Power Counting of Contact-Range Currents in Effective Field Theory

We analyze the power counting of two-body currents in nuclear effective field theories (EFTs). We find that the existence of non-perturbative physics at low energies, which is manifest in the existence of the deuteron and the 1S0 NN virtual bound state, combined with the appearance of singular potentials in versions of nuclear EFT that incorporate chiral symmetry, modifies the renormalization-group flow of the couplings associated with contact operators that involve nucleon-nucleon pairs and external fields. The order of these couplings is thereby enhanced with respect to the naive-dimensional-analysis estimate. Consequently, short-range currents enter at a lower order in the chiral EFT than has been appreciated up until now, and their impact on low-energy observables is concomitantly larger. We illustrate the changes in the power counting with a few low-energy processes involving external probes and the few-nucleon systems, including electron-deuteron elastic scattering and radiative neutron capture by protons.Comment: 5 pages. Minor revisions. Conclusions unchanged. Version to appear in Physical Review Letter

Spatial expansions and travelling waves of rabies in vampire bats

A major obstacle to anticipating the cross-species transmission of zoonotic diseases and developing novel strategies for their control is the scarcity of data informing how these pathogens circulate within natural reservoir populations. Vampire bats are the primary reservoir of rabies in Latin America, where the disease remains among the most important viral zoonoses affecting humans and livestock. Unpredictable spatiotemporal dynamics of rabies within bat populations have precluded anticipation of outbreaks and undermined widespread bat culling programs. By analysing 1146 vampire bat-transmitted rabies (VBR) outbreaks in livestock across 12 years in Peru, we demonstrate that viral expansions into historically uninfected zones have doubled the recent burden of VBR. Viral expansions are geographically widespread, but severely constrained by high elevation peaks in the Andes mountains. Within Andean valleys, invasions form wavefronts that are advancing towards large, unvaccinated livestock populations that are heavily bitten by bats, which together will fuel high transmission and mortality. Using spatial models, we forecast the pathways of ongoing VBR epizootics across heterogeneous landscapes. These results directly inform vaccination strategies to mitigate impending viral emergence, reveal VBR as an emerging rather than an enzootic disease and create opportunities to test novel interventions to manage viruses in bat reservoirs

Externalidades de información y la duración de las actividades de exportación a nivel de firma. Evidencia para Colombia

Estudios recientes enfatizan la importancia del margen extensivo (nuevos exportadores y nuevas actividades de exportación) para el crecimiento de las exportaciones en el largo plazo. De ahí que la duración de los nuevos exportadores en el mercado se constituya en un mecanismo importante para promover el crecimiento de las exportaciones. Dado que la actividad de los nuevos exportadores se caracteriza por una baja duración, es de interés académico y de política, indagar por los factores quela determinan. Este trabajo evalúa si las externalidades de información que se producen como resultado de la aglomeración de actividades de exportación en elespacio, llevan a que los exportadores desarrollen mejores estrategias y aumenten su duración en el mercado de exportación. Para esto se usan datos de las exportaciones de Colombia a nivel de transacción para el periodo 2004-2011. Los resultados muestran que la presencia de redes de exportación reduce el riesgo que enfrenta la actividad de exportación de una firma de salir del mercado y este impacto es más fuerte si las redes de exportación son más similares a la actividad de exportación que realiza la firma

Competitiveness of Colombian Departments observed from an Economic geography Perspective

SummaryIn this paper, we analyze the regional competitiveness concept and its measurement using the old and New Trade Theory and the New Economic Geography. The analysis shows that the competitiveness has no sense when is applied to the goods market, while has sense (however, not in all situations) when is applied to the productive factors market. Contrary to most approaches and measurements of the competitiveness of Colombian departments, we show that is possible to obtain simple measures which, in addition to being consistent with the conceptual framework of economic geography, are the product of the combination of a small number of variablesRegional competitiveness, New Trade Theory, Economic Geography, Colombian departments, Competitiveness Ranking

Técnicas de fijación interna asociadas a neuropatía radial en fracturas de diáfisis humera

