12 research outputs found
Applying Advanced Ground-Based Remote Sensing in the Southeast Asian Maritime Continent to Characterize Regional Proficiencies in Smoke Transport Modeling
This work describes some of the most extensive ground-based observations of the aerosol profile collected in Southeast Asia to date, highlighting the challenges in simulating these observations with amesoscale perspective. An 84-hWRFModel coupled with chemistry (WRF-Chem)mesoscale simulation of smoke particle transport at Kuching, Malaysia, in the southern Maritime Continent of Southeast Asia is evaluated relative to a unique collection of continuous ground-based lidar, sun photometer, and 4-h radiosonde profiling. The period was marked by relatively dry conditions, allowing smoke layers transported to the site unperturbed by wet deposition to be common regionally. The model depiction is reasonable overall. Core thermodynamics, including land/seabreeze structure, are well resolved. Total model smoke extinction and, by proxy, mass concentration are low relative to observation. Smoke emissions source products are likely low because of undersampling of fires in infrared sun-synchronous satellite products, which is exacerbated regionally by endemic low-level cloud cover. Differences are identified between the model mass profile and the lidar profile, particularly during periods of afternoon convective mixing. A static smoke mass injection height parameterized for this study potentially influences this result. The model does not resolve the convective mixing of aerosol particles into the lower free troposphere or the enhancement of near-surface extinction from nighttime cooling and hygroscopic effects
Recommended from our members
Community-Acquired Pneumonia and Risk of Cardiovascular Events in People Living With HIV.
Background Hospitalization with community-acquired pneumonia (CAP) is associated with an increased risk of cardiovascular disease (CVD) events in patients uninfected with HIV. We evaluated whether people living with HIV (PLWH) have a higher risk of CVD or mortality than individuals uninfected with HIV following hospitalization with CAP. Methods and Results We analyzed data from the Veterans Aging Cohort Study on US veterans admitted with their first episode of CAP from April 2003 through December 2014. We used Cox regression analyses to determine whether HIV status was associated with incident CVD events and mortality from date of admission through 30 days after discharge (30-day mortality), adjusting for known CVD risk factors. We included 4384 patients (67% [n=2951] PLWH). PLWH admitted with CAP were younger, had less severe CAP, and had fewer CVD risk factors than patients with CAP who were uninfected with HIV. In multivariable-adjusted analyses, CVD risk was similar in PLWH compared with HIV-uninfected (hazard ratio [HR], 0.89; 95% CI, 0.70-1.12), but HIV infection was associated with higher mortality risk (HR, 1.49; 95% CI, 1.16-1.90). In models stratified by HIV status, CAP severity was significantly associated with incident CVD and 30-day mortality in PLWH and patients uninfected with HIV. Conclusions In this study, the risk of CVD events during or after hospitalization for CAP was similar in PLWH and patients uninfected with HIV, after adjusting for known CVD risk factors and CAP severity. HIV infection, however, was associated with increased 30-day mortality after CAP hospitalization in multivariable-adjusted models. PLWH should be included in future studies evaluating mechanisms and prevention of CVD events after CAP
Recommended from our members
HIV status and the risk of ischemic stroke among men.
ObjectiveGiven conflicting data regarding the association of HIV infection and ischemic stroke risk, we sought to determine whether HIV infection conferred an increased ischemic stroke risk among male veterans.MethodsThe Veterans Aging Cohort Study-Virtual Cohort consists of HIV-infected and uninfected veterans in care matched (1:2) for age, sex, race/ethnicity, and clinical site. We analyzed data on 76,835 male participants in the Veterans Aging Cohort Study-Virtual Cohort who were free of baseline cardiovascular disease. We assessed demographics, ischemic stroke risk factors, comorbid diseases, substance use, HIV biomarkers, and incidence of ischemic stroke from October 1, 2003, to December 31, 2009.ResultsDuring a median follow-up period of 5.9 (interquartile range 3.5-6.6) years, there were 910 stroke events (37.4% HIV-infected). Ischemic stroke rates per 1,000 person-years were higher for HIV-infected (2.79, 95% confidence interval 2.51-3.10) than for uninfected veterans (2.24 [2.06-2.43]) (incidence rate ratio 1.25 [1.09-1.43]; p < 0.01). After adjusting for demographics, ischemic stroke risk factors, comorbid diseases, and substance use, the risk of ischemic stroke was higher among male veterans with HIV infection compared with uninfected veterans (hazard ratio 1.17 [1.01-1.36]; p = 0.04).ConclusionsHIV infection is associated with an increased ischemic stroke risk among HIV-infected compared with demographically and behaviorally similar uninfected male veterans
HIV infection and cardiovascular disease in women.
