40 research outputs found
Protocols for calibrating multibeam sonar
Author Posting. © Acoustical Society of America, 2005. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 117 (2005): 2013-2027, doi:10.1121/1.1869073.Development of protocols for calibrating multibeam sonar by means of the standard-target method is documented. Particular systems used in the development work included three that provide the water-column signals, namely the SIMRAD SM2000/90- and 200-kHz sonars and RESON SeaBat 8101 sonar, with operating frequency of 240 kHz. Two facilities were instrumented specifically for the work: a sea well at the Woods Hole Oceanographic Institution and a large, indoor freshwater tank at the University of New Hampshire. Methods for measuring the transfer characteristics of each sonar, with transducers attached, are described and illustrated with measurement results. The principal results, however, are the protocols themselves. These are elaborated for positioning the target, choosing the receiver gain function, quantifying the system stability, mapping the directionality in the plane of the receiving array and in the plane normal to the central axis, measuring the directionality of individual beams, and measuring the nearfield response. General preparations for calibrating multibeam sonars and a method for measuring the receiver response electronically are outlined. Advantages of multibeam sonar calibration and outstanding problems, such as that of validation of the performance of multibeam sonars as configured for use, are mentioned.Support by the National Science Foundation through Award
No. OCE-0002664, NOAA through Grant No.
NA97OG0241, and the Cooperative Institute for Climate and
Ocean Research (CICOR) through NOAA Contract No.
NA17RJ1223 is acknowledged
Comparison of granulocyte colony-stimulating factor (G-CSF)--mobilized peripheral blood progenitor cells and G-CSF--stimulated bone marrow as a source of stem cells in HLA-matched sibling transplantation
AbstractHLA-identical bone marrow or stem cell transplantation from a sibling is the preferred treatment for patients with chronic myelogenous leukemia, bone marrow failure syndromes, relapsed acute leukemia, and specific inborn errors of metabolism. Several groups have shown that granulocyte colony-stimulating factor (G-CSF)--mobilized peripheral blood progenitor cells (PBPCs) obtained from HLA-matched siblings are effective in reconstitution of marrow function after marrow ablative conditioning therapy. To evaluate whether G-CSF treatment before bone marrow harvest leads to enhanced recovery of PBPC counts and recovery from limited graft-versus-host disease (GVHD), we assessed the outcome of a sequential cohort of patients treated identically and then given either G-CSF--mobilized PBPCs or G-CSF--stimulated bone marrow from HLA-identical siblings. We show that the time to neutrophil engraftment is identical in the 2 cohorts, whereas platelet engraftment is earlier with the use of PBPCs. The incidence of acute GVHD was decreased, and that of chronic GVHD significantly decreased, in the group receiving bone marrow. Overall survival was not different between the 2 groups. Thus, G-CSF--stimulated bone marrow offers a source of stem cells that allows for early neutrophil engraftment with a decreased risk of GVHD.Biol Blood Marrow Transplant 2000;6(4A):434-40
Effects of morphine, nalorphine and naloxone on neocortical release of acetylcholine in the rat
The effects of morphine (10 mg/kg), nalorphine (1 and 10 mg/kg), and naloxone (1 mg/kg) were studied on the neocortical release of acetylcholine (ACh) in midpontine pretrigeminal transected rats. Morphine and, to a lesser extent, nalorphine decreased ACh release. Naloxone was ineffective alone but antagonized the action of morphine.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46384/1/213_2004_Article_BF00422643.pd
Rocky Mountain spotted fever vaccine in an animal model.
Formalin-killed, purified Rickettsia rickettsii vaccine was evaluated in a guinea pig model of R. rickettsii infection. Vaccinated guinea pigs were partially protected by the vaccine when challenged with virulent, viable rickettsiae. Greater protection was observed when higher doses of vaccine were given and when frequent booster injections were administered. Stimulation of cell-mediated immunity to the vaccine antigens was variable and also appeared to be achieved more reproducibly with booster vaccinations. Serum antibody was elicited by high doses of vaccine and by booster vaccinations. The presence of serum antibody was useful in predicting immunity to challenge with R. rickettsii
Comparison of molecular and microscopic techniques for detection of Treponema pallidum in genital ulcers.
We compared the ability of direct immunofluorescent staining (DFA) and the PCR to detect Treponema pallidum in specimens from patients with genital ulcer disease. Touch preparations from 156 patients with genital lesions were fixed in acetone and stained with a fluorescein-labeled monoclonal antibody specific for the 37-kDa antigen of T. pallidum. After microscopic examination, the smear was removed from the slide with a swab. DNA was extracted with phenol-chloroform and precipitated with isopropanol. Ten microliters of the extracted DNA was amplified by PCR using primers for the gene encoding the 47-kDa protein of T. pallidum and hybridized to an internal probe. Twenty-two of 156 specimens were positive for T. pallidum by DFA and PCR, while 127 were negative by both methods, yielding a concordance of 95.5% (kappa = 0.84). Four specimens were positive by PCR and negative by DFA, while three specimens were negative by PCR and positive by DFA. The DFA-negative, PCR-positive specimens may have resulted from the presence of large numbers of leukocytes on the slides, obscuring visualization of treponemes. The DFA-positive, PCR-negative results were not due to inhibition of the PCR since purified T. pallidum DNA was amplified when added to aliquots of these specimens. Negative results in these specimens were most likely due to inefficient recovery of their DNA. These data suggest that DFA and PCR are equivalent methods for detection of T. pallidum on touch preparations of genital lesions. Further refinements of the PCR assay are necessary for it to significantly improve the detection of T. pallidum in genital lesions
Humoral response of the mouse to Treponema pallidum.
To investigate the development of the humoral immune response of mice to infection with Treponema pallidum, Balb/c and C57Bl mice were injected intradermally with 10 x 10(6) virulent organisms. Serum samples were taken from the mice at weekly intervals after infection and used in the electrophoretic transblotting technique to detect T pallidum and T phagedenis biotype Reiter antigens. The serum samples taken from infected mice at 21, 42, 84, and 126 days after infection recognised two to 15 T pallidum antigens, with a gradual but continual increase in the number of antigens recognised. The same antisera to T pallidum recognised five cross reactive T phagedenis biotype Reiter antigens. Mice injected with 10 x 10(6) heat killed T pallidum organisms failed to recognise T pallidum antigens, as shown by the blotting technique. When mice infected with T pallidum were given antibiotics, the development of the humoral response was interrupted. These experiments indicated that mice respond more slowly than rabbits to T pallidum, which may be because T pallidum is weakly immunogenic in mice