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We provide a mathematical description of the imaging concept of the Spectrometer/Telescope for Imaging X-rays (STIX) onboard Solar Orbiter. Specifically, we describe the STIX indirect-imaging technique, which is based on spatial modulation of the X-ray photon flux by means of tungsten grids, and we show that each of 30 STIX imaging sub-collimators measures a Fourier component of the flaring X-ray source corresponding to a specific two-dimensional angular frequency. We also provide details about the count-distribution model, which describes the relationship between the photon flux and the measured pixel counts. The derived imaging model is the fundamental starting point both for the interpretation of STIX data and for the description of the data-calibration process. Finally, we provide an overview of the algorithms implemented for the solution of the imaging problem and a comparison of the results obtained with these different methods in the case of the SOL2022-03-31T18 flaring event. [ABSTRACT FROM AUTHOR]

The solar corona is the outer layer of the Sun's atmosphere. The brightness of the solar corona is a million times lower than that of the solar disk. The Earth's sky brightness itself is high enough to cover the coronal signal during ground-based observations. For this reason, the study of sky characteristics plays a fundamental role in observing the solar corona. To date, the only place with the sky characteristics that allow continuous coronagraphic measurements from Earth is at the MLO (Mauna Loa Observatory; Hawaii, ≈ 3400 m above sea level). This paper shows the results obtained as part of the "Extreme Solar Coronagraphy Antarctic Program Experiment" (ESCAPE) at Concordia Base, Antarctica (Dome C plateau-coord.: 75∘06′ S, 123∘20′ E, ≈ 3300 m above sea level) during the 37th campaign and gives a summary of all the sky-brightness measurements obtained from this site (34th and 35th campaigns). Dome C is confirmed to be a coronagraphic site with a sky brightness of about 1 × 10 − 6 B ⊙ . For the first time, it was also possible to detect a coronal signal and to compare it with what was measured by the COronal Solar Magnetism Observatory (COSMO) K-coronagraph (K-Cor) at the MLO. All these results were obtained by using a micropolarizer camera mounted within a coronagraph designed for Antarctic environments. [ABSTRACT FROM AUTHOR]

Purpose: With an increase in the number of adapted sports, the need to monitor sports performance in people with different abilities has grown. Indeed, a thorough evaluation of the sports gesture could prevent the occurrence of injuries, enable a continuous performance assessment, and allow to verify the compliance of the requirements for the competitions. Gesture kinematics provides an assessment of performance, while the muscle activities reveal the underlying strategies adopted by each athlete. In this context, we propose an instrumented evaluation to assess performance in Para-powerlifting. Our goal is to define and test a setup and a protocol to quantitatively assess the execution of bench press exercise in athletes with different abilities. Methods: We recruited an unimpaired athlete and three Paralympic athletes. They were requested to execute the bench press exercise while we recorded muscle activity and kinematic data from the upper body. We investigated the sport gesture by extracting parameters describing coordination, symmetry, and synchronism between arms, and motor variability while repeating the gesture. Results: Paralympic athletes performed the gestures with higher coordination between arms and low variability across repetitions compared to the unimpaired athlete, who was not at the Olympic level. All participants obtained similar kinematic performance by adopting different muscle strategies. Conclusions: This study is a proof of concept that the instrumented evaluation proposed here can allow to conduct a complete assessment of the bench press exercise, in terms of kinematics, muscle activity and performance in athletes with different abilities. [ABSTRACT FROM AUTHOR]

Wildfires have increased in the last years and, when caused by intentional illegal burnings, are frequently run out of control. Wildfire has been pointed out as an important source of polycyclic aromatic hydrocarbons (PAHs) and trace elements (TEs) — such as, As, Ni, and Pb — to environmental compartments, and thus may pose a risk to human health and to the ecosystem. In 2020, the Brazilian biome, Pantanal, faced the largest losses by wildfires in the last 22 years. Ashes from the topsoil layer in Pantanal were collected after these wildfires at 20 sites divided into the sediment, forest, PF, PS, and degraded sites. Toxicity and associated risks for human health were also evaluated. The areas highly impacted by wildfires and by artisanal gold mining activities showed higher concentrations for TEs and PAHs than the protected areas. Pb varied from 8 ± 4 to 224 ± 81 mg kg−1, and total PAH concentration ranged between 880 ± 314 and 1350 ± 70 ng g−1, at sites impacted by anthropogenic activities. Moreover, health risk assessments for TE and PAH indicated a potentially great risk for children and adults, via ingestion, inhalation, and dermal pathway. The carcinogenic risks exceeded reference values, for both TE and PAH, suggesting harmful conditions, especially for vulnerable groups, such as children and the elderly. [ABSTRACT FROM AUTHOR]

A method for the determination of four classes of potentially toxic substances (PTSs) was developed and applied in marine sediments, including (i) polycyclic aromatic hydrocarbons (PAHs), (ii) polychlorinated biphenyls (PCBs), (iii) polybrominated diphenyl ethers (PBDEs), and (iv) organochlorinated pesticides (OCPs). The method is based on ultrasonic extraction with a mixture of dichloromethane:methanol (9:1 v/v) and gas chromatography coupled with tandem mass spectrometry analysis (GC–MS/MS) in multiple reaction monitoring (MRM) mode. A total of 89 compounds were identified using two precursor-product ion standards for each analyte. The method detection limit (MDL; 0.001–0.055 ng g−1 dw) and method quantification limit (MQL; 0.002–0.184 ng g−1 dw) are below the usual thresholds of pollution adopted by international sediment quality guidelines. The method proved to be selective, sensitive, accurate, and linear, with the advantage of reducing sample handling time and consumable expenses (solvent, adsorbents). The developed method was successfully applied to surface sediments of Sepetiba Bay, Rio de Janeiro State, Brazil. Total concentrations of PAH (29.20–209.5 ng g−1 dw), PCB (0.06–2.16 ng g−1 dw), OCP (0.03–0.33 ng g−1 dw), and PBDE (0.06–0.21 ng g−1 dw) represent a baseline for these compounds and revealed mild to low levels of contamination in comparison to other coastal bays in SE Brazil. By using the proposed method, we expect this preliminary dataset can be expanded and include other similar coastal systems from developing countries marked by scarcity of information about levels, risk assessment, and specific sediment quality guidelines encompassing multiple classes of regulated and emerging organic contaminants. [ABSTRACT FROM AUTHOR]

