98 research outputs found

    Applets In Physics And Their Impact On The Development Of Thought

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    RESUMEN: En este trabajo se presenta una propuesta de enseñanza que involucra el uso de applets en las asignaturas de física mecánica de los programas ingeniería civil e ingeniería de sistemas de la Universidad Cooperativa de Colombia - sede Ibagué. El propósito de este estudio es conocer la incidencia de una estrategia didáctica centrada en el uso de applets y apoyada en la mediación de Feuerstein (1986,1988) como referente teórico. Se presenta un breve análisis tanto cuantitativo como cualitativo de la información recolectada, de donde se puede inferir que los estudiantes adquieren una motivación hacia el aprendizaje de conceptos físicos a partir de la interacción con estas potenciales herramientas, además de algunos indicios de aprendizaje significativo de dichos conceptos.ABSTARCT: In this work we present a teaching proposal that involves the use of applets in the courses of mechanical physics of the programs Civil Engineering and Systems Engineering in the Cooperative University of Colombia - Ibague. The purpose of this study is to know the incidence of a didactic strategy centered in the use of applets and supported in the mediation of Feuerstein (1986, 1988) as theoretical refeernce. It is presented a brief analysis, quantitative and qualitative, of the gathered information, from which we can infer that the students acquire a motivation toward the learning of physical concepts starting from the interaction with these potential tools, besides some indications of significant learning of these concepts

    Cat-Owner Relationship and Cat Behaviour : Effects of the COVID-19 Confinement and Implications for Feline Management

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    The aim of this study was to explore the effects of the Italian COVID-19 lockdown on the cat-owner relationship and on cat behaviour. In order to do so, we used a questionnaire to obtain information on the owner and cat's demographics, living environment, cat behaviour, and possible changes in some aspects of the cat-owner relationship. The questionnaire was distributed online when the lockdown was still ongoing and was completed by 548 cat owners, mainly women. Our findings suggest that the greater amount of time that owners spent at home with their cats, as a consequence of the social restrictions, had a positive effect on the owner's perception of their relationship with their cat (e.g., higher frequency of interaction, greater emotional closeness, reduced perceived costs of caring for the cat). Similarly, the lockdown seemed to have improved the welfare of many cats, as suggested by the positive changes in many of their behaviours, even for those cats with pre-existing behavioural problems. Overall, our findings suggest that the lockdown provided many cats with a more thriving physical and social environment. They also highlight the need to reconsider some cat management practices commonly implemented in non-exceptional circumstances. The restrictive measures implemented to stem the spread of COVID-19 abruptly changed the lives of many cats and their owners. This study explored whether the lockdown in Italy affected the cat-owner relationship, as well as cat behaviour and welfare. A survey that included questions on owner and cat's demographics, living environment, cat behaviour and a modified version of the Cat/Dog Relationship Scale (C/DORS) was distributed online during the lockdown and was completed by 548 cat owners, mainly women (81.6%). With regard to the C/DORS subscales, both emotional closeness and cat-owner interactions increased during confinement, as opposed to a reduction in perceived costs. The effect of the type of job, family role and owner's age on the C/DORS scores suggests that the relationship improved for those owners that, due to the lockdown, increased the time spent with their cats. For 58.8% of respondents, their cat's general behaviour did not change, but when changes occurred, they were mostly positive (20.4%). Attention-seeking and demanding behaviours were the most increased during lockdown (25.7%). Cats with pre-existing problematic behaviours tended to either remain stable or improve during confinement. The overall positive effects of lockdown-related environmental changes on a cat's behaviour suggest that some aspects of commonly implemented cat management practices should be revised to improve cat welfare in normal circumstances

    Assessing microplastic ingestion and occurrence of bisphenols and phthalates in bivalves, fish and holothurians from a Mediterranean marine protected area

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    Microplastic (MP) ingestion, along with accumulated plasticizers such as bisphenol A (BPA), bisphenol F (BPF), and bisphenol S (BPS), and phthalates represented by diethyl phthalate (DEP), dibutyl phthalate (DBP) and bis (2-ethylhexyl) phthalate (DEHP), were quantified in bivalves, fish, and holothurians collected from a coastal pristine area at the western Mediterranean Sea. MP ingestion in sediment-feeders holothurians (mean value 12.67 ± 7.31 MPs/individual) was statistically higher than ingestion in bivalves and fish (mean 4.83 ± 5.35 and 3 ± 4.44 MPs/individual, respectively). The main ingested polymers were polyethylene, polypropylene, and polystyrene. The levels of BPS, BPF, and DEHP were highest in bivalves' soft tissue; BPA and DBP had the highest levels in the holothurians’ muscle. In addition, the levels of all plasticizers assessed were lowest in fish muscle; only BPA levels in fish were higher than in bivalves, with intermediate values between those of bivalves and holothurians. This study provides data on exposure to MPs and plasticizers of different species inhabiting Cabrera Marine Protected Area (MPA) and highlights the differences in MP ingestion and levels of plasticizers between species with different ecological characteristics and feeding strategies.En prensa3,39

