848 research outputs found

    Analysis of Broadcast Authentication Mechanism in Selected Network Topologies

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    This paper deals with simulation of the broadcast authentication protocols using Colored Petri Nets and further optimizations in Matlab environment. Typical application of broadcast authentication protocols can be configurations where only one transmitter with multiple recipients exists (such as message exchange in sensor networks routing protocols, or the leader election process in sensors network). Authentication of every packet seems to be very effective way to mitigate an attack, however resulting in increase of end-to-end delay. To mitigate this drawback, the broadcast authentication protocols have been proposed. Concept of optimization of the broadcast authentication protocol DREAM parameters in a special case of fully N-ary tree and general random topology containing the same amount of nodes with regard to delay and energy consumption minimization is showed in the paper. Protocol DREAM was taken as an example of broadcast authenticating protocol to show how Color Petri Nets can be used to create a fully functional model of the protocol

    Multiscreen serum analysis of highly sensitized renal dialysis patients for antibodies toward public and private class I HLA determinants: Implications for computer-predicted acceptable and unacceptable donor mismatches in kidney transplantation

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    A multiscreen serum analysis program has been developed that permits a determination of antibody specificity for the vast majority of highly sensitized patients awaiting transplantation. This program is based on a 2 x 2 table analysis of correlations between serum reactivity with an HLA-typed cell panel and incorporates two modifications. One implements the concept of public HLA determinants based on the serologic crossreactivity among class I HLA antigens. The other modification derives from the premise that most highly sensitized patients maintain the same PRA and antibody profiles over many months and even years. Monthly screening results for patients with persistent PRA values can therefore be combined for analysis. For 132 of 150 highly sensitized patients with >50% PRA, this multiscreen serum analysis program yielded information about antibody specificity toward public and private class IHLA determinants. The vast majority of patients (108 of 112) with PRA values between 50 and 89% showed antibody specificity generally toward one, two, or three public markers and/or the more common private HLA-A, B antigens. For 24 of 38 patients with >90% PRA, it was possible to define one or few HLA-specific antibodies. The primary objective of the multiscreen program was to develop an algorithm about computer-predicted acceptable and unacceptable donor HLA-A, B antigens for patients with preformed antibodies. A retrospective analysis of kidney transplants into 89 highly sensitized patients has demonstrated that allografts with unacceptable HLA-A, B mismatches had significantly lower actuarial survival rates than those with acceptable mismatches (P = 0.01). This was shown for both groups of 32 primary transplants (44% vs. 67% after 1 year) and 60 retransplants (50% vs. 68%). Also, serum creatinine levels were significantly higher in patients with unacceptable class I mismatches (3.0 vs. 8.4 mg% [P = 0.007] after 2 weeks; 3.9 vs. 9.1 mg% [P = 0.014] after 4 weeks). Histopathologic analysis of allograft tissue specimens from 47 transplant recipients revealed a significantly higher incidence of humoral rejection (P = 0.02), but not cellular rejection, in the unacceptable mismatch group. These results suggest that the multiscreen program can establish which donor HLA-A, B mismatches must be avoided in kidney transplantation for most highly sensitized patients. For 18 of 150 high PRA renal dialysis patients, the multiscreen program could not define HLA-specific antibody. Most patients had >90% PRA, and many of their sera appeared to contain IgM type nonspecific lympho- cytotoxins that could be inactivated by dithioerythreitol (DTE). Preliminary studies have shown that this treatment enabled the detection of HLA-specific antibodies upon subsequent screening on many occasions. These data suggest that non-HLA specific reactivity revealed by multiscreen analysis can often be removed by DTE treatment. Multiscreen analysis offers an attractive approach to regional organ-sharing programs for highly sensitized renal transplant candidates. It enables the development of an efficient strategy for donor selection based on the computer assignment of acceptable HLA-A, B mismatches for each patient. © 1990 by Williams and Wilkins

