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

Delonix regia is a species with a worldwide importance due to its multiple properties and applications. It has low the germination due seed characteristics like testa permeability and presence of phenolic inhibitors, which inhibits the necessary flow of water and oxygen to enhance the process. The objective of this study was to characterize the morphology and germination response of D. regia seeds subjected to different pre-germination treatments. Methodologically, a completely randomized experimental design with four replicates of 25 seeds each was applied. The treatments were: physical, mechanical and combined scarification. In this context, it was possible to establish the quality of seeds by indicating their biometric traits and colorimetric characterization, which are advantageous tools to be used as classification systems for the species, since the size and color of the most suitable seeds for obtaining seedlings have been determined. In the assessment of the morphophysiological quality of the seeds, the interpretation of viability tests based on patterns and damage detection, by destructive and non-destructive methods, was achieved. Of the pregerminative treatments considered in this research, the physical scarification method by immersing the seeds for 15 minutes in water at 100 ºC, with cooling in water at room temperature, had a direct influence on most of the parameters analyzed to promote seedling emergence.

Ochroma pyramidale is a fast-growing species with high commercial value. The largest volumes of its wood are obtained from commercial plantations; however, there are very few studies of its production in nurseries. The objective of this study was analyse the effect of N, P, K concentration and fertilisation frequency on morpho-physiological response of O. pyramidale grown in biopots using response surface methodology. The experiment was set up using the response surface methodology for which 30 seedlings were used per experimental run. The experiment consisted of applying different concentrations of N, P, K and two fertilisation frequencies according to the optimal (Custom) design. The response variables were height increase, diameter increase and CO2 assimilation. From the results obtained, we confirmed the positive effect of N, P and K fertilisation on the variables under study. From the experimental data, a second-order quadratic polynomial model was found that allows the prediction of the morpho-physiological response of the species. The frequency of fertilisation during the time interval studied was not significant.

Paraguay an ecosystems are home to a great diversity of organisms in urban trees that include fungus-plant interactions, commonly called mycorrhizae. These mycorrhizaes present a number of subterranean hyphae that are difficult to visually appreciate and basidiocarps that grow together with certain forest species. Therefore, the objective of this research was to identify mycorrhizal associations between macrofungi and forest species that interact with each other in the urban trees of Asunción, Paraguay. For this, two squares (De las Américas and Infante Rivarola) and the Carlos Antonio López Park were selected as reference points. A tour was carried out to identify the floristic composition of urban trees in the aforementioned green spaces, and the observation of the existence of microrhizal fungi. The fruiting bodies of the macrofungi found were collected and taken to the Biology Laboratory of the Faculty of Agrarian Sciences of the National University of Asunción, they were dried for microscopic observation and identification. The forest species were identified using taxonomic keys, taking into account the size of the tree, the stem, the wood, the bark and the leaves. Three specimens of macrofungi of the genus Phlebopus were found associated with the trees of the Bignoniaceae and Fabaceae families in Asuncion green spaces. Two native forest species Handroanthus heptaphyllus (Vell.) Mattos, Jacaranda mimosifolia D. Don and one exotic Bauhinia variegata L. associated with the fungus Phlebopus sp.

Wild animals´ illegal or prohibited trade is a global problem and constitutes a serious risk to threatened and endangered species. The research was carried out in Niceto Pérez municipality, Río Frío locality in Guantánamo province. The objective was to determine the species of wild birds that are illegally traded and their abundance in the municipality. A total of 95 surveys were applied to people involved in poaching for various purposes. A total of 16 most traded species in the municipality were identified during the period from November 2018 to May 2019. 15 census routes of four m wide by 1 000 m long for a total of 6 ha were surveyed, within which ten counting points were established in each one, with a distance from each other of 100 m. All birds seen or heard during ten minutes were inventoried. As a result of the inventory, 20 bird species were counted, grouped into six orders, 15 families and 21 genera. The order Passeriformes was the most representative, 62 % were permanent residents; of these, only six species coincided with those reported in the surveys as illegally hunted. It was found that, there are significant differences in the areas studied between the months monitored, especially in those that coincide with the reproductive period of the species.

