The impact of educational technologies in higher education

The formation of human capital is key to countries’ social, cultural, and economic development. The current literature review pays considerable attention to the ever-increasing proliferation of technology in the careers of college and school graduates. While the presence of educational technology in higher education offers multiple benefits, its implementation also presents challenges. In that sense, the literature has considered multiple tools for improving learning processes. However, the results of such tools vary and are difficult to measure in terms of quality. In this literature review, we analyze the issues surrounding educational technology in higher education.La formación de capital humano es clave para el desarrollo social, cultural y económico de los países. Esta revisión de literatura presta una atención considerable a la introducción cada vez mayor de la tecnología en las carreras universitarias y en las escuelas de posgrados. Si bien la presencia de tecnología educativa en la educación superior ofrece múltiples beneficios, su implementación también presenta desafíos. En ese sentido, la literatura ha considerado múltiples herramientas para mejorar los procesos de aprendizaje. Ahora bien, los resultados de estas herramientas varían y son difíciles de medir en términos de calidad. En esta revisión de la literatura, analizamos los problemas que rodean la tecnología educativa en la educación superiorA formação de capital humano é fundamental para o desenvolvimento social, cultural e econômico dos países. Esta revisão de literatura presta uma atenção considerável à introdução cada vez maior da tecnologia nas carreiras universitárias e nas escolas de pós-graduações. Embora a presença de tecnologia educativa na educação superior ofereça múltiplos benefícios, sua implementação também apresenta desafios. Nesse sentido, a literatura tem considerado múltiplas ferramentas para melhorar os processos de aprendizagem. Agora bem, os resultados destas ferramentas variam e são difíceis de medir em termos de qualidade. Nesta revisão da literatura, analisamos os problemas que rodeiam a tecnologia educativa na educação superio

Butterflies as bioindicators of metal contamination

Anthropogenic trace metal contamination has significantly increased and has caused many hazardous consequences for the ecosystems and human health. The Terni basin valley (Central Italy) shows a heavy load of pollutants from industrial activities, while the characteristic orography structure of the valley favours air stagnation, thus limiting air pollution dispersal. The present study conducted in 2014 aimed to determine the concentration of ten metals in five species of butterflies at nine sites in the Terni valley along a 21-km-long transect, including both relatively pristine and industrial areas. At sites where soil contamination was high for a given metal, such as for chromium as in the case of site 4 (the closest to the steel plant) and for lead as in the case of site 2 (contaminated by a firing range), higher levels of contamination were observed in the tissues of butterflies. We found a correlation between soil contamination and the concentration of Cr, Al and Sr in the tissues of some species of butterflies. The sensitivity to contamination differed among the five species; in particular, Coenonympha pamphilus was generally the species that revealed the highest concentrations of all the ten trace metals at the sites closer to the industrial area. It is known that C. pamphilus is a sedentary species and that its host plants are the Poaceae, capable of accumulating high quantities of metals in their rhizosphere region, thus providing the link with soil contamination. Therefore, monitoring the metal concentration levels in butterflies might be a good indicator and a control tool of environmental quality, specifically in areas affected by high anthropogenic pollution loads linked to a specific source

Molecular characterization of Prototheca strains isolated from Italian dairy herds.

One hundred sixty-one Prototheca spp. strains isolated from composite milk and barn-surrounding environmental samples (bedding, feces, drinking, or washing water, surface swabs) of 24 Italian dairy herds were characterized by genotype-specific PCR analysis. Overall, 97.2% of strains isolated from composite milk samples were characterized as Prototheca zopfii genotype 2, confirming its role as the main mastitis pathogen, whereas Prototheca blaschkeae was only sporadically isolated (2.8%). Regarding environmental sampling, 84.9% of isolates belonged to P. zopfii genotype 2, 13.2% to P. blaschkeae, and 1.9% to P. zopfii genotype 1. The data herein contradict previous hypotheses about the supposed exclusive role of P. zopfii genotype 2 as the causative agent of protothecal mastitis and, on the contrary, confirm the hypothesis that such pathology could be caused by P. blaschkeae in a few instances

