Comparing Air Transport Policies for Small Remote Communities: U.S.A., Canada, Portugal, Spain and Brazil

This paper examines the regulatory status in the aviation industry, and the efforts of the U.S.A., Canada, Portugal, Spain and Brazil to adopt air transport policies and mechanisms to provide their populations with universal accessibility. A systems engineering grounded theory approach and a cross-national case-based comparison framework are used to look at the impacts of different policies and mechanisms on the air service to small remote communities. It is found that the success of a policy design critically depends on five factors: 1) the joint support of infrastructure investment, maintenance and operations and air services; 2) governments’ ability to promote competition and protect passengers in markets where competition does not exist; 3) the operating carrier’s choice of business model, technology for thin routes, and network; 4) political interest; and 5) local participation. Based on the evaluation of policy designs and assessment of policies in five substantially different national contexts and interviews with several stakeholders, the authors provide insights and suggest recommendations in small remote air transport policy for policy makers and practitioners. The recommendations are applicable to other countries reforming their aviation industries

Evaluation of Nanoparticle Uptake iii Co-culture Cancer Modeis

Co-culture models are currently bridging the gap between classical cultures and in vivo animal models. Exploring this novel approach unlocks the possibility to mimic the tumor microenvironment in vitro, through the establishment of cancer-stroma synergistic interactions. Notably, these organotypic models offer a perfect platform for the development and pre-clinical evaluation of candidate nanocarriers loaded with anti-tumoral drugs in a high throughput screening mode, with lower costs and absence of ethical issues. However, this evaluation was until now limited to co-culture systems established with precise cell ratios, not addressing the natural cell heterogeneity commonly found in different tumors. Therefore, herein the multifunctional nanocarriers efficiency was characterized in various fibroblast-MCF-7 co-culture systems containing different cell ratios, in order to unravel key design parameters that influence nanocarrier performance and the therapeutic outcome. The successful establishment of the co-culture models was confirmed by the tissue-like distribution of the different cells in culture. Nanoparticles incubation in the various co-culture systems reveals that these nanocarriers possess targeting specificity for cancer cells, indicating their suitability for being used in this illness therapy. Additionally, by using different co-culture ratios, different nanoparticle uptake profiles were obtained. These findings are of crucial importance for the future design and optimization of new drug delivery systems, since their real targeting capacity must be addressed in heterogenous cell populations, such as those found in tumors.PEst-OE/EGEJUI4D5G/201

Influence Of Backing And Matching Layers In Ultrasound Transducers Performance

In this work we have investigated the influence of the backing layer composition and the matching layer thickness in the performance of ultrasound transducers constructed with piezoelectric ceramic discs. We have constructed transducers with backing layers of different compositions, using mixtures of epoxy with alumina powder and/or Tungsten powder and with λ/4 or 3λ/4 thickness epoxy matching layers. The evaluation tests were performed in pulse-echo mode, with a flat target, and in transmission/reception mode, with a calibrated PVDF hydrophone. The acoustical field emitted by each transducer was mapped in order to measure the on-axis and transverse field profiles, the aperture size and the beam spreading. The bandwidths of the transducers were determined in pulse-echo mode. Comparing the evaluation tests results of two transducers constructed with the same backing layer, the one constructed with λ/4 thickness epoxy matching layer showed better performance. The results showed that the transducers constructed with epoxy, alumina and Tungsten powders backing layers have larger bandwidth. The larger depth of field was measured for transducers constructed with epoxy and Tungsten powder backing layers. These transducers and those constructed with epoxy, Tungsten and alumina powders backing layers showed the larger field intensities in the measured transverse profiles.50358696(1999) Standard Guide for Evaluating Characteristics of Ultrasonic Search Units, , ASTM E-1065 1999Desilets, C.S., Fraser, J.D., Kino, G.S., The design of efficient broad-band piezoelectric transducers (1978) IEEE Transactions on Sonics and Ultrasonics, SU-25 (3), pp. 115-125(1996) Ultrasonics Real Time Pulse-echo Systems: Test Procedures to Determine Performance Specification, , IEC-1390(1989) IEEE Guide for Medical Ultrasound Field Parameter Measurements, , IEEE American National Standard Std 790(1978) IEEE Standard on Piezoelectricity, , IEEE American National Standard Std 176Inoue, T., Ohta, M., Takahashi, S., Design of ultrasonic transducers with multiple acoustic matching layers for medical applications (1987) IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 34 (1)Lockwood, G.R., Turnbull, D.H., Foster, F.S., Fabrication of high frequency spherically shaped ceramic transducers (1994) IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 41 (2)Mitra, R., Saksena, T.K., Study on the vibrational characteristics of ultrasonic transducers using tapered piezoelectric ceramic elements (1995) Journal of the Acoustical Society of America, 58 (2)Sayers, C.M., Tait, C.E., Ultrasonic properties of transducer backing (1984) Ultrasonics, 22 (2

