Mathematical Simulators for the Study of the Integral Calculus of Engineering Students

Currently, technological tools have positioned themselves in the first places of human development, and higher education has not been the exception. This research aims to improve academic performance with the application of mathematical simulators (Wólfram Alpha, GeoGebra, Derive, and Matlab) as a didactic strategy for the study of integral calculus in engineering students. This research has a quantitative approach, which allows for the investigation of the data from academic activities; likewise, it includes an explanatory study with the purpose of verifying the relationship that exists between the dependent and independent variables. In addition, the method of the questionnaire technique with raised exercises was used, and then the qualification averages of the groups were taken. Similarly, the perspective provided a solid base to analyze the data objectively and establish statistical relationships between the variables involved. The methodology used in this study was to obtain precise and measurable information on the impact of mathematical simulators on learning integral calculus. The questionnaire technique with posed exercises made it possible to collect data directly from the participants, providing detailed information on their understanding and performance in relation to integral calculus. The exercises posed in the questionnaire served as a structured way to assess the knowledge and skills acquired by students. The design applied in the study is made up of two control and experimental groups, applying the pretest and posttest methods. For the analysis and interpretation of data, the parametric statistical student’s T-test was used for related samples, where the simulators significantly influenced the learning of integral calculus, at a significance level of 5%. The results of the analysis indicated that the mathematical simulators significantly influenced the learning of integral calculus. That is, statistically significant improvements were observed in the academic performance of the students after the intervention with the simulators. Briefly, the study used a two-group (control and experimental) design, applied pretest and posttest methods to assess academic performance, and used the Student’s T-test for related samples in data analysis. Therefore, the importance of the role of the teacher in the learning process of higher mathematics is exemplified. Keywords: mathematical simulators, integral calculus, Derive, GeoGebra, Wolfram, Matlab. Resumen Actualmente, las herramientas tecnológicas se han posicionado en los primeros lugares del desarrollo humano, y la Educación Superior no ha sido la excepción, el presente trabajo de investigación tiene como finalidad mejorar el rendimiento académico con la aplicación de los simuladores matemáticos (Wólfram Alpha, GeoGebra, Derive y Matlab), como estrategia didáctica del estudio del cálculo integral en los estudiantes de ingeniería. La investigación tiene un enfoque cuantitativo, el cual, permitió indagar los datos de actividades académicas, así mismo, comprende un estudio de tipo explicativo con el propósito de comprobar la relación que existe entre las variables dependiente e independiente. Además, se utilizó el método de la técnica del cuestionario con ejercicios planteados, luego, se tomó los promedios de calificación de los grupos. Así mismo, la perspectiva proporcionó una base sólida para analizar los datos de manera objetiva y establecer relaciones estadísticas entre las variables involucradas. En este estudio, se ha utilizado esta metodología para obtener información precisa y medible sobre el impacto de los simuladores matemáticos en el aprendizaje del cálculo integral. La técnica del cuestionario con ejercicios planteados ha permitido recopilar datos directamente de los participantes, brindando información detallada sobre su comprensión y desempeño en relación con el cálculo integral. Los ejercicios planteados en el cuestionario sirven como una forma estructurada de evaluar el conocimiento y las habilidades adquiridas por los estudiantes. El diseño aplicado en el estudio está constituido por dos grupos control y experimental, aplicando la prueba del pretest y postest. Para el análisis e interpretación de datos se utilizó la prueba estadística paramétrica T - Student para muestras relacionadas, donde, los simuladores influyeron de manera significativa en el aprendizaje del cálculo integral, a un nivel de significancia del 5%. Los resultados del análisis indicaron que los simuladores matemáticos influyeron de manera significativa en el aprendizaje del cálculo integral. Es decir, se observaron mejoras estadísticamente significativas en el rendimiento académico de los estudiantes después de la intervención con los simuladores. En pocas palabras, el estudio utilizó un diseño con dos grupos (control y experimental), aplicó pruebas de pretest y postest para evaluar el rendimiento académico, y empleó la prueba estadística T-Student para muestras relacionadas en el análisis de los datos. Los resultados mostraron que los simuladores matemáticos tuvieron un impacto significativo en el aprendizaje del cálculo integral, demostrando mejoras estadísticamente significativas en el rendimiento académico de los estudiantes. Por consiguiente, se ejemplifica la importancia del rol del docente en el proceso de aprendizaje de la matemática superior. Palabras Clave: simuladores matemáticos, Cálculo Integral, Derive, GeoGebra, Wólfram, Matlab

