Support vector machines for detecting age-related changes in running kinematics

Age-related changes in running kinematics have been reported in the literature using classical inferential statistics. However, this approach has been hampered by the increased number of biomechanical gait variables reported and subsequently the lack of differences presented in these studies. Data mining techniques have been applied in recent biomedical studies to solve this problem using a more general approach. In the present work, we re-analyzed lower extremity running kinematic data of 17 young and 17 elderly male runners using the Support Vector Machine (SVM) classification approach. In total, 31 kinematic variables were extracted to train the classification algorithm and test the generalized performance. The results revealed different accuracy rates across three different kernel methods adopted in the classifier, with the linear kernel performing the best. A subsequent forward feature selection algorithm demonstrated that with only six features, the linear kernel SVM achieved 100% classification performance rate, showing that these features provided powerful combined information to distinguish age groups. The results of the present work demonstrate potential in applying this approach to improve knowledge about the age-related differences in running gait biomechanics and encourages the use of the SVM in other clinical contexts. (C) 2010 Elsevier Ltd. All rights reserved.

Sensor arrays to detect humic substances and Cu(II) in waters

The interaction between poly(o-ethoxyaniline) (POEA) adsorbed onto solid substrates and humic substances (HS) and Cu(2+) ions has been investigated using UV-vis spectroscopy and atomic force microscopy (AFM). Both HS and Cu(2+) are able to dope POEA and change film morphology. This interaction was exploited in a sensor array made with nanostructured films of POEA, sulfonated lignin and HS, which could detect small concentrations of HS and Cu(2+) in water. (C) 2009 Elsevier B.V. All rights reserved.

Evaluation of three brands of drug interaction software for use in intensive care units

Objective To evaluate drug interaction software programs and determine their accuracy in identifying drug-drug interactions that may occur in intensive care units. Setting The study was developed in Brazil. Method Drug interaction software programs were identified through a bibliographic search in PUBMED and in LILACS (database related to the health sciences published in Latin American and Caribbean countries). The programs` sensitivity, specificity, and positive and negative predictive values were determined to assess their accuracy in detecting drug-drug interactions. The accuracy of the software programs identified was determined using 100 clinically important interactions and 100 clinically unimportant ones. Stockley`s Drug Interactions 8th edition was employed as the gold standard in the identification of drug-drug interaction. Main outcome Sensitivity, specificity, positive and negative predictive values. Results The programs studied were: Drug Interaction Checker (DIC), Drug-Reax (DR), and Lexi-Interact (LI). DR displayed the highest sensitivity (0.88) and DIC showed the lowest (0.69). A close similarity was observed among the programs regarding specificity (0.88-0.92) and positive predictive values (0.88-0.89). The DIC had the lowest negative predictive value (0.75) and DR the highest (0.91). Conclusion The DR and LI programs displayed appropriate sensitivity and specificity for identifying drug-drug interactions of interest in intensive care units. Drug interaction software programs help pharmacists and health care teams in the prevention and recognition of drug-drug interactions and optimize safety and quality of care delivered in intensive care units.

Normal Versus Pathological Voice Signals Using Wavelet Analysis and Least Squares Support-Vector Machines

State of Sao Paulo Research Foundation (FAPESP)

Support Tool to the Validation Process of Functional Requirements

The activity of validating identified requirements for an information system helps to improve the quality of a requirements specification document and, consequently, the success of a project. Although various different support tools to requirements engineering exist in the market, there is still a lack of automated support for validation activity. In this context, the purpose of this paper is to make up for that deficiency, with the use of an automated tool, to provide the resources for the execution of an adequate validation activity. The contribution of this study is to enable an agile and effective follow-up of the scope established for the requirements, so as to lead the development to a solution which would satisfy the real necessities of the users, as well as to supply project managers with relevant information about the maturity of the analysts involved in requirements specification.

Positioning of Deadeners for Vibration Reduction in Vehicle Roof Using Embedded Sensitivity

The noise, vibration and harshness (NVH) performance of passenger vehicles strongly depends on the fluid-structure interaction between the air in the vehicle cavity and the sheet metal structure of the vehicle. Most of the noise and vibration problems related to this interaction come from resonance peaks of the sheet metal, which are excited by external forces (road, engine, and wind). A reduction in these resonance peaks can be achieved by applying bitumen damping layers, also called deadeners, in the sheet metal. The problem is where these deadeners shall be fixed, which is usually done in a trial-and-error basis. In this work, one proposes the use of embedded sensitivity to locate the deadeners in the sheet metal of the vehicle, more specifically in the vehicle roof. Experimental frequency response functions (FRFs) of the roof are obtained and the data are processed by adopting the embedded sensitivity method, thus obtaining the sensitivity of the resonance peaks on the local increase in damping due to the deadeners. As a result, by examining the sensitivity functions, one can find the optimum location of the deadeners that maximize their effect in reducing the resonance peaks of interest. After locating the deadeners in the optimum positions, it was possible to verify a strong reduction in resonance peaks of the vehicle roof, thus showing the efficiency of the procedure. The main advantage of this procedure is that it only requires FRF measurements of the vehicle in its original state not needing any previous modification of the vehicle structure to find the sensitivity functions. [DOI: 10.1115/1.4000769]

