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Search Results: 1 - 10 of 210535 matches for " Sophie L. McHaffie "
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The Pancreas Is Altered by In Utero Androgen Exposure: Implications for Clinical Conditions Such as Polycystic Ovary Syndrome (PCOS)
Mick Rae, Cathal Grace, Kirsten Hogg, Lisa Marie Wilson, Sophie L. McHaffie, Seshadri Ramaswamy, Janis MacCallum, Fiona Connolly, Alan S. McNeilly, Colin Duncan
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0056263
Abstract: Using an ovine model of polycystic ovary syndrome (PCOS), (pregnant ewes injected with testosterone propionate (TP) (100 mg twice weekly) from day (d)62 to d102 of d147 gestation (maternal injection – MI-TP)), we previously reported female offspring with normal glucose tolerance but hyperinsulinemia. We therefore examined insulin signalling and pancreatic morphology in these offspring using quantitative (Q) RT-PCR and western blotting. In addition the fetal pancreatic responses to MI-TP, and androgenic and estrogenic contributions to such responses (direct fetal injection (FI) of TP (20 mg) or diethylstilbestrol (DES) (20 mg) at d62 and d82 gestation) were assessed at d90 gestation. Fetal plasma was assayed for insulin, testosterone and estradiol, pancreatic tissue was cultured, and expression of key β-cell developmental genes was assessed by QRT-PCR. In female d62MI-TP offspring insulin signalling was unaltered but there was a pancreatic phenotype with increased numbers of β-cells (P<0.05). The fetal pancreas expressed androgen receptors in islets and genes involved in β-cell development and function (PDX1, IGF1R, INSR and INS) were up-regulated in female fetuses after d62MI-TP treatment (P<0.05–0.01). In addition the d62MI-TP pancreas showed increased insulin secretion under euglycaemic conditions (P<0.05) in vitro. The same effects were not seen in the male fetal pancreas or when MI-TP was started at d30, before the male programming window. As d62MI-TP increased both fetal plasma testosterone (P<0.05) and estradiol concentrations (P<0.05) we assessed the relative contribution of androgens and estrogens. FI-TP (commencing d62) (not FI-DES treatment) caused elevated basal insulin secretion in vitro and the genes altered by d62MI-TP treatment were similarly altered by FI-TP but not FI-DES. In conclusion, androgen over-exposure alters fetal pancreatic development and β-cell numbers in offspring. These data suggest that that there may be a primary pancreatic phenotype in models of PCOS, and that there may be a distinct male and female pancreas.
Feasibility and Efficacy of Willpower Strengthening Exercises with University Students: A Randomised Control Pilot Study  [PDF]
Aileen M. Pidgeon, Sophie L. Monteath
Open Journal of Social Sciences (JSS) , 2013, DOI: 10.4236/jss.2013.16002
Abstract: This study examined the feasibility and efficacy of implementing intense brief willpower strengthening exercises with university students. Thirty-nine university students were randomly allocated into one of three groups: willpower strengthening exercise intervention groups, 4-7-8 Hands or postural adjustments, or a control group. Participants assigned to the active intervention groups were required to practice the relevant willpower strengthening exercise every hour, for six hours per day, over three days. The high participation and compliance rates of participants in the two active intervention groups, along with positive feedback, supported the feasibility of the willpower strengthening exercises with university students. Additionally, the 4-7-8 Hands and posture groups reported directional improvements in willpower compared to the control group. Future research is recommended to evaluate the efficacy of willpower strengthening exercises over a longer time period to allow for more practice and effect time.
