173,748 research outputs found
Análisis genético y molecular del síndrome de Maroteaux-Lamy
No full text[spa] Esta tesis es una contribución al conocimiento del síndrome de Maroteux-Lamy en el terreno de la genética molecular. El síndrome de Maroteaux-Lamy o mucopolisacaridosis de tipo VI (MPS VI) es una grave enfermedad hereditaria muy poco frecuente en humanos, provocada por la deficiencia de un único gen, que codifica la hidrolasa lisosómica N-acetilgalactosamino-4-sulfatasa o arilsulfatasa B (ARSB). La primera publicación incluída en la tesis engloba los resultados del análisis de las mutaciones encontradas en el gen ARSB de pacientes españoles y argentinos con MPS VI. Se han identificado todos los alelos responsables de la enfermedad, de los cuales 9 no habían sido publicados anteriormente. Mediante estudios de RT-PCR se han obtenido evidencias de que algunas de las mutaciones podían provocar la destrucción del correspondiente transcrito mutado mediante el mecanismo de nonsense-mediated RNA decay . El estudio también ofrece datos relativos a la clínica de los pacientes analizados, incluyendo la edad de diagnóstico, los principales síntomas fenotípicos y la concentración de glicosaminoglicanos totales excretados en orina, que constituyen datos importantes a la hora de intentar establecer relaciones genotipo-fenotipo. Cumpliendo con otro de los objetivos de la tesis, se realizó el análisis haplotípico de cuatro mutaciones comunes identificadas en pacientes españoles y argentinos con MPS VI y se apuntó a un posible origen único para dichos cambios. La segunda publicación presenta los estudios de expresión y caracterización bioquímica de la mayor parte de las proteínas mutadas que no habían sido descritas con anterioridad por otros autores. Por primera vez en la bibliografía, se explicitó que el cDNA mutado se había expresado en el mismo contexto haplotípico que en el paciente en relación con los dos cambios exónicos presentes en las bases de datos de SNPs, p.V358M y p.S384N. Ambas variantes se expresaron también de forma individual, siendo de especial interés los resultados obtenidos para el cambio p.S384N, que tradicionalmente se ha considerado como mutación patogénica sin que se hayan realizado estudios de expresión. El análisis bioquímico de la actividad enzimática in vitro de las proteínas mutadas se completó mediante análisis de western blot. También se realizaron estudios de inmunofluorescencia indirecta para valorar el grado de localización de la proteína ARSB mutada en los lisosomas de fibroblastos de pacientes. Finalmente se realizaron estudios a nivel de RNA para las mutaciones que introducen codones de parada prematuros en la secuencia codificante (sin sentido, de splicing). Mediante el tratamiento de cultivos de fibroblastos de pacientes con el inhibidor de la síntesis proteica cicloheximida, se puso de manifiesto que el mecanismo de nonsense-mediated RNA decay era responsable de la degradación de los transcritos portadores de cuatro de las mutaciones. El trabajo que ocupa el tercer artículo es una aproximación a una forma de terapia complementaria a la de sustitución enzimática ya establecida para los pacientes de MPS VI, que se podría aplicar a los pacientes portadores de mutaciones sin sentido. Se trata del primer intento en esta enfermedad de intentar suprimir los codones de terminación prematura mediante el uso de antibióticos aminoglicósidos. Los ensayos se realizaron tanto en células transfectadas como en una línea de fibroblastos humanos. Las mutaciones escogidas permitieron ensayar la influencia del contexto nucleotídico del codón de parada en la determinación de la eficacia de la supresión de terminación. Las células se incubaron en presencia de gentamicina y se compararon los niveles de mRNA y de actividad enzimática con los obtenidos en células sin tratar. Los resultados evidenciaron que, en líneas generales, el tratamiento con gentamicina para la supresión de codones sin sentido incrementa, aunque poco, la capacidad catalítica de la ARSB, y que la eficacia del proceso parece depender del contexto nucleotídico.