The Spectrometer/Telescope for Imaging X-rays (STIX) is one of six remote sensing instruments on-board Solar Orbiter. The telescope applies an indirect imaging technique that uses the measurement of 30 visibilities, i.e., angular Fourier components of the solar flare X-ray source. Hence, the imaging problem for STIX consists of the Fourier inversion of the data measured by the instrument. In this work, we show that the visibility amplitude and phase calibration of 24 out of 30 STIX sub-collimators has reached a satisfactory level for scientific data exploitation and that a set of imaging methods is able to provide the first hard X-ray images of solar flares from Solar Orbiter. Four visibility-based image reconstruction methods and one count-based are applied to calibrated STIX observations of six events with GOES class between C4 and M4 that occurred in May 2021. The resulting reconstructions are compared to those provided by an optimization algorithm used for fitting the amplitudes of STIX visibilities. We show that the five imaging methods produce results morphologically consistent with the ones provided by the Atmospheric Imaging Assembly on board the Solar Dynamic Observatory (SDO/AIA) in UV wavelengths. The χ 2 values and the parameters of the reconstructed sources are comparable between methods, thus confirming their robustness. [ABSTRACT FROM AUTHOR]

Reinforced concrete structural walls (RCSWs) are one of the most efficient lateral force-resisting systems used in buildings, providing sufficient strength, stiffness, and deformation capacities to withstand the forces generated during earthquake ground motions. Identifying the failure mode of the RCSWs is a critical task that can assist engineers and designers in choosing appropriate retrofitting solutions. This study evaluates the efficiency of three ensemble deep neural network models, including the model averaging ensemble, weighted average ensemble, and integrated stacking ensemble for predicting the failure mode of the RCSWs. The ensemble deep neural network models are compared against previous studies that used traditional well-known ensemble models (AdaBoost, XGBoost, LightGBM, CatBoost) and traditional machine learning methods (Naïve Bayes, K-Nearest Neighbors, Decision Tree, and Random Forest). The weighted average ensemble model is proposed as the best-suited prediction model for identifying the failure mode since it has the highest accuracy, precision, and recall among the alternative models. In addition, since complex and advanced machine learning-based models are commonly referred to as black-box, the SHapley Additive exPlanation method is also used to interpret the model workflow and illustrate the importance and contribution of the components that impact determining the failure mode of the RCSWs. [ABSTRACT FROM AUTHOR]

The evaluation of sky characteristics plays a fundamental role for many astrophysical experiments and ground-based observations. In solar physics, the main requirement for such observations is a very low sky brightness value, less than 10 − 6 of the solar disk brightness ( B ⊙ ). Few places match such a requirement for ground-based, out-of-eclipse coronagraphic measurements. One of these places is, for instance, the Mauna Loa Observatory (≈ 3400 m a.s.l.). Another candidate coronagraphic site is the Dome C plateau in Antarctica. In this article, we show the first results of the sky brightness measurements at Dome C with the Extreme Solar Coronagraphy Antarctic Program Experiment (ESCAPE) at the Italian–French Concordia Station, on Dome C, Antarctica (≈ 3300 m a.s.l.) during the 34th and 35th summer Campaigns of the Italian Piano Nazionale Ricerche Antartiche (PNRA). The sky brightness measurements were carried out with the internally occulted Antarctic coronagraph AntarctiCor. In optimal atmospheric conditions the sky brightness of Dome C has reached values of the order of 1.0 – 0.7 × 10 − 6 B ⊙ . [ABSTRACT FROM AUTHOR]

In the framework of the Hough transform technique to detect curves in images, we provide a bound for the number of Hough transforms to be considered for a successful optimization of the accumulator function in the recognition algorithm. Such a bound is consequence of geometrical arguments. We also show the robustness of the results when applied to synthetic datasets strongly perturbed by noise. An algebraic approach, discussed in the appendix, leads to a better bound of theoretical interest in the exact case. [ABSTRACT FROM AUTHOR]

Low cycle fatigue life of high-strength reinforcing steel bars (ASTM A706 Grade 80), using photogrammetry by RGB methodology is evaluated. Fatigue tests are performed on specimens under constant axial displacement with total strain amplitudes ranging from 0.01 to 0.05. The experimental observations indicate that buckling of high-strength reinforcing bars results in a damaging degradation of their fatigue life performance as the slenderness ratio increases, including an early rebar failure as the total strain amplitude increases since it achieves the plastic range faster. In addition to this, the results show that the ratio of the ultimate tensile strength to yield strength satisfies the minimum of 1.25 specified in ASTM A706 for reinforcement. On the other hand, the RGB methodology indicates that the axial strains measured by photogrammetry provide more accurate data since the registered results by the traditional experimental setup do not detect second-order effects, such as slippage or lengthening of the specimens within the clamps. Moreover, the RGB filter is faster than digital image correlation (DIC) because the RGB methodology requires a fewer computational cost than DIC algorithms. The RGB methodology allows to reduce the total strain amplitude up to 45% compared to the results obtained by the traditional setup. Finally, models relating total strain amplitude with half-cycles to failure and total strain amplitude with total energy dissipated for multiple slenderness ratios (L/d of 5, 10, and 15) are obtained. [ABSTRACT FROM AUTHOR]

