9,459 research outputs found

    Digit-only sauropod pes trackways from China - evidence of swimming or a preservational phenomenon?

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    For more than 70 years unusual sauropod trackways have played a pivotal role in debates about the swimming ability of sauropods. Most claims that sauropods could swim have been based on manus-only or manus-dominated trackways. However none of these incomplete trackways has been entirely convincing, and most have proved to be taphonomic artifacts, either undertracks or the result of differential depth of penetration of manus and pes tracks, but otherwise showed the typical pattern of normal walking trackways. Here we report an assemblage of unusual sauropod tracks from the Lower Cretaceous Hekou Group of Gansu Province, northern China, characterized by the preservation of only the pes claw traces, that we interpret as having been left by walking, not buoyant or swimming, individuals. They are interpreted as the result of animals moving on a soft mud-silt substrate, projecting their claws deeply to register their traces on an underlying sand layer where they gained more grip during progression. Other sauropod walking trackways on the same surface with both pes and manus traces preserved, were probably left earlier on relatively firm substrates that predated the deposition of soft mud and silt . Presently, there is no convincing evidence of swimming sauropods from their trackways, which is not to say that sauropods did not swim at all

    Learning and Matching Multi-View Descriptors for Registration of Point Clouds

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    Critical to the registration of point clouds is the establishment of a set of accurate correspondences between points in 3D space. The correspondence problem is generally addressed by the design of discriminative 3D local descriptors on the one hand, and the development of robust matching strategies on the other hand. In this work, we first propose a multi-view local descriptor, which is learned from the images of multiple views, for the description of 3D keypoints. Then, we develop a robust matching approach, aiming at rejecting outlier matches based on the efficient inference via belief propagation on the defined graphical model. We have demonstrated the boost of our approaches to registration on the public scanning and multi-view stereo datasets. The superior performance has been verified by the intensive comparisons against a variety of descriptors and matching methods

    Perceptual Embedding Consistency for Seamless Reconstruction of Tilewise Style Transfer

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    Style transfer is a field with growing interest and use cases in deep learning. Recent work has shown Generative Adversarial Networks(GANs) can be used to create realistic images of virtually stained slide images in digital pathology with clinically validated interpretability. Digital pathology images are typically of extremely high resolution, making tilewise analysis necessary for deep learning applications. It has been shown that image generators with instance normalization can cause a tiling artifact when a large image is reconstructed from the tilewise analysis. We introduce a novel perceptual embedding consistency loss significantly reducing the tiling artifact created in the reconstructed whole slide image (WSI). We validate our results by comparing virtually stained slide images with consecutive real stained tissue slide images. We also demonstrate that our model is more robust to contrast, color and brightness perturbations by running comparative sensitivity analysis tests

    International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) - the propagation of knowledge in ultrasound for the improvement of OB/GYN care worldwide: experience of basic ultrasound training in Oman.

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    BACKGROUND: The aim of this study is to evaluate effectiveness of a new ISUOG (International Society of Ultrasound in Obstetrics and Gynecology) Outreach Teaching and Training Program delivered in Muscat, Oman. METHODS: Quantitative assessments to evaluate knowledge and practical skills were administered before and after an ultrasound course for sonologists attending the ISUOG Outreach Course, which took place in November, 2017, in Oman. Trainees were selected from each region of the country following a national vetting process conducted by the Oman Ministry of Health. Twenty-eight of the participants were included in the analysis. Pre- and post-training practical and theoretical scores were evaluated and compared. RESULTS: Participants achieved statistically significant improvements, on average by 47% (p < 0.001), in both theoretical knowledge and practical skills. Specifically, the mean score in the theoretical knowledge test significantly increased from 55.6% (± 14.0%) to 81.6% (± 8.2%), while in the practical test, the mean score increased from 44.6% (± 19.5%) to 65.7% (± 23.0%) (p < 0.001). Performance was improved post-course among 27/28 participants (96.4%) in the theoretical test (range: 14 to 200%) and among 24/28 (85.7%) trainees in the practical skills test (range: 5 to 217%). CONCLUSION: Application of the ISUOG Basic Training Curriculum and Outreach Teaching and Training Course improved the theoretical knowledge and practical skills of local health personnel. Long-term re-evaluation is, however, considered imperative to ascertain and ensure knowledge retention

    Diagnosis of pancreaticobiliary malignancy by detection of minichromosome maintenance protein 5 in biliary brush cytology