Process oriented framework to support PLM implementation

Product lifecycle management (PLM) innovates as it defines both the product as a central element to aggregate enterprise information and the lifecycle as a new time dimension for information integration and analysis. Because of its potential benefits to shorten innovation lead-times and to reduce costs, PLM has attracted a lot of attention at industry and at research. However, the current PLM implementation stage at most organisations still does not apply the lifecycle management concepts thoroughly. In order to close the existing realisation gap, this article presents a process oriented framework to support effective PLM implementation. The framework central point consists of a set of lifecycle oriented business process reference models which links the necessary fundamental concepts, enterprise knowledge and software solutions to effectively deploy PLM. (c) 2007 Elsevier B.V. All rights reserved.

A coupled boundary element/differential equation method formulation for plate-beam interaction analysis

In this work, a new boundary element formulation for the analysis of plate-beam interaction is presented. This formulation uses a three nodal value boundary elements and each beam element is replaced by its actions on the plate, i.e., a distributed load and end of element forces. From the solution of the differential equation of a beam with linearly distributed load the plate-beam interaction tractions can be written as a function of the nodal values of the beam. With this transformation a final system of equation in the nodal values of displacements of plate boundary and beam nodes is obtained and from it, all unknowns of the plate-beam system are obtained. Many examples are analyzed and the results show an excellent agreement with those from the analytical solution and other numerical methods. (C) 2009 Elsevier Ltd. All rights reserved.

Performance evaluation and phylogenetic characterization of anaerobic fluidized bed reactors using ground tire and pet as support materials for biohydrogen production

This study evaluated two different support materials (ground tire and polyethylene terephthalate [PET]) for biohydrogen production in an anaerobic fluidized bed reactor (AFBR) treating synthetic wastewater containing glucose (4000 mg L(-1)). The AFBR, which contained either ground tire (R1) or PET (R2) as support materials, were inoculated with thermally pretreated anaerobic sludge and operated at a temperature of 30 degrees C. The AFBR were operated with a range of hydraulic retention times (HRT) between 1 and 8 h. The reactor R1 operating with a HRT of 2 h showed better performance than reactor R2, reaching a maximum hydrogen yield of 2.25 mol H(2) mol(-1) glucose with 1.3 mg of biomass (as the total volatile solids) attached to each gram of ground tire. Subsequent 16S rRNA gene sequencing and phylogenetic analysis of particle samples revealed that reactor R1 favored the presence of hydrogen-producing bacteria such as Clostridium, Bacillus, and Enterobacter. (C) 2010 Elsevier Ltd. All rights reserved.

Anaerobic degradation of linear alkylbenzene sulfonate (LAS) in fluidized bed reactor by microbial consortia in different support materials

Four anaerobic fluidized bed reactors filled with activated carbon (R1), expanded clay (R2), glass beads (R3) and sand (R4) were tested for anaerobic degradation of LAS. All reactors were inoculated with sludge from a UASB reactor treating swine wastewater and were fed with a synthetic substrate supplemented with approximately 20 mg l(-1) of LAS, on average. To 560 mg l(-1) COD influent, the maximum COD and LAS removal efficiencies were mean values of 97 +/- 2% and 99 +/- 2%, respectively, to all reactors demonstrating the potential applicability of this reactor configuration for treating LAS. The reactors were kept at 30 degrees C and operated with a hydraulic retention time (HRT) of 18 h. The use of glass beads and sand appear attractive because they favor the development of biofilms capable of supporting LAS degradation. Subsequent 16S rRNA gene sequencing and phylogenetic analysis of samples from reactors R3 and R4 revealed that these reactors gave rise to broad microbial diversity, with microorganisms belonging to the phyla Bacteroidetes, Firmicutes, Actinobacteria and Proteobacteria, indicating the role of microbial consortia in degrading the surfactant LAS. (C) 2010 Elsevier Ltd. All rights reserved.

