Quintom fields from chiral anisotropic cosmology

In this paper we present an analysis of a chiral anisotropic cosmological scenario from the perspective of quintom fields. In this setup quintessence and phantom fields interact in a non-standard (chiral) way within an anisotropic Bianchi type I background. We present our examination from two fronts: classical and quantum approaches. In the classical program we find analytical solutions given by a particular choice of the emerged relevant parameters. Remarkably, we present an explanation of the ''big-bang'' singularity by means of a ''big-bounce''. Moreover, isotropization is in fact reached as the time evolves. On the quantum counterpart the Wheeler-DeWitt equation is analytically solved for various instances given by the same parameter space from the classical study, and we also include the factor ordering $\rm Q$. Having solutions in this scheme we compute the probability density, which is in effect damped as the volume function and the scalar fields evolve; and it also tends towards a flat FLRW framework when the factor ordering constant $\rm Q \ll 0$. This result might indicate that for a fixed set of parameters, the anisotropies quantum-mechanically vanish for very small values of the parameter $\rm Q$. Finally, classical and quantum solutions reduce to their flat FLRW counterparts when the anisotropies vanish.Comment: 14 pages, 4 figure

Factores fisiológicos y sociales asociados a la masa corporal de jóvenes mexicanos con discapacidad intelectual

Este artículo pretende analizar algunos factores fisiológicos y sociales asociados a la masa corporal de jóvenes con discapacidad intelectual del norte de México

Movement velocity can be used to estimate the relative load during the bench press and leg press exercises in older women

Background: Movement velocity has been proposed as an effective tool to prescribe the load during resistance training in young healthy adults. This study aimed to elucidate whether movement velocity could also be used to estimate the relative load (i.e., % of the one-repetition maximum (1RM)) in older women. Methods: A total of 22 older women (age = 68.2 ± 3.6 years, bench press 1RM = 22.3 ± 4.7 kg, leg press 1RM = 114.6 ± 15.9 kg) performed an incremental loading test during the free-weight bench press and the leg press exercises on two separate sessions. The mean velocity (MV) was collected with a linear position transducer. Results: A strong linear relationship between MV and the relative load was observed for the bench press (%1RM = -130.4 MV + 119.3; r2 = 0.827, standard error of the estimate (SEE) = 6.10%1RM, p < 0.001) and leg press exercises (%1RM = -158.3 MV + 131.4; r2 = 0.913, SEE = 5.63%1RM, p < 0.001). No significant differences were observed between the bench press and leg press exercises for the MV attained against light-medium relative loads (>70%1RM), while the MV associated with heavy loads (>80%1RM) was significantly higher for the leg press. Conclusions: These results suggest that the monitoring of MV could be useful to prescribe the loads during resistance training in older women. However, it should be noted that the MV associated with a given %1RM is significantly lower in older women compared to young healthy individuals

The Secret Life of Translation Initiation in Prostate Cancer

Prostate cancer (PCa) is the second most prevalent cancer in men worldwide. Despite the advances understanding the molecular processes driving the onset and progression of this disease, as well as the continued implementation of screening programs, PCa still remains a significant cause of morbidity and mortality, in particular in low-income countries. It is only recently that defects of the translation process, i.e., the synthesis of proteins by the ribosome using a messenger (m)RNA as a template, have begun to gain attention as an important cause of cancer development in different human tissues, including prostate. In particular, the initiation step of translation has been established to play a key role in tumorigenesis. In this review, we discuss the state-of-the-art of three key aspects of protein synthesis in PCa, namely, misexpression of translation initiation factors, dysregulation of the major signaling cascades regulating translation, and the therapeutic strategies based on pharmacological compounds targeting translation as a novel alternative to those based on hormones controlling the androgen receptor pathway

Síntesis y caracterización de grafeno, por del método de Hummers y posterior reducción térmica con ácido ascórbico

La síntesis de grafeno se lleva a cabo en dos etapas importantes: oxidación y reducción, mejor conocidos como Óxido de Grafeno (GO) y Grafeno reducido (rG), estos han ido tomando relevancia en la investigación. El óxido de grafeno se comporta como un buen aislante, además se le atribuyen propiedades antibacterianas. El método de Hummers (Hummers, W. S.; Offeman 1958) resulta ser el más eficiente para la oxidación del grafito. Después del proceso de oxidación, es la reducción del óxido de grafeno. Los métodos de reducción de GO puede clasificarse en dos grupos: métodos químicos y métodos térmicos, obteniéndose productos que se aproximan al grafeno en diferentes grados estructurales y en consecuencia en sus propiedades eléctricas, térmicas y mecánicas; el rG presenta menor conductividad eléctrica que el grafeno, pero actualmente se están desarrollando prototipos innovadores junto con el grafeno, como fotodetectores, microprocesadores, pantallas planas flexibles para la telefonía móvil, ultracapacitadores, fotodetectores, baterías, reductoras de contaminantes y una amplia gama de aplicaciones (Ghosh, 2008).Graphene synthesis is carried out in two major phases: oxidation and reduction, better known as graphene oxide (GO) and reduced graphene (rG) have become increasingly relevant in the investigation. Graphene oxide acts as a good insulator, besides antibacterial properties are attributed. Hummers (Hummers, W. S.; Offeman 1958 method turns out to be the most efficient for the oxidation of graphite. After the oxidation process, it is reduced graphene oxide. The GO reduction methods can be classified into two groups: chemical methods and thermal methods, yielding products that approach the graphene in different structural levels and consequently on their electrical, thermal and mechanical properties; The RG has lower electrical conductivity than the graphene, but currently are developing innovative prototypes with graphene, such as photodetectors, microprocessors, flexible mobile flat screens, ultracapacitors, photodetectors, batteries, reducing pollutant and a wide range of applications (Ghosh, 2008)

