184 research outputs found

    Beak morphology in oviraptorids, based on extant birds and turtles

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    Oviraptorids are one of several groups of dinosaurs which have evolved beaks. Of extant beaked animals, birds and turtles are the best known. In this study, an anatomical comparison between oviraptorids, extant birds and turtles was made to try to reconstruct the beak in oviraptorids. The results show a close similarity in mandibular beak shape of parrots and oviraptorids, whereas turtles deviate. In the upper jaw, the oviraptorids show more resemblance to the latter group. The same bones, namely the premaxilla but also the maxilla and the nasal, were covered by ramphotheca in almost all the groups of birds, as well as in oviraptorids and turtles. Comparative evidence suggests that oviraptorids may have had a beak suited for an omnivorous diet, and the diet primarily consists of small prey, but also eggs, nuts and hard seeds. Keywords: oviraptorids, parrots, turtles, ramphotheca, skull anatomy, crest

    Diagnostic value of MRI for detecting recurrent soft-tissue sarcoma in a long-term analysis at a multidisciplinary sarcoma center

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    Background Soft-tissue sarcomas (STS) are rare tumors of the soft tissue. Recent diagnostic studies on STS mainly dealt with only few cases of STS and did not investigate the post-therapeutic performance of MRI in a routine clinical setting. Therefore, we assessed the long-term diagnostic accuracy of MRI for detecting recurrent STS at a multidisciplinary sarcoma center. The median age of the patients was 55.3 ± 18.2 years. Of the patients, 34.8% presented with recurrences. Here, 65 follow-up scans were true positive, 23 false positive, 6 false negative, and 961 true negative. The overall sensitivity and specificity of MRI for detecting recurrences were 92 and 98%, respectively, with an accuracy of 97%. For intramuscular lesions and after surgery alone the sensitivity was higher (95 and 97%, respectively) than for subcutaneous lesions and surgery with additional radiation therapy (83 and 86%, respectively), at similarly high specificities (96-98%). The 6 false-negative results were found in streaky (n = 2) and small ovoid/nodular (n = 4) recurring lesions. The false-positive lesions imitated streaky (n = 14), ovoid/nodular (n = 8), and polycyclic/multilobulated recurring tumors (n = 1). All false-positive results were found in patients in whom the primary tumors were polycyclic/multilobulated in appearance. Conclusion MRI shows a high diagnostic accuracy for detecting recurrent STS, with a high sensitivity and specificity. The diagnostic accuracy decreases in subcutaneous lesions and after surgery with radiation therapy, compared to intramuscular lesions and surgery alone. Radiologists should pay particular attention to streaky and small ovoid/nodular recurring lesions and patients with polycyclic/multilobulated primary tumors

    Configuration of soft-tissue sarcoma on MRI correlates with grade of malignancy

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    The aim of the study was to assess whether the configuration of primary soft-tissue sarcoma (STS) on MRI correlates with the grade of malignancy. 71 patients with histologically proven STS were included. Primary STS were examined for configuration, borders, and volume on MRI. The tumors were divided into high-grade (G3), intermediate-grade (G2) and low-grade (G1) STS according to the grading system of the French Federation of Cancer Centers Sarcoma Group (FNCLCC). 30 high-grade, 22 intermediate-grade and 19 low-grade primary STS lesions were identified. High- and intermediate-grade (G3/2) STS significantly most often appeared as polycyclic/multilobulated tumors (p < 0.001 and p = 0.002, respectively). Low-grade (G1) STS mainly showed an ovoid/nodular or streaky configuration (p = 0.008), and well-defined borders. The appearance of high-, intermediate- and low-grade STS with an ovoid/nodular configuration were mainly the same on MRI. All streaky G3/2 sarcoma and 17 of 20 patients with polycyclic/multilobulated G3 sarcoma showed infiltrative borders. High-grade streaky and polycyclic/multilobulated STS are larger in volume, compared to intermediate- and low-grade STS. . Configuration of STS on MRI can indicate the grade of malignancy. Higher-grade (G2/3) STS most often show a polycyclic/multilobulated configuration, while low-grade STS are mainly ovoid/nodular or streaky. Infiltrative behavior might suggest higher-grade STS in streaky and polycyclic/multilobulated STS

    En byhistorie i kleber

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    Naturhistorisk museum prydes av 62 løvehoder. Rehabiliteringen av bygningen avdekket, under sju lag med maling, at løvehodene på midtbygget fra 1865 var hogd i kleberstein, mens hodene på fløyene fra 1898 var støpt i betong. I protokollen etter direksjonen til Bergens Museum 15.oktober 1860 finner vi følgende nedtegnelse: Til bortkjøreldse af forskjellig klæberstene til Rakkerhougen fra Udgravningerne i Klosteret bevilgedes udredet derfor nogle. Midler (ca 22 Speds.). Mysteriet om hvor klebersteinene til løvehodene kom fra, kan dermed være delvis løst

