644 research outputs found

    Origem dos contrastes texturais de horizontes subsuperficiais em solos do Pantanal Norte

    Get PDF
    The Pantanal region can be characterized as a quaternary floodplain with predominant sedimentation in the form of alluvial fans. In the geomorphologic and sedimentary evolution, the avulsion process is inherent to this depositional system and its dynamics, together with surface water floods, influence soil sedimentation on this plain. The knowledge and differentiation of these two events can contribute to a better understanding of the variability of soil properties and distribution under the influence of these sedimentation processes. Therefore, this study investigated the genesis of soils in the Northern Pantanal with textural contrasts in deeper horizons and their relationship with the depositional system dynamics. We analyzed four soil profiles in the region of Barão de Melgaço, Mato Grosso State, Brazil (RPPN SESC Pantanal). Two profiles were sampled near the Rio Cuiabá (AP1 and AP4) and two near the Rio São Lourenço (AP10 and AP11). In AP11, the horizons contrast in particle size between the profile basis and the surface. In AP1, AP4 and AP10, the horizons overlaying the sand layer have similar particle size properties, mainly in terms of sand distribution. In the first case, floods (surface water) seem to have originated the horizons and layers with contrasting texture. In the second case, avulsion is the most pronounced process. Therefore, the two modes can form soils with contrasting texture that are discriminable by soil morphology, based on the distinct features associated to the specific sedimentation processes.O Pantanal caracteriza-se por ser uma planície inundável quaternária, com sedimentação predominantemente na forma de leques aluviais. Na evolução geomorfológica e sedimentar, é inerente a esse sistema deposicional o processo de avulsão, cuja dinâmica, associada aos fluxos de águas superficiais de cheias, impõe diferenças sedimentares importantes nessa planície. O entendimento e a diferenciação desses dois eventos podem ajudar na compreensão da variabilidade dos atributos e da distribuição dos solos associados a esses processos sedimentares. Nesse sentido, o objetivo deste trabalho foi estudar a gênese de solos do Pantanal Norte que apresentam contrastes texturais em profundidade e sua relação com a dinâmica do sistema deposicional. Quatro perfis foram estudados na região de Barão de Melgaço, MT (RPPN SESC Pantanal), dois próximos ao rio Cuiabá (AP1 e AP4) e dois próximos ao rio São Lourenço (AP10 e AP11). No AP11, os horizontes apresentam contrastes granulométricos desde a base do perfil até a superfície. No AP1, AP4 e AP10, os horizontes sobrejacentes a uma camada arenosa possuem granulometria semelhante entre si, principalmente na distribuição de areia. No primeiro caso, os fluxos de cheias, ou seja, de águas superficiais, parecem ter originado os horizontes e as camadas contrastantes na textura; no segundo, a avulsão é o processo mais evidente. Dessa forma, as duas vias podem formar solos com contrastes texturais e é possível distingui-los no campo pela morfologia, pois possuem peculiaridades que estão associadas aos processos sedimentares responsáveis pelos depósitos.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Embrapa Solos UEP RecifeFederal University of São PauloFederal University of Mato GrossoUniversity of São Paulo CENAUSP ESALQUNIFESPFAPESP: 2009/50422-3FAPESP: 2011/11905-9SciEL

    Topological Analysis of Metabolic Networks Integrating Co-Segregating Transcriptomes and Metabolomes in Type 2 Diabetic Rat Congenic Series

    Get PDF
    Background: The genetic regulation of metabolic phenotypes (i.e., metabotypes) in type 2 diabetes mellitus is caused by complex organ-specific cellular mechanisms contributing to impaired insulin secretion and insulin resistance. Methods: We used systematic metabotyping by 1H NMR spectroscopy and genome-wide gene expression in white adipose tissue to map molecular phenotypes to genomic blocks associated with obesity and insulin secretion in a series of rat congenic strains derived from spontaneously diabetic Goto-Kakizaki (GK) and normoglycemic Brown-Norway (BN) rats. We implemented a network biology strategy approach to visualise shortest paths between metabolites and genes significantly associated with each genomic block. Results: Despite strong genomic similarities (95-99%) among congenics, each strain exhibited specific patterns of gene expression and metabotypes, reflecting metabolic consequences of series of linked genetic polymorphisms in the congenic intervals. We subsequently used the congenic panel to map quantitative trait loci underlying specific metabotypes (mQTL) and genome-wide expression traits (eQTL). Variation in key metabolites like glucose, succinate, lactate or 3-hydroxybutyrate, and second messenger precursors like inositol was associated with several independent genomic intervals, indicating functional redundancy in these regions. To navigate through the complexity of these association networks we mapped candidate genes and metabolites onto metabolic pathways and implemented a shortest path strategy to highlight potential mechanistic links between metabolites and transcripts at colocalized mQTLs and eQTLs. Minimizing shortest path length drove prioritization of biological validations by gene silencing. Conclusions: These results underline the importance of network-based integration of multilevel systems genetics datasets to improve understanding of the genetic architecture of metabotype and transcriptomic regulations and to characterize novel functional roles for genes determining tissue-specific metabolism