    LIVER BIOCHEMISTRY PROFILE IN WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS) REARED IN CAPTIVITY

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    El presente estudio se llevó a cabo con 23 venados cola blanca (Odocoileus virginianus), de ambos sexos, y criados en cautiverio en la provincia de Lima, con el objetivo de determinar el perfil bioquímico sanguíneo hepático a través de los valores séricos de Bilirrubina Total y Directa, Proteínas Totales, Albúmina, Alanino Amino Transferasa (ALT), Aspartato Amino Transferasa (AST), Fosfatasa Alcalina (FA), y Gamma Glutamil Transferasa (GGT). Los animales (7 machos y 16 hembras), pertenecientes a tres zoológicos o zoocriaderos, fueron anestesiados con clorhidrato de ketamina o con la combinación de clorhidrato de ketamina y clorhidrato de xilacina. Se extrajo 7 ml de sangre por punción de la vena safena en tubos estériles sin anticoagulante, y los sueros fueron analizados con kits comerciales. Los valores encontrados (media ± DE) fueron para Bilirrubina Total: 0.6 ± 0.3 mg/dl; Bilirrubina Directa: 0.08 ± 0.06 mg/dl; Proteínas Totales: 6.6 ± 0.7 g/dl; Albúmina: 3.6 ± 0.5 g/dl; ALT: 26.0 ± 9.7 UI/l; AST: 87.6 ± 22.9 UI/l; FA: 73.9 ± 33.8 UI/l; y GGT: 42.5 ± 12.6 UI/l. No hubo diferencia estadística entre sexos con excepción de BT y albúmina (p<0.05).This study was carried out with 23 adult white-tailed deer (Odocoileus virginianus)of both sexes, kept in captivity in the province of Lima to establish reference liverbiochemistry profilevalues (Total and direct bilirubin, total protein, albumin, alanineamino transferase (ALT), aspartate amino transferase (AST), alkaline phosphatase (AF),and gamma glutamyl transferase (GGT). The animals (7 males and 16 females) were from three local zoos and were anesthesyzed with ketamine hydrochloride or with acombination of ketamine hydrochloride and xylazine hydrochloride. Blood samples (7ml) were collected from the saphenous vein in sterile tubes and serum was analyzedusing commercial kits. The values (mean ± SD) were Total Bilirubin: 0.6 ± 0.3 mg/dl;Direct Bilirubin: 0.08 ± 0.06 mg/dl; Total Protein: 6.6 ± 0.7 g/dl; Albumin: 3.6 ± 0.5 g/dl;ALT: 26.0 ± 9.7 UI/l; AST: 87.6 ± 22.9 UI/l; AF: 73.9 ± 33.8 UI/l, and GGT: 42.5 ± 12.6 UI/l.There were no statistical differences due to sex except for total bilirubin and albumin(p<0.05

    Reliability and validity of different methods of estimating the one-repetition maximum during the free-weight prone bench pull exercise

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    This study examined the reliability and validity of three methods of estimating the one-repetition maximum (1RM) during the free-weight prone bench pull exercise. Twenty-six men (22 rowers and four weightlifters) performed an incremental loading test until reaching their 1RM, followed by a set of repetitions-to-failure. Eighteen participants were re-tested to conduct the reliability analysis. The 1RM was estimated through the lifts-to-failure equations proposed by Lombardi and O'Connor, general load-velocity (L-V) relationships proposed by Sánchez-Medina and Loturco and the individual L-V relationships modelled using four (multiple-point method) or only two loads (two-point method). The direct method provided the highest reliability (coefficient of variation [CV] = 2.45% and intraclass correlation coefficient [ICC] = 0.97), followed by the Lombardi's equation (CV = 3.44% and ICC = 0.94), and no meaningful differences were observed between the remaining methods (CV range = 4.95-6.89% and ICC range = 0.81-0.91). The lifts-to-failure equations overestimated the 1RM (3.43-4.08%), the general L-V relationship proposed by Sánchez-Medina underestimated the 1RM (-3.77%), and no significant differences were observed for the remaining prediction methods (-0.40-0.86%). The individual L-V relationship could be recommended as the most accurate method for predicting the 1RM during the free-weight prone bench pull exercise