“Young” masters vs. elite swimmers: comparison of performance, energetics, kinematics and efficiency

Competition in masters swimming is getting tougher. Athletes are dedicating more time and effort to excel in masters competitions than they use to. Research question: What are the factors associated with masters and elite swimmers performance? Type of study: A cohort group comparison (young master versus elite swimmers) and a correlational study (association between selected variables and performance) were conducted. Purpose: The aim was to identify the energetics, kinematics and efficiency variables associated with young masters (former elite) and elite swimmers performance as well as compare it between both cohort groups. Methods: Twenty male swimmers (masters: N=8, 29.75±3.80-y; elite: N=12, 20.41±3.20-yld) performed a 7x200m freestyle swim. The performance (200m freestyle at official competition), velocity at which the 4 mmol.l-1 of blood lactate was assessed (V4), peak blood lactate concentrations (Lapeak), peak oxygen up-take (VO2peak), minimum velocity to elicited VO2peak (vVO2peak), total energy expenditure (Ėtot), stroke frequency (SF), stroke length (SL), mean swimming velocity (v), energy cost (C), stroke index (SI) and propelling efficiency (p) to check whether this was achieved. Results: Elite swimmers presented a better performance. V4, VO2peak, vVO2peak, Ėtot , SF, v and SI were significantly higher in elite swimmers. For both groups performance was associated with the V4, vVO2peak and v. In addition, elite swimmers’ performance was impaired with regard to the Lapeak. Conclusions: Young masters swimmers presented impairment in performance related to a decrease in the energetics profile and biomechanical behaviour. Nevertheless, their previous background as elite swimmers allowed them to maintain high swimming efficiency

Tracking the 2004-2008 Olympic cycle performance in long distance freestyle events

Swimming seems to be one of the most studied sport among Sport Sciences community. Researchers are constantly attempting to identify and understand the factors that can predict swimming performance with a higher accuracy (e.g., Silva et al., 2007)

Longitudinal assessment of elite swimmers performance leading to 2008 Beijing Olympic Games

The aim of this research was to track and analyze the stability of 400-m freestyle performance throughout elite swimmers preparation to the 2008 Beijing Olympic Game

Longitudinal assessment of swimming performance in the 200 m freestyle event

Several studies have been carried out in order to identify the factors that can predict swimming performance. However, all these studies only analyzed determinant factors in a single moment. It was not taken into account the longitudinal stability and changes, as a result of individual development, new training methods and technological sophistication

Análise longitudinal da performance em natação pura desportiva: abordagem exploratória