The onset of exanthema was delayed in the course of COVID-19 (during the recovery phase) and not in the initial acute stage when we can expect an RNAaemia with cutaneous vascular involvement. COVID-19, Skin, SARS-CO-V-2, Exanthema, Eosinophilia, DRESS Keywords: COVID-19; Skin; SARS-CO-V-2; Exanthema; Eosinophilia; DRESS EN COVID-19 Skin SARS-CO-V-2 Exanthema Eosinophilia DRESS 607 610 4 07/24/21 20210901 NES 210901 This comment refers to the article available online at https://doi.org/10.1007/s00403-020-02091-0. [Extracted from the article]

The deterioration of water quality worldwide is a serious environmental problem. Water managers still need operational tools to assess water issues and to inform water planning and decision-making. The aim of this article is to propose a 3-step methodological framework for assessing water pollution problems by combining a conceptual modeling tool (DPSIR) with the development of a quantitative model (Multi-Criteria Decision Model). This contribution provides a practical and flexible evaluation tool for conducting an integrated assessment of eutrophication and agrochemicals delivered to groundwater-dependent shallow lakes. It lays out action guidelines for decision-making environmental managers within the context of intermediate cities in developing countries. Forty-one indicators were identified to characterize the D-P-S-I compartments and for the multi-criteria model conceptualization. In this work, response options analysis consisted of evaluating and choosing water management instruments via a decision support tool. Two lake watersheds located in the peri-urban of two middle-size cities, in Argentina, were chosen to illustrate this methodological approach. The ensuing results allowed establishing a ranking of areas to prioritize, identifying a criteria and sub-criteria to focus on in order to set out action guidelines to minimize water pollution and eutrophication. These action guidelines are urgently needed in emerging countries, where financial, human resources and infrastructure are limited. The scarcity of such causes important implications regarding policy solutions for environmental issues. The implemented decision support tool in both lake watersheds provided a common basis for the understanding of the ongoing water pollution problems and a quantitative ranking (i.e., decision scores) for defining specific actions (responses) for human-induced stresses on such natural systems. [ABSTRACT FROM AUTHOR]

Three medium-carbon, high-silicon cast steels with different alloy contents were austempered at 330 °C for different holding times in order to obtain carbide-free bainitic microstructures. Aiming at evaluating the influence of holding time and microstructural features on strength and ductility, tensile properties were measured for each steel at selected austempering times. The results obtained indicate that it is possible to adjust holding time in order to obtain the best strength/ductility combination at determined austempering temperature. Moreover, it has been shown that the mechanical stability of retained austenite is the key factor in controlling tensile performance. Short austempering times result in low carbon enrichment of the austenite (low stability) and promote higher ultimate tensile strength and lower ductility. For longer austempering times, steels present a slight decrease in ultimate tensile strength but a marked increase in ductility. This work shows that it is possible to obtain cast steels with ultimate tensile strength of 1682 MPa, yield strength of 1493 MPa and total elongation of 12.5% by means of bainitic reaction. This strength/ductility combination and others reported in this study are remarkable for cast steels. [ABSTRACT FROM AUTHOR]

After spinal cord injury (SCI), patients face many physical and psychological issues including intestinal dysfunction and comorbidities, strongly affecting quality of life. The gut microbiota has recently been suggested to influence the course of the disease in these patients. However, to date only two studies have profiled the gut microbiota in SCI patients, months after a traumatic injury. Here we characterized the gut microbiota in a large Italian SCI population, within a short time from a not only traumatic injury. Feces were collected within the first week at the rehabilitation center (no later than 60 days after SCI), and profiled by 16S rRNA gene-based next-generation sequencing. Microbial profiles were compared to those publicly available of healthy age- and gender-matched Italians, and correlated to patient metadata, including type of SCI, spinal unit location, nutrition and concomitant antibiotic therapies. The gut microbiota of SCI patients shows distinct dysbiotic signatures, i.e. increase in potentially pathogenic, pro-inflammatory and mucus-degrading bacteria, and depletion of short-chain fatty acid producers. While robust to most host variables, such dysbiosis varies by lesion level and completeness, with the most neurologically impaired patients showing an even more unbalanced microbial profile. The SCI-related gut microbiome dysbiosis is very likely secondary to injury and closely related to the degree of completeness and severity of the lesion, regardless of etiology and time interval. This microbial layout could variously contribute to increased gut permeability and inflammation, potentially predisposing patients to the onset of severe comorbidities. [ABSTRACT FROM AUTHOR]

This work is focused on the study of the columnar-to-equiaxed transition in free graphite cast irons and the correlation of this phenomena with the temperature gradients during solidification. Samples of lamellar, compacted and spheroidal graphite irons were cast and their solidification macrostructures were revealed by application of the direct austempering after solidification technique. All the samples presented a sharp columnar-to-equiaxed transition and the determination of its location was carried out by visually inspecting each of the macrostructures obtained. In addition, computational simulations of filling and solidification of the castings were carried out to calculate the temperature gradient profiles along the whole volume of the casting samples. The comparison of experimental and numerical results showed that there is a critical temperature gradient value defining the columnar-to-equiaxed transition for all the free graphite cast irons samples analyzed in this work, regardless of their graphite morphology and casting geometry. [ABSTRACT FROM AUTHOR]

