2,829 research outputs found
First in-beam studies of a Resistive-Plate WELL gaseous multiplier
We present the results of the first in-beam studies of a medium size
(1010 cm) Resistive-Plate WELL (RPWELL): a single-sided THGEM
coupled to a pad anode through a resistive layer of high bulk resistivity
(10cm). The 6.2~mm thick (excluding readout electronics)
single-stage detector was studied with 150~GeV muons and pions. Signals were
recorded from 11 cm square copper pads with APV25-SRS readout
electronics. The single-element detector was operated in Ne\(5%
) at a gas gain of a few times 10, reaching 99
detection efficiency at average pad multiplicity of 1.2. Operation at
particle fluxes up to 10 Hz/cm resulted in 23 gain drop
leading to 5 efficiency loss. The striking feature was the
discharge-free operation, also in intense pion beams. These results pave the
way towards robust, efficient large-scale detectors for applications requiring
economic solutions at moderate spatial and energy resolutions.Comment: Accepted by JINS
Biocomposite macrospheres based on strontium-bioactive glass for application as bone fillers
Traditional bioactive glass powders are typically composed of irregular particles that can be packed into dense configurations presenting low interconnectivity, which can limit bone ingrowth. The use of novel biocomposite sphere formulations comprising bioactive factors as bone fillers are most advantageous, as it simultaneously allows for packing the particles in a 3-dimensional manner to achieve an adequate interconnected porosity, enhanced biological performance, and ultimately a superior new bone formation. In this work, we develop and characterize novel biocomposite macrospheres of Sr-bioactive glass using sodium alginate, polylactic acid (PLA), and chitosan (CH) as encapsulating materials for finding applications as bone fillers. The biocomposite macrospheres that were obtained using PLA have a larger size distribution and higher porosity and an interconnectivity of 99.7%. Loose apatite particles were observed on the surface of macrospheres prepared with alginate and CH by means of soaking into a simulated body fluid (SBF) for 7 days. A dense apatite layer was formed on the biocomposite macrospheresâ surface produced with PLA, which served to protect PLA from degradation. In vitro investigations demonstrated that biocomposite macrospheres had minimal cytotoxic effects on a human osteosarcoma cell line (SaOS-2 cells). However, the accelerated degradation of PLA due to the degradation of bioactive glass may account for the observed decrease in SaOS-2 cells viability. Among the biocomposite macrospheres, those composed of PLA exhibited the most promising characteristics for their potential use as fillers in bone tissue repair applications.This work was funded by grant #2019/15960-6, São Paulo Research Foundation in Brazil (FAPESP) and the Portuguese Foundation for Science and Technology (FCT), Reference UID/CTM/50025/2019 and FCT/Minister of Science, Technology and Higher Education in Portugal (MCTES) and by European Regional Development Fund (FEDER) funds through the COMPETE 2020 Program in the framework of ORAiDEA project (ref n° 39985 - AAC 31/SI/2017). The authors would also like to acknowledge Materials Research Center (CENIMAT) of the Associated Laboratory Institute of Nanostructures, Nanomodeling and Nanofabrication (i3N), NOVA University of LisbonCENIMAT|i3N and National Council for Scientific and Technological Development in Brazil CNPq (303149/2018-3). Ibrahim Fatih Cengiz acknowledges the FCT distinction attributed to him under the “Estímulo ao Emprego Científico” program (2021.01969.CEECIND). The authors thank the financial support provided under the projects: “HEALTH-UNORTE: Setting-up biobanks and regenerative medicine strategies to boost research in cardiovascular, musculoskeletal, neurological, oncological, immunological, and infectious diseases”, reference NORTE-01-0145-FEDER-000039, funded by the Norte Portugal Regional Coordination and Development Commission (CCDR-N), under the NORTE2020 Program; Projects LA/P/0037/2020, UIDP/50025/2020, and UIDB/50025/ 2020 of the Associate Laboratory i3N financed by national funds from FCT
A tale of two species: the importance of native ecosystems for long-term conservation on Príncipe Island, Gulf of Guinea
Since it was first described in 1901, the Príncipe thrush Turdus xanthorhynchus has been rare and restricted to the native forest in the south of Príncipe Island. The Obô giant land snail Archachatina bicarinata, however, was widespread across the island and at least locally abundant until the 1990s. Since then its population has collapsed, and now, like the thrush, it is also restricted to the native forest in the south of the island. Using species distribution modelling, we show that both species are currently strongly associated with rugged and remote areas of native forest at high altitudes. We argue that their current distribution might be negatively affected by anthropogenic pressures, as both are harvested, and also because invasive alien species are expected to have deleterious effects on these species, although further studies are needed to clarify interactions between these native and introduced species. The diachronic stories of these species highlight an overlooked value of native ecosystems: their role in the conservation of widespread species that might be unable to use anthropogenic landscapes in the future. They also reinforce the need for protected areas that strive to exclude most human activities in the context of particularly sensitive biodiversity, as is often the case on oceanic islands.info:eu-repo/semantics/publishedVersio