Survival Rate and Morphological Growth Patterns of Five Populations of \u3cem\u3eFestuca dolichophylla\u3c/em\u3e Under Similar Conditions

The majority of the natural grasslands of Perú are located in the Puna region; they are the only source of feed for raising animals in this area, and they also protect the soil from erosion. Festuca dolichophylla is a representative species with high productivity in this ecosystem. The aim of this study was to evaluate survival rate and morphological growth patterns of five populations of Festuca dolichophylla under similar conditions. Five accessions were obtained from each population: Pastales Huando Peasant Community - Huancavelica (CCPH), Lachocc South American Camelids Research and Development Center of the National University of Huancavelica (CIDCSL), Junin, Pasco, and Puno. Six cuttings were obtained from each accession. They were planted in a block design in a uniform soil in the CCPH. After twelve months of establishment all plants were cut to five cm in height and survival rate was estimated. Plant height, number of stems, and leaf number were monitored twice a month; growth rate, stem emergence rate, and leaf emergence rate were calculated and data was analyzed for each month. Accessions from Puno had a 96.67% survival rate, which was significantly higher (p\u3c0.05) than accessions from CIDCSL (43.33% survival) but similar to accessions from the other populations. The morphological growth patterns showed differences between populations and high variability along the evaluation period; this variability and differences are likely due to the genetic constitution of each accession since the environment was similar. This information is crucial for further genetic breeding programs; however, first a morphologic and genetic characterization is necessary. We also observed an orderly growth of this species; first, the plants grow in size, then they increase their stem number, and finally the number of leaves increases. To our knowledge this is the first study that compares morphological growth patterns in different populations of Festuca dolichophylla under similar conditions

Challenges in Chagas Disease Drug Discovery: a review

Chagas disease or American trypanosomiasis is a neglected tropical disease caused by the parasite Trypanosoma cruzi. Although the number of infected individuals has decreased, about 6-7 million people are infected worldwide. The chemotherapy drugs currently used are limited to benznidazole and nifurtimox. They are effective in acute phase, congenital transmission and children with chronic infection; however, recent clinical trials have shown limitations in adults with chronic infection, presenting drawbacks during the treatment. Thus, there is an urgent need for new effective, safe and affordable drugs to fight against this complex disease. There were high expectations for azole derivatives as they appeared to be the most promising drugs for the treatment of Chagas disease during the last decade; however, the disappointing results obtained so far in clinical trials evidenced the lack of correlation between preclinical and clinical development. Therefore, the feedback obtained from these studies should define the starting point for addressing a roadmap for the drug discovery process in the fight against this disease. To tackle this challenge, it is important to keep in mind the drug target profile, already defined by panels of experts, and the coordinated work involving multi-disciplinary networks focusing not only on the discovery of new drugs but also on the standardization of the protocols that would allow acceleration in the Chagas disease drug discovery process

NOTES ON THE NEST, BREEDING SEASON, AND ELEVATIONAL RANGE OF A RARE HUMMINGBIRD, THE PURPLE-BACKED SUNBEAM (AGLAEACTIS ALICIAE)

