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 024 : New firm formation and job creation by type of firm an type of region.

This series of research vignettes is aimed at sharing current and interesting research findings from our team of international Entrepreneurship researchers. This vignette, written by Mr. Darren Kavanagh and Professor Per Davidsson, takes a closer look at job creation by new firms.

Harvest strategy evaluation to optimise the sustainability and value of the Queensland scallop fishery. Queensland scallop fishery - FRDC Project No 2006/024 Final Report

Objective 1. Measure spatial and temporal trawl frequency of scallop grounds using VMS data. This will provide a relative measure of how often individual undersized scallops are caught and put through a tumbler 2. Estimate discard mortality and growth rates for saucer scallops using cage experiments. 3. Evaluate the current management measures, in particular the seasonal closure, rotational closure and seasonally varying minimum legal sizes using stock assessment and management modeling models. Recommend optimal range of management measures to ensure long-term viability and value of the Scallop fishery based on a formal management strategy evaluation. Outcomes acheived to date: 1. Improved understanding of the survival rates of discarded sub-legal scallops; 2. Preliminary von Bertalanffy growth parameters using data from tagged-and-released scallops; 3. Changing trends in vessels and fishing gear used in the Queensland scallop fishery and their effect on scallop catch rates over time using standardised catch rates quantified; 4. Increases in fishing power of vessels operating in the Queensland scallop fishery quantified; 5. Trawl intensity mapped and quantified for all Scallop Replenishment Areas; 6. Harvest Strategy Evaluations completed.

Teología, 1974, Tomo XI nº 023-024 (número completo)

Presentación / La Dirección -- Tomás de Aquino, maestro de vida social / Eduardo Briancesco -- “Fidei infusio” y revelación den Santo Tomás de Aquino / Ricardo Ferrara -- La Ley eterna en la teología de Santo Tomás / Domingo M. Basso -- Ley antigua y culto. Los preceptos ceremoniales de la Ley Antigua en la Suma Teológica de Santo Tomás de Aquino / Osvaldo D. Santagada -- La religión y el actuar humano en la Suma Teológica de Santo Tomás de Aquino / Román Bustinza -- El arte del bien pensar. Discurso en el Congreso Internacional Tomista / Pablo VI -- Santo Tomás de Aquino y los problemas fundamentales de nuestro tiempo. Congreso Internacional en el VII Centenario de su muerte / Ricardo Ferrara -- El acontecimiento, lugar teológico / Juan Carlos Scannone -- Notas bibliográficas -- Libros recibidos -- Índice del Tomo XI

Diário da Constituinte [gravação de vídeo] : [programa n. 024]

A Subcomissão do Sistema Financeiro da Assembleia Nacional Constituinte (ANC) recebeu Marcos Freire, Presidente da Caixa Econômica Federal (CEF) e Camilo Calazans, Presidente do Banco do Brasil, que apoiam o destino social para a poupança e pedem o fortalecimento de bancos sociais. A Subcomissão também recebeu Dejandir Dom Pasquale, Presidente do Banco Nacional de Crédito Cooperativo (BNCC) que sugeriu a criação de cooperativas de crédito para os trabalhadores, favorecendo o pequeno e o micro produtor. A Subcomissão do Poder Judiciário e do Ministério Público ouviu os especialistas em direito José Lamartine, Luiz Pinto Ferreira e Roberto de Oliveira Santos que propuseram a criação de uma corte constitucional visando a correta interpretação da Constituição. A Subcomissão dos Negros, Populações Indígenas, Pessoas Deficientes e Minorias recebe documento das Associações dos Pais e Amigos do Excepcionais (APAES) e da Sociedade Pestalozzi pedindo proteção especial para as pessoas deficientes.