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Search Results: 1 - 10 of 500126 matches for " FERNANDO MARTíNEZ PE?A "
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The Lautaro Basin: A record of inversion tectonics in northern Chile
Martínez,Fernando; Arriagada,César; Mpodozis,Constantino; Pea,Matías;
Andean geology , 2012,
Abstract: the triassic and jurassic tectonic history of northern chile has been dominated by extension, although clear evidence about the nature and geometry of the extensional basins and subsequent inversion structures has been adequately illustrated in only a few cases. in this contribution we present a structural study of the lautaro basin located at the western edge of the frontal cordillera in the atacama region of northern chile. the lautaro basin is a jurassic half-graben, filled by at least 2,600 m of marine deposits of the lautaro formation and developed on top of, at least 2,000 m of triassic volcanic successions of the la ternera formation, also accumulated during an earlier period of extensional deformation. detailed field mapping and construction of a regional balanced cross-section, supported by good exposures along the copiapó river valley, allow reconstruction of the structural style of both the jurassic and triassic extensional depocenters. new structural data have shown that the lautaro basin has a complex structural framework reflected in two major mesozoic extensional periods, overprinted by cenozoic inversion involving thin- and thick-skinned tectonics. shortening was accommodated by a combination of inversion of pre-existing normal faults, buttresses, development of footwall short-cuts, and both thin and thick-skinned thrusting. new estimates of shortening are up to 13.1 km (30%), while mesozoic extension is estimated to be 3 km (7%).
IDENTIFICACIóN DEL AGENTE CAUSANTE DE LA MARCHITEZ DE PROTEAS (Leucadendron sp.)
Salazar,Ingrid Carolina; Martínez Granja,Edgar; Pea,Fernando; Cabezas,Marco; Gómez,John;
Revista U.D.C.A Actualidad & Divulgación Científica , 2010,
Abstract: plantations of proteas are new at the department of cundinamarca, where businesses of production of leucadendron have been carried out. in these plantations a new disease denominated wilting has been observed. to identify the causal agent of this disease conventional plant pathological tests were conducted to isolate and to verify the pathogenicity of the causal agent under laboratory conditions. also a molecular characterization was conducted through extraction and amplification of dna. the dna amplified fragment was sequenced by bigdye? terminator v3.1 cycle sequencing kit according to the manufacturer specifications in a sequencer abi3730xl (applied biosystems). under laboratory conditions the pathogenicity and disease incidence caused by two isolates of fungi obtained were evaluated on the varieties gold strike and petra. the fungi were inoculated both individually and in mixture, using a completely randomized design with a factorial arrangement of 2 x 4. in the inoculations was used a suspension of 105 macroconidia ml-1 of water. also they were evaluated under field conditions at the same concentration and on the same varieties, using a complete block design with factorial arrangement of 2 x 4. the laboratory analysis indicated the presence of two species of fusarium, which were differentiated through the color of their colonies. according to the molecular analysis, they belong to f. oxysporum (white colony) and fusarium sp. (red colony). it was confirmed the pathogenicity of both species on the tested varieties.
The Lautaro Basin: A record of inversion tectonics in northern Chile La Cuenca Lautaro: un registro de inversión tectónica en el norte de Chile
Fernando Martínez,César Arriagada,Constantino Mpodozis,Matías Pea
Andean Geology , 2012,
Abstract: The Triassic and Jurassic tectonic history of northern Chile has been dominated by extension, although clear evidence about the nature and geometry of the extensional basins and subsequent inversion structures has been adequately illustrated in only a few cases. In this contribution we present a structural study of the Lautaro Basin located at the western edge of the Frontal Cordillera in the Atacama region of northern Chile. The Lautaro Basin is a Jurassic half-graben, filled by at least 2,600 m of marine deposits of the Lautaro Formation and developed on top of, at least 2,000 m of Triassic volcanic successions of the La Ternera Formation, also accumulated during an earlier period of extensional deformation. Detailed field mapping and construction of a regional balanced cross-section, supported by good exposures along the Copiapó River valley, allow reconstruction of the structural style of both the Jurassic and Triassic extensional depocenters. New structural data have shown that the Lautaro Basin has a complex structural framework reflected in two major Mesozoic extensional periods, overprinted by Cenozoic inversion involving thin- and thick-skinned tectonics. Shortening was accommodated by a combination of inversion of pre-existing normal