Increase of the Energy Necessary to Probe Ultraviolet Theories Due to the Presence of a Strong Magnetic Field

We use the gauge gravity correspondence to study the renormalization group flow of a double trace fermionic operator in a quark-gluon plasma subject to the influence of a strong magnetic field and compare it with the results for the case at zero temperature and no magnetic field, where the flow between two fixed points is observed. Our results show that the energy necessary to access the physics of the ultraviolet theory increases with the intensity of the magnetic field under which the processes happen. We provide arguments to support that this increase is scheme independent, and to exhibit further evidence we do a very simple calculation showing that the dimensional reduction expected in the gauge theory in this scenario is effective up to an energy scale that grows with the strength of such a background field. We also show that independently of the renormalization scheme, the coupling of the double trace operators in the ultraviolet fixed point increases with the intensity of the background field. These effects combined can change both, the processes that are expected to be involved in a collision experiment at a given energy and the azimuthal anisotropy of the measurements resulting of them.Comment: 23 pages, 10 figures. Added section about renormalization scheme independenc

Razones trigonométricas

Este capítulo es nuestro informe final de la unidad didáctica sobre razones trigonométricas. Es el trabajo final de MAD, la concentración en Educación Matemática de la maestría en Educación de la Universidad de los Andes. Este trabajo nace de constatar que muchos profesores de matemáticas de grado décimo usan las razones trigonométricas como herramienta para solucionar ejercicios de resolución de triángulos, aplicados a problemas, sin tener en cuenta el contexto propio del estudiante. De otro lado, la implementación en el aula de recursos o materiales para la enseñanza de la trigonometría se ha restringido al uso de la calculadora de funciones para determinar ángulos y longitudes en función de una razón trigonométrica particular. Desde esta problemática diseñamos, implementamos y evaluamos la unidad didáctica de razones trigonométricas como propuesta de innovación en la Institución de Educación Distrital (IED) José Joaquín Castro Martínez. Esta unidad didáctica promueve la construcción del concepto razones trigonométricas a partir de situaciones que tienen sentido para el estudiante y que son cercanas a su propio contexto

Shigellosis

artículo -- Universidad de Costa Rica, Instituto de Investigaciones en Salud. 1978Shigecllosis is an infectious disease caused by Shigellae, which are bacilli with capacity to invade the mucosa of the colon and less frequently the ileum. The disease occurs spora-dically and in epidemics with mild to severe clinical manifestations. The principal symptoms in severe cases (bacillary dysentery) are abdominal cramps, fever, tenesmus, and diarrhoea. Toxicosis and dehydration are common in young children. Asymptomatic infections (healthy carriers) are rare; convalescent carriers are common, particularly in children with growth retardation or protein-energy malnutritionUniversidad de Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA

Símbolos en la construcción de esquemas Splitting

En este artículo analizamos momentos y actividades de aula en los que junto con treinta niños de 4° (8-11 años) construimos de manera consensuada algunos símbolos para la exponenciación de enteros positivos; asimismo pretendemos destacar uno de los papeles más relevantes del símbolo en la posibilidad de comprender matemáticas: la reelaboración de esquemas mediante categorización de éstos en un nuevo esquema de orden superior

Level of physical activity and degree of disability in patients with chronic low back pain