Background: Aim of the study was to evaluate the value of automated breast ultrasound (AUS) in women with dense breast, in terms of reading times, diagnostic performance and interobserver agreement. The assessment of coronal images alone versus the complete multiplanar (MPR) views was evaluated. Methods: Between August and October 2017, consecutive patients with dense breast that were referred to our Institute, for post-mammography ultrasound assessment, pre-operative assessment or follow-up of known benign lesions, were invited to undergo an additional study with AUS. Three radiologists, (5, 15 and 25 years of experience in breast imaging), reviewed the exams twice: first assessing reconstructed coronal images alone, second the complete MPR views. Reading times, diagnostic performance and interobserver agreement were assessed. Results: One hundred eighty-eight women were included, for a total of 67 breast lesions, 25 (37%) malignant and 42 (63%) benign. Compared to MPR, coronal view was associated with: lower reading times, respectively, for the three readers: 83 ± 37, 84 ± 43 and 76 ± 30 versus 163 ± 109, 131 ± 57, 151 ± 42 s (p < 0.035); lower sensitivity: 44.8%, 62.1%, 55.2% versus 69.0% (p = 0.059), 65.5% (p = 0.063), 72.4% (p = 0.076), respectively; better specificity: 94.1%, 93.7%, 94.2% versus 89.5% (p = 0.093), 87.4% (p = 0.002), 91.6% (p = 0.383), respectively. Agreement between the most and the least experienced reader was fair to moderate for categorical variables and significant for continuous ones. Conclusion: The coronal view allows significantly lower reading times, a valuable feature in the screening setting, but its diagnostic performance makes the complete multiplanar assessment mandatory. [ABSTRACT FROM AUTHOR]

There is a current discussion concerning the austenite grains of lamellar graphite irons and its growth at different carbon equivalent contents. The term "grain" is often employed to refer not only to the primary austenite, but also to the colonies or cells formed during the eutectic solidification. This investigation applies advanced experimental methods to study the solidification of lamellar graphite iron. A better understanding of the solidification process should lead to the design of better casting procedures. Samples of lamellar graphite iron were cast and directly austempered after solidification in order to reveal their solidification macrostructure. A typical ingot structure was found, with a narrow columnar-to-equiaxed transition. Electron backscatter diffraction technique was applied to confirm these macroscopic observations. Color etching was employed to determine the size of eutectic colonies at the columnar and equiaxed regions. The EBSD results confirm previous proposals, revealing that the solidification grains result from the growth of austenite dendrites. These grains include several eutectic colonies or cells inside, all these colonies or cells having the same crystalline orientation as the primary austenite dendrite. An analysis of the critical gradient for columnar-to-equiaxed transition could be developed. The size of the eutectic colonies at the columnar zone was found to be smaller than the size of the eutectic colonies at the equiaxed zone. Besides, the size of equiaxed grains strongly decreased with the increase in cooling rate, while no evident differences were obtained when the size of the columnar grains was measured. [ABSTRACT FROM AUTHOR]

This paper describes the innovative optical design of the Metis coronagraph for the Solar Orbiter ESA-NASA mission. Metis is a multi-wavelength, externally occulted telescope for the imaging of the solar corona in both the visible and ultraviolet wavelength ranges. Metis adopts a novel occultation scheme for the solar disk, that we named "inverse external occulter", for reducing the extremely high thermal load on the instrument at the spacecraft perihelion. The core of the Metis optical design is an aplanatic Gregorian telescope common to both the visible and ultraviolet channels. A suitable dichroic beam-splitter, optimized for transmitting a narrow-band in the ultraviolet (121.6 nm, HI Lyman-α) and reflecting a broadband in the visible (580–640 nm) spectral range, is used to separate the two optical paths. Along the visible light optical path, a liquid crystal electro-optical modulator, used for the first time in space, allows making polarimetric measurements. [ABSTRACT FROM AUTHOR]

A method for the determination of polychlorinated biphenyls (PCBs) in water from urban rivers was implemented and validated. Extractions of dissolved and particulate PCBs were performed using solid-phase extraction and a pressurized solvent extraction system, respectively, and the analytes were identified and quantified by gas chromatography with tandem mass spectrometry in selected reaction monitoring mode with no further purification. The method was successfully developed for the determination of 41 PCBs with two precursor-product confirmations for each analyte. Low method detection limits (0.06–0.50 ng L−1) and good precision (≤ 20%; n = 8) were obtained, as well a linear response of the calibration curve ranging from 1.0 to 50 ng L−1. Method performance for real samples was tested with water collected weekly in triplicate during April 2018 from a eutrophic river in the city of Rio de Janeiro. The total (dissolved + particulate) PCB concentrations ranged from 2.17 to 5.29 ng L−1, above the threshold for river water quality standards in Brazil. [ABSTRACT FROM AUTHOR]

Purpose: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease leading to neuromuscular palsy and death. We propose a computational approach to [18F]-fluorodeoxyglucose (FDG) PET/CT images to analyze the structure and metabolic pattern of skeletal muscle in ALS and its relationship with disease aggressiveness. Materials and methods: A computational 3D method was used to extract whole psoas muscle's volumes and average attenuation coefficient (AAC) from CT images obtained by FDG PET/CT performed in 62 ALS patients and healthy controls. Psoas average standardized uptake value (normalized on the liver, N-SUV) and its distribution heterogeneity (defined as N-SUV variation coefficient, VC-SUV) were also extracted. Spinal cord and brain motor cortex FDG uptake were also estimated. Results: As previously described, FDG uptake was significantly higher in the spinal cord and lower in the brain motor cortex, in ALS compared to controls. While psoas AAC was similar in patients and controls, in ALS a significant reduction in psoas volume (3.6 ± 1.02 vs 4.12 ± 1.33 mL/kg; p < 0.01) and increase in psoas N-SUV (0.45 ± 0.19 vs 0.29 ± 0.09; p < 0.001) were observed. Higher heterogeneity of psoas FDG uptake was also documented in ALS (VC-SUV 8 ± 4%, vs 5 ± 2%, respectively, p < 0.001) and significantly predicted overall survival at Kaplan–Meier analysis. VC-SUV prognostic power was confirmed by univariate analysis, while the multivariate Cox regression model identified the spinal cord metabolic activation as the only independent prognostic biomarker. Conclusion: The present data suggest the existence of a common mechanism contributing to disease progression through the metabolic impairment of both second motor neuron and its effector. [ABSTRACT FROM AUTHOR]

