38 research outputs found

    La Història de les Mentalitats : una polèmica oberta

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    Com a presentació de la revista MANUSCRITS a la Universitat de Barcelona, s'organitzà el proppassat 5 de maig i a la Facultat de Geografia i Història, un debat-taula rodona sobre el tema "La història de les mentalitats: una polemica oberta". Hi varen participar : Josep Fontana, Ricardo Garcla Cárcel, Carlos Martínez Shaw, Josep Mª Salrach i Lluís Roura. La transcripció d'aquest debat és el que us oferim

    Pyroclastic volcanic ash as a potential precursor of alkali-activated binders - A case study from Tajogaite (La Palma, Canary Islands) volcano eruption

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    The volcanic eruption of Tajogaite in La Palma (Canary Islands, Spain) produced approximately 200 Mm3 of fine lapilli and ash. Using this volcanic ash (VA) to produce alkali-activated binders (AABs) fosters a sustainable approach to binder manufacturing, aligning with the principles of a circular economy and reducing reliance on non-renewable resources. The feasibility of using VA as a sole precursor for the formulation of sustainable AABs was evaluated based on its composition and physical-chemical properties. To this end, a comprehensive physicochemical characterization of VA was carried out and the physical, mechanical, and environmental properties of the binders formulated were analyzed. The physical-chemical analysis reveals the neoformation of typical secondary reaction products, such as NASH and (C,N)ASH gels. The microstructure analysis reveals that the AABs formulated using 6 M and 8 M NaOH activator solutions contain homogeneously dispersed unreacted VA particles within the binder matrix, providing increased cohesion and mechanical strength. The highest compressive resistance of AABs formulated using only VA as the precursor was achieved with a 6 M NaOH activator solution and a curing temperature of 60 ◦C, reaching a strength of 16 MPa. Although alkaline activation enhances the release of some metals and metalloids contained in the VA, the study of the environmental requirements at the end of the life cycle of the formulated AABs allows them to be classified as nonhazardous materials

    Time-Restricted Feeding during Puberty Ameliorates Adiposity and Prevents Hepatic Steatosis in a Mouse Model of Childhood Obesity

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    : Background: Time restricted feeding (TRF) refers to dietary interventions in which food access is limited during a specific timeframe of the day. TRFs have proven useful in improving metabolic health in adult subjects with obesity. Their beneficial effects are mediated, in part, through modulating the circadian rhythm. Nevertheless, the translation of these dietary interventions onto obese/overweight children and adolescents remains uncharacterized. The objective of this study is to explore the feasibility of temporal dietary interventions for improving metabolic health in the context of childhood obesity. Methods: We have previously developed a mouse model of early adiposity (i.e., childhood obesity) through litter size reduction. Mice raised in small litters (SL) became obese as early as by two weeks of age, and as adults, they developed several obesity-related co-morbidities, including insulin resistance, glucose intolerance and hepatic steatosis. Here, we explored whether two independent short-term chrono-nutritional interventions might improve metabolic health in 1-month-old pre-pubertal SL mice. Both TRFs comprised 8 h feeding/14 h fasting. In the first one (TRF1) Control and SL mice had access to the diet for 8 h during the dark phase. In the second intervention (TRF2) food was available during the light:dark transitions. Results: TRF1 did not alter food intake nor ameliorate adiposity in SL-TRF1. In contrast, SL-TRF2 mice showed unintentional reduction of caloric intake, which was accompanied by reduced total body weight and adiposity. Strikingly, hepatic triglyceride content was completely normalized in SL-TRF1 and SL-TRF2 mice, when compared to the ad lib-fed SL mice. These effects were partially mediated by (i) clock-dependent signals, which might modulate the expression of Pparg or Cpt1a, and (ii) clockindependent signals, such as fasting itself, which could influence Fasn expression. Conclusions: Time-restricted feeding is an effective and feasible nutritional intervention to improve metabolic health, namely hepatic steatosis, in a model of childhood obesity. These data open new avenues for future safe and efficient chrono-nutritional interventions aimed to improve metabolic health in children with overweight/obesity

    Neonatal overfeeding during lactation rapidly and permanently misaligns the hepatic circadian rhythm and programmes adult NAFLD

