594 research outputs found

    Hydrogeological model from hydrochemical and geocryologic records on the Cape Lamb of Vega Island, northern Antarctic Peninsula

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    The rapid changes that are taking place in the climate of the Antarctic Peninsula are triggering hydrological processes which had been limited or inactive for relatively long periods of time. These processes are evident in ice-free areas on the northern edge of the Antarctic Peninsula, such as Cape Lamb, and lead to intense draining of the surface and groundwater system throughout the brief Antarctic summer. The result is a movement of large amounts of water, sediments and nutrients that would be immobilized in other scenarios. This study proposes a model of the operation of the surface and groundwater system that could be valid for several ice-free areas in the region, based on the interpretation of field observations in Cape Lamb, the most extensive ice-free area on Vega Island. The model proposed is further supported by the interpretation of 56 chemical analyses of samples representing groundwater, active layer water, glacier ice and snowfall. The hydrochemical interpretation is supported primarily by four indicators (pH, electrical conductivity, D/18O ratio and SO4/Cl ratio) which have proven to be the most appropriate hydrochemical variables to differentiate the origin and interaction of the waters in the various sections of the system

    MiRNA expression profile of human subcutaneous adipose and during adipocyte differentiation

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    This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.[Background]: Potential regulators of adipogenesis include microRNAs (miRNAs), small non-coding RNAs that have been recently shown related to adiposity and differentially expressed in fat depots. However, to date no study is available, to our knowledge, regarding miRNAs expression profile during human adipogenesis. Thereby, the aim of this study was to investigate whether miRNA pattern in human fat cells and subcutaneous adipose tissue is associated to obesity and co-morbidities and whether miRNA expression profile in adipocytes is linked to adipogenesis. [Methodology/Principal Findings]: We performed a global miRNA expression microarray of 723 human and 76 viral mature miRNAs in human adipocytes during differentiation and in subcutaneous fat samples from non-obese (n=6) and obese with (n=9) and without (n=13) Type-2 Diabetes Mellitus (DM-2) women. Changes in adipogenesis-related miRNAs were then validated by RT-PCR. Fifty of 799 miRNAs (6.2%) significantly differed between fat cells from lean and obese subjects. Seventy miRNAs (8.8%) were highly and significantly up or down-regulated in mature adipocytes as compared to pre-adipocytes. Otherwise, 17 of these 799 miRNAs (2.1%) were correlated with anthropometrical (BMI) and/or metabolic (fasting glucose and/or triglycerides) parameters. We identified 11 miRNAs (1.4%) significantly deregulated in subcutaneous fat from obese subjects with and without DM-2. Interestingly, most of these changes were associated with miRNAs also significantly deregulated during adipocyte differentiation. [Conclusions/Significance]: The remarkable inverse miRNA profile revealed for human pre-adipocytes and mature adipocytes hints at a closely crosstalk between miRNAs and adipogenesis. Such candidates may represent biomarkers and therapeutic targets for obesity and obesity-related complications.This work was supported by research grants from the Ministerio de Educación y Ciencia (MEC) (SAF2008-02073), the Instituto de Salud Carlos III (CIBERObN, CB06/03/0010), and the Hospital Dr. Josep Trueta de Girona.Peer reviewe

    Decreased STAMP2 expression in association with visceral adipose tissue dysfunction

