The logarithmic spiral, autoisoptic curve

In the Line of Investigation that in the department of “Technical Drawing” in the School of Agriculture Engineering of Madrid, we carry out on the study of The Technical Curves and his singularities, we demonstrate an interesting property of the Logarithmic Spiral. The demonstrated property consists of which the logarithmic spiral is a autoisoptic curve, that is to say that if from a point P anyone of the spiral tangent straight lines draw up to the previous arc, these form a constant angle α. This demonstration is novel and in addition we get to contribute a method to calculate the angle α given the equation of the spiral

Computing Efficient Financial Strategies: An Extended Compromise Programming Approach

This paper proposes a mathematical model to plan the financial strategy of a large company. The model links the philosophy of new behavioural economics with the multiple criteria decision making paradigm. Within this theoretical approach, the proposed model is supported by more realistic behavioral hypotheses. After formulating the initial multi-objective programming model, it has, due to its underlying computational difficulties, to be transformed into an easily computable extended compromise programming model. The functional and empirical potential of the model is illustrated with the help of a case study concerning a “stock market quoted” Spanish company operating in the energy sector. This paper shows how such an approach can open up new prospects for research linking economic problems with applied mathematic

Social behavior of Euphractus sexcinctus during a reproductive event in a protected forest of northeastern Argentina

Esta nota reporta, por primera vez en Argentina, un evento que involucra comportamientos sociales (tolerancia, proximidad y olfateo), reproductivos (intento de montura y de persecución) y exploratorios (olfateo de las entradas, excavación y relleno con arena) de cinco individuos de Euphractus sexcinctus Linnaeus. 1758 en un bosque mesófilo del Parque Nacional Mburucuyá, provincia de Corrientes. Estos comportamientos fueron observados en cinco entradas de una posible madriguera común, un rasgo novedoso para esta especie. Para esta región, se sugiere un periodo de apareamiento de agosto a noviembre. Estas observaciones contribuyen con nuevos conocimientos sobre la historia natural de la especie en Argentina.In this note we describe for the f rst time in Argentina, an event that involved social (tolerance, proximity and sniff ng), reproductive (mounting and chasing) and exploratory (sniff ng entrances, digging and f lling) behaviors of five individuals of Euphractus sexcinctus Linnaeus, 1758 in a mesophile forest of Mburucuyá National Park, Corrientes Province. These behaviors were observed at five entrances of a possible common burrow, a new trait for this species. For this region, observations suggest a mating period from August to November. All these observations contribute with new knowledge to the natural history of the species in Argentina.Fil: Romero, Verónica Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Estación Biológica de Usos Múltiples (Sede Corrientes); ArgentinaFil: Kowalewski, Miguel Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Estación Biológica de Usos Múltiples (Sede Corrientes); ArgentinaFil: Gómez, Noelia Elízabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Estación Biológica de Usos Múltiples (Sede Corrientes); ArgentinaFil: Abba, Agustin Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentin

Pulse oximetry curves in healthy children living at moderate altitude : a cross-sectional study from the Ecuadorian Andes

In populations above 3,000 meters above sea level (m.a.s.l.) normal values of oxygen saturation (SpO2) above 90% have been reported. Few studies have been conducted in cities of moderate altitude (between 2,500 and 3,000 m a.s.l). We set out to describe the range of SpO2 values measured with a pulse oximeter in healthy children between 1 month and 12 years of age living in an Ecuadorian Andean city. A cross-sectional study was carried out in Quito, Ecuador, located at 2,810 m a.s.l. SpO2 measurement in healthy children of ages ranging from 1 month to 12 years of age residents in the city were recorded by pulse oximetry. Age and gender were recorded, and median and 2.5th and 5th percentile were drawn. Non parametric tests were used to compare differences in SpO2 values by age and gender. 1,378 healthy children were included for the study, 719 (52.2%) males. The median SpO2 for the entire population was 94.5%. No differences were observed between SpO2 median values by age and gender. The 2.5th percentile for global SpO2 measurements was 90%, in children under 5 years of age was 91% and it was 90% in children older than 7. Our results provide SpO2 values for healthy children from 1 to 12 years old residents in Quito, a city of moderate altitude. The SpO2 percentile curve could contribute as a healthy range for the clinical evaluation of children residing at this altitude

As lideranças e a diferenciação curricular inclusiva: que caminhos para a escola do século XXI?

