Prevalence of refractive error in Europe: the European Eye Epidemiology (E3) Consortium

To estimate the prevalence of refractive error in adults across Europe. Refractive data (mean spherical equivalent) collected between 1990 and 2013 from fifteen population-based cohort and cross-sectional studies of the European Eye Epidemiology (E³) Consortium were combined in a random effects meta-analysis stratified by 5-year age intervals and gender. Participants were excluded if they were identified as having had cataract surgery, retinal detachment, refractive surgery or other factors that might influence refraction. Estimates of refractive error prevalence were obtained including the following classifications: myopia ≤−0.75 diopters (D), high myopia ≤−6D, hyperopia ≥1D and astigmatism ≥1D. Meta-analysis of refractive error was performed for 61,946 individuals from fifteen studies with median age ranging from 44 to 81 and minimal ethnic variation (98 % European ancestry). The age-standardised prevalences (using the 2010 European Standard Population, limited to those ≥25 and <90 years old) were: myopia 30.6 % [95 % confidence interval (CI) 30.4–30.9], high myopia 2.7 % (95 % CI 2.69–2.73), hyperopia 25.2 % (95 % CI 25.0–25.4) and astigmatism 23.9 % (95 % CI 23.7–24.1). Age-specific estimates revealed a high prevalence of myopia in younger participants [47.2 % (CI 41.8–52.5) in 25–29 years-olds]. Refractive error affects just over a half of European adults. The greatest burden of refractive error is due to myopia, with high prevalence rates in young adults. Using the 2010 European population estimates, we estimate there are 227.2 million people with myopia across Europe.

Increasing Prevalence of Myopia in Europe and the Impact of Education

PURPOSE: To investigate whether myopia is becoming more common across Europe and explore whether increasing education levels, an important environmental risk factor for myopia, might explain any temporal trend.

DESIGN: Meta-analysis of population-based, cross-sectional studies from the European Eye Epidemiology (E(3)) Consortium.

PARTICIPANTS: The E(3) Consortium is a collaborative network of epidemiological studies of common eye diseases in adults across Europe. Refractive data were available for 61 946 participants from 15 population-based studies performed between 1990 and 2013; participants had a range of median ages from 44 to 78 years.

METHODS: Noncycloplegic refraction, year of birth, and highest educational level achieved were obtained for all participants. Myopia was defined as a mean spherical equivalent ≤-0.75 diopters. A random-effects meta-analysis of age-specific myopia prevalence was performed, with sequential analyses stratified by year of birth and highest level of educational attainment.

MAIN OUTCOME MEASURES: Variation in age-specific myopia prevalence for differing years of birth and educational level.

RESULTS: There was a significant cohort effect for increasing myopia prevalence across more recent birth decades; age-standardized myopia prevalence increased from 17.8% (95% confidence interval [CI], 17.6-18.1) to 23.5% (95% CI, 23.2-23.7) in those born between 1910 and 1939 compared with 1940 and 1979 (P = 0.03). Education was significantly associated with myopia; for those completing primary, secondary, and higher education, the age-standardized prevalences were 25.4% (CI, 25.0-25.8), 29.1% (CI, 28.8-29.5), and 36.6% (CI, 36.1-37.2), respectively. Although more recent birth cohorts were more educated, this did not fully explain the cohort effect. Compared with the reference risk of participants born in the 1920s with only primary education, higher education or being born in the 1960s doubled the myopia prevalence ratio-2.43 (CI, 1.26-4.17) and 2.62 (CI, 1.31-5.00), respectively-whereas individuals born in the 1960s and completing higher education had approximately 4 times the reference risk: a prevalence ratio of 3.76 (CI, 2.21-6.57).

CONCLUSIONS: Myopia is becoming more common in Europe; although education levels have increased and are associated with myopia, higher education seems to be an additive rather than explanatory factor. Increasing levels of myopia carry significant clinical and economic implications, with more people at risk of the sight-threatening complications associated with high myopia.

Forensic analysis of wooden safety matches - A case study

In this case, an individual was suspected of attempting to burn materials potentially relating to a murder case. A number of spent and unspent matches were seized at the scene by police for forensic examination. Coincidentally, a police raid at the suspect's house revealed a number of matchboxes, all of the same brand, containing matches that had a visual similarity to those recovered at the scene. Stable Isotope Profiling (SIP) was used to assess whether matches could either be distinguished or shown to be indistinguishable by 13C and 2H isotopic composition. These results were then compared to those from the X-ray diffraction (XRD) analysis of match heads and microscopy of the wood. SIP showed the scene matches and seized matches to be different, which was confirmed by XRD and microscopy analyses.

Mathematica in the classroom: new tools for exploring precalculus and differential calculus

Prémio de Melhor Artigo de Jovem Investigador atribuído pela empresa Timberlake, apresentado na 1ª Conferência Nacional sobre Computação Simbólica no Ensino e na Investigação - CSEI2012, que decorreu no IST nos dias 2 e 3 de Abril.

