"Cómo pintar el aire". Fundamentos científicos de la perspectiva atmosférica

La perspectiva aérea o atmosférica es juzgada por los pintores como parte esencial de la pintura, una vez establecidos los presupuestos geométricos de la representación naturalista mediante la perspectiva lineal. Leonardo da Vinci fue el primer autor en definir la perspectiva aérea o atmosférica, conocidos ya a través de L. B. Alberti los fundamentos geométricos de la perspectiva lineal en el tratado De Pictura (1435). Doscientos años después, tras la influyente publicación del Optics de Newton, contextualizadas bajo el espíritu racionalista del siglo XVIII, el artículo estudia las recomendaciones que desde la ciencia y los científicos (específicamente a través de tres figuras relevantes: Brook Taylor, J. H. Lambert y Gaspard Monge) se dan a los pintores con la pretensión de arbitrar una medición exacta del color, en confrontación con el tradicional empirismo del mundo artístico. Este tema puede considerarse un capítulo de gran interés en la larga historia de la pintura y la representación de los fenómenos atmosféricos, cuyos antecedentes teóricos tienen su inicio en el Débat sur le Coloris de la Académie Française del siglo XVII y sus resultados, conducirán hacia el nacimiento de la moderna Teoría del color, en respuesta a una cuestión tan compleja sobre cómo pintar el aire.

Los primeros pasos en el escorzo de la figura humana. "Un análisis desde la geometría"

A través de un recorrido histórico centrado en el Renacimiento, se exponen las aportaciones más significativas de teóricos y artistas en la evolución del escorzo de la figura humana desde un punto de vista geométrico. Los artistas que con sus dibujos y escritos ayudaban a otros en el aprendizaje de la representación, se apresuraron a incluir el estudio del escorzo en sus tratados, buscando métodos que facilitaran su dibujo sobre cualquier soporte y en cualquier posición en el espacio. En este artículo se analizan y enlazan los trazados propuestos por los estudiosos de la geometría, con las obras de arte que reflejan importantes avances en este sentido. Soportes como el lienzo, el muro o la bóveda, presentan al pintor superficies diferentes de trabajo y en distintas posiciones en el espacio. La figura humana, protagonista en la escena, tendrá que adaptarse a ellos para ser contemplada desde unos espacios arquitectónicos cada vez más amplios y con más posibilidades. Fue necesario dominar la perspectiva en la pintura, y muy particularmente en la mural, para ofrecer composiciones cada día más ambiciosas y sorprendentes.

Remote chiral induction in the organocatalytic hydrosilylation of aromatic ketones and ketimines

Lewis basic, metal-free pyridyloxazolines catalyze the redn. of prochiral arom. ketones and ketimines with Cl3SiH in good enantioselectivity (? 94% ee). Arene-arene interactions between the substrate and the catalyst are likely to play a role in the enantiodifferentiation process.

Beta-blocker usage and breast cancer survival: a nested case-control study within a UK clinical practice research datalink cohort.

Background: To investigate the association between post-diagnostic beta-blocker usage and risk of cancer-specific mortality in a large population-based cohort of female breast cancer patients.

Methods: A nested case-control study was conducted within a cohort of breast cancer patients identified from cancer registries in England(using the National Cancer Data repository) and diagnosed between 1998 and 2007. Patients who had a breast cancer-specific death(ascertained from Office of National Statistics death registration data) were each matched to four alive controls by year and age at diagnosis. Prescription data for these patients were available through the Clinical Practice Research Datalink. Conditional logistic regression models were used to investigate the association between breast cancer-specific death and beta-blocker usage.

Results: Post-diagnostic use of beta-blockers was identified in 18.9% of 1435 breast cancer-specific deaths and 19.4% of their 5697 matched controls,indicating little evidence of association between beta-blocker use and breast cancer-specific mortality [odds ratio (OR) = 0.97,95% confidence interval (CI) 0.83, 1.13]. There was also little evidence of an association when analyses were restricted to cardio non-selective beta-blockers (OR = 0.90, 95% CI 0.69, 1.17). Similar results were observed in analyses of drug dosage frequency and duration, and beta-blocker type.

