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Objective. Surgical guidewires are commonly used in placing fixation implants to stabilize fractures. Accurate positioning of these instruments is challenged by difficulties in 3D reckoning from 2D fluoroscopy. This work aims to enhance the accuracy and reduce exposure times by providing 3D navigation for guidewire placement from as little as two fluoroscopic images. Approach. Our approach combines machine learning-based segmentation with the geometric model of the imager to determine the 3D poses of guidewires. Instrument tips are encoded as individual keypoints, and the segmentation masks are processed to estimate the trajectory. Correspondence between detections in multiple views is established using the pre-calibrated system geometry, and the corresponding features are backprojected to obtain the 3D pose. Guidewire 3D directions were computed using both an analytical and an optimization-based method. The complete approach was evaluated in cadaveric specimens with respect to potential confounding effects from the imaging geometry and radiographic scene clutter due to other instruments. Main results. The detection network identified the guidewire tips within 2.2 mm and guidewire directions within 1.1°, in 2D detector coordinates. Feature correspondence rejected false detections, particularly in images with other instruments, to achieve 83% precision and 90% recall. Estimating the 3D direction via numerical optimization showed added robustness to guidewires aligned with the gantry rotation plane. Guidewire tips and directions were localized in 3D world coordinates with a median accuracy of 1.8 mm and 2.7°, respectively. Significance. The paper reports a new method for automatic 2D detection and 3D localization of guidewires from pairs of fluoroscopic images. Localized guidewires can be virtually overlaid on the patient's pre-operative 3D scan during the intervention. Accurate pose determination for multiple guidewires from two images offers to reduce radiation dose by minimizing the need for repeated imaging and provides quantitative feedback prior to implant placement. [ABSTRACT FROM AUTHOR]

Context: A significant opportunity remains to further increase the supply of premium sheepmeat products to Australia's customers, which requires a more rapid rebuilding of the national sheep flock. To help meet this challenge, developing relevant information for sheep producers to assist them to achieve a profitable flock-rebuilding outcome is viewed as highly desirable. Aims: (1) Develop flock-rebuild scenarios that track inventory, cashflow, profit and loss, and the overall balance sheet over a 5-year projection. (2) Model the impact on flock-rebuilding pathways of exposure to variation in supplementary-feed costs, purchase of stock and price received for sale animals and flock structure. (3) Model variation in benefits and costs for a range of production zones, enterprise types and flock-age profiles. Methods: Fourteen flock-rebuilding pathways were assessed for up to nine flock types, using a spreadsheet model that tracked inventory, cashflow, profit and loss, and the overall balance sheet over 5 years. Key results: The top four pathways for profitability and capacity to rapidly rebuild flock numbers include retention of more older ewes, purchasing young ewes, purchasing older ewes (mostly 5–6-year olds) in Merino and Merino-cross flock types only and joining ewe lambs in Maternal and Cleanskin flock types only. These pathways were not sensitive to variation in the cost of supplementary feed, stock prices or flock structure, although joining Merino ewe lambs became one of the top four pathways when feed costs were lower. Conclusions and implications: The well established practices of retaining ewes for longer and purchasing ewes, especially young ewes, have the most potential to both rapidly and profitably rebuild flock numbers. However, joining ewe lambs, particularly in Maternal and Cleanskin flocks, can also profitably contribute to rapid flock rebuilding. While reducing reproductive wastage or increasing reproductive potential were mostly profitable, they could not rapidly rebuild flock numbers. In contrast, accelerated lambing systems can rapidly rebuild flock numbers, but are only marginally profitable. The outlook for Australia's sheepmeat industry is very positive, with a significant opportunity available to further increase the supply of premium sheepmeat products to customers, by more rapidly rebuilding the national flock. This paper presents the findings of a study focussed on providing the confidence and material to sheep producers to choose optimal pathways to rebuild their flocks. At least 6 of the 14 alternatives investigated were deemed suitable for commercial use and not sensitive to variations in supplementary-feed costs, stock-purchasing and -sale prices. [ABSTRACT FROM AUTHOR]

