Roles, Functions and Necessary Competences for Teachers’ Assessment in b-Learning Contexts

AbstractHigher Education Institutions are committed to ensure spaces of combined education or b-learning. Associated with this aim, there is a concern about the roles and functions that the teacher performs and how to assess them. This study is located at the intersection of research in educational assessment and b-learning in Higher Education. Under this foresight, this research is developed in a descriptive and propositive manner, adopting a qualitative approach which –through the implementation of grounded theory- encodes and analyzes 105 texts selected to present the characterization of the roles, functions and competences that the teachers must perform at the different stages of the process for developing a course based on b-learning methodology

Genomic variation and population structure detected by single nucleotide polymorphism arrays in Corriedale, Merino and Creole sheep.

THE AIM OF THIS STUDY WAS TO INVESTIGATE THE GENETIC DIVERSITY WITHIN AND AMONG THREE BREEDS OF SHEEP: Corriedale, Merino and Creole. Sheep from the three breeds (Merino n = 110, Corriedale n = 108 and Creole n = 10) were genotyped using the Illumina Ovine SNP50 beadchip(®). Genetic diversity was evaluated by comparing the minor allele frequency (MAF) among breeds. Population structure and genetic differentiation were assessed using STRUCTURE software, principal component analysis (PCA) and fixation index (FST). Fixed markers (MAF = 0) that were different among breeds were identified as specific breed markers. Using a subset of 18,181 single nucleotide polymorphisms (SNPs), PCA and STUCTURE analysis were able to explain population stratification within breeds. Merino and Corriedale divergent lines showed high levels of polymorphism (89.4% and 86% of polymorphic SNPs, respectively) and moderate genetic differentiation (FST = 0.08) between them. In contrast, Creole had only 69% polymorphic SNPs and showed greater genetic differentiation from the other two breeds (FST = 0.17 for both breeds). Hence, a subset of molecular markers present in the OvineSNP50 is informative enough for breed assignment and population structure analysis of commercial and Creole breeds

The influence of anthropogenic activities on the concentration of pesticides, physicochemical and microbiological properties in the Chumbao river, Andahuaylas, Perú

The province of Andahuaylas is located in the region of Apurimac, a Peruvian city located in the Andes. Andahuaylas has three important districts: San Jerónimo, Andahuaylas and Talavera. These areas are highly populated, and their buildings are close to the Chumbao River. This research aimed to determine the influence of anthropogenic activities on the concentration of pesticides, physicochemical and microbiological characteristics in the Chumbao River. Five agricultural activities, 19 organochlorine pesticides, and 25 organophosphorus pesticides were studied. Eighteen physicochemical properties and two microbiological properties were also studied at seven sampling points along the Chumbao River during the rainy and dry seasons. Several veterinary and agricultural products were identified in the agricultural activities studied. However, no significant concentration values of organochlorine and organophosphate pesticides were found; no weed control products were found. In the case of livestock farming, albendazole and ivermectin are frequently used as anthelmintics. Organophosphate and pyrethroid insecticides are used to control flies and other ectoparasites. Several pesticides have been identified in the surveys in the case of quinoa, potato, and corn crops. Some of the physicochemical and microbiological properties are above environmental quality standards according to current Peruvian regulations; these properties increase at points where wastewater is discharged directly into the river. The study evidenced a progressive deterioration of water quality in the Chumbao River caused by anthropic activities in the basin. These may cause infectious and parasitic diseases in the urban population of the Chumbao river valley

Influence of elastically pinned magnetic domain walls on magnetization reversal in multiferroic heterostructures

In elastically coupled multiferroic heterostructures that exhibit full domain correlations between ferroelectricand ferromagnetic subsystems, magnetic domain walls are firmly pinned on top of ferroelectric domainboundaries. In this work, we investigate the influence of pinned magnetic domain walls on the magnetizationreversal process in a Co40Fe40B20 wedge film that is coupled to a ferroelectric BaTiO3 substrate via interfacestrain transfer.We show that the magnetic field direction can be used to select between two distinct magnetizationreversal mechanisms, namely, (1) double switching events involving alternate stripe domains at a time or(2) synchronized switching of all domains. Furthermore, scaling of the switching fields with domain widthand film thickness is also found to depend on the field orientation. These results are explained by considering the dissimilar energies of the two types of pinned magnetic domain walls that are formed in the system.Peer reviewe

