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

Propolis is a resinous substance produced by bees, and various investigations show that it has antioxidant, antimicrobial, and antifungal properties, which is why it is considered a great alternative as a natural preservative for foods and beverages, compared to artificial preservatives. The objective of this research work was to microbiologically evaluate the useful life of peach nectar with propolis as a natural preservative, under the parameters of NTS N°071-MINSA/DIGESA-V.01. The methodology used consisted of preparing nectar samples with different concentrations of propolis (0.03% and 0.05%) and storing them for two, five and nine days at room temperature, subsequently performing the seeding and microbiological count for mesophilic aerobes, coliforms total, molds and yeasts. The results showed a greater antimicrobial effect on total coliforms and molds, for nectar samples with propolis at 0.05%; and a greater antimicrobial effect on yeasts and mesophilic aerobes, for samples at 0.03%. Although the shelf life of the product could not be determined due to the high initial microbial loads, the potential preservative activity of propolis is evident.

Canine rabies is a current health problem, very important for public health, livestock production, and the economy. The objective of this research was to evaluate the Spatio-temporal distribution of canine rabies in the period 2009-2018 in Havana, Cuba. A descriptive, retrospective, passive, cross-sectional, observational study was conducted. For the statistical analysis, the Epidat software, version 3.1, based on a Microsoft Excel matrix, was used. The epidemiological indicators were determined: prevalence of cases, monthly time series, and cumulative trend of outbreaks. While, for the spatial analysis, the geographic coordinates were calculated from the centroid of each municipality. For visualization, the QGIS version 3.0.1 program and the GEOCUBA cartographic bases were used. The comparison of proportions was made for the positive cases between the peripheral and central areas, which were graphed in the statistical package BlueSky Statistics version 6.0.7. As a result, it was obtained that the highest population density of canines/km2 is found in the group of municipalities 10 of October - Centro Habana-Habana Vieja; followed in decreasing order by the West group (La Lisa-Playa-Marianao-Regla) and the lowest population density in the Cotorro-Guanabacoa-Habana del Este group. Highly significant proportions of foci were revealed in the peripheral geographical areas, compared to the central ones. It was shown in the monthly time series of rabies foci, a parallel behavior in time from 2009 to 2013, with an increase between February 2014 and October 2015, and a peak in the month of August, in addition, there was a decrease in the month of November 2018. It is concluded that there is a trend towards significant variations in the spatial and temporal distribution of canine rabies in Havana in the period 2009-2018.

Ulomoides dermestoides (Fairmare,1893), commonly known as the peanut weevil, is an insect belonging to the order Coleoptera, family Tenebrionidae; it is characterized by being a pest of different stored grains such as peanuts, corn, and oats, among others; generating large economic losses. Azadirachtin is a triterpenoid present in the leaves, seeds, and trunk of the Azadirachta indica A. Juss (Neem) tree, belonging to the Meliaceae family, which has demonstrated a biocidal effect on different pests, acting at a reproductive, hormonal, digestive and neurological level, without causing harmful effects. to the ecosystem. In this study, the biocidal and repellent effect of the extract and powder of A. indica leaves on U. dermestoides was evaluated by spraying the leaves dehydrated for 48 h at 40°C and their extract by hydrodistillation. The experimental design to evaluate the biocidal and repellent effect consisted of two groups with dilutions with distilled water in proportions of 1:0 and 1:1, respectively, both for the extract (Te1 and Te2) and for the powder (Tp1 and Tp2) and a control. for both evaluations (Ce and Cp). Obtaining as a result that it has a low biocidal effect in both presentations (extract and powder), but it has a greater repellent effect in both presentations.

The study of the population is of vital importance for the planning of a country, these are sources of information for administrative decision-making. In Cuba, there are national and provincial regularities regarding the main demographic variables, but particularities are appreciated in the municipalities; above all, in those with mountainous characteristics, as is the case of Manicaragua, in the Villa Clara province, in Cuba. The objective of the work is to describe the demographic variables of the Manicaragua municipality, Villa Clara between the years 2016 and 2019. Methods of the theoretical and empirical level were used, the review of documents being fundamental, focused on the analysis of statistical, national, provincial, and municipal from 2016 to 2019. The data obtained corroborate a negative annual growth rate in the years analyzed, ranging between (-9.5) in 2016, to (-10.9) in 2019, the population pre-employment decreased from 2016 to 2019 from 11,518 people to 10,460 people, the dependency ratio increased from 2016 (574 0/00) to (576 0/00) in 2019, with low birth rates prevailing in 2016 (10.2 per thousand) and (8.4 per thousand) in 2019, the general mortality varies, in a range from 9 0/00 as a minimum expression in 2016, to a maximum of 10.3 0/00 in 2018, while the migratory balance is negative in the period behaving in a range between 8 0/00 and 11 0/00. The population has aged by 260 more people, between 2016 and 2019. All this situation can compromise, in a relatively short time, the socio-economic stability of the territory.

