Interpretation of computational thinking evaluation results for enrollment prediction

During two generations (2016 and 2017) the computational thinking evaluation has been carried out in order to establish learning scenarios for new students, such interventions have been made in the Programming methodology course, it belonging to the career of Information Technology at the Technological University of Puebla in México. The results have led a personalized education for students, recognizing previous skills as well as trying to correct those missing, so that it acquires the competences respective, credit the course and improve the retention percentage of the first quarter. In this sense, when detecting possible skill gaps, is it possible to predict what will be the impact to maintain or decrease enrollment during and the end of quarter? The present work aims to answer the question by the results interpretation obtained from the computational thinking evaluation to 242 new students, generation 2018. Initially, it was stablished which would be the student's situation during and the end of four months from September to December based on the correct assessment reagents; three categories were determined: 1. Sure desertion, 2. Safe permanence, 3. Variable permanence. Later, 50 students who enrolled the next quarter (January-April 2019) were revised if they had been predicted properly; using a survey, the familiarity of key concepts of the subject Programming methodology was obtained with the aim of determining a correspondence with the evaluation of computational thinking skills, as well as the established situation, consequently, establishing the validity of predicting the enrollment

Synthesis of honokiol analogues and evaluation of their modulating action on VEGF protein secretion and telomerase-related gene expressions

A group of 36 biphenyl derivatives structurally related to honokiol were synthesized by means of Suzuki coupling reactions. Their cytotoxicities were evaluated and compared to that of honokiol. Some of the compounds were then evaluated for their ability to downregulate the secretion of the VEGF protein and the expression of the VEGF, hTERT, and c-Myc genes; the two latter involved in the activation of telomerase in tumoral cells. Some of the synthetized derivatives showed promising pharmacological features as they exhibited IC50 values in low micromolar range, good therapeutic margins, and a multiple mode of action on tumor cells based on the inhibition of VEGF and, at the same time, of the expression of genes related to the activation of telomerase

Discretizing a backward stochastic differential equation

We show a simple method to discretize Pardoux-Peng's nonlinear backward stochastic differential equation. This discretization scheme also gives a numerical method to solve a class of semi-linear PDEs

Formation of subsurface cracks in silicon wafers by grinding

Single-crystal silicon is an important material in the semiconductor and optical industries. However, being hard and brittle, a silicon wafer is vulnerable to subsurface cracks (SSCs) during grinding, which is detrimental to the performance and lifetime of a wafer product. Therefore, studying the formation of SSCs is important for optimizing SSC-removal processes and thus improving surface integrity. In this study, a statistical method is used to study the formation of SSCs induced during grinding of silicon wafers. The statistical results show that grinding-induced SSCs are not stochastic but anisotropic in their distributions. Generally, when grinding with coarse abrasive grains, SSCs form along the cleavage planes, primarily the {111} planes. However, when grinding with finer abrasive grains, SSCs tend to form along planes with a fracture-surface energy higher than that of the cleavage planes. These findings provide a guidance for the accurate detection of SSCs in ground silicon wafers. Keywords: Silicon wafer, Subsurface crack, Cleavage, Inclination angle, Thermal energ

Vibrational characteristics of rotating soft cylinders

Rotating structural components are omnipresent in engineering structures and natural world. This work investigates the effects of the centrifugal and Coriolis forces on the free vibrational characteristics of soft cylinders rotating with respect to the axis of symmetry based on the nonlinear elasticity and linear incremental theories. The formulations indicate that the biasing deformation, instantaneous elastic moduli, and incremental equations of motion strongly depend on the rotating speed. The characteristic equation for the natural frequency is derived using the state-space method and approximate laminate technique. The numerical examples included in this work demonstrate that the centrifugal and Coriolis forces might have significant effects on the vibrational characteristics of the cylinder. Results of this work will benefit the design and control of novel engineering systems with rotating soft cylinders or shafts

Diuretic Activity of Rubus idaeus L (Rosaceae) in Rats

Purpose: To evaluate the diuretic activity of Rubus idaeus L in experimental rats. Methods: Hot-water and methanol extract of three kinds of Rubus idaeus L. fruits were administered to experimental rats orally at a dose of 2 and 5 mg/kg. Hydrochlorothiazide (10 mg/kg) was used as positive control in study. The diuretic effect of the extracts was evaluated by measuring urine volume, sodium and potassium excretion in the urine. Results: Compared with the control group, significant increase in urine volume was observed from the experimental animal treated with wild raspberry methanol extract. In addition, we find that the methanol extract of wild raspberry fruits shows a potassium-conservation diuretic effect, which is a very interesting property in a phytodiuretic. Conclusion: Methanol extract of wild raspberry fruits have diuretic effect on experimental rats. This might be the first formal reports on diuretic effect of raspberry fruits, which can also, to some extent, explain the use of raspberry as a cure for renal diseases in Chinese traditional medical practice

Geometrical incompatibility guides pattern selection in growing bilayer tubes

Pattern selection and subsequent morphological evolution are of remarkable significance, since they are critical for living creatures to fulfill certain biological functions and also have widespread potential applications from disease diagnosis to advanced manufacturing. Geometrical incompatibility is omnipresent in biological systems and plays a critical role in pattern selection of the growing soft biological tissues. However, how geometrical incompatibility guides pattern selection in growing soft matter remains poorly understood. Here, we present a theoretical model to investigate the influence of geometrical incompatibility on pattern selection of growing bilayer tubes. Our linear stability analysis illustrates that an increase of the geometrical incompatibility parameter provokes the instability pattern transition from a longitudinal pattern to a two-dimensional (2D) pattern and then to a circumferential pattern. Based on the theoretical model, a series of quantificational experiments and finite element simulations are implemented to study how geometrical incompatibility guides pattern selection of growing bilayer tubes and explore the post-buckling evolution of the emerging patterns. Both the numerical simulations and experimental observations agree well with our theoretical predictions. In particular, with further growth far beyond the threshold, a secondary bifurcation is observed in the post-buckling evolution of the 2D pattern. This study suggests that geometrical incompatibility can serve as an implementable experimental tool to quantificationally guide pattern selection and subsequent morphological evolution of growing soft matter, which can be used for growth self-assembly and multifunctional surface manufacturing