[eng] Maroteaux-Lamy syndrome or mucopolysaccharidosis type VI (MPS VI) is a rare lysosomal, autosomal recessive storage disorder caused by a deficiency of the lysosomal enzyme N-acetylgalactosamine 4-sulfatase or arylsulfatase B (ARSB). The first aim of the thesis was to analyze the spectrum of mutations responsible for the disorder in Spanish and Argentinian MPS VI patients. We identified all the ARSB mutant alleles, nine of them novel. Clinical data of Spanish and Argentinian patients was also provided. Haplotype analysis indicated a common origin for most of the mutations found more than once. It was very difficult to stablish genotype-phenotype correlations. RT-PCR studies showed that some of these alleles could be responsible of the degradation of the ARSB mRNA transcripts by the mechanism of nonsense-mediated RNA decay. In the second study, functional characterization of seven missense mutations and polyporphisms found in the ARSB gene was presented. All the ARSB mutations studied had a significant effect on enzyme activity. Mutations were expressed on COS-7 cells in their original haplotype context with respect two non-synonymous SNPs, p.V358M and p.S384N. Our results showed that change p.S384N, formerly described as a pathogenic mutation, should be considered a functional polymorphism. Western blot analyses showed that the expressed mutations significantly reduced the amount of mature protein. Sub-cellular localization studies of ARSB proteins in fibroblasts from MPS VI patients were performed. RNA analysis confirmed that nonsense-mediated RNA decay had taken place for all mutant alleles which were candidates for causing RNA degradation by this mechanism. Finally, we reported the preliminary in vitro assays for restoring some amount of full-length and active ARSB protein, by means of gentamicin-induced translational read-through of premature stop codon mutations on different termination contexts. Gentamicin treatment on transfected COS-7 cells and fibroblasts from a MPS VI patient showed a slight recovery of ARSB activity and cDNA levels
Lamy B., Roux J. C. — Espace et société traditionnelle en zone rurale de colonisation
No full textW. A. Lamy B., Roux J. C. — Espace et société traditionnelle en zone rurale de colonisation. In: Population, 26ᵉ année, n°1, 1971. pp. 175-176
Ph. Pinchemel, J. Godard, R. Normand, C. Lamy- Lassalle,Visages de la Picardie, 1949
No full textBeaujeu-Garnier Jacqueline. Ph. Pinchemel, J. Godard, R. Normand, C. Lamy- Lassalle,Visages de la Picardie, 1949. In: L'information géographique, volume 13, n°4, 1949. p. 168
Ph. Pinchemel, J. Godard, R. Normand, C. Lamy- Lassalle,Visages de la Picardie, 1949
No full textBeaujeu-Garnier Jacqueline. Ph. Pinchemel, J. Godard, R. Normand, C. Lamy- Lassalle,Visages de la Picardie, 1949. In: L'information géographique, volume 13, n°4, 1949. p. 168
Variation of Saturn's UV aurora with SKR phase
No full textpeer reviewedIt is well known that a wide range of kronian magnetospheric phenomena, including the Saturn kilometric radiation (SKR), exhibit oscillations near the planetary rotation period. However, although the SKR is believed to be generated by unstable auroral electrons, no connection has been established to date between diurnal SKR modulations and UV auroral power. We use an empirical SKR phase determined from Cassini observations to order the 'quiet time' total emitted UV auroral power as observed by the Hubble Space Telescope in programs during the interval 2005-2009. Our results indicate that both the northern and southern UV powers are dependent on SKR phase, varying diurnally by factors of similar to 3. We also show that the UV variation originates principally from the morning half of the oval, consistent with previous observations of the SKR sources. Citation: Nichols, J. D., B. Cecconi, J. T. Clarke, S. W. H. Cowley, J.-C. Gerard, A. Grocott, D. Grodent, L. Lamy, and P. Zarka (2010), Variation of Saturn's UV aurora with SKR phase, Geophys. Res. Lett., 37, L15102, doi: 10.1029/2010GL044057
La convenzione
No full textLa convention, romanzo breve canadese di lingua francese, della scrittrice francofona quebecchese Suzanne Lamy
(Table 1) Age-Depth relation for ODP Site 202-1233
No full textdepht, sediment = mcd, meters composit depht / Dating Method: * Correlation to the 14C AMS dated core GeoB 3313-1 from the same location (Lamy et al., 2001, doi:10.1016/S0012-821X(00)00381-2) using the magnetic susceptibility and Ca relative concentration records
Testing the Attentional Dwelling Hypothesis of Attentional Capture
No full textData sets for the two experiments published in "Testing the Attentional Dwelling Hypothesis of Attentional Capture" by Lamy D., Darnell. M., Levy A. and Bublil, C. in `journal Of Cognition (2018
