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  1. Traitement de 46 malades porteurs de stades IV ORL par radiochimiothérapie concomitante selon un protocole permettant une radiosensibilisation de toutes les séances

    NASA Astrophysics Data System (ADS)

    Baillet, F.; Dessard-Diana, B.; Diana, C.; Simon, J. M.; Mazeron, J. J.; Pierga, J. Y.; Dendale, R.

    1998-04-01

    An external beam therapy with two fractions a day giving 48Gy with 16fractions and 45days, initialy palliative, has been shown to be well adapted for a simultaneous radiosensitizing chemotherapy employment. Associated to a cisplatin, fluorouracyl, etoposide and hydrea based chemotherapy, it has been applyed to 46patients with inoperable stages IV ORL tumors including 91% T4, 9% T3, 48% N2N3, 72% performans status equal or less than2. With a 30months observation median delay a clinical complete response at 4months is observed in 93%, with further locoregional relapses in 38%. One year survival is 58%, 2years 40%, 3years 35%. These results are equal or better than those obtained with hyperfractionnated, accelerated, hyper-fractionnated and accelerated, and classical radiotherapy. Une radiothérapie bifractionnée donnant 48 Gy en 16 séances et 45 jours, initialement palliative, s'est révélée bien adaptée pour l'emploi simultané d'une chimiothérapie radiosensibilisante. Associée à une chimiothérapie à base de cisplatine, fluoro-uracile, etoposide et hydrea, elle a été appliquée à 46 malades porteurs de cancers ORL de stade IV inopérables comprenant 91 % de T4, 9 % de T3, 48 % de N2N3, 72 % de performans status égaux ou inférieurs à 2. Avec un délai médian d'observation de 30 mois on observe 93 % de réponses cliniques complètes à 4 mois avec 38 % de récidives locorégionales ultérieures. La survie est de 58 % à 1 an, 40 % à 2 ans et de 35 % à 3 ans. Ces résultats sont égaux ou supérieurs à ceux qui ont été obtenus avec des radiothérapies hyperfractionnées, accélérées, hyperfractionnées et accélérées, et classiques.

  2. La pelade par plaques

    PubMed Central

    Spano, Frank; Donovan, Jeff C.

    2015-01-01

    Résumé Objectif Présenter aux médecins de famille des renseignements de base pour faire comprendre les schémas thérapeutiques et les résultats des traitements pour la pelade par plaques, de même que les aider à identifier les patients pour qui une demande de consultation en dermatologie pourrait s’imposer. Sources des données Une recension a été effectuée dans PubMed pour trouver des articles pertinents concernant le traitement de la pelade par plaques. Message principal La pelade par plaques est une forme auto-immune de perte pileuse qui touche à la fois les enfants et les adultes. Même s’il n’y a pas de mortalité associée à la maladie, la morbidité découlant des effets psychologiques de la perte des cheveux peut être dévastatrice. Lorsque la pelade par plaques et le sous-type de la maladie sont identifiés, un schéma thérapeutique approprié peut être amorcé pour aider à arrêter la chute des cheveux et possiblement faire commencer la repousse. Les traitements de première intention sont la triamcinolone intralésionnelle avec des corticostéroïdes topiques ou du minoxidil ou les 2. Les médecins de famille peuvent prescrire ces traitements en toute sécurité et amorcer ces thérapies. Les cas plus avancés ou réfractaires pourraient avoir besoin de diphénylcyclopropénone topique ou d’anthraline topique. On peut traiter la perte de cils avec des analogues de la prostaglandine. Les personnes ayant subi une perte de cheveux abondante peuvent recourir à des options de camouflage ou à des prothèses capillaires. Il est important de surveiller les troubles psychiatriques en raison des effets psychologiques profonds de la perte de cheveux. Conclusion Les médecins de famille verront de nombreux patients qui perdent leurs cheveux. La reconnaissance de la pelade par plaques et la compréhension du processus pathologique sous-jacent permettent d’amorcer un schéma thérapeutique approprié. Les cas plus graves ou r

  3. Realisation de composants tout-fibre passifs bases sur des fibres optiques a deux coeurs

    NASA Astrophysics Data System (ADS)

    Jacob Poulin, Anne C.

    2002-01-01

    Les composants passifs tout-optique sont des elements de choix dans les systemes de communications optiques. Cette these presente l'utilisation experimentale de fibres a deux coeurs dissimilaires pour la realisation de filtres passe-bande. Les fibres a deux coeurs ont la particularite de favoriser un couplage d'un coeur a l'autre a intervalles reguliers lorsque les coeurs sont exactement identiques. Dans le cas ou une legere difference apparait, ce couplage est rapidement reduit a zero. La premiere partie de la these montre comment, par l'emploi d'une geometrie de fibre appropriee, il est possible de compenser cette desyntonisation et de fabriquer des coupleurs 100%. Les filtres obtenus ayant toutefois une largeur de bande trop grande pour les besoins du marche des communications optiques, il est montre dans la deuxieme partie de la these comment, en alliant la technologie des reseaux de Bragg avec celle des coupleurs, il est possible de realiser des filtres operant en transmission et possedant d'excellentes caracteristiques spectrales, toujours avec ces memes fibres a deux coeurs.

  4. Électrooxydation du mésoérythritol sur platine, modifié ou non par des adatomes, en milieu acide

    NASA Astrophysics Data System (ADS)

    Cherqaoui, A.; Chbihi, M. El M.; Takky, D.; Kokoh, K. B.; Leger, J.-M.; Lamy, C.

    1999-03-01

    The electrocatalytic oxidation of meso-erythritol has been studied in 0.1 M HClO4 on platinum and on adatoms modified platinum. Preliminary investigations by cyclic voltammetry showed that erythritol was not reactive on a Pt electrode. Underpotential deposition of lead or thallium adatoms at platinum allowed to increase significantly the current densities. Long-time electrolyses were carried out using a three potential plateau program with different values of the oxidation potentials. Chromatographic analyses showed that the oxidation of erythritol led mainly to erythrose, erythrulose and to erythronic acid. Otherwise, electrolysis of erythritol on a Pt-Tl modified electrode orientated selectively the distribution of the reaction products towards the formation of erythrulose. L'oxydation électrocatalytique du mésoérythrytol a été étudiée en milieu acide HClO4 0,1 M sur le platine modifié ou non par des adatomes métalliques. Les études préliminaires réalisées par voltammétrie cyclique montrent que l'érythritol est très peu réactif sur le platine seul. La modification de la surface de l'électrode par dépôt en sous-tension d'adatomes de plomb et de thallium permet d'augmenter les densités de courant. Les électrolyses prolongées sont réalisées à l'aide d'un programme à trois paliers de potentiel et pour différentes valeurs de potentiel d'oxydation. Les analyses chromatographiques montrent que les produits d'oxydation sont l'érythrose, l'érythrulose et l'acide érythronique. D'autre part l'oxydation de l'érythritol sur le platine modifié par des adatomes de thallium conduit à une production sélective d'érythrulose.

  5. Brulures par Diluant

    PubMed Central

    Benbrahim, A.; Jerrah, H.; Diouri, M.; Bahechar, N.; Boukind, E.H.

    2009-01-01

    Summary La flamme de diluant est une cause non rare de brûlure dans le contexte marocain. Nous avons jugé intéressant de faire une étude épidémiologique sur la brûlure par flamme de diluant (BFD) au centre national des brûlés (CNB) du CHU Ibn-Rochd de Casablanca. Ce travail a été réalisé sur une période de 10 mois (septembre 2007/juin 2008). Le but du travail est de montrer les caractéristiques de ce type de brûlures pour les prévenir et ce par l'information sur le diluant, produit causant ces brûlures, et ses différents dangers, la brûlure notamment. Durant cette période, nous avons colligé 17 cas de BFD sur un total de 356 patients admis au CNB pour brûlures aiguës toute étiologie confondue. La moyenne d'age des patients concernés est de 32 ans. Ils sont presque tous de sexe masculin (16 hommes/1 femme) et ont des antécédents de toxicomanie et/ou de délinquance. Tous nos patients sont de bas niveau socio-économique et habitent dans des bidonvilles pour la plupart. La brûlure est souvent secondaire à une agression dans la rue (92% des cas). Concernant les caractéristiques de la brûlure, la surface cutanée brûlée moyenne est de 23%; elle est souvent profonde et siège surtout au niveau des membres supérieurs et du tronc. PMID:21991179

  6. Etude de l'effet de la température de dépôt ou de recuit sur la formation de l'interface Au/GaSb(100) par diffraction d'électrons lents et spectroscopies d'électrons Auger ou de pertes d'énergies

    NASA Astrophysics Data System (ADS)

    Rouanet, M.; Oueini, W.; Nouaoura, M.; Bertru, N.; Bonnet, J.; Lassabatere, L.

    1995-05-01

    Auger electron spectroscopy (AES), energy electron loss spectroscopy (EELS) and low energy electron diffraction (LEED) are used to precise the interaction of gold with GaSb(100) surfaces grown on GaSb substrates by molecular beam epitaxy (MBE). After the growth, the GaSb layers, produced in the laboratory, were transferred by the mean of an ultra vacuum lock chamber, into an other ultra vacuum devoted to the deposit of gold and to the physical studies. Measurements were first performed on the clean surfaces and then on surfaces covered by increasing amounts of gold (6 × 10^{13} 1.8 × 10^{16} atoms cm^{-2}) deposited on substrates brought at room temperature or at low temperature (220 K). The samples were then studied during the annealing up to 520 K. The results show, at the beginning of the deposition, gold was adsorbed on the MBE GaSb(100) surface. When the gold coverage increases and becomes higher than 10^{15} atomes cm^{-2}, Au diffuses into the bulk and forms alloys. Nous étudions par spectroscopie d'électrons Auger (SEA), spectroscopie de pertes d'énergies d'électrons lents (SPEEL) et diffraction d'électrons lents (DEL), l'adsorption de l'or sur des surfaces (100) de couches de GaSb obtenues au laboratoire par épitaxie par jets moléculaires (EJM) sur des substrats de GaSb, puis transférées pour dépôt et étude dans l'enceinte à ultravvide de dépôt métallique par l'intermédiaire d'un sas sous ultravide. Les mesures sont effectuées avant et après dépôts d'or (6 × 10^{13} 1,8 × 10^{16} atomes cm^{-2}) réalisés sur un substrat à la température ambiante ou refroidi à 220 K. Les échantillons sont ensuite étudiés pendant lerecuit jusqu'à 520 K. Les résultats obtenues montrent que l'or, dans un premier temps s'adsorbe sur la surface, puis, lorsque le dépôt augmente, diffuse dans le volume du matériau. cette diffusion, qui peut s'acompagner de la formation d'alliages, n'est cependant notable dans la gamme de température utilis

  7. Developpement d'algorithmes de reconstruction statistique appliques en tomographie rayons-X assistee par ordinateur

    NASA Astrophysics Data System (ADS)

    Thibaudeau, Christian

    La tomodensitometrie (TDM) permet d'obtenir, et ce de facon non invasive, une image tridimensionnelle de l'anatomie interne d'un sujet. Elle constitue l'evolution logique de la radiographie et permet l'observation d'un volume sous differents plans (sagittal, coronal, axial ou n'importe quel autre plan). La TDM peut avantageusement completer la tomographie d'emission par positrons (TEP), un outil de predilection utilise en recherche biomedicale et pour le diagnostic du cancer. La TEP fournit une information fonctionnelle, physiologique et metabolique, permettant la localisation et la quantification de radiotraceurs a l'interieur du corps humain. Cette derniere possede une sensibilite inegalee, mais peut neanmoins souffrir d'une faible resolution spatiale et d'un manque de repere anatomique selon le radiotraceur utilise. La combinaison, ou fusion, des images TEP et TDM permet d'obtenir cette localisation anatomique de la distribution du radiotraceur. L'image TDM represente une carte de l'attenuation subie par les rayons-X lors de leur passage a travers les tissus. Elle permet donc aussi d'ameliorer la quantification de l'image TEP en offrant la possibilite de corriger pour l'attenuation. L'image TDM s'obtient par la transformation de profils d'attenuation en une image cartesienne pouvant etre interpretee par l'humain. Si la qualite de cette image est fortement influencee par les performances de l'appareil, elle depend aussi grandement de la capacite de l'algorithme de reconstruction a obtenir une representation fidele du milieu image. Les techniques de reconstruction standards, basees sur la retroprojection filtree (FBP, filtered back-projection), reposent sur un modele mathematiquement parfait de la geometrie d'acquisition. Une alternative a cette methode etalon est appelee reconstruction statistique, ou iterative. Elle permet d'obtenir de meilleurs resultats en presence de bruit ou d'une quantite limitee d'information et peut virtuellement s'adapter a toutes formes

  8. Micro-usinage nanoseconde UV ou femtoseconde: état de l'art et comparaison

    NASA Astrophysics Data System (ADS)

    Lopez, J.; Salin, F.; Hernandez, M.-C.; Faucon, M.

    2003-06-01

    Jusqu'ici les applications liées au micro-usinage étaient principalement réservées aux sources de types Nd :YAG, pour les matériaux métalliques, ou Excimère, pour les polymères. Les avancées récentes dans le domaine des lasers à impulsions ultra-brèves (<10 ps), en terme de performances, fiabilité et coût, permettent aujourd'hui d'envisager des applications industrielles dans le domaine du niicro-usinage. Ces applications tirent profit de la possibilité d'usiner tout type matériau sans diffusion de chaleur hors du volume irradié. Après avoir rappeler les spécificités des interactions avec ces différents types de laser, nous présenterons quelques exemples de réalisations par rayonnement laser UV ou fenitoseconde.

  9. Prise en Charge du Syndrome de Lyell ou Necrolyse Epidermique Toxique

    PubMed Central

    Siah, S.; Baite, A.; Bakkali, H.; Atmani, M.; Ababou, K.; Ihrai, H.

    2009-01-01

    Summary Le syndrome de Lyell ou nécrolyse épidermique toxique (NET) est une pathologie très grave des dermatoses bulleuses d'étiologie médicamenteuse. Il se caractérise par une nécrose aiguë de l'épiderme sur toute la hauteur du corps muqueux. L'aspect clinique de la NET est celui d'une brûlure étendue du deuxième degré profond. A ce tableau s'associent constamment des lésions muqueuses et une atteinte multiviscérale qui aggrave le pronostic. Nous rapportons deux cas de NET qui illustrent l'importance d'une prise en charge précoce et multidisciplinaire de ces patients atteints au sein d'un service de réanimation des brûlés, dont les fondements reposent sur l'asepsie rigoureuse, l'apport hydroélectrolytique et nutritionnel, la prévention de l'infection et son traitement par une antibiothérapie adaptée, et un nursing et des soins locaux. L'efficacité supposée des immunoglobulines intraveineuses ne repose que sur des cas isolés et il n'y a pas encore d'études randomisées. PMID:21991170

  10. La pelade par plaques

    PubMed Central

    Spano, Frank; Donovan, Jeff C.

    2015-01-01

    Résumé Objectif Présenter aux médecins de famille des renseignements de base pour faire comprendre l’épidémiologie, la pathogenèse, l’histologie et l’approche clinique au diagnostic de la pelade par plaques. Sources des données Une recension a été effectuée dans PubMed pour trouver des articles pertinents concernant la pathogenèse, le diagnostic et le pronostic de la pelade par plaques. Message principal La pelade par plaques est une forme de perte pileuse auto-immune dont la prévalence durant une vie est d’environ 2 %. Des antécédents personnels ou familiaux de troubles auto-immuns concomitants, comme le vitiligo ou une maladie de la thyroïde, peuvent être observés dans un petit sous-groupe de patients. Le diagnostic peut souvent être posé de manière clinique en se fondant sur la perte de cheveux non cicatricielle et circulaire caractéristique, accompagnée de cheveux en « point d’exclamation » en périphérie chez ceux dont le problème en est aux premiers stades. Le diagnostic des cas plus complexes ou des présentations inhabituelles peut être facilité par une biopsie et un examen histologique. Le pronostic varie largement et de mauvais résultats sont associés à une apparition à un âge précoce, une perte importante, la variante ophiasis, des changements aux ongles, des antécédents familiaux ou des troubles auto-immuns concomitants. Conclusion La pelade par plaques est une forme auto-immune de perte de cheveux périodiquement observée en soins primaires. Les médecins de famille sont bien placés pour identifier la pelade par plaques, déterminer la gravité de la maladie et poser le diagnostic différentiel approprié. De plus, ils sont en mesure de renseigner leurs patients à propos de l’évolution clinique de la maladie ainsi que du pronostic général selon le sous-type de patients.

  11. Lignes directrices sur l’aiguillage des cas soupçonnés de cancer colorectal par un médecin de famille ou autre professionnel des soins primaires

    PubMed Central

    Del Giudice, M. Elisabeth; Vella, Emily T.; Hey, Amanda; Simunovic, Marko; Harris, William; Levitt, Cheryl

    2014-01-01

    Résumé Objectif Ces lignes directrices ont pour but d’aider les médecins de famille et les autres professionnels des soins primaires à reconnaître les caractéristiques qui devraient susciter leurs soupçons quant à la présence d’un cancer colorectal (CCR) chez leurs patients. Composition du comité Les membres du comité ont été choisis parmi les dirigeants régionaux des soins primaires au sein du Réseau provincial des soins primaires et de la lutte contre le cancer, les membres du Comité consultatif sur le dépistage du cancer colorectal de l’Ontario et les membres du Groupe sur le siège de la maladie, Cancer gastrointestinal, d’Action Cancer Ontario. Méthodes Ces lignes directrices sont le fruit d’une revue systématique et d’une synthèse des données probantes, ainsi que d’un examen formel par des intervenants canadiens pour valider la pertinence des recommandations. Rapport Des lignes directrices fondées sur des données probantes ont été élaborées pour améliorer la prise en charge des patients qui présentent des caractéristiques cliniques d’un CCR et ce, dans le contexte canadien. Conclusion Un équilibre judicieux entre une suspicion de CCR et le niveau de risque d’un tel cancer devrait favoriser une demande de consultation en temps opportun par les médecins de famille et les professionnels des soins primaires. Ces lignes directrices pourraient aussi orienter les décisions de demander une consultation à des programmes d’évaluation diagnostique du CCR.

  12. Lignes directrices sur l’aiguillage des cas soupçonnés de cancer du poumon par un médecin de famille ou autre professionnel des soins primaires

    PubMed Central

    Del Giudice, M. Elisabeth; Young, Sheila-Mae; Vella, Emily T.; Ash, Marla; Bansal, Praveen; Robinson, Andrew; Skrastins, Roland; Ung, Yee; Zeldin, Robert; Levitt, Cheryl

    2014-01-01

    Résumé Objectif Les présentes lignes directrices visent à aider les médecins de famille et autres généralistes à reconnaître les manifestations cliniques devant éveiller les soupçons quant à la présence d’un cancer du poumon chez les patients. Composition du comité Les membres du comité ont été choisis parmi les leaders régionaux en soins primaires du Réseau provincial des soins primaires et de la lutte contre le cancer d’Action Cancer Ontario et parmi les membres du Groupe sur le siège de la maladie, Cancer du poumon d’Action Cancer Ontario. Méthodes Les présentes lignes directrices sont le fruit d’une revue systématique des données probantes, d’une synthèse des données et d’un examen externe formel effectué par des intervenants canadiens qui ont validé la pertinence des recommandations. Rapport Ces lignes directrices fondées sur des données probantes ont été formulées pour améliorer la prise en charge en contexte canadien des patients qui présentent des manifestations cliniques du cancer du poumon. Conclusion Le dépistage et l’aiguillage précoces des patients atteints de cancer du poumon pourraient en fin de compte aider à réduire les morbidités et mortalités liées au cancer. Ces lignes directrices pourraient aussi s’avérer utiles dans la mise sur pied de programmes de diagnostic du cancer du poumon et pour aider les décideurs à veiller à ce que les ressources appropriées soient en place.

  13. Loren Pope Touted "No Name" Colleges in a Brand-Name World

    ERIC Educational Resources Information Center

    Hoover, Eric

    2008-01-01

    This article profiles Loren Pope, a college consultant and a former education editor at "The New York Times" who touted "no name" colleges and called the nation's most famous university, Harvard University, a rip-off. In his influential book "Colleges That Change Lives" (Penguin, 1996), Mr. Pope profiled 40 institutions--most of them small…

  14. Loren Pope Touted "No Name" Colleges in a Brand-Name World

    ERIC Educational Resources Information Center

    Hoover, Eric

    2008-01-01

    This article profiles Loren Pope, a college consultant and a former education editor at "The New York Times" who touted "no name" colleges and called the nation's most famous university, Harvard University, a rip-off. In his influential book "Colleges That Change Lives" (Penguin, 1996), Mr. Pope profiled 40 institutions--most of them small…

  15. Élaboration de films de molécules organiques par ablation par laser UV

    NASA Astrophysics Data System (ADS)

    Hernandez-Perez, M. A.; Garapon, C.; Champeaux, C.; Coleman, A. W.

    2006-12-01

    Les potentialités des méthodes de dépôt par ablation laser (PLD) pour la préparation de films minces de matériaux organiques sont illustrées par un bref rappel bibliographique et par des résultats expérimentaux concernant des molécules d'intérêt biologique (acides aminés, calix-arènes, protéines). Les films sont préparés par PLD avec un laser KrF sans dégradation de la structure chimique des molécules dans une gamme de fluences de quelques dizaines à quelques centaines de mJ/cm2. Les propriétés structurales et optiques des films sont étudiées en fonction de la fluence du laser et mettent en évidence des arrangements moléculaires particuliers induits par cette méthode de dépôt. Le guidage optique a été obtenu pour des films de toutes ces molécules.

  16. Manifestations neuropsychiatriques révélant une hémorragie cérébro-méningée causée par un accident d’électrisation: à propos d'une observation et revue de la literature

    PubMed Central

    Bugeme, Marcellin; Mukuku, Olivier

    2014-01-01

    Le courant électrique est susceptible de léser tout tissu de l'organisme rencontré lors de son passage, de manière transitoire ou définitive. Les hémorragies cérébro-méningées secondaires à un accident d’électrisation par courant électrique à haute tension sont très rarement rapportées dans la littérature. Nous rapportons un cas d'hémorragie cérébro-méningée révélée par des manifestations neuropsychiatriques causée par un AE par courant électrique à haute tension observée chez un enfant âgé de 6 ans à Lubumbashi, en République Démocratique du Congo. La particularité que présente notre observation est les manifestations neuropsychiatriques observées tardivement. PMID:25419328

  17. Functional conservation of the human EXT1 tumor suppressor gene and its Drosophila homolog tout velu.

    PubMed

    Dasgupta, Ujjaini; Dixit, Bharat L; Rusch, Melissa; Selleck, Scott; The, Inge

    2007-08-01

    Heparan sulfate proteoglycans play a vital role in signaling of various growth factors in both Drosophila and vertebrates. In Drosophila, mutations in the tout velu (ttv) gene, a homolog of the mammalian EXT1 tumor suppressor gene, leads to abrogation of glycosaminoglycan (GAG) biosynthesis. This impairs distribution and signaling activities of various morphogens such as Hedgehog (Hh), Wingless (Wg), and Decapentaplegic (Dpp). Mutations in members of the exostosin (EXT) gene family lead to hereditary multiple exostosis in humans leading to bone outgrowths and tumors. In this study, we provide genetic and biochemical evidence that the human EXT1 (hEXT1) gene is conserved through species and can functionally complement the ttv mutation in Drosophila. The hEXT1 gene was able to rescue a ttv null mutant to adulthood and restore GAG biosynthesis.

  18. Le diagnostic anténatal de la trisomie 21 par l'hybridation in situ en fluorescence (FISH): à propos des premiers tests réalisés au Maroc

    PubMed Central

    Lamzouri, Afaf; Natiq, Abdelhafid; Tajir, Mariam; Sendid, Mohamed; Sefiani, Abdelaziz

    2012-01-01

    Introduction Le but de cette étude était de présenter les premiers résultats de diagnostic anténatal de la trisomie 21 par la technique d'hybridation in situ en fluorescence (FISH) au Maroc et discuter son intérêt dans le diagnostic rapide de cette aneuploïdie. Méthodes Ce travail a été réalisé chez 23 femmes avec des grossesses à haut risque de trisomie 21. La moyenne d’âge des gestantes étaient de 37,43 ans avec des extrêmes de 21 et 43 ans. Toutes étaient musulmanes mariées, mariage légitimé par la Charia, dont trois mariages consanguins, sauf une originaire de la République Démocratique du Congo qui était chrétienne et concubine. La majorité des femmes étaient fonctionnaires et avaient un niveau de scolarisation moyen à élevé. Toutes les patientes ont bénéficié d'une consultation de génétique médicale au cours de laquelle il leur a été donné des informations sur la technique, son intérêt et ses limites. Il s'agit de femmes enceintes qui avaient soit un âge maternel élevé ou des signes d'appel échographiques et/ ou biochimiques. Une des patientes était porteuse d'une translocation robertsonienne t(14;21) équilibrée. Une amniocentèse a été réalisée chez toutes les gestantes et aucun avortement n'a était induit par ce geste invasif. L’âge gestationnel moyen à la première consultation était de 14 semaines d'aménorrhée (SA) et à l'amniocentèse était de 16 SA et 5 jours. L'analyse FISH a été réalisée, après consentement des couples, sur des cellules non cultivées à partir des échantillons de liquides amniotiques, en utilisant des sondes spécifiques du chromosome 21. Résultats Parmi les 23 patientes qui ont bénéficiées d'un diagnostic anténatal de la trisomie 21 par la technique FISH, nous avons pu rassurer 21 d'entre elles, et nous avons détecté deux cas de trisomie 21 fœtal. Conclusion La technique FISH permet un diagnostic anténatal rapide, en moins de 48h, de la trisomie 21 sur

  19. Traitement chirurgical par plaque à compression des fractures de Galeazzi chez l'adulte: à propos de 28 cas

    PubMed Central

    El Kadi, Khalid Ibn; Benabid, Mounir; Saliou, Sarr; Zizah, Said; Mezzani, Amine; Lahrach, Kamal; Marzouki, Amine; Boutayeb, Fawzi

    2013-01-01

    La fracture de Galeazzi associe une fracture diaphysaire du radius ou des deux os de l'avant bras à une luxation de l'articulation radio ulnaire distale. Décrite en 1934, sa fréquence varie chez l'adulte entre 2,7% et 6,8% de l'ensemble des fractures de l'avant bras. Le traitement admis de façon consensuel chez l'adulte est chirurgical reposant sur une ostéosynthèse stable par une plaque vissée de compression dynamique associée ou non à un embrochage de la radio ulnaire distale. Nous rapportons dans notre étude les résultats cliniques de 28 patients colligés au service de traumatologie et orthopédie A du CHU Hassan II de Fès sur une période de 06 ans. L’âge moyen de nos patients était de 30 ans avec prédominance masculine de 90%; tous nos patients ont présenté un traumatisme de poignet lors d'un accident de sport. Le côté droit était atteint dans 75% des cas. Le bilan radiologique objectiva une fracture diaphysaire du raduis associée à une luxation radio ulnaire distale; nous avons adopté la classification de de Mansat. Le traitement a consisté en une synthèse par une plaque vissée dynamique associée à un embrochage transversal chez six patients qui ont présenté une instabilité de la radio ulnaire distale. L'immobilisation par attelle plâtrée postérieure BABP était de mise. Après un recul de 36 mois, nos résultats ont été très satisfaisants suivant le score de Mestdagh, avec bonne récupération de la mobilité du poignet et reprise de toute activité sportive. PMID:24711861

  20. Entérite lupique récidivante améliorée par Azathioprine

    PubMed Central

    Marzouk, Sameh; Garbaa, Saida; Cherif, Yosra; Jallouli, Moez; Bahri, Fathi; Bahloul, Zouhir

    2015-01-01

    Les manifestations gastro-intestinales observées au cours du lupus érythémateux systémique sont fréquentes et peuvent intéresser n'importe quel segment du tractus digestif. L'entérite lupique constitue l'une des manifestations responsable de douleurs abdominales. Son traitement est basé essentiellement sur les corticoïdes. Le recours aux immunosuppresseurs est réservé aux formes récidivantes ou en cas d’échec des corticoïdes. Nous rapportons une nouvelle observation d'entérite lupique récidivante améliorée par azathioprine. Il s'agissait d'une femme âgée de 30 ans chez laquelle le diagnostic du lupus a été retenu en 2004. Un an après, elle a présenté des douleurs abdominales, des vomissements et des diarrhées. Les explorations ont conclu à une entérite lupique après élimination de toute autre cause notamment infectieuse. Elle a été traitée par des corticoïdes à forte dose. Cependant à chaque tentative de dégression, elle présentait la même symptomatologie. En 2010 l'azathioprine a été associé permettant de juguler la maladie et de diminuer la corticothérapie. PMID:26113946

  1. Developpement de techniques de diagnostic non intrusif par tomographie optique

    NASA Astrophysics Data System (ADS)

    Dubot, Fabien

    Que ce soit dans les domaines des procedes industriels ou de l'imagerie medicale, on a assiste ces deux dernieres decennies a un developpement croissant des techniques optiques de diagnostic. L'engouement pour ces methodes repose principalement sur le fait qu'elles sont totalement non invasives, qu'elle utilisent des sources de rayonnement non nocives pour l'homme et l'environnement et qu'elles sont relativement peu couteuses et faciles a mettre en oeuvre comparees aux autres techniques d'imagerie. Une de ces techniques est la Tomographie Optique Diffuse (TOD). Cette methode d'imagerie tridimensionnelle consiste a caracteriser les proprietes radiatives d'un Milieu Semi-Transparent (MST) a partir de mesures optiques dans le proche infrarouge obtenues a l'aide d'un ensemble de sources et detecteurs situes sur la frontiere du domaine sonde. Elle repose notamment sur un modele direct de propagation de la lumiere dans le MST, fournissant les predictions, et un algorithme de minimisation d'une fonction de cout integrant les predictions et les mesures, permettant la reconstruction des parametres d'interet. Dans ce travail, le modele direct est l'approximation diffuse de l'equation de transfert radiatif dans le regime frequentiel tandis que les parametres d'interet sont les distributions spatiales des coefficients d'absorption et de diffusion reduit. Cette these est consacree au developpement d'une methode inverse robuste pour la resolution du probleme de TOD dans le domaine frequentiel. Pour repondre a cet objectif, ce travail est structure en trois parties qui constituent les principaux axes de la these. Premierement, une comparaison des algorithmes de Gauss-Newton amorti et de Broyden- Fletcher-Goldfarb-Shanno (BFGS) est proposee dans le cas bidimensionnel. Deux methodes de regularisation sont combinees pour chacun des deux algorithmes, a savoir la reduction de la dimension de l'espace de controle basee sur le maillage et la regularisation par penalisation de Tikhonov

  2. La place de l'imagerie par résonance magnétique dans le carcinome lobulaire du sein

    PubMed Central

    Bouzoubaa, Wail; Laadioui, Meryem; Alaoui, Fatime Zahra Fdili; Jayi, Sofia; Bouguern, Hakima; Chaara, Hikmat; Melhouf, Moulay Abdelilah

    2014-01-01

    Le carcinome lobulaire reste une entité histologique peu fréquente du cancer du sein, toute fois la place qu'occupe le cancer du sein actuellement dans la cancérologie féminine, justifie la connaissance des particularités de ce type de cancer mammaire. Le diagnostic paraclinique est basée sur le couple écho-mammographie a la recherche de multifocalité, multicentricité ou bilatéralité, d'où l'intérêt de l'IRM qui est la technique la plus sensible pour la mise en évidence de ces lésions et qui est devenue un examen de pratique courante dans le carcinome lobulaire du sein. Par le présent travail, et sous la lumière de la revue de la littérature, nous allons essayer de dégager les aspects épidémiologiques, cliniques, et paracliniques, du carcinome lobulaire du sein, et insister sur les indications et l'intérêt de l'IRM dans la prise en charge de ce type histologique. PMID:25368710

  3. Modelisation par elements finis du muscle strie

    NASA Astrophysics Data System (ADS)

    Leonard, Mathieu

    Ce present projet de recherche a permis. de creer un modele par elements finis du muscle strie humain dans le but d'etudier les mecanismes engendrant les lesions musculaires traumatiques. Ce modele constitue une plate-forme numerique capable de discerner l'influence des proprietes mecaniques des fascias et de la cellule musculaire sur le comportement dynamique du muscle lors d'une contraction excentrique, notamment le module de Young et le module de cisaillement de la couche de tissu conjonctif, l'orientation des fibres de collagene de cette membrane et le coefficient de poisson du muscle. La caracterisation experimentale in vitro de ces parametres pour des vitesses de deformation elevees a partir de muscles stries humains actifs est essentielle pour l'etude de lesions musculaires traumatiques. Le modele numerique developpe est capable de modeliser la contraction musculaire comme une transition de phase de la cellule musculaire par un changement de raideur et de volume a l'aide des lois de comportement de materiau predefinies dans le logiciel LS-DYNA (v971, Livermore Software Technology Corporation, Livermore, CA, USA). Le present projet de recherche introduit donc un phenomene physiologique qui pourrait expliquer des blessures musculaires courantes (crampes, courbatures, claquages, etc.), mais aussi des maladies ou desordres touchant le tissu conjonctif comme les collagenoses et la dystrophie musculaire. La predominance de blessures musculaires lors de contractions excentriques est egalement exposee. Le modele developpe dans ce projet de recherche met ainsi a l'avant-scene le concept de transition de phase ouvrant la porte au developpement de nouvelles technologies pour l'activation musculaire chez les personnes atteintes de paraplegie ou de muscles artificiels compacts pour l'elaboration de protheses ou d'exosquelettes. Mots-cles Muscle strie, lesion musculaire, fascia, contraction excentrique, modele par elements finis, transition de phase

  4. Les Brulures Chimiques Par Le Laurier Rose

    PubMed Central

    Bakkali, H.; Ababou, M.; Nassim Sabah, T.; Moussaoui, A.; Ennouhi, A.; Fouadi, F.Z.; Siah, S.; Ihrai, H.

    2010-01-01

    Summary Le laurier rose ou Nerium oleander est un arbuste qui pousse naturellement dans les régions méditerranéennes. Au Maroc on le trouve dans les lieux humides. Il est réputé par ses risques de toxicité systémique en cas d'empoisonnement à cause de la présence de deux alcaloïdes, surtout l'oléandrine. La littérature illustre des cas d'utilisation locale des feuilles de cette plante contre la gale, les hémorroïdes et les furoncles. Nous rapportons deux cas de brûlures chimiques par le laurier rose de gravité différente. Cela doit aboutir à une information élargie de la population, ainsi qu'une réglementation stricte de sa commercialisation. PMID:21991211

  5. Une alternative au cobalt pour la synthese de nanotubes de carbone monoparoi par plasma inductif thermique

    NASA Astrophysics Data System (ADS)

    Carrier, Jean-Francois

    Les nanotubes de carbone de type monoparoi (C-SWNT) sont une classe recente de nanomateriaux qui ont fait leur apparition en 1991. L'interet qu'on leur accorde provient des nombreuses proprietes d'avant-plan qu'ils possedent. Leur resistance mecanique serait des plus rigide, tout comme ils peuvent conduire l'electricite et la chaleur d'une maniere inegalee. Non moins, les C-SWNT promettent de devenir une nouvelle classe de plateforme moleculaire, en servant de site d'attache pour des groupements reactifs. Les promesses de ce type particulier de nanomateriau sont nombreuses, la question aujourd'hui est de comment les realiser. La technologie de synthese par plasma inductif thermique se situe avantageusement pour la qualite de ses produits, sa productivite et les faibles couts d'operation. Par contre, des recherches recentes ont permis de mettre en lumiere des risques d'expositions reliees a l'utilisation du cobalt, comme catalyseur de synthese; son elimination ou bien son remplacement est devenu une preoccupation importante. Quatre recettes alternatives ont ete mises a l'essai afin de trouver une alternative plus securitaire a la recette de base; un melange catalytique ternaire, compose de nickel, de cobalt et d'oxyde d'yttrium. La premiere consiste essentiellement a remplacer la proportion massique de cobalt par du nickel, qui etait deja present dans la recette de base. Les trois options suivantes contiennent de nouveaux catalyseurs, en remplacement au Co, qui sont apparus dans plusieurs recherches scientifiques au courant des dernieres annees: le dioxyde de zircone (ZrO2), dioxyde de manganese (MnO2) et le molybdene (Mo). La methode utilisee consiste a vaporiser la matiere premiere, sous forme solide, dans un reacteur plasma a haute frequence (3 MHz) a paroi refroidi. Apres le passage dans le plasma, le systeme traverse une section dite de "croissance", isolee thermiquement a l'aide de graphite, afin de maintenir une certaine plage de temperature favorable a la

  6. THE MEASURES PAR PROJECT

    NASA Astrophysics Data System (ADS)

    Frouin, R. J.; Franz, B.

    2009-12-01

    The solar energy available for photosynthesis, known as PAR, controls the growth of phytoplankton and, therefore, regulates the composition and evolution of marine ecosystems. Knowing the spatial and temporal distribution of PAR over the oceans is critical to understanding biogeochemical cycles of carbon, nutrients, and oxygen, and to address important climate and global change issues such as the fate of anthropogenic atmospheric carbon dioxide. In view of this, a 12-year time series of PAR at the ocean surface, starting in September 1997, is being produced by the NASA Ocean Biology Processing Group from SeaWiFS, MODIS-Terra, and MODIS-Aqua data. The product covers the global oceans, with a spatial resolution of about 9.3x9.3 km (equal area grid) and a temporal resolution of one day. PAR is computed as the difference between the 400-700 nm solar flux incident on the top of the atmosphere (known) and reflected back to space by the atmosphere and surface (derived from satellite radiance), taking into account atmospheric absorption (modeled). Knowledge of pixel composition is not required, eliminating the need for cloud screening and arbitrary assumptions about sub-pixel cloudiness. Combining data from satellite sensors with different equatorial crossing times accounts for the diurnal variability of clouds and, therefore, increases accuracy on a daily time scale. The processing system, including routine check of accuracy and control of quality, is designed to operate during the entire lifetime of SeaWiFS and MODIS, and to accommodate future sensors with ocean-color capabilities. Maps of daily, weekly, and monthly PAR obtained from individual sensors are presented, as well as merged products. Accuracy is quantified in comparisons with other satellite estimates, the National Centers for Environmental Prediction reanalysis product, and in-situ measurements from fixed buoys and platforms. The good statistical performance makes the satellite PAR product suitable for large

  7. Facteurs prédictifs de la réponse à la CERA chez les hémodialysés chroniques naïfs de traitement par agent stimulant l’érythropoïèse

    PubMed Central

    Ezziani, Mariam; Najdi, Adil; Mikou, Souad; Hanin, Hakim; Arrayhani, Mohammed; Houssaini, Tarik Sqalli

    2015-01-01

    La correction et la stabilité du taux d'hémoglobine est un objectif majeur du traitement de l'anémie chez les hémodialysés chroniques. Toutefois, la cible d'hémoglobine > 11g/dl fixée par les recommandations demeure difficile à atteindre dans notre contexte. Le but de cette étude est d’évaluer la réponse au traitement par CERA (continuous erythropoietin receptor activator) chez une population d'hémodialysés chroniques naïfs de tout traitement par agent stimulant de l’érythropoïèse et étudier les différents facteurs associés à une mauvaise réponse au traitement. Il s'agit une étude prospective mono centrique faite au sein d'une population d’ hémodialysés chroniques. Ont été inclus les patients en hémodialyse depuis plus de 12 mois, naïfs de tout traitement par agent stimulant de l’érythropoïèse (ASE) et ayant un taux d'hémoglobine(Hb) < 10g/dl. L'administration régulière de la CERA et l'ajustement des doses ont été faits selon les recommandations. L’évaluation de la réponse, en fin de traitement, a porté sur l'atteinte ou non d'un taux d'hémoglobine cible > 11g/dl. Sur 87 patients en hémodialyse périodique, 22 (25,3%) sont naïfs de tout traitement par ASE. Il s'agit de 13 hommes et 9 femmes avec un âge moyen de 46 ± 19 ans et une ancienneté en hémodialyse de 67 ± 59 mois. Le taux initial d'hémoglobine est de 7,8 ± 1,3 g/dl. Au bout de 4 mois de traitement régulier par la CERA, le taux final d'Hb est de 10,9 ± 2,1g/dl et 63,6% des patients ont atteint la cible d'Hb > 11g/dl. La dose moyenne de CERA à la fin de l’étude est de 0,89 ± 0,35 µg/kg/15j. L'analyse des facteurs prédictifs montre que la réponse finale dépend du taux d'Hb initial (p = 0,002). En effet, quand le taux d'Hb initial est > 8 g/dl, le taux de réponse est de 88% vs 46% lorsque le taux d'Hb < 8g/dl (p1-3]. Cette complication commune de la maladie rénale chronique est multifactorielle dont le déficit en érythropoïétine est le

  8. Caracterisation des proprietes acoustiques des materiaux poreux a cellules ouvertes et a matrice rigide ou souple

    NASA Astrophysics Data System (ADS)

    Salissou, Yacoubou

    L'objectif global vise par les travaux de cette these est d'ameliorer la caracterisation des proprietes macroscopiques des materiaux poreux a structure rigide ou souple par des approches inverses et indirectes basees sur des mesures acoustiques faites en tube d'impedance. La precision des approches inverses et indirectes utilisees aujourd'hui est principalement limitee par la qualite des mesures acoustiques obtenues en tube d'impedance. En consequence, cette these se penche sur quatre problemes qui aideront a l'atteinte de l'objectif global precite. Le premier probleme porte sur une caracterisation precise de la porosite ouverte des materiaux poreux. Cette propriete en est une de passage permettant de lier la mesure des proprietes dynamiques acoustiques d'un materiau poreux aux proprietes effectives de sa phase fluide decrite par les modeles semi-phenomenologiques. Le deuxieme probleme traite de l'hypothese de symetrie des materiaux poreux selon leur epaisseur ou un index et un critere sont proposes pour quantifier l'asymetrie d'un materiau. Cette hypothese est souvent source d'imprecision des methodes de caracterisation inverses et indirectes en tube d'impedance. Le critere d'asymetrie propose permet ainsi de s'assurer de l'applicabilite et de la precision de ces methodes pour un materiau donne. Le troisieme probleme vise a mieux comprendre le probleme de transmission sonore en tube d'impedance en presentant pour la premiere fois un developpement exact du probleme par decomposition d'ondes. Ce developpement permet d'etablir clairement les limites des nombreuses methodes existantes basees sur des tubes de transmission a 2, 3 ou 4 microphones. La meilleure comprehension de ce probleme de transmission est importante puisque c'est par ce type de mesures que des methodes permettent d'extraire successivement la matrice de transfert d'un materiau poreux et ses proprietes dynamiques intrinseques comme son impedance caracteristique et son nombre d'onde complexe. Enfin, le

  9. Imagerie par contraste en reflexion ou transmission lors d'une procedure par laser au dioxyde de carbone

    NASA Astrophysics Data System (ADS)

    Bourdon, Alexandre

    The use of laser micromachining is now reaching maturity. Laser micromachining is now competing with traditional methods in procedures such as welding, cutting or melting. This thesis will focus on various aspects of the uses of laser in the industry. In each aspect we are drawing our attention on the method to image a given procedure in real-time. In this manuscript we are applying Maxwell's equations to describe the propagation of an electromagnetic wave across various interfaces between media. The approach is tantamount to using Fresnel equation by taking into account the thickness between two successive interfaces bounding a given medium. This theory becomes useful when investigating the evaporation of matter, welding of two dissimilar materials and etching at the surface of a substrate. The progression of welding and etching will be imaged in real-time using an effect of contrast. Various planes of observation that are available in our set-up will allow us to draw firm conclusions in real-time as the procedure develops. Using the principle of contrasting regions it was found that the progression of a laser procedure can be imaged and give interesting details as it evolves in time. It will be also possible to determine when it is time to stop the operation during a laser procedure when a substance evaporates on a substrate. In the case of a laser welding procedure, it will be shown that the imaging method can give some information about the quality of a weld between two different materials. Lastly, it will also be shown that we can image a laser etching procedure by using the contrast of reflectance in neighbouring regions.

  10. Optimisation d'une nanotechnologie liée à la post combustion automobile : étude par EXAFS, RMN & DRX de catalyseurs industriels Zn/Al2O3

    NASA Astrophysics Data System (ADS)

    Bazin, D.; Revel, R.; Klur, I.; Pourpoint, A.

    2002-07-01

    étraédriques) ou de substitution de la spinelle, son caractère lacunaire ne sont pas déterminés. La spectroscopie d'absorption X menée au seuil K du zinc prend alors le relais. De fait, tout en abordant la complexité du protocole de préparation de ces nanoentités, cet exemple illustre une réelle complémentarité entre l'ensemble de ces techniques puisque la mise en oeuvre de la spectroscopie d'absorption X prend son sens uniquement si une étude préalable a été menée par le biais de techniques classiques.

  11. Follow the Footprints: Discover the Hidden Talents of Your Children = Siga las huellas: Busque 105 tesoros escondidos en sus hijos = Swiv piti ou toutan: Chache jween tout don li genyen lot moun pa ka we. Teacher's Reference Edition.

    ERIC Educational Resources Information Center

    Florida State Dept. of Education, Tallahassee. Bureau of Instructional Support and Community Services.

    This brochure, in English, Spanish, and Haitian Creole, is intended to help parents identify children who are gifted and may need an education that goes beyond what is provided in their classrooms. It focuses on eight characteristics typical of such children with examples of behaviors showing the characteristic. The characteristics are: (1)…

  12. Par Pond vegetation status 1996

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1996-12-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995, and into the early spring and late summer of 1996. Communities similar to the pre-drawdown, Par Pond aquatic plant communities continue to become re-established. Emergent beds of maidencane, lotus, waterlily, watershield, and Pontederia are extensive and well developed. Measures of percent cover, width of beds, and estimates of area of coverage with satellite data indicate regrowth within two years of from 40 to 60% of levels prior to the draw down. Cattail occurrence continued to increase during the summer of 1996, especially in the former warm arm of Par Pond, but large beds common to Par Pond prior to the draw down still have not formed. Lotus has invaded and occupies many of the areas formerly dominated by cattail beds. To track the continued development of macrophytes in Par Pond, future surveys through the summer and early fall of 1997, along with the evaluation of satellite data to map the extent of the macrophyte beds of Par Pond, are planned.

  13. Etude par Imagerie à faible Niveau dans le proche Infrarouge d'une Emission de la haute Atmosphère

    NASA Astrophysics Data System (ADS)

    Pautet, Pierre-Dominique

    2000-12-01

    Le travail effectué a eu pour but la mise en place d'un protocole d'observation et de traitement des images, ainsi que les outils appropriés, visant à l'étude d'une émission de la haute atmosphère terrestre dans le proche infrarouge. Il existe actuellement des télescopes comme le VLT (Very Large Telescope), installé au Chili, qui permettent d'observer des astres et des galaxies distants de plusieurs millions de parsecs. A cause de l'expansion de l'Univers, des objets situés aussi loin s'éloignent très rapidement de nous. Le spectre de leur émission qui nous parvient alors est décalé vers le rouge ou l'infrarouge, du fait de l'effet Doppler. Il faut donc observer ces objets dans des longueurs d'onde appropriées. Malheureusement, l'atmosphère terrestre qui nous sépare d'eux est aussi le siège de nombreuses émissions qui peuvent venir perturber les mesures. De toutes ces émissions, la principale est due au radical OH dont les raies de rotation-vibration couvrent tout le spectre entre 0,7 et 2,5 microns. Cette émission a lieu au niveau d'une couche assez fine de la haute atmosphère appelée mésopause et située à environ 85 kilomètres d'altitude. Le travail effectué a eu pour but de mettre en évidence les principales caractéristiques de cette émission qui n'est pas uniforme et constante dans le temps. Un programme d'observations dans le proche infrarouge a été élaboré. Plusieurs algorithmes de traitement d'image ont été développés. Un programme d'inversion de perspective a été mis au point pour une utilisation en temps réel sur le terrain. Les caractéristiques des images peuvent être ensuite analysées. La première partie du mémoire comporte une description des différentes émissions lumineuses que l'on peut observer la nuit lorsque l'on regarde la voûte céleste. Ces émissions peuvent avoir deux origines: astronomique ou atmosphérique. Le problème de l'absorption atmosphérique et plus précisément les conditions

  14. Etude par spectrometrie raman de corticosteroides derives de la fluocortolone: trimethylacetate et caproate.

    PubMed

    Gamot, A P; Vergoten, G; Saudemon, M; Fleury, G

    1985-05-01

    Les spectres Raman de trois corticostéroïdes: fluocortolone base, triméthylacétate et caproate de fluocortolone (TMAF et CAF) ontétéenregistrésàl'état polycristallin entre 150 et 4000 cm(-1). Une attribution des raies observées est proposée. Elle a montréla complexitédu problème poséàsavoir la différenciation de trois composés de structure trés voisine. Cependant quelques intervalles de fréquences contenant des raies spécifiques sont susceptibles d'e^tre utilisés afin de permettre l'identification des composésétudiés. Il convient en premier lieu de distinguer tout particulièrement les raies situées entre 1500 et 1800 cm(-1). Dans l'intervalle 1580-1690 cm(-1) celles-ci sont intenses et spécifiques de la structure conjuguée Delta(1,4) 3-one des corticostéroi des ce qui permet de distinguer la classe de médicamentàlaquelle appartiennent les substancesétudiées. La zone de fréquence comprise entre 1690 et 1750 cm(-1) témoigne non seulement de la présence d'une fonction cétonique sur la chai^ne latérale mais aussi de l'existence d'une fonction ester suivant que l'on y trouve respectivement une ou deux raies (fluocortolone base 1701 cm(-1); TMAF 1728, 1745 cm(-1); CAF 1723, 1745 cm(-1). La fluocortolone base présenteà1635 cm(-1) une raie qui n'est pas retrouvée chez les dérivès estérifiés. En second lieu, nous retiendrons les zones spectrales représentatives des chai^nes latérales estŕrifiées fixées sur le carbone C(21): chai^ne triméthylacétate 340-360, 570-610, 750-810 cm(-1) (dans cette dernière région commune au caproate et au triméthylacétate la différenciation des deux composés se fait grâceàla raieà796 cm(-1) absente dans le spectre du caproate); chai^ne caproate 1310-1350 cm(-1) (dans cet intervalle, le caproate présente un profil très particulier avec trois raies d'intensitévoisine). Cet ensemble de résultats doite^tre utilisépour identifier ces substances par spectroscopie Raman sur des quantiti

  15. Exploration of locomotion in the ParA/ParB system

    NASA Astrophysics Data System (ADS)

    Jindal, Lavisha; Emberly, Eldon

    2015-03-01

    In many bacteria the ParA/ParB system is responsible for actively segregating DNA during replication. ParB precessively moves by hydrolyzing DNA bound ParA-ATP forming a depleted ParA region in its wake. Recent in-vitro experiments have shown that a ParB covered bead can traverse a ParA bound DNA substrate. It has been suggested that the formation of a gradient in ParA leads to diffusion-ratchet like motion of the ParB bead but its origin and potential consequences requires investigation. We have developed a deterministic model for the in-vitro ParA/ParB system and show that any amount of spatial noise in ParA can lead to the spontaneous formation of its gradient. The velocity of the bead is independent of this noise but depends on the scale over which ParA exerts a force on the bead and the scale over which ParB hydrolyzes ParA from the substrate. There is a particular ratio of these scales at which the velocity is a maximum. We also explore the effects of cooperative vs independent rebinding of ParA to the substrate. Our model shows how the driving force for ParB originates and highlights necessary conditions for directed motion in the in-vitro system that may provide insight into the in-vivo behaviour of the ParA/ParB system.

  16. Recuit thermique rapide de semi-conducteur par énergie micro-onde

    NASA Astrophysics Data System (ADS)

    Covas, M.; Gay, H. C.

    1993-05-01

    This paper proposes a new technique for rapid thermal annealing of semi-conductors. This technique is based on microwave energy, and offers the same advantages as the rapid thermal annealing by incoherent light, in terms of rapidity, and contamination. However, our technique reduces considerably the required energy for the annealing process. This technique has been compared to the rapid thermal by incoherent light: lab experiments, carried out on boron implanted silicon samples, showed that a power gain ratio of about 10 can be achieved. Nous proposons une méthode de recuit thermique rapide du silicium par énergie micro-onde. Cette technique offre les mêmes avantages que les traitements thermiques rapides par lumière incohérente, c'est-à-dire des durées de chauffage très brèves, limitant ainsi la diffusion des dopants, et un traitement plaquette par plaquette : les risques de contamination de tout un lot sont ainsi éliminés. De plus notre méthode requiert une faible énergie : pour parvenir à des recuits de qualité similaire à celle obtenue dans des fours de recuit rapide à lampes il faut un flux de puissance 10 fois plus faible.

  17. Le domaine des co-infections et des maladies concomitantes du Réseau canadien pour les essais VIH des IRSC : lignes directrices canadiennes pour la prise en charge et le traitement de la co-infection par le VIH et l’hépatite C chez les adultes

    PubMed Central

    Hull, Mark; Giguère, Pierre; Klein, Marina; Shafran, Stephen; Tseng, Alice; Côté, Pierre; Poliquin, Marc; Cooper, Curtis

    2014-01-01

    HISTORIQUE : De 20 % à 30 % des Canadiens qui vivent avec le VIH sont co-infectés par le virus de l’hépatite C (VHC), lequel est responsable d’une morbidité et d’une mortalité importantes. La prise en charge du VIH et du VHC est plus complexe en raison de l’évolution accélérée de la maladie hépatique, du choix et des critères d’initiation de la thérapie antirétrovirale et du traitement anti-VHC, de la prise en charge de la santé mentale et des toxicomanies, des obstacles socioéconomiques et des interactions entre les nouvelles thérapies antivirales à action directe du VHC et les antirétroviraux OBJECTIF : Élaborer des normes nationales de prise en charge des adultes co-infectés par le VHC et le VIH dans le contexte canadien. MÉTHODOLOGIE : Le Réseau canadien pour les essais VIH des Instituts de recherche en santé du Canada a réuni un groupe d’experts possédant des compétences cliniques en co-infection par le VIH et le VHC pour réviser les publications à jour ainsi que les lignes directrices et les protocoles en place. Après une vaste sollicitation afin d’obtenir des points de vue, le groupe de travail a approuvé des recommandations consensuelles, qu’il a caractérisées au moyen d’une échelle de qualité des preuves fondée sur la classe (bienfaits par rapport aux préjudices) et sur la catégorie (degré de certitude). RÉSULTATS : Toutes les personnes co-infectées par le VIH et le VHC devraient subir une évaluation en vue de recevoir un traitement du VHC. Les personnes qui ne sont pas en mesure d’entreprendre un traitement du VHC devraient être soignées pour le VIH afin de ralentir l’évolution de la maladie hépatique. La norme de traitement du VHC de génotype 1 est un régime comprenant de l’interféron pégylé et de la ribavirine dosée en fonction du poids, associés à un inhibiteur de la protéase du VHC. Pour les génotypes 2 ou 3, une bithérapie classique est recommandée pendant 24 semaines s

  18. Tunable, nonlinear Hong-Ou-Mandel interferometer

    NASA Astrophysics Data System (ADS)

    Oehri, D.; Pletyukhov, M.; Gritsev, V.; Blatter, G.; Schmidt, S.

    2015-03-01

    We investigate the two-photon scattering properties of a Jaynes-Cummings (JC) nonlinearity consisting of a two-level system (qubit) interacting with a single-mode cavity, which is coupled to two waveguides, each containing a single incident photon wave packet initially. In this scattering setup, we study the interplay between the Hong-Ou-Mandel (HOM) effect arising due to quantum interference and effective photon-photon interactions induced by the presence of the qubit. We calculate the two-photon scattering matrix of this system analytically and identify signatures of interference and interaction in the second-order auto- and cross-correlation functions of the scattered photons. In the dispersive regime, when qubit and cavity are far detuned from each other, we find that the JC nonlinearity can be used as an almost linear, in situ tunable beam splitter giving rise to ideal Hong-Ou-Mandel interference, generating a highly path-entangled two-photon NOON state of the scattered photons. The latter manifests itself in strongly suppressed waveguide cross-correlations and Poissonian photon number statistics in each waveguide. If the two-level system and the cavity are on resonance, the JC nonlinearity strongly modifies the ideal HOM conditions leading to a smaller degree of path entanglement and sub-Poissonian photon number statistics. In the latter regime, we find that photon blockade is associated with bunched autocorrelations in both waveguides, while a two-polariton resonance can lead to bunched as well as antibunched correlations.

  19. Un Theorem de Probabilite Zero ou un Dans Groupe Measurable or Topologique Quelconque (O-1 Theorem of Probability in a Measurable or Topological Group).

    DTIC Science & Technology

    1980-02-01

    tribu cylindrique engendree panles coordonn~es xt . ou de la tribu bore" ienne pour une topologie &’ plus fine que celle, ainduite par RrT Dans ce...2] Clairement le probleme concerne d’abird le groupe quotient X/G x G , qui, Si X est muni de la topologie e mais G non fermneO, nest pas separe pour...la topologie quotient (on ne sait rien sur la tribu 2 induite par 2 dans G) et le probl’eme peut etre pose dans (X, 2) groupe measurable (x x x’ -a

  20. Par Pond Fish, Water, and Sediment Chemistry

    SciTech Connect

    Paller, M.H.; Wike, L.D.

    1996-06-01

    The objectives of this report are to describe the Par Pond fish community and the impact of the drawdown and refill on the community, describe contaminant levels in Par Pond fish, sediments, and water and indicate how contaminant concentrations and distributions were affected by the drawdown and refill, and predict possible effects of future water level fluctuations in Par Pond.

  1. Directed and persistent movement arises from mechanochemistry of the ParA/ParB system

    NASA Astrophysics Data System (ADS)

    Hu, Longhua; Vecchiarelli, Anthony G.; Mizuuchi, Kiyoshi; Neuman, Keir C.; Liu, Jian

    The segregation of DNA prior to cell division is essential for faithful genetic inheritance. In many bacteria, segregation of the low-copy-number plasmids involves an active partition system composed of ParA ATPase and its stimulator protein ParB. Recent experiments suggest that ParA/ParB system motility is driven by a diffusion-ratchet mechanism in which ParB-coated plasmid both creates and follows a ParA gradient on the nucleoid surface. However, the detailed mechanism of ParA/ParB-mediated directed and persistent movement remains unknown. We develop a theoretical model describing ParA/ParB-mediated motility. We show that the ParA/ParB system can work as a Brownian ratchet, which effectively couples the ATPase-dependent cycling of ParA-nucleoid affinity to the motion of the ParB bound cargo. Paradoxically, the resulting processive motion relies on quenching diffusive plasmid motion through a large number of transient ParA/ParB-mediated tethers to the nucleoid surface. Our work sheds light on a new emergent phenomenon in which non-motor proteins work collectively via mechanochemical coupling to propel cargos -- an ingenious solution shaped by evolution to cope with the lack of processive motor proteins in bacteria.

  2. Evaluation d’un enseignement par les étudiants appliquée au module « aide à la rédaction de thèse»: destiné aux internes des hôpitaux des Armées au Centre d’épidémiologie et de Santé Publique des Armées, Marseille

    PubMed Central

    Kasouati, Jalal; Velut, Guillaume; Deparis, Xavier; Touloune, Farida

    2016-01-01

    Introduction En éducation, l'évaluation concerne les institutions de formation, les programmes, les enseignants ou les étudiants. Elle peut être prédictive, sommative ou formative. L'Evaluation d'un Enseignement par les Etudiants (EEE) est l'un des outils de ce dernier type. Objectif Évaluer l'enseignement de la première partie de la formation « aide à la rédaction de thèse ». Méthodes C'est une étude transversale classée dans le cadre « EEE » qui a porté sur le module « aide à la rédaction de thèse » dispensée au CESPA au profit de 27 participants préparant leur projet de fin d'étude. Résultats Le taux de réponse des participants présents était de 100%. D'un sexe ratio F/M de 2 et de une moyenne d'âge de 25,5 ans +/- 2,7 ans, les questionnés étaient majoritairement des internes de médecine générale. Plus de 85% affirmait n'avoir bénéficié d'aucune formation au préalable dans les domaines traités. Les participants avaient des attentes qui rejoignaient sommairement les objectifs de la formation. A part le rythme jugé non adapté par plus de la moitié, 80% des participants ont été satisfaits des autres aspects évalués et 95,8% parmi eux prévoyaient d'assister à la deuxième partie de la formation Pour tout les participants, la formation a permis d'amélioré de façon significative leur connaissance et aurais certainement un impact positif sur leurs travaux de recherche. Conclusion Notre travail était un moyen d'installer une certaine complicité entre les étudiants et les enseignants pour atteindre un objectif commun: « AMELIORER LA FORMATION ». PMID:27800091

  3. Caracterisation et transformation par hydroviscoreduction du brut lourd de Doba/Tchad: Strategie de pompage par pipeline

    NASA Astrophysics Data System (ADS)

    Dehkissia, Soumaine

    Le projet de la these est defini par rapport a la recente exploitation commerciale du brut lourd de Doba, une region du Tchad, pays enclave d'ou le brut ainsi produit doit etre achemine par pipeline. Le but dans ce travail est de caracteriser ce brut et de determiner une strategie thermique de transformation en vue de reduire de la facon la plus economique, la viscosite du brut pour permettre son transport par pipeline. Concernant la partie caracterisation, nous avons utilise entre autres, un rheometre rotatif et des analyseurs (LECO CHN-2000 & LECO S-144DR Elemental Analyzers) pour evaluer respectivement la viscosite et les elements tels que C, H, N, O, S. Sur la base des methodes de transformation disponibles, nous avons determine une strategie simple de transformation thermique par hydroviscoreduction , strategie dans laquelle, la fraction legere du brut comme le naphta (80--180°C), pourrait constituer la source d'hydrogene a utiliser. Le brut de Doba, a une faible teneur en soufre (0.14%) et sa densite specifique de 0.940 a 15.6°C, soit 18.8° API, le classe parmi les bruts lourds. Outre le point initial se situant a 85°C, la distillation du brut a revele que la fraction distillant avant 250°C ne represente que 10% (v/v) et que le craquage thermique du substrat debute a 300°C. Par ailleurs, outre son caractere Newtonien, les densites specifiques de la fraction lourde de l'essence (100--200°C) et de la fraction distillant au-dessus 350°C, etant respectivement de 0.813 (0.813 > 0.800) et de 0.951 (0.930 < 0.951 < 0.975), le brut de Doba est donc de type aromatique. Les viscosites du brut et du brut desasphalte, sont respectivement de 184.4 cSt et 152.4 cSt a 50°C, suggerant que le desasphaltage ne constitue pas une methode efficace pouvant aider au pompage du brut par pipeline, d'ou la necessite de transformation. Les resultats des travaux en autoclave montrent que, si le brut doit etre traite entierement, la viscosite de 25cSt 50°C, recommandee pour le

  4. Atomic Hong-Ou-Mandel experiment

    NASA Astrophysics Data System (ADS)

    Lopes, R.; Imanaliev, A.; Aspect, A.; Cheneau, M.; Boiron, D.; Westbrook, C. I.

    2015-04-01

    Two-particle interference is a fundamental feature of quantum mechanics, and is even less intuitive than wave-particle duality for a single particle. In this duality, classical concepts--wave or particle--are still referred to, and interference happens in ordinary space-time. On the other hand, two-particle interference takes place in a mathematical space that has no classical counterpart. Entanglement lies at the heart of this interference, as it does in the fundamental tests of quantum mechanics involving the violation of Bell's inequalities. The Hong, Ou and Mandel experiment is a conceptually simpler situation, in which the interference between two-photon amplitudes also leads to behaviour impossible to describe using a simple classical model. Here we report the realization of the Hong, Ou and Mandel experiment using atoms instead of photons. We create a source that emits pairs of atoms, and cause one atom of each pair to enter one of the two input channels of a beam-splitter, and the other atom to enter the other input channel. When the atoms are spatially overlapped so that the two inputs are indistinguishable, the atoms always emerge together in one of the output channels. This result opens the way to testing Bell's inequalities involving mechanical observables of massive particles, such as momentum, using methods inspired by quantum optics, and to testing theories of the quantum-to-classical transition. Our work also demonstrates a new way to benchmark non-classical atom sources that may be of interest for quantum information processing and quantum simulation.

  5. Atomic Hong-Ou-Mandel experiment.

    PubMed

    Lopes, R; Imanaliev, A; Aspect, A; Cheneau, M; Boiron, D; Westbrook, C I

    2015-04-02

    Two-particle interference is a fundamental feature of quantum mechanics, and is even less intuitive than wave-particle duality for a single particle. In this duality, classical concepts--wave or particle--are still referred to, and interference happens in ordinary space-time. On the other hand, two-particle interference takes place in a mathematical space that has no classical counterpart. Entanglement lies at the heart of this interference, as it does in the fundamental tests of quantum mechanics involving the violation of Bell's inequalities. The Hong, Ou and Mandel experiment is a conceptually simpler situation, in which the interference between two-photon amplitudes also leads to behaviour impossible to describe using a simple classical model. Here we report the realization of the Hong, Ou and Mandel experiment using atoms instead of photons. We create a source that emits pairs of atoms, and cause one atom of each pair to enter one of the two input channels of a beam-splitter, and the other atom to enter the other input channel. When the atoms are spatially overlapped so that the two inputs are indistinguishable, the atoms always emerge together in one of the output channels. This result opens the way to testing Bell's inequalities involving mechanical observables of massive particles, such as momentum, using methods inspired by quantum optics, and to testing theories of the quantum-to-classical transition. Our work also demonstrates a new way to benchmark non-classical atom sources that may be of interest for quantum information processing and quantum simulation.

  6. Hernie inguinale ou vésicale ?

    PubMed Central

    El Anzaoui, Jihad; El Harrech, Y.; Abbaka, N.; Touiti, D.; Lahkim, M.; Fihri, J. Fassi; Bakzaza, W.; Majdane, M.; Achour, A.

    2013-01-01

    Résumé Si la hernie inguinale est une pathologie fréquente en chirurgie digestive, elle touche rarement la vessie. La hernie vésicale ne se manifeste généralement par aucun signe particulier, et son diagnostic est le plus souvent peropératoire, parfois même postopératoire lors de l’apparition de complications. Le traitement est chirurgical ; il consiste à réintégrer la partie herniée et à réaliser une pariétorraphie. Le présent article fait état de l’observation médicale d’un patient présentant une hernie vésicale de découverte peropératoire. PMID:24475009

  7. Parallel Climate Analysis Toolkit (ParCAT)

    SciTech Connect

    Smith, Brian Edward

    2013-06-30

    The parallel analysis toolkit (ParCAT) provides parallel statistical processing of large climate model simulation datasets. ParCAT provides parallel point-wise average calculations, frequency distributions, sum/differences of two datasets, and difference-of-average and average-of-difference for two datasets for arbitrary subsets of simulation time. ParCAT is a command-line utility that can be easily integrated in scripts or embedded in other application. ParCAT supports CMIP5 post-processed datasets as well as non-CMIP5 post-processed datasets. ParCAT reads and writes standard netCDF files.

  8. Overproduction and localization of Mycobacterium tuberculosis ParA and ParB proteins

    PubMed Central

    Maloney, Erin; Madiraju, Murty; Rajagopalan, Malini

    2011-01-01

    SUMMARY The ParA and ParB family proteins are required for accurate partitioning of replicated chromosomes. The Mycobacterium tuberculosis genome contains parB, parA and two parA homologs, Rv1708 and Rv3213c. It is unknown if parA and its homologs are functionally related. To understand the roles of ParA and ParB proteins in M. tuberculosis cell cycle, we have evaluated the consequences of their overproduction and visualized their localization patterns in M. smegmatis. We show that cells overproducing of ParA, Rv1708 and Rv3213c and ParB are filamentous and multinucleoidal indicating defects in cell cycle progression. Visualization of green-fluorescent protein fusions of ParA and its homologues showed similar localization patterns with foci at poles, quarter-cell, midcell positions and spiral-like structures indicating that they are functionally related. On the other hand, the ParBGFP fusion protein localized only to the cell poles. The cyan and yellow fluorescent fusion proteins of ParA and ParB, respectively, colocalized at the cell poles indicating that these proteins interact and possibly associate with the chromosomal origin of replication. Collectively our results suggest that the M. tuberculosis Par proteins play important roles in cell cycle progression. PMID:20006309

  9. suPAR: The Molecular Crystal Ball

    PubMed Central

    Thunø, Maria; Macho, Betina; Eugen-Olsen, Jesper

    2009-01-01

    soluble urokinase Plasminogen Activator Receptor (suPAR) levels reflect inflammation and elevated suPAR levels are found in several infectious diseases and cancer. suPAR exists in three forms; suPARI-III, suPARII-III and suPARI which show different properties due to structural differences. Studies suggest that full-length suPAR is a regulator of uPAR/uPA by acting as uPA-scavenger, whereas the cleaved suPARII-III act as a chemotactic agent promoting the immune response via the SRSRY sequence in the linker-region. This review focus on the various suPAR fragments and their involvement in inflammation and pathogenic processes. We focus on the molecular mechanisms of the suPAR fragments and the link to the inflammatory process, as this could lead to medical applications in infectious and pathological conditions. PMID:19893210

  10. Brulure par Foudre. A Propos d’une Observation

    PubMed Central

    Mradmi, W.; Fassi-Fihri, J.; Mehaji, G.; Ezzoubi, M.; Diouri, M.; Bahechar, N.; Boukind, E.H.

    2005-01-01

    Summary Aussi loin que l’on remonte dans la littérature, on retrouve des récits relatant des accidents consécutifs à la fulguration chez l’homme. La foudre était alors associée à la colère des dieux ou à la notion de châtiment. La fulguration correspond à un transfert d’énergie entre un cumulonimbus de charge négative et un objet de charge positive se trouvant au niveau du sol. Les lésions déterminées sont à la fois thermiques et électrothermiques. Bien que l’arrêt cardiorespiratoire soit une cause bien documentée de décès, la plupart des cas rapportés dans la littérature décrivent un éventail très disparate des séquelles qui surviennent suite à cet accident. Les Auteurs rapportent le cas d’un patient atteint par la foudre en insistant particulièrement sur les complications neurologiques qui sont survenues en cours d’évolution. Se basant sur cette observation et sur une revue de la littérature, les Auteurs soulignent que le pronostic des patients atteints par la foudre est plus favorable que généralement rapporté. PMID:21990993

  11. Directed and persistent movement arises from mechanochemistry of the ParA/ParB system

    PubMed Central

    Hu, Longhua; Vecchiarelli, Anthony G.; Mizuuchi, Kiyoshi; Neuman, Keir C.; Liu, Jian

    2015-01-01

    The segregation of DNA before cell division is essential for faithful genetic inheritance. In many bacteria, segregation of low-copy number plasmids involves an active partition system composed of a nonspecific DNA-binding ATPase, ParA, and its stimulator protein ParB. The ParA/ParB system drives directed and persistent movement of DNA cargo both in vivo and in vitro. Filament-based models akin to actin/microtubule-driven motility were proposed for plasmid segregation mediated by ParA. Recent experiments challenge this view and suggest that ParA/ParB system motility is driven by a diffusion ratchet mechanism in which ParB-coated plasmid both creates and follows a ParA gradient on the nucleoid surface. However, the detailed mechanism of ParA/ParB-mediated directed and persistent movement remains unknown. Here, we develop a theoretical model describing ParA/ParB-mediated motility. We show that the ParA/ParB system can work as a Brownian ratchet, which effectively couples the ATPase-dependent cycling of ParA–nucleoid affinity to the motion of the ParB-bound cargo. Paradoxically, this resulting processive motion relies on quenching diffusive plasmid motion through a large number of transient ParA/ParB-mediated tethers to the nucleoid surface. Our work thus sheds light on an emergent phenomenon in which nonmotor proteins work collectively via mechanochemical coupling to propel cargos—an ingenious solution shaped by evolution to cope with the lack of processive motor proteins in bacteria. PMID:26647183

  12. Results of vitrifying Fernald OU-4 wastes

    SciTech Connect

    Merrill, R.A.; Janke, D.S.

    1993-02-01

    Three silos in Operable Unit 4 (OU-4) at the Feed Materials Production Center in Fernald, Ohio, contain residues from the processing of pitchblende ores. Silos 1 and 2, designated as K-65, contain the depleted ore with a BentoGrout cap over the material to reduce radon emanation, while Silo 3 contains calcined residue from processing solutions. The residues in the three silos contain radium, uranium, uranium daughters, and heavy metals (primarily lead). Vitrification tests were carried out on various mixtures of the above materials and the resulting glasses were analyzed. The vitrified residues all tested ``non-hazardous`` by the Toxicity Characteristic Leachate Procedure (TCLP) and demonstrated a high degree of durability by the Product Consistency Test (PCT). The specific gravity and radon emanation of both the vitrified and non-vitrified residue were measured. Volume reductions ranging from 50 to 68 percent were obtained while the radon emanation rate was reduced by a factor of about 500,000. Radon emanation from the vitrified residue is of the same order of magnitude as emanation from natural building materials such as brick or concrete.

  13. Results of vitrifying Fernald OU-4 wastes

    SciTech Connect

    Merrill, R.A. ); Janke, D.S. )

    1993-02-01

    Three silos in Operable Unit 4 (OU-4) at the Feed Materials Production Center in Fernald, Ohio, contain residues from the processing of pitchblende ores. Silos 1 and 2, designated as K-65, contain the depleted ore with a BentoGrout cap over the material to reduce radon emanation, while Silo 3 contains calcined residue from processing solutions. The residues in the three silos contain radium, uranium, uranium daughters, and heavy metals (primarily lead). Vitrification tests were carried out on various mixtures of the above materials and the resulting glasses were analyzed. The vitrified residues all tested non-hazardous'' by the Toxicity Characteristic Leachate Procedure (TCLP) and demonstrated a high degree of durability by the Product Consistency Test (PCT). The specific gravity and radon emanation of both the vitrified and non-vitrified residue were measured. Volume reductions ranging from 50 to 68 percent were obtained while the radon emanation rate was reduced by a factor of about 500,000. Radon emanation from the vitrified residue is of the same order of magnitude as emanation from natural building materials such as brick or concrete.

  14. [Ambroise Paré, landlord].

    PubMed

    Pion-Graff, Joëlle; Bonnichon, Philippe

    2010-01-01

    Paré is well-known through many papers. His incomes allowed him to have a middle-class Parisian living. It is impossible to have an accurate knowledge of his fortune before his death but we have a good idea of his landed property. In fact as a Parishioner of Saint-Andre-des-Arts Church he probably was a landlord only in Paris and its vicinity with a building (rue de l'Hirondelle), two houses (rue Garancière), Meudon, Cormeille-en-Parisis and La-Ville-Du-Bois which the authors describe the present state of.

  15. L’administration postnatale de corticoïdes pour traiter ou prévenir les affections pulmonaires chroniques chez les prématurés

    PubMed Central

    2002-01-01

    Le présent énoncé est conçu à l’intention des professionnels de la santé qui soignent des nouveau-nés et de jeunes nourrissons. Il vise à examiner les effets à court et à long terme de l’administration postnatale de corticoïdes systémiques et par inhalation pour prévenir ou traiter une affection pulmonaire chronique évolutive ou établie et à faire des recommandations quant à l’usage de corticoïdes chez les nourrissons à très faible poids de naissance. Le recours systématique à la dexaméthasone systémique pour prévenir ou traiter une affection pulmonaire chronique n’est pas recommandé chez les nourrissons à très faible poids de naissance.

  16. Congenital ureteropelvic junction obstruction: physiopathology, decoupling of tout court pelvic dilatation-obstruction semantic connection, biomarkers to predict renal damage evolution.

    PubMed

    Alberti, C

    2012-02-01

    The widespread use of fetal ultrasonography results in a frequent antenatally observation of hydronephrosis, ureteropelvic junction obstruction (UPJO) accounting for the greatest fraction of congenital obstructive nephropathy. UPJO may be considered, in most cases, as a functional obstructive condition, depending on defective fetal smooth muscle/nerve development at this level, with lack of peristaltic wave propagation--aperistaltic segment--and, therefore, poor urine ejection from the renal pelvis into the ureter. The UPJO-related physiopathologic events are, at first, the compliant dilatation of renal pelvis that, acting as hydraulic buffer, protects the renal parenchyma from the rising intrapelvic pressure-related potential damages, and, subsequently, beyond such phase of dynamic balance, the tubular cell stretch-stress induced by increased intratubular pressure and following parenchymal inflammatory lesions: inflammatory infiltrates, fibroblast proliferation, activation of myofibroblasts, tubulo-interstitial fibrosis. Reactive oxygen species (ROS), nitric oxide (NO), several chemo- and cytokines, growth factors, prostaglandins and eicosanoids, angiotensin-II are the main pathogenetic mediators of the obstructive nephropathy. Apoptosis of tubular cells is the major cause of the tubular atrophy, together with epithelial-mesenchymal transdifferentiation. Some criticisms on tout court semantic renal pelvis dilatation-obstruction connection have been raised considering that the renal pelvis expansion isn't, in any case, linked to an ostructive condition, as it may be verified by diuretic (furosemide) renogram together with scintiscan-based evaluation of differential renal function. In this regard, rather than repetitive invasive nuclear procedures that expose the children to ionizing radiations, an intriguing noninvasive strategy, based on the evaluation of urinary biomarkers and urinary proteome, can define the UPJO-related possible progress of parenchymal lesions

  17. PAR for the Course: A Congruent Pedagogical Approach for a PAR Methods Class

    ERIC Educational Resources Information Center

    Hammond, Joyce D.; Hicks, Maria; Kalman, Rowenn; Miller, Jason

    2005-01-01

    In the past two years, three graduate students and a senior faculty member have co-taught a participatory action research (PAR) course to undergraduate and graduate students. In this article the co-teachers advocate a set of pedagogical principles and practices in a PAR-oriented classroom that establishes congruency with community PAR projects in…

  18. La structure de l'eau liquide: Une etude thermique par spectroscopie infrarouge

    NASA Astrophysics Data System (ADS)

    Larouche, Pascal

    mesures de diffraction des rayons X ont aussi ete analysees. Les abondances tirees de l'analyse par facteurs des spectres infrarouges permettent de calculer les fonctions de distributions radiales des deux especes. Ces fonctions offrent la possibilite de connaitre les distances relatives entre les atomes. Avec ces distances en main, l'architecture des deux especes peut etre schematisee. Ces resultats originaux, combines a ceux issus de la spectroscopie infrarouge, permettent de montrer que la premiere espece est bien organisee, c'est-a-dire que le cube defini par un atome d'oxygene et les quatre autres atomes d'oxygene avec lesquels il est en liens-H est regulier, alors que pour l'espece chaude, les dimensions du cubes sont irregulieres. La comparaison entre les deux especes montre qu'elles etablissent toujours quatre liens-H et que leurs differences resident uniquement dans la geometrie des cubes. Finalement, deux hypotheses sont formulees comme fondement d'un modele de la structure de l'eau liquide. Premierement, l'empilement des cubes des deux especes permet de representer l'eau a toutes les temperatures, l'espece froide etant garante de la stabilite du liquide, alors que l'espece chaude a un effet destabilisant; et deuxiemement, le saut du proton stabilise les liens-H, de telle sorte que lorsque l'espece chaude devient trop abondante, ces defauts provoquent un arret des sauts de protons et les liens-H ainsi affaiblis se brisent et le liquide s'evapore.

