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Background/Objectives: Severe obesity is associated with cognitive deficits in adults without current or past neurological brain disturbances. This study examined the relationship between specific metabolic and vascular risk factors and cognitive performance on a computerized neurocognitive assessment battery in adults with BMI > 35. Subjects/Methods: 123 adults with Class II or III obesity, ages 20-75, were enrolled in a study of the cognitive and brain effects of reduced BMI and improved diabetes mellitus (DM) following bariatric surgery. Baseline clinical/cognitive assessments were conducted with the NIH Toolbox (NIH-TB) cognitive module prior to surgery, and in severely obese controls recruited from the community. Global, Fluid and Crystallized indices were derived from performance across nine tasks. Hierarchical regression analyses examined six obesity-associated clinical factors (BMI, HbA1c, and DM, hypertension, sleep apnea, and osteoarthritis diagnoses) relative to NIH-TB performance. Results: Fluid Cognition deficits were observed, greatest on attention-executive and cognitive processing speed tasks (Flanker and Pattern Comparison). DM diagnosis was most strongly associated with weaker cognitive performance (Global and Fluid Cognition), and with poorer performance on the Flanker, Pattern Comparison, Picture Sequencing, Verbal Learning, and Symbol Coding tasks. Elevated HbA1c was associated with weaker Card Sorting and Symbol Coding performance, hypertension with poorer Fluid Cognition, and osteoarthritis with lower List Sorting performance. Elevated BMI was only associated with Flanker performance, though DM was more strongly associated with this measure. Conclusion: Deficits of fluid cognitive functions (attention-executive, processing speed) exist among adults with Class II and III obesity. DM was most consistently associated with weaker NIH-TB performance. BMI was not as strongly associated with NIH-TB performance, perhaps reflecting the elevated BMI of the entire sample. That cognitive deficits were linked to specific obesity-associated comorbidities support the validity and potential clinical utility of the NIH-TB for the assessment and management of adults with severe obesity.

Alcohol Use Disorder (AUD) among people living with HIV (PLWH) is a significant public health concern. Despite the advent of effective antiretroviral therapy, up to 50% of PLWH still experience worsened neurocognition, which comorbid AUD exacerbates. We report converging lines of neuroimaging and neuropsychological evidence linking comorbid HIV/AUD to dysfunction in brain regions linked to executive function, learning and memory, processing speed, and motor control, and consequently to impairment in daily life. The brain shrinkage, functional network alterations, and brain metabolite disruption seen in individuals with HIV/AUD have been attributed to several interacting pathways: viral proteins and ethanol are directly neurotoxic and exacerbate each other’s neurotoxic effects; ethanol reduces antiretroviral adherence and increases viral replication; AUD and HIV both increase gut microbial translocation, promoting systemic inflammation and HIV transport into the brain by immune cells; and HIV may compound alcohol’s damaging effects on the liver, further increasing inflammation. We additionally review the neurocognitive effects of aging, Hepatitis C coinfection, obesity and cardiovascular disease, tobacco use, and nutritional deficiencies, all of which have been shown to compound cognitive changes in HIV, AUD, and in their comorbidity. Finally, we examine emerging questions in HIV/AUD research, including genetic and cognitive protective factors, the role of binge drinking in HIV/AUD-linked cognitive decline, and whether neurocognitive and brain functions normalize after drinking cessation.

Ozone, a major contributor to poor air quality, has an array of adverse effects on human, animal, and plant health. In the Los Angeles basin, a megacity that has pursued cleaner air for decades, unhealthy levels of ozone have decreased but remain stubbornly frequent even as the ozone precursors NOx (nitrogen oxides ≡ NO2 + NO) and VOC (volatile organic compounds) have decreased. We describe a combined analysis of decadal trends in these precursors, differences in emissions with day-of-week, and of the impact of temperature to assess the role of VOC and NOx and the likely effects of additional emission reductions on the occurrence of high ozone in the region.

Both canopy-level field measurements and laboratory studies suggest that uptake of NO2 through the leaf stomata of vegetation is a significant sink of atmospheric NOx. However, the mechanisms of this foliar NO2 uptake and their impact on NOx lifetimes remain incompletely understood. To understand the leaf-level processes affecting ecosystem-scale atmosphere–biosphere NOx exchange, we have conducted laboratory experiments of branch-level NO2 deposition fluxes to six coniferous and four broadleaf native California trees using a branch enclosure system with direct laser-induced fluorescence (LIF) detection of NO2. We report NO2 foliar deposition that demonstrates a large degree of inter-species variability, with maximum observed deposition velocities ranging from 0.15 to 0.51 cm s−1 during the daytime, as well as significant stomatal opening during the night. We also find that the contribution of mesophyllic processing to the overall deposition rate of NO2 varies by tree species but has an ultimately inconsequential impact on NOx budgets and lifetimes. Additionally, we find no evidence of any emission of NO2 from leaves, suggesting an effective unidirectional exchange of NOx between the atmosphere and vegetation.

Acyl peroxynitrates are formed in the atmosphere through the oxidation of NOx and are treated as temporary NOx sinks because they typically decompose to rerelease NOx on the time scale of a few hou...

