1,600 research outputs found

    Investigating the running abilities of Tyrannosaurus rex using stress-constrained multibody dynamic analysis

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    The running ability of Tyrannosaurus rex has been intensively studied due to its relevance to interpretations of feeding behaviour and the biomechanics of scaling in giant predatory dinosaurs. Different studies using differing methodologies have produced a very wide range of top speed estimates and there is therefore a need to develop techniques that can improve these predictions. Here we present a new approach that combines two separate biomechanical techniques (multibody dynamic analysis and skeletal stress analysis) to demonstrate that true running gaits would probably lead to unacceptably high skeletal loads in T. rex. Combining these two approaches reduces the high-level of uncertainty in previous predictions associated with unknown soft tissue parameters in dinosaurs, and demonstrates that the relatively long limb segments of T. rex—long argued to indicate competent running ability—would actually have mechanically limited this species to walking gaits. Being limited to walking speeds contradicts arguments of high-speed pursuit predation for the largest bipedal dinosaurs like T. rex, and demonstrates the power of multiphysics approaches for locomotor reconstructions of extinct animals

    Direct interaction between the Gulf Stream and the shelfbreak south of New England

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    © The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Scientific Reports 2 (2012): 553, doi:10.1038/srep00553.Sea surface temperature imagery, satellite altimetry, and a surface drifter track reveal an unusual tilt in the Gulf Stream path that brought the Gulf Stream to 39.9°N near the Middle Atlantic Bight shelfbreak—200 km north of its mean position—in October 2011, while a large meander brought Gulf Stream water within 12 km of the shelfbreak in December 2011. Near-bottom temperature measurements from lobster traps on the outer continental shelf south of New England show distinct warming events (temperature increases exceeding 6°C) in November and December 2011. Moored profiler measurements over the continental slope show high salinities and temperatures, suggesting that the warm water on the continental shelf originated in the Gulf Stream. The combination of unusual water properties over the shelf and slope in late fall and the subsequent mild winter may affect seasonal stratification and habitat selection for marine life over the continental shelf in 2012.Profiler data were made available by the Ocean Observatory Initiative (OOI) during the construction phase of the project. The OOI is funded by the National Science Foundation and managed by the Consortium for Ocean Leadership. Drifter data were provided by Tim Shaw and David Calhoun at Cape Fear Community College.GGGwas supported by NSFGrant OCE-1129125. RET was supported by the Postdoctoral Scholar Program at the Woods Hole Oceanographic Institution, with funding provided by the Cooperative Institute for the North Atlantic Region. MA was supported by the Penzance Endowed Fund in Support of Assistant Scientists

    Exploring the treatment burden of disease-modifying anti-rheumatic drug monitoring in people with rheumatoid arthritis

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    This is the final version. Available on open access from Oxford University Press via the DOI in this recordData availability: The data underlying this article are available in the article and in its own online supplementary material.OBJECTIVES: People with RA taking DMARDs require safety monitoring to identify potential side effects. The aim of this study was to explore the perspectives of patients and family members on DMARD monitoring and how the associated treatment burden could be minimized to optimize concordance and safety. METHODS: Thirteen adults with RA on DMARDs and three family members participated in semi-structured telephone interviews between July 2021 and January 2022. Data were analysed using a framework method. Findings were discussed with a group of stakeholders to develop implications for practice. RESULTS: Two main themes were identified: (i) making sense of drug monitoring; and (ii) work involved in drug monitoring. Participants perceived DMARDs as necessary to reduce symptoms, with drug monitoring providing an opportunity for a holistic assessment of wellbeing. Participants expressed a preference for face-to-face consultations, which allowed them to share their concerns, rather than remote, often transactional, care. The limited availability of convenient appointment times, travel requirements and parking increased the work involved for patients and family members. CONCLUSION: Drug monitoring was accepted as a necessity of DMARD treatment, but increased the work for people with RA related to organizing and attending appointments. The potential for treatment burden needs to be assessed proactively by clinicians when a DMARD is commenced. Where identified, strategies for minimizing the treatment burden can form part of a shared management plan, including the offer of regular contact with health professionals, with an emphasis on person-centred care.General Nursing Council for England and Wales Trust (GNCT)National Institute for Health and Care Research (NIHR

    Humans store about 1.5 megabytes of information during language acquisition

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    We introduce theory-neutral estimates of the amount of information learners possess about how language works. We provide estimates at several levels of linguistic analysis: phonemes, wordforms, lexical semantics, word frequency and syntax. Our best guess is that the average English-speaking adult has learned 12.5 million bits of information, the majority of which is lexical semantics. Interestingly, very little of this information is syntactic, even in our upper bound analyses. Generally, our results suggest that learners possess remarkable inferential mechanisms capable of extracting, on average, nearly 2000 bits of information about how language works each day for 18 years

    Economic geology: Volatile destruction

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    International audienceDirect evidence for the role of volatiles in magmatic ore formation has been elusive. Magma degassing at Merapi volcano in Indonesia is found to be directly linked to the selective leaching of metals from sulphide melts that ultimately form ore deposits

    Osteoporosis and fracture as risk factors for self-harm and suicide: a systematic review and meta-analysis

