2,200 research outputs found
Acceptability of artificial intelligence (AI)-led chatbot services in healthcare: A mixed-methods study
Background
Artificial intelligence (AI) is increasingly being used in healthcare. Here, AI-based chatbot systems can act as automated conversational agents, capable of promoting health, providing education, and potentially prompting behaviour change. Exploring the motivation to use health chatbots is required to predict uptake; however, few studies to date have explored their acceptability. This research aimed to explore participants’ willingness to engage with AI-led health chatbots.
Methods
The study incorporated semi-structured interviews (N-29) which informed the development of an online survey (N-216) advertised via social media. Interviews were recorded, transcribed verbatim and analysed thematically. A survey of 24 items explored demographic and attitudinal variables, including acceptability and perceived utility. The quantitative data were analysed using binary regressions with a single categorical predictor.
Results
Three broad themes: ‘Understanding of chatbots’, ‘AI hesitancy’ and ‘Motivations for health chatbots’ were identified, outlining concerns about accuracy, cyber-security, and the inability of AI-led services to empathise. The survey showed moderate acceptability (67%), correlated negatively with perceived poorer IT skills OR = 0.32 [CI95%:0.13–0.78] and dislike for talking to computers OR = 0.77 [CI95%:0.60–0.99] as well as positively correlated with perceived utility OR = 5.10 [CI95%:3.08–8.43], positive attitude OR = 2.71 [CI95%:1.77–4.16] and perceived trustworthiness OR = 1.92 [CI95%:1.13–3.25].
Conclusion
Most internet users would be receptive to using health chatbots, although hesitancy regarding this technology is likely to compromise engagement. Intervention designers focusing on AI-led health chatbots need to employ user-centred and theory-based approaches addressing patients’ concerns and optimising user experience in order to achieve the best uptake and utilisation. Patients’ perspectives, motivation and capabilities need to be taken into account when developing and assessing the effectiveness of health chatbots
The Changing AGN Population
We investigate how the fraction of broad-line sources in the AGN population
changes with X-ray luminosity and redshift. We first construct the rest-frame
hard-energy (2-8 keV) X-ray luminosity function (HXLF) at z=0.1-1 using Chandra
Lockman Hole-Northwest wide-area data, Chandra Deep Field-North 2 Ms data,
other Chandra deep field data, and the ASCA Large Sky Survey data. We find that
broad-line AGNs dominate above 3e43 ergs/s and have a mean luminosity of 1.3e44
ergs/s. Type II AGNs can only become an important component of the X-ray
population at Seyfert-like X-ray luminosities. We then construct z=0.1-0.5 and
z=0.5-1 HXLFs and compare them with both the local HXLF measured from HEAO-1 A2
survey data and the z=1.5-3 HXLF measured from soft-energy (0.5-2 keV) Chandra
and ROSAT data. We find that the number density of >1e44 ergs/s sources
(quasars) steadily declines with decreasing redshift, while the number density
of 1e43-1e44 ergs/s sources peaks at z=0.5-1. Strikingly, however, the number
density of broad-line AGNs remains roughly constant with redshift while their
average luminosities decline at the lower redshifts, showing another example of
cosmic downsizing.Comment: Accepted by The Astrophysical Journal Letters, 5 page
The Submillimeter Properties of the 1 Ms Chandra Deep Field North X-ray Sample
We present submillimeter observations for 136 of the 370 X-ray sources
detected in the 1 Ms exposure of the Chandra Deep Field North. Ten of the X-ray
sources are significantly detected in the submillimeter. The average X-ray
source in the sample has a significant 850 micron flux of 1.69+/-0.27 mJy. This
value shows little dependence on the 2-8 keV flux from 5e-16 erg/cm^2/s to
1e-14 erg/cm^2/s. The ensemble of X-ray sources contribute about 10% of the
extragalactic background light at 850 microns. The submillimeter excess is
found to be strongest in the optically faint X-ray sources that are also seen
at 20 cm, which is consistent with these X-ray sources being obscured and at
high redshift (z>1).Comment: 5 pages, submitted to The Astrophysical Journal Letter
The Chandra Large Area Synoptic X-ray Survey (CLASXS) of the Lockman Hole-Northwest: The X-ray Catalog
We present the X-ray catalog and basic results from our Chandra Large Area
Synoptic X-ray Survey (CLASXS) of the Lockman Hole-Northwest field. Our 9
ACIS-I fields cover a contiguous solid angle of ~0.4 sq. deg. and reach fluxes
of 5E-16 cgs (0.4-2 keV) and 3E-15 cgs (2-8keV). Our survey bridges the gap
between ultradeep pencil-beam surveys, such as the Chandra Deep Fields (CDFs),
and shallower, large area surveys, allowing a better probe of the X-ray sources
that contribute most of the 2-10 keV cosmic X-ray background (CXB). We find a
total of 525 X-ray point sources and 4 extended sources. At ~10E-14 cgs 2-8
keV, our number counts are significantly higher than those of several
non-contiguous, large area surveys. On the other hand, the integrated flux from
the CLASXS field, combined with ASCA and Chandra ultradeep surveys, is
consistent with results from other large area surveys, within the variance of
the CXB. Spectral evolution is seen in the hardening of the sources at fluxes
below 1E-14 cgs Above 4E1-14 cgs(0.4-8 keV), ~60 of the sources are variable.
