Synthesis of satellite (MODIS), aircraft (ICARTT), and surface (IMPROVE, EPA-AQS, AERONET) aerosol observations over eastern North America to improve MODIS aerosol retrievals and constrain surface aerosol concentrations and sources

We use an ensemble of satellite (MODIS), aircraft, and ground-based aerosol observations during the ICARTT field campaign over eastern North America in summer 2004 to (1) examine the consistency between different aerosol measurements, (2) evaluate a new retrieval of aerosol optical depths (AODs) and inferred surface aerosol concentrations (PM2.5) from the MODIS satellite instrument, and (3) apply this collective information to improve our understanding of aerosol sources. The GEOS-Chem global chemical transport model (CTM) provides a transfer platform between the different data sets, allowing us to evaluate the consistency between different aerosol parameters observed at different times and locations. We use an improved MODIS AOD retrieval based on locally derived visible surface reflectances and aerosol properties calculated from GEOS-Chem. Use of GEOS-Chem aerosol optical properties in the MODIS retrieval not only results in an improved AOD product but also allows quantitative evaluation of model aerosol mass from the comparison of simulated and observed AODs. The aircraft measurements show narrower aerosol size distributions than those usually assumed in models, and this has important implications for AOD retrievals. Our MODIS AOD retrieval compares well to the ground-based AERONET data (R = 0.84, slope = 1.02), significantly improving on the MODIS c005 operational product. Inference of surface PM2.5 from our MODIS AOD retrieval shows good correlation to the EPA-AQS data (R = 0.78) but a high regression slope (slope = 1.48). The high slope is seen in all AOD-inferred PM2.5 concentrations (AERONET: slope = 2.04; MODIS c005: slope = 1.51) and could reflect a clear-sky bias in the AOD observations. The ensemble of MODIS, aircraft, and surface data are consistent in pointing to a model overestimate of sulfate in the mid-Atlantic and an underestimate of organic and dust aerosol in the southeastern United States. The sulfate overestimate could reflect an excessive contribution from aqueous-phase production in clouds, while the organic carbon underestimate could possibly be resolved by a new secondary pathway involving dicarbonyls

Hierarchical Hollow Spheres of Fe 2 O 3 @Polyaniline for Lithium Ion Battery Anodes

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/101856/1/adma201302710-sup-0001-S1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/101856/2/adma201302710.pd

Synthesis of Satellite (MODIS), Aircraft (ICARTT), and Surface (IMPROVE, EPA-AQS, AERONET) Aerosol Observations over Eastern North America to Improve MODIS Aerosol Retrievals and Constrain Surface Aerosol Concentrations and Sources

We use an ensemble of satellite (MODIS), aircraft, and ground-based aerosol observations during the ICARTT field campaign over eastern North America in summer 2004 to (1) examine the consistency between different aerosol measurements, (2) evaluate a new retrieval of aerosol optical depths (AODs) and inferred surface aerosol concentrations $(PM_{2.5})$ from the MODIS satellite instrument, and (3) apply this collective information to improve our understanding of aerosol sources. The GEOS-Chem global chemical transport model (CTM) provides a transfer platform between the different data sets, allowing us to evaluate the consistency between different aerosol parameters observed at different times and locations. We use an improved MODIS AOD retrieval based on locally derived visible surface reflectances and aerosol properties calculated from GEOS-Chem. Use of GEOS-Chem aerosol optical properties in the MODIS retrieval not only results in an improved AOD product but also allows quantitative evaluation of model aerosol mass from the comparison of simulated and observed AODs. The aircraft measurements show narrower aerosol size distributions than those usually assumed in models, and this has important implications for AOD retrievals. Our MODIS AOD retrieval compares well to the ground-based AERONET data (R = 0.84, slope = 1.02), significantly improving on the MODIS c005 operational product. Inference of surface $PM_{2.5}$ from our MODIS AOD retrieval shows good correlation to the EPA-AQS data (R = 0.78) but a high regression slope (slope = 1.48). The high slope is seen in all AOD-inferred $PM_{2.5}$ concentrations (AERONET: slope = 2.04; MODIS c005: slope = 1.51) and could reflect a clear-sky bias in the AOD observations. The ensemble of MODIS, aircraft, and surface data are consistent in pointing to a model overestimate of sulfate in the mid-Atlantic and an underestimate of organic and dust aerosol in the southeastern United States. The sulfate overestimate could reflect an excessive contribution from aqueous-phase production in clouds, while the organic carbon underestimate could possibly be resolved by a new secondary pathway involving dicarbonyls.Engineering and Applied Science

