Cálculo de áreas planas en R2 usando las nuevas tecnologías

En la enseñanza de las matemáticas y en particular del cálculo diferencial e integral, el profesor busca que los conceptos correspondientes se puedan entender por los alumnos a través de ejemplos sencillos al principio, propone varias estrategias para encontrar la solución de un problema, trata de motivar a los estudiantes y de proporcionar ejemplos de aplicación. En varias de las asignaturas de matemáticas para estudiantes de ingeniería, un aspecto fundamental al analizar un tema en particular es usar al menos tres formas de representar un concepto: El aspecto analítico, el geométrico y el tabular. En el presente trabajo se muestra una estrategia alternativa complementaria para estudiar el concepto de la integral definida haciendo uso de software matemático

Ara militaris en el centro-occidente de Veracruz: registros recientes

Based on interviews and field observations, we present information about individuals of Military Macaw (Ara militaris) in the common of Caballo Blanco, in central western of Veracruz. We obtained observations in 2014 and 2015 on a site with cliffs covered by deciduous forest relicts. However, local people said they had seen Military Macaws in this area at least since 2012. It is important to continue working with the people of Caballo Blanco in order to ensure the preservation of this population of Military Macaw. Also, it is necessary to deepen aspects of their ecology on this site, which would be the only one with recent and constant presence of this species in Veracruz.RESUMEN. Con base en entrevistas y observaciones de campo, presentamos información sobre individuos de la guacamaya verde (Ara militaris) en la comunidad de Caballo Blanco, en el centro occidente de Veracruz. Se obtuvieron observaciones en 2014 y 2015 en un sitio con acantilados cubiertos por relictos de bosques caducifolios. Sin embargo, la población local dijo que había visto guacamayas verdes en esta área por lo menos desde 2012. Es importante seguir trabajando con la gente de Caballo Blanco para asegurar la preservación de esta población de guacamayas verdes. Además, es necesario profundizar aspectos de su ecología en este sitio, que sería el único con presencia reciente y constante de esta especie en Veracruz.

Extractos polifenólicos de las hojas de Ilex paraguariensis y Larrea divaricata y su potencial antioxidante y antiCOVID-19

Yerba mate (Ilex paraguariensis A.St. Hil) and jarilla (Larrea divaricata Cav.) leaves are commonly used as tea infusions in some Latin American countries. This study was conducted to evaluate the antioxidant activity (FRAP, ABTS, and DPPH) and the inhibitory potential of yerba mate and jarilla extracts on the 3CL protease (Mpro) from coronavirus SARS-COV-2 by a molecular docking approach. The main bioactive compounds present in the plant extracts were identified by HPLC-MS. According to the results, the extracts of yerba mate and jarilla showed high antioxidant activity in DPPH (> 91 %), ABTS (> 90 %), and FRAP (> 47 mg TE/g) assays. Additionally, the phenolic compounds present in yerba mate, quercetin-3-O-rutinoside (rutin) (-9.60 kcal/mol) and 3,4-dicaffeoylquinic acid (-8.20 kcal/mol) were more effective on Mpro than the antiviral drugs remdesivir and ribavirin. The compounds rutin and 3,4-dicaffeoylquinic acid have a high affinity and interaction with one of the catalytic residues Cys145 of Mpro. The glycosylation of phenolic compounds affects biological activities: positively anti-COVID-19 and negatively antioxidant. The results suggest that extracts of yerba mate and jarilla leaves could enhance the body's antioxidant defenses and can be used to improve health.Las hojas de yerba mate (Ilex paraguariensis A.St. Hil) y jarilla (Larrea divaricata Cav.) se usan comúnmente como infusión de té en algunos países de América Latina. Este estudio se realizó para evaluar la actividad antioxidante (FRAP, ABTS y DPPH) y el potencial inhibitorio de los extractos de yerba mate y jarilla sobre la proteasa 3CL (Mpro) de coronavirus SARS-COV-2 por enfoque de acoplamiento molecular. Los principales compuestos bioactivos presentes en los extractos de plantas fueron identificados por HPLC-MS. De acuerdo con los resultados, los extractos polifenólicos de yerba mate y jarilla presentaron alta actividad antioxidante en los ensayos DPPH (> 91 %), ABTS (> 90 %) y FRAP (> 47 mg TE/g). Además, los compuestos fenólicos presentes en la yerba mate, quercetina-3-O-rutinósido (rutina) (-9,60 kcal/mol) y ácido 3,4-dicafeoilquínico (-8,20 kcal/mol) han demostrado ser más efectivos (en Mpro) que los medicamentos antivirales remdesivir y ribavirin. Los compuestos rutina y ácido 3,4-dicafeoilquínico tienen alta afinidad e interacción con uno de los residuos catalíticos Cys145 de Mpro. Estos resultados sugieren que las hojas de yerba mate y jarilla podrían potenciar las defensas antioxidantes del organismo y podrían beneficiar la salud

