634 research outputs found
The Zeeman effect in the G band
We investigate the possibility of measuring magnetic field strength in G-band
bright points through the analysis of Zeeman polarization in molecular CH
lines. To this end we solve the equations of polarized radiative transfer in
the G band through a standard plane-parallel model of the solar atmosphere with
an imposed magnetic field, and through a more realistic snapshot from a
simulation of solar magneto-convection. This region of the spectrum is crowded
with many atomic and molecular lines. Nevertheless, we find several instances
of isolated groups of CH lines that are predicted to produce a measurable
Stokes V signal in the presence of magnetic fields. In part this is possible
because the effective Land\'{e} factors of lines in the stronger main branch of
the CH A--X transition tend to zero rather quickly for
increasing total angular momentum , resulting in a Stokes spectrum of
the G band that is less crowded than the corresponding Stokes spectrum. We
indicate that, by contrast, the effective Land\'{e} factors of the and
satellite sub-branches of this transition tend to for increasing .
However, these lines are in general considerably weaker, and do not contribute
significantly to the polarization signal. In one wavelength location near 430.4
nm the overlap of several magnetically sensitive and non-sensitive CH lines is
predicted to result in a single-lobed Stokes profile, raising the
possibility of high spatial-resolution narrow-band polarimetric imaging. In the
magneto-convection snapshot we find circular polarization signals of the order
of 1% prompting us to conclude that measuring magnetic field strength in
small-scale elements through the Zeeman effect in CH lines is a realistic
prospect.Comment: 22 pages, 6 figures. To be published in the Astrophysical Journa
Rule 10b-5: Birth of the Concept of Market Insider and Its Application in a Criminal Case - United States v. Chiarella
This Note examines the necessity of the expansion of the market insider by the Second Circuit Court of Appeals in United States v. Chairella. It goes on to analyze whether or not the criminal conviction under Rule 10b-5 of Chiarella was appropriate given the lack of notice
Outpatient antibiotic prescription trends in the United States: A national cohort study
OBJECTIVETo characterize trends in outpatient antibiotic prescriptions in the United StatesDESIGNRetrospective ecological and temporal trend study evaluating outpatient antibiotic prescriptions from 2013 to 2015SETTINGNational administrative claims data from a pharmacy benefits manager PARTICIPANTS. Prescription pharmacy beneficiaries from Express Scripts Holding CompanyMEASUREMENTSAnnual and seasonal percent change in antibiotic prescriptionsRESULTSApproximately 98 million outpatient antibiotic prescriptions were filled by 39 million insurance beneficiaries during the 3-year study period. The most commonly prescribed antibiotics were azithromycin, amoxicillin, amoxicillin/clavulanate, ciprofloxacin, and cephalexin. No significant changes in individual or overall annual antibiotic prescribing rates were found during the study period. Significant seasonal variation was observed, with antibiotics being 42% more likely to be prescribed during February than September (peak-to-trough ratio [PTTR], 1.42; 95% confidence interval [CI], 1.39–1.61). Similar seasonal trends were found for azithromycin (PTTR, 2.46; 95% CI, 2.44–3.47), amoxicillin (PTTR, 1.52; 95% CI, 1.42–1.89), and amoxicillin/clavulanate (PTTR, 1.78; 95% CI, 1.68–2.29).CONCLUSIONSThis study demonstrates that annual national outpatient antibiotic prescribing practices remained unchanged during our study period. Furthermore, seasonal peaks in antibiotics generally used to treat viral upper respiratory tract infections remained unchanged during cold and influenza season. These results suggest that inappropriate prescribing of antibiotics remains widespread, despite the concurrent release of several guideline-based best practices intended to reduce inappropriate antibiotic consumption; however, further research linking national outpatient antibiotic prescriptions to associated medical conditions is needed to confirm these findings.Infect Control Hosp Epidemiol 2018;39:584–589</jats:sec
Aircraft Configured for Flight in an Atmosphere Having Low Density
An aircraft is configured for flight in an atmosphere having a low density. The aircraft includes a fuselage, a pair of wings, and a rear stabilizer. The pair of wings extends from the fuselage in opposition to one another. The rear stabilizer extends from the fuselage in spaced relationship to the pair of wings. The fuselage, the wings, and the rear stabilizer each present an upper surface opposing a lower surface. The upper and lower surfaces have X, Y, and Z coordinates that are configured for flight in an atmosphere having low density
Sources of total, non-milk extrinsic, and intrinsic and milk sugars in the diets of older adults living in sheltered accommodation
