Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
139
result(s) for
"Thompson, Dave M"
Sort by:
Psychological distress and PTSD among clinicians in Roma, Lesotho during the COVID-19 pandemic
Background: Since 2020, the world has been battling the coronavirus disease 2019 (COVID-19) pandemic. The mortality and morbidity at the height of the pandemic sparked generalised fear and uncertainty about the future. Concerns were raised about the psychological impact of the pandemic on workers in healthcare systems globally. This study was conducted to establish the degree of psychological impact of the pandemic on frontline health workers in Lesotho.Methods: The study used a quantitative cross-sectional survey design. The Kessler psychological distress screening tool (K-10) and the post-traumatic stress disorder (PTSD) checklist for civilians (PCL-C) were administered to screen for psychological distress among clinical staff at St. Joseph’s Hospital in Roma and its four Health Centres. Additional open- and closed-ended questions were added for context. Data were analysed using Fisher’s exact tests, Pearson chi-square tests and correlation studies.Results: Of the 101 participants, 42 (41.6%) scored ≥ 24 on the K-10 scale (95% CI: 32.0% – 51.2%) indicating moderate to severe psychological distress and 32 (31.7%) scored ≥ 50 on the PCL-C checklist suggesting severe PTSD (95% CI: 24.5% – 42.9%). High scores on the K-10 were found more among men than women (17 [37.8%] vs. 4 [7.1%]; p ≤ 0.001). Post-traumatic stress disorder was more in the younger age group (p ≤ 0.03), in those reporting anxiety (p = 0.005) and those with more co-morbidities (p ≤ 0.001).Conclusion: This study revealed the grave psychological impact of the COVID-19 pandemic on frontline clinical health workers in Lesotho.Contribution: These data will assist health leaders and policymakers to implement mental health support interventions for health workers in future.
Journal Article
Epigenetic profiling for the molecular classification of metastatic brain tumors
Optimal treatment of brain metastases is often hindered by limitations in diagnostic capabilities. To meet this challenge, here we profile DNA methylomes of the three most frequent types of brain metastases: melanoma, breast, and lung cancers (
n
= 96). Using supervised machine learning and integration of DNA methylomes from normal, primary, and metastatic tumor specimens (
n
= 1860), we unravel epigenetic signatures specific to each type of metastatic brain tumor and constructed a three-step DNA methylation-based classifier (BrainMETH) that categorizes brain metastases according to the tissue of origin and therapeutically relevant subtypes. BrainMETH predictions are supported by routine histopathologic evaluation. We further characterize and validate the most predictive genomic regions in a large cohort of brain tumors (
n
= 165) using quantitative-methylation-specific PCR. Our study highlights the importance of brain tumor-defining epigenetic alterations, which can be utilized to further develop DNA methylation profiling as a critical tool in the histomolecular stratification of patients with brain metastases.
The treatment of brain metastases is often limited by the ability to diagnose their origins. Here the authors generate DNA methylomes from the three most frequent types of brain metastases, identify epigenetic signatures specific to each type of metastasis and construct a DNA methylation-based classifier (BrainMETH) to advance brain metastasis diagnosis.
Journal Article
Constraints on the Cosmic Expansion History from GWTC–3
We use 47 gravitational wave sources from the Third LIGO–Virgo–Kamioka Gravitational Wave Detector Gravitational Wave Transient Catalog (GWTC–3) to estimate the Hubble parameter H(z), including its current value, the Hubble constant H 0. Each gravitational wave (GW) signal provides the luminosity distance to the source, and we estimate the corresponding redshift using two methods: the redshifted masses and a galaxy catalog. Using the binary black hole (BBH) redshifted masses, we simultaneously infer the source mass distribution and H(z). The source mass distribution displays a peak around 34 M ⊙, followed by a drop-off. Assuming this mass scale does not evolve with the redshift results in a H(z) measurement, yielding H0=68−8+12kms−1Mpc−1 (68% credible interval) when combined with the H 0 measurement from GW170817 and its electromagnetic counterpart. This represents an improvement of 17% with respect to the H 0 estimate from GWTC–1. The second method associates each GW event with its probable host galaxy in the catalog GLADE+, statistically marginalizing over the redshifts of each event’s potential hosts. Assuming a fixed BBH population, we estimate a value of H0=68−6+8kms−1Mpc−1 with the galaxy catalog method, an improvement of 42% with respect to our GWTC–1 result and 20% with respect to recent H 0 studies using GWTC–2 events. However, we show that this result is strongly impacted by assumptions about the BBH source mass distribution; the only event which is not strongly impacted by such assumptions (and is thus informative about H 0) is the well-localized event GW190814.
Journal Article
Open Data from the Third Observing Run of LIGO, Virgo, KAGRA, and GEO
The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages.
Journal Article
Completion Dissection or Observation for Sentinel-Node Metastasis in Melanoma
Patients with melanoma and positive sentinel nodes were randomly assigned to completion lymph-node dissection or observation. Melanoma-specific survival did not differ significantly between the groups.
Sentinel-lymph-node biopsy is a standard procedure in the care of appropriately selected patients with melanoma. The first Multicenter Selective Lymphadenectomy Trial (MSLT-I) confirmed the value of early nodal evaluation and treatment.
1
–
3
This prospective, international, randomized trial showed that the pathologic status of the sentinel node or nodes was the most important prognostic factor and that patients who underwent sentinel-node biopsy had fewer recurrences of melanoma than patients who underwent wide excision and nodal observation. Among patients with intermediate-thickness melanomas (defined as 1.2 to 3.5 mm) and nodal metastases, early surgical treatment, guided by sentinel-node biopsy, was associated with increased . . .
