272 research outputs found
New horizons in the implementation and research of comprehensive geriatric assessment: knowing, doing and the “know-do” gap
In this paper we outline the relationship between the need to put existing applied health research knowledge into practice (the “know-do gap”) and the need to improve the evidence base (the “know gap”) with respect to the health care process used for older people with frailty known as comprehensive geriatric assessment (CGA).
We explore the reasons for the know-do gap and the principles of how these barriers to implementation might be overcome. We explore how these principles should affect the conduct of applied health research to close the know gap.
We propose that impaired flow of knowledge is an important contributory factor in the failure to implement evidence-based practice in comprehensive geriatric assessment; this could be addressed through specific knowledge mobilisation techniques. We describe that implementation failures are also produced by an inadequate evidence base which requires the co-production of research, addressing not only effectiveness but also the feasibility and acceptability of new services, the educational needs of practitioners, the organisational requirements of services, and the contribution made by policy. Only by tackling these issues in concert and appropriate proportion, will the know and know-do gaps for CGA be closed
Definitions of Urinary Tract Infection in Current Research: A Systematic Review
Defining urinary tract infection (UTI) is complex, as numerous clinical and diagnostic parameters are involved. In this systematic review, we aimed to gain insight into how UTI is defined across current studies. We included 47 studies, published between January 2019 and May 2022, investigating therapeutic or prophylactic interventions in adult patients with UTI. Signs and symptoms, pyuria, and a positive urine culture were required in 85%, 28%, and 55% of study definitions, respectively. Five studies (11%) required all 3 categories for the diagnosis of UTI. Thresholds for significant bacteriuria varied from 103 to 105 colony-forming units/mL. None of the 12 studies including acute cystitis and 2 of 12 (17%) defining acute pyelonephritis used identical definitions. Complicated UTI was defined by both host factors and systemic involvement in 9 of 14 (64%) studies. In conclusion, UTI definitions are heterogeneous across recent studies, highlighting the need for a consensus-based, research reference standard for UTI
Galactic star formation and accretion histories from matching galaxies to dark matter haloes
We present a new statistical method to determine the relationship between the
stellar masses of galaxies and the masses of their host dark matter haloes over
the entire cosmic history from z~4 to the present. This multi-epoch abundance
matching (MEAM) model self-consistently takes into account that satellite
galaxies first become satellites at times earlier than they are observed. We
employ a redshift-dependent parameterization of the stellar-to-halo mass
relation to populate haloes and subhaloes in the Millennium simulations with
galaxies, requiring that the observed stellar mass functions at several
redshifts be reproduced simultaneously. Using merger trees extracted from the
dark matter simulations in combination with MEAM, we predict the average
assembly histories of galaxies, separating into star formation within the
galaxies (in-situ) and accretion of stars (ex-situ). The peak star formation
efficiency decreases with redshift from 23% at z=0 to 9% at z=4 while the
corresponding halo mass increases from 10^11.8M\odot to 10^12.5M\odot. The star
formation rate of central galaxies peaks at a redshift which depends on halo
mass; for massive haloes this peak is at early cosmic times while for low-mass
galaxies the peak has not been reached yet. In haloes similar to that of the
Milky-Way about half of the central stellar mass is assembled after z=0.7. In
low-mass haloes, the accretion of satellites contributes little to the assembly
of their central galaxies, while in massive haloes more than half of the
central stellar mass is formed ex-situ with significant accretion of satellites
at z<2. We find that our method implies a cosmic star formation history and an
evolution of specific star formation rates which are consistent with those
inferred directly. We present convenient fitting functions for stellar masses,
star formation rates, and accretion rates as functions of halo mass and
redshift.Comment: 20 pages, 12 figures, 1 table, submitted to MNRA
Weak Lensing by Galaxies in Groups and Clusters: I.--Theoretical Expectations
Galaxy-galaxy lensing is rapidly becoming one of the most promising means to
accurately measure the average relation between galaxy properties and halo
mass. In order to obtain a signal of sufficient signal-to-noise, one needs to
stack many lens galaxies according to their property of interest, such as
luminosity or stellar mass. Since such a stack consists of both central and
satellite galaxies, which contribute very different lensing signals, the
resulting shear measurements can be difficult to interpret. In the past,
galaxy-galaxy lensing studies have either completely ignored this problem, have
applied rough isolation criteria in an attempt to preferentially select
`central' galaxies, or have tried to model the contribution of satellites
explicitely. However, if one is able to {\it a priori} split the galaxy
population in central and satellite galaxies, one can measure their lensing
signals separately. This not only allows a much cleaner measurement of the
relation between halo mass and their galaxy populations, but also allows a
direct measurement of the sub-halo masses around satellite galaxies. In this
paper, we use a realistic mock galaxy redshift survey to show that galaxy
groups, properly selected from large galaxy surveys, can be used to accurately
