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Abstract The specific activity of the $$\beta $$ β decay of $$^{39}$$ 39 Ar in atmospheric argon is measured using the DEAP-3600 detector. DEAP-3600, located 2 km underground at SNOLAB, uses a total of (3269 ± 24) kg of liquid argon distilled from the atmosphere to search for dark matter. This detector is well-suited to measure the decay of $$^{39}$$ 39 Ar owing to its very low background levels. This is achieved in two ways: it uses low background construction materials; and it uses pulse-shape discrimination to differentiate between nuclear recoils and electron recoils. With 167 live-days of data, the measured specific activity at the time of atmospheric extraction is (0.964 ± 0.001 $$_\textrm{stat}$$ stat ± 0.024 $$_\textrm{sys}$$ sys ) Bq/kg $$_\textrm{atmAr}$$ atmAr , which is consistent with results from other experiments. A cross-check analysis using different event selection criteria and a different statistical method confirms the result.

Abstract The DEAP-3600 detector searches for the scintillation signal from dark matter particles scattering on a 3.3 tonne liquid argon target. The largest background comes from $$^{39}\text{ Ar }$$ 39 Ar beta decays and is suppressed using pulse-shape discrimination (PSD). We use two types of PSD estimator: the prompt-fraction, which considers the fraction of the scintillation signal in a narrow and a wide time window around the event peak, and the log-likelihood-ratio, which compares the observed photon arrival times to a signal and a background model. We furthermore use two algorithms to determine the number of photons detected at a given time: (1) simply dividing the charge of each PMT pulse by the mean single-photoelectron charge, and (2) a likelihood analysis that considers the probability to detect a certain number of photons at a given time, based on a model for the scintillation pulse shape and for afterpulsing in the light detectors. The prompt-fraction performs approximately as well as the log-likelihood-ratio PSD algorithm if the photon detection times are not biased by detector effects. We explain this result using a model for the information carried by scintillation photons as a function of the time when they are detected.

Abstract DEAP-3600 is a liquid-argon scintillation detector looking for dark matter. Scintillation events in the liquid argon (LAr) are registered by 255 photomultiplier tubes (PMTs), and pulseshape discrimination (PSD) is used to suppress electromagnetic background events. The excellent PSD performance of LAr makes it a viable target for dark matter searches, and the LAr scintillation pulseshape discussed here is the basis of PSD. The observed pulseshape is a combination of LAr scintillation physics with detector effects. We present a model for the pulseshape of electromagnetic background events in the energy region of interest for dark matter searches. The model is composed of (a) LAr scintillation physics, including the so-called intermediate component, (b) the time response of the TPB wavelength shifter, including delayed TPB emission at $${\mathcal {O}}$$ O (ms) time-scales, and c) PMT response. TPB is the wavelength shifter of choice in most LAr detectors. We find that approximately 10% of the intensity of the wavelength-shifted light is in a long-lived state of TPB. This causes light from an event to spill into subsequent events to an extent not usually accounted for in the design and data analysis of LAr-based detectors.

