Comparison of spatial domain optimal trade-off maximum average correlation height (OT-MACH) filter with scale invariant feature transform (SIFT) using images with poor contrast and large illumination gradient

A spatial domain optimal trade-off Maximum Average Correlation Height (OT-MACH) filter has been previously developed and shown to have advantages over frequency domain implementations in that it can be made locally adaptive to spatial variations in the input image background clutter and normalised for local intensity changes. In this paper we compare the performance of the spatial domain (SPOT-MACH) filter to the widely applied data driven technique known as the Scale Invariant Feature Transform (SIFT). The SPOT-MACH filter is shown to provide more robust recognition performance than the SIFT technique for demanding images such as scenes in which there are large illumination gradients. The SIFT method depends on reliable local edge-based feature detection over large regions of the image plane which is compromised in some of the demanding images we examined for this work. The disadvantage of the SPOTMACH filter is its numerically intensive nature since it is template based and is implemented in the spatial domain. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

Retention of CO Ice and Gas Within 486958 Arrokoth

Kuiper Belt Objects (KBOs) represent some of the most ancient remnants of our solar system, having evaded significant thermal or evolutionary processing. This makes them important targets for exploration as they offer a unique opportunity to scrutinize materials that are remnants of the epoch of planet formation. Moreover, with recent and upcoming observations of KBOs, there is a growing interest in understanding the extent to which these objects can preserve their most primitive, hypervolatile ices. Here, we present a theoretical framework that revisits this issue for small, cold classical KBOs like Arrokoth. Our analytical approach is consistent with prior studies but assumes an extreme cold end-member thermophysical regime for Arrokoth, enabling us to capture the essential physics without computationally expensive simulations. Under reasonable assumptions for interior temperatures, thermal conductivities, and permeabilities, we demonstrate that Arrokoth can retain its original CO stock for Gyrs if it was assembled long after the decay of radionuclides. The sublimation of CO ice generates an effective CO `atmosphere' within Arrokoth's porous matrix, which remains in near vapor-pressure equilibrium with the ice layer just below, thereby limiting CO loss. According to our findings, Arrokoth expels no more than $\approx 10^{22}$ particles s$^{-1}$, in agreement with upper limits inferred from \textit{New Horizons}' 2019 flyby observations. While our framework challenges recent predictions, it can serve as a benchmark for existing numerical models and be applied to future KBO observations from next-generation telescopes.Comment: Under consideration for publication in ICARUS special conference issue: ACM 1

Gastrointestinal Transit Times in Health as Determined Using Ingestible Capsule Systems: A Systematic Review.

BACKGROUND: Ingestible capsule (IC) systems can assess gastrointestinal (GI) transit times as a surrogate for gut motility for extended periods of time within a minimally invasive, radiation-free and ambulatory setting. METHODS: A literature review of IC systems and a systematic review of studies utilizing IC systems to measure GI transit times in healthy volunteers was performed. Screening for eligible studies, data extraction and bias assessments was performed by two reviewers. A narrative synthesis of the results was performed. RESULTS: The literature review identified 23 different IC systems. The systematic review found 6892 records, of which 22 studies were eligible. GI transit time data were available from a total of 1885 healthy volunteers. Overall, seventeen included studies reported gastric emptying time (GET) and small intestinal transit time (SITT). Colonic transit time (CTT) was reported in nine studies and whole gut transit time (WGTT) was reported in eleven studies. GI transit times in the included studies ranged between 0.4 and 15.3 h for GET, 3.3-7 h for SITT, 15.9-28.9 h for CTT and 23.0-37.4 h for WGTT. GI transit times, notably GET, were influenced by the study protocol. CONCLUSIONS: This review provides an up-to-date overview of IC systems and reference ranges for GI transit times. It also highlights the need to standardise protocols to differentiate between normal and pathological function

15 years of comet photometry: A comparative analysis of 80 comets

In 1976 we began a program of narrowband photometry of comets that has encompassed well over 400 nights of observations. To date, the program has provided detailed information on 80 comets, 11 of which have been observed on multiple apparitions. In this paper we present the observed range of compositions (molecular production rate ratios) and dustiness (gas production compared with AF-rho) for a well sampled group of comets. Based on these results we present preliminary analysis of taxonomic groupings as well as the abundance ratios we associate with a 'typical' comet

Autosomal Dominant Retinal Dystrophies Caused by a Founder Splice Site Mutation, c.828+3A>T, in PRPH2 and Protein Haplotypes in trans as Modifiers.

