363 research outputs found
Improving the normalization of complex interventions: measure development based on normalization process theory (NoMAD): study protocol
<b>Background</b> Understanding implementation processes is key to ensuring that complex interventions in healthcare are taken up in practice and thus maximize intended benefits for service provision and (ultimately) care to patients. Normalization Process Theory (NPT) provides a framework for understanding how a new intervention becomes part of normal practice. This study aims to develop and validate simple generic tools derived from NPT, to be used to improve the implementation of complex healthcare interventions.<p></p>
<b>Objectives</b> The objectives of this study are to: develop a set of NPT-based measures and formatively evaluate their use for identifying implementation problems and monitoring progress; conduct preliminary evaluation of these measures across a range of interventions and contexts, and identify factors that affect this process; explore the utility of these measures for predicting outcomes; and develop an online users’ manual for the measures.<p></p>
<b>Methods</b> A combination of qualitative (workshops, item development, user feedback, cognitive interviews) and quantitative (survey) methods will be used to develop NPT measures, and test the utility of the measures in six healthcare intervention settings.<p></p>
<b>Discussion</b> The measures developed in the study will be available for use by those involved in planning, implementing, and evaluating complex interventions in healthcare and have the potential to enhance the chances of their implementation, leading to sustained changes in working practices
A Catalog of Broad Absorption Line Quasars from the Sloan Digital Sky Survey Early Data Release
We present a catalog of 224 broad absorption line quasars (BALQSOs) from the
Sloan Digital Sky Survey's Early Data Release Quasar Catalog, including a
relatively complete and homogeneous subsample of 131 BALQSOs. Since the
identification of BALQSOs is subject to considerable systematic uncertainties,
we attempt to create a complete sample of SDSS BALQSOs by combining the results
of two automated selection algorithms and a by-eye classification scheme. One
of these automated algorithms finds broad absorption line troughs by comparison
with a composite quasar spectrum. We present the details of this algorithm and
compare this method to that which uses a power-law fit to the continuum. The
BALQSOs in our sample are further classified as high-ionization BALQSOs
(HiBALs), low-ionization BALQSOs (LoBALs), and BALQSOs with excited iron
absorption features (FeLoBALs); composite spectra of each type are presented.
We further present a study of the properties of the BALQSOs in terms of the
balnicity distribution, which rises with decreasing balnicity. This
distribution of balnicities suggests that the fraction of quasars with
intrinsic outflows may be significantly underestimated.Comment: 36 pages, 7 figures (1 color), 2 tables, accepted by A
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Very High Density Clumps and Outflowing Winds in QSO Broad-Line Regions
Intercomparison of the spectra of seven high-luminosity quasi-stellar objects (QSOs) shows that there is a gradation of properties in their broad emission-line regions (BELRs) that can be understood as differing mixtures of different gas components. Six of these seven objects have unusually narrow BELR profiles, which greatly facilitates the disentangling of blends and measuring of weak lines. In the QSO 0207 - 398, the BELR is made up of at least three kinematically distinct components; its spectrum is in fact a composite of the spectra of the more homogeneous BELRs in the QSOs at either end of our sequence of properties. This paper focuses on the properties of the line-emitting region in Q0207 - 398 dubbed component "A," which has sharp (FWHM = 1000 km s^-1^), symmetric line profiles centered at zero velocity. We find that these lines are emitted in very dense (n_H_ ~ 10^12.5^ cm^-3^) gas at a characteristic radius r ~ 10^17.7^ cm from the continuum source and which emits a low-ionization spectrum including strong A1 III λ1857. The second component, "B," in Q0207 - 398 is the subject of a companion paper. It is characterized by high-ionization lines such as N V λ1240, O VI λ1034, and C IV λ1549 with profiles that peak at zero velocity but have a blue tail extending out to - 11,000 km s^-1^. It receives about the same incident flux as component A and therefore may lie at the same distance from the continuum