Biogenic silica and silicic acid benthic fluxes of a North-eastern Atlantic Abyssal Locality

Within the framework of the EU-funded BENGAL programme, the effects of seasonality on biogenic silica early diagenesis have been studied at the Porcupine Abyssal Plain (PAP), an abyssal locality located in the northeast Atlantic Ocean. Nine cruises were carried out between August 1996 and August 1998. Silicic acid (DSi) increased downward from 46.2 to 213 µM (mean of 27 profiles). Biogenic silica (BSi) decreased from ca. 2% near the sediment-water interface to <1% at depth. Benthic silicic acid fluxes as measured from benthic chambers were close to those estimated from non-linear DSi porewater gradients. Some 90% of the dissolution occurred within the top 5.5 cm of the sediment column, rather than at the sediment-water interface and the annual DSi efflux was close to 0.057 mol Si/m**2/yr. Biogenic silica accumulation was close to 0.008 mol Si/m**2/yr and the annual opal delivery reconstructed from sedimentary fluxes, assuming steady state, was 0.065 mol Si/m**2/yr. This is in good agreement with the mean annual opal flux determined from sediment trap samples, averaged over the last decade (0.062 mol Si/m**2/yr). Thus ca. 12% of the opal flux delivered to the seafloor get preserved in the sediments. A simple comparison between the sedimentation rate and the dissolution rate in the uppermost 5.5 cm of the sediment column suggests that there should be no accumulation of opal in PAP sediments. However, by combining the BENGAL high sampling frequency with our experimental results on BSi dissolution, we conclude that non-steady state processes associated with the seasonal deposition of fresh biogenic particles may well play a fundamental role in the preservation of BSi in these sediments. This comes about though the way seasonal variability affects the quality of the biogenic matter reaching the seafloor. Hence it influences the intrinsic dissolution properties of the opal at the seafloor and also the part played by non-local mixing events by ensuring the rapid transport of BSi particles deep into the sediment to where saturation is reached.

ACE research vignette 040: Three steps towards more corporate entrepreneurship within an organisation

This series of research vignettes is aimed at sharing current and interesting research findings from our team of international Entrepreneurship researchers. In this vignette, Henri Burgers investigates what managers can do to make their firm more entrepreneurial.

A meta-analysis of 87,040 individuals identifies 23 new susceptibility loci for prostate cancer

Genome-wide association studies (GWAS) have identified 76 variants associated with prostate cancer risk predominantly in populations of European ancestry. To identify additional susceptibility loci for this common cancer, we conducted a meta-analysis of > 10 million SNPs in 43,303 prostate cancer cases and 43,737 controls from studies in populations of European, African, Japanese and Latino ancestry. Twenty-three new susceptibility loci were identified at association P < 5 × 10(-8); 15 variants were identified among men of European ancestry, 7 were identified in multi-ancestry analyses and 1 was associated with early-onset prostate cancer. These 23 variants, in combination with known prostate cancer risk variants, explain 33% of the familial risk for this disease in European-ancestry populations. These findings provide new regions for investigation into the pathogenesis of prostate cancer and demonstrate the usefulness of combining ancestrally diverse populations to discover risk loci for disease.

Corrigendum to "Mapping hippocampal and ventricular change in Alzheimer disease" [NeuroImage 22 (2004) 1754-1766] (DOI:10.1016/j.neuroimage.2004.03.040)

We recently noticed an error in the demographic data in this article. The validity of the findings and the conclusions of the paper is not affected. However, there is an error in the reported sample size and in the means and standard deviations of the subjects’ ages and MMSE scores. We would like to correct this error, which came to light when we were re-analyzing the data for a meta-analysis. The error occurred because an older version of a spreadsheet was incorrectly used when reporting the sample composition. Instead of examining 12 Alzheimer's disease patients and 14 healthy elderly controls, we in fact examined 17 Alzheimer’s disease patients and 14 healthy elderly controls. All maps and morphometric data reported in the paper are correct, except that the sample size was in fact slightly higher than that originally reported, and the maps computed in the paper were based on the larger sample (which included five more subjects in the Alzheimer’s disease group). All of the maps and figures in the paper are correct, and the conclusions of the paper are unchanged. We apologize for this error, which falls under the sole responsibility of the first author. The corrected demographic information appears below.

Teología, 1982, Tomo XIX nº 040 (número completo)

Para mejorar entender la “Dives in Misericordia” / Eduardo Briancesco -- Renovación jurídica de la vida consagrada. Principios y líneas generales / Emilio Barcelón -- El amor al dinero: “Idolatría y Raíz de todos los Males”. Lecciones de patrística para los problemas de hoy / Carmelo Giaquinta -- Dos dramas quechuas sobre el Patrocinio que la Santísima Virgen María dispensa a los pecadores: “el pobre más rico” y “Usca Paucar” / Alberto Espezel – Francisco Blanco Martín -- Crónica de la Facultad -- Notas bibliográficas -- Libros recibidos -- índice volumen XIX

Diário da Constituinte [gravação de vídeo] : [programa n. 040]

Na Subcomissão da Educação, Cultura e Esportes da Assembleia Nacional Constituinte (ANC) João Calmon (PMDB-ES), relator da Subcomissão, explica sugestões para a educação no país que incluem a do ensino gratuito para todos, exceto no caso do ensino superior, com a possibilidade de não oferecer gratuidade aos alunos. A Subcomissão da Educação, Cultura e Esporte recebe Celso Furtado, Ministro da Cultura, que defende o fortalecimento da cultura nacional por meio do ensino. A Subcomissão de Defesa do Estado, da Sociedade e da sua Segurança discute o anteprojeto de Ricardo Fiuza (PFL-PE) que mantém os militares responsáveis pela ordem interna do país, desde que estejam submetidos à vontade do poder civil e que o serviço militar é obrigatório, salvo em casos de restrição religiosa. Na Subcomissão da Nacionalidade, da Soberania e das Relações Internacionais, João Hermann (PMDB-SP), o relator, explica a relação das empresas multinacionais, a tutela dos recursos naturais e o direitos dos falantes da língua portuguesa de se tornarem cidadãos brasileiros após um ano. Na Subcomissão do Sistema Eleitoral e Partidos Políticos, apresentado o anteprojeto de Francisco Rossi (PTB-SP), o relator sugere a livre formação de partidos e o voto distrital. Na Subcomissão de Orçamento e Fiscalização Financeira, José Luiz Maia (PDS-PI), o relator, propõe maior fiscalização dos gastos públicos.