faults, buttresses, development of footwall short-cuts, and both thin and thick-skinned thrusting. New estimates of shortening are up to 13.1 km (30%), while Mesozoic extension is estimated to be 3 km (7%). Durante el Triásico y Jurásico la evolución tectónica del norte de Chile fue dominada por extensión cortical. No obstante, evidencias claras acerca del estilo estructural y subsecuente inversión de las cuencas asociadas con el evento extensional, han sido ilustradas en pocos casos. En este trabajo, se presenta un estudio estructural de la Cuenca Lautaro, localizada en el borde occidental de la Cordillera Frontal, en la región de Atacama del norte de Chile. La Cuenca Lautaro, es un hemigraben que aloja al menos 2.600 m de depósitos marinos de la Formación Lautaro, acumulados sobre al menos 2.000 m de sucesiones volcánicas triásicas de la Formación La Ternera. Los excelentes afloramientos de la región permitieron construir una sección balanceada y restaurar el estilo estructural de los depocentros extensionales triásicos y jurásicos. Los resultados obtenidos muestran que la Cuenca Lautaro tiene una arquitectura estructural compleja, reflejada en dos episodios extensionales mayores. Posteriormente, se sobreimpone al menos un evento de inversión tectónica que desarrolla una tectónica mixta de piel fina y piel grues
PROPOSTA DE FISCALIZACIóN DAS RENDAS PROCEDENTES DA PRIMEIRA VENDA DE FUNGOS SILVESTRES COMESTIBLES DE INTERESE SOCIOECONóMICO
SONIA ESTEBAN LALEONA,PABLO DE FRUTOS MADRAZO,FERNANDO MARTíNEZ PEA
Revista Galega de Economía , 2012,
Abstract: The aim of this article is to study how the Tributary Agency could regulate the taxation of income tax of first commercialization of edible wild mushrooms with social an economic importance. The lack of adaptation of the present law to the characteristics of the passive subject is causing a very important fiscal fraud. It supposes the rupture of the general principles that must prevail in tributary matter. The proposal tries to correct this problem because, on the one hand, the implementation and later control of Tributary Agency is easier than actual model and, and the other hand, generates important advantages for the harvesters with a smaller hypothetic future resistance to be controlled. Thus, the simulations suppose an important fiscal saving for habitual commercial harvesters, simultaneously that a considerable reduction of its fiscal obligations.
IDENTIFICACIóN DEL AGENTE CAUSANTE DE LA MARCHITEZ DE PROTEAS (Leucadendron sp.) IDENTIFICATION OF THE CAUSAL AGENT OF THE WILTING OF PROTEAS (Leucadendron sp.)
Ingrid Carolina Salazar,Edgar Martínez Granja,Fernando Pea,Marco Cabezas
Revista U.D.C.A Actualidad & Divulgación Científica , 2010,
Abstract: Las proteas son de reciente establecimiento en el departamento de Cundinamarca, donde se han realizado proyectos empresariales de producción del género Leucadendron, cultivo que ha presentado la enfermedad denominada marchitez. Para identificar su agente causal, se llevó a cabo una investigación utilizando métodos convencionales de diagnóstico, para aislar el agente causal y comprobar su patogenicidad, en el laboratorio; además, se efectuó su caracterización molecular, mediante la extracción y la amplificación del ADN. El fragmento amplificado, se secuenció empleando BigDye Terminator v3.1 Cycle Sequencing Kit, según las especificaciones del manufacturero, en un secuenciador ABI3730XL (Applied Biosystems). En laboratorio, se evaluó la patogenicidad y el efecto de los dos fitopatógenos aislados sobre la incidencia de la enfermedad, en las variedades de proteas Gold Strike y Petra. Las cepas de los hongos, se inocularon individualmente y, en mezcla, aplicando un dise o completamente al azar, con arreglo factorial 2 x 4. En las inoculaciones, se empleó una suspensión de 105 mL-1 macroconidias; también se evaluaron en el campo, en igual concentración y sobre las mismas variedades, empleando un dise o de bloques completamente al azar, con arreglo factorial 2 x 4. En el diagnóstico de laboratorio, se encontraron dos cepas de Fusarium spp., diferenciadas por el color de la colonia. éstas correspondieron, en el análisis molecular, a dos especies: F. oxysporum (colonia blanca) y Fusarium sp. (colonia roja). Se confirmó la patogenicidad de las dos especies en las variedades evaluadas. Plantations of proteas are new at the department of Cundinamarca, where businesses of production of Leucadendron have been carried out. In these plantations a new disease denominated wilting has been observed. To identify the causal agent of this disease conventional plant pathological tests were conducted to isolate and to verify the pathogenicity of the causal agent under laboratory conditions. Also a molecular characterization was conducted through extraction and amplification of DNA. The DNA amplified fragment was sequenced by BigDye Terminator v3.1 Cycle Sequencing Kit according to the manufacturer specifications in a sequencer ABI3730XL (Applied Biosystems). Under laboratory conditions the pathogenicity and disease incidence caused by two isolates of fungi obtained were evaluated on the varieties Gold Strike and Petra. The fungi were inoculated both individually and in mixture, using a completely randomized design with a factorial arrangement of 2 x 4. In the inoculations wa
