995 resultados para Pre-emphasis
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En este trabajo se definen una serie de unidades litoestratigréficas para el Eoceno prepirenaico del Ripollés oriental (provincia de Gerona y Barcelona) y se da un corte general del mismo que pone de manifiesto los cambios de facies y las relaciones entre las distintas formaciones y miembros.
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Selostus: Lypsylehmien valkuaisruokinnan ja hedelmällisyyden yhteys: kirjallisuustutkimus valkuaisruokinnan vaikutuksista Suomen olosuhteissa
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El comentario que con el título de 'Objeciones a la parte gráfica .que ilustra un artículo de geofísica del Berguedá y Solsonés' realiza J.Ullastre a nuestro artículo 'Aportaciones de la prospección geofísica al estudio del subsuelo del Berguedá y Solsonés' publicado en el volumen 27 de esta revista dedicado en homenaje al Dr Oriol Riba, presenta algunos aspectos formales y otros de fondo que merece la pena puntualizar.
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[Vente. Art. 1859-12-17. Paris]
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Deficits in memory consolidation have been reported in adult patients with epilepsy but, not to our knowledge, in children. We report the long-term follow-up (9 y. o. to 18 y. o.) of a boy who suffered from temporal lobe epilepsy and underwent a left temporal lobectomy with amygdalo-hippocampal resection at the age of 10. He showed an abnormal forgetting rate when trying to encode new information and a significant deficit for retrieving remote episodic memories (when compared with his twin brother), both consistent with a consolidation disorder. His memory condition slightly improved after cessation of the epilepsy, nevertheless did not normalize. No standard memory assessment could pinpoint his memory problem, hence an adapted methodology was needed. We discuss the nature of the memory deficit, its possible causes and its clinical implications.
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This paper focused on four alternatives of analysis of experiments in square lattice as far as the estimation of variance components and some genetic parameters are concerned: 1) intra-block analysis with adjusted treatment and blocks within unadjusted repetitions; 2) lattice analysis as complete randomized blocks; 3) intrablock analysis with unadjusted treatment and blocks within adjusted repetitions; 4) lattice analysis as complete randomized blocks, by utilizing the adjusted means of treatments, obtained from the analysis with recovery of interblock information, having as mean square of the error the mean effective variance of this same analysis with recovery of inter-block information. For the four alternatives of analysis, the estimators and estimates were obtained for the variance components and heritability coefficients. The classification of material was also studied. The present study suggests that for each experiment and depending of the objectives of the analysis, one should observe which alternative of analysis is preferable, mainly in cases where a negative estimate is obtained for the variance component due to effects of blocks within adjusted repetitions.
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We investigated in conscious normotensive rats the effect of SKF64139 (2 mg i.v.), a potent phenylethanolamine N-methyltransferase (PNMT) inhibitor, on blood pressure responses to norepinephrine (40, 80, and 160 ng i.v.); methoxamine (2.5, 5 and 10 micrograms i.v.), a directly active sympathomimetic agent that is not taken up by adrenergic nerves; and tyramine (20, 40, and 80 micrograms i.v.), an indirectly acting sympathomimetic amine. The pressor effect of norepinephrine was not changed by 2 mg of SKF64139, while those of methoxamine and tyramine were significantly reduced. The dose-response curve to exogenous norepinephrine was also evaluated following blockade of norepinephrine uptake in the nerve endings using 0.25 mg desipramine i.v. This dose of desipramine had no effect on blood pressure increase induced by methoxamine. In rats pretreated with the neuronal uptake inhibitor desipramine in a dose that did not affect alpha-adrenoceptors, SKF64139 significantly decreased the pressor responses to norepinephrine. Increasing the dose of SKF64139 to 8 mg i.v. resulted in a significant fall in base-line blood pressure and in a blunted blood pressure response to norepinephrine. These data demonstrate that in vivo the PNMT inhibitor SKF64139 blocks alpha-adrenoceptors and inhibits neuronal uptake. The alpha-adrenoceptor blocking properties of SKF65139 are masked by simultaneous blockade of norepinephrine uptake when agonists with affinity for the uptake system are used. These findings need to be taken into account when interpreting cardiovascular effects of the PNMT inhibitor SKF64139.
