Self-stabilizing algorithms for Connected Vertex Cover and Clique decomposition problems

In many wireless networks, there is no fixed physical backbone nor centralized network management. The nodes of such a network have to self-organize in order to maintain a virtual backbone used to route messages. Moreover, any node of the network can be a priori at the origin of a malicious attack. Thus, in one hand the backbone must be fault-tolerant and in other hand it can be useful to monitor all network communications to identify an attack as soon as possible. We are interested in the minimum \emph{Connected Vertex Cover} problem, a generalization of the classical minimum Vertex Cover problem, which allows to obtain a connected backbone. Recently, Delbot et al.~\cite{DelbotLP13} proposed a new centralized algorithm with a constant approximation ratio of $2$ for this problem. In this paper, we propose a distributed and self-stabilizing version of their algorithm with the same approximation guarantee. To the best knowledge of the authors, it is the first distributed and fault-tolerant algorithm for this problem. The approach followed to solve the considered problem is based on the construction of a connected minimal clique partition. Therefore, we also design the first distributed self-stabilizing algorithm for this problem, which is of independent interest

Fast Structuring of Radio Networks for Multi-Message Communications

We introduce collision free layerings as a powerful way to structure radio networks. These layerings can replace hard-to-compute BFS-trees in many contexts while having an efficient randomized distributed construction. We demonstrate their versatility by using them to provide near optimal distributed algorithms for several multi-message communication primitives. Designing efficient communication primitives for radio networks has a rich history that began 25 years ago when Bar-Yehuda et al. introduced fast randomized algorithms for broadcasting and for constructing BFS-trees. Their BFS-tree construction time was $O(D \log^2 n)$ rounds, where $D$ is the network diameter and $n$ is the number of nodes. Since then, the complexity of a broadcast has been resolved to be $T_{BC} = \Theta(D \log \frac{n}{D} + \log^2 n)$ rounds. On the other hand, BFS-trees have been used as a crucial building block for many communication primitives and their construction time remained a bottleneck for these primitives. We introduce collision free layerings that can be used in place of BFS-trees and we give a randomized construction of these layerings that runs in nearly broadcast time, that is, w.h.p. in $T_{Lay} = O(D \log \frac{n}{D} + \log^{2+\epsilon} n)$ rounds for any constant $\epsilon>0$. We then use these layerings to obtain: (1) A randomized algorithm for gathering $k$ messages running w.h.p. in $O(T_{Lay} + k)$ rounds. (2) A randomized $k$-message broadcast algorithm running w.h.p. in $O(T_{Lay} + k \log n)$ rounds. These algorithms are optimal up to the small difference in the additive poly-logarithmic term between $T_{BC}$ and $T_{Lay}$. Moreover, they imply the first optimal $O(n \log n)$ round randomized gossip algorithm

AN O-TREE FOR FLOORPLAN

ABSTRACT: Floorplanning is the process to arranging the number of blocks in to boundary. Conventionally different trees are used for Floorplanning. Here a new representation called O-Tree is used. This O-tree is the representation of admissible placement and used for Floorplanning. The admissible placement is to move blocks either left or bottom of the boundary and it reduces the white spaces in the Floorplanning. A deterministic algorithm will propose for the Floorplanning. This algorithm is generating from the O-Tree representation. The effectiveness of the proposed algorithm will be tested in MCNC benchmark suites

Regulation of Iron-Related Molecules In the Rat Hippocampus: Sex- and Age-Associated Differences

Iron accumulation, especially that of free oxidized ferrous iron, has been shown to induce tissue oxidative damage and contribute to brain aging and the development of neurodegenerative disease. Here we examine whether sex and advanced age affect the expression of iron-related molecules that participate in regulating free iron levels (heme oxygenase I (HOI), iron-regulatory protein I (IRPI), and ferritin heavy chain (FTH)) and whether changes in the expression of these molecules are associated with differences in the expression of alpha-synuclein (ASN) which is thought to be a critical regulator in the pathogenesis of neurodegeneration. Using a well-established aging animal model, we demonstrate that the expression of HOI, FTH, and IRPI mRNAs is higher in the female hippocampus than that observed in male Fischer 344/NNiaHSD x Brown Norway/BiNia (F344BN) rats, regardless of age group. Consistent with these sexassociated alterations in iron-related regulators, the expression of ASN mRNA and protein in the female hippocampus was lower than that found in male rats. These results suggest a sex-dependent difference in regulating the expression of molecules involved in iron metabolism and neurodegeneration. A similar finding in humans, if present, may help to shed light on why sex may affect the incidence of neurodegenerative disorders