Introduction: The pathology of a mucoid degeneration of the anterior cruciate ligament (MDACL) has been mentioned in several publications but due to its rare incidence it is not a well-known pathology. Partial or complete resection of the ACL is the option of choice after failed non-surgical treatment. However, the success rate of both surgical techniques and the subsequent risk of an ACL instability is not known. The purpose of this study was to compare the clinical and radiological outcome between partial resection and complete resection of the ACL in patients with MDACL. Materials and methods: Patients with MDACL verified by MRI and persistent knee pain were treated by partial (Group I) or complete resection (Group II) of the ACL and were included in a controlled clinical trial after unsuccessful conservative treatment for at least 6 months. Demographic, clinical and radiological data including the thickness of ACL, ACL/intercondylar ratio, patient's age at the time of surgery, the presenting symptoms, range of motion and ligament stability assessed by the ACL ligament score (Lachman test) were collected. In addition, Tegner activity score and Lysholm score were evaluated preoperatively and at final follow-up after a minimum of 12 months. Results: At final follow-up with a mean of 16.8 ± 8.8 months (range 12–41; Group I: 18.3 ± 9.7 vs. Group II: 15.3 ± 8.0; ns), all patients were pain free. Postoperatively, positive Lachman tests were noted in all patients (100%) in Group II (n = 5 patients with grade II and n = 5 patients with grade III). In Group I, 8 patients (80%) showed a negative Lachman test (grade I) and 2 patients (20%) a slightly elongated Lachman test with a firm stop (grade II). The mean knee flexion at follow-up examination was 132° ± 7° (range 120°–140°; Group I: 129° ± 9° vs. Group II: 135° ± 4°; ns). In pairwise comparison, flexion angle increased significantly in both groups (Group I: p = 0.0124 and Group II: p < 0.001). Pairwise comparison of thickness of the ACL and ACL/intercondylar ratio prior to and post-surgery in Group I showed non-significant differences. Conclusion: Both arthroscopic debridement and complete resection of the ACL lead to improvement of clinical and radiological findings in isolated MDACL. However, complete resection of the ACL will result in higher instability. Therefore, partial resection might be the better treatment option, especially in young patients with MDACL. [ABSTRACT FROM AUTHOR]

Introduction: Anterior cruciate ligament (ACL) reconstruction is considered the first line treatment in ACL rupture. However, some patients return to high intensity sport activities and show a normal knee function without ACL reconstruction. Therefore, aim of this study was to evaluate the rate and prognostic factors of spontaneous healing in patients with ACL rupture and the short-term functional outcome. Methods: The rate, prognostic factors and short-term functional results of spontaneous healing in patients with ACL rupture were evaluated in 381 patients. Morphology of ACL rupture and extent of posterior tibial slope (PTS) were classified by MR- and x-ray imaging. In patients with normal knee stability in anesthesia examination and healed ACL during the arthroscopy 6 weeks after trauma ACL reconstruction was canceled. IKDC -, Tegner Activity Score, KT 1000 testing and radiological characteristics were collected 12 months postoperatively in these patients. Results: 14.17% of the patients with ACL rupture showed a spontaneous healing after 6 weeks. Femoral ACL-rupture (p < 0.02) with integrity of ligament stump > 50% (p < 0.001), without bundle separation (p < 0.001) and decreased PTS (p < 0.001) was found significantly more often in patients with a spontaneous healed ACL. The average IKDC score was high at 84,63 in patients with healed ACL at 1 year follow-up, but KT 1000 testing was inferior compared to non-injured side. Conclusion: Spontaneous healing of a ruptured ACL happened in 14% of the patients. Especially in low-demand patients with femoral single bundle lesions without increased posterior tibial slope delayed ACL surgery should be considered to await the possibility for potential spontaneous ACL healing. [ABSTRACT FROM AUTHOR]