Objetivo: Determinar qué tipo de técnica de fijación interna esta menos asociada al desarrollo de neuropatía radial en fracturas de diáfisis humeral. Material y Métodos: Estudio observacional – analítico, retrospectivo en 30 pacientes con el diagnóstico de fractura de diáfisis humeral postoperados con la técnicas de Reducción abierta con fijación interna (CPO) y la técnica mínimamente invasiva con placa (MIPO), a su vez divididos en dos grupos; 15 pacientes con neuropatía radial secundaria y 15 pacientes sin neuropatía radial secundaria o postoperatoria según los antecedentes de sus historias clínicas en el Hospital Víctor Lazarte Echegaray. Todos los pacientes fueron de ambos sexos, mayores de 18 años con un mínimo de un año desde su cirugía; se les aplicó el test de Quick DASH para evaluar el grado de discapacidad funcional del miembro superior relacionada a neuropatía radial. Resultados: Del total de la muestra, 18 pacientes (60%) fueron operados con CPO, de estos 18 pacientes, 12 presentaron neuropatía y 6 no lo hicieron; los intervenidos con MIPO fueron 12 pacientes (40%), de los cuales solo 3 presentaron neuropatía y 9 no la presentaron. De acuerdo al sexo, 14 pacientes (46,7%) fueron mujeres y 16 pacientes (53,3%) fueron varones, todos con una edad promedio de 48,3 años (rango, 18-80 años). Respecto al IMC, 26 pacientes (86,7%) tenían sobrepeso, 2 pacientes (6,7%) tenían obesidad y 2 pacientes (6,7%) tenían peso normal. Según el tipo de fractura se encontró 8 casos (26%) de tipo 12C.1, 7 casos (23%) de tipo 12B.2, 6 casos (20%) de tipo 12C.2, 6 casos (20%) de tipo 12C.3 y 3 casos (10%) de tipo 12A.1. Respecto a las comorbilidades 22 pacientes (73,3%) no tenía ninguna patología subyacente previa a la cirugía, solo 5 casos (16,7%) padecía de osteoporosis y 3 casos (10%) de diabetes mellitus tipo 2. Los 30 pacientes (100%) no presentaron complicaciones postoperatorias tempranas. Solo 2 pacientes (6,7%) desarrollaron pseudoartrosis y 28 pacientes (93,3%) llegaron a la consolidación completa. Se encontró menor asociación estadísticamente significativa (p=0,025) entre la MIPO y la neuropatía, comparada a la CPO y ningún resultado significativo de los variables intervinientes respecto a la neuropatía (p > 0,05). Conclusiones: La técnica MIPO está menos asociada a la neuropatía radial que la CPO de forma significativa y es una opción terapéutica confiable y segura, incluso en huesos osteoporóticos, preserva y previene el daño local a los tejidos blandos además logra un tiempo de consolidación menor al de otras técnicas de osteosíntesis.Objective: To determine what type of internal fixation technique is least associated with the development of radial neuropathy in humeral shaft fractures. Material and Methods: Observational - analytical, retrospective study in 30 patients with the diagnosis of postoperative humeral shaft fracture with the techniques of Open reduction with internal fixation (PCO) and the minimally invasive technique with plate (MIPO), in turn divided into two groups; 15 patients with secondary radial neuropathy and 15 patients without secondary or postoperative radial neuropathy according to the history of their medical records at the Víctor Lazarte Echegaray Hospital. All patients were of both sexes, older than 18 years with a minimum of one year since their surgery; The Quick DASH test was applied to assess the degree of functional disability of the upper limb related to radial neuropathy. Results: Of the total sample, 18 patients (60%) were operated on with PCO, of these 18 patients, 12 had neuropathy and 6 did not; 12 patients (40%) operated on with MIPO, of which only 3 had neuropathy and 9 did not. According to sex, 14 patients (46.7%) were women and 16 patients (53.3%) were men, all with a mean age of 48.3 years (range, 18-80). Regarding BMI, 26 patients (86.7%) were overweight, 2 patients (6.7%) were obese, and 2 patients (6.7%) were normal weight. According to the type of fracture, 8 cases (26%) of type 12C.1 were found, 7 cases (23%) of type 12B.2, 6 cases (20%) of type 12C.2, 6 cases (20%) of type 12C.3 and 3 cases (10%) of type 12A.1. Regarding comorbidities, 22 patients (73.3%) did not have any underlying pathology prior to surgery, only 5 cases (16.7%) suffered from osteoporosis and 3 cases (10%) from type 2 diabetes mellitus. The 30 patients (100%) did not present early postoperative complications. Only 2 patients (6.7%) developed pseudarthrosis and 28 patients (93.3%) reached complete union. A statistically significant less association (p = 0.025) was found between MIPO and neuropathy, with respect to PCO and no significant result of the intervening variables with respect to neuropathy (p> 0.05). Conclusions: The MIPO technique is significantly less associated with radial neuropathy than CPO and is a reliable and safe therapeutic option, even in osteoporotic bones, it preserves and prevents local tissue damage, and also achieves a consolidation time shorter than that of other osteosynthesis techniques.Tesi

Does the type of study on Covid-19 influence the value of Altmetrics?