Abstract The breeding biology and phenology of the endangered hummingbird Purple-backed Sunbeam (Aglaeactis aliciae) are not well known. We report observations of nesting A. aliciae near El Molino, in La Libertad Department, Peru. On 11 March 2018, we found a female building a nest while on 10 March 2019 we found an incubating female. We describe specific characteristics of the nest and breeding behavior of nesting females. Based on our observations and that of others, the timing of nesting for this species seems to correspond to the mid-to-late rainy season, extending from at least March to May. Additionally, our sightings suggest a higher upper elevational range limit for this range-restricted Andean hummingbird than previously reported; the elevational range should be considered to be 2900–3700 m a.s.l.Resumen ∙ Notas sobre el nido, temporada reproductiva y rango elevacional del Colibrí de Alicia (Aglaeactis aliciae) La biología reproductiva y la fenología del Colibrí de Alicia (Aglaeactis aliciae) – una especie de colibrí amenazada – son poco conocidas. Aquí reportamos observaciones de nidificación de A. aliciae en El Molino, Departamento La Libertad, Perú. El 11 de marzo de 2018 encontramos una hembra construyendo un nido, mientras que el 10 de marzo de 2019 encontramos a una hembra incubando. Describimos las características del nido y el comportamiento reproductivo de las hembras. En base a nuestras observaciones e información previa sugerimos que la temporada de nidificación se desarrolla desde mediados a fines de la temporada húmeda, extendiéndose desde marzo a mayo. Nuestras observaciones también indican que la especie se encuentra a mayores altitudes que lo reportado previamente y que su rango altitudinal seria 2900–3700 m s.n.m

Nutritional and energy value of Vicia sativa pods

Vicia sativa is one of the most important crops for livestock feed. Pods from Vicia sativa seed production are usually discarded. The objective of this study was to report the nutritional value of Vicia sativa pods. Report of the bromatological analysis was 17.58% for crude protein, 44.96% for neutral detergent fiber, and 55.81% for in vitro dry matter digestibility. Estimates of the energy value on dry matter basis (Mcal kg–1) were made for digestible and metabolizable energy, with values of 2.46 and 2.01, respectively. Vicia sativa pods promise enormous potential as a protein supplement on livestock diets when other sources are not available

Rare variants in dynein heavy chain genes in two individuals with situs inversus and developmental dyslexia : a case report

Background Developmental dyslexia (DD) is a neurodevelopmental learning disorder with high heritability. A number of candidate susceptibility genes have been identified, some of which are linked to the function of the cilium, an organelle regulating left-right asymmetry development in the embryo. Furthermore, it has been suggested that disrupted left-right asymmetry of the brain may play a role in neurodevelopmental disorders such as DD. However, it is unknown whether there is a common genetic cause to DD and laterality defects or ciliopathies. Case presentation Here, we studied two individuals with co-occurring situs inversus (SI) and DD using whole genome sequencing to identify genetic variants of importance for DD and SI. Individual 1 had primary ciliary dyskinesia (PCD), a rare, autosomal recessive disorder with oto-sino-pulmonary phenotype and SI. We identified two rare nonsynonymous variants in the dynein axonemal heavy chain 5 gene (DNAH5): a previously reported variant c.7502G > C; p.(R2501P), and a novel variant c.12043 T > G; p.(Y4015D). Both variants are predicted to be damaging. Ultrastructural analysis of the cilia revealed a lack of outer dynein arms and normal inner dynein arms. MRI of the brain revealed no significant abnormalities. Individual 2 had non-syndromic SI and DD. In individual 2, one rare variant (c.9110A > G;p.(H3037R)) in the dynein axonemal heavy chain 11 gene (DNAH11), coding for another component of the outer dynein arm, was identified. Conclusions We identified the likely genetic cause of SI and PCD in one individual, and a possibly significant heterozygosity in the other, both involving dynein genes. Given the present evidence, it is unclear if the identified variants also predispose to DD and further studies into the association between laterality, ciliopathies and DD are needed.Peer reviewe

Elevated Lactate as a Mortality Factor in Poly Traumatised Patients: A Systematic Review and Meta-Analysis