Amyloid Beta Inhibits Olfactory Bulb Activity and the Ability to Smell
Reynaldo Alvarado-Martínez, Karla Salgado-Puga, Fernando Pea-Ortega
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0075745
Abstract: Early olfactory dysfunction has been consistently reported in both Alzheimer’s disease (AD) and in transgenic mice that reproduce some features of this disease. In AD transgenic mice, alteration in olfaction has been associated with increased levels of soluble amyloid beta protein (Aβ) as well as with alterations in the oscillatory network activity recorded in the olfactory bulb (OB) and in the piriform cortex. However, since AD is a multifactorial disease and transgenic mice suffer a variety of adaptive changes, it is still unknown if soluble Aβ, by itself, is responsible for OB dysfunction both at electrophysiological and behavioral levels. Thus, here we tested whether or not Aβ directly affects OB network activity in vitro in slices obtained from mice and rats and if it affects olfactory ability in these rodents. Our results show that Aβ decreases, in a concentration- and time-dependent manner, the network activity of OB slices at clinically relevant concentrations (low nM) and in a reversible manner. Moreover, we found that intrabulbar injection of Aβ decreases the olfactory ability of rodents two weeks after application, an effect that is not related to alterations in motor performance or motivation to seek food and that correlates with the presence of Aβ deposits. Our results indicate that Aβ disrupts, at clinically relevant concentrations, the network activity of the OB in vitro and can trigger a disruption in olfaction. These findings open the possibility of exploring the cellular mechanisms involved in early pathological AD as an approach to reduce or halt its progress.
Drawing up an individual risk index for development of metachronous neoplastic lesions in resected colorectal cancer Elaboración de un índice individual del riesgo para el desarrollo de lesiones neoplásicas metacrónicas en el cáncer colorrectal resecado
Ana Borda,José María Martínez-Pe?uela,Fernando Borda,Miguel Mu?oz-Navas
Revista Espa?ola de Enfermedades Digestivas , 2012,
Abstract: Aim: to identify possible risk factors for the development of metachronous lesions in colorectal cancer (CRC) which would allow to establish a post-surgical individual prognostic index. Patients and methods: three hundred eighty-two surgically treated CRC were reviewed. We compared the incidence of metachronous lesions in 40 variables concerning patient clinical data and initial neoplastic findings. An individual risk index for metachronicity was drawn up including those variables which presented significant differences in multivariate logistic regression, dividing patients into three groups. Results: variables with prognostic value for metachronicity were distal cancer location: OR= 2.30 (1.03-5.13), alcohol intake: OR = 2.20 (1.08-4.48), presence of synchronous adenomas: isolated: OR = 2.47 (1.03-4.48), multiple: OR = 4.26 (1.78-10.17), and presence of synchronous advanced adenoma: OR= 2.91 (1.52-12.60). Tumor MUC-5 expression proved to have a protective role: OR = 0.23 (0.08-0.66). An individual risk score was established considering these variables and patients could be classified into three groups, with a discrimination power for metachronicity of p< 0.0000001. Classification in high and low risk groups had a sensitivity = 75.32%, specificity = 84.21%, positive predictive value = 75.34%, negative predictive value = 92.31% and global diagnostic accuracy = 80.75%. Conclusions: the identification of risk factors for the development of metachronous lesions allow to calculate, at the time of surgical treatment, an individual prognostic index and to classify patients into three different risk groups. In high and low risk groups, both specificity and accuracy were acceptable for the prognosis of metachronous lesions, being remarkable the negative predictive power of our classification, which could become relevant when planning a different endoscopic follow up of these patients. Objetivo: identificar posibles factores de riesgo para desarrollar lesiones metacrónicas en el cáncer colorrectal, elaborando un índice pronóstico individual del riesgo. Material y métodos: revisamos 382 cánceres colorrectales resecados. Comparamos la diferente incidencia de lesiones metacrónicas en 40 variables referentes al paciente y a las lesiones neoplásicas iniciales. Con aquellas que mostraron diferencias significativas en el análisis estadístico multivariable, elaboramos un índice individual de riesgo, clasificando los pacientes en 3 grupos de riesgo de metacronicidad. Resultados: las variables con valor pronóstico para la metacronicidad fueron: localización distal del cánce
Distribution, abundance and diversity of the extremely halophilic bacterium Salinibacter ruber