Purpose. Target localization in pulmonary interventions (e.g. transbronchial biopsy of a lung nodule) is challenged by deformable motion and may benefit from fluoroscopic overlay of the target to provide accurate guidance. We present and evaluate a 3D–2D image registration method for fluoroscopic overlay in the presence of tissue deformation using a multi-resolution/multi-scale (MRMS) framework with an objective function that drives registration primarily by soft-tissue image gradients. Methods. The MRMS method registers 3D cone-beam CT to 2D fluoroscopy without gating of respiratory phase by coarse-to-fine resampling and global-to-local rescaling about target regions-of-interest. A variation of the gradient orientation ( GO) similarity metric (denoted G O ′ ) was developed to downweight bone gradients and drive registration via soft-tissue gradients. Performance was evaluated in terms of projection distance error at isocenter (PDEiso). Phantom studies determined nominal algorithm parameters and capture range. Preclinical studies used a freshly deceased, ventilated porcine specimen to evaluate performance in the presence of real tissue deformation and a broad range of 3D–2D image mismatch. Results. Nominal algorithm parameters were identified that provided robust performance over a broad range of motion (0–20 mm), including an adaptive parameter selection technique to accommodate unknown mismatch in respiratory phase. The G O ′ metric yielded median PDEiso = 1.2 mm, compared to 6.2 mm for conventional GO. Preclinical studies with real lung deformation demonstrated median PDEiso = 1.3 mm with MRMS + G O ′ registration, compared to 2.2 mm with a conventional transform. Runtime was 26 s and can be reduced to 2.5 s given a prior registration within ∼5 mm as initialization. Conclusions. MRMS registration via soft-tissue gradients achieved accurate fluoroscopic overlay in the presence of deformable lung motion. By driving registration via soft-tissue image gradients, the method avoided false local minima presented by bones and was robust to a wide range of motion magnitude. [ABSTRACT FROM AUTHOR]

This article discusses the development of a tele-ultrasound program in Chile that aims to connect primary care centers in remote areas with specialist doctors in more complex centers. The program utilizes midwives trained in performing ultrasounds and digital technology to transmit high-quality ultrasound images to the specialist doctors for review and consultation. The study demonstrates the feasibility of this tele-ultrasound model, which allows for real-time advice, informed decision-making, and reduces the need for unnecessary patient transfers. [Extracted from the article]

Child undernutrition is a global health issue associated with a high burden of infectious disease. Undernourished children display an overabundance of intestinal pathogens and pathobionts, and these bacteria induce enteric dysfunction in undernourished mice; however, the cause of their overgrowth remains poorly defined. Here, we show that disease-inducing human isolates of Enterobacteriaceae and Bacteroidales spp. are capable of multi-species symbiotic cross-feeding, resulting in synergistic growth of a mixed community in vitro. Growth synergy occurs uniquely under malnourished conditions limited in protein and iron: in this context, Bacteroidales spp. liberate diet- and mucin-derived sugars and Enterobacteriaceae spp. enhance the bioavailability of iron. Analysis of human microbiota datasets reveals that Bacteroidaceae and Enterobacteriaceae are strongly correlated in undernourished children, but not in adequately nourished children, consistent with a diet-dependent growth synergy in the human gut. Together these data suggest that dietary cross-feeding fuels the overgrowth of pathobionts in undernutrition. Malnourished children experience a high burden of intestinal pathogens that exacerbate growth stunting, and preventing this pathogen overgrowth has proved challenging. Here the authors show that diet-specific bacterial crossfeeding contributes to the overgrowth of intestinal pathogens during child malnutrition. [ABSTRACT FROM AUTHOR]

We examine the influence of activity- and telluric-induced radial velocity (RV) signals on high-resolution spectra taken with an iodine absorption cell. We exclude 2- |$\mathring{\rm A}$| spectral chunks containing active and telluric lines based on the well-characterized K1V star α Centauri B and illustrate the method on Epsilon Eridani – an active K2V star with a long-period, low-amplitude planetary signal. After removal of the activity- and telluric-sensitive parts of the spectrum from the RV calculation, the significance of the planetary signal is increased and the stellar rotation signal disappears. In order to assess the robustness of the procedure, we perform Monte Carlo simulations based on removing random chunks of the spectrum. Simulations confirm that the removal of lines impacted by activity and tellurics provides a method for checking the robustness of a given Keplerian signal. We also test the approach on HD 40979, which is an active F8V star with a large-amplitude planetary signal. Our Monte Carlo simulations reveal that the significance of the Keplerian signal in the F star is much more sensitive to wavelength. Unlike the K star, the removal of active lines from the F star greatly reduces the RV precision. In this case, our removal of a K star active line from an F star does not a provide a simple useful diagnostic because it has far less RV information and heavily relies on the strong active lines. [ABSTRACT FROM AUTHOR]

