A robust fault detection and isolation filter design under sensitivity constraint: An LMI approach

This paper deals with the design of a residual generator (RG) for linear time‐invariant systems subject to simultaneous different faults, disturbances and measurement noises. The objective is to design an RG filter that maximizes the transmission from a potential fault to a related residual, while minimizing the ones from nuisances (disturbances, measurement noises and other faults). The isolation of each fault is carried out by designing a bank of RG filters, each one insensitive, as much as possible, to nuisances and capable of detecting the occurrence of its related fault. The design is carried out through ℋ︁_∞ filtering techniques under an eigenstructure assignment constraint. Under mild assumptions, the RG filter can be obtained by solving a λ‐parameterized linear matrix inequality optimization problem. A comparison with existing fault detection and isolation (FDI) methods is considered in order to exhibit the relative merits of the proposed method. Copyright © 2008 John Wiley & Sons, Ltd.     

A General Approach to L(h, k)-Label Interconnection Networks

Given two non-negative integers h and k,an L(h,k)-labeling of a graph G=(V,E) is a function from the set V to a set of colors,such that adjacent nodes take colors at distance at least h,and nodes at distance 2 take colors at distance at least k.The aim of the L(h,k)-labeling problem is to minimize the greatest used color.Since the decisional version of this problem is NP-complete,it is important to investigate particular classes of graphs for which the problem can be efficiently solved.It is well known that the most common interconnection topologies,such as Butterfly-like,Bene(?),CCC,Trivalent Cayley networks,are all characterized by a similar structure:they have nodes organized as a matrix and connections are divided into layers.So we naturally introduce a new class of graphs,called (1×n)-multistage graphs,containing the most common interconnection topologies,on which we study the L(h,k)-labeling.A general algorithm for L(h,k)-labeling these graphs is presented,and from this method an efficient L(2,1)-labeling for Butterfly and CCC networks is derived.Finally we describe a possible generalization of our approach.     

Recommender Systems Research: A Connection-Centric Survey

Recommender systems attempt to reduce information overload and retain customers by selecting a subset of items from a universal set based on user preferences. While research in recommender systems grew out of information retrieval and filtering, the topic has steadily advanced into a legitimate and challenging research area of its own. Recommender systems have traditionally been studied from a content-based filtering vs. collaborative design perspective. Recommendations, however, are not delivered within a vacuum, but rather cast within an informal community of users and social context. Therefore, ultimately all recommender systems make connections among people and thus should be surveyed from such a perspective. This viewpoint is under-emphasized in the recommender systems literature. We therefore take a connection-oriented perspective toward recommender systems research. We posit that recommendation has an inherently social element and is ultimately intended to connect people either directly as a result of explicit user modeling or indirectly through the discovery of relationships implicit in extant data. Thus, recommender systems are characterized by how they model users to bring people together: explicitly or implicitly. Finally, user modeling and the connection-centric viewpoint raise broadening and social issues—such as evaluation, targeting, and privacy and trust—which we also briefly address.     

Synthesis and Biological Characterization of Amidopropenyl Hydroxamates as HDAC Inhibitors

A series of amidopropenyl hydroxamic acid derivatives were prepared as novel inhibitors of human histone deacetylases (HDACs). Several compounds showed potency at <100 nM in the HDAC inhibition assays, sub‐micromolar IC₅₀ values in tests against three tumor cell lines, and remarkable stability in human and mouse microsomes was observed. Three representative compounds were selected for further characterization and submitted to a selectivity profile against a series of class I and class II HDACs as well as to preliminary in vivo pharmacokinetic (PK) experiments. Despite their high microsomal stability, the compounds showed medium‐to‐high clearance rates in in vivo PK studies as well as in rat and human hepatocytes, indicating that a major metabolic pathway is catalyzed by non‐microsomal enzymes.     

Gentamicin Arrests Cancer Cell Growth: The Intriguing Involvement of Nuclear Sphingomyelin Metabolism

The use of gentamicin for the treatment of bacterial infection has always been an interesting and highly speculated issue for the scientific community. Conversely, its effect on cancer cells has been very little investigated. We studied the effect of high doses of gentamicin on non-Hodgkin’s T-cell human lymphoblastic lymphoma (SUP-T1). We showed that gentamicin delayed cell growth and induced cell death in lymphoma cells with a rather mild effect on lymphocytes. In SUP-T1 cells, GAPDH, B2M, CDKN1A and CDKN1B were down-expressed in comparison with lymphocytes. Gentamicin treatment in SUP-T1 cells restored the expression of GAPDH, B2M and CDKN1A to values similar to those of lymphocytes and caused overexpression of CDKN1B. The drug acted via sphingomyelin metabolism; in whole cells, sphingomyelinase activity was stimulated, whereas in purified nuclei, sphingomyelinase activity was inhibited and that of sphingomyelin-synthase was stimulated, with a consequent high level of nuclear sphingomyelin content. We suggest that the increase of nuclear sphingomyelin might enrich the nucleus of lipid microdomains that act as a platform for active chromatin and, thus, might be responsible for gene expression. It is possible that in lymphoblastic lymphoma, high doses of gentamicin induce a beneficial therapeutic outcome.     