Influence of support material on the immobilization of biomass for the degradation of linear alkylbenzene sulfonate in anaerobic reactors

Two horizontal-flow anaerobic immobilized biomass reactors (HAIB) were used to study the degradation of the LAS surfactant: one filled with charcoal (HAIB1) and the other with a mixed bed of expanded clay and polyurethane foam (HAIB2). The reactors were fed with synthetic substrate supplemented with 14 mg l(-1) of LAS, kept at 30 +/- 2 degrees C and operated with a hydraulic retention time (HRT) of 12 h. The surfactant was quantified by HPLC. Spatial variation analyses were done to quantify organic matter and LAS consumption along the reactor length. The presence of the surfactant in the load did not affect the removal of organic matter (COD), which was close to 90% in both reactors for an influent COD of 550 ring l(-1). The results of a mass balance indicated that 28% of all LAS added to HAIB1 was removed by degradation. HAIB2 presented 27% degradation. Molecular biology techniques revealed microorgan isms belonging the uncultured Holophaga sp., uncultured delta Proteobacterium, uncultured Verrucomicrobium sp., Bacteroides sp. and uncultured gamma Proteobacterium sp. The reactor with biomass immobilized on charcoal presented lower adsorption and a higher kinetic degradation coefficient. So, it was the most suitable support for LAS anaerobic treatment. (c) 2008 Elsevier Ltd. All rights reserved.

Effects of interactions between algal densities and cadmium concentrations on Ceriodaphnia dubia fecundity and survival

The influence of different densities of the algae Pseudokirchneriella subcapitata on the chronic toxicity of cadmium to Ceriodaphnia dubia was investigated. The importance of algal cells as a source of metal to zooplankton was studied by exposing P. subcapitata cells to free cadmium ions and supplying the algae as food to C. dubia. The results of a bifactorial analysis (metal versus food levels) showed that metal toxicity to zooplankton was dependent on food level. Significant toxic effects on the fecundity and survival of C. dubia were observed at low metal concentrations with high algal density. Algae contaminated with Cd2+ were less toxic to cladoceran than was the Cd2+ in solution. Green algae retained cadmium and released low metal concentration in the test medium. We concluded that algal cells are an important route of exposure to metal and a factor that has an appreciable influence on the expression of metal toxicity to daphnids. (C) 2007 Elsevier Inc. All rights reserved.

Oxidative stress biomarkers of exposure in the blood of cichlid species from a metal-contaminated river

The oxidative stress biomarkers of exposure, such as reduced glutathione (GSH), activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and the levels of lipid peroxidation (LPO), were measured in the blood of three cichlid fish (Oreochromis niloticus, Tilapia rendalli, and Geophagus brasiliensis) taken during two seasons from two sites, unpolluted and polluted by industrial effluents, to evaluate the effectiveness of these biomarkers in assessing the impact of water contamination. The LPO levels in the blood were higher in fish from the metal-contaminated site and the chronic exposure led to significant changes in GPx, CAT, and SOD activities in all three cichlid species. The considerable variation of responses in these cichlids to water contamination evidenced differences in sensitivity to the metal contamination and/or in the potential to respond to it highlighting the importance of using a set of related biomarkers to assess the impact of water contamination. (C) 2007 Elsevier Inc. All rights reserved.

Digital versus Conventional Radiography for Imaging Fatigue Cracks in Riveted Lap Joints of Hybrid Glass Reinforced Fiber/Metal Laminate

A round robin program zoos conducted to assess the ability of three different X-radiographic systems for imaging internal fatigue cracks in riveted lap joints of composite glass reinforced fiber/metal laminate. From an engineering perspective, conventional film radiography and direct radiography have produced the best results, identifying and characterizing in detail internal damage on metallic faying surfaces of fastened glass reinforced fiber/metal laminate joints. On the other hand, computed radiographic images presented large projected geometric distortions and feature shifts due to the angular incident radiation beam, disclosing only partial internal cracking patterns.

Biohydrogen production in anaerobic fluidized bed reactors: Effect of support material and hydraulic retention time

This study evaluated two different support materials (polystyrene and expanded clay) for biohydrogen production in an anaerobic fluidized bed reactor (AFBR) treating synthetic wastewater containing glucose (4000 mg L(-1)). The AFBRs contained either polystyrene (R1) or expanded clay (R2) as support materials were inoculated with thermally pre-treated anaerobic sludge and operated at a temperature of 30 degrees C and a pH of approximately 5.5. The AFBRs were operated with a range of hydraulic retention times (HRTs) between 1 and 8 h. For R1 with an HRT of 2 h, the maximum hydrogen yield (HY) was 1.90 mol H(2) mol(-1) glucose, with 0.805 mg of biomass (as total volatile solids, or TVS) attached to each g of polystyrene. For R2 operated at an HRT of 2 h, the maximum HY was 2.59 mol H(2) moll glucose, with 1.100 mg of attached biomass (as TVS) g(-1) expanded clay. The highest hydrogen production rates (HPR) were 0.95 and 1.21 L h(-1) L(-1) for R1 and R2, respectively, using an HRT of 1 h. The H(2) content increased from 16-47% for R1 and from 22-51% for R2. No methane was detected in the biogas produced throughout the period of AFBR operation. These results show that the values of HY, HPR, H(2) content, and g of attached biomass g(-1) support material were all higher for AFBRs containing expanded clay than for reactors containing polystyrene. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.