1,838 research outputs found

    Federalism Disserved: the Drive for Deregulation

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    Supersonic Crossflow Transition Control in Ground and Flight Tests

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    This paper describes the use of distributed-roughness-element (DRE) patterns along a Mach 2 design swept-wing leading edge to increase the laminar flow extent and thereby reduce drag. One swept-wing model was tested in a supersonic wind tunnel as well as beneath a supersonic flight vehicle. Wing model surface data acquired during these tests included pressures, temperatures, and boundary-layer transition locations. Similarities and differences in experimental results are discussed. While wind tunnel and flight results show some differences, the wind tunnel results still provide key insights necessary for understanding how to design effective DRE patterns for use in flight applications. Experimental results demonstrate a DRE flow control effect observed in flight similar to that observed in the wind tunnel. Finally, a different perspective is discussed concerning what flow control role RE patterns might perform in any future swept-wing laminar flow control applications

    The Born-Oppenheimer Approach to the Matter-Gravity System and Unitarity

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    The Born-Oppenheimer approach to the matter-gravity system is illustrated and the unitary evolution for matter, in the absence of phenomena such as tunnelling or other instabilities, verified. The Born-Oppenheimer approach to the matter-gravity system is illustrated in a simple minisuperspace model and the corrections to quantum field theory on a semiclassical background exhibited. Within such a context the unitary evolution for matter, in the absence of phenomena such as tunnelling or other instabilities, is verified and compared with the results of other approaches. Lastly the simplifications associated with the use of adiabatic invariants to obtain the solution of the explicitly time dependent evolution equation for matter are evidenced.Comment: Latex, 12 pages. Revised version as accepted for publication by Class. and Quant. Grav. Some points explained and misprints correcte

    Adiabatic Invariant Treatment of a Collapsing Sphere of Quantized Dust

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    The semiclassical collapse of a sphere of quantized dust is studied. A Born-Oppenheimer decomposition is performed for the wave function of the system and the semiclassical limit is considered for the gravitational part. The method of adiabatic invariants for time dependent Hamiltonians is then employed to find (approximate) solutions to the quantum dust equations of motions. This allows us to obtain corrections to the adiabatic approximation of the dust states associated with the time evolution of the metric. The diverse non-adiabatic corrections are generally associated with particle (dust) creation and related fluctuations. The back-reaction due to the dominant contribution to particle creation is estimated and seen to slow-down the collapse.Comment: LaTeX, 16 pages, no figures, final version to appear in Class. and Quantum Gravit

    The 13-C(p,d) Reaction at 120 MeV

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    This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

    Comparing Water Level Estimation in Coastal and Shelf Seas From Satellite Altimetry and Numerical Models

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    Accurately resolving coastal Total Water Levels (TWL) is crucial for socio-economic and environmental reasons. Recent efforts in satellite altimetry and numerical modelling have improved accuracy over near-shore areas. In this study we used data from tide gauges (TGs), SAR-mode altimetry from two satellites (Sentinel-3A (S3) and CryoSat-2 (C2)), and a state-of-the-art high-resolution regional coupled environmental prediction model (Amm15) to undertake an inter-comparison between the observations and the model. The aim is to quantify our capability to measure TWL around the UK coast, and to quantify the capacity of the model to represent coastal TWL. Results show good agreement between the satellite and TG data (the mean correlation (R) over seventeen TGs between June 2016 and September 2017 is 0.85 for S3 and 0.80 for C2). The satellite-model comparison shows that the variability is well captured (R=0.98 for both satellite), however there is an offset (-0.23m for S3, -0.15m for C2) between the satellite and model data, that is near-constant across the domain. This offset is partly attributed to the difference in the reference level used by the satellites and the model, and residual differences linked to the temporal resolution of the model. The best agreement between model and satellite is seen away from the coast, further than 3-4km offshore. However, even within the coastal band, R remains high, ~0.95 (S3) and ~0.96 (C2). In conclusion, models are still essential to represent TWL in coastal regions where there is no cover from in-situ observations, but satellite altimeters can now provide valuable observations that are reliable much closer to the coast than before

    Southern GEMS groups II: HI distribution, mass functions and HI deficient galaxies

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    We investigate the neutral hydrogen (HI) content of sixteen groups for which we have multi-wavelength data including X-ray observations. Wide-field imaging of the groups was obtained with the 20-cm multibeam system on the 64-m Parkes telescope. We have detected ten previously uncatalogued HI sources, one of which has no visible optical counterpart. We examine the HI properties of the groups, compared to their X-ray characteristics, finding that those groups with a higher X-ray temperature and luminosity contain less HI per galaxy. The HI content of a group depends on its morphological make-up, with those groups dominated by early-type galaxies containing the least total HI. We determined the expected HI for the spiral galaxies in the groups, and found that a number of the galaxies were HI deficient. The HI deficient spirals were found both in groups with and without a hot intra-group medium. The HI deficient galaxies were not necessarily found at the centre of the groups, however, we did find that two thirds of HI deficient galaxies were found within about 1 Mpc from the group centre, indicating that the group environment is affecting the gas-loss from these galaxies. We determined the HI mass function for a composite sample of 15 groups, and found that it is significantly flatter than the field HI mass function. We also find a lack of high HI-mass galaxies in groups. One possible cause of this effect is the tidal stripping of HI gas from spiral galaxies as they are pre-processed in groups.Comment: accepted for publication in MNRAS, 26 pages, 13 Figures, 2 Appendice