    Segundo Congreso Salesiano de Ciencia, Tecnología e Innovación para la Sociedad

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    La segunda edición del Congreso Salesiano de Ciencia, Tecnología e Innovación para la Sociedad, CITIS, realizado el 2 y 3 de diciembre de 2015 y organizado por la Universidad Politécnica Salesiana (sede Guayaquil), ofreció un espacio idóneo para la presentación, difusión e intercambio de importantes investigaciones (nacionales e internacionales) a los docentes investigadores y a la comunidad universitaria en general. Los trabajos recogidos en estas Memorias Académicas pertenecen a diferentes líneas de investigación del área de la Ingeniería: Telecomunicaciones, Automatización y Control, Procesos Industriales, Sistemas Eléctricos de Potencia, Telemática e Informática Aplicada, áreas de interés en esta segunda edición del CITIS. Cabe destacar que se evidencia la preocupación por la dimensión humana y social mediante el desarrollo responsable de la ciencia y la tecnología. La realización de este Congreso ha puesto en evidencia la importancia y pertinencia de la actividad investigativa que se genera en las universidades (en proyectos desarrollados por los docentes investigadores e, incluso, por los estudiantes de grado y posgrado), así como los altos niveles de compromiso académico y social

    Differences in the immune response elicited by two immunization schedules with an inactivated SARS-CoV-2 vaccine in a randomized phase 3 clinical trial

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    BACKGROUND: The development of vaccines to control the COVID-19 pandemic progression is a worldwide priority. CoronaVac® is an inactivated SARS-CoV-2 vaccine approved for emergency use with robust efficacy and immunogenicity data reported in trials in China, Brazil, Indonesia, Turkey, and Chile. METHODS: This study is a randomized, multicenter, and controlled phase 3 trial in healthy Chilean adults aged ≥18 years. Volunteers received two doses of CoronaVac® separated by two (0-14 schedule) or four weeks (0-28 schedule). 2,302 volunteers were enrolled, 440 were part of the immunogenicity arm, and blood samples were obtained at different times. Samples from a single center are reported. Humoral immune responses were evaluated by measuring the neutralizing capacities of circulating antibodies. Cellular immune responses were assessed by ELISPOT and flow cytometry. Correlation matrixes were performed to evaluate correlations in the data measured. RESULTS: Both schedules exhibited robust neutralizing capacities with the response induced by the 0-28 schedule being better. No differences were found in the concentration of antibodies against the virus and different variants of concern between schedules. Stimulation of PBMCs with MPs induced the secretion of IFN-g and the expression of activation induced markers for both schedules. Correlation matrixes showed strong correlations between neutralizing antibodies and IFN-g secretion. CONCLUSIONS: Immunization with CoronaVac® in Chilean adults promotes robust cellular and humoral immune responses. The 0-28 schedule induced a stronger humoral immune response than the 0-14 schedule. FUNDING: Ministry of Health, Government of Chile, Confederation of Production and Commerce & Millennium Institute on Immunology and Immunotherapy, Chile. CLINICAL TRIAL NUMBER: NCT04651790

    A genome-wide association study identifies risk alleles in plasminogen and P4HA2 associated with giant cell arteritis

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    Giant cell arteritis (GCA) is the most common form of vasculitis in individuals older than 50 years in Western countries. To shed light onto the genetic background influencing susceptibility for GCA, we performed a genome-wide association screening in a well-powered study cohort. After imputation, 1,844,133 genetic variants were analysed in 2,134 cases and 9,125 unaffected controls from ten independent populations of European ancestry. Our data confirmed HLA class II as the strongest associated region (independent signals: rs9268905, P = 1.94E-54, per-allele OR = 1.79; and rs9275592, P = 1.14E-40, OR = 2.08). Additionally, PLG and P4HA2 were identified as GCA risk genes at the genome-wide level of significance (rs4252134, P = 1.23E-10, OR = 1.28; and rs128738, P = 4.60E-09, OR = 1.32, respectively). Interestingly, we observed that the association peaks overlapped with different regulatory elements related to cell types and tissues involved in the pathophysiology of GCA. PLG and P4HA2 are involved in vascular remodelling and angiogenesis, suggesting a high relevance of these processes for the pathogenic mechanisms underlying this type of vasculitis
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