Borg’s category ratio-scale (CR-10) is useful to predict the onset of blood lactate accumulation (OBLA) in young Mexicans adults, regardless their body mass

Objetivo: evaluar el valor predictivo de la escala de Borg (CR-10; 1-10) para el inicio de la acumulación de lactato en sangre (OBLA). Métodos: 91 jóvenes mexicanos realizaron tres pruebas de ejercicio submáximas no consecutivas. La frecuencia cardíaca (FC), el lactato en sangre y el consumo de oxígeno se registraron en cada determinación del CR-10. Se calcularon ecuaciones de regresión y los puntos de corte de FC y al OBLA. Resultados: La FC (86 lat/min) y el CR-10 (4.5) predijeron el OBLA con la misma certeza, independientemente de la masa corporal del sujeto. CR-10, la FC y el consumo de oxígeno explicaron independientemente más de 60% de la varianza asociada al OBLA. Conclusiones: CR-10 es útil para predecir el OBLA con casi la misma certeza que la FC, independientemente de la masa corporal del sujeto. Introductio

Evaluación del efecto antimicrobiano de saponita de Cu y Cu/Mg

Una vez realizada la síntesis y caracterización de Saponita, se procede a la preparación de sensidiscos con Mg, Al, Cu, en diferentes concentraciones, el Cu posee propiedades bactericidas es un inhibidor natural de crecimiento de microorganismos, de Igual manera Al y Mg, las características de las arcillas, nos permiten dopar estos materiales siendo así utilizados como catalizador, ya que presenta una alta acidez superficial por sustituciones isomórficas en la capa tetraédrica y con la incorporación de iones metálicos obtendremos materiales con diferentes propiedades de tipo bactericida, catalizador o aislante. El objetivo de este proyecto es emplear y comprobar la efectividad de las arcillas dopadas con diferentes concentraciones de Cu, Mg y Al, para realizar una evaluación el efecto bactericida e inhibitorio de estos materiales contra distintos agentes etiológicos en una prueba tipo antibiograma.After the synthesis and characterization of saponite, proceed to preparation sensidiscs with Mg, Al, Cu, in different concentrations, Cu has bactericidal properties is a natural inhibitor of growth of microorganisms, likewise Al and Mg, the characteristics of clays, allow us undoped these materials thus being used as a catalyst, and having a high surface acidity of isomorphic substitutions in the tetrahedral layer and the incorporation of metal ions obtain materials with different properties bactericidal type, catalyst or insulating. The objective of this project is to use and test the effectiveness of clays doped with different concentrations of Cu, Mg and Al, for an evaluation bactericidal and inhibitory effect of these materials against different etiologic agents in antibiogram test type

Diversidad de Coleoptera (Insecta) en dos comunidades vegetales del rancho Teseachi, Chihuahua, México

