103 research outputs found

    New biostratigraphic data from the Callovian-Oxfordian La Manga Formation, Neuquén Basin, Argentina: Evidence from an ammonite condensed level

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    The La Manga Formation constitutes most of the sedimentary record of the Callovian-Oxfordian in the Neuquén Basin. This stratigraphic unit represents the middle part of the Lotena Mesosequence, which is dominated by carbonates with interbedded shales, marls, and occasional sandstones. Based on detailed stratigraphic work in the stratotype section (La Manga Creek, Mendoza), the depositional environments and the sea-level history of the La Manga Formation have been interpreted. Petrographic and field observations led to identification of nine facies distributed in two informal units. Unit 1 was deposited on a outer ramp setting, while deposition of unit 2 took place in the intertidal-supratidal environments. A condensed level close to the base of unit 1 has yielded Rehmannia sp., Rehmannia cf. paucicostata (Tornq.) and Homoeoplanulites sp., from the Lower Callovian Bodenbenderi-Proximum Zones, and Peltoceratoides sp. and Rursiceras sp. from the Upper Callovian and also in the Lower Oxfordian Peltoceratoides-Parawedekindia Zone. The condensed level is overlain by a Middle Oxfordian succession characterized by Perisphinctes (?Arisphinctes) sp., Perisphinctes (?Kranaosphinctes) sp., Mirosphinctes sp., Perisphinctes (?Antilloceras) cf. prophetae Gygi & Hill., Perisphinctes (?Otosphinctes) sp., Perisphinctes (?Subdiscosphinctes) sp., and Perisphinctes (?Kranaosphinctes) cf. decurrens (Buck.) of the Perisphinctes-Araucanites Zone, which was correlated with the upper part of the Cordatum Standard Zone to the Transversarium Standard Zone, and probably to the lower part of the Bifurcatus Standard Zone. Unit 2 has yielded small Mirosphinctes sp., indicating an Oxfordian age. The sharp contact between the outer ramp facies of unit 1 and the overlying intertidal-supratidal facies of unit 2 can be interpreted as the result of an abrupt fall (forced regression) of the relative sea level during the end of Middle Oxfordian or Upper Oxfordian. These results could be used for comparison with other localities in the Neuquén Basin providing additional data for Lower Callovian-Middle Oxfordian deposits

    Regulation of extracellular matrix components byAmrZ is mediated by c‑di‑GMP in Pseudomonas ogarae F113

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    The AmrZ/FleQ hub has been identified as a central node in the regulation of environmental adaption in the plant growth-promoting rhizobacterium and model for rhizosphere colonization Pseudomonas ogarae F113. AmrZ is involved in the regulation of motility, biofilm formation, and bis-(3′-5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) turnover, among others, in this bacterium. The mutants in amrZ have a pleiotropic phenotype with distinguishable colony morphology, reduced biofilm formation, increased motility, and are severely impaired in competitive rhizosphere colonization. Here, RNA-Seq and qRT-PCR gene expression analyses revealed that AmrZ regulates many genes related to the production of extracellular matrix (ECM) components at the transcriptional level. Furthermore, overproduction of c-di-GMP in an amrZ mutant, by ectopic production of the Caulobacter crescentus constitutive diguanylate cyclase PleD*, resulted in increased expression of many genes implicated in the synthesis of ECM components. The overproduction of c-di-GMP in the amrZ mutant also suppressed the biofilm formation and motility phenotypes, but not the defect in competitive rhizosphere colonization. These results indicate that although biofilm formation and motility are mainly regulated indirectly by AmrZ, through the modulation of c-di-GMP levels, the implication of AmrZ in rhizosphere competitive colonization occurs in a c-di-GMP-independent manne

    Adaption of Pseudomonas ogarae F113 to the rhizosphere environment—The AmrZ-FleQ Hub