Objetivo: Determinar, en una población colombiana, el nivel de actividad física y el nivel de discapacidad en pacientes con dolor lumbar crónico y establecer la eventual existencia de asociación entre estas variables. Materiales y Métodos: En una unidad externa de rehabilitación en Manizales (Colombia), pacientes con dolor lumbar crónico completaron tanto el cuestionario de actividad física de Baecke como el de incapacidad de dolor lumbar de Oswestry. Resultados: Un total de 125 pacientes participaron en el estudio. El valor promedio del índice de Baecke fue de 7,9±0,9 con valores para hombres y mujeres de 7,8±0,1 y 8,0±0,7 respectivamente, sin que lograra demostrar una diferencia estadísticamente significativa entre los sexos. El valor promedio del índice de Oswestry fue de 40,7±18,3 con valores para hombres y mujeres de 38,4±18,8 y 42,4±17,7 respectivamente, sin que tampoco se lograra demostrar una diferencia estadísticamente significativa entre los sexos. Un valor del coeficiente de correlación de Pearson >0,05 demostró la inexistencia de relación entre el nivel de actividad física y el grado de discapacidad en los pacientes. Conclusiones: Los resultados describen una población de pacientes con dolor lumbar crónico que, comparada con lo reportado en otros estudios en estos pacientes, puede ser considerada como más activa y menos discapacitada, pero en la cual no existe correlación entre el nivel de actividad física y el grado de discapacidad. Así las cosas, los pacientes con dolor lumbar crónico parecen variar los niveles de actividad independientemente del grado de discapacidad.Objective: To determine the level of physical activity and the level of disability in patients with chronic low back pain in a Colombian population and to establish the possible association between these variables. Materials and Methods: In an outpatient rehabilitation unit in Manizales (Colombia), patients with chronic low back pain completed both the Baecke Physical Activity Questionnaire and Oswestry Lumbar Pain Inability. Results: A total of 125 patients participated in the study. The average value of the Baecke index was 7.9 ± 0.9, with values for men and women of 7.8 ± 0.1 and 8.0 ± 0.7 respectively, without being able to demonstrate a statistically significant difference between the Sexes. The average value of the Oswestry index was 40.7 ± 18.3 with average values for males and females of 38.4 ± 18.8 and 42.4±17.7 respectively. There was no statistically significant difference between the sexes. A Pearson correlation coefficient > 0.05 showed no relationship between the level of physical activity and the degree of disability in the patients. Conclusions: Results describe a population of patients with chronic low back pain who, compared to other studies in these patients, may be considered as more active and less disabled but in which there is no correlation between the level of physical activity and the degree of disability. Thus, patients with chronic low back pain appear to vary physical activity levels independently of the degree of disability

Infectious agents in acute and chronic diarrhea of chilhood

Capítulo de libro -- Universidad de Costa Rica, Instituto de Investigaciones en Salud. 1984Even today acute diarrheal disease is thought of by many laymen as well as by some medical professionals in developing countries as being a syndrome of alimentary origin. Despite recognition of shigellosis, cholera, salmonellosis, giardiasis, amebiasis, and other enteric infectious diseases, there has been much difficulty in accepting the fact that most of the "nonspecific" diarrheas in the general population were also of an infectious nature. The frequent appearance of diarrhea after onset of weaning in many animal species and in man (1) and the systematic failure in the past to find pathogenic agents in a majority of the diarrheas tended to rule out a microbial etiology. Epidemiologists, pediatricians, and microbiologists suspected that the nonspecific diarrheas of childhood were also of microbial or viral origin (2) because of their characteristics in poor urban and rural settings. First, in such ecosystems, diarrhea prevails if sanitation and personal hygiene are deficient. Second, infants and preschool children are more frequently and more severely affected than school children, adolescents, and adults, which stiggests the acquisition of immunity and host resistance. Third, acute diarrhea in the community follows a pattern similar to that of other infectious diseases in that secondary cases develop after contact with the index case, eventually resulting in self-limiting to extensive outbreaks or even epidemics of great magnitude. It is clear that if personal hygiene and environmental sanitation are deficient, diarrhea is prevalent. This explains the similarity in diarrhea morbidity and mortality between some contemporary developing nations and New York City at the turn of the century, when environmental conditions in New York were as deficient as they are today in some developing nations.Universidad de Costa Rica. Instituto de Investigaciones en SaludUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA

Public health implications of low birth weight

The present paper interpets the significance of anthropometric data of newborns from a typical Indian village of Guatemala and from the general population of Costa Rica. A good correlation exists between a deficient fetal growth and infant mortality and retarded physical growth. The significance of fetal growth retardation on early and late llnomalics and defects is discussed. The existing information reveals a high incidence of neonates with altered fetal growth and development in Latin America. This circumstance is the main factor . associated with the high infant mortality and retarded development observed in many populations of the Subcontinent. Presented at': Colloquium on "Prenatal and Perinatal Nutrition", held as part of the IV Latin American Nutrition Congress, Caracas. Venezuela, 21-27 Novar. bert 1976, under the sponsorship of the Latin American Nutrition Society (SLAN) Certain countries have attained a substantial improvement in the conditions affecting fetal growth, by implementing comprehensive health and development programs with a holistic approach. The interventions that need to be strengthened in order to improve fetal development in our nations are reviewed.El presente trabajo interpets la importancia de los datos antropométricos de los recién nacidos de un típico pueblo indígena de Guatemala y de la población general de Costa Rica. Existe una buena correlación entre un crecimiento fetal deficiente y la mortalidad infantil y el crecimiento físico retardado. La importancia de retraso del crecimiento fetal en principios y finales llnomalics y defectos se discute . La información disponible revela una alta incidencia de recién nacidos con fetal alterado el crecimiento y el desarrollo en América Latina. Esta circunstancia es el principal factor . asociado con el desarrollo y la mortalidad infantil retardado alta observada en muchas poblaciones del subcontinente . Presentado en ' : Coloquio sobre " Nutrición Prenatal y Perinatal " , celebrada en el marco del IV Congreso Latinoamericano de Nutrición , Caracas . Venezuela , 21-27 de Novar . bert 1976 , bajo el patrocinio de la Sociedad Latinoamericana de Nutrición ( SLAN ) Algunos países han alcanzado una mejora sustancial en las condiciones afectar el crecimiento fetal , mediante la implementación integral de la salud y el desarrollo programas con un enfoque holístico . Las intervenciones que necesitan ser fortalecidas con el fin de mejorar el desarrollo del feto en nuestras naciones son revisados ​​....UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA

