Análisis de modelos tipo SEIR utilizados en los inicios de la pandemia COVID-19 reportados en revistas de alto impacto / Analysis of SEIR-type models used at the beginning of COVID-19 pandemic reported in high-impact journals

Introducción El modelo matemático-epidemiológico Susceptible-Expuesto-Infectado-Recuperado (SEIR) ha sido empleado exhaustivamente en el contexto actual de la pandemia COVID-19. En sus inicios de una manera prevalente, donde se buscaba predecir la carga hospitalaria y evaluar las medidas sanitarias para contener su propagación. En este sentido, se han evidenciado fallas en las predicciones de los primeros modelos publicados. Se considera necesario evaluar las diferencias en el planteamiento y verificación de los modelos. Objetivos Categorizar las publicaciones científicas de revistas de alto impacto que propusieron modelos tipo SEIR para modelar la pandemia COVID-19 en sus inicios. Métodos Realizamos una revisión sistemática de los artículos publicados en revistas indexadas en , de primer cuartil y con factor de impacto mayor que dos, que cumplían con los criterios de selección e inclusión siguiendo los estándares PRISMA-ScR. Incluimos un total de 32 artículos que fueron evaluados según características demográficas como el mes de recepción y publicación, el país de origen de la información, la materia temática de la revista, y las características del modelamiento como la presencia de compartimentos adicionales, análisis gráfico, planteamiento de modelo conceptual, interpretación del número reproductivo básico y estimación de los parámetros empleados. Resultados Los artículos publicados en revistas del área médica y salud fueron predominantes en los meses de febrero a julio de 2020. Estos artículos emplearon con mayor frecuencia datos procedentes de China y se centraron mayoritariamente en modelos SEIR o con compartimento de cuarentena completa. Los artículos publicados en revistas del área matemática fueron predominantes en el período de agosto a diciembre de 2020, y emplearon datos procedentes de diversas regiones del mundo, considerando mayor diversidad de compartimentos como pacientes asintomáticos o en cuarentena parcial o completa. Conclusiones Los artículos analizados en su mayoría emplean modelos tipo SEIR ampliados con compartimentos adicionales. Existen discrepancias en la amplitud y calidad metodológica de los artículos publicados, según la materia temática de la revista. Se recomienda la unificación de criterios de calidad para la descripción de los modelos en cualquier revista.

Introduction The Susceptible-Exposed-Infected-Recovered (SEIR) mathematical-epidemiological model has been exhaustively used since de beggining of the COVID-19 pandemic. These models intended to predict hospital burden and evaluate health measures to contain its spread. In this sense, flaws have been evidenced in the predictions of the first published models. It is considered necessary to evaluate the differences in the approach and verification of the models. Objectives We carried out a systematic review of the articles published in journals indexed in the Web of Science, of the first quartile and with an impact factor greater than two, that met the selection and inclusion criteria following the PRISMA-ScR standards. We included a total of 32 articles, which were evaluated according to demographic characteristics such as the month of receipt and publication, the country of origin of the information, the subject matter of the journal, and the characteristics of the modeling such as the presence of additional compartments, graphical analysis, conceptual model approach, interpretation of the basic reproductive number, and estimation of parameters. Methods Articles published in medical and health journals were predominant from February to July 2020. These articles most frequently used data from China and mostly focused on SEIR or full quarantine compartment models. The articles published in journals in mathematics were predominant from August to December 2020. Models used data from different world regions, considering a greater diversity of compartments such as asymptomatic patients or partial or complete quarantine. Results The articles analyzed mostly use SEIR-type models expanded with additional compartments. There are discrepancies in the breadth and methodological quality of the articles published according to the journal's subject matter. The unification of quality criteria for describing the models in any journal is recommended. Conclusions The articles analyzed mostly use SEIR-type models expanded with additional compartments. There are discrepancies in the breadth and methodological quality of the articles published according to the journal's subject matter. The unification of quality criteria for describing the models in any journal is recommended.

Learning from transgenics: advanced gene editing technologies should also bridge the gap with traditional genetic selection

We highlight the importance of the mixed genetic approaches (classical and currents) to improve the social perception related to the GMOs acceptance. We pointed out that CRISPR/Cas9 events could carry DNA variability/rearrangements related to somaclonal variations or epigenetic changes that are independent from the editing per se. The transformation of single cells, followed by plant regeneration, is used to generate modified plants, transgenic or genome editing (CRISPR/Cas9). The incidence of undesirable somaclonal variations and/or epigenetic changes that might have occurred during in vitro multiplication and regeneration processes, must be carefully analyzed in replicates in field trials. One remarkable challenge is related to the time lapse that selects the modified elite genotypes, because these strategies may spend a variable amount of time before the results are commercialized, where in all the cases it should be take into account the genotype × environment interactions. Furthermore, this combination of techniques can create an encouraging bridge between the public opinion and the community of geneticists who are concerned with plant genetic improvement. In this context, either transgenesis or genomic editing strategies become complementary modern tools to facing the challenges of plant genetic improvement. Their applications will depend on case-by-case analysis, and when possible will necessary associate them to the schemes and bases of classic plant genetic improvement.

Morphometric and phytochemical characterization of chaura fruits (Gaultheria pumila): a native Chilean berry with commercial potential

BACKGROUND: For the first time, a morphometric characterization of chaura (Gaultheria pumila) fruits has been conducted between natural populations growing in the Villarrica National Park, Araucania Region, Chile. Chaura is a native Ericaceae from Chile that produces aromatic and tasty fruits which could be of agricultural interest. RESULTS: To influence the decision for a further domestication of G. pumila, both the fruit sizes (indicator of productivity) and the nutritional properties of the fruits have been determined from different subpopulations. Samples were a total of 74 plants and 15 fruits per plant which were randomly harvested following its natural distribution around the Villarrica volcano. Altogether, fresh weight, shape, color, diameter in the pole and the equatorial dimensions were determined as phenotypic traits of the G. pumila fruits. Meanwhile the total soluble solids, anthocyanin and pectin contents were calculated as nutritional traits of the Chaura fruits. Results showed a high phenotypic diversity between the sampled population with three main fruit shapes and three predominant colors. The round shapes were the most abundant, whereas a significant correlation was found among fruit size with weight and color. The highest fresh weight (597.3 mg), pole diameter (7.1 mm) and equatorial diameter (6.5 mm) were estimated in the pink color fruits. CONCLUSIONS: The total amount of anthocyanin was higher in red fruits, while the maximum pectin content was obtained in the round white fruits. Overall results must pave the way for a further domestication and introduction of the Chaura species in the agro-productive system in Chile.