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Drug screening is an important issue in clinical and forensic toxicology. Gas chromatography coupled to mass spectrometry (GC-MS) remains the gold standard technique for the screening of unknown compounds in urine samples. However, this technique requires substantial sample preparation, which is time consuming. Moreover, some common drugs such as cannabis cannot be easily detected in urine using general procedures. In this work, a sample preparation protocol for treating 200 μL of urine in less than 30 min is described. The enzymatic hydrolysis of glucuro-conjugates was performed in 5 min thanks to the use of microwaves. The use of a deconvolution software allowed reducing the GC-MS run to 10 min, without impairing the quality of the compound identifications. Comparing the results from 139 authentic urine samples to those obtained using the current routine analysis indicated this method performed well. Moreover, additional 5-min GC-MS/MS programs are described, enabling a very sensitive target screening of 54 drugs, including THC-COOH or buprenorphine, without further sample preparation. These methods appeared as an interesting alternative to immuno-assays based screening. The analytical strategy presented in this article proved to be a promising approach for systematic toxicological analysis (STA) of drugs in urine.
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Previous studies in the lab of Dr. Liliane Michalik, have shown thai the nuclear hormone receptor Peroxisome Proliferator Activated Receptor beta/delta (PPARß/ö) is an important regulator of skin homeostasis, being involved in the regulation of keratinocyte differentiation, inflammation, apoptosis, arid mouse skin wound healing. Studies of PPARß/ö knock out mice have suggested a possible role for this receptor in cancer. However, contradictory observations of the role for PPARß/ö on tumor growth have been published, depending on cellular contexts and biological models. Given the controversial role of PPARß/ö in skin carcinoma development, the main aim of this PhD work has been to further explore the implication of PPARß/ö in skin response to UV and skin tumor growth. This PhD dissertation is divided in four chapters. The first chapter describes the core part of the project, where I explored the changes in miRNA expression in the skin upon chronic UV irradiation of PPARß/ö wild type and knock-out mice. This analysis shed light on a miRNA- PPARß/ö signature and also predicted thai miR-21-3p (previously named miR-21*) is a key regulator of the PPARß/ö-dependent UV response in the pre-lesiona! skin. Using mice acutely UV-irradiated, ! further demonstrated that miR-21-3p is indirectly regulated by PPARß/ö through activation of Transforming Growth Factor (TGFß)-1 under UV exposure. I also show that miR-21-3p is deregulated in human cutaneous squamous celi carcinoma. In cultured keratinocytes, application of a miR-21 -3p mimic oligonucleotide sequence leads to the regulation of lipid metabolism-related pathway. In the second chapter, I demonstrate that the usage of an mRNA/miRNA combined bioinformatics analysis leads to the discovery of important pathways involved in the PPARß/ö-miRNA response of the skin to chronic UV irradiation, indeed, I validated angiogenesis and lipid metabolism as important functions regulated by PPARß/ö in this context. In the third chapter, we demonstrate that PPARß/5 knockout mice have decreased cutaneous squamous cell carcinomas incidence compared to wild type mice and that PPARß/5 directly activates the cSrc kinase gene. In the last chapter, we review novel insights into PPAR functions in keratinocytes and liver, with emphasis on PPARß/ö but also on PPARa. In summary, this PhD study shows that i) PPARß/5 is able to regulate biological function through regulation of miRNAs, and specifically through miR-21-3p, the passenger miRNA of the oncomiR miR-21, and that ii) the PPARß/5-dependent skin response to UV involves the regulation of angiogenesis and lipid metabolism. Furthermore, the bioinformatics study highlights the relevance of performing integrated