Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Review

Review

Review

Review

Las reseñas se consignan a continuación del libro (o artículo reseñado). Cuando éste se ha descrito en una entrega anterior de la Bibliografía, se pone entre paréntesis el número de ficha correspondiente. También se hacen referencias a ediciones anteriores de una obra, a tomos anteriores de una obra en curso de publicación, etc. En estos casos, la cifra que precede al número de referencia indica el volumen de la NRFH en que figura la ficha en cuestión. Así, el "núm. 39-39695" corresponde a la ficha 39695, la cual está en el volumen 39 de la NRFH. Cuando no hay cifra inicial, ha de entenderse que el número remite a una ficha incluida en el presente fascículo.

The COVID-19 pandemic has motivated a resurgence in the use of phenomenological growth models for predicting the early dynamics of infectious diseases. These models assume that time is a continuous variable, whereas in the present contribution the discrete versions of Gompertz and Generalized Logistic models are used for early monitoring and short-term forecasting of the spread of an epidemic in a region. The time-continuous models are represented mathematically by first-order differential equations, while their discrete versions are represented by first-order difference equations that involve parameters that should be estimated prior to forecasting. The methodology for estimating such parameters is described in detail. Real data of COVID-19 infection in Cuba is used to illustrate this methodology. The proposed methodology was implemented for the first thirty-five days and was used to predict accurately the data reported for the following twenty days.

The contribution of this research work focuses on understanding the biological behavior of time-varying electric fields, specifically in the eyeball, by proposing sensitive frequency ranges, specifically for primary open-angle glaucoma POAG and RP retinitis pigmentosa. These ranges were obtained from the analysis of the frequency spectrum of the signals used by other authors in transcorneal electrical stimulation TES therapies. This analysis was performed using an algorithm proposed in this work. The frequency spectra of the signals used in the TES were also compared with the frequency response of the cellular behavior evoked by genestein drug, in order to compare the frequency characteristics of the signals applied in the TES and the biological response of the drug. which causes the same effect in POAG.

The objective of fringe pattern analysis is to extract modulated experimental information in an image. Among the techniques used in the demodulation process is the Regularized Phase Tracking. In this technique, a functional is proposed which is usually solved with classical minimization methods. This paper presents a minimization method for this technique using the fixed-point technique, which presents a normalized error like classical minimization methods, but with a notable reduction in processing time.

Nitrogen (N) and Sulfur (S) are nutrients that have a strong uptake interaction. Therefore, the addition of these nutrients in the right ratio has a positive influence in plant development. This work is aiming to assess the effects of the interaction between NH4+ and SO42- at different concentrations, on the growth, physiology and macronutrient concentration in Lisianthus (Eustoma grandiflorum (Raf.) Shinn.) cv. Dark Pink ABC 1-2. The trial treatments included three concentrations of NH4+ (0, 2.5 and 5 meq L-1) and two concentrations of SO42- (7 y 10 meq L-1). The different concentrations of SO42- y NH4+ were based on Steiner’s nutrient solution modifications.  We used 10-liter black polyethylene containers and perlite substrate with particles size of 0.2-0.5mm in diameter. The results showed that the stem diameter and dry biomass production of roots, stems, flowers and total biomass were higher with 5 meq L-1 of NH4+ and 7 meq L-1 of SO42-. On the other hand, total leaf dry weight and plant height were higher with 2.5 meq L-1 of NH4+ and 7 meq L-1 of SO42-. The plants showed the same behavior in terms of photosynthesis, transpiration and stomatal conductance. We obtained the highest concentration of N and P by applying 2.5 meq L-1 of NH4+ with 10 meq L-1 of SO42. Furthermore, Mg, and S concentrations were higher when we supplied 2.5 meq L-1 of NH4+ with the two concentrations of SO42; while K and Ca were higher when we increased the concentration of NH4+ with 7 meq L-1 of SO42-. We obtained the best growth rate, biomass production and nutrient concentration  (K and Ca) in Lisianthus plants with 5 meq L-1 of NH4+/ 7 meq L-1 of SO42-; while physiological activity improved with 2.5 meq L-1 of NH4+ / 7 meq L-1 of SO42- ratio. 

Preparing a thesis implies executing logical-argumentative thinking. Ontogenetic, epistemological and psychological obstacles happen to appear in the development process. This research shows how the use of Toulmin's argumentative model and a set of psychodidactical strategies supported by the understanding of these obstacles by the thesis advisors or supervising professor, are beneficial for the successful execution of this type of logical thinking. These strategies are: 1) strategies to facilitate the logical course of thought; 2) strategies to strengthen the scientific self, and 3) strategies to facilitate the act of writing the text. To prove the benefit of both tools it is important to highlight the behaviour of the degree efficiency of eight postgraduate generations in Psychology from the National Autonomous University of Mexico (from 2011 to 2019, with a total of 77 students) who have succeeded with the use of both tools.