610 research outputs found

    Histological and molecular characterisation of feline humeral condylar osteoarthritis

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    <p>Background: Osteoarthritis (OA) is a clinically important and common disease of older cats. The pathological changes and molecular mechanisms which underpin the disease have yet to be described. In this study we evaluated selected histological and transcriptomic measures in the articular cartilage and subchondral bone (SCB) of the humeral condyle of cats with or without OA.</p> <p>Results: The histomorphometric changes in humeral condyle were concentrated in the medial aspect of the condyle. Cats with OA had a reduction in articular chondrocyte density, an increase in the histopathological score of the articular cartilage and a decrease in the SCB porosity of the medial part of the humeral condyle. An increase in LUM gene expression was observed in OA cartilage from the medial part of the humeral condyle.</p> <p>Conclusions: Histopathological changes identified in OA of the feline humeral condyle appear to primarily affect the medial aspect of the joint. Histological changes suggest that SCB is involved in the OA process in cats. Differentiating which changes represent OA rather than the aging process, or the effects of obesity and or bodyweight requires further investigation.</p&gt

    Conformational Changes of the Flavivirus E Glycoprotein

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    Dengue virus, a member of the Flaviviridae family, has a surface composed of 180 copies each of the envelope (E) glycoprotein and the membrane (M) protein. The crystal structure of an N-terminal fragment of E has been determined and compared with a previously described structure. The primary difference between these structures is a 10° rotation about a hinge relating the fusion domain DII to domains DI and DIII. These two rigid body components were used for independent fitting of E into the cryo-electron microscopy maps of both immature and mature dengue viruses. The fitted E structures in these two particles showed a difference of 27° between the two components. Comparison of the E structure in its postfusion state with that in the immature and mature virions shows a rotation approximately around the same hinge. Flexibility of E is apparently a functional requirement for assembly and infection of flaviviruses

    The Canada-UK Deep Submillimetre Survey: The Survey of the 14-hour field

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    We have used SCUBA to survey an area of 50 square arcmin, detecting 19 sources down to a 3sigma sensitivity limit of 3.5 mJy at 850 microns. We have used Monte-Carlo simulations to assess the effect of source confusion and noise on the SCUBA fluxes and positions, finding that the fluxes of sources in the SCUBA surveys are significantly biased upwards and that the fraction of the 850 micron background that has been resolved by SCUBA has been overestimated. The radio/submillmetre flux ratios imply that the dust in these galaxies is being heated by young stars rather than AGN. We have used simple evolution models based on our parallel SCUBA survey of the local universe to address the major questions about the SCUBA sources: (1) what fraction of the star formation at high redshift is hidden by dust? (2) Does the submillimetre luminosity density reach a maximum at some redshift? (3) If the SCUBA sources are proto-ellipticals, when exactly did ellipticals form? However, we show that the observations are not yet good enough for definitive answers to these questions. There are, for example, acceptable models in which 10 times as much high-redshift star formation is hidden by dust as is seen at optical wavelengths, but also acceptable ones in which the amount of hidden star formation is less than that seen optically. There are acceptable models in which very little star formation occurred before a redshift of three (as might be expected in models of hierarchical galaxy formation), but also ones in which 30% of the stars have formed by this redshift. The key to answering these questions are measurements of the dust temperatures and redshifts of the SCUBA sources.Comment: 41 pages (latex), 17 postscript figures, to appear in the November issue of the Astronomical Journa

    Rise of the Titans: Gas Excitation and Feedback in a Binary Hyper-Luminous Dusty Starburst Galaxy at z~6

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    We report new observations toward the hyper-luminous dusty starbursting major merger ADFS-27 (z=5.655), using ATCA and ALMA. We detect CO 2-1, 8-7, 9-8, 10-9 and H2O(321-221) emission, and a P-Cygni-shaped OH+(11-01) absorption/emission feature. We also tentatively detect H2O(321-312) and OH+(12-01) emission and CH+(1-0) absorption. We find a total cold molecular mass of M_gas = (2.1+/-0.2) x 10^11 (alpha_CO/1.0) Msun. We also find that the excitation of the star-forming gas is overall moderate for a z>5 dusty starburst, which is consistent with its moderate dust temperature. A high density, high kinetic temperature gas component embedded in the gas reservoir is required to fully explain the CO line ladder. This component is likely associated with the "maximum starburst" nuclei in the two merging galaxies, which are separated by only (140+/-13) km/s along the line of sight and 9.0 kpc in projection. The kinematic structure of both components is consistent with galaxy disks, but this interpretation remains limited by the spatial resolution of the current data. The OH+ features are only detected towards the northern component, which is also the one that is more enshrouded in dust and thus remains undetected up to 1.6 um even in our sensitive new HST/WFC3 imaging. The absorption component of the OH+ line is blueshifted and peaks near the CO and continuum emission peak while the emission is redshifted and peaks offset by 1.7 kpc from the CO and continuum emission peak, suggesting that the gas is associated with a massive molecular outflow from the intensely star-forming nucleus that supplies 125 Msun/yr of enriched gas to its halo.Comment: 20 pages, 11 figures, 6 tables; to appear in the Astrophysical Journal (accepted November 29, 2020

    Neural Excitability Alterations After Anterior Cruciate Ligament Reconstruction

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    Neuromuscular dysfunction is common after anterior cruciate ligament reconstruction (ACL-R). However, little is known about quadriceps spinal-reflex and descending corticomotor excitability after ACL-R. Understanding the effects of ACL-R on spinal-reflex and corticomotor excitability will help elucidate the origins of neuromuscular dysfunction

