Dissipació de l'energia per fregament : seqüència didàctica per a l'estudi de l'energia

Treball que correspon a les pràctiques que es fan als tallers REVIR organitzats pel CRECIM de la UAB. La seqüència pretén ajudar a l'estudiant de 4t ESO i 1r Batxillerat a construir el model escolar d'energia, i utilitzar-lo per interpretar fenòmens quotidians, com ara l'escalfament d'un fre per fregament i el seu posterior refredament per equilibri tèrmic amb l'entorn

Effects of passion, experience, and cultural politics on classical musicians’ practice during the COVID-19 pandemic

The widespread cancelation of cultural events during the early 2020 stages of the COVID-19 pandemic led professional performing musicians across the world to experience an increasing economic fragility that threatened their health and wellbeing. Within this “new normal,” developing countries have been at a higher risk due to their vulnerable health systems and cultural policies. Even in such difficult times, the music profession requires musicians to keep up their practicing routines, even if they have no professional commitments. This is because high level technical and expressive skills are crucial to sustaining a music career at a high performance level. However, it could be expected that not all musicians might have had the same engagement with music practice during lockdowns. In this study, we studied the experiences of 309 professional classical musicians based in European and Latin American countries with different levels of performing experience to examine their passionate (or lack thereof) engagement with music practice. Through the mixed methods combination of multigroup invariance and narrative analyses, we identified distinct profiles of musicians who displayed more harmonious or more obsessive passion orientations before and at the peak of the pandemic. We observed that musicians with higher levels of harmonious passion in particular were more capable of sustaining their practice at the peak of the pandemic and that these musicians were mostly located in Latin America—a paradox, considering that cultural politics supporting the careers of professional performing musicians and entrepreneurial education in Latin America are lacking to a great extent, especially in comparison with the European context. We explain this in terms of the “forced” self-management embraced by musicians in Latin American countries who want to engage with music practice both before and during the COVID-19 pandemic even if the music profession does not generate enough revenue for them

Infección por VPH en mujeres con artritis reumatoide

Antecedentes: el virus del papiloma humano (VPH) es el principal factor de riesgo de cáncer de cuello uterino, que sigue siendo la neoplasia más frecuente en nuestro país. Existen datos que muestran que los pacientes con inmunosupresión son más propensos a la infección por VPH. Objetivo: determinar la frecuencia de la infección por VPH en pacientes con artritis reumatoide comparada con mujeres pareadas por edad de población abierta. Material y métodos: estudio transversal, comparativo y observacional en mujeres con artritis reumatoide y mujeres sin enfermedad reumática a las que se les realizó citología cervical, detección y tipificación del VPH. Se analizaron los datos mediante las pruebas de la ji al cuadrado, exacta de Fisher, Mann Whitney y razón de momios. Resultados: se incluyeron 77 mujeres con artritis reumatoide comparadas con un grupo de 77 mujeres sin artritis reumatoide y de edad similar. Se encontró una frecuencia de infección por VPH en 37 pacientes con artritis reumatoide (48%) contra 17 mujeres sin ésta (22%) [OR 3.1551 IC 95%(1.56 – 6.35) p= 0.001]. Los tipos de VPH 83 y 59 fueron más frecuentes en las mujeres con artritis reumatoide mientras en los controles se encontró el 59, 81 y 54. No se encontró relación con la duración de la enfermedad, el uso de esteroides o inmunosupresión. Conclusiones: la infección por VPH es más frecuente en mujeres con artritis reumatoide comparada con las que no tienen esta enfermedad reumática

Oral cyanocobalamin is effective in the treatment of vitamin B12 deficiency in crohn’s disease

Cobalamin deficiency is common in patients with Crohn’s disease (CD). Intramuscular cobalamin continues to be the standard therapy for the deficiency and maintenance treatment in these patients, although oral route has been demonstrated to be effective in other pathologies with impaired absorption. Our aims were to evaluate the efficacy of oral therapy in the treatment of cobalamin deficiency and in long-term maintenance in patients with Crohn’s disease. We performed a multicenter retrospective cohort study that included 94 patients with Crohn’s disease and cobalamin deficiency. Seventy-six patients had B12 deficiency and 94.7% of them normalized their cobalamin levels with oral treatment. The most used dose was 1 mg/day, but there were no significant differences in treatment effectiveness depending on the dose used (=1 mg/24 h vs. <1 mg/24 h). Eighty-two patients had previous documented B12 deficiency and were treated with oral B12 to maintain their correct cobalamin levels. After a mean follow-up of 3 years, the oral route was effective as maintenance treatment in 81.7% of patients. A lack of treatment adherence was admitted by 46.6% of patients in who the oral route failed. In conclusion, our study shows that oral cyanocobalamin provides effective acute and maintenance treatment for vitamin B12 deficiency caused by CD with or without ileum resection

