Influence of boron content on the fracture toughness and fatigue crack propagation kinetics of bainitic steels

The relatively good combination of high strength and ductility makes bainitic steels a candidate to replace many other steels in industrial applications. However, in service, ductility and strength are not up to standard requirements. In many industrial components, toughness and fatigue performance are also very relevant. In the present study, bainitic steels with varying content of boron were fabricated, with the aim of analyzing the fracture toughness and changes in the fatigue life. The results show that a relatively small change in the boron content can cause a notable variation in the fracture toughness of bainitic steels. The maximum value obtained in fracture toughness was for the steel with the highest boron content. It was observed that the amount of interlath martensite constituents decreases in steels with the addition of boron, leading to the promotion of the presence of void coalescence and a remarkable rise in the toughness of bainitic steels. An increase on the fatigue life of the bainitic steels with an increase in the boron content was also observed, through analysis by means of Paris’ law. A comprehensive micrographic study was carried out in order to examine the mechanics of fatigue crack growth in the bainitic steels, revealing small longitudinal cracks in bainitic steels that lack boron. These cracks tend to disappear in bainitic steels that contain boron. To elucidate this behavior, micrographs of the surfaces generated by the crack growth process were taken, showing that several nano-cracks appeared between the bainite laths. It is finally argued that this high-energy consumption process of nano-crack nucleation and growth is the reason for the improved toughness and fatigue life observed in bainitic steels.Peer ReviewedPostprint (author's final draft

Implementación de un proyecto basado en la comunidad en un aula rural de inglés

Educational work within a social perspective has been a matter of interest and discussion of researchers and teachers whose work is framed within a pedagogy for social justice, community pedagogies, and critical literacy (Comber & Kamler, 2004). A social perspective to education requires that teachers in rural and urban contexts become socially and culturally committed to addressing the learning needs of EFL in classrooms. This article shares the outcomes of the experience of five pre-service teachers who explored a local community of a Colombian rural school with a group of 36 ninth-grade EFL students. The pre-service teachers crafted a project-based curriculum taking the community as the content that would empower the students to explore social and cultural aspects of their community while promoting their EFL learning. Data were collected during the four-month period of the pedagogical intervention through interviews, observations and students’ and teachers’ written reflections. The high school students carried out a series of tasks aimed at raising their awareness about their identity, questioning their surroundings and increasing their self-confidence while using their knowledge of English. La investigación en educación con perspectiva social ha sido un tema de interés y discusión para investigadores y profesores cuyo trabajo está enmarcado en la pedagogía para justicia social, pedagogía basada en la comunidad y literacidades críticas. Una perspectiva social para la educación requiere que los profesores en contextos rurales y urbanos estén social y culturalmente comprometidos en abordar las necesidades de aprendizaje de inglés en las aulas. Este artículo comparte los resultados de una experiencia de cinco docentes practicantes quienes exploraron una comunidad local en un colegio rural colombiano con un grupo de 36 estudiantes de grado noveno. Las docentes implementaron un currículo basado en proyectos, con temas de la comunidad como contenido principal, para empoderar a los estudiantes y así explorar aspectos culturales y sociales de su comunidad mientras se promovía el aprendizaje de inglés como lengua extranjera. Los datos fueron recogidos durante un periodo de cuatro meses de implementación de la intervención pedagógica a través de entrevistas, observaciones y reflexiones de estudiantes y profesores. Los estudiantes desarrollaron una serie de actividades enfocadas a incrementar la conciencia acerca de su identidad, a cuestionar y mejorar realidades de su entorno mientras fortalecían habilidades para incrementar su conocimientos del inglés.&nbsp

Genetic Predictors of Weight Loss and Weight Regain After Intensive Lifestyle Modification, Metformin Treatment, or Standard Care in the Diabetes Prevention Program

OBJECTIVE: We tested genetic associations with weight loss and weight regain in the Diabetes Prevention Program, a randomized controlled trial of weight loss–inducing interventions (lifestyle and metformin) versus placebo. RESEARCH DESIGN AND METHODS: Sixteen obesity-predisposing single nucleotide polymorphisms (SNPs) were tested for association with short-term (baseline to 6 months) and long-term (baseline to 2 years) weight loss and weight regain (6 months to study end). RESULTS: Irrespective of treatment, the Ala12 allele at PPARG associated with short- and long-term weight loss (−0.63 and −0.93 kg/allele, P ≤ 0.005, respectively). Gene–treatment interactions were observed for short-term (LYPLAL1 rs2605100, P$_{lifestyle*SNP}$ = 0.032; GNPDA2 rs10938397, P$_{lifestyle*SNP}$ = 0.016; MTCH2 rs10838738, P$_{lifestyle*SNP}$ = 0.022) and long-term (NEGR1 rs2815752, P$_{metformin*SNP}$ = 0.028; FTO rs9939609, P$_{lifestyle*SNP}$ = 0.044) weight loss. Three of 16 SNPs were associated with weight regain (NEGR1 rs2815752, BDNF rs6265, PPARG rs1801282), irrespective of treatment. TMEM18 rs6548238 and KTCD15 rs29941 showed treatment-specific effects (P$_{lifestyle*SNP}$ < 0.05). CONCLUSIONS: Genetic information may help identify people who require additional support to maintain reduced weight after clinical intervention

