Fermion mass hierarchy and non-hierarchical mass ratios in SU(5) x U(1)_F

We consider a SU(5) x U(1)_F GUT-flavor model in which the number of effects that determine the charged fermions Yukawa matrices is much larger than the number of observables, resulting in a hierarchical fermion spectrum with no particular regularities. The GUT-flavor symmetry is broken by flavons in the adjoint of SU(5), realizing a variant of the Froggatt-Nielsen mechanism that gives rise to a large number of effective operators. By assuming a common mass for the heavy fields and universality of the fundamental Yukawa couplings, we reduce the number of free parameters to one. The observed fermion mass spectrum is reproduced thanks to selection rules that discriminate among various contributions. Bottom-tau Yukawa unification is preserved at leading order, but there is no unification for the first two families. Interestingly, U(1)_F charges alone do not determine the hierarchy, and can only give upper bounds on the parametric suppression of the Yukawa operators.Comment: 14 pages, one figure. Few typos correcte

From Insult to Injury: How Disputes Begin and Escalate among Adolescents and Young Adults in Medellin, Colombia

This article aims to contribute to the understanding of circumstances, causes of initiation, and process of escalation of physical disputes or fights resulting in physical injury. We analyzed data from a case-control study of perpetrators of violence between the ages of 15 to 24 (n=373) in the city of Medellín, Colombia. The findings show that 89% of conflicts resulting in injury took place in public places and most often involved males (78%). Six percent involved the consumption of alcohol, 20% reported having used illicit drugs before the initiation of the confrontation. Circa 50% of disputes began because of verbal aggression. Alcohol consumption was found to be associated with verbal aggression towards a friend or companion but not to other circumstances that start disputes. Drug use was not associated with the initiation of disputes. In 18.5% of the cases, a weapon was used while 5% of these disputes ended in a homicide. In none of the cases in which homicide was the outcome was there bystander intervention. In contrast, homicide did not result in the cases in which bystanders intervened

Programa Jatropha Colombia :genética, agronomía, poscosecha y desarrollo agroindustrial del piñon de Colombia (2008-2012)

A partir de las experiencias de Asia, África y Centro América en la especie Jatropha curcas, Corpoica ha estructurado el Programa de Investigación en Jatropha. Este programa pretende identificar, en el corto plazo, las variedades más sobresalientes desde el punto de vista agronómico y de calidad del aceite, de un grupo de materiales comerciales introducidos en el país y que fueron colectadas en diferentes zonas agroecológicas. A partir de la información generada, será posible efectuar recomendaciones de carácter regional acerca de los materiales con mejor comportamiento, de modo que sirvan al sector productivo para establecer plantaciones comerciales

A Multiinstitutional Spanish Master’s Program in Ecosystem Restoration: Vision and Four-Year Experience

Since 2006, an innovative, multiinstitutional Spanish Master in Ecosystem Restoration (MER) is jointly offered by four major public universities in Madrid. In view of the high student demand—about 900 applications this academic year for only 30 places, a remarkable 75% rate of professional poststudy employment in a period of economic crisis, and the high number (> 40) of prestigious organizations involved in the program, we consider the MER program, although still young, to be very promising for the long term. We explain the process to create the MER and achieve the results obtained thus far. We describe its organization, report its vital statistics in terms of students, and identify some strengths and weaknesses observed to date. The MER program has evolved as a network of knowledge and experience that links universities, lecturers, researchers, students, private and public companies, NGOs, and administration centers. Our aim is to help other groups that may want to launch similar graduate-level ecological restoration degree programs

On the infinitude of prime elements

Let R be an infinite unique factorization domain with at most finitely many units. We discuss the infinitude of prime elements in R when R is arbitrary and when R satisfies the following property: if f and g are polynomials with coefficients in R such that f(r) divides g(r) for all rε R with f(r)≠ 0, then either g=0 or deg(f) ≤ deg(g).Sea R un dominio de factorización única que tiene a lo sumo un número finito de unidades. Nosotros discutimos la infinitud de elementos primos en R cuando R es arbitrario y cuando Rsatisface la siguiente propiedad: si f y g son polinomios con coeficientes en R tales que f(r)divide g(r) para todo rε R con f(r)≠ 0, entonces g=0 ó grado(f) ≤ grado(g)

Stable Extracellular RNA Fragments of Mycobacterium tuberculosis Induce Early Apoptosis in Human Monocytes via a Caspase-8 Dependent Mechanism

The molecular basis of pathogen-induced host cell apoptosis is well characterized for a number of microorganisms. Mycobacterium tuberculosis is known to induce apoptosis and it was shown that live but not heat killed M. tuberculosis stimulates this biological pathway in monocytes. The dependence of this activity on live bacilli led us to hypothesize that products released or secreted by M. tuberculosis are the primary apoptotic factors for human monocytes. Thus, the culture filtrate of in vitro grown M. tuberculosis strain H37Rv was fractioned by conventional chromatography and the apoptosis-inducing activity of individual fractions was measured on human monocytes. The tests employed included measurement of cell membrane damage, caspase activation, and cytokine release. Small molecular weight RNAs of M. tuberculosis were recognized as the predominant apoptosis inducing factors. The RNA was comprised primarily of tRNA and rRNA fragments that stably accumulate in the culture filtrate during early log-phase growth. The RNA fragments signaled through a caspase-8 dependent, caspase-1 and TNF-α independent pathway that ultimately compromised the human monocytes' ability to control M. tuberculosis infection. These studies provide the first report of bacterial RNA inducing apoptosis. They also provide a foundation to pursue pathways for secretion or release of nucleic acids from M. tuberculosis and the impact of secreted RNA fragments on pathogenesis