Magnetism of small V clusters embedded in a Cu fcc matrix: an ab initio study

We present extensive first principles density functional theory (DFT) calculations dedicated to analyze the magnetic and electronic properties of small V$_{n}$ clusters (n=1,2,3,4,5,6) embedded in a Cu fcc matrix. We consider different cluster structures such as: i) a single V impurity, ii) several V$_{2}$ dimers having different interatomic distance and varying local atomic environment, iii) V$_{3}$ and iv) V$_{4}$ clusters for which we assume compact as well as 2- and 1-dimensional atomic configurations and finally, in the case of the v) V$_{5}$ and vi) V$_{6}$ structures we consider a square pyramid and a square bipyramid together with linear arrays, respectively. In all cases, the V atoms are embedded as substitutional impurities in the Cu network. In general, and as in the free standing case, we have found that the V clusters tend to form compact atomic arrays within the cooper matrix. Our calculated non spin-polarized density of states at the V sites shows a complex peaked structure around the Fermi level that strongly changes as a function of both the interatomic distance and local atomic environment, a result that anticipates a non trivial magnetic behavior. In fact, our DFT calculations reveal, in each one of our clusters systems, the existence of different magnetic solutions (ferromagnetic, ferrimagnetic, and antiferromagnetic) with very small energy differences among them, a result that could lead to the existence of complex finite-temperature magnetic properties. Finally, we compare our results with recent experimental measurements.Comment: 7 pages and 4 figure

Las alternativas ciudadanas para otros mundos posibles: pensamiento y experiencias

El documento está conformado por tres partes: la primera define algunos conceptos y expone ciertas teorías sobre el desarrollo y las alternativas (los artículos que componen este apartado son: "Diversidad y dinamismo de las alternativas ciudadanas", "¿Desarrollo alternativo o alternativas al desarrollo? repensando el concepto desde el territorio y el sur global"); la segunda, hace referencia a la construcción de algunas experiencias concretas relacionadas con las alternativas ciudadanas ("La gestión compleja del agua", "La alternativa educativa intercultural wixárika"; "Los procesos sociales en la construcción de alternativas a conflictos ambientales en la cuenca alta del río Santiago"). La tercera parte consiste en una propuesta de investigación sobre las alternativas ciudadanas ("Las alternativas ciudadanas: una propuesta de análisis").ITESO, A.C

Generic boundaries in subtribe Saussureinae (Compositae: Cardueae): Insights from Hyb-Seq data

The subtribe Saussureinae is a highly speciose group with more than 600 species distributed in the Northern Hemisphere and is particularly species-rich at the high mountains of central and eastern Asia. Saussurea and Jurinea are the two main genera described within the subtribe. However, up to 15 satellite genera are recognized in some recent taxonomic treatments with an analytical viewpoint. For the first time, we carried out a complete sampling to clarify generic boundaries based on a well-resolved phylogeny of Saussureinae. We employed a Hyb-Seq technique that targets 1061 nuclear conserved ortholog loci designed for Compositae. After a filtering of potential paralogs, 588 loci were retained to infer phylogenetic trees under concatenation and coalescence approaches. High branch support resolution was recovered at the generic level, but a non-monophyletic pattern was detected for most of the genera as they are currently circumscribed. Accordingly, we propose a new generic delimitation based on the three main clades recovered in the backbone tree, which are also in agreement with morphological evidence: Dolomiaea, Saussurea, and Jurinea. Following this classification into three genera, 18 new combinations are proposed. This new genus delineation will be used as a basis for future evolutionary studies in the Saussureinae.Financial support from the Ministerio de Ciencia e Innovación (Project CGL2015-66703-P MINECO/FEDER, UE and Ph.D. grant to Sonia Herrando-Moraira) and the Catalan government (“Ajuts a grups consolidats” 2017-SGR1116) is also greatly acknowledged. This study has been performed under the Ph.D. program “Plant Biology and Biotechnology” of the Autonomous University of Barcelona (UAB)INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION TAXONOMIC IMPLICATIONS NOTE ADDED IN PROOF AUTHOR CONTRIBUTIONS ACKNOWLEDGMENT

Synthesis, Characterization, and Drug Delivery from pH- and Thermoresponsive Poly(N-Isopropylacrylamide)/ Chitosan Core/Shell Nanocomposites Made by Semicontinuous Heterophase Polymerization

Temperature-and pH-responsive core/shell nanoparticles were prepared by semicontinuous heterophase polymerization of Nisopropylacrylamide (NIPA) in the presence of chitosan micelles for drug delivery purposes. Micelles of chitosan, formed in an acetic acid aqueous solution at 70 ∘ C containing potassium persulfate, were fed with N-isopropylacrylamide (NIPA) at a controlled rate, to produce PNIPA/chitosan core/shell nanoparticles of about 350 nm. Then, the crosslinking agent, glutaraldehyde, was added to crosslink the nanoparticles. These nanocomposites were temperature-and pH-responsive, which make them suitable as controlled drug releasing agents. The nanoparticles exhibit thermoreversibility to heating-and-cooling cycles and show different responses depending on the releasing medium&apos;s pH. Drug delivery tests were performed, employing as a model drug, doxycycline hyclate