1,424 research outputs found
A Wideband, Four-Element, All-Digital Beamforming System for Dense Aperture Arrays in Radio Astronomy
Densely-packed, all-digital aperture arrays form a key area of technology
development required for the Square Kilometre Array (SKA) radio telescope. The
design of real-time signal processing systems for digital aperture arrays is
currently a central challenge in pathfinder projects worldwide. We describe
interim results of such work; an heirarchical, frequency-domain beamforming
architecture for synthesising a sky beam from the wideband antenna feeds of
digital aperture arrays.Comment: 4 pages, 6 figure
Feasibility study of Glucagon-like peptide-1 analogues for the optimization of Outcomes in obese patients undergoing AbLation for Atrial Fibrillation (GOAL-AF) protocol
BackgroundCatheter ablation for atrial fibrillation is recommended for symptomatic patients after failed medical therapy. Ablation has a higher failure rate in obese patients, and both the prevalence of atrial fibrillation and obesity are increasingly globally. The outcome of ablation can be improved if obese patients can achieve goal-oriented weight reduction prior to ablation. Conventional weight loss strategies, however, can be difficult to access and can delay ablation, thereby risking a lower chance of maintaining sinus rhythm. Effective weight-loss medications, such as the glucagon-like peptide inhibitor-1 drugs, offer the potential for incremental impact on weight loss over a shorter period of time as a bridging therapy. The aim of this study is to assess the feasibility of using liraglutide, a glucagon-like peptide inhibitor-1, in producing weight loss in obese patients before catheter ablation.MethodsThe study is an open-label, uncontrolled, prospective single-centre feasibility study of daily liraglutide injections in the treatment of obese patients for at least 13 weeks before and 52 weeks after AF ablation. Adult patients with symptomatic AF whose body mass indexââĽâ30 will be recruited from those planning to undergo ablation. Feasibility will be determined based on the recruitment rate, adherence to the medication, and the amount of weight loss achieved over the study period. Exploratory outcomes include changes in atrial structure, function, and fibrosis with weight loss evaluated by cardiac magnetic resonance imaging, electroanatomic mapping, and patient-reported outcome measure.DiscussionThis study will allow us to determine whether the use of liraglutide in obese patients with atrial fibrillation undergoing ablation is feasible with adequate recruitment. The additional information on adherence and average weight loss over the study period will inform the design of a future definitive randomized controlled trial.Trial registrationClinicalTrials.gov (NCT05221229). Registered on 2 February 2022.Trial fundingMetchley Park Medical Society and University of Birmingham Starter Fellowship, British Heart Foundation Accelerator Grant, Abbott Investigator-Initiated Study Grant
The effect of voluntary fasting and dehydration on flicker-induced retinal vascular dilation in a healthy individual: a case report
INTRODUCTION: Dynamic retinal vessel analysis represents a well-established method for the assessment of vascular reactivity during both normal conditions and after various provocations. We present a case where the subject showed abnormal retinal vessel reactivity after fasting voluntarily for 20 hours. CASE PRESENTATION: A healthy, 21-year-old man who fasted voluntarily for 20 hours exhibited abnormal retinal vascular reactivity (dilation and constriction) after flicker provocation as measured using the Dynamic Retinal Vessel Analyser (Imedos, Jena, Germany). CONCLUSION: The abnormal vascular reactivity induced by fasting was significant; abnormal levels of important nutrients due to fasting and dehydration could play a role through altering the concentration of vasoactive substances such as nitric oxide. This hypothesis needs further investigation
The Clinical Application of Polarization Pattern Perception