Introduction Musculoskeletal pain is prevalent in older adults representing the leading cause of disability in this population. Similarly, nearly half of older adults complain of difficulty sleeping. We aimed to explore the relationship between sleep quality with self-reported musculoskeletal pain, somatosensory and pain thresholds in community-dwelling older adults and further explore brain regions that may contribute to this association. Methods Older adults (>60 years old, n=69) from the NEPAL study completed demographic, pain and sleep assessments followed by a quantitative sensory testing battery. A subset (n=49) also underwent a 3T high-resolution, T1-weighted anatomical scan. Results Poorer sleep quality using the Pittsburgh Sleep Quality Index was positively associated with self-reported pain measures (all p's >0.05), but not somatosensory and pain thresholds (all p's >0.05). Using a non-parametric threshold-free cluster enhancement (TFCE) approach, worse sleep quality was significantly associated with lower cortical thickness in the precentral, postcentral, precuneus, superior parietal, and lateral occipital regions (TFCE-FWE-corrected at p

INTRODUCTION: Adipose tissue and adipocytes are primary regulators of insulin sensitivity and energy homeostasis. Defects in insulin sensitivity of the adipocytes predispose the body to insulin resistance (IR) that could lead to diabetes. However, the mechanisms mediating adipocyte IR remain elusive, which emphasizes the need to develop experimental models that can validate the insulin signaling pathways and discover new mechanisms in the search for novel therapeutics. Currently in vitro adipose organ-chip devices show superior cell function over conventional cell culture. However, none of these models represent disease states. Only when these in vitro models can represent both healthy and disease states, they can be useful for developing therapeutics. Here, we establish an organ-on-chip model of insulin-resistant adipocytes, as well as characterization in terms of insulin signaling pathway and lipid metabolism. METHODS: We differentiated, maintained, and induced insulin resistance into primary adipocytes in a microfluidic organ-on-chip. We then characterized IR by looking at the insulin signaling pathway and lipid metabolism, and validated by studying a diabetic drug, rosiglitazone. RESULTS: We confirmed the presence of insulin resistance through reduction of Akt phosphorylation, Glut4 expression, Glut4 translocation and glucose uptake. We also confirmed defects of disrupted insulin signaling through reduction of lipid accumulation from fatty acid uptake and elevation of glycerol secretion. Testing with rosiglitazone showed a significant improvement in insulin sensitivity and fatty acid metabolism as suggested by previous reports. CONCLUSIONS: The adipose-chip exhibited key characteristics of IR and can serve as model to study diabetes and facilitate discovery of novel therapeutics. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s12195-020-00636-x) contains supplementary material, which is available to authorized users.

BACKGROUND AND PURPOSE: Cardiovascular disease (CVD) encompasses a range of disorders that affect health and functioning in older adults. While cognitive declines have been linked to both cardiovascular and cerebral blood perfusion, protective neurovascular mechanisms raise the question whether cerebrovascular perfusion differs as a function of cardiovascular health status. The present study examined whether cerebrovascular perfusion significantly differs between healthy older adults with and without diagnosed CVD. The study also examined whether previously documented sex differences in cerebral perfusion would be replicated. METHODS: Twenty CVD patients without significant heart failure and 39 healthy controls were recruited to undergo a comprehensive assessment including an interview, echocardiogram, and magnetic resonance imaging (MRI). Arterial spin labeling (ASL) was used to quantify cerebral blood perfusion. RESULTS: Both groups exhibited mean left ventricular ejection fractions that fell within normal limits. In line with previous research, women exhibited significantly higher cerebral perfusion than men. There were no significant group differences in whole brain cerebrovascular perfusion, regional perfusion, or white matter perfusion by patient status after accounting for sex and age. CONCLUSIONS: These findings suggest that the effects of mild CVD on cerebrovascular perfusion are minimal. Future studies are needed to investigate the mechanisms involved in maintaining cerebrovascular perfusion in the context of altered peripheral perfusion determine and to determine whether this finding extends to more acute or severe CVD.

Chromatin modifiers play critical roles in epidermal development, but the functions of histone deacetylases in this context are poorly understood. The class I HDAC, HDAC3, is of particular interest because it plays divergent roles in different tissues by partnering with tissue-specific transcription factors. We found that HDAC3 is expressed broadly in embryonic epidermis and is required for its orderly stepwise stratification. HDAC3 protein stability in vivo relies on NCoR and SMRT, which function redundantly in epidermal development. However, point mutations in the NCoR and SMRT deacetylase-activating domains, which are required for HDAC3's enzymatic function, permit normal stratification, indicating that HDAC3's roles in this context are largely independent of its histone deacetylase activity. HDAC3-bound sites are significantly enriched for predicted binding motifs for critical epidermal transcription factors including AP1, GRHL, and KLF family members. Our results suggest that among these, HDAC3 operates in conjunction with KLF4 to repress inappropriate expression of Tgm1, Krt16, and Aqp3. In parallel, HDAC3 suppresses expression of inflammatory cytokines through a Rela-dependent mechanism. These data identify HDAC3 as a hub coordinating multiple aspects of epidermal barrier acquisition.