Razones trigonométricas: una experiencia de aula

Este documento contiene el análisis realizado en la fase de implementación a una de las tareas contenidas en la unidad didáctica razones trigonométricas. Tal unidad, fue el resultado de la investigación que realizamos al adelantar nuestros estudios de maestría. La primera parte busca justificar algunas de las razones consideradas para el desarrollo de la propuesta. Seguido a esto, construimos una caracterización de los referentes usados en la perspectiva del análisis didáctico. Luego, mostramos el estudio de caso a una tarea, describiendo las previsiones y los elementos de análisis anteriores a la fase de implementación, junto con las acciones realizadas por los estudiantes en contraste con las acciones previstas. Por último, se presentan unas reflexiones en torno a las debilidades y fortalezas encontradas en la implementación de la tarea y de los aportes de este trabajo a nuestra formación profesional

Rainbow polygons for colored point sets in the plane

Given a colored point set in the plane, a perfect rainbow polygon is a simple polygon that contains exactly one point of each color, either in its interior or on its boundary. Let $\operatorname{rb-index}(S)$ denote the smallest size of a perfect rainbow polygon for a colored point set $S$, and let $\operatorname{rb-index}(k)$ be the maximum of $\operatorname{rb-index}(S)$ over all $k$-colored point sets in general position; that is, every $k$-colored point set $S$ has a perfect rainbow polygon with at most $\operatorname{rb-index}(k)$ vertices. In this paper, we determine the values of $\operatorname{rb-index}(k)$ up to $k=7$, which is the first case where $\operatorname{rb-index}(k)\neq k$, and we prove that for $k\ge 5$, $$\frac{40\lfloor (k-1)/2 \rfloor -8}{19} \leq\operatorname{rb-index}(k)\leq 10 \bigg\lfloor\frac{k}{7}\bigg\rfloor + 11.$$ Furthermore, for a $k$-colored set of $n$ points in the plane in general position, a perfect rainbow polygon with at most $10 \lfloor\frac{k}{7}\rfloor + 11$ vertices can be computed in $O(n\log n)$ time.Comment: 23 pages, 11 figures, to appear at Discrete Mathematic

Types and Distribution of Bioactive Polyunsaturated Aldehydes in a Gradient from Mesotrophic to OligotrophicWaters in the Alborán Sea (Western Mediterranean)

Polyunsaturated aldehydes (PUAs) are bioactive molecules suggested as chemical defenses and infochemicals. In marine coastal habitats, diatoms reach high PUA production levels during bloom episodes. Two fractions of PUA can usually be analyzed: pPUA obtained via artificial breakage of collected phytoplankton cells and dissolved PUA already released to the environment (dPUA). In nature, resource supply arises as a main environmental controlling factor of PUA production. In this work, we monitored the vertical distribution and daily variation of pPUA associated with large-size phytoplankton and dPUA, at three sites located in the Alboran Sea from mesotrophic to oligotrophic waters. The results corroborate the presence of large-size PUA producers in oligotrophic and mesotrophic waters with a significant (58%-85%) diatom biomass. In addition to diatoms, significant correlations between pPUA production and dinoflagellate and silicoflagellate abundance were observed. 2E,4E/Z-Heptadienal was the most abundant aldehyde at the three sites with higher values (17.1 fg center dot cell(-1)) at the most oligotrophic site. 2E,4E/Z-Decadienal was the least abundant aldehyde, decreasing toward the oligotrophic site. For the first time, we describe the daily fluctuation of pPUA attributable to cellular physiological state and not exclusively to taxonomical composition. Our results demonstrate the persistence of threshold levels of dPUA deep in the water column, as well as the different chromatographic profiles of dPUA compared with pPUA. We propose different isomerization processes that alter the chemical structure of the released PUAs with unknown effects on their stability, biological function, and potential bioactivity