Tradable Pollution Permits and the Regulatory Game

This paper analyzes polluters\u27 incentives to move from a traditional command and control (CAC) environmental regulatory regime to a tradable permits (TPP) regime. Existing work in environmental economics does not model how firms contest and bargain over actual regulatory implementation in CAC regimes, and therefore fail to compare TPP regimes with any CAC regime that is actually observed. This paper models CAC environmental regulation as a bargaining game over pollution entitlements. Using a reduced form model of the regulatory contest, it shows that CAC regulatory bargaining likely generates a regulatory status quo under which firms with the highest compliance costs bargain for the smallest pollution reductions, or even no reduction at all. As for a tradable permits regime, it is shown that all firms are better off under such a regime than they would be under an idealized CAC regime that set and enforced a uniform pollution standard, but permit sellers (low compliance cost firms) may actually be better off under a TPP regime with relaxed aggregate pollution levels. Most importantly, because high cost firms (or facilities) are the most weakly regulated in the equilibrium under negotiated or bargained CAC regimes, they may be net losers in a proposed move to a TPP regime. When equilibrium costs under a TPP regime are compared with equilibrium costs under a status quo CAC regime, several otherwise paradoxical aspects of firm attitudes toward TPP type reforms can be explained. In particular, the otherwise paradoxical pattern of allowances awarded under Phase II of the 1990 Clean Air Act\u27s acid rain program, a pattern tending to favor (in Phase II) cleaner, newer generating units, is explained by the fact that under the status quo regime, a kind of bargained CAC, it was the newer cleaner units that were regulated, and which therefore had higher marginal control costs than did the largely unregulated older, plants. As a normative matter, the analysis here implies that the proper baseline for evaluating TPP regimes such as those contained in the Bush Administration\u27s recent Clear Skies initiative is not idealized, but nonexistent CAC regulatory outcomes, but rather the outcomes that have resulted from the bargaining game set up by CAC laws and regulations

Ecological Thresholds in the Savanna Landscape: Developing a Protocol for Monitoring the Change in Composition and Utilisation of Large Trees

BACKGROUND: Acquiring greater understanding of the factors causing changes in vegetation structure -- particularly with the potential to cause regime shifts -- is important in adaptively managed conservation areas. Large trees (> or =5 m in height) play an important ecosystem function, and are associated with a stable ecological state in the African savanna. There is concern that large tree densities are declining in a number of protected areas, including the Kruger National Park, South Africa. In this paper the results of a field study designed to monitor change in a savanna system are presented and discussed. METHODOLOGY/PRINCIPAL FINDINGS: Developing the first phase of a monitoring protocol to measure the change in tree species composition, density and size distribution, whilst also identifying factors driving change. A central issue is the discrete spatial distribution of large trees in the landscape, making point sampling approaches relatively ineffective. Accordingly, fourteen 10 m wide transects were aligned perpendicular to large rivers (3.0-6.6 km in length) and eight transects were located at fixed-point photographic locations (1.0-1.6 km in length). Using accumulation curves, we established that the majority of tree species were sampled within 3 km. Furthermore, the key ecological drivers (e.g. fire, herbivory, drought and disease) which influence large tree use and impact were also recorded within 3 km. CONCLUSIONS/SIGNIFICANCE: The technique presented provides an effective method for monitoring changes in large tree abundance, size distribution and use by the main ecological drivers across the savanna landscape. However, the monitoring of rare tree species would require individual marking approaches due to their low densities and specific habitat requirements. Repeat sampling intervals would vary depending on the factor of concern and proposed management mitigation. Once a monitoring protocol has been identified and evaluated, the next stage is to integrate that protocol into a decision-making system, which highlights potential leading indicators of change. Frequent monitoring would be required to establish the rate and direction of change. This approach may be useful in generating monitoring protocols for other dynamic systems