    Zivilluftfahrt in Österreich 2008

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    Mit insgesamt 24,8 Mio. beförderten Fluggästen (inklusive Transit) erhöhte sich das Fluggastaufkommen in Österreich im Erhebungsjahr 2008 gegenüber dem Vorjahr um 4,2%, wobei auf den planmäßigen Luftverkehr (Linienverkehr) 22,4 Mio. (+5,3%) und auf den nichtplanmäßigen Luftverkehr (Bedarfsverkehr) 2,3 Mio. (-5,3%) Flugpassagiere entfielen

    Zivilluftfahrt in Österreich 2006: Ergebnisse der Erhebung - ausgewählte Analysen

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    Mit insgesamt 21,6 Mio. beförderten Fluggästen (inklusive Transit) nahm das Fluggastaufkommen in Österreich im Erhebungsjahr 2006 gegenüber dem Vorjahr um 5,8% zu. Davon entfielen auf den planmäßigen Luftverkehr (Linienverkehr) 18,9 Mio., das ist ein Zuwachs von 7,4%, und auf den nichtplanmäßigen Luftverkehr (Bedarfsverkehr) 2,8 Mio. Flugpassagiere (-4,1%)

    Zivilluftfahrt in Österreich 2005: Ergebnisse und ausgewählte Analysen

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    Mit insgesamt 20,4 Mio. beförderten Fluggästen (inklusive Transit) nahm das Fluggastaufkommen in Österreich im Erhebungsjahr 2005 gegenüber dem Vorjahr um 7,2% zu. Davon entfielen auf den planmäßigen Luftverkehr (Linienverkehr) 17,6 Mio. (+10,9%) und auf den nichtplanmäßigen Luftverkehr (Bedarfsverkehr) 2,9 Mio. Flugpassagiere (-11,0%)

    Inhibitors of \u3cem\u3eN\u3csup\u3eα\u3c/sup\u3e\u3c/em\u3e-acetyl-l-ornithine Deacetylase: Synthesis, Characterization and Analysis of their Inhibitory Potency

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    A series of N α-acyl (alkyl)- and N α-alkoxycarbonyl-derivatives of l- and d-ornithine were prepared, characterized, and analyzed for their potency toward the bacterial enzyme N α-acetyl-l-ornithine deacetylase (ArgE). ArgE catalyzes the conversion of N α-acetyl-l-ornithine to l-ornithine in the fifth step of the biosynthetic pathway for arginine, a necessary step for bacterial growth. Most of the compounds tested provided IC50 values in the μM range toward ArgE, indicating that they are moderately strong inhibitors. N α-chloroacetyl-l-ornithine (1g) was the best inhibitor tested toward ArgE providing an IC50 value of 85 μM while N α-trifluoroacetyl-l-ornithine (1f), N α-ethoxycarbonyl-l-ornithine (2b), and N α-acetyl-d-ornithine (1a) weakly inhibited ArgE activity providing IC50 values between 200 and 410 μM. Weak inhibitory potency toward Bacillus subtilis-168 for N α-acetyl-d-ornithine (1a) and N α-fluoro- (1f), N α-chloro- (1g), N α-dichloro- (1h), and N α-trichloroacetyl-ornithine (1i) was also observed. These data correlate well with the IC50 values determined for ArgE, suggesting that these compounds might be capable of getting across the cell membrane and that ArgE is likely the bacterial enzymatic target

    Tunable far infrared studies of molecular parameters in support of stratospheric measurements

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    Lab studies were made in support of far infrared spectroscopy of the stratosphere using the Tunable Far InfraRed (TuFIR) method of ultrahigh resolution spectroscopy and, more recently, spectroscopic and retrieval calculations performed in support of satellite-based atmospheric measurement programs: the Global Ozone Monitoring Experiment (GOME), and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY)

    Romancing The Labor

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    This is a report of a creative body of work dealing with the adaptation of traditional industrial processes into contemporary sculpture. This thesis shows that admiration for labor is still present in sculpture by utilizing the techniques and language of industry for an aesthetic purpose. My work deals with these processes as an act of emulation and reverence to our industrial past. The objects demonstrate my respect and appreciation towards industry and labor, along with the beauty I find in the machinery, material, and processes. Through the adaptation of industrial processes I am able to re-envision turn of the century labor processes and reinforce an admiration for the work of the hands-on-laborer.  M.F.A
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