Características y determinantes de la demanda residencial de energía eléctrica en los Municipios del Eje cafetero

Maestría en Economía, Facultad de Ciencias Contables, Económicas y Administrativas.El mercado energético en Colombia, viene siendo objeto de estudio de gran interés ante la imperiosa necesidad de establecer los patrones de su funcionamiento, con miras a aportar elementos para los actores de la cadena de valor, desde la generación hasta la comercialización, por lo cual se hace un análisis de las variables principales que pueden determinar la demanda de energía eléctrica por parte de los hogares a nivel de los Departamentos de Caldas, Quindío y Risaralda, encontrando que conforme a la teoría, la demanda se encuentra relacionada con la tarifa, sin embargo el uso de instrumentos de política energética para regularla tiene impactos en el corto plazo, lo que induce a programas de choque para lograr efectividad, así mismo queda evidenciado las limitaciones para explicar el crecimiento económico desde la demanda de los hogares, lo que arroja resultados contradictorios en las mediciones previas, siendo complementario la tendencia a que en el mediano plazo se asista a un cambio en la estructura de consumo de los hogares en términos de la canasta energética provocado por una mayor conciencia ambiental por parte de las futuras generaciones

Pyramidal core-shell quantum dot under applied electric and magnetic fields

We have theoretically investigated the electronic states in a core/shell pyramidal quantum dot with GaAs core embedded in AlGaAs matrix. This system has a quite similar recent experimental realization through a cone/shell structure [Phys. Status Solidi-RRL 13, 1800245 (2018)]. The research has been performed within the efective mass approximation taking into account position-dependent efective masses and the presence of external electric and magnetic felds. For the numerical solution of the resulting three-dimensional partial diferential equation we have used a fnite element method. A detailed study of the conduction band states wave functions and their associated energy levels is presented, with the analysis of the efect of the geometry and the external probes. The calculation of the non-permanent electric polarization via the of-diagonal intraband dipole moment matrix elements allows to consider the related optical response by evaluating the coefcients of light absorption and relative refractive index changes, under diferent applied magnetic feld confgurations

Production of recombinant trichoderma reesei cellobiohydrolase ii in a new expression system based on wickerhamomyces anomalus

Q31-7Cellulase is a family of at least three groups of enzymes that participate in the sequential hydrolysis of cellulose. Recombinant expression of cellulases might allow reducing their production times and increasing the low proteins concentrations obtained with filamentous fungi. In this study, we describe the production of Trichoderma reesei cellobiohydrolase II (CBHII) in a native strain of Wickerhamomyces anomalus. Recombinant CBHII was expressed in W. anomalus 54-A reaching enzyme activity values of up to 14.5 U L−1. The enzyme extract showed optimum pH and temperature of 5.0–6.0 and 40°C, respectively. Enzyme kinetic parameters ( of 2.73 mM and Vmax of 23.1 µM min−1) were between the ranges of values reported for other CBHII enzymes. Finally, the results showed that an enzymatic extract of W. anomalus 54-A carrying the recombinant T. reesei CBHII allows production of reducing sugars similar to that of a crude extract from cellulolytic fungi. These results show the first report on the use of W. anomalus as a host to produce recombinant proteins. In addition, recombinant T. reesei CBHII enzyme could potentially be used in the degradation of lignocellulosic residues to produce bioethanol, based on its pH and temperature activity profile

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

Mamíferos: Evolución y nomenclatura dental

Teniendo en cuenta la vital importancia de la morfología y nomenclatura dental para estudios sistemáticos (evolución y clasificación) en mamíferos, y dada la escasa disponibilidad libre de fuentes bibliográficas comprensivas y actualizadas sobre este tema, se realizó está revisión con la intención de que la misma se convierta en un manual básico para cursos de mastozoología y zoología de vertebrados en nuestro medio. Además, una revisión como la aquí presentada, ayuda a construir puentes entre la biología y otras profesiones como la odontología, de cara a estudios paleontológicos, arqueológicos y forenses. Es por todo esto que se hace un breve repaso de las características distintivas de los mamíferos y se revisan los principales aspectos de su dentadura, como son su evolución, anatomía, nomenclatura y fórmulas dentarias, para con todo este bagaje sacar algunas conclusiones

Polifonía para pensar una pandemia

Polifonía para pensar una pandemia expresa, a través de diversas voces, las experiencias e inquietudes, los desafíos y aportes que desde distintas perspectivas disciplinares y humanas intentan nombrar, aprehender algo de aquello desvelado por la inusitada situación que nos embarga, la cual ha tocado a todos y cada de uno nosotros de diferentes formas, mostrándonos empero, de modo implacable, la fragilidad de la existencia y la responsabilidad que, como sociedades y habitantes de nuestro planeta, tenemos en las diversas esferas que configuran nuestras vidas. Estas voces se suman a aquellas que, desde otras latitudes, han contribuido a la reflexión y el análisis de esta experiencia sui generis; esperamos que resuenen a partir de ello otros ecos y otras disonancias