The WHO recommends limiting non-milk extrinsic sugars (NMES) consumption to ≤ 10 % energy to reduce the risk of unhealthy weight gain and dental caries, and to restrict frequency of intake to ≤ 4 times/d to reduce risk of dental caries. Older adults, especially those from low-income backgrounds, are at increased risk of dental caries, yet there is little information on sugars intake (frequency of intake and food sources) in this age group. The aim of this report is to present baseline data from a community-based dietary intervention study of older adults from socially deprived areas of North East England, on the quantity and sources of total sugars, NMES, and intrinsic and milk sugars, and on frequency of NMES intake. Dietary intake was assessed using two 3-d estimated food diaries, completed by 201 participants (170 female, thirty-one male) aged 65–85 years (mean 76·7 (sd 5·5) years) recruited from sheltered housing schemes. Total sugars represented 19·6 %, NMES 9·3 %, and intrinsic and milk sugars 10·3 % of daily energy intake. Eighty-one (40·3 %) exceeded the NMES intake recommendation. Mean frequency of NMES intake was 3·4 times/d. The fifty-three participants (26·4 %) who exceeded the frequency recommendation ( ≤ 4 times/d) obtained a significantly greater percentage of energy from NMES compared with those participants who met the recommendation. The food groups ‘biscuits and cakes’ (18·9 %), ‘soft drinks’ (13·1 %) and ‘table sugar’ (11·1 %) made the greatest contributions to intakes of NMES. Interventions to reduce NMES intake should focus on limiting quantity and frequency of intake of these food groups
Plastisol Gelation and Fusion Rheological Aspects
This study deals with the rheological aspects of poly-vinyl chloride (PVC) plastisol gelation and fusion processes in foamable formulations. Here, such processes are simulated by temperature-programmed experiment (5 K min−1) in which complex viscosity components are continuously recorded. Nineteen samples based on a PVC-VAC (vinyl acetate 95/5) copolymer with 100 phr plasticizer have been studied, differing only by the plasticizer structure. The sample shear modulus increases continuously with temperature until a maximum, long time after the end of the dissolution process as characterized by DSC. The temperature at the maximum varies between 345 and 428 K with a clear tendency to increase almost linearly with the plasticizer molar mass, and to vary with the flexibility and the degree of branching of the plasticizer molecule. The shear modulus increase is interpreted in terms of progressive “welding” of swelled particles by polymer chain reptation. The plasticizer nature would mainly affect the friction parameter of chain diffusio
Plasma modification of poly lactic acid solutions to generate high quality electrospun PLA nanofibers
Physical properties of pre-electrospinning polymer solutions play a key role in electrospinning as they strongly determine the morphology of the obtained electrospun nanofibers. In this work, an atmospheric-pressure argon plasma directly submerged in the liquid-phase was used to modify the physical properties of poly lactic acid (PLA) spinning solutions in an effort to improve their electrospinnability. The electrical characteristics of the plasma were investigated by two methods; V-I waveforms and Q-V Lissajous plots while the optical emission characteristics of the plasma were also determined using optical emission spectroscopy (OES). To perform a complete physical characterization of the plasma-modified polymer solutions, measurements of viscosity, surface tension, and electrical conductivity were performed for various PLA concentrations, plasma exposure times, gas flow rates, and applied voltages. Moreover, a fast intensified charge-couple device (ICCD) camera was used to image the bubble dynamics during the plasma treatments. In addition, morphological changes of PLA nanofibers generated from plasma-treated PLA solutions were observed by scanning electron microscopy (SEM). The performed plasma treatments were found to induce significant changes to the main physical properties of the PLA solutions, leading to an enhancement of electrospinnability and an improvement of PLA nanofiber formation
A Uniformly Derived Catalogue of Exoplanets from Radial Velocities
A new catalogue of extrasolar planets is presented by re-analysing a
selection of published radial velocity data sets using EXOFIT (Balan & Lahav
2009). All objects are treated on an equal footing within a Bayesian framework,
to give orbital parameters for 94 exoplanetary systems. Model selection
(between one- and two-planet solutions) is then performed, using both a visual
flagging method and a standard chi-square analysis, with agreement between the
two methods for 99% of the systems considered. The catalogue is to be made
available online, and this 'proof of concept' study may be maintained and
extended in the future to incorporate all systems with publicly available
radial velocity data, as well as transit and microlensing data.Comment: 16 pages, 6 figures, 6 table
Dentists’ requirements for continuing professional development in Ireland. A pilot study conducted at University College Cork
Aims: To determine the self-assessed continuing professional development (CPD) needs of dental practitioners and identify how each discipline can best be served by a dental CPD programme. To set findings in the context of the available literature and contribute to the development of CPD programmes. Method: Topics were arranged into eight disciplines: practice management; paediatric dentistry; preventive dentistry; orthodontics; behaviour management; dentistry for people with a disability; oral medicine and surgery; and, restorative dentistry. A web-based questionnaire was constructed and administered using a MarkClass 2.21 online survey tool. Results: Fifty-six self-reported assessment responses were received, with three-quarters of participants having graduated within the past 10 years. Topics in oral medicine and surgery attracted consistently high levels of interest. A tendency to favour topics with a perceived direct clinical application was observed. Topics recommended by the Dental Council as core areas for CPD were given a high level of priority by respondents. Conclusions: Traditional lectures remain a valued mode of CPD participation. Practical courses were valued across all dental topics offered. A varied approach to determining the requirements of dentists is essential to appropriately support the practitioner
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