68 research outputs found
CASAD -- Computer-Aided Sonography of Abdominal Diseases - the concept of joint technique impact
Ultrasound image is the primary (input) information for every ultrasonic examination. Since being used in ultrasound images analysis the both knowledge-base decision support and content-based image retrieval techniques have their own restrictions, the combination of these techniques looks promissory for covering the restrictions of one by advances of another. In this work we have focused on implementation of the proposed combination in the frame of CASAD (Computer-Aided Sonography of Abdominal Diseases) system for supplying the ultrasound examiner with a diagnostic-assistant tool based on a data warehouse of standard referenced images. This warehouse serves:
to manifest the diagnosis when the ecographist specifies the pathology and then looks through corresponding images to verify his opinion;
to suggest a second opinion by automatic analysis of the annotation of relevant images that were assessed from the repository using content-based image retrieval
Preoperative method of assessment of gallbladder lesion in acute cholecystitis
Background. To date acute cholecystitis remains one of the most common urgent abdominal diseases in which postoperative complications and mortality are possible.The aim. To assess the correlation of gamma-glutamyltranspeptidase and alkaline phosphatase concentrations in blood plasma with the form of acute cholecystitis.Methods. A study of 105 patients with acute calculous cholecystitis, 35 – with chronic calculous cholecystitis (comparison group), who underwent laparoscopic cholecystectomy, was performed. At admission to the hospital, the activity of gammaglutamyltranspeptidase (GGTP) and alkaline phosphatase in blood plasma was determined by kinetic colorimetric method.Results. A direct correlation was revealed between the level of GGTP concentration and the severity of destruction in the gallbladder wall. With catarrhal cholecystitis, it was 340 ± 116.9 U/l (p < 0.05), with phlegmonous – 108.1 ± 29.5 U/l (p < 0.05), with gangrenous – 32.9 ± 7.5 U/l (p < 0.05). Along with this, a direct correlation was revealed between the concentration of alkaline phosphatase and the severity of destruction in the gallbladder wall. In catarrhal cholecystitis, the enzyme activity was 160.3 ± 34.2 U/l (p < 0.05), in phlegmonous – 129.9 ± 14.6 U/l (p < 0.05), in gangrenous – 57 ± 18.5 U/l (p < 0.05).Conclusion. Determination of the concentration of GGTP and alkaline phosphatase in combination with other diagnostic criteria makes it possible to determine the presence of destructive forms of acute cholecystitis with high specificity and sensitivity before surgery
Determining Absorption, Emissivity Reduction, and Local Suppression Coefficients inside Sunspots
The power of solar acoustic waves is reduced inside sunspots mainly due to
absorption, emissivity reduction, and local suppression. The coefficients of
these power-reduction mechanisms can be determined by comparing time-distance
cross-covariances obtained from sunspots and from the quiet Sun. By analyzing
47 active regions observed by SOHO/MDI without using signal filters, we have
determined the coefficients of surface absorption, deep absorption, emissivity
reduction, and local suppression. The dissipation in the quiet Sun is derived
as well. All of the cross-covariances are width corrected to offset the effect
of dispersion. We find that absorption is the dominant mechanism of the power
deficit in sunspots for short travel distances, but gradually drops to zero at
travel distances longer than about 6 degrees. The absorption in sunspot
interiors is also significant. The emissivity-reduction coefficient ranges from
about 0.44 to 1.00 within the umbra and 0.29 to 0.72 in the sunspot, and
accounts for only about 21.5% of the umbra's and 16.5% of the sunspot's total
power reduction. Local suppression is nearly constant as a function of travel
distance with values of 0.80 and 0.665 for umbrae and whole sunspots
respectively, and is the major cause of the power deficit at large travel
distances.Comment: 14 pages, 21 Figure
Triggering an eruptive flare by emerging flux in a solar active-region complex
A flare and fast coronal mass ejection originated between solar active
regions NOAA 11514 and 11515 on July 1, 2012 in response to flux emergence in
front of the leading sunspot of the trailing region 11515. Analyzing the
evolution of the photospheric magnetic flux and the coronal structure, we find
that the flux emergence triggered the eruption by interaction with overlying
flux in a non-standard way. The new flux neither had the opposite orientation
nor a location near the polarity inversion line, which are favorable for strong
reconnection with the arcade flux under which it emerged. Moreover, its flux
content remained significantly smaller than that of the arcade (approximately
40 %). However, a loop system rooted in the trailing active region ran in part
under the arcade between the active regions, passing over the site of flux
emergence. The reconnection with the emerging flux, leading to a series of jet
emissions into the loop system, caused a strong but confined rise of the loop
system. This lifted the arcade between the two active regions, weakening its
downward tension force and thus destabilizing the considerably sheared flux
under the arcade. The complex event was also associated with supporting
precursor activity in an enhanced network near the active regions, acting on
the large-scale overlying flux, and with two simultaneous confined flares
within the active regions.Comment: Accepted for publication in Topical Issue of Solar Physics: Solar and
Stellar Flares. 25 pages, 12 figure
Recommended from our members
Spent fuel sabotage aerosol test program :FY 2005-06 testing and aerosol data summary.
