bogousslavsky, J; De Keyser, J; Diener, HC; Fieschi, C; Hacke, W; Kaste, M; Orgogozo, JM; Pulsinelli, W; Wahlgren, NG

1998-01-01

Although a considerable body of scientific data is now available on neuroprotection in acute ischaemic stroke, this field is not yet established in clinical practice. At its third meeting, the European Ad Hoc Consensus Group considered the potential for neuroprotection in acute stroke and the

The doctrine of joint criminal action in the ad hoc tribunals and its scope in the Rome Statute

Directory of Open Access Journals (Sweden)

Miren Odriozola-Gurrutxaga

2014-03-01

Full Text Available The first judgment of the International Criminal Court has confirmed that article 25 (3 of the Rome Statute adopts the theory of control of the act to distinguish between principals and accessories. On the contrary, since 2003, the ad hoc tribunals’ case law bases the notion of co-perpetration on the Joint Criminal Enterprise doctrine, using a subjective criterion approach. In this article we will first analyze the problems raised by that case law of the ad hoc tribunals, and then, we will study the article of the Rome Statute which apparently most resembles the Joint Criminal Enterprise doctrine: article 25 (3 (d. The article concludes that none of the three categories of that doctrine is included in the said provision.

The combination of phylogenetic analysis with epidemiological and serological data to track HIV-1 transmission in a sexual transmission case.

Directory of Open Access Journals (Sweden)

Min Chen

Full Text Available To investigate the linkage of HIV transmission from a man to a woman through unprotected sexual contact without disclosing his HIV-positive status.Combined with epidemiological information and serological tests, phylogenetic analysis was used to test the a priori hypothesis of HIV transmission from the man to the woman. Control subjects, infected with HIV through heterosexual intercourse, from the same location were also sampled. Phylogenetic analyses were performed using the consensus gag, pol and env sequences obtained from blood samples of the man, the woman and the local control subjects. The env quasispecies of the man, the woman, and two controls were also obtained using single genome amplification and sequencing (SGA/S to explore the paraphyletic relationship by phylogenetic analysis.Epidemiological information and serological tests indicated that the man was infected with HIV-1 earlier than the woman. Phylogenetic analyses of the consensus sequences showed a monophyletic cluster for the man and woman in all three genomic regions. Furthermore, gag sequences of the man and woman shared a unique recombination pattern from subtype B and C, which was different from those of CRF07_BC or CRF08_BC observed in the local samples. These indicated that the viral sequences from the two subjects display a high level of similarity. Further, viral quasispecies from the man exhibited a paraphyletic relationship with those from the woman in the Bayesian and maximum-likelihood (ML phylogenetic trees of the env region, which supported the transmission direction from the man to the woman.In the context of epidemiological and serological evidence, the results of phylogenetic analyses support the transmission from the man to the woman.

Adaptive Probabilistic Broadcasting over Dense Wireless Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Victor Gau

2010-01-01

Full Text Available We propose an idle probability-based broadcasting method, iPro, which employs an adaptive probabilistic mechanism to improve performance of data broadcasting over dense wireless ad hoc networks. In multisource one-hop broadcast scenarios, the modeling and simulation results of the proposed iPro are shown to significantly outperform the standard IEEE 802.11 under saturated condition. Moreover, the results also show that without estimating the number of competing nodes and changing the contention window size, the performance of the proposed iPro can still approach the theoretical bound. We further apply iPro to multihop broadcasting scenarios, and the experiment results show that within the same elapsed time after the broadcasting, the proposed iPro has significantly higher Packet-Delivery Ratios (PDR than traditional methods.

Secure and Usable Out-Of-Band Channels for Ad Hoc Mobile Device Interactions

OpenAIRE

Kainda , Ronald; Flechais , Ivan; Roscoe , A. W.

2010-01-01

International audience; Protocols for bootstrapping security in ad hoc mobile device interactions rely on users' ability to perform specific tasks such as transferring or comparing fingerprints of information between devices. The size of fingerprints depends on the level of technical security required by a given application but, at the same time, is limited by users' inability to deal with large amounts of data with high levels of accuracy. Large fingerprints provide high technical security b...