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    This is the author accepted manuscript. The final version is available from the Royal College of General Practitioners via the DOI in this recordData Sharing Statement: Full search criteria for MEDLINE is included in Supplementary file 1.Background: Increase in presentations of self-harm to primary care, a risk factor of suicide has led to a growing interest in identifying at-risk populations. Aim: To examine whether osteoporosis or fractures are risk factors for self-harm, suicidal ideation, and suicide. Design and Setting: Systematic review of observational studies in adults (18> years) which had examined the role of osteoporosis and/or fractures in subsequent self-harm, suicidal ideation, and/or suicide. Method: Six databases were searched from inception to July 2019. Additional citation tracking of eligible studies was done in November 2022. Screening, data extraction and quality assessment of full-text articles were performed independently by at least two authors. Where possible, meta-analysis was run on comparable risk estimates. Results and Conclusion: Fifteen studies were included, two examined the outcome of self-harm, three suicidal ideation and 10 suicide. In approximately half of studies on osteoporosis, the risk of suicidal ideation and suicide remained significant. However, pooling of adjusted odds ratios from three studies indicated no association between osteoporosis and suicide (1.14(95% confidence interval 0.88-1.49)). Nine studies examined the risk of a mixture of fracture types across different outcomes, limiting comparisons. However, all studies examining vertebral fracture (n=3) reported a significant adjusted negative association for self-harm and suicide. In conclusion, Patients with vertebral fractures may benefit from case-finding for mood disorders in primary care, which are risk factors for suicide, and the subsequent management. However, due to the limited number and quality of studies and mixed findings, further examination of these associations is warranted.National Institute for Health and Care Research (NIHR

    SuperCLASS - II. Photometric redshifts and characteristics of spatially resolved mu Jy radio sources

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    We present optical and near-infrared imaging covering a ∼1.53 deg2 region in the Super-Cluster Assisted Shear Survey (SuperCLASS) field, which aims to make the first robust weak lensing measurement at radio wavelengths. We derive photometric redshifts for ≈176 000 sources down to i′AB∼24 and present photometric redshifts for 1.4 GHz expanded Multi-Element Radio Linked Interferometer Network (e-MERLIN) and Karl G. Jansky Very Large Array (VLA) detected radio sources found in the central 0.26 deg2. We compile an initial catalogue of 149 radio sources brighter than S1.4 > 75 μJy and find their photometric redshifts span 0 7σ in the density map and we confirm the photometric redshifts are consistent with previously measured spectra from a few galaxies at the cluster centres

    The effect of Gonioscopy on keratometry and corneal surface topography

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    BACKGROUND: Biometric procedures such as keratometry performed shortly after contact procedures like gonioscopy and applanation tonometry could affect the validity of the measurement. This study was conducted to understand the short-term effect of gonioscopy on corneal curvature measurements and surface topography based Simulated Keratometry and whether this would alter the power of an intraocular lens implant calculated using post-gonioscopy measurements. We further compared the effect of the 2-mirror (Goldmann) and the 4-mirror (Sussman) Gonioscopes. METHODS: A prospective clinic-based self-controlled comparative study. 198 eyes of 99 patients, above 50 years of age, were studied. Exclusion criteria included documented dry eye, history of ocular surgery or trauma, diabetes mellitus and connective tissue disorders. Auto-Keratometry and corneal topography measurements were obtained at baseline and at three follow-up times – within the first 5 minutes, between the 10(th)-15(th )minute and between the 20(th)-25(th )minute after intervention. One eye was randomized for intervention with the 2-mirror gonioscope and the other underwent the 4-mirror after baseline measurements. t-tests were used to examine differences between interventions and between the measurement methods. The sample size was calculated using an estimate of clinically significant lens implant power changes based on the SRK-II formula. RESULTS: Clinically and statistically significant steepening was observed in the first 5 minutes and in the 10–15 minute interval using topography-based Sim K. These changes were not present with the Auto-Keratometer measurements. Although changes from baseline were noted between 20 and 25 minutes topographically, these were not clinically or statistically significant. There was no significant difference between the two types of gonioscopes. There was greater variability in the changes from baseline using the topography-based Sim K readings. CONCLUSION: Reversible steepening of the central corneal surface is produced by the act of gonioscopy as measured by Sim K, whereas no significant differences were present with Auto-K measurements. The type of Gonioscope used does not appear to influence these results. If topographically derived Sim K is used to calculate the power of the intraocular lens implant, we recommend waiting a minimum of 20 minutes before measuring the corneal curvature after gonioscopy with either Goldmann or Sussman contact lenses

    SuperCLASS - III. Weak lensing from radio and optical observations in Data Release 1

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    We describe the first results on weak gravitational lensing from the SuperCLASS survey: the first survey specifically designed to measure the weak lensing effect in radio-wavelength data, both alone and in cross-correlation with optical data. We analyse 1.53deg2 of optical data from the Subaru telescope and 0.26deg2 of radio data from the e-MERLIN and VLA telescopes (the DR1 data set). Using standard methodologies on the optical data only we make a significant (10σ) detection of the weak lensing signal (a shear power spectrum) due to the massive supercluster of galaxies in the targeted region. For the radio data we develop a new method to measure the shapes of galaxies from the interferometric data, and we construct a simulation pipeline to validate this method. We then apply this analysis to our radio observations, treating the e-MERLIN and VLA data independently. We achieve source densities of 0.5 arcmin−2 in the VLA data and 0.06 arcmin−2 in the e-MERLIN data, numbers which prove too small to allow a detection of a weak lensing signal in either the radio data alone or in cross-correlation with the optical data. Finally, we show preliminary results from a visibility-plane combination of the data from e-MERLIN and VLA which will be used for the forthcoming full SuperCLASS data release. This approach to data combination is expected to enhance both the number density of weak lensing sources available, and the fidelity with which their shapes can be measured
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