Reliable Multicast in Mobile Ad Hoc Wireless Networks

A mobile wireless ad hoc network (MANET) consists of a group of mobile nodes communicating wirelessly with no fixed infrastructure. Each node acts as source or receiver, and all play a role in path discovery and packet routing. MANETs are growing in popularity due to multiple usage models, ease of deployment and recent advances in hardware with which to implement them. MANETs are a natural environment for multicasting, or group communication, where one source transmits data packets through the network to multiple receivers. Proposed applications for MANET group communication ranges from personal network apps, impromptu small scale business meetings and gatherings, to conference, academic or sports complex presentations for large crowds reflect the wide range of conditions such a protocol must handle. Other applications such as covert military operations, search and rescue, disaster recovery and emergency response operations reflect the mission critical nature of many ad hoc applications. Reliable data delivery is important for all categories, but vital for this last one. It is a feature that a MANET group communication protocol must provide. Routing protocols for MANETs are challenged with establishing and maintaining data routes through the network in the face of mobility, bandwidth constraints and power limitations. Multicast communication presents additional challenges to protocols. In this dissertation we study reliability in multicast MANET routing protocols. Several on-demand multicast protocols are discussed and their performance compared. Then a new reliability protocol, R-ODMRP is presented that runs on top of ODMRP, a well documented best effort protocol with high reliability. This protocol is evaluated against ODMRP in a standard network simulator, ns-2. Next, reliable multicast MANET protocols are discussed and compared. We then present a second new protocol, Reyes, also a reliable on-demand multicast communication protocol. Reyes is implemented in the ns-2 simulator and compared against the current standards for reliability, flooding and ODMRP. R-ODMRP is used as a comparison point as well. Performance results are comprehensively described for latency, bandwidth and reliable data delivery. The simulations show Reyes to greatly outperform the other protocols in terms of reliability, while also outperforming R-ODMRP in terms of latency and bandwidth overhead

Paraphilias and paraphilic disorders in Parkinson's disease: a systematic review of the literature

This is the peer reviewed version of the following article: Solla, P., Bortolato, M., Cannas, A., Mulas, C. S. and Marrosu, F. (2015), Paraphilias and paraphilic disorders in Parkinson's disease: A systematic review of the literature. Mov Disord., 30: 604–613., which has been published in final form at http://doi.org/10.1002/mds.26157. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving

Non-Standard Errors

In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty: Non-standard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for better reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants

Reliable Group Communication in an Ad Hoc Network

In this paper an enhancement to the reliability of the ODMRP multicast ad hoc protocol is described. The enhancement attempts to increase the overall data packet delivery ratio by adding packet storage and retransmit operations coordinated by the multicast source. 1. Reliable Group Communication Reliable group communication has a relatively long history in wired networks. Reliable distributed group communication began with solutions to basic distributed problems and moved on to protocols for static group memberships. To get past certain limitations in the solutions for static memberships, the dynamic group membership model was proposed[1]. This introduced the concept of a Group Membership Service, responsible for group management. In this model a sender or third party based GMS has the following responsibilities: 1. handle group joins and leaves, 2. identify and remove ‘dead ’ nodes from list, 3. distribute group membership list to group, 4. flush unresolved messages from system before new group view is distributed, 5. sequence all messages uniquely, 6. coordinate a reliable delivery protocol (2pc), 7. coordinate storage of messages for retransmit, and 8. retransmit stored messages to requesting nodes. In this model, an individual node has the following responsibilities: 1. receive, order and deliver messages to the app. layer, 2. originate and transmit new messages. In wired group communication protocols, research has differentiated between sender based and receiver based responsibility for reliable message delivery [2]. In a receiver-based model, a clear advantage is that no overall group membership list is necessary. For a receiver based model, the top four GMS responsibilities listed disappear, leaving four remaining. Additionally, a third responsibility is added to the individual nodes, to NACK unreceived messages. For the four remaining GMS responsibilities, this paper takes the following approach: sequencing messages uniquely can be a standalone problem, as can the coordination of message delivery. These two responsibilities provide message-ordering guarantees in wired networks

