Metarregulated Learning Scale (MRL) in university students

El estudio tuvo como objetivo determinar la validez de constructo de la escala de aprendizaje metarregulado (AMR) en estudiantes universitarios. Se desarrolló con 430 estudiantes universitarios en educación virtual de Lima, utilizando los paquetes estadísticos SPSS v26, AMOS v24 y el R-Project v.1.2, y aportando evidencia psicométrica del proceso de validación. Se realizó análisis factorial exploratorio y confirmatorio; el análisis de fiabilidad y validez de constructo final se realizó a partir del cálculo de las medidas del alfa de Cronbach, coeficiente Omega y coeficiente Theta. Los resultados constatan la estructura original de cinco factores, aunque con menos elementos que la versión primaria; finalmente se obtiene un instrumento de 20 ítems que comprende 5 dimensiones calificadas; el mismo se ofrece a la comunidad científica y educativa con el ánimo de contribuir a entender mejor el aprendizaje de los estudiantes universitarios, dinamizado desde procesos de colaboración, metarreflexión, metacognición, autorregulación y cognición.The study aimed to determine the construct validity of the metaregulated learning scale (AMR) in university students. It was developed with 430 university students in virtual education in Lima, using the statistical packages SPSS v26, AMOS v24 and R-Project v.1.2, and providing psychometric evidence of the validation process. Exploratory and confirmatory factor analysis was performed; the reliability and validity analysis of the final construct was performed from the calculation of the Cronbach's alpha, Omega coefficient and Theta coefficient measures. The results confirm the original structure of five factors, although with fewer elements than the primary version; Finally, a 20-item instrument is obtained that includes 5 qualified dimensions; It is offered to the scientific and educational community with the aim of contributing to a better understanding of the learning of university students, dynamized from processes of collaboration, meta-reflection, metacognition, self-regulation and cognition

Iron-refractory iron deficiency anemia (Irida): a propósito de un caso

Poster [PC-130] Introducción: IRIDA es una entidad que cursa con anemia ferropénica, de herencia autosómica recesiva, aunque se han reportado algunos casos que son sólo heterocigotos (herencia autosómica dominante), debidos a mutaciones en el gen TMPRSS6 que codifica la proteína matriptasa-2. Se cree que la prevalencia de IRIDA es inferior a 1: 1.000.000, pero probablemente está infradiagnosticada. Caso clínico: Mujer de 17 años con antecedentes personales de retraso psicomotor y trastorno de espectro autista. Cariotipo 46 XX, descartándose síndrome X-frágil FRAXA, síndrome de Angelman y síndrome de Rett. Ha presentado varios episodios de trastornos de conducta con desorganización motora y dificultad de convivencia. Controlada en Hematología desde 2015 por anemia microcítica hipocrómica ferropénica sin respuesta al hierro oral y con respuesta parcial al hierro intravenoso. A lo largo del seguimiento en esta consulta se han descartado enfermedad celiaca (anticuerpos anti-gliadina (IgG e IgA), anti-transglutaminasa (IgA) negativos), helicobacter pylori (test del aliento negativo), pérdidas digestivas de hierro (sangre oculta en heces negativa), pérdidas urinarias y pulmonares. Ha presentado niveles bajos de hemoglobina (máximo 69 g/L) con microcitosis importante (máximo VCM 68, 50 fl) e índices de saturación de hasta 2, 5%. Desarrollo ponderoestatural y puberal normal. Tras recibir diferentes compuestos de hierro oral, sin respuesta a ninguno de ellos, se inicia tratamiento con hierro endovenoso, precisando medidas de contención para la administración del mismo, motivo por el que ha recibido tratamiento con hierro-carboximaltosa (Ferinject®) 500 mg, permitiendo administrar mayor cantidad de hierro en una sola dosis (Figura 1 y 2). Ante la sospecha de IRIDA se solicita un análisis de mutaciones puntuales en el gen TMPRSS6 que codifica la proteína matriptasa-2. La paciente no presenta mutaciones puntuales en las regiones analizadas, sin embargo, en el análisis de las secuencias se observan los siguientes polimorfismos (SNPs) en el gen TMPRSS6: p.Lys253Glu (exón 7), IVS7+23A>G (intrón 7), p.Val736Ala (exón17) interpretados como variantes benignas (no patogénicas). Conclusiones: Existen aproximadamente 69 defectos diferentes del gen TMPRSS6 en 65 familias diferentes. Sin embargo, están apareciendo nuevas mutaciones, no descritas por el momento y que podrían ser causa IRIDA, respaldando la hipótesis de que este síndrome clínico puede ser más común de lo que se pensaba anteriormente y su genética ser más heterogénea de lo que se describió inicialmente. Además se han descrito nuevos polimorfimos como p.Val736Ala que asocian mayor susceptibilidad al desarrollo de anemia ferropénica. Dado que su cuadro neurológico sigue sin diagnóstico preciso, ante la presencia concomitante de estos polimorfismos, se decide el estudio de secuenciación del exoma completo