More than half of the News mentions are not analyzed because period studied is very recent, while volume of information about Covid-19 is high. Scientific evidence Pyramid is well reflected by the Altmetric Attention Score. At the forefront we find Consensus development conferences & guidelines, given their great utility in a period of such uncertainty about the pandemic and the fact that they are usually backed by international organizations. Consensus development conferences are a way to bring together citizens, decision-makers and experts to address issues of public importance. Involve a series of experts who deliver scientific evidence on a subject. This category is followed by Clinical trials, at the peak of the pyramid of scientific evidence, since their results are highly valid and it can be considered the flame of scientific knowledge. Behind these two are the Systematic reviews and Meta-analyses, with similar values. On the other hand, Systematic review attempts to gather all available empirical research by using clearly defined systematic methods to obtain answers to a specific question. A meta-analysis is the statistical process of analyzing and combining results from several similar studies. Reviews, in addition to their educational component, are hypothesis generators, which is very important to analize a new topic such as Covid-19. The lowest values in all the altmetrics were Case reports; although they are useful to start a clinical investigation, is the base of the pyramid. The graphic trends of Twitter mentions and the Altmetric Attention Score are nearly identical, due to AAS collects the 95% of Twitter mentions. We can conclude that altmetric in biomedical research, specifically in the covid research front, could be highly determined by the type of study, and that altmetric can capture the utility or altmetric at attention marker

Museo Patrimonial del municipio de Marmato (Caldas) : desarrollo de la propuesta de museo virtual

El patrimonio cultural del municipio de Marmato (Caldas) está en riesgo de desaparecer debido al desplazamiento de su casco urbano para llevar a cabo proyectos de Gran Minería de en su territorio. Se descubrió una inmensa oportunidad de trabajo y análisis con miras a rescatar, organizar y difundir todo este legado histórico y cultural. Marmato, con más de 470 años de antigüedad, es uno de los municipios más antiguos de Colombia y el segundo territorio de mayor producción aurífera. Es un municipio muy diverso culturalmente ya que lo habitan indígenas y poblaciones afro-colombianas, con el objetivo de dar a conocer toda su riqueza cultural y ancestral, se propone el desarrollo de un Museo Virtual construido con base en estructuras y teorías de la Ciencia de la Información y la Bibliotecología, en relación estrecha con la museología. Se proponen igualmente estrategias de usabilidad, accesibilidad, posicionamiento web y pedagogía con el objetivo que toda esta riqueza expuesta sea conocida y reconocida por ciudadanos de cualquier parte del mundo.Profesional en Ciencia de la Información - Bibliotecólogo (a)Pregrad

Enseñanza de la astronomía, tensiones y distensiones frente al quehacer docente

Se propone una serie de reflexiones sobre el quehacer docente en la enseñanza de la astronomía, encontrando que las principales dificultades que tiene dicha enseñanza están ligadas a la escasa formación de docentes en el área, ante un panorama de mayor curiosidad e interacción con conocimientos astronómicos por pare del estudiantado colombiano. A partir de lo anterior se reconocen algunas alternativas de cambio y posibles distensiones, generadas desde la sugerencia de fortalecer la formación en el campo de la docencia en astronomía en la formación de las facultades de educación, de igual manera una perspectiva distinta del quehacer docente frente al conocimiento, pasando de transmitir o transferir conocimiento, a construir con los estudiantes. Finalmente se muestra un proceso de construcción experiencial que ha permitido la interacción entre científicos, docente y estudiantes, para el análisis de conocimientos astronómicos en el departamento de Boyacá en Colombia

¿Están las bibliotecas públicas mejorando la calidad de la educación? Cuando la provisión de bienes públicos no es suficiente

We analyze the relation between public, education-related infrastructure and the quality of education in schools using a case-study of the construction and implementation of two large public libraries in low-income areas in Bogotá, Colombia. We assess the impact of these libraries on quality of education by comparing results in national test scores (Saber 11°) for schools close and far from these libraries before (2000-2002) and after (2003-2008) the libraries’ opening. We find non-statistically different from zero differences that could be attributed to the libraries’ implementation. We also introduce Oaxaca-Blinder decomposition on Difference-in-Differences (DiD) estimates in order to assess if variation of traditional determinants of test scores for mathematics, verbal and science explain the result estimates. These results are robust to alternative specifications of DiD, a synthetic control approach and an alternative measure of distance