67 research outputs found

    Energy aware power save mode management in wireless mesh networks

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    In recent times Wireless Mesh Networks (WMN) have evolved as powerful networks for most commercial applications. Many contributions have been made to enhance the performance of WMN of which the enhancement of the network lifetime remains as one of the challenging area for research. IEEE standard proposed an amendment which introduced Power Save Mode (PSM) in order to increase the lifetime of WMN. It has three modes such as Active, Light Sleep and Deep Sleep. There exist a lot of literature on increasing energy efficiency by keeping node in Deep Sleep mode when it is not involved in transmission. But current Power Save Mode has some deficiency in low Packet Delivery Ratio (PDR). This paper presents Energy Aware Power Save Mode (EAPSM) which attempt to overcome the deficiency of low PDR by triggering PSM. EAPSM consist of three modules namely, remaining energy calculator, transmission mode identifier and PSM scheduler. EAPSM schedules PSM based on the constraints such as remaining energy of a node and its participation in transmission. The proposed method includes mathematical model and algorithms which gives improved performance over conventional PSM

    Minimum battery draining rate aware optimized link state routing in wireless mesh network

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    Wireless mesh network is a flexible, low cost and multi-purpose networking platform with wired infrastructure connected to the internet. In WMN nodes often have a limited battery supply to use for the sending and reception of transmissions. Routing protocols over WMN are an important issue and many proposals have been addressed to efficiently manage topology information, to offer network scalability and to prolong network lifetime. Optimized Link State Routing (OLSR) is a proactive type of routing which presents the advantage of finding a route between two nodes in the network in a very short time. It can consume lot of energy resources in selecting the Multi-point Relays (MPRs) and exchanging Topology Control information. To overcome this, we present a mechanisms for the OLSR routing protocol to improve its energy performance in Wireless Mesh Networks. We propose a Minimum Battery Draining Rate Aware (MDRA-OLSR) algorithm which utilizes the information collected by OLSR at every node in providing better network connectivity. We propose a modification in the MPR selection mechanism of OLSR protocol, based on the Willingness concept, in order to increase the network lifetime without losses of performance such as PDR, throughput etc. We consider both available energy and battery draining rate metric as a key criteria to select MPR in a set of MPRs. A comparison of an OLSR and MDRA-OLSR protocol is performed. The experiments are simulated using NS3 simulator by considering various situations such as changing speed of nodes, data rate and packet size by keeping the nodes position static and moving nodes dynamically. In this paper, we present the related works on utilization of energy as metric in routing, proposed model, simulation and discussions of the model in Wireless Mesh Networks

    Remote monitoring and discrete data capture of joint pain and other parameters via the NokiaN900 device: Enhancing patient/physician interaction

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    The new generation cellular phones have multi-functional capabilities such as imaging, video, audio recording and messaging in addition to providing internet access. In this paper we present an innovative application in the field of remote health monitoring using N900 Nokia tablet, which will serve as a communicating device between the patient and healthcare providers like doctors and nurses. Patients with arthritis require regular objective monitoring of their affected joints by healthcare providers requiring that patients report their subjective pain levels to their physicians. The application has a patient's module allowing the patient to select their pain level on a sliding scale from a graphical representation of various human joints and send this as an SMS to the doctor. The healthcare providers can review the pain level, save it to a database and make an informed decision about possible recommendations based on the data received via SMS. The doctor's module allows the doctor to capture all the attributes of an affected joint discretely using the graphical representation of the joints and associated dialog boxes. The complete Graphical User Interface (GUI) development and data base design are discussed and test cases are presented. We plan to evaluate the application in a real healthcare environment for usability, its role in improving patient satisfaction and health outcomes

