Routing restorable bandwidth guaranteed connections using maximum 2-route flows

Routing with service restorability is of much importance in Multi-Protocol Label Switched (MPLS) networks, and is a necessity in optical networks. For restoration, each connection has an active path and a link-disjoint backup path. The backup path enables service restoration upon active path failure. For bandwidth efficiency, backups may be shared. This requires that at least the aggregate backup bandwidth used on each link be distributed to nodes performing route computations. If this information is not available, sharing is not possible. Also, one scheme in use for restorability in optical networks is for the sender to transmit simultaneously on the two disjoint paths and for the receiver to choose data from the path with stronger signal. This has the advantage of fast receiver-initiated recovery upon failure but it does not allow backup sharing. In this paper, we consider the problem of efficient dynamic routing of restorable connections when backup sharing is not allowed. Our objective is to be able to route as many connections as possible for one-at-a-time arrivals and no knowledge of future arrivals. Since sharing cannot be used for achieving efficiency, the goal is to achieve efficiency by improved path selection. We show that by using the minimum-interference ideas used for nonrestorable routing, we can develop efficient algorithms that outperform previously proposed algorithms for restorable routing such as routing with the min-hop like objective of finding two disjoint paths with minimum total hop-count. We present two new and efficient algorithms for restorable routing without sharing, and one of them requires only shortest path computations. We demonstrate that both algorithms perform very well in comparison to previously proposed algorithms.     

Study of impact properties and morphology of 4,4′‐diaminodiphenyl methane cured epoxy resin toughened with acrylate‐based liquid rubbers

Randomized carboxyl poly(2‐ethylhexyl acrylate) (A‐1) and randomized epoxy poly(2‐ethylhexyl acrylate) (B‐1) rubbers were synthesized in the form of liquid rubber by a solution polymerization technique. The liquid rubbers A‐1 and B‐1 were characterized by ¹H NMR and IR spectroscopic analysis, non‐aqueous titration, viscosity measurements and gel permeation chromatography. The liquid rubbers A‐1 (M?_n = 3900 g mol^?1), B‐1 (M?_n = 4100 g mol^?1) and a (1:1) mixture of A‐1 and B‐1 were pre‐reacted with epoxy resin separately and the modified epoxy networks were made by curing with high temperature curing agent. The modified epoxy networks were evaluated by unnotched Izod impact testing. The morphology and toughening behaviour were analysed by scanning electron microscopy. Optimum properties were obtained with the mixture of A‐1 and B‐1. Copyright © 2003 Society of Chemical Industry     

Capital budgeting in information systems development

The results of an empirical study on the current usage of capital budgeting techniques for evaluating, terminating, and auditing information system investments are presented. Findings based on 134 senior MIS personnel and management executives indicate that capital budgeting has little impact on IS investment, and simple techniques such as payback period and cost benefit ratio are preferred over more sophisticated discount cash-flow models. Problems with cost and return estimations are shown to be the key factors that limit their use. It is suggested that the decision authority varies according to the project value and the type of decisions being undertaken.     

The distribution of tachykinin binding sites in the brain of an electric fish (Apteronotus leptorhynchus)

We mapped the distribution of tachykinin binding sites utilizing quantitative autoradiography of iodinated substance P and eledoisin as prototypic ligands for neurokinin-1 (NK1) and neurokinin-3 (NK3) receptors, respectively. The two ligands produced highly heterogenous and quantitatively different patterns of specific binding, suggesting that they revealed different tachykinin receptor subtypes. Although [125I]substance P and [125I]eledoisin binding were correlated in most brain regions, the binding of substance P was usually denser. [125I]substance P binding and substance P-like immunoreactivity were reasonably correlated in most brain areas, although discrepancies were found in some nuclei. Dense [125I]substance P binding was found in most areas of the subpallium and in parts of the pallium related to the olfactory system, as well as in the glomerular layer of the olfactory bulb. Moderate to dense binding of both ligands was observed in preoptic area, hypothalamus, habenula, parts of the thalamus and preglomerular complex. Especially noteworthy was the presence of [125I] substance P binding in the diencephalic prepacemaker nucleus, a region involved in the control of electroncommuncatory behavior. Substance P-like immunoreactivity is sexually dimorphic in certain diencephalic nuclei, including the prepacemaker nucleus (Weld and Maler, 1992); no obvious difference was seen between [125I]substance P or [125I]eledoisin binding in the brains of male versus female fish. In the mesencephalon striking laminar patterns of binding were seen in the torus semicircularis dorsalis and the optic tectum. Dense binding was also noted in the raphé nuclei, the locus ceruleus and the sensory nucleus of the vagus. Although binding of substance P in the electrosensory lateral line lobe and nucleus preeminentialis was light, it was distributed in a discrete fashion, suggesting a role of substance P in electrosensory processing.     

