LRRC8/VRAC anion channels enhance β-cell glucose sensing and insulin secretion

Glucose homeostasis depends critically on insulin that is secreted by pancreatic β-cells. Serum glucose, which is directly sensed by β-cells, stimulates depolarization- and Ca(2+)-dependent exocytosis of insulin granules. Here we show that pancreatic islets prominently express LRRC8A and LRRC8D, subunits of volume-regulated VRAC anion channels. Hypotonicity- or glucose-induced β-cell swelling elicits canonical LRRC8A-dependent VRAC currents that depolarize β-cells to an extent that causes electrical excitation. Glucose-induced excitation and Ca(2+) responses are delayed in onset, but not abolished, in β-cells lacking the essential VRAC subunit LRRC8A. Whereas Lrrc8a disruption does not affect tolbutamide- or high-K(+)-induced insulin secretion from pancreatic islets, it reduces first-phase glucose-induced insulin secretion. Mice lacking VRAC in β-cells have normal resting serum glucose levels but impaired glucose tolerance. We propose that opening of LRRC8/VRAC channels increases glucose sensitivity and insulin secretion of β-cells synergistically with K(ATP) closure. Neurotransmitter-permeable LRRC8D-containing VRACs might have additional roles in autocrine/paracrine signaling within islets

Running Gauge Couplings and Thresholds in the Type II Superstring

A distinctive feature of string unification is the possibility of unification by a non-simply-laced group. This occurs most naturally in four dimensional type~II string models where the gauge symmetry is realized by Kac-Moody algebras at different levels. We investigate the running coupling constants and the one-loop thresholds for such general models. As a specific case, we examine a $\rm SU(3)\times U(1)\times U(1)$ model and find that the threshold corrections lead to a small $6\%$ increase in the unification scale.Comment: 12 pages, IFP-432-UN

Supplementation with a Polyphenol-Rich Extract, TensLess® , Attenuates Delayed Onset Muscle Soreness and Improves Muscle Recovery from Damages After Eccentric Exercise.

High-intensity exercises are known to provoke delayed onset muscle soreness (DOMS). Delayed onset muscle soreness typically occurs within the first 24 h, peaks between 24 and 72 h, and can last as long as 5-7 days post-exercise. Delayed onset muscle soreness is a multifactorial process involving both mechanical and biochemical components, associated with clinical features that may limit range of motion, and athletes seek for effective recovery strategies to optimize future training sessions. TensLess® is a food supplement developed to help manage post-exercise recovery. The supplement has been investigated on 13 recreationally active athletes of both sex, during a randomized, double-blind, and crossover clinical investigation, including a 3-week washout period. The clinical investigation was based on the study of TensLess® effects for DOMS management and on the reduction of associated muscle damages following an eccentric exercise protocol. Supplementation with TensLess® induced significant decrease in DOMS perception (-33%; p = 0.008) as of the first 24 h; this was significantly correlated with a lowered release of muscle damage-associated biomarkers, namely myoglobin, creatinine, and creatine kinase, for the whole length of the recovery period. Taken together, these positive results clearly indicate that post-exercise supplementation with TensLess® may preserve myocytes and reduce soreness following eccentric exercise-induced damages, and, accordingly, significantly shorten muscle recovery.Actividad Física y Deport

Threshold Corrections and Gauge Symmetry in Twisted Superstring Models

Threshold corrections to the running of gauge couplings are calculated for superstring models with free complex world sheet fermions. For two N=1 $SU(2)\times U(1)^5$ models, the threshold corrections lead to a small increase in the unification scale. Examples are given to illustrate how a given particle spectrum can be described by models with different boundary conditions on the internal fermions. We also discuss how complex twisted fermions can enhance the symmetry group of an N=4 $SU(3)\times U(1)\times U(1)$ model to the gauge group $SU(3)\times SU(2)\times U(1)$. It is then shown how a mixing angle analogous to the Weinberg angle depends on the boundary conditions of the internal fermions.Comment: easier to Tex version, figures to be sent separatel

Validity of student satisfaction surveys to assess teaching quality: the UPCT case study (Cartagena, Spain)

