6,038 research outputs found
Occurrences of \u3ci\u3eEumorpha Fasciata, Hyles Gallii, Sphinx Franckii\u3c/i\u3e and \u3ci\u3eS. Vashti\u3c/i\u3e (Lepidoptera: Sphingidae) in Illinois
A recent survey of private and institutional collections in Illinois and surrounding states has provided specific information on the occurrences of four species of sphingids within Illinois: Eumorpha fasciata, Hyles gallii, Sphinx franckii, and S. vashti. Geographical and phenological data for these species are provided
Magnetoplasmons in layered graphene structures
We calculate the dispersion equations for magnetoplasmons in a single layer,
a pair of parallel layers, a graphite bilayer and a superlattice of graphene
layers in a perpendicular magnetic field. We demonstrate the feasibility of a
drift-induced instability of magnetoplasmons. The magnetoplasmon instability in
a superlattice is enhanced compared to a single graphene layer. The energies of
the unstable magnetoplasmons could be in the terahertz (THz) part of the
electromagnetic spectrum. The enhanced instability makes superlattice graphene
a potential source of THz radiation.Comment: 5 pages, 4 figure
Nurse telephone triage for same day appointments in general practice: multiple interrupted time series trial of effect on workload and costs
OBJECTIVE: To compare the workloads of general practitioners and nurses and costs of patient care for nurse telephone triage and standard management of requests for same day appointments in routine primary care. DESIGN: Multiple interrupted time series using sequential introduction of experimental triage system in different sites with repeated measures taken one week in every month for 12 months. SETTING: Three primary care sites in York. Participants: 4685 patients: 1233 in standard management, 3452 in the triage system. All patients requesting same day appointments during study weeks were included in the trial. MAIN OUTCOME MEASURES: Type of consultation (telephone, appointment, or visit), time taken for consultation, presenting complaints, use of services during the month after same day contact, and costs of drugs and same day, follow up, and emergency care. RESULTS: The triage system reduced appointments with general practitioner by 29-44%. Compared with standard management, the triage system had a relative risk (95% confidence interval) of 0.85 (0.72 to 1.00) for home visits, 2.41 (2.08 to 2.80) for telephone care, and 3.79 (3.21 to 4.48) for nurse care. Mean overall time in the triage system was 1.70 minutes longer, but mean general practitioner time was reduced by 2.45 minutes. Routine appointments and nursing time increased, as did out of hours and accident and emergency attendance. Costs did not differ significantly between standard management and triage: mean difference £1.48 more per patient for triage (95% confidence interval -0.19 to 3.15). CONCLUSIONS: Triage reduced the number of same day appointments with general practitioners but resulted in busier routine surgeries, increased nursing time, and a small but significant increase in out of hours and accident and emergency attendance. Consequently, triage does not reduce overall costs per patient for managing same day appointments
Masses and Internal Structure of Mesons in the String Quark Model
The relativistic quantum string quark model, proposed earlier, is applied to
all mesons, from pion to , lying on the leading Regge trajectories
(i.e., to the lowest radial excitations in terms of the potential quark
models). The model describes the meson mass spectrum, and comparison with
measured meson masses allows one to determine the parameters of the model:
current quark masses, universal string tension, and phenomenological constants
describing nonstring short-range interaction. The meson Regge trajectories are
in general nonlinear; practically linear are only trajectories for light-quark
mesons with non-zero lowest spins. The model predicts masses of many new
higher-spin mesons. A new meson is predicted with mass 1910 Mev. In
some cases the masses of new low-spin mesons are predicted by extrapolation of
the phenomenological short-range parameters in the quark masses. In this way
the model predicts the mass of to be MeV, and
the mass of to be MeV (the potential model predictions
are 100 Mev lower). The relativistic wave functions of the composite mesons
allow one to calculate the energy and spin structure of mesons. The average
quark-spin projections in polarized -meson are twice as small as the
nonrelativistic quark model predictions. The spin structure of reveals an
80% violation of the flavour SU(3). These results may be relevant to
understanding the ``spin crises'' for nucleons.Comment: 30 pages, REVTEX, 6 table
Multi-transition study and new detections of class II methanol masers
We have used the ATNF Mopra antenna and the SEST antenna to search in the
directions of several class II methanol maser sources for emission from six
methanol transitions in the frequency range 85-115 GHz. The transitions were
selected from excitation studies as potential maser candidates. Methanol
emission at one or more frequencies was detected from five of the maser
sources, as well as from Orion KL. Although the lines are weak, we find
evidence of maser origin for three new lines in G345.01+1.79, and possibly one
new line in G9.62+0.20.
