3,017 research outputs found

    Modular communication system

    Get PDF
    A modular communication system (10) can include an adaptable communication module (12) having a transceiver (13) coupled to a processor (14) and memory (20), and a first interface block (24) coupled to the processor, and a host device (30) having a power source (36), a user interface (34), and a second interface block (46). The host device can be among a plurality of host devices having different user interfaces and the processor is adaptable to control the different user interfaces when the first interface block recognizes the second interface block. The module can further include a DSP (16) and a display (18) coupled to the processor as well as an antenna (11). A host device can be a phone, a wristwatch, a camera or video phone, an MP3 player, a heart rate monitor, a game controller, a toy, a stroller, or a crib among other devices

    Integrating Imagery from Hull Mounted Sidescan Sonars with Multibeam Bathymetry

    Get PDF
    Multibeam echo sounders produce high quality bathymetric data, however, for acoustic imaging their alongtrack beamwidth is much wider than what is used on conventional sidescan sonars, so the imagery produced by sidescan sonars are of a better quality and are often preferred. A hullmounted combination instrument package that integrates both the accurate multibeam bathymetry and the high resolution sidescan imagery is an attractive and relatively low cost solution for detailed surveys of harbors, canals, rivers and other shallow areas. Especially in these shallow water areas the sidescan sonar benefits from being hull mounted rather than towed, since this arrangement is easier and safer to handle and the sensor position is known with high accuracy. The paper addresses how the backscatter from the hull-mounted sidescan sonar system can be radiometrically and geometrically corrected, by using the bathymetry from the multibeam echo sounder, and how the 2 data sets can be presented together in 2D and 3D. A practical experiment is described, whereby EM 3002D multibeam echo sounder and a hull mounted EA 400 sidescan sonar system are mounted together and deployed over the bow of a small survey launch. The co-registered data sets are analyzed using the UNH GEOCODER processing scheme, and the results are presented and interpreted in terms of capability to resolve small objects. A comparison is made between the EA 400 sidescan backscatter and the EM 3002D seabed imagery

    Evaluation of potential reference genes in real-time RT-PCR studies of Atlantic salmon

    Get PDF
    BACKGROUND: Salmonid fishes are among the most widely studied model fish species but reports on systematic evaluation of reference genes in qRT-PCR studies is lacking. RESULTS: The stability of six potential reference genes was examined in eight tissues of Atlantic salmon (Salmo salar), to determine the most suitable genes to be used in quantitative real-time RT-PCR analyses. The relative transcription levels of genes encoding 18S rRNA, S20 ribosomal protein, β-actin, glyceraldehyde-3P-dehydrogenase (GAPDH), and two paralog genes encoding elongation factor 1A (EF1A(A )and EF1A(B)) were quantified in gills, liver, head kidney, spleen, thymus, brain, muscle, and posterior intestine in six untreated adult fish, in addition to a group of individuals that went through smoltification. Based on calculations performed with the geNorm VBA applet, which determines the most stable genes from a set of tested genes in a given cDNA sample, the ranking of the examined genes in adult Atlantic salmon was EF1A(B)>EF1A(A)>β-actin>18S rRNA>S20>GAPDH. When the same calculations were done on a total of 24 individuals from four stages in the smoltification process (presmolt, smolt, smoltified seawater and desmoltified freshwater), the gene ranking was EF1A(B)>EF1A(A)>S20>β-actin>18S rRNA>GAPDH. CONCLUSION: Overall, this work suggests that the EF1A(A )and EF1A(B )genes can be useful as reference genes in qRT-PCR examination of gene expression in the Atlantic salmon

    Reference installation for the German grid initiative D-Grid

    Get PDF
    The D-Grid reference installation is a test platform for the German grid initiative. The main task is to create the grid prototype for software and hardware components needed in the D-Grid community. For each grid-related task field different alternative middleware is included. With respect to changing demands from the community, new versions of the reference installation are released every six months