source, but it is significantly less dense (n_H_ ~ 10^11^ cm^-3^). The remaining line emission from Q0207 - 398 is attributed to a component "C" which has reasonably broad (FWHM = 2000 km s^-1^), symmetric line profiles centered at zero velocity. Most of the Lyα and C III] λ1909 emission comes from this region, but it also contributes to C IV, N V, and many other lines. The spectrum of component C is in fact quite similar to that of "normal" QSOs. We interpret component A as the dense source for radiatively accelerated, outward flowing gas which we see as component B. Component A may consist of the ablated atmospheres of stars which have strayed too close to the QSO nucleus. In addition, component A's velocity width is essentially the same as that of the stellar population in the nucleus of M87. From the radius and velocity, we infer the presence of a central mass of only 10^7^-10^8^ M_sun_, if we are measuring virial motions and if the ionizing continuum is isotropic. An alternate possibility is that the narrow single-peaked component A profile comes from a rotating torus/accretion disk, probably seen face-on, in which case it is impossible to measure the central mass. We discuss the similarity between Mg II-type broad absorption line (BAL) QSOs and Q0207 - 398, which does not have BALs. In fact, the two Mg II-type BAL objects in our sample have spectra almost exactly like that of Q0207 - 398, except that component B is seen in absorption rather than in emission.Astronom
Average Properties of a Large Sample of z_abs ~ z_em associated Mg II Absorption Line Systems
We have studied a sample of 415 associated (z_ab z_em; relative velocity with
respect to QSO <3000km/s) Mg II absorption systems with 1.0<=z_ab<=1.86, in the
spectra of SDSS DR3 QSOs, to determine the dust content and ionization state in
the absorbers. We studied the dependence of these properties on the properties
of the QSOs and also, compared the properties with those of a similarly
selected sample of 809 intervening systems (apparent relative velocity with
respect to the QSO of >3000km/s), so as to understand their origin. From the
analysis of the composite spectra, as well as from the comparison of measured
equivalent widths in individual spectra, we conclude that the associated Mg II
absorbers have higher apparent ionization, measured by the strength of the C IV
absorption lines compared to the Mg II absorption lines, than the intervening
absorbers. The ionization so measured appears to be related to apparent
ejection velocity, being lower as the apparent ejection velocity is more and
more positive. There is clear evidence, from the composite spectra, for SMC
like dust attenuation in these systems; the 2175AA absorption feature is not
present. The extinction is almost twice that observed in the similarly selected
sample of intervening systems. We reconfirm that QSOs with non-zero FIRST radio
flux are intrinsically redder than the QSOs with no detection in the FIRST
survey. The incidence of associated Mg II systems in QSOs with non-zero FIRST
radio flux is 1.7 times that in the QSOs with no detection in the FIRST survey.
The associated absorbers in radio-detected QSOs which comprise about 12% of our
sample, cause 3 times more reddening than the associated absorbers in
radio-undetected QSOs. This excess reddening possibly suggests an intrinsic
nature for the associated absorbers in radio-detected QSOs.Comment: Accepted for publication in Ap
Language-free graphical signage improves human performance and reduces anxiety when working collaboratively with robots
As robots become more ubiquitous, and their capabilities extend, novice users will require intuitive instructional information related to their use. This is particularly important in the manufacturing sector, which is set to be transformed under Industry 4.0 by the deployment of collaborative robots in support of traditionally low-skilled, manual roles. In the first study of its kind, this paper reports how static graphical signage can improve performance and reduce anxiety in participants physically collaborating with a semi-autonomous robot. Three groups of 30 participants collaborated with a robot to perform a manufacturing-type process using graphical information that was relevant to the task, irrelevant, or absent. The results reveal that the group exposed to relevant signage was significantly more accurate in undertaking the task. Furthermore, their anxiety towards robots significantly decreased as a function of increasing accuracy. Finally, participants exposed to graphical signage showed positive emotional valence in response to successful trials. At a time when workers are concerned about the threat posed by robots to jobs, and with advances in technology requiring upskilling of the workforce, it is important to provide intuitive and supportive information to users. Whilst increasingly sophisticated technical solutions are being sought to improve communication and confidence in human-robot co-working, our findings demonstrate how simple signage can still be used as an effective tool to reduce user anxiety and increase task performance