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

Combined search for the quarks of a sequential fourth generation

Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO

Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV

A search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 inverse picobarns collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected particle and one or two jets

Measurement of the t t-bar production cross section in the dilepton channel in pp collisions at sqrt(s) = 7 TeV

The t t-bar production cross section (sigma[t t-bar]) is measured in proton-proton collisions at sqrt(s) = 7 TeV in data collected by the CMS experiment, corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurement is performed in events with two leptons (electrons or muons) in the final state, at least two jets identified as jets originating from b quarks, and the presence of an imbalance in transverse momentum. The measured value of sigma[t t-bar] for a top-quark mass of 172.5 GeV is 161.9 +/- 2.5 (stat.) +5.1/-5.0 (syst.) +/- 3.6(lumi.) pb, consistent with the prediction of the standard model.Comment: Replaced with published version. Included journal reference and DO

Measurement of the Z/gamma* + b-jet cross section in pp collisions at 7 TeV

The production of b jets in association with a Z/gamma* boson is studied using proton-proton collisions delivered by the LHC at a centre-of-mass energy of 7 TeV and recorded by the CMS detector. The inclusive cross section for Z/gamma* + b-jet production is measured in a sample corresponding to an integrated luminosity of 2.2 inverse femtobarns. The Z/gamma* + b-jet cross section with Z/gamma* to ll (where ll = ee or mu mu) for events with the invariant mass 60 < M(ll) < 120 GeV, at least one b jet at the hadron level with pT > 25 GeV and abs(eta) < 2.1, and a separation between the leptons and the jets of Delta R > 0.5 is found to be 5.84 +/- 0.08 (stat.) +/- 0.72 (syst.) +(0.25)/-(0.55) (theory) pb. The kinematic properties of the events are also studied and found to be in agreement with the predictions made by the MadGraph event generator with the parton shower and the hadronisation performed by PYTHIA.Comment: Submitted to the Journal of High Energy Physic

Search for anomalous t t-bar production in the highly-boosted all-hadronic final state

A search is presented for a massive particle, generically referred to as a Z', decaying into a t t-bar pair. The search focuses on Z' resonances that are sufficiently massive to produce highly Lorentz-boosted top quarks, which yield collimated decay products that are partially or fully merged into single jets. The analysis uses new methods to analyze jet substructure, providing suppression of the non-top multijet backgrounds. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 5 inverse femtobarns. Upper limits in the range of 1 pb are set on the product of the production cross section and branching fraction for a topcolor Z' modeled for several widths, as well as for a Randall--Sundrum Kaluza--Klein gluon. In addition, the results constrain any enhancement in t t-bar production beyond expectations of the standard model for t t-bar invariant masses larger than 1 TeV.Comment: Submitted to the Journal of High Energy Physics; this version includes a minor typo correction that will be submitted as an erratu

Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe

Compressed representation of a partially defined integer function over multiple arguments

In OLAP (OnLine Analitical Processing) data are analysed in an n-dimensional cube. The cube may be represented as a partially defined function over n arguments. Considering that often the function is not defined everywhere, we ask: is there a known way of representing the function or the points in which it is defined, in a more compact manner than the trivial one