Julep: A Framework for Reliable Distributed Computing in Java

Julep is an object-oriented testbed designed for analysis and comparison of temporal diversity fault tolerance mechanisms. It is written in Java, and runs as a layer underneath a distributed application. Julep can run on any standard COTS platform with a JVM, in homogeneous or heterogeneous environments. Julep is designed to quickly and easily incorporate new process recovery mechanisms, allowing accurate comparison between mechanisms for specific applications on specific hardware platforms. Julep's central Manager acts as a task location and status lookup service.A novel aspect of Julep is the implementation of `unbreakable' communication channels. Julep is flexible regarding its use of fault tolerant mechanisms. It can be used as a testbed to compare performance between implemented recovery mechanisms, as a framework within which new recovery mechanisms can be implemented and tested, or as an infrastructure to add fault tolerance to an existing distributed application. 1.1 Introduct..

APOE/C1/C4/C2 hepatic control region polymorphism influences plasma apoE and LDL cholesterol levels

We characterized 102 kb of chromosome 19 containing the apolipoprotein (APO) E/C1/C4/C2 cluster and two flanking genes for common DNA variants associated with plasma low-density lipoprotein cholesterol (LDL-C) level. DNA variants were identified by comparing sequences of 48 haploid hybrid cell lines. We genotyped participants (1943 Whites and 2046 African-Americans) of the Coronary Artery Risk Development in Young Adults study for 115 variants. After controlling for the effects of the APOE ε2/3/4 polymorphism, a single nucleotide polymorphism, rs35136575, in the downstream hepatic control region 2 (HCR-2) was associated with LDL-C in Caucasians (P = 0.0004), accounting for 1% of variation. We genotyped rs35136575 in the Atherosclerosis Risk in Communities (ARIC) cohort (3679 African-Americans and 10 427 Whites) and in the Genetic Epidemiology Network of Arteriopathy (GENOA) sibships (1381 African-Americans in 592 sibships, 1116 Caucasians in 503 sibships and 1378 Mexican-Americans in 416 sibships), finding association with LDL-C level in ARIC Caucasians (P = 0.0064). Lower plasma LDL-C was observed with the rare allele. Plasma apoE level was strongly associated with HCR-2 variant genotype in all three GENOA samples (P ≤ 0.002), indicating an effect on apoE concentration. Patterns of association for plasma apo A-I, apoB, LDL-C, high-density lipoprotein cholesterol, total cholesterol and triglyceride levels with rs35136575 in the population-based samples evaluated in this study suggest a pleiotropic effect that may be context-dependent

Comprehensive evaluation of apolipoprotein H gene (APOH) variation identifies novel associations with measures of lipid metabolism in GENOA*s⃞

Apolipoprotein H (apoH, also named β-2 glycoprotein I) is found on several classes of lipoproteins, and is involved in the activation of lipoprotein lipase in lipid metabolism. We have comprehensively investigated the association of variation in the apoH gene (APOH) with lipid traits in hepatic cholesterol transport, dietary cholesterol transport (DCT), and reverse cholesterol transport (RCT). Our study population consisted of families from the Genetic Epidemiology Network of Arteriopathy multicenter study that include African Americans, Mexican Americans, and European Americans. We individually tested 36 single-nucleotide polymorphisms (SNPs) that span the APOH locus, including nonsynonymous variants that result in known apoH charge isoforms. In addition, we constructed haplotypes from SNPs in the 5′ promoter region that comprise cis-acting regulatory elements, as well as haplotypes for multiple amino acid substitutions. We found point-wise significant associations of APOH variants with various lipid measures in the three racial groups. The strongest associations were found for DCT traits (triglyceride and apoE levels) in Mexican Americans with a nonsynonymous variant (SNP 14917, Cys306Gly) that may alter apoH protein folding in a region involved in phospholipid binding. In conclusion, family-based analyses of APOH variants have identified associations with measures of lipid metabolism in three American racial groups