Journal Article
Search for Gravitational-lensing Signatures in the Full Third Observing Run of the LIGO–Virgo Network
Gravitational lensing by massive objects along the line of sight to the source causes distortions to gravitational wave (GW) signals; such distortions may reveal information about fundamental physics, cosmology, and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO-Virgo network. We search for repeated signals from strong lensing by (1) performing targeted searches for subthreshold signals, (2) calculating the degree of overlap among the intrinsic parameters and sky location of pairs of signals, (3) comparing the similarities of the spectrograms among pairs of signals, and (4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by (1) frequency-independent phase shifts in strongly lensed images, and (2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the nondetection of GW lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects.
Journal Article
Searches for Gravitational Waves from Known Pulsars at Two Harmonics in the Second and Third LIGO-Virgo Observing Runs
We present a targeted search for continuous gravitational waves (GWs) from 236 pulsars using data from the third observing run of LIGO and Virgo (O3) combined with data from the second observing run (O2). Searches were for emission from the l = m = 2 mass quadrupole mode with a frequency at only twice the pulsar rotation frequency (single harmonic) and the l = 2, m = 1, 2 modes with a frequency of both once and twice the rotation frequency (dual harmonic). No evidence of GWs was found, so we present 95% credible upper limits on the strain amplitudes h 0 for the single-harmonic search along with limits on the pulsars’ mass quadrupole moments Q 22 and ellipticities ε. Of the pulsars studied, 23 have strain amplitudes that are lower than the limits calculated from their electromagnetically measured spin-down rates. These pulsars include the millisecond pulsars J0437−4715 and J0711−6830, which have spin-down ratios of 0.87 and 0.57, respectively. For nine pulsars, their spin-down limits have been surpassed for the first time. For the Crab and Vela pulsars, our limits are factors of ∼100 and ∼20 more constraining than their spin-down limits, respectively. For the dual-harmonic searches, new limits are placed on the strain amplitudes C 21 and C 22. For 23 pulsars, we also present limits on the emission amplitude assuming dipole radiation as predicted by Brans-Dicke theory.
Journal Article
Rapid recovery of ecosystem function following extreme drought in a South African savanna grassland
Climatic extremes, such as severe drought, are expected to increase in frequency and magnitude with climate change. Thus, identifying mechanisms of resilience is critical to predicting the vulnerability of ecosystems. An exceptional drought (
Journal Article
Overview of ADNI MRI
The magnetic resonance imaging (MRI) Core has been operating since Alzheimer's Disease Neuroimaging Initiative's (ADNI) inception, providing 20 years of data including reliable, multi‐platform standardized protocols, carefully curated image data, and quantitative measures provided by expert investigators. The overarching purposes of the MRI Core include: (1) optimizing and standardizing MRI acquisition methods, which have been adopted by many multicenter studies and trials worldwide and (2) providing curated images and numeric summary values from relevant MRI sequences/contrasts to the scientific community. Over time, ADNI MRI has become increasingly complex. To remain technically current, the ADNI MRI protocol has changed substantially over the past two decades. The ADNI 4 protocol contains nine different imaging types (e.g., three dimensional [3D] T1‐weighted and fluid‐attenuated inversion recovery [FLAIR]). Our view is that the ADNI MRI data are a greatly underutilized resource. The purpose of this paper is to educate the scientific community on ADNI MRI methods and content to promote greater awareness, accessibility, and use. Highlights The MRI Core provides multi‐platform standardized protocols, carefully curated image data, and quantitative analysis by expert groups. The ADNI MRI protocol has undergone major changes over the past two decades to remain technically current. As of April 25, 2024, the following numbers of image series are available: 17,141 3D T1w; 6877 FLAIR; 3140 T2/PD; 6623 GRE; 3237 dMRI; 2846 ASL; 2968 TF‐fMRI; and 2861 HighResHippo (see Table 1 for abbreviations). As of April 25, 2024, the following numbers of quantitative analyses are available: FreeSurfer 10,997; BSI 6120; tensor based morphometry (TBM) and TBM‐SYN 12,019; WMH 9944; dMRI 1913; ASL 925; TF‐fMRI NFQ 2992; and medial temporal subregion volumes 2726 (see Table 4 for abbreviations). ADNI MRI is an underutilized resource that could be more useful to the research community.
Journal Article
Search for Neutrino Emission from Hard X-Ray AGN with IceCube
Active galactic nuclei (AGN) are promising candidate sources of high-energy astrophysical neutrinos, since they provide environments rich in matter and photon targets where cosmic-ray interactions may lead to the production of gamma rays and neutrinos. We searched for high-energy neutrino emission from AGN using the Swift-BAT Spectroscopic Survey catalog of hard X-ray sources and 12 yr of IceCube muon track data. First, upon performing a stacked search, no significant emission was found. Second, we searched for neutrinos from a list of 43 candidate sources and found an excess from the direction of two sources, the Seyfert galaxies NGC 1068 and NGC 4151. We observed NGC 1068 at flux ϕνμ+ν¯μ = 4.02−1.52+1.58×10−11 TeV−1 cm−2 s−1 normalized at 1 TeV, with a power-law spectral index γ = 3.10 −0.22+0.26 , consistent with previous IceCube results. The observation of a neutrino excess from the direction of NGC 4151 is at a posttrial significance of 2.9σ. If interpreted as an astrophysical signal, the excess observed from NGC 4151 corresponds to a flux ϕνμ+ν¯μ = 1.51−0.81+0.99×10−11 TeV−1 cm−2 s−1 normalized at 1 TeV and γ = 2.83 −0.28+0.35 .
Journal Article