    Entre A Armadura E A Equação Não Fecha

    Get PDF
    Poem

    Regenerating 1 and 3b Gene Expression in the Pancreas of Type 2 Diabetic Goto-Kakizaki (GK) Rats

    Get PDF
    International audienceRegenerating (REG) proteins are associated with islet development, b-cell damage, diabetes and pancreatitis. Particularly, REG-1 and REG-3-beta are involved in cell growth/survival and/or inflammation and the Reg1 promoter contains interleukin-6 (IL-6)-responsive elements. We showed by transcriptome analysis that islets of Goto-Kakizaki (GK) rats, a model of spontaneous type 2 diabetes, overexpress Reg1, 3a, 3b and 3c, vs Wistar islets. Goto-Kakizaki rat islets also exhibit increased cytokine/chemokine expression/release, particularly IL-6. Here we analyzed Reg1 and Reg3b expression and REG-1 immuno-localization in the GK rat pancreas in relationship with inflammation. Isolated pancreatic islets and acinar tissue from male adult Wistar and diabetic GK rats were used for quantitative RT-PCR analysis. REG-1 immunohistochemistry was performed on paraffin sections with a monoclonal anti-rat REG-1 antibody. Islet cytokine/chemokine release was measured after 48 h-culture. Islet macrophage-positive area was quantified on cryostat sections using anti-CD68 and major histocompatibility complex (MHC) class II antibodies. Pancreatic exocrine-to-endocrine Reg1 and Reg3b mRNA ratios were markedly increased in Wistar vs GK rats. Conversely, both genes were upregulated in isolated GK rat islets. These findings were unexpected, because Reg genes are expressed in the pancreatic acinar tissue. However, we observed REG-1 protein labeling in acinar peri-ductal tissue close to islets and around large, often disorganized, GK rat islets, which may retain acinar cells due to their irregular shape. These large islets also showed peri-islet macrophage infiltration and increased release of various cytokines/ chemokines, particularly IL-6. Thus, IL-6 might potentially trigger acinar REG-1 expression and secretion in the vicinity of large diabetic GK rat islets. This increased acinar REG-1 expression might reflect an adaptive though unsuccessful response to deleterious microenvironment

    Diatoms and ceramic provenance: A cautionary tale

    Get PDF
    In order to answer the age-old question of whether a given pot was manufactured locally or elsewhere, some archaeologists have turned to geoarchaeological or bioarchaeological methods such as diatom analysis to establish potential clay sources. In this paper, we highlight the complexity of diatom analysis and illustrate how diatoms potentially coming from several sources may be introduced at different stages during the ceramic manufacturing process. Finally, we proceed to evaluate the reliability of diatom analysis as an archaeometric measurement for ceramic provenance, concluding that it may have a more limited usefulness within archaeology than its current frequency of use would indicate.Fil: Kligmann, Debora Myriam. Universidad de Buenos Aires. Facultad de Filosofía y Letras. Instituto de Arqueología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Calderari, Milena. Universidad de Buenos Aires; Argentin

    Prevalence of hyponatraemia in patients over the age of 65 who have an in-hospital fall

