3,296 research outputs found
Anisotropic reflectivity technique
Available from British Library Document Supply Centre- DSC:D44305/83 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo
Heavy meson chiral perturbation theory in finite volume
We present the first step towards the estimation of finite volume effects in
heavy-light meson systems using heavy meson chiral perturbation theory. We
demonstrate that these effects can be amplified in both light-quark and
heavy-quark mass extrapolations (interpolations) in lattice calculations. As an
explicit example, we perform a one-loop calculation for the neutral B meson
mixing system and show that finite volume effects, which can be comparable with
currently quoted errors, are not negligible in both quenched and partially
quenched QCD.Comment: Talk presented at Lattice2004(heavy), Fermilab, June 21st-26th, 2004.
Three pages, two figure
Investigating students seriousness during selected conceptual inventory surveys
Conceptual inventory surveys are routinely used in education research to
identify student learning needs and assess instructional practices. Students
might not fully engage with these instruments because of the low stakes
attached to them. This paper explores tests that can be used to estimate the
percentage of students in a population who might not have taken such surveys
seriously. These three seriousness tests are the pattern recognition test, the
easy questions test, and the uncommon answers test. These three tests are
applied to sets of students who were assessed either by the Force Concept
Inventory, the Conceptual Survey of Electricity and Magnetism, or the Brief
Electricity and Magnetism Assessment. The results of our investigation are
compared to computer simulated populations of random answers.Comment: 8 pages; submitted to Phys Rev PE
Conclusion: Rethinking African Governance and Development
This article draws together the main strands of argument being developed by the Africa Power and Politics Programme (APPP), as reflected in this IDS Bulletin. The central question is what kinds of governance arrangements work better to support the provision of the public goods that are essential to sustained and inclusive development in Africa. Evidence at local, sectoral and national levels is pointing to the overall conclusion that what works is often a ‘practical hybrid’, combining authoritative coordination with local problem?solving and constructive borrowing from local cultural repertoires. Consistent with the general idea of ‘going with the grain’, we find that the most likely source of the necessary vertical discipline is a developmental form of neo?patrimonialism, not ‘good governance’, as currently conceived. Similarly, local collective action to address bottlenecks in public goods provision is seldom enhanced by standard donor and NGO approaches to citizen or client empowerment
Letter to the Editor:What are the legal and ethical considerations of submitting radiology reports to ChatGPT?
This letter critically examines the recent article by Infante et al. assessing the utility of large language models (LLMs) like GPT-4, Perplexity, and Bard in identifying urgent findings in emergency radiology reports. While acknowledging the potential of LLMs in generating labels for computer vision, concerns are raised about the ethical implications of using patient data without explicit approval, highlighting the necessity of stringent data protection measures under GDPR
Resolved Debris Discs Around A Stars in the Herschel DEBRIS Survey
The majority of debris discs discovered so far have only been detected
through infrared excess emission above stellar photospheres. While disc
properties can be inferred from unresolved photometry alone under various
assumptions for the physical properties of dust grains, there is a degeneracy
between disc radius and dust temperature that depends on the grain size
distribution and optical properties. By resolving the disc we can measure the
actual location of the dust. The launch of Herschel, with an angular resolution
superior to previous far-infrared telescopes, allows us to spatially resolve
more discs and locate the dust directly. Here we present the nine resolved
discs around A stars between 20 and 40 pc observed by the DEBRIS survey. We use
these data to investigate the disc radii by fitting narrow ring models to
images at 70, 100 and 160 {\mu}m and by fitting blackbodies to full spectral
energy distributions. We do this with the aim of finding an improved way of
estimating disc radii for unresolved systems. The ratio between the resolved
and blackbody radii varies between 1 and 2.5. This ratio is inversely
correlated with luminosity and any remaining discrepancies are most likely
explained by differences to the minimum size of grain in the size distribution
or differences in composition. We find that three of the systems are well fit
by a narrow ring, two systems are borderline cases and the other four likely
require wider or multiple rings to fully explain the observations, reflecting
the diversity of planetary systems.Comment: 19 pages, 13 figures, 6 tables. Accepted for publication in MNRA
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