Four extended sources in CLASXS is consistent with the previously measured
LogN-LogS of galaxy clusters. We report the discovery of a gravitational
lensing arc associated with one of these sources. (Abridged)Comment: 67 pages, 26 figures, accepted for publication in the Astronomical
Journa
Telemonitoring after discharge from hospital with heart failure: cost-effectiveness modelling of alternative service designs.
Objectives To estimate the cost-effectiveness of remote monitoring strategies versus usual care for adults recently discharged after a heart failure (HF) exacerbation.
Design Decision analysis modelling of cost-effectiveness using secondary data sources.
Setting Acute hospitals in the UK.
Patients Patients recently discharged (within 28 days) after a HF exacerbation.
Interventions Structured telephone support (STS) via human to machine (STS HM) interface, (2) STS via human to human (STS HH) contact and (3) home telemonitoring (TM), compared with (4) usual care.
Main outcome measures The incremental cost per quality-adjusted life year (QALY) gained by each strategy compared to the next most effective alternative and the probability of each strategy being cost-effective at varying willingness to pay per QALY gained.
Results TM was the most cost-effective strategy in the scenario using these base case costs. Compared with usual care, TM had an estimated incremental cost effectiveness ratio (ICER) of £11 873/QALY, whereas STS HH had an ICER of £228 035/QALY against TM. STS HM was dominated by usual care. Threshold analysis suggested that the monthly cost of TM has to be higher than £390 to have an ICER greater than £20 000/QALY against STS HH. Scenario analyses performed using higher costs of usual care, higher costs of STS HH and lower costs of TM do not substantially change the conclusions.
Conclusions Cost-effectiveness analyses suggest that TM was an optimal strategy in most scenarios, but there is considerable uncertainty in relation to clear descriptions of the interventions and robust estimation of costs
Resolving the Submillimeter Background: the 850-micron Galaxy Counts
Recent deep blank field submillimeter surveys have revealed a population of
luminous high redshift galaxies that emit most of their energy in the
submillimeter. The results suggest that much of the star formation at high
redshift may be hidden to optical observations. In this paper we present
wide-area 850-micron SCUBA data on the Hawaii Survey Fields SSA13, SSA17, and
SSA22. Combining these new data with our previous deep field data, we establish
the 850-micron galaxy counts from 2 mJy to 10 mJy with a >3-sigma detection
limit. The area coverage is 104 square arcmin to 8 mJy and 7.7 square arcmin to
2.3 mJy. The differential 850-micron counts are well described by the function
n(S)=N_0/(a+S^3.2), where S is the flux in mJy, N_0=3.0 x 10^4 per square
degree per mJy, and a=0.4-1.0 is chosen to match the 850-micron extragalactic
background light. Between 20 to 30 per cent of the 850-micron background
resides in sources brighter than 2 mJy. Using an empirical fit to our >2 mJy
data constrained by the EBL at lower fluxes, we argue that the bulk of the
850-micron extragalactic background light resides in sources with fluxes near 1
mJy. The submillimeter sources are plausible progenitors of the present-day
spheroidal population.Comment: 5 pages, accepted by The Astrophysical Journal Letter
Cosmological Implications of the Very High Redshift GRB 050904
We report near simultaneous multi-color (RIYJHK) observations made with the
MAGNUM 2m telescope of the gamma ray burst GRB 050904 detected by the SWIFT
satellite. The spectral energy distribution shows a very large break between
the I and J bands. Using intergalactic transmissions measured from high
redshift quasars we show that the observations place a 95% confidence lower
limit of z=6.18 on the object, consistent with a later measured spectroscopic
redshift of 6.29 obtained by Kawai et al. (2005) with the Subaru telescope. We
show that the break strength in the R and I bands is consistent with that
measured in the quasars. Finally we consider the implications for the star
formation history at high redshift.Comment: Accepted for publication in the Astrophysical Journal. Expanded
introduction and discussio
Dusty star forming galaxies at high redshift
The global star formation rate in high redshift galaxies, based on optical
surveys, shows a strong peak at a redshift of z=1.5, which implies that we have
already seen most of the formation. High redshift galaxies may, however, emit
most of their energy at submillimeter wavelengths if they contain substantial
amounts of dust. The dust would absorb the starlight and reradiate it as
far-infrared light, which would be redshifted to the submillimeter range. Here
we report a deep survey of two blank regions of sky performed at submillimeter
wavelengths (450 and 850-micron). If the sources we detect in the 850-micron
band are powered by star formation, then each must be converting more than 100
solar masses of gas per year into stars, which is larger than the maximum star
formation rates inferred for most optically-selected galaxies. The total amount
of high redshift star formation is essentially fixed by the level of background
light, but where the peak occurs in redshift for the submillimeter is not yet
established. However, the background light contribution from only the sources
detected at 850-micron is already comparable to that from the
optically-selected sources. Establishing the main epoch of star formation will
therefore require a combination of optical and submillimeter studies.Comment: 10 pages + 2 Postscript figures, under embargo at Natur
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