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    Motility and biofilm formation are two crucial traits in the process of rhizosphere colonization by pseudomonads. The regulation of both traits requires a complex signaling network that is coordinated by the AmrZ-FleQ hub. In this review, we describe the role of this hub in the adaption to the rhizosphere. The study of the direct regulon of AmrZ and the phenotypic analyses of an amrZ mutant in Pseudomonas ogarae F113 has shown that this protein plays a crucial role in the regulation of several cellular functions, including motility, biofilm formation, iron homeostasis, and bis-(3′-5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) turnover, controlling the synthesis of extracellular matrix components. On the other hand, FleQ is the master regulator of flagellar synthesis in P. ogarae F113 and other pseudomonads, but its implication in the regulation of multiple traits related with environmental adaption has been shown. Genomic scale studies (ChIP-Seq and RNA-Seq) have shown that in P. ogarae F113, AmrZ and FleQ are general transcription factors that regulate multiple traits. It has also been shown that there is a common regulon shared by the two transcription factors. Moreover, these studies have shown that AmrZ and FleQ form a regulatory hub that inversely regulate traits such as motility, extracellular matrix component production, and iron homeostasis. The messenger molecule c-di-GMP plays an essential role in this hub since its production is regulated by AmrZ and it is sensed by FleQ and required for its regulatory role. This regulatory hub is functional both in culture and in the rhizosphere, indicating that the AmrZ-FleQ hub is a main player of P. ogarae F113 adaption to the rhizosphere environmentWork related to environmental adaption of pseudomonads in the authors’ laboratory is currently funded by a Spanish Ministerio de Ciencia e Innovación FEDER/EU Grant PID2021-125070OB-I0

    Transcriptomic analysis of pseudomonas ogarae F113 reveals the antagonistic roles of AmrZ and FleQ during rhizosphere adaption

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    Rhizosphere colonization by bacteria involves molecular and cellular mechanisms, such as motility and chemotaxis, biofilm formation, metabolic versatility, or biosynthesis of secondary metabolites, among others. Nonetheless, there is limited knowledge concerning the main regulatory factors that drive the rhizosphere colonization process. Here we show the importance of the AmrZ and FleQ transcription factors for adaption in the plant growth-promoting rhizobacterium (PGPR) and rhizosphere colonization model Pseudomonas ogarae F113. RNA-Seq analyses of P. ogarae F113 grown in liquid cultures either in exponential and stationary growth phase, and rhizosphere conditions, revealed that rhizosphere is a key driver of global changes in gene expression in this bacterium. Regarding the genetic background, this work has revealed that a mutation in fleQ causes considerably more alterations in the gene expression profile of this bacterium than a mutation in amrZ under rhizosphere conditions. The functional analysis has revealed that in P. ogarae F113, the transcription factors AmrZ and FleQ regulate genes involved in diverse bacterial functions. Notably, in the rhizosphere, these transcription factors antagonistically regulate genes related to motility, biofilm formation, nitrogen, sulfur, and amino acid metabolism, transport, signalling, and secretion, especially the type VI secretion systems. These results define the regulon of two important bifunctional transcriptional regulators in pseudomonads during the process of rhizosphere colonization