    Counselling for people affected by cancer: the impact outside a healthcare setting

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    Objectives: Study objectives were to measure the impact of counselling for people affected by cancer outside a national or private healthcare setting, such as a hospital or clinic, following treatment, and shed light on the nuances of this by gender, age and cancer status. Methods: CORE-10 was used to measure psychological distress amongst a practice-based sample affected by cancer including a comparator group of those who had not yet received counselling. Setting: The study was conducted in counselling offices outside a clinical or healthcare setting, both in terms of physical infrastructure, and in terms of funding mechanisms. Participants: 158 participants were selected based on the following inclusion criteria: completion of a full set of CORE-10; having completed six sessions of counselling at the time of analysis. Results: Results show psychological distress improves for all receiving counselling outside a national or private healthcare setting according to the CORE-10 scores. Those ‘affected by cancer’ are initially more distressed and benefit more from counselling than ‘cancer patients’. In comparison with females, male comparator group scores increase (gets worse) between ‘assessment’ and ‘first’ counselling session, before they have received any counselling.Conclusions: The paper concludes that counselling ‘outside’ a healthcare setting appears to be beneficial to anyone diagnosed or affected by cancer. Benefits vary by demographic group and exploring the meaning behind variations requires further, qualitative, investigation

    The Highest-Copy Repeats are Methylated in the Small Genome of the Early Divergent Vascular Plant Selaginella moellendorffii

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    Background The lycophyte Selaginella moellendorffii is a vascular plant that diverged from the fern/seed plant lineage at least 400 million years ago. Although genomic information for S. moellendorffii is starting to be produced, little is known about basic aspects of its molecular biology. In order to provide the first glimpse to the epigenetic landscape of this early divergent vascular plant, we used the methylation filtration technique. Methylation filtration genomic libraries select unmethylated DNA clones due to the presence of the methylation-dependent restriction endonuclease McrBC in the bacterial host. Results We conducted a characterization of the DNA methylation patterns of the S. moellendorffii genome by sequencing a set of S. moellendorffii shotgun genomic clones, along with a set of methylation filtered clones. Chloroplast DNA, which is typically unmethylated, was enriched in the filtered library relative to the shotgun library, showing that there is DNA methylation in the extremely small S. moellendorffii genome. The filtered library also showed enrichment in expressed and gene-like sequences, while the highest-copy repeats were largely under-represented in this library. These results show that genes and repeats are differentially methylated in the S.moellendorffii genome, as occurs in other plants studied. Conclusion Our results shed light on the genome methylation pattern in a member of a relatively unexplored plant lineage. The DNA methylation data reported here will help understanding the involvement of this epigenetic mark in fundamental biological processes, as well as the evolutionary aspects of epigenetics in land plants

    Quality of Life in Chronic Pancreatitis is Determined by Constant Pain, Disability/Unemployment, Current Smoking, and Associated Co-Morbidities

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    OBJECTIVES: Chronic pancreatitis (CP) has a profound independent effect on quality of life (QOL). Our aim was to identify factors that impact the QOL in CP patients. METHODS: We used data on 1,024 CP patients enrolled in the three NAPS2 studies. Information on demographics, risk factors, co-morbidities, disease phenotype, and treatments was obtained from responses to structured questionnaires. Physical and mental component summary (PCS and MCS, respectively) scores generated using responses to the Short Form-12 (SF-12) survey were used to assess QOL at enrollment. Multivariable linear regression models determined independent predictors of QOL. RESULTS: Mean PCS and MCS scores were 36.7+/-11.7 and 42.4+/-12.2, respectively. Significant (P \u3c 0.05) negative impact on PCS scores in multivariable analyses was noted owing to constant mild-moderate pain with episodes of severe pain or constant severe pain (10 points), constant mild-moderate pain (5.2), pain-related disability/unemployment (5.1), current smoking (2.9 points), and medical co-morbidities. Significant (P \u3c 0.05) negative impact on MCS scores was related to constant pain irrespective of severity (6.8-6.9 points), current smoking (3.9 points), and pain-related disability/unemployment (2.4 points). In women, disability/unemployment resulted in an additional 3.7 point reduction in MCS score. Final multivariable models explained 27% and 18% of the variance in PCS and MCS scores, respectively. Etiology, disease duration, pancreatic morphology, diabetes, exocrine insufficiency, and prior endotherapy/pancreatic surgery had no significant independent effect on QOL. CONCLUSIONS: Constant pain, pain-related disability/unemployment, current smoking, and concurrent co-morbidities significantly affect the QOL in CP. Further research is needed to identify factors impacting QOL not explained by our analyses
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