    Full text link
    Background and aim: Hyponatraemia is the most common electrolyte disorder. Some studies have found that it increases morbidity and mortality. There are new lines of research that are investigating the link between hyponatraemia and patient falls. Aim: To determine if hyponatraemia is associated with falls in elderly hospitalised patients. Methods: Design observational, analytical, case-control study. Study population: Patients older than 65 years who had fallen during their hospitalisation at Gregorio Marañón Hospital (Madrid) were considered cases. Patients who did not fall were considered to be controls, paired according to the following variables: hospital ward, age, length of hospital stay, gender and Downton fall risk index. The sample size was 206 subjects. Data collection: Socio-demographic factors, variables included in the falls record sheet, Downton fall risk index and sodium levels were studied (hyponatraemia was considered Na+&lt; 135 mmol/l). Analysis: A descriptive analysis was performed to determine the sample homogeneity. The OR was calculated, and an analytical analysis using Chi-square test and a multivariate logistic regression analysis were also performed. Results: Of 103 cases recruited, 61 were men (50.4%) and 42 were women (49.4%). Hyponatraemia was detected in 29 cases with an association with falls of P: 0.002. The adjusted OR was 3.708 (1.6-8.3), 95% CI. Risk factors for falls were identified as hyponatraemia and limb sensory deficits. Conclusions: Given that hyponatraemia could be considered a risk factor for falls, the inclusion of the determination of sodium level would be important for fall prevention strategies in the elderly.Fundamento y objetivo: La hiponatremia es el trastorno electrolítico más frecuente. Algunos estudios afirman que aumenta la morbimortalidad. Existen nuevas líneas de investigación que buscan la relación entre hiponatremia y caídas. Objetivo: Determinar si la hiponatremia es un factor relacionado con las caídas en ancianos hospitalizados. Método: Disen˜ o observacional analítico de casos y controles. Población de estudio: Se consideraron casos los pacientes mayores de 65 an˜ os que experimentaron una caída durante su ingreso en unidades de hospitalización del Hospital General Universitario Gregorio Maran˜ ón de Madrid. Los controles fueron pacientes que no wxperimentaron caída, pareados según las variables: unidad, edad, periodo de ingreso, género y Downton. El taman˜ o fue de 206 sujetos. Recogida de datos: Se estudiaron factores sociodemográficos, las variables incluidas en la ficha de registro de caídas y escala de Downton, y el sodio sérico. Se consideró hiponatremia Na+ < 135 mmol/l. Análisis: Se realizó un análisis descriptivo para valorar la homogeneidad de la muestra, un análisis analítico utilizando el test chi cuadrado, calculando la OR y un análisis multivariante con regresión logística. Resultados: De 103 casos, 61 eran hombres (50,4%) y 42 mujeres (49,4%). En 29 se detectó hiponatremia; la relación con las caídas fue p: 0,002. La OR ajustada fue de 3,708 (1,6-8,3), IC 95%. Se identificaron como factores de riesgo para las caídas: hiponatremia y déficits sensoriales en extremidade

    Parents' beliefs and their role in the development of children's interethnic attitudes.

    Get PDF
    openNella quotidianità quando si parla di pregiudizi il più delle volte si fa riferimento a giudizi sbagliati o incompleti formulati in modo superficiale senza conoscere fino in fondo un problema. Sono definibili come opinioni personali già formate in precedenza, nei confronti di persone o gruppi, che portano ad avere atteggiamenti scorretti quando si devono stabilire dei rapporti sociali. La figura del genitore, come si vedrà, formula credenze nei confronti dei bambini, in relazione allo sviluppo di possibili pregiudizi; i bambini, tuttavia, avrebbero ancora il dono di possedere la mente aperta e libera di viaggiare e amare incondizionatamente l’altro senza distinzione alcuna. Cosa accade? Per un attimo è bene lasciare da parte tutto ciò che si conosce riguardo questo argomento, si consiglia di liberare la mente e cominciare un nuovo cammino. All’inizio verranno forniti gli strumenti necessari per comprendere il lessico e fare chiarezza sul tema indagato, così che sia più facile seguire la lettura e sia possibile al tempo stesso riflettere in merito a quanto argomentato. Sarà importante delineare i confini e la figura del concetto, nella prima parte verrà presentata la definizione di pregiudizio, sarà tracciato un percorso di nascita e sviluppo con riferimenti alla storia e alla religione. Verrà trattato il rapporto pregiudizio-stereotipo da sempre oggetto di incertezza e confusione, un occhio di riguardo sarà volto al pregiudizio etnico, il richiamo alla psicologia sarà presente nel secondo capitolo, sarà illustrata la letteratura e gli studi fatti in merito al tema trattato. Un paragrafo sarà riservato anche al ruolo dell’insegnante. L’ultima parte invece sarà dedicata interamente alla ricerca svolta e all’analisi dei dati raccolti. Il cammino sarà guidato da esempi che potranno chiarificare quanto verrà presentato, per permettere al lettore di viversi a pieno il viaggio e comprende a fondo il tutto
    corecore