NASA's Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ, conducted in 2011–2014) campaign in the United States and the joint NASA and National Institute of Environmental Research (NIER) Korea–United States Air Quality Study (KORUS-AQ, conducted in 2016) in South Korea were two field study programs that provided comprehensive, integrated datasets of airborne and surface observations of atmospheric constituents, including nitrogen dioxide (NO2), with the goal of improving the interpretation of spaceborne remote sensing data. Various types of NO2 measurements were made, including in situ concentrations and column amounts of NO2 using ground- and aircraft-based instruments, while NO2 column amounts were being derived from the Ozone Monitoring Instrument (OMI) on the Aura satellite. This study takes advantage of these unique datasets by first evaluating in situ data taken from two different instruments on the same aircraft platform, comparing coincidently sampled profile-integrated columns from aircraft spirals with remotely sensed column observations from ground-based Pandora spectrometers, intercomparing column observations from the ground (Pandora), aircraft (in situ vertical spirals), and space (OMI), and evaluating NO2 simulations from coarse Global Modeling Initiative (GMI) and high-resolution regional models. We then use these data to interpret observed discrepancies due to differences in sampling and deficiencies in the data reduction process. Finally, we assess satellite retrieval sensitivity to observed and modeled a priori NO2 profiles. Contemporaneous measurements from two aircraft instruments that likely sample similar air masses generally agree very well but are also found to differ in integrated columns by up to 31.9 %. These show even larger differences with Pandora, reaching up to 53.9 %, potentially due to a combination of strong gradients in NO2 fields that could be missed by aircraft spirals and errors in the Pandora retrievals. OMI NO2 values are about a factor of 2 lower in these highly polluted environments due in part to inaccurate retrieval assumptions (e.g., a priori profiles) but mostly to OMI's large footprint (>312 km2).

NICU patients are disproportionately affected by any disaster due to their vulnerability and highly specialized care needs that require a multitude of resources. Research in disaster preparedness and its effect on NICU patients is limited. From March to May 2018, NICUs across California participated in a survey designed to assess their preparedness for a disaster. Of the 84 responding units, 99% were urban, 73% were nonprofit, and 65% were community NICUs. As for NICU participation in hospital training exercises for disaster preparedness, 10% did not participate in annual drills, 44% did once a year, 36% did twice a year, and 10% did more than two times per year. We showed that many NICUs had redundant systems in place and plans for various disasters; however, there is not consistent participation by NICUs in hospital training exercises for disaster preparedness.

Foliar deposition of NO2 removes a large fraction of the global soil-emitted NOx. Understanding the mechanisms of NOx foliar loss is important for constraining surface ozone, constraining NOx mixing ratios, and assessing the impacts of nitrogen inputs to ecosystems. We have constructed a 1-D multibox model with representations of chemistry and vertical transport to evaluate the impact of leaf-level processes on canopy-scale concentrations, lifetimes, and canopy fluxes of NOx. Our model is able to closely replicate canopy fluxes and above-canopy NOx daytime mixing ratios observed during two field campaigns, one in a western Sierra Nevada pine forest (BEARPEX-2009) and the other in a northern Michigan mixed hardwood forest (UMBS-2012). We present a conceptual argument for the importance of NO2 dry deposition and demonstrate that NO2 deposition can provide a mechanistic explanation for the canopy reduction of NOx. We show that foliar deposition can explain observations suggesting as much as ∼60 % of soil-emitted NOx is removed within forest canopies. Stomatal conductances greater than 0.1 cm s−1 result in modeled canopy reduction factors in the range of those used in global models, reconciling inferences of canopy NOx reduction with leaf-level deposition processes. We show that incorporating parameterizations for vapor pressure deficit and soil water potential has a substantial impact on predicted NO2 deposition in our model, with the percent of soil NOx removed within one canopy increasing by ∼15 % in wet conditions compared to dry conditions. NO2 foliar deposition was also found to have a significant impact on ozone and nitrogen budgets under both high- and low-NOx conditions.

Complex walking in older adults can be improved with task practice and might be further enhanced by pairing transcranial direct current stimulation (tDCS) to the dorsolateral prefrontal cortex. We tested the hypothesis that a single session of practice of a complex obstacle negotiation task paired with active tDCS in older adults would produce greater within-session improvements in walking performance and retention of gains, compared to sham tDCS and no tDCS conditions.A total of 50 older adults (mean age = 74.46 years ± 6.49) with self-reported walking difficulty were randomized to receive either active tDCS (active-tDCS group) or sham tDCS (sham-tDCS group) bilaterally to the dorsolateral prefrontal cortex or no tDCS (no-tDCS group). Each group performed ten practice trials of an obstacle negotiation task at their fastest safe speed. Retention of gains in walking performance was assessed with three trials conducted one week later. Within-session effects of practice and between-session retention effects on obstacle negotiation speed were examined.At the practice session, all three groups exhibited significant within-session gains in walking speed (p ≤ 0.005). However, the gains were significantly greater in the sham-tDCS group than in the active-tDCS and no-tDCS groups (p ≤ 0.03) and were comparable between the active-tDCS and no-tDCS groups (p = 0.89). At one-week follow-up, the active-tDCS group exhibited significant between-session retention of gains and continued "offline" improvement in walking speed (p = 0.005). The active-tDCS group showed significantly greater retention of gains than the no-tDCS (p = 0.02) but not the sham-tDCS group (p = 0.24).Pairing prefrontal active tDCS with a single session of obstacle negotiation practice may enhance one-week retention of gains in walking performance compared to no tDCS. However, the evidence is insufficient to suggest a benefit of active tDCS over sham tDCS for enhancing the gains in walking performance. Additional studies with a multisession intervention design and larger sample size are needed to further investigate these findings.The Clinicaltrials.gov registration number for the study is NCT03122236.