  19. Gliome du nerf optique révélé par un strabisme divergent

    PubMed Central

    Handor, Hanan; Laghmari, Mina; Hafidi, Zouheir; Daoudi, Rajae

    2014-01-01

    Les gliomes des nerfs optiques sont des tumeurs rares qui s'observent essentiellement chez l'enfant. L'exophtalmie et le strabisme sont les principaux signes révélateurs de la maladie. La neuroimagerie et notamment l'imagerie par résonnance magnétique est d'un grand apport dans le diagnostic et le suivi de ces tumeurs. La prise en charge thérapeutique de ces gliomes fait appel à différents moyens: l'exérèse chirurgicale, la chimiothérapie, la radiothérapie ou l'abstention sous surveillance. Les indications doivent être discutées au cas par cas. PMID:25309656

  20. Manipulation quantique de la lumière par un amplificateur non linéaire

    NASA Astrophysics Data System (ADS)

    Symul, T.; Bencheikh, K.; Levenson, J. A.

    2002-06-01

    Nous proposons un dispositif original, appelé Amplificateur Non Linéaire (ANL), permettant la génération et la manipulation d'états quantiques de la lumière. Ce dispositif permet une compression du bruit quantique de la lumière en dessous de la limite quantique standard plus efficace que celle obtenue par interactions non linéaires du second ordre ou du troisième ordre. Il permet également d'inverser les fluctuations quantiques en intensité de la lumière, et de produire des photons jumeaux ayant des corrélations quantiques plus élevées et plus robustes que ceux produits par un amplificateur paramétrique seul.

  1. Par Pond vegetation status Summer 1995 -- Summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1996-01-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995. Communities similar to the pre-drawdown, Par Pond aquatic plant communities are becoming re-established. Emergent beds of maidencane, lotus, waterlily, and watershield are extensive and well developed. Cattail occurrence continued to increase during the summer, but large beds common to Par Pond prior to the drawdown have not formed. Estimates from SPOT HRV, remote sensing satellite data indicated that as much as 120 hectares of emergent wetlands vegetation may have been present along the Par Pond shoreline by early October, 1995. To track the continued development of macrophytes in Par Pond, future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned.

  2. Émission X(L) du xénon par interaction laser-agrégats

    NASA Astrophysics Data System (ADS)

    Adoui, L.; Gobert, O.; Indelicato, P.; Lamour, E.; Meynadier, P.; Normand, D.; Perdrix, M.; Prigent, C.; Rozet, J.-P.; Vernhet, D.

    2003-06-01

    Nous avons étudié le rayonnement X provenant d'ions fortement multichargés (ge24+) présentant des lacunes en couche L produits lors de l'irradiation d'agrégats de xénon par des impulsions lumineuses issues d'un laser femtoseconde de puissance. Les résultats obtenus lors de la toute dernière campagne d'expériences réalisée auprès du serveur LUCA du SPAM/DRECAM au CEA/Saclay mettent en cause certains travaux antérieurs [4-6]. Des divergences marquées apparaissent tant au niveau de l'interprétation des spectres X que sur la variation du taux d'émission en fonction de l'éclairement et de la longueur d'onde.

  3. Etude par spectroscopie de Coulomb de points quantiques lateraux individuels et couples

    NASA Astrophysics Data System (ADS)

    Pioro-Ladriere, Michel

    Des points quantiques contenant un nombre discret et variable d'electrons sont formes dans un gaz bi-dimensionnel d'electrons a l'aide de grilles metalliques. Le transport electrique, le blocage de spin et la detection de charge sont employes comme outils spectroscopiques permettant de sonder les proprietes de ces nanostructures. Ces techniques permettent aussi de controler exactement le nombres d'electrons confines dans des points quantiques individuels et couples en utilisant un patron de grille judicieux. Une technique de refroidissement en tension est developpee afin de minimiser les effets parasites du bruit telegraphique. Ce type de bruit de charge deteriore la stabilite des nanostructures laterales par l'activation d'un minuscule courant de fuite entre les grilles et le gaz bi-dimensionnel. Un modele expliquant le role du refroidissement en tension sur le courant de fuite est presente. L'activation du courant de fuite est confirmee par detection de charge. Les effets des interactions entre les electrons pieges dans un point quantique sont ensuite etudies dans un regime ou il est possible de comparer les resulats experimentaux avec ceux obtenus par diagonalisation exacte. L'etude demontre que la phase associee au facteur de remplissage nu = 2 est instable au-dessus d'un nombre critique d'electrons. Cette instabilite est confirmee experimentalement par blocage de spin. On demontre aussi l'existence d'etats correles dans le regime des renversements de spin, associe au passage de la phase nu = 2 a nu = 1. Les etats correles sont identifies par spectroscopie en transport non lineaire. Cette caracterisation du diagramme de phase de points individuels permet de coupler deux points quantiques configures a nu = 2. Pour ce regime, la nanostructure se comporte comme un systeme a deux niveaux pouvant contenir entre un et quatre electrons de valence et ce, meme si le nombre total d'electrons est plus eleve. Les degres de liberte de charge et de spin des deux points

  4. Lait humain provenant d’une banque de dons ou acheté en ligne?

    PubMed Central

    St-Onge, Maude; Chaudhry, Shahnaz; Koren, Gideon

    2015-01-01

    Résumé Question Une de mes patientes m’a demandé si elle pourrait se procurer du lait humain par Internet pour allaiter son nourrisson s’il le fallait. L’usage de lait humain provenant d’une banque de dons est-il plus sécuritaire que son achat en ligne? Réponse L’Organisation mondiale de la Santé et l’American Academy of Pediatrics recommandent d’utiliser des dons de lait humain comme choix à privilégier lorsque le lait maternel n’est pas disponible. Cependant, la Société canadienne de pédiatrie n’approuve pas le partage de lait humain non traité. Le lait humain entreposé dans les banques de lait diffère de celui qu’on peut se procurer par Internet en raison du processus rigoureux de sélection des donneuses, des fréquentes inspections de la qualité, des procédés de transport règlementés et du processus de pasteurisation conforme aux directives établies par l’Agence canadienne d’inspection des aliments. La plupart des échantillons achetés en ligne contiennent des bactéries à gram négatif ou comptent au total plus de 104 unités formant colonies de bactéries aérobiques par millilitre; ils renferment aussi en moyenne au décompte total plus de bactéries aérobiques, de bactéries à gram négatif, de coliformes et de Staphylococcus spp que les échantillons des banques de lait. La croissance de la plupart des espèces de bactéries est associée au nombre de jours en transit, ce qui porte à croire que les conditions de collecte, d’entreposage et de transport sont médiocres pour le lait acheté en ligne.

  5. Un lymphangiome kystique rétropéritonéal révélé par des coliques néphrétiques

    PubMed Central

    El anzaoui, Jihad; Ghoundale, Omar; Touiti, Driss; El barni, Rachid; Mejdane, Abdelhadi; Fihri, Jawad Fassi; Lahkim, Mohammed; Achour, Abdsamad

    2015-01-01

    Résumé Le lymphangiome kystique (LK) est une tumeur rare des voies lymphatiques caractérisée par son évolution bénigne. La fréquence de la localisation rétropéritonéale est controversée. La découverte se fait le plus souvent dès l’enfance. L’évolution de la maladie peut être marquée par des complications graves, notamment compressives. Nous faisons état de l’observation médicale d’une femme de 30 ans chez qui l’on a découvert, à la suite de l’apparition de coliques néphrétiques récidivantes, un LK énorme occupant tout l’espace rétropéritonéal droit. Le diagnostic a été évoqué par l’urotomodensitométrie et confirmé par l’histologie. L’évolution après exérèse chirurgicale de la masse a été favorable, avec la disparition des coliques néphrétiques. PMID:25844099

  6. Le syndrome du canal d’Alcock ou névralgie pudendale : un diagnostic à ne pas méconnaître

    PubMed Central

    Ziouziou, Imad; Bennani, Hassan; Zizi, Mohamed; Karmouni, Tarik; Khader, Khalid El; Koutani, Abdellatif; Andaloussi, Ahmed Iben Attya

    2013-01-01

    Résumé Le syndrome du canal d’Alcock – ou névralgie pudendale – est lié à la compression chronique du nerf pudendal dans la fossette ischiorectale ou au niveau du ligament sacroépineux. Le diagnostic du syndrome d’Alcock est surtout clinique. Les examens complémentaires sont dominés par les explorations électrophysiologiques et le test de bloc anesthésique. Le diagnostic repose sur des critères bien précis, soit les critères de Nantes. La prise en charge doit être globale, comprenant un traitement médicamenteux, des infiltrations, des techniques de neuromodulation, et dans les cas graves ou résistants, un traitement chirurgical qui consiste à libérer le nerf pudendal. Les névralgies pudendales peuvent être rencontrées après traitement d’une incontinence urinaire d’effort par bande-lettes sous-urétrales (TVT). Ce syndrome motive des consultations en urologie, car la douleur intéresse le territoire du périnée et des organes génitaux. Des signes urinaires peuvent aussi accompagner cette douleur. Il est donc judicieux de connaître cette pathologie. PMID:23914265

  7. Comparative cactus architecture and par interception

    SciTech Connect

    Geller, G.N.; Nobel, P.S. )

    1987-07-01

    Because CO{sup 2} uptake by cacti can be limited by low levels of photosynthetically active radiation (PAR) and because plant form affects PAR interception, various cactus forms were studied using a computer model, field measurements, and laboratory phototropic studies. Model predictions indicated that CO{sub 2} uptake by individual stems at an equinox was greatest when the stem were vertical, but at the summer and the winter solstice CO{sub 2} uptake was greatest for stems titled 30{degree} away from the equator. Stem tilting depended on form and taxonomic group. Not only can the shape of cacti be affected by PAR, but also shape influences PAR interception and hence CO{sub 2} uptake.

  8. L’identification et traitement du trouble panique avec ou sans agoraphobie

    PubMed Central

    Foldes-Busque, Guillaume; Marchand, André; Landry, Pierre

    2007-01-01

    RÉSUMÉ OBJECTIF Renseigner les médecins de première ligne au sujet de l’identification précoce, du diagnostic et du traitement du trouble panique avec ou sans agoraphobie (TP/A). QUALITÉ DES DONNÉES Les données et recommandations présentées proviennent d’une recension des écrits scientifiques réalisée via les banques de données PsycLIT, PsyINFO et MEDLINE (1985 à 2006) en utilisant les descripteurs panic disorder, psychotherapy, psychosocial treatment, treatment et pharmacotherapy. Les recommandations formulées par les auteurs s’appuient sur des données probantes provenant d’études d’excellente qualité. Les informations concernant le diagnostic et l’évaluation du TP/A proviennent d’études épidémiologiques récentes, de consensus et d’opinions d’experts. PRINCIPAL MESSAGE Le TP/A est un trouble psychiatrique souvent rencontré en médecine de première ligne, mais il est fréquemment sous-diagnostiqué et sous-traité. L’identification précoce de ce trouble demande une attention particulière aux symptômes médicalement inexpliqués et, le cas échéant, le médecin doit utiliser des questions spécifiques permettant d’identifier d’éventuelles attaques de panique et de cerner leur signification pour le patient. Le traitement de premier choix pour ce trouble est une psychothérapie d’orientation cognitivo-comportementale administrée par un psychologue ou un psychiatre spécialisé. Si de telles ressources ne sont pas disponibles, le médecin peut opter pour un traitement psychopharmacologique. CONCLUSION Les médecins de famille peuvent jouer un rôle central dans l’identification et le traitement des patients souffrant d’un TP/A. PMID:17934032

  9. Ablation de ZnO par laser UV (193 nm) : nano-agrégats en phase gazeuse

    NASA Astrophysics Data System (ADS)

    Ozerov, I.; Bulgakov, A.; Nelson, D.; Castell, R.; Sentis, M.; Marine, W.

    2003-06-01

    La condensation de nano-agrégats d'oxyde de zinc en phase gazeuse est mise en évidence lors de l'ablation de ZnO massif par laser ArF pulsé. Nous comparons l'évolution spatio-temporelle de la forme du panache d'ablation (plume) de ZnO sous vide et sous atmosphère de gaz de couverture (oxygène et/ou hélium) à partir des images CCD et des résultats issus d'analyses spectroscopiques. L'expansion du plasma et la croissance des nano-clusters sont influencées par l'effet du confinement de la plume dû aux collisions entre les particules ablatées et les molécules de gaz ambiant ainsi que par les réactions chimiques dans le cas de l'oxygène. Le spectre de rayonnement du plasma est constitué principalement par l'émission d'atomes excités de Zn neutre. Nous avons observé la photoluminescence des nano-agrégats en suspension dans le gaz ainsi que leur décomposition par laser ArF.

  10. Étude par microscopie acoustique de couches minces de Ag2S déposées par spray

    NASA Astrophysics Data System (ADS)

    Amlouk, M.; Brunet, N.; Cros, B.; Belgacem, S.; Barjon, D.

    1997-09-01

    Silver sulfide Ag2S thin films have been prepared on pyrex glass substrates by the spray pyrolysis technique at 250 °C. We have analyzed by acoustic microscopy and particularly by acoustic signature V(z) these films with various thickness (0.4 2 μm). The acoustic signature, performed at 50, 130 and 570 MHz allow us to reach elastic properties of Ag2S material and specially Young modulus. Its value, of the order of 180 GPa, is consistent with the relative low linkage of Ag^+ in the structure and the character of fast-ion conductor of Ag2S. Besides elastic properties and using MEB and AFM investigations, we have shown that the V(z) signature gives valuable information about the bulk defects in the material. Finally, the experimental results have been discussed related to the dispersion curves of velocity of the first mode of Ag2S/pyrex system. Des couches minces de sulfure d'argent Ag2S sont préparées sur substrat de pyrex, à la température de 250 °C, par la technique de pulvérisation chimique réactive en phase liquide ou “spray". Ces dépôts, d'épaisseur variable (0,4 2 μm), sont analysés par microscopie acoustique et, plus particulièrement, par la méthode de relevé de la signature acoustique V(z). Cette signature, effectuée à différentes fréquences (50, 130, 570 MHz), a permis de caractériser les propriétés élastiques du matériau Ag2S. La valeur du module d'Young, de l'ordre de 180 GPa, est en accord avec la faible cohésion de la liaison Ag-S et le caractère de conducteur ionique rapide de Ag2S. Les observations par MEB et AFM permettent d'expliquer l'allure des courbes V(z) par les défauts de compacité liés à la méthode de préparation. Les résultats expérimentaux sont discutés en liaison avec la courbe de dispersion de vitesses du premier mode du système Ag2S/pyrex.

  11. Hong-Ou-Mandel interferometer with cavities: Theory

    SciTech Connect

    Olindo, C.; Sagioro, M. A.; Monken, C. H.; Padua, S.; Delgado, A.

    2006-04-15

    We study the number of coincidences in a Hong-Ou-Mandel interferometer exit whose arms have been supplemented with the addition of one or two optical cavities. The fourth-order correlation function at the beam splitter exit is calculated. In the regime where the cavities lengths are larger than the one-photon coherence length, photon coalescence and anticoalescence interference is observed. Feynman's path diagrams for the indistinguishable processes that lead to quantum interference are presented. The construction of an optical XOR gate is discussed as an application for the Hong-Ou-Mandel interferometer with two cavities.

  12. Techniques for measuring intercepted and absorbed PAR in corn canopies

    NASA Technical Reports Server (NTRS)

    Gallo, K. P.; Daughtry, C. S. T.

    1984-01-01

    The quantity of radiation potentially available for photosynthesis that is captured by the crop is best described as absorbed photosynthetically active radiation (PAR). Absorbed PAR (APAR) is the difference between descending and ascending fluxes. The four components of APAR were measured above and within two planting densities of corn (Zea mays L.) and several methods of measuring and estimating APAR were examined. A line quantum sensor that spatially averages the photosynthetic photon flux density provided a rapid and portable method of measuring APAR. PAR reflectance from the soil (Typic Argiaquoll) surface decreased from 10% to less than 1% of the incoming PAR as the canopy cover increased. PAR reflectance from the canopy decreased to less than 3% at maximum vegetative cover. Intercepted PAR (1 - transmitted PAR) generally overestimated absorbed PAR by less than 4% throughout most of the growing season. Thus intercepted PAR appears to be a reasonable estimate of absorbed PAR.

  13. Simulation de l'accretion de glace sur un obstacle bidimensionnel par la methode des bissectrices et par la modelisation des ruisselets et des gouttes de surface

    NASA Astrophysics Data System (ADS)

    Fortin, Guy

    Le LIMA (Laboratoire International des Materiaux Antigivre) en collaboration avec le CIRA (Italian Aerospace Research Centre) a developpe un logiciel simulant l'accretion de la glace en regimes sec et humide sur un objet bidimensionnel fixe. L'approche utilisee s'appuie sur les travaux de Lozowski pour les bilans energetiques, sur une etude du comportement du film d'eau, des ruisselets et des gouttes de surface pour le calcul des rugosites et des masses d'eau residuelle, ainsi que sur une methode de bissectrice pour l'evolution de la surface de glace. La contribution du CIRA a ete de fournir le logiciel pour le calcul des ecoulements et de la captation. Le bilan energetique base sur la conservation de l'energie est la sommation de la chaleur latente de fusion, d'evaporation et de sublimation, du rechauffement adiabatique et cinetique, et des pertes de chaleur par convection et conduction, ainsi que de l'evolution thermodynamique de l'eau de son etat initial a son etat final. La densite de la glace, qui a un impact important sur la simulation, est calculee a partir d'une correlation empirique developpee avec les cylindres tournants. En se basant sur les travaux de Al-Khalil et Hansman, le comportement des gouttes en regimes sec et humide a ete decrit analytiquement, ce qui a mene a determiner la hauteur maximale que peuvent atteindre les gouttes avant mouvement. Cette hauteur, appelee hauteur de mouvement, permet de determiner l'etat de l'eau sur la surface (film, ruisselets ou gouttes), ainsi que la hauteur des rugosites lorsque l'eau existe sous forme de gouttes ou de ruisselets. La hauteur de mouvement est determinee par l'equilibre entre les forces de cisaillement, induites par les effets aerodynamiques et gravitationnels evalues pour une goutte non deformee, et la force de cisaillement, induite par la tension de surface et la deformation de la goutte. Elle a ete validee en laboratoire et la precision obtenue pour la partie aerodynamique et gravitationnelle est

  14. Infection par le virus de l’hépatite E durant la grossesse

    PubMed Central

    Chaudhry, Shahnaz A.; Verma, Natasha; Koren, Gideon

    2015-01-01

    Résumé Question Plusieurs de mes patientes sont originaires de l’Asie du Sud-Est où le virus de l’hépatite E est assez commun. Quelles précautions puis-je leur suggérer de prendre avant de voyager dans cette région et quels sont les risques d’une infection par le VHE durant la grossesse? Réponse L’hépatite E est un pathogène présent dans l’eau qui se transmet par voie oro-fécale. Afin de réduire le risque de contracter le VHE lors de voyages dans des régions endémiques, il est important de maintenir des pratiques d’hygiène telles que se laver les mains avec de l’eau potable, particulièrement avant de manipuler de la nourriture, éviter de boire de l’eau ou d’utiliser des glaçons de pureté inconnue et ne pas manger de fruits ou de légumes non pelés. Actuellement, il n’existe aucun vaccin disponible au Canada pour le VHE. Une infection à l’hépatite E durant la grossesse, surtout durant le troisième trimestre, se caractérise par une infection plus sévère qui se transforme parfois en hépatite fulminante, augmentant ainsi les risques de mortalité et de morbidité maternelles et fœtales.

  15. Protease-activated receptor (PAR) 1 and PAR4 differentially regulate factor V expression from human platelets.

    PubMed

    Duvernay, Matthew; Young, Summer; Gailani, David; Schoenecker, Jonathan; Hamm, Heidi E; Hamm, Heidi

    2013-04-01

    With the recent interest of protease-activated receptors (PAR) 1 and PAR4 as possible targets for the treatment of thrombotic disorders, we compared the efficacy of protease-activated receptor (PAR)1 and PAR4 in the generation of procoagulant phenotypes on platelet membranes. PAR4-activating peptide (AP)-stimulated platelets promoted thrombin generation in plasma up to 5 minutes earlier than PAR1-AP-stimulated platelets. PAR4-AP-mediated factor V (FV) association with the platelet surface was 1.6-fold greater than for PAR1-AP. Moreover, PAR4 stimulation resulted in a 3-fold greater release of microparticles, compared with PAR1 stimulation. More robust FV secretion and microparticle generation with PAR4-AP was attributable to stronger and more sustained phosphorylation of myosin light chain at serine 19 and threonine 18. Inhibition of Rho-kinase reduced PAR4-AP-mediated FV secretion and microparticle generation to PAR1-AP-mediated levels. Thrombin generation assays measuring prothrombinase complex activity demonstrated 1.5-fold higher peak thrombin levels on PAR4-AP-stimulated platelets, compared with PAR1-AP-stimulated platelets. Rho-kinase inhibition reduced PAR4-AP-mediated peak thrombin generation by 25% but had no significant effect on PAR1-AP-mediated thrombin generation. In conclusion, stimulation of PAR4 on platelets leads to faster and more robust thrombin generation, compared with PAR1 stimulation. The greater procoagulant potential is related to more efficient FV release from intracellular stores and microparticle production driven by stronger and more sustained myosin light chain phosphorylation. These data have implications about the role of PAR4 during hemostasis and are clinically relevant in light of recent efforts to develop PAR antagonists to treat thrombotic disorders.

  16. Modifications vibrationnelles induites par différentes vapeurs acides sur les polyanilines

    NASA Astrophysics Data System (ADS)

    Cochet, M.; Quillard, S.; Buisson, J. P.; Lefrant, S.; Louarn, G.

    1998-06-01

    We present a comparative study of conductive form of polyaniline, i.e, polyemeraldine doped with HCl vapor or with HCSA upon m-cresol vapor. UV-Vis.-nir absorption measurements on polyaniline thin films, vs acid vapors time exposure, have been made. In the same way, Raman spectra have been recorded with different excitation lines from the blue and red ranges to the infrared region. Finally, an assignment of Raman bands observed, is proposed and confirmed by vibrational calculations based on valence-force-field. Nous présentons une étude comparative de la forme conductrice de la polyaniline, c'est-à-dire de la polyéméraldine dopée par des vapeurs d'HCl ou dopée par l'acide camphre sulfonique (HCSA) sous vapeurs de m-crésol. Des mesures d'absorption UV-Vis-proche infrarouge sur des films minces de polyaniline, en fonction du temps d'exposition aux vapeurs acides, ont été réalisées. Parallèlement, les spectres Raman ont été obtenus pour différentes longueurs d'onde d'excitation allant du visible jusqu'au proche infrarouge. Finalement, une attribution des bandes Raman observées est proposée et confirmée par des calculs vibrationnels basés sur des champs de force de valence.

  17. ParCAT: Parallel Climate Analysis Toolkit

    SciTech Connect

    Smith, Brian E.; Steed, Chad A.; Shipman, Galen M.; Ricciuto, Daniel M.; Thornton, Peter E.; Wehner, Michael; Williams, Dean N.

    2013-01-01

    Climate science is employing increasingly complex models and simulations to analyze the past and predict the future of Earth s climate. This growth in complexity is creating a widening gap between the data being produced and the ability to analyze the datasets. Parallel computing tools are necessary to analyze, compare, and interpret the simulation data. The Parallel Climate Analysis Toolkit (ParCAT) provides basic tools to efficiently use parallel computing techniques to make analysis of these datasets manageable. The toolkit provides the ability to compute spatio-temporal means, differences between runs or differences between averages of runs, and histograms of the values in a data set. ParCAT is implemented as a command-line utility written in C. This allows for easy integration in other tools and allows for use in scripts. This also makes it possible to run ParCAT on many platforms from laptops to supercomputers. ParCAT outputs NetCDF files so it is compatible with existing utilities such as Panoply and UV-CDAT. This paper describes ParCAT and presents results from some example runs on the Titan system at ORNL.

  18. PAR2 regulates regeneration, transdifferentiation, and death

    PubMed Central

    Piran, Ron; Lee, Seung-Hee; Kuss, Pia; Hao, Ergeng; Newlin, Robbin; Millán, José Luis; Levine, Fred

    2016-01-01

    Understanding the mechanisms by which cells sense and respond to injury is central to developing therapies to enhance tissue regeneration. Previously, we showed that pancreatic injury consisting of acinar cell damage+β-cell ablation led to islet cell transdifferentiation. Here, we report that the molecular mechanism for this requires activating protease-activated receptor-2 (PAR2), a G-protein-coupled receptor. PAR2 modulation was sufficient to induce islet cell transdifferentiation in the absence of β-cells. Its expression was modulated in an islet cell type-specific manner in murine and human type 1 diabetes (T1D). In addition to transdifferentiation, PAR2 regulated β-cell apoptosis in pancreatitis. PAR2's role in regeneration is broad, as mice lacking PAR2 had marked phenotypes in response to injury in the liver and in digit regeneration following amputation. These studies provide a pharmacologically relevant target to induce tissue regeneration in a number of diseases, including T1D. PMID:27809303

  19. ATP-regulated interactions between P1 ParA, ParB and non-specific DNA that are stabilized by the plasmid partition site, parS

    PubMed Central

    Havey, James C.; Vecchiarelli, Anthony G.; Funnell, Barbara E.

    2012-01-01

    Localization of the P1 plasmid requires two proteins, ParA and ParB, which act on the plasmid partition site, parS. ParB is a site-specific DNA-binding protein and ParA is a Walker-type ATPase with non-specific DNA-binding activity. In vivo ParA binds the bacterial nucleoid and forms dynamic patterns that are governed by the ParB–parS partition complex on the plasmid. How these interactions drive plasmid movement and localization is not well understood. Here we have identified a large protein–DNA complex in vitro that requires ParA, ParB and ATP, and have characterized its assembly by sucrose gradient sedimentation and light scattering assays. ATP binding and hydrolysis mediated the assembly and disassembly of this complex, while ADP antagonized complex formation. The complex was not dependent on, but was stabilized by, parS. The properties indicate that ParA and ParB are binding and bridging multiple DNA molecules to create a large meshwork of protein–DNA molecules that involves both specific and non-specific DNA. We propose that this complex represents a dynamic adaptor complex between the plasmid and nucleoid, and further, that this interaction drives the redistribution of partition proteins and the plasmid over the nucleoid during partition. PMID:21965538

  20. Antithrombotic effects of PAR1 and PAR4 antagonists evaluated under flow and static conditions.

    PubMed

    Hosokawa, Kazuya; Ohnishi, Tomoko; Miura, Naoki; Sameshima, Hisayo; Koide, Takehiko; Tanaka, Kenichi A; Maruyama, Ikuro

    2014-01-01

    Thrombin-mediated activation of human platelets involves the G-protein-coupled protease-activated receptors PAR1 and PAR4. Inhibition of PAR1 and/or PAR4 is thought to modulate platelet activation and subsequent procoagulant reactions. However, the antithrombotic effects of PAR1 and PAR4 antagonism have not been fully elucidated, particularly under flow conditions. A microchip-based flow chamber system was used to evaluate the influence of SCH79797 (PAR1 antagonist) and YD-3 (PAR4 antagonist) on thrombus formation mediated by collagen and tissue thromboplastin at shear rates simulating those experienced in small- to medium-sized arteries (600s(-1)) and large arteries and small veins (240s(-1)). At a shear rate of 600s(-1), SCH79797 (10μM) efficiently reduced fibrin-rich platelet thrombi and significantly delayed occlusion of the flow chamber capillary (1.44 fold of control; P<0.001). The inhibitory activity of SCH79797 was diminished at 240s(-1). YD-3 (20μM) had no significant effect at either shear rate. The antithrombotic effects of SCH79797 were significantly augmented when combined with aspirin and AR-C66096 (P2Y12 antagonist), but not with YD-3. In contrast, no significant inhibition of tissue factor-induced clot formation under static conditions was observed in blood treated with SCH79797 and YD-3, although thrombin generation in platelet-rich plasma was weakly delayed by these antagonists. Our results suggest that the antithrombotic activities of PAR1 and/or PAR4 antagonism is influenced by shear conditions as well as by combined platelet inhibition with aspirin and a P2Y12-antagonist. © 2013.

  1. Tumeur du sein révélée par une métastase gastrique découverte fortuitement

    PubMed Central

    Moussaoui, Aziz El; Assi, Fadi; Bental, Abdeslam

    2016-01-01

    Les métastases gastriques du cancer du sein sont rares, et leur découverte reste difficile, devant la symptomatologie qui est souvent non spécifique ou même absente. Nous rapportons une observation originale d'un carcinome canalaire du sein révélé par une métastase gastrique découverte de façon fortuite. PMID:28154673

  2. Sidi Ali Ou Azza (L4): A New Moroccan Fall

    NASA Astrophysics Data System (ADS)

    Chennaoui Aoudjehane, H.; Agee, C. B.; Aaranson, A.; Bouragaa, A.

    2016-08-01

    Sidi Ali Ou Azza is the latest meteorite fall in Morocco, it occurred on 28 July 2015 very close (about 40 km) to Tissint martian shergottite fall that occurred on 18 July 2011. It's one of the small group of 23 L4 ordinary chondrite falls.

  3. Griffe cubitale d'origine lépreuse traitée par transfert tendineux de Lasso Zancolli: à propos d'un cas

    PubMed Central

    El Alaoui, Adil; Sbiyaa, Mouhcine; Bah, Aliou; Rabhi, Ilyas; mezzani, Amine; Marzouki, Amine; Boutayeb, Fawzi

    2015-01-01

    La lèpre est une maladie infectieuse due à une mycobactérie (M. Leprae, Bacille de Hansen, ou BH) dont le tropisme nerveux est destructeur pour les cellules de Schwann. La localisation préférentielle des neuropathies tronculaire secondaire à la lèpre restent dominé par les zones ou les troncs nerveux traversent les défilés ostéo-ligamentaires inextensibles comme le défilé rétro-épitrochléen ou passe le nerf ulnaire. De nombreux travaux ont été consacrés à la souffrance nerveuse secondaire à la lèpre et surtout l'atteinte du nerf ulnaire qui se manifeste par une griffe des doigts. Le traitement dans ce cas est palliatif et fait appel à plusieurs techniques décrites dans la littérature. Nous rapportons dans ce travail un cas de griffe cubitale chez un patient lépreux traité par transfert tendineux de Lasso Zancolli. PMID:26985277

  4. Humanizing the Protease-Activated Receptor (PAR) Expression Profile in Mouse Platelets by Knocking PAR1 into the Par3 Locus Reveals PAR1 Expression Is Not Tolerated in Mouse Platelets

    PubMed Central

    French, Shauna L.; Paramitha, Antonia C.; Moon, Mitchell J.; Dickins, Ross A.; Hamilton, Justin R.

    2016-01-01

    Anti-platelet drugs are the mainstay of pharmacotherapy for heart attack and stroke prevention, yet improvements are continually sought. Thrombin is the most potent activator of platelets and targeting platelet thrombin receptors (protease-activated receptors; PARs) is an emerging anti-thrombotic approach. Humans express two PARs on their platelets–PAR1 and PAR4. The first PAR1 antagonist was recently approved for clinical use and PAR4 antagonists are in early clinical development. However, pre-clinical studies examining platelet PAR function are challenging because the platelets of non-primates do not accurately reflect the PAR expression profile of human platelets. Mice, for example, express Par3 and Par4. To address this limitation, we aimed to develop a genetically modified mouse that would express the same repertoire of platelet PARs as humans. Here, human PAR1 preceded by a lox-stop-lox was knocked into the mouse Par3 locus, and then expressed in a platelet-specific manner (hPAR1-KI mice). Despite correct targeting and the predicted loss of Par3 expression and function in platelets from hPAR1-KI mice, no PAR1 expression or function was detected. Specifically, PAR1 was not detected on the platelet surface nor internally by flow cytometry nor in whole cell lysates by Western blot, while a PAR1-activating peptide failed to induce platelet activation assessed by either aggregation or surface P-selectin expression. Platelets from hPAR1-KI mice did display significantly diminished responsiveness to thrombin stimulation in both assays, consistent with a Par3-/- phenotype. In contrast to the observations in hPAR1-KI mouse platelets, the PAR1 construct used here was successfully expressed in HEK293T cells. Together, these data suggest ectopic PAR1 expression is not tolerated in mouse platelets and indicate a different approach is required to develop a small animal model for the purpose of any future preclinical testing of PAR antagonists as anti-platelet drugs. PMID

  5. ParA and ParB coordinate chromosome segregation with cell elongation and division during Streptomyces sporulation.

    PubMed

    Donczew, Magdalena; Mackiewicz, Paweł; Wróbel, Agnieszka; Flärdh, Klas; Zakrzewska-Czerwińska, Jolanta; Jakimowicz, Dagmara

    2016-04-01

    In unicellular bacteria, the ParA and ParB proteins segregate chromosomes and coordinate this process with cell division and chromosome replication. During sporulation of mycelial Streptomyces, ParA and ParB uniformly distribute multiple chromosomes along the filamentous sporogenic hyphal compartment, which then differentiates into a chain of unigenomic spores. However, chromosome segregation must be coordinated with cell elongation and multiple divisions. Here, we addressed the question of whether ParA and ParB are involved in the synchronization of cell-cycle processes during sporulation in Streptomyces To answer this question, we used time-lapse microscopy, which allows the monitoring of growth and division of single sporogenic hyphae. We showed that sporogenic hyphae stop extending at the time of ParA accumulation and Z-ring formation. We demonstrated that both ParA and ParB affect the rate of hyphal extension. Additionally, we showed that ParA promotes the formation of massive nucleoprotein complexes by ParB. We also showed that FtsZ ring assembly is affected by the ParB protein and/or unsegregated DNA. Our results indicate the existence of a checkpoint between the extension and septation of sporogenic hyphae that involves the ParA and ParB proteins.

  6. ParA and ParB coordinate chromosome segregation with cell elongation and division during Streptomyces sporulation

    PubMed Central

    Donczew, Magdalena; Mackiewicz, Paweł; Wróbel, Agnieszka; Flärdh, Klas; Zakrzewska-Czerwińska, Jolanta

    2016-01-01

    In unicellular bacteria, the ParA and ParB proteins segregate chromosomes and coordinate this process with cell division and chromosome replication. During sporulation of mycelial Streptomyces, ParA and ParB uniformly distribute multiple chromosomes along the filamentous sporogenic hyphal compartment, which then differentiates into a chain of unigenomic spores. However, chromosome segregation must be coordinated with cell elongation and multiple divisions. Here, we addressed the question of whether ParA and ParB are involved in the synchronization of cell-cycle processes during sporulation in Streptomyces. To answer this question, we used time-lapse microscopy, which allows the monitoring of growth and division of single sporogenic hyphae. We showed that sporogenic hyphae stop extending at the time of ParA accumulation and Z-ring formation. We demonstrated that both ParA and ParB affect the rate of hyphal extension. Additionally, we showed that ParA promotes the formation of massive nucleoprotein complexes by ParB. We also showed that FtsZ ring assembly is affected by the ParB protein and/or unsegregated DNA. Our results indicate the existence of a checkpoint between the extension and septation of sporogenic hyphae that involves the ParA and ParB proteins. PMID:27248800

  7. suPAR and Team Nephrology

    PubMed Central

    2014-01-01

    Primary focal segmental glomerulosclerosis (FSGS) accounts for nearly 10 % of patients who require renal replacement therapy. Elevated circulating levels of soluble urokinase receptor (suPAR) have been identified as a biomarker to discriminate primary FSGS from other glomerulopathies. Subsequent reports have questioned the diagnostic utility of this test. In a study in BMC Medicine, Huang et al. demonstrate that urinary soluble urokinase receptor (suPAR) excretion assists in distinguishing primary FSGS from other glomerular diseases, and that high plasma suPAR concentrations are not directly linked to a decline in glomerular filtration rate (GFR). This observation suggests that further investigation of suPAR is warranted in patients with FSGS. It should be interpreted in light of a recent report that B7-1 is expressed in the podocytes of a subset of patients with FSGS, and that blocking this molecule may represent the first successful targeted intervention for this disease. These advances highlight the rapid pace of scientific progress in the field of nephrology. Nephrologists should work together, share resources, and expedite the design of protocols to evaluate these novel biomarkers in a comprehensive and scientifically valid manner. Please see related article http://www.biomedcentral.com/1741-7015/12/81. PMID:24885021

  8. Modélisation 2D par Eléments Finis de phénomènes micro-ondes en milieu ouvert

    NASA Astrophysics Data System (ADS)

    Nicolas, L.; Connor, K. A.; Salon, S. J.; Ruth, B. G.; Libelo, L. F.

    1992-11-01

    We present in this paper the modelization of open boundaries microwave problems using Finite Element method, for the design of antennas or for the study of electromagnetic scattering: Finite Element formulation, coupling with Boundary Element Method or with Absorbing Boundary Conditions, modelization of current sources, calculation of far field. In a second part, we show the results concerning a high power microwave launcher. Nous présentons ici notre activité dans le domaine de la modélisation bidimensionnelle de problèmes de de micro-ondes en milieu ouvert, pour la conception d'antennes ou l'étude de problèmes de diffraction électromagnétique: formulation par la méthode des Eléments Finis, prise en compte de l'infini par la méthode des Equations Intégrales de Frontière ou par des conditions aux limites absorbantes, modélisation des sources de courant, calcul du champ lointain. Dans une seconde partie, nous illustrons ces différentes méthodes par la modélisation d'une antenne haute puissance.

  9. PAR Corneal Topography System (PAR CTS): the clinical application of close-range photogrammetry.

    PubMed

    Belin, M W; Cambier, J L; Nabors, J R; Ratliff, C D

    1995-11-01

    The PAR Corneal Topography System (CTS) is a computer-driven corneal imaging system which uses close-range photogrammetry (rasterphotogrammetry) to measure and produce a topographic map of the corneal surface. The PAR CTS makes direct point-by-point measurements of surface elevation using a stereo-triangulation technique. The CTS uses a grid pattern composed of horizontal and vertical lines spaced about 0.2 mm (200 microns) apart. Each grid intersection comprises a surface feature which can be located in multiple images and used to generate an (x,y,z) coordinate. Unlike placido disc-based videokeratoscopes, the PAR CTS requires neither a smooth reflective surface nor precise spatial alignment for accurate imaging. In addition to surface elevation, the PAR CTS computes axial and tangential curvatures and refractive power. Difference maps are available in all curvatures, refractive power, and in absolute elevation.

  10. Eielson Air Force Base OU-1 baseline risk assessment

    SciTech Connect

    Jarvis, M.T.; Jarvis, T.T.; Van Houten, N.C.; Lewis, R.E.

    1993-09-01

    This Baseline Risk Assessment report is the second volume in a set of three volumes for operable Unit 1 (OU-1). The companion documents contain the Remedial Investigation and the Feasibility Study. Operable Unit 1 (OU-1) is one of several groups of hazardous waste sites located at Eielson Air Force Base (AFB) near Fairbanks, Alaska. The operable units at Eielson are typically characterized by petroleum, oil, lubricant/solvent contamination, and by the presence of organics floating at the water table. In 1989 and 1990, firms under contract to the Air Force conducted field studies to gather information about the extent of chemical contamination in soil, groundwater, and soil air pore space (soil gas) at the site. This report documents the results of a baseline risk assessment, which uses the 1989 and 1991 site characterization database to quantify the potential human health risk associated with past Base industrial activities in the vicinity of OU-1. Background data collected in 1992 were also used in the preparation of this report.

  11. View from west to east of PAR site resident engineer's ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View from west to east of PAR site resident engineer's office building (REOB) - Stanley R. Mickelsen Safeguard Complex, Resident Engineers Office Building, Southeast of intersection of PAR Access Road & Fourth Avenue, Nekoma, Cavalier County, ND

  12. A Combined Global and Local Approach to Elucidate Spatial Organization of the Mycobacterial ParB-parS Partition Assembly

    SciTech Connect

    B Chaudhuri; S Gupta; V Urban; M Chance; R DMello; L Smith; K Lyons; J Gee

    2011-12-31

    Combining diverse sets of data at global (size, shape) and local (residue) scales is an emerging trend for elucidating the organization and function of the cellular assemblies. We used such a strategy, combining data from X-ray and neutron scattering with H/D-contrast variation and X-ray footprinting with mass spectrometry, to elucidate the spatial organization of the ParB-parS assembly from Mycobacterium tuberculosis. The ParB-parS participates in plasmid and chromosome segregation and condensation in predivisional bacterial cells. ParB polymerizes around the parS centromere(s) to form a higher-order assembly that serves to recruit cyto-skeletal ParA ATPases and SMC proteins for chromosome segregation. A hybrid model of the ParB-parS was built by combining and correlating computational models with experiment-derived information about size, shape, position of the symmetry axis within the shape, internal topology, DNA-protein interface, exposed surface patches, and prior knowledge. This first view of the ParB-parS leads us to propose how ParB spread on the chromosome to form a larger assembly.

  13. Kallikrein 6 Signals through PAR1 and PAR2 to Promote Neuron Injury and Exacerbate Glutamate Neurotoxicity

    PubMed Central

    Yoon, Hyesook; Radulovic, Maja; Wu, Jianmin; Blaber, Sachiko I.; Blaber, Michael; Fehlings, Michael G.; Scarisbrick, Isobel A.

    2014-01-01

    CNS trauma generates a proteolytic imbalance contributing to secondary injury, including axonopathy and neuron degeneration. Kallikrein 6 (Klk6) is a serine protease implicated in neurodegeneration and here we investigate the role of protease activated receptors 1 (PAR1) and PAR2 in mediating these effects. First we demonstrate Klk6 and the prototypical activator of PAR1, thrombin, as well as PAR1 and PAR2, are each elevated in murine experimental traumatic spinal cord injury (SCI) at acute or subacute time points. Recombinant Klk6 triggered ERK1/2 signaling in cerebellar granule neurons and in the NSC34 spinal cord motoneuron cell line, in a PI3K and MEK-dependent fashion. Importantly, lipopeptide inhibitors of PAR1 or PAR2, and PAR1 genetic deletion, each reduced Klk6-ERK1/2 activation. In addition, Klk6 and thrombin promoted degeneration of cerebellar neurons and exacerbated glutamate neurotoxicity. Moreover, genetic deletion of PAR1 blocked thrombin-mediated cerebellar neurotoxicity and reduced the neurotoxic effects of Klk6. Klk6 also increased glutamate-mediated Bim signaling, PARP cleavage and lactate dehydrogenase (LDH) release in NSC34 motoneurons and these effects were blocked by PAR1 and PAR2 lipopeptide inhibitors. Taken together these data point to a novel Klk6-signaling axis in CNS neurons that is mediated by PAR1 and PAR2 and is positioned to contribute to neurodegeneration. PMID:23647384

  14. A Combined Global and Local Approach to Elucidate Spatial Organization of the Mycobacterial ParB-parS Partition

    SciTech Connect

    Chaudhuri, Barnali; Gupta, Sayan; Urban, Volker S; Chance, Mark; D'Mello, Rhijuta; Smith, Lauren; Lyons, Kelly; Gee, Jessica

    2010-01-01

    Combining diverse sets of data at global (size, shape) and local (residue) scales is an emerging trend for elucidating the organization and function of the cellular assemblies. We used such a strategy, combining data from X-ray and neutron scattering with H/D-contrast variation and X-ray footprinting with mass spectrometry, to elucidate the spatial organization of the ParB-parS assembly from Mycobacterium tuberculosis. The ParB-parS participates in plasmid and chromosome segregation and condensation in predivisional bacterial cells. ParB polymerizes around the parS centromere(s) to form a higher-order assembly that serves to recruit cyto-skeletal ParA ATPases and SMC proteins for chromosome segregation. A hybrid model of the ParB-parS was built by combining and correlating computational models with experiment-derived information about size, shape, position of the symmetry axis within the shape, internal topology, DNA-protein interface, exposed surface patches, and prior knowledge. This first view of the ParB-parS leads us to propose how ParB spread on the chromosome to form a larger assembly.

  15. Protection des ions organiques contre les dommages induits a l'ADN par les electrons de basse energie

    NASA Astrophysics Data System (ADS)

    Dumont, Ariane

    Il a ete demontre que les electrons de basse energie (EBE) peuvent induire des cassures simple brin (CSB) a l'ADN, via la formation d'anions transitoires qui decroissent par attachement dissociatif, ou dans d'autres etats electroniques dissociatifs menant a la fragmentation. Afin d'effectuer une etude complete des effets des electrons de basse energie sur la matiere biologique, il est necessaire de comprendre leur mecanismes d'interaction non seulement avec l'ADN, mais avec les constituants de son environnement. Les histones sont une composante importante de l'environnement moleculaire de l'ADN. Leur charge positive leur permet de s'associer aux groupements phosphate anionique de l'ADN. Le role principal de ces proteines basiques consiste a organiser l'ADN et l'empaqueter afin de former la chromatine. Les cations sont une autre composante importante de la cellule; ils jouent un role dans la stabilisation de la conformation B de l'ADN in vitro par leurs interactions avec les petits et grands sillons de l'ADN, ainsi qu'avec le groupement phosphate charge negativement. Avec les histones, ils participent egalement a la compaction de l'ADN pour former la chromatine. Cette etude a pour but de comprendre comment la presence d'ions organiques (sous forme de Tris et d'EDTA) a proximite de l'ADN modifie le rendement de cassures simple brin induit par les electrons de basse energie. Le Tris et l'EDTA ont-ete choisis comme objet d'etude, puisqu'en solution, ils forment le tampon standard pour solubiliser l'ADN dans les experiences in vitro (10mM Tris, 1mM EDTA). De plus, la molecule Tris possede un groupement amine alors que l'EDTA possede 4 groupements carboxyliques. Ensembles, ils peuvent se comporter comme un modele simple pour les acides amines. Le ratio molaire de 10 :1 de Tris par rapport a l'EDTA a pour but d'imiter le comportement des histones qui sont riches en arginine et lysine, acides amines possedant un groupement amine charge positivement additionnel. Des films d

  16. Host response biomarker in sepsis: suPAR detection.

    PubMed

    Giamarellos-Bourboulis, Evangelos J; Georgitsi, Marianna

    2015-01-01

    Recent studies of our group have shown that suPAR may complement APACHE II score for risk assessment in sepsis. suPAR may be measured in serum of patients by an enzyme immunosorbent assay developed by Virogates (suPARnostic™). Production of suPAR from circulating neutrophils and monocytes may be assessed after isolation of neutrophils and monocytes and ex vivo culture. This is followed by measurement of suPAR in culture supernatants.

  17. Facteurs de risque de mortalité par tuberculose pulmonaire

    PubMed Central

    Janah, Hicham; Souhi, Hicham; Kouismi, Hatim; Mark, Karima; Zahraoui, Rachida; Benamor, Jouda; Soualhi, Mona; Bourkadi, Jamal Eddine

    2014-01-01

    La tuberculose est une maladie infectieuse transmissible provoquée par myco-bacterium tuberculosis (bacille de Koch ou BK). Elle représente, selon les estimations del'Organisation Mondiale de la Santé (OMS), l'une des pathologies infectieuses causant le plus de décès au niveau mondial avec plus de 1 million de décès par an. Pour déterminer les facteurs de risque de mortalité au cours de la tuberculose pulmonaire à microscopie positive nous avons mené une étude rétrospective portant sur tous les cas de tuberculose pulmonaire à microscopie positive et qui étaient décédés au cours de leur hospitalisation. Cette étude a colligé 1803 cas de tuberculose sur une période de 2 ans et demi dont 46 sont décédés. La prévalence de décès est de 2,55%. La population se répartit en 32 hommes et 14 femmes. L’âge moyen était de 53ans ± 17 ans. Le tabagisme était retrouvé chez la moitié des cas. Une comorbidité était retrouvée dans 43%, avec 17% de diabète. Le délai de diagnostic avait une médiane de 60 jours avec percentile (30j; 105j). La symptomatologie clinique était dominée par la toux, la dyspnée et les expectorations soit respectivement: 97,8%, 69,6% et 67,4% des cas. Sur le plan radiologique les lésions étaient diffuses et bilatérales dans 76,1% des cas. Tous les patients étaient mis sous SRHZ. 11% avaient présenté une toxicité aux antibacillaires (de type hépatiques dans 3 cas et neurologiques dans 2 cas). Le délai médian de décès était de 8,5 jours (5j; 17j). Les causes de décès retrouvées étaient: Une hépatite fulminante (3 cas), une décompensation acido-cétosique (3 cas), un SDRA (2 cas), des hémoptysies foudroyantes (2 cas), et respectivement un cas secondaire à une décompensation de BPCO, une décompensation cardiaque, une hypoglycémie et un tableau d'anasarque. Cette étude suggère que le terrain, le retard diagnostique et les effets secondaires du traitement sont les principaux facteurs de risque de

  18. Drosophila 14-3-3/PAR-5 is an essential mediator of PAR-1 function in axis formation.

    PubMed

    Benton, Richard; Palacios, Isabel M; St Johnston, Daniel

    2002-11-01

    PAR-1 kinases are required to determine the anterior-posterior (A-P) axis in C. elegans and Drosophila, but little is known about their molecular function. We identified 14-3-3 proteins as Drosophila PAR-1 interactors and show that PAR-1 binds a domain of 14-3-3 distinct from the phosphoserine binding pocket. PAR-1 kinases phosphorylate proteins to generate 14-3-3 binding sites and may therefore directly deliver 14-3-3 to these targets. 14-3-3 mutants display identical phenotypes to par-1 mutants in oocyte determination and the polarization of the A-P axis. Together, these results indicate that PAR-1's function is mediated by the binding of 14-3-3 to its substrates. The C. elegans 14-3-3 protein, PAR-5, is also required for A-P polarization, suggesting that this is a conserved mechanism by which PAR-1 establishes cellular asymmetries.

  19. [Ambroise Paré in French literature].

    PubMed

    Dumaitre, P

    1995-01-01

    The 16th century by its passionate side has been the favourite one of authors of historical novels in which among the heroes of "cloak and dagger stories" appears sometime Ambroise Paré. Alexandre Dumas (the father) has shown him at the court of Charles IX in La Reine Margot (1845) where he does not however play a great role. On the contrary, Balzac in Le Martyr calviniste (1842) has given him a capital part close to the dying François II, whom he intended to trepanize but had to give up this idea as a consequence of the opposition of the queen-mother Catherine de Médicis. In the present century, Robert Merle in Paris ma bonne ville (Fortune de France, 3, 1980) shows Paré at the time of the Saint Barthélemy.

  20. [Ambroise Paré and Latin].

    PubMed

    Drouin, Emmanuel

    2010-06-01

    We report a study of a medical book written by Antoine Mizaud (Memorabilium utilium, in ac iucundorum aphorismos Arcanorum omnis generis locupletes, perpulchre digestae), which was written in Latin, but has been extensively annotated in French.The book is from the personal collection of one of the physicians of Napoleon III. There is an oral tradition within his family that one of the works in the book had been annotated by Ambroise Paré. We know very little, apart from a few receipts and his signature, about the writing of the master of French surgery. Did he understand the language of Galen? There are many annotated passages in the works of Pare which are in the book. We examine whether these annotations were actually made by Ambroise Paré or whether they were done for him.

  1. Combined DSEK and Transconjunctival Pars Plana Vitrectomy

    PubMed Central

    Sane, Mona; Shaikh, Naazli

    2016-01-01

    We report here three patients who underwent combined Descemet's stripping with endothelial keratoplasty and transconjunctival pars plana vitrectomy for bullous keratopathy and posterior segment pathology. A surgical technique and case histories are described. Anatomic and visual outcomes of combined Descemet's stripping with endothelial keratoplasty and vitrectomy were excellent. Our experience provides technical guidelines and limitations. The combined minimally invasive techniques allow for rapid anatomical recovery and return of function and visual acuity in a single sitting. PMID:27413563

  2. Par Pond refill water quality sampling

    SciTech Connect

    Koch, J.W. II; Martin, F.D.; Westbury, H.M.

    1996-08-01

    This study was designed to document anoxia and its cause in the event that the anoxia caused a fish kill. However, no fish kill was observed during this study, and dissolved oxygen and nutrient concentrations generally remained within the range expected for southeastern reservoirs. Par Pond water quality monitoring will continue during the second summer after refill as the aquatic macrophytes become reestablished and nutrients in the sediments are released to the water column.

  3. Fairy-Tale Physics Farewell to Reality Bankrupting Physics: Baggott-Unzicker-Jones Critiques Shame Physics' Shameless Media-Hype P.R. Spin-Doctoring Touting Sci-Fi Veracity-Abandonment ``Show-Biz'' Spectacle: Caveat Emptor!!!

    NASA Astrophysics Data System (ADS)

    Siegel, Edward

    2014-03-01

    Baggott[Farewell to Reality: How Fairy-Tale Physics Betrayed Search For Scientific Truth]-Unzicker [Bankrupting Physics: How Top Scientists Are Gambling Away Credibility] shame physics shameless rock-star media-hype P.R. spin-doctoring veracity-abandoning touting sci-fi show-biz aided by online proliferation of uncritical pop-sci science-writers verbal diarrhea, all spectacle vs little truth, lacking Kant-Popper skepticism/ falsification, lemming-like stampedes to truth abandonment, qualified by vague adverbs: might, could, should, may,...vs factual is! Physics, motivated by financial greed, swept up in its very own hype, touts whatever next big thing/cutting-edge bombast ad infinitum/ad nauseum, turning it into mere trendy carney sideshow, full of fury(FOF) but signifying absolutely nothing! Witness: GIGO claims string-theory holographic-universe causes cuprates optical conductivity; failed Anderson RVB cuprates theory vs. Keimer discovery all cuprates ``paramagnons'' bosons aka Overhauser SDWs; Overbye NYT holographic-universe jargonial-obfuscation comments including one from APS journals editor-in-chief re. its unintelligibility, FOF but signifying absolutely nothing INTELLIGIBLE!; Bak/BNL SOC tad late rediscovery of F =ma mere renaming of Siegel acoustic-emission!; 2007 physics Nobel-prize Fert-Gruenberg rediscovery of Siegel[JMMM 7,312(78); https://www.flickr.com/search/?q = GIANT-MAGNETORESISTANCE] GMR. Each trendy latest big thing modulo lack of prior attribution aka out and out bombastic chicanery! Siegel caveat emptor ``Buzzwordism, Bandwagonism, Sloganeering for Fun Profit Survival Ego'' sociological-dysfunctionality thrives!

  4. Fairy-Tale Physics Farewell to Reality Bankrupting Physics: Baggott-Unzicker-Jones Critiques Shame Physics' Shameless Media-Hype P.R. Spin-Doctoring Touting Sci-Fi Veracity-Abandonment ``Show-Biz'' Spectacle: Caveat Emptor!!!

    NASA Astrophysics Data System (ADS)

    Siegel, Edward

    2014-03-01

    Baggott[Farewell to Reality: How Fairy-Tale Physics Betrayed Search For Scientific Truth]-Unzicker [Bankrupting Physics: How Top Scientists Are Gambling Away Credibility] shame physics shameless rock-star media-hype P.R. spin-doctoring veracity-abandoning touting sci-fi show-biz aided by online proliferation of uncritical pop-sci science-writers verbal diarrhea, all spectacle vs little truth, lacking Kant-Popper skepticism/falsification, lemming-like stampedes to truth abandonment, qualified by vague adverbs: might, could, should, may,...vs factual is! Physics, motivated by financial greed, swept up in its very own hype, touts whatever next big thing/cutting-edge bombast ad infinitum/ad nauseum, turning it into mere trendy carney sideshow, full of fury(FOF) but signifying absolutely nothing! Witness: GIGO claims string-theory holographic-universe causes cuprates optical conductivity; failed Anderson RVB cuprates theory vs. Keimer discovery all cuprates ``paramagnons'' bosons aka Overhauser SDWs; Overbye NYT holographic-universe jargonial-obfuscation comments including one from APS journals editor-in-chief re. its unintelligibility, FOF but signifying absolutely nothing INTELLIGIBLE!; Bak/BNL SOC tad late rediscovery of F =ma mere renaming of Siegel acoustic-emission!; 2007 physics Nobel-prize Fert-Gruenberg rediscovery of Siegel[JMMM 7,312(78); https://www.flickr.com/search/?q=GIANT-MAGNETORESISTANCE] GMR. Each trendy latest big thing modulo lack of prior attribution aka out and out bombastic chicanery! Siegel caveat emptor ``Buzzwordism, Bandwagonism, Sloganeering for Fun Profit Survival Ego'' sociological-dysfunctionality thrives!

  5. Mesure du taux de la capture radiative du muon par l'hydrogene liquide

    NASA Astrophysics Data System (ADS)

    Jonkmans, Guy

    À basse énergie, l'interaction faible entre leptons et quarks est décrite par une interaction de la forme courant × courant de type V - A. La présence de l'interaction forte induit des couplages additionnels qui doivent être déterminés expérimentalement. De ceux-ci, le couplage pseudoscalaire induit, gp , est mesuré avec la plus grande incertitude et fait l'objet de la présente recherche. L'hypothèse du Courant Axial Partiellement Conservé (CAPC) et l'usage de la relation de Goldberger-Treiman relie gp au couplage axial ga . Cette relation a été vérifiée traditionnellement par la Capture Ordinaire du Muon (COM) à une valeur fixe du moment de transfert q. La Capture Radiative du Muon (CRM), m- p-->nnmg , est un meilleur outil pour l'étude de gp à cause de sa dépendance variable en q2 qui offre une plus grande sensibilité dans la partie à haute énergie du spectre des photons. Toutefois, le petit rapport d'embranchement (~10-8) de la CRM par rapport à la désintégration du muon a retardé cette mesure jusqu'à ce jour. La théorie et les difficultés expérimentales associées à la détection des photons de CRM sont présentées au deuxième chapitre. On décrit ensuite, au troisième chapitre, les composantes du système de détection. Ce détecteur est un spectromètre à paires de grand angle solide (~3p) et qui permet l'observation des photons par l'analyse des électrons et des positrons de photo-conversion. Ainsi, le bruit de fond important des neutrons de la COM ne constitue pas un problème pour cette mesure. Nous décrivons, au quatrième chapitre, toutes les étapes de l'analyse, nécessaires pour la réduction des multiples bruits de fond. Le cinquième chapitre présente le calcul des efficacités ainsi que l'estimation des erreurs systématiques. Le sixième chapitre démontre comment l'on extrait le rapport d'embranchement pour la CRM ainsi que la valeur ae gp . On insiste sur la dépendance de gp en fonction de la valeur de

  6. Le recours systématique à l’estimation échographique du poids fœtal en salle de naissances augmente-t-il le risque d’accouchement par césarienne?

    PubMed Central

    Dimassi, Kaouther; Ajroudi, Meryam; Saidi, Olfa; Salem, Safa; Robbana, Monia; Triki, Amel; Gara, Mohammed Faouzi

    2016-01-01

    L’échographie est un précieux outil utilisé quotidiennement en salle de travail. Ses applications sont multiples. L’objectif est d’évaluer si le recours systématique à une estimation échographique du poids fœtal et en salle de naissances augmente le risque d’accouchement par césarienne. Etude de cohorte monocentrique. Nous avons inclus toutes les parturientes avec des grossesses monofœtales qui avaient accouché à un terme ≥ 39 SA. Nous avons exclu toutes les patientes avec une contre indication à l'accouchement par voie basse ainsi que celles chez lesquelles une Estimation échographique du poids fœtal (EEPF) le jour de l'accouchement était jugée nécessaire à la prise de décision obstétricale. Les parturientes ainsi retenues ont été réparties en deux groupes: - G1 : parturientes ayant systématiquement eu une EEPF - G2: parturientes n’ayant pas eu cette EEPF. Nous avons comparé le taux d’accouchement par césarienne avec ajustement sur les potentiels facteurs confondants selon la régression logistique. 838 parturientes ont été retenues pour ce travail. La primiparité, l'EEPF ainsi que le poids à la naissance étaient des facteurs de risque d'accouchement par césarienne. Après ajustement aux facteurs confondants, l'EEFP réalisée systématiquement dans G1 s'est révélé être un facteur de risque indépendant d'accouchement par césarienne avec un OR =3,8 (IC95% = [2,67-5,48]). Ce risque augmentait significativement avec le poids estimé (PFE): OR=2,27(IC95;1,15-4,47;p=0.018) pour 3500 < PFE< 4000g et OR= 10,64(IC95; 4,28-26,41;p<0.001) pour PFE>4000g. L’EEPF réalisée systématiquement en salle de naissances représente un facteur de risque indépendant et potentiellement modifiable d’accouchement par césarienne. PMID:28250881

  7. Critical Role for PAR1 in Kallikrein 6-Mediated Oligodendrogliopathy

    PubMed Central

    Burda, Joshua E.; Radulovic, Maja; Yoon, Hyesook; Scarisbrick, Isobel A.

    2014-01-01

    Kallikrein 6 (Klk6) is a secreted serine protease preferentially expressed by oligodendroglia in CNS white matter. Elevated levels of Klk6 occur in actively demyelinating multiple sclerosis (MS) lesions and in cases of spinal cord injury (SCI), stroke and glioblastoma. Taken with recent evidence establishing Klk6 as a CNS-endogenous activator of protease-activated receptors (PARs), we hypothesized that Klk6 activates a subset of PARs to regulate oligodendrocyte physiology and potentially pathophysiology. Here, primary oligodendrocyte cultures derived from wild type or PAR1-deficient mice and the murine oligodendrocyte cell line, Oli-neu, were used to demonstrate that Klk6 mediates loss of oligodendrocyte processes and impedes morphological differentiation of oligodendrocyte progenitor cells (OPCs) in a PAR1-dependent fashion. Comparable gliopathy was also elicited by the canonical PAR1 agonist, thrombin, as well as PAR1-activating peptides (PAR1-APs). Klk6 also exacerbated ATP-mediated oligodendrogliopathy in vitro, pointing to a potential role in augmenting excitotoxicity. In addition, Klk6 suppressed the expression of proteolipid protein (PLP) RNA in cultured oligodendrocytes by a mechanism involving PAR1-mediated Erk1/2 signaling. Microinjection of PAR1 agonists, including Klk6 or PAR1-APs, into the dorsal column white matter of PAR+/+ but not PAR−/− mice promoted vacuolating myelopathy and a loss of immunoreactivity for myelin basic protein (MBP) and CC-1+ oligodendrocytes. These results demonstrate a functional role for Klk6-PAR1 signaling in oligodendroglial pathophysiology and suggest that PAR1 or PAR1-agonists may represent new targets to moderate demyelination and to promote myelin regeneration in cases of CNS white matter injury or disease. PMID:23832758

  8. Rachitisme patent révélé par la perte du contrôle des convulsions chez un garçon infirme moteur cérébral

    PubMed Central

    Awa, Hubert Désiré Mbassi; Chelo, David; Kinkela, Mina Njiki; Ndombo, Paul Olivier Koki

    2013-01-01

    La perte du contrôle des crises chez un patient compliant au traitement est toujours source de préoccupations diagnostiques, thérapeutiques et pronostiques. Nous rapportons un cas de rachitisme chez un patient de 4 ans, infirme moteur cérébral et épileptique sous traitement par phénobarbital depuis 2 ans; rachitisme découvert à la faveur d'une perte du contrôle épileptique. Le patient était admis pour des convulsions répétées en contexte afébrile. L'observance thérapeutique était bonne, et aucune convulsion n'avait été observée pendant les 12 mois précédents. Il ne recevait pas de vitamine D. Le rachitisme était suspecté cliniquement, et confirmé par les trouvailles radiologiques et biologiques. Le contrôle des crises était retrouvé dès le 3ème jour d'hospitalisation après apports de calcium intraveineux et de vitamine D. Les convulsions étaient imputées à une hypocalcémie sur rachitisme. La prise prolongée de phénobarbital sans supplémentation en vitamine D, ainsi qu'une exposition solaire insuffisante étaient incriminées. Avant toute escalade thérapeutique, des convulsions hypocalcémiques et un rachitisme doivent toujours être exclus devant une perte du contrôle des crises chez tout patient épileptique à mobilité réduite. Par ailleurs, une supplémentation en vitamine D et une exposition suffisante au soleil devront être recommandées pour certains traitements antiépileptiques au long cours. PMID:23503922

  9. The novel PAR2 ligand C391 blocks multiple PAR2 signalling pathways in vitro and in vivo

    PubMed Central

    Boitano, Scott; Hoffman, Justin; Flynn, Andrea N; Asiedu, Marina N; Tillu, Dipti V; Zhang, Zhenyu; Sherwood, Cara L; Rivas, Candy M; DeFea, Kathryn A; Vagner, Josef; Price, Theodore J

    2015-01-01

    Background and Purpose Proteinase-activated receptor-2 (PAR2) is a GPCR linked to diverse pathologies, including acute and chronic pain. PAR2 is one of the four PARs that are activated by proteolytic cleavage of the extracellular amino terminus, resulting in an exposed, tethered peptide agonist. Several peptide and peptidomimetic agonists, with high potency and efficacy, have been developed to probe the functions of PAR2, in vitro and in vivo. However, few similarly potent and effective antagonists have been described. Experimental Approach We modified the peptidomimetic PAR2 agonist, 2-furoyl-LIGRLO-NH2, to create a novel PAR2 peptidomimetic ligand, C391. C391 was evaluated for PAR2 agonist/antagonist activity to PAR2 across Gq signalling pathways using the naturally expressing PAR2 cell line 16HBE14o-. For antagonist studies, a highly potent and specific peptidomimetic agonist (2-aminothiazo-4-yl-LIGRL-NH2) and proteinase agonist (trypsin) were used to activate PAR2. C391 was also evaluated in vivo for reduction of thermal hyperalgesia, mediated by mast cell degranulation, in mice. Key Results C391 is a potent and specific peptidomimetic antagonist, blocking multiple signalling pathways (Gq-dependent Ca2+, MAPK) induced following peptidomimetic or proteinase activation of human PAR2. In a PAR2-dependent behavioural assay in mice, C391 dose-dependently (75 μg maximum effect) blocked the thermal hyperalgesia, mediated by mast cell degranulation. Conclusions and Implications C391 is the first low MW antagonist to block both PAR2 Ca2+ and MAPK signalling pathways activated by peptidomimetics and/or proteinase activation. C391 represents a new molecular structure for PAR2 antagonism and can serve as a basis for further development for this important therapeutic target. PMID:26140338

  10. Review of PAR parameterizations in ocean ecosystem models

    NASA Astrophysics Data System (ADS)

    Byun, Do-Seong; Wang, Xiao Hua; Hart, Deirdre E.; Zavatarelli, Marco

    2014-12-01

    Commonly-used empirical equations for calculating downward 'photosynthetically available radiation' or PAR were reviewed in order to identify a more theoretically-sound parameterization for application to ocean biogeochemical models. Three different forms of broadband PAR parameterization are currently employed in biogeochemical models, each of them originating from the downward irradiance formulations normally applied to ocean circulation models, which produce poor attenuation estimates for PAR. Two of the PAR formulations, a single-exponential function and a double-exponential function, are parameterized by multiplying surface irradiance by a coefficient determining the portion of underwater PAR. The third formulation uses the second term of the double-exponential function. After elucidating the theoretical problems of modeling PAR using these parameterizations, we suggest an improved, R-modified double-exponential PAR formulation, including Paulson and Simpson's (1977) parameter values. We also newly estimate PAR penetration via least-squares fitting of values digitized from Jerlov's (1976) observations in different oceanic water types, and compare this PAR-observation derived parameterization with our new, theoretical, R-modified parameterization. Finally, we discuss a universal limitation inherent in current theoretical approaches to PAR parameterization.

  11. Le premier examen gynécologique idéal imaginé par les jeunes filles

    PubMed Central

    Freyens, Anne; Dejeanne, Mélanie; Fabre, Elise; Rouge-Bugat, Marie-Eve; Oustric, Stéphane

    2017-01-01

    Résumé Objectif Explorer les représentations sur l’examen gynécologique (EG) et identifier les critères nécessaires à son bon déroulement chez des adolescentes n’ayant pas encore vécu cet examen. Type d’étude Enquête qualitative par entrevues semi-dirigées. Contexte Midi-Pyrénées (France) et Auvergne (France). Participants Jeunes filles de 15 à 19 ans qui n’ayant pas vécu l’EG. Méthodes Le mode de recrutement de l’échantillon a été double : sélection des jeunes filles par la technique boule-de-neige et sélection par la technique d’échantillonnage ciblé jusqu’à l’obtention de la saturation des données tout en cherchant la variation maximale dans les profils des sujets. Les questions ouvertes portaient sur les sources d’informations, les connaissances, les critères de bon déroulement et l’imaginaire autour de l’EG. Le verbatim a fait l’objet d’une analyse longitudinale immédiate rassemblant le contexte (notes des chercheurs) et les idées principales de l’entretien. Une analyse transversale thématique a été réalisée. Principales constatations Une méconnaissance générale des jeunes filles sur l’EG entretenait l’imaginaire autour de cet examen perçu comme obligatoire. L’EG idéal, selon les jeunes filles interrogées, aurait lieu chez une jeune fille qui se sentirait prête, informée préalablement, pouvant être accompagnée selon son souhait. Cet examen se déroulerait dans un environnement chaleureux et confortable afin de diminuer le sentiment de vulnérabilité. La qualité du lien avec le médecin conditionnerait l’acceptation de cet examen par les jeunes filles. Conclusion Une consultation dédiée à l’information, préalable à la consultation où a lieu l’EG, permettrait de diminuer les appréhensions, d’améliorer les connaissances des jeunes filles et de favoriser le bon déroulement du futur premier EG tant pour le médecin que pour la patiente. PMID:28807971

  12. Traitement par plasma thermique d'une liqueur caustique pour la destruction des cyanures

    NASA Astrophysics Data System (ADS)

    Fortin, Luc

    L'objectif principal de cette recherche est d'evaluer la possibilite de traiter le lixiviat de brasques usees produit par le procede LCL&L (Lixiviation a bas caustique et chaulage) par contact direct avec un jet de plasma thermique. L'utilisation d'un chalumeau au plasma permet d'eliminer les problemes de reaction avec les produits de combustion relies a l'utilisation de chalumeaux conventionnels (e.g. carbonatation du NaOH en Na2CO3). Le fait de se servir de ce type de chalumeau en mode submerge pour le traitement d'une solution liquide constitue l'originalite du projet. Les essais effectues dans le cadre de ce travail experimental sont realises a l'echelle banc d'essai dans un premier temps. Ils visent a determiner le taux de decomposition des cyanures contenus dans le lixiviat sous des conditions de plasma thermique en fonction de differents parametres et a faire la mise a l'echelle d'un reacteur pilote. La puissance electrique fournie au chalumeau, la temperature et la pression d'operation, le point d'addition d'eau, le volume de lixiviat traite et l'addition de peroxyde d'hydrogene (H2O2) comme co-reactif ont tous un impact sur le taux de destruction des cyanures trouve. Sous toutes les conditions etudiees, le reacteur plasma offre un taux de destruction plus rapide qu'un reacteur agite sous pression pour une meme concentration en cyanures. Ainsi, la comparaison de la constante cinetique obtenue pour le reacteur agite avec une constante similaire pour le reacteur plasma (pente du graphique -ln(C/C0) en fonction du temps) est de 0.04x10-3 s-1 vs 0.59x10-3 s-1 a 100°C et de 1.85x10-3 s-1' vs 3x10 -3 s-1s a 170°C. Ces resultats confirment que le plasma joue un role important sur la decomposition des cyanures et qu'il contribue a en augmenter le taux de destruction. Suite aux connaissances acquises sur le banc d'essai, un reacteur pilote est concu. Un chalumeau au plasma d'une puissance de 60 kW-150 kW et fonctionnant avec l'air comme gaz plasmagene y est

  13. A Conserved Mode of Protein Recognition and Binding in a ParD−ParE Toxin−Antitoxin Complex

    SciTech Connect

    Dalton, Kevin M.; Crosson, Sean

    2010-05-06

    Toxin-antitoxin (TA) systems form a ubiquitous class of prokaryotic proteins with functional roles in plasmid inheritance, environmental stress response, and cell development. ParDE family TA systems are broadly conserved on plasmids and bacterial chromosomes and have been well characterized as genetic elements that promote stable plasmid inheritance. We present a crystal structure of a chromosomally encoded ParD-ParE complex from Caulobacter crescentus at 2.6 {angstrom} resolution. This TA system forms an {alpha}{sub 2}{beta}{sub 2} heterotetramer in the crystal and in solution. The toxin-antitoxin binding interface reveals extensive polar and hydrophobic contacts of ParD antitoxin helices with a conserved recognition and binding groove on the ParE toxin. A cross-species comparison of this complex structure with related toxin structures identified an antitoxin recognition and binding subdomain that is conserved between distantly related members of the RelE/ParE toxin superfamily despite a low level of overall primary sequence identity. We further demonstrate that ParD antitoxin is dimeric, stably folded, and largely helical when not bound to ParE toxin. Thus, the paradigmatic model in which antitoxin undergoes a disorder-to-order transition upon toxin binding does not apply to this chromosomal ParD-ParE TA system.

  14. Coinfection pulmonaire par pneumocystis jirovecii et pseudomonas aeruginosa au cours du SIDA: à propos de deux cas

    PubMed Central

    Mamoudou, Savadogo; Bellaud, Guillaume; Ana, Canestri; Gilles, Pialoux

    2015-01-01

    Rapporter deux cas cliniques de coinfections pulmonaires par Pneumocystis jirovecii et par Pseudomonas aeruginosa chez des patients vivant avec le VIH. Les deux patients étaient âgés respectivement de 32 ans et 46 ans. Un patient a été pris en charge à l'hôpital Yalgado Ouédraogo de Ouagadougou au Burkina Faso et l'autre a été pris en charge à l'hôpital Ténon de Paris, en France. Les deux souffraient de pneumopathie confirmée à la radiographie et à la tomodensitométrie. L'un des patients était sévèrement immuno déprimé, contrairement à l'autre. L'examen bactériologique dans les crachats avait permis d'isoler Pseudomonas aeruginosa et Pneumocystis jirovecii chez les deux patients. Sous traitement, l’évolution a été favorable. Les coinfections morbides sont relativement fréquentes chez les patients vivant avec le VIH. Devant une symptomatologie respiratoire du sujet vivant avec le VIH, il faut savoir rechercher en plus du Bacille de Koch, Pneumocystis jirovecii et Pseudomonas aeruginosa par un lavage broncho alvéolaire. PMID:26516396

  15. Hong-Ou-Mandel Interference with a Single Atom

    PubMed Central

    Ralley, K. A.; Lerner, I. V.; Yurkevich, I. V.

    2015-01-01

    The Hong-Ou-Mandel (HOM) effect is widely regarded as the quintessential quantum interference phenomenon in optics. In this work we examine how nonlinearity can smear statistical photon bunching in the HOM interferometer. We model both the nonlinearity and a balanced beam splitter with a single two-level system and calculate a finite probability of anti-bunching arising in this geometry. We thus argue that the presence of such nonlinearity would reduce the visibility in the standard HOM setup, offering some explanation for the diminution of the HOM visibility observed in many experiments. We use the same model to show that the nonlinearity affects a resonant two-photon propagation through a two-level impurity in a waveguide due to a “weak photon blockade” caused by the impossibility of double-occupancy and argue that this effect might be stronger for multi-photon propagation. PMID:26365761

  16. Hong-Ou-Mandel Interference with a Single Atom

    NASA Astrophysics Data System (ADS)

    Ralley, K. A.; Lerner, I. V.; Yurkevich, I. V.

    2015-09-01

    The Hong-Ou-Mandel (HOM) effect is widely regarded as the quintessential quantum interference phenomenon in optics. In this work we examine how nonlinearity can smear statistical photon bunching in the HOM interferometer. We model both the nonlinearity and a balanced beam splitter with a single two-level system and calculate a finite probability of anti-bunching arising in this geometry. We thus argue that the presence of such nonlinearity would reduce the visibility in the standard HOM setup, offering some explanation for the diminution of the HOM visibility observed in many experiments. We use the same model to show that the nonlinearity affects a resonant two-photon propagation through a two-level impurity in a waveguide due to a “weak photon blockade” caused by the impossibility of double-occupancy and argue that this effect might be stronger for multi-photon propagation.

  17. Phase-unlocked Hong-Ou-Mandel interferometry

    NASA Astrophysics Data System (ADS)

    Abouraddy, Ayman F.; Yarnall, Timothy M.; Di Giuseppe, Giovanni

    2013-06-01

    There is a fundamental dimensional mismatch between the Hong-Ou-Mandel (HOM) interferometer and two-photon (2P) states: while the latter are represented using two temporal (or spectral) dimensions, the HOM interferometer allows access to only one temporal dimension. We introduce a linear 2P interferometer containing two independent delays spanning the 2P state. By “unlocking” the fixed phase relationship between the interfering 2P probability amplitudes in a HOM interferometer, one of these probability amplitudes now serves as a delay-free 2P reference against which the other beats, thereby resolving ambiguities in 2P state identification typical of HOM interferometry and extending its utility to a large family of 2P states.

  18. Douleurs induites par les soins: la réalité au Centre Hospitalier Universitaire de Befelatanana Antananarivo, Madagascar

    PubMed Central

    Mahavivola, Ernestho-Ghoud Indretsy; Olivah, Razanaparany Miarisoa Mireille; Mihary, Dodo; Hendriniaina, Rakotoharivelo; Lalao, Randriamboavonjy Rado; Henintsoa, Rakotonirainy Oliva; Fahafahantsoa, Rapelanoro Rabenja

    2014-01-01

    La douleur induite par les soins correspond à la douleur survenant lors des actes à visé diagnostique et/ou thérapeutique. A notre connaissance, nous n'avons pas encore des données disponibles pour les douleurs induites par les soins à l'Hôpital de Befelatanana. Nos objectifs étaient de décrire le profil épidémiologique de la douleur induite par les soins, d'identifier les principaux facteurs influençant sur l'intensité de la douleur et leurs retentissements chez les patients. Il s'agissait d'une étude rétrospective, transversale type un jour donné menée dans les douze services de Médecines au Centre Hospitalier Universitaire de Befelatanana en Novembre 2013. Cent deux patients ont été retenus dans l’étude et trois cent vingt trois actes douloureux étaient enregistrés. La fréquence de la douleur induite par les soins était de 69,86%. Le genre féminin prédominait dans 52% des cas (n = 53) avec un sex-ratio à 0,92. L’âge moyen était de 46 ans. Les ponctions vasculaires étaient l'acte prédominant dans 49,54% (n = 109) des cas. Les infirmiers réalisaient les soins dans 47,05% (n = 48) des cas. L'information verbale était la mesure préventive utilisée dans 57,84% des cas (n = 59). Le transport par marche à pied et au dos représentait 16,67% des cas (n = 17). Les patients naïfs des gestes étaient plus anxieux. Ces patients gardaient de mauvais souvenir dans 64,71% des cas (n = 66). La fréquence de douleur induite par les soins était trop élevée. Un effort important est nécessaire pour réduire la douleur induite par les soins PMID:25932071

  19. Geology and hydrocarbon potential of the Oued Mya basin, Algeria

    SciTech Connect

    Benamrane, O.; Messaoudi, M.; Messelles, H. )

    1993-09-01

    The Oued Mya hydrocarbon system is located in the Sahara basin. It is one of the best producing basins in Algeria, along with the Ghadames and Illizi basins. The stratigraphic section consists of Paleozoic and Mesozoic, and is about 5000 m thick. This intracratonic basin is limited to the north by the Toughourt saddle, and to the west and east it is flanked by regional arches, Allal-Tilghemt and Amguid-Hassi Messaoud, which culminate in the super giant Hassi Messaoud and Hassi R'mel hydrocarbon accumulations, respectively, producing oil from the Cambrian sands and gas from the Trissic sands. The primary source rock in this basin is lower Silurian shale, with an average thickness of 50 m and a total organic carbon of 6% (14% in some cases). Results of maturation modeling indicate that the lower Silurian source is in the oil window. The Ordovician shales are also source rocks, but in a second order. Clastic reservoirs are in the Trissic sequence, which is mainly fluvial deposits with complex alluvial channels, and the main target in the basin. Clastic reservoirs in the lower Devonian section have a good hydrocarbon potential east of the basin through a southwest-northwest orientation. The Late Trissic-Early Jurassic evaporites that overlie the Triassic clastic interval and extend over the entire Oued Mya basin, are considered to be a super-seal evaporite package, which consists predominantly of anhydrite and halite. For paleozoic targets, a large number of potential seals exist within the stratigraphic column. This super seal does not present oil dismigration possibilities. We can infer that a large amount of the oil generated by the Silurian source rock from the beginning of Cretaceous until now still is not discovered and significantly greater volumes could be trapped within structure closures and mixed or stratigraphic traps related to the fluvial Triassic sandstones, marine Devonian sands, and Cambrian-Ordovician reservoirs.