    Gyroscopic motion of superfluid trapped atomic condensates

    Full text link
    The gyroscopic motion of a trapped Bose gas containing a vortex is studied. We model the system as a classical top, as a superposition of coherent hydrodynamic states, by solution of the Bogoliubov equations, and by integration of the time-dependent Gross-Pitaevskii equation. The frequency spectrum of Bogoliubov excitations, including quantum frequency shifts, is calculated and the quantal precession frequency is found to be consistent with experimental results, though a small discrepancy exists. The superfluid precession is found to be well described by the classical and hydrodynamic models. However the frequency shifts and helical oscillations associated with vortex bending and twisting require a quantal treatment. In gyroscopic precession, the vortex excitation modes m=±1m=\pm 1 are the dominant features giving a vortex kink or bend, while the m=+2m=+2 is found to be the dominant Kelvin wave associated with vortex twisting.Comment: 18 pages, 7 figures, 1 tabl

    Continuity of Local Time: An applied perspective

    Full text link
    Continuity of local time for Brownian motion ranks among the most notable mathematical results in the theory of stochastic processes. This article addresses its implications from the point of view of applications. In particular an extension of previous results on an explicit role of continuity of (natural) local time is obtained for applications to recent classes of problems in physics, biology and finance involving discontinuities in a dispersion coefficient. The main theorem and its corollary provide physical principles that relate macro scale continuity of deterministic quantities to micro scale continuity of the (stochastic) local time.Comment: To appear in: "The fascination of Probability, Statistics and Their Applications. In honour of Ole E. Barndorff-Nielsen on his 80th birthday

    Effects of different photoperiod regimes on the smoltification and seawater adaptation of seawater-farmed rainbow trout (Oncorhynchus mykiss): Insights from Na+, K+-ATPase activity and transcription of osmoregulation and growth regulation genes

    Get PDF
    Photoperiod is thought to be the main zeitgeber that induces smoltification in salmonids. However, its effects on the smoltification of rainbow trout (Oncorhynchus mykiss) are not fully understood and no published data documents the effects of the photoperiod regime currently used commercially, continuous light (LL). The present study compared the effect of four different photoperiod regimes (i.e. advanced phase photoperiod (APP), delayed phase photoperiod (DPP), LL and simulated natural photoperiod (SNP)) on the smoltification and growth of juvenile rainbow trout during their freshwater phase of winter-spring and the following summer post smolt phase. Smoltification was evaluated by monitoring gill Na+,K+–ATPase (NKA) activity and transcription of NKA α-subunit isoforms 1a and 1b, and Na+,K+,2Cl− cotransporter 1a. Growth was measured as specific growth rate of both length and weight, and through molecular growth proxies such as the levels of circulating insulin-like growth factor 1 (IGF-I) in plasma and transcription of igf-I, igf binding protein 1b (igfbp1b), growth hormone receptor 1 (ghr1) and cathepsin L (ctsl) in the liver. Results indicate that APP induces a longer smolt window and higher levels of plasma IGF-I in both freshwater and seawater (two months post transfer), while DPP led to a shorter smolt window, lower plasma IGF-I levels in freshwater and seawater, an earlier decrease in liver igf-I and ctsl transcription in freshwater (as seen by modelling over time) and lower specific growth rate in freshwater. The transcription analysis of osmoregulatory genes complemented NKA activity and allowed for the detection of a transient response to light and of differences between the osmoregulatory capacity of parr and desmolted fish. Furthermore, an upregulation of the liver transcription of igf-I, ghr1 and ctsl was found in all treatments during the smolt window, which corresponded to the periods with highest growth. Finally, both plasma IGF-I and liver igf-I in seawater were found to be significantly correlated to fish growth in seawater. However, our data did not show that plasma IGF-I prior to seawater transfer could be used as a reliable predictor of growth in seawater. Overall, and especially when compared with other salmonid species, photoperiod seems to be a weaker inducer of smoltification in rainbow trout, according to the parameters that were tested, suggesting that other environmental cues might be more important drivers of this process
    • …
    corecore