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 of gravitational wave-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 amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst 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 non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Sedentary Behavior and Physical Activity of Older Adults

High levels of sedentary behavior increase the risk for chronic disease, loss of physical function, disability, and all-cause mortality. Oldest old adults (age 80 and older) and older adults in assisted living are especially at risk for health decline and frailty. Accurate sedentary behavior measurement is critical in order to assess associated health risks and the effectiveness of interventions for reducing sedentary behavior. There is great need for interventions to reduce sedentary behavior and increase light physical activity in older adults in assisted living. This type of intervention could reduce health risks, slow functional decline and frailty, and delay residents’ needs for higher-level care such as a nursing home. The aims of this dissertation are the following: 1) Characterize sedentary behavior in community-dwelling adults age 80 and older by conducting a systematic review and meta-analysis focused on volume of sedentary behavior and factors associated with sedentary behavior in this population; 2) Identify optimal methods for processing objectively measured sedentary behavior data by analyzing ActiGraph vertical axis and vector magnitude data with multiple combinations of filters, non-wear algorithm lengths, and cut-points and by comparing ActiGraph estimates to ActivPAL-measured sedentary time in inactive people with chronic obstructive pulmonary disease; 3) Gather feedback from assisted living residents on a proposed Active for Life in Assisted Living intervention by conducting one-on-one interviews. A secondary aim was to explore contextual factors that may influence how the intervention will be implemented with this population. For aim 1, twenty-one articles were included in the review and meta-analysis showed adults 80 years and older are sedentary for 10.6 hours during the waking day. Although few articles examined factors associated with sedentary behavior in this age group, older age, male gender, non-Hispanic white race/ethnicity, social disadvantage, and declining cognitive function (in men) were associated with increased sedentary time. For aim 2, a secondary data analysis was conducted with a sample of older adults with chronic obstructive pulmonary disease (n=59) who wore ActiGraph and ActivPAL devices for seven days. Thirty techniques for processing ActiGraph sedentary behavior data were compared to ActivPAL-measured sedentary behavior using the Bland-Altman method. The best ActiGraph technique was vector magnitude data with low frequency extension filter, 120-minute non-wear algorithm, and sedentary behavior cut-point of <40 counts/15 seconds (concordance correlation 0.839; mean difference -11.7 minutes/day). For aim 3, one-on-one semi-structured interviews were conducted with 20 assisted living residents. They were presented the proposed Active for Life intervention and asked questions to inform its development. Data were analyzed using content and thematic analysis. Assisted living residents recommended shorter intervention sessions, shorter overall intervention length, and framing the goal of the intervention as increasing light physical activity. The thematic analysis identified factors that could influence intervention implementation, including motivation, safety, beliefs about aging, varying abilities, social influences, and physical activity opportunities in AL. As a whole, the results of this dissertation contribute to our knowledge of sedentary behavior in older adults. Findings highlight the high volume of sedentary behavior in the oldest old, showing opportunity for intervention to reduce sedentary time. We also identified optimal methods for measuring sedentary behavior in older adults, which may guide data processing decisions. In addition, we gathered valuable feedback on a proposed intervention to reduce sedentary behavior of assisted living residents, an important first step in developing an intervention appropriate for this population.PHDNursingUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/171333/1/katewebs_1.pd

Primer Design for Detecting Single Nucleotide Polymorphisms within the Oxytocin Receptor Gene (OXTR) among Persons with Alzheimer Disease

Apathy, defined as a disorder of motivation with deficits in behavioral, emotional, and cognitive domains, is a prevalent behavioral symptom among persons with Alzheimer Disease (AD). Various complications have been associated with apathy, such as physical deconditioning, uncooperativeness with care, and social isolation. Little is known about the characteristics of persons with AD, including biological factors, that contribute to the presence and/or severity of apathy. Variations in the Oxytocin Receptor Gene (OXTR) are hypothesized to be candidate modifiers of apathy severity in persons with AD. OXTR is approximately 19,000 bp in length and is located on chromosome 3. A DNA variant within OXTR (rs53576) significantly predicted 19.4% of the variance in apathy severity as measured by the Apathy subscale of the Neuropsychiatric Inventory (NPI-Apathy) (F=3.379, p=.027), while controlling for cognitive status and number of Apolipoprotein E (APOE) e4 alleles in a previous study. The aims of this study were to design and successfully utilize primers and polymerase chain reaction (PCR) in order to amplify OXTR single nucleotide polymorphisms (SNPs) as a means to examine variations within OXTR that may be associated with apathy in persons with AD. Primer sets were designed to amplify seven SNPs (rs53576, rs237885, rs2254298, rs237887, rs2268493, rs2268498, and rs13316193) within OXTR and were tested using ten lab control human DNA samples. Gel electrophoresis results showed that bands migrated appropriate distances for the expected length of DNA fragments. This indicated successful DNA extraction, primer design, and amplification of all seven SNPs. Study findings may contribute to a risk profile for identifying individuals with AD most at risk for apathy based on OXTR genotype, with a long-term goal to design targeted nursing interventions to benefit these individuals

A Competency-based Tool for Resident Evaluation of Pediatric Emergency Department Faculty

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Device-measured sedentary behavior in oldest old adults: A systematic review and meta-analysis

Sedentary behavior contributes to health decline and frailty in older adults, especially the oldest old. The purpose of this systematic review was to synthesize evidence describing the volume of device-measured sedentary behavior and factors that influence sedentary behavior in community-dwelling adults aged 80 and older. Four electronic databases were searched in August 2018; the search was updated in September 2019 and December 2020. Twenty-one articles representing 16 unique datasets from six countries met inclusion criteria. Various devices and data processing methods were used to measure sedentary behavior; the most common device was the ActiGraph accelerometer. Sedentary time during the waking day ranged from 7.6 to 13.4 h/day. Studies using similar measurement methods (hip-worn ActiGraph with uniaxial cut-point <100 counts per minute) had a weighted mean of 10.6 h/day. Subgroup analyses revealed that male gender and age ≥85 may contribute to increased sedentary behavior. Only seven individual articles examined factors that influence sedentary behavior in the 80 and older age group; older age, male gender, non-Hispanic white race/ethnicity, social disadvantage, and declining cognitive function (in men) were associated with increased sedentary behavior. In conclusion, the oldest old are highly sedentary and little is known about factors that influence their sedentary behavior

Cardio-centric hemodynamic management improves spinal cord oxygenation and mitigates hemorrhage in acute spinal cord injury

Clinical neuroprotective strategies for acute spinal cord injury (SCI) have largely overlooked the heart. Here the authors show cardiac contractility is immediately impaired in a porcine model of T2 SCI, and cardio-centric treatment with dobutamine optimizes cord oxygenation and mitigates haemorrhage