208 research outputs found

    On-Line Sea Beam Acoustic Imaging

    Get PDF
    This paper describes a system designed and built at the Marine Physical Laboratory of the Scripps Institution of Oceanography to produce acoustic images of the seafloor on-line with a Sea Beammultibeam echo-sounder. This system uses a stand alone interface between the Sea Beam system and a grey-scale line-scan recorder. The interface is built around a Motorola 68000 microprocessor and has digitizing capabilities. It digitizes the detected echo signals from each of the 16 preformed beams inside the Sea Beam echo processor as well as the roll information given by the ship\u27s vertical reference. Theacoustic data are then roll compensated and combined into a port and a starboard time series. These time series are eventually output in digital format to a line-scan recorder which produces the grey scaleacoustic image. Results are discussed for Sea Beam acoustic images of the seafloor and of the Deep Scattering layers

    Funktionelle Insulintherapie (FIT) beim Typ-1-Diabetes

    Get PDF
    Zusammenfassung: Das Ziel der Insulinbehandlung bei Patienten mit Diabetes mellitus Typ 1 besteht darin, eine nahezu normoglykämische Blutzuckereinstellung unter Vermeidung von schweren Hypoglykämien zu erreichen, um einerseits die Entwicklung von mikro- und makrovaskulären Spätkomplikationen zu vermeiden und andererseits ein optimales körperliches Wohlbefinden zu ermöglichen. Die funktionelle Insulintherapie zusammen mit den heute verfügbaren kurz und lang wirksamen Analoginsulinen stellt eine Therapieoption für Patienten mit Diabetes mellitus Typ 1 dar, die dem physiologischen Insulinersatz sehr nahe kommt. Eine weitere Verfeinerung der Insulinabgabe lässt sich mit einer Insulinpumpentherapie erreichen. Die funktionelle Insulintherapie bietet dem Patienten eine größere Autonomie in der Selbstbehandlung und erheblich mehr Flexibilität in der Lebensgestaltung. Umgekehrt ist für ihre erfolgreiche Anwendung eine vermehrte und regelmäßige Blutzuckerselbstkontrolle unabdingba

    Simultaneous islet-kidney vs pancreas-kidney transplantation in type 1 diabetes mellitus: a 5year single centre follow-up

    Get PDF
    Aims/hypothesis: The aim of this study was to compare the long-term outcomes—in terms of glucose control, renal function and procedure-related complications—of simultaneous islet-kidney (SIK) transplantation with those of simultaneous pancreas-kidney (SPK) transplantation in patients with type 1 diabetes mellitus. Methods: HbA1c, need for insulin, GFR and complication rate were compared between 13 recipients of SIK and 25 recipients of SPK transplants at the same institution. The mean follow-up was 41months. Results: Two primary organ non-functions occurred in the SIK group. HbA1c did not differ at any time point during follow-up in the SIK group compared with the SPK group (mean during follow-up 6.3 vs 5.9%). Similarly, kidney function over time was not different between the two groups. A higher rate of insulin independence following SPK transplantation (after 1year 96 vs 31% in the SIK group) was counterbalanced by a higher rate of serious adverse events (40% relaparotomies vs 0% in the SIK group). Conclusions/interpretation: The endogenous insulin production achieved by islet transplantation, combined with optimal insulin therapy, was sufficient for maintaining near-normal glucose levels. In terms of glucose control, islet transplantation provides results comparable to those achieved with pancreas transplantation. However, SPK results in a higher rate of insulin independence, albeit at the cost of more surgical complications. These results have led to a new paradigm in islet transplantation at our institution, where the primary goal is not insulin independence, but good glucose control and avoidance of severe hypoglycaemi

    Evolution of AANAT: expansion of the gene family in the cephalochordate amphioxus

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The arylalkylamine <it>N</it>-acetyltransferase (AANAT) family is divided into structurally distinct vertebrate and non-vertebrate groups. Expression of vertebrate AANATs is limited primarily to the pineal gland and retina, where it plays a role in controlling the circadian rhythm in melatonin synthesis. Based on the role melatonin plays in biological timing, AANAT has been given the moniker "the Timezyme". Non-vertebrate AANATs, which occur in fungi and protists, are thought to play a role in detoxification and are not known to be associated with a specific tissue.</p> <p>Results</p> <p>We have found that the amphioxus genome contains seven <it>AANAT</it>s, all having non-vertebrate type features. This and the absence of <it>AANATs </it>from the genomes of Hemichordates and Urochordates support the view that a major transition in the evolution of the <it>AANATs </it>may have occurred at the onset of vertebrate evolution. Analysis of the expression pattern of the two most structurally divergent <it>AANAT</it>s in <it>Branchiostoma lanceolatum </it>(<it>bl</it>) revealed that they are expressed early in development and also in the adult at low levels throughout the body, possibly associated with the neural tube. Expression is clearly not exclusively associated with the proposed analogs of the pineal gland and retina. blAANAT activity is influenced by environmental lighting, but light/dark differences do not persist under constant light or constant dark conditions, indicating they are not circadian in nature. bfAANATα and bfAANATδ' have unusually alkaline (> 9.0) optimal pH, more than two pH units higher than that of vertebrate AANATs.</p> <p>Conclusions</p> <p>The substrate selectivity profiles of bfAANATα and δ' are relatively broad, including alkylamines, arylalkylamines and diamines, in contrast to vertebrate forms, which selectively acetylate serotonin and other arylalkylamines. Based on these features, it appears that amphioxus AANATs could play several roles, including detoxification and biogenic amine inactivation. The presence of seven AANATs in amphioxus genome supports the view that arylalkylamine and polyamine acetylation is important to the biology of this organism and that these genes evolved in response to specific pressures related to requirements for amine acetylation.</p

    Operational experience, improvements, and performance of the CDF Run II silicon vertex detector

    Full text link
    The Collider Detector at Fermilab (CDF) pursues a broad physics program at Fermilab's Tevatron collider. Between Run II commissioning in early 2001 and the end of operations in September 2011, the Tevatron delivered 12 fb-1 of integrated luminosity of p-pbar collisions at sqrt(s)=1.96 TeV. Many physics analyses undertaken by CDF require heavy flavor tagging with large charged particle tracking acceptance. To realize these goals, in 2001 CDF installed eight layers of silicon microstrip detectors around its interaction region. These detectors were designed for 2--5 years of operation, radiation doses up to 2 Mrad (0.02 Gy), and were expected to be replaced in 2004. The sensors were not replaced, and the Tevatron run was extended for several years beyond its design, exposing the sensors and electronics to much higher radiation doses than anticipated. In this paper we describe the operational challenges encountered over the past 10 years of running the CDF silicon detectors, the preventive measures undertaken, and the improvements made along the way to ensure their optimal performance for collecting high quality physics data. In addition, we describe the quantities and methods used to monitor radiation damage in the sensors for optimal performance and summarize the detector performance quantities important to CDF's physics program, including vertex resolution, heavy flavor tagging, and silicon vertex trigger performance.Comment: Preprint accepted for publication in Nuclear Instruments and Methods A (07/31/2013
    corecore