  20. A new model for estimating boreal forest fPAR

    NASA Astrophysics Data System (ADS)

    Majasalmi, Titta; Rautiainen, Miina; Stenberg, Pauline

    2014-05-01

    Life on Earth is continuously sustained by the extraterrestrial flux of photosynthetically active radiation (PAR, 400-700 nm) from the sun. This flux is converted to biomass by chloroplasts in green vegetation. Thus, the fraction of absorbed PAR (fPAR) is a key parameter used in carbon balance studies, and is listed as one of the Essential Climate Variables (ECV). Temporal courses of fPAR for boreal forests are difficult to measure, because of the complex 3D structures. Thus, they are most often estimated based on models which quantify the dependency of absorbed radiation on canopy structure. In this study, we adapted a physically-based canopy radiation model into a fPAR model, and compared modeled and measured fPAR in structurally different boreal forest stands. The model is based on the spectral invariants theory, and uses leaf area index (LAI), canopy gap fractions and spectra of foliage and understory as input data. The model differs from previously developed more detailed fPAR models in that the complex 3D structure of coniferous forests is described using an aggregated canopy parameter - photon recollision probability p. The strength of the model is that all model inputs are measurable or available through other simple models. First, the model was validated with measurements of instantaneous fPAR obtained with the TRAC instrument in nine Scots pine, Norway spruce and Silver birch stands in a boreal forest in southern Finland. Good agreement was found between modeled and measured fPAR. Next, we applied the model to predict temporal courses of fPAR using data on incoming radiation from a nearby flux tower and sky irradiance models. Application of the model to simulate diurnal and seasonal values of fPAR indicated that the ratio of direct-to-total incident radiation and leaf area index are the key factors behind the magnitude and variation of stand-level fPAR values.

  1. 2. HI PAR (ACQUISITION RADAR) TOWER AND ENLISTED MEN (EM) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. HI PAR (ACQUISITION RADAR) TOWER AND ENLISTED MEN (EM) BARRACKS WITH RADAR ATTACHED. - Nike Hercules Missile Battery Summit Site, Battery Control Administration & Barracks Building, Anchorage, Anchorage, AK

  2. Spectroscopie du Furanne et du Thiophene Par Diffusion Inelastique D'electrons

    NASA Astrophysics Data System (ADS)

    Lotfi, Said

    Nous avons etudie les molecules de furanne ( rm C_4H_4O) et de thiophene (rm C_4H_4O) au moyen de la spectroscopie de diffusion inelastique d'electrons. Pour (rm C_4H_4O), les spectres realises dans differentes conditions d'energie d'impact et d'angle de diffusion contiennent des singularites ou des families de pics correspondant a: (1) des vibrations de l'etat fondamental dans le domaine 0-0.5 eV, (2) des etats triplets ^3 B_1 et ^3 A_1 qui dominent la region 3-5.5 eV, (3) des etats de valences, entre 5 et 10 eV, dont certains son accompagnes de progressions vibrationnelles, soit ~ A _1B_2, ~ B ^1A_1 et ~ C ^1A_1, (4) toujours entre 5 et 10 eV, deux series de Ryhdberg (rm 1a_2to nda_2 et rm 1a_2to npb_2) qui convergent vers la premiere limite d'ionisation de la molecule, avec une progression vibrationnelle associee au mdoe nu_4 pour la seconde, et une troisieme serie (rm 2b_1to nsa_1 ) convergent vers la seconde limite d'ionisation accompagnee de la progression de mode nu _1. Pour rm C_4H_4S, nos spectres presentent les memes etats de vibration et les memes etats triplets que pour rm C_4H _4O. Nous avons releve egalement, dans la region de 5 a 10 eV, des etats de valence ~ A ^1A_1 (ou ~ A ^1B_2), ~ B ^1A_1 (ou ~ B ^1B _2) et ~ C ^1A_1 (ou ~ C ^1B_2). Pour la premiere fois, par la spectroscopie de diffusion inelastique d'electrons, de nombreux pics ont ete identifies et attribues, dans le cadre de ce travail. Il s'agit, notamment, des etats de vibration de l'etat electronique fondamental de ces molecules et egalement de certains etats de Rydberg dans le cas du furanne.

  3. Taare Zameen Par and dyslexic savants

    PubMed Central

    Chakravarty, Ambar

    2009-01-01

    The film Taare Zameen Par (Stars upon the Ground) portrays the tormented life at school and at home of a child with dyslexia and his eventual success after his artistic talents are discovered by his art teacher at the boarding school. The film hints at a curious neurocognitive phenomenon of creativity in the midst of language disability, as exemplified in the lives of people like Leonardo da Vinci and Albert Einstein, both of whom demonstrated extraordinary creativity even though they were probably affected with developmental learning disorders. It has been hypothesized that a developmental delay in the dominant hemisphere most likely ‘disinhibits’ the nondominant parietal lobe, unmasking talents—artistic or otherwise—in some such individuals. It has been suggested that, in remedial training, children with learning disorders be encouraged to develop such hidden talents to full capacity, rather than be subjected to the usual overemphasis on the correction of the disturbed coded symbol operations. PMID:20142854

  4. Comparison of Identify-Friend-Foe and Blue-Force Tracking Decision Support for Combat Identification (Comparaison des Systemes d’aide a la Decision Identification ami ou Ennemi et Suivi des Forces Bleues pour l’Identification au Combat)

    DTIC Science & Technology

    2011-02-01

    disposition de chaque soldat à pied. Deux expériences ont permis d’examiner l’efficacité des systèmes d’aide à la décision Identification ami ou ennemi (IAE...chaque fois qu’ils sont ciblés par une transmission donnée (infrarouge, radar, etc.). Les soldats munis du générateur et récepteur de signaux...rapidement et pourraient éventuellement être mises à la disposition de chaque soldat à pied. Deux expériences ont permis d’examiner l’efficacité des

  5. Transcriptome profiling reveals links between ParS/ParR, MexEF-OprN, and quorum sensing in the regulation of adaptation and virulence in Pseudomonas aeruginosa

    PubMed Central

    2013-01-01

    Background The ParS/ParR two component regulatory system plays critical roles for multidrug resistance in Pseudomonas aeruginosa. It was demonstrated that in the presence of antimicrobials, ParR enhances bacterial survival by distinct mechanisms including activation of the mexXY efflux genes, enhancement of lipopolysaccharide modification through the arn operon, and reduction of the expression of oprD porin. Results In this study, we report on transcriptomic analyses of P. aeruginosa PAO1 wild type and parS and parR mutants growing in a defined minimal medium. Our transcriptomic analysis provides the first estimates of transcript abundance for the 5570 coding genes in P. aeruginosa PAO1. Comparative transcriptomics of P. aeruginosa PAO1 and par mutants identified a total of 464 genes regulated by ParS and ParR. Results also showed that mutations in the parS/parR system abolished expression of the mexEF-oprN operon by down-regulating the regulatory gene mexS. In addition to the known effects on drug resistance genes, transcript abundances of the quorum sensing genes (rhlIR and pqsABCDE-phnAB) were higher in both parS and parR mutants. In accordance with these results, a significant portion of the ParS/ParR regulated genes belonged to the MexEF-OprN and quorum sensing regulons. Deletion of the par genes also led to increased phenazine production and swarming motility, consistent with the up-regulation of the phenazine and rhamnolipid biosynthetic genes, respectively. Conclusion Our results link the ParS/ParR two component signal transduction system to MexEF-OprN and quorum sensing systems in P. aeruginosa. These results expand our understanding of the roles of the ParS/ParR system in the regulation of gene expression in P. aeruginosa, especially in the absence of antimicrobials. PMID:24034668

  6. Le fibromatosis colli ou torticolis congénital: son diagnostic et sa prise en charge à propos de deux cas

    PubMed Central

    Tchaou, Mazamaesso; Pegbessou, Plaodezina Essobozou; Sonhaye, Lantam; Ahouanssou, Patricia Yékpé; Amadou, Abdoulatif; Kolou, Beresa; Kama, Lidi Bessi; Garba, Nouhou Mahamadou; Koussema, Lama Kegdigoma Agoda; N'dakéna, Koffi

    2015-01-01

    Le fibromatosis colli (FC) est pseudotumeur rare du muscle sterno-cléido-mastoïdien (SCM), à l'origine d'un torticolis dit congénital chez le nouveau-né ou le nourrisson. Le mécanisme étio-pathogénique de sa survenue est sujet à controverse. Son diagnostic fait appel à l’échographie qui permet de mettre en évidence un épaississement caractéristique du muscle. Nous rapportons deux cas diagnostiqués par l’échographie avec pour un cas une notion de malposition intra-utérine et pour l'autre cas une absence totale de malposition et de traumatisme obstétrical qui pourtant est évoqué comme élément du mécanisme de survenue du FC. PMID:26834927

  7. TMS suppression of right pars triangularis, but not pars opercularis, improves naming in aphasia

    PubMed Central

    Naeser, Margaret A.; Martin, Paula I.; Theoret, Hugo; Kobayashi, Masahito; Fregni, Felipe; Nicholas, Marjorie; Tormos, Jose M.; Steven, Megan S.; Baker, Errol H.; Pascual-Leone, Alvaro

    2011-01-01

    This study sought to discover if an optimum 1 cm2 area in the non-damaged right hemisphere (RH) was present, which could temporarily improve naming in chronic, nonfluent aphasia patients when suppressed with repetitive transcranial magnetic stimulation (rTMS). Ten minutes of slow, 1 Hz rTMS was applied to suppress different RH ROIs in eight aphasia cases. Picture naming and response time (RT) were examined before, and immediately after rTMS. In aphasia patients, suppression of right pars triangularis (PTr) led to significant increase in pictures named, and significant decrease in RT. Suppression of right pars opercularis (POp), however, led to significant increase in RT, but no change in number of pictures named. Eight normals named all pictures correctly; similar to aphasia patients, RT significantly decreased following rTMS to suppress right PTr, versus right POp. Differential effects following suppression of right PTr versus right POp suggest different functional roles for these regions. PMID:21864891

  8. Nécrolyse épidermique toxique induite par le phénobarbital chez un enfant Rwandais: à propos d'uncas

    PubMed Central

    Kaputu-Kalala-Malu, Célestin; Ntumba-Tshitenge, Olga; Misson, Jean-Paul

    2014-01-01

    Le syndrome de Lyell ou la nécrolyse épidermique toxique (TEN) est une des rares complications majeures du traitement par phénobarbital. Sa prise en charge n'est pas encore codifiée. Il requiert une intervention urgente, lourde et adaptée à chaque patient afin d'en réduire la mortalité. Nous décrivons un cas du syndrome de Lyell survenu une dizaine de jours après initiation du traitement antiépileptique par phénobarbital chez un enfant rwandais de deux ans. La complexité des lésions cutanéomuqueuses et leurs répercussions sur le plan général soulignent l'importance d'une prescription responsable et justifiée des médicaments antiépileptiques. PMID:25396028

  9. Tumour-suppression activity of the proapoptotic regulator Par4.

    PubMed

    García-Cao, Isabel; Duran, Angeles; Collado, Manuel; Carrascosa, Maria J; Martín-Caballero, Juan; Flores, Juana M; Diaz-Meco, Maria T; Moscat, Jorge; Serrano, Manuel

    2005-06-01

    The proapoptotic protein encoded by Par4 (prostate apoptosis response 4) has been implicated in tumour suppression, particularly in the prostate. We report here that Par4-null mice are prone to develop tumours, both spontaneously and on carcinogenic treatment. The endometrium and prostate of Par4-null mice were particularly sensitive to the development of proliferative lesions. Most (80%) Par4-null females presented endometrial hyperplasia by 9 months of age, and a significant proportion (36%) developed endometrial adenocarcinomas after 1 year of age. Similarly, Par4-null males showed a high incidence of prostate hyperplasia and prostatic intraepithelial neoplasias, and were extraordinarily sensitive to testosterone-induced prostate hyperplasia. Finally, the uterus and prostate of young Par4-null mice have increased levels of the apoptosis inhibitor XIAP (X-chromosome-linked inhibitor of apoptosis), supporting the previously proposed function of Par4 as an inhibitor of the (zeta)PKC (atypical protein kinase)-NF-(kappa)B (nuclear factor-(kappa)B)-XIAP pathway. These data show that Par4 has an important role in tumour suppression, with a particular relevance in the endometrium and prostate.

  10. Tumour-suppression activity of the proapoptotic regulator Par4

    PubMed Central

    García-Cao, Isabel; Duran, Angeles; Collado, Manuel; Carrascosa, Maria J.; Martín-Caballero, Juan; Flores, Juana M.; Diaz-Meco, Maria T.; Moscat, Jorge; Serrano, Manuel

    2005-01-01

    The proapoptotic protein encoded by Par4 (prostate apoptosis response 4) has been implicated in tumour suppression, particularly in the prostate. We report here that Par4-null mice are prone to develop tumours, both spontaneously and on carcinogenic treatment. The endometrium and prostate of Par4-null mice were particularly sensitive to the development of proliferative lesions. Most (80%) Par4-null females presented endometrial hyperplasia by 9 months of age, and a significant proportion (36%) developed endometrial adenocarcinomas after 1 year of age. Similarly, Par4-null males showed a high incidence of prostate hyperplasia and prostatic intraepithelial neoplasias, and were extraordinarily sensitive to testosterone-induced prostate hyperplasia. Finally, the uterus and prostate of young Par4-null mice have increased levels of the apoptosis inhibitor XIAP (X-chromosome-linked inhibitor of apoptosis), supporting the previously proposed function of Par4 as an inhibitor of the ζPKC (atypical protein kinase)–NF-κB (nuclear factor-κB)–XIAP pathway. These data show that Par4 has an important role in tumour suppression, with a particular relevance in the endometrium and prostate. PMID:15877079

  11. Simulation-Based Acquisition of the Future Air-Land Combat System (acquisition par la simulation des systemes futurs de combat aeroterresire)

    DTIC Science & Technology

    2003-11-01

    assistés par ordinateur appropriés ; conserver une approche utilisateur. Vérification, validation et traçabilité (des alternatives et des décisions) sont...nouveaux concepts pour le combat aéroterrestre ont été définis, basés sur une approche système de systèmes, et qui se fondent sur des avancées...technologiques récentes, comme les robots ou les capteurs miniaturisés. Afin d’explorer les différents concepts et d’engager les phases de conception des

  12. Hong Ou Mandel interferometer: A quantum measurement tool

    NASA Astrophysics Data System (ADS)

    Borjemscaia, Natalia

    Quantum computing research has been around for several decades, since it was first proposed by Richard Feynman. Many efforts have been made to utilize quantum systems in creation of new computing devices in the recent years. One of the essential tools used for characterization and manipulation of optical quantum systems is a Hong Ou Mandel (HOM) Interferometer. It is used in this work to provide information about propagation, distortion and degree of indistinguishability of single photons. This work provides complete characterization of an optical tunneling effect in dielectric Bragg gratings. Samples with different thin film configurations are examined and their corresponding propagation delay times are calculated with sub-femtosecond precision. It is determined that for specific configurations for dielectric stacks, propagation delays can exhibit superluminal behavior. The distortion due to this effect is also calculated using HOM profiles. HOM interferometer is also used to calculate the degree of coalescence between two dissimilar sources. Single photons generated by quantum dot emission and parametric down conversion are tailored through aggressive filtering techniques to be identical in their spectral, temporal and polarization profiles. The degree of their coalescence is then calculated in an attempt to create quantum interference. This work attempts to provide better understanding of single photon interactions through use of an HOM interferometer.

  13. A phase-unlocked Hong-Ou-Mandel interferometer

    NASA Astrophysics Data System (ADS)

    Yarnall, Timothy M.; Abouraddy, Ayman F.; Di Guiseppe, Giovanni

    2013-05-01

    There exists a fundamental dimensional mismatch between the Hong-Ou-Mandel (HOM) interferometer and two-photon states: while the latter are represented using two temporal (or spectral) dimensions, the HOM interferometer allows access to only one temporal dimension owing to its single delay element. We introduce a linear two-photon interferometer containing two independent delays spanning the two-photon state. By unlocking the fixed phase relationship between the interfering two-photon probability amplitudes in a HOM interferometer, one of these probability amplitudes now serves as a delay-free two-photon reference against which the other beats, thereby resolving ambiguities in two-photon state identification typical of HOM interferometry. We discuss the operation of this phase-unlocked HOM on a variety of input states focusing on instances where this new interferometer outperforms a traditional HOM interferometer: frequency-correlated states and states produced by a pulse doublet pump. Additionally, this interferometer affords the opportunity to synchronize two-photon states in a manner analogous to an HOM interferometer; moreover, it extends that capability to the aforementioned class of states.

  14. [Around Ambroise Paré: his pupils and friends].

    PubMed

    Dumaître, P

    1996-01-01

    The most important pupil of Paré was Jacques Guillemeau (1550-1613), a famous surgeon from Montpellier. He lived at Paré's during eight years and wrote there his first work "Traité des maladies des yeux" (1585) and was really his "spiritual son". The barber-surgeon Martin Boursier, husband of the famous midwife Louise Bourgeois stayed twenty years with Paré and she learned her practice in his works. Attracted by Paré's fame, Melchior Sebiz (1539-1625) who shall become a famous professor of medicine in Strasbourg attended Paré's lessons and "was with him in great friendship". Among his friends, Thierry de Héry (ca. 1505-ca. 1560), companion of his youth as a barber-surgeon and author of the first French book on syphilis seems to have been the dearest and the nearest to his heart.

  15. Structures of partition protein ParA with nonspecific DNA and ParB effector reveal molecular insights into principles governing Walker-box DNA segregation.

    PubMed

    Zhang, Hengshan; Schumacher, Maria A

    2017-03-01

    Walker-box partition systems are ubiquitous in nature and mediate the segregation of bacterial and archaeal DNA. Well-studied plasmid Walker-box partition modules require ParA, centromere-DNA, and a centromere-binding protein, ParB. In these systems, ParA-ATP binds nucleoid DNA and uses it as a substratum to deliver ParB-attached cargo DNA, and ParB drives ParA dynamics, allowing ParA progression along the nucleoid. How ParA-ATP binds nonspecific DNA and is regulated by ParB is unclear. Also under debate is whether ParA polymerizes on DNA to mediate segregation. Here we describe structures of key ParA segregation complexes. The ParA-β,γ-imidoadenosine 5'-triphosphate (AMPPNP)-DNA structure revealed no polymers. Instead, ParA-AMPPNP dimerization creates a multifaceted DNA-binding surface, allowing it to preferentially bind high-density DNA regions (HDRs). DNA-bound ParA-AMPPNP adopts a dimer conformation distinct from the ATP sandwich dimer, optimized for DNA association. Our ParA-AMPPNP-ParB structure reveals that ParB binds at the ParA dimer interface, stabilizing the ATPase-competent ATP sandwich dimer, ultimately driving ParA DNA dissociation. Thus, the data indicate how harnessing a conformationally adaptive dimer can drive large-scale cargo movement without the requirement for polymers and suggest a segregation mechanism by which ParA-ATP dimers equilibrate to HDRs shown to be localized near cell poles of dividing chromosomes, thus mediating equipartition of attached ParB-DNA substrates. © 2017 Zhang and Schumacher; Published by Cold Spring Harbor Laboratory Press.

  16. Recombination in the Human Pseudoautosomal Region PAR1

    PubMed Central

    Hinch, Anjali G.; Altemose, Nicolas; Noor, Nudrat; Donnelly, Peter; Myers, Simon R.

    2014-01-01

    The pseudoautosomal region (PAR) is a short region of homology between the mammalian X and Y chromosomes, which has undergone rapid evolution. A crossover in the PAR is essential for the proper disjunction of X and Y chromosomes in male meiosis, and PAR deletion results in male sterility. This leads the human PAR with the obligatory crossover, PAR1, to having an exceptionally high male crossover rate, which is 17-fold higher than the genome-wide average. However, the mechanism by which this obligatory crossover occurs remains unknown, as does the fine-scale positioning of crossovers across this region. Recent research in mice has suggested that crossovers in PAR may be mediated independently of the protein PRDM9, which localises virtually all crossovers in the autosomes. To investigate recombination in this region, we construct the most fine-scale genetic map containing directly observed crossovers to date using African-American pedigrees. We leverage recombination rates inferred from the breakdown of linkage disequilibrium in human populations and investigate the signatures of DNA evolution due to recombination. Further, we identify direct PRDM9 binding sites using ChIP-seq in human cells. Using these independent lines of evidence, we show that, in contrast with mouse, PRDM9 does localise peaks of recombination in the human PAR1. We find that recombination is a far more rapid and intense driver of sequence evolution in PAR1 than it is on the autosomes. We also show that PAR1 hotspot activities differ significantly among human populations. Finally, we find evidence that PAR1 hotspot positions have changed between human and chimpanzee, with no evidence of sharing among the hottest hotspots. We anticipate that the genetic maps built and validated in this work will aid research on this vital and fascinating region of the genome. PMID:25033397

  17. Recombination in the human Pseudoautosomal region PAR1.

    PubMed

    Hinch, Anjali G; Altemose, Nicolas; Noor, Nudrat; Donnelly, Peter; Myers, Simon R

    2014-07-01

    The pseudoautosomal region (PAR) is a short region of homology between the mammalian X and Y chromosomes, which has undergone rapid evolution. A crossover in the PAR is essential for the proper disjunction of X and Y chromosomes in male meiosis, and PAR deletion results in male sterility. This leads the human PAR with the obligatory crossover, PAR1, to having an exceptionally high male crossover rate, which is 17-fold higher than the genome-wide average. However, the mechanism by which this obligatory crossover occurs remains unknown, as does the fine-scale positioning of crossovers across this region. Recent research in mice has suggested that crossovers in PAR may be mediated independently of the protein PRDM9, which localises virtually all crossovers in the autosomes. To investigate recombination in this region, we construct the most fine-scale genetic map containing directly observed crossovers to date using African-American pedigrees. We leverage recombination rates inferred from the breakdown of linkage disequilibrium in human populations and investigate the signatures of DNA evolution due to recombination. Further, we identify direct PRDM9 binding sites using ChIP-seq in human cells. Using these independent lines of evidence, we show that, in contrast with mouse, PRDM9 does localise peaks of recombination in the human PAR1. We find that recombination is a far more rapid and intense driver of sequence evolution in PAR1 than it is on the autosomes. We also show that PAR1 hotspot activities differ significantly among human populations. Finally, we find evidence that PAR1 hotspot positions have changed between human and chimpanzee, with no evidence of sharing among the hottest hotspots. We anticipate that the genetic maps built and validated in this work will aid research on this vital and fascinating region of the genome.

  18. Developpement de mesures non destructives, par ondes ultrasonores, d'epaisseurs de fronts de solidification dans les reacteurs metallurgiques

    NASA Astrophysics Data System (ADS)

    Floquet, Jimmy

    Dans les cuves d'electrolyse d'aluminium, le milieu de reaction tres corrosif attaque les parois de la cuve, ce qui diminue leur duree de vie et augmente les couts de production. Le talus, qui se forme sous l'effet des pertes de chaleur qui maintiennent un equilibre thermique dans la cuve, sert de protection naturelle a la cuve. Son epaisseur doit etre controlee pour maximiser cet effet. Advenant la resorption non voulue de ce talus, les degats generes peuvent s'evaluer a plusieurs centaines de milliers de dollars par cuve. Aussi, l'objectif est de developper une mesure ultrasonore de l'epaisseur du talus, car elle serait non intrusive et non destructive. La precision attendue est de l'ordre du centimetre pour des mesures d'epaisseurs comprenant 2 materiaux, allant de 5 a 20 cm. Cette precision est le facteur cle permettant aux industriels de controler l'epaisseur du talus de maniere efficace (maximiser la protection des parois tout en maximisant l'efficacite energetique du procede), par l'ajout d'un flux thermique. Cependant, l'efficacite d'une mesure ultrasonore dans cet environnement hostile reste a demontrer. Les travaux preliminaires ont permis de selectionner un transducteur ultrasonore a contact ayant la capacite a resister aux conditions de mesure (hautes temperatures, materiaux non caracterises...). Differentes mesures a froid (traite par analyse temps-frequence) ont permis d'evaluer la vitesse de propagation des ondes dans le materiau de la cuve en graphite et de la cryolite, demontrant la possibilite d'extraire l'information pertinente d'epaisseur du talus in fine. Fort de cette phase de caracterisation des materiaux sur la reponse acoustique des materiaux, les travaux a venir ont ete realises sur un modele reduit de la cuve. Le montage experimental, un four evoluant a 1050 °C, instrumente d'une multitude de capteurs thermique, permettra une comparaison de la mesure intrusive LVDT a celle du transducteur, dans des conditions proches de la mesure

  19. Megestrol acetate NCD oral suspension -- Par Pharmaceutical: megestrol acetate nanocrystal dispersion oral suspension, PAR 100.2, PAR-100.2.

    PubMed

    2007-01-01

    Par Pharmaceutical has developed megestrol acetate (Megace ES) oral suspension for the treatment of anorexia, cachexia and a significant weight loss associated with AIDS. Par Pharmaceutical used Elan Corporation's NanoCrystal Dispersion (NCD) technology to develop an advanced, concentrated formulation of megestrol acetate with improved bioavailability, more rapid onset of action, more convenient dosing and a lower dosing regimen compared with the original marketed formulation of megestrol acetate oral suspension. Patients are administered a teaspoon (5mL) of the new NCD formulation once daily, compared with a daily 20mL dosage cup of the original formulation. The new megestrol acetate NCD formulation represents a line-extension of Par's megestrol acetate oral suspension (800mg/20mL, Megace O/S) that has been marketed for anorexia, cachexia and AIDS-related weight loss since July 2001. Par's megestrol acetate is the generic version of Bristol-Myers Squibb's Megace Oral Suspension. NanoCrystal Dispersion (NCD) is a trademark of Elan Corporation. Par Pharmaceutical will market megestol acetate NCD oral suspension under the Megace brand name. The company licensed the Megace name from Bristol-Myers Squib in August 2003. The US FDA approved megestrol acetate oral suspension (625 mg/mL) in July 2005 for the treatment of anorexia, cachexia or a significant, unexplained weight loss in patients with AIDS. The NDA for the product was accepted for review by the agency in September 2004, following its submission in June of that year.Par Pharmaceutical commenced the first of two phase III clinical trials of megestrol acetate oral suspension (PAR 100.2) in cancer-induced anorexia in the first quarter of 2006. However, this trial was discontinued in September 2006 because of slow patient enrolment. The company intends to discuss future development options in this indication with the FDA.New formulations or dosage forms of megestrol acetate concentrated suspension are also in

  20. Megestrol acetate NCD oral suspension--Par Pharmaceutical: megestrol acetate nanocrystal dispersion oral suspension, PAR 100.2, PAR-100.2.

    PubMed

    2007-01-01

    Par Pharmaceutical has developed megestrol acetate (Megace ES) oral suspension for the treatment of anorexia, cachexia and a significant weight loss associated with AIDS. Par Pharmaceutical used Elan Corporation's NanoCrystal Dispersion (NCD) technology to develop an advanced, concentrated formulation of megestrol acetate with improved bioavailability, more rapid onset of action, more convenient dosing and a lower dosing regimen compared with the original marketed formulation of megestrol acetate oral suspension. Patients are administered a teaspoon (5mL) of the new NCD formulation once daily, compared with a daily 20mL dosage cup of the original formulation. The new megestrol acetate NCD formulation represents a line-extension of Par's megestrol acetate oral suspension (800mg/20mL, Megace O/S) that has been marketed for anorexia, cachexia and AIDS-related weight loss since July 2001. Par's megestrol acetate is the generic version of Bristol-Myers Squibb's Megace Oral Suspension. NanoCrystal Dispersion (NCD) is a trademark of Elan Corporation. Par Pharmaceutical will market megestol acetate NCD oral suspension under the Megace brand name. The company licensed the Megace name from Bristol-Myers Squib in August 2003. The US FDA approved megestrol acetate oral suspension (625 mg/mL) in July 2005 for the treatment of anorexia, cachexia or a significant, unexplained weight loss in patients with AIDS. The NDA for the product was accepted for review by the agency in September 2004, following its submission in June of that year.Par Pharmaceutical commenced the first of two phase III clinical trials of megestrol acetate oral suspension (PAR 100.2) in cancer-induced anorexia in the first quarter of 2006. However, this trial was discontinued in September 2006 because of slow patient enrolment. The company intends to discuss future development options in this indication with the FDA.New formulations or dosage forms of megestrol acetate concentrated suspension are also in

  1. Condensation and localization of the partitioning protein ParB on the bacterial chromosome.

    PubMed

    Broedersz, Chase P; Wang, Xindan; Meir, Yigal; Loparo, Joseph J; Rudner, David Z; Wingreen, Ned S

    2014-06-17

    The ParABS system mediates chromosome segregation and plasmid partitioning in many bacteria. As part of the partitioning mechanism, ParB proteins form a nucleoprotein complex at parS sites. The biophysical basis underlying ParB-DNA complex formation and localization remains elusive. Specifically, it is unclear whether ParB spreads in 1D along DNA or assembles into a 3D protein-DNA complex. We show that a combination of 1D spreading bonds and a single 3D bridging bond between ParB proteins constitutes a minimal model for a condensed ParB-DNA complex. This model implies a scaling behavior for ParB-mediated silencing of parS-flanking genes, which we confirm to be satisfied by experimental data from P1 plasmids. Furthermore, this model is consistent with experiments on the effects of DNA roadblocks on ParB localization. Finally, we show experimentally that a single parS site is necessary and sufficient for ParB-DNA complex formation in vivo. Together with our model, this suggests that ParB binding to parS triggers a conformational switch in ParB that overcomes a nucleation barrier. Conceptually, the combination of spreading and bridging bonds in our model provides a surface tension ensuring the condensation of the ParB-DNA complex, with analogies to liquid-like compartments such as nucleoli in eukaryotes.

  2. Condensation and localization of the partitioning protein ParB on the bacterial chromosome

    PubMed Central

    Broedersz, Chase P.; Wang, Xindan; Meir, Yigal; Loparo, Joseph J.; Rudner, David Z.; Wingreen, Ned S.

    2014-01-01

    The ParABS system mediates chromosome segregation and plasmid partitioning in many bacteria. As part of the partitioning mechanism, ParB proteins form a nucleoprotein complex at parS sites. The biophysical basis underlying ParB–DNA complex formation and localization remains elusive. Specifically, it is unclear whether ParB spreads in 1D along DNA or assembles into a 3D protein–DNA complex. We show that a combination of 1D spreading bonds and a single 3D bridging bond between ParB proteins constitutes a minimal model for a condensed ParB–DNA complex. This model implies a scaling behavior for ParB-mediated silencing of parS-flanking genes, which we confirm to be satisfied by experimental data from P1 plasmids. Furthermore, this model is consistent with experiments on the effects of DNA roadblocks on ParB localization. Finally, we show experimentally that a single parS site is necessary and sufficient for ParB–DNA complex formation in vivo. Together with our model, this suggests that ParB binding to parS triggers a conformational switch in ParB that overcomes a nucleation barrier. Conceptually, the combination of spreading and bridging bonds in our model provides a surface tension ensuring the condensation of the ParB–DNA complex, with analogies to liquid-like compartments such as nucleoli in eukaryotes. PMID:24927534

  3. Pseudo-HELLP syndrome par carence en folates et/ou en vitamine B12: à propos d'un cas

    PubMed Central

    Benali, Mechaal; Bouassida, Mahdi; Dhouib, Firas; Bouzeidi, Kaled

    2014-01-01

    Plusieurs pathologies médicales peuvent interférer avec la grossesse et mimer le tableau biologique de HELLP syndrome. L’évolution naturelle de ce syndrome est d'une particulière gravité pour la mère et le fœtus, il convient d’éliminer rapidement les autres diagnostics afin d’éviter une extraction fœtale prématurée injustifiée. Nous rapportons le cas d'une parturiente qui s'est présentée avec un tableau évocateur d'un HELLP syndrome, rapporté finalement à une carence en folates et en vitamine B12. PMID:25404961

  4. Control of cleavage spindle orientation in Caenorhabditis elegans: The role of the genes par-2 and par-3

    SciTech Connect

    Cheng, N.N.; Kirby, C.M.; Kemphues, K.J.

    1995-02-01

    Polarized asymmetric divisions play important roles in the development of plants and animals. The first two embryonic cleavages of Caenorhabditis elegans provide an opportunity to study the mechanisms controlling polarized asymmetric divisions. The first cleavage is unequal, producing daughters with different sizes and fates. The daughter blastomeres divide with different orientations at the second cleavage; the anterior blastomere divides equally across the long axis of the egg, whereas the posterior blastomere divides unequally along the long axis. We report here the results of our analysis of the genes par-2 and par-3 with respect to their contribution to the polarity of these divisions. Strong loss-of-function mutations in both genes lead to an equal first cleavage and an altered second cleavage. Interestingly, the mutations exhibit striking gene-specific differences at the second cleavage. The par-2 mutations lead to transverse spindle orientations in both blastomeres, whereas par-3 mutations lead to longitudinal spindle orientations in both blastomeres. The spindle orientation defects correlate with defects in centrosome movements during both the first and the second cell cycle. Temperature shift experiments with par-2 (it5ts) indicate that the par-2(+) activity is not required after the two-cell stage. Analysis of double mutants shows that par-3 is epistatic to par-2. We propose a model wherein par-2(+) and par-3(+) act in concert during the first cell cycle to affect asymmetric modification of the cytoskeleton. This polar modification leads to different behaviors of centrosomes in the anterior and posterior and leads ultimately to blastomere-specific spindle orientations at the second cleavage. 44 refs., 5 figs., 5 tabs.

  5. Scleral Buckling for Rhegmatogenous Retinal Detachment Associated with Pars Planitis

    PubMed Central

    Ahn, Jae Kyoun

    2016-01-01

    Purpose. To evaluate the surgical outcome of scleral buckling (SB) in rhegmatogenous retinal detachment (RRD) patients associated with pars planitis. Methods. Retrospective review of RRD patients (32 eyes of pars planitis RRD and 180 eyes of primary RRD) who underwent SB. We compared primary and final anatomical success rates and visual outcomes between two groups. Results. Primary and final anatomical success were achieved in 25 (78.1%) and 31 (96.8%) eyes in the pars planitis RRD group and in 167 eyes (92.7%) and 176 eyes (97.7%) in primary RRD group, respectively. Both groups showed significant visual improvement (p < 0.001) and there were no significant differences in final visual acuity. Pars planitis RRD group was associated with higher rate of postoperative proliferative vitreoretinopathy (PVR) development (12.5% versus 2.8%, p = 0.031). Pars planitis and high myopia were significant preoperative risk factors and pseudophakia was borderline risk for primary anatomical failure after adjusting for various clinical factors. Conclusions. Pars planitis associated RRD showed inferior primary anatomical outcome after SB due to postoperative PVR development. However, final anatomical and visual outcomes were favorable. RRD cases associated with pars planitis, high myopia, and pseudophakia might benefit from different surgical approaches, such as combined vitrectomy and SB. PMID:27688907

  6. The Pars Triangularis in Dyslexia and ADHD

    PubMed Central

    Kibby, Michelle Y.; Kroese, Judith M.; Krebbs, Hillery; Hill, Crystal E.; Hynd, George W.

    2009-01-01

    Limited research has been conducted on the structure of the pars triangularis (PT) in dyslexia despite functional neuroimaging research finding it may play a role in phonological processing. Furthermore, research to date has not examined PT size in ADHD even though the right inferior frontal region has been implicated in the disorder. Hence, one of the purposes of this study was to examine the structure of the PT in dyslexia and ADHD. The other purposes included examining the PT in relation to overall expressive language ability and in relation to several specific linguistic functions given language functioning often is affected in both dyslexia and ADHD. Participants included 50 children: 10 with dyslexia, 15 with comorbid dyslexia/ADHD, 15 with ADHD, and 10 controls. Using a 2 (dyslexia or not) X 2 (ADHD or not) MANCOVA, findings revealed PT length and shape were comparable between those with and without dyslexia. However, children with ADHD had smaller right PT lengths than those without ADHD, and right anterior ascending ramus length was related to attention problems in the total sample. In terms of linguistic functioning, presence of an extra sulcus in the left PT was related to poor expressive language ability. In those with adequate expressive language functioning, left PT length was related to phonological awareness, phonological short-term memory and rapid automatic naming (RAN). Right PT length was related to RAN and semantic processing. Further work on PT morphology in relation to ADHD and linguistic functioning is warranted. PMID:19356794

  7. Multi-scale photoacoustic remote sensing (PARS) (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Haji Reza, Parsin; Bell, Kevan; Shi, W.; Zemp, Roger J.

    2016-03-01

    We introduce a novel multi-scale photoacoustic remote sensing (PARS) imaging system. Our system can provide optical resolution details for superficial structures as well as acoustic resolution for deep-tissue imaging down to 5 cm, in a non-contact setting. PARS system does not require any contact with the sample or ultrasound coupling medium. The optical resolution PARS (OR-OARS) system uses optically focused pulsed excitation with optical detection of photoacoustic signatures using a long-coherence interrogation beam co-focused and co-scanned with the excitation spot. In the OR-PARS initial pressures are sampled right at their subsurface origin where acoustic pressures are largest. The Acoustic resolution PARS (AR-PARS) picks up the surface oscillation of the tissue caused by generated photoacoustic signal using a modified version of Michelson interferometry. By taking advantage of 4-meters polarization maintaining single-mode fiber and a green fiber laser we have generated a multi-wavelength source using stimulated Raman scattering. Remote functional imaging using this multi-wavelength excitation source and PARS detection mechanism has been demonstrated. The oxygen saturation estimations are shown for both phantom and in vivo studies. Images of blood vessel structures for an In vivo chicken embryo model is demonstrated. The Phantom studies indicates ~3µm and ~300µm lateral resolution for OR-PARS and AR-PARS respectively. To the best of our knowledge this is the first dual modality non-contact optical and acoustic resolution system used for in vivo imaging.

  8. Predicted PAR1 inhibitors from multiple computational methods

    NASA Astrophysics Data System (ADS)

    Wang, Ying; Liu, Jinfeng; Zhu, Tong; Zhang, Lujia; He, Xiao; Zhang, John Z. H.

    2016-08-01

    Multiple computational approaches are employed in order to find potentially strong binders of PAR1 from the two molecular databases: the Specs database containing more than 200,000 commercially available molecules and the traditional Chinese medicine (TCM) database. By combining the use of popular docking scoring functions together with detailed molecular dynamics simulation and protein-ligand free energy calculations, a total of fourteen molecules are found to be potentially strong binders of PAR1. The atomic details in protein-ligand interactions of these molecules with PAR1 are analyzed to help understand the binding mechanism which should be very useful in design of new drugs.

  9. Limnological database for Par Pond: 1959 to 1980

    SciTech Connect

    Tilly, L.J.

    1981-03-01

    A limnological database for Par Pond, a cooling reservoir for hot reactor effluent water at the Savannah River Plant, is described. The data are derived from a combination of research and monitoring efforts on Par Pond since 1959. The approximately 24,000-byte database provides water quality, primary productivity, and flow data from a number of different stations, depths, and times during the 22-year history of the Par Pond impoundment. The data have been organized to permit an interpretation of the effects of twenty years of cooling system operations on the structure and function of an aquatic ecosystem.

  10. La prévention et le traitement des infections bactériennes chez les enfants aspléniques ou hypospléniques

    PubMed Central

    1999-01-01

    L’asplénie, qu’elle soit fonctionnelle ou anatomique, s’associe à un accroissement du risque d’infection potentiellement fatale ou constituant un danger de septicémie postsplénectomie (SPS). En raison du risque accru de bactériémie par des bactéries encapsulées chez les enfants aspléniques, la vaccination visant à prévenir une infection au Streptococcus pneumoniae, à l’Haemophilus influenzae de type b (Hib) et au Neiserria meningitidis est recommandée. Malgré la prévalence croissante de S pneumoniae pénicillinorésistant, on recommande aussi l’usage de pénicilline prophylactique chez les enfants aspléniques de moins de cinq ans, et pendant au moins un an après une splénectomie. La poursuite de la prophylaxie antibiotique après cette période dépend de la situation clinique de chaque enfant et de la prévalence de S pneumoniae pénicillinorésistant au sein de la collectivité. Lorsque des enfants aspléniques font de la fièvre ou présentent des symptômes non spécifiques, ils devraient faire l’objet d’une évaluation immédiate. Si on présume la présence de septicémie bactérienne, il faut procéder à une analyse du sang et des autres liquides organiques pertinents et entreprendre sur-le-champ une antibiothérapie à large spectre par voie parentérale, laquelle doit agir également contre les souches de S pneumoniae présentes dans la collectivité. Chez les enfants aspléniques souffrant d’une septicémie foudroyante à S pneumoniae, le taux de mortalité est élevé, malgré l’utilisation rapide d’une antibiothérapie convenable, d’où l’importance des mesures préventives.

  11. Techniques d'inspection par ondes guidees ultrasonores d'assemblages brases dans des reacteurs aeronautiques =

    NASA Astrophysics Data System (ADS)

    Comot, Pierre

    L'industrie aeronautique, cherche a etudier la possibilite d'utiliser de maniere structurelle des joints brases, dans une optique de reduction de poids et de cout. Le developpement d'une methode d'evaluation rapide, fiable et peu couteuse pour evaluer l'integrite structurelle des joints apparait donc indispensable. La resistance mecanique d'un joint brase dependant principalement de la quantite de phase fragile dans sa microstructure. Les ondes guidees ultrasonores permettent de detecter ce type de phase lorsqu'elles sont couplees a une mesure spatio-temporelle. De plus la nature de ce type d'ondes permet l'inspection de joints ayant des formes complexes. Ce memoire se concentre donc sur le developpement d'une technique basee sur l'utilisation d'ondes guidees ultrasonores pour l'inspection de joints brases a recouvrement d'Inconel 625 avec comme metal d'apport du BNi-2. Dans un premiers temps un modele elements finis du joint a ete utilise pour simuler la propagation des ultrasons et optimiser les parametres d'inspection, la simulation a permis egalement de demontrer la faisabilite de la technique pour la detection de la quantite de phase fragile dans ce type de joints. Les parametres optimises sont la forme de signal d'excitation, sa frequence centrale et la direction d'excitation. Les simulations ont montre que l'energie de l'onde ultrasonore transmise a travers le joint aussi bien que celle reflechie, toutes deux extraites des courbes de dispersion, etaient proportionnelles a la quantite de phase fragile presente dans le joint et donc cette methode permet d'identifier la presence ou non d'une phase fragile dans ce type de joint. Ensuite des experimentations ont ete menees sur trois echantillons typiques presentant differentes quantites de phase fragile dans le joint, pour obtenir ce type d'echantillons differents temps de brasage ont ete utilises (1, 60 et 180 min). Pour cela un banc d'essai automatise a ete developpe permettant d'effectuer une analyse similaire

  12. Positron Accumulator Ring (PAR) power supply

    SciTech Connect

    Fathizadeh, M.

    1995-08-01

    The Positron Accumulator Ring (PAR) consists of 8 dipole magnets connected in series. These magnets are energized via one 12-pulse dc power supply. The power supply consists of four phase controlled half-wave wye group converters. Each of the two half-wave converters are connected through an interphase transformer to obtain a full-wave converter with 120{degrees} conduction. The input voltage for these two half-wave converters are 180{degrees} apart. The two full-wave converters are connected in parallel through a third interphase transformer. This type of connection of the converters not only provides the required output current, it also improves the input power factor of the power supply. The output of the wye group converters is filtered through a passive L-R-C filter to reduce the ripple content of the output current. At low current values of the power supply the current ripple is high, thus a large filter is needed, which adds to the cost of the power supply, however at high output current levels, the current ripple is less severe. The large size of the filter can be reduced by adding an anti-parallel rectifier diode(D1) to the output of the power supply. A freewheeling diode(D2) is connected before the choke to circulate the current once the power supply is turned off. In order to measure the current in the magnet a high precision, low drift, zero flux current transductor is used. This transductor senses the magnet current which provides a feedback signal to control the gating of the converter`s thyristors. A true 14 bit Digital to Analog Converter (DAC) is programmed by the control computer for the required current value, providing a reference for the current regulator. Fast correction of the line transients is provided by a relatively fast voltage loop controlled by a high gain slow response current loop.

  13. Analyse du comportement thermique du sol d'une serre agricole par simulation dynamique

    NASA Astrophysics Data System (ADS)

    Monteil, C.; Amouroux, M.

    1997-02-01

    The overall energetical behaviour of a greenhouse is significantly affected by diurnal storage and nocturnal release of energy inside the soil, which is the only element with high thermal capacitance. Its specific part is analysed with a pre-existing dynamic simulation model. The first part of this paper studies the effects of 4kinds of heating exchangers along each month of an entire cultivation period: hot air convector, aerial metallic pipes with hot water circulation, radiant mulch or buried pipes with warm water circulation. The second part develops the hourly behaviour of both greenhouse and soil during a cold standard-day with each of the 4exchangers. The third part is a sensibility study to various classes of factors in the case of hot air convector exchanger: climatic environment, control policy, intrinsic properties of the greenhouse (soil characteristics, crop density, cover transparency). Le comportement énergétique global d'une serre agricole est influencé de manière parfois importante par le stockage diurne et la restitution nocturne d'énergie au sein de son sol, seul élément à grande capacité thermique. Le rôle spécifique joué par le sol est analysé en appliquant un modèle de simulation dynamique déjà existant. Une première partie compare les effets de 4types d'échangeurs de chauffage sur chaque mois d'une période de culture : aérotherme, tubes aériens à circulation d'eau chaude, paillage radiant ou tubes enterrés à circulation d'eau tiède. Une seconde partie développe le comportement horaire de la serre et du sol pour une journée-type froide en présence de chacun des échangeurs. Une troisième partie précise la sensibilité du bilan thermique de la serre et du sol à différents types de facteurs dans le cas d'un échangeur par aérotherme: environnement climatique, politique de contrôle de la serre, propriétés intrinsèques de la serre (caractéristiques du sol, densité de culture, transparence de la couverture).

  14. PARS: Programs for Analysis and Resizing of Structures, user manual

    NASA Technical Reports Server (NTRS)

    Haftka, R. T.; Prasad, B.; Tsach, U.

    1979-01-01

    PARS processors and their use, flutter analysis, sensitivity analysis for stresses, and resizing are presented. Design variable definition and interface with finite element model, static constraints and their derivatives, flutter derivatives, and optimization are discussed.

  15. View from southwest to northeast of PAR site fresh water ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View from southwest to northeast of PAR site fresh water pump house - Stanley R. Mickelsen Safeguard Complex, Fresh Water Pump House, In Limited Access Area, on Patrol Road next to Open Storage Reservoir No. 736, Nekoma, Cavalier County, ND

  16. The use of statistical techniques in par-level management.

    PubMed

    Klee, W B

    1994-02-01

    The total quality management movement has allowed the reintroduction of statistics in the materials management workplace. Statistical methods can be applied to the par level management process with significant results.

  17. View from northeast to southwest of PAR site sentry station; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View from northeast to southwest of PAR site sentry station; formerly the bachelor's enlisted men's quarter (BEQ) - Stanley R. Mickelsen Safeguard Complex, Sentry Station, North of Second Avenue & West of Electrical Switch Station No. 2, Nekoma, Cavalier County, ND

  18. Croissance epitaxiale de GaAs sur substrats de Ge par epitaxie par faisceaux chimiques

    NASA Astrophysics Data System (ADS)

    Belanger, Simon

    La situation energetique et les enjeux environnementaux auxquels la societe est confrontee entrainent un interet grandissant pour la production d'electricite a partir de l'energie solaire. Parmi les technologies actuellement disponibles, la filiere du photovoltaique a concentrateur solaire (CPV pour concentrator photovoltaics) possede un rendement superieur et mi potentiel interessant a condition que ses couts de production soient competitifs. La methode d'epitaxie par faisceaux chimiques (CBE pour chemical beam epitaxy) possede plusieurs caracteristiques qui la rendent interessante pour la production a grande echelle de cellules photovoltaiques a jonctions multiples a base de semi-conducteurs III-V. Ce type de cellule possede la meilleure efficacite atteinte a ce jour et est utilise sur les satellites et les systemes photovoltaiques a concentrateur solaire (CPV) les plus efficaces. Une des principales forces de la technique CBE se trouve dans son potentiel d'efficacite d'utilisation des materiaux source qui est superieur a celui de la technique d'epitaxie qui est couramment utilisee pour la production a grande echelle de ces cellules. Ce memoire de maitrise presente les travaux effectues dans le but d'evaluer le potentiel de la technique CBE pour realiser la croissance de couches de GaAs sur des substrats de Ge. Cette croissance constitue la premiere etape de fabrication de nombreux modeles de cellules solaires a haute performance decrites plus haut. La realisation de ce projet a necessite le developpement d'un procede de preparation de surface pour les substrats de germanium, la realisation de nombreuses sceances de croissance epitaxiale et la caracterisation des materiaux obtenus par microscopie optique, microscopie a force atomique (AFM), diffraction des rayons-X a haute resolution (HRXRD), microscopie electronique a transmission (TEM), photoluminescence a basse temperature (LTPL) et spectrometrie de masse des ions secondaires (SIMS). Les experiences ont permis

  19. Molecular Mechanisms of Par-4-Induced Apoptosis in Prostate Cancer

    DTIC Science & Technology

    2007-05-01

    Sambrook J, Fritsch EF, Maniatis T. (1989). Molecular Cloning : A Laboratory Manual (Cold Spring Harbor, New York: Cold Spring Harbor Laboratory...AD_________________ Award Number: W81XWH-05-1-0622 TITLE: Molecular Mechanisms of Par-4-Induced...SUBTITLE 5a. CONTRACT NUMBER Molecular Mechanisms of Par-4-Induced Apoptosis in Prostate Cancer 5b. GRANT NUMBER W81XWH-05-1-0622 5c. PROGRAM

  20. StePar: an automatic code for stellar parameter determination

    NASA Astrophysics Data System (ADS)

    Tabernero, H. M.; González Hernández, J. I.; Montes, D.

    2013-05-01

    We introduce a new automatic code (StePar) for determinig stellar atmospheric parameters (T_{eff}, log{g}, ξ and [Fe/H]) in an automated way. StePar employs the 2002 version of the MOOG code (Sneden 1973) and a grid of Kurucz ATLAS9 plane-paralell model atmospheres (Kurucz 1993). The atmospheric parameters are obtained from the EWs of 263 Fe I and 36 Fe II lines (obtained from Sousa et al. 2008, A&A, 487, 373) iterating until the excitation and ionization equilibrium are fullfilled. StePar uses a Downhill Simplex method that minimizes a quadratic form composed by the excitation and ionization equilibrium conditions. Atmospheric parameters determined by StePar are independent of the stellar parameters initial-guess for the problem star, therefore we employ the canonical solar values as initial input. StePar can only deal with FGK stars from F6 to K4, also it can not work with fast rotators, veiled spectra, very metal poor stars or Signal to noise ratio below 30. Optionally StePar can operate with MARCS models (Gustafson et al. 2008, A&A, 486, 951) instead of Kurucz ATLAS9 models, additionally Turbospectrum (Alvarez & Plez 1998, A&A, 330, 1109) can replace the MOOG code and play its role during the parameter determination. StePar has been used to determine stellar parameters for some studies (Tabernero et al. 2012, A&A, 547, A13; Wisniewski et al. 2012, AJ, 143, 107). In addition StePar is being used to obtain parameters for FGK stars from the GAIA-ESO Survey.

  1. Complications inattendues de la chirurgie: deux cas de brûlure par plaque de bistouri électrique

    PubMed Central

    Diop, B.; Sy, A.; Ba, P.A.; MBaye, B.; Wane, Y.; Sarre, S.M.

    2016-01-01

    Summary Les risques d’accidents électriques sont une réalité dans les blocs opératoires avec le nombre croissant d’équipements électriques, électroniques et de liquides inflammables utilisés. Le bistouri électrique demeure le dispositif le plus utilisé pour son effet électrochirurgical de coagulation ou section tissulaire. Lorsque qu’elle est défectueuse ou mal placée sur une surface réduite de la peau, la plaque du bistouri peut être à l’origine de brûlure cutanée classiquement profonde, de cicatrisation lente. Elle ajoute à l’affection initiale une surmorbidité iatrogène, inattendue, aux conséquences dévastatrices pour le patient, le chirurgien et parfois la structure hospitalière. Nous rapportons deux cas de brûlure cutanée par plaque de bistouri survenue en peropératoire lors de l’utilisation du bistouri électrique en mode monopolaire et discutons les aspects étiologiques, cliniques et préventifs. PMID:28289364

  2. Compression de l'artère iliaque externe par armature de kerboull: à propos d'un cas

    PubMed Central

    Elkoumiti, Nabil; El Hyaoui, Hicham; Achkoun, Abdessalam; Messoudi, Abdeljabar; Rahmi, Mohamed; Garch, Abdelhak

    2015-01-01

    Les complications vasculaires après arthroplastie totale de hanche sont exceptionnelles. Elles doivent être constamment redoutées car elles engagent à la fois le pronostic vital et le pronostic fonctionnel du membre opéré. Nous rapportons le cas d'une compression de l'artère iliaque externe diagnostiquée par angioTDM à 2 ans d'une reprise de prothése totale de la hanche, devant une symptomatologie atypique. Le mécanisme en cause était une compression de l'artère par une armature de Kerboul enfoncée en endo-pelvien. Une revue de la littérature des complications vasculaires survenant après une arthroplastie totale de hanche a permis de mettre en évidence la multiplicité des mécanismes et des présentations cliniques que peut avoir ce type de complications. La plupart de ces complications peuvent être au mieux prévenues ou traitées plus efficacement moyennant un bilan préopératoire et une surveillance postopératoire attentive. PMID:26958114

  3. Ablation d'un film d'or par laser à excimère

    NASA Astrophysics Data System (ADS)

    Sentis, M.; Hermann, J.; Pereira, A.; Delaporte, Ph.; Marine, W.; Perrière, J.; Bianchi, L.; Galli, R.

    2003-06-01

    Ces travaux de recherche ont été réalisés dans le cadre du projet de développement du Laser MégaJoule (LMJ). Parmi les expériences d'interaction laser - matière à très haut flux, certaines conduiront à un dépôt de particules d'or sur les éléments internes de la chambre d'interaction. Pour nettoyer ce dépôt de particules, la possibilité d'utiliser un procédé automatisé basé sur l'ablation laser a été étudiée. Un modèle numérique simplifié a été développé et une étude expérimentale réalisée sur des échantillons d'acier inoxydable ou de B4C recouverts d'un film d'or d'une épaisseur de ~20 nm déposés par PVD. Ces travaux montrent que plus de 95 % du film d'or peuvent être enlevés avec quelques tirs d'un laser XeCI dès que la densité d'énergie dépasse 3 J/cm^2.

  4. Couches minces de phosphates de titane par voie sol-gel

    NASA Astrophysics Data System (ADS)

    Schmutz, C.; Basset, E.; Barboux, P.

    1993-04-01

    Colloidal solutions of ferroelectrics (KTiOPO4) or ionic conductors (LiTi2(PO4)3) materials have been synthetized. These solutions have been used for thin film synthesis. They are obtained by polycondensation reactions between phosphoric acid esters PO(OH){3-x}(OR)x (with 0 < x < 3 and R = Et, ^nBu, ...) and titanium alkoxides. The ratio POH/Ti and the amount of hydrolysis and the parameters which control the condensation. Nous avons synthétisé des solutions colloïdales de précurseurs de phosphates tels que des ferroélectriques (KTiOPO4) ou des conducteurs ioniques (LiTi2(PO4)3) adaptées au dépôt en couches minces. Elles sont obtenues par des réactions de polycondensation contrôlées entre les esters de l'acide phosphorique PO(OH){3-x}(OR)x (avec 0

  5. La reconstruction du sourcil par greffon composite du cuir chevelu: une astuce pour faciliter la technique

    PubMed Central

    El Omari, Mounia; El Mazouz, Samir; Gharib, Noureddine; EL Abbassi, Abdallah

    2015-01-01

    Les sourcils jouent un rôle important dans l’équilibre esthétique du visage. Leur reconstruction ou ophriopoïése, après séquelle de brûlure fait partie intégrante du programme de réhabilitation de la face brûlée. Plusieurs techniques ont été décrites. Nous insistons ici sur l'intérêt d'une technique simple, à la portée de tous les chirurgiens, et dont la méthode et les résultats peuvent être améliorés par un dessin bien planifié des zones donneuse et receveuse: la greffe composite prélevée au niveau du cuir chevelu dessinée à l'aide d'un calque du sourcil controlatéral. PMID:26401195

  6. La structure des verres étudiée par diffraction des neutrons

    NASA Astrophysics Data System (ADS)

    Cormier, L.

    2003-09-01

    La diffraction des neutrons est une méthode largement utilisée pour déterminer la structure des matériaux amorphes et en particulier des verres. L'utilisation de la méthode de substitution isotopique permet d'extraire les fonctions de distribution de paires partielles centrées autour d'un élément choisi. Nous présentons quelques exemples récents d'études par diffraction des neutrons sur des verres qui ont permis de mieux comprendre à la fois le réseau polymérique de la matrice vitreuse et l'environnement local et à moyenne distance autour des cations. Ces études ont révélées un ordre structural s'étendant au delà des premiers voisins, jusque vers de distances d'environ 10Å. Le couplage avec d'autres méthodes expérimentales (diffraction anormale des rayons X) et des techniques de simulations (dynamique moléculaire, Monte Carlo Inverse ou RMC) sont indispensables pour affiner nos connaissances de la structure des verres.

  7. Histiocytose langerhansienne pulmonaire révélée par un pneumothorax: à propos d’un cas

    PubMed Central

    Sajiai, Hafsa; Rachidi, Mariam; Serhane, Hind; Aitbatahar, Salma; Amro, Lamyae

    2016-01-01

    L’histiocytose langerhansienne est une affection rare d’étiologie inconnue caractérisée par une infiltration d’un ou plusieurs organes, par des cellules de type Langerhans. Elle a une présentation clinique polymorphe. Nous rapportons le cas de Mr R.Y, âgé de 22 ans, tabagique à 8 PA, admis pour pneumothorax total spontané droit. Un drainage thoracique a été réalisé avec bonne évolution. La TDM thoracique de contrôle a objectivé de multiples formations kystiques diffuses prédominant aux lobes supérieurs. Un bilan a été réalisé à la recherche d’une histiocytose systémique mais s’est révélé négatif. L’évolution était marquée par la récidive du pneumothorax, le recours à une pleurodèse et la réalisation d’une biopsie pulmonaire qui a confirmé le diagnostic. Le diagnostic de l’HistiocytoseLangerhansienne doit être évoqué devant un pneumothorax sur poumon kystique. Le diagnostic est aisé devant un tableau clinique et radiologique évocateur. Néanmoins, les possibilités thérapeutiques restent limitées et la récidive du pneumothorax est fréquente. PMID:28154724

  8. The signaling adaptor GAB1 regulates cell polarity by acting as a PAR protein scaffold.

    PubMed

    Yang, Ziqiang; Xue, Bin; Umitsu, Masataka; Ikura, Mitsuhiko; Muthuswamy, Senthil K; Neel, Benjamin G

    2012-08-10

    Cell polarity plays a key role in development and is disrupted in tumors, yet the molecules and mechanisms that regulate polarity remain poorly defined. We found that the scaffolding adaptor GAB1 interacts with two polarity proteins, PAR1 and PAR3. GAB1 binds PAR1 and enhances its kinase activity. GAB1 brings PAR1 and PAR3 into a transient complex, stimulating PAR3 phosphorylation by PAR1. GAB1 and PAR6 bind the PAR3 PDZ1 domain and thereby compete for PAR3 binding. Consequently, GAB1 depletion causes PAR3 hypophosphorylation and increases PAR3/PAR6 complex formation, resulting in accelerated and enhanced tight junction formation, increased transepithelial resistance, and lateral domain shortening. Conversely, GAB1 overexpression, in a PAR1/PAR3-dependent manner, disrupts epithelial apical-basal polarity, promotes multilumen cyst formation, and enhances growth factor-induced epithelial cell scattering. Our results identify GAB1 as a negative regulator of epithelial cell polarity that functions as a scaffold for modulating PAR protein complexes on the lateral membrane. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Imagerie Resolue dans le Temps des Photons et Neutres Metastables Emis D'une Surface Par Stimulation Electronique

    NASA Astrophysics Data System (ADS)

    Leclerc, Gregoire

    L'appareil que nous presentons ici a ete mis au point pour permettre d'accumuler des images numeriques, resolues dans le temps, de la desorption par stimulation electronique (DSE) d'ions positifs et negatifs, de photons et de neutres metastables, tout en conservant des capacites de base de diffraction d'electrons lents (DEL) et de transmission d'electrons lents (TEL). Le spectrometre comporte un monochromateur d'electrons a secteur cylindrique de 127^ circ dont l'optique de sortie permet la focalisation du faisceau d'electrons sur une large gamme d'energies. Le detecteur consiste en un empilement de galettes de microcanaux et d'une anode resistive a encodage de division de charges. La reponse spatiale du detecteur a ete calibree et plusieurs causes de non-linearite ont ete localisees et corrigees. Des methodes de correction materielle et logicielle des distorsions spatiales sont presentees. La resolution temporelle des evenements est obtenue en pulsant le faisceau d'electrons, et de facon synchrone la detection, laquelle est couplee a un micro-ordinateur. La premiere partie de ce travail est consacree a la caracterisation du spectrometre et la presentation de nombreux parametres operationnels, obtenus soit au moment de la conception, soit experimentalement. Suit la presentation de donnees de DEL et de DSE pour le systeme Ar/Pt(111) en films minces a 15K. Les sequences temporelles d'images de metastables d'Ar desorbes ont revele la presence de plusieurs populations distinctes, ayant des distributions angulaires et distributions d'energie cinetique que nous avons pu separer. Les fonctions d'excitation de l'emission de photons et de la desorption de differentes composantes de metastables, ainsi que la dependance de ces signaux sur l'epaisseur des films d'Ar, sont aussi presentees et analysees. Les techniques que nous avons developpees ont permis de cerner les mecanismes en jeu pour la desorption et la luminescence.

  10. Déclenchement du travail à terme par le misoprostol: expérience d'une maternité tunisienne

    PubMed Central

    Ouerdiane, Nadia; Tlili, Nihel; Othmani, Kaouther; Daaloul, Walid; Masmoudi, Abdelwaheb; Hamouda, Sonia Ben; Bouguerra, Badreddine

    2016-01-01

    Evaluer l'efficacité et l'innocuité de l'utilisation du misoprostol par voie vaginale pour le déclenchement du travail à terme. Etude prospective réalisée au service de gynécologie obstétrique B de l'hôpital Charles Nicolle de Tunis sur une durée de 4 mois. La population sélectionnée concernait les patientes à terme devant bénéficier d'une maturation cervicale. Le misoprostol à la dose de 50 µg par voie vaginale toutes les 12 h était utilisé. Les paramètres étudiés étaient les anomalies contractiles, les anomalies du RCF, le mode d'accouchement, le délai d'accouchement et l’état néonatal. 44 patientes ont bénéficié d'une maturation cervicale par misoprostol. Le terme moyen était de 40 SA. Le taux de nullipare était de 23/44 (52%). Le taux d'accouchement par voie basse était de 31/44 (70.4%). 84% des patientes ont reçu une seule dose de misoprostol. Les anomalies du RCF ont été notées dans 14/44 (32%). Le taux de liquides méconiaux était de 12/44 (27%). Un score d'Apgar à 5 mn inférieur à 7 était noté chez 7/44 (16%). Un cas de rupture utérine était survenue chez une primipare et ce après une seule prise de misoprostol. Nos résultats sont décevants en raison de la survenue d'une rupture utérine et d'une morbidité néonatale importante. D'autres études prospectives multicentriques restent utiles pour mieux s'assurer de l'efficacité mais surtout de l'innocuité du misoprostol à dose faible pour le déclenchement du travail à terme. PMID:27583092

  11. Niveau socioéconomique et processus du recours aux soins par les familles de patients souffrant de troubles psychiques au Burkina Faso

    PubMed Central

    Yaogo, Ahmed; Sommer, Alain; Moulaï, Pierre; Chebili, Saïd; Abaoub-Germain, Agnès

    2014-01-01

    Introduction Le Burkina Faso a connu une amélioration constante depuis deux décennies de l'offre de soins en psychiatrie. De même, le taux d'alphabétisation sans cesse croissant s'accompagne d'une profonde modification des conceptions et des comportements. La présente étude visait à déterminer l′impact des déterminants socioéconomiques sur le processus du recours aux soins par les familles. Méthodes Il s'est agi d'une enquête transversale portant sur 200 familles, menée dans le service de psychiatrie du Centre Hospitalier Universitaire Yalgado Ouédraogo de Ouagadougou. Variable à expliquer: premier recours aux soins par les familles (guérisseur traditionnel ou prières religieuses vs. consultations psychiatrique ou médicale). Variable explicative: catégorie socioprofessionnelle classée en suivant la nomenclature des professions et catégories socioprofessionnelles; niveau d’études. L'analyse statistique a été effectuée à l'aide du logiciel SAS version 9.2. Le test du Khi deux a été utilisé. Résultats Il existait une association entre le choix du premier recours et la Profession et la catégorie socioprofessionnelledu « décideur » (p = 0.0006) ainsi que leniveau d’études du « décideur » (p = 0.0001). Conclusion La Profession et Catégorie Sociale et le niveau d'instruction scolaire pourraient être un marqueur important dans les politiques visant à optimiser les processus de recours aux soins des patients dans le circuit de soins. PMID:25161751

  12. Par Pond vegetation status Summer 1995 -- June survey descriptive summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1995-06-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the shoreline aquatic plant communities in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level, indicated that much of the original plant communities and the intermediate shoreline communities present on the exposed sediments have been lost. The extensive old-field and emergent marsh communities that were present on the exposed shoreline during the drawdown have been flooded and much of the pre-drawdown Par Pond aquatic plant communities have not had sufficient time for re-establishment. The shoreline does, however, have extensive beds of maidencane which extend from the shoreline margin to areas as deep as 2 and perhaps 3 meters. Scattered individual plants of lotus and watershield are common and may indicate likely directions of future wetland development in Par Pond. In addition, within isolated coves, which apparently received ground water seepage and/or stream surface flows during the period of the Par Pond draw down, extensive beds of waterlilies and spike rush are common. Invasion of willow and red maple occurred along the lake shoreline as well. Although not absent from this survey, evidence of the extensive redevelopment of the large cattail and eel grass beds was not observed in this first survey of Par Pond. Future surveys during the growing seasons of 1995, 1996, and 1997 along with the evaluation of satellite date to map the areal extent of the macrophyte beds of Par Pond are planned.

  13. Pars Planitis: Epidemiology, Clinical Characteristics, Management and Visual Prognosis

    PubMed Central

    Ozdal, Pinar Cakar; Berker, Nilufer; Tugal-Tutkun, Ilknur

    2015-01-01

    Pars planitis is an idiopathic chronic intermediate uveitis which predominantly affects children and adolescents, and accounts for 5-26.7% of pediatric uveitis. Although an autoimmune process with a genetic predisposition has been suggested, its etiology still remains unknown. The most common presenting symptoms are floaters and blurred vision. Diffuse vitreous cells, haze, snowballs and snowbanks are typical findings of pars planitis. Peripheral retinal vasculitis, optic disc edema and anterior segment inflammation are other well-known findings. Although pars planitis is known to be a benign form of uveitis in most cases, it may become a potentially blinding disease due to complications including cataract, cystoid macular edema, vitreous opacities and optic disc edema. Cystoid macular edema is the most common cause of visual morbidity. Band keratopathy, epiretinal membrane formation, vitreous condensation, neovascularizations, vitreous hemorrhage, retinal detachment, cyclitic membranes, glaucoma and amblyopia may develop as a consequence of the chronic course of the disease. Exclusion of infectious and non-infectious causes which may present with intermediate uveitis is of utmost importance before starting treatment. Treatment of pars planitis has been a controversial issue. There is no consensus specifically for treatment of cases with minimal inflammation and relatively good visual acuity. However, current experience shows that pars planitis may cause severe inflammation and needs an aggressive treatment. A stepladder approach including corticosteroids, immunosupressive agents, anti-tumor necrosis factor-alpha and pars plana vitrectomy and/or laser photocoagulation is the most commonly used method for treatment of pars planitis. Adequate control of inflammation and prompt detection of associated complications are crucial in order to improve the overall prognosis of the disease. PMID:27051493

  14. Dynamique sédimentaire comparative dans les bassins stéphano-permiens des Ida Ou Zal et Ida Ou Ziki, haut Atlas Occidental, MarocDynamic sedimentology of two Upper Stephano-Lower Permian basins: Ida Ou Zal and Ida Ou Ziki, western High Atlas, Morocco

    NASA Astrophysics Data System (ADS)

    Saber, H.; El-Wartiti, M.; Broutin, J.

    2001-05-01

    The intra-mountainous Ida Ou Zal Basin developed as a graben during the Stephanian (Carboniferous) and Lower Permian. Along its borders from east to west are the remnants of basal conglomerates. Passing laterally towards the centre of the basin are fine-grained fluvial-lacustrine sediments or flood-plain deposits. The important accumulation (1800 m) of sediments, associated with climatic and tectonic changes, caused substantial subsidence in a late orogenic setting. The remnants of sporadic volcanic products (shards) found in the Ida Ou Zal and the Ida Ou Zika Basins suggest nearby simultaneous magmatic activity. A comparison between the basins of Ida Ou Zal and Ida Ou Ziki suggest that the two basins formed a single unit, called the Souss Basin, ultimately terminated between the Lower Permian and Upper Permian times by a sinistral movement of the N70-80° Agadir Ou Anzizen Fault (west branch of the Tizi N'Test Fault) at the very end of the Hercynian Orogeny in Morocco.

  15. Methode d'identification parametrique pour la surveillance in situ des joints a recouvrement par propagation d'ondes vibratoires

    NASA Astrophysics Data System (ADS)

    Francoeur, Dany

    Cette these de doctorat s'inscrit dans le cadre de projets CRIAQ (Consortium de recherche et d'innovation en aerospatiale du Quebec) orientes vers le developpement d'approches embarquees pour la detection de defauts dans des structures aeronautiques. L'originalite de cette these repose sur le developpement et la validation d'une nouvelle methode de detection, quantification et localisation d'une entaille dans une structure de joint a recouvrement par la propagation d'ondes vibratoires. La premiere partie expose l'etat des connaissances sur l'identification d'un defaut dans le contexte du Structural Health Monitoring (SHM), ainsi que la modelisation de joint a recouvrements. Le chapitre 3 developpe le modele de propagation d'onde d'un joint a recouvrement endommage par une entaille pour une onde de flexion dans la plage des moyennes frequences (10-50 kHz). A cette fin, un modele de transmission de ligne (TLM) est realise pour representer un joint unidimensionnel (1D). Ce modele 1D est ensuite adapte a un joint bi-dimensionnel (2D) en faisant l'hypothese d'un front d'onde plan incident et perpendiculaire au joint. Une methode d'identification parametrique est ensuite developpee pour permettre a la fois la calibration du modele du joint a recouvrement sain, la detection puis la caracterisation de l'entaille situee sur le joint. Cette methode est couplee a un algorithme qui permet une recherche exhaustive de tout l'espace parametrique. Cette technique permet d'extraire une zone d'incertitude reliee aux parametres du modele optimal. Une etude de sensibilite est egalement realisee sur l'identification. Plusieurs resultats de mesure sur des joints a recouvrements 1D et 2D sont realisees permettant ainsi l'etude de la repetabilite des resultats et la variabilite de differents cas d'endommagement. Les resultats de cette etude demontrent d'abord que la methode de detection proposee est tres efficace et permet de suivre la progression d'endommagement. De tres bons resultats

  16. Mesure des stades de developpement du sapin baumier (Abies balsamea [L.] Mill.) par teledetection des maxima locaux sur images a tres haute resolution

    NASA Astrophysics Data System (ADS)

    Demers, Alain

    L'objectif principal de cette these est d'identifier les parametres cles pour lier le developpement morphologique de la cime du sapin baumier (Abies balsamea [L.] Mill.) aux patrons de reflectance qu'elle genere sur une image aerienne a haute resolution. La quantite et la distribution spatiale des aiguilles dans le sapin dependent de la structure des branches. Un mecanisme de ramification particulier (la reiteration) ressort comme le parametre cle pour lier l'augmentation de la biomasse foliaire et la forme de la branche. Les reiterats forment des agglomerats de feuillage qui engendrent des inegalites dans les patrons de reflectance de la cime. La reflectance est plus elevee ou il y a une forte concentration de reiterats (maximum local). On demontre que le developpement du sapin baumier se mesure au moyen de l'analyse des maxima locaux de la cime sur une image. La biomasse de l'arbre se mesure par la teledetection et l'analyse des patrons de reflectance de la cime, c'est-a-dire la mesure du niveau de reiteration par le decompte des maxima locaux de la cime. Cette etude demontre qu'il est possible de proceder a l'inventaire du volume de bois d'un peuplement par la teledetection de l'architecture des arbres.

  17. Par Pond vegetation status Summer 1995 -- October survey descriptive summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1995-11-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the emergent shoreline aquatic plant communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level and continued with this late October survey. Communities similar to the pre-drawdown Par Pond aquatic plant communities are becoming re-established; especially, beds of maiden cane, lotus, waterlily, and watershield are now extensive and well established. Cattail occurrence continues to increase, but large beds common to Par Pond prior to the drawdown have not formed. Future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned.

  18. Par Pond vegetation status Summer 1995 -- September survey descriptive summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1995-09-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the emergent shoreline aquatic plant communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level and continued with this mid-September survey. Communities similar to the pre-drawdown Par Pond aquatic plant communities are becoming re-established; especially, beds of maidencane, lotus, waterlily, and watershield are now extensive and well established. Cattail occurrence continues to increase, but large beds common to Par Pond prior to the drawdown have not formed. Future surveys during the late growing seasons of 1995, and throughout 1996 and 1997, along with the evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned.

  19. Approche au diagnostic de la maladie cœliaque chez les patients ayant une faible densité minérale osseuse ou des fractures de fragilité

    PubMed Central

    Rios, Lorena P.; Khan, Aliya; Sultan, Muhammad; McAssey, Karen; Fouda, Mona A.; Armstrong, David

    2013-01-01

    Résumé Objectif Présenter aux cliniciens une mise à jour sur le diagnostic de la maladie cœliaque (MC), ainsi que des recommandations sur les indications de procéder au dépistage de la MC chez les patients présentant une faible densité minérale osseuse (DMO) ou des fractures de fragilité. Qualité des données Un groupe de travail multidisciplinaire a élaboré des questions cliniquement pertinentes relativement au diagnostic de la MC servant de fondement à une recherche documentaire dans les bases de données MEDLINE, EMBASE et CENTRAL (de janvier 2000 à janvier 2009) à l’aide des mots clés en anglais celiac disease, osteoporosis, osteopenia, low bone mass et fracture. Les ouvrages scientifiques existants comportent des études de niveaux I et II. Message principal La prévalence estimée de la MC asymptomatique est de 2 % à 3 % chez les personnes qui ont une faible DMO. Par ailleurs, un dépistage ciblé est recommandé pour les patients qui ont des T-scores de −1,0 ou moins à la colonne vertébrale ou aux hanches ou des antécédents de fractures de fragilité associées à des symptômes ou à des problèmes reliés à la MC, des antécédents familiaux de MC ou de bas niveaux de calcium urinaire, une insuffisance en vitamine D et des niveaux à la hausse d’hormones parathyroïdiennes en dépit d’un apport suffisant en calcium et en vitamine D. Le dépistage de la MC devrait se faire pendant que le sujet consomme un régime alimentaire contenant du gluten. On procède au dépistage initial par le dosage d’immunoglobuline (Ig) A antitransglutaminase en utilisant la transglutaminase tissulaire humaine recombinante ou une autre transglutaminase tissulaire, en association avec l’immunofluorescence des IgA anti-endomysium. Une biopsie du duodénum est nécessaire pour confirmer le diagnostic de la MC. Le typage des antigènes des leucocytes humains peut aider à confirmer ou à exclure le diagnostic de la MC dans les cas où la s

  20. The pars interarticularis stress reaction, spondylolysis, and spondylolisthesis progression.

    PubMed

    Motley, G; Nyland, J; Jacobs, J; Caborn, D N

    1998-10-01

    To review the classification, etiology, clinical and radiologic evaluation, and management of the pars interarticularis stress reaction, spondylolysis, and spondylolisthesis progression. Grateful Med was searched from 1980 to 1998 using the terms "spondylolysis," "spondylolisthesis," "female athlete" "spondylogenic," and "pars interarticularis." The progression from pars interarticularis stress reaction through spondylolysis to spondylolisthesis is common in adolescent athletes, and, because of hormonal influences and cheerleading and gymnastic maneuvers, females are particularly at risk. Proper diagnosis and management include a thorough evaluation, radiographs (possibly with technetium bone scan or single-photon emission computed tomography), activity modification, dietary counseling, a therapeutic exercise program focusing on proper trunk and hip muscle strength and extensibility balances, and education regarding proper back postures, positioning, lifting mechanics, and jump landings. The athletic trainer plays an integral part in managing this injury progression, particularly with identifying at-risk individuals and intervening appropriately.

  1. Protease-activated receptor-2 (PAR2) in cardiovascular system.

    PubMed

    Bucci, Mariarosaria; Roviezzo, Fiorentina; Cirino, Giuseppe

    2005-10-01

    Vascular system is constituted by a complex and articulate network, e.g. arteries, arterioles, venules and veins, that requires a high degree of coordination between different elemental cell types. Proteinase-activated receptors (PARs) constitute a recent described family of 7-transmembrane G protein-coupled receptors that are activated by proteolysis. In recent years several evidence have been accumulated for an involvement of this receptor in the response to endothelial injury in vitro and in vivo experimental settings suggesting a role for PAR2 in the pathophysiology of cardiovascular system. This review will deal with the role of PAR2 receptor in the cardiovascular system analyzing both in vivo and in vitro published data. In particular this review will deal with the role of this receptor in vascular reactivity, ischemia/reperfusion injury, coronary atherosclerotic lesions and angiogenesis.

  2. Couches Minces de Titanate de Baryum Par Depot Organometallique

    NASA Astrophysics Data System (ADS)

    Ousi Benomar, Wahib

    1993-01-01

    Nous avons demontre la possibilite de realiser des couches minces de titanate de baryum par depot organometallique. Les films sont obtenus apres dissolution d'organometalliques choisis dans un solvant et une cuisson a une temperature determinee par thermogravimetrie. Apres un second traitement thermique a des temperatures plus elevees, les echantillons presentent une structure polycristalline tetragonale; les cristallites sont observes par microscopie electronique a balayage. La mesure de la constante dielectrique a permis de mettre en evidence une transition de phase de la structure tetragonale a la structure cubique a une temperature d'environ 125^circC. Les mesures d'indice ont ete effectuees. On note une augmentation de l'indice de refraction des films avec la temperature indiquant une meilleure densification des films. Nous avons aussi montre qu'il etait possible d'utiliser ce materiau en tant que guide d'onde optique pour pouvoir exploiter ses proprietes electrooptiques dans l'avenir.