Purpose: Determine the repeatability of and optimum stimulus parameters for testing polarization pattern perception in a real-world clinical population, and assess the ability of polarization perception to distinguish normal from abnormal eyes. Methods: Polarization perception was evaluated in staff and patients attending ophthalmology clinics at Warwick Hospital, UK. A series of visual stimuli were presented in pseudorandom order using a liquid-crystal-displayâbased polarization pattern generator. Stimuli included geometric patterns, gratings, checkerboards, and optotypes. Participants had one or both eyes diagnosed as normal or abnormal following ophthalmic examination, optical coherence tomography, and measures of visual acuity. Measurement scores were assigned to the eye(s) of each participant depending on the total number of stimuli perceived or identified. Results: Stimuli covered the range of spatial scales resolvable within polarization perception by normal and abnormal eyes. Different stimuli had different saliencies. For each stimulus type, polarization perception in the abnormal group was significantly reduced compared with normal eyes (P < 0.001). Relative stimulus salience was broadly similar for normal-eye and abnormal-eye viewing groups, being greatest for radially symmetric patterns and least for optotypes. Checkerboard pattern salience had an inverse logarithmic relationship with check fundamental spatial frequency. A devised metric covering the dynamic range of polarization perception was repeatable, and the score derived from the metric was reduced in the abnormal group compared with the normal group (P < 0.001). Conclusions: Clinically useful metrics of polarization perception distinguish between normal and abnormal eyes. Translational Relevance: Perception of spatial patterns formed of non-uniform polarization fields has potential as a quantitative clinical diagnostic measuremen
The Ursinus Weekly, April 14, 1952
MSGA plans for evaluation of professors ⢠Alumni to hear Dr. Furbay speak ⢠Language table meets ⢠Sophs, freshmen draw up petitions; Deadline April 16 ⢠Plans made to stop cheating ⢠Library acquires new books ⢠Operetta Sari scheduled for this weekend ⢠Cultural Olympics rate play highly ⢠French Club entertained ⢠Jean Shepherd speaks at annual Weekly banquet: KYW disc jockey presents radio difficulties, problems ⢠Heads named for YMCA ⢠Late permissions discussed in WSGA meeting ⢠Eight members to represent Pi Gamma Mu at Albright ⢠IRC hears Ulbricht ⢠German Club to hold hunt ⢠Editorials: The passive student; Truman\u27s steel seizure wrong ⢠Dean of Men leads busy life ⢠Bruin team drops opener by last inning Ford rally ⢠Ed Dawkins wins in Olympic tryout ⢠Bob Swett elected captain ⢠Former Ursinus star honored ⢠Vermont\u27s new citizenshttps://digitalcommons.ursinus.edu/weekly/1540/thumbnail.jp
Clustering of tau-immunoreactive pathology in chronic traumatic encephalopathy
Chronic traumatic encephalopathy (CTE) is a neurodegenerative disorder which may result from repetitive brain injury. A variety of tau-immunoreactive pathologies are present, including neurofibrillary tangles (NFT), neuropil threads (NT), dot-like grains (DLG), astrocytic tangles (AT), and occasional neuritic plaques (NP). In tauopathies, cellular inclusions in the cortex are clustered within specific laminae, the clusters being regularly distributed parallel to the pia mater. To determine whether a similar spatial pattern is present in CTE, clustering of the tau-immunoreactive pathology was studied in the cortex, hippocampus, and dentate gyrus in 11 cases of CTE and 7 cases of Alzheimerâs disease neuropathologic change (ADNC) without CTE. In CTE: (1) all aspects of tau-immunoreactive pathology were clustered and the clusters were frequently regularly distributed parallel to the tissue boundary, (2) clustering was similar in two CTE cases with minimal co-pathology compared with cases with associated ADNC or TDP-43 proteinopathy, (3) in a proportion of cortical gyri, estimated cluster size was similar to that of cell columns of the cortico-cortical pathways, and (4) clusters of the tau-immunoreactive pathology were infrequently spatially correlated with blood vessels. The NFT and NP in ADNC without CTE were less frequently randomly or uniformly distributed and more frequently in defined clusters than in CTE. Hence, the spatial pattern of the tau-immunoreactive pathology observed in CTE is typical of the tauopathies but with some distinct differences compared to ADNC alone. The spread of pathogenic tau along anatomical pathways could be a factor in the pathogenesis of the disease
Understanding employee resourcing in construction organizations