PurposeWe determined the phenotypic variation, disease progression, and potential modifiers of autosomal dominant retinal dystrophies caused by a splice site founder mutation, c.828+3A>T, in the PRPH2 gene.MethodsA total of 62 individuals (19 families) harboring the PRPH2 c.828+3A>T mutation, had phenotype analysis by fundus appearance, electrophysiology, and visual fields. The PRPH2 haplotypes in trans were sequenced for potential modifying variants and generalized estimating equations (GEE) used for statistical analysis.ResultsSeveral distinct phenotypes caused by the PRPH2 c.828+3A>T mutation were observed and fell into two clinical categories: Group I (N = 44) with mild pattern dystrophies (PD) and Group II (N = 18) with more severe cone-rod dystrophy (CRD), retinitis pigmentosa (RP), and central areolar chorioretinal dystrophy (CACD). The PRPH2 Gln304-Lys310-Asp338 protein haplotype in trans was found in Group I only (29.6% vs. 0%), whereas the Glu304-Lys310-Gly338 haplotype was predominant in Group II (94.4% vs. 70.4%). Generalized estimating equations analysis for PD versus the CRD/CACD/RP phenotypes in individuals over 43 years alone with the PRPH2 haplotypes in trans and age as predictors, adjusted for correlation within families, confirmed a significant effect of haplotype on severity (P = 0.03) with an estimated odds ratio of 7.16 (95% confidence interval [CI] = [2.8, 18.4]).ConclusionsThe PRPH2 c.828+3A>T mutation results in multiple distinct phenotypes likely modified by protein haplotypes in trans; the odds of having the CACD/RP-like phenotype (versus the PD phenotype) are 7.16 times greater with a Glu304-Lys310-Gly338 haplotype in trans. Further functional studies of the modifying haplotypes in trans and PRPH2 splice variants may offer therapeutic targets

Preschool and parental influences on physical activity and fundamental movement skills in preschool children from low socio-economic backgrounds: A qualitative study.

PA levels of children attending different preschools have been reported as varying greatly, with the characteristics of the preschool influencing a child’s PA level (Pate, Pfeiffer, Trost, Ziegler and Dowda, [2004], Pediatrics 114, 1258-1263). Parents and teachers have been known to overestimate the PA levels that children complete and this may place a decreased importance on encouraging and supporting PA in preschool children (Tucker, [2008], Early Childhood Research Quarterly, 23, 547-558). Settings with greater space and opportunities for outdoor play and PA are required, as a lack of space is a major cause of being overweight for 10-40% of children in developed countries (Blair, Wood and Sallis, [1994], Preventive Medicine, 23, 558-559). Mastery of Fundamental Movement Skills (FMS) is a prerequisite to functioning on a daily basis (Venetsanou and Kambas, [2011], Physical Education and Sport, 9, 81-90); they provide the building blocks for future motor skills and PA. Failure to achieve mastery in these skills could prevent preschool children from participating in PA. Therefore, the aim of this study was to investigate nursery staff and parents’ perceptions of preschool children’s PA, in relation to the environment, facilities, play and barriers to PA. With institutional ethics approval, focus groups were conducted in 4 preschools, with the inclusion of parents and staff of 3-5 year old children (n = 17, parents = 10, staff = 7) from North Warwickshire, England. Thematic analysis (Braun and Clarke, [2006], Qualitative Research in Psychology, 3, 77-101) was used to identify key themes and subthemes from the transcripts. Emergent themes included: outside exercise, outdoor equipment, the responsibility of PA, lack of exercise, modern lifestyles, time, cost, health and safety concerns of staff and staff training. Differences were apparent between preschools when discussing measurement of PA and FMS, PA at home, space in the settings and staff training. The findings suggest that preschools provide good opportunities for PA and FMS, especially for pre-schoolers from low socio-economic backgrounds. However, results also highlighted a need for more extensive training of staff in relation to PA and FMS opportunities. To increase PA and FMS in pre-schoolers, interventions are required which continue with the current levels of PA in preschools, combined with parental involvement to deliver PA; through encouraging indoor and outdoor activities and participating in less sedentary activities in the home environment. Interventions also need to provide staff training to support settings to deliver PA and FMS to preschool children.N/