Comparative effects of RRR-alpha- and RRR-gamma-tocopherol on proliferation and apoptosis in human colon cancer cell lines
Sharon E Campbell, William L Stone, Steven Lee, Sarah Whaley, Hongsong Yang, Min Qui, Paige Goforth, Devin Sherman, Derek McHaffie, Koyamangalath Krishnan
BMC Cancer , 2006, DOI: 10.1186/1471-2407-6-13
Abstract: The effectiveness of RRR-α- and RRR-γ-tocopherol at inhibiting cell growth and inducing apoptosis in colon cancer cell lines with varying molecular characteristics (SW480, HCT-15, HCT-116 and HT-29) and primary colon cells (CCD-112CoN, nontransformed normal phenotype) was studied. Colon cells were treated with and without RRR-α- or RRR-γ-tocopherol using varying tocopherol concentrations and time intervals. Cell proliferation and apoptosis were measured using the trypan blue assay, annexin V staining, DNA laddering and caspase activation.Treatment with RRR-γ-tocopherol resulted in significant cell death for all cancer cell lines tested, while RRR-α-tocopherol did not. Further, RRR-γ-tocopherol treatment showed no cytotoxicity to normal colon cells CCD-112CoN at the highest concentration and time point tested. RRR-γ-tocopherol treatment resulted in cleavage of PARP, caspase 3, 7, and 8, but not caspase 9. Differences in the percentage cell death and apoptosis were observed in different cell lines suggesting that molecular differences in these cell lines may influence the ability of RRR-γ-tocopherol to induce cell death.This is the first study to demonstrate that multiple colon cancer cell lines containing varying genetic alterations will under go growth reduction and apoptosis in the presence of RRR-γ-tocopherol without damage to normal colon cells. The amount growth reduction was dependent upon the molecular signatures of the cell lines. Since RRR-γ-tocopherol is effective at inhibition of cell proliferation at both physiological and pharmacological concentrations dietary RRR-γ-tocopherol may be chemopreventive, while pharmacological concentrations of RRR-γ-tocopherol may aid chemotherapy without toxic effects to normal cells demonstrated by most chemotherapeutic agents.Differences in the incidence of colorectal cancer throughout the world suggest that diet has a role in colorectal carcinogenesis [1]. Mediterranean diets, rich in vitamin E isoforms, are associated w
Une exposition en blanc
Sophie Lévy
Transatlantica : Revue d'études Américaines , 2006,
Abstract: Cette présentation est celle d’une exposition qui n’existe pas sur l’importance du blanc dans la peinture moderne américaine, et des enjeux historiques et théoriques qui pourraient la soutenir. Il est toujours difficile de parler d’une exposition qui n’existe pas, c’est à dire essayer de donner une structure verbale à un exercice visuel, et phénoménologique sans corps. L’expérience, déjà tentée, permet néanmoins de clarifier pour soi même le sens du projet et de mesurer une réception possible...
Inferring dynamic genetic networks with low order independencies
Sophie Lèbre
Mathematics , 2007,
Abstract: In this paper, we propose a novel inference method for dynamic genetic networks which makes it possible to face with a number of time measurements n much smaller than the number of genes p. The approach is based on the concept of low order conditional dependence graph that we extend here in the case of Dynamic Bayesian Networks. Most of our results are based on the theory of graphical models associated with the Directed Acyclic Graphs (DAGs). In this way, we define a minimal DAG G which describes exactly the full order conditional dependencies given the past of the process. Then, to face with the large p and small n estimation case, we propose to approximate DAG G by considering low order conditional independencies. We introduce partial qth order conditional dependence DAGs G(q) and analyze their probabilistic properties. In general, DAGs G(q) differ from DAG G but still reflect relevant dependence facts for sparse networks such as genetic networks. By using this approximation, we set out a non-bayesian inference method and demonstrate the effectiveness of this approach on both simulated and real data analysis. The inference procedure is implemented in the R package 'G1DBN' freely available from the CRAN archive.
Frequency permutation arrays
Sophie Huczynska,Gary L. Mullen
Mathematics , 2005,
Abstract: Motivated by recent interest in permutation arrays, we introduce and investigate the more general concept of frequency permutation arrays (FPAs). An FPA of length n=m lambda and distance d is a set T of multipermutations on a multiset of m symbols, each repeated with frequency lambda, such that the Hamming distance between any distinct x,y in T is at least d. Such arrays have potential applications in powerline communication. In this paper, we establish basic properties of FPAs, and provide direct constructions for FPAs using a range of combinatorial objects, including polynomials over finite fields, combinatorial designs, and codes. We also provide recursive constructions, and give bounds for the maximum size of such arrays.