The hydroxyl radical (OH) is the primary cleansing agent in the atmosphere. The abundance of OH in cities initiates the removal of local pollutants; therefore, it serves as the key species describing the urban chemical environment. We propose a machine learning (ML) approach as an efficient alternative to OH simulation using a computationally expensive chemical transport model. The ML model is trained on the parameters simulated from the WRF-Chem model, and it suggests that six predictive parameters are capable of explaining 76% of the OH variability. The parameters are the tropospheric NO₂ column, the tropospheric HCHO column, J(O¹D), H₂O, temperature, and pressure. We then use observations of the tropospheric NO₂ column and HCHO column from OMI as input to the ML model to enable measurement-based prediction of daily near surface OH at 1:30 pm local time across 49 North American cities over the course of 10 years between 2005 and 2014. The result is validated by comparing the OH predictions to measurements of isoprene, which has a source that is uncorrelated with OH and is removed rapidly and almost exclusively by OH in the daytime. We demonstrate that the predicted OH is, as expected, anticorrelated with isoprene. We also show that this ML model is consistent with our understanding of OH chemistry given the solely data-driven nature.

Anger can engender action by individuals and groups. It is thus important to understand anger’s behavioral phenotypes and their underlying neural substrates. Here we introduce a construct we term agentic anger, a state that motivates action to achieve risky goals. We test predictions of our neurobehavioral model in two proof-of-concept studies. Study 1 used the Incentive Balloon Analogue Risk Task (iBART) in a within-subjects, repeated measures design in 39 healthy volunteers to evaluate: a) impact of frustrative non-reward on agentic anger, assessed by self-reports of negative activation (NA), b) impact of achieved reward on exuberance, assessed by self-reports of positive activation (PA), c) their interrelationship, and d) their relationship with traits of positive emotion, negative emotion, immersive emotion and impulsivity. Task-induced NA was positively correlated with task-induced PA (r=0.56, p

Background Marijuana use is common in persons with HIV, but there is limited evidence of its relationship with potential health benefits or harms. Objective The Marijuana Associated Planning and Long-term Effects (MAPLE) study was designed to evaluate the impact of marijuana use on HIV-related health outcomes, cognitive function, and systemic inflammation. Methods The MAPLE study is a longitudinal cohort study of participants living with HIV who were recruited from 3 locations in Florida and were either current marijuana users or never regular marijuana users. At enrollment, participants completed questionnaires that included detailed marijuana use assessments, underwent interviewer-administered neurocognitive assessments, and provided blood and urine samples. Ongoing follow-ups included brief telephone assessments (every 3 months), detailed questionnaires (annually), repeated blood and urine samples (2 years), and linkage to medical records and statewide HIV surveillance data. Supplemental measures related to intracellular RNA, COVID-19, Alzheimer disease, and the gut microbiome were added after study initiation. Results The MAPLE study completed enrollment of 333 persons between 2018 and 2021. The majority of participants in the sample were ≥50 years of age (200/333, 60.1%), male (181/333, 54.4%), cisgender men (173/329, 52.6%), non-Hispanic Black (221/333, 66.4%), and self-reported marijuana users (260/333, 78.1%). Participant follow-up was completed in 2022, with annual updates to HIV surveillance data through at least 2027. Conclusions The MAPLE study is the largest cohort specifically designed to understand the use of marijuana and its effects on HIV-related outcomes. The study population has significant diversity across age, sex, gender, and race. The data will help clinicians and public health officials to better understand patterns of marijuana use associated with both positive and negative health outcomes, and may inform recommendations for future clinical trials related to medical marijuana and HIV. International Registered Report Identifier (IRRID) DERR1-10.2196/37153

Heavy-duty vehicles (HDV) contribute a significant, but decreasing, fraction of primary aerosol emissions in urban areas. Previous studies have shown spatial heterogeneity in compliance with regulation. Consequently, location-specific emissions factors are necessary to describe primary particulate matter (PM) emissions by HDV. Using near-road observations from the Bay Area Air Quality Management District (BAAQMD) network over the 2009–2020 period in combination with Caltrans measurements of vehicle number and type, we determine primary PM2.5 emission factors from HDV on highways in the San Francisco Bay Area. We demonstrate that HDV primary aerosol emission factors derived using this method are in line with observations by other studies, that they decreased a by a factor of ~7 in the past decade, and that they are still 2–3 times higher than would be expected if all HDV were in compliance with California HDV regulations.

Emissions and secondary photochemical products from the Daesan petrochemical complex (DPCC), on the west coast of South Korea, were measured from the NASA DC-8 research aircraft during the Korea-United States Air Quality campaign in 2016. The chemical evolution of petrochemical emissions was examined utilizing near-source and downwind plume transects. Small alkenes, such as ethene (C2H4), propene (C3H6), and 1,3-butadiene (C4H6), dominated the hydroxyl (OH) radical reactivity near the source region. The oxidation of these alkenes in the petrochemical plumes led to efficient conversion of nitrogen oxides (NOx) to nitric acid (HNO3), peroxycarboxylic nitric anhydrides (PANs), and alkyl nitrates (ANs), where the sum of the speciated reactive nitrogen contributes more than 80% of NOy within a few hours. Large enhancements of short-lived NOx oxidation products, such as hydroxy nitrates (HNs) and peroxyacrylic nitric anhydride, were observed, in conjunction with high ozone levels of up to 250 ppb, which are attributed to oxidation of alkenes such as 1,3-butadiene. Instantaneous ozone production rates, P(O3), near and downwind of the DPCC ranged from 9 to 24 ppb h−1, which were higher than those over Seoul. Ozone production efficiencies ranged from 6 to 10 downwind of the DPCC and were lower than 10 over Seoul. The contributions of alkenes to the instantaneous secondary organic aerosol (SOA) production rate, P(SOA), were estimated to be comparable to those of more common SOA precursors such as aromatics at intermediate distances from the DPCC. A model case study constrained to an extensive set of observations provided a diagnostic of petrochemical plume chemistry. The simulated plume chemistry reproduced the observed evolution of ozone and short-lived reactive nitrogen compounds, such as PANs and HNs as well as the rate and efficiency of ozone production. The simulated peroxy nitrates (PNs) budget included large contributions (approximately 30%) from unmeasured PNs including peroxyhydroxyacetic nitric anhydride and peroxybenzoic nitric anhydride. The large, predicted levels of these PAN compounds suggest their potential importance in chemical evolution of petrochemical plumes. One unique feature of the DPCC plumes is the substantial contribution of 1,3-butadiene to ozone and potentially SOA production. This work suggests that reductions in small alkene, especially 1,3-butadiene, emissions from the DPCC should be a priority for reducing downwind ozone.

