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

To test the island rule, the body size of P. mercatoris and P. aurata was measured, then statistical test and generalized linear models (GLM) were performed to explore changes in body length of both species. A smaller body length was evidenced in P. mercatoris supporting insular dwarfism. Additionally, P. mercatoris showed a trend of decreasing body size over time. This is the first report of the island rule in polyplacophorans. The temporal decrease in the size of P. mercatoris suggests a possible increase anthropogenic pressure, which should be studied to facilitate conservation and monitoring strategies.

The specialized herds of the high tropics of Nariño are characterized by semi-intensive breeding models, that is, feeding based on grazing and supplementation. The objective was to analyze the milk production of grazing Holstein cows under conditions of the high tropics, taking into account the energetic and protein metabolites, and their relationship with the dry matter intake (CMS/Kg/d), the body condition (BC), and the reproductive variables. Three periods of lactation were evaluated, thus, between 4-10 days (P1), 45-55 days (P2), and between 185-200 days (P3). The investigation was carried out in four dairy production farms. The forage supply consisted of a mixture of Lolium hybridum, Cenchrus clandestinus Hoschst ex Chiov, Holcus lanatus and Trifolium repens, plus commercial concentrate. A total of 24 Holstein animals (six per productive system) from three births onwards were used, from which blood samples were obtained to determine: non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHB), triglycerides, cholesterol, glucose, total protein (PT), and blood urea nitrogen (BUN). The results showed that milk production during P1 is influenced by CC and body weight (Kg) by +0.04 liters of milk per unit of change in this variable. In P2, the positive incidence variables were PT, BUN, glucose, NEFA, BHB, triglycerides, and cholesterol, and in P3, the increase in CMS made it possible to show that as lactation progresses in more than 180 days, the animals substantially improve their body condition; likewise the NEFA and BHB indicators are related to a better reproductive response.

The Meloidogyne incognita and M. javanica complex cause damage to the coffee plants’ roots with loss of productive potential. Traditional management against this complex is based on the use of chemical molecules which causes problems in soil health and harmful to the environment. In this regard, the Micosplag® biotechnological input [Paecilomyces lilacinus (Thom) Samson, 1974, Metarhizium anisopliae (Metsch) Sorokin and Beauveria bassiana (Balsamo) Vuillemin] and Tricho-D® (Trichoderma harzianum Rifai, 1969) were evaluated under greenhouse conditions against root-knot nematode complex. A dose of 2g. L-1 of water was used for Micosplag® and 10g. L-1 of water for Tricho-D®, applying a volume of 20mL.1 per plant. The nematode inoculation was carried out eight days after the sowing, using 2500 eggs per plant. Bioinputs were applied preventively and also as bioregulators of an existing nematodes population. Nine treatments, which corresponded to different moments of application of bioinputs in soil and soil plus vermocompost were evaluated. Results showed the lowest levels of infection when the Micosplag® bioinput was applied preventively (infection level of 6%), followed by the Tricho-D® treatment (infection 12%). There were statistical differences with the controls which were inoculated alone with the nematodes. When the two Bioinputs were applied preventively, they offered greater protection to the roots against nematodes. Dry weights of root and the aerial part of the plants showed the lowest values in treatments where the nematode was inoculated. Six months after the experiment was established, the three fungi that compose the Micosplag® Bioinput were isolated from the rhizosphere of the coffee plants.

Potato (Solanum tuberosum L.) cultivation is an important agricultural activity in the Andean region. The late blight Phytophthora infestans (Mont.) de Bary, considered one of the limiting diseases in production, represents a threat to food security and causes losses ranging from 30 to 100% of yield. This research evaluated the response to the disease in four commercial materials widely planted in the department of Nariño. The evaluation was carried out under field conditions, in the municipality of Pasto, at AGROSAVIA's Obonuco research center, with natural inoculum, under a randomized complete block design with four replications. The response variables evaluated were incidence, severity, leaf area index and yield in the commercial categories. The ICA Única variety, reported as highly resistant in 2001, presented damage levels close to 75%, with a yield reduction of 49.88%, caused mainly by low yields of first category tubers, indicating a loss of its level of resistance, with damage levels similar to the highly susceptible control Diacol Capiro, which presented 100% of the area with symptoms of the disease and a reduction of 89% in yield. The genotypes Pastusa Suprema with disease tolerance characteristics and Superior showed the best performance with a severity level of 30% in each case and yield reductions of 30.5% and 40.92%, respectively. The results highlight the importance of these genotypes and their role as pillars in the integrated management of the disease through the planting of varieties with favorable behavior against the disease.

The characterization of production systems is important to determine limitations and potentialities that allow their management. This type of diagnosis has not been carried out in the study region; therefore, there is no information on cocoa-based agroforestry systems. Therefore, traditional cocoa farms in the municipality of Los Andes, department of Nariño (Colombia), were social and economically characterized. Basic information was reviewed and a semi-structured survey was applied to a stratified random sample of 60 cocoa farmers. Eighteen qualitative and 20 quantitative variables were analyzed simultaneously with multiple correspondence analysis (MCA) and principal components analysis (PCA). In the PCA, five components explained 58.7% of the variability. The variables with the highest contribution were farm area, income from cocoa yields, income from agricultural production other than cocoa, and family labor. In the MCA, 11 components explained 58.43% of the variability. The most important components were farmers' schooling, transport type, loans, marketing, technical assistance, gender, land tenure, production systems, roads, and domestic animals. Finally, topographic and climatic conditions, inadequate roads and marketing of cocoa and the low adoption of technologies limit the competitiveness of the cocoa farms, hence the need to create favorable conditions to enhance the potential of cocoa agroforests.

