Persistence on airline accidents

This paper analyses airline accidents data from 1927-2006. The fractional integration methodology is adopted. It is shown that airline accidents are persistent and (fractionally) cointegrated with airline traffic. Thus, there exists an equilibrium relation between air accidents and airline traffic, with the effect of the shocks to that relationship disappearing in the long run. Policy implications are derived for countering accidents events.

Persistence in Airline Accidents

This paper analyses airline accident data from 1927-2006, through fractional integration. It is shown that airline accidents are persistent and (fractionally) cointegrated with airline traffic. There exists a negative relation between air accidents and airline traffic, with the effect of the shocks to that relationship disappearing in the long run. Policy implications are derived for countering accident events.Accidents; airline; Time series; Persistence; Long memory; Cointegration.

Brazilian Land Tenure and Conflicts: The Landless Peasants' Movement

This paper analyzes conflicts and violence in Brazil involving landless peasants occupying privately-owned land, for the period 2000-2008. It is the first study to be undertaken at a national level, with a contemporary data span, using a count data model that allows for heterogeneity, endogeneity and dynamics. Results from the estimated model show that the violent land occupation grows with left-wing political support for land occupation, rural population density, and agricultural credit, and decreases with poverty, agricultural productivity. The study discusses the interconnection of land reform, poverty and conflict.Land occupation, land reform, Brazil, poverty, conflict.

Assessing the embedded length of epoxy-bonded carbon laminates by pull-out bending tests

To evaluate the embedded length of epoxy-bonded fibre carbon laminates into concrete, pull-out bending tests were carried out. The laminates were embedded into concrete in order to prevent the phe-nomenon of peeling and to add extra protection against fire, therefore mobilising the potential of reinforce-ment of this composite material, with high tensile strength and stiffness. The bond-slip relationship obtained at the concrete-laminate interface can be used to define the corresponding constitutive law. This work de-scribes the tests that were performed, and discusses the results obtained in the preliminary experimental pro-gram carried out

Continuous aqueous two-phase system extraction using oscillatory flow reactor

Biotechnology has allowed the development of completely new products from health to food industry. The quality of the process since cell culture until formulation is crucial in their application. Nowadays, almost all biological products are still produced entirely in batch mode, which brings some drawbacks that can be overcome, operating in continuous mode. The continuous downstream processing can bring many advantages such as: automation and integration of unit operations, lower operator interaction with the equipment and consequently lower chance of errors; possibility of recycling buffers and auxiliary material; improvement of product quality, due to the greater uniformity of the process time; and increase of the process productivity. The usage of aqueous two-phase systems (ATPS) have been proven as an efficient operation for the clarification and purification of biological products, but despite this fact ATPS have had a limited use at large scale. On the one hand, ATPS extraction uses aqueous solutions that provide an ideal environment for biological molecules, on the other, the high salt concentrations and the cost of some polymers are the main drawbacks that make this process less cost-competitive comparing with others; however, the majority of ATPS extractions are still done in batchwise mode. Please click Additional Files below to see the full abstract

Levantamento e distribuiçao espacial de Ascidiacea nas Ilhas Currais, Paraná,Brasil

Orientadora: Rosana Moreira da RochaMonografia (Bacharelado) - Universidade Federal do Paraná. Setor de Ciencias Biológicas. Curso de Graduaçao em Ciencias BiológicasResumo : Ascídias colonizam substratos duros consolidados e a luz é um fator de grande influência na distribuição espacial vertical destes organismos. A costa do Estado do Paraná é uma das menores do Brasil, e os escassos substratos rochosos estão restritos a algumas pequenas ilhas próximas da costa. Os objetivos desse estudo foram conhecer a composição faunística de Ascidiacea nas Ilhas Currais, Paraná, e sua distribuição espacial. O lado sul da ilha é mais exposto à ação de ondas, ventos e correntes e o lado norte, mais abrigado e protegido. A coleta de dados ocorreu em ambos os lados da ilha e em diferentes profundidades (rasa, média e funda). Foram comparadas a distribuição e abundância de espécies entre as profundidades estudadas (verificação do efeito da luz na distribuição vertical), entre as porções norte e sul da ilha (verificação da homogeneidade do ambiente) e entre as estações do ano (verificação de variabilidade sazonal). As Ilhas Currais apresentam uma maior abundância de ascídias coloniais, principalmente da Família Didemnidae. Foi registrada uma riqueza total de 21 espécies, dentre as quais 6 são possíveis espécies novas, e 7 são novos registros para o Estado do Paraná. Não foi possível observar diferença na composição faunística de Ascidiacea nos lados norte e sul da ilha, bem como nas diferentes profundidades de amostragem. Porém, verificou-se uma nítida diferença entre as estações do ano, sendo observada· maior abundância de espécies na primavera

