Study of stellar populations in the bulges of barred galaxies

We have obtained long-slit spectroscopy for a sample of 20 early-type barred galaxies to study the influence of bars in the building of galaxy bulges. Line strength indices were measured and used to derive age and metallicity gradients in the bulge region by comparing with stellar population models. The same analysis was also carried out with similar data of unbarred galaxies taken from the literature. The bulges of barred galaxies seem to be more metal rich, at a given velocity dispersion (sigma), than the bulges of unbarred galaxies, as measured by some metallicity sensitive indices. There are indications that the ratio of relative abundance of alpha-elements with respect to iron, [E/Fe], derived for the bulges of barred galaxies tend to lie above the values of the unbarred galaxies at a given sigma. The metallicity gradients for the majority of the bulges are negative, less metal rich towards the end of the bulge. The gradient values show a large scatter for galaxies with sigma below 150 km/s. The age distribution is related to the presence of bulge substructure such as a nuclear ring or an inner disk. The metallicity of both the bulge and the bar are very well correlated indicating a close link between the enrichment histories of both components. Bulges of barred early type galaxies might have suffered a different chemical enrichment compared to the bulges of unbarred galaxies of the same morphological type, same central velocity dispersion and low inclination angles. The hinted stellar populations differences separating the bulges of barred and unbarred galaxies and the strong link existing between the metallicity of the bulge and the presence of a bar points to scenarios were they both form simultaneously in processes leading to rapid and massive episodes of star formation, possibly linked to the bar formation.Comment: Accepted for publication in Astronomy and Astrophysic

Agricultura de terrazas en el cerro Tenismo, Toluca. México

Los campesinos mexicanos practican diversos agroecosistemas tradicionales, caso particular, las terrazas.Los campesinos mexicanos practican diversos agroecosistemas tradicionales, caso particular, las terrazas. Este sistema es uno de los más antiguos en el Valle de Toluca y actualmente se encuentra en proceso de abandono. El objetivo fue caracterizar el sistema de terrazas del cerro Tenismo en Calixtlahuaca, Toluca, México, destacando sus componentes principales: muros de contención, zanja, vegetación, cultivos. A partir de la investigación cualitativa, observación directa y la descripción del agroecosistema, se analizan los componentes de quince terrazas de la ladera media y ladera alta del cerro Tenismo. Los resultados indican que las terrazas de Calixtlahuaca con muro de roca y metepantles (semiterraza), son un sistema importante que contribuye a la conservación de las laderas y de donde se obtienen cultivos de autoconsumo. Se concluye que el manejo que realizan los campesinos por medio de las terrazas (muros, zanjas y vegetación) tiene características agroecológicas que contribuyen a la preservación del ambiente.Universidad Autónoma del Estado de México Colegio de Ciencias Geográficas del Estado de México AC

Diseño de estrategias didácticas utilizando las TICS como herramienta para desarrollar un aprendizaje significativo en ciencias naturales de los grados 4 y 5 de primaria del Instituto Educativo María Montessori de Riohacha Guajira.

Este trabajo de grado consiste en un proceso de investigación, desarrollado en el Municipio de Riohacha. Promueve la implementación de estrategias pedagógicas que tienen como finalidad diseñar herramientas didácticas que permitan utilizar las Tics con los alumnos de los grados 4 y 5 en Ciencias Naturales.This undergraduate work consists of a research process, developed in the municipality of Riohacha. It promotes the implementation of pedagogical strategies that aim to design didactic tools that allow to use the Tics with the students of the grades 4 and 5 in natural sciences

Caracterización fenotípica de pacientes con reacciones de hipersensibilidad selectiva a anti-inflamatorios no esteroideos

Esperamos que los resultados proporcionen información necesaria para una clasificación más detallada de los diferentes fenotipos de las RS, así como para el diagnóstico y manejo clínico de estos pacientes. Fecha de lectura de Tesis Doctoral: 24 Febrero 2020Las reacciones de hipersensibilidad selectivas a AINE (RS) incluyen las inducidas por Ac IgE específicos, designadas SNIUAA (del inglés, single-NSAID-induced urticaria/angioedema or anaphylaxis), y las inducidas por linfocitos T, designadas SNIDR (del inglés single-NSAID-induced delayed hypersensitivity reactions). En España los fármacos más frecuentemente implicados son el metamizol, ibuprofeno, diclofenaco, AAS y paracetamol. Objetivos: 1)caracterizar fenotípicamente las RS; 2)evaluar la asociación de las RS con otras patologías; 3)analizar el valor de los diferentes métodos diagnósticos: historia clínica (HC), las pruebas cutáneas (PC) y la prueba de exposición controlada (PEC) y, 4)valorar la utilidad del TAB a metamizol. Resultados: 512 pacientes con RS, 461(90%) SNIUAA y 51(10%) SNIDR. El metamizol y el ibuprofeno fueron la causa más frecuente de SNIUAA y la anafilaxia la entidad clínica más frecuente (33.3%). En la SNIDR los mismos fármacos fueron los principales inductores y las entidades clínicas más frecuentes fueron el EFM (43.2%) y el EMP (31.6%). El 25.56% de pacientes con RS presentaban otras co-morbilidades de tipo alérgico. La HC fue la herramienta diagnóstica más importante en las SNIUAA (62.7% versus 35.3%), mientras que en las SNIDR el protagonismo fue mayor en el caso de las PC (47.1% versus 22.8%). El papel de la PEC con el AINE implicado fue muy similar en ambos tipos de reacciones (SNIUAA 14.5% versus SNIDR 17.6%). El análisis de los marcadores del basófilo CD63 y CD203c en las SNIUAA por metamizol mostró que ambos tenían la misma especificidad (87.5%) aunque la sensibilidad del primero es menor que la del segundo (61.9% versus 80.95%). Ambos marcadores mostraron una buena correlación, especialmente en el caso de las reacciones anafilácticas (r2=0.835)

XPA, XPC, and XPD Modulate Sensitivity in Gastric Cisplatin Resistance Cancer Cells

Cisplatin is an election drug widely used in clinic for the treatment of advanced gastric cancer. However, the heterogeneity of the gastric tumors and its resistance to the drugs, make in some cases the response very low and the prognosis unpredictable. In this manuscript we aim to find the molecular processes involved in cisplatin-induced apoptosis in two gastric cancer cell lines with different sensitivity to the treatment: AGS and MKN45. The apoptosis induction is higher in MKN45 than in AGS cells in response to CDDP. The intrinsic apoptotic pathway study revealed that MKN45 cells undergo degradation of Mcl-1 together with an increase of Bid and Bad levels, which results in sensitivity to CDDP. In addition, DNA repair NER pathway is impair in MKN45 cells due to low levels of XPC and the absence of translocation of XPA and XPD to the nucleus after stimuli. Altogether, these results suggest that NER and Bcl-2 protein family proteins are potential targets to improve the response to cisplatin treatment

Changes in total and inner retinal thicknesses in type 1 diabetes with no retinopathy after 8 years of follow-up

Purpose:To evaluate changes in retinal layer thickness in patients with Type 1 diabetes with no diabetic retinopathy after 8 years of follow-up. Methods:Ninety Type 1 diabetes and 60 control eyes were studied. Changes in the retinal nerve fiber layer, ganglion cell layer, and inner nuclear layer thicknesses in all Early Treatment Diabetic Retinopathy Study areas were evaluated. Results:The mean ages were 42.93 ± 13.62 and 41.52 ± 13.05 years in the diabetic and control group, respectively. In 2009, total retinal thickness was higher in diabetic patients; differences were statistically significant in all except the nasal areas. In both groups, the mean foveal thickness remained the same during the 8 years. Among diabetic patients, there was a significant reduction in total retinal thickness in all areas excluding the outer temporal one; controls only in the inferior areas. The thickness loss was due to the thinning of the inner retinal layers (inner nuclear layer, ganglion cell layer, and retinal nerve fiber layer). The controls showed a significant diminution in the retinal nerve fiber layer and in the ganglion cell layer areas. The inner nuclear layer showed a diminution in the diabetes mellitus group. Conclusion:Before the onset of diabetic retinopathy, Type 1 diabetes patients experience a diminution of their inner retinal layer thicknesses over time, supporting the hypothesis of retinal neurodegeneration

Acute stress response in gilthead sea bream (Sparus aurata L.) is time-of-day dependent: Physiological and oxidative stress indicators

Since fish show daily rhythms in most physiological functions, it should not be surprising that stressors may have different effects depending on the timing of exposure. In this study, we investigated the influence of time of day on the stress responses, at both physiological and cellular levels, in gilthead sea bream (Sparus aurataL.) submitted to air exposure for 30 s and then returned to their tank. One hour after air exposure, blood, hypothalamus and liver samples were taken. Six fish per experimental group (control and stressed) were sampled every 4 h during a 24-h cycle. Fish were fed in the middle of the light cycle (ML) and locomotor activity rhythms were recorded using infrared photocells to determine their daily activity pattern of behaviour, which showed a peak around feeding time in all fish. In the control group, cortisol levels did not show daily rhythmicity, whereas in the stressed fish, a daily rhythm of plasma cortisol was observed, being the average values higher than in the control group, with increased differences during the dark phase. Blood glucose showed daily rhythmicity in the control group but not in the stressed one which also showed higher values at all sampling points. In the hypothalamus of control fish, a daily rhythm ofcorticotropin-releasing hormone(crh) gene expression was observed, with the acrophase at the beginning of the light phase. However, in the stressed fish, this rhythm was abolished. The expression ofcrh-binding protein(crhbp) showed a peak at the end of the dark phase in the control group, whereas in the stressed sea bream, this peak was found at ML. Regarding hepatic gene expression of oxidative stress biomarkers: (i)cytochrome c oxidase 4showed daily rhythmicity in both control and stressed fish, with the acrophases located around ML, (ii)peroxiredoxin(prdx) 3 and5(prdx5) only presented daily rhythmicity of expression in the stressed fish, with the acrophase located at the beginning of the light cycle and (iii)uncoupling protein 1showed significant differences between sampling points only in the control group, with significantly higher expression at the beginning of the dark phase. Taken together, these results indicate that stress response in gilthead sea bream is time-dependent as cortisol level rose higher at night, and that different rhythmic mechanisms interplay in the control of neuroendocrine and cellular stress responses