Large wildfires influence regional atmospheric composition, but chemical complexity challenges model predictions of downwind impacts. Here, we elucidate key connections within gas-phase photochemistry and assess novel chemical processes via a case study of the 2013 California Rim Fire plume. Airborne in situ observations, acquired during the NASA Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) mission, illustrate the evolution of volatile organic compounds (VOCs), oxidants, and reactive nitrogen over 12 h of atmospheric aging. Measurements show rapid formation of ozone and peroxyacyl nitrates (PNs), sustained peroxide production, and prolonged enhancements in oxygenated VOCs and nitrogen oxides (NOx). Observations and Lagrangian trajectories constrain a 0-D puff model that approximates plume photochemical history and provides a framework for evaluating process interactions. Simulations examine the effects of (1) previously unmeasured reactive VOCs identified in recent laboratory studies and (2) emissions and secondary production of nitrous acid (HONO). Inclusion of estimated unmeasured VOCs leads to a 250 % increase in OH reactivity and a 70 % increase in radical production via oxygenated VOC photolysis. HONO amplifies radical cycling and serves as a downwind NOx source, although impacts depend on how HONO is introduced. The addition of initial HONO (representing primary emissions) or particulate nitrate photolysis amplifies ozone production, while heterogeneous conversion of NO2 suppresses ozone formation. Analysis of radical initiation rates suggests that oxygenated VOC photolysis is a major radical source, exceeding HONO photolysis when averaged over the first 2 h of aging. Ozone production chemistry transitions from VOC sensitive to NOx sensitive within the first hour of plume aging, with both peroxide and organic nitrate formation contributing significantly to radical termination. To simulate smoke plume chemistry accurately, models should simultaneously account for the full reactive VOC pool and all relevant oxidant sources.

Transportation represents the largest sector of anthropogenic CO2 emissions in urban areas in the United States. Timely reductions in urban transportation emissions are critical to reaching climate goals set by international treaties, national policies, and local governments. Transportation emissions also remain one of the largest contributors to both poor air quality (AQ) and to inequities in AQ exposure. As municipal and regional governments create policy targeted at reducing transportation emissions, the ability to evaluate the efficacy of such emission reduction strategies at the spatial and temporal scales of neighborhoods is increasingly important; however, the current state of the art in emissions monitoring does not provide the temporal, sectoral, or spatial resolution necessary to track changes in emissions and provide feedback on the efficacy of such policies at the abovementioned scale. The BErkeley Air Quality and CO2 Network (BEACO2N) has previously been shown to provide constraints on emissions from the vehicle sector in aggregate over a ∼ 1300 km2 multicity spatial domain. Here, we focus on a 5 km, high-volume, stretch of highway in the San Francisco Bay Area. We show that inversion of the BEACO2N measurements can be used to understand two factors that affect fuel efficiency: vehicle speed and fleet composition. The CO2 emission rate of the average vehicle (in grams per vehicle kilometer) is shown to vary by as much as 27 % at different times of a typical weekday because of changes in these two factors. The BEACO2N-derived emission estimates are consistent to within ∼ 3 % of estimates derived from publicly available measures of vehicle type, number, and speed, providing direct observational support for the accuracy of the EMission FACtor model (EMFAC) of vehicle fuel efficiency.

The diagnosis of post-cardiac ablation pericarditis is difficult as it requires the exclusion of the more common causes of chest pain, but in the right setting, non-invasive diagnostic tools are adequate. Here we present the case of a 60-year-old man who underwent atrial fibrillation ablation and subsequently developed severe mid-sternal chest pain and dyspnea one day later without significant electrocardiographic findings, a mildly elevated troponin T, and elevation of the right hemidiaphragm. The patient was managed conservatively. A two-dimensional transthoracic echocardiogram showed no regional wall motion abnormalities, significant transvalvular gradients, but showed minimal pericardial effusion. A sniff test was negative for diaphragmatic paralysis. After the diagnosis, the patient’s symptoms resolved with non-steroidal anti-inflammatory drugs and colchicine. This case of pericarditis after cardiac ablation highlights the possible differential diagnosis when confronted with post-ablation cardiac symptoms. Despite the classic presentation, the electrocardiogram showed no significant ST/PR changes. In the right clinical setting, non-invasive imaging may be appropriate management.

INTRODUCTION AND OBJECTIVE:MAG3 nuclear renograms are standard practice to document split renal function in patients with possible ureteropelvic junction (UPJ) obstruction. We hypothesized that qua...