BackgroundAmong people with HIV (PWH), COVID-19 is common and potentially severe. We leveraged REPRIEVE (Randomized Trial to Prevent Vascular Events in HIV) to assess the effects of statin therapy for cardiovascular disease prevention on COVID-19 outcomes (incidence and serious cases) among a global cohort of PWH.MethodsCOVID-19 data collection was implemented April 2020 to capture events from January 2020. COVID-19 was defined by positive test result or clinical diagnosis and serious COVID-19 according to the International Conference on Harmonisation definition. Among participants in follow-up on 1 January 2020, Cox proportional hazards modeling was used to estimate the hazard ratio (HR) of COVID-19 (pitavastatin/placebo), stratified by Global Burden of Disease region. Modification of statin effect following COVID-19 vaccination was evaluated via interaction with time-updated vaccination status.ResultsAmong 6905 PWH, 32% were natal female and 41% were Black or African American. The median age was 53 years and the 10-year atherosclerotic cardiovascular disease risk score 4.5%. Statin therapy did not reduce COVID-19 incidence (HR, 1.05; 95% CI, .95-1.15) but appeared to reduce incidence of serious COVID-19 (HR, 0.75; 95% CI, .52-1.09). Among 1701 PWH with COVID-19, the relative risk (pitavastatin/placebo) for serious COVID-19 was 0.73 (95% CI, .52-1.03). The treatment effect size for serious COVID-19 fell within the hypothesized range, but the 95% CI crossed 1 given fewer-than-anticipated cases (117 vs 200). Furthermore, 83% reported COVID-19 vaccination by end of study, with a strong protective effect on serious COVID-19 (HR, 0.27; 95% CI, .14-.53; P < .0001). A protective statin effect was observed prior to vaccination.ConclusionsAmong PWH, statin therapy had no effect on COVID-19 incidence but showed potential to reduce risk of serious COVID-19 prior to COVID-19 vaccination.Clinical trials registrationNCT02344290 (ClinicalTrials.gov).

Ferroptosis is implicated in viral neuropathogenesis and may underlie HIV-associated neurocognitive impairment (NCI). Emerging data also suggest differences in brain iron transport by sex. We hypothesized that circulating ferritins that inhibit ferroptosis associate with neurocognitive function and NCI in people with HIV (PWH) in a sex-biased manner. Serum ferritin heavy-chain-1 (FTH1), ferritin light-chain (FTL), and urinary F2-isoprostanes (uF2-isoPs, specific lipid peroxidation marker) were quantified in 324 PWH (including 61 women) with serial global (NPZ-4) and domain-specific neurocognitive testing. Biomarker associations with neurocognitive test scores and NCIs were evaluated by multivariable regression; correlations with uF2-isoPs were also assessed. Higher FTL and FTH1 levels were associated with less NCI in all PWH (adjusted odds ratios 0.53, 95% confidence interval (95% CI) 0.36-0.79 and 0.66, 95% CI 0.45-0.97, respectively). In women, higher FTL and FTH1 were also associated with better NPZ-4 (FTL adjusted beta (β) = 0.15, 95% CI 0.02-0.29; FTL-by-sex βinteraction = 0.32, p = 0.047) and domain-specific neurocognitive test scores. Effects on neurocognitive performance persisted for up to 5 years. Levels of both ferritins correlated inversely with uF2-isoPs in women (FTL: rho = -0.47, p < 0.001). Circulating FTL and FTH1 exert sustained, sex-biased neuroprotective effects in PWH, possibly by protecting against iron-mediated lipid peroxidation (ferroptosis). Larger studies are needed to confirm the observed sex differences and further delineate the underlying mechanisms.

BACKGROUND: Limited research has studied the influence of social determinants of health (SDoH) on the receipt, disease risk, and subsequent effectiveness of neutralizing monoclonal antibodies (nMAbs) for outpatient treatment of COVID-19. OBJECTIVE: To examine the influence of SDoH variables on receiving nMAb treatments and the risk of a poor COVID-19 outcome, as well as nMAb treatment effectiveness across SDoH subgroups. DESIGN: Retrospective observational study utilizing electronic health record data from four health systems. SDoH variables analyzed included race, ethnicity, insurance, marital status, Area Deprivation Index, and population density. PARTICIPANTS: COVID-19 patients who met at least one emergency use authorization criterion for nMAb treatment. MAIN MEASURE: We used binary logistic regression to examine the influence of SDoH variables on receiving nMAb treatments and risk of a poor outcome from COVID-19 and marginal structural models to study treatment effectiveness. RESULTS: The study population included 25,241 (15.1%) nMAb-treated and 141,942 (84.9%) non-treated patients. Black or African American patients were less likely to receive treatment than white non-Hispanic patients (adjusted odds ratio (OR) = 0.86; 95% CI = 0.82-0.91). Patients who were on Medicaid, divorced or widowed, living in rural areas, or living in areas with the highest Area Deprivation Index (most vulnerable) had lower odds of receiving nMAb treatment, but a higher risk of a poor outcome. For example, compared to patients on private insurance, Medicaid patients had 0.89 (95% CI = 0.84-0.93) times the odds of receiving nMAb treatment, but 1.18 (95% CI = 1.13-1.24) times the odds of a poor COVID-19 outcome. Age, comorbidities, and COVID-19 vaccination status had a stronger influence on risk of a poor outcome than SDoH variables. nMAb treatment benefited all SDoH subgroups with lower rates of 14-day hospitalization and 30-day mortality. CONCLUSION: Disparities existed in receiving nMAbs within SDoH subgroups despite the benefit of treatment across subgroups.