split the galaxy population in centrals and satellites. Stacking the resulting
centrals according to their group mass, estimated from the total group
luminosity, allows a remarkably accurate recovery of the masses and density
profiles of their host haloes. In addition, stacking the corresponding
satellite galaxies according to their projected distance from the group center
yields a lensing signal that can be used to accurate measure the masses of both
sub-haloes and host haloes. (Abridged)Comment: 16 pages, 10 figures, Accepted for publication in MNRA
Autocorrelations of stellar light and mass at z~0 and ~1: From SDSS to DEEP2
We present measurements of projected autocorrelation functions w_p(r_p) for
the stellar mass of galaxies and for their light in the U, B and V bands, using
data from the third data release of the DEEP2 Galaxy Redshift Survey and the
final data release of the Sloan Digital Sky Survey (SDSS). We investigate the
clustering bias of stellar mass and light by comparing these to projected
autocorrelations of dark matter estimated from the Millennium Simulations (MS)
at z=1 and 0.07, the median redshifts of our galaxy samples. All of the
autocorrelation and bias functions show systematic trends with spatial scale
and waveband which are impressively similar at the two redshifts. This shows
that the well-established environmental dependence of stellar populations in
the local Universe is already in place at z=1. The recent MS-based galaxy
formation simulation of Guo et al. (2011) reproduces the scale-dependent
clustering of luminosity to an accuracy better than 30% in all bands and at
both redshifts, but substantially overpredicts mass autocorrelations at
separations below about 2 Mpc. Further comparison of the shapes of our stellar
mass bias functions with those predicted by the model suggests that both the
SDSS and DEEP2 data prefer a fluctuation amplitude of sigma_8 0.8 rather than
the sigma_8=0.9 assumed by the MS.Comment: 10 pages, 4 figures, accepted for publication in Monthly Notices,
minor revisions in tex
Exercise for people living with frailty and receiving haemodialysis:a mixed-methods randomised controlled feasibility study
Objectives Frailty is highly prevalent in haemodialysis (HD) patients, leading to poor outcomes. This study aimed to determine whether a randomised controlled trial (RCT) of intradialytic exercise is feasible for frail HD patients, and explore how the intervention may be tailored to their needs.Design Mixed-methods feasibility.Setting and participants Prevalent adult HD patients of the CYCLE-HD trial with a Clinical Frailty Scale Score of 4–7 (vulnerable to severely frail) were eligible for the feasibility study.Interventions Participants in the exercise group undertook 6 months of three times per week, progressive, moderate intensity intradialytic cycling (IDC).Outcomes Primary outcomes were related to feasibility. Secondary outcomes were falls incidence measured from baseline to 1 year following intervention completion, and exercise capacity, physical function, physical activity and patient-reported outcomes measured at baseline and 6 months. Acceptability of trial procedures and the intervention were explored via diaries and interviews with n=25 frail HD patients who both participated in (n=13, 52%), and declined (n=12, 48%), the trial.Results 124 (30%) patients were eligible, and of these 64 (52%) consented with 51 (80%) subsequently completing a baseline assessment. n=24 (71% male; 59±13 years) dialysed during shifts randomly assigned to exercise and n=27 (81% male; 65±11 years) shifts assigned to usual care. n=6 (12%) were lost to follow-up. The exercise group completed 74% of sessions. 27%–89% of secondary outcome data were missing. Frail HD patients outlined several ways to enhance trial procedures. Maintaining ability to undertake activities of daily living and social participation were outcomes of primary importance. Participants desired a varied exercise programme.Conclusions A definitive RCT is feasible, however a comprehensive exercise programme may be more efficacious than IDC in this population.</div
Where Cosmic Dawn Breaks First: Mapping the Primordial Overdensity Powering a z 9 Ionized Bubble
Models of cosmic reionization predict that the earliest star-forming systems develop in primordial overdensities which, in turn, create ionized bubbles. With time, these bubbles grow and coalesce until the intergalactic medium is fully ionized. Since Lyman-alpha photons originating in these protoclusters can propagate freely through ionized gas, the highest redshift Lyman Alpha emitters (LAEs) act as valuable tracers of early ionized bubbles. We present evidence that the highest redshift LAE, EGSz8p7 (z=8.68), is likely embedded in such an overdensity. Collectively, in all of HST's deep fields, blank fields and gravitationally-lensed fields spanning >1000 arcmin^2 there are ~30 photometric candidates at z~9, yet a third lie within 3.75' (10 cMpc) of EGSz8p7. To confirm and exploit this extraordinary early overdensity we seek systemic redshifts and diagnostic features only JWST can provide. We propose blind, grism spectroscopy to map the ionized bubble around EGSz8p7 using the [OIII] doublet. A blind survey is optimal for determining a complete census of EGSz8p7's physical neighbors. Spitzer/IRAC color excesses at z>8 imply extreme [OIII] EWs (~6000 A) ensuring efficient use of JWST. Stellar population modeling of the sources around EGSz8p7 may give us the strongest constraints yet on when star-formation first commenced after the Big Bang (i.e., cosmic dawn). Our spectra will likewise constrain the ionizing photon production efficiency, a key unknown in reionization calculations. Our observing strategy is designed for maximum legacy value with a footprint overlapping the CEERS ERS survey and use of the wide F444W grism that will guarantee additional
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