This study aimed to explore the use and effect of agricultural credit disbursed from banks and financial institutions on banana yield in farmers from Valle del Cauca (Colombia) using data from the National Agricultural Census (2014). Additionally, it evaluated whether the effect of credit differs according to the items in which the farmer prefers to invest. For this purpose, because credits are not granted randomly, this research used the Propensity Score Matching (PSM) methodology to manage selection bias.  Initially, it was found through the probit model that having one's own agricultural machinery, using chemical fertilization to improve soil fertility, not belonging to an ethnic minority, and having some type of basic or higher education, increases the probability of obtaining an agricultural credit. On the other hand, the results suggest that credit has positive and significant effects on crop yield (6.2%), but the effect is greater if it is invested in land purchase and post-harvest processes, with an increase of 39% and 37% in yield, respectively.  On the other hand, this study also suggests that, if credit is invested in items not related to agricultural activity, yields can be affected with a 10% reduction. Finally, it is recommended that a public policy be implemented to encourage greater participation of banana farmers in Valle del Cauca in agricultural credit programs, given their low participation (10%) despite the high acceptability rate (86%).

This study evaluated the use of convolutional neural networks (CNN) in agricultural disease recognition, specifically for Botrytis fabae symptoms. An experimental bean culture was used to capture images of healthy and affected leaflets, which were then used to perform binary classification and severity classification tests using several CNN models. The results showed that CNN models achieved high accuracy in binary classification, but performance decreased in severity classification due to the complexity of the task. InceptionResNet and ResNet101 were the models that performed best in this task. The study also utilized the Grad-CAM algorithm to identify the most significant B. fabae symptoms recognized by the CNNs. Overall, these findings can be used to develop a smart farming tool for crop production support and plant pathology research.

Food-borne diseases (FDB) are responsible for causing approximately 600 million illnesses and 420,000 deaths per year. Biologically related FBDs are typically associated with ubiquitous microorganisms, with bacteria such as Li. monocytogenes, Escherichia coli, Salmonella and Staphylococcus aureus being frequently implicated. The use of probiotics is limited by adverse conditions, that can impair the stability of La. reuteri and the evaluation of its probiotic properties and effects on pathogenic bacteria. Therefore, it is crucial to develop effective strategies to protect probiotics during their use. This study was conducted aiming to determine the effect of microencapsulation by spray drying technique on the probiotic viability of La. reuteri on Li. monocytogenes under simulated gastric conditions. The research involved reconstituting, planting, and inoculating La. reuteri and Li. monocytogenes; determining fermentation kinetics; conducting spray drying microencapsulation; studying and characterizing of microencapsulation; testing for exopolysaccharides production; conducting temperature tests; assessing exposure to gastric conditions; and conducting antibiotic susceptibility and inhibition tests. Such investigations allowed the establishment of the exponential phase in Probiotic (PRO) culture medium at 18 h and in De Man, Rogosa and Sharpe agar (MRS) medium at 12 h, exopolysaccharide production positive and growth at different temperatures (1.95x1013 CFU/ml and 2.16x1012 CFU/ml), survival against gastric conditions (greater than 108 CFU/ml) and inhibitory effect of La. reuteri on Li. monocytogenes (halos larger than 2 mm). The probiotic La. reuteri microencapsulated in a binary matrix composed of inulin and maltodextrin expresses probiotic properties against Li. monocytogenes, which is responsible for FBD and great stability after undergoing simulated gastric conditions.

The need to have doctors specialized in Internal Medicine prepared to guarantee the quality of health services according to the always gradual demands of the population, continues to be a priority of the Cuban Health System. This preparation requires a deep mastery of both theoretical knowledge and those professional skills necessary for professional performance during the care of a number of medical problems related to the internal systems of the adult individual, their prevention and treatment from an integral conception of the human being; Among them, attention to pregnant women acquires a great connotation due to the high risk of appearance in the pregnancy stage of certain pathologies. In this sense, the objective of this work was to carry out a characterization of the training and development of professional skills of the Internal Medicine resident for the care of pregnant women with associated pathologies. A mixed approach was assumed on a sequential design for obtaining the information that allowed the performance of a triangulation of data. The main methods used in the empirical order were the interview to different sample groups and the observation of teaching activities; The analytical-synthetic and the inductive-deductive methods were used as theoretical methods. The results of the research allowed us to determine the main characteristics of the training and development of professional skills of Internal Medicine residents for the care of pregnant women with associated pathologies.

The teacher's management is very important in the development of students' scientific thinking; but for this to be the case, it is necessary for teachers to achieve this type of reasoning, the main characteristics of which are considered to be its strategic, critical, deep and complex nature. The objective of the article is to expose the results of an exploration of the thinking of a sample of 27 recently graduated teachers and seven in the last years of the Pedagogy-Psychology career to know to what extent their thinking styles were close to or far from scientific. Considering that problems challenge people's thinking, two instruments were used: a professional problem and a general social problem; the respondents had to explain how they would proceed to solve them. The results point to weaknesses in the strategic nature, depth, criticality and complexity in the way of thinking of the respondents. Other investigations consulted coincide with what was obtained and postulate the importance of the teaching-learning process being oriented towards supplying these deficiencies. It is concluded that, as a trend, the thinking of the people in the sample moves away from what they theoretically call scientific thinking.