Examination of the Feynman-Hibbs Approach in the Study of NeN_N-Coronene Clusters at Low Temperatures

Feynman-Hibbs (FH) effective potentials constitute an appealing approach for investigations of many-body systems at thermal equilibrium since they allow us to easily include quantum corrections within standard classical simulations. In this work we apply the FH formulation to the study of Ne$_N$-coronene clusters ($N=$ 1-4, 14) in the 2-14 K temperature range. Quadratic (FH2) and quartic (FH4) contributions to the effective potentials are built upon Ne-Ne and Ne-coronene analytical potentials. In particular, a new corrected expression for the FH4 effective potential is reported. FH2 and FH4 cluster energies and structures -obtained from energy optimization through a basin-hoping algorithm as well as classical Monte Carlo simulations- are reported and compared with reference path integral Monte Carlo calculations. For temperatures $T> 4$ K, both FH2 and FH4 potentials are able to correct the purely classical calculations in a consistent way. However, the FH approach fails at lower temperatures, especially the quartic correction. It is thus crucial to assess the range of applicability of this formulation and, in particular, to apply the FH4 potentials with great caution. A simple model of $N$ isotropic harmonic oscillators allows us to propose a means of estimating the cut-off temperature for the validity of the method, which is found to increase with the number of atoms adsorbed on the coronene molecule

Precarious employment and health: A qualitative study in Venezuelan immigrant population in Colombia

Background: Employment and working conditions are considered as an element that impacts on health inequalities, especially among vulnerable groups such as the immigrant population. This study aims to describe the characteristics of precarious employment in the Venezuelan immigrant population in Medellín (Colombia) according to its theoretical model and its relationship with the perception of their physical, mental, and psychosocial health. Methods: A qualitative study was conducted with a focused ethnography perspective. 31 people with Venezuelan origin and work experience were interviewed in the city of Medellin and its metropolitan area and 12 key informants from different formal and informal social organizations that work with the immigrant population. A narrative content analysis was carried manually and by using the Atlas.Ti 8.0 software. The principles of analytical induction were applied to carry out a thematic analysis of the main categories defined in the precarious employment framework. Results: The following characteristics of precarious employment were found: instability in employment conditions, work in the informal or submerged economy, limited empowerment, absence of social benefits, high vulnerability, low income, and a limited capacity for exercising labor rights. This situation affects mental health conditions, access to health services, and the presence of risks due to the work they perform. Conclusions: The Venezuelan working population in Medellín is found in a precarious employment situation. Inclusive social strategies and policies that take into account the reality of this population are required

Synthesis of mesoporous Ca-MCM catalysts and their use in suitable multicomponent synthesis of polyfunctionalized pyrans

Mesoporous Ca-MCM catalysts were prepared using a mixture of CaCO3, TEOS, cetyl trimethyl ammonium bromide (CTAB), triethanolamine (TEA), ethanol and H₂O. Three catalysts with different CaCO3 contents, M-Ca 1 %, M-Ca 5 % and M-Ca 10 %, respectively, were prepared and characterized by N₂ physisorption, XRD, FT-IR, XPS, TPD-CO₂ and Pyridine-FTIR. A green and simple protocol was developed for the synthesis of 6-amino-4H-pyran scaffolds through a multicomponent coupling reaction of an aldehyde, malononitrile, and 1,3-dicarbonyl compound in different reaction solvents. This procedure was performed at room temperature (20 °C), obtaining good and excellent yields of 4H-pyran derivatives. The mesoporous materials are insoluble in polar media, which allows easy removal of the reaction products without affecting their catalytic activity. The leaching test showed an excellent stability, and Ca-MCM catalysts can be used three times without appreciable loss of their catalytic activity.Centro de Investigación y Desarrollo en Ciencias AplicadasCentro de Investigación en Sanidad Vegeta

Liver injury in non-alcoholic fatty liver disease is associated with urea cycle enzyme dysregulation

The main aim was to evaluate changes in urea cycle enzymes in NAFLD patients and in two preclinical animal models mimicking this entity. Seventeen liver specimens from NAFLD patients were included for immunohistochemistry and gene expression analyses. Three-hundred-and-eighty-two biopsy-proven NAFLD patients were genotyped for rs1047891, a functional variant located in carbamoyl phosphate synthetase-1 (CPS1) gene. Two preclinical models were employed to analyse CPS1 by immunohistochemistry, a choline deficient high-fat diet model (CDA-HFD) and a high fat diet LDLr knockout model (LDLr −/−). A significant downregulation in mRNA was observed in CPS1 and ornithine transcarbamylase (OTC1) in simple steatosis and NASH-fibrosis patients versus controls. Further, age, obesity (BMI > 30 kg/m), diabetes mellitus and ALT werefound to be risk factors whereas A-allele from CPS1 was a protective factor from liver fibrosis. CPS1 hepatic expression was diminished in parallel with the increase of fibrosis, and its levels reverted up to normality after changing diet in CDA-HFD mice. In conclusion, liver fibrosis and steatosis were associated with a reduction in both gene and protein expression patterns of mitochondrial urea cycle enzymes. A-allele from a variant on CPS1 may protect from fibrosis development. CPS1 expression is restored in a preclinical model when the main trigger of the liver damage disappears.The research leading to these results has received funding from the Consejería de Salud de la Junta de Andalucía under grant agreement PC-0148-2016-0148 and PE-0451-2018 and Instituto de Salud Carlos III under grant agreements CD21/00095, PI16/01842, PI19/01404, PI19/00589, IFI18/00041, FI20/00201, CD18/00126 and EHD18PI04/2021. Rocío Gallego-Durán has received the Andrew K Burroughs Fellowship from European Association for the Study of the Liver (EASL), Aprendizaje de Nuevas Tecnologías fellowship from Asociación Española para el Estudio del Hígado (AEEH) and CIBERehd Grant to support researcher’s mobility