The quality of sawn wood is affected by the warping that it presents after drying, it is important then, to understand the mechanisms that regulate this deformation. Consequently, this work offers results of the influence of the variation and sawing patterns, dimensions and drying time of the pieces, on the warping of the sawn wood of Pinus caribaea var caribaea. The sawn pieces come from trees of the same origin, diameter and age. The study of the sawing variation was carried out with a methodology similar to that proposed Center of Forestry Studies, samples were taken with the same length and width but, of different thickness to every third of the selected piece. For the analysis of sawing schemes, sawn pieces were used taking into account the position of the medulla on the face, edge and center of the piece and pieces that do not contain it. The influence of the dimensions, were studied from taking pieces in different positions in radial direction with different dimensions (13 x100x3000) mm and (75x100x3000) mm were coded as: A, B and C by the distance to the medulla. Warpage measurements were made at 25, 60 and 90 days of drying. According to simple analysis of variance, the sawn pieces that experience less warpage are those that not contain medulla, those that do not experience variations in sawing, and those with greater thickness. Warping increases with drying time.

The survival of Swietenia mahagoni obtained in nursery with the application of arbuscular mycorrhizal fungi (AMF) and different organic substrates was evaluated. Plants produced on two levels of substrates: cocoa husk, coconut fiber and composted pine sawdust in 6:2:2 and 2:6:2 ratios, and four levels of mycorrhizal strains: Glomus cubense, Rhizoglomus irregulare, Funneliformis mosseae and non-mycorrhizal, were used for a total of eight treatments. Plants in the field were distributed under a randomized block experimental design, with four replications per treatment; the planting frame used was 2 x 2 m. The plantation was done after 30 days and the survival was assessed monthly until 12 months. During this time, the morphological variables: height and diameter were registered, and the height to diameter ratio and the relative growth rate were calculated. Survival analysis was performed using the Kaplan-Meier estimator and proportional hazards regression was performed to determine the risk of mortality as a function of morphological variables. At 12 months after planting, an average survival rate of 86.30 % was obtained, with higher percentage for plants inoculated with Glomus cubense and Rhizoglomus irregularestrains in the substrate composed of 20 % cocoa husk + 60 % coconut fiber + 20 % sawdust. Diameter was the morphological variable most related to the risk of mortality in the planting sites

In recent decades, the area affected and the severity of forest fires have increased in many regions of the world. Without anticipatory adjustments, climate change is likely to increase their frequency and intensity. This study aims to assess the possible impact of climate change on the initiation of forest fires in Las Tunas, The purpose of this study was to assess the possible impact of the climate change in forest fires initiation in Las Tunas, which is a most deforested region in Cuba thus a vulnerable region to aridity, drought and prone to forest fires. Taking into account the characteristics of the meteorological variables, the aridity conditions and the behavior of forest fires, a long-term risk index was used. It allows determining by months the areas with favorable conditions for the start and development of fires. Based on the possible changes in the meteorological variables in the RCP2.6 and RCP8.5 scenarios, this index was evaluated, which allowed obtaining the areas with the highest fire risk for the periods 2020-2049, 2050-2079 and 2080-2099. In general, in the territory of Las Tunas, there is a tendency to warmer conditions with reductions in rainfall, especially in the north coast. Besides, there is a decrease in relative humidity, which will lead to more areas affected by aridity and drought. Also, there will be larger areas with the presence of fire danger conditions for vegetation.

The technologicalisation of society has posed a great challenge for 21st century education, which has had to face it in order to provide quality digital literacy. These accelerated changes have repercussions in a number of areas, including the professionalisation of teachers due to the difficulties they face in updating their knowledge and adapting to the rapid pace of technology. Digital technologies are now indispensable in the working, social, economic, sporting, artistic, cultural, scientific and academic environments and are an essential element for academic and professional training. All of this highlights the need for a digital transformation in teaching and the acquisition of technological competences that respond to current challenges and thus offer comprehensive training for life, enabling evolution in the digital era and opening paths towards new, meaningful and innovative pedagogical practices. This study focuses on analysing the different existing competency frameworks necessary for teachers to develop throughout their professional and personal careers, as well as the importance of assessing their level of competence and knowing how to diagnose, in this way, the CDD acquired through various instruments of different typologies created for this purpose.

