58 research outputs found
Peri-Operative Risk Factors Associated with Post-Operative Cognitive Dysfunction (POCD): An Umbrella Review of Meta-Analyses of Observational Studies
This umbrella review aimed to systematically identify the peri-operative risk factors associated with post-operative cognitive dysfunction (POCD) using meta-analyses of observational studies. To date, no review has synthesised nor assessed the strength of the available evidence examining risk factors for POCD. Database searches from journal inception to December 2022 consisted of systematic reviews with meta-analyses that included observational studies examining pre-, intra- and post-operative risk factors for POCD. A total of 330 papers were initially screened. Eleven meta-analyses were included in this umbrella review, which consisted of 73 risk factors in a total population of 67,622 participants. Most pertained to pre-operative risk factors (74%) that were predominantly examined using prospective designs and in cardiac-related surgeries (71%). Overall, 31 of the 73 factors (42%) were associated with a higher risk of POCD. However, there was no convincing (class I) or highly suggestive (class II) evidence for associations between risk factors and POCD, and suggestive evidence (class III) was limited to two risk factors (pre-operative age and pre-operative diabetes). Given that the overall strength of the evidence is limited, further large-scale studies that examine risk factors across various surgery types are recommended
A Spectroscopic Study of Type Ibc Supernova Host Galaxies from Untargeted Surveys
We present the largest spectroscopic study of the host environments of Type
Ibc supernovae (SN Ibc) discovered exclusively by untargeted SN searches. Past
studies of SN Ibc host environments have been biased towards high-mass,
high-metallicity galaxies by focusing on SNe discovered in galaxy-targeted SN
searches. Our new observations more than double the total number of
spectroscopic stellar population age and metallicity measurements published for
untargeted SN Ibc host environments, and extend to a median redshift about
twice as large as previous statistical studies (z = 0.04). For the 12 SNe Ib
and 21 SNe Ic in our metallicity sample, we find median metallicities of
log(O/H)+12 = 8.48 and 8.61, respectively, but determine that the discrepancy
in the full distribution of metallicities is not statistically significant.
This median difference would correspond to only a small difference in the mass
loss via metal-line driven winds (<30%), suggesting this does not play the
dominant role in distinguishing SN Ib and Ic progenitors. However, the median
metallicity of the 7 broad-lined SN Ic (SN Ic-BL) in our sample is
significantly lower, log(O/H)+12 = 8.34. The age of the young stellar
population of SN Ic-BL host environments also seems to be lower than for SN Ib
and Ic, but our age sample is small. A synthesis of SN Ibc host environment
spectroscopy to date does not reveal a significant difference in SN Ib and Ic
metallicities, but reinforces the significance of the lower metallicities for
SN Ic-BL. This combined sample demonstrates that galaxy-targeted SN searches
introduce a significant bias for studies seeking to infer the metallicity
distribution of SN progenitors, and we identify and discuss other systematic
effects that play smaller roles. We discuss the path forward for making
progress on SN Ibc progenitor studies in the LSST era.Comment: 27 pages, 12 Figures, V2 as accepted by ApJ, more information at
http://www.cfa.harvard.edu/~nsanders/papers/Ibchosts/summary.htm
Randomized controlled trial of an Acceptance and Commitment Therapy and compassion-based group intervention for persons with inflammatory bowel disease: the LIFEwithIBD intervention
ObjectivesThis study tested the acceptability and efficacy of an Acceptance and Commitment Therapy and compassion-based intervention (LIFEwithIBD) in people with IBD through a two-arm RCT.MethodsParticipants were recruited at the Gastroenterology Department of the Coimbra University Hospital between June and September 2019. Of the 355 patients screened, those who accepted to participate were randomly assigned to one of two conditions: experimental group (LIFEwithIBD; n = 25) or control group (waitlist; n = 29). Participants completed self-report measures at baseline (T0), post-intervention (T1), and 3-month (T2) and 12-month (T3) follow-ups. Intervention acceptability was assessed. Efficacy was examined using intent-to-treat ANCOVA at post-intervention after adjusting for baseline values of depressive, anxiety, and