Improving accuracy on wave height estimation through machine learning techniques

Estimatabion of wave agitation plays a key role in predicting natural disasters, path optimization and secure harbor operation. The Spanish agency Puertos del Estado (PdE) has several oceanographic measure networks equipped with sensors for different physical variables, and manages forecast systems involving numerical models. In recent years, there is a growing interest in wave parameter estimation by using machine learning models due to the large amount of oceanographic data available for training, as well as its proven efficacy in estimating physical variables. In this study, we propose to use machine learning techniques to improve the accuracy of the current forecast system of PdE. We have focused on four physical wave variables: spectral significant height, mean spectral period, peak period and mean direction of origin. Two different machine learning models have been explored: multilayer perceptron and gradient boosting decision trees, as well as ensemble methods that combine both models. These models reduce the error of the predictions of the numerical model by 36% on average, demonstrating the potential gains of combining machine learning and numerical models

Cerebellar white matter disruption in Alzheimer’s Disease patients: a Diffusion Tensor Imaging study

The cognitive role of the cerebellum has recently gained much attention, and its pivotal role in Alzheimer’s disease (AD) has now been widely recognized. Diffusion tensor imaging (DTI) has been used to evaluate the disruption of the microstructural milieu in AD, and though several white matter (WM) tracts such as corpus callosum, inferior and superior longitudinal fasciculus, cingulum, fornix, and uncinate fasciculus have been evaluated in AD, data on cerebellar WM tracts are currently lacking. We performed a tractography-based DTI reconstruction of the middle cerebellar peduncle (MCP), and the left and right superior cerebellar peduncles separately (SCPL and SCPR) and addressed the differences in fractional anisotropy (FA), axial diffusivity (Dax), radial diffusivity (RD), and mean diffusivity (MD) in the three tracts between 50 patients with AD and 25 healthy subjects. We found that AD patients showed a lower FA and a higher RD compared to healthy subjects in MCP, SCPL, and SCPR. Moreover, a higher MD was found in SCPR and SCPL and a higher Dax in SCPL. This result is important as it challenges the traditional view that WM bundles in the cerebellum are unaffected in AD and might identify new targets for therapeutic interventions

Polymyalgia rheumatica: inflammation suppression with low dose of methylprednisolone or modified-release prednisone

OBJECTIVE: Polymyalgia rheumatica (PMR) is an inflammatory disease that affects people aged > 50 years, and is characterised by pain and morning stiffness in the shoulder and pelvic girdle with synovitis of the proximal joints and extra-articular synovial structures. It is currently mainly treated with glucocorticoids (GCs). The aim of the study was to evaluate changes in inflammatory markers and their correlations with cortisol levels after treatment with 6-methylprednisolone (6-MP) or modified- release prednisone (MR-P) in patients with "early" PMR. PATIENTS AND METHODS: The study involved 81 GC-naive with "early" PMR diagnosed on the basis of the 2012 EULAR/ACR criteria: 38 treated with 6-MP at a starting dose of 12 mg at 8.00 a.m, gradually tapered to 8, 4 and 2 mg/day, and 43 treated with MR-P at a starting dose of 10 mg at 10 p.m, tapered to 7, 5, 3, 2 and 1 mg. The markers of inflammation (ESR mm/h, CRP mg/dL and fibrinogen mg/dL), the circulating serum levels of cytokines (TNF alpha and IL-6), and morning serum cortisol levels were evaluated at baseline and during GC treatment. RESULTS: There were significant differences between baseline and the end of treatment in the serum levels of IL-6 (5.3 +/- 9.3 vs 2.8 +/- 3.3 pg/mL; p < 0.05) and CRP (2.1 +/- 3.3 vs 0.9 +/- 1.7 mg/dL; p < 0.01) in the patients treated with MR-P, and in serum cortisol levels (15.8 +/- 6.4 vs 13.6+5.6 mu g/dL; p < 0.01) in the patients treated with 6-MP. After the first month of treatment, 76.7% of the patients treated with MR-P had IL6 levels at or below the upper normal limit, whereas 52.6% of those treated with 6-MP had normal IL6 levels (p < 0.05). There was also a significant difference in the percentage of patients in whom the daily GC dose was tapered within eight months (6.7% in the MR-P group vs 25% in the 6-MP group; p < 0.001) and, by the end of the study, respectively 59.5% vs 35.1% patients were receiving a low GC dose or had discontinued treatment altogether (OR 2.7, 95% CI 1.0-6.77; p < 0.001). After six and 12 months, respectively 10.3% and 14.3% of the patients had discontinued MR-P, as against none of the patients treated with 6-MP (p < 0.05). CONCLUSIONS: In this prospective observational study of PMR patients receiving low-dose GCs, the changes in inflammatory markers were similar in those treated with 6-MP or MR-P, whereas morning cortisol levels remained unchanged only in the MR-P group. During the first month of treatment, MR-P chronotherapy given at bedtime significantly decreased IL-6 levels. The percentage of patients stopping GC treatment was higher in the MR-P group than in the 6-MP group