In recent decades, there have been policy changes affecting School-Age Educare (SAE) teachers in Sweden. Today, SAE teachers must be aware of the historical underpinnings, educational policy aims, and a 'new' undergraduate teacher education program. The aim of the present article is to explore in what way SAE teachers, graduated from the basic teacher program in 2020, describe their professional roles and experiences, during their first year in school practice. In order to analyze how SAE teachers experience structural tensions in school practice, Merton's [(1976). "Sociological ambivalence and other essays." The Free Press] concept of sociological ambivalence will be employed. The findings show examples of the ambivalent positions for SAE teachers within the school organization as well as outside schools. Consequently, the ambivalent positions for SAE teachers, along with the reform aim to transform the 'traditional' SAE teacher into ideas focusing on compulsory school teaching need attention when it comes to recruiting SAE teachers for future practice.

Similar to many countries in the Western world, educational reforms in Sweden have dramatically changed the educational system in the last few decades. The two reforms that we address in this paper concern "The Career Services for Teachers Reform" and "Teachers Salary Boost" which were implemented at the national level in Sweden in 2013 and 2017, respectively. In this ethnographic study we focus on the design features of these two contemporary reforms and how they impact on both the social and educational life of teachers and school leaders at a secondary high school. However, this change in organisational logic was not only a major digression from the academic tradition and its traditional character of "merit before birth". Due to design features within these reforms, the door to nepotism, real or imagined, was now wide open. Moreover, in the same way as these reforms represent something new to Swedish education, and to the teaching profession in particular, it is just one more step on a road already mapped out via the ongoing neo-liberalisation of society at large.

Older persons with HIV (PWH) experience high rates of cognitive impairment and frailty, and accelerated decline in physical function compared with the general population. Metformin use has been associated with beneficial effects on cognitive and physical function among older adults without HIV. The relationship between metformin use on these outcomes in PWH has not been evaluated. AIDS Clinical Trials Group (ACTG) A5322 is an observational cohort study of older PWH with annual assessments for cognition and frailty, including measures of physical function (e.g., gait speed and grip strength). Participants with diabetes who were prescribed antihyperglycemic medications were included in this analysis to evaluate the association between metformin and functional outcomes. Cross-sectional, longitudinal, and time-to-event models were used to evaluate the relationship between metformin exposure with cognitive, physical function, and frailty outcomes. Ninety-eight PWH met inclusion criteria and were included in at least one model. No significant associations between metformin use, frailty, physical, or cognitive function were noted in unadjusted or adjusted cross-sectional, longitudinal, or time-to-event models (p > .1 for all models). This study is the first to examine the association between metformin use on functional outcomes among older PWH. Although it did not ascertain significant associations between metformin use and functional outcomes, our small sample size, restriction to persons with diabetes, and lack of randomization to metformin therapy were limitations. Larger randomized studies are needed to determine whether metformin use has beneficial effects on cognitive or physical function in PWH. Clinical Trial Registration numbers: 02570672, 04221750, 00620191, and 03733132.