The observations, together with published maser observations at other
frequencies, are compared with methanol maser modelling for G345.01+1.79 and
NGC6334F. We find that the majority of observations in both sources are
consistent with a warm dust (175 K) pumping model at hydrogen density ~10^6
cm^-3 and methanol column density ~5 x 10^17 cm^-2. The substantial differences
between the maser spectra in the two sources can be attributed to the geometry
of the maser region.Comment: 13 pages, 6 figures, Accepted for publication in MNRA
A Multi-Wavelength Study of the Jet, Lobes and Core of the Quasar PKS 2101-490
We present a detailed study of the X-ray, optical and radio emission from the
jet, lobes and core of the quasar PKS 2101-490 as revealed by new Chandra, HST
and ATCA images. We extract the radio to X-ray spectral energy distributions
from seven regions of the 13 arcsecond jet, and model the jet X-ray emission in
terms of Doppler beamed inverse Compton scattering of the cosmic microwave
background (IC/CMB) for a jet in a state of equipartition between particle and
magnetic field energy densities. This model implies that the jet remains highly
relativistic hundreds of kpc from the nucleus, with a bulk Lorentz factor Gamma
~ 6 and magnetic field of order 30 microGauss. We detect an apparent radiative
cooling break in the synchrotron spectrum of one of the jet knots, and are able
to interpret this in terms of a standard one-zone continuous injection model,
based on jet parameters derived from the IC/CMB model. However, we note
apparent substructure in the bright optical knot in one of the HST bands. We
confront the IC/CMB model with independent estimates of the jet power, and find
that the IC/CMB model jet power is consistent with the independent estimates,
provided that the minimum electron Lorentz factor gamma_min > 50, and the knots
are significantly longer than the jet width, as implied by de-projection of the
observed knot lengths.Comment: 16 pages, 10 figures, 6 table
Properties of the Strange Axial Mesons in the Relativized Quark Model
We studied properties of the strange axial mesons in the relativized quark
model. We calculated the decay constant in the quark model and showed how
it can be used to extract the mixing angle
() from the weak decay . The ratio is the most sensitive
measurement and also the most reliable since the largest of the theoretical
uncertainties factor out. However the current bounds extracted from the
TPC/Two-Gamma collaboration measurements are rather weak: we typically obtain
at 68\% C.L. We also calculated the
strong OZI-allowed decays in the pseudoscalar emission model and the flux-tube
breaking model and extracted a mixing angle of . Our analysis also indicates that the heavy quark limit does not give a
good description of the strange mesons.Comment: Revised version to be published in Phys. Rev. D. Minor changes. Latex
file uses revtex version 3 and epsfig, 4 postcript figures are attached. The
full postcript version with embedded figures is available at
ftp://ftp.physics.carleton.ca/pub/theory/godfrey/ocipc9512.ps.
Discovery of an X-ray Jet and Extended Jet Structure in the Quasar PKS 1055+201
This letter reports rich X-ray jet structures found in the Chandra
observation of PKS 1055+201. In addition to an X-ray jet coincident with the
radio jet we detect a region of extended X-ray emission surrounding the jet as
far from the core as the radio hotspot to the North, and a similar extended
X-ray region along the presumed path of the unseen counterjet to the Southern
radio lobe. Both X-ray regions show a similar curvature to the west, relative
to the quasar. We interpret this as the first example where we separately
detect the X-ray emission from a narrow jet and extended, residual jet plasma
over the entire length of a powerful FRII jet.Comment: Accepted for publication in Ap. J. Letters. 4 pages, 3 figure
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