Cytomegalovirus Pulmonary Involvement in an Immunocompetent Adult

Cytomegalovirus (CMV) is a linear double-stranded DNA virus that may cause severe and potentially fatal infection in immunocompromised hosts. In immunocompetent individuals, the infection is typically mild or asymptomatic. However, in the last years, some cases of severe cytomegalovirus infection in immunocompetent individuals have been described. Clinical Presentation. 'e authors present a male patient aged 42 years, without specific medical history, who presented a 15-day history of fever, headache, night sweats, odynophagia, and bilateral otalgia, without improvement after four days of therapy with amoxicillin/clavulanic acid. Blood count and biochemistry were performed with liver cytolysis pattern. Chest teleradiography showed diffuse interstitial infiltrate. 'oracic CT scan revealed areas in a ground glass with a cross-linking component in the left and right upper lung lobes compatible with an inflammatory/infectious process. Blood serology was positive for CMV IgG and IgM. 'e detection on blood and bronchoalveolar lavage of CMV DNA by polymerase chain reaction (PCR) was also positive. Ganciclovir was started based on the clinical features and the result of CMV serology. After 48 hours, there was a significant clinical improvement, with remission of fever, and he was discharged on the 13th day of hospitalization with oral valganciclovir, completing a 21-day antiviral course at home. Conclusion. With this clinical case, the authors highlight the importance of considering CMV infection in evaluating patients with pneumonia, even in immunocompetent ones, particularly in those with no clinical improvement with antibiotics instituted for bacterial pneumonia, and when other causes have been ruled outinfo:eu-repo/semantics/publishedVersio

Evaluation of potential resistance development by cells adhered to antimicrobial surfaces

Publicado em "Biofilms7: microbial works of art"Immobilization of antimicrobials onto a surface has been proposed as a promising approach to fight biomaterial-associated infections (BAI). In this study, three antimicrobials, currently under investigation for use in medical devices, were evaluated for the risk of inducing bacterial resistance after their immobilization. An antibiotic, a quaternary ammonium compound (QAC) and an antimicrobial peptide (AMP) were immobilized onto polydimethylsiloxane (PDMS) using a mussel-inspired coating strategy. Results showed that antimicrobial surfaces exhibited contact-killing activity and were able to impair biofilm establishment. However, and similar to previously reported studies, a complete biofilm eradication was not achieved. The potential development of resistance towards these antimicrobials immobilized were then evaluated by continuously recovering the cells adhered to these antimicrobial surfaces and allowing them to adhere to new modified surfaces for a total of 10 passages. As a control, the same procedure was performed for unmodified PDMS. After 10 days, the cells recovered from the un- and modified surfaces were used to determine the MIC and MBC of antimicrobials. No propensity for developing bacterial resistance was found for immobilized QAC or AMP as the same susceptibility pattern was obtained for cells recovered from unmodified or modified surfaces. Cells recovered from the surfaces modified with antibiotic, exhibited a higher MBC as compared to cells recovered from unmodified PDMS. This study highlighted the risk associated to the immobilization of antibiotics and the promising potential of QAC and AMP to be used in the design of materials able to prevent BAI

Distinguishing the albedo of exoplanets from stellar activity

Light curves show the flux variation from the target star and its orbiting planets as a function of time. In addition to the transit features created by the planets, the flux also includes the reflected light component of each planet, which depends on the planetary albedo. This signal is typically referred to as phase curve and could be easily identified if there were no additional noise. As well as instrumental noise, stellar activity, such as spots, can create a modulation in the data, which may be very difficult to distinguish from the planetary signal. We analyze the limitations imposed by the stellar activity on the detection of the planetary albedo, considering the limitations imposed by the predicted level of instrumental noise and the short duration of the observations planned in the context of the CHEOPS mission. As initial condition, we have assumed that each star is characterized by just one orbiting planet. We built mock light curves that included a realistic stellar activity pattern, the reflected light component of the planet and an instrumental noise level, which we have chosen to be at the same level as predicted for CHEOPS. We then fit these light curves to try to recover the reflected light component, assuming the activity patterns can be modeled with a Gaussian process.We estimate that at least one full stellar rotation is necessary to obtain a reliable detection of the planetary albedo. This result is independent of the level of noise, but it depends on the limitation of the Gaussian process to describe the stellar activity when the light curve time-span is shorter than the stellar rotation. Finally, in presence of typical CHEOPS gaps in the simulations, we confirm that it is still possible to obtain a reliable albedo.Comment: Accepted for publication in A&A, 14 pages, 12 figure