International comovement of stock market returns: a wavelet analysis

The assessment of the comovement among international stock markets is of key interest, for example, for the international portfolio diversification literature. In this paper, we re-examine such comovement by resorting to a novel approach, wavelet analysis. Wavelet analysis allows one to measure the comovement in the time-frequency space. In this way, one can characterize how international stock returns relate in the time and frequency domains simultaneously, which allows one to provide a richer analysis of the comovement. We focus on Germany, Japan, UK and US and the analysis is done at both the aggregate and sectoral levels.

Coincident and Leading Indicators for the Euro Area: A Frequency Band Approach

In the context of a common monetary policy, tracking euro area economic developments becomes essential. The aim of this paper is to build monthly coincident and leading composite indicators for the euro area business cycle. However, instead of looking at the overall comovement between the variables as it is standard in the literature, we show how one can resort to both time and frequency domain analysis to achieve additional insight about their relationship. We find that, in general, the lead/lag properties of economic indicators depend on the cycles periodicity. Following a frequency band approach, we take advantage of this in the construction of the coincident and leading composite indicators. The resulting indicators are analysed and a comparison with other composite indicators proposed in the literature is made.

Effect of cooking on arsenic concentration in rice

This study assessed the effect of rinsing and boiling on total content of As (tAs) and of its inorganic and organic forms in different types of rice (polished and brown) from Spain and Ecuador. Rice was subjected to five different treatments. The results showed that the treatment consisting of three grain rinsing cycles followed by boiling in excess water showed a significant decrease in tAs content compared with raw rice. Regarding As species, it is worth noting that the different treatments significantly reduced the content of the most toxic forms of As. The estimated lifetime health risks indicate that pre-rinsing alone can reduce the risk by 50%, while combining it with discarding excess water can reduce the risk by 83%; therefore, the latter would be the preferable method.Universidad de las Fuerzas Armadas-ESPE through Project 2015- PIC-017, Xunta de Galicia-Consellería de Educación, Universidades e Formación Profesional, Plan Galego IDT, Consolidation of competitive research groups (ref. ED31C2018/12), and Cross-Research in Environmental Technologies (CRETUS, AGRUP2015/02, ref. 2018-PG100). XLOP is grateful for the financial support from the Proyecto PROMETEO (SENESCYT Ecuador).info:eu-repo/semantics/publishedVersio

Árvores de Risco

Árvores de Risco Para além da sua beleza e formas graciosas, a árvore em meio urbano desempenha uma série de funções benéficas. Deve haver uma preocupação em assegurar a vitalidade e a segurança das árvores em meio urbano, sobretudo nas áreas de domínio público mas também nas áreas de uso privado. Neste sentido é importante o reconhecimento das denominadas “árvores de risco”. Uma árvore é considerada de risco se possui uma estrutura debilitada aliada ao facto de poder vir a atingir pessoas ou bens em caso de queda total ou parcial (Dujesiefken et al. 2005; Smiley et al. 2007)

Hypothetical answers to continuous queries over data streams

Continuous queries over data streams may suffer from blocking operations and/or unbound wait, which may delay answers until some relevant input arrives through the data stream. These delays may turn answers, when they arrive, obsolete to users who sometimes have to make decisions with no help whatsoever. Therefore, it can be useful to provide hypothetical answers - "given the current information, it is possible that X will become true at time t" - instead of no information at all. In this paper we present a semantics for queries and corresponding answers that covers such hypothetical answers, together with an online algorithm for updating the set of facts that are consistent with the currently available information

Organochlorine Compounds in Beached Plastics and Marine Organisms

Here we compare bioaccumulation factors in marine organisms to partition ratios in marine debris for dichlorodiphenyltrichloroethane and polychlorinated biphenyls. Both organochlorines are synthetic persistent organic pollutants emitted into the environment since the beginning of the last century in approximately equal amounts. Their vast use and dispersion have resulted in approximately similar median concentrations of the two organochlorines in some pelagic organisms, namely in the liver and muscle tissue of fish. Molluscs, on the other hand, show higher median uptake of PCBs (median = 2.34 ng/g) than of DDTs (median = 1.70 ng/g), probably reflecting more localized conditions. We found that the bioaccumulation factors can be several orders of magnitude higher than the partition ratios. For instance, the median concentrations of organochlorines in the different matrices of fish, birds, and mammals are between one to four orders of magnitude higher than those found in marine debris, when lipid-normalized; or up to two orders of magnitude when measured as wet-weight. But, in molluscs, bioaccumulation/partition equals unity, which agrees with previous studies using passive samplers. Future research should focus on reducing sources of uncertainty by 1) homogenization of chemical procedures; 2) better assessment of chemical partition equilibrium between water and polymers in environmental conditions; 3) use of (multi)polymer passive samplers better aimed at mimicking uptake of specific living tissues.info:eu-repo/semantics/publishedVersio