Indication of Anisotropy in Electromagnetic Propagation over Cosmological Distances

We report a systematic rotation of the plane of polarization of electromagnetic radiation propagating over cosmological distances. The effect is extracted independently from Faraday rotation, and found to be correlated with the angular positions and distances to the sources. Monte Carlo analysis yields probabilistic P-values of order 10^(-3) for this to occur as a fluctuation. A fit yields a birefringence scale of order 10^(25) meters. Dependence on redshift z rules out a local effect. Barring hidden systematic bias in the data, the correlation indicates a new cosmological effect.Comment: 5 pages, 1 figure, ReVTeX. For more information, see http://www.cc.rochester.edu/college/rtc/Borge/aniso.htm

A new constant-pressure molecular dynamics method for finite system

In this letter, by writing the volume as a function of coordinates of atoms, we present a new constant-pressure molecular dynamics method with parameters free. This method is specially appropriate for the finite system in which the periodic boundary condition does not exist. Simulations on the carbon nanotube and the Ni nanoparticle clearly demonstrate the validity of the method. By using this method, one can easily obtain the equation of states for the finite system under the external pressure.Comment: RevTex, 5 pages, 3 figures, submitted to Phys. Rev. Let

The impact of changing provider remuneration on clinical activity and quality of care: evaluation of a pilot NHS contract in Northern Ireland

Objectives A pilot NHS dental contract was introduced in Northern Ireland between 2015 and 2016, which involved changing the method for paying general dental practitioners working in the NHS from Fee-For-Service (FFS) to capitation-based payments, providing an opportunity for a robust evaluation. We investigated the impact of a change in payment methods on clinical activity and the quality of care provided. Design A difference-in-difference (DiD) evaluation was applied to clinical activity data from pilot NHS dental practices in Northern Ireland compared to matched control NHS practices, and applied to a questionnaire survey of patient-rated outcomes of health outcomes and care quality. We estimated the impact on access to care, treatment activity levels, practice finances and patient-rated outcomes of care of a change from FFS to a capitation-based system for one year, as well as the impact of a reversion back to FFS at the end of the pilot period. Results The monthly number of registered patients in the pilot practices increased more than the control practices during the capitation period, by 1.5 registrations per 1,000 registered patients. The monthly reductions in the volumes of all treatments in the pilot practices during the capitation period was much larger than the control practices, with 175 fewer treatment items. All measures rapidly returned to baseline levels following reversion from capitation back to FFS. NHS income per month increased in pilot practices, by £5,920 per month (calculated on FFS item cost basis) more than controls in the capitation period. The analysis of patient questionnaires suggest found that patients notices differences only in waiting times, skill-mix and number of radiographs, but not on other measures of healthcare process and quality. Conclusion General dental practitioners working in the NHS respond rapidly and consistently to changes in provider payment methods. A move from FFS to a capitation-based system had little impact on access to care, but did produce large reductions in clinical activity and patient charge income. Patients noticed little change in the service they received. This shows that changes in remuneration contracts have the potential to meet policy goals, such as meeting the expectations of patients within a predictable cost envelope. However, it is unlikely that all policy goals can be met simply by changing payment methods. Therefore, work is also needed to identify and evaluate interventions that can complement changes in remuneration to achieve desirable outcomes