    Spermatogonial stem cell sensitivity to capsaicin: An in vitro study

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    <p>Abstract</p> <p>Background</p> <p>Conflicting reports have been published on the sensitivity of spermatogenesis to capsaicin (CAP), the pungent ingredient of hot chili peppers. Here, the effect of CAP on germ cell survival was investigated by using two testis germ cell lines as a model. As CAP is a potent agonist of the transient receptor potential vanilloid receptor 1 (TRPV1) and no information was available of its expression in germ cells, we also studied the presence of TRPV1 in the cultured cells and in germ cells in situ.</p> <p>Methods</p> <p>The rat spermatogonial stem cell lines Gc-5spg and Gc-6spg were used to study the effects of different concentrations of CAP during 24 and 48 h. The response to CAP was first monitored by phase-contrast microscopy. As germ cells appear to undergo apoptosis in the presence of CAP, the activation of caspase 3 was studied using an anti activated caspase 3 antibody or by quantifying the amount of cells with DNA fragmentation using flow cytometry. Immunolocalization was done with an anti-TRPV1 antibody either with the use of confocal microscopy to follow live cell labeling (germ cells) or on Bouin fixed paraffin embedded testicular tissues. The expression of TRPV1 by the cell lines and germ cells was confirmed by Western blots.</p> <p>Results</p> <p>Initial morphological observations indicated that CAP at concentrations ranging from 150 uM to 250 uM and after 24 and 48 h of exposure, had deleterious apoptotic-like effects on both cell lines: A large population of the CAP treated cell cultures showed signs of DNA fragmentation and caspase 3 activation. Quantification of the effect demonstrated a significant effect of CAP with doses of 150 uM in the Gc-5spg cell line and 200 uM in the Gc-6spg cell line, after 24 h of exposure. The effect was dose and time dependent in both cell lines. TRPV1, the receptor for CAP, was found to be expressed by the spermatogonial stem cells in vitro and also by premeiotic germ cells in situ.</p> <p>Conclusion</p> <p>CAP adversely affects spermatogonial survival in vitro by inducing apoptosis to those cells and TRPV-1, a CAP receptor, may be involved in this effect as this receptor is expressed by mitotic germ cells.</p

    The chemopreventive polyphenol Curcumin prevents hematogenous breast cancer metastases in immunodeficient mice

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    Dissemination of metastatic cells probably occurs long before diagnosis of the primary tumor. Metastasis during early phases of carcinogenesis in high risk patients is therefore a potential prevention target. The plant polyphenol Curcumin has been proposed for dietary prevention of cancer. We therefore examined its effects on the human breast cancer cell line MDA-MB-231 in vitro and in a mouse metastasis model. Curcumin strongly induces apoptosis in MDA- MB- 231 cells in correlation with reduced activation of the survival pathway NF kappa B, as a consequence of diminished I kappa B and p65 phosphorylation. Curcumin also reduces the expression of major matrix metalloproteinases (MMPs) due to reduced NF kappa B activity and transcriptional downregulation of AP-1. NF kappa B/p65 silencing is sufficient to downregulate c-jun and MMP expression. Reduced NF kappa B/AP-1 activity and MMP expression lead to diminished invasion through a reconstituted basement membrane and to a significantly lower number of lung metastases in immunodeficient mice after intercardiac injection of 231 cells (p=0.0035). 68% of Curcumin treated but only 17% of untreated animals showed no or very few lung metastases, most likely as a consequence of down-regulation of NF kappa B/AP-1 dependent MMP expression and direct apoptotic effects on circulating tumor cells but not on established metastases. Dietary chemoprevention of metastases appears therefore feasible. Copyright (c) 2007 S. Karger AG, Basel

    Absence of XMRV and Closely Related Viruses in Primary Prostate Cancer Tissues Used to Derive the XMRV-Infected Cell Line 22Rv1

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    The 22Rv1 cell line is widely used for prostate cancer research and other studies throughout the world. These cells were established from a human prostate tumor, CWR22, that was serially passaged in nude mice and selected for androgen independence. The 22Rv1 cells are known to produce high titers of xenotropic murine leukemia virus-related virus (XMRV). Recent studies suggested that XMRV was inadvertently created in the 1990's when two murine leukemia virus (MLV) genomes (pre-XMRV1 and pre-XMRV-2) recombined during passaging of the CWR22 tumor in mice. The conclusion that XMRV originated from mice and not the patient was based partly on the failure to detect XMRV in early CWR22 xenografts. While that deduction is certainly justified, we examined the possibility that a closely related virus could have been present in primary tumor tissue. Here we report that we have located the original prostate tumor tissue excised from patient CWR22 and have assayed the corresponding DNA by PCR and the tissue sections by fluorescence in situ hybridization for the presence of XMRV or a similar virus. The primary tumor tissues lacked mouse DNA as determined by PCR for intracisternal A type particle DNA, thus avoiding one of the limitations of studying xenografts. We show that neither XMRV nor a closely related virus was present in primary prostate tissue of patient CWR22. Our findings confirm and reinforce the conclusion that XMRV is a recombinant laboratory-generated mouse virus that is highly adapted for human prostate cancer cells