  3. Keratometric alterations following the 25-gauge transconjunctival sutureless pars plana vitrectomy versus the conventional pars plana vitrectomy.

    PubMed

    Citirik, Mehmet; Batman, Cosar; Bicer, Tolga; Zilelioglu, Orhan

    2009-09-01

    To assess the alterations in keratometric astigmatism following the 25-gauge transconjunctival sutureless pars plana vitrectomy versus the conventional pars plana vitrectomy. Sixteen consecutive patients were enrolled into the study. Conventional vitrectomy was applied to eight of the cases and 25-gauge transconjunctival sutureless vitrectomy was performed in eight patients. Keratometry was performed before and after the surgery. In the 25-gauge transconjunctival sutureless pars plana vitrectomy group, statistically significant changes were not observed in the corneal curvature in any post-operative follow-up measurement (p > 0.05); whereas in the conventional pars plana vitrectomy group, statistically significant changes were observed in the first postoperative day (p = 0.01) and first postoperative month (p = 0.03). We noted that these changes returned to baseline in three months (p = 0.26). Both 25-gauge transconjunctival sutureless and conventional pars plana vitrectomy are effective surgical modalities for selected diseases of the posterior segment. Surgical procedures are critical for the visual rehabilitation of the patients. The post-operative corneal astigmatism of the vitrectomised eyes can be accurately determined at least two months post-operatively.

  4. Both PHYTOCHROME RAPIDLY REGULATED1 (PAR1) and PAR2 Promote Seedling Photomorphogenesis in Multiple Light Signaling Pathways1[C][W][OPEN

    PubMed Central

    Zhou, Peng; Song, Meifang; Yang, Qinghua; Su, Liang; Hou, Pei; Guo, Lin; Zheng, Xu; Xi, Yulin; Meng, Fanhua; Xiao, Yang; Yang, Li; Yang, Jianping

    2014-01-01

    Arabidopsis (Arabidopsis thaliana) seedlings undergo photomorphogenesis in the light and etiolation in the dark. Light-activated photoreceptors transduce the light signals through a series of photomorphogenesis promoting or repressing factors to modulate many developmental processes in plants, such as photomorphogenesis and shade avoidance. CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1) is a conserved RING finger E3 ubiquitin ligase, which mediates degradation of several photomorphogenesis promoting factors, including ELONGATED HYPOCOTYL5 (HY5) and LONG HYPOCOTYL IN FAR-RED1 (HFR1), through a 26S proteasome-dependent pathway. PHYTOCHROME RAPIDLY REGULATED1 (PAR1) was first detected as an early repressed gene in both phytochrome A (phyA)-mediated far-red and phyB-mediated red signaling pathways, and subsequent studies showed that both PAR1 and PAR2 are negative factors of shade avoidance in Arabidopsis. However, the role of PAR1 and PAR2 in seedling deetiolation, and their relationships with other photomorphogenesis promoting and repressing factors are largely unknown. Here, we confirmed that both PAR1 and PAR2 redundantly enhance seedling deetiolation in multiple photoreceptor signaling pathways. Their transcript abundances are repressed by phyA, phyB, and cryptochrome1 under far-red, red, and blue light conditions, respectively. Both PAR1 and PAR2 act downstream of COP1, and COP1 mediates the degradation of PAR1 and PAR2 through the 26S proteasome pathway. Both PAR1 and PAR2 act in a separate pathway from HY5 and HFR1 under different light conditions, except for sharing in the same pathway with HFR1 under far-red light. Together, our results substantiate that PAR1 and PAR2 are positive factors functioning in multiple photoreceptor signaling pathways during seedling deetiolation. PMID:24335334

  5. Traumatisme de la main par injection a haute pression

    PubMed Central

    Mabchoure, K.; Diouri, M.; Bahechar, N.; Chlihi, A.

    2016-01-01

    Summary Les traumatismes de la main par injection à haute pression sont des accidents relativement rares et souvent mal connus par le praticien. Les lésions qui dépendent du produit injecté et du site d’injection sont pourvoyeuses de séquelles esthétiques et fonctionnelles lourdes. Le traitement repose sur la chirurgie, l’antibiothérapie et la rééducation précoce et spécifique. Nous rapportons notre expérience ainsi qu’une revue de la littérature. PMID:27857654

  6. PAR-3 oligomerization may provide an actin-independent mechanism to maintain distinct par protein domains in the early Caenorhabditis elegans embryo.

    PubMed

    Dawes, Adriana T; Munro, Edwin M

    2011-09-21

    Par proteins establish discrete intracellular spatial domains to polarize many different cell types. In the single-cell embryo of the nematode worm Caenorhabditis elegans, the segregation of Par proteins is crucial for proper division and cell fate specification. Actomyosin-based cortical flows drive the initial formation of anterior and posterior Par domains, but cortical actin is not required for the maintenance of these domains. Here we develop a model of interactions between the Par proteins that includes both mutual inhibition and PAR-3 oligomerization. We show that this model gives rise to a bistable switch mechanism, allowing the Par proteins to occupy distinct anterior and posterior domains seen in the early C. elegans embryo, independent of dynamics or asymmetries in the actin cortex. The model predicts a sharp loss of cortical Par protein asymmetries during gradual depletion of the Par protein PAR-6, and we confirm this prediction experimentally. Together, these results suggest both mutual inhibition and PAR-3 oligomerization are sufficient to maintain distinct Par protein domains in the early C. elegans embryo.

  7. Restauration adaptative des contours par une approche inspiree de la prediction des performances

    NASA Astrophysics Data System (ADS)

    Rousseau, Kami

    'amplitudes de detecteurs " classiques " afin de fournir de nouvelles cartes d'amplitude du gradient. Le seuillage de ces contours donne des cartes de contours " optimisees ". Sur les images aeroportees du jeu de donnees South Florida, la mediane des mesures-F de la pour l'algorithme de Sobel passe de 51,3 % avant la fusion a 56,4 % apres. La mediane des mesures-F pour l'algorithme de Kirsch ameliore est de 56,3 % et celle de Frei-Chen ameliore est de 56,3 %. Pour l'algorithme de Sobel avec seuillage adaptatif, la mesure-F mediane est de 52,3 % avant fusion et de 57,2 % apres fusion. En guise de comparaison, la mesure-F mediane pour le detecteur de Moon, mathematiquement optimal pour contours de type " rampe ", est de 53,3 % et celle de l'algorithme de Canny, est de 61,1 %. L'applicabilite de notre algorithme se limite aux images qui, apres filtrage, ont un rapport signal sur bruit superieur ou egal a 20. Sur les photos au sol du jeu de donnees de South Florida, les resultats sont comparables a ceux obtenus sur les images aeroportees. Par contre, sur le jeu de donnees de Berkeley, les resultats n'ont pas ete concluants. Sur une imagette IKONOS du campus de l'Universite de Sherbrooke, pour l'algorithme de Sobel, la mesure-F est de 45,7 % +/-0,9 % avant la fusion et de 50,8 % apres. Sur une imagette IKONOS de l'Agence Spatiale Canadienne, pour l'algorithme de Sobel avec seuillage adaptatif, la mesure-F est de 35,4 % +/-0,9 % avant la fusion et de 42,2 % apres. Sur cette meme image, l'algorithme de Argyle (Canny sans post-traitement) a une mesure-F de 35,1 % +/-0,9 % avant fusion et de 39,5 % apres. Nos travaux ont permis d'ameliorer la banque d'indicateurs de Chalmond, rendant possible le pretraitement avant le seuillage de la carte de gradient. A chaque etape, nous proposons un choix de parametres permettant d'utiliser efficacement la methode proposee. Les contours corriges sont plus fins, plus complets et mieux localises que les contours originaux. Une etude de sensibilite a ete

  8. Sphères diélectriques non concentriques par MMP-3D

    NASA Astrophysics Data System (ADS)

    Kiener, S.; Ney, M.

    1992-11-01

    The aim of this communication is to present shortly the well known MMP coeds (Multiple Multipoles Programs) based on the GMT (Generalized Multipole Technique). A specific application is also computed. The scattering of a plane wave on spherical dielectric resonators is a classical problem with an analytic solution. For non concentric spheres, the analytic computation requires a “heavy” formalism and some approximation. However, this problem can be computed with the MMP 3D codes. Great care will be given to the self validation process of the computation with special features belonging to the code as well as external validation which is given, in the case of the single sphere, by the Mie's series and for the non concentric spheres by results computed with another numerical method. Cette communication se propose de présenter rapidement les codes MMP (Multiples MultiPôles) basés sur la TMG (Technique des Multipôles Généralisés) et ensuite de montrer une application spécifique. La diffraction d'une onde plane sur des sphères diélectriques en résonance avec ou sans pertes est un problème classique et qui possède une solution analytique. En revanche, si l'on cherche à calculer à généraliser le problème avec des sphères non concentriques, un formalisme complexe et quelques approximations sont nécessaires. Ce problème peut être calculés par les codes MMP 3D. On s'attachera aussi à valider les résultats d'une manière interne en utilisant les possibilités du code ainsi que d'une manière externe en comparant avec les séries de Mie, mais aussi avec les résultats obtenus par une autre méthode numérique.

  9. Influence d'une substitution partielle du ciment par du laitier de hauts fourneaux sur la résistance des mortiers en milieu acide

    NASA Astrophysics Data System (ADS)

    Achoura, D.; Lanos, Ch.; Jauberthie, R.; Redjel, B.

    2004-11-01

    Le stockage de produits chimiques dans du béton présente souvent des problèmes de durabilité dus aux attaques chimiques. Inévitablement les concentrations élevées sont les plus dangereuses. Le but de notre étude est de déterminer les changements de phases qui apparaissent dans le béton lorsqu'on substitue une partie du ciment par du laitier de haut fourneaux. Les échantillons sont conservés dans des solutions acides différents anions (HCl, H{2}SO{4}, H{3}PO{4} et CH{3}COOH) et différentes concentrations (0,1; 0,25 et 0,5M). Les formations qui apparaissent sont déterminées par diffraction X et observées au MEB. Les solutions sulfatiques conduisent à une formation de gypse en surface et d'ettringite au contact de la matrice cimentaire. Avec l'acide acétique, il y a formation de calcium acétate hydrate sous forme spongieuse tandis que, avec l'acide phosphatique, la formation de calcium hydrogeno phosphate hydrate est très superficielle. Enfin, avec l'acide chlorhydrique, la surface du mortier est recouverte de chlorure de calcium dihydrate et d'hydroxyde de fer. Les résistances mécaniques sont plus ou moins affectées par la concentration mais aussi et surtout par la nature des acides avec dans l'ordre le plus agressif H{2}SO{4} puis HCl et CH{3}COOH enfin peu de modification pour H{3}PO{4}.

  10. The Hong-Ou-Mandel effect in the context of few-photon scattering.

    PubMed

    Longo, Paolo; Cole, Jared H; Busch, Kurt

    2012-05-21

    The Hong-Ou-Mandel effect is studied in the context of two-photon transport in a one-dimensional waveguide with a single scatterer. We numerically investigate the scattering problem within a time-dependent, wave-function-based framework. Depending on the realization of the scatterer and its properties, we calculate the joint probability of finding both photons on either side of the waveguide after scattering. We specifically point out how Hong-Ou-Mandel interferometry techniques could be exploited to identify effective photon-photon interactions which are mediated by the scatterer. The Hong-Ou-Mandel dip is discussed in detail for the case of a single two-level atom embedded in the waveguide, and dissipation and dephasing are taken into account by means of a quantum jump approach.

  11. Are You Up to PAR? (Program Administrative Review).

    ERIC Educational Resources Information Center

    Southwest Regional Resource Center, Salt Lake City, UT.

    The document focuses on the workings of PAR (Program Administrative Review), a method by which local education agencies (LEAs) and state operated programs (SOPs) in Utah can conduct ongoing self-evaluation and identify areas where additional efforts are needed to improve the quality of programs and services for handicapped children. It is…

  12. Par Pond vegetation status summer 1995 - July survey descriptive summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1995-07-01

    A survey of the emergent shoreline aquatic plant, communities began in June 1995, three months after the refilling of Par Pond to approximately 200 feet (61 meters) above mean sea level, and continued with this July survey. Aquatic plant communities, similar to the pre-drawdown Par Pond communities, are becoming reestablished. Beds of maidencane (Panicum hemitomon), lotus (Nelumbo lutea), water lily (Nymphaea odorata), and watershield (Brasenia schreberi) are now extensive and well established. In addition, within isolated coves, extensive beds of water lilies and spike-rush (Eleocharis sp.) are common. Cattail occurrence has increased since refill, but large beds common to Par Pond prior to the drawdown have not formed. Invasion of willow (Salix sp.) and red maple (Acer rubrum) occurred along the lake shoreline during drawdown. The red maples along the present shoreline are beginning to show evidence of stress and mortality from flooding over the past four months. Some of the willows appear to be stressed as well. The loblolly pines (Pinus taeda), which were flooded in all but the shallow shoreline areas, are now dead. Future surveys are planned for the growing seasons of 1995, 1996, and 1997, along with the evaluation of satellite data for mapping the areal extent of the macrophyte beds of Par Pond.

  13. BOREAS RSS-10 TOMS Circumpolar One-Degree PAR Images

    NASA Technical Reports Server (NTRS)

    Dye, Dennis G.; Holben, Brent; Nickeson, Jaime (Editor); Hall, Forrest G. (Editor); Smith, David E. (Technical Monitor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) Remote Sensing Science (RSS)-10 team investigated the magnitude of daily, seasonal, and yearly variations of Photosynthetically Active Radiation (PAR) from ground and satellite observations. This data set contains satellite estimates of surface-incident PAR (400-700 nm, MJ/sq m) at one-degree spatial resolution. The spatial coverage is circumpolar from latitudes of 41 to 66 degrees north. The temporal coverage is from May through September for years 1979 through 1989. Eleven-year statistics are also provided: (1) mean, (2) standard deviation, and (3) coefficient of variation for 1979-89. The PAR estimates were derived from the global gridded ultraviolet reflectivity data product (average of 360, 380 nm) from the Nimbus-7 Total Ozone Mapping Spectrometer (TOMS). Image mask data are provided for identifying the boreal forest zone, and ocean/land and snow/ice-covered areas. The data are available as binary image format data files. The PAR data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  14. Radiological impact of Par Pond drawdown from liquid effluent pathways

    SciTech Connect

    Carlton, W.H.; Hamby, D.M.

    1991-10-25

    The water level of Par Pond has been lowered over the past several months to reduce the effects in the event of catastrophic dam failure while assessing the condition of the dam and determining if repairs are necessary. In lowering the level of Par Pond, 60 billion liters of water containing low levels of tritium and cesium-137 were discharged to several onsite streams. SRS surface streams flow to the Savannah River. An assessment made to determine the total amount of tritium and Cs-137 discharged and to estimate the consequences to downstream Savannah River users. It is estimated that a total of 160 curies of tritium were displaced from Par Pond to the Savannah River between June 28, 1991 and September 19, 1991. This release could hypothetically result in a maximum individual dose of 3. 2{times}10{sup {minus}4} mrem and a total (80-km and drinking water populations) population dose of 1.4{times}10{sup {minus}2} person-rem. Likewise, a maximum individual dose of 5.0{times}10{sup {minus}2} mrem and a total population dose of 1.7{times}10{sup {minus}1} person- rem are predicted as a result of an estimated 0.21 curies of Cs-137 being discharged from Par Pond to the Savannah River.

  15. PAR-5 is a PARty hub in the germline

    PubMed Central

    Aristizábal-Corrales, David; Schwartz Jr, Simo; Cerón, Julián

    2013-01-01

    As our understanding of how molecular machineries work expands, an increasing number of proteins that appear as regulators of different processes have been identified. These proteins are hubs within and among functional networks. The 14-3-3 protein family is involved in multiple cellular pathways and, therefore, influences signaling in several disease processes, from neurobiological disorders to cancer. As a consequence, 14-3-3 proteins are currently being investigated as therapeutic targets. Moreover, 14-3-3 protein levels have been associated with resistance to chemotherapies. There are seven 14-3-3 genes in humans, while Caenorhabditis elegans only possesses two, namely par-5 and ftt-2. Among the C. elegans scientific community, par-5 is mainly recognized as one of the par genes that is essential for the asymmetric first cell division in the embryo. However, a recent study from our laboratory describes roles of par-5 in germ cell proliferation and in the cellular response to DNA damage induced by genotoxic agents. In this review, we explore the broad functionality of 14-3-3 proteins in C. elegans and comment on the potential use of worms for launching a drugs/modifiers discovery platform for the therapeutic regulation of 14-3-3 function in cancer. PMID:24058859

  16. Promiscuous stimulation of ParF protein polymerization by heterogeneous centromere binding factors.

    PubMed

    Machón, Cristina; Fothergill, Timothy J G; Barillà, Daniela; Hayes, Finbarr

    2007-11-16

    The segrosome is the nucleoprotein complex that mediates accurate segregation of bacterial plasmids. The segrosome of plasmid TP228 comprises ParF and ParG proteins that assemble on the parH centromere. ParF, which exemplifies one clade of the ubiquitous ParA superfamily of segregation proteins, polymerizes extensively in response to ATP binding. Polymerization is modulated by the ParG centromere binding factor (CBF). The segrosomes of plasmids pTAR, pVT745 and pB171 include ParA homologues of the ParF subgroup, as well as diverse homodimeric CBFs with no primary sequence similarity to ParG, or each other. Centromere binding by these analogues is largely specific. Here, we establish that the ParF homologues of pTAR and pB171 filament modestly with ATP, and that nucleotide hydrolysis is not required for this polymerization, which is more prodigious when the cognate CBF is also present. By contrast, the ParF homologue of plasmid pVT745 did not respond appreciably to ATP alone, but polymerized extensively in the presence of both its cognate CBF and ATP. The co-factors also stimulated nucleotide-independent polymerization of cognate ParF proteins. Moreover, apart from the CBF of pTAR, the disparate ParG analogues promoted polymerization of non-cognate ParF proteins suggesting that filamentation of the ParF proteins is enhanced by a common mechanism. Like ParG, the co-factors may be modular, possessing a centromere-specific interaction domain linked to a flexible region containing determinants that promiscuously stimulate ParF polymerization. The CBFs appear to function as bacterial analogues of formins, microtubule-associated proteins or related ancillary factors that regulate eucaryotic cytoskeletal dynamics.

  17. Infection par le VIH chez les patientes atteintes de cancer du sein en Guinée (Afrique de l'Ouest)

    PubMed Central

    Traore, Bangaly; Diane, Solomana; Sow, Mamadou Saliou; Keita, Mamady; Conde, Mamoudou; Traore, Fodé Amara; Kourouma, Tidiane

    2015-01-01

    L'objectif était de déterminer la prévalence de l'infection à VIH chez les patientes atteintes de cancer du sein et de comparer les caractéristiques anatomocliques et thérapeutiques de ces cancers du sein par rapports aux patientes non infectées par le VIH. Il s'agissait d'une étude rétrospective et analytique comparant les dossiers de patientes atteintes de cancers du sein histologiquement confirmés, infectées ou non par le VIH à l'unité de chirurgie oncologique de Donka, CHU de Conakry, de 2007 à 2012. Nous avons colligé 278 patientes présentant un cancer du sein dont 14 (5,0%) infectées par le VIH et 264 (95,0%) non infectées par le VIH. Les différences observées entre ces deux groupes de patientes étaient respectivement: âge médian (36,8 vs 49,0 ans), la ménopause (21,4% vs 53,4%), le nombre des patientes traitées (50,0% contre 77,1%) et la survenue de décès (78,6% vs 50,8%). Aucune différence n'a été notée dans la présentation clinique, histologique et le retard de consultation. Dans notre étude, la prévalence de l'infection à VIH chez les patients atteints de cancer du sein est élevée. L’âge jeune des patients, la faible accessibilité au traitement et la mortalité élevée doivent être confirmés par une étude sur un échantillon plus large. PMID:26523196

  18. Conception, instrumentation, modelisation et analyse d'un element de stockage d'energie par chaleur latente

    NASA Astrophysics Data System (ADS)

    Millette, Jocelyn

    Des elements de stockage de chaleur utilisant l'electricite comme source d'energie sont utilises presentement en Europe ou la tarification de l'electricite varie en fonction du temps. Dans un contexte ou la dereglementation du marche de l'electricite s'opere massivement en Amerique du Nord, ce type d'appareil est susceptible d'etre beaucoup plus utilise afin de faire une gestion efficace de la consommation electrique. En assurant un meilleur facteur d'utilisation des installations de production, transport et distribution, les utilites pourront etre plus competitives. Les appareils disponibles sur le marche stockent l'energie sous forme sensible (ESECS), ce qui amene differents inconvenients: poids considerable, temperature elevee. Un nouveau type d'appareil est propose dans cette etude: un element de stockage d'energie par chaleur latente (ESECL). Cette etude traite donc de la conception de tels appareils. La demarche de conception proposee dans cette etude s'articule autour du choix des materiaux, du choix du concept de l'echangeur de chaleur. A ce sujet, les materiaux a changement de phase (MCP) etant generalement de mauvais conducteur thermique sous forme solide, la surface d'echange doit etre grande afin d'obtenir une puissance de destockage convenable. Le concept retenu est un element multicouches. D'apres la revue de litterature, la conception d'un element de stockage multicouches par chaleur latente n'a jamais ete abordee. Afin de pouvoir calculer les performances d'un ESECL a construire, un modele NTU-epsilon a ete developpe a cette fin. Contrairement. a ce qui est reporte dans la litterature, le modele developpe tient compte de la surchauffe et de la chaleur sensible dans le MCP solide. Afin d'etablir le modele, la convection naturelle dans le MCP liquide est negligee et un regime quasi permanent est considere dans le MCP. Un prototype d'ESECL a ete construit et instrumente dans le but d'eprouver la demarche de conception et de valider le modele developpe

  19. Controle sismique d'un batiment en acier de 1 etage par amortisseurs elastomeres et contreventements en Chevron

    NASA Astrophysics Data System (ADS)

    Girard, Olivier

    Actuellement, le principe de dimensionnement a la capacite est fortement utilise dans le domaine du genie parasismique. De maniere simplifiee, cette methode de dimensionnement consiste a dissiper l'energie injectee a une structure lors d'une secousse sismique par la deformation inelastique d'un element structural sacrificiel. Cette methode de dimensionne-ment permet d'obtenir des structures economiques, car cette dissipation d'energie permet de reduire substantiellement les efforts qui se retrouvent a l'interieur de la structure. Or, la consequence de ce dimensionnement est la presence de degats importants a la structure qui suivent a la secousse sismique. Ces degats peuvent engendrer des couts superieurs aux couts d'erection de la structure. Bien entendu, sachant que les secousses sismiques d'importances sont des phenomenes rares, l'ingenieur est pret a accepter ce risque afin de diminuer les couts initiaux de construction. Malgre que cette methode ait permis d'obtenir des constructions economiques et securitaires, il serait interessant de developper un systeme qui permettrait d'obtenir des performances de controle des efforts sismiques comparables a un systeme dimensionne selon un principe de dimensionnement a la capacite sans les consequences negatives de ces systemes. En utilisant les principes d'isolation a la base, il a ete possible de developper un systeme de reprise des forces sismiques (SRFS). qui permet d'obtenir un controle des efforts sismiques concurrentiels tout en gardant une structure completement elastique. Ce systeme consiste u inserer un materiel elastomere entre l'assemblage de la poutre et des contreventements a l'interieur d'un cadre contrevente conventionnel. Cette insertion permet de diminuer substantiellement la rigidite laterale du batiment, ce qui a pour consequence d'augmenter la valeur de la periode fondamentale du batiment dans lequel ces cadres sont inseres. Ce phenomene est appele le saut de periode. Ce saut de periode permet de

  20. Re-Signifying Participatory Action Research (PAR) in Higher Education: What Does "P" Stand for in PAR?

    ERIC Educational Resources Information Center

    Santos, Doris

    2016-01-01

    While carrying out a study aimed at understanding the contribution of participatory action research (PAR) to the political realm in contemporary higher education, a problematic situation was found when doing a literature review in the field of action research. This problem concerns the intermittent appearance of the "participatory"…

  1. Re-Signifying Participatory Action Research (PAR) in Higher Education: What Does "P" Stand for in PAR?

    ERIC Educational Resources Information Center

    Santos, Doris

    2016-01-01

    While carrying out a study aimed at understanding the contribution of participatory action research (PAR) to the political realm in contemporary higher education, a problematic situation was found when doing a literature review in the field of action research. This problem concerns the intermittent appearance of the "participatory"…

  2. Calcul par simulation des paramètres dosimétriques pour le noyau cellulaire après irradiation α in vitro

    NASA Astrophysics Data System (ADS)

    Le Foll, L.; Bailly, I.; Fritsch, P.

    1998-04-01

    Determination of absorbed dose in biological targets after high LET α particules irradiation needs heavy calculations. A softwave has been developed in order to allow everyone to calculate hit probability and absorbed dose. It is particularly adapted to the study of cell cultures irradiated with electrodeposited source or α-beam accelerator. It is based first, on a random generator of α-track homogeneously distributed in 4π, second, on the evaluation of energy loss in the different media along the track and then on a statistical analysis of the results. This method is accurate and low time consuming. The target is either modelised by an ellipsoid or represented by its 3D shape recorded using confocal microscopy. Des calculs dosimétriques complexes sont nécessaires pour l'évaluation des doses délivrées dans des cibles biologiques après irradiation par des particules α de haut TEL. Un logiciel a été développé pour rendre facilement accessible le calcul de la probabilité pour atteindre la cible et de la dose absorbée. il est particulièrement adapté à l'étude des cultures cellulaires irradiées par des sources électrodéposées de radionucléides ou des accélérateurs de particules. Il repose sur un générateur de traces aléatoires, sur une approximation de la perte d'énergie dans les différents milieux traversés et sur une exploitation statistique des résultats obtenus. Cette méthode s'avère précise et rapide. La cible est modélisée par un ellipsoïde ou représentée par son image 3D obtenue en microscopie confocale.

  3. Novas determinações dos parâmetros atmosféricos das estrelas anãs brancas DA

    NASA Astrophysics Data System (ADS)

    Giovannini, O.; Costa, A. F. M.; Kepler, S. O.

    2003-08-01

    Nós temos selecionado uma amostra de estrelas anãs brancas DA (atmosfera de hidrogênio) a partir dos índices de Strömgren cujos valores estão próximos a região de instabilidade das estrelas anãs brancas DA variáveis, as chamadas estrelas DAV ou ZZ Ceti. O objetivo é determinar os parâmetros fundamentais (temperatura efetiva, Teff, aceleração da gravidade, log g, e massa) destas estrelas para verificar quais os parâmetros estelares estão envolvidos com o mecanismo de pulsação das estrelas DAV. Nós obtemos, até agora, mais de 120 espectros óticos de estrelas DA. Entre as estrelas selecionadas há 20 estrelas variáveis (DAV). Assim, podemos verificar se existem ou não estrelas não variáveis dentro da faixa de instabilidade das estrelas ZZ Ceti. Neste trabalho nós apresentamos a determinação dos parâmetros atmosféricos (temperatura efetiva, Teff, e aceleração da gravidade, log g) das estrelas anãs brancas DA usando os novos modelos de atmosfera ML2/a = 0.6. Estes modelos têm sido utilizados recentemente por fornecerem uma excelente consistência interna na determinação das temperaturas nas regiões do ultra-violeta e ótico. Os parâmetros atmosféricos são determinados espectroscopicamente através da comparação do fluxo de energia das linhas de Balmer (Hb à H9) entre os espectros observados e sintéticos (gerados pelos modelos de atmosfera). As temperaturas obtidas com os novos modelos são, em geral, menores (~ 1000 K menos) que as temperaturas determinadas anteriormente, com modelos ML1. Os valores de log g não mudaram significativamente (menos de 10%). A faixa de instabilidade das DAVs está entre 11000 e 13000 K, consistente com dados de outros autores.

  4. Targeting a Proteinase-Activated Receptor 4 (PAR4) Carboxyl Terminal Motif to Regulate Platelet Function.

    PubMed

    Ramachandran, Rithwik; Mihara, Koichiro; Thibeault, Pierre; Vanderboor, Christina M; Petri, Björn; Saifeddine, Mahmoud; Bouvier, Michel; Hollenberg, Morley D

    2017-04-01

    Thrombin initiates human platelet aggregation by coordinately activating proteinase-activated receptors (PARs) 1 and 4. However, targeting PAR1 with an orthosteric-tethered ligand binding-site antagonist results in bleeding, possibly owing to the important role of PAR1 activation on cells other than platelets. Because of its more restricted tissue expression profile, we have therefore turned to PAR4 as an antiplatelet target. We have identified an intracellular PAR4 C-terminal motif that regulates calcium signaling and β-arrestin interactions. By disrupting this PAR4 calcium/β-arrestin signaling process with a novel cell-penetrating peptide, we were able to inhibit both thrombin-triggered platelet aggregation in vitro and clot consolidation in vivo. We suggest that targeting PAR4 represents an attractive alternative to blocking PAR1 for antiplatelet therapy in humans.

  5. Urokinase Plasminogen Activator Receptor (uPAR) Targeted Nuclear Imaging and Radionuclide Therapy

    PubMed Central

    Li, Dan; Liu, Shuanglong; Shan, Hong; Conti, Peter; Li, Zibo

    2013-01-01

    Urokinase-type plasminogen activator receptor (uPAR) is a glycosylphosphatidylinositol (GPI)-anchored protein. Besides regulating proteolysis, uPAR could also activate many intracellular signaling pathways that promote cell motility, invasion, proliferation, and survival through cooperating with transmembrane receptors. uPAR is overexpressed across a variety of tumors and is associated with cancer invasion and metastasis. In order to meet the demand for a rapid development and potential clinical application of anti-cancer therapy based on uPA/uPAR system, it is desirable to develop non-invasive imaging methods to visualize and quantify uPAR expression in vivo. In this review, we will discuss recent advances in the development of uPAR-targeted nuclear imaging and radionuclide therapy agents. The successful development of molecular imaging probes to visualize uPAR expression in vivo would not only assist preclinical researches on uPAR function, but also eventually impact patient management. PMID:23843898

  6. Par-4 downregulation promotes breast cancer recurrence by preventing multinucleation following targeted therapy.

    PubMed

    Alvarez, James V; Pan, Tien-Chi; Ruth, Jason; Feng, Yi; Zhou, Alice; Pant, Dhruv; Grimley, Joshua S; Wandless, Thomas J; Demichele, Angela; Chodosh, Lewis A

    2013-07-08

    Most deaths from breast cancer result from tumor recurrence, but mechanisms underlying tumor relapse are largely unknown. We now report that Par-4 is downregulated during tumor recurrence and that Par-4 downregulation is necessary and sufficient to promote recurrence. Tumor cells with low Par-4 expression survive therapy by evading a program of Par-4-dependent multinucleation and apoptosis that is otherwise engaged following treatment. Low Par-4 expression is associated with poor response to neoadjuvant chemotherapy and an increased risk of relapse in patients with breast cancer, and Par-4 is downregulated in residual tumor cells that survive neoadjuvant chemotherapy. Our findings identify Par-4-induced multinucleation as a mechanism of cell death in oncogene-addicted cells and establish Par-4 as a negative regulator of breast cancer recurrence. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Colectomie laparoscopique versus colectomie par laparotomie dans le traitement des adénocarcinomes coliques non métastatiques

    PubMed Central

    Bayar, Rached; Mzoughi, Zeineb; Djebbi, Achref; Halek, Ghassen; Khalfallah, Mohamed Taher

    2016-01-01

    Introduction La colectomie laparoscopique pour cancer colorectal constitue, de plus en plus, le traitement de référence. L’objectif de notre travail est de montrer que les résultats à court terme etla sécurité oncologique que procure la voie laparoscopique sont au moins équivalents à ceux de la laparotomie dans le traitement des adénocarcinomes coliques non métastatiques. Nous nous proposons également d’étudier l’impact de la courbe d’apprentissage sur les résultats de la laparoscopie dans ces cancers. Méthodes Il s’agit d’une étude rétrospective incluant tousles patients opérés pour des adénocarcinomes coliques résécablessur une période de 6 ans. La population de l’étude était répartie en 2 groupes, selon la voie d’abord utilisée initialement. Le groupe « OC » comprenait 35 patients opérés par laparotomie médiane et le groupe « LAC » comprenait 30 patients opérés par laparoscopie. Toutes les données étaient analysées au moyen du logiciel SPSS version 19.0. Résultats Notre étude n’a pas montré de différence significative dans les résultats à court terme entre les 2 groupes à savoir la morbidité per-opératoire, le séjour hospitalier, le séjour en milieu de réanimation ainsi que la morbi-mortalité postopératoire. Concernant les résultats à long terme, il n’y avait également pas de différence significative en termes de complications tardives, type de récidive, survie globale et survie sans récidive. La sécurité oncologique, attestée par les limites de résections et le nombre de ganglions prélevés, n’était pas significativement différente entre les deux groupes. Le temps opératoire était significativement plus long en laparoscopie (p < 0,001). Le taux de conversion était de 33%. Il est passé de 67% au cours des 2 premières années de l’étude à 13% au cours des 2 dernières années. La conversion de la laparoscopie en laparotomie n’avait pas d’impact significatif ni sur

  8. Activite locomotrice de souris isolees, de deux lignees consanguines, dans un environnement semi-naturel ou en cages d'elevage.

    PubMed

    Le Pape, G; Lassalle, J M

    1979-10-01

    Des enregistrements continus d'activité locomotrice ont été effectués sur des souris mâles isolées des lignées Balb/c et C57bl/6, vivant en cages d'élevage ou en milieu semi- naturel. Les résultats montrent que les différences entre ces deux situations ne sont pas perçues de la même façon par les animaux des deux lign'ees: alors qu'en cages d'élevage les souris des deux lignées experiment la même quantité totale d'activaté, en milieu semi-naturel les souris Balb/c sont plus actives que les C57bl/6. En outre, l≐s différences observées entre les lignées pour la repartition de l'activité au cours du nycthèmere s'inversent lorsque l'on passe d'une situation à l'autre. L'étude de la variabilité fait aparaître une dispersion plus grande des performances dans la lignée C57bl/6 en cages d'élevage, alors qu'en milieu semi-naturel la dispersion est plus chez Bal/c. Copyright © 1979. Published by Elsevier B.V.

  9. FIELD SCALE EVALUATION OF TREATMENT OF TCE IN A BIOWALL AT THE OU-1 SITE

    EPA Science Inventory

    A passive reactive barrier (Biowall) was installed at the OU-1 site at Altus Air Force Base, Oklahoma to treat TCE contamination in ground water from a landfill. Depth to ground water varies from 1.8 to 2.4 meters below land surface. To intercept and treat the plume of contamin...

  10. FIELD SCALE EVALUATION OF TREATMENT OF TCE IN A BIOWALL AT THE OU-1 SITE

    EPA Science Inventory

    A passive reactive barrier (Biowall) was installed at the OU-1 site at Altus Air Force Base, Oklahoma to treat TCE contamination in ground water from a landfill. Depth to ground water varies from 1.8 to 2.4 meters below land surface. To intercept and treat the plume of contamin...

  11. Attic cholesteatoma with tiny retraction of pars flaccida.

    PubMed

    Lee, Jun Ho; Hong, Seok Min; Kim, Chang Woo; Park, Yeo Hoon; Baek, So-Hye

    2015-04-01

    This clinical study was performed to analyze the characteristics of attic cholesteatoma occurring behind a tiny retraction of the pars flaccida, which was classified as Tos type I or II and had an intact pars tensa of the tympanic membrane. The clinical records of patients who underwent tympanomastoidectomy for attic cholesteatoma at a tertiary care referral center (Kangdong Sacred Heart Hospital of Seoul, Korea) between March 2004 and December 2012 were retrospectively reviewed. Eleven patients (five men and six women) who underwent tympanomastoidectomy between March 2004 and December 2012 for attic cholesteatoma occurring behind a tiny attic retraction were included. The mean age of patients was 41.1 years (range 20-58 years) and the mean duration of follow-up was 29.5 months (range 13-52 months). Every patient had a unilateral cholesteatoma, and the opposite side was normal except in one patient. Hearing loss was the most common symptom, followed by earfullness and otalgia. Five patients had type I attic retraction, and six patients had type II attic retraction. No patient had definite scutum erosion. Interestingly, during regular postoperative checkup, one patient was found incidentally for the opposite ear. Six patients had a cholesteatoma sac that was separated from the pars flaccida, whereas in five patients it was in contact with the pars flaccida but was easily separated. Six patients had a limited cholesteatoma within the epitympanum, and five patients had extension beyond the epitympanum. The average air-bone gap was 24.3±10.1dB before the operation and 14.2±6.6dB after the operation. Every patient had an intact tympanic membrane without retraction pocket postoperatively. There was no recurrence of cholesteatoma during follow-up. The rate of attic cholesteatomas occurring behind a tiny retraction of the pars flaccida was 7.7% (11 of 142 patients with attic cholesteatoma). Attic retractions must be followed closely using endoscopy, microscopy, and

  12. ParCAT: A Parallel Climate Analysis Toolkit

    NASA Astrophysics Data System (ADS)

    Haugen, B.; Smith, B.; Steed, C.; Ricciuto, D. M.; Thornton, P. E.; Shipman, G.

    2012-12-01

    Climate science has employed increasingly complex models and simulations to analyze the past and predict the future of our climate. The size and dimensionality of climate simulation data has been growing with the complexity of the models. This growth in data is creating a widening gap between the data being produced and the tools necessary to analyze large, high dimensional data sets. With single run data sets increasing into 10's, 100's and even 1000's of gigabytes, parallel computing tools are becoming a necessity in order to analyze and compare climate simulation data. The Parallel Climate Analysis Toolkit (ParCAT) provides basic tools that efficiently use parallel computing techniques to narrow the gap between data set size and analysis tools. ParCAT was created as a collaborative effort between climate scientists and computer scientists in order to provide efficient parallel implementations of the computing tools that are of use to climate scientists. Some of the basic functionalities included in the toolkit are the ability to compute spatio-temporal means and variances, differences between two runs and histograms of the values in a data set. ParCAT is designed to facilitate the "heavy lifting" that is required for large, multidimensional data sets. The toolkit does not focus on performing the final visualizations and presentation of results but rather, reducing large data sets to smaller, more manageable summaries. The output from ParCAT is provided in commonly used file formats (NetCDF, CSV, ASCII) to allow for simple integration with other tools. The toolkit is currently implemented as a command line utility, but will likely also provide a C library for developers interested in tighter software integration. Elements of the toolkit are already being incorporated into projects such as UV-CDAT and CMDX. There is also an effort underway to implement portions of the CCSM Land Model Diagnostics package using ParCAT in conjunction with Python and gnuplot. Par

  13. Is There an "F" in Your PAR? Understanding, Teaching and Doing Action Research

    ERIC Educational Resources Information Center

    Lorenzetti, Liza; Walsh, Christine Ann

    2014-01-01

    Participatory Action Research (PAR) is increasingly recognized within academic research and pedagogy. What are the benefits of including feminism within participatory action research and teaching? In responding to this question, we discuss the similarities and salient differences between PAR and feminist informed PAR (FPAR). There are eight themes…

  14. Troubles psychotiques précipités par le mariage : étude de trois observations

    PubMed Central

    Jaweher, Masmoudi; Kammoun, Mohamed Faouzi; Inès, Feki; Imen, Baati; Rim, Sallami; Abdelaziz, Jaoua

    2013-01-01

    Le mariage est un évènement très investi dans notre culture arabo-musulmane. Il présente une situation à grande charge émotionnelle et ayant un vécu stressant. C'est ainsi qu'il peut être à l'origine de la décompensation de certains troubles psychiatriques. Ce moment particulier de déclenchement de la pathologie peut altérer significativement l'adaptation familiale et sociale du patient en question, le rendant dépendant en partie ou en totalité à une institution. Dans ce travail, nous proposons d’étudier certains facteurs psychiques, sociaux et culturels pouvant aboutir à la précipitation des manifestations psychotiques par le mariage. Il s'agit de l’étude de trois observations cliniques, deux hommes et une femme, hospitalisés dans le service de psychiatrie A du CHU Hédi Chaker de Sfax et qui ont développés des manifestations psychotiques de façon concomitante à leur mariage. La durée moyenne de survenue des crises a été de vingt ans, le diagnostic retenu a été celui de trouble bipolaire dans deux cas et d'une schizophrénie indifférenciée chez le troisième patient. L’évolution s'est faite vers une chronicisation de deux malades et une dépendance institutionnelle dans le troisième cas. La précipitation des troubles psychotiques par le mariage, reste un phénomène en relation intime avec les composantes culturelles, elles-mêmes sont déterminantes dans la prise en charge ultérieure de ces patients. PMID:23785551

  15. Gas physical conditions and kinematics of the giant outflow Ou4

    NASA Astrophysics Data System (ADS)

    Corradi, Romano L. M.; Grosso, Nicolas; Acker, Agnès; Greimel, Robert; Guillout, Patrick

    2014-10-01

    Context. The recently discovered bipolar outflow Ou4 has a projected size of more than one degree in the plane of the sky. It is apparently centred on the young stellar cluster - whose most massive representative is the triple system HR 8119 - inside the H ii region Sh 2-129. The driving source, the nature, and the distance of Ou4 are not known. Aims: The basic properties of Ou4 and its environment are investigated to shed light on the origin of this remarkable outflow. Methods: Deep narrow-band imagery of the whole nebula at arcsecond resolution was obtained to study the details of its morphology. Long-slit spectroscopy of the bipolar lobe tips was secured to determine the gas ionisation mechanism, physical conditions, and line-of-sight velocities. An estimate of the proper motions at the tip of the south lobe using archival plate images was attempted. The existing multi-wavelength data for Sh 2-129 and HR 8119 were also comprehensively reviewed. Results: The observed morphology of Ou4, its emission-line spatial distribution, line flux ratios, and the kinematic modelling developed adopting a bow-shock parabolic geometry, illustrate the expansion of a shock-excited fast collimated outflow. The observed radial velocities of Ou4 and its reddening are consistent with those of Sh 2-129 and HR 8119. The improved determination of the distance to HR 8119 (composed of two B0 V and one B0.5 V stars) and Sh 2-129 is 712 pc. We identify in WISE images at 22 μm an emission bubble of 5' radius (1 pc at the distance above) emitted by hot (107 K) dust grains, located inside the central part of Ou4 and corresponding to several [O iii] emission features of Ou4. Conclusions: The apparent position of Ou4 and the properties studied in this work are consistent with the hypothesis that Ou4 is located inside the Sh 2-129 H ii region, suggesting that it was launched some 90 000 yr ago by HR 8119. The outflow total kinetic energy is estimated to be ≈4 × 1047 ergs. However, we cannot

  16. Les fractures de jambe à fibula intact: traitement orthopédique ou enclouage centromédullaire? (étude comparative à propos de 60 cas)

    PubMed Central

    Abouchane, Merouane; Fadili, Assia; Belmoubarik, Amine; EL Andaloussi, Yassir; Nechad, Mohammed

    2015-01-01

    La fracture de jambe à fibula intact (FJFI) est caractérisée par un potentiel de déplacement minime ainsi le pronostic semble bon, souvent associées à des difficultés de réduction de consolidation ou de cal vicieux. Notre but est de comparer les résultats du traitement orthopédique et de l'enclouage centromédullaire (ECM). Entre janvier 2006 et janvier 2011, on a traité 60 fractures de jambe à fibula intact. 31 patients ont bénéficié d'un ECM, dont 14 fois était statique, 16 fois dynamique et simple une fois, avec un appui compris entre le 2eme jour (pour la plupart des patients) et la sixième semaine. 29 patients ont bénéficiés d'un traitement orthopédique après réduction par plâtre cruro-pédieux avec libération du genou après 4 semaines avec appui total chez la plupart des patients. La durée de consolidation été de 4 mois en moyenne pour les patients traites par ECM et de 6 mois pour les patients traites orthopédiquement. On a noté 3 cas de pseudarthrose dans notre série d’étude soit 5%: 2 observées chez le groupe de l'ECM soit 6,4% et un cas pour le groupe du traitement orthopédique soit 3,8%. 6 cas de déplacement secondaires ont été note chez les patients traites orhtopédiquement à j15 du traitement, pour 5 patients le déplacement été jugé tolérable et pour un seul patient (trouble angulaire supérieur à 10°) ayant nécessité un ECM. 13 cas soit 54% de cal vicieux angulaire supérieur à 10 dans notre série tous traités orthopédiquement versus aucun cas de cal vicieux chez les patients du groupe du traitement par ECM. Cliniquement: tous les patients traités par ECM ont présenté une mobilité du genou et de la cheville normale. Les patients traités orthopédiquement ont tous bénéficié d'une rééducation du genou libération du genou et confection d'un plâtre type Sarmiento et celle de la cheville après son ablation définitive, ainsi aucun de nos patients n'a gardé une raideur après avoir termin

  17. Endophthalmitis following 27-Gauge Pars Plana Vitrectomy for Vitreous Floaters

    PubMed Central

    Lin, Zhong; Wu, Rong Han; Moonasar, Nived

    2016-01-01

    Purpose To report a case of Staphylococcus epidermidis endophthalmitis following 27-gauge pars plana vitrectomy for symptomatic vitreous floaters. Methods The clinical course and imaging findings, including fundus optomap, and spectral domain optical coherence tomography of a 24-year-old male patient were documented. Results The patient, with a preoperative best-corrected visual acuity (BCVA) of 1.0, developed endophthalmitis following 27-gauge pars plana vitrectomy for symptomatic vitreous floaters. After a series of treatments, including emergent vitreous tap and silicone oil injection, antibiotic treatment, and silicone oil removal, the patient regained a BCVA of 0.6. Conclusion Although rare, the potential risk of endophthalmitis should be explicitly discussed with patients considering surgical intervention for vitreous floaters. PMID:28101041

  18. Intraoperative raster photogrammetry--the PAR Corneal Topography System.

    PubMed

    Belin, M W

    1993-01-01

    The PAR Corneal Topography System (CTS) is a computer-driven corneal imaging system that uses close-range raster photogrammetry to measure and produce a topographic map of the corneal surface. The CTS determines distortion in a projected two-dimensional grid. Unlike Placido-disc-based videokeratoscopes, the PAR CTS produces a true topographic map (elevation map) and requires neither a smooth reflective surface nor precise spatial alignment for accurate imaging. Because the system uses two noncoaxial optical paths, it can be integrated into other optical devices. A modified CTS was integrated into an experimental erbium: YAG photoablative laser. The CTS successfully imaged corneas before, after, and during laser photoablation. Its ability to image nonreflective surfaces and to be integrated into other optical systems may make it suitable for intraoperative refractive monitoring.

  19. Exploration of a new series of PAR1 antagonists.

    PubMed

    Planty, Bruno; Pujol, Chantal; Lamothe, Marie; Maraval, Catherine; Horn, Clemens; Le Grand, Bruno; Perez, Michel

    2010-03-01

    Two series of new PAR1 antagonists have been identified. The first incorporates a cinnamoylpiperidine motif and the second a cinnamoylpyridine pattern. The synthesis, biological activity and structure-activity relationship of these compounds are presented. In each series, one analog showed potent in vivo antithrombotic activity in a rat AV shunt model, with up to 53% inhibition at 1.25mpk iv for compound 30.

  20. The Pars Interarticularis Stress Reaction, Spondylolysis, and Spondylolisthesis Progression

    PubMed Central

    Motley, Gina; Nyland, John; Jacobs, Jake; Caborn, David N. M.

    1998-01-01

    Objective: To review the classification, etiology, clinical and radiologic evaluation, and management of the pars interarticularis stress reaction, spondylolysis, and spondylolisthesis progression. Data Sources: Grateful Med was searched from 1980 to 1998 using the terms “spondylolysis,” “spondylolisthesis,” “female athlete” “spondylogenic,” and “pars interarticularis.” Data Synthesis: The progression from pars interarticularis stress reaction through spondylolysis to spondylolisthesis is common in adolescent athletes, and, because of hormonal influences and cheerleading and gymnastic maneuvers, females are particularly at risk. Proper diagnosis and management include a thorough evaluation, radiographs (possibly with technetium bone scan or single-photon emission computed tomography), activity modification, dietary counseling, a therapeutic exercise program focusing on proper trunk and hip muscle strength and extensibility balances, and education regarding proper back postures, positioning, lifting mechanics, and jump landings. Conclusions/Recommendations: The athletic trainer plays an integral part in managing this injury progression, particularly with identifying at-risk individuals and intervening appropriately. ImagesFigure 4. PMID:16558534

  1. La modélisation par Reverse Monte Carlo (RMC)

    NASA Astrophysics Data System (ADS)

    McGreevy, R. L.

    2003-09-01

    La technique de modélisation par Reverse Monte Carlo (RMC) est une méthode générale de modélisation structurale à partir d'un ensemble de données expérimentales. Cette méthode étant très souple, elle peut s'appliquer à de nombreux types de données. Jusqu'à présent ces applications comprennent : la diffraction des neutrons (y compris la substitution isotopique), la diffraction des rayons X (y compris la diffusion anomale), la diffraction des électrons, la RMN (les techniques d'angle magique et de 2ème moment) et l'EXAFS. Les systèmes étudiés sont également d'une grande variété : liquides, verres, polymères, cristaux et matériaux magnétiques, par exemple. Ce cours présente les bases de la méthode RMC en signalant certaines des idées fausses répandues. L'accent sera mis sur le fait que les modèles structuraux obtenus par RMC ne sont ni'uniques' ni 'exacts' ; cependant ils sont souvent utiles à la compréhension soit de la structure du système, soit des relations entre structure et autres propriétés physiques.

  2. Accuracy of the PAR corneal topography system with spatial misalignment.

    PubMed

    Belin, M W; Zloty, P

    1993-01-01

    The PAR Corneal Topography System is a computerized corneal imaging system which uses close-range raster photogrammetry to measure and produce a topographic map of the corneal surface. Raster photogrammetry is a standard method of extracting object information by projecting a known pattern onto an object and recording the distortion when viewed from an oblique angle. Unlike placido disc based videokeratoscopes, the PAR system requires neither a smooth reflective surface nor precise spatial alignment for accurate imaging. We studied both the accuracy of the system with purposeful misalignment (defocusing) of the test object and determined the ability to image freshly deepithelialized, keratectomized, and photoablated corneas. The PAR system was both accurate and reproducible in imaging calibrated spheres within a defined zone in space. Whole cadaver eyes were imaged both before and immediately after removal of the epithelium, lamellar keratectomy, and laser photoablation. The system demonstrated the ability to image irregular, deepithelialized, and keratectomized corneas. The ability to maintain accuracy without precise alignment and the facility to image freshly deepithelialized and keratectomized corneas may make the system suitable for intraoperative refractive monitoring.

  3. Two cases of malignant glaucoma unresolved by pars plana vitrectomy

    PubMed Central

    Hosoda, Yoshikatsu; Akagi, Tadamichi; Yoshimura, Nagahisa

    2014-01-01

    Malignant glaucoma, which is characterized by a shallow or flat anterior chamber with high intraocular pressure, can usually be resolved by pars plana vitrectomy with anterior hyaloidectomy. We describe two cases in which malignant glaucoma was refractory to conventional treatment and complete vitrectomy. Case one an 88-year-old woman with pseudoexfoliation glaucoma underwent trabeculotomy and subsequently developed malignant glaucoma. Four months after transient recovery by pars plana vitrectomy, the malignant glaucoma recurred. She underwent peripheral iridectomy and local zonulectomy with successful control of her intraocular pressure. In case two, an 85-year-old man had a history of pseudoexfoliation glaucoma. Seven months after phacoemulsification and intraocular lens implantation, he developed malignant glaucoma that was refractory to pars plana vitrectomy. He underwent peripheral iridectomy, goniosynechialysis and trabectome surgery resulting in the successful control of his intraocular pressure. In rare cases of malignant glaucoma refractive to vitrectomy, peripheral iridectomy with or without local zonulectomy is a reasonable and minimally invasive surgical procedure. PMID:24729683

  4. The Role of Neurosecretory Neurons in the Pars Intercerebralis and Pars Lateralis in Reproductive Diapause of the Blowfly, Protophormia terraenovae

    NASA Astrophysics Data System (ADS)

    Shiga, S.; Numata, H.

    Microlesions of the brain were made to examine the role of neurosecretory neurons in the pars intercerebralis (PI) and pars lateralis (PL) in the induction of reproductive diapause of the female blowfly Protophormia terraenovae. Under both diapause-inducing (LD 12 : 12, 20° C) and diapause-averting conditions (LD 18 : 6, 25° C), the ovaries invariably failed to develop when the PI was removed. When the PL was removed bilaterally, the ovaries developed in most of the females, irrespective of the rearing conditions. Removal of the PL prevented females from entering reproductive diapause. These results show that certain neurosecretory neurons in the PI are necessary for vitellogenesis, and that the PL contains inhibitory neurons which suppress vitellogenesis during reproductive diapause.

  5. Dynamic Filament Formation by a Divergent Bacterial Actin-Like ParM Protein

    PubMed Central

    Brzoska, Anthony J.; Jensen, Slade O.; Barton, Deborah A.; Davies, Danielle S.; Overall, Robyn L.; Skurray, Ronald A.; Firth, Neville

    2016-01-01

    Actin-like proteins (Alps) are a diverse family of proteins whose genes are abundant in the chromosomes and mobile genetic elements of many bacteria. The low-copy-number staphylococcal multiresistance plasmid pSK41 encodes ParM, an Alp involved in efficient plasmid partitioning. pSK41 ParM has previously been shown to form filaments in vitro that are structurally dissimilar to those formed by other bacterial Alps. The mechanistic implications of these differences are not known. In order to gain insights into the properties and behavior of the pSK41 ParM Alp in vivo, we reconstituted the parMRC system in the ectopic rod-shaped host, E. coli, which is larger and more genetically amenable than the native host, Staphylococcus aureus. Fluorescence microscopy showed a functional fusion protein, ParM-YFP, formed straight filaments in vivo when expressed in isolation. Strikingly, however, in the presence of ParR and parC, ParM-YFP adopted a dramatically different structure, instead forming axial curved filaments. Time-lapse imaging and selective photobleaching experiments revealed that, in the presence of all components of the parMRC system, ParM-YFP filaments were dynamic in nature. Finally, molecular dissection of the parMRC operon revealed that all components of the system are essential for the generation of dynamic filaments. PMID:27310470

  6. ParB Partition Proteins: Complex Formation and Spreading at Bacterial and Plasmid Centromeres

    PubMed Central

    Funnell, Barbara E.

    2016-01-01

    In bacteria, active partition systems contribute to the faithful segregation of both chromosomes and low-copy-number plasmids. Each system depends on a site-specific DNA binding protein to recognize and assemble a partition complex at a centromere-like site, commonly called parS. Many plasmid, and all chromosomal centromere-binding proteins are dimeric helix-turn-helix DNA binding proteins, which are commonly named ParB. Although the overall sequence conservation among ParBs is not high, the proteins share similar domain and functional organization, and they assemble into similar higher-order complexes. In vivo, ParBs “spread,” that is, DNA binding extends away from the parS site into the surrounding non-specific DNA, a feature that reflects higher-order complex assembly. ParBs bridge and pair DNA at parS and non-specific DNA sites. ParB dimers interact with each other via flexible conformations of an N-terminal region. This review will focus on the properties of the HTH centromere-binding protein, in light of recent experimental evidence and models that are adding to our understanding of how these proteins assemble into large and dynamic partition complexes at and around their specific DNA sites. PMID:27622187

  7. Specific and non-specific interactions of ParB with DNA: implications for chromosome segregation

    PubMed Central

    Taylor, James A.; Pastrana, Cesar L.; Butterer, Annika; Pernstich, Christian; Gwynn, Emma J.; Sobott, Frank; Moreno-Herrero, Fernando; Dillingham, Mark S.

    2015-01-01

    The segregation of many bacterial chromosomes is dependent on the interactions of ParB proteins with centromere-like DNA sequences called parS that are located close to the origin of replication. In this work, we have investigated the binding of Bacillus subtilis ParB to DNA in vitro using a variety of biochemical and biophysical techniques. We observe tight and specific binding of a ParB homodimer to the parS sequence. Binding of ParB to non-specific DNA is more complex and displays apparent positive co-operativity that is associated with the formation of larger, poorly defined, nucleoprotein complexes. Experiments with magnetic tweezers demonstrate that non-specific binding leads to DNA condensation that is reversible by protein unbinding or force. The condensed DNA structure is not well ordered and we infer that it is formed by many looping interactions between neighbouring DNA segments. Consistent with this view, ParB is also able to stabilize writhe in single supercoiled DNA molecules and to bridge segments from two different DNA molecules in trans. The experiments provide no evidence for the promotion of non-specific DNA binding and/or condensation events by the presence of parS sequences. The implications of these observations for chromosome segregation are discussed. PMID:25572315

  8. Symmetry breaking and polarization of the C. elegans zygote by the polarity protein PAR-2

    PubMed Central

    Zonies, Seth; Motegi, Fumio; Hao, Yingsong; Seydoux, Geraldine

    2010-01-01

    Polarization of the C. elegans zygote is initiated by ECT-2-dependent cortical flows, which mobilize the anterior PAR proteins (PAR-3, PAR-6 and PKC-3) away from the future posterior end of the embryo marked by the sperm centrosome. Here, we demonstrate the existence of a second, parallel and redundant pathway that can polarize the zygote in the absence of ECT-2-dependent cortical flows. This second pathway depends on the polarity protein PAR-2. We show that PAR-2 localizes to the cortex nearest the sperm centrosome even in the absence of cortical flows. Once on the cortex, PAR-2 antagonizes PAR-3-dependent recruitment of myosin, creating myosin flows that transport the anterior PAR complex away from PAR-2 in a positive-feedback loop. We propose that polarity in the C. elegans zygote is initiated by redundant ECT-2- and PAR-2-dependent mechanisms that lower PAR-3 levels locally, triggering a positive-feedback loop that polarizes the entire cortex. PMID:20392744

  9. Symmetry breaking and polarization of the C. elegans zygote by the polarity protein PAR-2.

    PubMed

    Zonies, Seth; Motegi, Fumio; Hao, Yingsong; Seydoux, Geraldine

    2010-05-01

    Polarization of the C. elegans zygote is initiated by ECT-2-dependent cortical flows, which mobilize the anterior PAR proteins (PAR-3, PAR-6 and PKC-3) away from the future posterior end of the embryo marked by the sperm centrosome. Here, we demonstrate the existence of a second, parallel and redundant pathway that can polarize the zygote in the absence of ECT-2-dependent cortical flows. This second pathway depends on the polarity protein PAR-2. We show that PAR-2 localizes to the cortex nearest the sperm centrosome even in the absence of cortical flows. Once on the cortex, PAR-2 antagonizes PAR-3-dependent recruitment of myosin, creating myosin flows that transport the anterior PAR complex away from PAR-2 in a positive-feedback loop. We propose that polarity in the C. elegans zygote is initiated by redundant ECT-2- and PAR-2-dependent mechanisms that lower PAR-3 levels locally, triggering a positive-feedback loop that polarizes the entire cortex.

  10. Characterization of a Par j 1/Par j 2 mutant hybrid with reduced allergenicity for immunotherapy of Parietaria allergy.

    PubMed

    Bonura, A; Passantino, R; Costa, M A; Montana, G; Melis, M; Bondì, M Luisa; Butteroni, C; Barletta, B; Corinti, S; Di Felice, G; Colombo, P

    2012-03-01

    Parietaria pollen is one of the major cause of pollinosis in the southern Europe. Specific immunotherapy is the only treatment able to modify the natural outcome of the disease restoring a normal immunity against allergens. We designed a recombinant molecule (PjEDloop1) comprised of genetic-engineered variants of the major allergens of the Parietaria pollen (Par j 2/Par j 1). Purity and chemical-physical properties of the derivative were analysed by RP-HPLC chromatography and Photon Correlation Spectroscopy. Immunological activity was evaluated by means of Western blotting, ELISA inhibition and PBMC proliferation assay in 10 Parietaria allergic patients. Basophil activation was studied in six subjects. The immunogenicity of the hybrid was studied looking at the immune responses induced in a mouse model of sensitization. The PjEDloop1 hybrid was produced as a purified recombinant protein with high stability in solution. Western blot, ELISA inhibition and basophil activation test showed that the PjEDloop1 displays a remarkable reduced IgE binding and anaphylactic activity. CD3 reactivity was conserved in all patients. Mice immunization with the rPjEDloop1 induced antibodies and T cell responses comparable to that obtained by the wild type allergens. Such antibodies shared the specificities to rPar j 1 and rPar j 2 with human IgE antibodies. Our results demonstrated that a mutant hybrid expressing genetically engineered forms of the major P. judaica allergens displayed reduced allergenicity and retained T cell reactivity for the induction of protective antibodies in vaccination approaches for the treatment of Parietaria pollinosis. © 2011 Blackwell Publishing Ltd.

  11. Developmental Control of a parAB Promoter Leads to Formation of Sporulation-Associated ParB Complexes in Streptomyces coelicolor

    PubMed Central

    Jakimowicz, Dagmara; Mouz, Sebastien; Zakrzewska-Czerwińska, Jolanta; Chater, Keith F.

    2006-01-01

    The Streptomyces coelicolor partitioning protein ParB binds to numerous parS sites in the oriC-proximal part of the linear chromosome. ParB binding results in the formation of large complexes, which behave differentially during the complex life cycle (D. Jakimowicz, B. Gust, J. Zakrzewska-Czerwinska, and K. F. Chater, J. Bacteriol. 187:3572-3580, 2005). Here we have analyzed the transcriptional regulation that underpins this developmentally specific behavior. Analysis of promoter mutations showed that the irregularly spaced complexes present in vegetative hyphae are dependent on the constitutive parABp1 promoter, while sporulation-specific induction of the promoter parABp2 is required for the assembly of arrays of ParB complexes in aerial hyphae and thus is necessary for efficient chromosome segregation. Expression from parABp2 depended absolutely on two sporulation regulatory genes, whiA and whiB, and partially on two others, whiH and whiI, all four of which are needed for sporulation septation. Because of this pattern of dependence, we investigated the transcription of these four whi genes in whiA and whiB mutants, revealing significant regulatory interplay between whiA and whiB. A strain in which sporulation septation (but not vegetative septation) was blocked by mutation of a sporulation-specific promoter of ftsZ showed close to wild-type induction of parABp2 and formed fairly regular ParB-enhanced green fluorescent protein foci in aerial hyphae, ruling out strong morphological coupling or checkpoint regulation between septation and DNA partitioning during sporulation. A model for developmental regulation of parABp2 expression is presented. PMID:16484182

  12. Intérêt de la thérapie antivirale par voie orale dans le traitement des nécroses rétiniennes aigues

    PubMed Central

    Haouzi, Samia El; Jait, Amina; Lezrek, Omar; Samira, Tachfouti; Amina, Laghmari; Cherkaoui, Ouafa; Abdellouahed, Karman; Daoudi, Rajae

    2016-01-01

    Le syndrome de nécrose rétinienne aiguë (RNA) est un syndrome uvéitique rare mais dévastateur pour la vue (pronostic visuel ++). Son diagnostic doit être précoce du fait de sa gravité et du risque de bilatéralisation. C’est une entité rare causée par les virus du groupe Herpès. Chez les patients immunodéprimés, les complications de l’ARN syndrome conduisent souvent à une perte d’acuité visuelle. La confirmation de ce diagnostic dès la découverte de la maladie par la réaction de polymérase en chaîne (PCR) et par le coefficient de charge immunitaire (CCI) le plus souvent par ponction d’humeur aqueuse permet d’optimiser la prise en charge en diminuant le temps nécessaire à une confirmation diagnostique. L’ARN syndrome est de très mauvais pronostic spontané. Des études récentes ont montré que la thérapie orale antivirale (valaciclovir, famciclovir et valganciclovir) et intravitréenne sans traitement intraveineux initial est un traitement efficace de l’ARN. Nous présentons ici le tableau clinique d’un jeune patient âgé de 39 ans admis aux urgences pour baisse d’acuité visuelle. L’examen ophtalmologique a objectivé une nécrose rétinienne aigue unilatérale. Il fut traité par une thérapie antivirale orale (valaciclovir) associée à une corticothérapie et l’évolution était très favorable. Le pronostic de la nécrose rétinienne aiguë ou ARN syndrome est le plus souvent sévère. Le traitement de cette affection doit être le plus précoce possible afin de limiter une bilatéralisation et la survenue des complications. Cette observation confirme que la thérapie orale antivirale (valaciclovir, famciclovir et valganciclovir) sans traitement intraveineux initial est un traitement efficace de l’ARN. PMID:27795766

  13. Ostéosynthèse des fractures des métacarpiens et des phalanges de la main par mini plaque: à propos de 12 cas

    PubMed Central

    Moncef, Erraji; Abdelhafid, Derfoufi; Abdessamad, Kharraji; Omar, Agoumi; Najib, Abdeljaouad; Abdelkrim, Daoudi; Hicham, Yacoubi

    2016-01-01

    Le traitement des fractures instables des métacarpes et des phalanges reste un objet de controverse. Peu de séries ont été rapportées dans la littérature, rendant leur analyse difficile. Nous rapportons une étude rétrospective comportant 12 patients, opérés par cette technique, ayant eu des fractures déplacées des métacarpes ou des phalanges, sur une période de deux ans. Les résultats globaux ont été bons dans 75% des cas, moyenne dans 16,5% des cas et mauvais dans 8,5% des cas. La stabilité du montage par mini plaques des fractures instables des métacarpiens et des phalanges ont permis une mobilisation précoce des articulations de la main, évitant ainsi la raideur. PMID:27800079

  14. Prise en charge d’un afflux massif de brûles lors d’une situation de catastrophe par incendie au Maroc

    PubMed Central

    Siah, S.; Hatimi, E.M.; Ihrai, H.; Drissi Kamili, N.

    2012-01-01

    Summary La brûlure est l’une des lésions les plus fréquemment rencontrées lors de catastrophes naturelles ou lors de catastrophes d’origine humaine (incendies de lieux publics d’origine accidentelle, ou en temps de guerre ou encore lors d’attentats terroristes). La prise en charge et le triage de brûlés en nombre reste un problème difficile; ceci souligne la nécessité d’une réflexion et de prévisions de ces crises en insistant sur la formation des médecins et des soignants. Les défis à relever sont multiples: les soins aux brûlés requièrent un nombre important de personnel qualifié; les évacuations doivent être planifiées en fonction de la gravité de la brûlure et des lésions associées; les stocks et lots de dotation (en particulier en topiques anti-infectieux et en cristalloïdes) doivent être suffisants et adéquats. Les services hospitaliers de l’Hôpital Militaire d’Instruction Mohammed V de Rabat doivent pouvoir être rapidement adaptés pour accueillir et surtout isoler ces patients. L’hypothèse d’une catastrophe par incendie avec afflux massif de brûlés à l’hôpital militaire d’instruction Mohammed V de Rabat ne doit laisser place à aucune improvisation. PMID:23467075

  15. Hong-Ou-Mandel interferometer with one and two photon pairs

    NASA Astrophysics Data System (ADS)

    Cosme, Olavo; Pádua, S.; Bovino, Fabio A.; Mazzei, A.; Sciarrino, Fabio; de Martini, Francesco

    2008-05-01

    We study the Hong-Ou-Mandel interferometer in the regime of spontaneous parametric down-conversion with high pump beam power at the crystal. In this regime one and two photons from a pump pulsed laser beam generate one and two pairs of photons, respectively. These photons are then directed to the beam splitter of the interferometer and detected at its exit in coincidence. An interesting phenomenon is observed: The reduction of the visibility of the Hong-Ou-Mandel coincidence peak (or dip) with the increase of pump power. We study the relation between the visibility of the fourth-order interference pattern and the power of the pumping laser beam for type I and type II phase-matching crystals. Our theoretical calculations are in good agreement with the experimental results.

  16. High visibility Hong-Ou-Mandel interference via a time-resolved coincidence measurement

    NASA Astrophysics Data System (ADS)

    Tsujimoto, Yoshiaki; Sugiura, Yukihiro; Tanaka, Motoki; Ikuta, Rikizo; Miki, Shigehito; Yamashita, Taro; Terai, Hirotaka; Fujiwara, Mikio; Yamamoto, Takashi; Koashi, Masato; Sasaki, Masahide; Imoto, Nobuyuki

    2017-05-01

    We report on the observation of a high visibility Hong-Ou-Mandel interference of two heralded photons emitted from a spontaneous parametric down conversion~(SPDC) pumped by continuous-wave~(cw) light. A non-degenerate photon pair at 1541~nm and 1580~nm is generated by cw-pumped SPDC through a periodically poled lithium niobate waveguide. The heralded single photon at 1541~nm is prepared by the detection of the photon at 1580~nm. We performed the experiment of the Hong-Ou-Mandel interference between heralded single photons in separated time bins and observed a high visibility interference. All detectors we used are superconducting nanowire single-photon detectors and an overall temporal resolution of the photon detection is estimated as 85 ps, which is sufficiently shorter than the coherence time of the heralded photons.

  17. Complete three photon Hong-Ou-Mandel interference at a three port device.

    PubMed

    Mährlein, Simon; von Zanthier, Joachim; Agarwal, Girish S

    2015-06-15

    We report the possibility of completely destructive interference of three indistinguishable photons on a three port device providing a generalisation of the well known Hong-Ou-Mandel interference of two indistinguishable photons on a two port device. Our analysis is based on the underlying mathematical framework of SU(3) transformations rather than SU(2) transformations. We show the completely destructive three photon interference for a large range of parameters of the three port device and point out the physical origin of such interference in terms of the contributions from different quantum paths. As each output port can deliver zero to three photons the device generates higher dimensional entanglement. In particular, different forms of entangled states of qudits can be generated depending on the device parameters. Our system is different from a symmetric three port beam splitter which does not exhibit a three photon Hong-Ou-Mandel interference.

  18. Hong-Ou-Mandel Interference between Two Deterministic Collective Excitations in an Atomic Ensemble

    NASA Astrophysics Data System (ADS)

    Li, Jun; Zhou, Ming-Ti; Jing, Bo; Wang, Xu-Jie; Yang, Sheng-Jun; Jiang, Xiao; Mølmer, Klaus; Bao, Xiao-Hui; Pan, Jian-Wei

    2016-10-01

    We demonstrate deterministic generation of two distinct collective excitations in one atomic ensemble, and we realize the Hong-Ou-Mandel interference between them. Using Rydberg blockade we create single collective excitations in two different Zeeman levels, and we use stimulated Raman transitions to perform a beam-splitter operation between the excited atomic modes. By converting the atomic excitations into photons, the two-excitation interference is measured by photon coincidence detection with a visibility of 0.89(6). The Hong-Ou-Mandel interference witnesses an entangled NOON state of the collective atomic excitations, and we demonstrate its two times enhanced sensitivity to a magnetic field compared with a single excitation. Our work implements a minimal instance of boson sampling and paves the way for further multimode and multiexcitation studies with collective excitations of atomic ensembles.

  19. Hong-Ou-Mandel Interference between Two Deterministic Collective Excitations in an Atomic Ensemble.

    PubMed

    Li, Jun; Zhou, Ming-Ti; Jing, Bo; Wang, Xu-Jie; Yang, Sheng-Jun; Jiang, Xiao; Mølmer, Klaus; Bao, Xiao-Hui; Pan, Jian-Wei

    2016-10-28

    We demonstrate deterministic generation of two distinct collective excitations in one atomic ensemble, and we realize the Hong-Ou-Mandel interference between them. Using Rydberg blockade we create single collective excitations in two different Zeeman levels, and we use stimulated Raman transitions to perform a beam-splitter operation between the excited atomic modes. By converting the atomic excitations into photons, the two-excitation interference is measured by photon coincidence detection with a visibility of 0.89(6). The Hong-Ou-Mandel interference witnesses an entangled NOON state of the collective atomic excitations, and we demonstrate its two times enhanced sensitivity to a magnetic field compared with a single excitation. Our work implements a minimal instance of boson sampling and paves the way for further multimode and multiexcitation studies with collective excitations of atomic ensembles.

  20. Collective cell migration requires suppression of actomyosin at cell-cell contacts mediated by DDR1 and the cell polarity regulators Par3 and Par6.

    PubMed

    Hidalgo-Carcedo, Cristina; Hooper, Steven; Chaudhry, Shahid I; Williamson, Peter; Harrington, Kevin; Leitinger, Birgit; Sahai, Erik

    2011-01-01

    Collective cell migration occurs in a range of contexts: cancer cells frequently invade in cohorts while retaining cell-cell junctions. Here we show that collective invasion by cancer cells depends on decreasing actomyosin contractility at sites of cell-cell contact. When actomyosin is not downregulated at cell-cell contacts, migrating cells lose cohesion. We provide a molecular mechanism for this downregulation. Depletion of discoidin domain receptor 1 (DDR1) blocks collective cancer-cell invasion in a range of two-dimensional, three-dimensional and 'organotypic' models. DDR1 coordinates the Par3/Par6 cell-polarity complex through its carboxy terminus, binding PDZ domains in Par3 and Par6. The DDR1-Par3/Par6 complex controls the localization of RhoE to cell-cell contacts, where it antagonizes ROCK-driven actomyosin contractility. Depletion of DDR1, Par3, Par6 or RhoE leads to increased actomyosin contactility at cell-cell contacts, a loss of cell-cell cohesion and defective collective cell invasion.

  1. Arthrose due au genu varum: traitement par osteotomie tibiale de valgisation

    PubMed Central

    Moussa, Abdou Kadri; Lukulunga, Loubet Unyendje; Mahfoud, Mustapha; El Bardouni, Ahmed; Ismail, Farid; Kharmaz, Mohamed; Berrada, Mohammed Saleh; El Yaacoubi, Moradh

    2014-01-01

    clichés nous ont permis de classer l'arthrose du genou selon Ahlbäck. 72,5% des patients, présentaient une arthrose débutante. Le pangonogramme a été réalisé pour mesurer la déviation axiale du génu varum. La déviation angulaire: HKA (angle entre le centre de la tête fémorale et le milieu de la cheville) préopératoire a varié entre 163° et 176°, soit une moyenne de 175,46°. Une correction moyenne de déviation de 11,3° a été réalisée avec des extrêmes de 7 à 19°. Cet angle de correction (DAC) qui variait de 7 à 19° a été supérieur à 15° dans 57,39%s inférieur à 15° chez 38%. 27,4% des patients avaient une déviation angulaire importante avec une arthrose avancée. Après un bilan préopératoire et une planification opératoire 73% des patients ont été opérés sous anesthésie loco-régionale. Pour l'ostéotomie tibiale de fermeture, la voie d'abord a été la voie de Gernez antérolatérale, utilisée chez 56 cas (48,6%), l'ostéotomie tibiale d'ouverture (la voie d'abord était Gernez antéro-médiale) effectuée dans 20 cas (17,3%);et l'ostéotomie curviplane, a été réalisée par une voie d'abord longitudinale médiane dans 39%. Les ostéosynthèses ont été réalisées dans 51 cas (44,3%) par les agrafes de Blount, dans 54 cas (46,9%) par la plaque en T ou en L et dans 11 cas par une plaque en col de cygne. En per-opératoire nous avons enregistré deux (02) cas de fractures du plateau tibial médial, en post-opératoire on a eu 1 cas d'infection superficielle et comme complications tardives une raideur du genou (18,2%) et 3,4% de pseudarthrose, une récidive du génu varum dans 19,1% (n = 22) après 3 années de recul. Les résultats du traitement ont été bons dans 78,4% selon le score HSS. L'OTV sur genu varum a été réalisé chez des patients relativement âgés avec la prédominance du sexe féminin. Les techniques utilisées dépendaient de la préférence du chirurgien. Les résultats sont probants malgré la fr

  2. Faut-il continuer à infiltrer le scalp par un anesthésique local pour une craniotomie?

    PubMed Central

    Doumiri, Mouhssine; Motiaa, Youssef; Razine, Rachid; Amor, Morad; Moussaoui, Abdelmajid; Kabbaj, Saad; Maazouzi, Wajdi

    2015-01-01

    'augmentation de la PAM était également significativement plus élevée dans le groupe placebo (96,45± 3,53mmHg vs 94,75± 3,76mmHg) (p = 0,041). Nous n'avons pas noté de troubles de rythme ou d'hypertension artérielle par les solutions adrénalinées à 1/200000. Par contre, six cas d'hypotension artérielle ont été notés (3cas dans chaque groupe) après 2 minutes de l'infiltration et ayant répandu au remplissage par 500 ml de sérum salé 0,9%. Conclusion L'infiltration par la lidocaïne procure une stabilité hémodynamique (PAM et FC) statistiquement significative. Les autres études rapportées dans la littérature et avec un échantillon réduit ont permis de retrouver une différence significative concernant uniquement la PAM et non la fréquence cardiaque. PMID:26759693

  3. ParABS Systems of the Four Replicons of Burkholderia cenocepacia: New Chromosome Centromeres Confer Partition Specificity†

    PubMed Central

    Dubarry, Nelly; Pasta, Franck; Lane, David

    2006-01-01

    Most bacterial chromosomes carry an analogue of the parABS systems that govern plasmid partition, but their role in chromosome partition is ambiguous. parABS systems might be particularly important for orderly segregation of multipartite genomes, where their role may thus be easier to evaluate. We have characterized parABS systems in Burkholderia cenocepacia, whose genome comprises three chromosomes and one low-copy-number plasmid. A single parAB locus and a set of ParB-binding (parS) centromere sites are located near the origin of each replicon. ParA and ParB of the longest chromosome are phylogenetically similar to analogues in other multichromosome and monochromosome bacteria but are distinct from those of smaller chromosomes. The latter form subgroups that correspond to the taxa of their hosts, indicating evolution from plasmids. The parS sites on the smaller chromosomes and the plasmid are similar to the “universal” parS of the main chromosome but with a sequence specific to their replicon. In an Escherichia coli plasmid stabilization test, each parAB exhibits partition activity only with the parS of its own replicon. Hence, parABS function is based on the independent partition of individual chromosomes rather than on a single communal system or network of interacting systems. Stabilization by the smaller chromosome and plasmid systems was enhanced by mutation of parS sites and a promoter internal to their parAB operons, suggesting autoregulatory mechanisms. The small chromosome ParBs were found to silence transcription, a property relevant to autoregulation. PMID:16452432

  4. Is PAR a Good Investment? Understanding the Costs and Benefits of Teacher Peer Assistance and Review Programs

    ERIC Educational Resources Information Center

    Papay, John P.; Johnson, Susan Moore

    2012-01-01

    Peer Assistance and Review (PAR) is a local labor-management initiative designed to improve teacher quality. In PAR, expert "consulting teachers" mentor, support, and evaluate novice and underperforming veteran teachers. Evaluations under PAR can lead to dismissals. The authors examine the costs and benefits of PAR, both financial and…

  5. Anterior PAR Proteins Function During Cytokinesis and Maintain DYN-1 at the Cleavage Furrow in Caenorhabditis elegans

    PubMed Central

    Pittman, Kelly J.; Skop, Ahna R.