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    10 páginas, 6 figuras, 2 tablas.-- et al.[Context]: Six-transmembrane protein of prostate 2 (STAMP2) is a counter-regulator of inflammation and insulin resistance according to findings in mice. However, there have been contradictory reports in humans. [Objective]: We aimed to explore STAMP2 in association with inflammatory and metabolic status of human obesity. [Design, Patients, and Methods]: STAMP2 gene expression was analyzed in adipose tissue samples (171 visceral and 67 sc depots) and during human preadipocyte differentiation. Human adipocytes were treated with macrophage-conditioned medium, TNF-α, and rosiglitazone. [Results]: In visceral adipose tissue, STAMP2 gene expression was significantly decreased in obese subjects, mainly in obese subjects with type 2 diabetes. STAMP2 gene expression and protein were significantly and inversely associated with obesity phenotype measures (body mass index, waist, hip, and fat mass) and obesity-associated metabolic disturbances (systolic blood pressure and fasting glucose). In addition, STAMP2 gene expression was positively associated with lipogenic (FASN, ACC1, SREBP1, THRSP14, TRα, and TRα1), CAV1, IRS1, GLUT4, and CD206 gene expression. In sc adipose tissue, STAMP2 gene expression was not associated with metabolic parameters. In both fat depots, STAMP2 gene expression in stromovascular cells was significantly higher than in mature adipocytes. STAMP2 gene expression was significantly increased during the differentiation process in parallel to adipogenic genes, being increased in preadipocytes derived from lean subjects. Macrophage-conditioned medium (25%) and TNF-α (100 ng/ml) administration increased whereas rosiglitazone (2 μM) decreased significantly STAMP2 gene expression in human differentiated adipocytes. [Conclusions]: Decreased STAMP2 expression (mRNA and protein) might reflect visceral adipose dysfunction in subjects with obesity and type 2 diabetes.Peer reviewe

    A qualitative study on the effect of gamification in higher education to promote motivation in students

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    This research presents a qualitative study which has been carried out with undergratuate students belonging to the degree of Pre-Primary teacher at the University Centre "Sagrada Familia" in Úbeda. Researchers measured the degree of motivation of the students before, during and after designing and carrying out a BreakOut Edu for 5-year-old students. In this process, teacher coordination was encouraged throughout the project since it involved university teachers from different subjects. The role of these teachers was that of being guides to support students, acting in a coordinated way so that the activity encompassed contents from all of the subjects. The research methodology was based on the implementation of this activity and, after that, on surveying the participating students. Subsequently, data were analysed by using Nvivo 11Pro software for qualitative analysis. The results show that this type of actions greatly increases student motivation as well as it also favours the acquisition of contents.La investigación que se presenta en este trabajo se ha realizado con alumnado de tercer curso del grado en maestro de educación infantil del Centro Universitario “Sagrada Familia” de Úbeda (Adscrito a la Universidad de Jaén). Se estudió la motivación que este alumnado presentaba antes, durante y después de realizar un BreakOut Edu para alumnos de 5 años. En este proceso, se fomentó la coordinación docente ya que implicaba a profesorado de distintas asignaturas del grado que actuaron como guías de apoyo al alumnado en todo momento, actuando de forma coordinada para que la actividad englobara contenidos de todas ellas. La metodología de investigación se basó en la puesta en práctica de esta actividad, encuestando después al alumnado participante. Los datos fueron analizados posteriormente con el programa Nvivo 11Pro para datos cualitativos. Los resultados muestran que este tipo de actuaciones aumenta en gran medida la motivación del alumnado y a su vez favorece la adquisición de contenidos

    Circulating omentin concentration increases after weight loss

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    Omentin-1 is a novel adipokine expressed in visceral adipose tissue and negatively associated with insulin resistance and obesity. We aimed to study the effects of weight loss-induced improved insulin sensitivity on circulating omentin concentrations. METHODS: Circulating omentin-1 (ELISA) concentration in association with metabolic variables was measured in 35 obese subjects (18 men, 17 women) before and after hypocaloric weight loss. RESULTS: Baseline circulating omentin-1 concentrations correlated negatively with BMI (r = -0.58, p < 0.001), body weight (r = -0.35, p = 0.045), fat mass (r = -0.67, p < 0.001), circulating leptin (r = -0.7, p < 0.001) and fasting insulin (r = -0.37, p = 0.03). Circulating omentin-1 concentration increased significantly after weight loss (from 44.9 +/- 9.02 to 53.41 +/- 8.8 ng/ml, p < 0.001). This increase in circulating omentin after weight loss was associated with improved insulin sensitivity (negatively associated with HOMA value and fasting insulin, r = -0.42, p = 0.02 and r = -0.45, p = 0.01, respectively) and decreased BMI (r = -0.54, p = 0.001). CONCLUSION: As previously described with adiponectin, circulating omentin-1 concentrations increase after weight loss-induced improvement of insulin sensitivity