A better understanding of the chemistry of nitrogen oxides (NOx) is crucial to effectively reducing air pollution and predicting future air quality. The response of NOx lifetime to perturbations in emissions or in the climate system is set in large part by whether NOx loss occurs primarily by the direct formation of HNO3 or through the formation of alkyl and multifunctional nitrates (RONO2). Using 15 years of detailed in situ observations, we show that in the summer daytime continental boundary layer the relative importance of these two pathways can be well approximated by the relative likelihood that OH will react with NO2 or instead with a volatile organic compound (VOC). Over the past decades, changes in anthropogenic emissions of both NOx and VOCs have led to a significant increase in the overall importance of RONO2 chemistry to NOx loss. We find that this shift is associated with a decreased effectiveness of NOx emissions reductions on ozone production in polluted areas and increased transport of NOx from source to receptor regions. This change in chemistry, combined with changes in the spatial pattern of NOx emissions, is observed to be leading to a flatter distribution of NO2 across the United States, potentially transforming ozone air pollution from a local issue into a regional one.

A shifting lifetime for NO x Nitrogen oxides (NO x ) have a central role in controlling air quality, so designing effective strategies to combat air pollution, especially by ozone and particulate matter, depends on knowing their atmospheric abundances. Those abundances depend not only on NO x production rates but also on their lifetimes. Laughner and Cohen report that NO x lifetimes can be measured directly from satellite observations of nitrogen dioxide. They used data on 49 North American cities to show how NO x lifetimes there changed between 2005 and 2014. Accounting for this change in lifetime should help to reconcile conflicting trends between bottom-up and top-down emissions estimates. Science , this issue p. 723

Lightning is an important NOx source representing ∼10 % of the global source of odd N and a much larger percentage in the upper troposphere. The poor understanding of spatial and temporal patterns of lightning contributes to a large uncertainty in understanding upper tropospheric chemistry. We implement a lightning parameterization using the product of convective available potential energy (CAPE) and convective precipitation rate (PR) coupled with the Kain–Fritsch convective scheme (KF/CAPE-PR) into the Weather Research and Forecasting-Chemistry (WRF-Chem) model. Compared to the cloud-top height (CTH) lightning parameterization combined with the Grell 3-D convective scheme (G3/CTH), we show that the switch of convective scheme improves the correlation of lightning flash density in the southeastern US from 0.30 to 0.67 when comparing against the Earth Networks Total Lightning Network; the switch of lightning parameterization contributes to the improvement of the correlation from 0.48 to 0.62 elsewhere in the US. The simulated NO2 profiles using the KF/CAPE-PR parameterization exhibit better agreement with aircraft observations in the middle and upper troposphere. Using a lightning NOx production rate of 500 mol NO flash−1, the a priori NO2 profile generated by the simulation with the KF/CAPE-PR parameterization reduces the air mass factor for NO2 retrievals by 16 % on average in the southeastern US in the late spring and early summer compared to simulations using the G3/CTH parameterization. This causes an average change in NO2 vertical column density 4 times higher than the average uncertainty.

Background: Endogenous carbon monoxide (CO) production is primarily due to heme degradation, which also results in the equimolar production of bilirubin. Thus, estimates of total body CO production can serve as indices of total body bilirubin formation. The elimination rate of CO from a person’s body (CO washout rate) after exposure to an elevated ambient CO concentration is determined by a variety of factors, and is very different between babies and adults. Objective: We determined CO washout rates for babies using a simplified technique to measure total body CO excretion rates (VeCO). Methods: Using a simplified technique, we measured the times to reach an approximate steady state after a change in ambient CO concentration (decay time constant) and CO washout rates in normal newborn infants using non-linear least squares curve fitting. Results: We found a mean CO washout time of 18.7 ± 4.2 min and a CO equilibration (decay time) constant of 0.12 ± 0.04/min (0.08–0.21) for newborn infants. Conclusions: We confirm that CO washout rates for babies are much faster than those for adults. Therefore, measurements of carboxyhemoglobin (COHb) or end-tidal CO (ETCO), corrected for ambient CO, (COHbc and ETCOc, respectively) can be used as surrogates for VeCO and can provide accurate estimates of endogenous CO (VCO) and bilirubin production rates under normal environmental conditions. Such measurements can be used to identify infants with severe hyperbilirubinemia due to hemolysis and thus at high risk for bilirubin neurotoxicity.

Predicting the activation of submicrometer particles into cloud droplets in the atmosphere remains a challenge. The importance of surface tension, σ (mN m−1), in these processes has been evidenced by several works, but information on the "surfactants" lowering σ in actual atmospheric particles remains scarce. In this work, PM1 aerosols from urban, coastal, and remote regions of Europe (Lyon, France, Rogoznica, Croatia, and Pallas, Finland, respectively) were investigated and found to contain amphiphilic surfactants in concentrations up to 2.8 μg m−3 in the air and 1.3 M in the particle dry volume. In Pallas, correlations with the PM1 chemical composition showed that amphiphilic surfactants were present in the entire range of particle sizes, supporting recent works. This implied that they were present in hundreds to thousands of particles cm−3 and not only in a few large particles, as it has been hypothesized. Their adsorption isotherms and critical micelle concentration (CMC) were also determined. The low CMC obtained (3 × 10−5−9 × 10−3 M) implies that surface tension depression should be significant for all the particles containing these compounds, even at activation (growth factor ∼ 10). Amphiphilic surfactants are thus likely to enhance the CCN ability of submicrometer atmospheric particles.