Comprehensive Analysis of Established Dyslipidemia-Associated Loci in the Diabetes Prevention Program

Background-We assessed whether 234 established dyslipidemia-associated loci modify the effects of metformin treatment and lifestyle intervention (versus placebo control) on lipid and lipid subfraction levels in the Diabetes Prevention Program randomized controlled trial. Methods and Results-We tested gene treatment interactions in relation to baseline-adjusted follow-up blood lipid concentrations (high-density lipoprotein [HDL] and low-density lipoprotein-cholesterol, total cholesterol, and triglycerides) and lipoprotein subfraction particle concentrations and size in 2993 participants with pre-diabetes. Of the previously reported single-nucleotide polymorphism associations, 32.5% replicated at PP>1.1×10-16) with their respective baseline traits for all but 2 traits. Lifestyle modified the effect of the genetic risk score for large HDL particle numbers, such that each risk allele of the genetic risk scores was associated with lower concentrations of large HDL particles at follow-up in the lifestyle arm (β=-0.11 μmol/L per genetic risk scores risk allele; 95% confidence interval,-0.188 to-0.033; P=5×10-3; Pinteraction=1×10-3 for lifestyle versus placebo), but not in the metformin or placebo arms (P>0.05). In the lifestyle arm, participants with high genetic risk had more favorable or similar trait levels at 1-year compared with participants at lower genetic risk at baseline for 17 of the 20 traits. Conclusions-Improvements in large HDL particle concentrations conferred by lifestyle may be diminished by genetic factors. Lifestyle intervention, however, was successful in offsetting unfavorable genetic loading for most lipid traits. Clinical Trial Registration-URL: https://www.clinicaltrials.gov. Unique Identifier: NCT00004992

Prevención de autolesiones y suicidio: una experiencia desde el cuidado de enfermería para docentes de educación secundaria

Introduction: Suicide is the deliberate act of taking one's own life with explicit or implicit evidence that it was self-inflicted and with the intention of causing one's own death. It is a public health problem due to the impact it generates on families and societies, due to the loss of many years of life that could have been lived. Objective: to strengthen the knowledge of the teachers of the Francisco José de Caldas Educational Institution in the management of self-harm and suicide. Materials and methods: an educational workshop was carried out based on the course Prevention of self-harm and suicide: empowerment of primary health care professionals of the Pan American Health Organization (PAHO), aimed at teachers of the Educational Institution Francisco Jose de Caldas de Villavicencio. Results: 57 10th and 11th grade teachers, from the institution's morning and afternoon sessions, between 35 and 60 years of age, with a predominance of females, participated. Conclusion: mental health is an important factor of direct influence on the quality of life of adolescents, consequently, it is essential to strengthen the knowledge of teachers in the identification of warning signs and the prevention of injuries in students.Introducción: el suicidio es el acto deliberado de quitarse la vida con evidencia, explícita o implícita, de que fue autoinfligido y con la intención de provocar el propio fallecimiento. Es un problema de salud pública por el impacto que genera en las familias y las sociedades, debido a la pérdida de muchos años de vida que pudieron ser vividos. Objetivo: fortalecer los conocimientos de los docentes de la Institución Educativa Francisco José de Caldas en el manejo de la autolesión y el suicidio. Materiales y métodos: se realizó un taller educativo con base en el curso Prevención de la autolesión y el suicidio: empoderamiento de los profesionales de atención primaria de salud de la Organización Panamericana de la Salud (OPS), dirigido a docentes de la Institución Educativa Francisco José de Caldas de Villavicencio. Resultados: se contó con la participación de 57 docentes de 10 y 11 grado, de las jornadas mañana y tarde de la institución, entre los 35 y 60 años de edad, con predominio del sexo femenino. Conclusión: la salud mental es un factor importante de influencia directa en la calidad de vida de los adolescentes, en consecuencia, es indispensable el fortalecimiento de los conocimientos de los docentes en la identificación de las señales de alarma y la prevención de lesiones en los estudiantes

Analysis of protein-coding genetic variation in 60,706 humans

Large-scale reference data sets of human genetic variation are critical for the medical and functional interpretation of DNA sequence changes. We describe the aggregation and analysis of high-quality exome (protein-coding region) sequence data for 60,706 individuals of diverse ethnicities generated as part of the Exome Aggregation Consortium (ExAC). This catalogue of human genetic diversity contains an average of one variant every eight bases of the exome, and provides direct evidence for the presence of widespread mutational recurrence. We have used this catalogue to calculate objective metrics of pathogenicity for sequence variants, and to identify genes subject to strong selection against various classes of mutation; identifying 3,230 genes with near-complete depletion of truncating variants with 72% having no currently established human disease phenotype. Finally, we demonstrate that these data can be used for the efficient filtering of candidate disease-causing variants, and for the discovery of human “knockout” variants in protein-coding genes

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis