Uso de mini dumper eléctrico para la mejora de la productividad en el sistema de acarreo en el Proyecto Avispa Nivel 740, por Ecmina S.A.C. - U.M. San Juan de Chorunga

La presente investigación tiene como objetivo principal, mejorar la productividad en el sistema de acarreo, con el uso de Mini Dumpers Eléctricos en el Proyecto Avispa - Nivel 740, por ECMINA de la Unidad Minera San Juan de Chorunga de la Compañía Century Mining Perú. El tipo de investigación es cuantitativa con diseño descriptivo cuasi experimental ya que se tomó datos en un único momento, con los resultados obtenidos se pudo confirmar que se viene incumpliendo el tonelaje diario de mineral solicitado por Planta, que es de 30 TM/día, llegando solo a transportar solo 22 TM/día, debido al uso de carros mineros Z-20, que requieren 2 o 3 trabajadores para realizar el acarreo. Después de realizar estudios de factibilidad y producción, se adquirió 2 Mini Dumpers Eléctricos, lo que permitió cumplir satisfactoriamente con el pedido de planta en menor tiempo, asimismo estos equipos serán utilizados en labores operacionales de desarrollo de la mina acarreando mineral estéril. Con la implementación de los Mini Dumpers eléctricos se bajó los costos de producción, reducción los tiempos de acarreo en la Empresa Contratista Minera ECMINA S.A.C. La cual será la encargada de ejecutar el Proyecto Avispa

Description of the antipredatory head-wobble behaviour in Chilean rear-fanged snakes Tachymenis peruviana Wiegmann, 1835 and Tachymenis chilensis coronellina Werner, 1898 (Serpentes, Dipsadidae)

In this work, we describe the first records of head-wobble behaviour for Tachymenis peruviana and T. chilensis coronellina. We analyse this behaviour (occurrence, frequency) and accompanying displays in both species. Of particular note is that T. ch. coronellina exhibited more frequent head-wobbling than T. peruviana and, in both records, wind activity was observed during this antipredatory behaviour

The Science Performance of JWST as Characterized in Commissioning

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures; https://iopscience.iop.org/article/10.1088/1538-3873/acb29

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Indice de Caries Dental en Estudiantes con Síndrome de Down del Centro Educativo Básica Especial N° 12 "La Luz del Mundo". Chaclacayo, Lima 2015

El presente estudio tuvo como objetivo determinar el índice de caries dental en estudiantes con Síndrome de Down del Centro Educativo Básica Especial Nº 12 “La Luz del Mundo”. Chaclacayo, Lima 2015. El estudio fue de tipo observacional, prospectivo, transversal y descriptivo. La muestra estuvo conformada por 82 estudiantes con Síndrome de Down de 3 a 17 años. Se utilizó el índice de ceod y CPOD para evaluar la caries dental. Según los resultados, se encontró que el valor promedio del índice de ceod fue 2,96 y del CPOD fue 1,32. La frecuencia de dientes deciduos cariados, extracciones indicadas y obturadas, el 58% del total de dientes con extracción indicada pertenecen al sexo masculino; sin embargo no se encontró relación estadísticamente significativa, mientras que la frecuencia de dientes permanentes cariados, perdidos y obturados, el 78,38% del total de dientes cariados corresponde al sexo masculino y el 100% del total de dientes obturados pertenecen al femenino, encontrándose una relación estadísticamente significativa. La frecuencia de dientes deciduos cariados según edad el 24,64% corresponde al grupo etario de 7 a 10 años, la frecuencia de dientes permanentes cariados según edad el 22,09% pertenecen al grupo etario de 9 a 11 años. La frecuencia de estudiantes con caries dental del sexo masculino fue de 70% y el 50% de estudiantes del sexo femenino no presentaron caries dental

The Science Performance of JWST as Characterized in Commissioning

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies

Weaning from mechanical ventilation in intensive care units across 50 countries (WEAN SAFE): a multicentre, prospective, observational cohort study

Background Current management practices and outcomes in weaning from invasive mechanical ventilation are poorly understood. We aimed to describe the epidemiology, management, timings, risk for failure, and outcomes of weaning in patients requiring at least 2 days of invasive mechanical ventilation. Methods WEAN SAFE was an international, multicentre, prospective, observational cohort study done in 481 intensive care units in 50 countries. Eligible participants were older than 16 years, admitted to a participating intensive care unit, and receiving mechanical ventilation for 2 calendar days or longer. We defined weaning initiation as the first attempt to separate a patient from the ventilator, successful weaning as no reintubation or death within 7 days of extubation, and weaning eligibility criteria based on positive end-expiratory pressure, fractional concentration of oxygen in inspired air, and vasopressors. The primary outcome was the proportion of patients successfully weaned at 90 days. Key secondary outcomes included weaning duration, timing of weaning events, factors associated with weaning delay and weaning failure, and hospital outcomes. This study is registered with ClinicalTrials.gov, NCT03255109. Findings Between Oct 4, 2017, and June 25, 2018, 10 232 patients were screened for eligibility, of whom 5869 were enrolled. 4523 (77·1%) patients underwent at least one separation attempt and 3817 (65·0%) patients were successfully weaned from ventilation at day 90. 237 (4·0%) patients were transferred before any separation attempt, 153 (2·6%) were transferred after at least one separation attempt and not successfully weaned, and 1662 (28·3%) died while invasively ventilated. The median time from fulfilling weaning eligibility criteria to first separation attempt was 1 day (IQR 0–4), and 1013 (22·4%) patients had a delay in initiating first separation of 5 or more days. Of the 4523 (77·1%) patients with separation attempts, 2927 (64·7%) had a short wean (≤1 day), 457 (10·1%) had intermediate weaning (2–6 days), 433 (9·6%) required prolonged weaning (≥7 days), and 706 (15·6%) had weaning failure. Higher sedation scores were independently associated with delayed initiation of weaning. Delayed initiation of weaning and higher sedation scores were independently associated with weaning failure. 1742 (31·8%) of 5479 patients died in the intensive care unit and 2095 (38·3%) of 5465 patients died in hospital. Interpretation In critically ill patients receiving at least 2 days of invasive mechanical ventilation, only 65% were weaned at 90 days. A better understanding of factors that delay the weaning process, such as delays in weaning initiation or excessive sedation levels, might improve weaning success rates