The use of as-rolled cold forming steels opens new potential for lightweight construction in the automotive industry. Cold-rolled grades with a tensile strength up to 1100MPa are on the market. However, the high strength limits the cold forming performance. A local softening in areas of high degree of deformation can be a solution to this conflict. In this work, basic studies on softening of a sheet metal were conducted. A fiber-coupled diode laser with a maximum laser power of 12 kW and a rectangular laser spot were used for laser heat treatment of the steel grade ZE 1100. It is shown that a local softening can be achieved even with short term heating. The softening is due to partly or full recrystallization of the microstructure. The tensile strength and the yield point can be reduced by about half, and the elongation at break can be increased by a factor of seven. [ABSTRACT FROM AUTHOR]

Metal artifacts present a challenge to cone-beam CT (CBCT) image-guided surgery, obscuring visualization of metal instruments and adjacent anatomy—often in the very region of interest pertinent to the imaging/surgical tasks. We present a method to reduce the influence of metal artifacts by prospectively defining an image acquisition protocol—viz., the C-arm source-detector orbit—that mitigates metal-induced biases in the projection data. The metal artifact avoidance (MAA) method is compatible with simple mobile C-arms, does not require exact prior information on the patient or metal implants, and is consistent with 3D filtered backprojection (FBP), more advanced (e.g. polyenergetic) model-based image reconstruction (MBIR), and metal artifact reduction (MAR) post-processing methods. The MAA method consists of: (i) coarse localization of metal objects in the field-of-view (FOV) via two or more low-dose scout projection views and segmentation (e.g. a simple U-Net) in coarse backprojection; (ii) model-based prediction of metal-induced x-ray spectral shift for all source-detector vertices accessible by the imaging system (e.g. gantry rotation and tilt angles); and (iii) identification of a circular or non-circular orbit that reduces the variation in spectral shift. The method was developed, tested, and evaluated in a series of studies presenting increasing levels of complexity and realism, including digital simulations, phantom experiment, and cadaver experiment in the context of image-guided spine surgery (pedicle screw implants). The MAA method accurately predicted tilted circular and non-circular orbits that reduced the magnitude of metal artifacts in CBCT reconstructions. Realistic distributions of metal instrumentation were successfully localized (0.71 median Dice coefficient) from 2–6 low-dose scout views even in complex anatomical scenes. The MAA-predicted tilted circular orbits reduced root-mean-square error (RMSE) in 3D image reconstructions by 46%–70% and 'blooming' artifacts (apparent width of the screw shaft) by 20–45%. Non-circular orbits defined by MAA achieved a further ∼46% reduction in RMSE compared to the best (tilted) circular orbit. The MAA method presents a practical means to predict C-arm orbits that minimize spectral bias from metal instrumentation. Resulting orbits—either simple tilted circular orbits or more complex non-circular orbits that can be executed with a motorized multi-axis C-arm—exhibited substantial reduction of metal artifacts in raw CBCT reconstructions by virtue of higher fidelity projection data, which are in turn compatible with subsequent MAR post-processing and/or polyenergetic MBIR to further reduce artifacts. [ABSTRACT FROM AUTHOR]