Electromagnetic energy harvesting using magnetic levitation architectures: a review
Motion-driven electromagnetic energy harvesters have the ability to provide low-cost and customizable electric powering. They are a well-suited technological solution to autonomously supply a broad range of high-sophisticated devices. This paper presents a detailed review focused on major breakthroughs in the scope of electromagnetic energy harvesting using magnetic levitation architectures. A rigorous analysis of twenty-one design configurations was made to compare their geometric and constructive parameters, optimization methodologies and energy harvesting performances. This review also explores the most relevant models (analytical, semi-analytical, empirical and finite element method) already developed to make intelligible the physical phenomena of their transduction mechanisms. The most relevant approaches to model each physical phenomenon of these transduction mechanisms are highlighted in this paper. Very good agreements were found between
experimental and simulation tests with deviations lower than 15%. Moreover, the external motion excitations and electric energy harvesting outputs were also comprehensively compared and critically discussed. Electric power densities up to 8 mW/cm^3 (8 kW/m^3) have already been achieved; for resistive loads, the maximum voltage and current were 43.4 V and 150 mA, respectively, for volumes up to 235 cm^3. Results highlight the potential of these harvesters to convert mechanical energy into electric energy both for large-scale and small-scale applications. Moreover, this paper proposes future research directions towards efficiency maximization and minimization of energy production costs.in publicatio
False-negative reactions to the comparative intradermal tuberculin test for bovine tuberculosis.
According to the Brazilian National Program for the Control and Eradication of Animal Brucellosis and Tuberculosis (PNCEBT), the routine tests for the diagnosis of bovine tuberculosis in the country are the simple intradermal tuberculin test (SITT) of the Ministry of Agriculture, Livestock and Food Supply (MAPA), the caudal fold test and the comparative intradermal tuberculin test (CITT). The latter is also used as a confirmatory test. A group of 53 animals from three dairy herds in a focal area for bovine tuberculosis, that were submitted to depopulation in the state of Rio Grande do Sul, were submitted to the CITT. Tissues were cultured and the resulting colonies were confirmed by PCR and DNA sequencing. Among the 53 animals analyzed using the CITT, 32 (60.4%) were negative, 14 (26.4%) were positive and seven (13.2%) results were inconclusive. The CITT detected 11 of the 39 animals with culture-confirmed M. bovis infection as positive. Among the total of 14 uninfected animals based on cultures, the CBT detected eight as negative. Thus, the CITT demonstrated sensitivity of 28.2% and specificity of 57.1% for the population sampled. A total of 24/32 (75.0%) of the animals with negative CITT results were culture positive (confirmed by PCR) and were considered false negatives based on the CITT. The maintenance of these false-negative animals in herds has serious implications for the control of the disease, since they can be a source of infection. The addition of complementary tests could help identify such animals and increase the odds of diagnostic success.Título em português: Reações falso-negativas ao teste cervical comparativo para tuberculose bovina
Severity of Ascites Is Associated with Increased Mortality in Patients with Cirrhosis Secondary to Biliary Atresia
Very few prior studies have investigated the presence of ascites as a prognostic factor in children with cirrhosis. To the best of our knowledge, there are no prior studies evaluating the relationship between severity of ascites and patient survival in children with biliary atresia and cirrhosis.Clinically detectable ascites is associated with decreased 1-year survival of children with biliary atresia. These patients should be treated with caution and prioritized for liver transplantation.Background Very few prior studies have investigated the presence of ascites as a prognostic factor in children with cirrhosis.
To the best of our knowledge, there are no prior studies evaluating the relationship between severity of ascites and patient
survival in children with biliary atresia and cirrhosis.
Aims To evaluate the association between severity of ascites and survival of children with cirrhosis and biliary atresia.