Abstract: Importance: SARS-CoV-2 infection can result in ongoing, relapsing, or new symptoms or other health effects after the acute phase of infection; termed post-acute sequelae of SARS-CoV-2 infection (PASC), or long COVID. The characteristics, prevalence, trajectory and mechanisms of PASC are ill-defined. The objectives of the Researching COVID to Enhance Recovery (RECOVER) Multi-site Observational Study of PASC in Adults (RECOVER-Adult) are to: (1) characterize PASC prevalence; (2) characterize the symptoms, organ dysfunction, natural history, and distinct phenotypes of PASC; (3) identify demographic, social and clinical risk factors for PASC onset and recovery; and (4) define the biological mechanisms underlying PASC pathogenesis. Methods: RECOVER-Adult is a combined prospective/retrospective cohort currently planned to enroll 14,880 adults aged ≥18 years. Eligible participants either must meet WHO criteria for suspected, probable, or confirmed infection; or must have evidence of no prior infection. Recruitment occurs at 86 sites in 33 U.S. states, Washington, DC and Puerto Rico, via facility– and community-based outreach. Participants complete quarterly questionnaires about symptoms, social determinants, vaccination status, and interim SARS-CoV-2 infections. In addition, participants contribute biospecimens and undergo physical and laboratory examinations at approximately 0, 90 and 180 days from infection or negative test date, and yearly thereafter. Some participants undergo additional testing based on specific criteria or random sampling. Patient representatives provide input on all study processes. The primary study outcome is onset of PASC, measured by signs and symptoms. A paradigm for identifying PASC cases will be defined and updated using supervised and unsupervised learning approaches with cross– validation. Logistic regression and proportional hazards regression will be conducted to investigate associations between risk factors, onset, and resolution of PASC symptoms. Discussion: RECOVER-Adult is the first national, prospective, longitudinal cohort of PASC among US adults. Results of this study are intended to inform public health, spur clinical trials, and expand treatment options.

Founding populations of the first Americans likely occupied parts of Beringia during the Last Glacial Maximum (LGM). The timing, pathways, and modes of their southward transit remain unknown, but blockage of the interior route by North American ice sheets between ~26 and 14 cal kyr BP (ka) favors a coastal route during this period. Using models and paleoceanographic data from the North Pacific, we identify climatically favorable intervals when humans could have plausibly traversed the Cordilleran coastal corridor during the terminal Pleistocene. Model simulations suggest that northward coastal currents strengthened during the LGM and at times of enhanced freshwater input, making southward transit by boat more difficult. Repeated Cordilleran glacial-calving events would have further challenged coastal transit on land and at sea. Following these events, ice-free coastal areas opened and seasonal sea ice was present along the Alaskan margin until at least 15 ka. Given evidence for humans south of the ice sheets by 16 ka and possibly earlier, we posit that early people may have taken advantage of winter sea ice that connected islands and coastal refugia. Marine ice-edge habitats offer a rich food supply and traversing coastal sea ice could have mitigated the difficulty of traveling southward in watercraft or on land over glaciers. We identify 24.5 to 22 ka and 16.4 to 14.8 ka as environmentally favorable time periods for coastal migration, when climate conditions provided both winter sea ice and ice-free summer conditions that facilitated year-round marine resource diversity and multiple modes of mobility along the North Pacific coast.

BackgroundCytomegalovirus (CMV) infection is thought to result in increased immune activation in people with human immunodeficiency virus (HIV, PWH). Although some data have linked asymptomatic CMV infection to cardiovascular disease among PWH, it remains unknown whether CMV is associated with increased or high-risk coronary plaque.MethodsThe Randomized Trial to Prevent Vascular Events in HIV (REPRIEVE) enrolled PWH aged 40-75 years on stable antiretroviral therapy (ART) with low-to-moderate atherosclerotic cardiovascular disease (ASCVD) risk. Among a subset of US REPRIEVE participants, coronary plaque was assessed by coronary computed tomography angiography. Here, we assessed the relationship between CMV immunoglobulin G (IgG) titer and (1) levels of immune activation, (2) inflammatory biomarkers, and (3) coronary plaque phenotypes at study entry.ResultsOf 672 participants, mean age was 51 years, 83% were men, median ASCVD risk score was 4.5%, and 66% had current CD4+ T-cell count ≥500 cells/mm3. Higher CMV IgG quartile group was associated with older age and lower current and nadir CD4+ T-cell counts. CMV IgG titer was associated with specific inflammatory biomarkers (sCD163, MCP-1, interleukin [IL]-6, hsCRP) in univariate analysis, but not after controlling for HIV-specific factors. In contrast, CMV IgG titer was not associated with coronary artery disease indexes, including presence of plaque, coronary artery calcium (CAC) score >0, vulnerable plaque presence, or Leaman score >5.ConclusionsNo meaningful association was seen between CMV IgG titer and coronary artery disease indexes among ART-treated PWH at study enrollment. Longitudinal assessments in REPRIEVE will determine the relationship of CMV IgG titer to plaque progression and cardiovascular events.Clinical trials registrationNCT02344290.