[ES] El programa DOCENTIA de ANECA se de­sarrolló como base para los modelos me­diante los cuales las universidades espa­ñolas evalúan la docencia del profesorado, una necesidad ligada a los requerimientos de transparencia y de mejora continua que están en la esencia del EEES. Entre los in­dicadores habituales en estos modelos destacan las encuestas de satisfacción de los estudiantes, cuya validez es objeto de debate desde el origen de su utilización. Una de las opiniones críticas más extendi­das sostiene que las encuestas no son una buena referencia, porque contienen ses­gos inasumibles. Con el objetivo de com­probar si existen realmente esos sesgos, se ha realizado un estudio estadístico a partir de los datos de indicadores de calidad en la Universidad Politécnica de Cartagena. Se ha empleado la regresión lineal múlti­ple, mediante el procedimiento conocido como regresión hacia atrás, para identifi­car las variables que pudieran influir en las valoraciones que hacen los estudiantes y cuantificar su efecto. El principal resultado del estudio es que las variables analizadas, que suelen citarse como causas de sesgo, muestran una influencia poco o nada signi­ficativa sobre los resultados de las encues­tas. Por otra parte, es importante subrayar que hay aspectos de la actividad docente que solamente pueden evaluarse a partir de la observación sistemática que hacen los estudiantes. Por todo ello considera­mos que las encuestas de satisfacción son un indicador indispensable, y es funda­mental que el peso que se les asigna en el modelo de evaluación docente refleje su importancia.[EN]  ANECA´s DOCENTIA program was developed to support the evaluation of teaching by the Spanish universities. Nowadays, teaching quality evaluation is a need linked to the transparency and continuous improvement requirements inherent to the European Higher Education Area. The indicators on the quality models frequently include student evaluation of teaching (SET), whose validity is the subject of a broad debate from the beginning of its use. One of the most widespread critical opinions argues that student surveys are not a good reference, as they contain non-assumable biases. With the aim of verify whether these biases actually exist, a statistical study has been carried out based on quality indicators data from the Technical University of Cartagena. Multiple linear regression has been used, through backward stepwise regression, to identify variables that may influence students’ opinions and to quantify their effects. The main result is that the variables analyzed, many of which are often cited as causes of bias, show little or no significant influence on student satisfaction with teaching. It is also important to remark that there are aspects of the teaching activity that can only be evaluated from the systematic observation made by students. Therefore, we believe that student surveys are an essential indicator, and their weight within teaching evaluation models should reflect their relevance.García Martín, A.; Montero Cases, T.; García León, J.; Vázquez Arenas, G. (2020). Validez de las encuestas de satisfacción de los estudiantes para evaluar la calidad docente: el caso de la UPCT (Cartagena). REDU. Revista de Docencia Universitaria. 18(1):275-290. https://doi.org/10.4995/redu.2020.12996OJS275290181Abadía, A.R., Bueno, C., Ubieto-Artur, M.I., Márquez, M.D., Sabaté, S., Jorba, H., Pagès, T. (2015). Competencias del buen docente universitario. Opinión de los estudiantes. REDU, Revista de Docencia Universitaria, 13(2), 363-390. https://doi.org/10.4995/redu.2015.5453Benton, S.L., Cashin, W.E. (2013). Student ratings of instruction in college and university courses. En M.B. Paulsen (ed.), Higher Education: Handbook of Theory and Research (pp. 279-326). https://doi.org/10.1007/978-94-017-8005-6_7Berk, R.A. (2014). Should student outcomes be used to evaluate teaching? Journal of Faculty Development, 28(2), 87-96. Recuperado de https://pdfs.semanticscholar. org/72dc/eb08a40f9019c72d5f20971bd3413fe06efd.pdfBoring, A. (2017). Gender biases in student evaluations of teaching. Journal of Public Economics, 145, 27-41. https://doi.org/10.1016/j.jpubeco.2016.11.006Casero, A. (2010). Factores moduladores de la percepción de la calidad docente. RELIEVE, Revista Electrónica de Investigación y Evaluación Educativa, 16(2), 1-17. https://doi.org/10.7203/relieve.16.2.4135Centra, J.A. (2003). Will teachers receive higher student evaluations by giving higher grades and less course work? Research in Higher Education, 44(5), 495-518. https://doi.org/10.1023/A:1025492407752Cohen, P.A. (1983). Comment on a selective review of the validity of student ratings of teaching. The Journal of Higher Education, 54(4), 