Forecasting Euro Area Aggregates with Bayesian VAR and VECM Models

This paper focuses on Bayesian Vector Auto-Regressive (BVAR) models for the euro area. A modified hyperparameterization scheme based on the Minnesota prior that takes into account the economic nature of the variables in the model is used. The merits of incorporating long-run relationships are also discussed. Alternative methods to estimate eventual cointegrating relations in the variables are considered, and the problem of choice of appropriate prior distributions for BVAR with Error Correction Mechanism (BECM) models is addressed. Results show that using a flat prior on factor loadings can seriously endanger the forecasting performance of BECM models. Overall, the BVAR model in levels outperforms all other models across variables and forecasting horizons. This is in contrast with other empirical studies where some gains could be obtained when incorporating long-run relationships in the model.

Automatic extraction of quotes and topics from news feeds

The explosive growth in information production poses increasing challenges to consumers, confronted with problems often described as information overow. We present verbatim, a software system that can be used as a personal information butler to help structure and lter information. We address a small part of the information landscape, namely quotes extraction from portuguese news. This problem includes several challenges, specically in the areas of information extraction and topic distillation. We present a full description of the problems and our adopted approach. verbatim is available online at http://irlab.fe.up.pt/p/verbatim

The Montado agroforestry system microclimatic specificity in the context of global change

The effects of oak trees on microclimatic parameters in Quercus rotundifolia Lam. woodland in the Alentejo, Southern Portugal, are reported. Results show that oak tree create a marked differentiation in the grass matrix, between open and undercanopy areas. Compared to open areas, it presents lower soil moisture beneath the oak canopy, lower soil temperatures and lower photosynthetically active radiation (PAR). Soil temperatures outside trees canopy were generally higher than undercanopy areas, reaching twice its values during the winter. The decrease of soil water content is more rapid in areas outside the trees canopy action, but the replenishment starts early and is faster in those areas. PAR intercepted by tree canopy is greater than 60%, and affects dramatically herbaceous production. Different climatic conditions due to the presence of the tree, associated with greater variability in chemistry environment undercanopy, if combined with the IPCC forecasts for Mediterranean region, pose new challenges in the management of the montado areas

Phenotypical and molecular characterization of portuguese usher syndrome patients

