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Search Results: 1 - 10 of 118847 matches for " Kimberly T Sibille "
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Chronic pain, perceived stress, and cellular aging: an exploratory study
Kimberly T Sibille, Taimour Langaee, Ben Burkley, Yan Gong, Toni L Glover, Chris King, Joseph L Riley, Christiaan Leeuwenburgh, Roland Staud, Laurence A Bradley, Roger B Fillingim
Molecular Pain , 2012, DOI: 10.1186/1744-8069-8-12
Abstract: The relationship between chronic pain, stress, and TL was analyzed in 36 ethnically diverse, older adults, half of whom reported no chronic pain and the other half had chronic knee osteoarthritis (OA) pain. Subjects completed a physical exam, radiographs, health history, and psychosocial questionnaires. Blood samples were collected and TL was measured by quantitative polymerase chain reaction (qPCR). Four groups were identified characterized by pain status and the Perceived Stress Scale scores: 1) no pain/low stress, 2) no pain/high stress, chronic pain/low stress, and 4) chronic pain/high stress. TL differed between the pain/stress groups (p = 0.01), controlling for relevant covariates. Specifically, the chronic pain/high stress group had significantly shorter TL compared to the no pain/low stress group. Age was negatively correlated with TL, particularly in the chronic pain/high stress group (p = 0.03).Although preliminary in nature and based on a modest sample size, these findings indicate that cellular aging may be more pronounced in older adults experiencing high levels of perceived stress and chronic pain.A recent Institute of Medicine report documents the public health consequences of chronic pain in America with estimates of 116 million adults affected and costs of $635 billion annually [1]. One of the challenges illuminated in the report is the difficulty in identifying specific pathophysiological targets due to significant variability in the experience of chronic pain. Consequently, biological markers reflecting the physiological burden of chronic pain on an individual system would offer significant clinical and scientific utility.Leukocyte telomere length (TL) is a measure of cellular aging and is associated with age-related disease onset, chronic health conditions, psychosocial stress, and mortality [2-5]. Importantly, recent findings indicate a direct relationship between telomeres and mitochondria, connecting for the first time two major theories of ag
Effect of estrogen on manganese-induced toxicity on embryonic astrocytes  [PDF]
Tyler T. Huynh, Kimberly J. Baker, Harold L. Komiskey
Advances in Bioscience and Biotechnology (ABB) , 2013, DOI: 10.4236/abb.2013.410A1002

Manganese (Mn) is a natural trace metal that is essential for many physiological functions in the human body. Astrocytes in the central nervous system are susceptible reservoirs for Mn accumulation. Estrogen, a steroidal hormone, has been shown to mitigate Mn-induced toxicity in cultures of postnatal astrocytes. However, differences in expression/inducibility of glutamate transporters and glutamine synthetase, transmitters, and the natural gonadal steroids and their receptors are known to occur in astrocyte cultures derived from various stages of fetal and postnatal development. Cultures of embryonic (E18) hippocampal astrocytes were examined in this study for the ability of 17 β-estradiol (E2) to protect them from Mn toxicity by up regulating gene expression of a glutamate transporter. Primary rat hippocampal astrocytes were pretreated with β-Estradiol (E2) in vitro and subsequently, Mn sulfate (MnSO4). The amount of toxic damage to the astrocytes was measured by quantifying glial fibrillary acidic protein (GFAP) with a sandwiched Enzyme-Linked Immunosorbent Assay (ELISA). ELISA analysis indicated Mn exposure at 100 μM, 300 μM, or 600 μM significantly increased GFAP levels. However, E2 concentrations at 10 nM or 30 nM significantly reduced Mn-induced GFAP concentrations at 100 μM. Cells pretreated with 10 nM or 30 nM of E2 significantly lowered GFAP levels. The Water-Soluble Tetrazolium-8 (WST-8) method was utilized to determine cell viability. The WST-8 assay showed that Mn concentrations of 100 μM, 300 μM, or 600 μM significantly reduced the dehydrogenase activity, thereby decreasing the number of viable astrocytes. Enzyme activity with 600 μM of Mn was significantly decreased when compared with 100 μM of Mn, revealing a dose-dependent effect. However, the dehydrogenase activity in cells treated with 600 μM Mn was significantly increased