Current perspective in the treatment of bile duct injuries

The laparoscopic cholecystectomy is considered the gold standard for the treatment of benign gallbladder disease, which is associated with an increased incidence of biliary injuries. These types of injuries are multicausal, and anatomical variations or anatomical perception errors are the most common risk factors. The objective of this study is to describe the evolution in the management of bile duct injuries and actual, diagnostic tools, incidence, prognosis and treatment. A literature research about diagnosis and treatment of iatrogenic bile duct injuries as well as their impact on the incidence of morbidity and mortality, based on a 30-year period, was performed on Medline, Cochrane, Embase, MedScape and PubMed database, for all studies that met the eligibility criteria. A thorough quality assessment of all included studies was performed. Synthesis of the results was achieved by narrative review. The bile duct injury is a complication that requires a complex therapy and multidisciplinary management. Reconstruction and treatment techniques have been evolving. The selection of adequate treatment will impact on the patient´s quality of life. The results of the existing studies reporting on iatrogenic bile duct injuries are useful; because the iatrogenic bile duct injuries are complex alterations and constitute one of the most serious complications of a cholecystectomy and require a comprehensive approach, immediate repair, proper drainage and timely referral to adequate treatment to improve long-term prognosis. According to the literature review, currently there better treatments such as absorbable prosthesis, which improve the prognosis and patient´s quality of life, and represent less risk of complications in short/long term.

Instalacion y configuracion de zentyal server 6.2 e implementacion de servicios de infraestructura I.T.

instalación y configuración de zentyal server 6.2 e implementación de servicios de infraestructura i.t.installation and configuration of zentyal 6.2 server and implementation of infrastructure services i.t

Los mitos del miedo

De noche, solo. ¿Cuál será la amenaza letal esta vez? En la sala, pegado a tu asiento, la víctima eres tú. El cine despertó los mitos más escalofriantes y acercó a nuestras puertas a personajes que nunca dejarán de perseguirnos. Las figuras del horror trascienden en el tiempo, pero la mutación ha sido unfactor decisivo en su evolución. Hemos querido recopilar su historia, sobre todo reciente, y representaciones más notables. En este espacio los hombres lobo, los vampiros, los fantasmas o los serial killers están al acecho

Hyperhomocystinemia as a Cause of Cerebral Ischemia in a Young Patient, Presentation of a Case in Northwestern Colombia

La asociación entre hiperhomocisteinemia y accidente cerebrovascular está bien documentada en la literatura. Sin embargo, existen informes limitados que revelan eventos de accidente cerebrovascular en la población joven afectada por hiperhomocisteinemia. En este articulo presentamos un caso que muestra una hiperhomocisteinemia que provocó un accidente cerebrovascular isquémico en un paciente de 16 años. El paciente acudió a urgencias por mareos y debilidad en las extremidades del hemicuerpo derecho, no pérdida del conocimiento. El examen neurológico preliminar nomostró signos cerebelosos positivos, el examen físico y el estudio diagnóstico final confirmó un isquémico del territorio de la cerebral media izquierda secundario a  hiperhomocisteinemia ya que el protocolo diagnostico no mostro causas arrítmicas, aterotromboticas ni malformaciones vasculares, no foramen ni comunicaciones interventriculares o auriculares, se encontró una hiperhomocistinemia marcada. Discutimos la presentación del caso, el estudio diagnóstico, en este atípico caso en un paciente proveniente de zona rural de Santander.The association between hyperhomocysteinemia and stroke is well documented in the literature. However, there are limited reports revealing stroke events in the young population affected by hyperhomocysteinemia. In this article we present a case showing hyperhomocysteinemia that caused an ischemic stroke in a 16-year-old patient. The patient went to the emergency room due to dizziness and weakness in the extremities of the right hemibody, not loss of consciousness. The preliminary neurological examination did not show positive cerebellar signs, the physical examination and the final diagnostic study confirmed an ischemic condition of the left middle cerebral territory secondary to hyperhomocysteinemia since the diagnostic protocol did not show arrhythmic, atherothrombotic or vascular malformations causes, no foramen or interventricular communications or headphones, marked hyperhomocysteinemia was found. We discuss the presentation of the case, the diagnostic study, in this atypical case in a patient from rural Santander