448-458. https://doi.org/10.2307/1981907Elizondo, A., Novo, A., Silvestre, M. (2010). Igualdad de mujeres y hombres en las universidades españolas. Instituto de la Mujer, Madrid. Recuperado de http://www.inmujer.gob.es/areasTematicas/estudios/serieEstudios/docs/ igualdadUniversidades.pdfEmery, C.R., Kramer, T.R., Tian, R.G. (2003). Return to academic standards: a critique of student evaluations of teaching effectiveness. Quality Assurance in Education, 11(1), 37-46. https://doi.org/10.1108/09684880310462074Fernández Rico, J.E., Fernández, S., Álvarez, A., Martínez Camblor, P. (2007). Éxito académico y satisfacción de estudiantes con la enseñanza universitaria. RELIEVE, Revista Electrónica de Investigación y Evaluación Educativa, 13(2). https://doi.org/10.7203/relieve.13.2.4207Franklin, M. (2016). Student evaluations of teaching in business and accounting courses: a perspective and a suggested improvement. Cogent Business & Management, 3(1), 1-17. https://doi.org/10.1080/23311975.2016.1226458García Martín, A., García-León, J. (2017). Una experiencia de medición de la carga de trabajo percibida por los estudiantes para facilitar la coordinación horizontal. REDU, Revista de Docencia Universitaria, 15(1), 81-104. https://doi.org/10.4995/redu.2017.5987Greenwald, A.G., Gillmore, G.M. (1997). No pain, no gain? The importance of measuring course workload in student ratings of instruction. Journal of Educational Psychology, 89(4), 743-751. https://doi.org/10.1037/0022-0663.89.4.743Hammonds, F., Mariano, G.J., Ammons, G., Chambers, S. (2016). Student evaluations of teaching: improving teaching quality in higher education. Perspectives: Policy and Practice in Higher Education, 21(1), 26-33. https://doi.org/10.1080/13603108.2016.1227388Isla-Díaz, R., Marrero-Hernández, H., Hess-Medler, S., Soriano, M., Acosta-Rodríguez, S., Pérez-Monteverde, M.V., Blanco-Freijo, M. (2018). Una mirada longitudinal: ¿Es el "Docentia" útil para la evaluación del profesorado universitario? RELIEVE, Revista Electrónica de Investigación y Evaluación Educativa, 24(2). https://doi.org/10.7203/relieve.24.2.12142Jones, J. (1989). Students' ratings of teacher personality and teaching competence. Higher Education, 18(5), 551-558. https://doi.org/10.1007/BF00138747López-Aguado, M. (2018). La evaluación de la calidad de títulos universitarios. Dificultades percibidas por los responsables de los sistemas de garantía de calidad. Educación XX1, 21(1), 263-284. https://doi.org/10.5944/educxx1.20195Marsh, H., Roche, L. (1997). Making students' evaluations of teaching effectiveness effective. American Psychologist, 52(11), 1187-1197. https://doi.org/10.1037/0003-066X.52.11.1187Marsh, H. (2007). Students' evaluations of university teaching: dimensionality, reliability, validity, potential biases and usefulness. En R.P. Perry and J.C. Smart (eds.), The Scholarship of Teaching and Learning in Higher Education: An Evidence-Based Perspective, 319-383. Springer. https://doi.org/10.1007/1-4020-5742-3_9Mas Torelló, O. (2012). Las competencias del docente universitario: la percepción del alumno, de los expertos y del propio protagonista. REDU - Revista de Docencia Universitaria, 10(2), 299-318. https://doi.org/10.4995/redu.2012.6109Murray, H.G. (2005). Student evaluation of teaching: has it made a difference? Paper presented at the Annual Meeting of the Society for Teaching and Learning in Higher Education, Charlottetown, Prince Edward Island. Recuperado de https://www.stlhe.ca/wp-content/uploads/2011/07/Student-Evaluation-of- Teaching1.pdfRamírez, M.I., Montoya, J. (2014). La evaluación de la calidad de la docencia en la universidad: Una revisión de la literatura. REDU, Revista de Docencia Universitaria, 12 (2), 77-95. https://doi.org/10.4995/redu.2014.5641Sánchez, F., Rubio, R., Alonso, E., Retamal, K. (2009). La valoración de la actividad docente. Algo más que la opinión de los estudiantes. Boletín de Psicología, 97, 71-92. Recuperado de https://www.uv.es/seoane/boletin/previos/N97-5.pdfSpooren, P., Mortelmans, D., Thijssen, P. (2012). 'Content' versus 'style': acquiescence in student evaluation of teaching? British Educational Research Journal, 38(1), 3-21. https://doi.org/10.1080/01411926.2010.523453Uttl, B., White, C.A., Gonzalez, D. (2017). Meta-analysis of faculty's teaching effectiveness: Student evaluation of teaching ratings and student learning are not related. Studies in Educational Evaluation 54, 22-42. https://doi.org/10.1016/j.stueduc.2016.08.007Wolbring, T., y Treischl, E. (2016). Selection bias in students' evaluation of teaching. Causes of student absenteeism and its consequences for course ratings and rankings. Research in Higher Education, 57, 51-71. https://doi.org/10.1007/s11162-015-9378-