Objective To evaluate the incidence and durability of compensatory hypertrophy with solitary kidneys in the setting of those with multicystic dysplastic kidney (MCDK) or Wilms tumor (WT) status postnephrectomy. Patients and Methods We conducted a retrospective cohort study of patients with MCDK and WT. MCDK patients were verified by sonographic findings prenatally. WT patients entered our study at time of nephrectomy. We compared the natural history of hypertrophy between the 2 cohorts via renal length measurement. We performed linear regression to predict creatinine clearance from renal length after adjusting for age and cohort status (MCDK versus WT). Results Fifty-two patients (56%) were diagnosed with WT, and 71 patients (44%) with MCDK patients met study criteria with a median age of postnatal ultrasound at 1.6 months (interquartile range 0.5-3.6). The median (IQR) follow-up time was 7.5 years. At the time of nephrectomy, 25/52 (48%) of Wilms patients had contralateral hypertrophy, while at diagnosis 22/71 (31%) of MCDK patients had contralateral hypertrophy, P = .03. Contralateral hypertrophy was a consistent finding throughout follow-up. As renal length increases by 1 cm, glomerular filtration rate increased by 7.8 mL/min/m2 (95% confidence interval 1.8-13.8, P = .01). Conclusion Contralateral hypertrophy appears to be a compensatory mechanism for unilateral kidney pathology as demonstrated by MCDK and WT patients. Hypertrophy often occurs at the time of diagnosis and appears to be a permanent finding as children reach their teenage years. Additionally, in nonhydronephrotic kidneys, increases in renal length correlate with improvement in glomerular filtration rate. Overall, the majority of children with solitary kidneys demonstrate compensatory hypertrophy.

Emission regulations of the power and industry sectors have been identified as the major driver of PM2.5 mitigation over China during 2013-2017. In this study, we use ground-based observations of four air pollutants (CO, NO2, SO2, and PM2.5) to show that additional stringent emission policies on the industrial, transportation, and residential sectors during the new 3-year protection plan (2018-2020) have accelerated the improvement of China's air quality. Based on regional (North and South China) trends of annual mean measurements, significant reductions are observed for all four pollutants during 2017-2020. These decreasing trends are found to be >30% stronger than 2015-2017 for NO2, CO, and PM2.5. For CO and PM2.5, the acceleration is the strongest in winter and North China, when and where the residential clean-heating actions were implemented. While for NO2, the accelerations are pronounced regardless of region or season, reflecting nationwide measures to reduce NOx emissions from industrial and transportation activities. SO2 concentration reductions that were already substantial before 2017 are maintained but not accelerated, consistent with the dominance of end-of-pipe measures rather than a structural change of energy fuels. Our investigation highlights the value of multi-pollutant analysis to relate emission policies with air quality changes.

Neural dedifferentiation refers to an age-related phenomenon whereby brain functions that are localized to specific, distinct, and differentiated brain areas in young adults become less so as people reach more advanced age. Older adults tend to exhibit greater spread of cortical activation on fMRI during cognitive processing compared to younger adults, with evidence that this occurs during visuoperceptual processing. Some age-related functional changes are considered compensatory, but whether dedifferentiation is compensatory is not clearly understood. The current study assessed dedifferentiation and visual discrimination performance during simultaneous match-to-sample tasks from the Visual Assessment Battery (VAB) among 40 healthy middle-aged and older adults using fMRI. Task-relevant regions of interest (ROIs) were created in the dorsal stream for discrimination of spatial location, the ventral stream for shape, and an area encompassing V5 for velocity. Dedifferentiation, or less specificity in functional activation, was associated with greater discrimination accuracy and more years of education. Secondary analyses showed that reduced functional activation in task-relevant ROIs was associated with faster discrimination speed. Age was unassociated with functional activation. Results suggest that dedifferentiation is compensatory. Lack of age effects suggest that other factors beyond age, such as cognitive or brain reserve, may better predict performance when considering cognitive skills that are relatively stable as adults age, such as visual discrimination.

Obesity affects nearly one billion globally and can lead to life-threatening sequelae. Consequently, there is an urgent need for novel therapeutics. We have previously shown that laminin, alpha 4 (Lama4) knockout in mice leads to resistance to adipose tissue accumulation; however, the relationship between LAMA4 and obesity in humans has not been established. In this study we measured laminin-α chain and collagen mRNA expression in the subcutaneous white adipose tissue (sWAT) of mice placed on chow (RCD) or 45% high fat diet (HFD) for 8 weeks, and also in HFD mice then placed on a “weight loss” regimen (8 weeks HFD followed by 6 weeks RCD). To assess extracellular matrix (ECM) components in humans with obesity, laminin subunit alpha mRNA and protein expression was measured in sWAT biopsies of female control subjects (BMI35) both before and three months after surgery. Lama4 was significantly higher in sWAT of HFD compared to RCD mice at both the RNA and protein level (pLAMA4 mRNA (pLama4 or LAMA4 expression was detected following short-term weight loss in either mouse or human samples, respectively. From these results we propose a significant association between obesity and elevated LAMA4 expression in humans, as well as in mouse models of obesity. Further studies should clarify the mechanisms underlying this association to target LAMA4 effectively as a potential therapy for obesity.