Modified Polymeric Biosorbents from Rumex acetosella for the Removal of Heavy Metals in Wastewater

The contamination of water resources by effluents from various industries often contains heavy metals, which cause irreversible damage to the environment and health. The objective was to evaluate different biosorbents from the weed Rumex acetosella to remove metal cations in wastewater. Drying, grinding and sieving of the stems was carried out to obtain the biomass, re taining the fractions of 250 to 500 µm and 500 to 750 µm, which served to obtain the biosorbents in natura (unmodified), acidic, alkaline, and mixed. Proximal analysis, PZC, TOC, removal capacity, influence of pH, functional groups, thermal analysis, structural characteristics, adsorption iso therms, and kinetic study were evaluated. The 250 µm mixed treatment was the one that presented the highest removal percentages, mainly due to the OH, NH, -C-H, COOH, and C-O functional groups achieving the removal of up to 96.14% of lead, 36.30% of zinc, 34.10% of cadmium and 32.50% of arsenic. For contact times of 120 min and an optimum pH of 5.0, a loss of cellulose mass of 59% at 328 °C and a change in the surface of the material were also observed, which allowed for obtaining a topography with greater chelating capacity, and the Langmuir and pseudo-second or der models were better fitted to the adsorption data. The new biosorbents could be used in wastewater treatment economically and efficiently

Rheological and functional properties of dark chocolate with partial substitution of peanuts and sacha inchi

Chocolate is a widely consumed product, due to the contribution of fats and antioxidant compounds; the addition of other components makes it possible to increase the content of polyunsaturated fatty acids, although they can affect its rheological properties. The influence of the partial addition of peanut paste and Sacha Inchi on the rheological and functional properties of dark chocolate was evaluated. Cocoa beans, peanuts, and Sacha Inchi were refined in order to obtain the cocoa paste (PC), peanut paste (PM), and Sacha Inchi paste (PSI). Then, mixtures between 0 to 20% of PM and PSI were formulated, and the rheological properties were evaluated at 30, 40, and 50 C; these were adjusted to mathematical models. Functional groups were identified by FTIR in ATR mode, and it was observed that the partial addition of PM and PSI did not show significant changes in the shear stress and apparent viscosity of the mixture, although they did show dependence on temperature. The Herschel–Bulkley model showed a better adjustment (R2 > 0.999), reporting behavior index values, n < 1.0, and indicating pseudo-plastic behavior for pastes and formulations. The yield limit ty and the consistency index kH increased significantly with the addition of PM and PSI, but they decreased with increasing temperature. The activation energy show values between 13.98 to 18.74 kJ/mol, and it increased significantly with the addition of PM and PSI. Infrared analysis evidenced the presence of polyunsaturated fatty acids, coming mainly from PSI and PM. The addition of PM and PSI does not influence the rheological properties and allows for an increase in the content of polyunsaturated fatty acids

Microencapsulation of Erythrocytes Extracted from Cavia porcellus Blood in Matrices of Tara Gum and Native Potato Starch

Ferropenic anemy is the leading iron deficiency disease in the world. The aim was to encapsulate erythrocytes extracted from the blood of Cavia porcellus, in matrices of tara gum and native potato starch. For microencapsulation, solutions were prepared with 20% erythrocytes; and encapsulants at 5, 10, and 20%. The mixtures were spray-dried at 120 and 140 ◦C. The iron content in the erythrocytes was 3.30 mg/g and between 2.32 and 2.05 mg/g for the encapsulates (p < 0.05). The yield of the treatments varied between 47.84 and 58.73%. The moisture, water activity, and bulk density were influenced by the temperature and proportion of encapsulants. The total organic carbon in the atomized samples was around 14%. The particles had diverse reddish tonalities, which were heterogeneous in their form and size; openings on their surface were also observed by SEM. The particle size was at the nanometer level, and the zeta potential (ζ) indicated a tendency to agglomerate and precipitation the solutions. The presence of iron was observed on the surface of the atomized by SEM-EDX, and FTIR confirmed the encapsulation due to the presence of the chemical groups OH, C-O, C-H, and N-H in the atomized. On the other hand, high percentages of iron release in vitro were obtained between 88.45 and 94.71%. The treatment with the lowest proportion of encapsulants performed at 140 ◦C obtained the best results and could potentially be used to fortify different functional foods

