534 research outputs found
From Service to Experience: Understanding and Defining the Hospitality Business
Failure adequately to define or understand hospitality as a commercial phenomenon has created a fragmented academic environment and a schizophrenia in the industry that has the potential to limit its development as a global industry. This article suggests that, by redefining hospitality as behaviour and experience, a new perspective emerges that has exciting implications for the management of hospitality businesses. A framework to describe hospitality in the commercial domain is proposed. This framework suggests a focus on the host–guest relationship, generosity, theatre and performance, ‘lots of little surprises’, and the security of strangers – a focus that provides guests with experiences that are personal, memorable and add value to their lives
Spectral Properties From Lyman-alpha to H-alpha For An Essentially Complete Sample of Quasars I: Data
We have obtained quasi-simultaneous ultraviolet-optical spectra for 22 out of
23 quasars in the complete PG-X-ray sample with redshift, z<0.4, and M_B<-23.
The spectra cover rest-frame wavelengths from at least Lyman-alpha to H-alpha.
Here we provide a detailed description of the data, including careful
spectrophotometry and redshift determination. We also present direct
measurements of the continua, strong emission lines and features, including
Lyman-alpha, SiIV+OIV], CIV, CIII], SiIII], MgII, H-beta, [OIII],
He5876+NaI5890,5896, H-alpha, and blended iron emission in the UV and optical.
The widths, asymmetries and velocity shifts of profiles of strong emission
lines show that CIV and Lyman-alpha are very different from H-beta and H-alpha.
This suggests that the motion of the broad line region is related to the
ionization structure, but the data appears not agree with the radially
stratified ionization structure supported by reverberation mapping studies, and
therefore suggest that outflows contribute additional velocity components to
the broad emission line profiles.Comment: 42 pages, 10 figures, 13 tables. Accepted by AJ. Supplemental figures
not included. Full version available at
http://physics.uwyo.edu/~shang/pgxpaper/ShangPaper.pd
The Intrinsic Absorber in QSO 2359-1241: Keck and HST Observations
We present detailed analyses of the absorption spectrum seen in QSO 2359-1241
(NVSS J235953-124148). Keck HIRES data reveal absorption from twenty
transitions arising from: He I, Mg I, Mg II, Ca II, and Fe II. HST data show
broad absorption lines (BALs) from Al III 1857, C IV 1549, Si IV 1397, and N V
1240. Absorption from excited Fe II states constrains the temperature of the
absorber to 2000K < T < 10,000K and puts a lower limit of 10^5 cm^{-3} on the
electron number density. Saturation diagnostics show that the real column
densities of He I and Fe II can be determined, allowing to derive meaningful
constraints on the ionization equilibrium and abundances in the flow. The
ionization parameter is constrained by the iron, helium and magnesium data to
-3.0 < log(U) < -2.5 and the observed column densities can be reproduced
without assuming departure from solar abundances. From comparison of the He I
and Fe II absorption features we infer that the outflow seen in QSO 2359-1241
is not shielded by a hydrogen ionization front and therefore that the existence
of low-ionization species in the outflow (e.g., Mg II, Al III, Fe II) does not
necessitate the existence of such a front. We find that the velocity width of
the absorption systematically increases as a function of ionization and to a
lesser extent with abundance. Complementary analyses of the radio and
polarization properties of the object are discussed in a companion paper
(Brotherton et al. 2000).Comment: 30 pages, 9 figures, in press with the Ap
Conspiracy theories as part of history: The role of societal crisis situations
In the present contribution we examine the link between societal crisis situations and belief in conspiracy theories. Contrary to common assumptions, belief in conspiracy theories has been prevalent throughout human history. We first illustrate historical incidents suggesting that societal crisis situations—defined as impactful and rapid societal change that calls established power structures, norms of conduct, or even the existence of specific people or groups, into question —have stimulated belief in conspiracy theories. We then review the psychological literature to explain why this is the case. Evidence suggests that the aversive feelings that people experience when in crisis—fear, uncertainty, the feeling of being out of control—stimulate a motivation to make sense of the situation, increasing the likelihood of perceiving conspiracies in social situations. We then explain that after being formed, conspiracy theories can become historical narratives that may spread through cultural transmission. We conclude that conspiracy theories originate particularly in crisis situations, and may form the basis for how people subsequently remember and mentally represent a historical event
The Compact Structure of Radio-Loud Broad Absorption Line Quasars
We present the results of EVN+MERLIN VLBI polarization observations of 8
Broad Absorption Line (BAL) quasars at 1.6 GHz, including 4 LoBALs and 4 HiBALs
with either steep or flat spectra on VLA scales. Only one steep-spectrum
source, J1122+3124, shows two-sided structure on the scale of 2 kpc. The other
four steep-spectrum sources and three flat-spectrum sources display either an
unresolved image or a core-jet structure on scales of less than three hundred
parsecs. In all cases the marginally resolved core is the dominant radio
component. Linear polarization in the cores has been detected in the range of a
few to 10 percent. Polarization, together with high brightness temperatures
(from 2*10^9-5*10^10 K), suggest a synchrotron origin for the radio emission.