    Chiari’s Network as a Cause of Fetal and Neonatal Pathology

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    Chiari’s network is a remnant of the eustachian valve located in the right atrium. Incomplete involution of the fetal sinus venosus valves results in “redundant” Chiari’s network, which may compromise cardiovascular function. This report describes a case with the novel finding of prenatal compromise due to redundant Chiari’s network and an uncommon case with significant postnatal symptoms. In both cases, the symptoms (fetal hydrops and postnatal cyanosis) resolved spontaneously. The variety of cardiovascular pathologies described in the literature is believed to be associated with persistence of a Chiari network. Knowledge about this not always harmless structure is important for perinatologists, pediatricians, and pediatric cardiologists alike. The clinical importance of this rare pathology is that prenatal counseling may anticipate a generally positive outcome and that surgical intervention generally should be avoided

    Intuitive and Informal Knowledge in Preschoolers’ Development of Probabilistic Thinking

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    Preschoolers develop a wide range of mathematical informal knowledge and intuitive thinking before they enter formal, goal-oriented education. In their everyday activities young children get engaged with situations that enhance them to develop skills, concepts, strategies, representations, attitudes, constructs and operations concerning a wide range of mathematical notions. Recently there is scientific interest in linking children’s informal and formal knowledge in order to provide them with opportunities to avoid biases aiming at formulating, perceiving, reflecting on and exercising probabilistic notions. The current study investigates preschoolers’ (N=90) intuitive understanding of the likelihood of events in a probabilistic task with spinners. Participants, at the age of 4 to 6, are tested on their predictions of the most probable outcome prior to and after an instructive session of reasoning. The probabilistic task, based on constructivist principles, includes methodological alterations concerning the sample space and the themes of the stimuli. Educational implications are further discussed under the general point of view that in order to link informal to formal mathematical learning in preschool classroom, the subject content and the cognitive capacity of children are important to match

    Herschel ATLAS: The cosmic star formation history of quasar host galaxies

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    We present a derivation of the star formation rate per comoving volume of quasar host galaxies, derived from stacking analyses of far-infrared to mm-wave photometry of quasars with redshifts 0 IAB >-32 We use the science demonstration observations of the first ~16 deg2 from the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) in which there are 240 quasars from the Sloan Digital Sky Survey (SDSS) and a further 171 from the 2dF-SDSS LRG and QSO (2SLAQ) survey. We supplement this data with a compilation of data from IRAS, ISO, Spitzer, SCUBA and MAMBO. H-ATLAS alone statistically detects the quasars in its survey area at > 5σ at 250, 350 and 500 μm. From the compilation as a whole we find striking evidence of downsizing in quasar host galaxy formation: low-luminosity quasars with absolute magnitudes in the range 22 > IAB > -24 have a comoving star formation rate (derived from 100 μm rest-frame luminosities) peaking between redshifts of 1 and 2, while high-luminosity quasars with IAB IAB >-24 quasars evolves as (1 + z)2.3±0.7 at z I > -28. We tentatively interpret this as a combination of gas consumption reducing fuel for both black hole accretion and star formation.We thank the anonymous referee for useful comments. This work was funded in part by STFC (grants PP/D002400/1 and ST/G002533/1). Funding for the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the NSF, the U.S. Department of Energy, NASA, the Japanese Monbukagakusho, the Max Planck Society, and HEFCE

    Burden of Illness in UK Subjects with Reported Respiratory Infections Vaccinated or Unvaccinated against Influenza: A Retrospective Observational Study

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    <div><p>Objective</p><p>Detailed data are lacking on influenza burden in the United Kingdom (UK). The objective of this study was to estimate the disease burden associated with influenza-like illness (ILI) in the United Kingdom stratified by age, risk and influenza vaccination status.</p><p>Methods</p><p>This retrospective, cross-sectional, exploratory, observational study used linked data from the General Practice Research Database and the Hospital Episode Statistics databases to estimate resource use and cost associated with ILI in the UK.</p><p>Results</p><p>Data were included from 156,193 patients with ≥1 general practitioner visit with ILI. There were 21,518 high-risk patients, of whom 12,514 (58.2%) were vaccinated and 9,004 (41.8%) were not vaccinated, and 134,675 low-risk patients, of whom 17,482 (13.0%) were vaccinated and 117,193 (87.0%) were not vaccinated. High-risk vaccinated patients were older (p<0.001) and had more risk conditions (p<0.001). High-risk (odds ratio [OR] 2.16) or vaccinated (OR 1.19) patients had a higher probability of >1 general practitioner visit compared with low-risk and unvaccinated patients. Patients who were high-risk and vaccinated had a reduced risk of >1 general practitioner visit (OR 0.82; p<0.001). High-risk individuals who were also vaccinated had a lower probability of ILI-related hospitalisation than individuals who were high-risk or vaccinated alone (OR 0.59). In people aged ≥65 years, the mortality rate was lower in vaccinated than unvaccinated individuals (OR 0.75). The cost of ILI-related GP visits and hospital admissions in the UK over the study period in low-risk vaccinated patients was £27,391,142 and £141,932,471, respectively. In low-risk unvaccinated patients the corresponding values were £168,318,709 and £112,534,130, respectively.</p><p>Conclusions</p><p>Although vaccination rates in target groups have increased, many people are still not receiving influenza vaccination, and the burden of ILI in the United Kingdom remains substantial. Improving influenza vaccination uptake may have the potential to reduce this burden.</p></div
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