Over-activation of prefrontal cortex during walking has been reported in older adults versus young adults. Heighted activity in prefrontal cortex suggests a shift toward an executive control strategy to control walking. A potential contributing factor is degraded functioning of pattern-generating locomotor circuits in the central nervous system that are important to walking coordination. Somatosensory information is a crucial input to these circuits, so age-related impairment of somatosensation would be expected to compromise the neural control of walking. The present study tested the hypothesis that poorer somatosensation in the feet of older adults will be associated with greater recruitment of the prefrontal cortex during walking. This study also examines the extent to which somatosensory function and prefrontal activity are associated with performance on walking and balance assessments.Forty seven older adults (age 74.6 ± 6.8 years; 32 female) participated in walking assessments (typical walking and obstacle negotiation) and Berg Balance Test. During walking, prefrontal activity was measured with functional near infrared spectroscopy (fNIRS). Participants also underwent somatosensory testing with Semmes-Weinstein monofilaments.The primary findings is that worse somatosensory monofilament level was associated with greater prefrontal cortical activity during typical walking (r = 0.38, p = 0.008) and obstacle negotiation (r = 0.40, p = 0.006). For the obstacle negotiation task, greater prefrontal activity was associated with faster walking speed (p = 0.004). Poorer somatosensation was associated with slower typical walking speed (p = 0.07) and obstacles walking speed (p 0.001), as well as poorer balance scores (p = 0.03).The study findings are consistent with a compensation strategy of recruiting prefrontal/executive control resources to overcome loss of somatosensory input to the central nervous system. Future research should further establish the mechanisms by which somatosensory impairments are linked to the neural control and performance of walking tasks, as well as develop intervention approaches.

Declines in processing speed performance occur in aging and are a critical marker of functional independence in older adults. Studies suggest that Useful Field of View (UFOV) training may ameliorate cognitive decline. Despite its efficacy, little is known about the neural correlates of this task. Within the current study, 233 healthy older adults completed a UFOV-based task while undergoing functional magnetic resonance imaging (fMRI). During the “stimulus” portion of this task, participants must identify a target in the center of the screen and the location of a target in the periphery, among distractors. During the “probe” portion, participants must decide if the object in the center and the location of the target in the periphery were identical to the “stimulus” screen. Widespread bilateral whole-brain activation was observed when activation patterns of the “probe” contrast were subtracted from the “stimulus” contrast. Conversely, the subtraction of “stimulus” from “probe” was associated with discrete activation patterns consisting of 13 clusters. Additionally, when evaluating the variance associated with task accuracy, specific subregions were identified that may be critical for task performance. Our data elucidate the functional neural correlates of a UFOV-based task, a task used in both cognitive training paradigms and assessment of function.

Objective The present study aimed to determine whether specific cognitive domains part of the Montreal Cognitive Assessment (MoCA) are significantly lower in community-dwelling older adults with chronic pain compared with older adults without pain and whether these domains would be associated with self-reported pain, disability, and somatosensory function. Design Secondary data analysis, cross-sectional. Setting University of Florida. Subjects Individuals over 60 years old enrolled in the Neuromodulatory Examination of Pain and mobility Across the Lifespan (NEPAL) study were included if they completed the MoCA and other study measures (n = 62). Most participants reported pain on most days during the past three months (63%). Methods Subjects underwent a health assessment (HAS) and a quantitative sensory testing (QST) session. Health/medical history, cognitive function and self-reported pain measures were administered during the HAS. Mechanical and thermal detection, and thermal pain thresholds were assessed during the QST session. Results Older adults with chronic pain had lower MoCA scores compared with controls on domains of executive function, attention, memory, and language (P Conclusion Our results support previous findings that individuals with chronic pain tend to show poorer cognitive functioning compared with pain-free controls in domains of attention and executive function. Our findings also extend these findings to community-dwelling older adults, who are already most vulnerable to age-related cognitive declines.

In order to infer greenhouse gas emissions from a source region, several top-down approaches can confirm or constrain the existing emission inventories. In this work an adopted version of a Bayesian inversion framework [1] will be presented. Methane emissions are derived from the column concentrations measured with six EM27/SUN FTIR spectrometers using ground based direct sunlight spectroscopy. The measurement campaign was carried out in the San Francisco Bay Area in 2016. The framework uses the STILT generated footprints, which represent the surface-interaction of an air-parcel on its trajectory to the measurement site and thus describe the sensitivity of the measured concentration at a certain location to its surrounding source emissions. The dot product of the footprint matrix with a gridded emission inventory matrix results in expected concentration enhancements at the measurement site as a prior estimate. Here, we use the 1km-gridded local methane inventory by the Bay Area Air Quality Management District (BAAQMD).Due to the long-term stability of methane, the air parcel holds a non-zero background concentration, which is not negligible. This poses a major challenge in the inversion. The existing Bayesian framework constrains a background concentration as well as a scaling factor for the inventory from the measurements. Within the existing framework, the assumption is made that all instruments eventually experience the same, time dependent background concentration. This assumption holds well for flat terrain with undisturbed wind-fields.However, in the presence of complex topography, such as San Francisco Bay Area, the background source regions may differ significantly for the individual measurement sites. Here, we present an approach to account for differing background concentrations seen by multiple measurement sites:The adopted inversion allows to have individual background concentrations for each measurement site. This is strongly constrained by background covariances, which represent the background in common with the remaining measurement sites. These covariances are calculated from the STILT trajectories.[1] Jones, T. S., Franklin, J. E., Chen, J., Dietrich, F., Hajny, K. D., Paetzold, J. C., Wenzel, A., Gately, C., Gottlieb, E., Parker, H., Dubey, M., Hase, F., Shepson, P. B., Mielke, L. H., and Wofsy, S. C.: Assessing Urban Methane Emissions using Column Observing Portable FTIR Spectrometers and a Novel Bayesian Inversion Framework, Atmos. Chem. Phys. Discuss. [preprint], https://doi.org/10.5194/acp-2020-1262, in review, 2021.