The use of social networks as a tool for flipped classroom methodology: a practical experience in higher education framework

The objective of this project is to continue improving the quality of the teaching-learning processes and to encourage motivation, thus achieving less dropout, for this we are going to continue applying the FC (Flipped Classroom) adding, as a novelty, the use of SN (Social Networks), in different ways: as interactive and the effective tools for the development of the FC; to evaluate the different networks available; to encourage students to be an active part in their learning process, through the creation of content; to allow the transmission of knowledge and collaboration through SN, between students and student-teachers; and to evaluate the motivation and academic performance of students with the application of SN. To develop the project, that will be carried out in the next academic course, we propose the creation of focus groups with students in order to obtain information on the use of networks in their subjects; an extensive bibliographic review of the use of SN in HE; study of the different SN in order to know their main advantages and disadvantages in relation to their application to HE; train of the teaching staff in the use of the most important SN; define of experiences for the application of SN with the FC methodology; and a final satisfaction survey and evaluation of academic results of the students at the end of each of the subject.info:eu-repo/semantics/publishedVersio

Capacitando comunidades marginales a través de un medio masivo de comunicación

Se toma como muestra al partido de La Matanza situado en la provincia de Buenos Aires, el cual cuenta con más de 1.500.000 habitantes. Esta población que supera en número a la de 19 provincias tomadas separadamente, es solo inferior a la Ciudad Autónoma de la Provincia de Buenos Aires y las provincias de Buenos Aires, Córdoba, Santa Fe y Mendoza. Dentro de este Partido conviven comunidades residenciales junto a marginales, por ello se hace un estudio a fin de cuantificar la brecha tecnológica y luego aplicar una metodología que permita acercar el conocimiento a las zonas más marginales a fin de disminuir dicha brecha e incluir a las mismas en la sociedad del conocimiento.Eje: Tecnología Informática Aplicada en EducaciónRed de Universidades con Carreras en Informática (RedUNCI

Implementación de una estrategia para reducir la brecha tecnológica

En el presente artículo se muestra la existencia de la brecha tecnológica entre las comunidades que utilizan las TICs (Tecnologías de la Información y Comunicación) como parte de su vida cotidiana y aquellas que no poseen ningún tipo de conocimiento al respecto. Es posible a través de los resultados arrojados por un relevamiento realizado en comunidades con características socio-culturales distintas evidenciar la distancia en materia de tecnología que separa a las comunidades. Tomando conciencia de la existencia de la brecha tecnológica, en este trabajo se presentan los resultados de implementar una estrategia que les permita a los ciudadanos con escasos recursos, que residen en las zonas más marginales, acceder al conocimiento.Presentado en el VIII Workshop Tecnología Informática aplicada en Educación (WTIAE)Red de Universidades con Carreras en Informática (RedUNCI

Implementación de una estrategia para reducir la brecha tecnológica

En el presente artículo se muestra la existencia de la brecha tecnológica entre las comunidades que utilizan las TICs (Tecnologías de la Información y Comunicación) como parte de su vida cotidiana y aquellas que no poseen ningún tipo de conocimiento al respecto. Es posible a través de los resultados arrojados por un relevamiento realizado en comunidades con características socio-culturales distintas evidenciar la distancia en materia de tecnología que separa a las comunidades. Tomando conciencia de la existencia de la brecha tecnológica, en este trabajo se presentan los resultados de implementar una estrategia que les permita a los ciudadanos con escasos recursos, que residen en las zonas más marginales, acceder al conocimiento.Presentado en el VIII Workshop Tecnología Informática aplicada en Educación (WTIAE)Red de Universidades con Carreras en Informática (RedUNCI

The P34G mutation reduces the transforming activity of K-Ras and N-Ras in NIH 3T3 cells but not of H-Ras

Retraction in The P34G mutation reduces the transforming activity of K-Ras and N-Ras in NIH 3T3 cells but not of H-Ras. [J Biol Chem. 2018]Ras proteins (H-, N-, and K-Ras) operate as molecular switches in signal transduction cascades controlling cell proliferation, differentiation, or apoptosis. The interaction of Ras with its effectors is mediated by the effector-binding loop, but different data about Ras location to plasma membrane subdomains and new roles for some docking/scaffold proteins point to signaling specificities of the different Ras proteins. To investigate the molecular mechanisms for these specificities, we compared an effector loop mutation (P34G) of three Ras isoforms (H-, N-, and K-Ras4B) for their biological and biochemical properties. Although this mutation diminished the capacity of Ras proteins to activate the Raf/ERK and the phosphatidylinositol 3-kinase/AKT pathways, the H-Ras V12G34 mutant retained the ability to cause morphological transformation of NIH 3T3 fibroblasts, whereas both the N-Ras V12G34 and the K-Ras4B V12G34 mutants were defective in this biological activity. On the other hand, although both the N-Ras V12G34 and the K-Ras4B V12G34 mutants failed to promote activation of the Ral-GDS/Ral A/PLD and the Ras/Rac pathways, the H-Ras V12G34 mutant retained the ability to activate these signaling pathways. Interestingly, the P34G mutation reduced specifically the N-Ras and K-Ras4B in vitro binding affinity to Ral-GDS, but not in the case of H-Ras. Thus, independently of Ras location to membrane subdomains, there are marked differences among Ras proteins in the sensitivity to an identical mutation (P34G) affecting the highly conserved effector-binding loop.This work was supported in part by Programa General del Conocimiento (BMC2001-0057), Intramural Instituto de Salud Carlos III (ISCIII) (01/16), and SAF2003-02604 (Ministerio de Ciencia y Tecnología) grants (to J. M. R.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.S