Highlights on novel technologies for the detection of antibodies to Ro60, Ro52, and SS-B

Objective. We aimed to compare a chemiluminescent immunoassay (CIA, QUANTA Flash) on BIO-FLASH with a multiplex flow immunoassay (MFI) on BioPlex 2200 for the detection of antibodies to Ro60, Ro52, and SS-B. Methods. The study included 241 samples, from patients suffering from systemic autoimmune diseases (n = 108) as well as disease controls (n = 133). All samples were tested for anti-Ro52, anti-Ro60, and anti-SS-B (La) antibodies on QUANTA Flash (INOVA Diagnostics, San Diego, USA) and BioPlex 2200 (Bio-Rad Laboratories Inc., Hercules, USA). Discrepant samples were tested by two independent methods: BlueDot/ANA and QUANTRIX Microarray (both D-tek, Belgium). Results. The overall qualitative agreements were 95.4% (95% confidence interval, CI 92.0-97.7%) for anti-Ro52, 98.8% (95% CI 96.4-99.7%) for anti-Ro60, and 91.7% (95% CI 87.5-94.9%) for anti-SS-B antibodies. There were 34 discrepant samples among all assays (20 anti-SS-B, 11 anti-Ro52, 3 anti-Ro60). 30/33 of retested samples (by D-tek dot blot) agreed with the QUANTA Flash results. Similar findings were obtained with QUANTRIX Microarray kit. Conclusion. QUANTA Flash and BioPlex 2200 show good qualitative agreement. The clinical performances were similar for anti-Ro52 and anti-Ro60 autoantibodies while differences were observed for anti-SS-B (La) antibodies

Development and characterization of novel auxetic structures based on re-entrant hexagon design produced from braided composites

This paper reports the first attempt of developing macro-scale auxetic structures based on re-entrant hexagon design from braided composite materials for civil engineering applications. Braided composite rods (BCRs) were produced and arranged as longitudinal and horizontal elements to produce three types of auxetic structures: (1) basic re-entrant hexagon structure, (2) basic structure modified by adding straight longitudinal elements and (3): structure-2 modified by changing structural angle. The influence of various material and structural parameters as well as structure type on Poisson's ratio and tensile properties was thoroughly investigated. The auxetic behaviour was found to strongly depend on the structural angle and straight elements, resulting in lower auxeticity with lower angles and in presence of straight elements. Material parameters influenced the auxetic behaviour to a lesser extent and a decrease in auxetic behaviour was noticed with increase in core fibre linear density and using stiffer fibres such as carbon. The reverse effect was observed in case of tensile strength and work of rupture. Among these structures, structure-3 exhibited good auxetic behaviour, balanced tensile properties, and high energy absorption capacity and their auxetic behaviour could be well predicted with the developed analytical model. Therefore, these novel structures present good potential for strengthening of civil structures.The authors gratefully acknowledge the financial support for carrying out this research work from University of Minho, under the scheme of "Strategic plan of school of engineering - Agenda 2020: Multidisciplinary projects.

Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011