mRNA and miRNA genome-wide studies in order to better screen mRNAs and/or miRNAs of interest in the biological context of diseases. - Des études préalables dans le laboratoire du Dr. Liliane Michalik ont démontré que le récepteur nucléaire PPARß/5 est un régulateur important de l'homéostasie de la peau, étant impliqué dans la régulation de la différenciation des keratinocytes, dans l'inflammation, dans l'apoptose et dans la cicatrisation de la peau chez !a souris. L'étude de souris knock-out pour le gène PPARß/5, ont suggérées un rôle possible de ce récepteur dans le cancer. Cependant, des observations opposées ont été publiées suggérant un rôle pro- ou anti- cancer selon le tissue impliqué et le type- cellulaire. En considérant cette controverse autour du rôle de PPARß/5 dans le développement des cancers de la peau, le but principal de mon projet de recherche aura été d'approfondir l'exploration du rôle de PPARß/5 dans la réponse de la peau aux UVs et dans le développement du cancer. Cette dissertation de thèse est divisée en quatre parties. Une première partie, représentant le coeur de mon travail de recherche, décrit la découverte de l'implication des microRNAs (rniRNAs) dans la réponse aux UVs de PPARß/ö et plus spécifiquement l'implication du miRNA miR- 21 -3p (précédemment nommé miR-21*). En étudiant un modèle de souris irradiées de manière aigüe aux UVs, nous montrons que ia régulation de miR-21-3p est PPARß/ö-däpenaante et que cette régulation à lieu par l'intermédiaire du facteur de transcription TGFß-1. Dans des cultures de keratinocytes Humains, la transfecticn d'une séquence oligonucléotidique similaire à celle de miR-21-3p (mimic), montre l'implication de rniR-21-3p dans des fonctions importantes pour le développement des cancers telles que le métabolisme des lipides. Dans un second chapitre, nous montrons que l'usage d'une méthode bioinformatique combinant l'expression des ARN messagers et des miRNAs permet de mettre en évidence des fonctions biologiques importantes lors de ia réponse de PPARß/ö à l'irradiation chronique. L'angiogenèse, le stress oxydatif et le métabolisme des lipides font partie de ces fonctions régulées par PPARß/5 dans la peau irradiée aux UVs. Nous mettons également en évidence la régulation du gène LpcatS par PPARß/5 dans la peau irradiée aux UV ainsi que dans des keratinocytes humains suggérant un rôle pour PPARß/5 dans le remodelage des lipides membranaires. Dans une troisième partie, nous établissons un lien entre la régulation de l'oncogène Src et l'activation de PPARß/5 dans les carcinomes spinocellulaires de la peau. Finalement dans un quatrième chapitre, nous faisons une revue des dernières recherches portées sur le rôle de PPARß/5 et de PPARa dans le foie et ia peau. En résumé ce projet de thèse représente un avancement pour la recherche sur rimplication de PPARß/5 dans la réponse aux UVs de la peau. Pour la première fois, un lien est établi entre ce facteur de transcription et la régulation de microRNAs dans le cadre du carcinome spinocellulare. Jusqu'alors resté dans l'ombre de rniR-21-5p, miR-21-3p est en fait fortement augmenté à la fois dans un modèle de souris d'irradiation aux UVs ainsi que dans ie carcinome spinocellulare chez i'humain. De nouvelles fonctions biologiques pour PPARß/5 ont été également mises en évidence dans ce travail, comme la régulation de l'angiogenèse ou du métabolisme des lipides dans Sa peau. De plus cette dissertation valorise l'intérêt d'une association entre le travail de laboratoire et celui de la bioinformatique.
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Es el propósito del presente artículo estudiar la evolución de los conceptos básicos matemáticos en relación con la evolución madurativa del niño, con la finalidad de adecuar los contenidos matemáticos de la enseñanza para la etapa preescolar. Las matemáticas que se proponen no se definen ni como ¿tradicionales¿ ni como ¿modernas¿ La propuesta es, en cambio, de una didáctica que busca situaciones matemáticamente relacionables. El contenido hace referencia tanto a la formación del número natural (cardinal y ordinal) como a la formación de clases.