Tradução e legendagem do documentário Fárria

Trabalho de Projeto Apresentado ao Instituto de Contabilidade e Administração do Porto para a obtenção do grau de Mestre em Tradução e Interpretação Especializadas, sob orientação da Mestre Graça Chorão e coorientação da Mestre Paula Almeida

Object transportation by multiple mobile robots controlled by attractor dynamics: theory and implementation

Dynamical systems theory is used as a theoretical language and tool to design a distributed control architecture for teams of mobile robots, that must transport a large object and simultaneously avoid collisions with (either static or dynamic) obstacles. Here we demonstrate in simulations and implementations in real robots that it is possible to simplify the architectures presented in previous work and to extend the approach to teams of n robots. The robots have no prior knowledge of the environment. The motion of each robot is controlled by a time series of asymptotical stable states. The attractor dynamics permits the integration of information from various sources in a graded manner. As a result, the robots show a strikingly smooth an stable team behaviour.

Classificações geomecânicas mineiras para o dimensionamento de maciços rochosos: o aplicativo MGC-RocDesign|Calc

Este trabalho tem como objetivo destacar a importância da utilização de software de geoengenharia no estudo das classificações de maciços rochosos nas engenharias de minas e geotécnica. Esta investigação pretendeu demonstrar a importância das classificações geomecânicas e índices geológico‐geomecânicos, tais como a Rock Mass Rating (RMR), Rock Tunnelling Quality Index (Q‐system), Surface Rock Classification (SRC), Rock Quality Designation (RQD), Geological Strength Index (GSI) and Hydro‐Potential Value (HP). Para esse efeito foi criada e desenvolvida uma calculadora geomecânica – MGC‐RocDesign|CALC: ‘Mining Geomechanics Classification systems for rock engineering design (version beta)’ – para de certa forma tornar mais simples, rápido e preciso o estudo das classificações geomecânicas sem que seja necessário recorrer manualmente às fastidiosas tabelas das classificações. A MGC‐RocDesign|CALC foi criada e desenvolvida no programa de folha de cálculo Microsoft Excel™ em linguagem Visual Basic for Applications© proporcionando o ambiente de carregamento de dados mais apelativos para o utilizador. Foi ainda integrada neste aplicativo a Calculadora Geotech|CalcTools que resulta da fusão das bases de dados ScanGeoData|BGD e SchmidtData|UCS criadas por Fonseca et al. (2010). Toda a informação foi integrada numa base de dados dinâmica associada a uma plataforma cartográfica em Sistemas de Informação Geográfica. Apresenta‐se como caso de estudo um dos trechos subterrâneos do maciço rochoso da antiga mina de volfrâmio das Aveleiras/Tibães (Mosteiro de Tibães, Braga, NW de Portugal). Além disso, apresenta‐se uma proposta de zonamento geomecânico do maciço rochoso da antiga mina das Aveleiras/Tibães com o objetivo de apoiar o dimensionamento de maciços rochosos. Por fim, apresenta‐se uma reflexão em termos de aplicabilidade, das potencialidades e das limitações da Calculadora Geomecânica MGC‐RocDesign|CALC.

Estudo da antiga mina de volfrâmio das Aveleiras (Mire de Tibães): cartografia geotécnica e avaliação geomecânica

Este trabalho tem como objetivo sublinhar a importância de um estudo geológico‐geotécnico para apoiar a cartografia geotécnica do maciço rochoso subterrâneo da antiga mina de volfrâmio das Aveleiras (Mosteiro de Tibães, Braga). Foi realizado um trabalho de campo sistemático, ao longo de uma rede de galerias subterrâneas com uma extensão aproximada de 155 m. Estas galerias são constituídas, principalmente, por rochas metassedimentares, embora aflorem rochas graníticas num pequeno trecho de uma das galerias. A técnica de amostragem linear de descontinuidades aplicada ao grau de compartimentação do maciço rochoso esteve na base de todos os dados geológicos, geotécnicos e geomecânicos. Além disso, foram coligidos e integrados os dados de campanhas de campo anteriores, realizadas entre 2006 e 2011. Foram igualmente descritos os métodos de avaliação dos dados de campo, bem como a análise estatística dos parâmetros geológico‐geotécnicos. O zonamento geotécnico do maciço rochoso das Aveleiras foi desenvolvido tendo em conta o comportamento do maciço rochoso in situ, e foi apoiado por ensaios laboratoriais de resistência do material‐rocha através do Ensaio de Carga Pontual. Apresenta‐se uma proposta preliminar de zonamento geomecânico com o objectivo de apoiar o projeto de engenharia de maciços rochosos.

Niagara Bruce Trail Club Fonds, 1962-2014, n.d.