Los Cuadriláteros Cíclicos Como Herramienta en la Resolución de Problemas

El principal interés del libro “Los Cuadriláteros Cíclicos Como Herramienta en la Resolución de Problemas”, es introducir al lector al tema de los cuadriláteros cíclicos, los cuales son cuadriláteros que se pueden inscribir en una circunferencia. En este trabajo se exponen algunas de sus caracterizaciones, propiedades y teoremas, resaltando la importancia de su aplicación en la resolución de problemas geométricos. Este libro se encuentra dividido en dos partes: Cuadriláteros Cíclicos y Problemas. En la primera parte, se exponen preliminares geométricos que se deben tener en cuenta al abordar el estudio de los cuadriláteros cíclicos, para luego dar paso a teoremas y caracterizaciones. En la segunda parte, se presentan problemas tomados de diferentes competencias matemáticas y textos de geometría, incluyendo algunas soluciones donde el uso de las propiedades de los cuadriláteros cíclicos juegan un papel determinante, y se presenta una amplia recopilación de problemas con los que se pretende que el lector pueda practicar y adquirir más habilidades en la resolución de problemas geométricos relacionados con cuadriláteros cíclicos. Este texto hace parte de los resultados obtenidos con el proyecto de investigación “Resolución de problemas: Olimpiadas Universitarias de Matemáticas UDENAR”, financiado por la Vicerrectoría de Investigaciones, Posgrados y Relaciones Internacionales de la Universidad de Nariño

A targeted likelihood estimation comparing cefepime and piperacillin/tazobactam in critically ill patients with community-acquired pneumonia (CAP)

Cefepime and piperacillin/tazobactam are antimicrobials recommended by IDSA/ATS guidelines for the empirical management of patients admitted to the intensive care unit (ICU) with community-acquired pneumonia (CAP). Concerns have been raised about which should be used in clinical practice. This study aims to compare the effect of cefepime and piperacillin/tazobactam in critically ill CAP patients through a targeted maximum likelihood estimation (TMLE). A total of 2026 ICU-admitted patients with CAP were included. Among them, (47%) presented respiratory failure, and (27%) developed septic shock. A total of (68%) received cefepime and (32%) piperacillin/tazobactam-based treatment. After running the TMLE, we found that cefepime and piperacillin/tazobactam-based treatments have comparable 28-day, hospital, and ICU mortality. Additionally, age, PTT, serum potassium and temperature were associated with preferring cefepime over piperacillin/tazobactam (OR 1.14 95% CI [1.01–1.27], p = 0.03), (OR 1.14 95% CI [1.03–1.26], p = 0.009), (OR 1.1 95% CI [1.01–1.22], p = 0.039) and (OR 1.13 95% CI [1.03–1.24], p = 0.014)]. Our study found a similar mortality rate among ICU-admitted CAP patients treated with cefepime and piperacillin/tazobactam. Clinicians may consider factors such as availability and safety profiles when making treatment decisions

Violence witnessing, perpetrating and victimization in medellin, Colombia: a random population survey

<p>Abstract</p> <p>Background</p> <p>The burden of injury from violence and the costs attributable to violence are extremely high in Colombia. Despite a dramatic decline in homicides over the last ten years, homicide rate in Medellin, Colombia second largest city continues to rank among the highest of cities in Latin America. This study aims to estimate the prevalence and distribution of witnesses, victims and perpetrators of different forms of interpersonal violence in a representative sample of the general population in Medellin in 2007.</p> <p>Methods</p> <p>A face-to-face survey was carried out on a random selected, non-institutionalized population aged 12 to 60 years, with a response rate of 91% yielding 2,095 interview responses.</p> <p>Results</p> <p>We present the rates of prevalence for having been a witness, victim, or perpetrator for different forms of violence standardized using the WHO truncated population pyramid to allow for cross-national comparison. We also present data on verbal aggression, fraud and deception, yelling and heavy pranks, unarmed aggression during last year, and armed threat, other severe threats, robbery, armed physical aggression, and sexual aggression during the lifetime, by age, sex, marital and socioeconomic status, and education. Men reported the highest prevalence of being victims, perpetrators and witnesses in all forms of violence, except for robbery and sexual violence. The number of victims per perpetrator was positively correlated with the severity of the type of violence. The highest victimization proportions over the previous twelve months occurred among minors. Perpetrators are typically young unmarried males from lower socio-economic strata.</p> <p>Conclusions</p> <p>Due to very low proportion of victimization report to authorities, periodic surveys should be included in systems for epidemiological monitoring of violence, not only of victimization but also for perpetrators. Victimization information allows quantifying the magnitude of different forms of violence, while data on factors associated with aggression and perpetrators are necessary to estimate risk and protective factors that are essential to sound policies for violence prevention formulation.</p