Potential of Nutraceutical Supplementation in the Modulation of White and Brown Fat Tissues in Obesity-Associated Disorders: Role of Inflammatory Signalling

The high incidence of obesity is associated with an increasing risk of several chronic diseases such as cardiovascular disease, type 2 diabetes and non-alcoholic fatty liver disease (NAFLD). Sustained obesity is characterized by a chronic and unsolved inflammation of adipose tissue, which leads to a greater expression of proinflammatory adipokines, excessive lipid storage and adipogenesis. The purpose of this review is to clarify how inflammatory mediators act during adipose tissue dysfunction in the development of insulin resistance and all obesity-associated diseases. In particular, we focused our attention on the role of inflammatory signaling in brown adipose tissue (BAT) thermogenic activity and the browning of white adipose tissue (WAT), which represent a relevant component of adipose alterations during obesity. Furthermore, we reported the most recent evidence in the literature on nutraceutical supplementation in the management of the adipose inflammatory state, and in particular on their potential effect on common inflammatory mediators and pathways, responsible for WAT and BAT dysfunction. Although further research is needed to demonstrate that targeting pro-inflammatory mediators improves adipose tissue dysfunction and activates thermogenesis in BAT and WAT browning during obesity, polyphenols supplementation could represent an innovative therapeutic strategy to prevent progression of obesity and obesity-related metabolic diseases.     

Parametrical analysis of the railways dynamic response at high speed moving loads

Railway Engineering Science - The paper introduces some findings about a sensitivity analysis conducted on every geometrical and mechanical parameters which characterize the use of a railway...     

Severe damage of alumina-on-alumina hip implants: Wear assessments at a microscopic level

Six retrieved alumina hip implants were investigated for severe damage after a mean follow-up of 13 years (range: 8–21 years) using a multivariable approach: a coordinate measuring machine was used to quantify volumetric wear, the surface was characterized by scanning electron microscopy, and fluorescence and Raman spectroscopy were used to investigate the phenomenon on a micrometer crystal scale.All the femoral heads exhibited significant loss of roundness with heavy deviation from the original sphericity, showing an average volumetric wear of 602 ± 3 mm³. A smooth surface with occasional pits and agglomerates was observed; formation of craters and loss of surface integrity was revealed.The femoral heads characterized by the highest volumetric wear underwent the most significant stress on a micrometer crystal scale (i.e. the most pronounced changes in the width of the fluorescence and Raman bands).     

Sediment record and atmospheric deposition of brominated flame retardants and organochlorine compounds in Lake Thun, Switzerland: lessons from the past and evaluation of the present

Chronology of brominated fame retardants (BFRs), a class of currentlywidely used chemicals, was compared to the respective historical profiles of legacy organochlorine compounds in three dated sediment cores from a prealpine lake (Lake Thun, Switzerland). Concentrations of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) started to increase in the 1980s-1990s. In the more recent sediment layers, PBDEs still had steady or increasing concentrations, whereas for HBCDs one sediment core revealed a decreasing trend. In contrast to the contemporary BFRs, concentrations of legacy organochlorines, such as polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), and dichlorodiphenyl trichloroethane (DDT), peaked in deeper sediment layers deposited some decades ago. Measurements of atmospheric deposition and evaluation of wastewater discharges pointtoward deposition on the lake surface as a relevant input pathway and wastewater as a minor source of POPs in Lake Thun. The effect of the environmental awareness and the regulations taken in the 1970s to reduce environmental pollution of organochlorines is well reflected in the analyzed sediment cores. The sediment burden closely follows estimated time trends of consumption and emission of PCBs and DDT. The current residues in sediment of BFRs are still lower than the historical peak levels of organochlorines. However, current atmospheric deposition of BFRs is similar to deposition of PCBs. Considering the high amount of BFRs presently stocked in the anthroposphere in flame proofed materials, further measures to reduce emissions during BFRs life cycle are recommended to prevent high environmental pollution as it occurred for the organochlorine compounds.