Surgical reduction of pelvic dislocation is a challenging procedure with poor long-term prognosis if reduction does not accurately restore natural morphology. The procedure often requires long fluoroscopic exposure times and trial-and-error to achieve accurate reduction. We report a method to automatically compute the target pose of dislocated bones in preoperative CT and provide 3D guidance of reduction using routine 2D fluoroscopy. A pelvic statistical shape model (SSM) and a statistical pose model (SPM) were formed from an atlas of 40 pelvic CT images. Multi-body bone segmentation was achieved by mapping the SSM to a preoperative CT via an active shape model. The target reduction pose for the dislocated bone is estimated by fitting the poses of undislocated bones to the SPM. Intraoperatively, multiple bones are registered to fluoroscopy images via 3D–2D registration to obtain 3D pose estimates from 2D images. The method was examined in three studies: (1) a simulation study of 40 CT images simulating a range of dislocation patterns; (2) a pelvic phantom study with controlled dislocation of the left innominate bone; (3) a clinical case study investigating feasibility in images acquired during pelvic reduction surgery. Experiments investigated the accuracy of registration as a function of initialization error (capture range), image quality (radiation dose and image noise), and field of view (FOV) size. The simulation study achieved target pose estimation with translational error of median 2.3 mm (1.4 mm interquartile range, IQR) and rotational error of 2.1° (1.3° IQR). 3D–2D registration yielded 0.3 mm (0.2 mm IQR) in-plane and 0.3 mm (0.2 mm IQR) out-of-plane translational error, with in-plane capture range of ±50 mm and out-of-plane capture range of ±120 mm. The phantom study demonstrated 3D–2D target registration error of 2.5 mm (1.5 mm IQR), and the method was robust over a large dose range, down to 5 Gy/frame (an order of magnitude lower than the nominal fluoroscopic dose). The clinical feasibility study demonstrated accurate registration with both preoperative and intraoperative radiographs, yielding 3.1 mm (1.0 mm IQR) projection distance error with robust performance for FOV ranging from 340 × 340 mm2 to 170 × 170 mm2 (at the image plane). The method demonstrated accurate estimation of the target reduction pose in simulation, phantom, and a clinical feasibility study for a broad range of dislocation patterns, initialization error, dose levels, and FOV size. The system provides a novel means of guidance and assessment of pelvic reduction from routinely acquired preoperative CT and intraoperative fluoroscopy. The method has the potential to reduce radiation dose by minimizing trial-and-error and to improve outcomes by guiding more accurate reduction of joint dislocations. [ABSTRACT FROM AUTHOR]

Deposition of semiconductors on bendable substrates is a crucial step toward flexible circuitry and deposition by a roll-to-roll process. Since most bendable substrates have limited temperature stability (normally degradation starts between 150 °C and 300 °C), processing temperatures are typically below that of rigid substrates. Amorphous oxide semiconductors (AOSs) such as indium gallium zinc oxide (IGZO) can be fabricated at room temperature (RT) and exhibit electron mobilities >10 cm2 V−1 s−1 being a pre-requisite for application in backplanes of displays. While IGZO is already commercially exploited, the search for alternative materials is highly relevant because indium and gallium are rare and expensive. Zinc tin oxide (ZTO) is a promising AOS since zinc and tin are highly abundant and cheap. In this letter, we discuss RT-fabricated n-type ZTO thin films used as the channel material in flexible inverter circuits based on junction field-effect transistors. RT-fabricated nickel oxide is used as a semitransparent p-type gate material. The devices are fabricated on flexible polyimide and exhibit an excellent peak gain magnitude of 464 and uncertainty level as low as 130 mV at a supply voltage of only 3 V. They are characterized before and after bending at various radii. Even after bending at 2 mm radius, the inverters behave still very well. [ABSTRACT FROM AUTHOR]

Cardiovascular (CV) morbidity is the major cause of death in patients with Systemic Lupus Erythematosus (SLE). Previous studies on mannose-binding lectin (MBL) gene polymorphisms in SLE patients suggest that low levels of complement MBL are associated with cardiovascular disease (CVD). However, as large studies on MBL deficiency based on resulting MBL plasma concentrations are lacking, the aim of our study was to analyze the association of MBL concentrations with CVD in SLE patients. Plasma MBL levels SLE patients included in the Swiss SLE Cohort Study were quantified by ELISA. Five different CV organ manifestations were documented. Of 373 included patients (85.5% female) 62 patients had at least one CV manifestation. Patients with MBL deficiency (levels below 500 ng/ml or 1000 ng/ml) had no significantly increased frequency of CVD (19.4% vs. 15.2%, P = 0.3 or 17.7% vs. 15.7%, P = 0.7). After adjustment for traditional CV risk factors, MBL levels and positive antiphospholipid serology (APL+) a significant association of CVD with age, hypertension, disease duration and APL+ was demonstrated. In our study of a large cohort of patients with SLE, we could not confirm previous studies suggesting MBL deficiency to be associated with an increased risk for CVD. [ABSTRACT FROM AUTHOR]