As a result of the declaration of the global pandemic due to COVID-19, universities around the world had to adapt their classes to the online mode for long periods or alternate this mode with face-to-face. The lack of planning related to this change could have consequences on teaching. This study aimed to know the perception of university students about online classes during this pandemic period and to analyze some variables associated with the degree of acceptance of these classes. To do this, 266 students belonging to 20 different degrees and 14 Spanish universities have been surveyed. A questionnaire was developed based on previous studies to collect information on the experience of the students with the online modality, the comparison between the online and face-to-face modality in terms of advantages and disadvantages, and satisfaction with the online modality. The results indicate that more than half of the students surveyed prefer face-to-face training, although they perceive some advantages associated with online training. Students also perceived face-to-face training as more effective in achieving learning objectives. Satisfaction with online teaching was related to greater interaction with peers, greater student involvement in training, and better perception of the role the teacher.

Resumo: Este estudo tem como foco a análise do Tratado da Argumentação no discurso, a Nova Retórica, na obra “Eu sei porque o pássaro canta na gaiola”, de Maya Angelou. O objetivo geral da pesquisa é analisar os processos argumentativos presentes na obra. Em vista, analisar as teses, valores e as suas hierarquias em excertos retirados do livro a fim de entender o contexto social, histórico, econômico e cultural da oradora durante o período de segregação racial no sul dos Estados Unidos. Além disso, o artigo busca compreender as teses defendidas pela oradora diante das adversidades e vivências que compõem sua trajetória, tais como: injustiça social, pobreza, abuso sexual, machismo, desigualdade social, dentre outros. Metodologicmente, a pesquisa é de cunho qualitativo e apresenta caráter documental e emprega-se o método dedutivo para analisar o corpus do trabalho, visto que há a utilização do aporte bibliográfico em teóricos que discutiram acerca da temática. O corpus é constituído por seis excertos da obra “Eu sei porque o pássaro canta na gaiola”, de Maya Angelou. Os resultados apontam que o discurso do orador apresenta teses, valores e suas hierarquias. Observa-se que a oradora consegue convencer o auditório, tendo como principal ferramenta a argumentação no discurso. A pesquisa evidenciou que a argumentação compõe a linguagem humana, sendo uma forma de manifestar, denunciar e convencer o próximo de sua realidade, ou seja, do contexto em que o orador se insere. Em suma, fica clarividente o papel que a literatura exerceu como suporte para sobrevivência às adversidades pelas quais aa oradora/narradora destina a tese a fim de convencer o auditório. Palavras-Chave: Argumentação;  Maya Angelou; Autobiografia; Literatura Afro-Americana. Abstract: This study focuses on the analysis of the Treatise on Argumentation in Discourse, the New Rhetoric, in the work “I know why the bird sings in the cage”, by Maya Angelou. The general objective of the research is to analyse the argumentative processes present in the work. In view, analyse the theses, values and their hierarchies in excerpts taken from the book in order to understand the social, historical, economic and cultural context of the speaker during the period of racial segregation in the south of the United States. In addition, the article seeks to understand the theses defended by the speaker in the face of adversity and experiences that make up her trajectory, such as: social injustice, poverty, sexual abuse, machismo, social inequality, among others. Methodologically, the research is of a qualitative nature and presents a documentary character and the deductive method is used to analyse the corpus of the work, since there is the use of the bibliographic contribution in theorists who discussed the theme. The corpus consists of six excerpts from the work “I know why the bird sings in the cage”, by Maya Angelou. The results show that the speaker's speech presents theses, values and their hierarchies. It is observed that the speaker manages to convince the audience, having as main tool the argumentation in the speech. The research showed that argumentation composes human language, being a way of expressing, denouncing and convincing others of their reality, that is, of the context in which the speaker is inserted. In short, the role that literature played as a support for surviving the adversities for which the speaker/narrator intended the thesis in order to convince the audience is clear.Keywords: Argumentation; Maya Angelou; Autobiography; African American Literature.