1,448 research outputs found
Mini High Temperature Test Unit Final Design Report
Lawrence Livermore National Laboratory has invested considerable effort to develop new standard for nuclear grade HEPA filters that can withstand high temperatures along with methods to optimally test not only the experimental filter media, but also new frame seals and media binders. Therefore, LLNL in collaboration with Cal Poly has designed and built a Mini High Temperature Testing Unit (MHTTU) to recreate conditions observed during a fire and to test different materials in an effective, inexpensive, regulated and reliable method. The existing prototype was unable to achieve the ideal testing conditions of 1000°F air at the low flow rates of 1.25-12 ACFM; therefore, this project looks to optimize previous efforts on building a portable and reliable MHTTU to collect more information and perform different tests in various materials utilized in the construction of ceramic HEPA filters. Based on previous teams’ inputs, our team performed a heat transfer analysis to determine critical heat loss points and to optimize the design of the MHTTU. After several idea generation sessions, it was decided to modified the geometry of the testing chamber and the insulation of the system. The MHTTU also lacks a robust control system and a user interface; therefore, a more reliable interface and more versatility during the tests were implemented in the system. With the current design, we were able to improve the maximum temperature of the system to 837°F; however, we were not able to fulfill heat up time of 15 minutes. After carefully recording the temperature of the surrounding material during testing, we believe that the immersion heater is not powerful enough to have an effective heat transfer to air. After testing was completed, it was confirmed that the heater coils cannot reach 1000°F in less than 15 minutes of heat up. Therefore, a more powerful heater is needed to achieve testing parameters
Complicaciones en el periodo neonatal de los recién nacidos con bajo peso al nacer en el periodo comprendido entre 2008-2009
Es importante poder identificar a los recién nacidos que presenta RCIU ya que el 28,6% presentaron hipoglicemia, la cual si no es manejada adecuadamente puede presentar secuelas neurológicas a largo plazo. Como único dato estadÃsticamente significativo encontramos que los recién nacidos con RCIU hijos de madre con STORCH presentaron RCIU simétrico, por lo tanto se debe hacer énfasis en un adecuado control prenatal. Los recién nacidos con RCIU hijos de madre con preeclampsia tiene mayor riesgo de presentar complicaciones en el periodo neonatal. Es necesario continuar con esta lÃnea de investigación ya que estos pacientes tienen riesgo metabólico a mediano y a largo plaz
Understanding the effects of Covid-19 on P2P hospitality: Comparative classification analysis for Airbnb-Barcelona
[EN] The Covid-19 pandemic has produced significant changes in tourism markets around the world. The large amount of data available on the Airbnb platform, one of the world's largest hosting services, makes it an ideal prospecting place to try to find out what the aftermath of this event has been. This paper explores the entire Airbnb housing stock in the city of Barcelona with the aim of identifying the key characteristics of the homes that have remained operational during the 2019-2021 period. We carried out this analysis by using two classification methods, the random forest and logistic regression with elastic net. The objective is to classify the houses that have remained on the platform against those that have not. Finally, we analyze the results obtained and compare both the general performance of the models and the individual information of each variable through partial dependence plots (PDP). We found a better performance of Random Forest over logistic regression, but not significant differences in the relevant variables chosen by each method. It is worth noting the importance of the geographical location, the number of amenities in the home or the price in the survival of the homes.Argente Del Castillo MartÃnez, JP.; Albaladejo, IP. (2022). Understanding the effects of Covid-19 on P2P hospitality: Comparative classification analysis for Airbnb-Barcelona. En 4th International Conference on Advanced Research Methods and Analytics (CARMA 2022). Editorial Universitat Politècnica de València. 221-228. https://doi.org/10.4995/CARMA2022.2022.1509122122
Bilateral laparoscopic synchronous adrenalectomy in bilateral pheochromocytoma: experience in 8 patients
