1,086 research outputs found
Economists\u27 Publication Patterns
The results presented in this paper give a comprehensive picture of the extent of publishing by economists. While it is obvious that the traditional emphasis on refereed journal articles captures only a part of economists\u27 research output, to date it has been difficult to determine how large a part of that output was not being measured. This note provides the necessary perspective and presents information on the relative productivity of faculty at different institutional types and with different years of experience
How getting the right actors involved can help successful local policies spread across the country
One of the oft-cited advantages of the US system of government is that it gives state and local governments the ability to innovate in policymaking. But how can policies which are successful in one area be taken up elsewhere? In new research which examines the introduction by states of drug courts for non-violent offenders, James W. Douglas, Ringa Raudla, and Roger E. Hartley write that the spread of such policies is influenced by other governments who have already adopted the policy, state and local governments, and professional, national, and regional associations and lobby groups. Without the support of such key actors, they write, successful local policy innovations are unlikely to spread widely
Proceedings of the 16th Annual Meeting of the Society for Pediatric Dermatology
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75156/1/j.1525-1470.1992.tb00329.x.pd
State Court Budgeting and Judicial Independence: Clues from Oklahoma and Virginia
Perceived assaults on the independence of the judiciary have called new attention to how courts obtain their funding. Little scholarly activity has examined the question of how courts negotiate the politics of budgeting in state arenas. Expanding our knowledge in this area is necessary if we are to understand fully how budgeting affects the ability of the judiciary to effectively play its vital role as an independent branch in American government. Through the use of elite interviews with state court administrators, executive budget officers, and legislative budget analysts in Oklahoma and Virginia, this article examines whether the independence of state courts is under assault by budgetary politics. The evidence questions whether state executive and legislative powers of the purse pose serious threats to the independence of courts.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
First On-Sky Demonstration of a Scintillation Correction technique using Tomographic Wavefront Sensing
Scintillation noise significantly limits high precision ground-based photometry of bright stars. In this paper we present the first ever on-sky demonstration of scintillation correction. The technique uses tomographic wavefront sensing to estimate the spatial-temporal intensity fluctuations induced by high altitude optical turbulence. With an estimate of the altitudes and relative strengths of the turbulent layers above the telescope, the wavefront sensor data from multiple guide stars can be combined to estimate the phase aberrations of the wavefront at each altitude through the use of a tomographic algorithm. This 3D model of the phase aberrations can then be used to estimate the intensity fluctuations across the telescope pupil via Fresnel propagation. The measured photometric data for a given target within the field of view can then be corrected for the effects of scintillation using this estimate in post-processing. A simple proof-of-concept experiment using a wavefront sensor and a stereo-SCIDAR turbulence profiler attached to the 2.5m Isaac Newton Telescope was performed for a range of exposure times using the Orion Trapezium cluster as the reference stars. The results from this on-sky demonstration as well as simulations estimating the expected performance for a full tomographic AO system with laser guide stars are presented. On-sky the scintillation index was reduced on average by a factor of 1.9, with a peak of 3.4. For a full tomographic system we expect to achieve a maximum reduction in the scintillation index by a factor of ∼25
Optical sparse telescope arrays and scintillation noise
Fresnel propagation of starlight after it passes through high altitude turbulence in the Earth’s atmosphere results in random fluctuations of the intensity at ground level, known as scintillation. This effect adds random noise to photometric measurements with ground-based optical telescopes. Spatial correlation of the intensity fluctuations means that the fractional photometric noise due to scintillation may be substantially smaller for a sparse array of small aperture telescopes than for a single large aperture of the same total area. Assuming that the photometric noise for each telescope is independent, averaging the light curves measured by N telescopes reduces the noise by a factor of N−−√. For example, for bright stars, the signal-to-noise ratio of