    2013-01-01

    PAR proteins are key regulators of cellular polarity and have links to the endocytic machinery and the actin cytoskeleton. Our data suggest a unique role for PAR proteins in cytokinesis. We have found that at the onset of cytokinesis, anterior PAR-6 and posterior PAR-2 proteins are redistributed to the furrow membrane in a temporal and spatial manner. PAR-6 and PAR-2 localize to the furrow membrane during ingression but PAR-2-GFP is distinct in that it is excluded from the extreme tip of the furrow. Once the midbody has formed, PAR-2-GFP becomes restricted to the midbody region (the midbody plus the membrane flanking it). Depletion of both anterior PAR proteins, PAR-3 and PAR-6, led to an increase in multinucleate embryos, suggesting that the anterior PAR proteins are necessary during cytokinesis and that PAR-3 and PAR-6 function in cytokinesis may be partially redundant. Lastly, anterior PAR proteins play a role in the maintenance of DYN-1 in the cleavage furrow. Our data indicate that the PAR proteins are involved in the events that occur during cytokinesis and may play a role in promoting the membrane trafficking and remodeling events that occur during this time. PMID:22887994

  6. Anterior PAR proteins function during cytokinesis and maintain DYN-1 at the cleavage furrow in Caenorhabditis elegans.

    PubMed

    Pittman, Kelly J; Skop, Ahna R

    2012-10-01

    PAR proteins are key regulators of cellular polarity and have links to the endocytic machinery and the actin cytoskeleton. Our data suggest a unique role for PAR proteins in cytokinesis. We have found that at the onset of cytokinesis, anterior PAR-6 and posterior PAR-2 proteins are redistributed to the furrow membrane in a temporal and spatial manner. PAR-6 and PAR-2 localize to the furrow membrane during ingression but PAR-2-GFP is distinct in that it is excluded from the extreme tip of the furrow. Once the midbody has formed, PAR-2-GFP becomes restricted to the midbody region (the midbody plus the membrane flanking it). Depletion of both anterior PAR proteins, PAR-3 and PAR-6, led to an increase in multinucleate embryos, suggesting that the anterior PAR proteins are necessary during cytokinesis and that PAR-3 and PAR-6 function in cytokinesis may be partially redundant. Lastly, anterior PAR proteins play a role in the maintenance of DYN-1 in the cleavage furrow. Our data indicate that the PAR proteins are involved in the events that occur during cytokinesis and may play a role in promoting the membrane trafficking and remodeling events that occur during this time. Copyright © 2012 Wiley Periodicals, Inc.

  7. A model for the condensation of the bacterial chromosome by the partitioning protein ParB

    NASA Astrophysics Data System (ADS)

    Broedersz, Chase; Wingreen, Ned

    2013-03-01

    The molecular machinery responsible for faithful segregation of the chromosome in bacteria such as Caulobacter crescentus and Bacillus subtilis includes the ParABS a.k.a. Spo0J/Soj partitioning system. In Caulobacter, prior to division, hundreds of ParB proteins bind to the DNA near the origin of replication, and localize to one pole of the cell. Subsequently, the ParB-DNA complex is translocated to the far pole by the binding and retraction of the ParA spindle-like apparatus. Remarkably, the localization of ParB proteins to specific regions of the chromosome appears to be controlled by only a few centromeric parS binding sites. Although lateral interactions between DNA-bound ParB are likely to be important for their localization, the long-range order of ParB domains on the chromosome appears to be inconsistent with a picture in which protein-protein interactions are limited to neighboring DNA-bound proteins. We developed a coarse-grained Brownian dynamics model that allows for lateral and 3D protein-protein interactions among bound ParB proteins. Our model shows how such interactions can condense and organize the DNA spatially, and can control the localization and the long-range order of the DNA-bound proteins.

  8. A three-dimensional ParF meshwork assembles through the nucleoid to mediate plasmid segregation

    PubMed Central

    McLeod, Brett N.; Allison-Gamble, Gina E.; Barge, Madhuri T.; Tonthat, Nam K.; Schumacher, Maria A.; Hayes, Finbarr

    2017-01-01

    Abstract Genome segregation is a fundamental step in the life cycle of every cell. Most bacteria rely on dedicated DNA partition proteins to actively segregate chromosomes and low copy-number plasmids. Here, by employing super resolution microscopy, we establish that the ParF DNA partition protein of the ParA family assembles into a three-dimensional meshwork that uses the nucleoid as a scaffold and periodically shuttles between its poles. Whereas ParF specifies the territory for plasmid trafficking, the ParG partner protein dictates the tempo of ParF assembly cycles and plasmid segregation events by stimulating ParF adenosine triphosphate hydrolysis. Mutants in which this ParG temporal regulation is ablated show partition deficient phenotypes as a result of either altered ParF structure or dynamics and indicate that ParF nucleoid localization and dynamic relocation, although necessary, are not sufficient per se to ensure plasmid segregation. We propose a Venus flytrap model that merges the concepts of ParA polymerization and gradient formation and speculate that a transient, dynamic network of intersecting polymers that branches into the nucleoid interior is a widespread mechanism to distribute sizeable cargos within prokaryotic cells. PMID:28034957

  9. PAR-2 expression in the gingival crevicular fluid reflects chronic periodontitis severity.

    PubMed

    Fukushima, Henrique; Alves, Vanessa Tubero Euzebio; Carvalho, Verônica Franco de; Ambrósio, Lucas Macedo Batitucci; Eichler, Rosangela Aparecida Dos Santos; Carvalho, Maria Helena Catelli de; Saraiva, Luciana; Holzhausen, Marinella

    2017-01-26

    Recent studies investigating protease-activated receptor type 2 (PAR-2) suggest an association between the receptor and periodontal inflammation. It is known that gingipain, a bacterial protease secreted by the important periodontopathogen Porphyromonas gingivalis can activate PAR-2. Previous studies by our group found that PAR-2 is overexpressed in the gingival crevicular fluid (GCF) of patients with moderate chronic periodontitis (MP). The present study aimed at evaluating whether PAR-2 expression is associated with chronic periodontitis severity. GCF samples and clinical parameters, including plaque and bleeding on probing indices, probing pocket depth and clinical attachment level, were collected from the control group (n = 19) at baseline, and from MP patients (n = 19) and severe chronic periodontitis (SP) (n = 19) patients before and 6 weeks after periodontal non-surgical treatment. PAR-2 and gingipain messenger RNA (mRNA) in the GCF of 4 periodontal sites per patient were evaluated by Reverse Transcription Polymerase Chain Reaction (RT-qPCR). PAR-2 and gingipain expressions were greater in periodontitis patients than in control group patients. In addition, the SP group presented increased PAR-2 and gingipain mRNA levels, compared with the MP group. Furthermore, periodontal treatment significantly reduced (p <0.05) PAR-2 expression in patients with periodontitis. In conclusion, PAR-2 is associated with chronic periodontitis severity and with gingipain levels in the periodontal pocket, thus suggesting that PAR-2 expression in the GCF reflects the severity of destruction during periodontal infection.

  10. Par3 regulates invasion of pancreatic cancer cells via interaction with Tiam1.

    PubMed

    Guo, Xingjun; Wang, Min; Zhao, Yan; Wang, Xin; Shen, Ming; Zhu, Feng; Shi, Chengjian; Xu, Meng; Li, Xu; Peng, Feng; Zhang, Hang; Feng, Yechen; Xie, Yu; Xu, Xiaodong; Jia, Wei; He, Ruizhi; Jiang, Jianxin; Hu, Jun; Tian, Rui; Qin, Renyi

    2016-08-01

    The conserved polarity complex, which comprises partitioning-defective proteins Par3, Par6, and the atypical protein kinase C, affects various cell-polarization events, including assembly of tight junctions. Control of tight junction assembly is closely related to invasion and migration potential. However, as the importance of conserved polarity complexes in regulating pancreatic cancer invasion and metastasis is unclear, we investigated their role and mechanism in pancreatic cancers. We first detect that the key protein of the conserved polarity complex finds that only Par3 is down-regulated in pancreatic cancer tissues while Par6 and aPKC show no difference. What is more, Par3 tissues level was significantly and positively associated with patient overall survival. Knocking-down Par3 promotes pancreatic cancer cells invasion and migration. And Par3 requires interaction with Tiam1 to affect tight junction assembly, and then affect invasion and migration of pancreatic cancer cells. Then, we find that tight junction marker protein ZO-1 and claudin-1 are down-regulated in pancreatic cancer tissues. And the relationship of the expression of Par3 and ZO-1 in pancreatic cancer tissue is linear correlation. We establish liver metastasis model of human pancreatic cancer cells in Balb/c nude mice and find that knocking down Par3 promotes invasion and metastasis and disturbs tight junction assembly in vivo. Taken together, these results suggest that the Par3 regulates invasion and metastasis in pancreatic cancers by controlling tight junction assembly.

  11. MAP kinase signaling antagonizes PAR-1 function during polarization of the early Caenorhabditis elegans embryo.

    PubMed

    Spilker, Annina C; Rabilotta, Alexia; Zbinden, Caroline; Labbé, Jean-Claude; Gotta, Monica

    2009-11-01

    PAR proteins (partitioning defective) are major regulators of cell polarity and asymmetric cell division. One of the par genes, par-1, encodes a Ser/Thr kinase that is conserved from yeast to mammals. In Caenorhabditis elegans, par-1 governs asymmetric cell division by ensuring the polar distribution of cell fate determinants. However the precise mechanisms by which PAR-1 regulates asymmetric cell division in C. elegans remain to be elucidated. We performed a genomewide RNAi screen and identified six genes that specifically suppress the embryonic lethal phenotype associated with mutations in par-1. One of these suppressors is mpk-1, the C. elegans homolog of the conserved mitogen activated protein (MAP) kinase ERK. Loss of function of mpk-1 restored embryonic viability, asynchronous cell divisions, the asymmetric distribution of cell fate specification markers, and the distribution of PAR-1 protein in par-1 mutant embryos, indicating that this genetic interaction is functionally relevant for embryonic development. Furthermore, disrupting the function of other components of the MAPK signaling pathway resulted in suppression of par-1 embryonic lethality. Our data therefore indicates that MAP kinase signaling antagonizes PAR-1 signaling during early C. elegans embryonic polarization.

  12. Function, expression, specificity, diversity and incompatibility of actinobacteriophage parABS systems.

    PubMed

    Dedrick, Rebekah M; Mavrich, Travis N; Ng, Wei L; Cervantes Reyes, Juan C; Olm, Matthew R; Rush, Rachael E; Jacobs-Sera, Deborah; Russell, Daniel A; Hatfull, Graham F

    2016-08-01

    More than 180 individual phages infecting hosts in the phylum Actinobacteria have been sequenced and grouped into Cluster A because of their similar overall nucleotide sequences and genome architectures. These Cluster A phages are either temperate or derivatives of temperate parents, and most have an integration cassette near the centre of the genome containing an integrase gene and attP. However, about 20% of the phages lack an integration cassette, which is replaced by a 1.4 kbp segment with predicted partitioning functions, including plasmid-like parA and parB genes. Phage RedRock forms stable lysogens in Mycobacterium smegmatis in which the prophage replicates at 2.4 copies/chromosome and the partitioning system confers prophage maintenance. The parAB genes are expressed upon RedRock infection of M. smegmatis, but are downregulated once lysogeny is established by binding of RedRock ParB to parS-L, one of two centromere-like sites flanking the parAB genes. The RedRock parS-L and parS-R sites are composed of eight directly repeated copies of an 8 bp motif that is recognized by ParB. The actinobacteriophage parABS cassettes span considerable sequence diversity and specificity, providing a suite of tools for use in mycobacterial genetics. © 2016 John Wiley & Sons Ltd.

  13. Structures of actin-like ParM filaments show architecture of plasmid-segregating spindles.

    PubMed

    Bharat, Tanmay A M; Murshudov, Garib N; Sachse, Carsten; Löwe, Jan

    2015-07-02

    Active segregation of Escherichia coli low-copy-number plasmid R1 involves formation of a bipolar spindle made of left-handed double-helical actin-like ParM filaments. ParR links the filaments with centromeric parC plasmid DNA, while facilitating the addition of subunits to ParM filaments. Growing ParMRC spindles push sister plasmids to the cell poles. Here, using modern electron cryomicroscopy methods, we investigate the structures and arrangements of ParM filaments in vitro and in cells, revealing at near-atomic resolution how subunits and filaments come together to produce the simplest known mitotic machinery. To understand the mechanism of dynamic instability, we determine structures of ParM filaments in different nucleotide states. The structure of filaments bound to the ATP analogue AMPPNP is determined at 4.3 Å resolution and refined. The ParM filament structure shows strong longitudinal interfaces and weaker lateral interactions. Also using electron cryomicroscopy, we reconstruct ParM doublets forming antiparallel spindles. Finally, with whole-cell electron cryotomography, we show that doublets are abundant in bacterial cells containing low-copy-number plasmids with the ParMRC locus, leading to an asynchronous model of R1 plasmid segregation.

  14. Urokinase type plasminogen activator receptor (uPAR) as a new therapeutic target in cancer

    PubMed Central

    Montuori, Nunzia; Pesapane, Ada; Rossi, Francesca W; Giudice, Valentina; De Paulis, Amato; Selleri, Carmine; Ragno, Pia

    2016-01-01

    The urokinase (uPA)-type plasminogen activator receptor (uPAR) is a GPI-anchored receptor that focuses urokinase (uPA) proteolytic activity on the cell surface. uPAR also regulates cell adhesion, migration and proliferation, protects from apoptosis and contributes to epithelial mesenchymal transition (EMT), independently of uPA enzymatic activity. Indeed, uPAR interacts with beta1, beta2 and beta3 integrins, thus regulating their activities. uPAR cross-talks with receptor tyrosine kinases through integrins and regulates cancer cell dormancy, proliferation and angiogenesis. Moreover, uPAR mediates uPA-dependent cell migration and chemotaxis induced by fMet-Leu-Phe (fMLF), through its association with fMLF-receptors (fMLF-Rs). Further, uPAR is an adhesion receptor because it binds vitronectin (VN), a component of provisional extracellular matrix. High uPAR expression predicts for more aggressive disease in several cancer types for its ability to increase invasion and metastasis. In fact, uPAR has been hypothesized to be the link between tumor cell dormancy and proliferation that usually precedes the onset of metastasis. Thus, inhibiting uPAR could be a feasible approach to affect tumor growth and metastasis. Here, we review the more recent advances in the development of uPAR-targeted anti-cancer therapeutic agents suitable for further optimization or ready for the evaluation in early clinical trials. PMID:27896223

  15. PAR-1 contributes to the innate immune response during viral infection

    PubMed Central

    Antoniak, Silvio; Owens, A. Phillip; Baunacke, Martin; Williams, Julie C.; Lee, Rebecca D.; Weithäuser, Alice; Sheridan, Patricia A.; Malz, Ronny; Luyendyk, James P.; Esserman, Denise A.; Trejo, JoAnn; Kirchhofer, Daniel; Blaxall, Burns C.; Pawlinski, Rafal; Beck, Melinda A.; Rauch, Ursula; Mackman, Nigel

    2013-01-01

    Coagulation is a host defense system that limits the spread of pathogens. Coagulation proteases, such as thrombin, also activate cells by cleaving PARs. In this study, we analyzed the role of PAR-1 in coxsackievirus B3–induced (CVB3-induced) myocarditis and influenza A infection. CVB3-infected Par1–/– mice expressed reduced levels of IFN-β and CXCL10 during the early phase of infection compared with Par1+/+ mice that resulted in higher viral loads and cardiac injury at day 8 after infection. Inhibition of either tissue factor or thrombin in WT mice also significantly increased CVB3 levels in the heart and cardiac injury compared with controls. BM transplantation experiments demonstrated that PAR-1 in nonhematopoietic cells protected mice from CVB3 infection. Transgenic mice overexpressing PAR-1 in cardiomyocytes had reduced CVB3-induced myocarditis. We found that cooperative signaling between PAR-1 and TLR3 in mouse cardiac fibroblasts enhanced activation of p38 and induction of IFN-β and CXCL10 expression. Par1–/– mice also had decreased CXCL10 expression and increased viral levels in the lung after influenza A infection compared with Par1+/+ mice. Our results indicate that the tissue factor/thrombin/PAR-1 pathway enhances IFN-β expression and contributes to the innate immune response during single-stranded RNA viral infection. PMID:23391721

  16. Microscopie en champ proche par réflexion

    NASA Astrophysics Data System (ADS)

    Spajer, M.; Courjon, D.; Sarayeddine, K.; Jalocha, A.; Vigoureux, J.-M.

    1991-01-01

    This communication presents two techniques for high resolution surface analysis. In the first one, the illumination beam is totally reflected under the object surface, which must be transparent. The evanescent wave confined on the surface is frustrated locally by a dielectric probe of nanometric dimension which scans the objetc. A horizontal resolution of 10 nm and a vertical one of 1 nm have been obtained. In the second one, more adapted to metallic objects, the surface is illuminated by the near-field of the stylus, in which the reflected beam is Partially launched. First results dealing with the characterization of the dielectric stylus are presented. Cette communication présente deux techniques permettant l'analyse de surface haute résolution. Dans la première, le faisceau d'éclairage est réfléchi totalement sous la surface de l'objet, nécessairement transparent. L'onde évanescente qui l'accompagne est frustrée localement par une pointe diélectrique de dimension nanométrique balayant la surface. Une résolution de 10 nm horizontalement et de 1nm verticalement a été obtenue. Dans la seconde, qui permet d'étudier un objet opaque, celui-ci est éclairé par le champ proche émis par la pointe, dans laquelle le faisceau réfléchi est partiellement réinjecté. Les premiers résultats concernant la caractérisation de la pointe sont présentés.

  17. Expression of Par3 polarity protein correlates with poor prognosis in ovarian cancer.

    PubMed

    Nakamura, Hiroe; Nagasaka, Kazunori; Kawana, Kei; Taguchi, Ayumi; Uehara, Yuriko; Yoshida, Mitsuyo; Sato, Masakazu; Nishida, Haruka; Fujimoto, Asaha; Inoue, Tomoko; Adachi, Katsuyuki; Nagamatsu, Takeshi; Arimoto, Takahide; Oda, Katsutoshi; Osuga, Yutaka; Fujii, Tomoyuki

    2016-11-17

    Previous studies have shown that the cell polarity protein partitioning defective 3 (Par3) plays an essential role in the formation of tight junctions and definition of apical-basal polarity. Aberrant function of this protein has been reported to be involved in epithelial-mesenchymal transition (EMT) and cancer invasion. The aim of this study was to examine the functional mechanism of Par3 in ovarian cancer. First, we investigated the association between Par3 expression level and survival of 50 ovarian cancer patients. Next, we conducted an in vitro analysis of ovarian cancer cell lines, focusing on the cell line JHOC5, to investigate Par3 function. To investigate the function of Par3 in invasion, the IL-6/STAT3 pathway was analyzed upon Par3 knockdown with siRNA. The effect of siRNA treatment was assessed by qPCR, ELISA, and western blotting. Invasiveness and cell proliferation following treatment with siRNA against Par3 were investigated using Matrigel chamber, wound healing, and cell proliferation assays. Expression array data for ovarian cancer patient samples revealed low Par3 expression was significantly associated with good prognosis. Univariate analysis of clinicopathological factors revealed significant association between high Par3 levels and peritoneal dissemination at the time of diagnosis. Knockdown of Par3 in JHOC5 cells suppressed cell invasiveness, migration, and cell proliferation with deregulation of IL-6/STAT3 activity. Taken together, these results suggest that Par3 expression is likely involved in ovarian cancer progression, especially in peritoneal metastasis. The underlying mechanism may be that Par3 modulates IL-6 /STAT3 signaling. Here, we propose that the expression of Par3 in ovarian cancer may control disease outcome.

  18. PAR1 is selectively over expressed in high grade breast cancer patients: a cohort study

    PubMed Central

    Hernández, Norma A; Correa, Elma; Avila, Esther P; Vela, Teresa A; Pérez, Víctor M

    2009-01-01

    Background The protease-activated receptor (PAR1) expression is correlated with the degree of invasiveness in cell lines. Nevertheless it has never been directed involved in breast cancer patients progression. The aim of this study was to determine whether PAR1 expression could be used as predictor of metastases and mortality. Methods In a cohort of patients with infiltrating ductal carcinoma studied longitudinally since 1996 and until 2007, PAR1 over-expression was assessed by immunoblotting, immunohistochemistry, and flow citometry. Chi-square and log rank tests were used to determine whether there was a statistical association between PAR1 overexpression and metastases, mortality, and survival. Multivariate analysis was performed including HER1, stage, ER and nodes status to evaluate PAR1 as an independent prognostic factor. Results Follow up was 95 months (range: 2–130 months). We assayed PAR1 in a cohort of patients composed of 136 patients; we found PAR1 expression assayed by immunoblotting was selectively associated with high grade patients (50 cases of the study cohort; P = 0.001). Twenty-nine of 50 (58%) patients overexpressed PAR1, and 23 of these (46%) developed metastases. HER1, stage, ER and PAR1 overexpression were robustly correlated (Cox regression, P = 0.002, P = 0.024 and P = 0.002 respectively). Twenty-one of the 50 patients (42%) expressed both receptors (PAR1 and HER1 P = 0.0004). We also found a statistically significant correlation between PAR1 overexpression and increased mortality (P = 0.0001) and development of metastases (P = 0.0009). Conclusion Our data suggest PAR1 overexpression may be involved in the development of metastases in breast cancer patient and is associated with undifferentiated cellular progression of the tumor. Further studies are needed to understand PAR1 mechanism of action and in a near future assay its potential use as risk factor for metastasis development in high grade breast cancer patients. PMID:19538737

  19. uPAR regulates bronchial epithelial repair in vitro and is elevated in asthmatic epithelium

    PubMed Central

    Nijmeh, Hala S; Brightling, Christopher E; Sayers, Ian

    2011-01-01

    Background The asthma-associated gene urokinase plasminogen activator receptor (uPAR) may be involved in epithelial repair and airway remodelling. These processes are not adequately targeted by existing asthma therapies. A fuller understanding of the pathways involved in remodelling may lead to development of new therapeutic opportunities. uPAR expression in the lung epithelium of normal subjects and patients with asthma was investigated and the contribution of uPAR to epithelial wound repair in vitro was studied using primary bronchial epithelial cells (NHBECs). Methods Bronchial biopsy sections from normal subjects and patients with asthma were immunostained for uPAR. NHBECs were used in a scratch wound model to investigate the contribution of the plasminogen pathway to repair. The pathway was targeted via blocking of the interaction between urokinase plasminogen activator (uPA) and uPAR and overexpression of uPAR. The rate of wound closure and activation of intracellular signalling pathways and matrix metalloproteinases (MMPs) were measured. Results uPAR expression was significantly increased in the bronchial epithelium of patients with asthma compared with controls. uPAR expression was increased during wound repair in monolayer and air-liquid interface-differentiated NHBEC models. Blocking the uPA–uPAR interaction led to attenuated wound repair via changes in Erk1/2, Akt and p38MAPK signalling. Cells engineered to have raised levels of uPAR showed attenuated repair via sequestration of uPA by soluble uPAR. Conclusions The uPAR pathway is required for efficient epithelial wound repair. Increased uPAR expression, as seen in the bronchial epithelium of patients with asthma, leads to attenuated wound repair which may contribute to the development and progression of airway remodelling in asthma. This pathway may therefore represent a potential novel therapeutic target for the treatment of asthma. PMID:22139533

  20. [Relationships of rice canopy PAR interception and light use efficiency to grain yield].

    PubMed

    Tang, Liang; Zhu, Xiang-Cheng; Cao, Meng-Ying; Cao, Wei-Xing; Zhu, Yan

    2012-05-01

    Taking two rice cultivars (Liangyoupeijiu and Wuxiangjing 14) with different plant types as test materials, a 2-year field experiment was conducted to study the relationships of rice canopy photosynthetically active radiation (PAR) interception and light use efficiency to grain yield under three planting densities and five nitrogen (N) application rates. From tillering to maturing stage, the average PAR reflectance in all treatments was 3.45%. The ratio of reflected PAR to the total loss of PAR from tillering to heading stage was 10.90%, which was significantly lower than that (22.06%) from heading to maturiting stage. The PAR conversion efficiency from tillering to maturing stage decreased with increasing planting density but increased with increasing nitrogen rate, and the conversion efficiency was significantly higher from tillering to heading than from heading to maturing stage. The PAR use efficiency from tillering to maturing stage increased with the increase of planting density and nitrogen application rate, and the average PAR use efficiency of Liangyoupeijiu (1.83 g x MJ(-1)) was significantly higher than that of Wuxiangjing 14 (1.42 g x MJ(-1)). Due to the longer growth period of Wuxiangjing 14, its incident PAR and intercepted PAR under midium and high planting densities were higher, as compared with Liangyoupeijiu. The grain yield was significantly positively correlated with the canopy PAR interceptance and use efficiency at different growth stages, but less correlated with the PAR conversion efficiency. To increase the canopy PAR use efficiency and conversion efficiency on the basis of maintaining higher PAR interception rate could be an effective way to increase rice yield.

  1. Par-4-mediated recruitment of Amida to the actin cytoskeleton leads to the induction of apoptosis

    SciTech Connect

    Boosen, Meike; Vetterkind, Susanne; Koplin, Ansgar; Illenberger, Susanne; Preuss, Ute . E-mail: u.preuss@uni-bonn.de

    2005-12-10

    Par-4 (prostate apoptosis response-4) sensitizes cells to apoptotic stimuli, but the exact mechanisms are still poorly understood. Using Par-4 as bait in a yeast two-hybrid screen, we identified Amida as a novel interaction partner, a ubiquitously expressed protein which has been suggested to be involved in apoptotic processes. Complex formation of Par-4 and Amida occurs in vitro and in vivo and is mediated via the C-termini of both proteins, involving the leucine zipper of Par-4. Amida resides mainly in the nucleus but displays nucleo-cytoplasmic shuttling in heterokaryons. Upon coexpression with Par-4 in REF52.2 cells, Amida translocates to the cytoplasm and is recruited to actin filaments by Par-4, resulting in enhanced induction of apoptosis. The synergistic effect of Amida/Par-4 complexes on the induction of apoptosis is abrogated when either Amida/Par-4 complex formation or association of these complexes with the actin cytoskeleton is impaired, indicating that the Par-4-mediated relocation of Amida to the actin cytoskeleton is crucial for the pro-apoptotic function of Par-4/Amida complexes in REF52.2 cells. The latter results in enhanced phosphorylation of the regulatory light chain of myosin II (MLC) as has previously been shown for Par-4-mediated recruitment of DAP-like kinase (Dlk), suggesting that the recruitment of nuclear proteins involved in the regulation of apoptotic processes to the actin filament system by Par-4 represents a potent mechanism how Par-4 can trigger apoptosis.

  2. A systematic computation scheme of PAR-WIG cruising performance

    NASA Astrophysics Data System (ADS)

    Ando, Shigenori

    1993-08-01

    A systematic computation scheme is presented for PAR-WIG cruising performance, on a FORTRAN program. It is suitable for implementation on PCs. Effects of many parameters on the transportation efficiency are explored. Two concepts are presented in three views and artist impressions. One is a smallest single-crewman vehicle for experiment, sports, or pleasure. The other is a large vehicle for civil transportation. Both have twin hulls, which are quite suitable for installing a 'SMALL-TAIL-WIG' or 'WIG-let' to establish longitudinal attitude stability.

  3. BOREAS TE-12 Incoming PAR Through the Forest Canopy Data

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Papagno, Andrea (Editor); Walter-Shea, Elizabeth A.; Mesarch, Mark A.

    2000-01-01

    The Boreal Ecosystem-Atmospheric Study (BOREAS) TE-12 (Terrestrial Ecology) team collected photosynthetically active radiation (PAR) data sets in support of its efforts to characterize and interpret information on shoot geometry, leaf optical properties, leaf water potential, and leaf gas exchange. The data were collected at the Southern Study Area-Old Black Spruce (SSA-OBS) site from 04-Jul-1996 to 25-Jul-1996. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  4. Recalculation of shielding for the addition of a PAR

    SciTech Connect

    Moe, H.J.

    1988-08-01

    The shielding estimates for the Electron and Positron Linacs and the Booster Synchrotron, contained in the 1987 Conceptual Design Report (CDR) of the APS (ANL-87-15), have been reviewed and recalculated, along with newly initiated calculations of the required shielding for the addition of a Positron Accumulator Ring (PAR). Several new assumptions with respect to beam intensity, projected losses in the system, and assumed operational time have been incorporated into the calculations. Details of the previous calculations, which describe the methodology used, may be found in APS Light Source Note LS-90.

  5. David Kasner, MD, and the Road to Pars Plana Vitrectomy

    PubMed Central

    Blodi, Christopher F.

    2016-01-01

    David Kasner, MD (1927–2001), used his extensive dissections of eye bank eyes and experiences in teaching cataract surgery to resident physicians to realize that excision of vitreous when present in the anterior chamber of eyes undergoing cataract surgery was preferable to prior intraoperative procedures. Noting that eyes tolerated his maneuvers, he then performed planned subtotal open-sky vitrectomies; first on a traumatized eye in 1961, then on two eyes of patients with amyloidosis (1966–1967). The success of these operations was noted by others, most particularly Robert Machemer, MD. Kasner’s work directly led to further surgical developments, including closed pars plana vitrectomy. PMID:27660504

  6. Détention provisoire des jeunes femmes accusées d'avortement clandestin ou d'infanticide au Sénégal

    PubMed Central

    Soumah, Mohamed Maniboliot; Pemba, Liliane Flore

    2012-01-01

    Introduction L'activité sexuelle chez les jeunes les expose à un accroissement du risque de contracter des grossesses non désirées. Le recours à l'avortement clandestin avec son corollaire de complications peut entrainer le décès de la jeune femme. Avortement et infanticide sont interdits et sanctionnés par la loi sénégalaise. Comment ces jeunes femmes vivent-elles leur détention? Existe-il des alternatives à la détention pour éviter leur désocialisation? Méthodes Cette étude rétrospective portait sur la maison d'arrêt des femmes de Dakar située à Liberté 6, un quartier de Dakar. Nous avons procédé à des entretiens avec des femmes détenues à la maison d'arrêt des femmes de Dakar et suspectées d'infanticide ou d'avortement clandestin. Résultats Les femmes de notre échantillon ont une moyenne d’âge inférieure à 25 ans avec parmi elles une fille mineure de 16 ans. Nous avons trouvé 18,51% de femmes suspectées d'infanticide ou d'avortement. Dans notre étude 50% des femmes sont originaires de la périphérie et de la banlieue de Dakar et presque 44% proviennent des autres régions du pays. La durée moyenne de détention provisoire est de neuf mois. Conclusion Malgré leur qualification distincte dans le code pénal: l'infanticide est un crime et l'avortement un délit, les femmes suspectées d'avoir commis ces actes sont soumises à de longues détentions préventives. PMID:22937189

  7. Evaluation du potentiel radiosensibilisateur ou radioprotecteur/antioxydant de quelques composes selectionnes par dosimetrie par gel de polyacrylamide et dosimetre de Fricke, et utilisation de la filamentation par impulsion laser infrarouge fenitoseconde comme un nouveau et puissant faisceau pour la radiotherapie du cancer

    NASA Astrophysics Data System (ADS)

    Meesat, Ridthee

    In radiation treatment, a sufficiently high radiation dose must be delivered to the tissue volumes containing the tumor cells while the lowest possible dose should be deposited in surrounding healthy tissue. We developed an original approach that is fast and easy to implement for the early assessment of the efficiency of radiation sensitizers and protectors. In addition, we characterized a new femtosecond laser pulse irradiation technique. We are able to deposit a considerable dose with a very high dose rate inside a well-controlled macroscopic volume without deposition of energy in front or behind the target volume. The radioprotective efficiency was measured by irradiation of the Fricke solution incorporating a compound under study and measuring the corresponding production of ferric ions G(Fe3+). The production of ferric ions is most sensitive to the radical species produced in the radiolysis of water. We studied experimentally and simulated with a full Monte-Carlo computer code the radiation-induced chemistry of Fricke/cystamine solutions. Results clearly indicate that the protective effect of cystamine originates from its radical-capturing ability, which allows this compound to compete with the ferrous ions for the various free radicals - especially ·OH radicals and H· atoms - formed during irradiation of the surrounding water. The sensitizing capacity of radiation sensitizers was measured by irradiation of a polyacrylamide gel (PAG) dosimeter incorporating a compound under study and measuring the corresponding increase in the gradient between spin-spin relaxation rate (R2) and absorbed dose. We measured an irradiation energy-dependent increase in R 2-dose sensitivity for halogenated compounds or a decrease for radioprotectors. Finally, we studied a novel laser irradiation method called "filamentation". We showed that this phenomenon results in an unprecedented deposition of energy and the dose rate thus achieved exceeds by orders of magnitude values previously reported for the most intense clinical radiotherapy systems. Moreover, the length of the dose-free entrance region was adjusted by selecting the duration of femtosecond laser pulses. In addition, we provided evidence that the biological damage caused by this irradiation was similar to other ionizing radiation sources. Keywords: Radiotherapy, radiosensitization, radioprotection, laser, filamentation, dosimetry.

  8. Cavernome portal chez l’enfant révélé par une hémorragie digestive: à propos d’un cas

    PubMed Central

    Basse, Idrissa; Guèye, Ndéye Rama Diagne; Diop, Dina Cyrienne Obambi; Diawara, Ndiémé Ndiaye; Ba, Aïssatou; Seck, Ndiogou; Thiongane, Aliou; Ba, Abou; Ndongo, Aliou Abdoulaye; Fall, Amadou Lamine; Boiro, Djibril; Thiam, Lamine; Mbengue, Marie

    2016-01-01

    Le cavernome portal est une anomalie vasculaire veineuse caractérisée par la formation d’un réseau de veines dont le calibre est augmenté et au sein duquel chemine un sang portal. Il est la conséquence d’une occlusion thrombotique et toujours chronique du système porte extra hépatique. C’est une des causes les plus fréquentes d’hypertension portale chez l’enfant. Ainsi sa gravité est surtout liée au risque important d’hémorragies digestives. Très peu de cas ont été décrits dans la littérature notamment africaine. Nous rapportons l’observation d’un garçon de 4 ans reçu pour hématémèse de grande abondance, méléna et vertiges qui présentait à l’examen un syndrome anémique. Le bilan biologique retrouvait une anémie sévère hypochrome microcytaire avec une fonction rénale ethépatique normale. L’endoscopie oeso-gastrique montrait des varices oesophagiennes grade III avec signes rouges. L’échographie abdominale mit en évidence un lacis veineux portal en faveur d’un cavernome. Le scanner abdominal confirmait le cavernome porte avec syndrome d’hypertension portale et anomalie vasculaire à type d’abouchement ectopique de la veine splénique au tronc formé par la veine gonadique et la veine mésentérique inférieure. Sur le plan thérapeutique une transfusion sanguine a été effectuée et il a été mis sous bétabloquant. Le cavernome portal peut être une complication majeure de malformations vasculaires souvent méconnues. Il faut y penser devant toute hémorragie digestive chez l’enfant. La prise en charge doit être urgente et adaptée pour éviter une évolution fatale. PMID:28292120

  9. Ensemble des troubles causés par l'alcoolisation fœtale : lignes directrices canadiennes concernant le diagnostic

    PubMed Central

    Chudley, Albert E.; Conry, Julianne; Cook, Jocelynn L.; Loock, Christine; Rosales, Ted; LeBlanc, Nicole

    2005-01-01

    Résumé LE DIAGNOSTIC DE L'ENSEMBLE DES TROUBLES CAUSÉS PAR L'ALCOOLISATION FÉTALE (ETCAF) est complexe et l'élaboration de lignes directrices concernant le diagnostic est justifiée. Un sous-comité du Comité consultatif national de l'Agence de santé publique du Canada sur l'Ensemble des troubles causés par l'alcoolisation fœtale a examiné, analysé et intégré les méthodes de diagnostic actuelles afin de parvenir à une méthode de diagnostic normalisée faisant le consensus au Canada. L'objet du présent document est d'examiner et de clarifier l'utilisation des systèmes de diagnostic actuels et de formuler des recommandations quant à leur application pour le diagnostic des déficiences liées à l'ETCAF chez des individus de tous les âges. Les lignes directrices sont fondées sur un vaste consensus de praticiens et d'autres intervenants spécialisés dans le domaine. Ces lignes directrices ont été organisées en sept catégories, soit le dépistage et l'orientation vers les spécialistes, l'examen physique et le diagnostic différentiel, l'évaluation du comportement neurologique, le traitement et le suivi, les antécédents de consommation d'alcool de la mère pendant la grossesse, les critères du diagnostic pour le syndrome d'alcoolisation fœtale (SAF), SAF partiel et troubles neurologiques du développement liés à l'alcool, l'harmonisation de l'Institute of Medicine (IOM) et des approches du Code diagnostique à 4 chiffres. Le diagnostic exige une évaluation complète des antécédents, ainsi qu'un examen physique et du comportement neurologique, tout en recourant à une approche multidisciplinaire. Les présentes lignes directrices pour le diagnostic du syndrome d'alcoolisation fœtale et des déficiences qui y sont associées sont les premières à avoir été élaborées au Canada et elles sont fondées sur la consultation d'un grand éventail de spécialistes du diagnostic.

  10. Mutations in the gyrB, parC, and parE genes of quinolone-resistant isolates and mutants of Edwardsiella tarda.

    PubMed

    Kim, Myoung Sug; Jun, Lyu Jin; Shin, Soon Bum; Park, Myoung Ae; Jung, Sung Hee; Kim, Kwangil; Moon, Kyung Ho; Jeong, Hyun Do

    2010-12-01

    The full length genes gyrB (2,415 bp), parC (2,277 bp), and parE (1,896 bp) in Edwardsiella tarda were cloned by PCR with degenerate primers based on the sequence of the respective quinolone resistance-determining region (QRDR), followed by elongation of 5' and 3' ends using cassette ligation-mediated PCR (CLMP). Analysis of the cloned genes revealed open reading frames (ORFs) encoding proteins of 804 (GyrB), 758 (ParC), and 631 (ParE) amino acids with conserved gyrase/topoisomerase features and motifs important for enzymatic function. The ORFs were preceded by putative promoters, ribosome binding sites, and inverted repeats with the potential to form cruciform structures for binding of DNA-binding proteins. When comparing the deduced amino acid sequences of E. tarda GyrB, ParC, and ParE with those of the corresponding proteins in other bacteria, they were found to be most closely related to Escherichia coli GyrB (87.6% identity), Klebsiella pneumoniae ParC (78.8% identity) and Salmonella typhimurium ParE (89.5% identity), respectively. The two topoisomerase genes, parC and parE, were found to be contiguous on the E. tarda chromosome. All 18 quinoloneresistant isolates obtained from Korea thus far did not contain subunit alternations apart from a substitution in GyrA (Ser83→Arg). However, an alteration in the QRDR of ParC (Ser84→Ile) following an amino acid substitution in GyrA (Asp87→Gly) was detected in E. tarda mutants selected in vitro at 8 microng/ml ciprofloxacin (CIP). A mutant with a GyrB (Ser464→Leu) and GyrA (Asp87→Gly) substitution did not show a significant increase in the minimum inhibitory concentration (MIC) of CIP. None of the in vitro mutants exhibited mutations in parE. Thus, gyrA and parC should be considered to be the primary and secondary targets, respectively, of quinolones in E. tarda.

  11. The Par3 polarity protein is an exocyst receptor essential for mammary cell survival

    PubMed Central

    Ahmed, Syed Mukhtar; Macara, Ian G.

    2017-01-01

    The exocyst is an essential component of the secretory pathway required for delivery of basolateral proteins to the plasma membranes of epithelial cells. Delivery occurs adjacent to tight junctions (TJ), suggesting that it recognizes a receptor at this location. However, no such receptor has been identified. The Par3 polarity protein associates with TJs but has no known function in membrane traffic. We now show that, unexpectedly, Par3 is essential for mammary cell survival. Par3 silencing causes apoptosis, triggered by phosphoinositide trisphosphate depletion and decreased Akt phosphorylation, resulting from failure of the exocyst to deliver basolateral proteins to the cortex. A small region of PAR3 binds directly to Exo70 and is sufficient for exocyst docking, membrane-protein delivery and cell survival. PAR3 lacking this domain can associate with the cortex but cannot support exocyst function. We conclude that Par3 is the long-sought exocyst receptor required for targeted membrane-protein delivery. PMID:28358000

  12. The Scribble and Par complexes in polarity and migration: friends or foes?

    PubMed

    Humbert, Patrick O; Dow, Lukas E; Russell, Sarah M

    2006-12-01

    The Par complex [consisting of Bazooka (also called Par3), Par6 and aPKC] is a well-described regulator of cell polarity whose role in many aspects of cell morphogenesis is under intense investigation. Recently, another set of proteins known as the Scribble complex (consisting of Scribble, Discs large and Lethal giant larvae) has also been shown to be important in polarity regulation in several settings. Here, we describe the current status of Scribble in polarity and review evidence from various model systems that indicates an essential but context-dependent role for the Scribble and Par complexes in directed cell migration. Based on the known interactions of Scribble and Par complexes with each other and with other signalling pathways, we propose models by which Par and Scribble might interact to regulate cell migration.

  13. Estimating Photosynthetically Available Radiation (PAR) at the Earth's surface from satellite observations

    NASA Technical Reports Server (NTRS)

    Frouin, Robert

    1993-01-01

    Current satellite algorithms to estimate photosynthetically available radiation (PAR) at the earth' s surface are reviewed. PAR is deduced either from an insolation estimate or obtained directly from top-of-atmosphere solar radiances. The characteristics of both approaches are contrasted and typical results are presented. The inaccuracies reported, about 10 percent and 6 percent on daily and monthly time scales, respectively, are useful to model oceanic and terrestrial primary productivity. At those time scales variability due to clouds in the ratio of PAR and insolation is reduced, making it possible to deduce PAR directly from insolation climatologies (satellite or other) that are currently available or being produced. Improvements, however, are needed in conditions of broken cloudiness and over ice/snow. If not addressed properly, calibration/validation issues may prevent quantitative use of the PAR estimates in studies of climatic change. The prospects are good for an accurate, long-term climatology of PAR over the globe.

  14. Fluoroquinolone Resistance Mutations in the parC, parE, and gyrA Genes of Clinical Isolates of Viridans Group Streptococci

    PubMed Central

    González, Irene; Georgiou, Marios; Alcaide, Fernando; Balas, Delia; Liñares, Josefina; de la Campa, Adela G.

    1998-01-01

    The nucleotide sequences of the quinolone resistance-determining regions (QRDRs) of the parC and gyrA genes from seven ciprofloxacin-resistant (Cpr) isolates of viridans group streptococci (two high-level Cpr Streptococcus oralis and five low-level Cpr Streptococcus mitis isolates) were determined and compared with those obtained from susceptible isolates. The nucleotide sequences of the QRDRs of the parE and gyrB genes from the five low-level Cpr S. mitis isolates and from the NCTC 12261 type strain were also analyzed. Four of these low-level Cpr isolates had changes affecting the subunits of DNA topoisomerase IV: three in Ser-79 (to Phe or Ile) of ParC and one in ParE at a position not previously described to be involved in quinolone resistance (Pro-424). One isolate did not show any mutation. The two high-level Cpr S. oralis isolates showed mutations affecting equivalent residue positions of ParC and GyrA, namely, Ser-79 to Phe and Ser-81 to Phe or Tyr, respectively. The parC mutations were able to transform Streptococcus pneumoniae to ciprofloxacin resistance, while the gyrA mutations transformed S. pneumoniae only when mutations in parC were present. These results suggest that DNA topoisomerase IV is a primary target of ciprofloxacin in viridans group streptococci, DNA gyrase being a secondary target. PMID:9797205

  15. Fluoroquinolone resistance mutations in the parC, parE, and gyrA genes of clinical isolates of viridans group streptococci.

    PubMed

    González, I; Georgiou, M; Alcaide, F; Balas, D; Liñares, J; de la Campa, A G

    1998-11-01

    The nucleotide sequences of the quinolone resistance-determining regions (QRDRs) of the parC and gyrA genes from seven ciprofloxacin-resistant (Cpr) isolates of viridans group streptococci (two high-level Cpr Streptococcus oralis and five low-level Cpr Streptococcus mitis isolates) were determined and compared with those obtained from susceptible isolates. The nucleotide sequences of the QRDRs of the parE and gyrB genes from the five low-level Cpr S. mitis isolates and from the NCTC 12261 type strain were also analyzed. Four of these low-level Cpr isolates had changes affecting the subunits of DNA topoisomerase IV: three in Ser-79 (to Phe or Ile) of ParC and one in ParE at a position not previously described to be involved in quinolone resistance (Pro-424). One isolate did not show any mutation. The two high-level Cpr S. oralis isolates showed mutations affecting equivalent residue positions of ParC and GyrA, namely, Ser-79 to Phe and Ser-81 to Phe or Tyr, respectively. The parC mutations were able to transform Streptococcus pneumoniae to ciprofloxacin resistance, while the gyrA mutations transformed S. pneumoniae only when mutations in parC were present. These results suggest that DNA topoisomerase IV is a primary target of ciprofloxacin in viridans group streptococci, DNA gyrase being a secondary target.

  16. La distribution radiale de L'UO 2 dans la phase vitreuse dans des crayons D'UO 2-SiO 2 obtenus par injection dans des moules de cuivre

    NASA Astrophysics Data System (ADS)

    Goran, Maria

    1980-11-01

    Une méthode d'analyse rationnelle a été mise au point qui doit permettre de déterminer la quantité de phase cristalline UO 2 dans les masses vitrocéramiques et la variation de cette quantité en fonction de la distance á la surface de l'échantillon. Cette méthode a été utilisée pour déterminer la distribution radiale de l'UO 2 dans la phase vitreuse dans des aiguilles d'UO 2-SiO 2 obtenus par injection dans des moules de cuivre. La teneur en d'UO 2 dans la phase vitreuse présente une variation très importante dans une couche périphérique de l'échantillon de 60 μm d'épaisseur environ; la valeur moyenne dans cette couche dépasse d'un ordre de grandeur la valeur moyenne dans tout la section. Cette région correspond á une vitesse de refroidissement qui dépasse 10 6°C/s.

  17. Cathepsin S Causes Inflammatory Pain via Biased Agonism of PAR2 and TRPV4*

    PubMed Central

    Zhao, Peishen; Lieu, TinaMarie; Barlow, Nicholas; Metcalf, Matthew; Veldhuis, Nicholas A.; Jensen, Dane D.; Kocan, Martina; Sostegni, Silvia; Haerteis, Silke; Baraznenok, Vera; Henderson, Ian; Lindström, Erik; Guerrero-Alba, Raquel; Valdez-Morales, Eduardo E.; Liedtke, Wolfgang; McIntyre, Peter; Vanner, Stephen J.; Korbmacher, Christoph; Bunnett, Nigel W.

    2014-01-01

    Serine proteases such as trypsin and mast cell tryptase cleave protease-activated receptor-2 (PAR2) at R36↓S37 and reveal a tethered ligand that excites nociceptors, causing neurogenic inflammation and pain. Whether proteases that cleave PAR2 at distinct sites are biased agonists that also induce inflammation and pain is unexplored. Cathepsin S (Cat-S) is a lysosomal cysteine protease of antigen-presenting cells that is secreted during inflammation and which retains activity at extracellular pH. We observed that Cat-S cleaved PAR2 at E56↓T57, which removed the canonical tethered ligand and prevented trypsin activation. In HEK and KNRK cell lines and in nociceptive neurons of mouse dorsal root ganglia, Cat-S and a decapeptide mimicking the Cat-S-revealed tethered ligand-stimulated PAR2 coupling to Gαs and formation of cAMP. In contrast to trypsin, Cat-S did not mobilize intracellular Ca2+, activate ERK1/2, recruit β-arrestins, or induce PAR2 endocytosis. Cat-S caused PAR2-dependent activation of transient receptor potential vanilloid 4 (TRPV4) in Xenopus laevis oocytes, HEK cells and nociceptive neurons, and stimulated neuronal hyperexcitability by adenylyl cyclase and protein kinase A-dependent mechanisms. Intraplantar injection of Cat-S caused inflammation and hyperalgesia in mice that was attenuated by PAR2 or TRPV4 deletion and adenylyl cyclase inhibition. Cat-S and PAR2 antagonists suppressed formalin-induced inflammation and pain, which implicates endogenous Cat-S and PAR2 in inflammatory pain. Our results identify Cat-S as a biased agonist of PAR2 that causes PAR2- and TRPV4-dependent inflammation and pain. They expand the role of PAR2 as a mediator of protease-driven inflammatory pain. PMID:25118282

  18. Cathepsin S causes inflammatory pain via biased agonism of PAR2 and TRPV4.

    PubMed

    Zhao, Peishen; Lieu, TinaMarie; Barlow, Nicholas; Metcalf, Matthew; Veldhuis, Nicholas A; Jensen, Dane D; Kocan, Martina; Sostegni, Silvia; Haerteis, Silke; Baraznenok, Vera; Henderson, Ian; Lindström, Erik; Guerrero-Alba, Raquel; Valdez-Morales, Eduardo E; Liedtke, Wolfgang; McIntyre, Peter; Vanner, Stephen J; Korbmacher, Christoph; Bunnett, Nigel W

    2014-09-26

    Serine proteases such as trypsin and mast cell tryptase cleave protease-activated receptor-2 (PAR2) at R(36)↓S(37) and reveal a tethered ligand that excites nociceptors, causing neurogenic inflammation and pain. Whether proteases that cleave PAR2 at distinct sites are biased agonists that also induce inflammation and pain is unexplored. Cathepsin S (Cat-S) is a lysosomal cysteine protease of antigen-presenting cells that is secreted during inflammation and which retains activity at extracellular pH. We observed that Cat-S cleaved PAR2 at E(56)↓T(57), which removed the canonical tethered ligand and prevented trypsin activation. In HEK and KNRK cell lines and in nociceptive neurons of mouse dorsal root ganglia, Cat-S and a decapeptide mimicking the Cat-S-revealed tethered ligand-stimulated PAR2 coupling to Gαs and formation of cAMP. In contrast to trypsin, Cat-S did not mobilize intracellular Ca(2+), activate ERK1/2, recruit β-arrestins, or induce PAR2 endocytosis. Cat-S caused PAR2-dependent activation of transient receptor potential vanilloid 4 (TRPV4) in Xenopus laevis oocytes, HEK cells and nociceptive neurons, and stimulated neuronal hyperexcitability by adenylyl cyclase and protein kinase A-dependent mechanisms. Intraplantar injection of Cat-S caused inflammation and hyperalgesia in mice that was attenuated by PAR2 or TRPV4 deletion and adenylyl cyclase inhibition. Cat-S and PAR2 antagonists suppressed formalin-induced inflammation and pain, which implicates endogenous Cat-S and PAR2 in inflammatory pain. Our results identify Cat-S as a biased agonist of PAR2 that causes PAR2- and TRPV4-dependent inflammation and pain. They expand the role of PAR2 as a mediator of protease-driven inflammatory pain. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. The PARA-suite: PAR-CLIP specific sequence read simulation and processing

    PubMed Central

    Kloetgen, Andreas; Borkhardt, Arndt; Hoell, Jessica I.

    2016-01-01

    Background Next-generation sequencing technologies have profoundly impacted biology over recent years. Experimental protocols, such as photoactivatable ribonucleoside-enhanced cross-linking and immunoprecipitation (PAR-CLIP), which identifies protein–RNA interactions on a genome-wide scale, commonly employ deep sequencing. With PAR-CLIP, the incorporation of photoactivatable nucleosides into nascent transcripts leads to high rates of specific nucleotide conversions during reverse transcription. So far, the specific properties of PAR-CLIP-derived sequencing reads have not been assessed in depth. Methods We here compared PAR-CLIP sequencing reads to regular transcriptome sequencing reads (RNA-Seq) to identify distinctive properties that are relevant for reference-based read alignment of PAR-CLIP datasets. We developed a set of freely available tools for PAR-CLIP data analysis, called the PAR-CLIP analyzer suite (PARA-suite). The PARA-suite includes error model inference, PAR-CLIP read simulation based on PAR-CLIP specific properties, a full read alignment pipeline with a modified Burrows–Wheeler Aligner algorithm and CLIP read clustering for binding site detection. Results We show that differences in the error profiles of PAR-CLIP reads relative to regular transcriptome sequencing reads (RNA-Seq) make a distinct processing advantageous. We examine the alignment accuracy of commonly applied read aligners on 10 simulated PAR-CLIP datasets using different parameter settings and identified the most accurate setup among those read aligners. We demonstrate the performance of the PARA-suite in conjunction with different binding site detection algorithms on several real PAR-CLIP and HITS-CLIP datasets. Our processing pipeline allowed the improvement of both alignment and binding site detection accuracy. Availability The PARA-suite toolkit and the PARA-suite aligner are available at https://github.com/akloetgen/PARA-suite and https

  20. Participation of the urokinase-type plasminogen activator receptor (uPAR) in neutrophil transendothelial migration.

    PubMed

    Pliyev, Boris K; Antonova, Olga A; Menshikov, Mikhail

    2011-05-01

    The mechanisms underlying migration of neutrophils across endothelium are not completely understood. The urokinase-type plasminogen activator receptor (uPAR) plays a key role in neutrophil adhesion and migration. In the present study, we addressed whether uPAR regulates neutrophil transendothelial migration. We first showed that siRNA-mediated knockdown of uPAR in human umbilical vein endothelial cells (HUVECs) did not affect neutrophil migration across HUVEC monolayers indicating that endothelial uPAR does not regulate neutrophil transmigration. In contrast, the transmigration was significantly inhibited by Fab' fragment of anti-uPAR monoclonal antibody and proteolytically inactive urokinase (uPA), whereas inhibition of proteolytical activity of endogenous uPA (with amiloride or plasminogen activator inhibitor-1) did not affect the transmigration. Both the anti-uPAR Fab' fragment and proteolytically inactive uPA did not exert significant effects upon the transmigration conducted in the presence of F(ab')(2) fragment of blocking antibody to integrin Mac-1 indicating that uPAR regulates Mac-1-dependent transmigration. Mac-1-dependent, but not Mac-1-independent, transmigration was significantly reduced in the presence of N-acetyl-d-glucosamine and d-mannose, the saccharides that disrupt uPAR/Mac-1 association, but was unaffected in the presence of control saccharides (d-sorbitol and sucrose). We conclude that physical association of uPAR with Mac-1 mediates the regulatory effect of uPAR over the transmigration. Finally, we provide evidence that the functional cooperation between uPAR and Mac-1 is essential at both adhesion and diapedesis steps of neutrophil migration across endothelium. Thus, uPAR expressed on neutrophil plasma membrane regulates transendothelial migration independently of uPA proteolytical activity and acting as a cofactor for integrin Mac-1.

  1. Evaluation des résultats après traitement des lésions intra épithéliales du col utérin par la cryothérapie: étude préliminaire au Centre Hospitalier Universitaire de Yaoundé: A propos de 21 cas

    PubMed Central

    Ndoua, Claude Cyrille Noa; Tebeu, Pierre Marie; Kemfang, Jean Dupont; Kasia, Jean Marie

    2015-01-01

    Nous rapportons les résultats d'une série de 21 cas de prise en charge par cryothérapie de lésions intra-épithéliales cervicales au Centre Hospitalier et Universitaire (CHU) de Yaoundé. Notre objectif principal était d’évaluer les résultats préliminaires de la prise en charge des lésions précancéreuses éligibles pour la cryothérapie. Il s'agissait d'une étude transversale descriptive qui s'est étalée sur 24 mois. Etaient inclus dans l’étude toutes les femmes traitées par cryothérapie. Nous avons exclu les patientes traitées par une autre méthode, les patientes perdues de vue et les dossiers incomplets. Le statut cervical a été déterminé à 6 semaines, 6 mois et 12 mois. Les complications précoces et tardives ont également été répertoriées. Au total 95.2% des lésions étaient cicatrisées à 6 semaines. A 6 mois, toutes les lésions avaient disparu et au 12ème mois, la guérison était effective chez 95.2% des patientes. Les saignements et l'hydrorrhée étaient les principales complications tardives avec des fréquences respectives de 66.7% et 95.2%. Aucun cas de sténose cervicale n'a été répertorié. La cryothérapie peut être utilisée comme méthode de traitement pour des lésions précancéreuses du col. PMID:26140068

  2. The two Cis-acting sites, parS1 and oriC1, contribute to the longitudinal organisation of Vibrio cholerae chromosome I.

    PubMed

    David, Ariane; Demarre, Gaëlle; Muresan, Leila; Paly, Evelyne; Barre, François-Xavier; Possoz, Christophe

    2014-07-01

    The segregation of bacterial chromosomes follows a precise choreography of spatial organisation. It is initiated by the bipolar migration of the sister copies of the replication origin (ori). Most bacterial chromosomes contain a partition system (Par) with parS sites in close proximity to ori that contribute to the active mobilisation of the ori region towards the old pole. This is thought to result in a longitudinal chromosomal arrangement within the cell. In this study, we followed the duplication frequency and the cellular position of 19 Vibrio cholerae genome loci as a function of cell length. The genome of V. cholerae is divided between two chromosomes, chromosome I and II, which both contain a Par system. The ori region of chromosome I (oriI) is tethered to the old pole, whereas the ori region of chromosome II is found at midcell. Nevertheless, we found that both chromosomes adopted a longitudinal organisation. Chromosome I extended over the entire cell while chromosome II extended over the younger cell half. We further demonstrate that displacing parS sites away from the oriI region rotates the bulk of chromosome I. The only exception was the region where replication terminates, which still localised to the septum. However, the longitudinal arrangement of chromosome I persisted in Par mutants and, as was reported earlier, the ori region still localised towards the old pole. Finally, we show that the Par-independent longitudinal organisation and oriI polarity were perturbed by the introduction of a second origin. Taken together, these results suggest that the Par system is the major contributor to the longitudinal organisation of chromosome I but that the replication program also influences the arrangement of bacterial chromosomes.

  3. The polarity protein Par3 regulates APP trafficking and processing through the endocytic adaptor protein Numb.

    PubMed

    Sun, Miao; Asghar, Suwaiba Z; Zhang, Huaye

    2016-09-01

    The processing of amyloid precursor protein (APP) into β-amyloid peptide (Aβ) is a key step in the pathogenesis of Alzheimer's disease (AD), and trafficking dysregulations of APP and its secretases contribute significantly to altered APP processing. Here we show that the cell polarity protein Par3 plays an important role in APP processing and trafficking. We found that the expression of full length Par3 is significantly decreased in AD patients. Overexpression of Par3 promotes non-amyloidogenic APP processing, while depletion of Par3 induces intracellular accumulation of Aβ. We further show that Par3 functions by regulating APP trafficking. Loss of Par3 decreases surface expression of APP by targeting APP to the late endosome/lysosome pathway. Finally, we show that the effects of Par3 are mediated through the endocytic adaptor protein Numb, and Par3 functions by interfering with the interaction between Numb and APP. Together, our studies show a novel role for Par3 in regulating APP processing and trafficking. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. The polarity protein Par3 regulates APP trafficking and processing through the endocytic adaptor protein Numb

    PubMed Central

    Sun, Miao; Asghar, Suwaiba Z.; Zhang, Huaye

    2016-01-01

    The processing of amyloid precursor protein (APP) into β-amyloid peptide (Aβ) is a key step in the pathogenesis of Alzheimer’s disease (AD), and trafficking dysregulations of APP and its secretases contribute significantly to altered APP processing. Here we show that the cell polarity protein Par3 plays an important role in APP processing and trafficking. We found that the expression of full length Par3 is significantly decreased in AD patients. Overexpression of Par3 promotes non-amyloidogenic APP processing while depletion of Par3 induces intracellular accumulation of Aβ. We further show that Par3 functions by regulating APP trafficking. Loss of Par3 decreases surface expression of APP by targeting APP to the late endosome/lysosome pathway. Finally, we show that the effects of Par3 are mediated through the endocytic adaptor protein Numb, and Par3 functions by interfering with the interaction between Numb and APP. Together, our studies show a novel role for Par3 in regulating APP processing and trafficking. PMID:27072891

  5. A Desired PAR-Achieving Precoder Design for Multiuser MIMO OFDM Based on Concentration of Measure

    NASA Astrophysics Data System (ADS)

    Cha, Hyun-Su; Kim, Dong Ku

    2017-03-01

    For multi-user multiple-input and multiple-output (MIMO) wireless communications in orthogonal frequency di- vision multiplexing systems, we propose a MIMO precoding scheme providing a desired peak-to-average power ratio (PAR) at the minimum cost that is defined as received SNR degradation. By taking advantage of the concentration of measure, we formulate a convex problem with constraint on the desired PAR. Consequently, the proposed scheme almost exactly achieves the desired PAR on average, and asymptotically attains the desired PAR at the 0.001 point of its complementary cumulative distribution function, as the number of subcarriers increases.

  6. Tryptase-PAR2 axis in experimental autoimmune prostatitis, a model for chronic pelvic pain syndrome.

    PubMed

    Roman, Kenny; Done, Joseph D; Schaeffer, Anthony J; Murphy, Stephen F; Thumbikat, Praveen

    2014-07-01

    Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) affects up to 15% of the male population and is characterized by pelvic pain. Mast cells are implicated in the murine experimental autoimmune prostatitis (EAP) model as key to chronic pelvic pain development. The mast cell mediator tryptase-β and its cognate receptor protease-activated receptor 2 (PAR2) are involved in mediating pain in other visceral disease models. Prostatic secretions and urines from CP/CPPS patients were examined for the presence of mast cell degranulation products. Tryptase-β and PAR2 expression were examined in murine EAP. Pelvic pain and inflammation were assessed in the presence or absence of PAR2 expression and upon PAR2 neutralization. Tryptase-β and carboxypeptidase A3 were elevated in CP/CPPS compared to healthy volunteers. Tryptase-β was capable of inducing pelvic pain and was increased in EAP along with its receptor PAR2. PAR2 was required for the development of chronic pelvic pain in EAP. PAR2 signaling in dorsal root ganglia led to extracellular signal-regulated kinase (ERK)1/2 phosphorylation and calcium influx. PAR2 neutralization using antibodies attenuated chronic pelvic pain in EAP. The tryptase-PAR2 axis is an important mediator of pelvic pain in EAP and may play a role in the pathogenesis of CP/CPPS.

  7. Cancer-Selective Apoptotic Effects of Extracellular and Intracellular Par-4

    PubMed Central

    Bhattarai, Tripti Shrestha; Rangnekar, Vivek M.

    2010-01-01

    Selectivity toward cancer cells is the most desirable element in cancer therapeutics. Par-4 is a cancer cell-selective pro-apoptotic protein that functions intracellularly in the cytoplasmic and nuclear compartments, as a tumor suppressor. Moreover, recent findings indicate that the Par-4 protein is secreted by cells, and extracellular Par-4 induces cancer cell-specific apoptosis by interaction with the cell-surface receptor GRP78. This review describes the mechanisms underlying the apoptotic effects of both extracellular and intracellular Par-4 acting via its effector domain SAC. PMID:20440265

  8. TRIM21 is a novel regulator of Par-4 in colon and pancreatic cancer cells

    PubMed Central

    Nguyen, Jeffrey Q.; Irby, Rosalyn B.

    2017-01-01

    ABSTRACT The prostate apoptosis response protein 4 (Par-4) is a tumor-suppressor that has been shown to induce cancer-cell selective apoptosis in a variety of cancers. The regulation of Par-4 expression and activity is a relatively understudied area, and identifying novel regulators of Par-4 may serve as novel therapeutic targets. To identify novel regulators of Par-4, a co-immunoprecipitation was performed in colon cancer cells, and co-precipitated proteins were identified by mass-spectometry. TRIM21 was identified as a novel interacting partner of Par-4, and further shown to interact with Par-4 endogenously and through its PRY-SPRY domain. Additional studies show that TRIM21 downregulates Par-4 levels in response to cisplatin, and that TRIM21 can increase the resistance of colon cancer cells to cisplatin. Furthermore, forced Par-4 expression can sensitize pancreatic cancer cells to cisplatin. Finally, we demonstrate that TRIM21 expression predicts survival in pancreatic cancer patients. Our work highlights a novel mechanism of Par-4 regulation, and identifies a novel prognostic marker and potential therapeutic target for pancreatic cancer. PMID:27830973

  9. Tryptase - PAR2 axis in Experimental Autoimmune Prostatitis, a model for Chronic Pelvic Pain Syndrome

    PubMed Central

    Roman, Kenny; Done, Joseph D.; Schaeffer, Anthony J.; Murphy, Stephen F.; Thumbikat, Praveen

    2014-01-01

    Chronic prostatitis/Chronic pelvic pain syndrome (CP/CPPS) affects up to 15% of the male population and is characterized by pelvic pain. Mast cells are implicated in the murine experimental autoimmune prostatitis (EAP) model as key to chronic pelvic pain development. The mast cell mediator tryptase-β and its cognate receptor protease-activated receptor 2 (PAR2) are involved in mediating pain in other visceral disease models. Prostatic secretions and urines from CP/CPPS patients were examined for the presence of mast cell degranulation products. Tryptase-β and PAR2 expression were examined in murine experimental autoimmune prostatitis (EAP). Pelvic pain and inflammation were assessed in the presence or absence of PAR2 expression and upon PAR2 neutralization. Tryptase-β and carboxypeptidase A3 were elevated in CP/CPPS compared to healthy volunteers. Tryptase-β was capable of inducing pelvic pain and was increased in EAP along with its receptor PAR2. PAR2 was required for the development of chronic pelvic pain in EAP. PAR2 signaling in dorsal root ganglia lead to ERK1/2 phosphorylation and calcium influx. PAR2 neutralization using antibodies attenuated chronic pelvic pain in EAP. The tryptase-PAR2 axis is an important mediator of pelvic pain in EAP and may play a role in the pathogenesis of CP/CPPS. PMID:24726923

  10. Amorçage d'une décharge dans le vide entre deux electrodes d'argent ou des alliages argent-nickel

    NASA Astrophysics Data System (ADS)

    Zouache, N.; Lefort, A.

    1997-03-01

    Comparison of the characteristics of an electric are breakdown in vacuum between two silver or silver-nickel alloy electrodes prompted us to study the evolution of the breakdown voltage with electrode separation, with resistance value placed between the anode and the high voltage supply used for the breakdown, and with the effect of conditionning by heating in vacuum. The measurement of the commutation time and delay time, and the observations by a metallographic microscope of the electrodes surfaces after one breakdown, enabled us to evidence the origin of the electric arc for each of the studied materials. La comparaison des caractéristiques de l'amorçage d'un arc électrique dans le vide entre deux électrodes bombées de 8mm de diamètre et de rayon de courbure en surface de 16mm, constituées d'argent ou de son alliage avec le nickel, nous a amené à étudier l'évolution de la tension d'amorçage avec plusieurs paramètres : la distance inter-électrodes, les valeurs de la résistance intercalée entre la source haute tension servant au claquage et les électrodes et le conditionnement par chauffage sous vide des électrodes. La mesure du temps de commutation, du temps de retard et les observations au microscope métallographique de la surface des électrodes après un amorçage donnent des informations sur l'origine de l'arc électrique concernant chaque matériau étudié.

  11. Plates-formes de microscopie et fluorescence par resonance de plasmons de surface appliquees a l'imagerie cellulaire

    NASA Astrophysics Data System (ADS)

    Chabot, Vincent

    L'elaboration de nouveaux medicaments repose sur les etudes pharmacologiques, dont le role est d'identifier de nouveaux composes actifs ou de nouvelles cibles pharmacologiques agissant entre autres au niveau cellulaire. Recemment, la detection basee sur la resonance des plasmons de surface (SPR) a ete appliquee a l'etude de reponses cellulaires. Cette methode de detection, permettant d'observer des variations d'indice de refraction associes a de faibles changements de masse a la surface d'un metal, a l'avantage de permettre l'etude d'une population de cellules vivantes en temps reel, sans necessiter l'introduction d'agents de marquage. Pour effectuer la detection au niveau de cellules individuelles, on peut employer la microscopie SPR, qui consiste a localiser spatialement la detection par un systeme d'imagerie. Cependant, la detection basee sur la SPR est une mesure sans marquage et les signaux mesures sont attribues a une reponse moyennee des differentes sources cellulaires. Afin de mieux comprendre et identifier les composantes cellulaires generant le signal mesure en SPR, il est pertinent de combiner la microscopie SPR avec une modalite complementaire, soit l'imagerie de fluorescence. C'est dans cette problematique que s'insere ce projet de these, consistant a concevoir deux plates-formes distinctes de microscopie SPR et de fluorescence optimisees pour l'etude cellulaire, de sorte a evaluer les possibilites d'integration de ces deux modalites en un seul systeme. Des substrats adaptes pour chaque plate-forme ont ete concus et realises. Ces substrats employaient une couche d'argent passivee par l'ajout d'une mince couche d'or. La stabilite et la biocompatibilite des substrats ont ete validees pour l'etude cellulaire. Deux configurations permettant d'ameliorer la sensibilite en sondant les cellules plus profondement ont ete evaluees, soit l'emploi de plasmons de surface a longue portee et de guides d'onde a gaine metallique. La sensibilite accrue de ces

  12. Hong-Ou-Mandel interference between triggered and heralded single photons from separate atomic systems

    NASA Astrophysics Data System (ADS)

    Leong, Victor; Kosen, Sandoko; Srivathsan, Bharath; Gulati, Gurpreet Kaur; Cerè, Alessandro; Kurtsiefer, Christian

    2015-06-01

    We present Hong-Ou-Mandel interference of single photons generated via two different physical processes by two independent atomic systems: scattering by a single atom, and parametric generation via four-wave mixing in a cloud of cold atoms. Without any spectral filtering, we observe a visibility of V =62 ±4 % . After correcting for accidental coincidences, we obtain V =93 ±6 % . The observed interference demonstrates the compatibility of the two sources, forming the basis for an efficient quantum interface between different physical systems.

  13. How nonlinear optical effects degrade Hong-Ou-Mandel like interference

    NASA Astrophysics Data System (ADS)

    Mirza, Imran M.; van Enk, S. J.

    2015-05-01

    Two-photon interference effects, such as the Hong-Ou-Mandel (HOM) effect, can be used to characterize to what extent two photons are identical [20]. Furthermore, these interference effects underly linear optics quantum computation. We show here how nonlinear optical effects, such as those mediated by atoms or quantum dots in a cavity, degrade the interference. This implies that, on the one hand, nonlinearities are to be avoided if one wishes to utilize the interference, but on the other hand, one may be able to measure or detect nonlinearities by observing the disappearance of the interference.

  14. Spatial two-photon interference in a Hong-Ou-Mandel interferometer

    SciTech Connect

    Kim, Heonoh; Kwon, Osung; Kim, Wonsik; Kim, Taesoo

    2006-02-15

    We report the observation of the cosine modulation in the coincidence rates from a Hong-Ou-Mandel (HOM) interferometer. Spatial interference fringes are seen by minute rotations of one mirror about the vertical axis, while the beam splitter is fixed in the center position. The results show that the maximum visibility of the fringe is 0.81, and the photon pairs separated by less than 1.52 mm in the source plane are measured to be indistinguishable. It turns out that it is possible to invert the HOM dips to peaks by the rotation of the mirror.

  15. Tolerance and biomarkers as useful tools for assessing environmental quality in the Oued Souss estuary (Bay of Agadir, Morocco).

    PubMed

    Ait Alla, A; Mouneyrac, C; Durou, C; Moukrim, A; Pellerin, J

    2006-05-01

    The aim of this study was to assess aquatic environmental quality of Oued Souss (Agadir, Morocco). This estuary has been subjected for a long time to large amounts of sewage discharges and industrial effluents. Since November 2002, no waste outlets have been discharged in this site due to their connection to a wastewater purification plant. Firstly, we have compared metal tolerance of the annelid polychaete (Nereis diversicolor) originating from Oued Souss and a relatively clean site (Oualidia, Morocco). Secondly, we have evaluated with a multi-marker approach (acetylcholinesterase [AChE], glutathione-S-transferases [GSTs], catalase, thiobarbituric acid reactive substances [TBARs]) responses of worms to the pollution gradient. Results have shown that worms from Oued Souss have acquired tolerance to copper and zinc due to a long-term sub-lethal metal exposure and this metal tolerance was maintained in spite of the end of wastewater discharges in this site. Higher catalase, GSTs and TBARs values have been observed in worms from Oued Souss sampled before implantation of wastewater treatment. The multi-marker approach confirms that these worms have been submitted to various contaminants. In contrast, high inhibition in AChE activities measured in worms from Oued Souss could be explained by the continuous agricultural influence of nearest areas. The level of contamination was probably maintained since biomarker values were generally higher in worms from Oued Souss when compared to Oualidia.

  16. Common variants in the human platelet PAR4 thrombin receptor alter platelet function and differ by race

    PubMed Central

    Edelstein, Leonard C.; Simon, Lukas M.; Lindsay, Cory R.; Kong, Xianguo; Teruel-Montoya, Raúl; Tourdot, Benjamin E.; Chen, Edward S.; Ma, Lin; Coughlin, Shaun; Nieman, Marvin; Holinstat, Michael; Shaw, Chad A.

    2014-01-01

    Human platelets express 2 thrombin receptors: protease-activated receptor (PAR)-1 and PAR4. Recently, we reported 3.7-fold increased PAR4-mediated aggregation kinetics in platelets from black subjects compared with white subjects. We now show that platelets from blacks (n = 70) express 14% more PAR4 protein than those from whites (n = 84), but this difference is not associated with platelet PAR4 function. Quantitative trait locus analysis identified 3 common single nucleotide polymorphisms in the PAR4 gene (F2RL3) associated with PAR4-induced platelet aggregation. Among these single nucleotide polymorphisms, rs773902 determines whether residue 120 in transmembrane domain 2 is an alanine (Ala) or threonine (Thr). Compared with the Ala120 variant, Thr120 was more common in black subjects than in white subjects (63% vs 19%), was associated with higher PAR4-induced human platelet aggregation and Ca2+ flux, and generated greater inositol 1,4,5-triphosphate in transfected cells. A second, less frequent F2RL3 variant, Phe296Val, was only observed in blacks and abolished the enhanced PAR4-induced platelet aggregation and 1,4,5-triphosphate generation associated with PAR4-Thr120. PAR4 genotype did not affect vorapaxar inhibition of platelet PAR1 function, but a strong pharmacogenetic effect was observed with the PAR4-specific antagonist YD-3 [1-benzyl-3(ethoxycarbonylphenyl)-indazole]. These findings may have an important pharmacogenetic effect on the development of new PAR antagonists. PMID:25293779

  17. Le champ critique de claquage de films d'oxyde de polyphénylène réalisés par voie électrochimique

    NASA Astrophysics Data System (ADS)

    Adohi, B.; Gosse, J. P.; Gosse, B.

    1991-10-01

    The electrical breakdown of thin films of polyphenylene oxide electrochemically deposited on stainless steel plane substrates has been studied. First it was examined the dependence of the medium surrounding the dielectric and the electrodes (nature, hydrostatic pressure) on the breakdown voltage and on its statistical distribution. Between sphere and plane electrodes, it appears that even for pressurified gases, breakdown of the film is caused by the gas breakdown. We have analysed the discharges occurring at atmosphere pressure in the test cell. Breakdown of the film occurred when the electric field due to the charge deposited on its surface was about 230 V/μm. We have also studied self-healing capacitors with PPO as a dielectric, and determined the life-time of this material. On a étudié le claquage électrique de films minces d'oxyde de polyphénylène de quelques microns d'épaisseur déposés par voie électrochimique sur un plan en acier inoxydable. L'étude a d'abord été faite en rampe de tension continue dans la géométrie d'électrodes sphèreplan, en fonction du milieu ambiant liquide ou gazeux. L'influence de la pression sur la rigidité diélectrique du matériau, les distributions statistiques de Weibull et les cratères formés au moment du claquage, dans les différents milieux et dans les deux polarités de l'électrode sphérique montrent que le claquage du matériau est causé par des décharges qui se produisent dans le milieu environnant. A partir de l'analyse quantitative de ces décharges, on propose comme critère de caractérisation de la rupture d'un matériau sounmis aux décharges, le champ créé au moment de la rupture par les charges déposées à sa surface. On a réalisé ensuite des échantillons plans << autocicatrisables >> par dépôt de couches minces d'aluminium (quelques milliers d'Å d'épaisseur) sur le film de PPO. On étudie dans cette configuration la durée de vie du matériau.

  18. Oxydation catalytique du Phénol par le peroxyde d'hydrogène en présence d'argiles pontées par des espèces mixtes [Al-Cu

    NASA Astrophysics Data System (ADS)

    Abdellaoui, M.; Barrault, J.; Bouchoule, C.; Srasra, N. F.; Bergaya, F.

    1999-03-01

    îdoudi) ou à celle de la Laponite (L). Par ailleurs, la stabilité, l'activité et la teneur en cuivre dépendent fortement de la méthode de préparation.

  19. Mapping transmembrane residues of proteinase activated receptor 2 (PAR2) that influence ligand-modulated calcium signaling.

    PubMed

    Suen, J Y; Adams, M N; Lim, J; Madala, P K; Xu, W; Cotterell, A J; He, Y; Yau, M K; Hooper, J D; Fairlie, D P

    2017-03-01

    Proteinase-activated receptor 2 (PAR2) is a G protein-coupled receptor involved in metabolism, inflammation, and cancers. It is activated by proteolysis, which exposes a nascent N-terminal sequence that becomes a tethered agonist. Short synthetic peptides corresponding to this sequence also activate PAR2, while small organic molecules show promising PAR2 antagonism. Developing PAR2 ligands into pharmaceuticals is hindered by a lack of knowledge of how synthetic ligands interact with and differentially modulate PAR2. Guided by PAR2 homology modeling and ligand docking based on bovine rhodopsin, followed by cross-checking with newer PAR2 models based on ORL-1 and PAR1, site-directed mutagenesis of PAR2 was used to investigate the pharmacology of three agonists (two synthetic agonists and trypsin-exposed tethered ligand) and one antagonist for modulation of PAR2 signaling. Effects of 28 PAR2 mutations were examined for PAR2-mediated calcium mobilization and key mutants were selected for measuring ligand binding. Nineteen of twenty-eight PAR2 mutations reduced the potency of at least one ligand by >10-fold. Key residues mapped predominantly to a cluster in the transmembrane (TM) domains of PAR2, differentially influence intracellular Ca(2+) induced by synthetic agonists versus a native agonist, and highlight subtly different TM residues involved in receptor activation. This is the first evidence highlighting the importance of the PAR2 TM regions for receptor activation by synthetic PAR2 agonists and antagonists. The trypsin-cleaved N-terminus that activates PAR2 was unaffected by residues that affected synthetic peptides, challenging the widespread practice of substituting peptides for proteases to characterize PAR2 physiology.

  20. Proceedings of the International Symposium on Air Breathing Engines (2nd), Held in Ranmoor House, Sheffield University on 24th-29th March 1974

    DTIC Science & Technology

    1974-03-01

    appareils d’enregistre- ment (10) (appateil photographique ou camera). Lors de l’enregistrement l’eclairement est fourni par un flash de trds courte...raccord6s par une coupure supportant un saut de la fonction de courant 6gal h la difförence entre les valeurs 548< de y sur 1’extrados et l’intrados...sur la ligne sonique /L-y/,,a 1 ä travers la coupure On enlöve la singularity amont dans tout le plan en utilisant une fonction de courant

  1. Intersections et Convergence

    DTIC Science & Technology

    2000-01-01

    ardus : Par exemple, celui d’intersections, ou racines. Nos ordinateurs se bloquaient. De toute ur- gence, il fallait mettre sur pied une m6thode... ordinateurs atteignaient la limite du quart d’heure qui, par pr~caution, en limitait la dur~e! Et de plus, il fallait agir vite, tr~s vite. .. .pour...l’cipoque ohi le calcul des fonctions n’citait pas encore tr~s au point, au niveau des ordinateurs , les formules simplificies de Arc sin et Arc cos nous

  2. Nonlinear optical effects and Hong-Ou-Mandel interference in cavity quantum electrodynamics

    NASA Astrophysics Data System (ADS)

    Mirza, Imran M.; van Enk, Steven J.