Le parler occitan de Chiomonte (Italie) : situation linguistique et sociolinguistique (au contact de l’italien, du fran ais, du piémontais et du francoproven al)
Sibille Jean
SHS Web of Conferences , 2012, DOI: 10.1051/shsconf/20120100233
Abstract: Le parler occitan de Chiomonte (Italie) : situation linguistique et sociolinguistique (au contact de l’italien, du fran ais, du piémontais et du francoproven al) La Haute Vallée de Suse (ou Vallée d’Oulx), du c té italien du col du Montgenèvre, ainsi que la vallée du Haut Cluson, étaient jadis partie intégrante du Dauphiné. Elles on été cédées par la France au Royaume de Piémont-Savoie lors du traité d’Utrecht en 1713. Elles sont devenues italiennes lors de l’unification de l’Italie en 1861. L’italien s’y est substitué au fran ais comme langue dominante (et officielle) au tournant du XIXe et du XXe siècle. Dans la Haute Vallée de Suse, le vernaculaire occitan est en contact avec deux autres langues vernaculaires : le franco-proven al parlée dans la moyenne vallée et le piémontais parlé à Suse et dans la basse vallée, près de Turin. Chiomonte est le dernier village occitanophone à la fois au nord et à l’est : à 3 km on parle francoproven al, à 7 km piémontais. Le parler de Chiomonte fait partie de l’ensemble dialectal occitan dénommé vivaro-alpin, mais de par sa situation il présente des affinités aréale avec des parlers situés hors de la zone occitane (piémontais et francoproven aux) et est influencé par un double superstrat : fran ais à date ancienne et italien pour la période plus récente. Il présente des caractéristiques communes avec la partie la plus septentrionale de la zone nord occitane. Les adultes autochtones de Chiomonte sont souvent trilingues, voire quadrilingues, mais on observe des différences entre les générations. La transmission familiale de l’occitan a cessé dans les années 1950-1970, et le parler occitan de Chiomonte, bien qu’il compte encore un nombre significatif de locuteurs – pas toujours très agés – est un idiome en grand danger. Le fait que, de ce c té-ci de la frontière le parler local ne soit pas dévalorisés dans les représentations collectives est de peu de poids face aux mutations économiques et sociales, et aux médias qui favorisent la généralisation de l’italien. Le piémontais, en expansion dans les années 1960-1970 est également en recul et la connaissance du fran ais a considérablement régressé chez les plus jeunes. C’est ainsi qu’en quatre générations, on est passé d’un quadrilinguisme quasi général, à un quasi monolinguisme italien.
Time-Domain Diversity in Ultra-Wideband MIMO Communications
Alain Sibille
EURASIP Journal on Advances in Signal Processing , 2005, DOI: 10.1155/asp.2005.316
Abstract: The development of ultra-wideband (UWB) communications is impeded by the drastic transmitted power limitations imposed by regulation authorities due to the ¢ € polluting ¢ € character of these radio emissions with respect to existing services. Technical solutions must be researched in order either to limit the level of spectral pollution by UWB devices or to increase their reception sensitivity. In the present work, we consider pulse-based modulations and investigate time-domain multiple-input multiple-output (MIMO) diversity as one such possible solution. The basic principles of time-domain diversity in the extreme (low multipath density) or intermediate (dense multipath) UWB regimes are addressed, which predict the possibility of a MIMO gain equal to the product Nt —Nr of the numbers of transmit/receive antenna elements when the channel is not too severe. This analysis is confirmed by simulations using a parametric empirical stochastic double-directional channel model. They confirm the potential interest of MIMO approaches solutions in order to bring a valuable performance gain in UWB communications.