Homoleptic [ONO]2Ti(IV) type complexes of amino-acid-tethered phenolato, Schiff-base ligands: Synthesis, characterization, time-resolved fluorescence spectroscopy, and cytotoxicity against ovarian and colon cancer cells

Six homoleptic Ti(IV) compounds of dianionic tridentate Schiff base ligands were synthesized from chiral amino acids, 2-hydroxybenzaldehyde and Ti(OiPr)4. The compounds were spectroscopically characterized and the molecular geometries were established by X-ray crystallography. The ligands coordinated the titanium via carboxylate-O-, imine-N-, and phenoxide-O atoms. Two isomers were identified; each based on a trans-N2O4 donor set, but one with trans carboxylate-O atoms and another with each carboxylate-O atom trans to a phenoxide-O atom. Photophysical profiles exhibited faster excited-state relaxation in the solid phase than in solution. Marked cytotoxicities were recorded toward human ovarian A2780 and colon HT-29 cancer cells with IC50 values ranging between 23±2 and 103±3 µM. Comparative hydrolytic stability studies by NMR in 10% D2O solutions provided t1/2 values of up to 15±2 h, with little correlation to cytotoxicity implying a role of hydrolysis products in the reactivity and identifying steric bulk as a contributor to stability and solubility

Exposure to Cerium Oxide Nanoparticles Is Associated With Activation of Mitogen-activated Protein Kinases Signaling and Apoptosis in Rat Lungs

Objectives: With recent advances in nanoparticle manufacturing and applications, potential exposure to nanoparticles in various settings is becoming increasing likely. No investigation has yet been performed to assess whether respiratory tract exposure to cerium oxide (CeO2) nanoparticles is associated with alterations in protein signaling, inflammation, and apoptosis in rat lungs. Methods: Specific-pathogen-free male Sprague-Dawley rats were instilled with either vehicle (saline) or CeO2 nanoparticles at a dosage of 7.0 mg/kg and euthanized 1, 3, 14, 28, 56, or 90 days after exposure. Lung tissues were collected and evaluated for the expression of proteins associated with inflammation and cellular apoptosis. Results: No change in lung weight was detected over the course of the study; however, cerium accumulation in the lungs, gross histological changes, an increased Bax to Bcl-2 ratio, elevated cleaved caspase-3 protein levels, increased phosphorylation of p38 MAPK, and diminished phosphorylation of ERK-1/2-MAPK were detected after CeO2 instillation (p\u3c0.05). Conclusions: Taken together, these data suggest that high-dose respiratory exposure to CeO2 nanoparticles is associated with lung inflammation, the activation of signaling protein kinases, and cellular apoptosis, which may be indicative of a long-term localized inflammatory response

TC21/RRas2 regulates glycoprotein VI–FcRγ‐mediated platelet activation and thrombus stability

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145353/1/jth14197.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145353/2/jth14197_am.pd

Measures of sun exposure and sun protection practices for behavioural and epidemiological research

Objective: To develop, in a collaborative project, core measures of sun exposure and sun protection habits, since the lack of standard outcome measures hampers comparison of population surveys and interventions used in skin cancer prevention research. Design: A work group of investigators evaluated available questionnaire measures of sun exposure and protection. Their deliberations led to a proposed set of core questionnaire items for adults, adolescents aged 11 to 17 years, and children 10 years or younger. These core items were used in cognitive testing by the investigators. Cross-site summaries of methods, response samples, and descriptive data were prepared. Setting: Nine locations across the United States. Participants: The study population comprised 81 individuals. Results: No unusual response patterns were detected in any of the respondent groups or for any specific question. Some revisions to the survey items resulted from the need for clarification or emphasis of frames of reference such as adding or underlining key phrases in a question. Conclusions: The combination of expert review followed by cognitive interviewing yielded standardized core survey items with good clarity and applicability for measuring sun exposure and sun protection behaviors across a broad range of populations. They are appropriate for studies tracking morbidity and/or mortality and evaluating prevention program effects