Trabalho final de mestrado integrado em Medicina (Oftalmologia), apresentado à Faculdade de Medicina da Universidade de Coimbra.Introduction: Usher syndrome (USH) is a recessive inherited disease characterized by sensorineural hearing loss (HL), visual loss due to retinitis pigmentosa (RP) and, in some cases, vestibular dysfunction. This syndrome is the most common cause that affects those two major senses, vision and hearing and encompasses three clinical sub-types (USH1, USH2 and USH3) as well as some additional atypical forms. Usher type II is the most common clinical form, in all published series; since the USH2A gene is the most commonly mutated gene, our aim is to characterize from a molecular and phenotypical standpoint, a cohort of 48 portuguese Usher patients, determine if they carry mutations in USH2A gene and establish potential genotype-phenotype correlations. Methods: Forty eight affected individuals were characterized from a molecular standpoint, and those carrying USH2A underwent complete phenotypical ophthalmological examination including, fundus photography, fundus autofluorescence (FAF), full-field ERG, multifocal electrophysiology (MF ERG), and ENT assessment. Results: Disease-causing mutations in the USH2A gene were identified in 15 patients, of ten independent families. Consanguinity could be documented in 40% of families. Fourteen different USH2A mutations were detected (6 missense, 14 nonsense, 1 small rearrangement, 2 large gene rearrangements and 6 splice-site mutations), eight patients were homozygous and 7, either compound heterozygous or heterozygous. Mutations in the DFNB31 gene (USH2D) were also identified in heterozygosity in two siblings. Five novel mutations were identified: three intragenic deletions encompassing several exons c. 7121_9258del, USH2A exon 3-exon34 del, USH2A exon 39 – exon 47 del, a nonsense mutation, c.7932G>A, and a deep intronic homozygous mutation c.4988-19T>G, all of them showing potential to interfere with protein function. Concerning to ophthalmological phenotype, nyctalopia was consistently the presenting complaint in 100% of patients. Best Corrected Visual Acuity (BCVA) varied from 0.1 and 0.8, at the last evaluation. Fundus appearance was compatible with RP in all probands varying from isolated peripheral bone spicules, patchy retinal pigment epithelium (RPE) areas of atrophy, thin vessels and normal discs (20%), to pale discs, near confluent peripheral bone spicules, extensive atrophic RPE changes and thin vessels (47%) to typical RP with preserved macula (33%). The full field ERG disclosed, in the majority, an unrecordable response (87%) and two probands had a severely attenuated, yet recordable, response (13%). Multifocal ERG analysis showed decreased central peak (100% cohort cases lower than 100microV), and occasional drift of the peak of maximal response to an extrafoveal hexagone. FAF revealed that 77% presented a typical ring of hyperautofluorescence while the remainder disclosed patchy hypoautofluorescence. Conclusion: We characterized from both clinical and genetic standpoints, the first series of Portuguese patients with type II Usher syndrome. Molecular characterization is essencial to improve early diagnosis of USH and better understand the molecular pathomechanism so that is possible to develop treatment strategies to stop or revert the degenerative process of the retina, in a near future.Introdução: A síndroma de Usher é uma condição com transmissão autossómica recessiva caracterizada por surdez neurossensorial, perda de visão por Retinopatia Pigmentar e, em alguns casos, disfunção vestibular. Esta síndroma é a causa mais comum da afeção destes dois sentidos, visão e audição, englobando três sub-tipos clínicos (USH1, USH2 e USH3) bem como formas atípicas adicionais. USH2 é o sub-tipo clinico mais comum, em todas as series publicadas; sendo USH2A o gene mais comummente mutado, o nosso objectivo é caracterizar de um ponto de vista molecular e fenotípico 48 portugueses com Síndrome de Usher, determinar se são portadores de mutações no gene USH2A e estabelecer potenciais correlações genótipo-fenótipo. Métodos: Quarenta e oito indivíduos com a síndroma da Usher foram caracterizados do ponto de vista molecular, submetendo-se os portadores de USH2A a um exame oftalmológico fenotípico completo, fundoscopia, auto-fluorescência da retina, eletrorretinograma full field, eletrorretinograma multifocal e avaliação otorrinolaringológica. Resultados: Mutações patológicas no gene USH2A foram identificadas em 15 pacientes, de 10 famílias não-relacionadas. Em 40% das famílias foi possível documentar consanguinidade. Detetaram-se 14 mutações diferentes no gene USH2A (6 missense, 14 nonsense, 1 pequeno rearranjo, 2 grandes rearranjos e 6 mutações de splicing; em 8 doentes as alterações genéticas eram homozigóticas e em 7, heterozigóticas compostas ou em heterozigotia. Foram igualmente identificadas mutações no gene DFNB31 em heterozigotia, em 2 irmãos. Foram identificadas cinco novas mutações: três delecções intragénicas envolvendo vários exões c. 7121_9258del, USH2A exon 3- exon 34 del, USH2A exon 39 – exon 47 del, uma mutação nonsense c.7932G>A, e uma mutação homozigótica deep intronic c.4988-19T>G, todas mostrando potencial interferência com a função proteica. No que diz respeito ao fenótipo oftalmológico, a nictalopia foi, de forma consistente, o sinal de apresentação em 100% dos doentes. A melhor acuidade visual corrigida variou entre 0.1 a 0.8, na última avaliação. Os aspetos fundoscópicos eram compatíveis com Retinopatia Pigmentar em todos os doentes, variando de espículas ósseas periféricas isoladas, áreas dispersas de atrofia do epitélio pigmentar da retina, vasos de calibre reduzido e disco óptico normal (20%), disco pálido, espículas ósseas confluentes periféricas, atrofia de áreas extensas do epitélio pigmentar da retina e redução importante do calibre vascular (47%) a um padrão típico de RP com preservação da mácula (33%). No ERG, a maioria dos doentes apresentou uma resposta indetetável (87%), com somente 2 doentes a revelar uma resposta profundamente atenuada mas detetável (13%). O MfERG evidenciou uma redução da amplitude do pico central (100% dos casos inferior a 100microV), e ocasionais picos de resposta maxima detetados fora do hexagono extra-foveal. A auto-fluorescência mostrou em 77% dos casos o típico anel de hiperautofluorescência macular enquanto nos restantes se observou um padrão mosqueado de hipoautofluorescência. Conclusão: Caracterizámos do ponto de vista clínico e genético, a primeira série de doentes portugueses com Síndroma de Usher tipo 2. A caracterização molecular é essencial para aprimorar o diagnóstico precoce desta síndroma e melhor conhecer os mecanismos patogénicos de forma a permitir o desenvolvimento de estratégias terapêuticas para frenar ou reverter este processo degenerativo da retina, num futuro próximo