Efficacy and safety of baricitinib or ravulizumab in adult patients with severe COVID-19 (TACTIC-R): a randomised, parallel-arm, open-label, phase 4 trial

Background From early in the COVID-19 pandemic, evidence suggested a role for cytokine dysregulation and complement activation in severe disease. In the TACTIC-R trial, we evaluated the efficacy and safety of baricitinib, an inhibitor of Janus kinase 1 (JAK1) and JAK2, and ravulizumab, a monoclonal inhibitor of complement C5 activation, as an adjunct to standard of care for the treatment of adult patients hospitalised with COVID-19. Methods TACTIC-R was a phase 4, randomised, parallel-arm, open-label platform trial that was undertaken in the UK with urgent public health designation to assess the potential of repurposing immunosuppressants for the treatment of severe COVID-19, stratified by a risk score. Adult participants (aged ≥18 years) were enrolled from 22 hospitals across the UK. Patients with a risk score indicating a 40% risk of admission to an intensive care unit or death were randomly assigned 1:1:1 to standard of care alone, standard of care with baricitinib, or standard of care with ravulizumab. The composite primary outcome was the time from randomisation to incidence (up to and including day 14) of the first event of death, invasive mechanical ventilation, extracorporeal membrane oxygenation, cardiovascular organ support, or renal failure. The primary interim analysis was triggered when 125 patient datasets were available up to day 14 in each study group and we included in the analysis all participants who were randomly assigned. The trial was registered on ClinicalTrials.gov (NCT04390464). Findings Between May 8, 2020, and May 7, 2021, 417 participants were recruited and randomly assigned to standard of care alone (145 patients), baricitinib (137 patients), or ravulizumab (135 patients). Only 54 (39%) of 137 patients in the baricitinib group received the maximum 14-day course, whereas 132 (98%) of 135 patients in the ravulizumab group received the intended dose. The trial was stopped after the primary interim analysis on grounds of futility. The estimated hazard ratio (HR) for reaching the composite primary endpoint was 1·11 (95% CI 0·62–1·99) for patients on baricitinib compared with standard of care alone, and 1·53 (0·88–2·67) for ravulizumab compared with standard of care alone. 45 serious adverse events (21 deaths) were reported in the standard-of-care group, 57 (24 deaths) in the baricitinib group, and 60 (18 deaths) in the ravulizumab group. Interpretation Neither baricitinib nor ravulizumab, as administered in this study, was effective in reducing disease severity in patients selected for severe COVID-19. Safety was similar between treatments and standard of care. The short period of dosing with baricitinib might explain the discrepancy between our findings and those of other trials. The therapeutic potential of targeting complement C5 activation product C5a, rather than the cleavage of C5, warrants further evaluation

Single-dose administration and the influence of the timing of the booster dose on immunogenicity and efficacy of ChAdOx1 nCoV-19 (AZD1222) vaccine: a pooled analysis of four randomised trials.

