1,113 research outputs found

    Academic Procrastination, Self-Esteem and Self-Efficacy in University Students: Comparative Study in Two Peruvian Cities

    Get PDF
    The present study aims to determine the relationship between academic procrastination, self-esteem and self-efficacy in undergraduate students in two Peruvian cities. The population consisted of 13,767 students, from which a sample of 1,494 was extracted. The subjects were selected from eight universities: five private and one public, from the city of Metropolitan Lima; and two universities, one public and one private, from the city of Arequipa. The instruments used were the Academic Procrastination Scale (EPA), the Scale of Specific Perceived Self-Efficacy in Academic Situations (EAPESA) and the Rosemberg Self-Esteem Scale. The results allow us to conclude that, in terms of perceived effectiveness, the relationship is slightly higher in the city of Arequipa, reiterating this with respect to academic procrastination, where the relationship is also slightly higher. Finally, with regard to self-esteem, the trend continues to indicate a greater relationship in Arequip

    Local Anesthetics in Odontology

    Get PDF
    Pain has been a faithful companion of human beings and is a result of most of the dental procedures and illness; therefore a good control of dental pain is inevitable and feasible. The administration of local anesthetics has come to be the standard of care of dental profession. All local anesthetics are effective and high safety margin in all patients including childhood. The choice of using a local anesthetic depends on time of the surgical procedure, patient’s medical history, and the interaction between local anesthetics and patient usual medications. The use of vasoconstrictors is priority in surgical/dental bleeding, but it must be used with caution in patients with cardiovascular disease to avoid a dental catastrophe. Dentists should be experts in dental-anesthetic techniques and in pharmacology of local anesthetics, since they are the most used medications in odontology. The accidental injection or a high absorption of local anesthetics in blood results in systemic toxicity. In such situation sedation, stunning, diplopia, sensory disturbances, disorientation, muscles spasm, respiratory depression, seizures, or cardiac arrest may be present; the dentist must immediately recognize this clinical complication to stablish an early treatment

    Factorial design for preparing chitosan nanoparticles and its use for loading and controlled release of indole-3-acetic acid with effect on hydroponic lettuce crops

    Get PDF
    The excessive use of agrochemicals generates damage to the environment, so their controlled release from biodegradable nanoparticles represents a good solution. In this study, chitosan nanoparticles (CNPs) were prepared by ionic gelation with sodium tripolyphosphate (TPP), according to a 24 factorial design to evaluate the effect of different factors (chitosan amount, TPP amount, agitation speed, and agitation time) influencing the nanoparticle size (NPS) and the polydispersity index (PDI). Once established the proper conditions by the factorial design, CNPs were prepared and loaded with indole-3-acetic acid (CNP-IAA). The nanoparticles loaded with chitosan:IAA mass ratio equal to 1:0.25, showed the higher loading capacity, thus were then used for the release tests and hydroponic lettuces crops. The analysis by dynamic light scattering (DLS) reveals a mean diameter for CNPs and CNP-IAA of ~149 and ~183 nm, respectively. Moreover, further characterization by thermogravimetric analysis, Fourier transform infrared spectroscopy and scanning electron microscopy, indicates that nanoparticles were effectively loaded with IAA. In addition, the release assays results were adjusted to the Korsmeyers-Peppas mathematical model, showing that 100% of the hormone is released in about 48 h. Also, the model fitting suggests that the release process is carried out in two steps: the first of releasing by diffusion followed by a second of sustained-release. Accordingly, our results prove that CNPs-IAA applied to the hydroponic crop of the Crocantela variety crisp lettuce (Latuca sativa L.), have a beneficial effect on the plant growth producing an increase of 30.9% in the number of lettuce leaves

    Optimization of the ellagic acid synthesis process at the bioreactor level using non-conventional yeasts

    Get PDF
    Ellagic acid (EA) is a phenolic biomolecule. For its biosynthesis, a source of ellagitannins is required, such as strawberries and yeasts, as precursors of the tannase and β-glucosidase enzymes responsible for hydrolysis of ellagitannins. Two experimental mixture designs were applied., varying the yeast concentration and the number of ellagitannins in the culture medium, evaluating the enzymatic activity and ellagic acid biosynthesis. Aiming to find the optimal compositions of the non-conventional yeasts assessed in the research to biosynthesize ellagic acid feasibly and efficiently using a response surface performing the statistical analysis in the StatGraphics® program for obtaining a higher yield and optimizing the ellagic acid synthesis process, the results indicate that the strains Candida parapsilosis ITM LB33 and Debaryomyces hansenii ISA 1510 have a positive effect on the synthesis of ellagic acid, since as its concentration increases in the mixture the concentration of ellagic acid in the medium also increases; on the other hand, the addition of Candida utilis ITM LB02 causes a negative effect, resulting in the compositions of 0.516876, 0.483124 and 2.58687E-9 respectively, for a treatment under the same conditions, an optimal value of ellagic acid production would be obtained. With an approximate value of 7.33036 mg/mL