Methods All children with cirrhosis secondary to biliary atresia evaluated at our institution from 2000 to 2014 were included
in this study. Patients were classified into four groups: NA = no ascites; A1 = grade 1 ascites; A2 = grade 2 ascites; and
A3 = grade 3 ascites. The primary endpoint of the study was mortality within the first year after patient inclusion. Ninetyday
mortality was also evaluated. Prognostic factors related to both endpoints also were studied. [...]info:eu-repo/semantics/publishedVersio
Gestão: análise do desempenho econômico-financeiro de organizações brasileiras de capital aberto de ensino superior
In 2007, in Brazil, emerged the first three open-capital educational companies, named Anhanguera, Estácio and Kroton. The objective of this study was to determine and analyze the economic-financial performance of these Higher Education Institutions (HEI) with shares in the Brazilian stock market from 2007 to 2013. The following indicators were used: a) generation of value measured by E.V.A; b) cash generation capacity measured by EBITDA; and c) financial situation evaluated by the Fleuriet Method. With descriptive methodology and documentary analysis, the performance of HEI was calculated, analyzed and compared. The results showed that all three presented a solid financial situation, with great divergence while the cash generation capacity. In the period studied, only Estácio generated value to shareholders. The results of the research also revealed that the economic and financial performance of these HEIs is very dependent on government policies for access and financing of higher education.En 2007, en Brasil, surgieron las tres primeras empresas educativas de capital abierto, denominadas Anhanguera, Estácio y Kroton. El objetivo de este estudio fue determinar y analizar el desempeño económico-financiero de estas Instituciones de Enseñanza Superior (IES) con acciones en el mercado accionario brasileño, en el período de 2007 a 2013. Se utilizaron indicadores de: a) generación de valor medido por el E.V.A .; b) capacidad de generación de caja medida por el EBITDA; y c) situación financiera evaluada por el método Fleuriet. Con metodología descriptiva y análisis documental se verificaron, analizaron y compararon los resultados de la IES. Los resultados demostraron que las tres presentaron una situación financiera sólida, con gran divergencia en cuanto a la capacidad de generación de caja. En el período estudiado, sólo la Estácio generó valor a los accionistas. Los resultados de la investigación también revelaron que el desempeño económico-financiero de estas IES es muy dependiente de las políticas gubernamentales de acceso y financiamiento de la enseñanza superior.Em 2007, no Brasil, surgiram as três primeiras empresas educacionais de capital aberto, denominadas Anhanguera, Estácio e Kroton. O objetivo deste estudo foi apurar e analisar o desempenho econômico-financeiro destas Instituições de Ensino Superior (IES) com ações no mercado acionário brasileiro, no período de 2007 a 2013. Utilizou-se indicadores de: a) geração de valor mensurado pelo E.V.A.; b) capacidade de geração de caixa mensurada pelo EBITDA; e c) situação financeira avaliada pelo Método Fleuriet. Com metodologia descritiva e análise documental foram apurados, analisados e comparados os desempenhos da IES. Os resultados demonstraram que as três apresentaram situação financeira sólida, com grande divergência quando à capacidade de geração de caixa. No período estudado, apenas a Estácio gerou valor aos acionistas. Os resultados da pesquisa também revelaram que o desempenho econômico-financeiro destas IES é muito dependente das políticas governamentais de acesso e financiamento do ensino superior
Testing the persistence of Carcharodontosauridae (Theropoda) in the Upper Cretaceous of Patagonia based on dental evidence
The deposits corresponding to the Upper Cretaceous Neuquén and San Jorge Gulf basins from northern and central Patagonia have provided two of the most complete sequences of terrestrial vertebrate faunas of all Gondwanan landmasses. Among the carnivorous components, the carcharodontosaurid theropods appeared as common elements during the Early Cretaceous and the earliest Late Cretaceous in northern and central Patagonia. Although recorded mostly in the lower Turonian, isolated teeth suggest their presence in younger strata in northern and central Patagonia, reaching the clade in the region as late as the early Maastrichtian. Here, we verify the assignment of such isolated teeth previously identified as belonging to Carcharodontosauridae from the Upper Cretaceous strata of northern and central Patagonia. Using three different methods, namely a cladistic analysis performed on a dentition-based data matrix, and discriminant and cluster analyses conducted on a large dataset of theropod crown measurements, we assign a tooth from Candeleros Formation to carcharodontosaurid theropods and teeth from Cerro Lisandro, Bajo Barreal, Portezuelo, Plottier and Allen formations to abelisaurid theropods. These new reappraisals provide additional evidence about the extinction of Carcharodontosauridae in South America at about the late Turonian–earliest Coniacian as part of a general faunistic turnover event, with the last clear evidence of this lineage in Patagonia coming from the early–middle Turonian.Fil: Meso, Jorge Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaFil: Juárez Valieri, R. D.. Gobierno de la Provincia de Río Negro. Ministerio de Turismo, Cultura y Deporte. Secretaría de Cultura; ArgentinaFil: Porfiri, Juan Domingo. Museo del Desierto Patagónico; Argentina. Universidad Nacional del Comahue. Museo de Ciencias Naturales; Argentina. Universidad Nacional del Comahue. Facultad de Ingeniería; ArgentinaFil: Da Silva Correa, Samuel Aparecido. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaFil: Martinelli, Agustín Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Casal, G. A.. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Canudo, J. I.. Universidad de Zaragoza; EspañaFil: Poblete, F.. Museo del Desierto Patagónico; ArgentinaFil: Dos Santos, D.. Museo del Desierto Patagónico; Argentina. Universidad Nacional del Comahue. Museo de Ciencias Naturales; Argentina. Universidad Nacional del Comahue. Facultad de Ingeniería; Argentin
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