Leakage-resilient security architecture for mobile IPv6 in wireless overlay networks

The coupling of mobility and quality-of-service with security is a challenge that should be addressed in future wireless overlay systems. The mobility of a node can disrupt or even intermittently disconnect an ongoing real-time session because a secure handover must be performed to ensure continuous connectivity. The duration of the such interruptions is called disruption time or handover delay and can heavily affect the user satisfaction. The handover procedure needs to protect its integrity and confidentiality-otherwise, the packets may be rerouted to a malicious node and the legitimate handover may not be performed. The security procedure to ensure this should not lengthen significantly the handover delay to provide good quality real-time services. In this paper, we focus on the network-layer mobility, specifically, on Mobile Internet protocol version 6 (MIPv6) since it is the natural candidate for providing such mobility in future systems. To solve the problem of on-path attackers and prevent leakage of secrets, we propose a security architecture for MIPv6 based on leakage resilient-authenticated key establishment (LR-AKE) protocol and its cooperation with public key infrastructure. The proposed architecture prevents against on-path attackers which was not addressed in the specifications of MIPv6, and also provides robustness against leakage of secret values. Using analytical models, we evaluate MIPv6 handover delay for real-time services. We identify the crucial factors affecting the handover delay among transmission delays of MIPv6, security and LR-AKE messages, queueing delays and en/decryption delays.     

Identification of a glycoprotein from rat liver mitochondrial inner membrane and demonstration of its origin in the endoplasmic reticulum

Employing antisera against various subfractions of rat liver mitochondria (mitoplast, inner membrane, intermembrane, and matrix) as well as metabolically radiolabeled BRL-3A rat liver cells, we undertook a search for the presence of glycoproteins in this major cellular compartment for which little information in regard to glycoconjugates was available. Subsequent to [35S]methionine labeling of BRL-3A cells, a peptide:N-glycosidase-sensitive protein (45 kDa) was observed by SDS-polyacrylamide gel electrophoresis of the inner membrane immunoprecipitate, which was reduced to a molecular mass of 42 kDa by this enzyme. The 45-kDa protein was readily labeled with [2-3H]mannose, and indeed the radioactivity of the inner membrane immunoprecipitate was almost exclusively present in this component. Moreover, antisera directed against mitochondrial NADH-ubiquinone oxidoreductase (complex I) or F1F0-ATPase (complex V) also precipitated a 45-kDa protein from BRL-3A cell lysates as the predominant mannose-radiolabeled constituent. Endo-beta-N-acetylglucosaminidase completely removed the radiolabel from this glycoprotein, and the released oligosaccharides were of the partially trimmed polymannose type (Glc1Man9GlcNAc to Man8GlcNAc). Cycloheximide as well as tunicamycin resulted in total inhibition of radiolabeling of the inner membrane glycoprotein, and moreover, pulse-chase studies employing metrizamide density gradient centrifugation demonstrated that the glycoprotein was initially present in the endoplasmic reticulum (ER) and subsequently appeared in a mitochondrial location. Early movement of the glycoprotein to the mitochondria after synthesis in the ER was also evident from the limited processing undergone by its N-linked oligosaccharides; this stood in contrast to lysosomal glycoproteins in which we noted extensive conversion to complex oligosaccharides. Our findings suggest that the 45-kDa glycoprotein migrates from ER to mitochondria by the previously observed contact sites between the two organelles. Furthermore, the presence of this glycoprotein in at least two major mitochondrial multienzyme complexes would be consistent with a role in mitochondrial translocations.     

Adrenal gland incidentaloma in the oncologic patient: is its histologic study obligatory?

