46 research outputs found
ILORIN: Identifier-locator resolution for infrastructure-less networks
This word is at: 2012 Third International Conference on the Network of the Future (NOF) took place 21-23 November in
Tunis, Tunisia. web event http://www.ati.es/spip.php?article2118In order to overcome the limitations of the current Internet addressing, it is generally accepted that the Future Internet needs a separation between identifiers and network locators. Such identifier-locator split is also needed in infrastructureless networks, such as Mobile ad hoc Networks (MANETs) and Delay Tolerant Networks, since they are an integral part of the Future Internet. Despite the amount of work in infrastructurebased networks, only a few proposals have considered how to apply this identifier-locator split in infrastructure-less networks. The contribution of this paper is an identifier-locator resolution system that can work in sparse MANETs, which are prone to network partitions. Our approach is an identifier-locator association discovery system, which uses periodic beacons to exchange the resolution information, avoiding the establishment of shared state between nodes. Our system exploits the broadcast nature of the wireless medium, opportunistic encounters, and information replication to disseminate identifier-locator associations across the network. The results of our extensive experiments demonstrate that our solution outperforms the related work, achieving a higher identifier-locator association discovery rate. Index Terms—Identifier-Locator split, Resolution system, Mobile Ad Hoc Network, Delay Tolerant Network.This work has been funded by the VERDIKT Programme
of the Norwegian Research Council throughthe DT-Stream
project (project number 183312/S10) and the Regional Government of
Madrid through the MEDIANET project (MEDIANET S2009/TIC-1468)Publicad
Using routing information to optimize synchronization of replicated event notification mediators in sparse MANETs
Mobile Ad-Hoc Networks maintain information about reachable nodes in the routing table. In many application scenarios, human groups play an important role. This is visible at the network level as independent network partitions which are for some time stable before their members change through merging or partitioning. We use the information from stable routing tables to optimize the synchronization of Mediators in our Distributed Event Notification System. In a stable partition each node has the same information, thus a single Mediator can efficiently coordinate the synchronization, while all other Mediators just receive updates. We show in our experiments that just a few seconds are needed until routing tables stabilize and all nodes have a common view of the partition. We present a heuristic which each individual node uses to determine the proper time to synchronize. Furthermore, we show how exceptions, like disappearing coordinating Mediators and unexpected messages, can be efficiently handled
Meta-analysis of epigenome-wide association studies in newborns and children show widespread sex differences in blood DNA methylation
Publisher Copyright: © 2022 The AuthorsBackground: Among children, sex-specific differences in disease prevalence, age of onset, and susceptibility have been observed in health conditions including asthma, immune response, metabolic health, some pediatric and adult cancers, and psychiatric disorders. Epigenetic modifications such as DNA methylation may play a role in the sexual differences observed in diseases and other physiological traits. Methods: We performed a meta-analysis of the association of sex and cord blood DNA methylation at over 450,000 CpG sites in 8438 newborns from 17 cohorts participating in the Pregnancy And Childhood Epigenetics (PACE) Consortium. We also examined associations of child sex with DNA methylation in older children ages 5.5â10 years from 8 cohorts (n = 4268). Results: In newborn blood, sex was associated at Bonferroni level significance with differences in DNA methylation at 46,979 autosomal CpG sites (p < 1.3 Ă 10â7) after adjusting for white blood cell proportions and batch. Most of those sites had lower methylation levels in males than in females. Of the differentially methylated CpG sites identified in newborn blood, 68% (31,727) met look-up level significance (p < 1.1 Ă 10â6) in older children and had methylation differences in the same direction. Conclusions: This is a large-scale meta-analysis examining sex differences in DNA methylation in newborns and older children. Expanding upon previous studies, we replicated previous findings and identified additional autosomal sites with sex-specific differences in DNA methylation. Differentially methylated sites were enriched in genes involved in cancer, psychiatric disorders, and cardiovascular phenotypes.Peer reviewe
Epigenome-wide meta-analysis of blood DNA methylation in newborns and children identifies numerous loci related to gestational age
