Improving bandwidth efficiency in fault‐tolerant opaque IP over optical mesh networks

Adequately providing fault tolerance while using network capacity efficiently is a major topic of research in optical networks. In order to improve the network utilization, grooming of low‐rate connections in optical networks has been usually performed at the edge of the network. However, in all‐optical networks once a channel is assigned, its entire capacity is dedicated to the users independently of its grooming capabilities. As current users don't usually require such big capacities, bandwidth inefficiencies still occur. In this paper we address this issue introducing unlimited grooming per link (UGPL), a new restoration mechanism for opaque mesh optical networks that grooms connections on a per‐link basis. Simulation results show that UGPL provides the best bandwidth efficiency and the best blocking probability compared to traditional 1 + 1 protection and 1 : N end‐to‐end sharing schemes. Furthermore, we show that the 1 : N end‐to‐end restoration scheme provides no benefits over the simpler and faster 1 + 1 protection scheme. Copyright © 2004 John Wiley & Sons, Ltd.     

Synthesis and structure elucidation of estrogen quinones conjugated with cysteine, N-acetylcysteine, and glutathione

A micromechanical model for predicting the densification of particulate matter under hydrostatic loading was developed to account for the time-dependent response of materials to applied loads. Viscoelastic material response used in the analysis was based upon a standard three-parameter rheological model. Compaction data under closed die conditions were collected using an Instron analyzer for different rates of applied load. Densification during the loading phase of PMMA/coMMA powder, a pharmaceutical polymeric coating material, was well predicted by the proposed algorithm, which contrasts with the prediction implied through a static indentation model. Secondary factors which affect compaction such as die-wall friction are also briefly discussed.     

Streamlining the digital economy: how to avert a tragedy of thecommons

To achieve its unique potential in a digital economy, the Internet must be able to guarantee a quality of service. Solving this problem requires the integration of economic principles and engineering design. The authors describe their work on a control mechanism that is decentralized and computationally feasible     

Improved quantitation of minimal residual disease in multiple myeloma using real-time polymerase chain reaction and plasmid-DNA complementarity determining region III standards

The complementarity determining region III of the rearranged immunoglobulin heavy chain gene has been the target for tumor-specific PCR assays for the detection and follow-up of B-cell malignancies. Previously, these assays have relied on gel-based end point data collection methods (i.e., band densitometry) and, thus, have provided at best a semiquantitative assessment of tumor levels. We show the development of a novel, real-time TaqMan PCR assay to quantitate residual multiple myeloma cells in clinical samples after high-dose chemotherapy and autologous stem cell transplantation. We provide evidence that real-time PCR is reproducible, sensitive, and quantitative. In a 40-replicate PCR experiment targeting the beta-actin gene, the coefficient of variation for threshold cycle data was 1.6%, whereas it increased to 13.6% and 31%, respectively, for end point fluorescence and gel densitometry. Moreover, in an experiment directly comparing standard curves obtained from band densitometry and threshold cycle data, the standard curve constructed from threshold cycle data had a multiple R2 value of 1.00 and demonstrated a dynamic range >4 logs, compared with the 2-log linear range of gel densitometry. Finally, we show that when a complementarity determining region III-specific PCR primer is used in conjunction with a consensus primer for the immunoglobulin heavy chain joining gene, plasmid DNA can be used as a readily available and effective substitute for clonal plasma-cell genomic DNA when preparing standards. By applying real-time PCR to the analysis of clinical samples, we are able to quantitate levels of tumor involvement with unparalleled reproducibility and statistical confidence. Real-time PCR technology may well provide the accuracy and reliability necessary for minimal residual disease detection to have real prognostic significance.     

Characterization of rust phases formed on low carbon steel exposed to natural marine environment of Chennai harbour – South India

The corrosion behaviour of low carbon steel exposed to marine atmospheric, splash and immersion zones has been systematically studied by exposing steel specimens for a period of 12 months at the boat basin corrosion station of Chennai harbour, Chennai, Tamil Nadu, South India. The literature on similar work has been thoroughly reviewed which led to the initiation of this study for the first time at this harbour. The corrosion product (rust) on the specimens at 1, 2, 3 and 12 months was obtained and characterized by Fourier transform infrared spectroscopy (FT‐IR) and X‐ray diffraction (XRD) analysis. Acaganeite was the rust phase identified in the splash zone as revealed by the FT‐IR and XRD analysis. The other dominant phases were lepidocrocite, goethite and ferroxyhite. Small amounts of magnetite were also found to be present. The transformation of phases was observed in this investigation and discussed. A remarkable difference in the FT‐IR and XRD patterns of the corrosion products at the splash and immersion zones were noticed and the corresponding phases formed were reported in this paper. The rate of corrosion in all the three zones was compared.     

Digital simulation of the dynamic travel characteristics of an electric liftDigitale simulation dynamischer charakteristika elektrischer aufzüge

A representative vibration model for an electric lift is developed and analysed. Apart from the equations of motion for the lift components, equations are also derived for the rate of change of the rope tensions assuming that the rope elasticity is inversely proportional to rope length. Since an analytical solution is not possible, a Continuous System Modeling Program (CSMP) is written to simulate the lift operation in the computer. Results of a trial computer run for a typical lift which is accelerated down and suddenly stopped by application of the emergency safety clamp are given.     

Antigen activation rescues recent thymic emigrants from programmed cell death in the BB rat

One of the diabetes susceptibility genes of the BB rat is a mutation at the lyp locus that decreases the thymic output of T cells and the life span of most recent thymic emigrants (RTE). Consequently, there is a 10-fold reduction in the number of CD4+ and CD8+ T cells in secondary lymphoid organs. Results presented in this work demonstrate that the BB rat lyp mutation is associated with an accelerated apoptotic death in vitro of mature CD4+ 8- and CD4- 8+ thymocytes and peripheral T cells. The stability of the pool of recirculating T cells (PRL) of BB rats over time results from a > 10-fold increase in the mitotic activity of T cells as assessed in vivo by bromodeoxyuridine incorporation. This increased mitotic activity is not observed when BB T cells develop in the context of a normal sized PRL. MHC haploidentical WF and BB rats differ at minor histocompatibility loci. Intravenous injection of (WF x BB)F1 T cells into euthymic BB rats led to the rejection of donor T cells within 3 wk by unprimed recipients and within 1 wk by primed recipients. This secondary immune response was unaffected by postpriming thymectomy. F1 T cells were not rejected, but rather expanded after their injection into thymectomized BB rats that had been primed as early as 48 h after thymectomy. These results strongly suggest that the BB rat PRL is devoid of long-lived naive T cells and that rescue of recent thymic emigrants from programmed cell death is initiated by Ags, exclusively.     

Improvements in horizontality performance as a function of type of training

90 undergraduates with low spatial perceptual ability were assigned to one of three groups of control, learner-guided instructions, and tutor-guided instructions. The groups differed in amount and type of spatial training administered in a laboratory setting. Participants completed horizontality and vertically spatial perceptual tasks immediately after pretesting and again one month later. Both groups given training showed more accurate performance at posttest than at pretest. In addition, the learner-guided instruction group outperformed the tutor-guided instruction group and control group at posttest and on novel but related tasks. Gender differences in posttest performance favoring males (n = 35) were obtained in the tutor-guided performance group and control group but not in the learner-guided instruction group. The number of hints the latter needed during training was predictive of posttest performance. Implications for assessment and remediation of undergraduates' spatial perceptual abilities are discussed.