Histo-pathological evaluation of response to 6 and 12 months of interferon alpha therapy

BACKGROUND AND AIMS: Interferon-alfa (IFN-alfa) has recently been introduced for chronic C hepatitis treatment; however, the response rate is merely 25-50%. The aims of this follow-up study were to compare the efficacy of 6 and 12-month IFN-alfa treatment via liver biopsy scores and to evaluate the correlation with the biochemical response. PATIENTS AND METHODS: 20 chronic C hepatitis patients were studied. 10 patients received IFN-alfa therapy for 6 months, and 10 for 12 months (3 million units three times a week). Liver biopsy material was taken before and after therapy. RESULTS: There was a significant serum alanine aminotransferase (ALT) level improvement in both groups, but a significant histological improvement in necroinflammatory activity (grade) occurred only in the 12-month group. The Chevallier stage scores demonstrated a significant progression in both groups. CONCLUSIONS: 12-month IFN-alfa treatment affords a better response in the liver histology grade and serum ALT level, but not the stage; a normal ALT does not guarantee hepatitis inactivity. Liver biopsies appear indispensable for monitoring the fibrotic changes in chronic C hepatitis.     

Evidence for direct cellular protective effect of PL-10 substances (synthesized parts of body protection compound, BPC) and their specificity to gastric mucosal cells

The direct gastric mucosal cellular effect of four PL-10 substances (a synthesized part of human body protection compound, BPC containing 14 or 15 amino acids) was studied on freshly isolated rat gastric mucosal cells and on a mouse myeloma cell line (Sp2/0-Ag14) in an ethanol-induced cell injury model. The examined substances were not toxic for the cells. Two of them proved to be significantly protective against the direct cellular damaging effect of ethanol (PL 10.1.15AK-3 in 5 microg/ml dose and PL 10.1.AK14-2 dose-dependently, ED50=50 ng/ml) on gastric mucosal cells. This cytoprotective effect was failured on mouse myeloma cells. Based on these results a part of the in vivo protection induced by BPC seems to be a direct cellular protective effect to gastric mucosal cells.     

Fungal biotechnology in food and feed processing

Fungi are of excellent value nutritionally, and of great importance to vegetarians. Edible mushrooms are excellent sources of protein, have low-fat content and are free of cholesterol. They are easily cultivable and are consumed either in fresh or processed form. Yeasts and filamentous fungi secrete a plethora of important enzymes in the growth medium together with other secondary metabolites. Most of these are hydrolytic in nature being employed in different food processing industries as well as in refinement of fodder quality. Edible filamentous fungi producing these enzymes present an added advantage for their use in food and feed. In this article these aspects will be discussed along with the results from edible mushroom Termitomyces clypeatus, producing a wide variety of hydrolytic enzymes and products, from our laboratory. It is likely that the functional understanding of different enzyme classes will provide new applications within the food industry in the future.     

Determination of Si-metal work function differences by MOS capacitance technique

Very accurate and reliable values of the difference between silicon electron affinity, χ_Si, and the metal work function, Φ_M, have been obtained for seven different metals by the MOS flat-band capacitance technique. Different MOS structures with the same interface charge density and the same metal but varying oxide thickness were manufactured on the same wafer by employing a small temperature gradient during steam oxidation in an r.f. induction heated vertical furnace. The flat-band voltage, V_FB, vs oxide thickness, t_ox, graphs obtained are very good straight lines. Use of both p- and n-Si in case of the metals Au and Cr produced two values of the silicon bandgap E_G. The value of E_G obtained in case of Au differed from the established value of 1·11 eV at room temperature by ?0·04 eV only, and by 0·07 eV in case of Cr. This gives an indication of the experimental accuracy of the Φ_HS = Φ_M ? χ_Si values. $\text{Φ}{}_{\mathrm{MS}}{}^1$ obtained by this technique is 0·73 eV for Ag. ?0·11 eV for Al, 0·82 eV for Au, ?0·06 eV for Cr, 0·63 eV for Cu, ?1·05 eV for Mg, and ?0·82 eV for Sn. The total inaccuracy is limited to $\text{?0.06}\text{+0.03}\text{eV}$.     

Interface charge characteristics of MOS structures with different metals on steam grown oxides

Characteristics of interface states and interface charges of MOS structures with steam grown oxides and different metal contacts were investigated. Steam oxidation was carried out in an RF furnace under the influence of a d.c. bias. Interface state density N_is as well as the interface charge density at flat band Q_ic^FB were found to be independent of the oxide thickness between 150 and 5000 Å, independent of steam oxidation temperature between 900 and 1150°C, but dependent on the contact metal. Metals with smaller work functions were found to have lower N_is and Q_ic^FB. Post oxidation annealing in nitrogen at high temperatures reduced both N_is and Q_ic^FB. The silicon type had no influence on the interface state density, but p-type silicon had a higher interface charge density at flat band than n-type silicon. Post metallization annealing in nitrogen at low temperatures completely removed a slight slow trapping instability observed before the heat treatment but increased Q_ic^FB. MOS structures with oxides grown without bias had much higher interface state density as well as Q_ic^FB, however a short postmetallization annealing was very effective in greatly reducing these. The above experimental facts suggest that the interface charges result from acceptor type interface states and fixed positive charges at or near the interface. Protons or SiH groups are very likely to be the source of the fixed positive charges while likely source for the acceptor states are the OH radicals.     

NMR evidence against covalent attachment of an aldehyde ''transition-state'' analogue to alpha-chymotrypsin

The growth responses of an acetate-utilizing isolate of Butyrivibrio fibrisolvens to CO2, acetate and pyruvate were determined using a chemically-defined medium. Carbon dioxide was essential for growth and both acetate and pyruvate increased growth. 14C from [I-14C]pyruvate appeared predominantly in formate and lactate. These results, together with those obtained with enzyme preparations, indicated pyruvate synthase, pyruvate-CO2 exchange and pyruvate formate lyase to be active.