Conclusions: In this large UK population-based cohort of breast cancer patients,there was little evidence of an association between post-diagnostic beta-blocker usage and breast cancer progression. Further studies which include information on tumour receptor status are warranted to determine whether response to beta-blockers varies by tumour subtypes.

Towards a Mourne National Park?Emergent prospects and pitfalls fromarticulating needs in a local context

This paper examines the prospects for sustainable rural tourism within a rural development paradigm. Specifically, an adaptive management approach is proposed as a means of understanding and accommodating the different goals and interests that exist within multi-functional rural areas. This model allows priorities to change in line with particular situations while remaining sensitive to economic, environmental, social and cultural impacts. The proposed Mourne National Park in Northern Ireland, also designated an Area of Outstanding Natural Beauty (AONB), forms the backdrop for this study. Through a critique of a consultation process that was undertaken with the community the question is posed: can a sustainable rural tourism approach achieve meaningful community engagement and thereby reflect the needs of the community? Central to the analysis are the power differentials between the various partners participating in this model of governance. The conclusions consider implications for rural communities, revealing how trusting and meaningful relationships are central to facilitating collaboration, cooperation and adaptation.

Volatility and VaR Forecasting in the Madrid Stock Exchange

This paper provides an empirical study to assess the forecasting performance of a wide range of models for predicting volatility and VaR in the Madrid Stock Exchange. The models performance was measured by using different loss functions and criteria. The results show that FIAPARCH processes capture and forecast more accurately the dynamics of IBEX-35 returns volatility. It is also observed that assuming a heavy-tailed distribution does not improve models ability for predicting volatility. However, when the aim is forecasting VaR, we find evidence of that the Student’s t FIAPARCH outperforms the models it nests the lower the target quantile.

Wavelet analysis of human DNA

This paper studies the human DNA in the perspective of signal processing. Six wavelets are tested for analyzing the information content of the human DNA. By adopting real Shannon wavelet several fundamental properties of the code are revealed. A quantitative comparison of the chromosomes and visualization through multidimensional and dendograms is developed.

Interoperabilidade ferroviária: infraestrutura (Bitola)

Dissertação para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de Vias de Comunicação e Transportes

Análise do transporte ferroviário de mercadorias associado à problemática da diferença de bitola entre linhas da rede ferroviária: estudo do caso prático: ligação do porto de Aveiro ao corredor internacional de mercadorias E-80

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Civil

Cultural innovation and transmission of tool use in wild chimpanzees:evidence from field experiments

Animal Cognition, V.6, pp. 213-223

Behavioural development in a matching-to-sample task and token use by an infant chimpanzee reared by his mother

Animal Cognition, V.6, pp. 259–267

A onda de calor de Agosto de 2003 e os seus efeitos sobre a mortalidade da população portuguesa

RESUMO - Portugal continental, como outros países europeus, foi afectado por uma onda de calor de grande intensidade no Verão de 2003, com efeitos na mortalidade da população. O excesso de óbitos associados à onda de calor foi estimado pela comparação do número de óbitos observados entre 30 de Julho e 15 de Agosto de 2003 e o número de óbitos esperados se a população tivesse estado exposta às taxas de mortalidade médias do biénio 2000-2001 no respectivo período homólogo. Os óbitos esperados foram calculados com ajustamento para a idade. O número de óbitos observados (O) foi superior ao número esperado (E) em todos os dias do período estudado e o seu excesso global foi estimado em 1953 óbitos (excesso relativo de 43%), dos quais 1317 (61%) ocorreram no sexo feminino e 1742 no grupo de 75 e + anos (89%). A nível distrital, Portalegre teve o maior aumento relativo do número de óbitos (+89%) e Aveiro o menor (+18%). Numa área geográfica contínua do interior do território (Guarda, Castelo Branco, Portalegre e Évora) houve aumentos relativos superiores a 80%. Em termos absolutos, o maior excesso de óbitos ocorreu no distrito de Lisboa (mais cerca de 396) e no do Porto (mais cerca de 183). As causas de morte «golpe de calor» e «desidratação e outros distúrbios metabólicos» tiveram os aumentos relativos mais elevados (razões O/E de, respectivamente, 70 e 8,65). Os maiores aumentos absolutos do número de óbitos ocorreram no grupo das «doenças do aparelho circulatório» (mais 758), nas «doenças do aparelho respiratório» (mais 255) e no conjunto de «todas as neoplasias malignas» (mais 131). No período da onda de calor e no período de comparação, a percentagem dos óbitos que ocorreu nos hospitais (52% e 56%), no domicílio (32 e 33%) e em «outros locais» foi semelhante. A discussão sobre os factores que condicionaram a obtenção dos valores apresentados, relativos ao excesso de óbitos por sexo, grupo etário, distrito, causa e local da morte, permite concluir que os mesmos se afiguram adequados para medir a ordem de grandeza e caracterizar o efeito da onda de calor na mortalidade. O erro aleatório, medido pelos intervalos de confiança, e alguns possíveis erros sistemáticos associados ao período de comparação escolhido não deverão afectar de modo relevante as estimativas.

