426 research outputs found
Using PBIS in Your GNETS Classroom
Our program has developed a data collection system that integrates PBIS expectations and student’s individual IEP goals and exit criteria. We have meshed our PBIS matrix with our previously used Social Skills so that there is a direct correlation of the Social Skills instruction and the PBIS expectations that we use program wide. We have matched our PBIS rules to social skills that have been broken down into a step by step task analysis
Tropospheric sources and sinks of gas-phase acids in the Colorado Front Range
We measured organic and inorganic gas-phase acids in the
Front Range of Colorado to better understand their tropospheric sources and
sinks using a high-resolution time-of-flight chemical ionization mass
spectrometer. Measurements were conducted from 4 to 13 August 2014 at the
Boulder Atmospheric Observatory during the Front Range Air Pollution and
Photochemistry Éxperiment. Diurnal increases in mixing ratios are
consistent with photochemical sources of HNO3, HNCO, formic, propionic,
butyric, valeric, and pyruvic acid. Vertical profiles taken on the 300 m
tower demonstrate net surface-level emissions of alkanoic acids, but net
surface deposition of HNO3 and pyruvic acid. The surface-level alkanoic
acid source persists through both day and night, and is thus not solely
photochemical. Reactions between O3 and organic surfaces may contribute
to the surface-level alkanoic acid source. Nearby traffic emissions and
agricultural activity are a primary source of propionic, butyric, and
valeric acids, and likely contribute photochemical precursors to HNO3
and HNCO. The combined diel and vertical profiles of the alkanoic acids and
HNCO are inconsistent with dry deposition and photochemical losses being the
only sinks, suggesting additional loss mechanisms.</p
Sources and Secondary Production of Organic Aerosols in the Northeastern United States during WINTER
Most intensive field studies investigating aerosols have been conducted in summer, and thus, wintertime aerosol sources and chemistry are comparatively poorly understood. An aerosol mass spectrometer was flown on the National Science Foundation/National Center for Atmospheric Research C‐130 during the Wintertime INvestigation of Transport, Emissions, and Reactivity (WINTER) 2015 campaign in the northeast United States. The fraction of boundary layer submicron aerosol that was organic aerosol (OA) was about a factor of 2 smaller than during a 2011 summertime study in a similar region. However, the OA measured in WINTER was almost as oxidized as OA measured in several other studies in warmer months of the year. Fifty‐eight percent of the OA was oxygenated (secondary), and 42% was primary (POA). Biomass burning OA (likely from residential heating) was ubiquitous and accounted for 33% of the OA mass. Using nonvolatile POA, one of two default secondary OA (SOA) formulations in GEOS‐Chem (v10‐01) shows very large underpredictions of SOA and O/C (5×) and overprediction of POA (2×). We strongly recommend against using that formulation in future studies. Semivolatile POA, an alternative default in GEOS‐Chem, or a simplified parameterization (SIMPLE) were closer to the observations, although still with substantial differences. A case study of urban outflow from metropolitan New York City showed a consistent amount and normalized rate of added OA mass (due to SOA formation) compared to summer studies, although proceeding more slowly due to lower OH concentrations. A box model and SIMPLE perform similarly for WINTER as for Los Angeles, with an underprediction at ages \u3c6 hr, suggesting that fast chemistry might be missing from the models
Transmission of Human Papillomavirus in Heterosexual Couples
Rate of transmission from penis to cervix was lower than that from cervix to penis; 13 different genotypes were sexually transmitted
Heterogeneous N2O5 Uptake During Winter: Aircraft Measurements During the 2015 WINTER Campaign and Critical Evaluation of Current Parameterizations
Nocturnal dinitrogen pentoxide (N2O5) heterogeneous chemistry impacts regional air quality and the distribution and lifetime of tropospheric oxidants. Formed from the oxidation of nitrogen oxides, N2O5 is heterogeneously lost to aerosol with a highly variable reaction probability, γ(N2O5), dependent on aerosol composition and ambient conditions. Reaction products include soluble nitrate (HNO3 or NO3−) and nitryl chloride (ClNO2). We report the first‐ever derivations of γ(N2O5) from ambient wintertime aircraft measurements in the critically important nocturnal residual boundary layer. Box modeling of the 2015 Wintertime INvestigation of Transport, Emissions, and Reactivity (WINTER) campaign over the eastern United States derived 2,876 individual γ(N2O5) values with a median value of 0.0143 and range of 2 × 10−5 to 0.1751. WINTER γ(N2O5) values exhibited the strongest correlation with aerosol water content, but weak correlations with other variables, such as aerosol nitrate and organics, suggesting a complex, nonlinear dependence on multiple factors, or an additional dependence on a nonobserved factor. This factor may be related to aerosol phase, morphology (i.e., core shell), or mixing state, none of which are commonly measured during aircraft field studies. Despite general agreement with previous laboratory observations, comparison of WINTER data with 14 literature parameterizations (used to predict γ(N2O5) in chemical transport models) confirms that none of the current methods reproduce the full range of γ(N2O5) values. Nine reproduce the WINTER median within a factor of 2. Presented here is the first field‐based, empirical parameterization of γ(N2O5), fit to WINTER data, based on the functional form of previous parameterizations
Recommended from our members
The radiation chemistry of homogeneous reactor systems. III. Homogeneous catalysis of the hydrogen-oxygen reaction.