Introduction: According to global health estimates from the World Health Organization (WHO) injuries represent 8% of world deaths. There are systematic reviews that relate lactate and mortality in trauma patients but do not focus on multiple trauma patients. Objective: To determine if elevated lactate is a mortality factor in multiple trauma patients. Methodology: A systematic review and meta-analysis of observational studies were carried out. The search was carried out in 4 databases: PUBMED, Embase, Scopus, and Web of Science. Data were pooled using a random effects model and summary statistics were calculated using odds ratios (ORs) with their respective 95% confidence intervals (95% CI). Results: Nine studies were included (n=5302). A significant association was found between elevated admission lactate with mortality (OR: 1.80; 95% CI 1.11 to 2.91) and 72-hour mortality (OR: 1.24; 95% CI 1.02 to 1.50). No statistically significant association was found for the analysis of elevated admission lactate and 28-day mortality (OR: 1.24; 95% CI 1.02 to 1.50). Finally, elevated admission lactate is associated with mortality regardless of time (OR: 1.34; 95% CI 1.19 to 1.50). Conclusion: Elevated admission lactate is associated with mortality and 72-hour mortality in multiple trauma patients. No significant association was found between elevated admission lactate and 30-day mortality. Elevated intake of lactate is associated with mortality independent of time

Diagnostic Accuracy of Anthropometric Markers of Obesity for Prediabetes: A Systematic Review and Meta-Analysis

Introduction: Prediabetes is a significant public health concern due to its high risk of progressing to diabetes. Anthropometric measures of obesity, including body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) have been demonstrated as key risk factors in the development of prediabetes. However, there is a lack of clarity on the diagnostic accuracy and cut-off points of these measures. Objective: To determine the diagnostic accuracy of these anthropometric measures for their most effective use in identifying prediabetes. Methodology: A systematic review (SR) with metanalysis of observational studies was carried out. The search was conducted in four databases: Pubmed/Medline, SCOPUS, Web of Science, and EMBASE. For the meta-analysis, sensitivity and specificity, together with their 95% confidence intervals (CI 95%) were calculated. Results: Among all the manuscripts chosen for review, we had four cross-sectional studies, and three were classified as cohort studies. The forest plots showed the combined sensitivity and specificity for both cross-sectional and cohort studies. For cross-sectional studies, the values were as follows: BMI had a sensitivity of 0.63 and specificity of 0.56, WC had a sensitivity of 0.59 and specificity of 0.58, and WHtR had a sensitivity of 0.63 and specificity of 0.73. In the cohort studies, the combined sensitivity and specificity were: BMI at 0.70 and 0.45, WC at 0.68 and 0.56, and WHtR at 0.68 and 0.56, respectively. All values are provided with 95% confidence intervals. Conclusions: This systematic review and meta-analysis evaluated the diagnostic accuracy of BMI, WC, and WHtR in identifying prediabetes. The results showed variations in sensitivity and specificity, with WHtR having the highest specificity in cross-sectional studies and BMI having improved sensitivity in cohort studies

A Comparative Study of Conventional and Microwave‐Assisted Synthesis of Quinoxaline 1,4‐di‐N‐oxide N‐acylhydrazones Derivatives Designed as Antitubercular Drug Candidates

Quinoxaline 1,4‐di‐N‐oxide (QdNO) and N‐acylhydrazone subunit are considered privileged scaffolds in medicinal chemistry because of its wide spectrum of biological activities, such as antibacterial, antitubercular, antiviral, anticancer, and antifungal. Beirut's reaction is the mostly commonly employed synthetic method to obtain QdNO; however, extended time, low yields, and byproduct formation are common features observed during the synthesis. Microwave‐assisted organic synthesis (MW) has gained popularity as an effective way to speed up chemical reactions, increasing yields and selectivity of a variety of reactions. Therefore, in an effort to synthesize compounds with potential to tuberculosis treatment, we reported herein the use of MW as a tool to obtain new QdNO derivatives containing the N‐acylhydrazone subunit. Four different synthetic routes were evaluated by using different benzofuroxan derivatives in the Beirut's reaction. The synthetic route D, which employed a dioxolan‐benzofuroxan derivative, has shown to be the best condition to obtain the desired hybrid quinoxaline. MW drastically reduces the reaction time to obtain all compounds compared to conventional heating. For compound 13, for example, the use of MW instead of conventional heating was able to reduce the reaction time in 192‐fold. In conclusion, the use of a benzofuroxan derivative without additional electrophilic sites besides N‐oxide nitrogen and the employment of the microwave‐assisted synthesis have proved to be the optimum condition to obtain quinoxaline 1,4‐di‐N‐oxide N‐acylhydrazone derivatives

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London