Clinical and genetic investigation of a large Tunisian family with complete achromatopsia: identification of a new nonsense mutation in GNAT2 gene.

Complete achromatopsia is a rare autosomal recessive disease associated with CNGA3, CNGB3, GNAT2 and PDE6C mutations. This retinal disorder is characterized by complete loss of color discrimination due to the absence or alteration of the cones function. The purpose of the present study was the clinical and the genetic characterization of achromatopsia in a large consanguineous Tunisian family. Ophthalmic evaluation included a full clinical examination, color vision testing and electroretinography. Linkage analysis using microsatellite markers flanking CNGA3, CNGB3, GNAT2 and PDE6C genes was performed. Mutations were screened by direct sequencing. A total of 12 individuals were diagnosed with congenital complete achromatopsia. They are members of six nuclear consanguineous families belonging to the same large consanguineous family. Linkage analysis revealed linkage to GNAT2. Mutational screening of GNAT2 revealed three intronic variations c.119-69G>C, c.161+66A>T and c.875-31G>C that co-segregated with a novel mutation p.R313X. An identical GNAT2 haplotype segregating with this mutation was identified, indicating a founder mutation. All patients were homozygous for the p.R313X mutation. This is the first report of the clinical and genetic investigation of complete achromatopsia in North Africa and the largest family with recessive achromatopsia involving GNAT2; thus, providing a unique opportunity for genotype-phenotype correlation for this extremely rare condition.

Pretargeted radioimmunotherapy using genetically engineered antibody-streptavidin fusion proteins for treatment of non-hodgkin lymphoma.

Purpose: Pretargeted radioimmunotherapy (PRIT) using streptavidin (SAv)-biotin technology can deliver higher therapeutic doses of radioactivity to tumors than conventional RIT. However, "endogenous" biotin can interfere with the effectiveness of this approach by blocking binding of radiolabeled biotin to SAv. We engineered a series of SAv FPs that downmodulate the affinity of SAv for biotin, while retaining high avidity for divalent DOTA-bis-biotin to circumvent this problem.Experimental Design: The single-chain variable region gene of the murine 1F5 anti-CD20 antibody was fused to the wild-type (WT) SAv gene and to mutant SAv genes, Y43A-SAv and S45A-SAv. FPs were expressed, purified, and compared in studies using athymic mice bearing Ramos lymphoma xenografts.Results: Biodistribution studies showed delivery of more radioactivity to tumors of mice pretargeted with mutant SAv FPs followed by (111)In-DOTA-bis-biotin [6.2 +/- 1.7% of the injected dose per gram (%ID/gm) of tumor 24 hours after Y43A-SAv FP and 5.6 +/- 2.2%ID/g with S45A-SAv FP] than in mice on normal diets pretargeted with WT-SAv FP (2.5 +/- 1.6%ID/g; P = 0.01). These superior biodistributions translated into superior antitumor efficacy in mice treated with mutant FPs and (90)Y-DOTA-bis-biotin [tumor volumes after 11 days: 237 +/- 66 mm(3) with Y43A-SAv, 543 +/- 320 mm(3) with S45A-SAv, 1129 +/- 322 mm(3) with WT-SAv, and 1435 +/- 212 mm(3) with control FP (P < 0.0001)].Conclusions: Genetically engineered mutant-SAv FPs and bis-biotin reagents provide an attractive alternative to current SAv-biotin PRIT methods in settings where endogenous biotin levels are high. Clin Cancer Res; 17(23); 7373-82. (C)2011 AACR.