Background Preterm birth and shorter duration of pregnancy are associated with increased morbidity in neonatal and later life. As the epigenome is known to have an important role during fetal development, we investigated associations between gestational age and blood DNA methylation in children. Methods We performed meta-analysis of Illumina's HumanMethylation450-array associations between gestational age and cord blood DNA methylation in 3648 newborns from 17 cohorts without common pregnancy complications, induced delivery or caesarean section. We also explored associations of gestational age with DNA methylation measured at 4-18 years in additional pediatric cohorts. Follow-up analyses of DNA methylation and gene expression correlations were performed in cord blood. DNA methylation profiles were also explored in tissues relevant for gestational age health effects: fetal brain and lung. Results We identified 8899 CpGs in cord blood that were associated with gestational age (range 27-42 weeks), at Bonferroni significance, P <1.06 x 10(- 7), of which 3343 were novel. These were annotated to 4966 genes. After restricting findings to at least three significant adjacent CpGs, we identified 1276 CpGs annotated to 325 genes. Results were generally consistent when analyses were restricted to term births. Cord blood findings tended not to persist into childhood and adolescence. Pathway analyses identified enrichment for biological processes critical to embryonic development. Follow-up of identified genes showed correlations between gestational age and DNA methylation levels in fetal brain and lung tissue, as well as correlation with expression levels. Conclusions We identified numerous CpGs differentially methylated in relation to gestational age at birth that appear to reflect fetal developmental processes across tissues. These findings may contribute to understanding mechanisms linking gestational age to health effects.Peer reviewe
Meta-analysis of epigenome-wide association studies in neonates reveals widespread differential DNA methylation associated with birthweight
Birthweight is associated with health outcomes across the life course, DNA methylation may be an underlying mechanism. In this meta-analysis of epigenome-wide association studies of 8,825 neonates from 24 birth cohorts in the Pregnancy And Childhood Epigenetics Consortium, we find that DNA methylation in neonatal blood is associated with birthweight at 914 sites, with a difference in birthweight ranging from -183 to 178 grams per 10% increase in methylation (P-Bonferroni <1.06 x 10(-7)). In additional analyses in 7,278 participants,Peer reviewe
Syndromics: A Bioinformatics Approach for Neurotrauma Research
Substantial scientific progress has been made in the past 50Â years in delineating many of the biological mechanisms involved in the primary and secondary injuries following trauma to the spinal cord and brain. These advances have highlighted numerous potential therapeutic approaches that may help restore function after injury. Despite these advances, bench-to-bedside translation has remained elusive. Translational testing of novel therapies requires standardized measures of function for comparison across different laboratories, paradigms, and species. Although numerous functional assessments have been developed in animal models, it remains unclear how to best integrate this information to describe the complete translational âsyndromeâ produced by neurotrauma. The present paper describes a multivariate statistical framework for integrating diverse neurotrauma data and reviews the few papers to date that have taken an information-intensive approach for basic neurotrauma research. We argue that these papers can be described as the seminal works of a new field that we call âsyndromicsâ, which aim to apply informatics tools to disease models to characterize the full set of mechanistic inter-relationships from multi-scale data. In the future, centralized databases of raw neurotrauma data will enable better syndromic approaches and aid future translational research, leading to more efficient testing regimens and more clinically relevant findings
A Note on the Complexity of Some Quality of Information Optimisation Problems in Sensor Networks
We prove that a selection of quality of information optimisation problems related to event detection in sensor networks are NP-hard
Reconsidering Consistency Management in Shared Data Spaces for Emergency and Rescue Applications
Abstract: Efficient information sharing is very important for emergency and rescue operations. These operations often have to be performed in environments where no communication infrastructure exists. Therefore, Mobile Ad-Hoc Network (MANET) technologies need to be leveraged for generic information sharing services. However, MANETs are using the shared medium of wireless networks, i.e., IEEE 802.11, which means that bandwidth is limited and mobility might cause network partitions. In order to achieve high availability of important information and increase overall system performance, replication can be used. The drawback of aggressive replication is the problem of inconsistencies and the costs of possible conflict resolution strategies. Since emergency and rescue operations are only operating for a short time compared to classical database applications, storage space might not be considered a bottleneck even for small devices: Instead of deleting and updating data, data versions are created, and each application can influence the choice of consistency model for its data and use its own policy to resolve conflicts. Such an approach does not only allow for application specific conflict resolution, but also enables traceability of what happened and has been registered, in the aftermath of the emergency and rescue operation.