Solar neutrino detection in a large volume double-phase liquid argon experiment

Precision measurements of solar neutrinos emitted by specific nuclear reaction chains in the Sun are of great interest for developing an improved understanding of star formation and evolution. Given the expected neutrino fluxes and known detection reactions, such measurements require detectors capable of collecting neutrino-electron scattering data in exposures on the order of 1 ktonne yr, with good energy resolution and extremely low background. Two-phase liquid argon time projection chambers (LAr TPCs) are under development for direct Dark Matter WIMP searches, which possess very large sensitive mass, high scintillation light yield, good energy resolution, and good spatial resolution in all three cartesian directions. While enabling Dark Matter searches with sensitivity extending to the "neutrino floor" (given by the rate of nuclear recoil events from solar neutrino coherent scattering), such detectors could also enable precision measurements of solar neutrino fluxes using the neutrino-electron elastic scattering events. Modeling results are presented for the cosmogenic and radiogenic backgrounds affecting solar neutrino detection in a 300 tonne (100 tonne fiducial) LAr TPC operating at LNGS depth (3,800 meters of water equivalent). The results show that such a detector could measure the CNO neutrino rate with ~15% precision, and significantly improve the precision of the 7Be and pep neutrino rates compared to the currently available results from the Borexino organic liquid scintillator detector.Comment: 21 pages, 7 figures, 6 table

A Study of the Residual 39Ar Content in Argon from Underground Sources

The discovery of argon from underground sources with significantly less 39Ar than atmospheric argon was an important step in the development of direct-detection dark matter experiments using argon as the active target. We report on the design and operation of a low background detector with a single phase liquid argon target that was built to study the 39Ar content of the underground argon. Underground argon from the Kinder Morgan CO2 plant in Cortez, Colorado was determined to have less than 0.65% of the 39Ar activity in atmospheric argon.Comment: 21 pages, 10 figure