Coleoptera is one of the most diverse and studied order of insects. However, knowledge of its diversity in Chihuahua is scarce. In this study, the diversity of beetles in two plant communities (Navajita grass pasture and oak-pine forest) was compared. The collections were made monthly through a period of six months, from June to November of 2018. Transects were defined in both communities where two methods of collection were used (manual and pitfall traps). We determined the species richness and abundance for each plant community. To assess the diversity of Coleoptera species per vegetation type, a species effective method was performed. To evaluate the change in relative abundances, a range-abundance curve was graphed, and a non-metric multidimensional scaling was performed in order to evaluate the similarity between communities. 209 organisms were obtained, represented by 12 families, 29 genera and 42 morpho species and species. The largest number of individuals and species was found in the Oak-pine forest. However, the index showed that there is greater diversity in grasslands (16.6 effective species) than in the oak-pine forests (8.5 effective species). The similarity between communities was low, which may be determined by the presence of associated exclusive species for each type of forest community (20 for the pine-oak forest and 14 for the grassland) 13 species, seven genera and one family are listed as new records for the state of Chihuahua.Los coleópteros son el orden de insectos más diverso y estudiado del mundo. Sin embargo, el conocimiento de su diversidad en Chihuahua es escaso. En este estudio se comparó la diversidad de coleópteros en dos comunidades vegetales (pastizal de zacate navajita y bosque de encino-pino). Las colectas se realizaron mensualmente en un periodo de seis meses, de junio a noviembre de 2018. Se definieron transectos lineales en ambas comunidades donde se emplearon dos métodos de recolecta. Se determinó la riqueza específica y la abundancia para cada comunidad vegetal. Para evaluar la diversidad de especies de coleópteros para cada tipo de vegetación, se utilizó el método del número de especies efectivas. Para evaluar cómo cambian las abundancias relativas se utilizó una curva de rango-abundancia y se realizó un escalamiento multidimensional no-métrico para evaluar la similitud entre comunidades. Se obtuvo un total de 209 individuos, clasificados en 12 familias, 29 géneros y 42 especies y morfo especies. El mayor número de individuos y de especies se encontró en el bosque de encino-pino. Sin embargo, los índices demostraron que existe una mayor diversidad en los pastizales (16.6 especies efectivas) comparada con los bosques de encino-pino (8.5 especies efectivas). La similitud entre comunidades fue baja, lo cual puede estar determinada por la presencia de especies exclusivas asociadas para cada comunidad (20 para el bosque de pino-encino y 14 para el pastizal). Se enlistan 13 especies, siete géneros y una familia como nuevos registros para el estado de Chihuahua

Propuesta de una secuencia didáctica en la enseñanza del tema “ácidos y bases” en el nivel secundaria

En este trabajo se analizan las ideas previas sobre el conocimiento del tema ácido-base de un grupo de estudiantes de la Escuela Secundaria Técnica No. 15 “Prof. Joaquín Arroyo Herrera”, ubicada en el Estado de Tlaxcala, se diseña una secuencia didáctica como propuesta para modificar sus concepciones previas y de esta forma obtengan una construcción de su conocimiento. La secuencia didáctica que se presenta incluye actividades experimentales resaltando la importancia del aprendizaje por experimentación debido a que los contenidos de los cursos de química no deben presentarse con un énfasis teórico y abstracto, pues ello provocaría la animadversión en los estudiantes. Los resultados revelan que la aplicación de la secuencia didáctica permitió a los estudiantes obtener un aprendizaje significativo y profundo, con una mejor comprensión de los conceptos y principios químicos relacionados con característica y propiedades de los ácidos y bases a nivel macroscópico lo cual se manifiesta una mejor percepción hacia el tema.In this work the previous ideas about knowledge of acid-base issue of a group of students from the Technical High School No. 15 discusses "Prof. Joaquin Arroyo Herrera ", located in the state of Tlaxcala, a teaching sequence as a proposal to modify their preconceptions and thus obtain a construction of knowledge is designed. The didactic sequence presented includes experimental activities highlighting the importance of learning by experimentation because the contents of chemistry courses should not be presented with a theoretical and abstract emphasis, as this would cause animosity among students. The results show that the application of the teaching sequence allowed students to obtain a meaningful and deep learning, with a better understanding of the concepts and principles related to chemical characteristic properties of acids and bases at the macroscopic level which is manifested better perception towards the issue

Axillobifemoral bypass for total abdominal occlusion secondary to Takayasu's arteritis:A case report

INTRODUCTION: Takayasu's arteritis (TA) is a rare disease that mainly affects large arteries. Approximately 20% of TA patients will require surgical intervention secondary to arterial complications such as intermittent claudication, persistent hypertension refractory to treatment, and heart failure. PRESENTATION OF CASE: The case of a 22-year-old female with TA of five years of evolution is presented. The patient deteriorated clinically after five years of corticosteroid and immunosuppressant management requiring surgical intervention with an axillobifemoral bypass for a total abdominal occlusion. Onset, pre-surgical and post-surgical Doppler ultrasonography as well as abdominal angiotomographies document and corroborate the patient's clinical and hemodynamic improvement. DISCUSSION: Very limited literature exists regarding surgical interventions for TA patients. While most reported cases present an endovascular surgical management. Open surgical procedures have lower rates of restenosis than endovascular management. Although endovascular management is less invasive than extra-anatomical axillobifemoral bypass, the patient was not a candidate for endovascular stent graft placement due to the increased risk for vascular injury and subsequent perforation. Approximately a fifth of TA patients are candidates for surgical intervention over time. CONCLUSION: Vascular surgery in TA cases becomes an option when the patient does not improve clinically after administration of medical treatment. Although endovascular management has fewer complications, the rate of restenosis is higher. Patients at risk of restenosis and who have increased perioperative vascular risk can benefit from open surgical procedures. Surgical management should be tailored to the patient's needs