Insights from Water Quality of High Andean Springs for Human Consumption in Perú

The headwaters of the high Andean basin in Peru accumulate water from the mist, rain, snow, and hail, and it is transported superficially and underground to low-lying areas, mostly used for drinkable purposes. The natural water in these areas might be altered due to legal and illegal mining extraction. The aim of the study was to evaluate the water quality for human consumption. Seventeen water samples were examined from Andahuaylas (A), San Jerónimo (S), Talavera (T), and Chiara (CH) districts located between 2813 and 4004 m altitude in the Andes. We used physic ochemical, microbiological, and metal parameters, and the results were compared to permissible levels established by the WHO and ECA-Peru to examine samples collected in the dry and rainy seasons in 2019. Application of principal component analysis (PCA) identified areas and conditioning parameters. Extractive mining activity influences the quality of springs due to the presence of metals, especially antimony (Sb), arsenic (As), cadmium (Cd), and lead (Pb), values of which are higher than values permissible for human consumption, being higher in the dry season (p < 0.05). In addition, the presence of cations and particulate matter affects physico-chemical parameters, for example turbidity. PCA showed that parameters for water characterization are season-independent, and water quality in the springs would be conditioned by the presence of metals, especially in Andahuaylas and Talavera zones, as well as the parameters that are associated with dissolved solids in the water (turbidity and fluorides). A frequent monitoring program of springs and groundwater is recommended, with the purpose to protect water from contamination and guarantee safe water availability in low-lying and urbanized areas

Obtaining of activated carbon from seeds of eucalyptus by chemical activation with H3PO4. Characterization and evaluation of adsorption capacity of phenol from aqueous solution

Resumen Se sintetizo carbón activado a partir de cáscara de semillas de eucalipto (Eucalyptus globulus Labil), por el método de activación química empleando como agente activante ácido fosfórico, a dos diferentes concentraciones; 30 y 80 % v/v. Los carbones se caracterizaron texturalmente mediante fisisorción de N2, se determinó la superficie específica aparente por el método B.E.T., donde se obtuvieron valores de 2009 y 1027 m2 g-1, se utilizó la ecuación Dubinin-Radushkevich para obtener el volumen de microporo donde se reportan valores de 0.65 y 0.32 cm3 g-1. Se determinó mediante el método Bohem que los carbones son de carácter ácido, aspecto corroborado por la determinación del pH en el punto de carga cero. Se establecieron interacciones energéticas de los sólidos frente a soluciones de HCl y NaOH mediante calorimetría de inmersión, encontrando gran correlación con el contenido de grupos ácidos y básicos de los sólidos. Finalmente se evaluó la capacidad de adsorción de los sólidos con fenol desde solución acuosa, ya que este es un contaminante prioritario, donde se evidenció gran capacidad de adsorción de los dos carbones debido a las amplias áreas superficiales, volúmenes de microporo y la química superficial de los sólidos. Abstract Activated carbons were prepared from shell Eucalyptus (Eucalyptus globulus Labil) by chemical activation using as activating agent solutions of phosphoric acid, at two different concentrations; 30 and 80% v/v. Carbons were texturally characterized by N2 physisorption, the apparent surface area was determined by B.E.T., method, values obtained were 2009 and 1027 m2 g-1. Dubinin-Radushkevich equation was used to obtain the micropore volume with values of 0.65 and 0.32 cm3 g-1. Boehm method established that the carbons are acidic aspect confirmed by determining the point of zero charge. Solid energetic interactions against HCl and NaOH solutions were established by immersion calorimetry finding great correlation with the content of acidic and basic groups of the solids. Finally, the adsorption capacity of the solid was evaluated with phenol from aqueous solution since this is a priority pollutant, where high adsorption capacity of the two carbons was evident due to the large surface area, micropore volume and surface chemistry of solids