stress symptoms (primary outcomes). Linear mixed models for all longitudinal outcomes were also analysed. Inflammatory and disease biomarkers were determined at T0 and T3.ResultsAcceptability results revealed a high level of satisfaction and perceived usefulness regarding the intervention. Both groups experienced a significant decrease in stress symptoms and IBD symptom perception at T1. No significant differences were observed at follow-up for the primary outcomes. The experimental group reported significantly lower Crohn’s disease Symptom severity at T2 than the control group. Post-hoc analyses designed to mitigate floor effects revealed substantial treatment effects for the experimental group regarding anxiety symptoms. No significant differences were observed in clinical biomarkers from T0 to T3.ConclusionThe LIFEwithIBD intervention shows promising, although preliminary, benefits for managing disease activity and reducing anxiety symptoms in IBD patients with high severity of psychological distress.Clinical trial registration: https://www.clinicaltrials.gov/ct2/show/NCT03840707, identifier NCT03840707
Dust and Metal Column Densities in Gamma-Ray Burst Host Galaxies
In this paper we present the results from the analysis of a sample of 28
gamma-ray burst (GRB) afterglow spectral energy distributions, spanning the
X-ray through to near-infrared wavelengths. This is the largest sample of GRB
afterglow spectral energy distributions thus far studied, providing a strong
handle on the optical depth distribution of soft X-ray absorption and
dust-extinction systems in GRB host galaxies. We detect an absorption system
within the GRB host galaxy in 79% of the sample, and an extinction system in
71% of the sample, and find the Small Magellanic Cloud (SMC) extinction law to
provide an acceptable fit to the host galaxy extinction profile for the
majority of cases, consistent with previous findings. The range in the soft
X-ray absorption to dust-extinction ratio, N_{H,X}/Av, in GRB host galaxies
spans almost two orders of magnitude, and the typical ratios are significantly
larger than those of the Magellanic Clouds or Milky Way. Although dust
destruction could be a cause, at least in part, for the large N_{H,X}/Av
ratios, the good fit provided by the SMC extinction law for the majority of our
sample suggests that there is an abundance of small dust grains in the GRB
environment, which we would expect to have been destroyed if dust destruction
were responsible for the large N_{H,X}/Av ratios. Instead, our analysis
suggests that the distribution of N_{H,X}/Av in GRB host galaxies may be mostly
intrinsic to these galaxies, and this is further substantiated by evidence for
a strong negative correlation between N_{H,X}/Av and metallicity for a
subsample of GRB hosts with known metallicity. Furthermore, we find the
N_{H,X}/Av ratio and metallicity for this subsample of GRBs to be comparable to
the relation found in other more metal-rich galaxies.Comment: 23 pages, 10 figures, accepted for publication in MNRA
Small chromosomes among Danish Candida glabrata isolates originated through different mechanisms
We analyzed 192 strains of the pathogenic yeast Candida glabrata from patients, mainly suffering from systemic infection, at Danish hospitals during 1985-1999. Our analysis showed that these strains were closely related but exhibited large karyotype polymorphism. Nine strains contained small chromosomes, which were smaller than 0.5 Mb. Regarding the year, patient and hospital, these C. glabrata strains had independent origin and the analyzed small chromosomes were structurally not related to each other (i.e. they contained different sets of genes). We suggest that at least two mechanisms could participate in their origin: (i) through a segmental duplication which covered the centromeric region, or (ii) by a translocation event moving a larger chromosome arm to another chromosome that leaves the centromere part with the shorter arm. The first type of small chromosomes carrying duplicated genes exhibited mitotic instability, while the second type, which contained the corresponding genes in only one copy in the genome, was mitotically stable. Apparently, in patients C. glabrata chromosomes are frequently reshuffled resulting in new genetic configurations, including appearance of small chromosomes, and some of these resulting "mutant" strains can have increased fitness in a certain patient "environment"
The large trans-Neptunian object 2002 TC302 from combined stellar occultation, photometry, and astrometry data