The aim of the study was to describe the intellectual function of working memory capacity (WMC) in university students from a case study. The study was conducted from June to July 2022 and in a random probabilistic way, six research seed students belonging to the National University "San Luis Gonzaga" (Ica, Peru) were selected. The WMC analysis was done through two types of didactic games (DG) with different degrees of complexity: 1st) the Divinance of colored cubes and 2nd) the marking and recognition of three sea shells between a total number of 100 shells. Each DG was replicated twice the first for stimulation of mental concentration in the face of the WMC analysis. The DG was replicated twice and in the case of the second, the immediate time (s) of recognition was measured where the comparison of the medians was, through the U-Whitney test. It was observed that the time of each replica and the coincidence error in the DG of the marking and recognition of the three shells was: U = 11.0 and p = 0.25. Although the coincidence error decreased in replica 2 and denoted higher CMT. It is concluded that the intellectual function of the CMT is possible from the JD since they represent an emotional stimulus. However, practices are needed that improve learning and particularly, from observation to an understanding of the objects to be selected.

Wetlands provide multiple ecosystem services that multiply the social, economic, and environmental development of the population; However, these problems undergo environmental problems that accelerate the eutrophication process. The purpose of this research was to evaluate the trophic states of Medio Mundo’s main lagoon of the Albufera Regional Conservation (ACRAMM). For this, the Carlson Trophic State Index modified by Toledo (IETM) was used and a predictive mathematical model for the total water phosphorus was formulated; where the dependent variable was represented by the parameter and the independent ones, by the reflections of Sentinel-2 images. The ACRAMM, according to the phosphorus model, was eutrophic on the first 5 dates evaluated (IETMPT> 65.56) and from oligotrophic to eutrophic with a tendency to increase from south to north on the last date (IETMPT = 38.29-56.99). These results lead to the conclusion that the trophic status of the ACRAMM is in the highest classification of the index, mainly by the following polluting sources: agricultural drainage, industrial wastewater dumping, open oxidation ponds at Medio Mundo town, grazing activities, tourist facilities and water pumping stations installed at adjacent areas.

The absorption of heavy metals by growing plants is an environmental problem for human consumption. The aim of the study was to describe the biological absorption coefficient in Zea mays due to lead exposure in the Quitasol solid waste dump in Abancay, Apurímac, Peru. Three sampling points (PM1, PM2, and PM3) of the agricultural soil where the biological absorption coefficient (BAC) was determined were selected through a random probability sampling, through the relationship between the concentration of assimilable lead in the root and the concentration of assimilable lead in the soil. The BCA ranged from 0.06 to 0.91 where there were statistically significant differences between sampling points 1 and 3 compared with 2. It was observed that the CAB concentrations were higher than the value 0, which indicates that the plant is absorbing lead and could produce phytotoxicity effects in Z. mays, as well as bioaccumulation. It is concluded that the biological absorption coefficient in Z. mays shows that the soil is contaminated and, given the environmental conditions, the sowing and consumption of this crop is not adequate, as it would have effects on human health.

One of the most complex problems faced by universities is to achieve from the initial training process that all subjects respond to the profession so that when the student begins his working life, he will be able to solve new challenges of science and technology. In the teaching-learning process of the Physics subject, which was developed in the Bachelor's Degree in Nursing at the University of Medical Sciences of Villa Clara, Cuba, there are insufficiencies to achieve the integration of Physics and the biological subjects that make up the "Health Technology and Nursing" careers. In this sense, the objective is to propose a workshop system for the teaching-learning process of the Physics subject. Different methods were used to collect and process the information. The proposal was submitted to experts' criteria, who assessed it as pertinent and the opinions issued by them allowed perfecting it before its introduction in the pedagogical process of Physics, which revealed novel results once implemented in the course 2020-2021.

The present work has as its main objective to evaluate the potential of the use of physic nut (Jatropha curcas L). for the generation of biofuel, through a literature review. The physic nut is a shrub of economic importance, due to its various industrial uses. It is relevant for the development of bioenergy, due to the high concentration of oil in its seeds, which is why it is used for the production of biodiesel, while the shells of its fruits can be considered for the production of ethanol due to its high cellulose content. The cake obtained after the oil extraction process is a useful organic by-product that contains considerable amounts of macro and micronutrients, being suitable for agricultural use as organic fertilizer, and if the cake goes through a detoxification process, it can be used as animal feed.  

This note reports observations on the distribution Lontra felina (Molina, 1782) "marine otter" in eight new sites located in the district of Ventanilla, in the region of Callao, as well as in the districts of Santa Rosa, Ancón and Aucallama, in Lima, Perú. The fieldwork was carried out between January and June 2022 and six live animals and four freshly dead otters were observed. Both Bahía Blanca, in the district of Ventanilla, and the beaches of the Navy Club at Ancón, were the locations with more observations.