    PARADIGMA EVOLUTIVO EN LA FORMULACIÓN DE RACIONES PARA GANADO BOVINO (EVOLUTIONARY PARADIGM IN THE FORMULATION OF RATIONS FOR BOVINE CATTLE)

    Get PDF
    ResumenEl interés de la industria ganadera por la salud del animal ha impulsado el estudio de la preparación de raciones con los nutrientes necesarios para un mayor rendimiento en la producción de leche. El cuidado de una buena alimentación está directamente relacionado con la calidad y cantidad de leche producida por una vaca. Este trabajo propone una técnica evolutiva para la formulación de raciones con el objetivo de maximizar la producción de leche en el ganado bovino. El problema de la formulación de raciones es complejo debido a que no sólo se considera su peso, edad, especie y estado físico del animal, sino también, factores como la proteína cruda digerible, los nutrientes totales digeribles y la materia seca digerible son importantes en este proceso. En este trabajo, un Algoritmo Genético con representación binaria es propuesto para resolver el problema en la formulación de raciones. Los resultados obtenidos muestran que la aplicación del Algoritmo Genético en la preparación de raciones es una alternativa muy competitiva y eficiente, que alcanza un mayor rendimiento que los métodos tradicionales en la producción de leche para ganado bovino.Palabra(s) Clave: Algoritmo genético, Nutrición animal, Nutrientes, Rendimiento. AbstractThis work proposes an evolutionary technique for the formulation of food rations with the objective to maximize milk production in cattle. The interest of the livestock industry by the animal's health has promoted the study of the preparation of rations with the necessary nutrients for increased performance in the production of milk. The care of a good power supply guarantees the quality and quantity of milk produced by a cow. The problem of ration formulation is complex due to the fact that not only is considered your weight, age and physical condition of the animal, but in addition, factors such as the digestible crude protein, total digestible nutrients and the digestible dry matter are important in this process. A Genetic Algorithm with binary representation is proposed in the formulation of rations. The results are interesting and competitive reaching greater performance in the production of milk.Keywords: Animal nutrition, Genetic algorithm, Nutrients, Performance

    El Aprendizaje en el Siglo XXI: ¿Cuáles son los Retos Docentes Respecto del Aprendizaje de los Estudiantes en la Escuela del Reencuentro?

    Get PDF
    Currently, primary education teachers face challenges regarding student learning at the reunion school, the 21st century is fraught with challenges due to the management of students' emotions. The objective of the research was to analyze teacher perceptions regarding what they consider to be the main challenges they face with their students at the reunion school, prioritizing the emotional sphere and the management of competencies that are intrinsically developed in the teaching process. learning. An exploratory quantitative work was carried out with a non-experimental cross-sectional design and a representative sample of the Rafael Herrera Elementary School No. 16 of the State of Durango, the results show that there is a real challenge within the school environment to successfully face the learning of the students of the educational institution, due to the changes in their socio-emotional development, there are also teachers who show difficulty in expressing emotions of happiness during their practice, they consider that as teachers the proper management of emotions, likewise, the need to externalize an update where the best interest of NNA is prioritized, betting on the true achievement of learning before the characteristics of the students.Actualmente los docentes de educación primaria enfrentan retos respecto al aprendizaje de los estudiantes en la escuela del reencuentro, el siglo XXI está plasmado de desafíos debido al manejo de emociones de los alumnos. La investigación tuvo como objetivo analizar las percepciones docentes respecto a cuáles consideran que son los principales retos que enfrentan con sus alumnos en la escuela de reencuentro, priorizando el ámbito emocional y el manejo de competencias que se desarrollan de manera intrínseca en el proceso de enseñanza-aprendizaje. Se realizó un trabajo cuantitativo de tipo exploratorio con un diseño no experimental transversal y una muestra representativa de la Escuela Primaria  No 16 Rafael Herrera del Estado de Durango, los resultados muestran que existe un desafío real dentro del ámbito escolar para enfrentar con éxito el aprendizaje de los estudiantes de la institución educativa, debido a los cambios en su desarrollo socioemocional, además existen docentes que muestran dificultad para manifestar emociones de felicidad durante su práctica, consideran que como maestros  el manejo adecuado de las emociones es importante, así mismo, se externa la necesidad de una actualización  donde  se priorice el interés superior de  NNA apostando  al verdadero logro de los aprendizajes ante las características de los estudiantes
    corecore