    Digital image correlation after focused ion beam micro-slit drilling: A new technique for measuring residual stresses in hardmetal components at local scale

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    A new method has been developed for measuring residual stresses at the surface of hardmetal components with higher spatial resolution than standard X-ray diffraction methods. It is based on measuring the surface displacements produced when stresses are partially released by machining a thin slit perpendicularly to the tested surface. Slit machining is carried out by focused ion beam (FIB). Measurement of the displacement fields around the FIB slit are performed by applying an advanced digital image correlation algorithm based on Fourier analysis with sub-pixel resolution. This method compares SEM images of the same area of the hardmetal surface before and after slitting. The method has been successfully applied to as-ground and femto-laser textured surfaces showing good correlation with the standard sin2 ψ XRD technique. It is concluded that texturing induced by laser pulses in the femtoseconds regime is not perfectly adiabatic, since residual stresses are reduced by 15

    The MRC1/CD68 ratio is positively associated with adipose tissue lipogenesis and with muscle mitochondrial gene expression in humans

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    This is an open-access article distributed under the terms of the Creative Commons Attribution License.[Background]: Alternative macrophages (M2) express the cluster differentiation (CD) 206 (MCR1) at high levels. Decreased M2 in adipose tissue is known to be associated with obesity and inflammation-related metabolic disturbances. Here we aimed to investigate MCR1 relative to CD68 (total macrophages) gene expression in association with adipogenic and mitochondrial genes, which were measured in human visceral [VWAT, n = 147] and subcutaneous adipose tissue [SWAT, n = 76] and in rectus abdominis muscle (n = 23). The effects of surgery-induced weight loss were also longitudinally evaluated (n = ).[Results]: MCR1 and CD68 gene expression levels were similar in VWAT and SWAT. A higher proportion of CD206 relative to total CD68 was present in subjects with less body fat and lower fasting glucose concentrations. The ratio MCR1/CD68was positively associated with IRS1gene expression and with the expression of lipogenic genes such as ACACA, FASN and THRSP, even after adjusting for BMI. The ratio MCR1/CD68 in SWAT increased significantly after the surgery-induced weight loss (+44.7%; p = 0.005) in parallel to the expression of adipogenic genes. In addition, SWAT MCR1/CD68ratio was significantly associated with muscle mitochondrial gene expression (PPARGC1A, TFAM and MT-CO3). AT CD206 was confirmed by immunohistochemistry to be specific of macrophages, especially abundant in crown-like structures. [Conclusion]: A decreased ratio MCR1/CD68 is linked to adipose tissue and muscle mitochondrial dysfunction at least at the level of expression of adipogenic and mitochondrial genes. © 2013 moreno-navarrete et al.This work was supported by grant SAF-2009-10461 and grant PI11-00214 from the Ministerio de Economía y Competitividad, Spain.Peer Reviewe

    Serum HER-2 concentration is associated with insulin resistance and decreases after weight loss.