There is no apparent difference in the radio orphologies or polarization
between low-ionization and high-ionization BAL QSOs nor between flat- and
steep-spectrum sources. We discuss the orientation of BAL QSOs with both flat
and steep spectra, and consider a possible evolutionary scenario for BAL QSOs.
In this scenario, BAL QSOs are probably the young population of radio sources,
which are Compact Steep Spectrum or GHz peaked radio source analog at the low
end of radio power.Comment: 16 pages, 3 figures, 4 tables; accepted for publication in MNRA
The FIRST Bright Quasar Survey. II. 60 Nights and 1200 Spectra Later
We have used the VLA FIRST survey and the APM catalog of the POSS-I plates as
the basis for constructing a new radio-selected sample of optically bright
quasars. This is the first radio-selected sample that is competitive in size
with current optically selected quasar surveys. Using only two basic criteria,
radio-optical positional coincidence and optical morphology, quasars and BL
Lacs can be identified with 60% selection efficiency; the efficiency increases
to 70% for objects fainter than magnitude 17. We show that a more sophisticated
selection scheme can predict with better than 85% reliability which candidates
will turn out to be quasars.
This paper presents the second installment of the FIRST Bright Quasar Survey
with a catalog of 636 quasars distributed over 2682 square degrees. The quasar
sample is characterized and all spectra are displayed. The FBQS detects both
radio-loud and radio-quiet quasars out to a redshift z>3. We find a large
population of objects of intermediate radio-loudness; there is no evidence in
our sample for a bimodal distribution of radio characteristics. The sample
includes ~29 broad absorption line quasars, both high and low ionization, and a
number of new objects with remarkable optical spectra.Comment: 41 pages plus 39 gifs which contain all quasar spectra. Accepted for
publication in the Astrophysical Journal Supplement Serie
Simultaneous X-ray and UV spectroscopy of the Seyfert 1 galaxy NGC 5548.II. Physical conditions in the X-ray absorber
We present the results from a 500 ks Chandra observation of the Seyfert 1
galaxy NGC 5548. We detect broadened emission lines of O VII and C VI in the
spectra, similar to those observed in the optical and UV bands. The source was
continuously variable, with a 30 % increase in luminosity in the second half of
the observation. No variability in the warm absorber was detected between the
spectra from the first 170 ks and the second part of the observation. The
velocity structure of the X-ray absorber is consistent with the velocity
structure measured simultaneously in the ultraviolet spectra. We find that the
highest velocity outflow component, at -1040 km/s, becomes increasingly
important for higher ionization parameters. This velocity component spans at
least three orders of magnitude in ionization parameter, producing both highly
ionized X-ray absorption lines (Mg XII, Si XIV) as well as UV absorption lines.
A similar conclusion is very probable for the other four velocity components.
Based upon our observations, we argue that the warm absorber probably does not
manifest itself in the form of photoionized clumps in pressure equilibrium with
a surrounding wind. Instead, a model with a continuous distribution of column
density versus ionization parameter gives an excellent fit to our data. From
the shape of this distribution and the assumption that the mass loss through
the wind should be smaller than the accretion rate onto the black hole, we
derive upper limits to the solid angle as small as 10^{-4} sr. From this we
argue that the outflow occurs in density-stratified streamers. The density
stratification across the stream then produces the wide range of ionization
parameter observed in this source. Abridged.Comment: 21 pages, 12 figures accepted for publication in A&
Reduction of low- and high-grade cervical abnormalities associated with high uptake of the HPV bivalent vaccine in Scotland
In Scotland, a national HPV immunisation programme began in 2008 for 12-13 year olds, with a catch-up campaign from 2008-2011 for those under the age of 18. To monitor the impact of HPV immunisation on cervical disease at the population level, a programme of national surveillance was established. We analysed colposcopy data from a cohort of women born between 1988-1992 who entered the Scottish Cervical Screening Programme (SCSP) and were aged 20-21 in 2008-2012. By linking datasets from the SCSP and colposcopy services, we observed a significant reduction in diagnoses of cervical intraepithelial neoplasia 1 (CIN 1) (RR 0.71, 95% CI 0.58 to 0.87, p=0.0008), CIN 2 (RR 0.5, 95% CI 0.4, 0.63, p<0.0001) and CIN 3 (RR 0.45, 95% CI 0.35 to 0.58, p< 0.0001) for women who received 3 doses of vaccine compared with unvaccinated women. To our knowledge, this is one of the first studies to show a reduction of low and high grade cervical intraepithelial neoplasia associated with high uptake of the HPV bivalent vaccine at the population level. These data are very encouraging for countries that have achieved high HPV vaccine uptake
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