BACKGROUND: The ChAdOx1 nCoV-19 (AZD1222) vaccine has been approved for emergency use by the UK regulatory authority, Medicines and Healthcare products Regulatory Agency, with a regimen of two standard doses given with an interval of 4-12 weeks. The planned roll-out in the UK will involve vaccinating people in high-risk categories with their first dose immediately, and delivering the second dose 12 weeks later. Here, we provide both a further prespecified pooled analysis of trials of ChAdOx1 nCoV-19 and exploratory analyses of the impact on immunogenicity and efficacy of extending the interval between priming and booster doses. In addition, we show the immunogenicity and protection afforded by the first dose, before a booster dose has been offered. METHODS: We present data from three single-blind randomised controlled trials-one phase 1/2 study in the UK (COV001), one phase 2/3 study in the UK (COV002), and a phase 3 study in Brazil (COV003)-and one double-blind phase 1/2 study in South Africa (COV005). As previously described, individuals 18 years and older were randomly assigned 1:1 to receive two standard doses of ChAdOx1 nCoV-19 (5 × 1010 viral particles) or a control vaccine or saline placebo. In the UK trial, a subset of participants received a lower dose (2·2 × 1010 viral particles) of the ChAdOx1 nCoV-19 for the first dose. The primary outcome was virologically confirmed symptomatic COVID-19 disease, defined as a nucleic acid amplification test (NAAT)-positive swab combined with at least one qualifying symptom (fever ≥37·8°C, cough, shortness of breath, or anosmia or ageusia) more than 14 days after the second dose. Secondary efficacy analyses included cases occuring at least 22 days after the first dose. Antibody responses measured by immunoassay and by pseudovirus neutralisation were exploratory outcomes. All cases of COVID-19 with a NAAT-positive swab were adjudicated for inclusion in the analysis by a masked independent endpoint review committee. The primary analysis included all participants who were SARS-CoV-2 N protein seronegative at baseline, had had at least 14 days of follow-up after the second dose, and had no evidence of previous SARS-CoV-2 infection from NAAT swabs. Safety was assessed in all participants who received at least one dose. The four trials are registered at ISRCTN89951424 (COV003) and ClinicalTrials.gov, NCT04324606 (COV001), NCT04400838 (COV002), and NCT04444674 (COV005). FINDINGS: Between April 23 and Dec 6, 2020, 24 422 participants were recruited and vaccinated across the four studies, of whom 17 178 were included in the primary analysis (8597 receiving ChAdOx1 nCoV-19 and 8581 receiving control vaccine). The data cutoff for these analyses was Dec 7, 2020. 332 NAAT-positive infections met the primary endpoint of symptomatic infection more than 14 days after the second dose. Overall vaccine efficacy more than 14 days after the second dose was 66·7% (95% CI 57·4-74·0), with 84 (1·0%) cases in the 8597 participants in the ChAdOx1 nCoV-19 group and 248 (2·9%) in the 8581 participants in the control group. There were no hospital admissions for COVID-19 in the ChAdOx1 nCoV-19 group after the initial 21-day exclusion period, and 15 in the control group. 108 (0·9%) of 12 282 participants in the ChAdOx1 nCoV-19 group and 127 (1·1%) of 11 962 participants in the control group had serious adverse events. There were seven deaths considered unrelated to vaccination (two in the ChAdOx1 nCov-19 group and five in the control group), including one COVID-19-related death in one participant in the control group. Exploratory analyses showed that vaccine efficacy after a single standard dose of vaccine from day 22 to day 90 after vaccination was 76·0% (59·3-85·9). Our modelling analysis indicated that protection did not wane during this initial 3-month period. Similarly, antibody levels were maintained during this period with minimal waning by day 90 (geometric mean ratio [GMR] 0·66 [95% CI 0·59-0·74]). In the participants who received two standard doses, after the second dose, efficacy was higher in those with a longer prime-boost interval (vaccine efficacy 81·3% [95% CI 60·3-91·2] at ≥12 weeks) than in those with a short interval (vaccine efficacy 55·1% [33·0-69·9] at <6 weeks). These observations are supported by immunogenicity data that showed binding antibody responses more than two-fold higher after an interval of 12 or more weeks compared with an interval of less than 6 weeks in those who were aged 18-55 years (GMR 2·32 [2·01-2·68]). INTERPRETATION: The results of this primary analysis of two doses of ChAdOx1 nCoV-19 were consistent with those seen in the interim analysis of the trials and confirm that the vaccine is efficacious, with results varying by dose interval in exploratory analyses. A 3-month dose interval might have advantages over a programme with a short dose interval for roll-out of a pandemic vaccine to protect the largest number of individuals in the population as early as possible when supplies are scarce, while also improving protection after receiving a second dose. FUNDING: UK Research and Innovation, National Institutes of Health Research (NIHR), The Coalition for Epidemic Preparedness Innovations, the Bill & Melinda Gates Foundation, the Lemann Foundation, Rede D'Or, the Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca