Biología molecular del complejo multigénico hGH-hPL : Potencial transcripcional de sus genes en un sistema de transcripción in vitro

Tesis (Maestría en Ciencias con Especialidad en Biología Molecular e Ingeniería Genética) UANL.UANLhttp://www.uanl.mx

Solving PDEs by variational physics-informed neural networks: an a posteriori error analysis

We consider the discretization of elliptic boundary-value problems by variational physics-informed neural networks (VPINNs), in which test functions are continuous, piecewise linear functions on a triangulation of the domain. We define an a posteriori error estimator, made of a residual-type term, a loss-function term, and data oscillation terms. We prove that the estimator is both reliable and efficient in controlling the energy norm of the error between the exact and VPINN solutions. Numerical results are in excellent agreement with the theoretical predictions

Variational Physics Informed Neural Networks: the role of quadratures and test functions

In this work we analyze how quadrature rules of different precisions and piecewise polynomial test functions of different degrees affect the convergence rate of Variational Physics Informed Neural Networks (VPINN) with respect to mesh refinement, while solving elliptic boundary-value problems. Using a Petrov-Galerkin framework relying on an inf-sup condition, we derive an a priori error estimate in the energy norm between the exact solution and a suitable high-order piecewise interpolant of a computed neural network. Numerical experiments confirm the theoretical predictions and highlight the importance of the inf-sup condition. Our results suggest, somehow counterintuitively, that for smooth solutions the best strategy to achieve a high decay rate of the error consists in choosing test functions of the lowest polynomial degree, while using quadrature formulas of suitably high precision.Comment: 20 pages, 22 figure

Versión española de la Escala de Justicia Organizacional de Colquitt

Organizational justice (OJ) is an important predictor of different work attitudes and behaviors. Colquitt’s Organizational Justice Scale (COJS) was designed to assess employees’ perceptions of fairness. This scale has four dimensions: distributive, procedural, informational, and interpersonal justice. The objective of this study is to validate it in a Spanish sample. Method: The scale was administered to 460 Spanish employees from the service sector. 40.4% were men and 59.6% women. Results: The Confirmatory Factor Analysis (CFA) supported the four dimensions structure for Spanish version of COJS. This model showed a better fi t to data that the others models tested. Cronbach’s alpha obtained for subscales ranged between .88 and .95. Correlations of the Spanish version of COJS with measures of incivility and job satisfaction were statistically significant and had a moderate to high magnitude, indicating a reasonable degree of construct validity. Conclusions: The Spanish version of COJS has adequate psychometric properties and may be of value in assessing OJ in Spanish settingLa justicia organizacional (JO) es un predictor importante de diferentes actitudes y conductas organizacionales. La Escala de Justicia Organizacional de Colquitt (EJOC) fue desarrollada para evaluar las percepciones de justicia de los empleados. Tiene cuatro dimensiones: justicia distributiva, procedimental, informativa e interpersonal. El objetivo de este estudio es validarla en una muestra española. Método: la escala fue administrada a una muestra de 460 trabajadores españoles del sector servicios. El 40,4% fueron hombres y el 59,6% mujeres. Resultados: el Análisis Factorial Confirmatorio (AFC) apoyó la estructura de cuatro dimensiones para la versión española de la EJOC. Este modelo mostró un mejor ajuste de los datos que los otros modelos probados. El alfa de Cronbach obtenido para las subescalas varió entre .88 y .95. Las correlaciones de la versión española con las escalas de incivismo y satisfacción laboral fueron estadísticamente signifi cativas y de una magnitud moderada a alta, lo que indica un grado razonable de validez de constructo. Conclusiones: la versión española de la EJOC tiene propiedades psicométricas adecuadas y puede ser de utilidad en la evaluación de la JO en el entorno españo

TORC1 controls G1-S cell cycle transition in yeast via Mpk1 and the greatwall kinase pathway

The target of rapamycin complex 1 (TORC1) pathway couples nutrient, energy and hormonal signals with eukaryotic cell growth and division. In yeast, TORC1 coordinates growth with G₁–S cell cycle progression, also coined as START, by favouring the expression of G₁ cyclins that activate cyclin-dependent protein kinases (CDKs) and by destabilizing the CDK inhibitor Sic1. Following TORC1 downregulation by rapamycin treatment or nutrient limitation, clearance of G₁ cyclins and C-terminal phosphorylation of Sic1 by unknown protein kinases are both required for Sic1 to escape ubiquitin-dependent proteolysis prompted by its flagging via the SCFCdc4 (Skp1/Cul1/F-box protein) ubiquitin ligase complex. Here we show that the stabilizing phosphorylation event within the C-terminus of Sic1 requires stimulation of the mitogen-activated protein kinase, Mpk1, and inhibition of the Cdc55 protein phosphatase 2A (PP2ACdc55) by greatwall kinase-activated endosulfines. Thus, Mpk1 and the greatwall kinase pathway serve TORC1 to coordinate the phosphorylation status of Sic1 and consequently START with nutrient availability

Paleoseismology of active faults based on multiscale seismic imaging

The study of active structures offshore requires very-high resolution seismic imaging in order to observe the most recent layers below sea floor. In the other hand, high penetration methods are necessary to observe deeper reflections for understanding the evolution of the structure throughout the time. The aim of our study is to establish the seismic potential of the offshore segment of the Carboneras Fault, Eastern Betics, based on multiscale seismic imaging. Three different scale methods have been acquired and are compared here: very-high-resolution sub-bottom profiler TOPAS, very-high-resolution single-channel seismic (Sparker) and high-resolution multi-channel seismic. From seismic profiles, faulted Quaternary layers suggest that the Carboneras Fault is active. Sediment coring and dating analysis are used to consider ages for key reflectors observed in TOPAS profiles, and a change in the vertical slip-rate through the Quaternary is inferred.Peer Reviewe

Efecto de la relacion copa/raiz sobre la deshidratacion prematura de bayas en vid vinifera cv: Merlot

21 p.Durante la temporada 2002-2003 se efectuó un ensayo para encontrar la posible relación entre la razón copa/raíz y la incidencia de la deshidratación prematura de bayas (DPB) en cv. Merlot. La razón fue cambiada cortando el follaje a una altura pre-determinada 15 días antes de pinta y retrasando la eliminación de brotes del tronco. Los tratamientos fueron T1= Control, T2= 50% del area foliar del control, T3= 75% del área foliar del control y T4= Eliminación retrasada de brotes del tronco. El área foliar y la razón copalraiz fue menor en T2 y T3. T4 no fue efectivo para cambiar estos valores. La incidencia fue menor para T2 y T3, cayendo el porcentaje de plantas afectadas desde un 52% del control a 22,9% y 31,3% para T2 y T3 respectivamente y desde 52,4% de racimos afectados a 16,6% y 21,2% para los mismos tratamientos. Finalmente, el porcentaje de racimos afectados dentro del rango de moderado a severo cayo desde 25% del control a 5,2% y 3,9% para T2 y T3

Circadian variation in the neoplasic hepatocytes proliferation from the ES 15 tumor

Como numerosos procesos biológicos, la proliferación de diversas poblaciones celulares animales presenta un ritmo circadiano. La respuesta diferencial a la ciclofosfamida ha sido relacionada con la periodicidad mitótica diaria en un carcinoma mamario de ratón. El presente trabajo analiza la evolución de la actividad mitótica, a lo largo de un ciclo de 24 h, de los hepatocitos neoplásicos del tumor E515 (hepatocarcinoma diferenciado, de crecimiento lento), 38 ratones machos, adultos de la cepa C3H/5, fueron injertados con el tumor en el tejido celular subcutáneo. Al cabo de 10 semanas los portadores fueron colocados durante tres semanas en condiciones de estandarización para análisis de periodicidad. Pasado ese lapso los mismos se repartieron en 6 lotes (n=5-8) que se sacrificaron cada 4 horas a partir de la hora 00:00 hasta abarcar un período de 24 h, tras recibir una dosis de Colchicina (2 µg/g/0,O1 ml). Las muestras del tumor se procesaron para observación microscópica bajo objetivo de inmersión. En los cortes se determinó por conteo mitótico el índice de metafases colchicínicas por 1.000 núcleos. Se observó que la actividad mitótica presenta su valor mínimo a las 04:00 horas y el máximo a las 16:00 h. Esta diferencia es estadísticamente significativa (P < 0,001). Este conocimiento es de utilidad para cualquier ensayo experimental que implique aspectos relacionados con la regulación del crecimiento del mismo tumor.As most of biological processes, the proliferation of a variety of mammalian cell populations shows a circadian rhythm. The differential response of a mouse mammary carcinoma to the endoxan (cyclophosphamide) administration, has been related to its daily mitotic periodicity. In this work we analyze the evolution of the mitotic activity, through a 24 h period, of the E515 tumor hepatocytes (Slow growing differentiated hepatocarcinoma). Thirty eight C3H/S inbred male adult mice, were grafted with the tumor in the hypodermis. Ten weeks later they were standardized for periodicity analysis during three weeks. After this time, they were separated in six groups (N=5-8) and one group every’ 4 h for a day was sacrificed. Four hours before killing, the mice received an IP injection of colchicine in a doses of 2 µg/g/0,O1 ml of distilled water. The colchicine metaphases were controlled on slides an the mitotic index per 1000 nuclei was determined. The lowest mitotic activity at 04:00 h and the highest at 16:O0 h were observed. The difference was highly significant (p < 0,001). The knowledge of this data is very useful for experimental assays related to any aspect of the same tumor growth regulation.Facultad de Ciencias Veterinaria

Evaluation and correction of aberrations in an optical correlator by phase-shifting interferometry

We propose a new method for evaluating and correcting aberrations in a Vander Lugt correlator. The technique is achieved with liquid-crystal displays of the correlator and allows the task to be performed in situ. We present the theory on which the method is based and the experimental results that we obtained by applying it in a convergent correlator