    REVISIÓN DE TEMA: PAPEL DE LA ACTIVIDAD FÍSICA EN EL MANEJO NO FARMACOLÓGICO DEL SÍNDROME DE INTESTINO IRRITABLE

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    Irritable bowel syndrome (IBS) is the most common gastroenterological diagnosis, with a high overall prevalence ranging from 5% to 21%. This chronic recurrent disease course is characterized by its overlap with other functional disorders and its impact on quality of life of the patients. Currently there are few treatments that offer satisfactory symptomatic relief, so in the effective management of IBS importance has been given to counseling on changes in lifestyle, physical activity, diet, among others. This approach to personal effort by the patient is based on the relationship of the chronic stress state with the exacerbation of IBS symptoms. Brain-gut interactions may play a role in the association between physical activity and symptoms in IBS. Most studies agree that interventions that promote increased physical activity improve IBS gastrointestinal symptoms; as well as different aspects of quality of life, fatigue, depression and long-term anxietyEl síndrome de intestino irritable (SII) es el diagnóstico gastroenterológico más común, con una elevada prevalencia global que oscila entre el 5% al 21%. Esta enfermedad de curso recurrente crónico se caracteriza por su traslape con otros trastornos funcionales y  su afectación en la calidad de vida de los pacientes. Actualmente son pocos los tratamientos que ofrecen un alivio sintomático satisfactorio, por lo que en el manejo efectivo del SII se ha dado importancia a la consejería sobre cambios en el estilo de vida, actividad física, dieta, entre otros. Este enfoque de esfuerzo personal por parte del paciente se sustenta en la relación del estado de estrés crónico con la exacerbación de los síntomas de SII. Las interacciones cerebro-intestino pueden jugar un rol en la asociación entre la actividad física y los síntomas en el SII. La mayoría de estudios concuerdan que las intervenciones que propician el aumento de la actividad física mejoran los síntomas gastrointestinales del SII; así como diferentes aspectos de la calidad de vida, fatiga, depresión y ansiedad a largo plazo

    Enfermedad celiaca e infertilidad no explicada: papel del tamizaje. Revisión de literatura.

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    Celiac disease (CD) is a chronic inflammatory disorder caused by an abnormal immune response induced by a permanent intolerance to wheat, barley and rye in the diet. This diagnosis is performed by blood screening tests in conjunction with endoscopic confirmation and biopsy. CD has been associated with other autoimmune diseases and systemic manifestations. In recent years, the relationship of CD with unexplained infertility has been studied with greater relevance. Among the pathophysiological mechanisms nutritional deficiency and specific autoimmune processes are highlighted either at the time of conception or that these mechanisms are priorly developed causing ovarian deficiency . CD screening in infertile patients has been proposed ;however, this has generated controversy due to its utility. Although the relationship between these pathologies is strong, it has been shown in different studies that the utility when performing such routine screening depends on the type of population and its prevalenceLa enfermedad celíaca (EC) es un trastorno inflamatorio crónico causado por una respuesta inmune anormal inducida por una intolerancia permanente al trigo, la cebada y el centeno en la dieta. Dicho diagnostico se realiza por medio de pruebas sanguíneas de tamizaje en conjunto con confirmación endoscópica y biopsia. La EC se ha asociado a otras enfermedades autoinmunes y manifestaciones sistémicas. En los últimos años se ha estudiado con mayor relevancia la relación de EC con la infertilidad no explicada, dentro de los mecanismos fisiopatológicos se destaca la deficiencia nutricional y procesos autoinmunes especificos ya sea en el momento de la concepción o que estos mecanismos se desarrollen previo provocando deficiencia ovárica. Se ha propuesto realizar el tamizaje de EC en pacientes infertiles, sin embargo ha generado controversia debido a su utilidad. Si bien es cierto la relación entre dichas patologías es fuerte, se ha demostrado en los diferentes estudios que la utillidad en realizar dicho tamizaje de rutina depende del tipo de población y su prevalenci

    Field scale biodegradation of total petroleum hydrocarbons and soil restoration by Ecopiles: microbiological analysis of the process

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    Ecopiling is a method for biodegradation of hydrocarbons in soils. It derives from Biopiles, but phytoremediation is added to biostimulation with nitrogen fertilization and bioaugmentation with local bacteria. We have constructed seven Ecopiles with soil heavily polluted with hydrocarbons in Carlow (Ireland). The aim of the study was to analyze changes in the microbial community during ecopiling. In the course of 18 months of remediation, total petroleum hydrocarbons values decreased in 99 and 88% on average for aliphatics and aromatics, respectively, indicating a successful biodegradation. Community analysis showed that bacterial alfa diversity (Shannon Index), increased with the degradation of hydrocarbons, starting at an average value of 7.59 and ending at an average value of 9.38. Beta-diversity analysis, was performed using Bray-Curtis distances and PCoA ordination, where the two first principal components (PCs) explain the 17 and 14% of the observed variance, respectively. The results show that samples tend to cluster by sampling time instead of by Ecopile. This pattern is supported by the hierarchical clustering analysis, where most samples from the same timepoint clustered together. We used DSeq2 to determine the differential abundance of bacterial populations in Ecopiles at the beginning and the end of the treatment. While TPHs degraders are more abundant at the start of the experiment, these populations are substituted by bacterial populations typical of clean soils by the end of the biodegradation process. Similar results are found for the fungal community, indicating that the microbial community follows a succession along the process. This succession starts with a TPH degraders or tolerant enriched community, and finish with a microbial community typical of clean soil