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Slender RC walls are often used in Chile and commonly, due to architectural constraint, the length of walls increases (setback) between floors designated for parking space and upper floors. These types of elements are commonly called flag walls. In this research, the behavior of slender reinforced concrete walls with a constant axial load and a cyclic lateral displacement is numerically studied, in order to compare the results obtained with previous tests. Two different model alternatives are considered: a finite element model and a strut-and-tie model. The selected models allow understanding local response, as well as, distribution of internal forces, which is also relevant information for wall design and detailing. The studied finite element model, based on quadrilateral elements with 3 degrees of freedom per node (2 translational and 1 rotation) and a model of smeared reinforced concrete material based on a rotating angle approach, is able to correctly capture the global response, showing the capacity, degradation and failure mode obtained in the tests. On the other hand, a parametric analysis is performed for models of walls with higher aspect ratio (tall buildings) with small discontinuities, showing a larger impact in deformation capacity due to the high concentration of damage at the discontinuity. These results indicate that in 25-floor high walls (or taller) a reduction of displacement capacity of 40% for discontinuities located at the first floor could be observed. In addition, by incorporating the effect of the slabs into the model, the results indicate that a pure flexure model is an adequate and sufficient tool for analysis. Finally, a strut-and-tie model is also proposed for each direction of the lateral load, whose results are compared with the estimated load calculated with the strains measured by photogrammetry. The considered strut-and-tie model for the case of lateral load with tension in the continuous wall boundary is similar to the wall without discontinuity, which is consistent with the measured strains. For both lateral loading directions, the estimated forces of the horizontally distributed bars and boundary reinforcements are consistent with photogrammetry in the lower zone of the wall, where cracking is relevant. The strut-and-tie model also adequately interprets the effect of the discontinuous bar on the discontinuous boundary of the wall. All these results can help designing and detailing flag walls. [ABSTRACT FROM AUTHOR]

This paper presents information on development, calibration, and validation of three companion macroscopic modeling approaches for nonlinear analysis of reinforced concrete (RC) structural walls, including: (1) the baseline two-dimensional two-node formulation of the Shear–Flexure-Interaction Multiple-Vertical-Line-Element-Model (SFI-MVLEM), (2) extension of the baseline SFI-MVLEM for modeling of squat walls (SFI-MVLEM-SQ), and (3) extension of the baseline SFI-MVLEM to a three-dimensional four-node element for simulation of non-planar RC walls under multi-directional loading (SFI-MVLEM-3D). The models are implemented in the computational platform OpenSees. Models presented are calibrated and validated against experimental results obtained from tests on RC wall specimens that cover a wide range of physical and behavioral characteristics, including: (1) one slender, two moderately-slender and one medium-rise planar RC walls tested under in-plane loading used for validation of the baseline SFI-MVLEM, (2) three squat planar RC wall specimens tested under in-plane loading used for validation of the SFI-MVLEM-SQ, and (3) one T-shaped and one U-shaped RC wall specimen tested under unidirectional and multi-directional loading, respectively, used for validation of SFI-MVLEM-3D. The comprehensive comparisons between analytically-obtained and experimentally-measured wall responses suggest that the analytical models proposed can accurately simulate both global and local wall responses, within their range of applicability. The models capture load–displacement response features of the walls, including lateral load capacity, lateral stiffness, cyclic stiffness degradation, and pinching characteristics, as well as nonlinear shear deformations and their coupling with flexural deformations during cyclic loading. Comparisons between experimental and analytical results at local response levels suggest that the models can also replicate distributions and magnitudes of wall vertical strains and curvatures at various locations. Overall, the analytical models presented provide robust and reliable tools for nonlinear analysis of RC walls, with a wide range of applicability. [ABSTRACT FROM AUTHOR]

In this article, a simple and accurate quadrilateral thin flat layered shell element formulation for the nonlinear analysis of reinforced concrete (RC) wall systems under static and cycling loads is presented. The 4 node shell element, with 6 degree of freedom (DOF) per node (3 displacements and 3 rotations) is created by superposing the quadrilateral layered membrane element with drilling degrees of freedom (12 DOF, 2 displacement and 1 rotation per node) developed by Rojas et al. (Eng Struct 124:521–538, 2016), and the Discrete Kirchhoff Quadrilateral Element (12 DOF, 1 displacement and 2 rotations) formulated by Batoz and Tahar (Int J Numer Methods Eng 18(11):1655–1677, 1982), to model the in-plane and the out of plane bending behavior of the shell element, respectively. In addition, to model the complex behavior and coupling of the axial, flexural and shear behavior, observed in complex RC wall structures, the transversal section of the shell element consists of a layered system of fully bonded, smeared steel reinforcement and smeared orthotropic concrete material with the rotating angle formulation. The formulation used a tangent stiffness matrix approach, which include the coupling of membrane and bending effects. For verification, the shell element formulation is used to model a set of experimental results for T-shaped RC walls that are available in the literature. The proposed element is robust, simple to implement, and it can predict the global results (load vs. displacement and maximum capacity) and also the local behavior (vertical strain at the base level along the web and the flange) observed in RC wall structures. [ABSTRACT FROM AUTHOR]

Investigation were carried out targeting distribution and source apportioning of hydrocarbons in surface sediments from shallow to deep waters in the Campos Basin, one of the most important oil-producing provinces in Brazil. The observed levels of aliphatic (≤ 124 μg g−1) and polycyclic aromatic hydrocarbons (PAHs ≤ 599 ng g−1) are lower than those considered relevant for environmental risk to the benthic habitats. Higher median concentrations of aliphatic hydrocarbons (8.49 μg g−1) and PAHs (84.8 ng g−1) in the middle slope sediments (700–1000-m water depths) showed the influence of hydrodynamics upon hydrocarbon accumulation in the sediments. Diagnostic ratios and conventional statistical analysis applied to hydrocarbon data produced insufficient information on the contribution of different sources. These traditional approaches do not consider the potential changes affecting source assignment and therefore cannot deal with the uncertainties. The fuzzy logic applied as an alternative method for data treatment successfully incorporated the uncertainties in the differentiation between petrogenic and pyrolytic sources, including those due to degradation. Moreover, by using fuzzy logic, it was possible to identify that water circulation patterns, mass transport, deposition, and degradation processes are more relevant factors in determining hydrocarbon composition than source proximity. [ABSTRACT FROM AUTHOR]

In developing countries, conflict between the objectives of environmental policies and those focused on economic development, a low availability of human resources and infrastructure, and the lack of continuity and incentives, contribute to the inability to successfully implement environmental policies. Moreover, in these countries, population growth in the peri-urban areas has resulted in serious water pressures, poor water management, and severe non-point source pollution. The aim of this paper is to implement a procedure of aquifer pollution risk assessment for identifying priority areas in an urban-rural interface based on multi-criteria decision tools. In this sense, a multi-criteria decision model was designed, in terms of environmental and socio-economic criteria and sub-criteria relevant to water resource management, by using the software Criterium Decision Plus 4.0. This model was applied to the northwestern peri-urban area of Mar del Plata City, Argentina, which is embedded in the second most important fruit-horticultural belt of the country. Here, groundwater is the only source of water supply. The proposed decision model allowed establishing a ranking of priority areas for defining action guidelines in order to minimize the risk of pollution of the aquifer. Aquifer pollution hazard criterion mainly contributes to alternatives classified as very high priority whilst in the case of low and very low priority classes, social vulnerability criterion mostly influences the final results. The first alternatives will require an intervention in a short-term time horizon, and the last ones must be monitored in order to avoid their shift to a worse environmental condition. [ABSTRACT FROM AUTHOR]

This work evaluates the factors affecting the presence of organochlorine pesticides in Pampeano aquifer in the Quequén Grande River watershed, Buenos Aires Province, Argentina. Eighteen sampling sites were selected in order to have representatives of different type of wells and types of soil. Among the analyzed compounds, endosulfan showed the highest concentrations (4.75 ng l− 1 mean), which could be related to use in the recent past. Others important pesticides groups detected were HCHs (1.1 ng l− 1 mean) and heptachlors (2.17 ng l− 1mean). The analysis of the results show that the thickness of the unsaturated zone is the main factor related to the concentrations of pesticides and there were no differences according to wells or soil types. Although agricultural use of most OCPs has been banned in Argentina from more than 30 years ago, their residues are still detected in groundwater of the region, indicating their high persistence. [ABSTRACT FROM AUTHOR]

Aims and Objectives: The aim of the current study is to present our experience in lumbar spine interventional procedures performed with a newly developed multimodal echo-navigator (EcoNav) and to evaluate short-term clinical outcomes of a series of patients affected by facet joint disease (FJD) treated with steroid and anaesthetic injection under fusion-imaging guidance, compared to a cohort of patients that received the same treatment under computed tomography (CT) guidance.Methods: Sixty-five consecutive patients (34 females; mean age 68.3 ± 12.8 years) with a clinical diagnosis of non-radicular low back pain lasting for more than 6-weeks and magnetic resonance (MR) or CT confirmed FJD were enrolled for image-guided FJI. Twenty-eight patients underwent FJI with fusion-guided technique, while CT-guided procedures were performed in the other cases. Clinical and procedural data were recorded and compared at a mean follow-up of 6.1 ± 2.0 months.Results: A significant improvement in clinical parameters was observed for both fusion-guided and CT-guided group. Comparing both groups, no statistically significant difference could be detected neither at baseline conditions nor during the follow-up period. No significant periprocedural complication occurred in both groups. A satisfaction rate of 92.3 and 81.1% was reported for fusion-guided and CT-guided group, respectively.Conclusion: EcoNav fusion-imaging system represents a safe, feasible, effective and reproducible guidance option in FJD infiltration procedures, also avoiding use of ionising radiations. [ABSTRACT FROM AUTHOR]

RC structural slender walls under large seismic excitation are expected to reach base moment capacity mainly affected by the first vibration mode. However, the base shear could be affected by higher modes once yielding in flexure has occurred, which might result in base shear underestimation in linear design. In this work, an experimental program is carried out on five RC rectangular walls 1:10 scaled. All five specimens considered irregularities at base, common in construction and one specimen did not consider shear reinforcement or boundary detailing. Tests are carried on a unidirectional shaking table and excitation is based on two Chile earthquake records with different intensities. Damage is concentrated at the wall base for all specimens; primary due to flexure with some participation of shear. For one of the records an average amplification of 1.3 is obtained, and a decrease in height of the resultant equivalent lateral force closes to 0.4 hw. By increasing the intensity of the input record, amplification grows to an average of 1.7, while it decreases drastically when subjected to input records with low frequency content. No significant difference is observed in shear amplification in specimens with a base central opening, nor with setback, even though the cracking and failure mode was different for such specimens. Ductility demand shows no correlation when two different earthquakes are considered, whereas the frequency content and Arias intensity (Ia) of the input record directly affected the shear amplification. [ABSTRACT FROM AUTHOR]