Indexación: Web of Science; ScieloAim: To evaluate 8 cases of bilateral pheochromocytoma and laparoscopic synchronous treatment. Patients and Methods: From May 1999 to May 2010, 8 patients with bilateral pheochromocytoma were found. A complete preoperative workup was done. Results: We perform 8 transperitoneal laparoscopic bilateral synchronous adrenalectomy. There was no open converted procedure. Mean operative time was 184.37 min. (range 95 to 300 min). Mean hospital stay was 3.8 days (range 3 to 5 days). Mean blood loss was 191.25 ml (range 0 to 500 min). In 7 cases the histopathological result was of pheochromocytoma and 1 as a malignant pheochomocytoma based on its histology. Conclusions: With very well establish diagnostic disease, an appropriate anesthetic strategy and as surgical skills, laparoscopic bilateral synchronic adrenalectomy is a feasible and safe surgical technique for bilateral pheochromocytomas.Introducción: La incidencia del feocromocitoma varÃa entre un 0,005 y un 0,1% y de estos sólo un 10% se presenta en forma bilateral. El objetivo de este trabajo es presentar nuestra experiencia en adrenalectomÃa laparoscópica bilateral sincrónica en pacientes con diagnóstico de feocromocitoma bilateral. Se revisa la literatura y se analizan nuestros resultados. Material y Métodos: Se realiza una revisión retrospectiva de todos los pacientes sometidos a una adrenelectomÃa laparoscópica bilateral sincrónica entre mayo de 1999 y mayo de 2010, con diagnóstico de un feocromocitoma bilateral. Todos los pacientes fueron estudiados con medición de catecolaminas plasmáticas y urinarias y estudio por imágenes. Resultados: Se realizaron 8 adrenelectomÃas laparoscópicas bilaterales sincrónicas. El tiempo promedio de cirugÃa fue de 184 min (rango 95-300 min). La estadÃa intrahospitalaria media fue de 3,8 dÃas (rango de 3-5 dÃas). El promedio de sangrado fue de 83 ml (rango 0-500 ml). El diagnóstico histopatológico fue de feocromocitoma en todas las muestras, en un caso se diagnosticó un feocromocitoma maligno. No hubo conversión a cirugÃa abierta. Conclusiones: La adrene-lectomÃa laparoscópica bilateral sincrónica para feocromocitomas bilaterales es un procedimiento seguro y de baja morbilidad, realizada por un cirujano con experiencia en cirugÃa laparoscópica. Es necesario tener previamente el diagnóstico de certeza para el manejo anestésico y postquirúrgico adecuado para estos pacientes.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-40262011000600005&nrm=is
Nematicidal activity of essential oils and organic amendments from Asteraceae against root-knot nematodes
The essential oil of Chrysanthemum coronarium flowerheads showed strong nematicidal activity in vitro and in growthchamber experiments. Essential oil concentrations of 2, 4, 8 and 16 μL mL−1, significantly reduced hatch, J2 survival
(determined by final value and area under curves of cumulative percentage hatch or mortality) and reproduction rate of Meloidogyne artiellia in vitro, with the lowest values occurring at 16 μL mL−1. In pot trials with chickpea cv. PV 61,
essential oil concentrations of 10–40 μL per 500 cm3 soil, applied on sterile cotton pellets, also significantly reduced the nematode’s reproduction rate. The biological processes of mortality and hatching/reproduction were adequately described by the monomolecular and expanded negative exponential models, respectively. Effectiveness of soil amendment
with either flowers, leaves, roots or seeds of C. coronarium, and flowers from several species of Asteraceae (Chrysanthemum segetum, Calendula maritima, Calendula officinalis and Calendula suffruticosa) at 5 g per 500 cm3 soil was tested for suppression of M. artiellia and growth of chickpea cv. PV 61 under growth-chamber conditions. In these tests, flowers of all five Asteraceae species and various parts of C. coronarium significantly reduced reproduction rates of M. artiellia, by 83·0–95·9%, with the minimum rates occurring in infected chickpea plants amended with flowers of C. officinalis and C. suffruticosa. The in vitro and in planta results suggest that the essential oil of C. coronarium and organic amendments from Asteraceae species may serve as nematicides.This research, part of a PhD study by P.P., was supported by grant SC98-022 and a fellowship from the Instituto Nacional de TecnologÃas Agroalimentarias (INIA).Peer reviewe
Reemplazo ureteral con apéndice cecal
Indexación: Web of Science; ScieloWe report two cases with ureteral lesions. A 34 years male with a residual retroperitoneal mass caused by a testicular cancer, that persisted after chemotherapy. During the surgical excision of the mass, the involvement of the right ureter was discovered. A 43 years old female with a left ureteral lesion secondary to radiation therapy and with a non-functioning contralateral kidney. In both cases a ureteral replacement with the cecal appendix was performed, without surgical complications. After five years of follow up, the urinary tract of the male patient is normal. The female patient required an endoscopic incision of the connection between the appendix and the urinary bladder, eight years after