Advancing the estimation of future climate impacts within the United States
Evidence of the physical and economic impacts of climate change is a
critical input to policy development and decision-making. In addition to the
magnitude of potential impacts, detailed estimates of where, when, and to
whom those damages may occur; the types of impacts that will be most
damaging; uncertainties in these damages; and the ability of adaptation to
reduce potential risks are all interconnected and important considerations.
This study utilizes the reduced-complexity model, the Framework for
Evaluating Damages and Impacts (FrEDI), to rapidly project economic and
physical impacts of climate change across 10 000 future scenarios for
multiple impact sectors, regions, and populations within the contiguous
United States (US). Results from FrEDI show that net national damages
increase overtime, with mean climate-driven damages estimated to reach
USD 2.9 trillion (95 % confidence interval (CI): USD 510 billion to USD 12 trillion)
annually by 2090. Detailed FrEDI results show that for the analyzed sectors
the majority of annual long-term (e.g., 2090) damages are associated with
climate change impacts to human health, including mortality attributable to
climate-driven changes in temperature and air pollution (O3 and
PM2.5) exposure. Regional results also show that annual long-term
climate-driven damages vary geographically. The Southeast (all regions are as defined in Fig. 5) is projected to
experience the largest annual damages per capita (mean: USD 9300 per person
annually; 95 % CI: USD 1800–USD 37 000 per person annually), whereas the
smallest damages per capita are expected in the Southwest (mean: USD 6300
per person annually; 95 % CI: USD 840–USD 27 000 per person annually).
Climate change impacts may also broaden existing societal inequalities,
with, for example, Black or African Americans being disproportionately affected by
additional premature mortality from changes in air quality. Lastly, FrEDI
projections are extended through 2300 to estimate the net present
climate-driven damages within US borders from marginal changes in
greenhouse gas emissions. Combined, this analysis provides the most detailed
illustration to date of the distribution of climate change impacts within
US borders.</p
Anthropogenic Control over Wintertime Oxidation of Atmospheric Pollutants
Anthropogenic air pollutants such as nitrogen oxides (NO(x) = NO + NO(2)), sulfur dioxide (SO(2)), and volatile organic compounds (VOC), among others, are emitted to the atmosphere throughout the year from energy production and use, transportation, and agriculture. These primary pollutants lead to the formation of secondary pollutants such as fine particulate matter (PM(2.5)) and ozone (O(3)) and perturbations to the abundance and lifetimes of short-lived greenhouse gases. Free radical oxidation reactions driven by solar radiation govern the atmospheric lifetimes and transformations of most primary pollutants and thus their spatial distributions. During winter in the mid and high latitudes, where a large fraction of atmospheric pollutants are emitted globally, such photochemical oxidation is significantly slower. Using observations from a highly instrumented aircraft, we show that multi-phase reactions between gas-phase NO(x) reservoirs and aerosol particles, as well as VOC emissions from anthropogenic activities, lead to a suite of atypical radical precursors dominating the oxidizing capacity in polluted winter air, and thus, the distribution and fate of primary pollutants on a regional to global scale
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