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    Background: Biliary brush cytology is the standard method of evaluating biliary strictures, but is insensitive at detecting malignancy. In pancreaticobiliary cancer minichromosome maintenance replication proteins (MCM 2–7) are dysregulated in the biliary epithelium and MCM5 levels are elevated in bile samples. This study aimed to validate an immunocolorimetric ELISA assay for MCM5 as a pancreaticobiliary cancer biomarker in biliary brush samples. methods: Biliary brush specimens were collected prospectively at ERCP from patients with a biliary stricture. Collected samples were frozen at −80 °C. The supernatant was washed and lysed cells incubated with HRP-labelled anti-MCM5 mouse monoclonal antibody. Test positivity was determined by optical density absorbance. Patients underwent biliary brush cytology or additional investigations as per clinical routine. results: Ninety-seven patients were included in the study; 50 had malignant strictures. Median age was 65 years (range 21–94) and 51 were male. Compared with final diagnosis the MCM5 assay had a sensitivity for malignancy of 65.4% compared with 25.0% for cytology. In the 72 patients with paired MCM5 assay and biliary brush cytology, MCM5 demonstrated an improved sensitivity (55.6% vs 25.0%; P=0.0002) for the detection of malignancy. conclusions: Minichromosome maintenance replication protein5 is a more sensitive indicator of pancreaticobiliary malignancy than standard biliary brush cytology

    Endoscopic versus percutaneous drainage of symptomatic pancreatic fluid collections: a 14-year experience from a tertiary hepatobiliary centre

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    INTRODUCTION: Endoscopic transmural drainage (ED) or percutaneous drainage (PD) has mostly replaced surgery for the initial management of patients with symptomatic pancreatic fluid collections (PFCs). This study aimed to compare outcomes for patients undergoing ED or PD of symptomatic PFCs. METHODS: Between January 2000 and December 2013, all patients who required PD or ED of a PFC were included. Rates of treatment success, length of hospital stay, adverse events, re-interventions and length of follow-up were recorded retrospectively in all cases. RESULTS: In total, 164 patients were included in the study; 109 patients underwent ED; and 55 had PD alone. During the 14-year study period, the incidence of ED increased and PD fell. In the 109 patients who were managed by ED, treatment success was considerably higher than in those managed by PD (70 vs. 31 %). Rates of procedural adverse events were higher in the ED cohort compared to the PD group (10 vs. 1 %), but patients managed by ED required fewer interventions (median of 1.8 vs. 3.3) had lower rates of residual collections (21 vs. 67 %) and need for surgical intervention (4 vs. 11 %). In the ED group, treatment success was similar for walled-off pancreatic necrosis (WOPN) and pseudocysts (67 vs. 72 %, P = 0.77). There were no procedure-related deaths. CONCLUSION: Compared with PD, ED of symptomatic PFCs was associated with higher rates of treatment success, lower rates of re-intervention, including surgery and shorter lengths of hospital stay. Outcomes in WOPN were comparable to those in patients with pseudocysts

    Influenza transmission in a cohort of households with children: 2010-2011

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    Long-term efficacy and safety of dichlorphenamide for treatment of primary periodic paralysis

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    Introduction/Aim: Long-term efficacy and safety of dichlorphenamide (DCP) were characterized in patients with primary periodic paralysis (PPP). Methods: Patients with PPP in a double-blind, placebo-controlled study were randomly assigned to receive DCP 50 mg twice daily or placebo for 9 weeks, followed by a 52-week open-label DCP treatment phase (DCP/DCP and placebo/DCP populations). Efficacy (attack rate, severity-weighted attack rate) and safety were assessed in patients completing the study (61 weeks). In this post hoc analysis, efficacy and safety data were pooled from hyperkalemic and hypokalemic substudies. Results: Sixty-three adults (age, 19-76 years) completed the double-blind phase; 47 (74.6%) of these patients completed 61 weeks. There were median decreases in weekly attack and severity-weighted attack rates from baseline to week 61 (DCP/DCP [n = 25], −1.00 [P < .0001]; placebo/DCP [n = 20], −0.63 [P = .01] and DCP/DCP, −2.25 [P < .0001]; placebo/DCP, −1.69 [P = .01]). Relatively smaller median decreases in weekly attack and severity-weighted attack rates occurred from weeks 9 to 61 among patients receiving DCP continuously (n = 26; −0.14 [P = .1] and −0.24 [P = .09]) than among those switching from placebo to DCP after 9 weeks (n = 16; −1.04 [P = .049] and −2.72 [P = .08]). Common adverse events (AEs) were paresthesia and cognition-related events, which typically first occurred within 1 month of blinded treatment initiation and in rare cases led to treatment discontinuation. Dose reductions were frequently associated with common AE resolution. Discussion: One-year open-label DCP treatment after a 9-week randomized, controlled study confirmed long-term DCP remains safe and effective for chronic use. Tolerability issues (paresthesia, cognition-related AEs) were manageable in most patients
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