Efficacy of lisdexamfetamine dimesylate in children with attention-deficit/hyperactivity disorder previously treated with methylphenidate: a post hoc analysis

Directory of Open Access Journals (Sweden)

Jain Rakesh

2011-11-01

Full Text Available Abstract Background Attention-deficit/hyperactivity disorder (ADHD is a common neurobehavioral psychiatric disorder that afflicts children, with a reported prevalence of 2.4% to 19.8% worldwide. Stimulants (methylphenidate [MPH] and amphetamine are considered first-line ADHD pharmacotherapy. MPH is a catecholamine reuptake inhibitor, whereas amphetamines have additional presynaptic activity. Although MPH and amphetamine can effectively manage ADHD symptoms in most pediatric patients, many still fail to respond optimally to either. After administration, the prodrug stimulant lisdexamfetamine dimesylate (LDX is converted to l-lysine and therapeutically active d-amphetamine in the blood. The objective of this study was to evaluate the clinical efficacy of LDX in children with ADHD who remained symptomatic (ie, nonremitters; ADHD Rating Scale IV [ADHD-RS-IV] total score > 18 on MPH therapy prior to enrollment in a 4-week placebo-controlled LDX trial, compared with the overall population. Methods In this post hoc analysis of data from a multicenter, randomized, double-blind, forced-dose titration study, we evaluated the clinical efficacy of LDX in children aged 6-12 years with and without prior MPH treatment at screening. ADHD symptoms were assessed using the ADHD-RS-IV scale, Conners' Parent Rating Scale-Revised short form (CPRS-R, and Clinical Global Impressions-Improvement scale, at screening, baseline, and endpoint. ADHD-RS-IV total and CPRS-R ADHD Index scores were summarized as mean (SD. Clinical response for the subgroup analysis was defined as a ≥ 30% reduction from baseline in ADHD-RS-IV score and a CGI-I score of 1 or 2. Dunnett test was used to compare change from baseline in all groups. Number needed to treat to achieve one clinical responder or one symptomatic remitter was calculated as the reciprocal of the difference in their proportions on active treatment and placebo at endpoint. Results Of 290 randomized participants enrolled, 28

Intelligent QoS routing algorithm based on improved AODV protocol for Ad Hoc networks

Science.gov (United States)

Huibin, Liu; Jun, Zhang

2016-04-01

Mobile Ad Hoc Networks were playing an increasingly important part in disaster reliefs, military battlefields and scientific explorations. However, networks routing difficulties are more and more outstanding due to inherent structures. This paper proposed an improved cuckoo searching-based Ad hoc On-Demand Distance Vector Routing protocol (CSAODV). It elaborately designs the calculation methods of optimal routing algorithm used by protocol and transmission mechanism of communication-package. In calculation of optimal routing algorithm by CS Algorithm, by increasing QoS constraint, the found optimal routing algorithm can conform to the requirements of specified bandwidth and time delay, and a certain balance can be obtained among computation spending, bandwidth and time delay. Take advantage of NS2 simulation software to take performance test on protocol in three circumstances and validate the feasibility and validity of CSAODV protocol. In results, CSAODV routing protocol is more adapt to the change of network topological structure than AODV protocol, which improves package delivery fraction of protocol effectively, reduce the transmission time delay of network, reduce the extra burden to network brought by controlling information, and improve the routing efficiency of network.

Analisis Unjuk Kerja Aplikasi VoIP Call Android di Jaringan MANET [Performance Analysis of VoIP Call Application Android in MANET (Mobile Ad Hoc Network

Directory of Open Access Journals (Sweden)

Ryan Ari Setyawan

2015-06-01

Full Text Available Penelitian ini bertujuan menganalisis kinerja aplikasi  VoIP call android di jaringan MANET (mobile ad hoc network.  Hasil pengujian menunjukan bahwa aplikasi VoIP call android dapat digunakan di jaringan MANET. Delay yang dihasilkan paling besar di pengujian indoor dengan jarak 11-15 meter yakni sebesar 0,014624811 seconds. Packet loss yang dihasilkan pada range 1%-2% sedangkan standar packet loss yang ditetapkan oleh CISCO untuk layanan aplikasi VoIP adalah < 5%. Jitter yang dihasilkan yakni antara 0,01-0,06 seconds sedangkan standar yang ditetapkan oleh CISCO adalah ≤ 30 ms atau 0,03 seconds. Throughput yang dihasilkan pada proses pengujian yakni antar 161 kbps-481 kbps. *****This study aims to analyze the performance of VOIP call android application in the MANET (mobile ad hoc network. The results showed that VoIP applications could be implemented in MANET network. The highest  delay is produced in indoor testing  with distance of 11-15 meters,  which is equal to 0.014624811 seconds. Packet loss is generated in the range of 1% -2%, while packet loss standards set by Cisco for VoIP application services are <5%. The jitter is between 0.01 to 0.06 seconds, while the standard set by CISCO is ≤ 30 ms or 0.03 seconds. Throughput generated in the testing process is between 161 kbps-481 kbps.

