Design of capacitated survivable networks with a single Facility

In this paper we focus on the single-facility capacitated survivable network design problem. We optimize simultaneously the network topology and the link dimensioning in order to route all traffic commodities according to survivability requirements. The latter are actually expressed in terms of the spare capacity required to address link failures in the context of different rerouting strategies. We present a mixed-integer linear programming model solved by combining several approaches. To tackle the high dimensionality and to separate the continuous and integer variables, we use Benders' decomposition and a cutting-plane approach. Going beyond the proposed method itself, we examine and compare two well-known restoration techniques: local and end-to-end reroutings. Numerous computational results for realistic network instances provide a comparison of these rerouting mechanisms in terms of installed capacities, network density as well as overall costs and CPU time.     

Assessment of deep vein thrombosis prophylaxis in surgical patients: a study conducted at Nancy University Hospital, France

OBJECTIVE: This retrospective evaluation aimed to assess the adequacy of prophylaxis against thromboembolism prescribed to surgical patients at the authors' institution, and to compare it with generally accepted published guidelines. Aspects considered were indications for prophylaxis, regimens used and monitoring. METHODS: Eleven units (nine surgical and two surgical intensive care) took part in the survey on a voluntary basis. The clinical audit system used involved developing a set of criteria based on existing guidelines, comparing observed practice with those recommendations, analysing the factors underlying any deviation and developing corrective measures. RESULTS: When the medical records of 117 patients hospitalized in October 1995 were examined, prophylaxis against deep vein thrombosis was documented in 86 (low molecular weight heparin in 85, dextran in one). No associated physical preventative measures were recorded. Indications and dosage were appropriately handled in 90.7% and 75.2% of patients, respectively. Ninety-five cases were outside the reference criteria: 74 for excluded surgical indications, 13 which involved laparoscopy, and eight in which spinal or epidural anaesthesia was administered. Platelet count was performed in 73.8% of cases before prophylactic treatment, and in 23.10% during its course. Anti-Xa activity was measured in 0.4% of cases. Analysis of causes showed that guidelines were not complied with either because of lack of organization, or because of disagreement with them. DISCUSSION: In this study, indications for prophylaxis were well established and heparin dosages used were not fundamentally flawed. The weak point in practice was a failure to carry out platelet counts, particularly during the course of treatment. Appropriate corrective action consists of disseminating guidelines and relevant information, and using a preoperative checklist to assess thromboembolic risk. CONCLUSION: Physicians agree that opportunities to improve preventative practices exist, and that the quality improvement programme should be pursued.     

Characterization of background concentrations in upper Manhattan, New York apartments for select contaminants identified in World Trade Center dust

Residential indoor concentration of asbestos, lead, synthetic vitreous fiber (SVF), crystalline silica, calcite, gypsum, dioxin, and polycyclic aromatic hydrocarbons (PAHs) were measured in 25 residences and 9 building-interior common areas in upper Manhattan, NY. This was done to characterize the background levels of contaminants, identified in dust related to the collapse of the World Trade Center towers, at locations that were minimally impacted by the dust fallout. The study was initiated due to the paucity of background concentrations on building-related materials and combustion byproducts in urban residential dwellings. Asbestos, lead, SVF, crystalline silica, and dioxin were detected at very low concentration at some locations, and many samples tested below their respective analysis detection limits. Almost all of the environmental samples for PAHs, calcite, gypsum, and certain other building materials tested below their respective analysis detection limits. A comparative analysis to the limited literature data showed general agreement with the values found in this study. This study provides insight into the levels of these contaminants in lower Manhattan residential buildings prior to the attack, and these data will serve to enhance the available database for characterizing indoor environments for these contaminants.     

Synthesis and Evaluation of N‐Phenylpyrrolamides as DNA Gyrase B Inhibitors

ATP‐competitive inhibitors of DNA gyrase and topoisomerase IV are among the most interesting classes of antibacterial drugs that are unrepresented in the antibacterial pipeline. We developed 32 new N‐phenylpyrrolamides and evaluated them against DNA gyrase and topoisomerase IV from E. coli and Staphylococcus aureus. Antibacterial activities were studied against Gram‐positive and Gram‐negative bacterial strains. The most potent compound displayed an IC₅₀ of 47 nm against E. coli DNA gyrase, and a minimum inhibitory concentration (MIC) of 12.5 μm against the Gram‐positive Enterococcus faecalis. Some compounds displayed good antibacterial activities against an efflux‐pump‐deficient E. coli strain (MIC=6.25 μm ) and against wild‐type E. coli in the presence of efflux pump inhibitor PAβN (MIC=3.13 μm ). Here we describe new findings regarding the structure–activity relationships of N‐phenylpyrrolamide DNA gyrase B inhibitors and investigate the factors that are important for the antibacterial activity of this class of compounds.     

