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

The purpose of this study has been to investigate the dynamics of dengue transmission in the 76 municipalities that make up the main island of Puerto Rico, for weeks 1 to 4 and 32 to 36 of 2014. A Bayesian spatial model was used to study the possible relationship between incidence, socioeconomic, climatic and environmental variables. Once the models are proposed, the settings are compared with indices such as WAIC (Watanabe, 2010), to determine which one represents the data best. It is also determined by the I-Moran index if there is spatial correlation in the residuals, since the existence of the index is an indicator that the adjustment is not good to some extent. Temperature and precipitation data should have been previously interpolated, since the stations that collect them are not in the population centers, to see the calculations the reader may refer to (Hernández-González, 2017).

The main objective of this research is to analyse the use of online social networks among the student body who takes secondary education, through the establishment of risks and preventive steps for a correct communication. The research was conducted under a quantitative approach with a explicative position. The population was formed by 1895 students, distributed in the III cycle of basic education and diversified education, from day high schools of the educative district 02, Sarapiquí canton, this is why it was opted to take a stratified statistic sample of 320 students.  As a result, it is determined that the 99% of the interviewees use electronic devices to communicate through internet, with a 96% the cellular phone. It is identified that 75% learnt only to use internet and a 95% uses social networks, a 96% whatsapp, 86% facebook, 67% Instagram, and a 31% snapchat. Moreover, it is evidenced that 83% of the students are alone when using social networks and only 33% of the educative institutions taught them about this topic. Apart from that, 80% of the parents do not establish controls on its use.  In conclusion, the student body of secondary uses mainly the cell phone to communicate and access social networks online, such as: Whatsapp, Facebook, and Instagram. In addition, it is established some differences on the relation to know and apply security and privacy policies on the use of those means of communication, it is shown  the lack of knowledge by the participants on the educative action: the teacher, student and parents, with regards to the risks and preventive steps when communicating through social networks.

This study was conducted in order to determine whether adding products based on microorganisms could increase, through their natural dynamics and their interaction with native microflora and microfauna populations, the variability of the soil and, therefore, the optimum plot size for rice trials in Bagaces, Guanacaste, Costa Rica.  This trial was conducted at the same farm where the optimum plot size was defined for rice trials in the area (Vargas & Navarro 2014). Four uniformity trials were planted, one for each product used: Trichoderma, Bioactivado, Nitrobacter, and Micro Plus. The data obtained was used to apply the maximum curvature method. The point of maximum curvature was determined using the partial derivative of the regression equation, which relates the plot size (X) with the corresponding variation coefficient (Y). None of the product’s point of maximum curvature exceeded the scope defined by Vargas & Navarro (2014) from 15 m2 to 20 m2. None of the indices of heterogeneity obtained exceeded the 0.83 value (the scope of the scale for this measure ranges from 0 to 1, where 0 indicates total homogeneity and 1 total heterogeneity) (Vargas & Navarro 2014), which shows that very diverse soils can be found in the same farm.  Finally, the variance analysis showed differences in the production obtained with each product. A 17tm/ha production was obtained with Bioactivado, which triples the normal production of the farm.

Soil management is essential in the context of climate change adaptation, but baseline information is first required for its management, use and conservation. This project aimed to address the poor documentation of the soil in the forest section of the Finca Experimental Interdisciplinaria de Modelos Agroecológicos in Turrialba, Costa Rica. The aim of this study was to analyze the effect of land use on physicochemical characteristics of the soil to contrast the processes associated with forest management and evaluate the temporal effect of zonification on soil characteristics. A series of biological variables were also determined to evaluate response uniformity within the forest. For all the studied area, soil texture was classified as medium and coarse and chemical fertility was medium to high without major differences among land use sections. However, color, apparent density (0.6-1.4 g/cm3), porosity (48.2-77.7 %) and infiltration velocity (552-3405 mm/day) were influenced by soil texture and land use. Soil respiration had a high average of 46.33 µg C-CO2/gh and no differences in biological variables were observed within the forest. The information obtained in this study demonstrated that forest cover has had a stronger impact on structural variables in relation with other land use types. The forest, however, seemed to have developed as a functional homogeneous unit.

The phenofases of Blakea scarlatina and its association with biophysical factors were studied, from March 2014 to October 2015. The sample was selected in order of appearance. The phenofases were evaluated every month, with a scale of 0 to four. Budding and leaf abscission occurred during the study, the last one except in June 2014. Flowering occurred in 64% of the research, this makes B. scarlatina an attractive ornamental species. Intraspecific differences were recorded in the phenofases. The leaf abscission and budding were inversely proportional to the temperature. Flowering was associated with temperature, inverse case with relative humidity. Fruiting was associated with precipitation.

The article reflects on the situation at which the United States waged a trade war against China, positioning international trade as an instrument of international policy, to achieve objectives that go beyond the issue Economic. This situation of trade crisis is considered to be in the interest of geopolitical positioning by the United States. Moreover, it is claimed that this situation represents an affront to the international liberal order, which has historically been led by the United States, but is on this occasion eroding its traditional free trade stances; with the aim of affecting its closest international competitor by global hegemony, represented by China.

The purpose of the following work is to analyze and identify the causes of fetal death in Ecuador, to evaluate the current death rates and estimate a relationship with the possible growth in case of decriminalization of abortion, an alarming growth of this in relation to previous years, if it becomes legally accepted. For this, the study of a sample of 1818 data extracted from a medical database was carried out, which included statistical and descriptive probabilistic analysis in which a contingency table was applied for the operationalization of our variables, position statistics were used, made Poisson distribution, all this based on a programming language in R. as with the free software Rstudio being its programming language R