Reducing the Training Samples for Damage Detection of Existing Buildings through Self-Space Approximation Techniques.

Data-driven methodologies are among the most effective tools for damage detection of complex existing buildings, such as heritage structures. Indeed, the historical evolution and actual behaviour of these assets are often unknown, no physical models are available, and the assessment must be performed only based on the tracking of a set of damage-sensitive features. Selecting the most representative state indicators to monitor and sampling them with an adequate number of records are therefore essential tasks to guarantee the successful performance of the damage detection strategy. Despite their relevance, these aspects have been frequently taken for granted and little attention has been paid to them by the scientific community working in the field of Structural Health Monitoring. The present paper aims to fill this gap by proposing a multistep strategy to drive the selection of meaningful pairs of correlated features in order to support the damage detection as a one-class classification problem. Numerical methods to reduce the number of necessary acquisitions and estimate the performance of approximation techniques are also provided. The analyses carried out to test and validate the proposed strategy exploit a dense dataset collected during the long-term monitoring of an outstanding heritage structure, i.e., the Church of 'Santa Maria de Belém' in Lisbon.

Effects of combination tocopherols and alpha lipoic acid therapy on oxidative stress and inflammatory biomarkers in chronic kidney disease.

OBJECTIVE: Although increased oxidative stress and inflammation are highly prevalent in chronic kidney disease (CKD), few studies have investigated whether oral antioxidant therapy can alter markers of inflammation or oxidative stress in patients with CKD. The purpose of this study was to investigate whether a combination of mixed tocopherols and alpha lipoic acid (ALA) would alter biomarkers of oxidative stress and inflammation in subjects with stage 3 to 4 CKD. METHODS: This was a prospective, randomized, double-blind, placebo-controlled pilot trial. In all, 62 subjects were enrolled and were randomly assigned to receive a combination of mixed tocopherols 666 IU/day, in addition to ALA 600 mg/day, or their matching placebos for a total of 8 weeks. Plasma F(2)-isoprostane and protein thiol concentration were measured as biomarkers of oxidative stress, and C-reactive protein and interleukin-6 concentration as biomarkers of systemic inflammation. RESULTS: There were no significant differences in demographics, diabetic status, or estimated glomerular filtration rate between study treatment and placebo groups at baseline. Of the 62 randomized subjects, 58 (93%) completed the study protocol. After 2 months of treatment, there were no significant changes in the concentrations of F(2)-isoprostanes, protein thiols, C-reactive protein, and interleukin-6 with respect to treatment with mixed tocopherols and ALA as compared with matching placebos, whether analyzed as intention to treat or as treated. Diabetic status and baseline body mass index did not influence the results. CONCLUSIONS: Combination of oral mixed tocopherols and ALA treatment for 2 months does not influence biomarkers of oxidative stress and inflammation in patients with stage 3 to 4 CKD.

Determinants of plasma adiponectin levels in nondiabetic subjects with moderate to severe chronic kidney disease.

OBJECTIVE: Our objective was to determine factors associated with adiponectin levels in subjects with stage III to IV chronic kidney disease (CKD). DESIGN: We used a cross-sectional analysis. SETTING: All kidney-disease subjects and controls were recruited at Vanderbilt University Medical Center (Nashville, TN) and Maine Medical Center (Portland, ME). PATIENTS: We recruited 95 stage III to IV CKD subjects. Kidney-disease subjects with history of diabetes mellitus were excluded from the study. INTERVENTIONS: There were no interventions. RESULTS: Subjects with stage IV CKD had significantly higher adiponectin levels compared with those with stage III CKD (30.6 +/- 22.8 microg/mL vs. 21.1 +/- 14.6 microg/mL mean +/- SD, P = .05). Adiponectin was significantly correlated with gender (P = .01), high-density lipoproteins (P < .001), triglycerides (P = .004), and weight (P = .04) upon unadjusted analysis. Using multiple linear regression analysis, gender (P = .03), high-density lipoproteins (P = .001), triglycerides (P = .04), and high-sensitivity C-reactive protein (P = .004) were independently associated with adiponectin. CONCLUSIONS: Gender, high-density lipoproteins, triglycerides, and high-sensitivity C-reactive protein are major determinants of adiponectin levels in nondiabetic stage III to IV CKD. Insulin resistance, body mass index, and body fat percentage were not associated with adiponectin levels. Plasma adiponectin levels are difficult to interpret in the setting of CKD because of multiple confounders that may influence the relationship between adiponectin, adiposity, and insulin resistance.

Oxidative stress and inflammation are associated with adiposity in moderate to severe CKD.

Adiposity contributes to inflammation and oxidative stress in the general population, but this association has not been examined in the chronic kidney disease (CKD) population. We investigated the relationship between body mass index, body fat percentage, and markers of inflammation (C-reactive protein) and oxidative stress (F(2)-isoprostanes and protein thiols) in 184 patients with stages III to IV CKD and 43 healthy controls. We found that, on average, patients with CKD had 62% higher F(2)-isoprostanes, 7% lower protein thiols (a measure of endogenous anti-oxidant capacity, inversely related to protein oxidation), and 150% higher C-reactive protein levels than healthy controls (all unadjusted P < 0.001). In separate multivariable linear regression models, body mass index and body fat percentage each positively correlated with levels of F(2)-isoprostanes and C-reactive protein and negatively correlated with levels of protein thiols among patients with CKD after adjusting for age, sex, race, hypertension, diabetes mellitus, smoking history, estimated glomerular filtration rate, total cholesterol, serum albumin, and study site. We conclude that increased adiposity may amplify the oxidative stress and inflammation that accompany moderate to severe CKD. Interventions focused on weight loss may decrease the inflammatory and oxidative burden in CKD, which may ultimately attenuate cardiovascular risk in this population.

Atmospheric wavefront phase recovery by use of specialized hardware: graphical processing units and field-programmable gate arrays.

To achieve the wavefront phase-recovery stage of an adaptive-optics loop computed in real time for 32 x 32 or a greater number of subpupils in a Shack-Hartmann sensor, we present here, for what is to our knowledge the first time, preliminary results that we obtained by using innovative techniques: graphical processing units (GPUs) and field-programmable gate arrays (FPGAs). We describe the stream-computing paradigm of the GPU and adapt a zonal algorithm to take advantage of the parallel computational power of the GPU. We also present preliminary results we obtained by use of FPGAs on the same algorithm. GPUs have proved to be a promising technique, but FPGAs are already a feasible solution to adaptive-optics real-time requirements, even for a large number of subpupils.