BackgroundAmong people with HIV (PWH), sex differences in presentations of atherosclerotic cardiovascular disease (ASCVD) may be influenced by differences in coronary plaque parameters, immune/inflammatory biomarkers, or relationships therein.MethodsREPRIEVE, a primary ASCVD prevention trial, enrolled antiretroviral therapy (ART)-treated PWH. At entry, a subset of US participants underwent coronary computed tomography angiography (CTA) and immune phenotyping (n = 755 CTA; n = 725 CTA + immune). We characterized sex differences in coronary plaque and immune/inflammatory biomarkers and compared immune-plaque relationships by sex. Unless noted otherwise, analyses adjust for ASCVD risk score.ResultsThe primary analysis cohort included 631 males and 124 females. ASCVD risk was higher among males (median: 4.9% vs 2.1%), while obesity rates were higher among females (48% vs 21%). Prevalence of any plaque and of plaque with either ≥1 visible noncalcified portion or vulnerable features (NC/V-P) was lower among females overall and controlling for relevant risk factors (RR [95% CI] for any plaque: .67 [.50, .92]; RR for NC/V-P: .71 [.51, 1.00] [adjusted for ASCVD risk score and body mass index]). Females showed higher levels of IL-6, hs-CRP, and D-dimer and lower levels of Lp-PLA2 (P < .001 for all). Higher levels of Lp-PLA2, MCP-1, and oxLDL were associated with higher plaque (P < .02) and NC/V-P prevalence, with no differences by sex. Among females but not males, D-dimer was associated with higher prevalence of NC/V-P (interaction P = .055).ConclusionsAmong US PWH, females had a lower prevalence of plaque and NC/V-P, as well as differences in key immune/inflammatory biomarkers. Immune-plaque relationships differed by sex for D-dimer but not other tested parameters. Clinical Trial Registration. ClinicalTrials.gov; identifier: NCT0234429 (date of initial registration: 22 January 2015).

BackgroundConflicting evidence exists on the impact of cannabis use on antiretroviral therapy (ART) adherence among people with human immunodeficiency virus (PWH). We leveraged data collected among older PWH to characterize longitudinal associations between cannabis use and ART adherence.MethodsAIDS Clinical Trials Group (ACTG) A5322 study participants were categorized as

People with HIV on combination antiretroviral therapy (ART) have longer life expectancy and are increasingly experiencing age-related comorbidities. Thus, aging with HIV has become a central issue in clinical care and research, which has been particularly challenging with the intersection of the ongoing coronavirus (COVID)-19 pandemic. Since 2009, the International Workshop on HIV and Aging has served as a multidisciplinary platform to share research findings from cross-disciplinary fields along with community advocates to address critical issues in HIV and aging. In this article, we summarize the key oral presentations from the 12th Annual International Workshop on HIV and Aging, held virtually on September 23rd and 24th, 2021. The topics ranged from basic science research on biological mechanisms of aging to quality of life and delivery of care under the COVID-19 pandemic. This workshop enriched our understanding of HIV and aging under the COVID-19 pandemic, identified challenges and opportunities to combat the impact of COVID-19 on HIV communities, and also provided updated research and future directions of the field to move HIV and aging research forward, with the ultimate goal of successful aging for older people with HIV.