A Abordagem Laparoscópica na Apendicite Aguda

Background: The appendectomy is the most frequently performed surgery in the Emergency Service. The introduction of the lapa- roscopic approach (LA) in the treatment of acute appendicitis has not received, in the surgical community, the same acceptance that it obtained in other acute conditions. With this work, the authors present the growing acceptance that the LA has been acquiring in the Surgical Service that they represent, and they also want to demonstrate the advantages of this approach towards the laparotomic approach. Materials and Methods: Observational retrospective study consisting of patients undergoing appendectomy for acute appendicitis between 01/11/2008 to 31/10/2010 in the Emergency Service of the CHTS, EPE. Results: In the presented series 477 patients were subjected to an appendectomy, 9,6% of which through an LA. For both surgical approaches, the average age was 33,1 years (CI 91%:29,6-37,4) to LA and 37,3 years (CI 91%:31,7-38, 9) to laparotomic approach, p = 0,11; the female gender represented 19,0% of patients undergoing LA and 42,0% of patients undergoing laparotomy, p = 0,03. The duration of the hospital stay in LA was 3,2 days (CI 91% :2,4-4, 0) and 4,2 days (CI 91%:3,9-4, 4) in the laparotomic approach, p = 0,041 ; postoperative complications occurred in 7,7% of patients undergoing laparotomy and 8,7% of patients receiving LA, p = 0,8. There was no mortal- ity in this series.Conclusions: The LA, in the treatment of acute appendicitis, increased considerably over the two years of the study. It allows better cosmetic results and shorter hospital stay. It revelas a complication rate similar to the one of the laparotomic approach and can be used safely in patients with complicated acute appendicitis.  Keywords: acute appendicitis, appendectomy, laparoscopic approach    Introdução: A apendicectomia é a cirurgia efectuada com mais frequência no Serviço de Urgência. A introdução da abordagem lapa- roscópica (AL) no tratamento da apendicite aguda não recebeu, na comunidade cirúrgica, a mesma aceitação que obteve em outras patologias agudas. Com este trabalho, os autores apresentam a crescente aceitação que a AL tem vindo a adquirir no Serviço Cirúr- gico que representam e pretendem, também, expor as vantagens desta abordagem em relação à abordagem laparotómica. Material e Métodos: Estudo retrospectivo observacional constituído por doentes submetidos a apendicectomia, por apendicite aguda, entre 01/11/2008 e 31/10/2010 no Serviço de Urgência do CHTS, EPE. Resultados: Na série apresentada foram submetidos a apendicec- tomia 477 doentes, 9,6% por AL. Para as duas abordagens cirúrgicas, a média de idades foi de 33,1 anos (IC 91%:29,6-37,4) para a AL e 37,3 anos (IC 91%:31,7-38,9) para a abordagem laparotómica, p=0,11; o género feminino representou 19,0% dos doentes submetidos a AL e 42,0% dos doentes submetidos a abordagem laparotómica, p=0,03. O tempo de internamento na AL foi de 3,2 dias (IC 91%:2,4-4,0) e 4,2 dias (IC 91%:3,9-4,4) na abordagem laparotómica, p=0,041; as complicações pós-operatórias ocorreram em 7,7% dos doentes submetidos a abordagem laparotómica e em 8,7% dos doentes submetidos a AL, p=0,8. A mortalidade foi nula nesta série. Conclusões: A AL, no tratamento da apendicite aguda, aumentou consideravelmente ao longo dos dois anos a que se refere o estudo. Permite obter melhores resultados estéticos e menor tempo de internamento. Apresenta uma taxa de complicações idêntica à abordagem laparotómica e pode ser utilizada, de forma segura, em doentes com apendicite aguda complicada. Palavras-Chave: apendicite aguda, apendicectomia, abordagem laparoscópica.

The Nylon Scintillator Containment Vessels for the Borexino Solar Neutrino Experiment

Borexino is a solar neutrino experiment designed to observe the 0.86 MeV Be-7 neutrinos emitted in the pp cycle of the sun. Neutrinos will be detected by their elastic scattering on electrons in 100 tons of liquid scintillator. The neutrino event rate in the scintillator is expected to be low (~0.35 events per day per ton), and the signals will be at energies below 1.5 MeV, where background from natural radioactivity is prominent. Scintillation light produced by the recoil electrons is observed by an array of 2240 photomultiplier tubes. Because of the intrinsic radioactive contaminants in these PMTs, the liquid scintillator is shielded from them by a thick barrier of buffer fluid. A spherical vessel made of thin nylon film contains the scintillator, separating it from the surrounding buffer. The buffer region itself is divided into two concentric shells by a second nylon vessel in order to prevent inward diffusion of radon atoms. The radioactive background requirements for Borexino are challenging to meet, especially for the scintillator and these nylon vessels. Besides meeting requirements for low radioactivity, the nylon vessels must also satisfy requirements for mechanical, optical, and chemical properties. The present paper describes the research and development, construction, and installation of the nylon vessels for the Borexino experiment

Discovery of underground argon with low level of radioactive 39Ar and possible applications to WIMP dark matter detectors

We report on the first measurement of 39Ar in argon from underground natural gas reservoirs. The gas stored in the US National Helium Reserve was found to contain a low level of 39Ar. The ratio of 39Ar to stable argon was found to be <=4x10-17 (84% C.L.), less than 5% the value in atmospheric argon (39Ar/Ar=8x10-16). The total quantity of argon currently stored in the National Helium Reserve is estimated at 1000 tons. 39Ar represents one of the most important backgrounds in argon detectors for WIMP dark matter searches. The findings reported demonstrate the possibility of constructing large multi-ton argon detectors with low radioactivity suitable for WIMP dark matter searches.Comment: 6 pages, 2 figures, 2 table