Context. Deriving physical properties of trans-Neptunian objects is important for the understanding of our Solar System. This requires observational efforts and the development of techniques suitable for these studies. Aims. Our aim is to characterize the large trans-Neptunian object (TNO) 2002 TC302. Methods. Stellar occultations offer unique opportunities to determine key physical properties of TNOs. On 28 January 2018, 2002 TC302 occulted a mv ~ 15.3 star with designation 593-005847 in the UCAC4 stellar catalog, corresponding to Gaia source 130957813463146112. Twelve positive occultation chords were obtained from Italy, France, Slovenia, and Switzerland. Also, four negative detections were obtained near the north and south limbs. This represents the best observed stellar occultation by a TNO other than Pluto in terms of the number of chords published thus far. From the 12 chords, an accurate elliptical fit to the instantaneous projection of the body can be obtained that is compatible with the near misses. Results. The resulting ellipse has major and minor axes of 543 ± 18 km and 460 ± 11 km, respectively, with a position angle of 3 ± 1 degrees for the minor axis. This information, combined with rotational light curves obtained with the 1.5 m telescope at Sierra Nevada Observatory and the 1.23 m telescope at Calar Alto observatory, allows us to derive possible three-dimensional shapes and density estimations for the body based on hydrostatic equilibrium assumptions. The effective diameter in equivalent area is around 84 km smaller than the radiometrically derived diameter using thermal data from Herschel and Spitzer Space Telescopes. This might indicate the existence of an unresolved satellite of up to ~300 km in diameter, which is required to account for all the thermal flux, although the occultation and thermal diameters are compatible within their error bars given the considerable uncertainty of the thermal results. The existence of a potential satellite also appears to be consistent with other ground-based data presented here. From the effective occultation diameter combined with absolute magnitude measurements we derive a geometric albedo of 0.147 ± 0.005, which would be somewhat smaller if 2002 TC302 has a satellite. The best occultation light curves do not show any signs of ring features or any signatures of a global atmosphere.Funding from Spanish projects AYA2014-56637-C2-1-P, AYA2017-89637-R, from FEDER, and Proyecto de Excelencia de la Junta de Andalucía 2012-FQM1776 is acknowledged. We would like to acknowledge financial support by the Spanish grant AYA-RTI2018-098657-JI00 “LEO-SBNAF” (MCIU/AEI/FEDER, UE) and the financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award for the Instituto de Astrofísica de Andalucía (SEV- 2017-0709). Part of the research received funding from the European Union’s Horizon 2020 Research and Innovation Programme, under grant agreement no. 687378 and from the ERC programme under Grant Agreement no. 669416 Lucky Star. The following authors acknowledge the respective CNPq grants: FB-R 309578/2017-5; RV-M 304544/2017-5, 401903/2016-8; J.I.B.C. 308150/2016-3; MA 427700/2018-3, 310683/2017-3, 473002/2013-2. This study was financed in part by the Coordenação de Aperfeiaçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001 and the National Institute of Science and Technology of the e-Universe project (INCT do e-Universo, CNPq grant 465376/2014-2). GBR acknowledges CAPES-FAPERJ/PAPDRJ grant E26/203.173/2016, MA FAPERJ grant E-26/111.488/2013 and ARGJr FAPESP grant 2018/11239-8. E.F.-V. acknowledges support from the 2017 Preeminent Postdoctoral Program (P3) at UCF. C.K., R.S., A.F-T., and G.M. have been supported by the K-125015 and GINOP-2.3.2-15-2016-00003 grants of the Hungarian National Research, Development and Innovation Office (NKFIH), Hungary. G.M. was also supported by the Hungarian National Research, Development and Innovation Office (NKFIH) grant PD-128 360. R.K. and T.P. were supported by the VEGA 2/0031/18 grant
The Endoplasmic Reticulum Stress Response in Neuroprogressive Diseases: Emerging Pathophysiological Role and Translational Implications