Cardiovascular and mortality benefits of sodium-glucose co-transporter-2 inhibitors in patients with type 2 diabetes mellitus : CVD-Real Catalonia

Evidence from prospective cardiovascular (CV) outcome trials in type 2 diabetes (T2DM) patients supports the use of sodium-glucose co-transporter-2 inhibitors (SGLT2i) to reduce the risk of CV events. In this study, we compared the risk of several CV outcomes between new users of SGLT2i and other glucose-lowering drugs (oGLDs) in Catalonia, Spain. CVD-REAL Catalonia was a retrospective cohort study using real-world data routinely collected between 2013 and 2016. The cohorts of new users of SGLT2i and oGLDs were matched by propensity score on a 1:1 ratio. We compared the incidence rates and hazard ratio (HR) for all-cause death, hospitalization for heart failure, chronic kidney disease, and modified major adverse CV event (MACE; all-cause mortality, myocardial infarction, or stroke). After propensity score matching, 12,917 new users were included in each group. About 27% of users had a previous history of CV disease. In the SGLT2i group, the exposure time was 60% for dapagliflozin, 26% for empagliflozin and 14% for canagliflozin. The use of SGLT2i was associated with a lower risk of heart failure (HR: 0.59; 95% confidence interval [CI] 0.47-0.74; p < 0.001), all-cause death (HR = 0.41; 95% CI 0.31-0.54; p < 0.001), all-cause death or heart failure (HR = 0.55; 95% CI 0.47-0.63; p < 0.001), modified MACE (HR = 0.62; 95% CI 0.52-0.74; p < 0.001), and chronic kidney disease (HR = 0.66; 95% CI 0.54-0.80; p < 0.001). In this large, retrospective observational study of patients with T2DM from a Catalonia, initiation of SGLT-2i was associated with lower risk of mortality, as well as heart failure and CKD. The online version contains supplementary material available at 10.1186/s12933-021-01323-5

Selective Adsorption and Chiral Amplification of Amino Acids in Vermiculite Clay -Implications for the origin of biochirality

Smectite clays are hydrated layer silicates that, like micas, occur naturally in abundance. Importantly, they have readily modifiable interlayer spaces that provide excellent sites for nanochemistry. Vermiculite is one such smectite clay and in the presence of small chain-length alkyl-NH3Cl ions, forms sensitive, 1-D ordered model clay systems with expandable nano-pore inter-layer regions. These inter-layers readily adsorb organic molecules. N-propyl NH3Cl vermiculite clay gels were used to determine the adsorption of alanine, lysine and histidine by chiral HPLC. The results show that during reaction with fresh vermiculite interlayers, significant chiral enrichment of either L- and D-enantiomers occurs depending on the amino acid. Chiral enrichment of the supernatant solutions is up to about 1% per pass. In contrast, addition to clay interlayers already reacted with amino acid solutions resulted in little or no change in D/L ratio during the time of the experiment. Adsorption of small amounts of amphiphilic organic molecules in clay inter-layers is known to produce Layer-by-Layer or Langmuir-Blodgett films. Moreover atomistic simulations show that self-organization of organic species in clay interlayers is important. These non-centrosymmetric, chirally active nanofilms may cause clays to act subsequently as chiral amplifiers, concentrating organic material from dilute solution and having different adsorption energetics for D- and L-enantiomers. The additional role of clays in RNA oligimerization already postulated by Ferris and others, together with the need for the organization of amphiphilic molecules and lipids noted by Szostak and others, suggests that such chiral separation by clays in lagoonal environments at normal biological temperatures might also have played a significant role in the origin of biochirality.Comment: 17 Pages, 2 Figures, 4 Table

Shared care: a pathway for the rejuvenation of home haemodialysis?

There much evidence for the benefits to patients of being able to manage their own haemodialysis rather following the thrice weekly model of most in-centre dialysis programmes. Numbers of patients dialysing at home remains disappointingly small and there are considerable variations between renal centres. Shared care models have been promoted as a route of encouraging greater take-up of home haemodialysis (HHD). There is currently little available evidence to support this assertion. Barriers have been identified to increasing self-management by haemodialysis patients, many of which apply to both shared care and HHD programmes. Overcoming the barriers, many of which are institutional is key to increasing numbers of patients dialysing at home. The development of shared care initiatives alone will not foster greater HHD engagement rather the cultural and other barriers to both must be overcome if such growth is to be seen