19,466 research outputs found

    Freshwater Culture Of Salmonids In Recirculating Aquaculture Systems (RAS) With Emphasis On The Monitoring And Control Of Key Environmental Parameters

    Get PDF
    This report is intended as a briefing paper on Recirculating Aquaculture Systems with emphasis on the monitoring of water quality parameters relating to the freshwater culture of the Arctic charr Salvelinus alpinus

    Does the far-infrared/radio correlation in spiral galaxies extend to the spatial domain

    Get PDF
    A comparison is made between the spatial distribution of the thermal far-infrared and non-thermal radio emission of nearby spiral galaxies. This is done in an attempt to improve our understanding of the well known correlation between the integrated Infrared Astronomy Satellite (IRAS) far-infrared and radio emission of spiral galaxies, e.g., de Jong et al., 1985, Helou et al., 1986. A physical explanation for this correlation is not straight forward due to the ambiguous nature of the origin of the far-infrared and radio, and the dependence of the non-thermal radio on each galaxies' magnetic field. It is now widely believed that the infrared emission detected in the longer wavelength IRAS wavebands (less than 50 microns) arises from at least two distinct sources, e.g., Cox et al., 1986, Persson and Helou, 1987: (1) a warm (T approx. 40 K) component associated with dense dust clouds heated by embedded O and B type stars; and (2) a cooler (T approx. 20 K) component associated with diffuse dust distributed throughout the interstellar matter (ISM) heated by the interstellar radiation field. A link between the warm component and the radio via electrons originating in Type II supernovae (the ultimate fate of many of the O and B type stars responsible for the warm component) has been suggested by numerous authors. The supporting evidence is scarce and inconclusive. Researchers have attempted to provide some insight into the problem by looking at the spatial distribution of the different components in some nearby spiral galaxies, starting with the face-on spiral M51. The source of the far-infrared data is the IRAS chopped photometric channel (CPC) instrument. Warm and cold far-infrared fluxes integrated over all wavelengths and the radio intensity at two frequencies are plotted against radius. All plots are to a common resolution of 100 arcsec, the radio data originating from the Cambridge Low Frequency Synthesis Telescope (151 MHz) and the VLA (1490 MHz, from Condon, 1987). The warm and cold regions are assumed to be representedby a single galactic wide temperatures of 50 K and 20 K respectively. A dust emissivity of 1 has been assumed. The form of the plots is little effected by varying these assumptions. The radio and cold component curves appear to follow each other most closely, in contradiction to the simple OB star/type II supernovae hypothesis

    Radiocarbon dating results from the Beakers and Bodies Project

    Get PDF
    The Beakers and Bodies Project is a two-year project based in Marischal Museum, University of Aberdeen, funded by the Leverhulme Trust. It is assessing the beaker-related evidence from North-East Scotland (between the Moray Firth and the Firth of Tay), including the dating and stable isotope analyses of some 40 human skeletons from museum collections. The project builds on the North-East dates resulting from the Beaker People Project (Parker Pearson, 2006; Sheridan et al., 2006) and earlier programmes and studies (e.g. Shepherd, 1986). It also includes a consideration of beaker typology and manufacture, burial contexts, grave goods, human osteology and evidence for diet from stable isotope analysis

    Graphical Methods in Device-Independent Quantum Cryptography

    Get PDF
    We introduce a framework for graphical security proofs in device-independent quantum cryptography using the methods of categorical quantum mechanics. We are optimistic that this approach will make some of the highly complex proofs in quantum cryptography more accessible, facilitate the discovery of new proofs, and enable automated proof verification. As an example of our framework, we reprove a previous result from device-independent quantum cryptography: any linear randomness expansion protocol can be converted into an unbounded randomness expansion protocol. We give a graphical proof of this result, and implement part of it in the Globular proof assistant.Comment: Publishable version. Diagrams have been polished, minor revisions to the text, and an appendix added with supplementary proof

    Folding of a single domain protein entering the endoplasmic reticulum precedes disulfide formation

    Get PDF
    The relationship between protein synthesis, folding and disulfide formation within the endoplasmic reticulum (ER) is poorly understood. Previous studies have suggested pre-existing disulfide links are absolutely required to allow protein folding and, conversely, that protein folding occurs prior to disulfide formation. To address the question of what happens first within the ER; that is, protein folding or disulfide formation, we studied folding events at the early stages of polypeptide chain translocation into the mammalian ER using stalled translation intermediates. Our results demonstrate that polypeptide folding can occur without complete domain translocation. Protein disulfide isomerase (PDI) interacts with these early intermediates, but disulfide formation does not occur unless the entire sequence of the protein domain is translocated. This is the first evidence that folding of the polypeptide chain precedes disulfide formation within a cellular context and highlights key differences between protein folding in the ER and refolding of purified proteins

    Financial Options For Mortgagors In A Declining Economic Market

    Get PDF
    Certainly, the current economic situation has drawn the focus of a large portion of the country to the lending industry and housing market. As lenders change their lending requirements in response to the credit crunch and pundits propose reforms designed to avoid future problems, part of this focus and momentum should be on the plight of the mortgagor’s in this country. This article will examine the varying options currently available to mortgagors who are in difficult financial circumstances. Providing various alternatives, each of which falls short of achieving their ideal goals
    • …
    corecore