Development of a Panel of Genome-Wide Ancestry Informative Markers to Study Admixture Throughout the Americas

Most individuals throughout the Americas are admixed descendants of Native American, European, and African ancestors. Complex historical factors have resulted in varying proportions of ancestral contributions between individuals within and among ethnic groups. We developed a panel of 446 ancestry informative markers (AIMs) optimized to estimate ancestral proportions in individuals and populations throughout Latin America. We used genome-wide data from 953 individuals from diverse African, European, and Native American populations to select AIMs optimized for each of the three main continental populations that form the basis of modern Latin American populations. We selected markers on the basis of locus-specific branch length to be informative, well distributed throughout the genome, capable of being genotyped on widely available commercial platforms, and applicable throughout the Americas by minimizing within-continent heterogeneity. We then validated the panel in samples from four admixed populations by comparing ancestry estimates based on the AIMs panel to estimates based on genome-wide association study (GWAS) data. The panel provided balanced discriminatory power among the three ancestral populations and accurate estimates of individual ancestry proportions (R2>0.9 for ancestral components with significant between-subject variance). Finally, we genotyped samples from 18 populations from Latin America using the AIMs panel and estimated variability in ancestry within and between these populations. This panel and its reference genotype information will be useful resources to explore population history of admixture in Latin America and to correct for the potential effects of population stratification in admixed samples in the region

Genome-Wide Association Study Identifies a Functional SIDT2 Variant Associated With HDL-C (High-Density Lipoprotein Cholesterol) Levels and Premature Coronary Artery Disease

ObjectiveLow HDL-C (high-density lipoprotein cholesterol) is the most frequent dyslipidemia in Mexicans, but few studies have examined the underlying genetic basis. Our purpose was to identify genetic variants associated with HDL-C levels and cardiovascular risk in the Mexican population.Approach and resultsA genome-wide association studies for HDL-C levels in 2335 Mexicans, identified four loci associated with genome-wide significance: CETP, ABCA1, LIPC, and SIDT2. The SIDT2 missense Val636Ile variant was associated with HDL-C levels and was replicated in 3 independent cohorts (P=5.9×10−18 in the conjoint analysis). The SIDT2/Val636Ile variant is more frequent in Native American and derived populations than in other ethnic groups. This variant was also associated with increased ApoA1 and glycerophospholipid serum levels, decreased LDL-C (low-density lipoprotein cholesterol) and ApoB levels, and a lower risk of premature CAD. Because SIDT2 was previously identified as a protein involved in sterol transport, we tested whether the SIDT2/Ile636 protein affected this function using an in vitro site-directed mutagenesis approach. The SIDT2/Ile636 protein showed increased uptake of the cholesterol analog dehydroergosterol, suggesting this variant affects function. Finally, liver transcriptome data from humans and the Hybrid Mouse Diversity Panel are consistent with the involvement of SIDT2 in lipid and lipoprotein metabolism.ConclusionsThis is the first genome-wide association study for HDL-C levels seeking associations with coronary artery disease in the Mexican population. Our findings provide new insight into the genetic architecture of HDL-C and highlight SIDT2 as a new player in cholesterol and lipoprotein metabolism in humans

Desarrollo tecnológico en ingeniería automotriz

El proceso de investigación y desarrollo tecnológico está directamente relacionado con una adecuada metodología de procesos industriales, que cada vez son más exigentes en competitividad, eficiencia energética y de normativas ambientales. Este libro contempla resultados de un proceso de investigación y desarrollo de nuevas técnicas aplicadas en el campo de la Ingeniería Automotriz desde cuatro aristas: eficiencia energética y contaminación ambiental, planificación del transporte, ingeniería del mantenimiento aplicada al transporte y desagregación tecnológica. Este libro conmemora 20 años de formación universitaria salesiana en el sector de transporte y recoge las experiencias y resultados obtenidos asociados con el desarrollo tecnológico en ingeniería automotriz. Para lograr este objetivo, se ha convocado a la comunidad científica, académica y profesionales de la industria automotriz a participar en la publicación. Cada capítulo fue sometido a revisión, evaluación y aprobación por un comité científico altamente calificado, proveniente de seis países: Colombia, Ecuador, España, Guinea Ecuatorial, México y Venezuela. Este trabajo ha sido posible gracias al gran apoyo de la Universidad Politécnica Salesiana (UPS sede Cuenca), Ecuador y Universidad de Los Andes (ULA)