    Peritidal cyclic sedimentation from La Manga Formation (Oxfordian), Neuquén Basin, Mendoza, Argentina

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    The La Manga Formation consists of marine carbonates and represents most of the sedimentary record of the Callovian-Oxfordian in the Neuquén Basin. Three localities in the southern Mendoza province were studied and their cyclicity was determined by means of facies analysis and their vertical arrangement. Facies of inner ramp, that were deposited in extremely shallow-water environments with intermittent subaerial exposures have been broken down into shallow subtidal, and intertidalesupratidal environments. Shallow subtidal facies are arranged into decimetre scale upward-hallowing cycles composed of marls, laminated or massive mudstones or bioclastic wackestones and intraclastic wackestone-packstones. Intertidal-supratidal centimetre-scale cycles consist of an upward-shallowing succession of restricted facies, overlaid by horizontal or crinkle microbial laminites, flat pebble conglomerates or breccias beds. The defined cycles show a shallowing upward trend in which the evidence of relative sea-level lowering is accepted. The interpretation of Fischer plots allowed the recognition of changes in accommodation space

    Enfermedades crónicas

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    Adherencia al tratamiento farmacológico y relación con el control metabólico en pacientes con DM2Aluminio en pacientes con terapia de reemplazo renal crónico con hemodiálisis en Bogotá, ColombiaAmputación de extremidades inferiores: ¿están aumentando las tasas?Consumo de edulcorantes artificiales en jóvenes universitariosCómo crecen niños normales de 2 años que son sobrepeso a los 7 añosDiagnóstico con enfoque territorial de salud cardiovascular en la Región MetropolitanaEfecto a corto plazo de una intervención con ejercicio físico, en niños con sobrepesoEfectos de la cirugía bariátrica en pacientes con síndrome metabólico e IMC < 35 KG/M2Encuesta mundial de tabaquismo en estudiantes de profesiones de saludEnfermedades crónicas no transmisibles: Consecuencias sociales-sanitarias de comunidades rurales en ChileEpidemiología de las muertes hospitalarias por patologías relacionadas a muerte encefálica, Chile 2003-2007Estado nutricional y conductas alimentarias en adolescentes de 4º medio de la Región de CoquimboEstudio de calidad de vida en una muestra del plan piloto para hepatitis CEvaluación del proceso asistencial y de resultados de salud del GES de diabetes mellitus 2Factores de riesgo cardiovascular en población universitaria de la Facsal, universidad de TarapacáImplicancias psicosociales en la génesis, evolución y tratamiento de pacientes con hipertensión arterial esencialInfarto agudo al miocardio (IAM): Realidad en el Hospital de Puerto Natales, 2009-2010Introducción de nuevas TIC y mejoría de la asistencia a un programa de saludNiños obesos atendidos en el Cesfam de Puerto Natales y su entorno familiarPerfil de la mortalidad por cáncer de cuello uterino en Río de JaneiroPerfil del paciente primo-consultante del Programa de Salud Cardiovascular, Consultorio Cordillera Andina, Los AndesPrevalencia de automedicación en mujeres beneficiarias del Hospital Comunitario de Til-TiPrevalencia de caries en población preescolar y su relación con malnutrición por excesoPrevalencia de retinopatía diabética en comunas dependientes del Servicio de Salud Metropolitano Occidente (SSMOC)Problemas de adherencia farmacológica antihipertensiva en población mapuche: Un estudio cualitativoRol biológico de los antioxidantes innatos en pacientes portadores de VIH/SidaSobrepeso en empleados de un restaurante de una universidad pública del estado de São Paul
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