This multinational, multi-phase spent fuel sabotage test program is quantifying the aerosol particles produced when the products of a high energy density device (HEDD) interact with and explosively particulate test rodlets that contain pellets of either surrogate materials or actual spent fuel. This program has been underway for several years. This program provides source-term data that are relevant to some sabotage scenarios in relation to spent fuel transport and storage casks, and associated risk assessments. This document focuses on an updated description of the test program and test components for all work and plans made, or revised, primarily during FY 2005 and about the first two-thirds of FY 2006. It also serves as a program status report as of the end of May 2006. We provide details on the significant findings on aerosol results and observations from the recently completed Phase 2 surrogate material tests using cerium oxide ceramic pellets in test rodlets plus non-radioactive fission product dopants. Results include: respirable fractions produced; amounts, nuclide content, and produced particle size distributions and morphology; status on determination of the spent fuel ratio, SFR (the ratio of respirable particles from real spent fuel/respirables from surrogate spent fuel, measured under closely matched test conditions, in a contained test chamber); and, measurements of enhanced volatile fission product species sorption onto respirable particles. We discuss progress and results for the first three, recently performed Phase 3 tests using depleted uranium oxide, DUO{sub 2}, test rodlets. We will also review the status of preparations and the final Phase 4 tests in this program, using short rodlets containing actual spent fuel from U.S. PWR reactors, with both high- and lower-burnup fuel. These data plus testing results and design are tailored to support and guide, follow-on computer modeling of aerosol dispersal hazards and radiological consequence assessments. This spent fuel sabotage--aerosol test program, performed primarily at Sandia National Laboratories, with support provided by both the U.S. Department of Energy and the Nuclear Regulatory Commission, had significant inputs from, and is strongly supported and coordinated by both the U.S. and international program participants in Germany, France, and the U.K., as part of the international Working Group for Sabotage Concerns of Transport and Storage Casks, WGSTSC
Fucoidan-degrading fungal strains: screening, morphometric evaluation, and influence of medium composition
Ten different fungal strains from the genus Aspergillus, Penicillium, and Mucor
were screened for fucoidan hydrolyzing ability aiming to find microorganisms able to
produce sulfated fucan-degrading enzymes. Screening was carried out by measuring the
strains kinetic and morphometric behavior over plate assays using Laminaria japonica
fucoidan as only carbon source, testing three nitrogen sources (urea, peptone, and sodium
nitrate). The selected fungal strains were subsequently used in submerged fermentations,
which were performed for (1) selection of the strains able to growth over fucoidan medium
and (2) media selection, testing the synergy of fucoidan with other sugars for inducing high
enzyme titles. Radial expansion and hyphae parameters were observed for Aspergillus niger
PSH, Mucor sp. 3P, and Penicillium purpurogenum GH2 grown only over fucoidan-urea
medium. A. niger PSH showed the maximum enzymatic activity values, which were
significantly different (p<0.05) from those achieved by the other selected fungi. Sucrose
addition to fucoidan media proportioned the highest fucoidanase activity values for this
fungal strain. This research allowed establishing optimal conditions for metabolites
synthesis by fungal stains able to act toward fucoidan ramified matrix.Mexican
Science and Technology Council (CONACYT
Lifetimes of High-Degree p Modes in the Quiet and Active Sun
We study variations of the lifetimes of high-degree solar p-modes in the
quiet and active Sun with the solar activity cycle. The lifetimes in the degree
range 300 - 600 and frequency 2.5 - 4.5 mHz were computed from SOHO/MDI data in
an area including active regions and quiet Sun using the time-distance
technique. We applied our analysis to the data in four different phases of
solar activity: in 1996 (at minimum), 1998 (rising phase), 2000 (at maximum)
and 2003 (declining phase). The results from the area with active regions show
that the lifetime decreases as activity increases. The maximal lifetime
variations are between solar minimum in 1996 and maximum in 2000; the relative
variation averaged over all mode degree values and frequencies is a decrease of
about 13%. The lifetime reductions relative to 1996 are about 7% in 1998 and
about 10% in 2003. The lifetime computed in the quiet region still decreases
with solar activity although the decrease is smaller. On average, relative to
1996, the lifetime decrease is about 4% in 1998, 10% in 2000 and 8% in 2003.
Thus, measured lifetime increases when regions of high magnetic activity are
avoided. Moreover, the lifetime computed in quiet regions also shows variations
with activity cycle.Comment: 13 pages, 5 figures; Accepted for publication in Solar Physic
Abel Symposia
Discrete Morse theory has recently lead to new developments in the theory of random geometric complexes. This article surveys the methods and results obtained with this new approach, and discusses some of its shortcomings. It uses simulations to illustrate the results and to form conjectures, getting numerical estimates for combinatorial, topological, and geometric properties of weighted and unweighted Delaunay mosaics, their dual Voronoi tessellations, and the Alpha and Wrap complexes contained in the mosaics
- …