    A longitudinal study of gene expression in healthy individuals

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    <p>Abstract</p> <p>Background</p> <p>The use of gene expression in venous blood either as a pharmacodynamic marker in clinical trials of drugs or as a diagnostic test requires knowledge of the variability in expression over time in healthy volunteers. Here we defined a normal range of gene expression over 6 months in the blood of four cohorts of healthy men and women who were stratified by age (22–55 years and > 55 years) and gender.</p> <p>Methods</p> <p>Eleven immunomodulatory genes likely to play important roles in inflammatory conditions such as rheumatoid arthritis and infection in addition to four genes typically used as reference genes were examined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), as well as the full genome as represented by Affymetrix HG U133 Plus 2.0 microarrays.</p> <p>Results</p> <p>Gene expression levels as assessed by qRT-PCR and microarray were relatively stable over time with ~2% of genes as measured by microarray showing intra-subject differences over time periods longer than one month. Fifteen genes varied by gender. The eleven genes examined by qRT-PCR remained within a limited dynamic range for all individuals. Specifically, for the seven most stably expressed genes (CXCL1, HMOX1, IL1RN, IL1B, IL6R, PTGS2, and TNF), 95% of all samples profiled fell within 1.5–2.5 Ct, the equivalent of a 4- to 6-fold dynamic range. Two subjects who experienced severe adverse events of cancer and anemia, had microarray gene expression profiles that were distinct from normal while subjects who experienced an infection had only slightly elevated levels of inflammatory markers.</p> <p>Conclusion</p> <p>This study defines the range and variability of gene expression in healthy men and women over a six-month period. These parameters can be used to estimate the number of subjects needed to observe significant differences from normal gene expression in clinical studies. A set of genes that varied by gender was also identified as were a set of genes with elevated expression in a subject with iron deficiency anemia and another subject being treated for lung cancer.</p

    Susceptibility of Human Lymphoid Tissue Cultured ex vivo to Xenotropic Murine Leukemia Virus-Related Virus (XMRV) Infection

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    BACKGROUND: Xenotropic murine leukemia virus-related virus (XMRV) was generated after a recombination event between two endogenous murine leukemia viruses during the production of a prostate cancer cell line. Although the associations of the XMRV infection with human diseases appear unlikely, the XMRV is a retrovirus of undefined pathogenic potential, able to replicate in human cells in vitro. Since recent studies using animal models for infection have yielded conflicting results, we set out an ex vivo model for XMRV infection of human tonsillar tissue to determine whether XMRV produced by 22Rv1 cells is able to replicate in human lymphoid organs. Tonsil blocks were infected and infection kinetics and its pathogenic effects were monitored RESULTS: XMRV, though restricted by APOBEC, enters and integrates into the tissue cells. The infection did not result in changes of T or B-cells, immune activation, nor inflammatory chemokines. Infectious viruses could be recovered from supernatants of infected tonsils by reinfecting DERSE XMRV indicator cell line, although these supernatants could not establish a new infection in fresh tonsil culture, indicating that in our model, the viral replication is controlled by innate antiviral restriction factors. CONCLUSIONS: Overall, the replication-competent retrovirus XMRV, present in a high number of laboratories, is able to infect human lymphoid tissue and produce infectious viruses, even though they were unable to establish a new infection in fresh tonsillar tissue. Hereby, laboratories working with cell lines producing XMRV should have knowledge and understanding of the potential biological biohazardous risks of this virus

    Cluster based approach to minimize delay in energy aware routing for ieee 802.11s Wireless Mesh Networks under mobility conditions

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    Minimization of delay in data collection at base station is one of the major concerns in cluster based Wireless Mesh Network. There exists few other techniques for the cluster head selection in wireless mesh network such as selecting a node with maximum energy as a cluster head. In this work, We consider dynamic nodes with single hop topology with in the static cluster. To minimize the delay that occurs in transmission and reception of data, the proposed model includes four modules namely, Cluster head selection, slot allocation, slot scheduling and data collection process. In proposed model, cluster head selection is based on the maximum energy, number of links and link duration. Link duration is considered in order to avoid the link breakage that occurs before the transmission of data. Slot allocation is based on the available energy [E avail) and the required energy (E req). Slot scheduling is carried out based on the link duration. A node with minimum link duration will be given higher priority to avoid re-transmission that indirectly results in minimization of delay. Data at the base station will be collected as they are scheduled. Mathematical model of the proposed model is presented in this work and it shows that proposed model minimizes delay compared to the existing there by improving network efficiency
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