Statistical Modeling of Antenna: Urban Equipment Interactions for LTE Access Points
Xin Zeng,Alain Sibille
International Journal of Antennas and Propagation , 2012, DOI: 10.1155/2012/292018
Abstract: The latest standards for wireless networks such as LTE are essentially based on small cells in order to achieve a large network capacity. This applies for antennas to be deployed at street level or even within buildings. However, antennas are commonly designed, simulated, and measured in ideal conditions, which is not the real situation for most applications where antennas are often deployed in proximity to objects acting as disturbers. In this paper, three conventional wireless access point scenarios (antenna-wall, antenna-shelter, and antenna lamppost) are investigated for directional or omnidirectional antennas. The paper first addresses the definition of three performance indicators for such scenarios and secondly uses such parameters towards the statistical analysis of the interactions between the wall and the antennas. 1. Introduction With the development of new wireless communication systems and standards, antennas of base stations or access points are more likely deployed at street level in proximity to walls and urban furniture other than the traditional antennas for GSM networks which are mounted on rooftops with few neighboring disturbers [1–3]. The effect of surrounding disturbers may be strong or weak and is very sensitive to the antenna location and antenna characteristics. Unfortunately, antennas are commonly designed, simulated, and measured in isolation from anything else as much as possible, which is not a realistic use case. For instance, the radiation pattern of a dipole mounted beside a wall is highly perturbed, indicating the severe performance degradation to omnidirectionality (see below). Unfortunately, such disturbances are highly variable and impact the behavior of antennas in an uneasily predictable manner, with significant consequences in terms of cell coverage. The latter can be quantitatively evaluated through, for example, ray tracing of even empirical propagation simulation tools, but it will be very costly to compute the propagation for many realizations of disturbed antenna characteristics. For this reason, a reasonable approach is first to develop a statistical model for the antenna radiation behavior, before combining it with a model of simulation of the propagation. It is the goal of this paper, keeping in mind that statistical models lend themselves to the tuning of the trade-off between complexity and accuracy, depending on the number of parameters involved in the statistical distributions. For instance, [4] gives an example of this approach through radiation patterns series expansions. Actually, the evaluation of
Differentially Expressed Genes in Major Depression Reside on the Periphery of Resilient Gene Coexpression Networks
Chris Gaiteri,Etienne Sibille
Frontiers in Neuroscience , 2011, DOI: 10.3389/fnins.2011.00095
Abstract: The structure of gene coexpression networks reflects the activation and interaction of multiple cellular systems. Since the pathology of neuropsychiatric disorders is influenced by diverse cellular systems and pathways, we investigated gene coexpression networks in major depression, and searched for putative unifying themes in network connectivity across neuropsychiatric disorders. Specifically, based on the prevalence of the lethality–centrality relationship in disease-related networks, we hypothesized that network changes between control and major depression-related networks would be centered around coexpression hubs, and secondly, that differentially expressed (DE) genes would have a characteristic position and connectivity level in those networks. Mathematically, the first hypothesis tests the relationship of differential coexpression to network connectivity, while the second “hybrid” expression-and-network hypothesis tests the relationship of differential expression to network connectivity. To answer these questions about the potential interaction of coexpression network structure with differential expression, we utilized all available human post-mortem depression-related datasets appropriate for coexpression analysis, which spanned different microarray platforms, cohorts, and brain regions. Similar studies were also performed in an animal model of depression and in schizophrenia and bipolar disorder microarray datasets. We now provide results which consistently support (1) that genes assemble into small-world and scale-free networks in control subjects, (2) that this efficient network topology is largely resilient to changes in depressed subjects, and (3) that DE genes are positioned on the periphery of coexpression networks. Similar results were observed in a mouse model of depression, and in selected bipolar- and schizophrenia-related networks. Finally, we show that baseline expression variability contributes to the propensity of genes to be network hubs and/or to be DE in disease. In summary, our results suggest that the small-world and scale-free properties of gene networks are resilient to pathological changes in major depression, and that the network structure may constrain the extent to which a gene may be DE in the illness, hence informing further gene-network-based mechanistic studies of neuropsychiatric disorders.