An Exploratory Study of Altruism in Greek Children: Relations with Empathy, Resilience and Classroom Climate  [PDF]
Sophie Leontopoulou
Psychology (PSYCH) , 2010, DOI: 10.4236/psych.2010.15047
Abstract: The aims of this exploratory study were two-fold: a. to identify any relations between children’s altruism and a set of demographic and other personal and social characteristics of Greek children, such as empathy, resilience and classroom climate; and b. to examine the psychometric properties of a newly-developed measure of altruistic behaviour in children, namely the Altruistic Behaviour Questionnaire (ABQ). 232 male and female students of the 5th and 6th class of Primary School in Northern Greece participated in this study. The ABQ was found to have adequate internal consistency and concurrent and construct validity. Using a hierarchical regression analysis, altruism in children was found to be reliably predicted by participants’ gender and academic performance, by empathy and also by resilience; nevertheless, the more socially determined variable of classroom climate only marginally predicted altruism. The importance of including training in the development and manifestation of altruism in emotional education programmes and resilience interventions at school is highlighted.
Evaluation of the Effects of Corticosteroids on Histamine Release by ex Vivo Cutaneous Microdialysis  [PDF]
Carol Courderot-Masuyer, Sophie Robin,lène Tauzin, Sylvain Harbon, Sophie Mac-Mary, Alexandre Guichard, Patrice Muret, Philippe Humbert
Journal of Cosmetics, Dermatological Sciences and Applications (JCDSA) , 2013, DOI: 10.4236/jcdsa.2013.33035
Abstract:

The purpose of the study was to evaluate the effects of corticosteroids on histamine release and to compare their potency with the MacKenzie classification based on their vasoconstrictor effects. Thanks to ex Vivo cutaneous microdialysis, we studied histamine-induced release over a period of time on excised abdominal skin from women. Eight corticosteroids were topically applied with occlusive dressing onto the skin, above probes, before anti-IgE injection. Histamine levels were assessed by an EIA method. In order to compare the different corticosteroids, AUC was calculated allowing an estimation of the amount of released histamine for 60 min of ex vivo cutaneous microdialysis. Diflucortolone 0.1% and micronized betamethasone dipropionate 0.05% are considered as corticosteroids with high potency in MacKenzie classification. Betamethasone dipropionate associated with propylene glycol 0.05%, belongs to a stronger class in Mackenzie classification. Our results showed that the decrease in histamine release was more important with difluocortolone than with both of these corticosteroids. Therefore there was no correlation between the vasoconstrictor potency of topical corticosteroids and their ability to inhibit histamine release.

Time Perception and Dynamics of Facial Expressions of Emotions
Sophie L. Fayolle, Sylvie Droit-Volet
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0097944
Abstract: Two experiments were run to examine the effects of dynamic displays of facial expressions of emotions on time judgments. The participants were given a temporal bisection task with emotional facial expressions presented in a dynamic or a static display. Two emotional facial expressions and a neutral expression were tested and compared. Each of the emotional expressions had the same affective valence (unpleasant), but one was high-arousing (expressing anger) and the other low-arousing (expressing sadness). Our results showed that time judgments are highly sensitive to movements in facial expressions and the emotions expressed. Indeed, longer perceived durations were found in response to the dynamic faces and the high-arousing emotional expressions compared to the static faces and low-arousing expressions. In addition, the facial movements amplified the effect of emotions on time perception. Dynamic facial expressions are thus interesting tools for examining variations in temporal judgments in different social contexts.
An EM algorithm for estimation in the Mixture Transition Distribution model
Sophie Lèbre,Pierre-Yves Bourguinon
Mathematics , 2008,
Abstract: The Mixture Transition Distribution (MTD) model was introduced by Raftery to face the need for parsimony in the modeling of high-order Markov chains in discrete time. The particularity of this model comes from the fact that the effect of each lag upon the present is considered separately and additively, so that the number of parameters required is drastically reduced. However, the efficiency for the MTD parameter estimations proposed up to date still remains problematic on account of the large number of constraints on the parameters. In this paper, an iterative procedure, commonly known as Expectation-Maximization (EM) algorithm, is developed cooperating with the principle of Maximum Likelihood Estimation (MLE) to estimate the MTD parameters. Some applications of modeling MTD show the proposed EM algorithm is easier to be used than the algorithm developed by Berchtold. Moreover, the EM Estimations of parameters for high-order MTD models led on DNA sequences outperform the corresponding fully parametrized Markov chain in terms of Bayesian Information Criterion. A software implementation of our algorithm is available in the library seq++ at http://stat.genopole.cnrs.fr/seqpp
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