Josefa Antón, Arantxa Pea, Fernando Santos, Manuel Martínez-García, Philippe Schmitt-Kopplin, Ramon Rosselló-Mora
Aquatic Biosystems , 2008, DOI: 10.1186/1746-1448-4-15
Abstract: During the summer of 1998, in the course of a study focused on the identification by fluorescence in situ hybridization (FISH) of the then uncultured square archaeon, high proportions of Bacteria were detected by FISH in crystallizer ponds from solar salterns [1]. Although bacterial 16S rRNA gene sequences had been previously detected in these environments [2,3], that was the first report on high abundance of potentially active Bacteria, for which the candidatus name of "Salinibacter" was proposed. Shortly after, some of these Bacteria could be grown in pure culture and were characterized taxonomically [4,5]. The candidatus species was finally classified as a new genus and species, and named as Salinibacter ruber gen. nov. sp. nov. In these last few years a considerable advance in the knowledge of these microorganisms has been achieved [6-8] and even its genome has been completely sequenced and annotated [9].According to phylogenetic reconstructions based on the 16S rRNA gene [5] and on the inter-spacer region between the 16S and 23S rRNA genes [10] S. ruber can be affiliated with the phylum Bacteroidetes, being its closest related cultured organism Rhodothermus marinus, a thermophilic, slightly halophilic marine bacterium. The clade comprising R. marinus and S. ruber appeared as a deep branch within the phylum, placed close to the node of bifurcation of the superphylum that comprises Bacteroidetes and Chlorobi [11]. The phylogenetic position of S. ruber was further studied analyzing a total of 22 genes from the genome of S. ruber strain M31 [12]. All these genes had essential functions for the organism, were dispersed within the genome, and rendered a final alignment informative enough for phylogenetic reconstructions. Although single genes supported different topologies, the tree topology of concatenated genes was identical to that previously observed based on small subunit 16S rRNA gene analysis [12], a further confirmation of the validity of this gene for geneal
Tratamiento del tinnitus en hipoacusias neurosensoriales de curvas descendentes por modulación de los neurotransmisores con el uso de acamprosato: Experiencia clínica
Pea Martínez,Alejandro;
Revista de otorrinolaringología y cirugía de cabeza y cuello , 2007, DOI: 10.4067/S0718-48162007000100003
Abstract: background: sensorineural tinnitus is correlated to several inner ear and auditory pathway disorders. however noxas originating from different auditory pathway levels may be similarly manifested in the auditory cortex. a likely candidate for these shared messengers are neurotransmitters. two neurotransmitters have been described in the afferent auditory pathways: glutamate, which is excitatory and gaba, which is inhibitory. different studies have shown that sensorineural tinnitus is caused by an imbalance of these two neurotransmitters with an excitatory predominance. acamprosate, a drug used in the treatment of alcoholism, might act modulating the balance glutamate-gaba. it could have a similar effect in the auditive afferent pathway. only one research study on the use of acamprosate for tinnitus treatment has been published, which a result of over 80% of either relief or disappearance of tinnitus. aim: to investigate the actual usefulness of acamprosate in tinnitus treatments, since in the previously mentioned study the results were subjectively measured, with no follow up. methods: twenty patients treated with acamprosate during a period of one month were studied; tinnitus psychoacoustic and psychoemotional assessment (thi) were carried out. results: out of twenty patients, in two tinnitus disappeared, in six, it was reduced in 5 or more db and in these same patients thi improved in 50% or more. in 12 patients there was a very slight improvement or no changes at all. conclusions: it would be possible to modulate successfully the neurotransmitters of the afferent auditory pathway in some patients suffering from severe tinnitus using acamprosate. this is an original study with physiopathological bases, which offers new therapeutic perspectives
Evaluación de la incapacidad provocada por el tinnitus: homologación lingüística nacional del Tinnitus Handicap Inventory (THI)
Pea Martínez,Alejandro;
Revista de otorrinolaringología y cirugía de cabeza y cuello , 2006, DOI: 10.4067/S0718-48162006000300009
Abstract: the evaluation of neurosensorial tinnitus is highly important in the study of these patients; there are two ways of conducting this study, firstly tinnitometry, which involves the confrontation of frequency and intensity, the maskability of tinnitus and the search for the residual inhibition and secondly and most important, psycho-emotional medicine. the best known and valued test for this purpose is the tinnitus handicap inventory (thi). in this article, a national linguistic homologation of this test is proposed, that allows for reliable and truthful answers
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