Radiation hardness of CMS pixel barrel modules
T. Rohe,A. Bean,W. Erdmann,H. -C. Kaestli,S. Khalatyan,B. Meier,V. Radicci,J. Sibille
Physics , 2010, DOI: 10.1016/j.nima.2010.03.157
Abstract: Pixel detectors are used in the innermost part of the multi purpose experiments at LHC and are therefore exposed to the highest fluences of ionising radiation, which in this part of the detectors consists mainly of charged pions. The radiation hardness of all detector components has thoroughly been tested up to the fluences expected at the LHC. In case of an LHC upgrade, the fluence will be much higher and it is not yet clear how long the present pixel modules will stay operative in such a harsh environment. The aim of this study was to establish such a limit as a benchmark for other possible detector concepts considered for the upgrade. As the sensors and the readout chip are the parts most sensitive to radiation damage, samples consisting of a small pixel sensor bump-bonded to a CMS-readout chip (PSI46V2.1) have been irradiated with positive 200 MeV pions at PSI up to 6E14 Neq and with 21 GeV protons at CERN up to 5E15 Neq. After irradiation the response of the system to beta particles from a Sr-90 source was measured to characterise the charge collection efficiency of the sensor. Radiation induced changes in the readout chip were also measured. The results show that the present pixel modules can be expected to be still operational after a fluence of 2.8E15 Neq. Samples irradiated up to 5E15 Neq still see the beta particles. However, further tests are needed to confirm whether a stable operation with high particle detection efficiency is possible after such a high fluence.
Prompt directional detection of galactic supernova by combining large liquid scintillator neutrino detectors
V. Fischer,T. Chirac,T. Lasserre,C. Volpe,M. Cribier,M. Durero,J. Gaffiot,T. Houdy,A. Letourneau,G. Mention,M. Pequignot,V. Sibille,M. Vivier
Physics , 2015, DOI: 10.1088/1475-7516/2015/08/032
Abstract: Core-collapse supernovae produce an intense burst of electron antineutrinos in the few-tens-of-MeV range. Several Large Liquid Scintillator-based Detectors (LLSD) are currently operated worldwide, being very effective for low energy antineutrino detection through the Inverse Beta Decay (IBD) process. In this article, we develop a procedure for the prompt extraction of the supernova location by revisiting the details of IBD kinematics over the broad energy range of supernova neutrinos. Combining all current scintillator-based detector, we show that one can locate a canonical supernova at 10 kpc with an accuracy of 45 degrees (68% C.L.). After the addition of the next generation of scintillator-based detectors, the accuracy could reach 12 degrees (68% C.L.), therefore reaching the performances of the large water Cerenkov neutrino detectors. We also discuss a possible improvement of the SuperNova Early Warning System (SNEWS) inter-experiment network with the implementation of a directionality information in each experiment. Finally, we discuss the possibility to constrain the neutrino energy spectrum as well as the mass of the newly born neutron star with the LLSD data
Cost and Calorie Analysis of Fast Food Consumption in College Students  [PDF]
Kimberly B. Heidal, Sarah E. Colby, Ginger T. Mirabella, Khalid S. Al-Numair, Brenda Bertrand, Kevin H. Gross
Food and Nutrition Sciences (FNS) , 2012, DOI: 10.4236/fns.2012.37124
Abstract: The purpose of this research was to assess money spent and calories consumed by college students from fast food restaurants located on and around a southern college campus. A convenience sample (n = 152) of undergraduate college students (aged 18 - 24) at a southern university participated in a survey that measured dietary intake from seven local fast food chains using a researcher developed food frequency questionnaire and a lifestyle behavior survey that collected data on health practices. A strong positive correlation was found between total monthly fast food expense and total monthly fast food caloric consumption (r(150) = 0.94, p < 0.05), indicating a significant linear relationship between the two variables. An independent-samples t test comparing the mean monthly fast food restaurant expense males to females found a significant difference between the two groups (t(150) = 4.19, p < 0.05).The more money spent by college students contributed to a higher amount of calories consumed from fast food in a typical month. Future research needs to determine if college students are contributing to the high obesity rate and if limiting fast food restaurants on and around college campuses would help decrease fast food consumption in college students.
Single and Multiple Scattering in UWB Bicone Arrays
Raffaele D'Errico,Alain Sibille
International Journal of Antennas and Propagation , 2008, DOI: 10.1155/2008/129584
Abstract: An analysis of interactions between radiators in a UWB biconical array, drawing attention to single and multiple scatterings, is carried out. The complementarity between electrical coupling and radiation scattering is argued. The point source approximation is discussed and shown to be insufficient. An approximation of radiation scattering based on angular averaging of the scattering coefficient is proposed. This approach yields a reduction of the problem complexity, which is especially interesting in UWB multiple antenna systems, because of the large bandwidth. Multiple scattering between radiators is shown to be a second-order effect. Finally, a time domain approach is used in order to investigate pulse distortion and quantify the exactness of the proposed scattering model.
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