BackgroundHIV infection is associated with increased risk of cardiovascular disease (CVD) in men. Whether HIV is an independent risk factor for CVD in women has not yet been established.Methods and resultsWe analyzed data from the Veterans Aging Cohort Study on 2187 women (32% HIV infected [HIV(+)]) who were free of CVD at baseline. Participants were followed from their first clinical encounter on or after April 01, 2003 until a CVD event, death, or the last follow-up date (December 31, 2009). The primary outcome was CVD (acute myocardial infarction [AMI], unstable angina, ischemic stroke, and heart failure). CVD events were defined using clinical data, International Classification of Diseases, Ninth Revision, Clinical Modification codes, and/or death certificate data. We used Cox proportional hazards models to assess the association between HIV and incident CVD, adjusting for age, race/ethnicity, lipids, smoking, blood pressure, diabetes, renal disease, obesity, hepatitis C, and substance use/abuse. Median follow-up time was 6.0 years. Mean age at baseline of HIV(+) and HIV uninfected (HIV(-)) women was 44.0 versus 43.2 years (P<0.05). Median time to CVD event was 3.1 versus 3.7 years (P=0.11). There were 86 incident CVD events (53%, HIV(+)): AMI, 13%; unstable angina, 8%; ischemic stroke, 22%; and heart failure, 57%. Incident CVD/1000 person-years was significantly higher among HIV(+) (13.5; 95% confidence interval [CI]=10.1, 18.1) than HIV(-) women (5.3; 95% CI=3.9, 7.3; P<0.001). HIV(+) women had an increased risk of CVD, compared to HIV(-) (hazard ratio=2.8; 95% CI=1.7, 4.6; P<0.001).ConclusionsHIV is associated with an increased risk of CVD in women
Recommended from our members
Prehypertension, hypertension, and the risk of acute myocardial infarction in HIV-infected and -uninfected veterans.
BackgroundCompared to uninfected people, human immunodeficiency virus (HIV)-infected individuals may have an increased risk of acute myocardial infarction (AMI). Currently, HIV-infected people are treated to the same blood pressure (BP) goals (<140/90 or <130/80 mm Hg) as their uninfected counterparts. Whether HIV-infected people with elevated BP have excess AMI risk compared to uninfected people is not known. This study examines whether the association between elevated BP and AMI risk differs by HIV status.MethodsThe Veterans Aging Cohort Study Virtual Cohort (VACS VC) consists of HIV-infected and -uninfected veterans matched 1:2 on age, sex, race/ethnicity, and clinical site. For this analysis, we analyzed 81 026 people with available BP data from VACS VC, who were free of cardiovascular disease at baseline. BP was the average of the 3 routine outpatient clinical measurements performed closest to baseline (first clinical visit after April 2003). BP categories used in the analyses were based on criteria of the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Analyses were performed using Cox proportional hazards regression.ResultsOver 5.9 years (median), 860 incident AMIs occurred. Low/high prehypertensive and untreated/treated hypertensive HIV-infected individuals had increased AMI risk compared to uninfected, untreated normotensive individuals (hazard ratio [HR], 1.60 [95% confidence interval {CI}, 1.07-2.39]; HR, 1.81 [95% CI, 1.22-2.68]; HR, 2.57 [95% CI, 1.76-3.76]; and HR, 2.76 [95% CI, 1.90-4.02], respectively).ConclusionsHIV, prehypertensive BP, and hypertensive BP were associated with an increased risk of AMI in a cohort of HIV-infected and -uninfected veterans. Future studies should prospectively investigate whether HIV interacts with BP to further increase AMI risk
Recommended from our members
Factors associated with phosphatidylethanol (PEth) sensitivity for detecting unhealthy alcohol use: An individual patient data meta-analysis.
BackgroundObjective measurement of alcohol consumption is important for clinical care and research. Adjusting for self-reported alcohol use, we conducted an individual participant data (IPD) meta-analysis to examine factors associated with the sensitivity of phosphatidylethanol (PEth), an alcohol metabolite, among persons self-reporting unhealthy alcohol consumption.MethodsWe identified 21 eligible studies and obtained 4073 observations from 3085 participants with Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) positive scores (≥3 for women and ≥4 for men) and PEth measurements. We conducted 1-step IPD meta-analysis using mixed effects models with random intercepts for study site. We examined the associations between demographic (sex, race/ethnicity, and age) and biologic (body mass index-BMI, hemoglobin, HIV status, liver fibrosis, and venous versus finger-prick blood collection) variables with PEth sensitivity (PEth≥8 ng/ml), adjusting for the level of self-reported alcohol use using the AUDIT-C score.ResultsOne third (31%) of participants were women, 32% were African, 28% African American, 28% White, and 12% other race/ethnicity. PEth sensitivity (i.e., ≥8 ng/ml) was 81.8%. After adjusting for AUDIT-C, we found no associations of sex, age, race/ethnicity, or method of blood collection with PEth sensitivity. In models that additionally included biologic variables, those with higher hemoglobin and indeterminate and advanced liver fibrosis had significantly higher odds of PEth sensitivity; those with higher BMI and those living with HIV had significantly lower odds of PEth sensitivity. African Americans and Africans had higher odds of PEth sensitivity than whites in models that included biologic variables.ConclusionsAmong people reporting unhealthy alcohol use, several biological factors (hemoglobin, BMI, liver fibrosis, and HIV status) were associated with PEth sensitivity. Race/ethnicity was associated with PEth sensitivity in some models but age, sex, and method of blood collection were not. Clinicians should be aware of these factors, and researchers should consider adjusting analyses for these characteristics where possible
Factors associated with phosphatidylethanol (PEth) sensitivity for detecting unhealthy alcohol use: An individual patient data meta-analysis.