We measured the occurrence and seasonal variations of glyphosate and its metabolite, aminomethylphosphonic acid (AMPA), in different environmental compartments within the limits of an agricultural basin. This topic is of high relevance since glyphosate is the most applied pesticide in agricultural systems worldwide. We were able to quantify the seasonal variations of glyphosate that result mainly from endo-drift inputs, that is, from direct spraying either onto genetically modified (GM) crops (i.e., soybean and maize) or onto weeds in no-till practices. We found that both glyphosate and AMPA accumulate in soil, but the metabolite accumulates to a greater extent due to its higher persistence. Knowing that glyphosate and AMPA were present in soils (> 93% of detection for both compounds), we aimed to study the dispersion to other environmental compartments (surface water, stream sediments, and groundwater), in order to establish the degree of non-point source pollution. Also, we assessed the relationship between the water-table depth and glyphosate and AMPA levels in groundwater. All of the studied compartments had variable levels of glyphosate and AMPA. The highest frequency of detections was found in the stream sediments samples (glyphosate 95%, AMPA 100%), followed by surface water (glyphosate 28%, AMPA 50%) and then groundwater (glyphosate 24%, AMPA 33%). Despite glyphosate being considered a molecule with low vertical mobility in soils, we found that its detection in groundwater was strongly associated with the month where glyphosate concentration in soil was the highest. However, we did not find a direct relation between groundwater table depth and glyphosate or AMPA detections. This is the first simultaneous study of glyphosate and AMPA seasonal variations in soil, groundwater, surface water, and sediments within a rural basin. [ABSTRACT FROM AUTHOR]

Health education is fundamental in the management of RA patients. This study explored patient needs for educational material appropriate for RA patients in our region through a website. This study includes seven focus groups and semi-structured interviews across 4 countries (Argentina, Chile, Colombia, and Mexico) with 71 RA patients. Transcripts were analyzed by anthropologists using qualitative analysis (QA), resulting in themes and subthemes to be developed. Five themes and over 50 subthemes of interest were identified by patients. Grouped into categories as follows: (1) knowing the disease, (2) living with arthritis, (3) treatment and therapies for RA, (4) psychosocial support, and (5) information for families. A response was written by the team in plain Spanish on patient subthemes of interest including additional areas that the team considered relevant. Three videos for YouTube were produced: on patient-doctor relationships, patients at work, and home and at the clinic. Illustrations in a comic book format on RA diagnosis were created. The educational site on RA of PANLAR can be found at htpp://artritisreumatoide.cl. This project accomplished a comprehensive list of RA patient interests, revealing the complex relationship between the information on the disease, the experience of a chronic disease, and the way in which patients approach, conceive, and manage their disease. We expect to gather information on how the website will be used in the future for patients and their families and maintain and improve the website as well as adapt its content to different socioeconomic realities. [ABSTRACT FROM AUTHOR]

This work deals with the piston failures found in diesel engines functioning in light trucks. The failure was a hole inside the bowl located at the top of the piston, which is the combustion chamber of the engine. This hole progressed and finds its way out between the second and third rings. The operational characteristics of the engine were analyzed in order to elucidate the probable acting failure mechanisms. For the evaluation, obviously were assessed the damaged pistons but also pistons of the same engine without the mentioned failure and a new piston. Different studies and measurements were carried out such as microstructural morphologies and transformations, hardness, fracture surface analysis and chemical composition. The piston design, the material used and the operational conditions (thermal and mechanical) were studied with the purpose of determining the failure origin. It was concluded that thermomechanical fatigue along with some degree of degradation suffered by the material is responsible of the reported failure. [ABSTRACT FROM AUTHOR]

Purpose: In amyotrophic lateral sclerosis, functional alterations within the brain have been intensively assessed, while progression of lower motor neuron damage has scarcely been defined. The aim of the present study was to develop a computational method to systematically evaluate spinal cord metabolism as a tool to monitor disease mechanisms. Methods: A new computational three-dimensional method to extract the spinal cord from F-FDG PET/CT images was evaluated in 30 patients with spinal onset amyotrophic lateral sclerosis and 30 controls. The algorithm identified the skeleton on the CT images by using an extension of the Hough transform and then extracted the spinal canal and the spinal cord. In these regions, F-FDG standardized uptake values were measured to estimate the metabolic activity of the spinal canal and cord. Measurements were performed in the cervical and dorsal spine and normalized to the corresponding value in the liver. Results: Uptake of F-FDG in the spinal cord was significantly higher in patients than in controls ( p < 0.05). By contrast, no significant differences were observed in spinal cord and spinal canal volumes between the two groups. F-FDG uptake was completely independent of age, gender, degree of functional impairment, disease duration and riluzole treatment. Kaplan-Meier analysis showed a higher mortality rate in patients with standardized uptake values above the fifth decile at the 3-year follow-up evaluation (log-rank test, p < 0.01). The independence of this value was confirmed by multivariate Cox analysis. Conclusion: Our computational three-dimensional method enabled the evaluation of spinal cord metabolism and volume and might represent a potential new window onto the pathophysiology of amyotrophic lateral sclerosis. [ABSTRACT FROM AUTHOR]