We evaluated the performance of an automatic polymerase chain reaction (PCR) detection system for identification of Mycobacterium tuberculosis in respiratory specimens. Six hundred and two respiratory specimens, including 557 sputa and 45 bronchial washing samples, were analyzed using the COBAS AMPLICOR Mycobacterium tuberculosis (MTB) test. The results were compared with those obtained from acid-fast microscopy, conventional culture, and clinical history. In cases of discrepancy between the results of the COBAS AMPLICOR MTB test and culture, the medical history of the patient was reviewed, the COBAS AMPLICOR MTB test was repeated, and the gene encoding M. tuberculosis superoxide dismutase was screened using PCR (SOD-PCR). Fourteen samples were excluded because the internal control test result was negative. Of 57 specimens that were culture positive for Mycobacterium species, 40 appeared to have growth of M. tuberculosis and 21 were smear positive for acid-fast bacteria. The sensitivity, specificity, and positive and negative predictive values for the COBAS AMPLICOR MTB test evaluated at our laboratory were 85.0% (34/40), 99.3% (544/548), 89.5% (34/38), and 98.9% (544/550), respectively. Three specimens that were culture positive for M. tuberculosis but negative by COBAS AMPLICOR MTB test were positive when rechecked by both COBAS AMPLICOR MTB test and SOD-PCR. Among the four specimens with positive reactions on both COBAS AMPLICOR MTB test and SOD-PCR that were culture negative, two were from patients who had been receiving antituberculosis treatment, one was from a patient who had been treated for tuberculosis for 1 year, and the other was from a patient who died of sepsis with adult respiratory distress syndrome. In more than 70% of smear-negative and culture-positive specimens and 86.4% of smear-positive specimens, M. tuberculosis was identified by the COBAS AMPLICOR MTB test within 10 hours after receipt of the specimens. Our data show that the COBAS AMPLICOR MTB test provides rapid and accurate detection of M. tuberculosis in respiratory specimens.     

Parametric sensitivity of fracture behaviour of concrete

The fictitious crack method (FCM) is applied to determine the load-deflection diagrams of notched plain concrete beams under three-point bending using various forms of strain softening in the stress-deformation relationship. The results indicate that there is a need to determine a more realistic relationship.     

Symmetry and model checking

We show how to exploit symmetry in model checking for concurrent systems containing many identical or isomorphic components. We focus in particular on those composed of many isomorphic processes. In many cases we are able to obtain significant, even exponential, savings in the complexity of model checking.The author's work was supported in part by NSF Grant CCR 941-5496, Semiconductor Research Corporation Contract 95-DP-388, and Texas Advanced Technology Program Grant 003658-250.The author's work was supported in part by NSF Grant CCR-9212183.     

Effects of Rician faded and log-normal shadowed signals on spectrumefficiency in microcellular radio

An assessment of spectrum efficiency for a microcellular land mobile radio system is presented by considering the desired signal as (fast) Rician fading with (slow) log-normal shadowing and cochannel interfering signals as uncorrelated (fast) Rayleigh fading superimposed over (slow) log-normal shadowing. Spectrum efficiency is defined in terms of reuse distance, i.e., cluster size, traffic intensity, bandwidth of the system, and area of a cell by considering cochannel interference probability. The expression for cochannel interference probability is derived using appropriate path-loss law for microcells for four different cases: Rician plus log-normal desired signal and Rayleigh plus log-normal interfering signals; Rician desired signal and Rayleigh fading plus log-normal shadowing interfering signals; Rician desired signal and Rayleigh interfering signals; and both desired and interfering signals as Rician fading. The performance of a microcellular system is compared with that of a conventional macrocellular system     

APPLICATION OF NORMAL AND DERIVATIVE ULTRAVIOLET ABSORPTION SPECTROSCOPY FOR THK DETERMINATION OF AROMATIC HYDROCARBONS IN GAS OILS

Ultraviolet absorption spectroscopy, has an immense potential for characterization of aromatic hydrocarbons in distillate petroleum fractions. The second derivative ultraviolet spectroscopy has improved the understanding of complex aromatic structures, such as polynuclear aromatics, which are present in gas oil fractions. Normal and second derivative ultraviolet spectroscopy of gas oils and their separated fractions are discussed in detail and conclusions are drawn regarding mono-di-and polynuclear aromatics in various gas oils.     

Optimization of ingredients for the manufacture of soft-serve ice-cream (Softy) by response surface methodology (RSM)

Soft ice-cream samples were prepared with different proportions of cream and skimmed milk powder (SMP) and were examined for quality by physico-chemical parameters and sensory attributes. The specific proportions of cream and SMP were designed using the central composite rotatable design (CCRD). Response surface analysis indicated that sensory flavour, texture and overall acceptability (OAA) scores of soft ice-cream varied from 7.12 to 8.86, 6.66 to 8.03 and 6.90 to 8.45, respectively. The differences in the sensory scores for respective attributes were highly significant ( P ≤  0.01). The soft ice-cream containing a minimum level of 3.24% cream and 4.94% SMP resulted in a product having a minimum of 4.3% fat, 5.7% lactose and 33% total solids, with a minimum OAA score of 8. The derived mathematical second-order polynomial models against cream (X) and SMP (Y) were found to be adequate as coefficients of multiple determinants ( R ²) were more than 80% except for melting resistance.