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    Childhood obesity is a strong risk factor for adult obesity, type 2 diabetes, and cardiovascular disease. The mechanisms that link early adiposity with late-onset chronic diseases are poorly characterised. We developed a mouse model of early adiposity through litter size reduction. Mice reared in small litters (SLs) developed obesity, insulin resistance, and hepatic steatosis during adulthood. The liver played a major role in the development of the disease. Objective: To gain insight into the molecular mechanisms that link early development and childhood obesity with adult hepatic steatosis and insulin resistance. Methods: We analysed the hepatic transcriptome (Affymetrix) of control and SL mice to uncover potential pathways involved in the long-term programming of disease in our model. Results: The circadian rhythm was the most significantly deregulated Gene Ontology term in the liver of adult SL mice. Several core clock genes, such as period 1e3 and cryptochrome 1e2, were altered in two-week-old SL mice and remained altered throughout their life course until they reached 4e6 months of age. Defective circadian rhythm was restricted to the periphery since the expression of clock genes in the hypothalamus, the central pacemaker, was normal. The period-cryptochrome genes were primarily entrained by dietary signals. Hence, restricting food availability during the light cycle only uncoupled the central rhythm from the peripheral and completely normalised hepatic triglyceride content in adult SL mice. This effect was accompanied by better re-alignment of the hepatic period genes, suggesting that they might have played a causal role in mediating hepatic steatosis in the adult SL mice. Functional downregulation of Per2 in hepatocytes in vitro confirmed that the period genes regulated lipid-related genes in part through peroxisome proliferator-activated receptor alpha (Ppara). Conclusions: The hepatic circadian rhythm matures during early development, from birth to postnatal day 30. Hence, nutritional challenges during early life may misalign the hepatic circadian rhythm and secondarily lead to metabolic derangements. Specific time-restricted feeding interventions improve metabolic health in the context of childhood obesity by partially re-aligning the peripheral circadian rhythm

    A novel satellite mission concept for upper air water vapour, aerosol and cloud observations using integrated path differential absorption LiDAR limb sounding

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    We propose a new satellite mission to deliver high quality measurements of upper air water vapour. The concept centres around a LiDAR in limb sounding by occultation geometry, designed to operate as a very long path system for differential absorption measurements. We present a preliminary performance analysis with a system sized to send 75 mJ pulses at 25 Hz at four wavelengths close to 935 nm, to up to 5 microsatellites in a counter-rotating orbit, carrying retroreflectors characterized by a reflected beam divergence of roughly twice the emitted laser beam divergence of 15 µrad. This provides water vapour profiles with a vertical sampling of 110 m; preliminary calculations suggest that the system could detect concentrations of less than 5 ppm. A secondary payload of a fairly conventional medium resolution multispectral radiometer allows wide-swath cloud and aerosol imaging. The total weight and power of the system are estimated at 3 tons and 2,700 W respectively. This novel concept presents significant challenges, including the performance of the lasers in space, the tracking between the main spacecraft and the retroreflectors, the refractive effects of turbulence, and the design of the telescopes to achieve a high signal-to-noise ratio for the high precision measurements. The mission concept was conceived at the Alpbach Summer School 2010

    Clinical and outcome comparison of genetically positive vs. negative patients in a large cohort of suspected familial hypocalciuric hypercalcemia

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    Biochemical suspicion of familial hypocalciuric hypercalcemia (FHH) might provide with a negative (FHH-negative) or positive (FHH-positive) genetic result. Understanding the differences between both groups may refine the identification of those with a positive genetic evaluation, aid management decisions and prospective surveillance. We aimed to compare FHH-positive and FHH-negative patients, and to identify predictive variables for FHH-positive cases. Retrospective, national multi-centre study of patients with suspected FHH and genetic testing of the CASR, AP2S1 and GNA11 genes. Clinical, biochemical, radiological and treatment data were collected. We established a prediction model for the identification of FHH-positive cases by logistic regression analysis and area under the ROC curve (AUROC) was estimated. We included 66 index cases, of which 30 (45.5%) had a pathogenic variant. FHH-positive cases were younger (p = 0.029), reported more frequently a positive family history (p < 0.001), presented higher magnesium (p < 0.001) and lower parathormone levels (p < 0.001) and were less often treated for hypercalcemia (p = 0.017) in comparison to FHH-negative cases. Magnesium levels showed the highest AUROC (0.825, 95%CI: 0.709-0.941). The multivariate analysis revealed that family history and magnesium levels were independent predictors of a positive genetic result. The predictive model showed an AUROC of 0.909 (95%CI: 0.826-0.991). The combination of magnesium and a positive family history offered a good diagnostic accuracy to predict a positive genetic result. Therefore, the inclusion of magnesium measurement in the routine evaluation of patients with suspected FHH might provide insight into the identification of a positive genetic result of any of the CaSR-related genes

    Com trobar elements rars de la taula periòdica a Catalunya?

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    Hi ha molts mecanismes de concentració d'elements químics a partir de la seva dispersió geoquímica per tal de formar dipòsits minerals d'interès econòmic. La diversitat de processos geològics que han configurat el subsòl de Catalunya permet esperar una gran diversitat de recursos, molts d'ells explotats ja de fa segles. En aquest treball es discuteixen les possibilitats que alguns recursos d'elements rars, mai investigats en detall, es puguin trobar a Catalunya, i es conclou que hi ha recursos potencials en aquests elements formats per processos de fraccionament magmàtic, hidrotermal i supergènic

    Com fer un article divulgatiu. Integrant coneixements i desenvolupant competències

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    Activitat dissenyada per proporcionar als estudiants uns fonaments clars per escriure bones memòries, informes o articles en el seu futur professional. Neix de la necessitat de millorar la seva competència comunicativa escrita, i es basa en la redacció conjunta (professors + estudiants de diferent nivell) d'un article divulgatiu, amb revisió externa, i en la seva posterior presentació i divulgació. Es pretén també fomentar la metodologia docent d'Aprenentatge-Servei (ApS) entre els estudiant
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