Sarcocystis spp. are protozoan parasites with a heteroxenous life cycle, which produce cysts in the muscle of herbivorous animals. In these animal species, sarcocystosis is frequently asymptomatic, although it may occur with high prevalence. Seven Sarcocystis spp. have been described in red deer ( Cervus elephus). The aim of this study was to determine the prevalence of sarcocystosis, and to perform the morphological and molecular characterization of Sarcocystis spp. found in wild red deer of the Nahuel Huapi National Park (NHNP), Patagonia, Argentina. Full necropsies of 62 red deer killed by hunters in the NHNP and neighboring areas were performed. Samples of heart and skeletal muscle were examined histologically and selected samples were also examined by transmission electron microscopy (TEM), PCR and sequencing. Sarcocystis spp. thin walled cysts were detected in 62 % (38/62) of heart, and in 22 % (3/14) of skeletal muscle samples examined histologically. TEM revealed a smooth and thin cyst wall (≤1 μm), with scarce and separated ribbon-like protrusions. A total of three partial and one full 18S ribosomal RNA (rRNA) gene sequences were obtained, and showed the highest identity (≥99 %) with Sarcocystis taeniata, a species described in moose ( Alces alces). The morphological and molecular results indicate that red deer in Argentina are frequently infected with S. taeniata, a species for which the definitive host is unknown. The present results also confirm that Sarcocystis spp. using cervids as intermediate host are not host-specific. Further studies are needed to improve the epidemiological knowledge of Sarcocystosis in red deer. [ABSTRACT FROM AUTHOR]

Mendoza is the province that has the largest irrigated area in Argentina where water resources depend mainly on snowmelt and glacier melting in the closed Andes Mountain. In this region the Blanco River Basin is one of the most important, covering about 300 km2 flowing from the highest peaks to Potrerillos Dam (1300 masl). The objective of this work was to make a preliminary characterization of stable isotopes in surface and groundwater, ice and snowmelt to contribute to a better understanding of the hydrologic cycle in the region, using a Los Gatos DLT-100 analyzer. Hydrochemical analyses were performed on 157 samples. The isotopic composition of rain water is more enriched than streamwater, clearly indicating that the stream recharge sources are at higher altitude. The discharge regime of the streams indicates that snowmelt is the main water origin, and considering the theoretical evolution of isotopes in meltwater, the composition of streams corresponds to the first meltwater, without fractionation. Then, it is more depleted than the original snow. The ice isotopic composition is more enriched than streamwater, indicating that snowmelt is the main recharge source. The hydrochemical results indicate the importance of geology in determining streamwater composition, which is integrated with isotopic data to achieve a better comprehension of the hydrological system. [ABSTRACT FROM AUTHOR]

The Hough transform is a standard pattern recognition technique introduced between the 1960s and the 1970s for the detection of straight lines, circles, and ellipses with several applications including the detection of symmetries in images. Recently, based on algebraic geometry arguments, the procedure has been extended to the automated recognition of special classes of algebraic plane curves. This allows us to detect curves of symmetry present in images, that is, curves that recognize midpoints maps of various shapes extracted by an ad hoc symmetry algorithm, here proposed. Further, in the case of straight lines, the detection of lines of symmetry allows us, by a pre-processing step of the image, to improve the efficiency of the recognition algorithm on which the Hough transform technique is founded, without loss of generality and additional computational costs. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic (46 PAHs) and aliphatic hydrocarbons (C−C) were studied in atmospheric particulate matter sampled in Rio de Janeiro Metropolitan Area (RJMA). In total, 236 samples from six different sites were collected simultaneously and weekly over 1 year (January-December 2011) allowing a robust atmospheric characterization of fine particulate matter (PM). Hydrocarbon concentration was in general low compared to previous studies in the area (PAHs range 0.25-19.3 ng m), possibly due to changes in fuel composition over time. Precipitation is the main meteorological parameter that rules particulate and hydrocarbon concentration, modifying PAH typology by scavenging. Aliphatic and aromatic diagnostic ratios gave indications conflicting with combustion features. However, ratios showed differences among sites. Principal component analysis (PCA) associated to multiple linear regressions (MLR) allowed quantitative estimate of sources and effectively indicated vehicular emission as the main hydrocarbon source in the atmospheric particulate matter. [ABSTRACT FROM AUTHOR]

In this work, 14 polycyclic aromatic hydrocarbons (PAHs) included in the United States Environmental Protection Agency pollutant priority list were analyzed in the surface water of the upper urbanized part of Almendares River, the most important water course in Havana, Cuba. Surface water from five sampling sites was collected at the end of dry season and analyzed by high-performance liquid chromatography-fluorescence detection method after solid phase extraction procedure. Total PAHs concentrations varied from 836 to 15 811 ng L with a geometric mean value of 2512 ng L. PAH typology was dominated by low molecular-weight PAHs (2- to 3-ring components). Pollutant source appraisal was determined by diagnostic ratios method in five sampling sites. Factor analysis of normalized samples was used to concentration identified two factors as the main significant pollutant sources and to cluster similar sampling sites corresponding to petrogenic and combustion inputs, respectively. Ecological risks were considered. For animal aquatic life, acute toxicity values exceed the permissible values in the more-polluted sampling sites. [ABSTRACT FROM AUTHOR]

We develop a formal procedure for the automated recognition of rational and elliptic curves in medical and astronomical images. The procedure is based on the extension of the Hough transform concept to the definition of Hough transform of special classes of algebraic curves. We first introduce a catalogue of curves that satisfy the conditions to be automatically extracted from an image and the recognition algorithm, then we illustrate the power of this method to identify skeleton profiles in clinical X-ray tomography maps and front ends of solar eruptions in astronomical images provided by the NASA solar dynamics observatory satellite. [ABSTRACT FROM AUTHOR]