Com este artigo pretende-se analisar num primeiro momento, o conceito de diferenciação curricular no plano conceptual e dentro de um quadro de análise que permita aprofundar e clarificar o seu sentido no contexto da escola para todos e no enquadramento da massificação da escolarização, fazendo referência à globalização a qual traz novos aspectos para o debate em torno da finalidade da escola. Analisa-se num segundo momento, o papel da liderança democrática e participativa no desempenho do binómio curricular (currículo nacional e projectos curriculares) na medida em que a articulação entre níveis centrais e de escola para o desenvolvimento da diferenciação curricular inclusiva se constitui como meta indispensável para algo assim. Considera-se nesta perspectiva a liderança propulsora da diferenciação curricular inclusiva na dimensão da praxis curricular das escolas e dos professores. Por último relaciona-se esta problemática com a perspectiva da teoria crítica no quadro de escolas entendidas como boas escolas

Estrategias de comunicación digital: Análisis del facebook de la Policía Nacional del Perú durante el año 2021

La presente investigación se encuentra justificada a través de la recopilación de datos, testimonios e investigaciones acerca del análisis del Facebook de la Policía Nacional del Perú durante el año 2021. Es así que se pudo identificar diferentes estrategias de comunicación empleadas que ayudan a optimizar la comunicación digital. La elección del tema tuvo sustento en lo importante que es para el comunicador la comprensión y la lógica que utiliza la plataforma digital, los pasos a seguir para formular una estrategia, las buenas experiencias y prácticas que le permitan formular información efectiva hacia un público digital. El objetivo general es analizar las estrategias de comunicación digital en el Facebook de la Policía Nacional del Perú durante el año 2021. Teniendo en cuenta el presente objetivo y su finalidad se optó por la utilización de una metodología cualitativa, que se llevó a cabo mediante una guía de observación y entrevistas a personas capacitadas y entendidas del tema, con la finalidad de obtener datos y testimonios que ayuden a llegar a obtener una conclusión. De esta manera es que, se concluye que se pudo analizar las estrategias de comunicación del Facebook de la Policía Nacional del Perú, pues se pudieron identificar el desarrollo estrategias de comunicación como la de confianza, posicionamiento y expansión

Estudio de accesibilidad a las zonas verdes urbanas mediante Sistemas de Información Geográfica

La creciente preocupación por parte de la sociedad respecto del medio ambiente que nos rodea, ha hecho que las administraciones de ámbito local recojan las inquietudes de los ciudadanos e intenten dar soluciones mediante la creación de lo que se viene a denominar espacios verdes urbanos: son nuestros parques y jardines públicos. Sin embargo, día a día surgen nuevas demandas por parte de los distintos grupos sociales, pasando de la mera creación o representación estética del campo en la ciudad a dotar a estos entornos de elementos en los que la practicidad toma un valor relevante. El objetivo del presente trabajo es servir como instrumento de información a las distintas administraciones en su labor de planificación de zonas verdes urbanas utilizando para ello Sistemas de Información Geográfic

Tutorial 2.0 on Technical Drawing 3D and Visualization

In recent years, the continuous incorporation of new technologies in the learning process has been an important factor in the educational process (1). The Technical University of Madrid (UPM) promotes educational innovation processes and develops projects related to the improvement of the education quality. The experience that we present fits into the Educational Innovation Project (EIP) of the E.U. of Agricultural Engineering of Madrid. One of the main objectives of the EIP is to Take advantage of the new opportunities offered by the Learning and Knowledge Technologies in order to enrich the educational processes and teaching management (2)

Methodological biases in observational hospital studies of COVID-19 treatment effectiveness: pitfalls and potential

Introduction This study aims to discuss and assess the impact of three prevalent methodological biases: competing risks, immortal-time bias, and confounding bias in real-world observational studies evaluating treatment effectiveness. We use a demonstrative observational data example of COVID-19 patients to assess the impact of these biases and propose potential solutions.Methods We describe competing risks, immortal-time bias, and time-fixed confounding bias by evaluating treatment effectiveness in hospitalized patients with COVID-19. For our demonstrative analysis, we use observational data from the registry of patients with COVID-19 who were admitted to the Bellvitge University Hospital in Spain from March 2020 to February 2021 and met our predefined inclusion criteria. We compare estimates of a single-dose, time-dependent treatment with the standard of care. We analyze the treatment effectiveness using common statistical approaches, either by ignoring or only partially accounting for the methodological biases. To address these challenges, we emulate a target trial through the clone-censor-weight approach.Results Overlooking competing risk bias and employing the naive Kaplan-Meier estimator led to increased in-hospital death probabilities in patients with COVID-19. Specifically, in the treatment effectiveness analysis, the Kaplan-Meier estimator resulted in an in-hospital mortality of 45.6% for treated patients and 59.0% for untreated patients. In contrast, employing an emulated trial framework with the weighted Aalen-Johansen estimator, we observed that in-hospital death probabilities were reduced to 27.9% in the X-treated arm and 40.1% in the non-X-treated arm. Immortal-time bias led to an underestimated hazard ratio of treatment.Conclusion Overlooking competing risks, immortal-time bias, and confounding bias leads to shifted estimates of treatment effects. Applying the naive Kaplan-Meier method resulted in the most biased results and overestimated probabilities for the primary outcome in analyses of hospital data from COVID-19 patients. This overestimation could mislead clinical decision-making. Both immortal-time bias and confounding bias must be addressed in assessments of treatment effectiveness. The trial emulation framework offers a potential solution to address all three methodological biases