Search for Narrow Diphoton Resonances and for gamma-gamma+W/Z Signatures in p\bar p Collisions at sqrt(s)=1.8 TeV
We present results of searches for diphoton resonances produced both
inclusively and also in association with a vector boson (W or Z) using 100
pb^{-1} of p\bar p collisions using the CDF detector. We set upper limits on
the product of cross section times branching ratio for both p\bar
p\to\gamma\gamma + X and p\bar p\to\gamma\gamma + W/Z. Comparing the inclusive
production to the expectations from heavy sgoldstinos we derive limits on the
supersymmetry-breaking scale sqrt{F} in the TeV range, depending on the
sgoldstino mass and the choice of other parameters. Also, using a NLO
prediction for the associated production of a Higgs boson with a W or Z boson,
we set an upper limit on the branching ratio for H\to\gamma\gamma. Finally, we
set a lower limit on the mass of a `bosophilic' Higgs boson (e.g. one which
couples only to \gamma, W, and Z$ bosons with standard model couplings) of 82
GeV/c^2 at 95% confidence level.Comment: 30 pages, 11 figure
Search for the Supersymmetric Partner of the Top-Quark in Collisions at
We report on a search for the supersymmetric partner of the top quark (stop)
produced in events using of
collisions at recorded with the Collider Detector at
Fermilab. In the case of a light stop squark, the decay of the top quark into
stop plus the lightest supersymmetric particle (LSP) could have a significant
branching ratio. The observed events are consistent with Standard Model production and decay. Hence, we set limits on the branching ratio of
the top quark decaying into stop plus LSP, excluding branching ratios above 45%
for a LSP mass up to 40 {\rm GeV/c}.Comment: 11 pages, 4 figure
Measurement of the Strong Coupling Constant from Inclusive Jet Production at the Tevatron Collider
We report a measurement of the strong coupling constant, ,
extracted from inclusive jet production in collisions at
1800 GeV. The QCD prediction for the evolution of with
jet transverse energy is tested over the range 40<<450 GeV using
for the renormalization scale. The data show good agreement with QCD in
the region below 250 GeV. In the text we discuss the data-theory comparison in
the region from 250 to 450 GeV. The value of at the mass of the
boson averaged over the range 40<<250 GeV is found to be
. The associated theoretical uncertainties are mainly due to the choice
of renormalization scale (^{+6%}_{-4%}) and input parton distribution
functions (5%).Comment: 7 pages, 3 figures, using RevTeX. Submitted to Physical Review
Letter
Measurement of the p\bar{p}\sqrt{s}$ = 1.8 TeV
We update the measurement of the top production cross section using the CDF
detector at the Fermilab Tevatron. This measurement uses decays to
the final states +jets and +jets. We search for quarks from
decays via secondary-vertex identification or the identification of
semileptonic decays of the and cascade quarks. The background to the
production is determined primarily through a Monte Carlo simulation.
However, we calibrate the simulation and evaluate its uncertainty using several
independent data samples. For a top mass of 175 , we measure
pb and pb using
the secondary vertex and the lepton tagging algorithms, respectively. Finally,
we combine these results with those from other decay channels and
obtain pb.Comment: The manuscript consists of 130 pages, 35 figures and 42 tables in
RevTex. The manuscript is submitted to Physical Review D. Fixed typo in
author lis
Double Diffraction Dissociation at the Fermilab Tevatron Collider
We present results from a measurement of double diffraction dissociation in
collisions at the Fermilab Tevatron collider. The production cross
section for events with a central pseudorapidity gap of width
(overlapping ) is found to be [] at [630]
GeV. Our results are compared with previous measurements and with predictions
based on Regge theory and factorization.Comment: 10 pages, 4 figures, using RevTeX. Submitted to Physical Review
Letter
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