Prevention of venous thromboembolism. Survey of in-hospital medical practice

Prostate-specific antigen (PSA) is the most important tumor marker for early detection, staging, and monitoring of men with prostatic cancer today. However, its sensitivity and specificity are not sufficient to use it as a single tool for screening for men with clinically localized prostate cancer. Recently, assays have become available that selectively detect several of the various molecular forms of PSA, especially the unbound or free PSA. Several studies have shown the clinical usefulness of percent free PSA (free PSA/total PSA) for the early detection of men with clinically localized prostate cancer. However, the use of percent free PSA for staging of prostate cancer remains controversial. Based on the case scenario presented, the value of total PSA and percent free PSA for the staging of men with clinically localized prostate cancer is reviewed.     

Effects of sodium bicarbonate on striated muscle metabolism and intracellular pH during endotoxic shock

The effects of HCO3Na load on acid-base balance and muscle intracellular bioenergetics have been investigated using 31P-magnetic resonance spectroscopy in an experimental model of endotoxinic shock. Anesthetized, mechanically ventilated, and paralyzed rats (n = 16) were given an intravenous bolus of Escherichia coli lipopolysaccharide (15 mg/kg). When shock was established they were randomly assigned to receive either HCO3Na intravenously (2 mmol/kg in 2 min) or an equimolar saline injection. Lipopolysaccharide induced a significant decrease in the levels of mean arterial pressure (58 +/- 6 vs. 120 +/- 8 mmHg), arterial pH (7.20 +/- .03 vs. 7.35 +/- .01), intracellular pH (6.86 +/- .04 vs. 7.08 +/- .01), a marked hyperlactatemia (7 +/- 3 vs. 1.2 +/- .2 mmol/L) and a drop in the phosphocreatine-inorganic phosphate ratio. In the bicarbonate-loaded rats, mean arterial pressure further decreased whereas it remained unchanged in the saline group. Bicarbonate increased arterial pH and PaCO2 transiently. In the saline group, arterial pH decreased and PaCO2 remained stable. In both groups, intracellular pH and high energy phosphates had a similar evolution. In this model of septic shock, partial correction of arterial pH using HCO3Na did not reduce the metabolic cellular injury in skeletal muscle. Based on these results, HCO3Na may be of limited therapeutic value in severe septic metabolic acidosis.     

Assigning spare capacities in mesh survivable networks

This paper analyses one key issue of designing reliable networks: assignment of spare capacities in transmission networks. The spare capacities are optimized to facilitate the restoration of single failures. This problem can be formulated as an integer linear program and approximated by its continuous relaxation. This model is based on arc-path formulation especially efficient for dealing with end-to-end rerouting and providing appreciable economies in comparison with local rerouting. The main idea of our method resides in a linear programming decomposition, which permits us to solve problems for medium and large networks. Our approach could be applicable to both STM and ATM-based networks. This method was tested successfully on medium and large DCS-meshed networks and some numerical examples are given to illustrate its performances in terms of CPU time and ratio of optimality. This revised version was published online in June 2006 with corrections to the Cover Date.     

Fate of an uncompleted posthypnotic suggestion.

Used 50 male undergraduates to test the possibility that Ss who resist completing a posthypnotic suggestion may, at a later time, in a situation which is not seen as related to the hypnotic session, carry out the earlier suggested behavior. Such Ss were found to fall within the medium range of hypnotizability as evaluated over 3 sessions by the Stanford Scales of Hypnotizability. Ss with low hypnotizability failed to complete the posthypnotic suggestion and did not demonstrate a subsequent tendency toward the earlier suggested behavior. Ss with high hypnotizability tended to complete the posthypnotic suggestion and, in about 1/2 of the cases, demonstrated a subsequent tendency toward the earlier suggested behavior. Within the medium range of hypnotizability were found those Ss who did not complete the posthypnotic suggestion, but subsequently, in the extrahypnotic setting, behaved in accordance with the earlier suggestion. Hypnotizability as an overall characteristic was clearly related to the demonstration of this action tendency. (19 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)