Panel Discussion : Report of the APS Ad-Hoc Committee on LGBT Issues

Science.gov (United States)

Atherton, Tim; Barthelemy, Ramon; Garmon, Savannah; Reeves, Kyle; APS Ad-Hoc Committee on LGBT Issues Team

Following the presentation of the findings and recommendations of the APS Ad-Hoc Committee on LGBT Issues (C-LGBT) by Committee Chair Michael Falk, a panel discussion will be held featuring several members of the committee. The discussion will focus on how APS can best ensure the recommendations of the committee are carried out in a timely fashion and other ideas on future APS efforts toward LGBT inclusion in physics. Discussion topics will also include the research and other input that shaped the committee's findings and recommendations.

Molecular epidemiological analysis of Saffold cardiovirus genotype 3 from upper respiratory infection patients in Taiwan.

Science.gov (United States)

Lin, Tsuey-Li; Lin, Ting-Han; Chiu, Shu-Chun; Huang, Yuan-Pin; Ho, Cheng-Mao; Lee, Chia-Chi; Wu, Ho-Sheng; Lin, Jih-Hui

2015-09-01

Saffold cardiovirus (SAFV) belongs to the Cardiovirus genus of Picornaviridae family, and may be a relevant new human pathogen; Thus far, eleven genotypes have been identified. The SAFV type 3 (SAFV-3) is thought to be the major genotype and is detected relatively frequently in children with acute gastroenteritis and respiratory illness. The epidemiology and pathogenicity of SAFV-3 remain unclear. To investigate the genomic and epidemiologic profiles of SAFV-3 infection in Taiwan. Virus was detected in respiratory samples from children suffering for URI. SAFV-3 isolates were detected by isolation on cell culture and IF assay. The molecular typing was performed by RT-PCR and was sequenced to compare with reference strains available in the NCBI GeneBank. Serum samples were collected from 2005 to 2013 in Taiwan for seroprevalence investigation. A total of 226 specimens collected from children with URIs, 22 (9.73%) were positive for SAFV-3. The majority of SAFV-3 infections were found in children less than 6 years of age (14 of 22, 63.6%). Genetic analysis of VP1 coding region of Taiwanese isolates shown an 83.2-97.7% difference from other available SAFV-3 sequences in NCBI GenBank. Phylogenetic analysis revealed there is three genetic groups of SAFV-3 co-circulated in Taiwan during the study period. In addition, seroprevalence investigation results indicated that SAFV-3 infection occurs early in life and 43.7-77.8% of children aged between 6 months to 9 years old, had neutralizing antibodies against SAFV-3. SAFV-3 may have circulated in Taiwan for some time and it appears to be one of the etiological agents responsible for URIs in children. Copyright © 2015 Elsevier B.V. All rights reserved.

Pregabalin versus SSRIs and SNRIs in benzodiazepine-refractory outpatients with generalized anxiety disorder: a post hoc cost-effectiveness analysis in usual medical practice in Spain

Directory of Open Access Journals (Sweden)

De Salas-Cansado M

2012-06-01

Full Text Available Marina De Salas-Cansado,1 José M Olivares,2 Enrique Álvarez,3 Jose L Carrasco,4 Andoni Barrueta,5 Javier Rejas,51Trial Form Support Spain, Madrid; 2Department of Psychiatry, Hospital Meixoeiro, Complejo Hospitalario Universitario, Vigo; 3Department of Psychiatry, Hospital de la Santa Creu i San Pau, Barcelona; 4Department of Psychiatry, Hospital Clínico San Carlos, Madrid; 5Health Outcomes Research Department, Medical Unit, Pfizer Spain, Alcobendas, Madrid, SpainBackground: Generalized anxiety disorder (GAD is a prevalent health condition which seriously affects both patient quality of life and the National Health System. The aim of this research was to carry out a post hoc cost-effectiveness analysis of the effect of pregabalin versus selective serotonin reuptake inhibitors (SSRIs/serotonin norepinephrine reuptake inhibitors (SNRIs in treated benzodiazepine-refractory outpatients with GAD.Methods: This post hoc cost-effectiveness analysis used secondary data extracted from the 6-month cohort, prospective, noninterventional ADAN study, which was conducted to ascertain the cost of illness in GAD subjects diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria. Benzodiazepine-refractory subjects were those who claimed persistent symptoms of anxiety and showed a suboptimal response (Hamilton Anxiety Rating Scale ≥16 to benzodiazepines, alone or in combination, over 6 months. Patients could switch to pregabalin (as monotherapy or addon or to an SSRI or SNRI, alone or in combination. Effectiveness was expressed as quality-adjusted life years gained, and the perspective was that of the National Health System in the year 2008. A sensitivity analysis was performed using bootstrapping techniques (10,000 resamples were obtained in order to obtain a cost-effectiveness plane and a corresponding acceptability curve.Results: A total of 282 subjects (mean Hamilton Anxiety Rating Scale score 25.8 were