The search for Earth-like planets around late-type stars using ultrastable spectrographs requires a very precise characterization of the stellar activity and the magnetic cycle of the star, since these phenomena induce radial velocity (RV) signals that can be misinterpreted as planetary signals. Among the nearby stars, we have selected Barnard's Star (Gl 699) to carry out a characterization of these phenomena using a set of spectroscopic data that covers about 14.5 yr and comes from seven different spectrographs: HARPS, HARPS-N, CARMENES, HIRES, UVES, APF, and PFS; and a set of photometric data that covers about 15.1 yr and comes from four different photometric sources: ASAS, FCAPT–RCT, AAVSO, and SNO. We have measured different chromospheric activity indicators (H α, Ca  ii  HK, and Na  i D), as well as the full width at half-maximum (FWHM), of the cross-correlation function computed for a sub-set of the spectroscopic data. The analysis of generalized Lomb–Scargle periodograms of the time series of different activity indicators reveals that the rotation period of the star is 145 ± 15 d, consistent with the expected rotation period according to the low activity level of the star and previous claims. The upper limit of the predicted activity-induced RV signal corresponding to this rotation period is about 1 m s−1. We also find evidence of a long-term cycle of 10 ± 2 yr that is consistent with previous estimates of magnetic cycles from photometric time series in other M stars of similar activity levels. The available photometric data of the star also support the detection of both the long-term and the rotation signals. [ABSTRACT FROM AUTHOR]

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Copyright of HOLOS is the property of Instituto Federal do Rio Grande do norte - IFRN and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Today, manufacturers in the automotive industry have to find a compromise between ensuring maximum safety for passengers, which is achieved by the use of high stiffness materials, and a minimum CO2 footprint. These aims are achieved primarily by the usage of lightweight designs. With respect to the car body, high-strength steels—such as the manganese boron steel MBW® 1500 (22MnB5)—fulfil these requirements. Workpieces made of 22MnB5 have a high tensile strength of about 1500 MPa, respectively, enabling reduction of the sheet thickness. However, this high strength is not favorable in all sections of a part, especially those which are relevant for safety. In order to locally adjust the mechanical properties of MBW 1500, a laser-based heat treatment process has been developed to meet the requirements of high ductility in the deformation zones for better crash performance and in joining areas. By means of laser radiation, the brittle martensitic microstructure of MBW 1500 is either tempered or transformed into a ferrite/perlite-dominated microstructure. While the feasibility of the laser softening of high-strength steels with diode laser systems using a tophat intensity profile at a maximum feed rate of 1.0 m/min has already been shown, the present work focuses on the increase in the feed rate of laser softening using an adapted intensity distribution. This distribution is generated using a free-form optics and is designed in such a way that a homogeneous temperature profile on the workpiece's surface is induced. As a result, the feed rate can be increased maintaining homogeneous softening across the sheet thickness. [ABSTRACT FROM AUTHOR]

Fouling of spiral-wound reverse osmosis (SWRO) membrane systems is a pervasive problem. Here we demonstrate that a mobile, low cost magnetic resonance imaging (MRI) apparatus operating at the earth’s magnetic field (low magnetic field, LF) can non-invasively (i) image the inside of a SWRO membrane system with glass fiber outside casing in a pressure vessel during cross flow operation and can (ii) detect the location of foulant, in this study sodium alginate. LF-MRI images of the module were successfully acquired in less than eight minutes using a spin-echo protocol, the internal structure of the modules was clearly evident and images compared well with high resolution MRIs obtained using a large-sized, costly high magnetic field superconducting MRI system. By parameter optimisation (specifically the echo time employed) it was possible to differentiate flowing and stagnant fluid in the clean and fouled membrane systems, and to determine the presence of alginate foulant on the feed-side of the fouled SWRO membrane system. This study motivates further investigation of the sensitivity of LF-MRI and the development of bespoke low cost LF-MRI hardware for the monitoring of industrial SWRO membrane installations. [ABSTRACT FROM AUTHOR]