O estudo teve como objectivo analisar a estabilidade da performance na prova de 400m livres ao longo da carreira desportiva. Foram analisados 45 nadadores masculinos, durante sete épocas consecutivas (desde a categoria de Infantil B até Sénior). A performance foi analisada com recurso ao melhor tempo em cada categoria na prova de 400m Livres em piscina curta. Foi efectuada a análise da estabilidade das médias, pela observação dos quartis ao longo da carreira desportiva, assim como a tendência central (média) e respectiva dispersão (um desvio-padrão). Foi ainda analisada a variação entre valores médios com recurso à ANOVA medidas repetidas e respectivo post-hoc teste (Bonferroni). Analisou-se ainda a estabilidade normativa pela auto-correlação entre as sete categorias (Pearson). Foi calculado o Kappa de Cohen (K) com um intervalo de confiança de 95%. Para todos os procedimentos estatísticos foi utilizado o programa informático SPSS 13,0 à excepção do K, o qual foi calculado através do programa estatístico Longitudinal Data Analysis. Foram verificadas diferenças significativas entre os valores médios de performance entre todas as categorias. Os valores de auto-correlação variaram entre o moderado e o elevado ao longo da carreira desportiva. Constata-se que na passagem de Juvenil B para A, a estabilidade torna-se elevada (>0,60). O valor de K, expressando a estabilidade ao longo de toda a carreira desportiva, é baixo (K = 0.327 ± 0,046). Em síntese, a predição do nível competitivo na categoria sénior com base na performance nas categorias de formação é reduzido. Todavia, a passagem de Juvenil B para A parece ser um momento marcante, onde a capacidade preditiva aumenta de forma acentuada

The isolation and importance of Simbu group viruses in South Africa

The five viruses used in this study were isolated from cattle. An additional virus was recovered from a pool of biting midges, (Culicaides spp). The six viruses shared common group specific antigens in the cross-complement fixation test but in the cross-serum-virus neutralization test, they were shown to be three distinct viruses. In the cross-serum-virus microneutralization test utilizing reference sera and viruses of the Simbu serogroup it was demonstrated that they represented local strains of Shamonda, Shuni and Saba virus. Using suckling mice and the chicken embryo as a model it was shown that the South African strains of Shuni and Sabo virus also exhibited variable peripheral infectivity for suckling mice, a characteristic which was distinct from their teratogenic properties as determined in chicken embryos. Although mortality was higher the local strains of Shuni, Sabo and Shamonda virus also induced dramatic deformities in the chicken embryo. Additional mouse-brain passage of a local strain of Shuni virus, markedly reduced the peripheral infectivity of the virus, without apparently affecting its teratogenic potential at for the chicken embryo.Die 5 virusse wat in hierdie studie gebruik is, oorspronklik uit beeste geisoleer. 'n Bykomstige virus is uit 'n poel van bytende muggies (Culicaides spp.) herwin. Die 6 virusse deel gemeenskaplike groepspesifieke antigene in die kruis-komplementbindingstoets, maar in die kruis-serum-virus neutralisasietoets is hulle as drie aparte virusse opgewys. In die kruis-serum-virus mikroneutralisasietoets met verwysings sera en virusse van die Simbu serogroep is gedemonstreer dat hulle lokale stamme van die Shamonda, Shuni en Sabo virusse verteenwoordig. Deur die gebruik van die baba-muis en kuiken embrio model, is daar getoon dat die Suid-Afrikaanse stamme van Shuni en Sabo virus, ook 'n wissellende perifere besmetlikheid vir baba-muise toon, 'n kenmerk wat skynbaar apart is van hul teratogene kenmerke soos bepaal in kuiken embrios. Alhoewel mortaliteit hoer was, het die lokale stamme van Shuni, Sabo en Shamonda virusse ook dramatiese misvormings in die kuiken-embrio geinduseer. Verdere muisbrein passasie van 'n lokale stam van Shuni virus, het die perifere besmetlikheid van die virus verminder, skynbaar sonder om sy teratogene potensiaal vir die kuiken-embrio in elk geval, te affekteer.Dissertation (MMedVet)--University of Pretoria, 1984.Veterinary Tropical DiseasesMMedVetUnrestricte

Tracking the 2004-2008 Olympic cycle performance in long distance freestyle events

As world records are being broken so often, tracking the swimmer’s performance is important to analyze its progression between competitions, and help coaches to define realistic goals and training methods. The aim of this study was to track the long distance freestyle events performance during the 2004-2008 Olympic Cycle