The Bruce trail is Canada’s longest and oldest continuous footpath. The trail runs along the Niagara Escarpment from Niagara to Tobermory through private and public land. The main trail is 890 km long and the side trails measure 400 km. In 1961, a “Save the Escarpment” conference was held in Hamilton. Gerry Wolfram, a writer for the St. Catharines Standard proposed that a committee be formed to develop a hiking trail. The Peninsula Field Naturalists Club formed a committee and President Bert Lowe contacted landowners along the proposed route to gain permission to cross their properties. Through Bert Lowe’s effort and dedication, the trail was completed in October 1963. The trail was officially opened on May 24th, 1964 in a ceremony at Queenston. The Niagara group joined the Bruce Trail Association in 1968 at which time the Niagara Bruce Trail Club was formed. The Bruce Trail Association is a charitable, membership-based volunteer organization. Their goal is to preserve public access to the Niagara Escarpment while restoring its natural habitat. The head office of the Bruce Trail Association is located in Hamilton, Ontario. The Niagara Bruce Trail Club’s goal is to secure and preserve a natural corridor along the Niagara Escarpment while providing education, awareness, and access for the public and the future. The club has organized many hikes including special hikes such as the one to commemorate the St. Catharines Centennial. The club has also hosted children’s hikes, cross country skiing hikes, wildflower hikes, jogging hikes, snowshoe hikes and bike outings. They hold annual events such as the End to End hike which is a 3 day walk from Grimsby to Queenston and the 30 km Laura Secord hike to commemorate Laura Secord’s famous walk. Charity hikes have also been held for the Heart and Stroke Foundation and the Lung Association as well as other causes. Major changes have taken place along the trail throughout the years, some of these include: a reroute which eliminated the tunnel passage (1976) and a bridge which eliminated the need to walk to Mountain Road to cross the Queen Elizabeth Way (2008). Other major changes and clean-up projects have been undertaken by the club. The Bruce Trail Conservancy (formerly Association) is made up of 9 clubs including: Niagara Bruce Trail Club (Queenston to Grimsby), Iroquia Bruce Trail Club (Grimsby to Kelso), Toronto Bruce Trail Club (Kelso to Cheltenham), Caledon Hills Bruce Trail Club (Cheltenham to Mono Centre), Dufferin Hi-Land Bruce Trail Club (Mono Centre to Lavender), Blue Mountains Bruce Trail Club (Lavender to Craigleath), Beaver Valley Bruce Trail Club (Craigleath to Blantyre), Sydenham Bruce Trail Club (Blantyre to Wiarton) and Peninsula Bruce Trail Club (Wiarton to Tobermory). Sources: http://www.niagarabrucetrail.org/index.html and http://brucetrail.org/

Towards Web 3.0

Page 1. Towards Web 3.0... • Web 1.0 • Web 2.0 • Web 3.0 • Technology hype? • Internet as seen by our kids? Page 2. Random Trivia: Brazil has more Orkut users than citizens Page 3. The war is over. Platforms have won. Applications have lost Page 4. Page 5. Blogosphere • The blogosphere is made up of all blogs and their interconnections Page 6. Social bookmarking Page 7. Page 8. Page 9. Page 10. Page 11. Page 12. Page 13. Page 14. Towards Web 3.0 Page 15. Page 16. Wolfram Alpha Page 17. Page 18. Page 19. Page 20. Page 21. Page 22

Bieberbach's Conjecture, the de Branges and Weinstein Functions and the Askey-Gasper Inequality

The Bieberbach conjecture about the coefficients of univalent functions of the unit disk was formulated by Ludwig Bieberbach in 1916 [Bieberbach1916]. The conjecture states that the coefficients of univalent functions are majorized by those of the Koebe function which maps the unit disk onto a radially slit plane. The Bieberbach conjecture was quite a difficult problem, and it was surprisingly proved by Louis de Branges in 1984 [deBranges1985] when some experts were rather trying to disprove it. It turned out that an inequality of Askey and Gasper [AskeyGasper1976] about certain hypergeometric functions played a crucial role in de Branges' proof. In this article I describe the historical development of the conjecture and the main ideas that led to the proof. The proof of Lenard Weinstein (1991) [Weinstein1991] follows, and it is shown how the two proofs are interrelated. Both proofs depend on polynomial systems that are directly related with the Koebe function. At this point algorithms of computer algebra come into the play, and computer demonstrations are given that show how important parts of the proofs can be automated.

A generic polynomial solution for the differential equation of hypergeometric type and six sequences of orthogonal polynomials related to it

In this work, we present a generic formula for the polynomial solution families of the well-known differential equation of hypergeometric type s(x)y"n(x) + t(x)y'n(x) - lnyn(x) = 0 and show that all the three classical orthogonal polynomial families as well as three finite orthogonal polynomial families, extracted from this equation, can be identified as special cases of this derived polynomial sequence. Some general properties of this sequence are also given.

Orthogonal polynomials and recurrence equations, operator equations and factorization

This article surveys the classical orthogonal polynomial systems of the Hahn class, which are solutions of second-order differential, difference or q-difference equations. Orthogonal families satisfy three-term recurrence equations. Example applications of an algorithm to determine whether a three-term recurrence equation has solutions in the Hahn class - implemented in the computer algebra system Maple - are given. Modifications of these families, in particular associated orthogonal systems, satisfy fourth-order operator equations. A factorization of these equations leads to a solution basis.