In recent years the literature on employee resourcing has consistently advocated the importance of adopting a holistic, strategic approach to employee deployment decision making rather than adopting a reactive needs-based approach. This is particularly problematic in construction where the multi-project environment leads to constantly changing resource requirements and to changing demands over a project's life cycle. This can lead to inappropriate decisions, which fail to meet the longer-term needs of both construction organizations and their employees. A structured and comprehensive understanding of the current project team deployment practices within large construction organizations was developed. Project deployment practices were examined within seven case study contracting firms. The emergent themes that shaped the decision-making processes were grouped into five broad clusters comprising human resource planning, performance/career management, team deployment, employee involvement and training and development. The research confirms that a reactive and ad hoc approach to the function prevails within the firms investigated. This suggests a weak relationship between the deployment process and human resource planning, team deployment, performance management, employee involvement and training and development activities. It is suggested that strategic HR-business partnering could engender more transparent and productive relationships in this crucial area
The Differential Contribution of Macular Pigments and Foveal Anatomy to the Perception of Maxwellâs Spot and Haidingerâs Brushes
The relationship of macular pigments and foveal anatomy to the perception of Maxwellâs spot (MS) and Haidingerâs brushes (HB) entoptic phenomena were investigated. Dual-wavelength-autofluorescence and OCT were used to define macular pigment density and foveal anatomy in 52 eyes. MS was generated by alternating unpolarized red/blue and red/green uniform field illumination. HB was generated by alternating the linear polarization axis of a uniform blue field. In Experiment 1, horizontal widths of MS and HB were measured using a micrometer system and compared with macular pigment densities and OCT-defined morphometry. MS radius (mean 1.4°) was significantly less than HB radius (mean 1.6°), with the spatial extent of both phenomena falling between the boundaries of the foveola and foveal pit. Multiple regression showed MS and HB radii to be significantly associated with the macular pigment spatial profile radius. HB radius, but not MS radius, was also significantly associated with foveolar morphometry. Experiment 2 compared perceptual profiles of MS with macular pigment distribution patterns and demonstrated close agreement. The size and appearance of MS is a direct indicator of macular pigment density and distribution. Measures of HB radii are less specific, with dependence on both macular pigment density and foveal structure
Mapping of bioavailable strontium isotope ratios in France for archaeological provenance studies
Strontium isotope ratios (â¸âˇSr/â¸âśSr) of archaeological samples (teeth and bones) can be used to track mobility and migration across geologically distinct landscapes. However, traditional interpolation algorithms and classification approaches used to generate Sr isoscapes are often limited in predicting multiscale â¸âˇSr/â¸âśSr patterning. Here we investigate the suitability of plant samples and soil leachates from the IRHUM database (www.irhumdatabase.com) to create a bioavailable â¸âˇSr/â¸âśSr map using a novel geostatistical framework. First, we generated an â¸âˇSr/â¸âśSr map by classifying â¸âˇSr/â¸âśSr values into five geologically-representative isotope groups using cluster analysis. The isotope groups were then used as a covariate in kriging to integrate prior geological knowledge of Sr cycling with the information contained in the bioavailable dataset and enhance â¸âˇSr/â¸âśSr predictions. Our approach couples the strengths of classification and geostatistical methods to generate more accurate â¸âˇSr/â¸âśSr predictions (Root Mean Squared ErrorâŻ=âŻ0.0029) with an estimate of spatial uncertainty based on lithology and sample density. This bioavailable Sr isoscape is applicable for provenance studies in France, and the method is transferable to other areas with high sampling density. While our method is a step forward in generating accurate â¸âˇSr/â¸âśSr isoscapes, the remaining uncertainty also demonstrates that fine-modelling of â¸âˇSr/â¸âśSr variability is challenging and requires more than geological maps for accurately predicting â¸âˇSr/â¸âśSr variations across the landscape. Future efforts should focus on increasing sampling density and developing predictive models to further quantify and predict the processes that lead to â¸âˇSr/â¸âśSr variability.Funding was provided by ARC
DP110101415 (Grßn, Spriggs, Armstrong, Maureille and Falguères)
Understanding the migrations of prehistoric populations through direct
dating and isotopic tracking of their mobility patterns. Part of this research
was supported by the Australian French Association for Science &
Technology through the ACT Science Fellowship program (2013) to M.
Willme
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