The endoplasmic reticulum (ER) is the main cellular organelle involved in protein synthesis, assembly and secretion. Accumulating evidence shows that across several neurodegenerative and neuroprogressive diseases, ER stress ensues, which is accompanied by over-activation of the unfolded protein response (UPR). Although the UPR could initially serve adaptive purposes in conditions associated with higher cellular demands and after exposure to a range of pathophysiological insults, over time the UPR may become detrimental, thus contributing to neuroprogression. Herein, we propose that immune-inflammatory, neuro-oxidative, neuro-nitrosative, as well as mitochondrial pathways may reciprocally interact with aberrations in UPR pathways. Furthermore, ER stress may contribute to a deregulation in calcium homoeostasis. The common denominator of these pathways is a decrease in neuronal resilience, synaptic dysfunction and even cell death. This review also discusses how mechanisms related to ER stress could be explored as a source for novel therapeutic targets for neurodegenerative and neuroprogressive diseases. The design of randomised controlled trials testing compounds that target aberrant UPR-related pathways within the emerging framework of precision psychiatry is warranted
A unifying view of Gamma Ray Burst Afterglows
We selected a sample of 33 Gamma Ray Bursts (GRBs) detected by Swift, with
known redshift and optical extinction at the host frame. For these, we
constructed the de-absorbed and K-corrected X-ray and optical rest frame light
curves. These are modelled as the sum of two components: emission from the
forward shock due to the interaction of a fireball with the circum-burst medium
and an additional component, treated in a completely phenomenological way. The
latter can be identified, among other possibilities, as "late prompt" emission
produced by a long lived central engine with mechanisms similar to those
responsible for the production of the "standard" early prompt radiation. Apart
from flares or re-brightenings, that we do not model, we find a good agreement
with the data, despite of their complexity and diversity. Although based in
part on a phenomenological model with a relatively large number of free
parameters, we believe that our findings are a first step towards the
construction of a more physical scenario. Our approach allows us to interpret
the behaviour of the optical and X-ray afterglows in a coherent way, by a
relatively simple scenario. Within this context it is possible to explain why
sometimes no jet break is observed; why, even if a jet break is observed, it is
often chromatic; why the steepening after the jet break time is often shallower
than predicted. Finally, the decay slope of the late prompt emission after the
shallow phase is found to be remarkably similar to the time profile expected by
the accretion rate of fall-back material (i.e. proportional to t^{-5/3}),
suggesting that this can be the reason why the central engine can be active for
a long time.Comment: 20 pages, 17 figures, Accepted for publication in MNRA
Targeting dietary restraint to reduce binge eating: A randomised controlled trial of a blended internet- And smartphone app-based intervention
Abstract
Background
Existing internet-based prevention and treatment programmes for binge eating are composed of multiple distinct modules that are designed to target a broad range of risk or maintaining factors. Such multi-modular programmes (1) may be unnecessarily long for those who do not require a full course of intervention and (2) make it difficult to distinguish those techniques that are effective from those that are redundant. Since dietary restraint is a well-replicated risk and maintaining factor for binge eating, we developed an internet- and app-based intervention composed solely of cognitive-behavioural techniques designed to modify dietary restraint as a mechanism to target binge eating. We tested the efficacy of this combined selective and indicated prevention programme in 403 participants, most of whom were highly symptomatic (90% reported binge eating once per week).
Method
Participants were randomly assigned to the internet intervention (n = 201) or an informational control group (n = 202). The primary outcome was objective binge-eating frequency. Secondary outcomes were indices of dietary restraint, shape, weight, and eating concerns, subjective binge eating, disinhibition, and psychological distress. Analyses were intention-to-treat.
Results
Intervention participants reported greater reductions in objective binge-eating episodes compared to the control group at post-test (small effect size). Significant effects were also observed on each of the secondary outcomes (small to large effect sizes). Improvements were sustained at 8 week follow-up.
Conclusions
Highly focused digital interventions that target one central risk/maintaining factor may be sufficient to induce meaningful change in core eating disorder symptoms.
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