    Pure quantum interference among single photons is one of the key ingredients to perform linear optics quantum computation (LOQC). The Hong-Ou-Mandel interference (HOMI) [C. K. Hong, Z. Y. Ou and L. Mandel, Phys. Rev. Lett. 59, (18), 2044-2046 (1987)] i.e. complete destructive interference between two identical and indistinguishable photons simultaneously entering input ports of a 50/50 beam splitter, is a well-known example in this context. In this talk, I'll present our theoretical study of HOMI in a coupled Jaynes-Cummings array. In particular and by applying quantum jump/trajectory formalism, I'll focus on how partial quantum interference between two photons survive both non-linearities produced by two-level emitter and spectral filtering due to optical cavities in our coupled cavity array setup [Imran M. Mirza and Steven J. van Enk, Opt. Comm. 343, 172-177 (2015)]. Along with LOQC, this work is crucial from the perspective of exploiting coupled cavity arrays to store single photons reliably (without altering their temporal and spectral traits) [Imran M. Mirza, Steven J. van Enk and Jeff Kimble, JOSA B, 10, 2640-2649, (2013)].

  3. Water quality assessment of a highly polluted Mediterranean River - Oued Fez (Morocco)

    NASA Astrophysics Data System (ADS)

    Perrin, J.-L.; Bellarbi, M.; Raïs, N.; Chahinian, N.; Moulin, P.; Ijjaali, M.

    2012-04-01

    In the South of the Mediterranean basin, many rivers are characterized by an alternation of very long dry periods only cut by short flood events. Currently, the socio-economical development of these zones is limited by water scarcity and poor quality of the water resources. Indeed human activities, generally concentrated in overpopulated cities, generate large quantity of domestic and industrial effluents which are directly rejected in the environment without any treatment. In Morocco, the well known city of Fez illustrates perfectly this situation, observed in most developing countries. The oued Fez receives continuously the non-treated domestic and industrial effluents (90.000 m3/day) of the city and pollutes all the downstream water bodies. Indeed, it is a tributary of the Sebou River, a major body of great economical importance used for irrigation and freshwater supply. This study aims at characterising and quantifying the pollutant concentrations and fluxes in various points of oued Fez's hydrological network and assessing its impact on the Sebou River; this river's preservation being considered a national priority in Morocco. A coupled water quality-water quantity monitoring scheme has been implemented on oued Fez since 2008. In addition to basic hydrological data, water quality samples are collected at regular intervals at 8 locations where discharge is simultaneously measured using an Acoustic Doppler Current Profiler (ADCP). Water samples are analysed for different forms of nitrogen (nitrates, nitrites, ammonium and total nitrogen), phosphorus (soluble reactive phosphorus and total phosphorus) but also total chromium which is used in the leather tanning processes, one of the most important industrial production of the city of Fez, using a photospectrometer (Hach Lange DR 2800 VIS-photometer (Germany). The results of 17 sampling campaigns, carried out over 3 hydrological years, indicate that the rural areas contribute mostly to baseflow during the wet

  4. Conception de lois de pilotage robustes et sequencement de gains par l'approche de systemes lineaires a parametres variants

    NASA Astrophysics Data System (ADS)

    Hentabli, Kamel

    Cette recherche s'inscrit dans le cadre du projet de recherche Active Control Technology entre l'Ecole de Technologie Superieure et le constructeur Bombardier Aeronautique . Le but est de concevoir des strategies de commandes multivariables et robustes pour des modeles dynamiques d'avions. Ces strategies de commandes devraient assurer a l'avion une haute performance et satisfaire des qualites de vol desirees en l'occurrence, une bonne manoeuvrabilite, de bonnes marges de stabilite et un amortissement des mouvements phugoides et rapides de l'avion. Dans un premier temps, nous nous sommes principalement interesses aux methodes de synthese LTI et plus exactement a l'approche Hinfinity et la mu-synthese. Par la suite, nous avons accorde un interet particulier aux techniques de commande LPV. Pour mener a bien ce travail, nous avons envisage une approche frequentielle, typiquement Hinfinity. Cette approche est particulierement interessante, dans la mesure ou le modele de synthese est construit directement a partir des differentes specifications du cahier des charges. En effet, ces specifications sont traduites sous forme de gabarits frequentiels, correspondant a des ponderations en entree et en sortie que l'on retrouve dans la synthese Hinfinity classique. Par ailleurs, nous avons utilise une representation de type lineaire fractionnelle (LFT), jugee mieux adaptee pour la prise en compte des differents types d'incertitudes, qui peuvent intervenir sur le systeme. De plus, cette representation s'avere tres appropriee pour l'analyse de la robustesse via les outils de la mu-analyse. D'autre part, afin d'optimiser le compromis entre les specifications de robustesse et de performance, nous avons opte pour une structure de commande a 2 degres de liberte avec modele de reference. Enfin, ces techniques sont illustrees sur des applications realistes, demontrant ainsi la pertinence et l'applicabilite de chacune d'elle. Mots cles. Commande de vol, qualites de vol et manoeuvrabilite

  5. Microscopie par rayons X dans la fenêtre de l'eau : faisabilité et intérêt pour la biologie d'un instrument de laboratoire

    NASA Astrophysics Data System (ADS)

    Adam, J. F.; Moy, J. P.

    2005-06-01

    La biologie étudie des structures ou des phénomènes sub-cellulaires. Pour cela la microscopie est la technique d'observation privilégiée. La résolution spatiale de la microscopie optique s'avère bien souvent insuffisante pour de telles observations. Les techniques plus résolvantes, comme la microscopie électronique par transmission sont souvent destructrices et d'une complexité peu adaptée aux besoins des biologistes. La microscopie par rayons X dans la fenêtre de l'eau permet l'imagerie rapide de cellules dans leur milieu naturel, nécessite peu de préparation et offre des résolutions de quelques dizaines de nanomètres. De plus, il existe un bon contraste naturel entre les structures carbonées (protéines, lipides) et l'eau. Actuellement cette technique est limitée aux centres de rayonnement synchrotron, ce qui impose une planification et des déplacements incompatibles avec les besoins de la biologie. Un tel microscope fonctionnant avec uns source de laboratoire serait d'une grande utilité. Ce document présente un état de l'art de la microscopie par rayons X dans la fenêtre de l'eau. Un cahier des charges détaillé pour un appareil de laboratoire ayant les performances optiques requises par les biologistes est présenté et confronté aux microscopes X de laboratoire déjà existants. Des solutions concernant la source et les optiques sont également discutées.

  6. Regulation of long-term repopulating hematopoietic stem cells by EPCR/PAR1 signaling

    PubMed Central

    Gur-Cohen, Shiri; Kollet, Orit; Graf, Claudine; Esmon, Charles T.; Ruf, Wolfram; Lapidot, Tsvee

    2016-01-01

    The common developmental origin of endothelial and hematopoietic cells is manifested by coexpression of several cell surface receptors. Adult murine bone marrow (BM) long-term repopulating hematopoietic stem cells (LT-HSCs), endowed with the highest repopulation and self-renewal potential, express endothelial protein C receptor (EPCR), which is used as a marker to isolate them. EPCR/PAR1 signaling in endothelial cells has anticoagulant and anti-inflammatory roles, while thrombin/PAR1 signaling induces coagulation and inflammation. Recent studies define two new PAR1-mediated signaling cascades that regulate EPCR+ LT-HSC BM retention and egress. EPCR/PAR1 signaling facilitates LT-HSC BM repopulation, retention, survival, and chemotherapy resistance by restricting nitric oxide (NO) production, maintaining NOlow LT-HSC BM retention with increased VLA4 expression, affinity, and adhesion. Conversely, acute stress and clinical mobilization upregulate thrombin generation and activate different PAR1 signaling which overcomes BM EPCR+ LT-HSC retention, inducing their recruitment to the bloodstream. Thrombin/PAR1 signaling induces NO generation, TACE-mediated EPCR shedding, and upregulation of CXCR4 and PAR1, leading to CXCL12-mediated stem and progenitor cell mobilization. This review discusses new roles for factors traditionally viewed as coagulation related, which independently act in the BM to regulate PAR1 signaling in bone- and blood-forming progenitor cells, navigating their fate by controlling NO production. PMID:26928241

  7. Bacterial DNA segregation dynamics mediated by the polymerizing protein ParF

    PubMed Central

    Barillà, Daniela; Rosenberg, Mark F; Nobbmann, Ulf; Hayes, Finbarr

    2005-01-01

    Prokaryotic DNA segregation most commonly involves members of the Walker-type ParA superfamily. Here we show that the ParF partition protein specified by the TP228 plasmid is a ParA ATPase that assembles into extensive filaments in vitro. Polymerization is potentiated by ATP binding and does not require nucleotide hydrolysis. Analysis of mutations in conserved residues of the Walker A motif established a functional coupling between filament dynamics and DNA partitioning. The partner partition protein ParG plays two separable roles in the ParF polymerization process. ParF is unrelated to prokaryotic polymerizing proteins of the actin or tubulin families, but is a homologue of the MinD cell division protein, which also assembles into filaments. The ultrastructures of the ParF and MinD polymers are remarkably similar. This points to an evolutionary parallel between DNA segregation and cytokinesis in prokaryotic cells, and reveals a potential molecular mechanism for plasmid and chromosome segregation mediated by the ubiquitous ParA-type proteins. PMID:15775965

  8. Inactivation of the candidate tumor suppressor par-4 in endometrial cancer.

    PubMed

    Moreno-Bueno, Gema; Fernandez-Marcos, Pablo J; Collado, Manuel; Tendero, Mercedes J; Rodriguez-Pinilla, Socorro M; Garcia-Cao, Isabel; Hardisson, David; Diaz-Meco, Maria T; Moscat, Jorge; Serrano, Manuel; Palacios, Jose

    2007-03-01

    Recently, it has been shown that mice deficient in the proapoptotic protein prostate apoptosis response 4 (Par-4) are specifically prone to develop endometrial carcinomas. Based on this, we have examined here the possible role of Par-4 as a tumor suppressor gene in human endometrial cancer. Using cDNA arrays, quantitative reverse transcription-PCR, and immunohistochemistry, we detected Par-4 down-regulation in approximately 40% of endometrial carcinomas. This alteration was not associated with phosphatase and tensin homologue (PTEN), K-RAS, or beta-catenin mutations, but was more frequent among tumors showing microsatellite instability (MSI) or among tumors that were estrogen receptor positive. Mutational analysis of the complete coding sequence of Par-4 in endometrial cancer cell lines (n = 6) and carcinomas (n = 69) detected a mutation in a single carcinoma, which was localized in exon 3 [Arg (CGA) 189 (TGA) Stop]. Interestingly, Par-4 promoter hypermethylation was detected in 32% of the tumors in association with low levels of Par-4 protein and was more common in MSI-positive carcinomas. Par-4 promoter hypermethylation and silencing was also detected in endometrial cancer cell lines SKUT1B and AN3CA, and reexpression was achieved by treatment with the demethylating agent 5'-aza-2'-deoxycytidine. Together, these data show that Par-4 is a relevant tumor suppressor gene in human endometrial carcinogenesis.

  9. Participatory Action Research (PAR) cum Action Research (AR) in Teacher Professional Development: A Literature Review

    ERIC Educational Resources Information Center

    Morales, Marie Paz E.

    2016-01-01

    This paper reviews Participatory Action Research as an approach to teacher professional development. It maps the origins of Participatory Action Research (PAR) and discusses the benefits and challenges that have been identified by other researchers in utilizing PAR approaches in conducting research. It draws ideas of combining the features of…

  10. Questioning Our Questions: Assessing Question Asking Practices to Evaluate a yPAR Program

    ERIC Educational Resources Information Center

    Grace, Sarah; Langhout, Regina Day

    2014-01-01

    The purpose of this research was to examine question asking practices in a youth participatory action research (yPAR) after school program housed at an elementary school. The research question was: In which ways did the adult question asking practices in a yPAR setting challenge and/or reproduce conventional models of power in educational…

  11. Loss of Par3 promotes lung adenocarcinoma metastasis through 14-3-3ζ protein

    PubMed Central

    Tong, Song; Xia, Tian; Fan, Kai; Jiang, Ke; Zhai, Wei; Li, Jing-Song; Wang, Si-Hua; Wang, Jian-Jun

    2016-01-01

    Partitioning defective protein 3 (Par3) can activate the Tiam1/Rac pathway to inhibit invasion and metastasis in many cancers; however, the role of Par3 in lung adenocarcinoma remains unknown. Here we show that Par3 is downregulated in lung adenocarcinoma tissues and is associated with higher rates of lymph node metastasis and recurrence. Our functional study demonstrated that knock-down of Par3 promoted lung adenocarcinoma cell growth, cell migration, tumor formation, and metastasis, all of which were effectively inhibited when 14-3-3ζ was silenced. We found that Par3 binded with 14-3-3ζ protein and also showed that Par3 abrogated the binding of 14-3-3ζ to Tiam1, which was responsible for Rac1 activation. Knock-down of 14-3-3ζ inhibited Tiam1/Rac-GTP activation and blocked the invasive behavior of cells lacking Par3. These data suggest that loss of Par3 promotes metastatic behavior in lung adenocarcinoma cells through 14-3-3ζ protein. PMID:27588399

  12. Human bronchial epithelial cells express PAR-2 with different sensitivity to thermolysin.

    PubMed

    Ubl, Joachim J; Grishina, Zoryana V; Sukhomlin, Tatiana K; Welte, Tobias; Sedehizade, Fariba; Reiser, Georg

    2002-06-01

    Protease-activated receptor-2 (PAR-2) plays a role in inflammatory reactions in airway physiology. Proteases cleaving the extracellular NH(2) terminus of receptors activate or inactivate PAR, thus possessing a therapeutic potential. Using RT-PCR and immunocytochemistry, we show PAR-2 in human airway epithelial cell lines human bronchial epithelial (HBE) and A549. Functional expression of PAR-2 was confirmed by Ca(2+) imaging studies using the receptor agonist protease trypsin. The effect was abolished by soybean trypsin inhibitor and mimicked by the specific PAR-2 peptide agonist SLIGKV. Amplitude and duration of PAR-2-elicited Ca(2+) response in HBE and A549 cells depend on concentration and time of agonist superfusion. The response is partially pertussis toxin (PTX) insensitive, abolished by the phospholipase C inhibitor U-73122, and diminished by the inositol 1,4,5-trisphosphate receptor antagonist 2-aminoethoxydiphenyl borate. Cathepsin G altered neither the resting Ca(2+) level nor PAR-2-elicited Ca(2+) response. Thermolysin, a prototypic bacterial metalloprotease, induced a dose-dependent Ca(2+) response in HBE, but not A549, cells. In both cell lines, thermolysin abolished the response to a subsequent trypsin challenge but not to SLIGKV. Thus different epithelial cell types express different PAR-2 with identical responses to physiological stimuli (trypsin, SLIGKV) but different sensitivity to modifying proteases, such as thermolysin.

  13. Par3 controls neural crest migration by promoting microtubule catastrophe during contact inhibition of locomotion

    PubMed Central

    Moore, Rachel; Theveneau, Eric; Pozzi, Sara; Alexandre, Paula; Richardson, Joanna; Merks, Anne; Parsons, Maddy; Kashef, Jubin; Linker, Claudia; Mayor, Roberto

    2013-01-01

    There is growing evidence that contact inhibition of locomotion (CIL) is essential for morphogenesis and its failure is thought to be responsible for cancer invasion; however, the molecular bases of this phenomenon are poorly understood. Here we investigate the role of the polarity protein Par3 in CIL during migration of the neural crest, a highly migratory mesenchymal cell type. In epithelial cells, Par3 is localised to the cell-cell adhesion complex and is important in the definition of apicobasal polarity, but the localisation and function of Par3 in mesenchymal cells are not well characterised. We show in Xenopus and zebrafish that Par3 is localised to the cell-cell contact in neural crest cells and is essential for CIL. We demonstrate that the dynamics of microtubules are different in different parts of the cell, with an increase in microtubule catastrophe at the collision site during CIL. Par3 loss-of-function affects neural crest migration by reducing microtubule catastrophe at the site of cell-cell contact and abrogating CIL. Furthermore, Par3 promotes microtubule catastrophe by inhibiting the Rac-GEF Trio, as double inhibition of Par3 and Trio restores microtubule catastrophe at the cell contact and rescues CIL and neural crest migration. Our results demonstrate a novel role of Par3 during neural crest migration, which is likely to be conserved in other processes that involve CIL such as cancer invasion or cell dispersion. PMID:24173803

  14. Par3 controls neural crest migration by promoting microtubule catastrophe during contact inhibition of locomotion.

    PubMed

    Moore, Rachel; Theveneau, Eric; Pozzi, Sara; Alexandre, Paula; Richardson, Joanna; Merks, Anne; Parsons, Maddy; Kashef, Jubin; Linker, Claudia; Mayor, Roberto

    2013-12-01

    There is growing evidence that contact inhibition of locomotion (CIL) is essential for morphogenesis and its failure is thought to be responsible for cancer invasion; however, the molecular bases of this phenomenon are poorly understood. Here we investigate the role of the polarity protein Par3 in CIL during migration of the neural crest, a highly migratory mesenchymal cell type. In epithelial cells, Par3 is localised to the cell-cell adhesion complex and is important in the definition of apicobasal polarity, but the localisation and function of Par3 in mesenchymal cells are not well characterised. We show in Xenopus and zebrafish that Par3 is localised to the cell-cell contact in neural crest cells and is essential for CIL. We demonstrate that the dynamics of microtubules are different in different parts of the cell, with an increase in microtubule catastrophe at the collision site during CIL. Par3 loss-of-function affects neural crest migration by reducing microtubule catastrophe at the site of cell-cell contact and abrogating CIL. Furthermore, Par3 promotes microtubule catastrophe by inhibiting the Rac-GEF Trio, as double inhibition of Par3 and Trio restores microtubule catastrophe at the cell contact and rescues CIL and neural crest migration. Our results demonstrate a novel role of Par3 during neural crest migration, which is likely to be conserved in other processes that involve CIL such as cancer invasion or cell dispersion.

  15. 12 CFR 925.19 - Par value and price of stock.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Par value and price of stock. 925.19 Section 925.19 Banks and Banking FEDERAL HOUSING FINANCE BOARD FEDERAL HOME LOAN BANK MEMBERS AND HOUSING ASSOCIATES MEMBERS OF THE BANKS Stock Requirements § 925.19 Par value and price of stock. The capital...

  16. Slmb antagonises the aPKC/Par-6 complex to control oocyte and epithelial polarity.

    PubMed

    Morais-de-Sá, Eurico; Mukherjee, Avik; Lowe, Nick; St Johnston, Daniel

    2014-08-01

    The Drosophila anterior-posterior axis is specified when the posterior follicle cells signal to polarise the oocyte, leading to the anterior/lateral localisation of the Par-6/aPKC complex and the posterior recruitment of Par-1, which induces a microtubule reorganisation that localises bicoid and oskar mRNAs. Here we show that oocyte polarity requires Slmb, the substrate specificity subunit of the SCF E3 ubiquitin ligase that targets proteins for degradation. The Par-6/aPKC complex is ectopically localised to the posterior of slmb mutant oocytes, and Par-1 and oskar mRNA are mislocalised. Slmb appears to play a related role in epithelial follicle cells, as large slmb mutant clones disrupt epithelial organisation, whereas small clones show an expansion of the apical domain, with increased accumulation of apical polarity factors at the apical cortex. The levels of aPKC and Par-6 are significantly increased in slmb mutants, whereas Baz is slightly reduced. Thus, Slmb may induce the polarisation of the anterior-posterior axis of the oocyte by targeting the Par-6/aPKC complex for degradation at the oocyte posterior. Consistent with this, overexpression of the aPKC antagonist Lgl strongly rescues the polarity defects of slmb mutant germline clones. The role of Slmb in oocyte polarity raises an intriguing parallel with C. elegans axis formation, in which PAR-2 excludes the anterior PAR complex from the posterior cortex to induce polarity, but its function can be substituted by overexpressing Lgl.

  17. Bacterial actin homolog ParM: arguments for an apolar, antiparallel double helix.

    PubMed

    Erickson, Harold P

    2012-09-28

    The bacterial actin homolog ParM has always been modeled as a polar filament, comprising two parallel helical strands, like actin itself. I present arguments here that ParM may be an apolar filament, in which the two helical strands are antiparallel. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Questioning Our Questions: Assessing Question Asking Practices to Evaluate a yPAR Program

    ERIC Educational Resources Information Center

    Grace, Sarah; Langhout, Regina Day

    2014-01-01

    The purpose of this research was to examine question asking practices in a youth participatory action research (yPAR) after school program housed at an elementary school. The research question was: In which ways did the adult question asking practices in a yPAR setting challenge and/or reproduce conventional models of power in educational…

  19. The parA resolvase performs site-specific genomic excision in Arabidopsis

    USDA-ARS?s Scientific Manuscript database

    We have designed a site-specific excision detection system in Arabidopsis to study the in planta activity of the small serine recombinase ParA. Using a transient expression assay as well as stable transgenic plant lines, we show that the ParA recombinase is catalytically active and capable of perfo...

  20. Loss of Par3 promotes lung adenocarcinoma metastasis through 14-3-3ζ protein.

    PubMed

    Song, Tong; Tian, Xia; Kai, Fan; Ke, Jiang; Wei, Zhai; Jing-Song, Li; Si-Hua, Wang; Jian-Jun, Wang

    2016-09-27

    Partitioning defective protein 3 (Par3) can activate the Tiam1/Rac pathway to inhibit invasion and metastasis in many cancers; however, the role of Par3 in lung adenocarcinoma remains unknown. Here we show that Par3 is downregulated in lung adenocarcinoma tissues and is associated with higher rates of lymph node metastasis and recurrence. Our functional study demonstrated that knock-down of Par3 promoted lung adenocarcinoma cell growth, cell migration, tumor formation, and metastasis, all of which were effectively inhibited when 14-3-3ζ was silenced. We found that Par3 binded with 14-3-3ζ protein and also showed that Par3 abrogated the binding of 14-3-3ζ to Tiam1, which was responsible for Rac1 activation. Knock-down of 14-3-3ζ inhibited Tiam1/Rac-GTP activation and blocked the invasive behavior of cells lacking Par3. These data suggest that loss of Par3 promotes metastatic behavior in lung adenocarcinoma cells through 14-3-3ζ protein.

  1. Solar PAR and UVR modify the community composition and photosynthetic activity of sea ice algae.

    PubMed

    Enberg, Sara; Piiparinen, Jonna; Majaneva, Markus; Vähätalo, Anssi V; Autio, Riitta; Rintala, Janne-Markus

    2015-10-01

    The effects of increased photosynthetically active radiation (PAR) and ultraviolet radiation (UVR) on species diversity, biomass and photosynthetic activity were studied in fast ice algal communities. The experimental set-up consisted of nine 1.44 m(2) squares with three treatments: untreated with natural snow cover (UNT), snow-free (PAR + UVR) and snow-free ice covered with a UV screen (PAR). The total algal biomass, dominated by diatoms and dinoflagellates, increased in all treatments during the experiment. However, the smaller biomass growth in the top 10-cm layer of the PAR + UVR treatment compared with the PAR treatment indicated the negative effect of UVR. Scrippsiella complex (mainly Scrippsiella hangoei, Biecheleria baltica and Gymnodinium corollarium) showed UV sensitivity in the top 5-cm layer, whereas Heterocapsa arctica ssp. frigida and green algae showed sensitivity to both PAR and UVR. The photosynthetic activity was highest in the top 5-cm layer of the PAR treatment, where the biomass of the pennate diatom Nitzschia frigida increased, indicating the UV sensitivity of this species. This study shows that UVR is one of the controlling factors of algal communities in Baltic Sea ice, and that increased availability of PAR together with UVR exclusion can cause changes in algal biomass, photosynthetic activity and community composition. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Design and synthesis of peptides from bacterial ParE toxin as inhibitors of topoisomerases.

    PubMed

    Barbosa, Luiz Carlos Bertucci; Garrido, Saulo Santesso; Garcia, Anderson; Delfino, Davi Barbosa; Santos, Laura do Nascimento; Marchetto, Reinaldo

    2012-08-01

    Toxin-antitoxin (TA) proteic systems encode a toxin and an antitoxin that regulate the growth and death of bacterial cells under various stress conditions. The ParE protein is a toxin that inhibits DNA gyrase activity and thereby blocks DNA replication. Based on the Escherichia coli ParE structure, a series of linear peptides were designed and synthesized by solid-phase methodology. The ability of the peptides to inhibit the activity of bacterial topoisomerases was investigated. Four peptides (ParELC3, ParELC8, ParELC10 and ParELC12), showed complete inhibition of DNA gyrase supercoiling activity with an IC(100) between 20 and 40 μmol L(-1). In contrast to wild-type ParE, the peptide analogues were able to inhibit the DNA relaxation of topoisomerase IV, another type IIA bacterial topoisomerase, with lower IC(100) values. Interestingly only ParELC12 displayed inhibition of the relaxation activity of human topoisomerase II. Our findings reveal new inhibitors of bacterial topoisomerases and are a good starting point for the development of a new class of antibacterial agents that targets the DNA topoisomerases.

  3. Study Challenges Touted Link Between Eczema and Heart Disease

    MedlinePlus

    ... analyzed the medical records of nearly 260,000 Canadians between the ages of 30 and 74. They ... The findings were published recently in the British Journal of Dermatology . SOURCE: Brown University, news release, June ...

  4. Parents, Teachers Tout Classroom Councils to Boost Engagement

    ERIC Educational Resources Information Center

    Harris, Rebecca

    2012-01-01

    A local Early Head Start parent recently traveled to Washington, DC, to share a new parent engagement strategy with White House officials. Nastassia Jackson and her children's teachers hope the time is ripe for the idea to catch on. Their pitch: A parent board, like a miniature local school council, that "administrates alongside the teachers" and…

  5. Test Touted as 2 Studies Question Its Value

    ERIC Educational Resources Information Center

    Basken, Paul

    2008-01-01

    Two years after many colleges resisted attempts by the Bush administration to impose more rigorous methods of student assessment, a leading coalition of private institutions is pressing its members to adopt an increasingly popular standardized achievement test. The push to adopt the assessment comes as the test faces new questions over its…

  6. Contribution à la modélisation du soudage TIG des tôles minces d'acier austénitique 304L par un modèle source bi-elliptique, avec confrontation expérimentale

    NASA Astrophysics Data System (ADS)

    Aissani, M.; Maza, H.; Belkessa, B.; Maamache, B.

    2005-05-01

    Ce travail contribue dans la modélisation du phénomène du soudage de l'acier inoxydable Austénitique 304L, afin d'étudier le comportement thermique d'un joint de soudure, obtenu par le procédé de soudage à l'arc électrique TIG (Tungsten-Inert-Gas). Le modèle simulant la source d'énergie de soudage, utilise une distribution surfacique Gaussienne du flux de chaleur provenant de l'arc électrique. La forme de cette source est supposée circulaire pour un premier cas et de forme bi-elliptique pour un second cas, tout en procédant à l'évaluation des champs et cycles thermiques à chaque instant, pour déterminer l'étendu des zones à risque, et l'effet de la vitesse de soudage sur ces dernières. Permettant ainsi de remonter par la suite, aux problèmes de contraintes résiduelles et déformations générées dans l'assemblage soudé. L'équation de chaleur régissant le problème est discrétisée par la méthode des volumes finis. Les calculs sont effectués en considérant que les propriétés physiques et thermiques ainsi que les conditions aux limites de convection et rayonnement, sont dépendante de la température. Pour évaluer la précision du modèle, une comparaison avec des mesures expérimentales de température d'un essai de soudage a été effectuée, les résultats indiquent un bon accord.

  7. Par-4 inhibits Akt and suppresses Ras-induced lung tumorigenesis

    PubMed Central

    Joshi, Jayashree; Fernandez-Marcos, Pablo J; Galvez, Anita; Amanchy, Ramars; Linares, Juan F; Duran, Angeles; Pathrose, Peterson; Leitges, Michael; Cañamero, Marta; Collado, Manuel; Salas, Clara; Serrano, Manuel; Moscat, Jorge; Diaz-Meco, Maria T

    2008-01-01

    The atypical PKC-interacting protein, Par-4, inhibits cell survival and tumorigenesis in vitro, and its genetic inactivation in mice leads to reduced lifespan, enhanced benign tumour development and low-frequency carcinogenesis. Here, we demonstrate that Par-4 is highly expressed in normal lung but reduced in human lung cancer samples. We show, in a mouse model of lung tumours, that the lack of Par-4 dramatically enhances Ras-induced lung carcinoma formation in vivo, acting as a negative regulator of Akt activation. We also demonstrate in cell culture, in vivo, and in biochemical experiments that Akt regulation by Par-4 is mediated by PKCζ, establishing a new paradigm for Akt regulation and, likely, for Ras-induced lung carcinogenesis, wherein Par-4 is a novel tumour suppressor. PMID:18650932

  8. ParA-like protein uses nonspecific chromosomal DNA binding to partition protein complexes.

    PubMed

    Roberts, Mark A J; Wadhams, George H; Hadfield, Katie A; Tickner, Susan; Armitage, Judith P

    2012-04-24

    Recent data have shown that plasmid partitioning Par-like systems are used by some bacterial cells to control localization of protein complexes. Here we demonstrate that one of these homologs, PpfA, uses nonspecific chromosome binding to separate cytoplasmic clusters of chemotaxis proteins upon division. Using fluorescent microscopy and point mutations, we show dynamic chromosome binding and Walker-type ATPase activity are essential for cluster segregation. The N-terminal domain of a cytoplasmic chemoreceptor encoded next to ppfA is also required for segregation, probably functioning as a ParB analog to control PpfA ATPase activity. An orphan ParA involved in segregating protein clusters therefore uses a similar mechanism to plasmid-segregating ParA/B systems and requires a partner protein for function. Given the large number of genomes that encode orphan ParAs, this may be a common mechanism regulating segregation of proteins and protein complexes.

  9. Loss of the Par3 polarity protein promotes breast tumorigenesis and metastasis.

    PubMed

    McCaffrey, Luke Martin; Montalbano, JoAnne; Mihai, Constantina; Macara, Ian G

    2012-11-13

    Loss of epithelial organization is a hallmark of carcinomas, but whether polarity regulates tumor growth and metastasis is poorly understood. To address this issue, we depleted the Par3 polarity gene by RNAi in combination with oncogenic Notch or Ras(61L) expression in the murine mammary gland. Par3 silencing dramatically reduced tumor latency in both models and produced invasive and metastatic tumors that retained epithelial marker expression. Par3 depletion was associated with induction of MMP9, destruction of the extracellular matrix, and invasion, all mediated by atypical PKC-dependant JAK/Stat3 activation. Importantly, Par3 expression is significantly reduced in human breast cancers, which correlates with active aPKC and Stat3. These data identify Par3 as a regulator of signaling pathways relevant to invasive breast cancer.

  10. Compression Myelopathy due to Proliferative Changes around C2 Pars Defects without Instability

    PubMed Central

    Kimura, Tetsuya; Tezuka, Fumitake; Abe, Mitsunobu; Yamashita, Kazuta; Takata, Yoichiro; Higashino, Kosaku; Sairyo, Koichi

    2016-01-01

    We report a case with compression myelopathy due to proliferative changes around the C2 pars defects without instability. A 69-year-old man presented with progressive clumsy hands and spastic gait. Plain radiographs showed bilateral spondylolysis (pars defects) at C2 and fusion between C2 and C3 spinous processes. Dynamic views revealed mobility through the pars defects, but there was no apparent instability. Computed tomography showed proliferative changes at the pars defects, which protruded into spinal canal. On magnetic resonance imaging, the spinal cord was compressed and intramedullary high signal change was found. A diagnosis of compression myelopathy due to proliferative changes around the C2 pars defects was made. We performed posterior decompression. Postoperatively, symptoms have been alleviated and images revealed sufficient decompression and no apparent instability. In patients with the cervical spondylolysis, myelopathy caused by instability or slippage have been periodically reported. The present case involving C2 spondylolysis is extremely rare. PMID:27340539

  11. Inhibition of uPAR-TGFβ crosstalk blocks MSC-dependent EMT in melanoma cells.

    PubMed

    Laurenzana, Anna; Biagioni, Alessio; Bianchini, Francesca; Peppicelli, Silvia; Chillà, Anastasia; Margheri, Francesca; Luciani, Cristina; Pimpinelli, Nicola; Del Rosso, Mario; Calorini, Lido; Fibbi, Gabriella

    2015-07-01

    The capacity of cancer cells to undergo epithelial-to-mesenchymal transition (EMT) is now considered a hallmark of tumor progression, and it is known that interactions between cancer cells and mesenchymal stem cells (MSCs) of tumor microenvironment may promote this program. Herein, we demonstrate that MSC-conditioned medium (MSC-CM) is a potent inducer of EMT in melanoma cells. The EMT profile acquired by MSC-CM-exposed melanoma cells is characterized by an enhanced level of mesenchymal markers, including TGFβ/TGFβ-receptors system upregulation, by increased invasiveness and uPAR expression, and in vivo tumor growth. Silencing TGFβ in MSC is found to abrogate ability of MSC to promote EMT characteristics in melanoma cells, together with uPAR expression, and this finding is strengthened using an antagonist peptide of TGFβRIII, the so-called P17. Finally, we demonstrate that the uPAR antisense oligonucleotide (uPAR aODN) may inhibit EMT of melanoma cells either stimulated by exogenous TGFβ or MSC-CM. Thus, uPAR upregulation in melanoma cells exposed to MSC-medium drives TGFβ-mediated EMT. On the whole, TGFβ/uPAR dangerous liaison in cancer cell/MSC interactions may disclose a new strategy to abrogate melanoma progression. Mesenchymal stem cell (MSC)-conditioned medium induces EMT-like profile in melanoma. MSC-derived TGFβ promotes uPAR and TGFβ/TGFβ-receptor upregulation in melanoma. TGFβ gene silencing in MSCs downregulates uPAR expression and EMT in melanoma. uPAR downregulation prevents MSC-induced EMT-like profile in melanoma cells. Inhibition of the dangerous TGFβ/uPAR relationship might abrogate melanoma progression.

  12. PAR Interception and Utilization in Different Maize and Soybean Intercropping Patterns

    PubMed Central

    Liu, Xin; Rahman, Tanzeelur; Yang, Feng; Song, Chun; Yong, Taiwen; Liu, Jiang; Zhang, Cuiying; Yang, Wenyu

    2017-01-01

    The crop intercepted photosynthetically active radiation (PAR) and radiation use efficiency (RUE) vary markedly in different intercropping systems. The HHLA (horizontally homogeneous leaf area) and ERCRT (extended row crop radiation transmission) models have been established to calculate the intercepted PAR for intercrops. However, there is still a lack of study on the intercepted PAR and RUE under different intercropping configurations using different models. To evaluate the intercepted PAR and RUE in maize and soybean under different intercropping systems, we tested different strip intercropping configurations (SI1, SI2, and SI3 based on ERCRT model) and a row intercropping configurations (RI based on HHLA model) in comparison to monoculture. Our results showed that the intercepted PAR and RUE of intercropping systems were all higher than those of monoculture. The soybean intercepted PAR in strip intercropping was 1.35 times greater than that in row intercropping. In row intercropping (RI), the lack of soybean intercepted PAR resulted in a significant reduction of soybean dry matter. Therefore, it is not the recommended configuration for soybean. In strip intercropping patterns, with the distance between maize strip increased by 0.2 m, the intercepted PAR of soybean increased by 20%. The SI2 (maize row spacing at 0.4 m and the distance between maize strip at 1.6 m) was the recommended configuration to achieve the highest value of intercepted PAR and RUE among tested strip intercropping configurations. The method of dry matter estimation using intercepted PAR and RUE is useful in simulated experiments. The simulated value was verified in comparison with experimental data, which confirmed the credibility of the simulation model. Moreover, it also provides help in the development of functional-structural plant model (FSPM). PMID:28056056

  13. Circulating suPAR as a biomarker of disease severity in children with proteinuric glomerulonephritis.

    PubMed

    Soltysiak, Jolanta; Zachwieja, Jacek; Benedyk, Anna; Lewandowska-Stachowiak, Maria; Nowicki, Michal; Ostalska-Nowicka, Danuta

    2016-04-12

    The increase of circulating urokinase plasminogen activator receptor (suPAR) was demonstrated in various diseases showing its prognostic value as well as the link to the inflammatory reaction. In glomerular diseases suPAR was consider to be a causative factor of proteinuria. In present study we aimed to evaluate serum concentration of suPAR in children with primary and secondary glomerulonephritis (GN) and its association with disease severity. The study involved 22 children with minimal change disease (MCD), 9 with primary focal segmental glomerulosclerosis (FSGS), 7 with Henoch-Schönlein nephritis (HSN), 7 with lupus nephritis (LN) and 16 controls. Serum suPAR was significantly higher in children with FSGS and LN than controls (respectively: 4.47±1.39 ng/mL vs. 3.23±0.76 ng/mL; p=0.011 and 6.17±1.12 ng/mL vs. 3.23±0.76 ng/mL; p<0.0001). Further, suPAR was increased in LN when compared to FSGS (p=0.031). In the total group suPAR showed negative correlation with eGFR, serum complement C3 and positive with left ventricular mass index. In children with MCD and FSGS the inverse association of suPAR with eGFR was also shown. In children with primary and secondary glomerulonphritis suPAR levels is not associated with proteinuria. In primary GN elevated suPAR levels may result from reduced eGFR reflecting renal damage. In LN, circulating suPAR can be increased further indicating both multi-organ involvement and systemic inflammation reflecting disease severity.

  14. uPAR and cathepsin B inhibition enhanced radiation-induced apoptosis in gliomainitiating cells

    PubMed Central

    Malla, Rama Rao; Gopinath, Sreelatha; Alapati, Kiranmai; Gorantla, Bharathi; Gondi, Christopher S.; Rao, Jasti S.

    2012-01-01

    Glioblastomas present as diffuse tumors with invasion into normal brain tissue and frequently recur or progress after radiation as focal masses because of glioma-initiating cells. The role of the urokinase-type plasminogen activator receptor (uPAR) and cathepsin B in stem-like phenotype has been extensively studied in several solid tumors. In the present study, we demonstrated that selection of glioma-initiating cells using CD133 expression leads to a specific enrichment of CD133+ cells in both U87 and 4910 cells. In addition, CD133+ cells exhibited a considerable amount of other stem cell markers, such as Nestin and Sox-2. Radiation treatment significantly enhanced uPAR and cathepsin B levels in glioma-initiating cells. To downregulate radiation-induced uPAR and cathepsin B expression, we used a bicistronic shRNA construct that simultaneously targets both uPAR and cathepsin B (pCU). Downregulation of uPAR and cathepsin B using pCU decreased radiation-enhanced uPAR and cathepsin B levels and caused DNA damage-induced apoptosis in glioma cell lines and glioma-initiating cells. The most striking finding of this study is that knockdown of uPAR and cathepsin B inhibited ongoing transcription by suppressing BrUTP incorporation at γH2AX foci. In addition, uPAR and cathepsin B gene silencing inversely regulated survivin and H2AX expression in both glioma cells and glioma-initiating cells. Pretreatment with pCU reduced radiation-enhanced expression of uPAR, cathepsin B, and survivin and enhanced DNA damage in pre-established glioma in nude mice. Taken together, our in vitro and in vivo findings suggest that uPAR and cathepsin B inhibition might serve as an adjunct to radiation therapy to target glioma-initiating cells and, therefore, for the treatment of glioma. PMID:22573309

  15. Résultats de la chirurgie avancée de la cataracte par tunnélisation: à propos de 262 cas réalisés au CHR de Banfora (Burkina Faso)

    PubMed Central

    Djiguimdé, Pierre Windinmanégdé; Diomandé, Ibrahim Abib; Ahnoux-Zabsonré, Ahgbatouhabéba; Koffi, Konan Virgile; Meda, Tierinyê Armand; Diomandé, Gossé François; Sanou, Jerôme; Meda-Hien, Gertude; Sankara, Paté; Meda, Nonfounikoun

    2015-01-01

    La cataracte demeure la première cause de cécité dans les pays en voie de développement posant un problème de santé publique. Le but de cette étude est de faire le bilan d'une activité de chirurgie avancée de la cataracte par la technique dite de « phacoalternative » ou par tunnélisation. Il s'agissait d'une étude prospective de base réalisée au Burkina Faso portant sur la chirurgie de la cataracte par la technique de tunnélisation. L’âge moyen de nos patients atteints de cataracte était de 62,47 ± 12,77 ans avec un sex-ratio de 0,98. La majorité des patients opérés (82,82%) étaient des cultivateurs et des ménagères. L'acuité visuelle de loin était réduite à la perception lumineuse dans 68,70% des cas. La profondeur moyenne de la chambre antérieure était de 2,98 ± 0,53 mm. L’épaisseur moyenne du cristallin était de 3,55 ± 0,75 mm. La longueur axiale moyenne de l’œil de nos patients opérés de la cataracte était de 22,88 ± 0,90 mm. La puissance réfractive moyenne estimée de la cornée était de 43,21 ± 2,03 dioptries chez nos patients. La puissance moyenne estimée de l'implant intra oculaire (IOL) utilisé était de23,11 ± 2,35D. La majorité (79,6%) de nos patients avait une bonne acuité visuelle après la chirurgie de la cataracte par tunnélisation. La chirurgie de la cataracte par tunnélisation est une technique révolutionnaire adaptée aux pays pauvres d'Afrique. Elle permet une lutte efficace à moindre coût contre la cécité par cataracte dans nos régions. La tunnélisation est une technique chirurgicale adaptée pour lutter efficacement contre la cécité due à la cataracte en Afrique. PMID:27022426

  16. Spectrometrie de resines par essais d'impact

    NASA Astrophysics Data System (ADS)

    Blanc, R. H.

    1991-12-01

    éthodes se complètent. Elles évitent tout échauffement du milieu. Elles viennent combler une lacune entre les méthodes vibratoires et ultrasonores en fournissant leurs résultats dans une bande de fréquence de une et demi à deux décades dans la gamme des fréquences audibles, 20Hz-20kHz.

  17. Hong-Ou-Mandel interference of entangled Hermite-Gauss modes

    NASA Astrophysics Data System (ADS)

    Zhang, Yingwen; Prabhakar, Shashi; Rosales-Guzmán, Carmelo; Roux, Filippus S.; Karimi, Ebrahim; Forbes, Andrew

    2016-09-01

    Hong-Ou-Mandel (HOM) interference is demonstrated experimentally for entangled photon pairs in the Hermite-Gauss (HG) basis. We use two Dove prisms in one of the paths of the photons to manipulate the entangled quantum state that enters the HOM interferometer. It is demonstrated that, when entangled photon pairs are in a symmetric Bell state in the Laguerre-Gauss (LG) basis, they will remain symmetric after decomposing them into the HG basis, thereby resulting in no coincidence events after the HOM interference. On the other hand, if the photon pairs are in an antisymmetric Bell state in the LG basis, then they will also be antisymmetric in the HG basis, thereby producing only coincidence events as a result of the HOM interference.

  18. Laser cooling atoms to indistinguishability: Atomic Hong-Ou-Mandel interference and entanglement through spin exchange

    NASA Astrophysics Data System (ADS)

    Kaufman, Adam

    2016-05-01

    Motional control of neutral atoms has a rich history and increasingly interest has turned to single-atom control. In my thesis work, we created a platform to individually prepare single bosonic atoms in highly pure quantum states, by developing methods to laser cool single atoms to the vibrational ground state of optical tweezer traps. Applying this toolset, we observe the atomic Hong-Ou-Mandel effect when we arrange for atom tunneling to play the role of a balanced beam splitter between two optical tweezers. In another experiment, we utilize spin exchange to create entanglement, which we then verify after spatially separating the atoms to observe their non-local correlations. Merging these results with our recent demonstration of deterministic loading of atomic arrays, our results establish the concept of quantum gas assembly, which could be applied to a variety of systems ranging from the production of single dipolar molecules to the assembly of low-entropy arrays of atoms.

  19. Multiparticle Correlations in Mesoscopic Scattering: Boson Sampling, Birthday Paradox, and Hong-Ou-Mandel Profiles

    NASA Astrophysics Data System (ADS)

    Urbina, Juan-Diego; Kuipers, Jack; Matsumoto, Sho; Hummel, Quirin; Richter, Klaus

    2016-03-01

    The interplay between single-particle interference and quantum indistinguishability leads to signature correlations in many-body scattering. We uncover these with a semiclassical calculation of the transmission probabilities through mesoscopic cavities for systems of noninteracting particles. For chaotic cavities we provide the universal form of the first two moments of the transmission probabilities over ensembles of random unitary matrices, including weak localization and dephasing effects. If the incoming many-body state consists of two macroscopically occupied wave packets, their time delay drives a quantum-classical transition along a boundary determined by the bosonic birthday paradox. Mesoscopic chaotic scattering of Bose-Einstein condensates is, then, a realistic candidate to build a boson sampler and to observe the macroscopic Hong-Ou-Mandel effect.

  20. Effects of interactions on the generalized Hong-Ou-Mandel effect

    NASA Astrophysics Data System (ADS)

    Gertjerenken, B.; Kevrekidis, P. G.

    2015-09-01

    We numerically investigate the influence of interactions on the generalized Hong-Ou-Mandel (HOM) effect for bosonic particles in a (quasi-)one-dimensional set-up with weak harmonic confinement and show results for the cases of N = 2, N = 3 and N = 4 bosons interacting with a beam splitter, whose role is played by a δ-barrier. In particular, we focus on the effect of attractive interactions and compare the results with the repulsive case, as well as with the analytically available results for the non-interacting case (that we use as a benchmark). We observe a fermionization effect both for growing repulsive and attractive interactions, i.e., the dip in the HOM coincidence count is progressively smeared out, for increasing interaction strengths. The role of input asymmetries is also explored.

  1. Measurement of photon indistinguishability to a quantifiable uncertainty using a Hong-Ou-Mandel interferometer

    SciTech Connect

    Thomas, Peter J.; Cheung, Jessica Y.; Chunnilall, Christopher J.; Dunn, Malcolm H.

    2010-04-10

    We present a method for using the Hong-Ou-Mandel (HOM) interference technique to quantify photon indistinguishability within an associated uncertainty. The method allows the relative importance of various experimental factors affecting the HOM visibility to be identified, and enables the actual indistinguishability, with an associated uncertainty, to be estimated from experimentally measured quantities. A measurement equation has been derived that accounts for the non-ideal performance of the interferometer. The origin of each term of the equation is explained, along with procedures for their experimental evaluation and uncertainty estimation. These uncertainties are combined to give an overall uncertainty for the derived photon indistinguishability. The analysis was applied to measurements from an interferometer sourced with photon pairs from a parametric downconversion process. The measured photon indistinguishably was found to be 0.954+/-0.036 by using the prescribed method.

  2. Interactions between the hydrology and hydrochemistry of an intermittent southern Mediterranean River- Oued Fez (Morocco)

    NASA Astrophysics Data System (ADS)

    Perrin, J.-L.; Bellarbi, M.; Chahinian, N.; Raïs, N.; Moulin, P.; Ijjaali, M.

    2012-04-01

    Mediterranean catchments are often characterized by highly variable rainfall inputs and intermittent flows. In comparison to the existing knowledge on their hydrological behaviour, the interactions between flow conditions and pollution levels remain less documented. This study aims at filling that gap through a case study on Oued Fez (Morocco). Oued Fez is an intermittent river located in central-eastern Morocco. It has a 615 km2 catchment 10% of which corresponds to the city of Fez, the 3rd biggest in the kingdom (1.2 M inhabitants). Oued Fes is a tributary of the Sebou River, a major body of great economical importance used for irrigation and freshwater supply. A coupled water quality-water quantity monitoring scheme has been implemented on Oued Fez since 2008. In addition to basic hydrological data, water quality samples are collected at regular intervals at 8 locations where discharge is simultaneously measured using an Acoustic Doppler Current Profiler (ADCP). Water samples are analysed for different forms of nitrogen (nitrates, nitrites, ammonium and total nitrogen) and phosphorus (soluble reactive phosphorus and total phosphorus) using a photospectrometer (Hach Lange DR 2800 VIS-photometer (Germany). The results of the study indicate that, despite variations in annual rainfall, the catchment's hydrological response is controlled by the urban impervious zones during floods. The rural areas contribute mostly to baseflow during the wet period while non-treated anthropogenic inputs constitute most of the flow during the dry period. This in turn affects the water quality results. Indeed: - during low flow conditions the pollution levels are very high and total nitrogen and total phosphorus concentrations reach 45 mg/l N and 6.5 mg/l P respectively at the most polluted sites. - during average and high flow conditions the pollution levels decrease due to dilution. Total nitrogen and total phosphorus concentrations reach 32 mg/l N and 3.5 mg/l P respectively with

  3. Hong-Ou-Mandel experiment for temporal investigation of single-electron fractionalization

    PubMed Central

    Freulon, V.; Marguerite, A.; Berroir, J.-M.; Plaçais, B.; Cavanna, A.; Jin, Y.; Fève, G.

    2015-01-01

    Coulomb interaction has a striking effect on electronic propagation in one-dimensional conductors. The interaction of an elementary excitation with neighbouring conductors favours the emergence of collective modes, which eventually leads to the destruction of the Landau quasiparticle. In this process, an injected electron tends to fractionalize into separated pulses carrying a fraction of the electron charge. Here we use two-particle interferences in the electronic analogue of the Hong-Ou-Mandel experiment in a quantum Hall conductor at filling factor 2 to probe the fate of a single electron emitted in the outer edge channel and interacting with the inner one. By studying both channels, we analyse the propagation of the single electron and the generation of interaction-induced collective excitations in the inner channel. These complementary pieces of information reveal the fractionalization process in the time domain and establish its relevance for the destruction of the quasiparticle, which degrades into the collective modes. PMID:25896625

  4. Interactions and Charge Fractionalization in an Electronic Hong-Ou-Mandel Interferometer

    NASA Astrophysics Data System (ADS)

    Wahl, Claire; Rech, Jérôme; Jonckheere, Thibaut; Martin, Thierry

    2014-01-01

    We consider an electronic analog of the Hong-Ou-Mandel (HOM) interferometer, where two single electrons travel along opposite chiral edge states and collide at a quantum point contact. Studying the current noise, we show that because of interactions between copropagating edge states, the degree of indistinguishability between the two electron wave packets is dramatically reduced, leading to reduced contrast for the HOM signal. This decoherence phenomenon strongly depends on the energy resolution of the packets. Insofar as interactions cause charge fractionalization, we show that charge and neutral modes interfere with each other, leading to satellite dips or peaks in the current noise. Our calculations explain recent experimental results [E. Bocquillon, et al., Science 339, 1054 (2013)] where an electronic HOM signal with reduced contrast was observed.

  5. Two-dimensional fermionic Hong-Ou-Mandel interference with massless Dirac fermions

    NASA Astrophysics Data System (ADS)

    Khan, M. A.; Leuenberger, Michael N.

    2014-08-01

    We propose a two-dimensional Hong-Ou-Mandel (HOM) type interference experiment for massless Dirac fermions in graphene and 3D topological insulators. Since massless Dirac fermions exhibit linear dispersion, similar to photons in vacuum, they can be used to obtain the HOM interference intensity pattern as a function of the delay time between two massless Dirac fermions. We show that while the Coulomb interaction leads to a significant change in the angle dependence of the tunneling of two identical massless Dirac fermions incident from opposite sides of a potential barrier, it does not affect the HOM interference pattern. We apply our formalism to develop a massless Dirac fermion beam splitter (BS) for controlling the transmission and reflection coefficients. We calculate the resulting time-resolved correlation function for two identical massless Dirac fermions scattering off the BS.

  6. Hong-Ou-Mandel experiment for temporal investigation of single-electron fractionalization.

    PubMed

    Freulon, V; Marguerite, A; Berroir, J-M; Plaçais, B; Cavanna, A; Jin, Y; Fève, G

    2015-04-21

    Coulomb interaction has a striking effect on electronic propagation in one-dimensional conductors. The interaction of an elementary excitation with neighbouring conductors favours the emergence of collective modes, which eventually leads to the destruction of the Landau quasiparticle. In this process, an injected electron tends to fractionalize into separated pulses carrying a fraction of the electron charge. Here we use two-particle interferences in the electronic analogue of the Hong-Ou-Mandel experiment in a quantum Hall conductor at filling factor 2 to probe the fate of a single electron emitted in the outer edge channel and interacting with the inner one. By studying both channels, we analyse the propagation of the single electron and the generation of interaction-induced collective excitations in the inner channel. These complementary pieces of information reveal the fractionalization process in the time domain and establish its relevance for the destruction of the quasiparticle, which degrades into the collective modes.

  7. Hong-Ou-Mandel experiment for temporal investigation of single-electron fractionalization

    NASA Astrophysics Data System (ADS)

    Freulon, V.; Marguerite, A.; Berroir, J.-M.; Plaçais, B.; Cavanna, A.; Jin, Y.; Fève, G.

    2015-04-01

    Coulomb interaction has a striking effect on electronic propagation in one-dimensional conductors. The interaction of an elementary excitation with neighbouring conductors favours the emergence of collective modes, which eventually leads to the destruction of the Landau quasiparticle. In this process, an injected electron tends to fractionalize into separated pulses carrying a fraction of the electron charge. Here we use two-particle interferences in the electronic analogue of the Hong-Ou-Mandel experiment in a quantum Hall conductor at filling factor 2 to probe the fate of a single electron emitted in the outer edge channel and interacting with the inner one. By studying both channels, we analyse the propagation of the single electron and the generation of interaction-induced collective excitations in the inner channel. These complementary pieces of information reveal the fractionalization process in the time domain and establish its relevance for the destruction of the quasiparticle, which degrades into the collective modes.

  8. Optimal quantum cloning of orbital angular momentum photon qubits through Hong-Ou-Mandel coalescence

    NASA Astrophysics Data System (ADS)

    Nagali, Eleonora; Sansoni, Linda; Sciarrino, Fabio; de Martini, Francesco; Marrucci, Lorenzo; Piccirillo, Bruno; Karimi, Ebrahim; Santamato, Enrico

    2009-12-01

    The orbital angular momentum (OAM) of light, associated with a helical structure of the wavefunction, has great potential in quantum photonics, as it allows a higher dimensional quantum space to be attached to each photon. Hitherto, however, the use of OAM has been hindered by difficulties in its manipulation. Here, by making use of the recently demonstrated spin-OAM information transfer tools, we report the first observation of the Hong-Ou-Mandel coalescence of two incoming photons having non-zero OAM into the same outgoing mode of a beamsplitter. The coalescence can be switched on and off by varying the input OAM state of the photons. Such an effect has then been used to carry out the 1 --> 2 universal optimal quantum cloning of OAM-encoded qubits, using the symmetrization technique already developed for polarization. These results are shown to be scalable to quantum spaces of arbitrary dimensions, even combining different degrees of freedom of the photons.

  9. Spectrally resolved Hong-Ou-Mandel interference between independent photon sources

    NASA Astrophysics Data System (ADS)

    Jin, Rui-Bo; Gerrits, Thomas; Fujiwara, Mikio; Wakabayashi, Ryota; Yamashita, Taro; Miki, Shigehito; Terai, Hirotaka; Shimizu, Ryosuke; Takeoka, Masahiro; Sasaki, Masahide

    2015-11-01

    Hong-Ou-Mandel (HOM) interference between independent photon sources (HOMI-IPS) is the fundamental block for quantum information processing, such as quantum gate, Shor's algorithm, Boson sampling, etc. All the previous HOMI-IPS experiments were carried out in time-domain, however, the spectral information during the interference was lost, due to technical difficulties. Here, we investigate the HOMI-IPS in spectral domain using the recently developed fast fiber spectrometer, and demonstrate the spectral distribution during the HOM interference between two heralded single-photon sources, and two thermal sources. This experiment can not only deepen our understanding of HOMI-IPS in the spectral domain, but also be utilized to improve the visibility by post-processing spectral filtering.

  10. Hong-Ou-Mandel interference of two phonons in trapped ions

    NASA Astrophysics Data System (ADS)

    Toyoda, Kenji; Hiji, Ryoto; Noguchi, Atsushi; Urabe, Shinji

    2015-11-01

    The quantum statistics of bosons and fermions manifest themselves in the manner in which two indistinguishable particles interfere quantum mechanically. When two photons, which are bosonic particles, enter a beam-splitter with one photon in each input port, they bunch together at either of the two output ports. The corresponding disappearance of the coincidence count is the Hong-Ou-Mandel effect. Here we show the phonon counterpart of this effect in a system of trapped-ion phonons, which are collective excitations derived by quantizing vibrational motions that obey Bose-Einstein statistics. We realize a beam-splitter transformation of the phonons by employing the mutual Coulomb repulsion between ions, and perform a two-phonon quantum interference experiment using that transformation. We observe an almost perfect disappearance of the phonon coincidence between two ion sites, confirming that phonons can be considered indistinguishable bosonic particles. The two-particle interference demonstrated here is purely a quantum effect, without a classical counterpart, hence it should be possible to demonstrate the existence of entanglement on this basis. We attempt to generate an entangled state of phonons at the centre of the Hong-Ou-Mandel dip in the coincidence temporal profile, under the assumption that the entangled phonon state is successfully generated if the fidelity of the analysis pulses is taken into account adequately. Two-phonon interference, as demonstrated here, proves the bosonic nature of phonons in a trapped-ion system. It opens the way to establishing phonon modes as carriers of quantum information in their own right, and could have implications for the quantum simulation of bosonic particles and analogue quantum computation via boson sampling.

  11. Hong-Ou-Mandel interference of two phonons in trapped ions.

    PubMed

    Toyoda, Kenji; Hiji, Ryoto; Noguchi, Atsushi; Urabe, Shinji

    2015-11-05

    The quantum statistics of bosons and fermions manifest themselves in the manner in which two indistinguishable particles interfere quantum mechanically. When two photons, which are bosonic particles, enter a beam-splitter with one photon in each input port, they bunch together at either of the two output ports. The corresponding disappearance of the coincidence count is the Hong-Ou-Mandel effect. Here we show the phonon counterpart of this effect in a system of trapped-ion phonons, which are collective excitations derived by quantizing vibrational motions that obey Bose-Einstein statistics. We realize a beam-splitter transformation of the phonons by employing the mutual Coulomb repulsion between ions, and perform a two-phonon quantum interference experiment using that transformation. We observe an almost perfect disappearance of the phonon coincidence between two ion sites, confirming that phonons can be considered indistinguishable bosonic particles. The two-particle interference demonstrated here is purely a quantum effect, without a classical counterpart, hence it should be possible to demonstrate the existence of entanglement on this basis. We attempt to generate an entangled state of phonons at the centre of the Hong-Ou-Mandel dip in the coincidence temporal profile, under the assumption that the entangled phonon state is successfully generated if the fidelity of the analysis pulses is taken into account adequately. Two-phonon interference, as demonstrated here, proves the bosonic nature of phonons in a trapped-ion system. It opens the way to establishing phonon modes as carriers of quantum information in their own right, and could have implications for the quantum simulation of bosonic particles and analogue quantum computation via boson sampling.

  12. Tuberculose du médio-pied, une localisation inhabituelle: à propos d’un cas

    PubMed Central

    Hachimi, Hicham; Tahiri, Latifa; Kadi, Nadira; Ibrahimi, Abdelhalim; Elmrini, Abdelmajid; Harzy, Taoufik

    2012-01-01

    La tuberculose ostéoarticulaire représente 2 à 5% de l’ensemble des tuberculoses, la localisation au médio-pieds est rare. Nous en rapportons le cas d’une patiente âgée de 18 ans, qui présente depuis 2 ans des douleurs du médio-pied droit inflammatoires avec tuméfactio, La radiographie a montré des géodes et des érosions des os naviculaire et cunéiformes. L’IRM a orienté vers le dignostic de tuberculose confirm par biospie et étude anathomopathologique. C’est pourquoi devant tout tableau clinique traînant ou devant toute lésion osseuse suspecte ou de présentation atypique le diagnostic de tuberculose doit être évoqué afin d’éviter un retard diagnostique. PMID:22593789

  13. Proteinase-Activated Receptor-1 and Immunomodulatory Effects of a PAR1-Activating Peptide in a Mouse Model of Prostatitis

    PubMed Central

    Stanton, M. Mark; Nelson, Lisa K.; Benediktsson, Hallgrimur; Hollenberg, Morley D.; Buret, Andre G.; Ceri, Howard

    2013-01-01

    Background. Nonbacterial prostatitis has no established etiology. We hypothesized that proteinase-activated receptor-1 (PAR1) can play a role in prostatitis. We therefore investigated the effects of PAR1 stimulation in the context of a new model of murine nonbacterial prostatitis. Methods. Using a hapten (ethanol-dinitrobenzene sulfonic acid- (DNBS-)) induced prostatitis model with both wild-type and PAR1-null mice, we examined (1) the location of PAR1 in the mouse prostate and (2) the impact of a PAR1-activating peptide (TFLLR-NH2: PAR1-TF) on ethanol-DNBS-induced inflammation. Results. Ethanol-DNBS-induced inflammation was maximal at 2 days. In the tissue, PAR1 was expressed predominantly along the apical acini of prostatic epithelium. Although PAR1-TF on its own did not cause inflammation, its coadministration with ethanol-DNBS reduced all indices of acute prostatitis. Further, PAR1-TF administration doubled the prostatic production of interleukin-10 (IL-10) compared with ethanol-DNBS treatment alone. This enhanced IL-10 was not observed in PAR1-null mice and was not caused by the reverse-sequence receptor-inactive peptide, RLLFT-NH2. Surprisingly, PAR1-TF, also diminished ethanol-DNBS-induced inflammation in PAR1-null mice. Conclusions. PAR1 is expressed in the mouse prostate and its activation by PAR1-TF elicits immunomodulatory effects during ethanol-DNBS-induced prostatitis. However, PAR1-TF also diminishes ethanol-DNBS-induced inflammation via a non-PAR1 mechanism by activating an as-yet unknown receptor. PMID:24459330

  14. Proteinase-activated receptor-1 and immunomodulatory effects of a PAR1-activating peptide in a mouse model of prostatitis.

    PubMed

    Stanton, M Mark; Nelson, Lisa K; Benediktsson, Hallgrimur; Hollenberg, Morley D; Buret, Andre G; Ceri, Howard

    2013-01-01

    Nonbacterial prostatitis has no established etiology. We hypothesized that proteinase-activated receptor-1 (PAR1) can play a role in prostatitis. We therefore investigated the effects of PAR1 stimulation in the context of a new model of murine nonbacterial prostatitis. Using a hapten (ethanol-dinitrobenzene sulfonic acid- (DNBS-)) induced prostatitis model with both wild-type and PAR1-null mice, we examined (1) the location of PAR1 in the mouse prostate and (2) the impact of a PAR1-activating peptide (TFLLR-NH2: PAR1-TF) on ethanol-DNBS-induced inflammation. Ethanol-DNBS-induced inflammation was maximal at 2 days. In the tissue, PAR1 was expressed predominantly along the apical acini of prostatic epithelium. Although PAR1-TF on its own did not cause inflammation, its coadministration with ethanol-DNBS reduced all indices of acute prostatitis. Further, PAR1-TF administration doubled the prostatic production of interleukin-10 (IL-10) compared with ethanol-DNBS treatment alone. This enhanced IL-10 was not observed in PAR1-null mice and was not caused by the reverse-sequence receptor-inactive peptide, RLLFT-NH2. Surprisingly, PAR1-TF, also diminished ethanol-DNBS-induced inflammation in PAR1-null mice. PAR1 is expressed in the mouse prostate and its activation by PAR1-TF elicits immunomodulatory effects during ethanol-DNBS-induced prostatitis. However, PAR1-TF also diminishes ethanol-DNBS-induced inflammation via a non-PAR1 mechanism by activating an as-yet unknown receptor.

  15. Prévalence de l'hépatite B chez les personnes infectées par le VIH à Parakou au Bénin

    PubMed Central

    Dovonou, Comlan Albert; Amidou, Salimanou Ariyoh; Kpangon, Amadohoué Arsène; Traoré, Yacoubou Adam; Godjedo, Togbemabou Primous Martial; Satondji, Assongba Joseph; Wachinou, Ablo Prudence; Issa-Djibril, Fatioulaye Mahamadi; Fourn, Léonard; Zannou, Djimon Marcel; Gandaho, Prosper

    2015-01-01

    Introduction La co-infection avec l'hépatite B est l'un des défis majeurs de la prise en charge du VIH depuis l'amélioration de l'accès aux antirétroviraux en Afrique. La présente étude visait à estimer la prévalence de l'hépatite B chez les personnes séropositives au VIH à Parakou et décrire les facteurs associés. Méthodes Il s'agit d'une étude transversale menée de Mai 2011 à Juin 2012 dans le service de Médecine du CHU de Parakou. Ont été inclus tous les adultes séropositifs au VIH vus en consultation ou hospitalisés. Les données ont été collectées par interviews et dépouillement de dossiers médicaux. L'antigène HBs a été recherché par un test rapide et l'ALAT a été dosé. L'analyse des données a été faite avec le logiciel EpiInfo 3.5.1. Les proportions ont été comparées grâce au test de Chi-deux ou au test de Fisher au seuil de significativité de 5%. Un modèle de régression logistique multivariable a permis d'expliquer la prévalence de l'hépatite B. Résultats Sur les 744 sujets inclus on a dénombré 555 femmes. L’âge moyen était de 35,5 + 10,1 ans. La prévalence de l'hépatite B a été estimée à 16,9% (IC95: 14,3%-19,9%). Cette prévalence était plus élevée chez les sujets originaires du Borgou/Alibori et ceux au stade 4 de l'OMS. Conclusion La prévalence de la co-infection VIH/VHB au CHU Parakou est élevée. Le dispositif national de prise en charge et de prévention de l'hépatite B chez les personnes séropositives au VIH doit être renforcé. PMID:26097629

  16. La prise en charge des troubles de santé mentale par les omnipraticiens du Québec

    PubMed Central

    Fleury, Marie-Josée; Farand, Lambert; Aubé, Denise; Imboua, Armelle

    2012-01-01

    Résumé Objectif Cette recherche vise à documenter la prise en charge des troubles mentaux (TM) par les omnipraticiens. Type d’étude Il s’agit d’une étude mixte intégrant un questionnaire auto-administré et des entrevues qualitatives. La banque de données administratives des actes médicaux de la Régie de l’assurance maladie du Québec a aussi été analysée. Contexte La province de Québec. Participants Un total de 1415 omnipraticiens de différents lieux de pratiques ont été sollicités pour le questionnaire; 970 ont été rejoints. Un sous-groupe de 60 omnipraticiens a été rejoint pour les entrevues. Principaux paramètres à l'étude La prévalence annuelle des consultations reliées à des TM courants (TMC) ou graves (TMG), les pratiques cliniques, les pratiques de collaboration, les facteurs facilitant ou entravant la prise en charge des TM, ainsi que les recommandations pour l’amélioration du système de soins. Résultats Le taux de réponse a été de 41% (n = 398 omnipraticiens) pour le questionnaire et de 63% (n = 60) pour les entrevues. Environ 25 % des visites chez les omnipraticiens sont associées à des TM. Presque tous les omnipraticiens prennent en charge des TMC et se sentent compétents pour le faire, à l’inverse de la situation retrouvée pour les TMG. Près de 20 % des TMC sont référés (principalement à des intervenants psychosociaux), alors que près de 75 % des TMG sont référés (surtout en psychiatrie et à l’urgence). Plus de 50 % des omnipraticiens affirment n’entretenir aucun contact avec l’une ou l’autre des ressources de santé mentale. Plusieurs facteurs influencent la prise en charge des TM: les profils des patients (complexité des TM, troubles concomitants); les caractéristiques des omnipraticiens (réseau informel, formation); la culture professionnelle (travail en silo, mécanismes cliniques formalisés); le milieu institutionnel (multidisciplinarité, salariat); l’organisation des

  17. Régulation de la production, par des cellules endothéliales, de cytokines pro-inflammatoires après irradiation

    NASA Astrophysics Data System (ADS)

    van der Meeren, A.; Lafont, H.; Mathé, D.

    1998-04-01

    Gamma irradiation leads to an increased production of interleukin- (IL)-6 and IL-8 by human endothelial cells. In order to regulate the radio-induced production of these pro-inflammatory cytokines, we used the immunoregulatory cytokines IL-4 and IL-10. These agents were added either before or after a 10 Gy-irradiation. Our results show that it is possible to decrease the radio-induced production of IL-6 and IL-8 with the use of IL-4 and IL-10. Differences in the intensity of the response have been observed according to the time of treatment. The anti-inflammatory potential of both IL-4 and IL-10 was more pronounced when added after irradiation. Après irradiation gamma, des cellules endothéliales humaines ont une production accrue des interleukines (IL-) -6 et -8. Dans le but de réguler la production de ces cytokines pro-inflammatoires, nous avons utilisé des cytokines dites anti-inflammatoires, l'IL-4 et l'IL-10. Ces agents ont été ajoutés soit avant soit après une irradiation de 10Gy. Nos résultats montrent qu'il est possible de diminuer les productions radio-induites d'IL-6 et d'IL-8 par l'IL-4 et l'IL-10. Des différences dans l'intensité de la réponse ont toutefois été observées selon que l'IL-4 ou l'IL-10 ont été ajoutées avant ou après irradiation; leur efficacité anti-inflammatoire étant plus marquée lorsque les cytokines sont ajoutées après l'irradiation.

  18. PAR1 activation induces rapid changes in glutamate uptake and astrocyte morphology

    PubMed Central

    Sweeney, Amanda M.; Fleming, Kelsey E.; McCauley, John P.; Rodriguez, Marvin F.; Martin, Elliot T.; Sousa, Alioscka A.; Leapman, Richard D.; Scimemi, Annalisa

    2017-01-01

    The G-protein coupled, protease-activated receptor 1 (PAR1) is a membrane protein expressed in astrocytes. Fine astrocytic processes are in tight contact with neurons and blood vessels and shape excitatory synaptic transmission due to their abundant expression of glutamate transporters. PAR1 is proteolytically-activated by bloodstream serine proteases also involved in the formation of blood clots. PAR1 activation has been suggested to play a key role in pathological states like thrombosis, hemostasis and inflammation. What remains unclear is whether PAR1 activation also regulates glutamate uptake in astrocytes and how this shapes excitatory synaptic transmission among neurons. Here we show that, in the mouse hippocampus, PAR1 activation induces a rapid structural re-organization of the neuropil surrounding glutamatergic synapses, which is associated with faster clearance of synaptically-released glutamate from the extracellular space. This effect can be recapitulated using realistic 3D Monte Carlo reaction-diffusion simulations, based on axial scanning transmission electron microscopy (STEM) tomography reconstructions of excitatory synapses. The faster glutamate clearance induced by PAR1 activation leads to short- and long-term changes in excitatory synaptic transmission. Together, these findings identify PAR1 as an important regulator of glutamatergic signaling in the hippocampus and a possible target molecule to limit brain damage during hemorrhagic stroke. PMID:28256580

  19. Improved Satellite-based Photosysnthetically Active Radiation (PAR) for Air Quality Studies

    NASA Astrophysics Data System (ADS)

    Pour Biazar, A.; McNider, R. T.; Cohan, D. S.; White, A.; Zhang, R.; Dornblaser, B.; Doty, K.; Wu, Y.; Estes, M. J.

    2015-12-01

    One of the challenges in understanding the air quality over forested regions has been the uncertainties in estimating the biogenic hydrocarbon emissions. Biogenic volatile organic compounds, BVOCs, play a critical role in atmospheric chemistry, particularly in ozone and particulate matter (PM) formation. In southeastern United States, BVOCs (mostly as isoprene) are the dominant summertime source of reactive hydrocarbon. Despite significant efforts in improving BVOC estimates, the errors in emission inventories remain a concern. Since BVOC emissions are particularly sensitive to the available photosynthetically active radiation (PAR), model errors in PAR result in large errors in emission estimates. Thus, utilization of satellite observations to estimate PAR can help in reducing emission uncertainties. Satellite-based PAR estimates rely on the technique used to derive insolation from satellite visible brightness measurements. In this study we evaluate several insolation products against surface pyranometer observations and offer a bias correction to generate a more accurate PAR product. The improved PAR product is then used in biogenic emission estimates. The improved biogenic emission estimates are compared to the emission inventories over Texas and used in air quality simulation over the period of August-September 2013 (NASA's Discover-AQ field campaign). A series of sensitivity simulations will be performed and evaluated against Discover-AQ observations to test the impact of satellite-derived PAR on air quality simulations.

  20. Evidence for a DNA-relay mechanism in ParABS-mediated chromosome segregation.

    PubMed

    Lim, Hoong Chuin; Surovtsev, Ivan Vladimirovich; Beltran, Bruno Gabriel; Huang, Fang; Bewersdorf, Jörg; Jacobs-Wagner, Christine

    2014-05-23

    The widely conserved ParABS system plays a major role in bacterial chromosome segregation. How the components of this system work together to generate translocation force and directional motion remains uncertain. Here, we combine biochemical approaches, quantitative imaging and mathematical modeling to examine the mechanism by which ParA drives the translocation of the ParB/parS partition complex in Caulobacter crescentus. Our experiments, together with simulations grounded on experimentally-determined biochemical and cellular parameters, suggest a novel 'DNA-relay' mechanism in which the chromosome plays a mechanical function. In this model, DNA-bound ParA-ATP dimers serve as transient tethers that harness the elastic dynamics of the chromosome to relay the partition complex from one DNA region to another across a ParA-ATP dimer gradient. Since ParA-like proteins are implicated in the partitioning of various cytoplasmic cargos, the conservation of their DNA-binding activity suggests that the DNA-relay mechanism may be a general form of intracellular transport in bacteria.DOI: http://dx.doi.org/10.7554/eLife.02758.001.

  1. Par-4/NF-κB Mediates the Apoptosis of Islet β Cells Induced by Glucolipotoxicity

    PubMed Central

    QiNan, Wu; XiaGuang, Gan; XiaoTian, Lei; WuQuan, Deng; Ling, Zhang; Bing, Chen

    2016-01-01

    Apoptosis of islet β cells is a primary pathogenic feature of type 2 diabetes, and ER stress and mitochondrial dysfunction play important roles in this process. Previous research has shown that prostate apoptosis response-4 (Par-4)/NF-κB induces cancer cell apoptosis through endoplasmic reticulum (ER) stress and mitochondrial dysfunction. However, the mechanism by which Par-4/NF-κB induces islet β cell apoptosis remains unknown. We used a high glucose/palmitate intervention to mimic type 2 diabetes in vitro. We demonstrated that the high glucose/palmitate intervention induced the expression and secretion of Par-4. It also causes increased expression and activation of NF-κB, which induced NIT-1 cell apoptosis and dysfunction. Overexpression of Par-4 potentiates these effects, whereas downregulation of Par-4 attenuates them. Inhibition of NF-κB inhibited the Par-4-induced apoptosis. Furthermore, these effects occurred through the ER stress cell membrane and mitochondrial pathway of apoptosis. Our findings reveal a novel role for Par-4/NF-κB in islet β cell apoptosis and type 2 diabetes. PMID:27340675

  2. Protease-activated receptors (PARs)--biology and role in cancer invasion and metastasis.

    PubMed

    Wojtukiewicz, Marek Z; Hempel, Dominika; Sierko, Ewa; Tucker, Stephanie C; Honn, Kenneth V

    2015-12-01

    Although many studies have demonstrated that components of the hemostatic system may be involved in signaling leading to cancer progression, the potential mechanisms by which they contribute to cancer dissemination are not yet precisely understood. Among known coagulant factors, tissue factor (TF) and thrombin play a pivotal role in cancer invasion. They may be generated in the tumor microenvironment independently of blood coagulation and can induce cell signaling through activation of protease-activated receptors (PARs). PARs are transmembrane G-protein-coupled receptors (GPCRs) that are activated by a unique proteolytic mechanism. They play important roles in vascular physiology, neural tube closure, hemostasis, and inflammation. All of these agents (TF, thrombin, PARs-mainly PAR-1 and PAR-2) are thought to promote cancer invasion and metastasis at least in part by facilitating tumor cell migration, angiogenesis, and interactions with host vascular cells, including platelets, fibroblasts, and endothelial cells lining blood vessels. Here, we discuss the role of PARs and their activators in cancer progression, focusing on TF- and thrombin-mediated actions. Therapeutic options tailored specifically to inhibit PAR-induced signaling in cancer patients are presented as well.

  3. Targeting uPAR with antagonistic recombinant human antibodies in aggressive breast cancer.

    PubMed

    LeBeau, Aaron M; Duriseti, Sai; Murphy, Stephanie T; Pepin, Francois; Hann, Byron; Gray, Joe W; VanBrocklin, Henry F; Craik, Charles S

    2013-04-01

    Components of the plasminogen activation system, which are overexpressed in aggressive breast cancer subtypes, offer appealing targets for development of new diagnostics and therapeutics. By comparing gene expression data in patient populations and cultured cell lines, we identified elevated levels of the urokinase plasminogen activation receptor (uPAR, PLAUR) in highly aggressive breast cancer subtypes and cell lines. Recombinant human anti-uPAR antagonistic antibodies exhibited potent binding in vitro to the surface of cancer cells expressing uPAR. In vivo these antibodies detected uPAR expression in triple negative breast cancer (TNBC) tumor xenografts using near infrared imaging and (111)In single-photon emission computed tomography. Antibody-based uPAR imaging probes accurately detected small disseminated lesions in a tumor metastasis model, complementing the current clinical imaging standard (18)F-fluorodeoxyglucose at detecting non-glucose-avid metastatic lesions. A monotherapy study using the antagonistic antibodies resulted in a significant decrease in tumor growth in a TNBC xenograft model. In addition, a radioimmunotherapy study, using the anti-uPAR antibodies conjugated to the therapeutic radioisotope (177)Lu, found that they were effective at reducing tumor burden in vivo. Taken together, our results offer a preclinical proof of concept for uPAR targeting as a strategy for breast cancer diagnosis and therapy using this novel human antibody technology.

  4. Blocking PAR2 Alleviates Bladder Pain and Hyperactivity via TRPA1 Signal.

    PubMed

    Chen, Daihui; Liu, Nian; Li, Mao; Liang, Simin

    2016-01-01

    Bladder disorders associated with interstitial cystitis are frequently characterized by increased contractility and pain. The goals of this study were to examine 1) the effects of blocking proteinase-activated receptor-2 (PAR2) on the exaggerated bladder activity and pain evoked by cystitis and 2) the underlying mechanisms responsible for the role of PAR2 in regulating cystic sensory activity. The protein expression of PAR2 was amplified in rats with cystitis by inducing it with systemic administration of cyclophosphamide (CYP) as compared with control rats. Blocking PAR2 by intrathecal infusion of PAR2 antagonist FSLLRY-NH2 attenuated bladder hyperactivity and pain. In addition, blocking PAR2 attenuated the transient receptor potential A1 (TRPA1) signal pathway, whereas inhibition of the TRPA1 decreased bladder hyperactivity and pain. The data revealed specific signaling pathways leading to CYP-induced bladder hyperactivity and pain, including the activation of PAR2 and TRPA1. Inhibition of these pathways alleviates cystic pain. Targeting one or more of these signaling molecules may present new opportunities for treatment and management of overactive bladder and pain often observed in cystitis.

