Universal temporal features of rankings in competitive sports and games

Many complex phenomena, from the selection of traits in biological systems to hierarchy formation in social and economic entities, show signs of competition and heterogeneous performance in the temporal evolution of their components, which may eventually lead to stratified structures such as the wealth distribution worldwide. However, it is still unclear whether the road to hierarchical complexity is determined by the particularities of each phenomena, or if there are universal mechanisms of stratification common to many systems. Human sports and games, with their (varied but simplified) rules of competition and measures of performance, serve as an ideal test bed to look for universal features of hierarchy formation. With this goal in mind, we analyse here the behaviour of players and team rankings over time for several sports and games. Even though, for a given time, the distribution of performance ranks varies across activities, we find statistical regularities in the dynamics of ranks. Specifically the rank diversity, a measure of the number of elements occupying a given rank over a length of time, has the same functional form in sports and games as in languages, another system where competition is determined by the use or disuse of grammatical structures. Our results support the notion that hierarchical phenomena may be driven by the same underlying mechanisms of rank formation, regardless of the nature of their components. Moreover, such regularities can in principle be used to predict lifetimes of rank occupancy, thus increasing our ability to forecast stratification in the presence of competition

Rodríguez del Rosal, Eduardo

Se describen los valores de diferentes parámetros químicos en 60 ovinos de la raza Tabasco o Pelibuey en Hueytamalco, Pue. Los animales fueron separados en grupos de acuerdo al sexo y edad: machos adultos enteros, hembras adultas en lactación, machos y heInstituto Nacional de Investigaciones Forestales, Agrícolas y Pecuaria

Hernández Ortíz, Rubén

El presente trabajo se llevó a cabo para conocer el efecto de la Ivermectina sobre la garrapata común del ganado (Boophilus microplus). Se emplearon ocho bovinos Hereford infestados artificialmente con 10,000 larvas en tres ocasiones a Intervalos de nueveInstituto Nacional de Investigaciones Forestales, Agrícolas y Pecuaria

Resistencia natural contra la tuberculosis en ganado. Revisión

Bovine tuberculosis (bTB) is a chronic disease of cattle and other animal species caused by Mycobacterium bovis. The importance of bTB is that it represents a risk to public health, and causes economic losses to the livestock industry. Because of this, many countries have established control and eradication programs with partial success. Therefore, the search for new strategies to control this disease is relevant. In Mexico, the prevalence of bTB is estimated in 16 % in dairy cattle and in less than 1 % in beef cattle; however, field studies have proved that in spite of the high prevalence in some herds (25-35 %), and long periods of exposure (3 to 5 yr average), the prevalence never reaches 100 %; this suggests that some animals are naturally resistant to tuberculosis. Considering that clinical manifestation of bTB depends on the interaction of various factors, it is reasonable to think that genetic variations in the host can be associated to resistance to this disease. This review, presents the state of the art in this matter; it describes the results of studies performed in different animal species and humans with the purpose of detecting genetic variation associated with disease resistance. The main genes associated with resistance are described and discussed individually. The conclusion is that genetic variation in cattle is associated with resistance to tuberculosis, and that this variation can be identified, measured, and incorporated into the current process of animal selection in the livestock industry to obtain animals more resistant to infection.En México, la prevalencia de tuberculosis bovina se estima en 16% en ganado para leche, y en poco menos del 1% para ganado para carne, sin embargo, observaciones de campo indican que, a pesar de las altas prevalencias en algunos hatos (25-35%) y la exposición por largos periodos, la prevalencia nunca llega al 100%, lo que sugiere que algunos animales son naturalmente resistentes a la enfermedad. Considerando que la manifestación clínica de la tuberculosis depende de la interacción de factores del hospedero, del patógeno y del medio ambiente, es lógico pensar que las variaciones genéticas en el hospedero pueden estar asociadas a resistencia o susceptibilidad a esta enfermedad. En este trabajo se presenta el resultado de una revisión minuciosa de los reportes en la literatura sobre este tema. Se describen de manera resumida los trabajos realizados con el objetivo de identificar variaciones genéticas entre individuos que manifiestan la enfermedad y aquellos que no enferman en diferentes especies: conejos, venado, bovinos y otros, incluyendo al humano. Se hace mención especial en los genes más frecuentemente relacionados con resistencia, por ejemplo el gen Nramp1, y la manera en que estos están asociados a factores del hospedero, tales como la respuesta inmune. Se concluye que es posible identificar elementos moleculares que lleven a la selección genética de animales resistentes a la tuberculosis, y a otras enfermedades, que pueden ser incorporados a los procesos ya existentes de selección de ganado

Granulomatosis alérgica con presentación inusual

La granulomatosis alérgica es poco frecuente y de causa desconocida. La prostatitis como parte de la extensión de esta enfermedad es rara, sólo existen 12 casos reportados en la literatura. Se presenta un paciente de 26 años de edad, mestizo, con antecedentes de asma bronquial alérgica en la niñez, que en 1993 ingresó por manifestaciones disúricas. Se le detecta tumoración prostática que se concluye histológicamente como prostatitis granulomatosa alérgica. Se comenzó tratamiento con 60 mg de prednisona oral en dosis decrecientes; 1 año después. cuando el mantenimiento es de 5 mg en días alternos, presenta fiebre y aparece eritema nudoso en la porción interna de ambos pies. Se constata eosinofilia periférica y la histología de estos nódulos coincide con la de la próstata, se concluye como una granulomatosis alérgica. Al aumentar la dosis de esteroides desaparecieron completamente las manifestaciones. Se hace una revisión de esta entidad sin encontrar casos de prostatitis como su inicio

Molecular epidemiology of cattle tuberculosis in Mexico through whole-genome sequencing and spoligotyping.

Mycobacterium bovis infection in cattle persists in Mexico, posing a threat to human health. Control of bovine tuberculosis, through the National Program Against Bovine Tuberculosis, has led to the decrease of disease prevalence in most of the country, except for high dairy production regions. Genotyping of M. bovis has been performed mainly by spoligotyping and variable number tandem repeats (VNTR), but higher resolution power can be useful for a finer definition of the spread of the disease. Whole genome sequencing and spoligotyping was performed for a set of 322 M. bovis isolates from different sources in Mexico: Baja California, Coahuila, Estado de Mexico, Guanajuato, Hidalgo, Jalisco, Queretaro and Veracruz, from dairy and beef cattle, as well as humans. Twelve main genetic clades were obtained through WGS and genetic diversity analysis. A clear differentiation of the Baja California isolates was seen as they clustered together exclusively. However, isolates from the central states showed no specific clustering whatsoever. Although WGS proves to have higher resolving power than spoligotyping, and since there was concordance between WGS and spoligotyping results, we consider that the latter is still an efficient and practical method for monitoring bovine tuberculosis in developing countries, where resources for higher technology are scarce