The Electrocatalytic Oxidation of Small Organic Molecules : from Fundamental Studies to Applications in Energy Technology
No full textInternational audienceThe electrocatalytic oxidation of small organic molecules, such as formic acid and methanol, both in acid and alkaline medium, has been the subject of many investigations due to their fundamental interest in the field of Electrocatalysis [1] and Energy Technology (Fuel Cells [2] and Electrolysis [3-4]). Andrzej Wieckowski was one of the first to carry out fundamental studies on the mechanism of the adsorption and oxidation of formic acid and methanol on platinum electrodes using a radiochemical method coupled to electrochemical techniques [5-7]. The use of single crystal electrodes brought a new insight in understanding the role of the catalytic electrode in the adsorption of both formic acid [8-10] and methanol [11-12] on low-index Pt(h,k,l) and Au(h,k,l) electrodes. On the other hand the early development of Infrared Reflectance Spectroscopy by Alan Bewick allowed identifying unambiguously the presence of linearly adsorbed CO as the main adsorbed species resulting from the dissociative chemisorption of HCOOH or CH3OH and blocking the active sites of smooth Pt electrodes [13-14]. As a consequence the adsorption of CO [15] was particularly studied on carbon supported Pt nanoparticles working as catalytic layers in Direct Methanol Fuel Cells (DMFC) [16] or Direct Formic Acid Fuel Cells (DFAFC) [17]. In order to decrease the amount of adsorbed CO resulting from the chemisorption of HCOOH or CH3OH different bimetallic and ternary Pt-based or Pd-based catalysts were developed, particularly for the Direct Oxidation Fuel Cells [18-19]. In this communication we will present several results on the investigation of the reaction mechanism of the electro-oxidation of formic acid and methanol on well-defined smooth electrodes and carbon supported nanocatalysts using combined electrochemical methods and physico-chemical methods (radiochemical technique and Infrared Reflectance spectroscopy). The understanding of reaction mechanisms leads to a better knowledge of the role of the electrode nature and structure allowing conceiving more efficient electrocatalysts. This will be illustrated by some results relevant of energy technology, e.g. the Direct Oxidation Fuel Cell (DMFC, DFAFC) and the Proton Exchange Membrane Electrolysis Cell (PEMEC) to produce clean hydrogen to feed a Proton Exchange Membrane Fuel Cell (PEMFC). References : [1] Catalysis and Electrocatalysis at Nanoparticle Surfaces, A. Wieckowski, E. Savinova and C. Vayenas (Eds.), Marcel Decker Inc., New-York (2002). [2] Electrocatalysis of Direct Methanol Fuel Cells, H. Zhang and H. Liu (Eds.), Wiley-VCH, Weinheim (2009). [3] S. R. Narayanan, W. Chun, B. Jeffries-Nakamura, T. I. Valdez, US Patent 6533919, March 18, 2003. [4] C. Lamy, A. Devadas, M. Simoes, C. Coutanceau, Electrochim. Acta, 60 (2012) 112-120. [5] A. Wieckowski, J. Sobkowski, A. J. Onska, J. Electroanal. Chem., 55 (1974) 383-389. [6] A. Wieckowski, J. Sobkowski, J. Electroanal. Chem., 63 (1975) 365-377. [7] P. Waszczuk, A. Wieckowski, P. Zelenay, S. Gottesfeld, C. Coutanceau, J.-M. Léger, C. Lamy, J. Electroanal. Chem., 511 (2001) 55-64. [8] R.R. Adzic, W.E. O'Grady, S. Srinivasan, Surf. Sci., 94 (1980) L191-L194. [9] J. Clavilier, R. Parsons, R. Durand, J.-M. Léger, C. Lamy, J. Electroanal. Chem., 124 (1981) 321-326. [10] A. Hamelin, C. Lamy, S. Maximovitch, C.R. Acad. Sci., 282 C (1976) 403-406. [11] J. Clavilier, C. Lamy, J-M. Léger, J. Electroanal. Chem., 125 (1981) 249-254. [12] E. Herrero, K. Franaszczuk, A. Wieckowski, J. Phys. Chem., 98 (1994) 5074-5083. [13] B. Beden, A. Bewick, C. Lamy, K. Kunimatsu, J. Electroanal. Chem., 121 (1981) 343-347. [14] B. Beden, A. Bewick, C. Lamy, J. Electroanal. Chem., 150 (1983) 505-511. [15] C. Rice, Y.Y. Tong, E. Oldfield, A. Wieckowski, F. Hahn, F. Gloaguen, J.-M. Léger, C. Lamy, J. Phys. Chem. B, 104 (2000) 5803-5807. [16] S. Park, Y.Y. Tong, A. Wieckowski, M.J. Weaver, Langmuir, 18 (2002) 3233-3240. [17] C. Rice, S. Ha, R.I. Masel, P. Waszczuk, A. Wieckowski, T. Barnard, J. Power Sources, 111 (2002) 83-89. [18] C. Lamy, A. Lima, V. Le Rhun, F. Delime, C. Coutanceau, J.-M. Léger, J. Power Sources, 105 (2002) 283-296. [19] C. Rice, S. Ha, R.I. Masel, A. Wieckowski, J. Power Sources, 115 (2003) 229-235
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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