Enabling Real-Time Video Services over Ad-Hoc Networks Opens the Gates for E-learning in Areas Lacking Infrastructure

Directory of Open Access Journals (Sweden)

Johannes Karlsson

2009-10-01

Full Text Available In this paper we suggest a promising solution to come over the problems of delivering e-learning to areas with lack or deficiencies in infrastructure for Internet and mobile communication. We present a simple, reasonably priced and efficient communication platform for providing e-learning. This platform is based on wireless ad-hoc networks. We also present a preemptive routing protocol suitable for real-time video communication over wireless ad-hoc networks. Our results show that this routing protocol can significantly improve the quality of the received video. This makes our suggested system not only good to overcome the infrastructure barrier but even capable of delivering a high quality e-learning material.

The Epidemiology of Injuries in Mixed Martial Arts: A Systematic Review and Meta-analysis.

Science.gov (United States)

Lystad, Reidar P; Gregory, Kobi; Wilson, Juno

2014-01-01

Mixed martial arts (MMA) has experienced a surge in popularity since emerging in the 1990s, but the sport has also faced concomitant criticism from public, political, and medical holds. Notwithstanding the polarized discourse concerning the sport, no systematic review of the injury problems in MMA has been published to date. To systematically review the epidemiologic data on injuries in MMA and to quantitatively estimate injury incidence and risk factor effect sizes. Systematic review and meta-analysis; Level of evidence, 4. Electronic searching of PubMed, Scopus, CINAHL, EMBASE, AMED, and SPORTDiscus databases to identify studies reporting on the epidemiology of injuries in MMA. Random-effects models were used to obtain pooled summary estimates of the injury incidence rate per 1000 athlete-exposures (IIRAE) and rate ratios with 95% confidence intervals (CIs). Heterogeneity was evaluated with the I (2) statistic. A total of 6 studies were eligible for inclusion in this review. The IIRAE summary estimate was found to be 228.7 (95% CI, 110.4-473.5). No studies reported injury severity. The most commonly injured anatomic region was the head (range, 66.8%-78.0%) followed by the wrist/hand (range, 6.0%-12.0%), while the most frequent injury types were laceration (range, 36.7%-59.4%), fracture (range, 7.4%-43.3%), and concussion (range, 3.8%-20.4%). The most notable risk factors pertained to the outcome of bouts. Losers incurred 3 times as many injuries as winners, and fighters in bouts ending with knockout or technical knockout incurred more than 2 times as many injuries as fighters in bouts ending with submission. Notwithstanding the paucity of data, the injury incidence in MMA appears to be greater than in most, if not all, other popular and commonly practiced combat sports. In general, the injury pattern in MMA is very similar to that in professional boxing but unlike that found in other combat sports such as judo and taekwondo. More epidemiologic research is

Vehicular ad hoc networks standards, solutions, and research

CERN Document Server

Molinaro, Antonella; Scopigno, Riccardo

2015-01-01

This book presents vehicular ad-hoc networks (VANETs) from the their onset, gradually going into technical details, providing a clear understanding of both theoretical foundations and more practical investigation. The editors gathered top-ranking authors to provide comprehensiveness and timely content; the invited authors were carefully selected from a list of who’s who in the respective field of interest: there are as many from Academia as from Standardization and Industry sectors from around the world. The covered topics are organized around five Parts starting from an historical overview of vehicular communications and standardization/harmonization activities (Part I), then progressing to the theoretical foundations of VANETs and a description of the day-one standard-compliant solutions (Part II), hence going into details of vehicular networking and security (Part III) and to the tools to study VANETs, from mobility and channel models, to network simulators and field trial methodologies (Part IV), and fi...

Data management issues in mobile ad hoc networks.

Science.gov (United States)

Hara, Takahiro

2017-01-01

Research on mobile ad hoc networks (MANETs) has become a hot research topic since the middle 1990's. Over the first decade, most research focused on networking techniques, ignoring data management issues. We, however, realized early the importance of data management in MANETs, and have been conducting studies in this area for 15 years. In this review, we summarize some key technical issues related to data management in MANETs, and the studies we have done in addressing these issues, which include placement of data replicas, update management, and query processing with security management. The techniques proposed in our studies have been designed with deep considerations of MANET features including network partitioning, node participation/disappearance, limited network bandwidth, and energy efficiency. Our studies published in early 2000's have developed a new research field as data management in MANETs. Also, our recent studies are expected to be significant guidelines of new research directions. We conclude the review by discussing some future directions for research.