Field experiences have shown that the use of geosynthetics improves the trafficability of unpaved roads on soft subsoil. Specifically, the thickness of the base course and therefore the amount of high quality geomaterials e.g. crushed gravel can be reduced. Until now, the design is mainly based on empirical approaches based on results from experiments obtained in field tests. The thickness of the base course is increased until an adequate bearing capacity of the unpaved road is reached. There are extensive studies throughout the literature that confirm the mechanism of the bearing capacity improvement, but mostly cover only individual effects such as the influence of the bearing layer thickness at constant subsoil strength. Therefore, they cannot be extended to a general theory and design approach that can account for all of the important variables. To investigate the effectiveness of different geosynthetics in unpaved roads a series of loading tests on geotextile reinforced, unpaved roads were carried out both in the laboratory and in the field. Beside the bearing strength and stiffness of the soft subsoil, the base course thickness as well as the type, and hence the strength of the geosynthetics were varied in the tests. This paper presents a brief summary of the experimental results that may be used to evaluate models to predict the bearing capacity of unpaved roads. [ABSTRACT FROM AUTHOR]

Dynamic light scattering in the depolarized geometry has been used to investigate the pretransitional behavior of diblock copolymer melts near the order–disorder transition (ODT). Besides the segmental orientational dynamics, an additional slow relaxation process contributes to the dynamic depolarized intensity. This new relaxation mode exhibits an almost exponential shape, a wave vector (q) independent relaxation rate, and a strongly temperature dependent amplitude that compares with the temperature dependence of the maximum of the static structure factor at q*, measured with small-angle x-ray scattering. An account for the characteristics of this new relaxation process is based on the coupling between orientation and order parameter fluctuations. The depolarized intensity is due to orientation and/or extension of the copolymer chains in the pretransitional state above the ODT, with the relevant length scale of the slow orientation fluctuations being close to 2π/q*. [ABSTRACT FROM AUTHOR]

Barnard’s star is a red dwarf, and has the largest proper motion (apparent motion across the sky) of all known stars. At a distance of 1.8 parsecs1, it is the closest single star to the Sun; only the three stars in the α Centauri system are closer. Barnard’s star is also among the least magnetically active red dwarfs known2,3 and has an estimated age older than the Solar System. Its properties make it a prime target for planetary searches; various techniques with different sensitivity limits have been used previously, including radial-velocity imaging4-6, astrometry7,8 and direct imaging9, but all ultimately led to negative or null results. Here we combine numerous measurements from high-precision radial-velocity instruments, revealing the presence of a low-amplitude periodic signal with a period of 233 days. Independent photometric and spectroscopic monitoring, as well as an analysis of instrumental systematic effects, suggest that this signal is best explained as arising from a planetary companion. The candidate planet around Barnard’s star is a cold super-Earth, with a minimum mass of 3.2 times that of Earth, orbiting near its snow line (the minimum distance from the star at which volatile compounds could condense). The combination of all radial-velocity datasets spanning 20 years of measurements additionally reveals a long-term modulation that could arise from a stellar magnetic-activity cycle or from a more distant planetary object. Because of its proximity to the Sun, the candidate planet has a maximum angular separation of 220 milliarcseconds from Barnard’s star, making it an excellent target for direct imaging and astrometric observations in the future. Analysis of 20 years of observations of Barnard’s star from seven facilities reveals a signal with a period of 233 days that is indicative of a companion planet. [ABSTRACT FROM AUTHOR]

The development of hot stamped manganese–boron steels established new potentials for lightweight constructions for applications in the automotive industry. This type of high strength steel allows the usage of thin sheet thicknesses resulting in low specific weight retaining the optimized performance of passive safety. The parts have a high tensile strength of about 1500 MPa. However, this high strength is not favorable in all sections of a part, especially those which are relevant for safety or for joining. To ensure the requirements for the crash properties or the joining areas, a high ductility is required in these areas. A way to overcome this problem is a local softening of the crash and joining zones via laser heat treatment. By means of laser radiation, the brittle martensitic microstructure is either tempered or transformed into a ferrite/perlite dominated microstructure. A fiber-coupled diode laser with a maximum laser power of 12 kW and rectangular laser spot is used for the laser heat treatment. The temperature is controlled by a monochromic pyrometer integrated into the optical system. Generally, the necessary process feed rate of the heat treatment process is low (about 1000 mm/min), as a homogeneous result of the heat treatment is pursued. As the feed rates increase (up to 8000 mm/min), the temperature distribution across the thickness of the material becomes more inhomogeneous. With the topside being hotter than the backside, the material is tempered with a varying intensity resulting in a hardness distribution across the thickness. The influencing parameters for this effect are being characterized, and the mechanical properties of the anisotropic material are investigated. [ABSTRACT FROM AUTHOR]