  5. Blocking PAR2 Alleviates Bladder Pain and Hyperactivity via TRPA1 Signal

    PubMed Central

    Chen, Daihui; Liu, Nian; Li, Mao

    2016-01-01

    Abstract Bladder disorders associated with interstitial cystitis are frequently characterized by increased contractility and pain. The goals of this study were to examine 1) the effects of blocking proteinase-activated receptor-2 (PAR2) on the exaggerated bladder activity and pain evoked by cystitis and 2) the underlying mechanisms responsible for the role of PAR2 in regulating cystic sensory activity. The protein expression of PAR2 was amplified in rats with cystitis by inducing it with systemic administration of cyclophosphamide (CYP) as compared with control rats. Blocking PAR2 by intrathecal infusion of PAR2 antagonist FSLLRY-NH2 attenuated bladder hyperactivity and pain. In addition, blocking PAR2 attenuated the transient receptor potential A1 (TRPA1) signal pathway, whereas inhibition of the TRPA1 decreased bladder hyperactivity and pain. The data revealed specific signaling pathways leading to CYP-induced bladder hyperactivity and pain, including the activation of PAR2 and TRPA1. Inhibition of these pathways alleviates cystic pain. Targeting one or more of these signaling molecules may present new opportunities for treatment and management of overactive bladder and pain often observed in cystitis. PMID:28123833

  6. PAR-2 receptor-induced effects on human eccrine sweat gland cells.

    PubMed

    L Bovell, Douglas; Kofler, Barbara; Lang, Roland

    2009-01-01

    Serine proteases can induce cell signaling by stimulating G-protein-coupled receptors, called proteinase-activated receptors (PAR's) on a variety of epithelial cells. While PAR-2, one such receptor, activates cell signaling in a secretory cell line derived from human sweat glands, there was no information on their presence and effects on intact sweat glands. PAR-2 presence and activation of eccrine sweat glands isolated from human skin samples was investigated using Western blot analysis, immunohistochemistry, electron microscopy (EM) and Ca(2+) imaging. Anti-human PAR-2 antibody demonstrated the presence of these receptors in eccrine sweat glands. EM showed that PAR-2 activation resulted in degranulation of secretory cells. Ca(2+) imaging using PAR-2 activators demonstrated a two phase increase in [Ca(2+)](i) which was dependent on extracellular Ca(2+) for the second phase, and that the response could be blocked by prior incubation with xestospongin, the IP(3) receptor blocker. The results demonstrated that PAR-2 receptors are present in human sweat gland secretory cells and that these receptors are functionally active and can induce changes associated with secretory events in eccrine glands.

  7. CERCLA interim action at the Par Pond unit: A case study

    SciTech Connect

    Hickey, H.M.; Matthews, S.S.; Neal, L.W.; Weiss, W.R.

    1993-11-01

    The Par Pond unit designated under CERCLA consists of sediments within a Savannah River Site (SRS) cooling water reservoir. The sediments are contaminated with radionuclides and nonradioactive constituents from nuclear production reactor operations. The mercury in Par Pond is believed to have originated from the Savannah River. Because of Par Pond Dam safety Issues, the water level of the reservoir was drawn down, exposing more than 1300 acres of contaminated sediments and triggering the need for CERCLA interim remedial action. This paper presents the interim action approach taken with Par Pond as a case study. The approach considered the complexity of the Par Pond ecosystem, the large size of Par Pond, the volume of contaminated sediments, and the institutional controls existing at SRS. The Environmental Protection Agency (EPA) considers units with large volumes of low-concentration wastes, as is the case with Par Pond, to be {open_quotes}special sites.{close_quotes} Accordingly, EPA guidance establishes that the range of alternatives developed focus primarily on containment options and other remedial approaches that mitigate potential risks associated with the {open_quotes}special site.{close_quotes} The remedial alternatives, according to EPA, are not to be prohibitively expensive or difficult to implement. This case study also is representative of the types of issues that will need to be addressed within the Department of Energy (DOE) complex as nuclear facilities are transitioned to inactive status and corrective/remedial actions are warranted.

  8. Proteinase-activated receptors (PARs) – focus on receptor-receptor-interactions and their physiological and pathophysiological impact

    PubMed Central

    2013-01-01

    Proteinase-activated receptors (PARs) are a subfamily of G protein-coupled receptors (GPCRs) with four members, PAR1, PAR2, PAR3 and PAR4, playing critical functions in hemostasis, thrombosis, embryonic development, wound healing, inflammation and cancer progression. PARs are characterized by a unique activation mechanism involving receptor cleavage by different proteinases at specific sites within the extracellular amino-terminus and the exposure of amino-terminal “tethered ligand“ domains that bind to and activate the cleaved receptors. After activation, the PAR family members are able to stimulate complex intracellular signalling networks via classical G protein-mediated pathways and beta-arrestin signalling. In addition, different receptor crosstalk mechanisms critically contribute to a high diversity of PAR signal transduction and receptor-trafficking processes that result in multiple physiological effects. In this review, we summarize current information about PAR-initiated physical and functional receptor interactions and their physiological and pathological roles. We focus especially on PAR homo- and heterodimerization, transactivation of receptor tyrosine kinases (RTKs) and receptor serine/threonine kinases (RSTKs), communication with other GPCRs, toll-like receptors and NOD-like receptors, ion channel receptors, and on PAR association with cargo receptors. In addition, we discuss the suitability of these receptor interaction mechanisms as targets for modulating PAR signalling in disease. PMID:24215724

  9. [Development of agonists/antagonists for protease-activated receptors (PARs) and the possible therapeutic application to gastrointestinal diseases].

    PubMed

    Sekiguchi, Fumiko

    2005-06-01

    Protease-activated receptors (PARs), a family of G-protein-coupled seven-transmembrane-domain receptors, are activated by proteolytic unmasking of the N-terminal cryptic tethered ligand by certain serine proteases. Among four PAR family members cloned to date, PAR-1, PAR-2, and PAR-4 can also be activated through a non-enzymatic mechanism, which is achieved by direct binding of exogenously applied synthetic peptides based on the tethered ligand sequence, known as PARs-activating peptides, to the body of the receptor. Various peptide mimetics have been synthesized as agonists for PARs with improved potency, selectivity, and stability. Some peptide mimetics and/or nonpeptide compounds have also been developed as antagonists for PAR-1 and PAR-4. PARs are widely distributed in the mammalian body, especially throughout the alimentary systems, and play various roles in physiological/pathophysiological conditions, i.e., modulation of salivary, gastric, or pancreatic glandular exocrine secretion, gastrointestinal smooth muscle motility, gastric mucosal cytoprotection, suppression/facilitation of visceral pain and inflammation, etc. Thus PARs are now considered novel therapeutic targets, and development of selective agonists and/or antagonists for PARs might provide a novel strategy for the treatment of various diseases that are resistant to current therapeutics.

  10. Design of 118 MHz twelfth harmonic cavity of APS PAR

    SciTech Connect

    Kang, Y.W.; Kustom, R.L.; Bridges, J.F.

    1992-10-22

    Two radio frequency (RF) cavities are needed in the Positron Accumulator Ring (PAR) of the Advanced Photon Source. One is for the first harmonic frequency at 9.8 MHz, and the other is for the twelfth harmonic frequency at 118 MHz. This note reports on the design of the 118 MHz RF cavity. Computer models are used to find the mode frequencies, impedances, Q-factors, and field distributions in the cavity. The computer codes MAFIA, URMEL, and URMEL-T are useful tools which model and simulate the resonance characteristics of a cavity. These codes employ the finite difference method to solve Maxwell`s equations. MAFIA is a three-dimensional problem solver and uses square patches to approximate the inner surface of a cavity. URMEL and URMEL-T are two-dimensional problem solvers and use rectangular and triangular meshes, respectively. URMEL-T and MAFIA can handle problems with arbitrary dielectric materials located inside the boundary. The cavity employs a circularly cylindrical ceramic window to limit the vacuum to the beam pipe. The ceramic window used in the modeling will have a wall thickness of 0.9 cm. This wall thickness is not negligible in determining the resonant frequencies of the cavity. In the following, results of two- and three-dimensional modeling of the cavities using the URMEL-T and MAFIA codes are reported.

  11. [Association of epiretinal membranes with macular edema in pars planitis].

    PubMed

    Salcedo-Villanueva, G; Arellanes-García, L; Fromow-Guerra, J; Hernández-Quintela, E

    2014-01-01

    Pars planitis (PP) is a form of intermediate uveitis that manifests with several posterior segment complications, including cystoid macular edema (CME) and epiretinal membrane formation (ERM). On the presence of CME the patient is usually treated with anti-inflammatory and/or immunosuppressive drugs. However the presence of CME may coexist with ERM formation, and therefore the treatment could be different. To determine the association between ERM and CME in PP. Case control series. The charts of patients diagnosed with PP were retrospectively reviewed. All patients had fluorescein angiogram (FA) and spectral domain optical coherence tomography (SD-OCT). Presence of ERM was determined by SD-OCT, while CME was determined by FA. Contingency tables were used to determine the risk of developing CME with ERM. 31 eyes presented ERM. 16 eyes presented CME. Relative risk to have CME and ERM was 0.971, with a P value of 0.77 (χ(2)). There is no association between ERM formation and the development of CME. There is no evidence to suggest a surgical approach as first line of treatment with the presence of ERM in PP. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  12. Plaies des membres par agression: analyse de 245 dossiers

    PubMed Central

    Boufettal, Monsef; Mahfoud, Mustapha; Ismael, Farid; Kharmaz, Mohamed; Bardouni, Ahmed El; Berrada, Mohamed Saleh; Yaacoubi, Moradh El

    2015-01-01

    Il s'agit d'une étuderétrospective, analytique, monocentrique rentrant dans le cadre d'une étude épidémiologique s’étalant sur une période de trois années (de 2010 à 2012) durant laquelle nous avons revu les dossiers de 245 patients victimes de violence et d'agression. Nous avons exclu les lésions simples traitées en ambulatoire. Par conséquent, nous nous sommes limités aux cas de blessures ayant nécessité une prise en charge spécialisée au bloc opératoire. Les objectifs de notre travail étaient de connaitre la fréquence des agressions au service de traumatologie du CHU de Rabat, classer les différents types de lésions, évaluer leur gravité, mettre la lumière sur les populations les plus touchées et enfin montrer les différentes modalités de prise en charge thérapeutiques. PMID:26918078

  13. Photometric monitoring of the young star Par 1724 in Orion

    NASA Astrophysics Data System (ADS)

    Neuhäuser, R.; Koeltzsch, A.; Raetz, St.; Schmidt, T. O. B.; Mugrauer, M.; Young, N.; Bertoldi, F.; Roell, T.; Eisenbeiss, T.; Hohle, M. M.; Vaňko, M.; Ginski, C.; Rammo, W.; Moualla, M.; Broeg, C.

    2009-05-01

    We report new photometric observations of the ˜ 200 000 year old naked weak-line run-away T Tauri star Par 1724, located north of the Trapezium cluster in Orion. We observed in the broad band filters B, V, R, and I using the 90 cm Dutch telescope on La Silla, the 80 cm Wendelstein telescope, and a 25 cm telescope of the University Observatory Jena in Großschwabhausen near Jena. The photometric data in V and R are consistent with a ˜ 5.7 day rotation period due to spots, as observed before between 1960ies and 2000. Also, for the first time, we present evidence for a long-term 9 or 17.5 year cycle in photometric data (V band) of such a young star, a cycle similar to that to of the Sun and other active stars. Based on observations obtained with telescopes of the University Observatory Jena, which is operated by the Astrophysical Institute of the Friedrich-Schiller-University; a telescope of the University Observatory Munich on Mount Wendelstein, the 0.9m ESO-Dutch telescope on La Silla, Chile, and with the All Sky Automated Survey (ASAS) project (www.astrouw.edu.pl/asas).

  14. Modelisation numerique et validation experimentale d'un systeme de protection contre le givre par elements piezoelectriques

    NASA Astrophysics Data System (ADS)

    Harvey, Derek

    Le degivrage au moyen d'actuateurs piezoelectriques est considere comme une avenue prometteuse pour le developpement de systemes a faible consommation d'energie applicables aux helicopteres legers. Ce type de systeme excite des frequences de resonances d'une structure pour produire des deformations suffisantes pour rompre l'adherence de la glace. Par contre, la conception de tel systeme demeure generalement mal comprise. Ce projet de maitrise etudie l'utilisation de methodes numeriques pour assister la conception des systemes de protection contre le givre a base d'elements piezoelectriques. La methodologie retenue pour ce projet a ete de modeliser differentes structures simples et de simuler l'excitation harmonique des frequences de resonance au moyen d'actuateurs piezoelectriques. Le calcul des frequences de resonances ainsi que la simulation de leur excitation a ensuite ete validee a l'aide de montages experimentaux. La procedure a ete realisee pour une poutre en porte-a-faux et pour une plaque plane a l'aide du logiciel de calcul par elements finis, Abaqus. De plus, le modele de la plaque plane a ete utilise afin de realiser une etude parametrique portant sur le positionnement des actuateurs, l'effet de la rigidite ainsi que de l'epaisseur de la plaque. Finalement, la plaque plane a ete degivree en chambre climatique. Des cas de degivrage ont ete simules numeriquement afin d'etudier la possibilite d'utiliser un critere base sur la deformation pour predire le succes du systeme. La validation experimentale a confirme la capacite du logiciel a calculer precisement a la fois les frequences et les modes de resonance d'une structure et a simuler leur excitation par des actuateurs piezoelectriques. L'etude revele que la definition de l'amortissement dans le modele numerique est essentiel pour l'obtention de resultats precis. Les resultats de l'etude parametrique ont demontre l'importance de minimiser l'epaisseur et la rigidite afin de reduire la valeur des frequences

  15. Caractérisation par ellipsométrie spectroscopique de films minces de tellurure de bismuth obtenus par voie électrochimique

    NASA Astrophysics Data System (ADS)

    Zimmer, A.; Stein, N.; Boulanger, C.; Johann, L.

    2004-12-01

    Des films de tellurure de bismuth (Bi2Te3) d’épaisseur proche de 1 mm ont été développés par voie électrochimique. Leurs indices optiques ont été déterminés par ellipsométrie spectroscopique (SE). Le domaine spectral des indices optiques s’étend de 400 nm à 1300 nm. L’ellipsométrie spectroscopique à angle d’incidence variable (VASE) a été utilisée pour corréler les données SE. Cette partie a été complétée par des analyses par microscopie à force atomique (AFM) qui ont permis de déterminer la rugosité des films. A partir de ces résultats et en associant l’absorption fondamentale des films de Bi2Te3 à une transition indirecte, l’énergie de bande interdite a été évaluée à 0,3 eV. Par ailleurs des mesures associant ellipsométrie spectroscopique à temps réel et électrochimie ont pu être réalisées. Ainsi les premiers instants de croissance ont été observés.

  16. Small caliber arterial endothelial cells calcium signals elicited by PAR2 are preserved from endothelial dysfunction

    PubMed Central

    Hennessey, John C; Stuyvers, Bruno D; McGuire, John J

    2015-01-01

    Endothelial cell (EC)-dependent vasodilation by proteinase-activated receptor 2 (PAR2) is preserved in small caliber arteries in disease states where vasodilation by muscarinic receptors is decreased. In this study, we identified and characterized the PAR2-mediated intracellular calcium (Ca2+)-release mechanisms in EC from small caliber arteries in healthy and diseased states. Mesenteric arterial EC were isolated from PAR2 wild-type (WT) and null mice, after saline (controls) or angiotensin II (AngII) infusion, for imaging intracellular calcium and characterizing the calcium-release system by immunofluorescence. EC Ca2+ signals comprised two forms of Ca2+-release events that had distinct spatial-temporal properties and occurred near either the plasmalemma (peripheral) or center of EC. In healthy EC, PAR2-dependent increases in the densities and firing rates of both forms of Ca2+-release were abolished by inositol 1,4,5- trisphosphate receptor (IP3R) inhibitor, but partially reduced by transient potential vanilloid channels inhibitor ruthenium red (RR). Acetylcholine (ACh)-induced less overall Ca2+-release than PAR2 activation, but enhanced selectively the incidence of central events. PAR2-dependent Ca2+-activity, inhibitors sensitivities, IP3R, small- and intermediate-conductance Ca2+-activated potassium channels expressions were unchanged in EC from AngII WT. However, the same cells exhibited decreases in ACh-induced Ca2+-release, RR sensitivity, and endothelial nitric oxide synthase expression, indicating AngII-induced dysfunction was differentiated by receptor, Ca2+-release, and downstream targets of EC activation. We conclude that PAR2 and muscarinic receptors selectively elicit two elementary Ca2+ signals in single EC. PAR2-selective IP3R-dependent peripheral Ca2+-release mechanisms are identical between healthy and diseased states. Further study of PAR2-selective Ca2+-release for eliciting pathological and/or normal EC functions is warranted. PMID:25729579

  17. Evaluation of orthodontists' perception of treatment need and the peer assessment rating (PAR) index.

    PubMed

    McGorray, S P; Wheeler, T T; Keeling, S D; Yurkiewicz, L; Taylor, M G; King, G J

    1999-08-01

    This paper examines the relationship between orthodontists' subjective assessment of treatment need and objective measurements obtained during standardized intra- and extraoral examinations. Logistic regression modeling was used to develop predictive models of treatment need. Data were obtained from 1155 eighth-grade students by four orthodontists who used standardized examination forms to assess demographics, trauma, skeletal relationships, morphologic malocclusion traits, and mandibular function. At the conclusion of the examination, the orthodontist rated the subjective treatment need as none, elective, recommended, soon, or immediate. For some analyses, the categories were collapsed to represent no need and need. The peer assessment rating (PAR) index (American validated version) was computed from the clinical exam findings and scoring of dental models; PAR scores were used to document malocclusion severity and treatment difficulty. Spearman rank correlation coefficients quantified the relationship between PAR scores and need categories. Logistic regression analysis modeled treatment need using components of the PAR index as well as other variables. The components of these models, as well as sensitivity and specificity, were compared with malocclusion severity/treatment difficulty scores obtained from malocclusion assessments using the PAR index. The five subjective treatment need categories and the PAR index scores were significantly correlated (rho = 0.62, p<0.001). Significant differences were detected between the need and no need groups for all PAR components (p<0.001). PAR index scores and predicted probabilities from logistic regression models performed equally well for classification purposes (no need, need). The data suggest that the PAR index is highly correlated with orthodontists' subjective assessment of treatment need when that assessment is made in the absence of financial considerations and patient desires.

  18. Expression of prostate apoptosis response (Par-4) is associated with progesterone receptor in breast cancer.

    PubMed

    Zapata-Benavides, Pablo; Méndez-Vázquez, José L; González-Rocha, Talina R; Zamora-Avila, Diana E; Franco-Molina, Moises A; Garza-Garza, Raúl; Rodriguez-Padilla, Cristina

    2009-10-01

    The prostate apoptosis response (Par-4) gene encodes a proapoptotic protein that selectively induces apoptosis in cancer cells after diverse apoptotic stimuli. Par-4 expression and its association with other biomarkers have not been reported in breast cancer. The purpose of this study was to determine Par-4 expression in breast cancer samples and its association with other biomarkers and clinical factors (T-stage, age, nodal status). Paraffin-embedded section samples of breast cancer were evaluated by immunohistochemical analysis to determine Par-4, estrogen receptor (ER), progesterone receptor (PgR), c-erbB2, Ki67, p53 and bcl-2 expression. The correlation between Par-4 and the other biomarkers and clinical factors was determined by multivariate analysis. Thirty five percent (n=21) of samples were PAR-4 positive and 64.4% (n=38) were negative. The hormonal status was 64% ER positive (n=38), 35% ER-negative (n=21) and 40.7% PgR positive (n=24), 59.3% PgR negative (n=35). The majority (90%) of the samples presented clear cytoplasmic localization and a small portion (10%) was cytoplasmic and nuclear. Univariate analysis indicates that the Par-4 expression has a significant inverse association (p=0.04) only with expression of PgR and not with the other variables analyzed. Normal breast tissue analyzed was negative for Par-4 immunostaining. Our results suggest that, in breast cancer, Par-4 plays a similar tumor suppressor gene role as reported in endometrial carcinoma. 2009. Published by Elsevier Inc.

  19. KSHV-Mediated Regulation of Par3 and SNAIL Contributes to B-Cell Proliferation

    PubMed Central

    Jha, Hem C.; Sun, Zhiguo; Upadhyay, Santosh K.; El-Naccache, Darine W.; Singh, Rajnish K.; Sahu, Sushil K.; Robertson, Erle S.

    2016-01-01

    Studies have suggested that Epithelial–Mesenchymal Transition (EMT) and transformation is an important step in progression to cancer. Par3 (partitioning-defective protein) is a crucial factor in regulating epithelial cell polarity. However, the mechanism by which the latency associated nuclear antigen (LANA) encoded by Kaposi's Sarcoma associated herpesvirus (KSHV) regulates Par3 and EMTs markers (Epithelial-Mesenchymal Transition) during viral-mediated B-cell oncogenesis has not been fully explored. Moreover, several studies have demonstrated a crucial role for EMT markers during B-cell malignancies. In this study, we demonstrate that Par3 is significantly up-regulated in KSHV-infected primary B-cells. Further, Par3 interacted with LANA in KSHV positive and LANA expressing cells which led to translocation of Par3 from the cell periphery to a predominantly nuclear signal. Par3 knockdown led to reduced cell proliferation and increased apoptotic induction. Levels of SNAIL was elevated, and E-cadherin was reduced in the presence of LANA or Par3. Interestingly, KSHV infection in primary B-cells led to enhancement of SNAIL and down-regulation of E-cadherin in a temporal manner. Importantly, knockdown of SNAIL, a major EMT regulator, in KSHV cells resulted in reduced expression of LANA, Par3, and enhanced E-cadherin. Also, SNAIL bound to the promoter region of p21 and can regulate its activity. Further a SNAIL inhibitor diminished NF-kB signaling through upregulation of Caspase3 in KSHV positive cells in vitro. This was also supported by upregulation of SNAIL and Par3 in BC-3 transplanted NOD-SCID mice which has potential as a therapeutic target for KSHV-associated B-cell lymphomas. PMID:27463802

  20. The different origins of magnetic fields and activity in the Hertzsprung gap stars, OU Andromedae and 31 Comae

    NASA Astrophysics Data System (ADS)

    Borisova, A.; Aurière, M.; Petit, P.; Konstantinova-Antova, R.; Charbonnel, C.; Drake, N. A.

    2016-06-01

    Context. When crossing the Hertzsprung gap, intermediate-mass stars develop a convective envelope. Fast rotators on the main sequence, or Ap star descendants, are expected to become magnetic active subgiants during this evolutionary phase. Aims: We compare the surface magnetic fields and activity indicators of two active, fast rotating red giants with similar masses and spectral class but different rotation rates - OU And (Prot = 24.2 d) and 31 Com (Prot = 6.8 d) - to address the question of the origin of their magnetism and high activity. Methods: Observations were carried out with the Narval spectropolarimeter in 2008 and 2013. We used the least-squares deconvolution (LSD) technique to extract Stokes V and I profiles with high signal-to-noise ratio to detect Zeeman signatures of the magnetic field of the stars. We then provide Zeeman-Doppler imaging (ZDI), activity indicators monitoring, and a precise estimation of stellar parameters. We use state-of-the-art stellar evolutionary models, including rotation, to infer the evolutionary status of our giants, as well as their initial rotation velocity on the main sequence, and we interpret our observational results in the light of the theoretical Rossby numbers. Results: The detected magnetic field of OU Andromedae (OU And) is a strong one. Its longitudinal component Bl reaches 40 G and presents an about sinusoidal variation with reversal of the polarity. The magnetic topology of OU And is dominated by large-scale elements and is mainly poloidal with an important dipole component, as well as a significant toroidal component. The detected magnetic field of 31 Comae (31 Com) is weaker, with a magnetic map showing a more complex field geometry, and poloidal and toroidal components of equal contributions. The evolutionary models show that the progenitors of OU And and 31 Com must have been rotating at velocities that correspond to 30 and 53%, respectively, of their critical rotation velocity on the zero age main sequence

  1. X-ray diving in the center of Sh2-129: looking for the driving source of Ou4

    NASA Astrophysics Data System (ADS)

    Grosso, Nicolas

    2012-10-01

    The outflow phenomenon is associated both with the early and the last phase of the stellar evolution. Recently, a unique bipolar outflow with an angular size of 1.2 degrees was discovered in the blister HII region Sh2-129. Ou4, nicknamed "The Giant Squid", is to our knowledge the bipolar outflow with the largest angular size ever found. We propose joint XMM-Newton/EPIC (35 ks) and Chandra/HRC-I (16 ks) observations to look for the driving source of Ou4 and to clarify the nature of this object.

  2. Provenance of the oil in par-fried French fries after finish frying.

    PubMed

    Al-Khusaibi, Mohammed; Gordon, Michael H; Lovegrove, Julie A; Niranjan, Keshavan

    2012-01-01

    Frozen par-fried French fries are finish-fried either by using the same type of oil used for par frying, or a different type. The nutritive quality of the final oil contained in the product depends on the relative amounts and the fatty acid (FA) composition of the oils used for par frying and finish frying. With the aim of understanding the provenance of the oil in the final product, par-fried French fries-either purchased ready or prepared in the laboratory-were finish fried in oils different from the ones used for par frying. The moisture content, oil content, and FA compositions of the par-fried and finish-fried products were experimentally determined, and the relative amounts of each of the oils present in the final product were calculated using the FAs as markers and undertaking a mass balance on each component FA. The results demonstrate that 89% to 93% of the total oil in the final product originates from the finish-frying step. The study also shows that a significant proportion of the oil absorbed during par frying is expelled from the product during finish frying. Further, the expulsion of par-frying oil was found to occur in the early stages of the finish-frying step. Experiments involving different combinations of par-frying and finish-frying oils showed that the relative proportions of the 2 oils did not depend on the individual fatty acid profiles. This study concludes that any positive health benefits of using an oil having a favorable FA profile for par frying, can potentially be lost, if the oil used for finish frying has a less favorable composition. This paper estimates the relative amounts of oil in French fries that have been fried in 2 stages-a par-frying step and a finish-frying step-which is commonly practiced in food service establishments as well as homes. The 2 key conclusions are: (1) nearly 90% of the oil content of the final product is the one used for finish frying; that is, a processor may use very good oil for par frying but if the

  3. Drug efflux and parC mutations are involved in fluoroquinolone resistance in viridans group streptococci.

    PubMed

    Ferrándiz, M J; Oteo, J; Aracil, B; Gómez-Garcés, J L; De La Campa, A G

    1999-10-01

    Nine ciprofloxacin-resistant viridans group streptococci isolated from asymptomatic carriers were analyzed. Identification to the species level by using three different commercial systems and a PCR-based approach was inconsistent. The nucleotide sequences of fragments of the parC, parE, gyrA, and gyrB genes showed considerable intra- and interspecies variations, and these variations mainly involved silent mutations. Three isolates had changes in Ser-79 of ParC (to Phe or Tyr). Phenotypic characterization indicated that eight of the nine isolates had a putative efflux mechanism that would confer low-level resistance to ciprofloxacin.

  4. Drug Efflux and parC Mutations Are Involved in Fluoroquinolone Resistance in Viridans Group Streptococci

    PubMed Central

    Ferrándiz, María José; Oteo, Jesús; Aracil, Belén; Gómez-Garcés, Jose Luis; De La Campa, Adela G.

    1999-01-01

    Nine ciprofloxacin-resistant viridans group streptococci isolated from asymptomatic carriers were analyzed. Identification to the species level by using three different commercial systems and a PCR-based approach was inconsistent. The nucleotide sequences of fragments of the parC, parE, gyrA, and gyrB genes showed considerable intra- and interspecies variations, and these variations mainly involved silent mutations. Three isolates had changes in Ser-79 of ParC (to Phe or Tyr). Phenotypic characterization indicated that eight of the nine isolates had a putative efflux mechanism that would confer low-level resistance to ciprofloxacin. PMID:10508036

  5. Epidémiologie et prise en charge des infections du per-partum à la maternité du centre hospitalier départemental de l'Ouémé-Plateau au Bénin

    PubMed Central

    Saizonou, Jacques; Ouédraogo, Laurent; Paraiso, Moussiliou Noël; Ayélo, Paul; Kpozèhouen, Alphonse; Daraté, René; Traoré, Esther

    2014-01-01

    Introduction La présente étude avait pour objectif de mesurer l'ampleur des infections du per-partum à la maternité du Centre Hospitalier Départemental de l'Ouémé-Plateau d'analyser les conditions de survenue et de prise en charge dans la perspective de l'amélioration des soins et services maternels et néonataux. Méthodes Une étude descriptive et analytique a été conduite de Août 2009 à Février 2010 et a impliqué 110 mères victimes d'infections du per-partum; elles ont été soumises à un questionnaire durant tout leur séjour hospitalier; des observations des pratiques de prise en charge des prestataires de soins ont été menées et des registres et autres supports de données sanitaires ont été exploités. L'analyse des données a été effectuée à l'aide du logiciel Epi Info 6.4 dans sa version française. Résultats L'incidence des infections du per-partum était de 5,9 pour 100 accouchements (110/ 1875); les types d'infections les plus incriminés étaient les endométrites (27,3%), les chorioamniotites (18,2%), les infections du site opératoire (12,7%) et les infections urinaires (2,7%). Les examens cliniques ont été relativement acceptables. En revanche, les examens biologiques ont été très insuffisants expliquant l'imprécision importante au niveau des diagnostics. L'antibiothérapie a été instaurée systématiquement. Le taux de mortinaissance était de 25,6% et les enfants de petit poids représentaient 23,2%. Conclusion L'incidence des infections du per-partum dans la présente étude était assez élevée. Des efforts de préventions et de dépistage de ces infections sont nécessaire afin d'améliorer la qualité des soins PMID:25120854

  6. Prostate apoptosis response 4 (PAR4) expression modulates WNT signaling pathways in MCF7 breast cancer cells: A possible mechanism underlying PAR4-mediated docetaxel chemosensitivity

    PubMed Central

    De Bessa Garcia, Simone Aparecida; Pavanelli, Ana Carolina; Melo, Natália Cruz E; Nagai, Maria Aparecida

    2017-01-01

    Docetaxel is an effective drug for the treatment of metastatic breast cancer. However, the exact mechanisms and/or markers associated with chemosensitivity or resistance to docetaxel remain unclear. We previously showed that the expression of prostate apoptosis response 4 (PAR4) inhibits the growth of MCF7 breast cancer cells and increases their sensitivity to docetaxel. Using cDNA microarray analysis, we evaluated transcriptome changes in MCF7 cells expressing increased levels of PAR4 and control cells before and after docetaxel treatment. Some of the top gene networks generated from the differentially expressed genes were related to the wingless-type MMTV integration 1 (WNT) canonical (WNT/β-catenin) and non-canonical (β-catenin-independent) pathways. The Human WNT signaling pathway RT2 profiler™ PCR array was used to validate the effects of PAR4 on the expression pattern of genes involved in the WNT pathway. CACNAD2A3, GDF5 and IL6 were upregulated and NANOG was downregulated in the MCF7 breast cancer cells expressing increased levels of PAR4 after treatment with docetaxel, likely indicating inactivation of the WNT/β-catenin pathway. Upregulation of FGF7, LEF1 and TWIST1 indicated activation of the WNT/β-catenin pathway. Although preliminary, our findings could be of particular interest for understanding the action of PAR4 in chemosensitivity, particularly to increase the specificity and effectiveness of drug treatment and overcome resistance to chemotherapy. Further studies are needed to better understand the biological roles of PAR4 in the regulation of WNT pathways in breast cancer cells in response to docetaxel and other chemotherapeutic agents. PMID:28259909

  7. The Geoland2 BioPar burned area product

    NASA Astrophysics Data System (ADS)

    Tansey, K.; Bradley, A.; Smets, B.; van Best, C.; Lacaze, R.

    2012-04-01

    The European Commission Geoland2 project intends to constitute a major step forward to the implementation of the GMES Land Monitoring Core Service (LMCS). The Bio-geophysical Parameters (BioPar) Core Monitoring Service aims at setting-up pre-operational infrastructures for providing regional, European, and global bio-geophysical variables, both in near real time and off-line mode, for describing the vegetation state, the radiation budget at the surface, and the water cycle. The burned area product is part of the BioPar portfolio. The burned area product further builds on the experience of the Global Burned Area (GBA2000) and L3JRC projects. In the GBA2000 project, several algorithms were developed for different geographical regions of the world, and applied to a 1-year time series (the year 2000) of SPOT-VEGETATION data. In the L3JRC project, a single algorithm was improved and applied to a 7-year global dataset of SPOT-VEGETATION data. Since the conception of the Geoland2 project, work has been undertaken to improve the L3JRC algorithm, mainly based on user comments and feedback. Furthermore, the Geoland2 burned area product specification has been developed to meet the requirements of the Core Information Service, specifically LandCarbon and Natural Resource Monitoring in Africa (Narma). The Geoland2 burned area product has the following improvements over the L3JRC product: • It resolves issues with users extracting statistics and burned area estimates for time periods considered to be outside the main seasons for burning. Specifically, this deals with issues in northern latitude winters. • The number of pre-processing steps has been shortened, reducing processing time. • An improved land-water mask has been used. This resolves a problem around the coastlines of land masses which were frequently being detected as being burned. • A season metric calculation is performed over a 1x1 degree grid. For each grid cell, a date is logged against the start of the

  8. Intrinsic and integrative properties of substantia nigra pars reticulata neurons

    PubMed Central

    Zhou, Fu-Ming; Lee, Christian R.

    2011-01-01

    The GABA projection neurons of the substantia nigra pars reticulata (SNr) are output neurons for the basal ganglia and thus critical for movement control. Their most striking neurophysiological feature is sustained, spontaneous high frequency spike firing. A fundamental question is: what are the key ion channels supporting the remarkable firing capability in these neurons? Recent studies indicate that these neurons express tonically active TRPC3 channels that conduct a Na-dependent inward current even at hyperpolarized membrane potentials. When the membrane potential reaches −60 mV, a voltage-gated persistent sodium current (INaP) starts to activate, further depolarizing the membrane potential. At or slightly below −50 mV, the large transient voltage-activated sodium current (INaT) starts to activate and eventually triggers the rapid rising phase of action potentials. SNr GABA neurons have a higher density of (INaT), contributing to the faster rise and larger amplitude of action potentials, compared with the slow-spiking dopamine neurons. INaT also recovers from inactivation more quickly in SNr GABA neurons than in nigral dopamine neurons. In SNr GABA neurons, the rising phase of the action potential triggers the activation of high-threshold, inactivation-resistant Kv3-like channels that can rapidly repolarize the membrane. These intrinsic ion channels provide SNr GABA neurons with the ability to fire spontaneous and sustained high frequency spikes. Additionally, robust GABA inputs from direct pathway medium spiny neurons in the striatum and GABA neurons in the globus pallidus may inhibit and silence SNr GABA neurons, whereas glutamate synaptic input from the subthalamic nucleus may induce burst firing in SNr GABA neurons. Thus, afferent GABA and glutamate synaptic inputs sculpt the tonic high frequency firing of SNr GABA neurons and the consequent inhibition of their targets into an integrated motor control signal that is further fine-tuned by neuromodulators

  9. Unitary synaptic connections among substantia nigra pars reticulata neurons

    PubMed Central

    Wilson, Charles J.

    2016-01-01

    Neurons in substantia nigra pars reticulata (SNr) are synaptically coupled by local axon collaterals, providing a potential mechanism for local signal processing. Because SNr neurons fire spontaneously, these synapses are constantly active. To investigate their properties, we recorded spontaneous inhibitory postsynaptic currents (sIPSCs) from SNr neurons in brain slices, in which afferents from upstream nuclei are severed, and the cells fire rhythmically. The sIPSC trains contained a mixture of periodic and aperiodic events. Autocorrelation analysis of sIPSC trains showed that a majority of cells had one to four active unitary inputs. The properties of the unitary IPSCs (uIPSCs) were analyzed for cells with one unitary input, using a model of periodic presynaptic firing and stochastic synaptic transmission. The inferred presynaptic firing rates and coefficient of variation of interspike intervals (ISIs) corresponded well with direct measurements of spiking in SNr neurons. Methods were developed to estimate the success probability, amplitude distributions, and kinetics of the uIPSCs, while removing the contribution from aperiodic sIPSCs. The sIPSC amplitudes were not increased upon release from halorhodopsin silencing, suggesting that most synapses were not depressed at the spontaneous firing rate. Gramicidin perforated-patch recordings indicated that the average reversal potential of spontaneous inhibitory postsynaptic potentials was −64 mV. Because of the change in driving force across the ISI, the unitary inputs are predicted to have a larger postsynaptic impact when they arrive late in the ISI. Simulations of network activity suggest that this very sparse inhibitory coupling may act to desynchronize the activity of SNr neurons while having only a small effect on firing rate. PMID:26961101

  10. Landslide susceptibility modelling using Fuzzy Logic in the oued Larbaa basin (Oriental Rif, Morocco)

    NASA Astrophysics Data System (ADS)

    Zezere, J. L.; Sadiki, A.; Faleh, A.; Elkoulali, E.; Garcia, R. A. C.; Oliveira, S. C.

    2009-04-01

    Together with flash floods and soil erosion, landslides are relevant natural hazards that affect marly slopes in the oued Larbaa basin, located in the Oriental Rif, Morocco. Landslides have been generated important economic, social and ecological effects, by the destruction of farming lands, and by the collapse and interruption of roads and other human infrastructures (e.g., houses). The reduction of socio-economic losses due to landslide activity needs to be accomplished through the implementation of a comprehensive mitigation landslide risk program. The first task of this program is the definition of landslide susceptible areas based on the study of relationships between spatial distribution of past landslides and the cartographic set of landslide predisposing factors. Therefore, the major aim of this work is to create a landslide susceptibility map for the study area. The oued Larbaa basin, located northwards the Taza city, has an area of 245 km2 and the elevation ranges between 450 m and 1300 m. Morphology is characterized by rounded hills cutting marly formations essentially of Cretaceous age. Land use is dominated by cereal cultures and a few sparse tree plantations. Natural vegetation shows a very high level of degradation and usually appears as shrub tufts. The inventory of instability events has been made for the study area and it includes both rainfall-triggered rotational and shallow translational slides. These landslides were included into a GIS database that comprises also the following landslide predisposing factors: slope angle, aspect and curvature, inverse wetness index, lithology and land use. The susceptibility assessment was carried out for each type of landslide (rotational slides and shallow translational slides) under the assumption that future landslides will occur under the same environmental patterns that generated landslides in the past. The modelling of landslide susceptibility was made using the Fuzzy Logic method (Fuzzy Algebraic

  11. Synthèse de matériaux hybrides polymère-argile par polymérisation photo-induite

    NASA Astrophysics Data System (ADS)

    Benfarhi, S.; Decker, C.; Keller, L.; Zahouily, K.; Bendaikha, T.

    2005-05-01

    L'objectif de cette étude est de synthétiser des matériaux nanocomposites très résistants par un procédé rapide et non polluant, la polymérisation réticulante Pour celà, nous avons incorporé de l'argile préalablement rendue organophile dans des résines multifonctionnelles. Des phyllosilicates (bentonite, montmorillonite) ont été traitées par divers sels d'ammonium pour les rendre organophiles et ainsi compatibles avec la matrice polymère. La polymérisation de la résine lors de l'exposition au rayonnement ultraviolet a été suivie in situ à l'aide de la spectroscopie infrarouge résolue dans le temps. Dans tous les cas, l'argile organophile n'influence pas ou très peu la cinétique de la réaction de photopolymérisation. Le matériau nanocomposite ainsi obtenu est parfaitement transparent, insoluble dans les solvants organiques et présente des propriétés mécaniques nettement améliorées par rapport à la résine seule et au microcomposite, pour un taux de charges compris entre 2 et 5%. L'addition de nanoparticules permet entre autre de réduire de manière efficace la brillance de revêtements UV (plus de 50% pour une résine chargée à 2%). L'association intime de la charge et du liant organique à l'échelle moléculaire confère enfin à ce matériau des propriétés barrières (aux gaz et àl'eau) supérieures celles de la matrice polymère photoréticulée.

  12. Evaluation du niveau de connaissance des patients sur la gestion du traitement par les antis vitamines K dans le service de cardiologie de Ouagadougou

    PubMed Central

    Samadoulougou, André; Temoua Naibe, Dangwé; Mandi, Germain; Yameogo, Relwendé Aristide; Kabore, Elisé; Millogo, Georges; Yameogo, Nobila Valentin; Kologo, Jonas Koudougou; Thiam/Tall, Anna; Toguyeni, Boubacar Jean Yves; Zabsonre, Patrice

    2014-01-01

    Introduction Les antivitamines K (AVK), traitement anticoagulant oral le plus largement prescrit, posent un réel problème de santé publique du fait de leur risque iatrogène. L'objectif de cette étude était de préciser le niveau de connaissance des patients sur la gestion de leur traitement par les AVK. Méthodes Il s'est agi d'une enquête transversale descriptive réalisée au CHU-Yalgado Ouédraogo, sur une période de 03 mois : du 1er mars au 31 mai 2012. Un questionnaire a été administré aux patients bénéficiant d'un traitement AVK depuis au moins un mois. Résultats Soixante-dix patients ont été inclus dans l'étude dont 30 hommes. L'âge moyen était de 49 ans ± 16 ans. Les cardiopathies et la maladie thromboembolique veineuse justifiant l'institution du traitement AVK étaient retrouvées respectivement dans 58,6% et 41,4% des cas. Le nom de l'AVK et la raison exacte du traitement étaient connus respectivement dans 91,4% et 67,1% des cas. Plus de la moitié des patients (68,6%) savaient que les AVK rendaient le sang plus fluide. Quarante-six patients (65,7%) citaient l'INR comme examen biologique de surveillance du traitement et seulement 28 patients (40%) connaissaient les valeurs cibles. La majorité des patients ne connaissait pas les risques encourus en cas de surdosage (72,8%) et de sous-dosage (71,4%). Une automédication par anti-inflammatoire non stéroïdien était signalée par 18 patients (25,7%). Les choux (74,3%) et la laitue (62,9%), aliments à consommer avec modération, étaient les plus cités. Conclusion Les connaissances des patients sur la gestion des AVK étaient fragmentaires et insuffisantes pour assurer la sécurité et l'efficacité du traitement. La création d'un programme d'éducation thérapeutique sur les AVK s'avère alors nécessaire. PMID:25870741

  13. Urokinase receptor (uPAR) ligand based recombinant toxins for human cancer therapy.

    PubMed

    de Virgilio, Maddalena; Silvestris, Franco

    2011-01-01

    The urokinase receptor (uPAR) exerts essential functions in the pathophysiology of cancers and therefore constitutes an important drug target. In order to generate efficient drugs against uPAR, a new approach includes chimeric proteins associating one molecular address to specifically target uPAR and one bacterial or plant toxin that will eventually kill the tumoural cell. Using this frame, several recombinant toxins have been designed namely DTAT, DTAT13, EGFATFKDEL 7 mut, and ATF-SAP. As molecular address, all of these fusion proteins use the amino-terminal fragment of urokinase that binds with high affinity to uPAR through its growth factor domain (GFD). The various toxin moieties were derived from either diphtheria toxin, Pseudomonas exotoxin A (PE38), or saporin. In this review, we describe the rational, design, production and therapeutic anti-cancer potential of these chimeric toxins.

  14. Detection of pars plana rupture by ultrasound biomicroscopy after cannula dislodgement during cataract wound hydration.

    PubMed

    Yonekawa, Yoshihiro; Thomas, Benjamin J; Lau-Sickon, Laurie K; Anderson, Bradley J; Ruby, Alan J

    2017-01-01

    Ultrasound biomicroscopy (UBM) is a valuable diagnostic modality for imaging anterior ocular structures. Its utility has been well studied in anterior segment, lenticular, and pars plicata pathologies. However, imaging of the pars plana has been seldom described. We present the case of a 66-year-old woman referred for vitreous hemorrhage after expulsive cannula dislodgement into the posterior segment during wound hydration at the end of cataract surgery. B-scan ultrasonography initially detected a very anterior abnormality, but the resolution was insufficient for accurate diagnosis. Subsequent UBM clearly showed rupture of the pars plana and a mild cyclodialysis cleft. To our knowledge, this is the first report of a pars plana rupture detected by ultrasound, which expands the diagnostic capacities and indications for UBM.

  15. ParTIES: a toolbox for Paramecium interspersed DNA elimination studies.

    PubMed

    Denby Wilkes, Cyril; Arnaiz, Olivier; Sperling, Linda

    2016-02-15

    Developmental DNA elimination occurs in a wide variety of multicellular organisms, but ciliates are the only single-celled eukaryotes in which this phenomenon has been reported. Despite considerable interest in ciliates as models for DNA elimination, no standard methods for identification and characterization of the eliminated sequences are currently available. We present the Paramecium Toolbox for Interspersed DNA Elimination Studies (ParTIES), designed for Paramecium species, that (i) identifies eliminated sequences, (ii) measures their presence in a sequencing sample and (iii) detects rare elimination polymorphisms. ParTIES is multi-threaded Perl software available at https://github.com/oarnaiz/ParTIES. ParTIES is distributed under the GNU General Public Licence v3. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  16. Paracoccidioides brasiliensis induces cytokine secretion in epithelial cells in a protease-activated receptor-dependent (PAR) manner.

    PubMed

    de Oliveira, Priscila; Juliano, Maria Aparecida; Tanaka, Aparecida Sadae; Carmona, Adriana Karaoglanovic; Dos Santos, Saara Maria Batista; de Barros, Bianca Carla Silva Campitelli; Maza, Paloma Korehisa; Puccia, Rosana; Suzuki, Erika

    2017-04-01

    Paracoccidioides brasiliensis is one of the etiological agents of the human systemic mycosis paracoccidioidomycosis. Protease-activated receptors (PARs) are expressed in many cell types and comprise a family of G protein-coupled receptors (PAR-1, PAR-2, and PAR-4), which may be activated by proteases secreted by several pathogens. In the present study, we showed that the pathogenic fungus P. brasiliensis secretes components that promote interleukin (IL)-6 and IL-8 secretion by the lung epithelial cell line A549. Cytokine secretion was reduced by antagonistic peptides for PAR-1 and PAR-2, but not for PAR-4. P. brasiliensis proteases were isolated from fungal culture supernatants in a p-aminomethylbenzamidine-Sepharose column. The obtained fractions were tested for enzymatic activity against fluorescence resonance energy transfer (FRET) peptides derived from sequences that spanned the activation sites of human PARs. The eluted fraction, termed PbP, contained protease activities that were able to hydrolyze the FRET peptides. PbP also induced IL-6 and IL-8 secretion in A549 epithelial cells, which was reduced upon heat inactivation of PbP, incubation with antagonistic peptides for PAR-1 and PAR-2, and the protease inhibitors aprotinin, leupeptin, and E-64. Together, these results show for the first time that P. brasiliensis yeasts secrete proteases that activate PARs in lung epithelial cells, leading to cytokine secretion.

  17. PAR2 expression in peripheral blood monocytes of patients with rheumatoid arthritis

    PubMed Central

    Crilly, A; Burns, E; Nickdel, M B; Lockhart, J C; Perry, M E; Ferrell, P W; Baxter, D; Dale, J; Dunning, L; Wilson, H; Nijjar, J S; Gracie, J A; Ferrell, W R; McInnes, I B

    2012-01-01

    Objectives Proteinase-activated receptor 2 (PAR2) is a G protein-coupled receptor activated by serine proteinases with proinflammatory activity. A study was undertaken to investigate the presence and functional significance of PAR2 expression on rheumatoid arthritis (RA)-derived leucocyte subsets. Methods Venous blood was obtained from patients with RA and osteoarthritis (OA) as well as healthy control subjects. Surface expression of PAR2 on peripheral blood mononuclear cells (PBMCs) was analysed by flow cytometry and interleukin 6 (IL-6) generation by ELISA. Results Patients with RA had elevated but variable surface expression of PAR2 on CD14+ monocytes compared with control subjects (median (1st to 3rd quartiles) 1.76% (0.86–4.10%) vs 0.06% (0.03–0.81%), p<0.0001). CD3+ T cells showed a similar pattern with significantly higher PAR2 expression in patients with RA compared with controls (3.05% (0.36–11.82%) vs 0.08% (0.02–0.28%), p<0.0001). For both subsets, PAR2 expression was significantly higher (p<0.00001) in patients with high levels of disease activity: PAR2 expression for both CD14+ and CD3+ cells correlated to C reactive protein and erythrocyte sedimentation rate. Furthermore, in a cohort of patients with newly diagnosed RA, elevated PAR2 expression in both CD14+ and CD3+ cells was significantly reduced 3 months after methotrexate or sulfasalazine treatment and this reduction correlated significantly with the reduction in the 28-joint Disease Activity Scale score (p<0.05). PAR2 expression on cells from patients with OA was low, similar to levels seen in control subjects. Generation of IL-6 by monocytes in response to a selective PAR2 agonist was significantly greater in patients with RA than in patients with OA and control subjects (p<0.05). Conclusions These findings are consistent with a pathogenic role for PAR2 in RA. PMID:22294633

  18. Systemic sclerosis-like histopathological features in the myocardium of uPAR-deficient mice.

    PubMed

    Manetti, Mirko; Rosa, Irene; Fazi, Marilena; Guiducci, Serena; Carmeliet, Peter; Ibba-Manneschi, Lidia; Matucci-Cerinic, Marco

    2016-02-01

    Cardiomyopathy is among the leading causes of death from systemic sclerosis (SSc). Urokinase-type plasminogen activator receptor (uPAR)-deficient mice have been recently reported to display important histopathological hallmarks of SSc, including dermal fibrosis, reduced dermal capillary density, and pulmonary fibrosis. Here, we investigated whether uPAR-deficient mice could display the histopathological features of SSc-related cardiomyopathy. Ventricular myocardial specimens from uPAR-deficient and wild-type mice at 12 and 24 weeks of age were analysed by both light microscopy and transmission electron microscopy. Picrosirius red staining and hydroxyproline content of myocardial specimens were quantified. Myofibroblast and microvessel counts were determined by immunofluorescence for α-smooth muscle actin and CD31, respectively. Endothelial cell apoptosis was assessed by a combined TUNEL/CD31 immunofluorescence assay. Expression of uPAR in human SSc and control ventricular myocardial autopsy specimens was determined by immunohistochemistry. The myocardium of 24-week-old uPAR-deficient mice displayed focal ischaemic lesions with cardiomyocyte hypertrophy, myofibril rarefaction and contraction band necrosis. At 24 weeks of age, interstitial and perivascular collagen deposition and myofibroblast counts were significantly greater in myocardial tissue of uPAR-deficient mice than in wild-type mice. In uPAR-deficient mice, myocardial fibrosis was paralleled by microvascular endothelial cell apoptosis and reduced capillary density. uPAR expression was significantly downregulated in the myocardium of patients with SSc. Typical histopathological features of SSc-related cardiomyopathy are mimicked by uPAR-deficient mice. The downregulation of uPAR in the myocardium of patients with SSc may suggest similar underlying pathogenetic mechanisms. uPAR-deficient mice could be used as a preclinical model to study the mechanisms and therapeutic approaches of myocardial involvement

  19. ParFit: A Python-Based Object-Oriented Program for Fitting Molecular Mechanics Parameters to ab Initio Data.

    PubMed

    Zahariev, Federico; De Silva, Nuwan; Gordon, Mark S; Windus, Theresa L; Dick-Perez, Marilu

    2017-03-27

    A newly created object-oriented program for automating the process of fitting molecular-mechanics parameters to ab initio data, termed ParFit, is presented. ParFit uses a hybrid of deterministic and stochastic genetic algorithms. ParFit can simultaneously handle several molecular-mechanics parameters in multiple molecules and can also apply symmetric and antisymmetric constraints on the optimized parameters. The simultaneous handling of several molecules enhances the transferability of the fitted parameters. ParFit is written in Python, uses a rich set of standard and nonstandard Python libraries, and can be run in parallel on multicore computer systems. As an example, a series of phosphine oxides, important for metal extraction chemistry, are parametrized using ParFit. ParFit is in an open source program available for free on GitHub ( https://github.com/fzahari/ParFit ).

  20. Ambroise Paré IV: The early history of artificial limbs (from robotic to prostheses).

    PubMed

    Hernigou, Philippe

    2013-06-01

    One of the earliest written references to prosthetics is found in a book published in France in 1579. That year, French surgeon Ambroise Paré (1510-1590) published his complete works, part of which described some of the artificial limbs he fitted on his amputees. As a military surgeon, Paré had removed many a soldier's shattered arm or leg, and he eventually began designing and building artificial limbs to help the men who had been maimed.

  1. Molecular mechanism of bundle formation by the bacterial actin ParM

    SciTech Connect

    Popp, David; Narita, Akihiro; Iwasa, Mitsusada; Robinson, Robert C.

    2010-01-22

    The actin homolog ParM plays a microtubule-like role in segregating DNA prior to bacterial cell division. Fluorescence and cryo-electron microscopy have shown that ParM forms filament bundles between separating DNA plasmids in vivo. Given the lack of ParM bundling proteins it remains unknown how ParM bundles form at the molecular level. Here we show using time-lapse TIRF microscopy, under in vitro molecular crowding conditions, that ParM-bundle formation consists of two distinct phases. At the onset of polymerization bundle thickness and shape are determined in the form of nuclei of short helically disordered filaments arranged in a liquid-like lattice. These nuclei then undergo an elongation phase whereby they rapidly increase in length. At steady state, ParM bundles fuse into one single large aggregate. This behavior had been predicted by theory but has not been observed for any other cytomotive biopolymer, including F-actin. We employed electron micrographs of ParM rafts, which are 2-D analogs of 3-D bundles, to identify the main molecular interfilament contacts within these suprastructures. The interface between filaments is similar for both parallel and anti-parallel orientations and the distribution of filament polarity is random within a bundle. We suggest that the interfilament interactions are not due to the interactions of specific residues but rather to long-range, counter ion mediated, electrostatic attractive forces. A randomly oriented bundle ensures that the assembly is rigid and that DNA may be captured with equal efficiency at both ends of the bundle via the ParR binding protein.

  2. The membrane-anchored serine protease, TMPRSS2, activates PAR-2 in prostate cancer cells

    PubMed Central

    2004-01-01

    TMPRSS2 is a type II transmembrane-bound serine protease that has gained interest owing to its highly localized expression in the prostate and its overexpression in neoplastic prostate epithelium. Once activated, the serine protease domain of TMPRSS2 is released from the cell surface into the extracellular space. PAR (protease-activated receptor)-2 belongs to a family of G-protein-coupled receptors (PAR-1–4) that are activated by specific serine proteases, which are expressed in many normal and malignant cell types. Previous in vitro studies on prostate cancer cells suggest a role for PAR-2 in prostate cancer metastasis. A polyclonal anti-human TMPRSS2 antibody was generated against the TMPRSS2 serine protease domain. The antibody showed specific reactivity with recombinant expressed TMPRSS2, and so was used to extract and purify the cleaved active TMPRSS2 protease from prostate cancer cells. Reverse transcriptase PCR and Western blot analysis were used to show the expression of both TMPRSS2 and PAR-2 in the androgen-dependent LNCaP prostate cancer cell line. Treatment of LNCaP cells with the cellular immunopurified TMPRSS2 protease induced a transient increase in intracellular calcium, which is indicative of G-protein-coupled-receptor activation. This calcium mobilization was inhibited by cellular pre-treatment with a specific PAR-2 antagonist, but not with a PAR-1 antagonist; inhibition of the protease activity also failed to mobilize calcium, suggesting that TMPRSS2 is capable of cleaving and thereby activating the PAR-2 receptor. The calcium mobilization was also inhibited by cellular pre-treatment with suramin or 2-APB (2-aminoethoxydiphenyl borate), indicating that a G-protein pathway is involved and that subsequent calcium release is mainly from intracellular stores. The present study describes how TMPRSS2 may contribute to prostate tumour metastasis via the activation of PAR-2. PMID:15537383

  3. The membrane-anchored serine protease, TMPRSS2, activates PAR-2 in prostate cancer cells.

    PubMed

    Wilson, Susan; Greer, Brett; Hooper, John; Zijlstra, Andries; Walker, Brian; Quigley, James; Hawthorne, Susan

    2005-06-15

    TMPRSS2 is a type II transmembrane-bound serine protease that has gained interest owing to its highly localized expression in the prostate and its overexpression in neoplastic prostate epithelium. Once activated, the serine protease domain of TMPRSS2 is released from the cell surface into the extracellular space. PAR (protease-activated receptor)-2 belongs to a family of G-protein-coupled receptors (PAR-1-4) that are activated by specific serine proteases, which are expressed in many normal and malignant cell types. Previous in vitro studies on prostate cancer cells suggest a role for PAR-2 in prostate cancer metastasis. A polyclonal anti-human TMPRSS2 antibody was generated against the TMPRSS2 serine protease domain. The antibody showed specific reactivity with recombinant expressed TMPRSS2, and so was used to extract and purify the cleaved active TMPRSS2 protease from prostate cancer cells. Reverse transcriptase PCR and Western blot analysis were used to show the expression of both TMPRSS2 and PAR-2 in the androgen-dependent LNCaP prostate cancer cell line. Treatment of LNCaP cells with the cellular immunopurified TMPRSS2 protease induced a transient increase in intracellular calcium, which is indicative of G-protein-coupled-receptor activation. This calcium mobilization was inhibited by cellular pre-treatment with a specific PAR-2 antagonist, but not with a PAR-1 antagonist; inhibition of the protease activity also failed to mobilize calcium, suggesting that TMPRSS2 is capable of cleaving and thereby activating the PAR-2 receptor. The calcium mobilization was also inhibited by cellular pre-treatment with suramin or 2-APB (2-aminoethoxydiphenyl borate), indicating that a G-protein pathway is involved and that subsequent calcium release is mainly from intracellular stores. The present study describes how TMPRSS2 may contribute to prostate tumour metastasis via the activation of PAR-2.

  4. Common variants in the human platelet PAR4 thrombin receptor alter platelet function and differ by race.

    PubMed

    Edelstein, Leonard C; Simon, Lukas M; Lindsay, Cory R; Kong, Xianguo; Teruel-Montoya, Raúl; Tourdot, Benjamin E; Chen, Edward S; Ma, Lin; Coughlin, Shaun; Nieman, Marvin; Holinstat, Michael; Shaw, Chad A; Bray, Paul F

    2014-11-27

    Human platelets express 2 thrombin receptors: protease-activated receptor (PAR)-1 and PAR4. Recently, we reported 3.7-fold increased PAR4-mediated aggregation kinetics in platelets from black subjects compared with white subjects. We now show that platelets from blacks (n = 70) express 14% more PAR4 protein than those from whites (n = 84), but this difference is not associated with platelet PAR4 function. Quantitative trait locus analysis identified 3 common single nucleotide polymorphisms in the PAR4 gene (F2RL3) associated with PAR4-induced platelet aggregation. Among these single nucleotide polymorphisms, rs773902 determines whether residue 120 in transmembrane domain 2 is an alanine (Ala) or threonine (Thr). Compared with the Ala120 variant, Thr120 was more common in black subjects than in white subjects (63% vs 19%), was associated with higher PAR4-induced human platelet aggregation and Ca2+ flux, and generated greater inositol 1,4,5-triphosphate in transfected cells. A second, less frequent F2RL3 variant, Phe296Val, was only observed in blacks and abolished the enhanced PAR4-induced platelet aggregation and 1,4,5-triphosphate generation associated with PAR4-Thr120. PAR4 genotype did not affect vorapaxar inhibition of platelet PAR1 function, but a strong pharmacogenetic effect was observed with the PAR4-specific antagonist YD-3 [1-benzyl-3(ethoxycarbonylphenyl)-indazole]. These findings may have an important pharmacogenetic effect on the development of new PAR antagonists. © 2014 by The American Society of Hematology.

  5. Clinical relevance and cellular source of elevated soluble urokinase plasminogen activator receptor (suPAR) in acute liver failure.

    PubMed

    Koch, Alexander; Zimmermann, Henning W; Gassler, Nikolaus; Jochum, Christoph; Weiskirchen, Ralf; Bruensing, Jan; Buendgens, Lukas; Dückers, Hanna; Bruns, Tony; Gerken, Guido; Neumann, Ulf P; Adams, David H; Trautwein, Christian; Canbay, Ali; Tacke, Frank

    2014-10-01

    Acute liver failure (ALF) is a life-threatening condition with a high mortality rate. The expression of urokinase plasminogen activator receptor (uPAR, CD87) and release of its shedded receptor into serum as soluble uPAR (suPAR) have been closely related to immune activation and prognosis in systemic inflammation and cirrhosis. We now aimed at investigating the clinical relevance and cellular source of uPAR and circulating suPAR in ALF. Serum suPAR concentrations were measured in 48 ALF patients and 62 healthy controls from a German liver transplantation centre. Hepatic immune cell subsets and uPAR expression were studied by FACS, qPCR and immunohistochemistry. Circulating suPAR levels were significantly increased in ALF patients, independent from the underlying aetiology, in comparison to controls. Serum suPAR concentrations were closely correlated with parameters reflecting liver cell injury, decreased liver function and the model of end-stage liver disease (MELD) score in ALF patients. By immunohistochemistry from explanted livers, ALF was associated with distinct immune cell accumulation and strong up-regulation of intrahepatic uPAR mRNA expression. CD87 (uPAR) expression was specifically detected on intrahepatic 'non-classical' monocytes (CD14(+) CD16(+) ), NKT and CD56(dim) NK cells isolated from human liver, but not on parenchymal or other non-parenchymal hepatic cell types. Membrane-bound uPAR was rapidly cleaved from monocytes upon inflammatory stimulation by lipopolysaccharide (LPS) and partially by co-cultured lymphocytes. Similar to its prognostic properties in patients with sepsis or cirrhosis, intrahepatic uPAR activation and serum suPAR concentrations might serve as an interesting biomarker in ALF. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Brief communication: Population variation in human maxillary premolar accessory ridges (MxPAR).

    PubMed

    Burnett, Scott E; Hawkey, Diane E; Turner, Christy G

    2010-02-01

    The purpose of this brief communication is to report the results of an analysis of maxillary premolar accessory ridges (MxPAR), a common but understudied accessory ridge that may occur both mesial and distal to the central ridge of the buccal cusp of upper premolars. We developed a new five-grade scoring plaque to better categorize MxPAR variation. Subsequently, we conducted a population analysis of MxPAR frequency in 749 dental casts of South African Indian, American Chinese, Alaskan Eskimo, Tohono O'odham (Papago), Akimel O'odham (Pima), Solomon Islander, South African Bantu, and both American and South African Whites. Northeast Asian and Asian-derived populations exhibited the highest MxPAR frequencies while Indo-European samples (South African Indians, American and South African Whites) exhibited relatively low frequencies. The Solomon Islanders and South African Bantu samples exhibited intermediate frequencies. Our analysis indicates that statistically significant differences in MxPAR frequency exist between major geographic populations. As a result, the MxPAR plaque has now been added to the Arizona State University Dental Anthropology System, an important contribution as maxillary premolar traits are underrepresented in analyses of dental morphology. 2009 Wiley-Liss, Inc.

  7. The RNA-binding protein ATX-2 regulates cytokinesis through PAR-5 and ZEN-4

    PubMed Central

    Gnazzo, Megan M.; Uhlemann, Eva-Maria E.; Villarreal, Alex R.; Shirayama, Masaki; Dominguez, Eddie G.; Skop, Ahna R.

    2016-01-01

    The spindle midzone harbors both microtubules and proteins necessary for furrow formation and the completion of cytokinesis. However, the mechanisms that mediate the temporal and spatial recruitment of cell division factors to the spindle midzone and midbody remain unclear. Here we describe a mechanism governed by the conserved RNA-binding protein ATX-2/Ataxin-2, which targets and maintains ZEN-4 at the spindle midzone. ATX-2 does this by regulating the amount of PAR-5 at mitotic structures, particularly the spindle, centrosomes, and midbody. Preventing ATX-2 function leads to elevated levels of PAR-5, enhanced chromatin and centrosome localization of PAR-5–GFP, and ultimately a reduction of ZEN-4–GFP at the spindle midzone. Codepletion of ATX-2 and PAR-5 rescued the localization of ZEN-4 at the spindle midzone, indicating that ATX-2 mediates the localization of ZEN-4 upstream of PAR-5. We provide the first direct evidence that ATX-2 is necessary for cytokinesis and suggest a model in which ATX-2 facilitates the targeting of ZEN-4 to the spindle midzone by mediating the posttranscriptional regulation of PAR-5. PMID:27559134

  8. Examining relational empowerment for elementary school students in a yPAR program.

    PubMed

    Langhout, Regina Day; Collins, Charles; Ellison, Erin Rose

    2014-06-01

    This paper joins relational empowerment, youth empowerment, and Bridging Multiple Worlds frameworks to examine forms of relational empowerment for children in two intermediary institutions-school and a youth participatory action research after-school program (yPAR ASP). Participants were twelve children, most of whom were Latina/o and from im/migrant families, enrolled in a yPAR ASP for 2 years. A mixed-method approach was utilized; we analyzed children's interviews, self-defined goals, and their social networks to examine their experiences of relational empowerment. We conclude that children experienced each of the five relational empowerment factors-collaborative competence, bridging social divisions, facilitating others' empowerment, mobilizing networks, and passing on a legacy-in the yPAR ASP setting, and some factors in school. These experiences, however, were more pronounced in the yPAR ASP setting. Additionally, social network analyses revealed that a small but meaningful percentage of actors bridged worlds, especially home and family, but by year 2, also school and the yPAR ASP. Finally, most helpers for school-based goals came from school, but a sizable number came from family, friends, and home worlds, and by year 2, also came from the yPAR ASP. Implications range from theoretical to methodological development, including the use of social network analysis as a tool to descriptively examine relational power in context.

  9. Hep par-1: a novel immunohistochemical marker for differentiating hepatocellular carcinoma from metastatic carcinoma.

    PubMed

    Hanif, Razia; Mansoor, Samina

    2014-03-01

    To evaluate the diagnostic utility of Hep par-1 in differentiating hepatocellular carcinoma from metastatic carcinoma taking histopathology as a gold standard. Comparative cross-sectional study. Pathology Department, Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, from April 2007 to February 2008. Hep par-1 immunohistochemical stain was performed on 60 cases of liver carcinoma, 30 cases each of metastatic and hepatocellular carcinoma. Information regarding patient age, gender, sign and symptoms, radiographic findings, histological grade of tumour, and expression of Hep par-1 on hepatocellular and metastatic carcinoma were recorded on proforma sheet. Sensitivity, specificity, positive and negative predictive values, and accuracy of Hep par-1 were calculated using the formulas. Hep par-1 expression was noted in 25 out of 30 cases of hepatocellular carcinoma (83%). Out of 30 cases of metastatic carcinoma, only one case expressed staining in < 5% tumour cells and remaining 29 cases showed no reactivity. The age of the patients with hepatocellular carcinoma ranged from 40 to 76 years with a median age of 60.5 years and 40 - 75 years for metastatic carcinomas with a median age of 57.5 years. Hep par-1 is a reliable immunohistochemical marker for cases of hepatocellular carcinoma (HCC). It can be used along with other markers in morphologically difficult cases when differential diagnosis lies between poorly differentiated HCC and metastatic carcinoma of liver.

  10. Spatial Estimates of GPP Using LiDAR- and Quickbird-Derived fPAR

    NASA Astrophysics Data System (ADS)

    Cook, B. D.; Bolstad, P. V.; Naesset, E.; Heinsch, F. A.; Anderson, R. S.; Garrigues, S.; Morisette, J. T.; Nickeson, J. E.; Hilton, T. W.; Davis, K. J.; Roman, M. O.

    2007-12-01

    Regional- to global-scale gross primary production (GPP) is commonly estimated with light-use efficiency models, which are largely dependent on remotely sensed estimates of the fraction of photosynthetically active radiation absorbed by vegetation (fPAR). Methodologies to quantify spatial variability of fPAR and improve GPP estimates have not been established for mixed forests and heterogeneous landscapes in the Great Lakes Region, and are needed to estimate photosynthetic sinks for the Mid-Continent Regional Intensive Campaign. In this study, hemispheric photos were collected during the 2006 growing season to estimate fPAR, plant area index (PAI), leaf inclination angle, and clumping factors in >130 lowland and upland stands within the footprint of a 400 m eddy covariance flux tower near Park Falls, Wisconsin, USA. Airborne LiDAR and Quickbird imagery were acquired during leaf-on and leaf-off periods to make predictions of canopy structure, and resulting PAI/fPAR estimates were compared with litterfall measurements and products derived from the Moderate Resolution Spectroradiometer (MODIS). GPP was modeled with the MODIS MOD17A2 algorithm, using fine-resolution land cover and fPAR inputs that were spatially aggregated into units ranging from 30 m to 1 km square. Uncertainties and errors associated with fPAR methods and spatial resolutions are discussed based on agreement with flux tower observations.

  11. PAR3-aPKC regulates Tiam1 by modulating suppressive internal interactions.

    PubMed

    Matsuzawa, Kenji; Akita, Hiroki; Watanabe, Takashi; Kakeno, Mai; Matsui, Toshinori; Wang, Shujie; Kaibuchi, Kozo

    2016-05-01

    Tiam1 is one of the most extensively analyzed activators of the small GTPase Rac. However, fundamental aspects of its regulation are poorly understood. Here we demonstrate that Tiam1 is functionally suppressed by internal interactions and that the PAR complex participates in its full activation. The N-terminal region of Tiam1 binds to the protein-binding and catalytic domains to inhibit its localization and activation. Atypical PKCs phosphorylate Tiam1 to relieve its intramolecular interactions, and the subsequent stabilization of its interaction with PAR3 allows it to exert localized activity. By analyzing Tiam1 regulation by PAR3-aPKC within the context of PDGF signaling, we also show that PAR3 directly binds PDGF receptor β. Thus we provide the first evidence for the negative regulation of Tiam1 by internal interactions, elucidate the nature of Tiam1 regulation by the PAR complex, and reveal a novel role for the PAR complex in PDGF signaling. © 2016 Matsuzawa et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  12. PAR3-aPKC regulates Tiam1 by modulating suppressive internal interactions

    PubMed Central

    Matsuzawa, Kenji; Akita, Hiroki; Watanabe, Takashi; Kakeno, Mai; Matsui, Toshinori; Wang, Shujie; Kaibuchi, Kozo

    2016-01-01

    Tiam1 is one of the most extensively analyzed activators of the small GTPase Rac. However, fundamental aspects of its regulation are poorly understood. Here we demonstrate that Tiam1 is functionally suppressed by internal interactions and that the PAR complex participates in its full activation. The N-terminal region of Tiam1 binds to the protein-binding and catalytic domains to inhibit its localization and activation. Atypical PKCs phosphorylate Tiam1 to relieve its intramolecular interactions, and the subsequent stabilization of its interaction with PAR3 allows it to exert localized activity. By analyzing Tiam1 regulation by PAR3-aPKC within the context of PDGF signaling, we also show that PAR3 directly binds PDGF receptor β. Thus we provide the first evidence for the negative regulation of Tiam1 by internal interactions, elucidate the nature of Tiam1 regulation by the PAR complex, and reveal a novel role for the PAR complex in PDGF signaling. PMID:26941335

  13. Role of protease-activated receptors 2 (PAR2) in ocular infections and inflammation

    PubMed Central

    Tripathi, Trivendra; Alizadeh, Hassan

    2015-01-01

    Protease-activated receptors (PARs) belong to a unique family of G protein-coupled receptors (GPCRs) that are cleaved at an activation site within the N-terminal exodomain by a variety of proteinases, essentially of the serine (Ser) proteinase family. After cleavage, the new N-terminal sequence functions as a tethered ligand, which binds intramolecularly to activate the receptor and initiate signaling. Cell signals induced through the activation of PARs appear to play a significant role in innate and adoptive immune responses of the cornea, which is constantly exposed to proteinases under physiological or pathophysiological conditions. Activation of PARs interferes with all aspects of the corneal physiology such as barrier function, transports, innate and adoptive immune responses, and functions of corneal nerves. It is not known whether the proteinase released from the microorganism can activate PARs and triggers the inflammatory responses. The role of PAR2 expressed by the corneal epithelial cells and activation by serine protease released from microorganism is discussed here. Recent evidences suggest that activation of PAR2, by the serine proteinases, play an important role in innate and inflammatory responses of the corneal infection. PMID:26078987

  14. Breaking the epithelial polarity barrier in cancer: the strange case of LKB1/PAR-4

    PubMed Central

    Partanen, Johanna I.; Tervonen, Topi A.; Klefström, Juha

    2013-01-01

    The PAR clan of polarity regulating genes was initially discovered in a genetic screen searching for genes involved in asymmetric cell divisions in the Caenorhabditis elegans embryo. Today, investigations in worms, flies and mammals have established PAR proteins as conserved and fundamental regulators of animal cell polarization in a broad range of biological phenomena requiring cellular asymmetries. The human homologue of invertebrate PAR-4, a serine–threonine kinase LKB1/STK11, has caught attention as a gene behind Peutz–Jeghers polyposis syndrome and as a bona fide tumour suppressor gene commonly mutated in sporadic cancer. LKB1 functions as a master regulator of AMP-activated protein kinase (AMPK) and 12 other kinases referred to as the AMPK-related kinases, including four human homologues of PAR-1. The role of LKB1 as part of the energy sensing LKB1-AMPK module has been intensively studied, whereas the polarity function of LKB1, in the context of homoeostasis or cancer, has gained less attention. Here, we focus on the PAR-4 identity of LKB1, discussing the weight of evidence indicating a role for LKB1 in regulation of cell polarity and epithelial integrity across species and highlight recent investigations providing new insight into the old question: does the PAR-4 identity of LKB1 matter in cancer? PMID:24062587

  15. Diversity of Soil Microbial Communities from an Iron Mining Area (Oued Zem, Morocco)

    NASA Astrophysics Data System (ADS)

    Mohamed, Nouri; Abdelmajid, Haddioui

    2017-03-01

    Microbial communities in the soil were collected from 20 samples of an iron mining area (Ait Ammar, Oued Zem, Morocco), and unaffected samples were analysed to identify the effects of metal concentrations on functional diversity (Biolog® EcoPlates), and structural diversity (polymerase chain reaction-denaturing gradient gel electrophoresis of 16S rDNA). Aliivibrio fischeri is mainly used for evaluating polluted soil. The functional diversity was assessed by using such indices as area under substrate utilisation curve, richness, Shannon- Weaver and evenness indices. The analysis of similarities and the non-metric multidimensional scaling analyses of DGGE profiles showed that metals in the soil do not have a significant influence on bacteria. Principal component analysis of Biolog data revealed the similarity in the metabolic profiles of mining samples. These results suggest that the direction and the distance from the iron mine tailings do not have significant effects on the metabolic and structural diversity of the soil bacterial population. The toxicity of metals in soils heavily contaminated with Fe and P did not affect the quantities of microbial populations and did not significantly change the microbial diversity of contaminated soils.

  16. High visibility Hong-Ou-Mandel interference via a time-resolved coincidence measurement.

    PubMed

    Tsujimoto, Yoshiaki; Sugiura, Yukihiro; Tanaka, Motoki; Ikuta, Rikizo; Miki, Shigehito; Yamashita, Taro; Terai, Hirotaka; Fujiwara, Mikio; Yamamoto, Takashi; Koashi, Masato; Sasaki, Masahide; Imoto, Nobuyuki

    2017-05-29

    A high visibility Hong-Ou-Mandel (HOM) interference between two independently prepared photons plays an important role in various photonic quantum information processing. In a standard HOM experiment using photons generated by pulse-pumped spontaneous parametric down conversion (SPDC), larger detection time windows than the coherence time of photons have been employed for measuring the HOM visibility and/or drawing the HOM dip. If large amounts of stray photons continuously exist within the detection time windows, employing small detection time windows is favorable for reducing the effect of background noises. Especially, such a setup is helpful for the HOM experiment using continuous wave (cw)-pumped SPDC and the time-resolved coincidence measurement. Here we argue that the method for determining the HOM visibility used in the previous cw experiments tends to suffer from distortion arising from biased contribution of the background noises. We then present a new method with unbiased treatment of the cw backgrounds. By using this method, we experimentally demonstrate a high visibility HOM interference of two heralded telecom photons independently generated by SPDC with employing cw pump light. An observed HOM visibility is 0.87 ± 0.04, which is as high as those observed by using pulse-pumped SPDC photons.

  17. Hong-Ou-Mandel Interference with Atomic Many-Body States

    NASA Astrophysics Data System (ADS)

    Islam, Rajibul; Lukin, Alexander; Ma, Ruichao; Preiss, Philipp; Rispoli, Matthew; Tai, M. Eric; Greiner, Markus

    2015-05-01

    Hong-Ou-Mandel (HOM) interference experiments are a powerful probe for the indistinguishability and underlying quantum statistics of particles. In the classic HOM experiment, a pair of identical photons incident on different input ports of a beamsplitter exits via the same output port. Using the precise control and readout afforded by our quantum gas microscope, we present an implementation of this classic experiment using massive bosons in a doublewell optical potential. Identical states are prepared on each site of the doublewell and by lowering the tunnel coupling between the sites for specific times, we drive a beam splitter operation between the sites. For single-atom Fock input states, we have realized a high fidelity beamsplitter operation and observed an HOM interference contrast of >90%. By generalizing to more complex initial states on the input ports, we have been able to establish HOM experiment protocols as a robust approach towards studying the indistinguishability of many-body states as well as probe interaction-induced effects. These techniques open a path towards the measurement of purity in a quantum system and entanglement entropy in many-body states.

  18. Hong-Ou-Mandel Interference Between Triggered And Heralded Single Photons From Separate Atomic Systems

    NASA Astrophysics Data System (ADS)

    Cere, Alessandro; Leong, Victor; Kaur Gulati, Gurpreet; Srivathsan, Bharath; Kosen, Sandoko; Kurtsiefer, Christian

    2015-05-01

    The realization of quantum networks and long distance quantum communication rely on the capability of generating entanglement between separated nodes. We demonstrate the compatibility of two different sources of single photons: a single atom and four-wave mixing in a cold cloud of atoms. The four-wave mixing process in a cloud of cold 87Rb generates photon pairs. The cascade level scheme used ensures the generation of heralded single photons with exponentially decaying temporal envelope. The temporal shape of the heralding photons matches the shape of photons emitted by spontaneous decay but for the shorter coherence time A single 87Rb atom is trapped in an far-off-resonance optical dipole trap and can be excited with high probability using a short (~3 ns) intense pulse of resonant light, emitting a single photon by spontaneous decay. A large numerical aperture lens collects ~4% of the total fluorescence. The heralded and the triggered photons are launched into a Houng-Ou-Mandel interferometer: a symmetrical beam-splitter with outputs connected to single photon detectors. Scanning the relative delay between the two sources we observe the HOM dip with a maximum visibility of 70 +/-4%.

  19. Electronic Hong-Ou-Mandel interferometry in two-dimensional topological insulators

    NASA Astrophysics Data System (ADS)

    Ferraro, D.; Wahl, C.; Rech, J.; Jonckheere, T.; Martin, T.

    2014-02-01

    The edge states of a two-dimensional topological insulator are characterized by their helicity, a very remarkable property which is related to the time-reversal symmetry and the topology of the underlying system. We theoretically investigate a Hong-Ou-Mandel-type setup as a tool to probe it. Collisions of two electrons with the same spin show a Pauli dip, analogous to the one obtained in the integer quantum Hall case. Moreover, the collisions between electrons of opposite spin also lead to a dip, known as Z2 dip, which is a direct consequence of the constraints imposed by time-reversal symmetry. In contrast to the integer quantum Hall case, the visibility of these dips is reduced by the presence of the additional edge channels, and crucially depends on the properties of the quantum point contact. As a unique feature of this system, we show the possibility of three-electron interference, which leads to a total suppression of the noise independently of the point contact configuration. This is assured by the peculiar interplay between Fermi statistics and topology. This work intends to extend the domain of applicability of electron quantum optics.