BackgroundObjective measurement of alcohol consumption is important for clinical care and research. Adjusting for self-reported alcohol use, we conducted an individual participant data (IPD) meta-analysis to examine factors associated with the sensitivity of phosphatidylethanol (PEth), an alcohol metabolite, among persons self-reporting unhealthy alcohol consumption.MethodsWe identified 21 eligible studies and obtained 4073 observations from 3085 participants with Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) positive scores (≥3 for women and ≥4 for men) and PEth measurements. We conducted 1-step IPD meta-analysis using mixed effects models with random intercepts for study site. We examined the associations between demographic (sex, race/ethnicity, and age) and biologic (body mass index-BMI, hemoglobin, HIV status, liver fibrosis, and venous versus finger-prick blood collection) variables with PEth sensitivity (PEth≥8 ng/ml), adjusting for the level of self-reported alcohol use using the AUDIT-C score.ResultsOne third (31%) of participants were women, 32% were African, 28% African American, 28% White, and 12% other race/ethnicity. PEth sensitivity (i.e., ≥8 ng/ml) was 81.8%. After adjusting for AUDIT-C, we found no associations of sex, age, race/ethnicity, or method of blood collection with PEth sensitivity. In models that additionally included biologic variables, those with higher hemoglobin and indeterminate and advanced liver fibrosis had significantly higher odds of PEth sensitivity; those with higher BMI and those living with HIV had significantly lower odds of PEth sensitivity. African Americans and Africans had higher odds of PEth sensitivity than whites in models that included biologic variables.ConclusionsAmong people reporting unhealthy alcohol use, several biological factors (hemoglobin, BMI, liver fibrosis, and HIV status) were associated with PEth sensitivity. Race/ethnicity was associated with PEth sensitivity in some models but age, sex, and method of blood collection were not. Clinicians should be aware of these factors, and researchers should consider adjusting analyses for these characteristics where possible
Prehypertension, hypertension, and the risk of acute myocardial infarction in HIV-infected and -uninfected veterans.
BackgroundCompared to uninfected people, human immunodeficiency virus (HIV)-infected individuals may have an increased risk of acute myocardial infarction (AMI). Currently, HIV-infected people are treated to the same blood pressure (BP) goals (<140/90 or <130/80 mm Hg) as their uninfected counterparts. Whether HIV-infected people with elevated BP have excess AMI risk compared to uninfected people is not known. This study examines whether the association between elevated BP and AMI risk differs by HIV status.MethodsThe Veterans Aging Cohort Study Virtual Cohort (VACS VC) consists of HIV-infected and -uninfected veterans matched 1:2 on age, sex, race/ethnicity, and clinical site. For this analysis, we analyzed 81 026 people with available BP data from VACS VC, who were free of cardiovascular disease at baseline. BP was the average of the 3 routine outpatient clinical measurements performed closest to baseline (first clinical visit after April 2003). BP categories used in the analyses were based on criteria of the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Analyses were performed using Cox proportional hazards regression.ResultsOver 5.9 years (median), 860 incident AMIs occurred. Low/high prehypertensive and untreated/treated hypertensive HIV-infected individuals had increased AMI risk compared to uninfected, untreated normotensive individuals (hazard ratio [HR], 1.60 [95% confidence interval {CI}, 1.07-2.39]; HR, 1.81 [95% CI, 1.22-2.68]; HR, 2.57 [95% CI, 1.76-3.76]; and HR, 2.76 [95% CI, 1.90-4.02], respectively).ConclusionsHIV, prehypertensive BP, and hypertensive BP were associated with an increased risk of AMI in a cohort of HIV-infected and -uninfected veterans. Future studies should prospectively investigate whether HIV interacts with BP to further increase AMI risk