Copyright of Arthroskopie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Summary: We estimated the prevalence of sarcopenia and its impact on disability in older people. Sarcopenia was found to contribute to higher disability scores. However, our study was not able to show any influence of sarcopenia on the rate of functional decline. This directs attention to an accurate diagnosis of sarcopenia as the onset may be influenced, but its rate may not. Introduction: The objectives of this study using data from a population-based cohort were to estimate the prevalence of sarcopenia in older people in Germany and to test the hypothesis that sarcopenia is associated with disability in older adults. Methods: Cross-sectional ( n = 927) and longitudinal analyses ( n = 859) of participants aged ≥65 years at baseline from southern Germany enrolled in the Cooperative Health Research in the Region Augsburg (KORA)-Age study (2009-2012). Sarcopenia was defined based on the European Working Group on Sarcopenia in Older People (EWGSOP) algorithm which includes the presence of both low muscle mass and low muscle function (strength or performance). Disability status was measured by the Health Assessment Questionnaire-Disability Index (HAQ-DI). The presence of disability was defined as HAQ-DI >0. Directed acyclic graphs (DAGs) were constructed to identify potential confounders. The effect of sarcopenia on disability was analyzed using linear mixed effect models with disability values as a continuous outcome. Results: The overall prevalence of sarcopenia was 5.7% (men 4.0%, women 7.5%) and increased with age. The 3-year incidence of disability was 32.7%. After adjustment for potential confounders, presence of sarcopenia was significantly associated with higher disability scores (0.142 [confidence interval 0.029-0.254]). Conclusion: The prevalence of sarcopenia is consistent with estimates from other European studies using this algorithm. Our results suggest that sarcopenia can contribute to higher disability scores in older adults. However, our study was not able to show any influence of sarcopenia on the rate of functional decline using the EWGSOP diagnostic algorithm for sarcopenia. This directs attention to an accurate diagnosis of sarcopenia as the onset may be influenced, but its rate may not. [ABSTRACT FROM AUTHOR]

Aims. Our new program with HARPS aims to detect mean motion resonant planetary systems around stars which were previously reported to have a single bona fide planet, often based only on sparse radial velocity data. Methods. Archival and new HARPS radial velocities for the K2V star HD 27894 were combined and fitted with a three-planet self-consistent dynamical model. The best-fit orbit was tested for long-term stability. Results. We find clear evidence that HD 27894 is hosting at least three massive planets. In addition to the already known Jovian planet with a period Pb ≈ 18 days we discover a Saturn-mass planet with Pc ≈ 36 days, likely in a 2:1 mean motion resonance with the first planet, and a cold massive planet (≈5.3 MJup) with a period Pd ≈ 5170 days on a moderately eccentric orbit (ed = 0.39). Conclusions. HD 27894 is hosting a massive, eccentric giant planet orbiting around a tightly packed inner pair of massive planets likely involved in an asymmetric 2:1 mean motion resonance. HD 27894 may be an important milestone for probing planetary formation and evolution scenarios. [ABSTRACT FROM AUTHOR]

The Doppler measurements of stars are diluted and distorted by stellar activity noise. Different choices of noise models and statistical methods have led to much controversy in the confirmation of exoplanet candidates obtained through analysing radial velocity data. To quantify the limitation of various models and methods, we compare different noise models and signal detection criteria for various simulated and real data sets in the Bayesian framework. According to our analyses, the white noise model tend to interpret noise as signal, leading to false positives. On the other hand, the red noise models are likely to interpret signal as noise, resulting in false negatives. We find that the Bayesian information criterion combined with a Bayes factor threshold of 150 can efficiently rule out false positives and confirm true detections.We further propose a Goldilocks principle aimed at modelling radial velocity noise to avoid too many false positives and too many false negatives. We propose that the noise model with RHK-dependent jitter is used in combination with the moving average model to detect planetary signals for M dwarfs. Our work may also shed light on the noise modelling for hotter stars, and provide a valid approach for finding similar principles in other disciplines. [ABSTRACT FROM AUTHOR]