the surgical procedure. Three years after the endoscopic procedure the repaired urinary tract is in good conditions.Objetivo: Presentar dos casos de reemplazo ureteral con apéndice cecal y revisar la literatura relacionada al tema. Material y Método: Presentamos dos casos de lesión ureteral. Un paciente de 34 años con masa retroperitoneal residual post quimioterapia englobando el uréter derecho, secundaria a un tumor testicular, y una paciente de 43 años monorrena funcional con lesión ureteral izquierda actÃnica. Resultados: En ambos casos se realizó un reemplazo ureteral, derecho e izquierdo, sin complicaciones intraoperatorias. El seguimiento alejado a 5 y 11 años muestra indemnidad de la vÃa urinaria. Conclusión: Estos 2 casos, con seguimiento prolongado, apoyan la factibilidad del uso del apéndice cecal como variante para el reemplazo ureteral en lesiones extensas.http://ref.scielo.org/n85xn
A DNA packaging motor inchworms along one strand allowing it to adapt to alternative double-helical structures
Ring ATPases that translocate disordered polymers possess lock-washer architectures that they impose on their substrates during transport via a hand-over-hand mechanism. Here, we investigate the operation of ring motors that transport ordered, helical substrates, such as the bacteriophage Ï•29 dsDNA packaging motor. This pentameric motor alternates between an ATP loading dwell and a hydrolysis burst wherein it packages one turn of DNA in four steps. When challenged with DNA-RNA hybrids and dsRNA, the motor matches its burst to the shorter helical pitches, keeping three power strokes invariant while shortening the fourth. Intermittently, the motor loses grip on the RNA-containing substrates, indicating that it makes optimal load-bearing contacts with dsDNA. To rationalize these observations, we propose a helical inchworm translocation mechanism in which, during each cycle, the motor increasingly adopts a lock-washer structure during the ATP loading dwell and successively regains its planar form with each power stroke during the burst
Noticias falsas y creencias infundadas en la era de la posverdad
The dissemination of fake news embodies a pressing problem for democracy that is exacerbated by theubiquity of information available on the Internet and by the exploitation of those who, appealing to theemotionality of audiences, have capitalized on the injection of falsehoods into the social fabric. In thisstudy, through a cross-sectional, correlational and non-experimental design, the relationship betweencredibility in the face of fake news and some types of dysfunctional thoughts was explored in a sampleof Chilean university students. The results reveal that greater credibility in fake news is associated withhigher scores of magical, esoteric and naively optimistic thinking, beliefs that would be the meetingpoint for a series of cognitive biases that operate in the processing of information. The highest correlationis found with the paranormal beliefs facet and, particularly, with ideas about the laws of mentalattraction, telepathy and clairvoyance. Significant differences were also found in credibility in fake newsas a function of the gender of the participants, with the female gender scoring higher on average thanthe male gender. These findings highlight the need to promote critical thinking, skepticism and scientificattitude in all segments of society.La difusión de noticias falsas encarna un apremiante problema para la democracia que se ve agudizadopor la ubicuidad de la información disponible en el internet y por el aprovechamiento de quienes, apelandoa la emocionalidad de las audiencias, han capitalizado a su favor la inyección de falsedades en elentramado social. En este estudio a través de un diseño transversal, correlacional y no experimental seexploró la relación entre credibilidad frente a las noticias falsas y algunos tipos de pensamientos disfuncionales en una muestra de estudiantes universitarios chilenos. Los resultados develan que una mayorcredibilidad en noticias falsas va aparejada con mayores puntajes de pensamiento mágico, esotérico eingenuamente optimista, creencias que serÃan el punto de encuentro para una serie de sesgos cognitivosque operan en el procesamiento de la información. La correlación más alta se encuentra con la faceta decreencias paranormales y, particularmente, con las ideas acerca de las leyes de atracción mental, la telepatÃay la clarividencia. También se hallaron diferencias significativas en la credibilidad en noticias falsasen función del género de los participantes, encontrando que el género femenino puntúa una media másalta que el género masculino. Estos hallazgos ponen en relieve la necesidad de promover el pensamientocrÃtico, el escepticismo y la actitud cientÃfica en todos los segmentos de la sociedad
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