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    HER2/neu is a member of the epidermal growth factor receptor family easily detectable in the serum of cancer patients. We aimed to evaluate circulating HER-2 concentrations in association with insulin resistance in healthy and obese subjects. METHODS: Insulin sensitivity (minimal model) and serum HER-2 concentrations were evaluated in a cross sectional study in men (cohort 1, n = 167) and longitudinally after weight loss in obese subjects (cohort 2, n = 30). RESULTS: Serum HER-2 concentrations were positively associated with BMI and waist circumference (both r = 0.18, p = 0.02), post-load glucose (r = 0.28, p = 0.001) and fasting triglycerides (r = 0.26, p = 0.001); and negatively associated with insulin sensitivity (r = -0.29, p = 0.002, n = 109). Subjects with type 2 diabetes showed significantly increased soluble serum HER-2 concentrations. In different multivariate regression models, fasting triglycerides emerged as the factor that independently contributed to 10-11% of serum HER-2 variance.Serum HER-2 concentrations correlated significantly with fasting triglycerides and insulin sensitivity index in subjects from cohort 2. Weight loss led to a significant decrease of serum HER-2 concentrations. The change in serum HER-2 concentrations were significantly associated with the change in percent body fat and fasting triglycerides in young (below the median age of the cohort) subjects. CONCLUSIONS: Serum HER-2 concentrations might be implicated in the pathophysiology of insulin resistance and associated comorbidities

    Study of caveolin-1 gene expression in whole adipose tissue and its subfractions and during differentiation of human adipocytes

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    <p>Abstract</p> <p>Context</p> <p>Caveolins are 21-24 kDa integral membrane proteins that serve as scaffolds to recruit numerous signaling molecules. Specific subclasses of caveolae carry out specific functions in cell metabolism. In particular, triglycerides are synthesized at the site of fatty acid entry in one of these caveolae classes.</p> <p>Objective and Methods</p> <p>We studied the expression of caveolin-1 (<it>CAV-1</it>) gene in association with metabolic variables in 90 visceral and 55 subcutaneous adipose tissue samples from subjects with a wide range of fat mass, in the stromovascular fraction (SVC) and isolated adipocytes, and during differentiation of human adipocytes.</p> <p>Results</p> <p><it>CAV-1 </it>gene expression was significantly decreased in visceral adipose tissue (v-<it>CAV-1</it>) of obese subjects. v-<it>CAV-1 </it>was positively associated with several lipogenic genes such as acetyl-coA carboxylase (<it>ACACA</it>, r = 0.34, p = 0.004) and <it>spot-14 </it>(r = 0.33, p = 0.004). In non-obese subjects v-<it>CAV-1 </it>also correlated with fatty acid synthase (<it>FAS</it>, r = 0.60, p < 0.0001). Subcutaneous (sc) adipose tissue (s<it>c-CAV-1</it>) gene expression was not associated with these lipogenic factors when obese and non-obese subjects were studied together. In obese subjects, however, sc-<it>CAV-1 </it>was associated with fatty acid synthase (<it>FAS</it>, r = 0.36, p = 0.02), sterol regulatory element binding protein-1c (<it>SREBP-1c </it>(r = 0.58, p < 0.0001), <it>ACACA </it>(r = 0.33, p = 0.03), <it>spot-14 </it>(r = 0.36, p = 0.02), <it>PPAR-γ co-activator-1 </it>(<it>PGC-1</it>, r = 0.88, n = 19). In these obese subjects, <it>sc-CAV-1 </it>was also associated with fasting triglycerides (r = -0.50, p < 0.0001).</p> <p><it>CAV-1 </it>expression in mature adipocytes was significantly higher than in stromal vascular cells. <it>CAV-1 </it>gene expression in adipocytes from subcutaneous adipose tissue (but not in adipocytes from visceral adipose tissue) was significatively associated with fasting triglycerides. <it>CAV-1 </it>gene expression did not change significantly during differentiation of human preadipocytes from lean or obese subjects despite significant increase of FAS gene expression.</p> <p>Conclusion</p> <p>Decreased <it>CAV-1 </it>gene expression was simultaneously linked to increased triglycerides and decreased lipogenic gene expression among obese subjects, paralleling the observations of hypertriglyceridemia in <it>CAV-1 </it>knockout mice. However, the regulation of <it>CAV-1 </it>gene expression seems independent of the adipogenic program.</p
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