a 2.54 m telescope can be achieved for an array of thirty 20 cm telescopes if the scintillation noise measured for each telescope is uncorrelated. In this paper, we present results from simulation and from observations at the Isaac Newton Telescope. These explore the impact that several parameters have on the measured correlation of the scintillation noise between neighbouring telescopes. We show that there is significant correlation between neighbouring telescopes with separations parallel to the wind direction of the dominant high altitude turbulent layer. We find that the telescopes in an array should be separated by at least twice their aperture diameter so that there is negligible correlation of the photometric noise. We discuss additional benefits of using sparse telescope arrays, including reduced cost and increased field of view
The Frequency of Ras Mutations in Cancer
Ras is frequently mutated in cancer, however, there is a lack of consensus in the literature regarding the cancer mutation frequency of Ras, with quoted values varying from 10%–30%. This variability is at least in part due to the selective aggregation of data from different databases and the dominant influence of particular cancer types and particular Ras isoforms within these datasets. To provide a more definitive figure for Ras mutation frequency in cancer, we cross-referenced the data in all major publicly accessible cancer mutation databases to determine reliable mutation frequency values for each Ras isoform in all major cancer types. These percentages were then applied to current U.S. cancer incidence statistics to estimate the number of new patients each year that have Ras-mutant cancers. We find that approximately 19% of patients with cancer harbor Ras mutations, equivalent to approximately 3.4 million new cases per year worldwide. We discuss the Ras isoform and mutation-specific trends evident within the datasets that are relevant to current Ras-targeted therapies
Ferrets exclusively synthesize Neu5Ac and express naturally humanized influenza A virus receptors
Mammals express the sialic acids N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc) on cell surfaces, where they act as receptors for pathogens, including influenza A virus (IAV). Neu5Gc is synthesized from Neu5Ac by the enzyme cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMAH). In humans, this enzyme is inactive and only Neu5Ac is produced. Ferrets are susceptible to human-adapted IAV strains and have been the dominant animal model for IAV studies. Here we show that ferrets, like humans, do not synthesize Neu5Gc. Genomic analysis reveals an ancient, nine-exon deletion in the ferret CMAH gene that is shared by the Pinnipedia and Musteloidia members of the Carnivora. Interactions between two human strains of IAV with the sialyllactose receptor (sialic acid—α2,6Gal) confirm that the type of terminal sialic acid contributes significantly to IAV receptor specificity. Our results indicate that exclusive expression of Neu5Ac contributes to the susceptibility of ferrets to human-adapted IAV strains
Effect of base sequence on the DNA cross-linking properties of pyrrolobenzodiazepine (PBD) dimers
Pyrrolo[2,1-c][1,4]benzodiazepine (PBD) dimers are synthetic sequence-selective DNA minor-groove cross-linking agents that possess two electrophilic imine moieties (or their equivalent) capable of forming covalent aminal linkages with guanine C2-NH2 functionalities. The PBD dimer SJG-136, which has a C8–O–(CH2)3–O–C8′′ central linker joining the two PBD moieties, is currently undergoing phase II clinical trials and current research is focused on developing analogues of SJG-136 with different linker lengths and substitution patterns. Using a reversed-phase ion pair HPLC/MS method to evaluate interaction with oligonucleotides of varying length and sequence, we recently reported (JACS, 2009, 131, 13 756) that SJG-136 can form three different types of adducts: inter- and intrastrand cross-linked adducts, and mono-alkylated adducts. These studies have now been extended to include PBD dimers with a longer central linker (C8–O–(CH2)5–O–C8′), demonstrating that the type and distribution of adducts appear to depend on (i) the length of the C8/C8′-linker connecting the two PBD units, (ii) the positioning of the two reactive guanine bases on the same or opposite strands, and (iii) their separation (i.e. the number of base pairs, usually ATs, between them). Based on these data, a set of rules are emerging that can be used to predict the DNA–interaction behaviour of a PBD dimer of particular C8–C8′ linker length towards a given DNA sequence. These observations suggest that it may be possible to design PBD dimers to target specific DNA sequences
“I’ll meet you at our bench”: adaptation, innovation and resilience among VCSE organisations who supported marginalised and minoritised communities during the Covid-19 pandemic in Northern England – a qualitative focus group study
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