    Assessing Models using Monte Carlo Simulations

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    We establish a framework for assessing the validity of a given model using Monte Carlo simulations and inferences based on sampling distributions. Using this framework, we show that geometric brownian motion alone cannot generate a majority of the patterns in the distribution of stock returns and wealth creation. Our paper represents an often overlooked departure from the traditional way of validating asset pricing models, in which implications are derived, parameters calibrated, and magnitudes compared to empirical data. Instead, we seek to leverage the power of large numbers by conducting numerous simulations and assessing the probability that they contain our realized stock market

    Medical Imaging Decision And Support (MIDAS):Study protocol for a multi-centre cluster randomized trial evaluating the ESR iGuide

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    Objectives: Medical imaging plays an essential role in healthcare. As a diagnostic test, imaging is prone to substantial overuse and potential overdiagnosis, with dire consequences to patient outcomes and health care costs. Clinical decision support systems (CDSSs) were developed to guide referring physicians in making appropriate imaging decisions. This study will evaluate the effect of implementing a CDSS (ESR iGuide) with versus without active decision support in a physician order entry on the appropriate use of imaging tests and ordering behaviour. Methods: A protocol for a multi-center cluster-randomized trial with departments acting as clusters, combined with a before-after-revert design. Four university hospitals with eight participating departments each for a total of thirty-two clusters will be included in the study. All departments start in control condition with structured data entry of the clinical indication and tracking of the imaging exams requested. Initially, the CDSS is implemented and all physicians remain blinded to appropriateness scores based on the ESR imaging referral guidelines. After randomization, half of the clusters switch to the active intervention of decision support. Physicians in the active condition are made aware of the categorization of their requests as appropriate, under certain conditions appropriate, or inappropriate, and appropriate exams are suggested. Physicians may change their requests in response to feedback. In the revert condition, active decision support is removed to study the educational effect. Results/conclusions: The main outcome is the proportion of inappropriate diagnostic imaging exams requested per cluster. Secondary outcomes are the absolute number of imaging exams, radiation from diagnostic imaging, and medical costs. Trial registration number: Approval from the Medical Ethics Review Committee was obtained under protocol numbers 20–069 (Augsburg), B 238/21 (Kiel), 20–318 (Lübeck) and 2020–15,125 (Mainz). The trial is registered in the ClinicalTrials.gov</p

    Do changes in persistent organic pollutants after bariatric surgery cause endocrine disruption?

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    Background Bariatric surgery results in weight loss, marked endocrine changes and the release of persistent organic pollutants (POPs). The release of POPs might cause endocrine disruption. The study aimed to explore associations between POPs and adiponectin, leptin and ghrelin in subjects undergoing bariatric surgery. Methods: The study included 63 subjects with severe obesity (men/women: 13/50), age (years): 45.0 (8.5), and BMI (kg/m2) 39.1 (3.4). Analyses of adiponectin, leptin and ghrelin and POPs (hexachlorobenzene (HCB), dichlorodiphenyldichloroethylene (p,p’-DDE), polychlorinated biphenyl (PCB) 118 (dioxin-like compound; dl), and sum 6 PCB (PCB 28, -52, −101, −138, −153, and −180) were performed before and 12 months after bariatric surgery. Results: There were significant increases in adiponectin and all POPs and a fall in leptin after surgery. The main finding was the highly significant associations between adiponectin and all POPs. The increase in HCB explained 38% of the variation in adiponectin. Conclusions: If the POP-associated increase in adiponectin is a causal effect, the release of POPs might have important clinical consequences. Adiponectin has both positive and negative clinical effects exerted by essentially unknown mechanisms. The effects of released POPs on the metabolic functions in subjects undergoing bariatric surgery deserve further evaluation. © 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Do changes in persistent organic pollutants after bariatric surgery cause endocrine disruption?publishedVersio

    Induction of Empathy by the Smell of Anxiety

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    The communication of stress/anxiety between conspecifics through chemosensory signals has been documented in many vertebrates and invertebrates. Here, we investigate how chemosensory anxiety signals conveyed by the sweat of humans (N = 49) awaiting an academic examination are processed by the human brain, as compared to chemosensory control signals obtained from the same sweat donors in a sport condition. The chemosensory stimuli were pooled according to the donation condition and administered to 28 participants (14 males) synchronously to breathing via an olfactometer. The stimuli were perceived with a low intensity and accordingly only about half of the odor presentations were detected by the participants. The fMRI results (event-related design) show that chemosensory anxiety signals activate brain areas involved in the processing of social emotional stimuli (fusiform gyrus), and in the regulation of empathic feelings (insula, precuneus, cingulate cortex). In addition, neuronal activity within attentional (thalamus, dorsomedial prefrontal cortex) and emotional (cerebellum, vermis) control systems were observed. The chemosensory perception of human anxiety seems to automatically recruit empathy-related resources. Even though the participants could not attentively differentiate the chemosensory stimuli, emotional contagion seems to be effectively mediated by the olfactory system
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