  20. Salt wedge determination using electrical sounding method in the region of Oued Nador (Tipaza, Algeria)

    NASA Astrophysics Data System (ADS)

    Amine Bechkit, Mohamed; Benaïssa, Zahia; Ouadfeul, Sid Ali; Deghmoum, Feriel

    2017-04-01

    The marine intrusion of freshwater aquifers by salt water results in soil degradation due to their salinization. The present survey aims to study the position of the fresh water - salt water interface using electric sounding method in the region of Oued Nador (Tipaza, Algeria). It is important to know the position of this interface for the continuation of the aquifer exploitation. For this, we conducted, in this zone, seven electric soundings oriented north-west south-east, with Schlumberger electrodes configuration. The inversion of the apparent resistivity data via the IP2Win software allowed us to recover the true values of electrical resistivity. The exploitation of obtained data requires the implementation of a geo-electric section, and for the interpretation, the results of a standard electrical sounding, acquired near the study area, are used. The results of this geophysical study allowed us to locate the freshwater - salt water contact with resistivity values that can reach 50 ohm m for freshwater formation, and less than 10 ohm m for saturated saltwater formation. The depth of the contact between fresh water and salt water increases gradually from 38 m to 40 m near the coast, and this over a distance of 0 m to 500 m, and then rises abruptly beyond a distance of 500 m at the borehole N°3 where it reaches the maximum depth of 97 m. Key words: Electrical survey - Salt wedge - Electrical resistivity - Aquifer - Intrusion.

  1. The 'ouR-HOPE' approach for ethics and communication about neonatal neurological injury.

    PubMed

    Racine, Eric; Bell, Emily; Farlow, Barbara; Miller, Steven; Payot, Antoine; Rasmussen, Lisa Anne; Shevell, Michael I; Thomson, Donna; Wintermark, Pia

    2017-02-01

    Predicting neurological outcomes of neonates with acute brain injury is an essential component of shared decision-making, in order to guide the development of treatment goals and appropriate care plans. It can aid parents in imagining the child's future, and guide timely and ongoing treatment decisions, including shifting treatment goals and focusing on comfort care. However, numerous challenges have been reported with respect to evidence-based practices for prognostication such as biases about prognosis among clinicians. Additionally, the evaluation or appreciation of living with disability can differ, including the well-known disability paradox where patients self-report a good quality of life in spite of severe disability. Herein, we put forward a set of five practice principles captured in the "ouR-HOPE" approach (Reflection, Humility, Open-mindedness, Partnership, and Engagement) and related questions to encourage clinicians to self-assess their practice and engage with others in responding to these challenges. We hope that this proposal paves the way to greater discussion and attention to ethical aspects of communicating prognosis in the context of neonatal brain injury.

  2. Hong-Ou-Mandel interference with two independent weak coherent states

    NASA Astrophysics Data System (ADS)

    Hua, Chen; Xue-Bi, An; Juan, Wu; Zhen-Qiang, Yin; Shuang, Wang; Wei, Chen; Zhen-Fu, Han

    2016-02-01

    Recently, the Hong-Ou-Mandel (HOM) interference between two independent weak coherent pulses (WCPs) has been paid much attention due to the measurement-device-independent (MDI) quantum key distribution (QKD). Using classical wave theory, articles reported before show that the visibility of this kind of HOM-type interference is ≤ 50%. In this work, we analyze this kind of interference using quantum optics, which reveals more details compared to the wave theory. Analyses confirm the maximum visibility of 50%. And we conclude that the maximum visibility of 50% comes from the two single-photon states in WCPs, without considering the noise. In the experiment, we successfully approach the visibility of 50% by using WCPs splitting from the single pico-second laser source and phase scanning. Since this kind of HOM interference is immune to slow phase fluctuations, both the realized and proposed experiment designs can provide stable ways of high-resolution optical distance detection. Project supported by the National Basic Research Program of China (Grants Nos. 2011CBA00200 and 2011CB921200), the National Natural Science Foundation of China (Grant Nos. 61201239, 61205118, 11304397, and 61475148) and the “Strategic Priority Research Program (B)” of the Chinese Academy of Sciences (Grant No. XDB01030100 and XDB01030300).

  3. Causes de décès des patients infectés par le VIH dans le Centre tunisien

    PubMed Central

    Chelli, Jihène; Bellazreg, Foued; Aouem, Abir; Hattab, Zouhour; Mesmia, Hèla; Lasfar, Nadia Ben; Hachfi, Wissem; Masmoudi, Tasnim; Chakroun, Mohamed; Letaief, Amel

    2016-01-01

    La trithérapie antirétrovirale a contribué à une baisse considérable de la mortalité liée au VIH. Les causes de décès sont dominées par les infections opportunistes dans les pays en voie de développement et par les maladies cardiovasculaires et les cancers dans les pays développés. L’objectif était de déterminer les causes et les facteurs de risque de décès des patients infectés par le VIH dans le Centre Tunisien. Une étude transversale auprès des patients infectés par le VIH âgés de plus de 15 ans suivis à Sousse et à Monastir entre 2000 et 2014. Le décès était considéré lié au VIH si la cause était un évènement classant SIDA ou s’il était la conséquence d’une infection opportuniste d’étiologie indéterminée avec des CD4 < 50/mm3, non lié au VIH si la cause n’était pas un évènement classant SIDA, et de cause inconnue si aucune information n’était disponible. Deux cents treize patients, 130 hommes (61%) et 83 femmes (39%), d’âge moyen 40±11 ans ont été inclus. Cinquante quatre patients sont décédés, avec une mortalité de 5,4/100 patients-années. La mortalité annuelle a baissé de 5,8% en 2000-2003 à 2,3% en 2012-2014. La survie était de 72% à 5 ans et de 67% à 10 ans. Les décès étaient liés au VIH dans 70,4% des cas. Les causes de décès les plus fréquentes étaient la pneumocystose pulmonaire et la cryptococcose neuroméningée dans 6 cas (11%) chacune. Les facteurs de risque de décès étaient les antécédents d’infections opportunistes, la durée de la trithérapie antirétrovirale < 12 mois et le tabagisme. Le renforcement du dépistage, l’initiation précoce de la trithérapie antirétrovirale, et la lutte contre le tabagisme sont nécessaires afin de réduire la mortalité chez les patients infectés par le VIH en Tunisie. PMID:28292068

  4. Étude micromécanique de la disparition du seuil de fissuration par fatigue d'un alliage de titane biphasé à fort K_{max}

    NASA Astrophysics Data System (ADS)

    Mignot, F.; Doquet, V.; Sarrazin-Baudoux, C.; Petit, J.

    2003-03-01

    L'alliage Ti6246 présente, lors d'essais de fissuration par fatigue à K_{max} constant et ΔK décroissant un comportement atypique : lorsque K_{max}ge 0.7KIC, on observe, sous air comme sous vide, au lieu du seuil attendu, un régime de propagation à vitesse constante, dix fois plus élevée à l'ambiante qu'à 500^{circ}C. Le fluage, qui se manifeste dès l'ambiante dans cet alliage semble jouer un rôle dans ce phénomène. Toutefois, des analyses par spectrométrie de masse d'ions secondaires font apparaître une sur-concentration en hydrogène au voisinage d'une fissure développée dans le régime anormal. Des essais de fissuration, traction et fluage sont donc entrepris sur le matériau brut, appauvri ou enrichi en hydrogène, pour partie dans la chambre d'un microscope électronique à balayage, dans le but d'explorer ce phénomène. On constate qu'un enrichissement en hydrogène augmente la ductilité du matériau et sa tendance au fluage à l'ambiante et un enrichissement plus prononcé la diminue.

  5. Granulome conjonctival suite à un traumatisme par épine végétale négligé: à propos d’un cas

    PubMed Central

    Elghazi, Taha; Eljai, Amine; Elkaddoumi, Maryama; Lazrek, Omar; saoudi, Sofia Hassani; Belkbir, Taib; Amazouzi, Abdellah; Cherkaoui, Lalla Ouafae; Daoudi, Rajae

    2016-01-01

    Il est parfois difficile de détecter un corps étranger végétal intraoculaire, principalement dans les cas où l'histoire du traumatisme oculaire n'est pas claire, ou chez les patients qui consultent plusieurs mois après le traumatisme. Nous rapportons un cas rare d'un enfant de 7 ans qui s'est auto traumatisé au niveau de l'œil gauche par une épine végétale de cactus, 3 mois avant son admission, ce qui a entraîné un granulome conjonctival temporal supérieur avec réaction inflammatoire du segment antérieur. L'exploration chirurgicale a été réalisée permettant l'extraction de l'épine avec une exérèse totale du granulome. Une légère amélioration clinique et de l'acuité visuelle a été notée puis le globe oculaire a évolué vers la phtyse quelque mois après l'extraction. PMID:28154701

  6. Caractérisation de la structure des membranes ionomères (NAFION^{tinytextregistered}) par diffusion de rayons X aux petits angles

    NASA Astrophysics Data System (ADS)

    Rubatat, L.; Rollet, A. L.; Diat, O.; Gébel, G.

    2002-07-01

    Ionomer membranes, like Nafion^{tinytextregistered} used in fuel cell, present a nano- phase separation between domains with different ionic concentrations. Up to now models describe the ionic domains as spheres of about 40 Å diameter. Small angles X-ray scattering studies over a large range of wave vectors, lead to a new assumption for the Nafion structure, describing the polymer aggregation as elongated objects surrounding by the ionic charges. Les membranes ionomères de type Nafion^{tinytextregistered} utilisées en pile à combustible, sont caractérisées par une nano-séparation de phases entre des domaines plus ou moins riches en sites ioniques. Les modèles proposés pour décrire ces domaines ioniques, les représentent généralement sous forme de sphères de 40 Å de diamètre. L'étude en diffusion de rayons X que nous avons menée récemment, sur une large gamme de vecteurs d'ondes, nous permet de proposer une vision différente de la structure du Nafion en considérant une agrégation de polymères sous formes d'objets très allongés, avec en surface les charges ioniques.

  7. Ocular trauma treated with pars plana vitrectomy: early outcome report

    PubMed Central

    Mansouri, Mohammad Reza; Tabatabaei, Seyed Ali; Soleimani, Mohammad; Kiarudi, Mohammad Yaser; Molaei, Saber; Rouzbahani, Mehdi; Mireshghi, Meysam; Zaeferani, Mohsen; Ghasempour, Mehrbod

    2016-01-01

    AIM To evaluate demographic variables and visual outcomes, among patients with ocular injuries involving the posterior segment, managed with pars plana vitrectomy. METHODS The records of patients were studied retrospectively from March to September 2010, to determine the age, gender, place of occurrence of trauma, visual acuity, anatomical site, nature of injury, wound length, the presence of an afferent pupillary defect, and the timing of vitrectomy. The Ocular Trauma Score was measured. The minimum follow-up from presentation was 6mo. RESULTS Ninety patients (77 males, 13 females), with a mean age of 32.7±15.8y were included over the 6-month period. The majority of cases occurred in the workplace (47 patients), followed by home (14 patients). The mean visual acuity (logMAR) of patients significantly improved from 2.36±0.72 preoperatively to 1.50±1.14 postoperatively. Twenty-three patients had preoperative vision better than 2.0 logMAR, the postoperative visual acuity was significantly better among these patients than patients with worse than 2.0 logMAR (P<0.001). Visual improvement between groups with early vitrectomy (<7d) and delayed vitrectomy (>7d) was not significantly different (P=0.66). Postoperative visual acuity was not significantly different between patients with injury in Zone I and II (P=0.64), but patients with injury in Zone III had significantly poorer visual acuity (P=0.02). Patients with relative afferent pupillary defect had significantly poorer postoperative visual acuity (P=0.02). Preoperative visual acuity, the difference of preoperative and postoperative visual acuity, and postoperative visual acuity were significantly different between groups with different ocular trauma scores (P<0.001). CONCLUSION Trauma is more likely to occur in men under 40y of age and in the workplace. The favorable final visual outcome is associated with the absence of afferent pupillary defect, ocular trauma score and presenting visual acuity as well as the zone

  8. PERSISTENT CORNEAL EPITHELIAL DEFECT AFTER PARS PLANA VITRECTOMY.

    PubMed

    Chen, Hsi-Fu; Yeung, Ling; Yang, Ko-Jen; Sun, Chi-Chin

    2016-01-01

    To investigate the incidence, risk factors, and clinical course of persistent corneal epithelial defects (PCED) after pars plana vitrectomy (PPV). The charts of 426 consecutive patients (511 eyes) who received PPV from January 2008 to December 2011 were reviewed. Corneal complications were defined as the presence of corneal epithelial defects, corneal edema, or superficial punctate keratopathy at least 1 week after vitrectomy. The PCED was defined as corneal epithelial defects lasting longer than 2 weeks after vitrectomy despite conventional treatment. The demographic, preoperative, intraoperative, and postoperative data were compared between PCED and non-PCED corneal complication groups to evaluate the risk factors and clinical outcomes. Postoperative corneal complications developed in 103 of 460 (22.4%) eyes. Diabetes was associated with postoperative corneal epithelial defects (P = 0.021) and superficial punctate keratopathy (P = 0.022) but not corneal edema (P = 0.925). Among 103 eyes with corneal complications, 21 eyes developed PCED. The eyes with PCED had poor final visual acuity, with 23.8% (5/21) of the eyes in the PCED group having visual acuity of 20/200 or better compared with 51.2% (42/82) of the eyes in the non-PCED group (P = 0.024). Logistic regression analysis demonstrated that diabetes mellitus (P = 0.025), use of perfluoropropane (P = 0.001), and assistance of a first-year resident (P = 0.029) were statistically significant risk factors for PCED after PPV. There was also a high incidence of geographic herpes simplex virus epithelial keratitis among recalcitrant PCEDs lasting longer than 4 weeks (36%, 4/11 eyes). The overall incidence of PCED after PPV was 4.8%. Diabetes mellitus, intravitreal tamponade with perfluoropropane, and assistance of a first-year resident were risk factors for PCED after PPV. Persistent corneal epithelial defects after PPV were correlated with poor postoperative visual outcomes. Early and aggressive management is

  9. Targeting of peptide conjugated magnetic nanoparticles to urokinase plasminogen activator receptor (uPAR) expressing cells

    NASA Astrophysics Data System (ADS)

    Hansen, Line; Unmack Larsen, Esben Kjær; Nielsen, Erik Holm; Iversen, Frank; Liu, Zhuo; Thomsen, Karen; Pedersen, Michael; Skrydstrup, Troels; Nielsen, Niels Chr.; Ploug, Michael; Kjems, Jørgen

    2013-08-01

    Ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles are currently being used as a magnetic resonance imaging (MRI) contrast agent in vivo, mainly by their passive accumulation in tissues of interest. However, a higher specificity can ideally be achieved when the nanoparticles are targeted towards cell specific receptors and this may also facilitate specific drug delivery by an enhanced target-mediated endocytosis. We report efficient peptide-mediated targeting of magnetic nanoparticles to cells expressing the urokinase plasminogen activator receptor (uPAR), a surface biomarker for poor patient prognosis shared by several cancers including breast, colorectal, and gastric cancers. Conjugation of a uPAR specific targeting peptide onto polyethylene glycol (PEG) coated USPIO nanoparticles by click chemistry resulted in a five times higher uptake in vitro in a uPAR positive cell line compared to nanoparticles carrying a non-binding control peptide. In accordance with specific receptor-mediated recognition, a low uptake was observed in the presence of an excess of ATF, a natural ligand for uPAR. The uPAR specific magnetic nanoparticles can potentially provide a useful supplement for tumor patient management when combined with MRI and drug delivery.Ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles are currently being used as a magnetic resonance imaging (MRI) contrast agent in vivo, mainly by their passive accumulation in tissues of interest. However, a higher specificity can ideally be achieved when the nanoparticles are targeted towards cell specific receptors and this may also facilitate specific drug delivery by an enhanced target-mediated endocytosis. We report efficient peptide-mediated targeting of magnetic nanoparticles to cells expressing the urokinase plasminogen activator receptor (uPAR), a surface biomarker for poor patient prognosis shared by several cancers including breast, colorectal, and gastric cancers. Conjugation of a uPAR specific

  10. Role of the parCBA Operon of the Broad-Host-Range Plasmid RK2 in Stable Plasmid Maintenance

    PubMed Central

    Easter, Carla L.; Schwab, Helmut; Helinski, Donald R.

    1998-01-01

    The par region of the stably maintained broad-host-range plasmid RK2 is organized as two divergent operons, parCBA and parDE, and a cis-acting site. parDE encodes a postsegregational killing system, and parCBA encodes a resolvase (ParA), a nuclease (ParB), and a protein of unknown function (ParC). The present study was undertaken to further delineate the role of the parCBA region in the stable maintenance of RK2 by first introducing precise deletions in the three genes and then assessing the abilities of the different constructs to stabilize RK2 in three strains of Escherichia coli and two strains of Pseudomonas aeruginosa. The intact parCBA operon was effective in stabilizing a conjugation-defective RK2 derivative in E. coli MC1061K and RR1 but was relatively ineffective in E. coli MV10Δlac. In the two strains in which the parCBA operon was effective, deletions in parB, parC, or both parB and parC caused an approximately twofold reduction in the stabilizing ability of the operon, while a deletion in the parA gene resulted in a much greater loss of parCBA activity. For P. aeruginosa PAO1161Rifr, the parCBA operon provided little if any plasmid stability, but for P. aeruginosa PAC452Rifr, the RK2 plasmid was stabilized to a substantial extent by parCBA. With this latter strain, parA and res alone were sufficient for stabilization. The cer resolvase system of plasmid ColE1 and the loxP/Cre system of plasmid P1 were tested in comparison with the parCBA operon. We found that, not unlike what was previously observed with MC1061K, cer failed to stabilize the RK2 plasmid with par deletions in strain MV10Δlac, but this multimer resolution system was effective in stabilizing the plasmid in strain RR1. The loxP/Cre system, on the other hand, was very effective in stabilizing the plasmid in all three E. coli strains. These observations indicate that the parA gene, along with its res site, exhibits a significant level of plasmid stabilization in the absence of the parC and

  11. Heat stress-induced disruption of endothelial barrier function is via PAR1 signaling and suppressed by Xuebijing injection.

    PubMed

    Xu, Qiulin; Liu, Jingxian; Wang, Zhenglian; Guo, Xiaohua; Zhou, Gengbiao; Liu, Yanan; Huang, Qiaobing; Su, Lei

    2015-01-01

    Increased vascular permeability leading to acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) is central to the pathogenesis of heatstroke. Protease-activated receptor 1 (PAR1), the receptor for thrombin, plays a key role in disruption of endothelial barrier function in response to extracellular stimuli. However, the role of PAR1 in heat stress-induced endothelial hyper-permeability is unknown. In this study, we measured PAR1 protein expression in heat-stressed human umbilical venous endothelial cells (HUVECs), investigated the influences of PAR1 on endothelial permeability, F-actin rearrangement, and moesin phosphorylation by inhibiting PAR1 with its siRNA, neutralizing antibody (anti-PAR1), specific inhibitor(RWJ56110), and Xuebijing injection (XBJ), a traditional Chinese medicine used for sepsis treatment, and evaluated the role of PAR1 in heatstroke-related ALI/ARDS in mice by suppressing PAR1 with RWJ56110, anti-PAR1and XBJ. We found that heat stress induced PAR1 protein expression 2h after heat stress in endothelial cells, caused the release of endothelial matrix metalloprotease 1, an activator of PAR1, after 60 or 120 min of heat stimulation, as well as promoted endothelial hyper-permeability and F-actin rearrangement, which were inhibited by suppressing PAR1 with RWJ56110, anti-PAR1 and siRNA. PAR1 mediated moesin phosphorylation, which caused F-actin rearrangement and disruption of endothelial barrier function. To corroborate findings from in vitro experiments, we found that RWJ56110 and the anti-PAR1 significantly decreased lung edema, pulmonary microvascular permeability, protein exudation, and leukocytes infiltrations in heatstroke mice. Additionally, XBJ was found to suppress PAR1-moesin signal pathway and confer protective effects on maintaining endothelial barrier function both in vitro and in vivo heat-stressed model, similar to those observed above with the inhibition of PAR1. These results suggest that PAR1 is a potential

  12. Combination with CK19 Might Increase the Prognostic Power of Hep Par 1 in Hepatocellular Carcinoma after Curative Resection.

    PubMed

    Jin, Ye; Liang, Zhi-Yong; Zhou, Wei-Xun; Zhou, Li

    2017-07-31

    Hepatocyte Paraffin 1 (Hep Par 1) and cytokeratin 19 (CK19) were shown to be associated with post-surgical prognosis of hepatocellular carcinoma (HCC). However, further validation might be needed. Besides, their combined evaluation has not been reported. The present study was designed to address the issues. Expressions of Hep Par 1 and CK19 were detected using tissue microarray-based immunohistochemical staining in 79 patients with HCC underwent curative hepatectomy. Their associations with cliniopathologic variables, overall and recurrence-free survival were analyzed. Hep Par 1 was highly expressed in 61 patients (77.2%), whereas CK19 was positive in 8 patients (10.1%). Moreover, expressions of these two proteins were all associated with tumor-node-metastasis (TNM) stage and vascular invasion. It was found that high Hep Par 1 expression was univariately associated with good overall and recurrence-free survival, while CK19 was marginally prognostic. Also in univariate analyses, combination of the two markers more effectively predicted for long-term prognosis in HCC than Hep Par 1 did. However, neither Hep Par 1 nor Hep Par 1/CK19 was multivariately significant. Finally, Hep Par 1/CK19 combined with TNM stage might obtain more satisfactory outcome prediction, especially for overall survival. Combination of CK19 with Hep Par 1 might have higher prognostic power, which might be further improved by adding TNM stage, than Hep Par 1 alone, in resected HCC. Of course, subsequent confirmation is necessary.

  13. Estimation of photosynthetically available radiation (PAR) from OCEANSAT-I OCM using a simple atmospheric radiative transfer model

    NASA Astrophysics Data System (ADS)

    Tripathy, Madhumita; Raman, Mini; Chauhan, Prakash

    2015-10-01

    Photosynthetically available radiation (PAR) is an important variable for radiation budget, marine and terrestrial ecosystem models. OCEANSAT-1 Ocean Color Monitor (OCM) PAR was estimated using two different methods under both clear and cloudy sky conditions. In the first approach, aerosol optical depth (AOD) and cloud optical depth (COD) were estimated from OCEANSAT-1 OCM TOA (top-of-atmosphere) radiance data on a pixel by pixel basis and PAR was estimated from extraterrestrial solar flux for fifteen spectral bands using a radiative transfer model. The second approach used TOA radiances measured by OCM in the PAR spectral range to compute PAR. This approach also included surface albedo and cloud albedo as inputs. Comparison between OCEANSAT-1 OCM PAR at noon with in situ measured PAR shows that root mean square difference was 5.82% for the method I and 7.24% for the method II in daily time scales. Results indicate that methodology adopted to estimate PAR from OCEANSAT-1 OCM can produce reasonably accurate PAR estimates over the tropical Indian Ocean region. This approach can be extended to OCEANSAT-2 OCM and future OCEANSAT-3 OCM data for operational estimation of PAR for regional marine ecosystem applications.

  14. Post-translational regulation of the cleaved fragment of Par-4 in ovarian and endometrial cancer cells

    PubMed Central

    Brasseur, Kevin; Fabi, François; Adam, Pascal; Parent, Sophie; Lessard, Laurent; Asselin, Eric

    2016-01-01

    We recently reported the caspase3-dependent cleavage of Par-4 resulting in the accumulation of a 25kDa cleaved-Par-4 (cl-Par-4) fragment and we investigated in the present study the mechanisms regulating this fragment using cl-Par-4-expressing stable clones derived from ovarian and endometrial cancer cell lines. Cl-Par-4 protein was weakly express in all stable clones despite constitutive expression. However, upon cisplatin treatment, cl-Par-4 levels increased up to 50-fold relative to baseline conditions. Treatment of stable clones with proteasome and translation inhibitors revealed that cisplatin exposure might in fact protect cl-Par-4 from proteasome-dependent degradation. PI3K and MAPK pathways were also implicated as evidenced by an increase of cl-Par-4 in the presence of PI3K inhibitors and a decrease using MAPK inhibitors. Finally using bioinformatics resources, we found diverse datasets showing similar results to those we observed with the proteasome and cl-Par-4 further supporting our data. These new findings add to the complex mechanisms regulating Par-4 expression and activity, and justify further studies addressing the biological significance of this phenomenon in gynaecological cancer cells. PMID:27175591

  15. Iduna is a poly(ADP-ribose) (PAR)-dependent E3 ubiquitin ligase that regulates DNA damage

    PubMed Central

    Kang, Ho Chul; Lee, Yun-Il; Shin, Joo-Ho; Andrabi, Shaida A.; Chi, Zhikai; Gagné, Jean-Philippe; Lee, Yunjong; Ko, Han Seok; Lee, Byoung Dae; Poirier, Guy G.; Dawson, Valina L.; Dawson, Ted M.

    2011-01-01

    Ubiquitin mediated protein degradation is crucial for regulation of cell signaling and protein quality control. Poly(ADP-ribose) (PAR) is a cell-signaling molecule that mediates changes in protein function through binding at PAR binding sites. Here we characterize the PAR binding protein, Iduna, and show that it is a PAR-dependent ubiquitin E3 ligase. Iduna’s E3 ligase activity requires PAR binding because point mutations at Y156A and R157A eliminate Iduna’s PAR binding and Iduna’s E3 ligase activity. Iduna’s E3 ligase activity also requires an intact really interesting new gene (RING) domain because Iduna possessing point mutations at either H54A or C60A is devoid of ubiquitination activity. Tandem affinity purification reveals that Iduna binds to a number of proteins that are either PARsylated or bind PAR including PAR polymerase-1, 2 (PARP1, 2), nucleolin, DNA ligase III, KU70, KU86, XRCC1, and histones. PAR binding to Iduna activates its E3 ligase function, and PAR binding is required for Iduna ubiquitination of PARP1, XRCC1, DNA ligase III, and KU70. Iduna’s PAR-dependent ubiquitination of PARP1 targets it for proteasomal degradation. Via PAR binding and ubiquitin E3 ligase activity, Iduna protects against cell death induced by the DNA damaging agent N-methyl-N-nitro-N-nitrosoguanidine (MNNG) and rescues cells from G1 arrest and promotes cell survival after γ-irradiation. Moreover, Iduna facilitates DNA repair by reducing apurinic/apyrimidinic (AP) sites after MNNG exposure and facilitates DNA repair following γ-irradiation as assessed by the comet assay. These results define Iduna as a PAR-dependent E3 ligase that regulates cell survival and DNA repair. PMID:21825151

  16. Intercomparison of Groundwater Flow Monitoring Technologies at Site OU 1, Former Fort Ord, California

    SciTech Connect

    Daley, P F; Jantos, J; Pedler, W H; Mandell, W A

    2005-09-20

    This report presents an intercomparison of three groundwater flow monitoring technologies at a trichloroethylene (TCE) groundwater plume at Operational Unit 1 (OU 1) adjacent to the former Fritzsche Army Airfield at the former Fort Ord Army Base, located on Monterey Bay in northern Monterey County, California. Soil and groundwater at this site became contaminated by fuels and solvents that were burned on a portion of OU 1 called the Fire Drill Area (FDA) as part of firefighter training from 1962 and 1985. Cont Contamination is believed to be restricted to the unconfined A-aquifer, where water is reached at a depth of approximately 60 to 80 feet below the ground surface; the aquifer is from 15 to 20 feet in thickness, and is bounded below by a dense clay layer, the Salinas Valley Aquitard. Soil excavation and bioremediation were initiated at the site of fire training activities in the late 1980s. Since that time a pump-and-treat operation has been operated close to the original area of contamination, and this system has been largely successful at reducing groundwater contamination in this source area. However, a trichloroethylene (TCE) groundwater plume extends approximately 3000 ft (900 m) to the northwest away from the FDA. In this report, we have augmented flow monitoring equipment permanently installed in an earlier project (Oldenburg et al., 2002) with two additional flow monitoring devices that could be deployed in existing monitoring wells, in an effort to better understand their performance in a nearly ideal, homogeneous sand aquifer, that we expected would exhibit laminar groundwater flow owing to the site's relatively simple hydrogeology. The three flow monitoring tools were the Hydrotechnics{reg_sign} In In-Situ Permeable Flow Sensor (ISPFS), the RAS Integrated Subsurface Evaluation Hydrophysical Logging tool (HPL), and the Lawrence Livermore National Laboratory Scanning Colloidal Borescope Flow Meter (SCBFM). All three devices produce groundwater flow

  17. Exacerbation of Apoptosis of Cortical Neurons Following Traumatic Brain Injury in Par-4 Transgenic Mice

    PubMed Central

    Payette, Daniel J; Xie, Jun; Shirwany, Najeeb; Guo, Qing

    2008-01-01

    Traumatic brain injury (TBI) is a significant clinical problem, yet few effective strategies for treating it have emerged. People that sustain and survive a TBI are left with significant cognitive, behavioral, and communicative disabilities. Apoptotic neuronal death occurs following TBI. Prostate apoptosis response-4 (Par-4) is a death domain-containing protein initially characterized as a critical regulator of apoptosis in prostate cancer cells. We have recently generated and characterized Par-4 transgenic mice in which the expression of the par-4 transgene was limited to cells of neuronal lineage. We now provide evidence that, in cortical neurons from these mice, Par-4 drastically increases apoptotic neuronal death in both in vitro and in vivo models of TBI. In vitro experiments were performed in 7-day-old primary cultures of cortical neurons using a previously published, scratch-induced mechanical trauma model. Neurons that overexpress Par-4 showed not only a significant decrease in overall neuron survival after TBI compared to wild-type cells, but also exhibited a sharper decrease in mitochondrial transmembrane potential, a higher degree of free radical accumulation, and earlier activation of caspase-3 than wild-type cells did. In vivo experiments were performed utilizing a weight drop TBI model. A significantly increased volume of cortical injury and exacerbated activation of caspase-3 were observed in Par-4 transgenic mice when compared to those in wild-type mice. These data suggests that aberrant Par-4 expression exacerbates neuronal cell death following TBI by altering mitochondrial function, enhancing oxidative damage, and execution of apoptosis via caspase activation. PMID:18784822

  18. Evaluation of treatment and posttreatment changes of protraction facemask treatment using the PAR index.

    PubMed

    Ngan, P; Yiu, C

    2000-10-01

    The purpose of this study was to use the Peer Assesment Rating (PAR) index score to evaluate the treatment and posttreatment changes of Class III patients treated by protraction facemask. The sample consisted of 20 Chinese children, 6 to 11 years old, with Class III skeletal malocclusion who had been treated with maxillary expansion and a protraction facemask. The average treatment time was 8.2 months, followed by 1 year of retention with a Class III functional appliance. Study casts were taken pretreatment (T1), posttreatment (T2), 1 year follow-up (T3), and 2 years follow-up (T4). After treatment, PAR scores were calculated for each time period. Differences among the 4 time periods were analyzed with the Wilcoxin matched-pairs test. Significant reductions in PAR scores were found at T2 (56%), T3 (70%), and T4 (63%) compared with T1. Immediately posttreatment (T2), 17 (85%) of 20 patients had improved PAR scores by a reduction of at least 30%. Reductions were caused primarily by correction of the anterior crossbite. One year after treatment (T3), further reductions in PAR score were noted (P <.01) as a result of better alignment of the anterior segment, improvement of the buccal occlusion, and overbite and midline corrections. Two years after treatment (T4), PAR scores were higher than at the previous time period. The increases were due to relapses in overjet (4 of 20 patients), overbite, and centerline corrections. These results indicate that significant reductions in the severity of Class III malocclusion can be achieved with early orthopedic facemask treatment. In most cases, further improvement in the PAR score can be expected 1 and 2 years after treatment. In a few patients, the benefits of early treatment are negated by relapses in overjet, overbite, and centerline corrections during the follow-up period.

  19. A method for estimating the diffuse attenuation coefficient (KdPAR)from paired temperature sensors

    USGS Publications Warehouse

    Read, Jordan S.; Rose, Kevin C.; Winslow, Luke A.; Read, Emily K.

    2015-01-01

    A new method for estimating the diffuse attenuation coefficient for photosynthetically active radiation (KdPAR) from paired temperature sensors was derived. We show that during cases where the attenuation of penetrating shortwave solar radiation is the dominant source of temperature changes, time series measurements of water temperatures at multiple depths (z1 and z2) are related to one another by a linear scaling factor (a). KdPAR can then be estimated by the simple equation KdPAR ln(a)/(z2/z1). A suggested workflow is presented that outlines procedures for calculating KdPAR according to this paired temperature sensor (PTS) method. This method is best suited for conditions when radiative temperature gains are large relative to physical noise. These conditions occur frequently on water bodies with low wind and/or high KdPARs but can be used for other types of lakes during time periods of low wind and/or where spatially redundant measurements of temperatures are available. The optimal vertical placement of temperature sensors according to a priori knowledge of KdPAR is also described. This information can be used to inform the design of future sensor deployments using the PTS method or for campaigns where characterizing sub-daily changes in temperatures is important. The PTS method provides a novel method to characterize light attenuation in aquatic ecosystems without expensive radiometric equipment or the user subjectivity inherent in Secchi depth measurements. This method also can enable the estimation of KdPAR at higher frequencies than many manual monitoring programs allow.

  20. ParsEval: parallel comparison and analysis of gene structure annotations

    PubMed Central

    2012-01-01

    Background Accurate gene structure annotation is a fundamental but somewhat elusive goal of genome projects, as witnessed by the fact that (model) genomes typically undergo several cycles of re-annotation. In many cases, it is not only different versions of annotations that need to be compared but also different sources of annotation of the same genome, derived from distinct gene prediction workflows. Such comparisons are of interest to annotation providers, prediction software developers, and end-users, who all need to assess what is common and what is different among distinct annotation sources. We developed ParsEval, a software application for pairwise comparison of sets of gene structure annotations. ParsEval calculates several statistics that highlight the similarities and differences between the two sets of annotations provided. These statistics are presented in an aggregate summary report, with additional details provided as individual reports specific to non-overlapping, gene-model-centric genomic loci. Genome browser styled graphics embedded in these reports help visualize the genomic context of the annotations. Output from ParsEval is both easily read and parsed, enabling systematic identification of problematic gene models for subsequent focused analysis. Results ParsEval is capable of analyzing annotations for large eukaryotic genomes on typical desktop or laptop hardware. In comparison to existing methods, ParsEval exhibits a considerable performance improvement, both in terms of runtime and memory consumption. Reports from ParsEval can provide relevant biological insights into the gene structure annotations being compared. Conclusions Implemented in C, ParsEval provides the quickest and most feature-rich solution for genome annotation comparison to date. The source code is freely available (under an ISC license) at http://parseval.sourceforge.net/. PMID:22852583

  1. Detecting Plant Photoprotective Response to Water Stress Through Variation In PAR Reflectance

    NASA Astrophysics Data System (ADS)

    Zygielbaum, A. I.; Arkebauer, T. J.; Walter-Shea, E.

    2012-12-01

    Published papers over several decades have shown increasing leaf-level optical reflectance with decreasing leaf water content. Our experimental results using maize and sorghum showed this increase consistently, caused by variation in optical absorption, in the visible (photosynthetically active radiation - PAR) and middle infrared (MIR) spectral regions. Relatively smaller response, driven by variation in optical scatter, was observed in near infrared (NIR). The concomitant increasing reflectance in the PAR and MIR regions is perplexing. PAR reflectance is dominated by chlorophyll absorption while MIR reflectance is dominated by water molecule absorption. However, changes in chlorophyll concentration, determined by chemical extraction, were too small to account for the variation in PAR reflectance. PAR and MIR reflectances were also influenced by the strength of incident light. Hence PAR reflectance appears to be modulated not only by pigment concentration, the classical description, but also by the strength of incident light and the severity of water deficit. We previously reported that these findings were consistent with chloroplast avoidance movement, a plant photoprotective response, which limits light absorption by pigments. We report here our continuing investigation of this phenomenon. In addition to reflectance measurements, time-lapse microscope images of leaves under increasing water deficit conditions were obtained. These show a brightening between veins which strongly supports our assertion that changes in PAR reflectance accompanying water deficit are caused primarily by chloroplast avoidance movement. Our results suggest that leaf, and possibly canopy, reflectance can therefore be used to detect and measure plant stress. These results also indicate that chloroplast avoidance movement may cause poor estimates of leaf chlorophyll content using techniques based on fluoresced, reflected or transmitted light.

  2. Lumbar lordosis and pars interarticularis fractures: a case-control study.

    PubMed

    Bugg, William G; Lewis, Mark; Juette, Arne; Cahir, John G; Toms, Andoni P

    2012-07-01

    The aim of this study is to examine the relationship between lumbar lordosis and pars interarticularis fractures. In this retrospective case-control study we compare the angle of lumbar lordosis and the angle of the S1 vertebral endplate (as a measure of pelvic tilt) in patients with bilateral L5 pars interarticularis fractures with age- and sex-matched control cases with normal MRI examinations of the lumbar spine. Twenty-nine cases of bilateral L5 pars interarticularis fractures with matched control-cases were identified on MRI (16 male, 13 female, age 9-63 years). The angle of lordosis was measured between the inferior L4 and superior S1 vertebral endplates on a standing lateral lumbar spine radiograph for both groups. The mean angle of lordosis about the L5 vertebra was 36.9° (SD = 6.5°) in the pars interarticularis fracture group, and 30.1° (SD = 6.4°) in the control group. The difference between the two groups was significant (mean difference 6.8°, Student's t test: P < 0.001). The mean angle of sacral tilt measured was 122.2° (SD = 10.16°) for controls and 136.4° (SD = 10.86°) for patients with pars defects. The difference in the means of 14.2° was statistically significantly different (P < 0.0001). Sacral tilt represented by a steeply angled superior endplate of S1 is associated with a significantly increased angle of lordosis, between L4 and S1, and pars fractures at L5. Steep angulation of the first sacral vertebral segment maybe the predisposing biomechanical factor that leads to pincer-like impingement of the pars interarticularis and then spondylolysis.

  3. uPA/uPAR system activation drives a glycolytic phenotype in melanoma cells.

    PubMed

    Laurenzana, Anna; Chillà, Anastasia; Luciani, Cristina; Peppicelli, Silvia; Biagioni, Alessio; Bianchini, Francesca; Tenedini, Elena; Torre, Eugenio; Mocali, Alessandra; Calorini, Lido; Margheri, Francesca; Fibbi, Gabriella; Del Rosso, Mario

    2017-09-15

    In this manuscript, we show the involvement of the uPA/uPAR system in the regulation of aerobic glycolysis of melanoma cells. uPAR over-expression in human melanoma cells controls an invasive and glycolytic phenotype in normoxic conditions. uPAR down-regulation by siRNA or its uncoupling from integrins, and hence from integrin-linked tyrosine kinase receptors (IL-TKRs), by an antagonist peptide induced a striking inhibition of the PI3K/AKT/mTOR/HIF1α pathway, resulting into impairment of glucose uptake, decrease of several glycolytic enzymes and of PKM2, a checkpoint that controls metabolism of cancer cells. Further, binding of uPA to uPAR regulates expression of molecules that govern cell invasion, including extracellular matrix metallo-proteinases inducer (EMPPRIN) and enolase, a glycolytyc enzyme that also serves as a plasminogen receptor, thus providing a common denominator between tumor metabolism and phenotypic invasive features. Such effects depend on the α5β1-integrin-mediated uPAR connection with EGFR in melanoma cells with engagement of the PI3K-mTOR-HIFα pathway. HIF-1α trans-activates genes whose products mediate tumor invasion and glycolysis, thus providing the common denominator between melanoma metabolism and its invasive features. These findings unveil a unrecognized interaction between the invasion-related uPAR and IL-TKRs in the control of glycolysis and disclose a new pharmacological target (i.e., uPAR/IL-TKRs axis) for the therapy of melanoma. © 2017 UICC.

  4. Early intraplatelet signaling enhances the release of human platelet PAR-1 and -4 amino-terminal peptides in response to thrombin.

    PubMed

    Ofosu, Frederick A; Dewar, Lori; Song, Yingqi; Cedrone, Aisha C; Hortelano, Gonzalo; Craven, Sharon J

    2009-02-24

    Activation of washed human platelets initiated with alpha-thrombin, SFLLRN, or AYPGKF invariably results in the generation of PAR-1-(1-41) and PAR-4-(1-47). PAR-1-(1-41) and PAR-4-(1-47) are amino-terminal peptides generated when PAR-1 and -4 are cleaved in their first extracellular domains after R(41) and R(47), respectively, to expose the tethered ligand domains of PAR-1 and -4. Since soybean trypsin inhibitor decreases generation of PAR-1-(1-41) and PAR-4-(1-47) and other platelet aggregation-related responses to these three agonists, but does not inactivate alpha-thrombin, a platelet trypsin-like proteinase apparently activates PAR-1 and -4 to propagate PAR-dependent platelet responses. This study identified the signaling pathways implicated in the generation of the platelet proteinase that in turn produces PAR-1-(1-41) and PAR-4-(1-47), to thereby drive the subsequent PAR-dependent platelet aggregation-related responses to alpha-thrombin, SFLLRN, or AYPGKF. Only inhibitors of signaling enzymes that prevented ATP release (forskolin, PGE(1), or BIMI-1) prevented or delayed the generation of PAR-1-(1-41) and PAR-4-(1-47) in response to all three agonists. SBTI prevented platelet aggregation initiated by alpha-thrombin, SFLLRN, or AYPGKF but did so less effectively when it was added 10 s after each agonist. Thus, the platelet-derived proteinase acts within 10 s of each agonist addition to generate PAR-1-(1-41) and PAR-4-(1-47). Furthermore, alpha-thrombin may not effectively catalyze PAR-1-(1-41) and PAR-4-(1-47) generation. We propose that unidentified ATP-dependent phosphorylation reactions catalyzed by PKC help to generate the platelet-derived proteinase that propagates human platelet PAR-1 and -4 activation by the three agonists.

  5. Protease-activated receptor-2 (PAR-2): structure-function study of receptor activation by diverse peptides related to tethered-ligand epitopes.

    PubMed

    Maryanoff, B E; Santulli, R J; McComsey, D F; Hoekstra, W J; Hoey, K; Smith, C E; Addo, M; Darrow, A L; Andrade-Gordon, P

    2001-02-15

    Protease-activated receptor-2 (PAR-2) is a tethered-ligand, G-protein-coupled receptor that is activated by proteolytic cleavage or by small peptides derived from its cleaved N-terminal sequence, such as SLIGRL-NH2. To assess specific PAR activity, we developed an immortalized murine PAR-1 (-/-) cell line transfected with either human PAR-2 or PAR-1. A "directed" library of more than 100 PAR agonist peptide analogues was synthesized and evaluated for PAR-2 and PAR-1 activity to establish an in-depth structure-function profile for specific action on PAR-2. The most potent agonist peptides (EC50 = 2-4 microM) had Lys at position 6, Ala at position 4, and pFPhe at position 2; however, these also exhibited potent PAR-1 activity (EC50 = 0.05-0.35 microM). We identified SLIARK-NH2 and SL-Cha-ARL-NH2 as relatively potent, highly selective PAR-2 agonists with EC50 values of 4 microM. Position 1 did not tolerate basic, acidic, or large hydrophobic amino acids. N-Terminal capping by acetyl eliminated PAR-2 activity, although removal of the amino group reduced potency by just 4-fold. At position 2, substitution of Leu by Cha or Phe gave equivalent PAR-2 potency, but this modification also activated PAR-1, whereas Ala, Asp, Lys, or Gln abolished PAR-2 activity; at position 3, Ile and Cha were optimal, although various amino acids were tolerated; at position 4, Ala or Cha increased PAR-2 potency 2-fold, although Cha introduced PAR-1 activity; at position 5, Arg or Lys could be replaced successfully by large hydrophobic amino acids. These results with hexapeptide C-terminal amides that mimic the native PAR-2 ligand indicate structural modes for obtaining optimal PAR-2 activity, which could be useful for the design of PAR-2 antagonists.

  6. Identification of a New Epitope in uPAR as a Target for the Cancer Therapeutic Monoclonal Antibody ATN-658, a Structural Homolog of the uPAR Binding Integrin CD11b (αM)

    PubMed Central

    Wei, Ying; Donate, Fernando; Juarez, Jose; Parry, Graham; Chen, Liqing; Meehan, Edward J.; Ahn, Richard W.; Ugolkov, Andrey; Dubrovskyi, Oleksii; O'Halloran, Thomas V.; Huang, Mingdong; Mazar, Andrew P.

    2014-01-01

    The urokinase plasminogen activator receptor (uPAR) plays a role in tumor progression and has been proposed as a target for the treatment of cancer. We recently described the development of a novel humanized monoclonal antibody that targets uPAR and has anti-tumor activity in multiple xenograft animal tumor models. This antibody, ATN-658, does not inhibit ligand binding (i.e. uPA and vitronectin) to uPAR and its mechanism of action remains unclear. As a first step in understanding the anti-tumor activity of ATN-658, we set out to identify the epitope on uPAR to which ATN-658 binds. Guided by comparisons between primate and human uPAR, epitope mapping studies were performed using several orthogonal techniques. Systematic site directed and alanine scanning mutagenesis identified the region of aa 268–275 of uPAR as the epitope for ATN-658. No known function has previously been attributed to this epitope Structural insights into epitope recognition were obtained from structural studies of the Fab fragment of ATN-658 bound to uPAR. The structure shows that the ATN-658 binds to the DIII domain of uPAR, close to the C-terminus of the receptor, corroborating the epitope mapping results. Intriguingly, when bound to uPAR, the complementarity determining region (CDR) regions of ATN-658 closely mimic the binding regions of the integrin CD11b (αM), a previously identified uPAR ligand thought to be involved in leukocyte rolling, migration and complement fixation with no known role in tumor progression of solid tumors. These studies reveal a new functional epitope on uPAR involved in tumor progression and demonstrate a previously unrecognized strategy for the therapeutic targeting of uPAR. PMID:24465541

  7. La recherche de la surexpression de la protéine et l'amplification du gène HER2 dans le cancer de l'estomac par immunohistochimie et Hybridation in Situ: expérience du CHU HASSAN II de Fès

    PubMed Central

    El Fatemi, Hinde; Hammas, Nawal; Idrissi, Karima; Mellas, Nawfel; Bennani, Amal; Amarti, Afaf; Cayre, Anne; Penault-llorca, Frederique; Mesbahi, Omar

    2012-01-01

    La surexpression de l'Her2 a été détectée dans plusieurs cancers et a été particulièrement étudiée dans le cancer du sein. Elle est décrite dans 10 à 30% des adénocarcinomes gastriques. Un statut HER2 positif est un facteur de mauvais pronostic et un facteur prédictif de la réponse à l'herceptine (trastuzumab). Cet article présente les résultats d'une étude préliminaire portant sur 31 cas de tumeurs gastriques, et dont le but est d’évaluer la surexpression de l’ HER2 dans les adénocarcinomes gastriques avancés tout en comparant nos résultats avec ceux de la littérature. Le taux des cas surexprimant l'Her2 dans notre étude (35.5%) est proche de celui noté par Aoyaji et al (34%), mais il est supérieur à celui noté dans la plupart des séries de la littérature notamment une vaste étude baptisée TOGA. La poursuite de cette étude par un échantillon plus large est nécessaire afin de mieux comprendre les particularités de ce cancer dans notre contexte. PMID:23397021

  8. 200-DV-1OU Sediment and Pore Water Analysis and Report for Samples at Borehole C8096

    SciTech Connect

    Lindberg, Michael J.

    2011-10-01

    This is an analytical data report for sediment samples received at 200-DV-1 OU. On August 30, 2011 sediment samples were received from 200-DV-1 OU Borehole C8096 for geochemical studies. The analyses for this project were performed at the 331 building located in the 300 Area of the Hanford Site. The analyses were performed according to Pacific Northwest National Laboratory (PNNL) approved procedures and/or nationally recognized test procedures. The data sets include the sample identification numbers, analytical results, estimated quantification limits (EQL), and quality control data. The preparatory and analytical quality control requirements, calibration requirements, acceptance criteria, and failure actions are defined in the on-line QA plan 'Conducting Analytical Work in Support of Regulatory Programs' (CAW). This QA plan implements the Hanford Analytical Services Quality Assurance Requirements Documents (HASQARD) for PNNL.

  9. Indochinamon ou (Crustacea: Potamidae) as a new second intermediate host for Paragonimus harinasutai in Luang Prabang Province, Lao PDR.

    PubMed

    Sohn, Woon-Mok; Ryu, Jae-Sook; Min, Duk-Young; Song, Hyun-Ouk; Rim, Han-Jong; Vonghachack, Youthanavanh; Bouakhasith, Daluny; Banouvong, Virasack

    2009-03-01

    Paragonimus harinasutai metacercariae were found in a species of freshwater crab, Indochinamon ou, collected in a small stream of Namback District, Luang Prabang Province, Lao PDR. Adult flukes were recovered after experimental infection of the metacercariae to dogs. Metacercariae were round or slightly elliptical, 0.666 x 0.626 mm in average size, and had a thin cyst wall of about 20 microm in thickness, a black excretory bladder, convoluted ceca, and some pinkish materials in the body. Adults were somewhat elongated, 95.2 x 36.5 mm in average size, covered with single-tipped tegumental spines, had a smaller oral sucker than the ventral sucker, a moderately branched ovary, and 5-6 lobulated testes. Eggs were ovoid and bilaterally symmetrical in shape, 79 x 45 microm in average size, and had a uniformly thickened shell. By the present study, it has been confirmed that I. ou is a new second intermediate host for P. harinasutai.

  10. Cortical Polarity of the RING Protein PAR-2 Is Maintained by Exchange Rate Kinetics at the Cortical-Cytoplasmic Boundary.

    PubMed

    Arata, Yukinobu; Hiroshima, Michio; Pack, Chan-Gi; Ramanujam, Ravikrishna; Motegi, Fumio; Nakazato, Kenichi; Shindo, Yuki; Wiseman, Paul W; Sawa, Hitoshi; Kobayashi, Tetsuya J; Brandão, Hugo B; Shibata, Tatsuo; Sako, Yasushi

    2016-08-23

    Cell polarity arises through the spatial segregation of polarity regulators. PAR proteins are polarity regulators that localize asymmetrically to two opposing cortical domains. However, it is unclear how the spatially segregated PAR proteins interact to maintain their mutually exclusive partitioning. Here, single-molecule detection analysis in Caenorhabditis elegans embryos reveals that cortical PAR-2 diffuses only short distances, and, as a result, most PAR-2 molecules associate and dissociate from the cortex without crossing into the opposing domain. Our results show that cortical PAR-2 asymmetry is maintained by the local exchange reactions that occur at the cortical-cytoplasmic boundary. Additionally, we demonstrate that local exchange reactions are sufficient to maintain cortical asymmetry in a parameter-free mathematical model. These findings suggest that anterior and posterior PAR proteins primarily interact through the cytoplasmic pool and not via cortical diffusion.

  11. EBV LMP-1 negatively regulates expression and pro-apoptotic activity of Par-4 in nasopharyngeal carcinoma cells.

    PubMed

    Lee, Jeng-Woei; Liu, Po-Fan; Hsu, Lee-Ping; Chen, Peir-Rong; Chang, Chung-Hsing; Shih, Wen-Ling

    2009-07-08

    Latent membrane protein-1 (LMP-1) of the Epstein-Barr virus (EBV) is closely associated with nasopharyngeal carcinoma (NPC), and in this study we sought to determine whether the pro-apoptotic activity of prostate apoptosis response-4 (Par-4) is modulated by LMP-1 in NPC cells. We found that LMP-1 diminished the pro-apoptotic activity of Par-4 and negatively regulated Par-4 protein by de novo synthesis; moreover, although LMP-1 accelerated a Par-4 activator, PKA, we demonstrated that LMP-1 also activated the PI3K/Akt pathway and increased Bcl-2 expression to suppress the activity of Par-4. Consequently, our results revealed a novel negative action of LMP-1 on the pro-apoptosis protein Par-4 by the coordination of multiple signaling pathways.

  12. Spatiotemporal Variability of Global and Diffuse PAR in the Amazon Region and its Significance for Tropical Forest Photosynthesis

    NASA Astrophysics Data System (ADS)

    Dye, D. G.

    2003-12-01

    This study examines seasonal and inter-annual variation in surface fluxes of global and diffuse photosynthetically active radiation (PAR, 400-700 nm) in the tropical forest of the Amazon region. Spatial and temporal patterns of global and diffuse PAR are determined from reanalysis data from the National Center for Environmental Prediction (NCEP), and from the SeaWIFS Solar Surface Irradiance (SSI) data set. The PAR data and satellite-derived estimates of leaf area index (LAI) are applied to an existing sun-shade model of forest canopy photosynthesis. The seasonality of atmospheric scattering (quantified as the diffuse fraction of global PAR) as a determining factor for the relative influence of variation and trends in incident PAR on tropical forest photosynthesis is quantitatively evaluated. The results provide insight into the role of the surface PAR regime in the dynamics of ecosystem-atmosphere carbon exchange in the Amazon and other tropical forest regions.

  13. Towards an Improved LAI Collection Protocol via Simulated and Field-Based PAR Sensing.

    PubMed

    Yao, Wei; Kelbe, David; Leeuwen, Martin van; Romanczyk, Paul; Aardt, Jan van

    2016-07-14

    In support of NASA's next-generation spectrometer-the Hyperspectral Infrared Imager (HyspIRI)-we are working towards assessing sub-pixel vegetation structure from imaging spectroscopy data. Of particular interest is Leaf Area Index (LAI), which is an informative, yet notoriously challenging parameter to efficiently measure in situ. While photosynthetically-active radiation (PAR) sensors have been validated for measuring crop LAI, there is limited literature on the efficacy of PAR-based LAI measurement in the forest environment. This study (i) validates PAR-based LAI measurement in forest environments, and (ii) proposes a suitable collection protocol, which balances efficiency with measurement variation, e.g., due to sun flecks and various-sized canopy gaps. A synthetic PAR sensor model was developed in the Digital Imaging and Remote Sensing Image Generation (DIRSIG) model and used to validate LAI measurement based on first-principles and explicitly-known leaf geometry. Simulated collection parameters were adjusted to empirically identify optimal collection protocols. These collection protocols were then validated in the field by correlating PAR-based LAI measurement to the normalized difference vegetation index (NDVI) extracted from the "classic" Airborne Visible Infrared Imaging Spectrometer (AVIRIS-C) data ( R 2 was 0.61). The results indicate that our proposed collecting protocol is suitable for measuring the LAI of sparse forest (LAI < 3-5 ( m 2 / m 2 )).

  14. PAR-1 mediated apoptosis of breast cancer cells by V. cholerae hemagglutinin protease.

    PubMed

    Ray, Tanusree; Pal, Amit

    2016-05-01

    Bacterial toxins have emerged as promising agents in cancer treatment strategy. Hemagglutinin (HAP) protease secreted by Vibrio cholerae induced apoptosis in breast cancer cells and regresses tumor growth in mice model. The success of novel cancer therapies depends on their selectivity for cancer cells with limited toxicity for normal tissues. Increased expression of Protease Activated Receptor-1 (PAR-1) has been reported in different malignant cells. In this study we report that HAP induced activation and over expression of PAR-1 in breast cancer cells (EAC). Immunoprecipitation studies have shown that HAP specifically binds with PAR-1. HAP mediated activation of PAR-1 caused nuclear translocation of p50-p65 and the phosphorylation of p38 which triggered the activation of NFκB and MAP kinase signaling pathways. These signaling pathways enhanced the cellular ROS level in malignant cells that induced the intrinsic pathway of cell apoptosis. PAR-1 mediated apoptosis by HAP of malignant breast cells without effecting normal healthy cells in the same environment makes it a good therapeutic agent for treatment of cancer.

  15. Active zone proteins are transported via distinct mechanisms regulated by Par-1 kinase

    PubMed Central

    Barber, Kara R.; Sherman, Michael

    2017-01-01

    Disruption of synapses underlies a plethora of neurodevelopmental and neurodegenerative disease. Presynaptic specialization called the active zone plays a critical role in the communication with postsynaptic neuron. While the role of many proteins at the active zones in synaptic communication is relatively well studied, very little is known about how these proteins are transported to the synapses. For example, are there distinct mechanisms for the transport of active zone components or are they all transported in the same transport vesicle? Is active zone protein transport regulated? In this report we show that overexpression of Par-1/MARK kinase, a protein whose misregulation has been implicated in Autism spectrum disorders (ASDs) and neurodegenerative disorders, lead to a specific block in the transport of an active zone protein component- Bruchpilot at Drosophila neuromuscular junctions. Consistent with a block in axonal transport, we find a decrease in number of active zones and reduced neurotransmission in flies overexpressing Par-1 kinase. Interestingly, we find that Par-1 acts independently of Tau-one of the most well studied substrates of Par-1, revealing a presynaptic function for Par-1 that is independent of Tau. Thus, our study strongly suggests that there are distinct mechanisms that transport components of active zones and that they are tightly regulated. PMID:28222093

  16. Rassf5 and Ndr kinases regulate neuronal polarity through Par3 phosphorylation in a novel pathway.

    PubMed

    Yang, Rui; Kong, Eryan; Jin, Jing; Hergovich, Alexander; Püschel, Andreas W

    2014-08-15

    The morphology and polarized growth of cells depend on pathways that control the asymmetric distribution of regulatory factors. The evolutionarily conserved Ndr kinases play important roles in cell polarity and morphogenesis in yeast and invertebrates but it is unclear whether they perform a similar function in mammalian cells. Here, we analyze the function of mammalian Ndr1 and Ndr2 (also known as STK38 or STK38L, respectively) in the establishment of polarity in neurons. We show that they act downstream of the tumor suppressor Rassf5 and upstream of the polarity protein Par3 (also known as PARD3). Rassf5 and Ndr1 or Ndr2 are required during the polarization of hippocampal neurons to prevent the formation of supernumerary axons. Mechanistically, the Ndr kinases act by phosphorylating Par3 at Ser383 to inhibit its interaction with dynein, thereby polarizing the distribution of Par3 and reinforcing axon specification. Our results identify a novel Rassf5-Ndr-Par3 signaling cascade that regulates the transport of Par3 during the establishment of neuronal polarity. Their role in neuronal polarity suggests that Ndr kinases perform a conserved function as regulators of cell polarity.

  17. Lambeaux autofermants pour le traitement des brulures electriques du scalp par haut voltage

    PubMed Central

    Hafidi, J.; El Mazouz, S.; El Mejatti, H.; Fejjal, N.; Gharib, N.E.; Abbassi, A.; Belmahi, A.M.

    2011-01-01

    Summary Les brûlures électriques par haut voltage sont responsables de gros dégâts tissulaires en immédiat et dans les jours suivant l’accident du fait de la chaleur importante dégagée par effet joule et de la thrombose microvasculaire évolutive. Les pertes de substances du scalp secondaires à ces brûlures nécessitent une couverture par lambeaux vu la destruction du périoste et du calvarium en regard. De juin 1997 à juin 2008, 15 patients ont été traités pour des pertes de substance du scalp secondaires à des brûlures électriques par haut voltage de diamètre allant de 8 à 11 cm et siégeant dans la région tonsurale. Ces patients ont été opérés dans la première semaine suivant l’accident. Les pertes de substance du scalp de taille moyenne secondaires à ces brûlures peuvent être couvertes per primam de façon fiable par des lambeaux locaux axialisés et multiples. Nous relatons l’expérience du Service de Chirurgie Plastique du Centre Hospitalier Universitaire Ibn-Sina, Rabat, Maroc, dans la gestion et la prise en charge de ces brûlures. PMID:22262963

  18. uPAR induces epithelial–mesenchymal transition in hypoxic breast cancer cells

    PubMed Central

    Lester, Robin D.; Jo, Minji; Montel, Valérie; Takimoto, Shinako; Gonias, Steven L.

    2007-01-01

    Hypoxia activates genetic programs that facilitate cell survival; however, in cancer, it may promote invasion and metastasis. In this study, we show that breast cancer cells cultured in 1.0% O2 demonstrate changes consistent with epithelial–mesenchymal transition (EMT). Snail translocates to the nucleus, and E-cadherin is lost from plasma membranes. Vimentin expression, cell migration, Matrigel invasion, and collagen remodeling are increased. Hypoxia-induced EMT is accompanied by increased expression of the urokinase-type plasminogen activator receptor (uPAR) and activation of cell signaling factors downstream of uPAR, including Akt and Rac1. Glycogen synthase kinase-3β is phosphorylated, and Snail expression is increased. Hypoxia-induced EMT is blocked by uPAR gene silencing and mimicked by uPAR overexpression in normoxia. Antagonizing Rac1 or phosphatidylinositol 3-kinase also inhibits development of cellular properties associated with EMT in hypoxia. Breast cancer cells implanted on chick chorioallantoic membranes and treated with CoCl2, to model hypoxia, demonstrate increased dissemination. We conclude that in hypoxia, uPAR activates diverse cell signaling pathways that cooperatively induce EMT and may promote cancer metastasis. PMID:17664334

  19. Participatory action research (PAR) in middle school: opportunities, constraints, and key processes.

    PubMed

    Ozer, Emily J; Ritterman, Miranda L; Wanis, Maggie G

    2010-09-01

    Late childhood and early adolescence represent a critical transition in the developmental and academic trajectory of youth, a time in which there is an upsurge in academic disengagement and psychopathology. PAR projects that can promote youth's sense of meaningful engagement in school and a sense of efficacy and mattering can be particularly powerful given the challenges of this developmental stage. In the present study, we draw on data from our own collaborative implementation of PAR projects in secondary schools to consider two central questions: (1) How do features of middle school settings and the developmental characteristics of the youth promote or inhibit the processes, outcomes, and sustainability of the PAR endeavor? and (2) How can the broad principles and concepts of PAR be effectively translated into specific intervention activities in schools, both within and outside of the classroom? In particular, we discuss a participatory research project conducted with 6th and 7th graders at an urban middle school as a means of highlighting the opportunities, constraints, and lessons learned in our efforts to contribute to the high-quality implementation and evaluation of PAR in diverse urban public schools.

  20. Nanomechanical recognition of prognostic biomarker suPAR with DVD-ROM optical technology

    NASA Astrophysics Data System (ADS)

    Bache, Michael; Bosco, Filippo G.; Brøgger, Anna L.; Frøhling, Kasper B.; Sonne Alstrøm, Tommy; Hwu, En-Te; Chen, Ching-Hsiu; Eugen-Olsen, Jesper; Hwang, Ing-Shouh; Boisen, Anja

    2013-11-01

    In this work the use of a high-throughput nanomechanical detection system based on a DVD-ROM optical drive and cantilever sensors is presented for the detection of urokinase plasminogen activator receptor inflammatory biomarker (uPAR). Several large scale studies have linked elevated levels of soluble uPAR (suPAR) to infectious diseases, such as HIV, and certain types of cancer. Using hundreds of cantilevers and a DVD-based platform, cantilever deflection response from antibody-antigen recognition is investigated as a function of suPAR concentration. The goal is to provide a cheap and portable detection platform which can carry valuable prognostic information. In order to optimize the cantilever response the antibody immobilization and unspecific binding are initially characterized using quartz crystal microbalance technology. Also, the choice of antibody is explored in order to generate the largest surface stress on the cantilevers, thus increasing the signal. Using optimized experimental conditions the lowest detectable suPAR concentration is currently around 5 nM. The results reveal promising research strategies for the implementation of specific biochemical assays in a portable and high-throughput microsensor-based detection platform.

  1. Nanomechanical recognition of prognostic biomarker suPAR with DVD-ROM optical technology.

    PubMed

    Bache, Michael; Bosco, Filippo G; Brøgger, Anna L; Frøhling, Kasper B; Alstrøm, Tommy Sonne; Hwu, En-Te; Chen, Ching-Hsiu; Eugen-Olsen, Jesper; Hwang, Ing-Shouh; Boisen, Anja

    2013-11-08

    In this work the use of a high-throughput nanomechanical detection system based on a DVD-ROM optical drive and cantilever sensors is presented for the detection of urokinase plasminogen activator receptor inflammatory biomarker (uPAR). Several large scale studies have linked elevated levels of soluble uPAR (suPAR) to infectious diseases, such as HIV, and certain types of cancer. Using hundreds of cantilevers and a DVD-based platform, cantilever deflection response from antibody-antigen recognition is investigated as a function of suPAR concentration. The goal is to provide a cheap and portable detection platform which can carry valuable prognostic information. In order to optimize the cantilever response the antibody immobilization and unspecific binding are initially characterized using quartz crystal microbalance technology. Also, the choice of antibody is explored in order to generate the largest surface stress on the cantilevers, thus increasing the signal. Using optimized experimental conditions the lowest detectable suPAR concentration is currently around 5 nM. The results reveal promising research strategies for the implementation of specific biochemical assays in a portable and high-throughput microsensor-based detection platform.

  2. The PAR index for evaluation of treatment outcomes in orthodontics: a clinical audit of 50 cases.

    PubMed

    Fadiga, Mohamed Siddick; Diouf, Joseph Samba; Diop Ba, Khady; Gueye, Idrissa; Ngom, Papa Ibrahima; Diagne, Falou

    2014-03-01

    In the context of this study, a clinical audit of cases treated by a single orthodontist was carried out to illustrate one practical application of the PAR index. Fifty pairs of dental casts taken from the patient group before and at the end of orthodontic treatment were evaluated by an orthodontist trained in the use of the PAR index. This evaluation shows that the average overall PAR score for the subjects included in the study fell from an initial value of 25.64 ± 11.73 points to 1.78 ± 2.79 points at the end of orthodontic treatment. The average reduction attributable to orthodontic treatment was 23.86 ± 0.95 points, for an average percentage reduction of 93.36 ± 9.02%. When cases were classified according to the degree of improvement suggested by the nomogram of the PAR index, 23 (46%) were in the "Improved" category after treatment, and 27 cases (54%) in the "Greatly improved" category. This adds up to a total of 100% in these two categories, with none in the "No better" or "Worse" categories. It should be recalled that a high standard of orthodontic treatment is considered to be reached when the average percentage reduction of the PAR score exceeds 70% and when the number of cases in the "Worse or no better" category is below 5%. Copyright © 2014. Published by Elsevier Masson SAS.

  3. Towards an Improved LAI Collection Protocol via Simulated and Field-Based PAR Sensing

    PubMed Central

    Yao, Wei; Kelbe, David; van Leeuwen, Martin; Romanczyk, Paul; van Aardt, Jan

    2016-01-01

    In support of NASA’s next-generation spectrometer—the Hyperspectral Infrared Imager (HyspIRI)—we are working towards assessing sub-pixel vegetation structure from imaging spectroscopy data. Of particular interest is Leaf Area Index (LAI), which is an informative, yet notoriously challenging parameter to efficiently measure in situ. While photosynthetically-active radiation (PAR) sensors have been validated for measuring crop LAI, there is limited literature on the efficacy of PAR-based LAI measurement in the forest environment. This study (i) validates PAR-based LAI measurement in forest environments, and (ii) proposes a suitable collection protocol, which balances efficiency with measurement variation, e.g., due to sun flecks and various-sized canopy gaps. A synthetic PAR sensor model was developed in the Digital Imaging and Remote Sensing Image Generation (DIRSIG) model and used to validate LAI measurement based on first-principles and explicitly-known leaf geometry. Simulated collection parameters were adjusted to empirically identify optimal collection protocols. These collection protocols were then validated in the field by correlating PAR-based LAI measurement to the normalized difference vegetation index (NDVI) extracted from the “classic” Airborne Visible Infrared Imaging Spectrometer (AVIRIS-C) data (R2 was 0.61). The results indicate that our proposed collecting protocol is suitable for measuring the LAI of sparse forest (LAI < 3–5 (m2/m2)). PMID:27428969

  4. Role of PAR2 in regulating oxaliplatin-induced neuropathic pain via TRPA1.

    PubMed

    Tian, Liujun; Fan, Tianren; Zhou, Nan; Guo, Hui; Zhang, Weijie

    2015-01-01

    Oxaliplatin (OXL) is a third-generation chemotherapeutic agent commonly used to treat metastatic digestive tumors; however, one of the main limiting complications of OXL is neuropathic pain. In this study, the underlying mechanisms responsible for OXL evoked-neuropathic pain were examined. Using a rat model, the results demonstrated that intraperitoneal (i.p.) injection of OXL significantly increased mechanical pain and cold sensitivity as compared with control animals (P < 0.05 vs. control rats). Blocking proteinase-activated receptor 2 (PAR2) significantly attenuated mechanical pain and cold sensitivity observed in control rats and OXL rats (P < 0.05 vs. vehicle control). The attenuating effect of PAR2 on mechanical pain and cold sensitivity were significantly smaller in OXL-rats than in control rats. The role played by PAR2 downstream signaling pathways [namely, transient receptor potential ankyrin 1 (TRPA1)] in regulating OXL evoked-neuropathic pain was also examined. The data shows that TRPA1 expression was upregulated in the lumbar dorsal root ganglion (DRG) of OXL rats and blocking TRPA1 inhibited mechanical pain and heightened cold sensitivity (P < 0.05 vs. control rats). Blocking PAR2 also significantly decreased TRPA1 expression in the DRG. Findings in this study show that OXL intervention amplifies mechanical hyperalgesia and cold hypersensitivity and PAR2 plays an important role in regulating OXL-induced neuropathic pain via TRPA1 pathways.

  5. Sensitization of TRPA1 by PAR2 contributes to the sensation of inflammatory pain.

    PubMed

    Dai, Yi; Wang, Shenglan; Tominaga, Makoto; Yamamoto, Satoshi; Fukuoka, Tetsuo; Higashi, Tomohiro; Kobayashi, Kimiko; Obata, Koichi; Yamanaka, Hiroki; Noguchi, Koichi

    2007-07-01

    Proinflammatory agents trypsin and mast cell tryptase cleave and activate PAR2, which is expressed on sensory nerves to cause neurogenic inflammation. Transient receptor potential A1 (TRPA1) is an excitatory ion channel on primary sensory nerves of pain pathway. Here, we show that a functional interaction of PAR2 and TRPA1 in dorsal root ganglion (DRG) neurons could contribute to the sensation of inflammatory pain. Frequent colocalization of TRPA1 with PAR2 was found in rat DRG neurons. PAR2 activation increased the TRPA1 currents evoked by its agonists in HEK293 cells transfected with TRPA1, as well as DRG neurons. Application of phospholipase C (PLC) inhibitors or phosphatidylinositol-4,5-bisphosphate (PIP(2)) suppressed this potentiation. Decrease of plasma membrane PIP(2) levels through antibody sequestration or PLC-mediated hydrolysis mimicked the potentiating effects of PAR2 activation at the cellular level. Thus, the increased TRPA1 sensitivity may have been due to activation of PLC, which releases the inhibition of TRPA1 from plasma membrane PIP(2). These results identify for the first time to our knowledge a sensitization mechanism of TRPA1 and a novel mechanism through which trypsin or tryptase released in response to tissue inflammation might trigger the sensation of pain by TRPA1 activation.

  6. Participatory Action Research (PAR) in Middle School: Opportunities, Constraints, and Key Processes

    PubMed Central

    Ritterman, Miranda L.; Wanis, Maggie G.

    2010-01-01

    Late childhood and early adolescence represent a critical transition in the developmental and academic trajectory of youth, a time in which there is an upsurge in academic disengagement and psychopathology. PAR projects that can promote youth’s sense of meaningful engagement in school and a sense of efficacy and mattering can be particularly powerful given the challenges of this developmental stage. In the present study, we draw on data from our own collaborative implementation of PAR projects in secondary schools to consider two central questions: (1) How do features of middle school settings and the developmental characteristics of the youth promote or inhibit the processes, outcomes, and sustainability of the PAR endeavor? and (2) How can the broad principles and concepts of PAR be effectively translated into specific intervention activities in schools, both within and outside of the classroom? In particular, we discuss a participatory research project conducted with 6th and 7th graders at an urban middle school as a means of highlighting the opportunities, constraints, and lessons learned in our efforts to contribute to the high-quality implementation and evaluation of PAR in diverse urban public schools. PMID:20676754

  7. "It was like reading a detective novel": Using PAR to work together for culture change.

    PubMed

    Fortune, Darla; McKeown, Janet; Dupuis, Sherry; de Witt, Lorna

    2015-08-01

    Participatory action research (PAR), with its focus on engagement and collaboration, is uniquely suited to enhancing culture change initiatives in dementia care. Yet, there is limited literature of its application to culture change approaches in care settings, and even less in dementia specific care contexts. To address these gaps in the literature, the purpose of this paper is to examine the complexities of a PAR project aimed at changing the culture of dementia care in two diverse dementia care settings, including a long term care (LTC) and community care setting. Drawing from data gathered throughout the PAR process, we unpack the challenges experienced by participants working together to guide culture change within their respective care settings. These challenges include: overextending selves through culture change participation; fluctuating group membership; feeling uncertainty, confusion and apprehension about the process; frustratingly slow process; and seeking diverse group representation in decision making. We also highlight the potential for appreciative inquiry (AI) to be integrated with PAR to guide a process whereby participants involved in culture change initiatives can develop strategies to mitigate challenges they experience. We view the challenges and strategies shared here as being constructive to would-be culture change agents and hope this paper will move others to consider the use of PAR when engaging in culture change initiatives. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. CD80, suPAR and nephrotic syndrome in a case of NPHS2 mutation.

    PubMed

    Cara-Fuentes, Gabriel; Araya, Carlos; Wei, Changli; Rivard, Christopher; Ishimoto, Takuji; Reiser, Jochen; Johnson, Richard J; Garin, Eduardo H

    2013-01-01

    Podocin mutations are characterized by progression to end stage renal disease and histologic findings of Focal Segmental Glomerulosclerosis (FSGS). CD80 is a podocytes protein that may play a role in proteinuria, particularly in Minimal Change Disease whereas the soluble urokinase receptor (suPAR) is characteristically elevated in the serum of FSGS patients. In a patient with nephrotic syndrome and podocin mutation, urinary and serum CD80 as well as suPAR were measured using commercially available kits. Urinary CD80 molecular size was determined by western blot analysis. Glomerular staining for CD80 and podocin was performed. Patient displayed marked elevated CD80 and mildly increased suPAR urinary levels compared to controls. Serum CD80 level was within the range observed in normal controls. Serum suPAR level was elevated, albeit in the lower range reported for patients with primary FSGS. Immunofluorescence examination of kidney biopsy revealed glomerular CD80 expression. The combination of serum and urinary biomarkers can help differentiate various forms of FSGS. High urinary CD80 and elevated serum and urinary suPAR might represent a profile to differentiate this genetic form of FSGS from primary FSGS.

  9. Towards an improved LAI collection protocol via simulated field-based PAR sensing

    SciTech Connect

    Yao, Wei; Van Leeuwen, Martin; Romanczyk, Paul; van Aardt, Jan; Kelbe, David

    2016-07-14

    In support of NASA’s next-generation spectrometer—the Hyperspectral Infrared Imager (HyspIRI)—we are working towards assessing sub-pixel vegetation structure from imaging spectroscopy data. Of particular interest is Leaf Area Index (LAI), which is an informative, yet notoriously challenging parameter to efficiently measure in situ. While photosynthetically-active radiation (PAR) sensors have been validated for measuring crop LAI, there is limited literature on the efficacy of PAR-based LAI measurement in the forest environment. This study (i) validates PAR-based LAI measurement in forest environments, and (ii) proposes a suitable collection protocol, which balances efficiency with measurement variation, e.g., due to sun flecks and various-sized canopy gaps. A synthetic PAR sensor model was developed in the Digital Imaging and Remote Sensing Image Generation (DIRSIG) model and used to validate LAI measurement based on first-principles and explicitly-known leaf geometry. Simulated collection parameters were adjusted to empirically identify optimal collection protocols. Furthermore, these collection protocols were then validated in the field by correlating PAR-based LAI measurement to the normalized difference vegetation index (NDVI) extracted from the “classic” Airborne Visible Infrared Imaging Spectrometer (AVIRIS-C) data (R2 was 0.61). The results indicate that our proposed collecting protocol is suitable for measuring the LAI of sparse forest (LAI < 3–5 ( m2/m2)).

  10. Towards an improved LAI collection protocol via simulated field-based PAR sensing

    DOE PAGES

    Yao, Wei; Van Leeuwen, Martin; Romanczyk, Paul; ...

    2016-07-14

    In support of NASA’s next-generation spectrometer—the Hyperspectral Infrared Imager (HyspIRI)—we are working towards assessing sub-pixel vegetation structure from imaging spectroscopy data. Of particular interest is Leaf Area Index (LAI), which is an informative, yet notoriously challenging parameter to efficiently measure in situ. While photosynthetically-active radiation (PAR) sensors have been validated for measuring crop LAI, there is limited literature on the efficacy of PAR-based LAI measurement in the forest environment. This study (i) validates PAR-based LAI measurement in forest environments, and (ii) proposes a suitable collection protocol, which balances efficiency with measurement variation, e.g., due to sun flecks and various-sized canopymore » gaps. A synthetic PAR sensor model was developed in the Digital Imaging and Remote Sensing Image Generation (DIRSIG) model and used to validate LAI measurement based on first-principles and explicitly-known leaf geometry. Simulated collection parameters were adjusted to empirically identify optimal collection protocols. Furthermore, these collection protocols were then validated in the field by correlating PAR-based LAI measurement to the normalized difference vegetation index (NDVI) extracted from the “classic” Airborne Visible Infrared Imaging Spectrometer (AVIRIS-C) data (R2 was 0.61). The results indicate that our proposed collecting protocol is suitable for measuring the LAI of sparse forest (LAI < 3–5 ( m2/m2)).« less

  11. The DNA binding parvulin Par17 is targeted to the mitochondrial matrix by a recently evolved prepeptide uniquely present in Hominidae

    PubMed Central

    Kessler, Daniel; Papatheodorou, Panagiotis; Stratmann, Tina; Dian, Elke Andrea; Hartmann-Fatu, Cristina; Rassow, Joachim; Bayer, Peter; Mueller, Jonathan Wolf

    2007-01-01

    Background The parvulin-type peptidyl prolyl cis/trans isomerase Par14 is highly conserved in all metazoans. The recently identified parvulin Par17 contains an additional N-terminal domain whose occurrence and function was the focus of the present study. Results Based on the observation that the human genome encodes Par17, but bovine and rodent genomes do not, Par17 exon sequences from 10 different primate species were cloned and sequenced. Par17 is encoded in the genomes of Hominidae species including humans, but is absent from other mammalian species. In contrast to Par14, endogenous Par17 was found in mitochondrial and membrane fractions of human cell lysates. Fluorescence of EGFP fusions of Par17, but not Par14, co-localized with mitochondrial staining. Par14 and Par17 associated with isolated human, rat and yeast mitochondria at low salt concentrations, but only the Par17 mitochondrial association was resistant to higher salt concentrations. Par17 was imported into mitochondria in a time and membrane potential-dependent manner, where it reached the mitochondrial matrix. Moreover, Par17 was shown to bind to double-stranded DNA under physiological salt conditions. Conclusion Taken together, the DNA binding parvulin Par17 is targeted to the mitochondrial matrix by the most recently evolved mitochondrial prepeptide known to date, thus adding a novel protein constituent to the mitochondrial proteome of Hominidae. PMID:17875217