The CCRUSH Study: Coarse and fine particulate matter measurements in northeastern Colorado 2009-2012

Coarse (PM10-2.5) and fine (PM2.5) particulate matter in the atmosphere adversely affect human health and influence climate. While PM2.5 is relatively well studied, less is known about the sources and fate of PM10-2.5. The Colorado Coarse Rural-Urban Sources and Health (CCRUSH) study measured PM10-2.5 and PM2.5 mass concentrations, as well as the fraction of semi-volatile material (SVM) in each size regime (SVM2.5, SVM10-2.5), for three years in Denver and comparatively rural Greeley, Colorado. Agricultural operations east of Greeley appear to have contributed to the peak PM10-2.5 concentrations there, but concentrations were generally lower in Greeley than in Denver. Traffic-influenced sites in Denver had PM10-2.5 concentrations that averaged from 14.6 to 19.7 µg/m**3 and mean PM10-2.5/PM10 ratios of 0.56 to 0.70, higher than at residential sites in Denver or Greeley. PM10-2.5 concentrations were more temporally variable than PM2.5 concentrations. Concentrations of the two pollutants were not correlated. Spatial correlations of daily averaged PM10-2.5 concentrations ranged from 0.59 to 0.62 for pairs of sites in Denver and from 0.47 to 0.70 between Denver and Greeley. Compared to PM10-2.5, concentrations of PM2.5 were more correlated across sites within Denver and less correlated between Denver and Greeley. PM10-2.5 concentrations were highest during the summer and early fall, while PM2.5 and SVM2.5 concentrations peaked in winter during periodic multi-day inversions. SVM10-2.5 concentrations were low at all sites. Diurnal peaks in PM10-2.5 and PM2.5 concentrations corresponded to morning and afternoon peaks of traffic activity, and were enhanced by boundary layer dynamics. SVM2.5 concentrations peaked around noon on both weekdays and weekends. PM10-2.5 concentrations at sites located near highways generally increased with wind speeds above about 3 m/s. Little wind speed dependence was observed for the residential sites in Denver and Greeley.

(Table 1) Radiocarbon results from this study

The Indonesian Arc represents the subduction of the Indian-Australian plate beneath Asia. It has been the scene of catastrophic tectonic activity, including the recent 2004 M=9.1 Aceh earthquake and resulting Indian Ocean tsunami. We have dated planktonic forams associated with historic tephras (Tambora, 1815 and Krakatau, 1883) in marine sediment cores to determine radiocarbon reservoir ages for 2 locations along the arc. Our best estimates for 19th century regional reservoir corrections (DeltaR) are +90 ± 40 yr for surface-dwelling species and +220 ± 40 yr for mixed planktic assemblages containing some upper thermocline species, but scatter in the data suggests that past surface reservoir ages may have varied by about ±100 yr. We used the results of this study to investigate a proposed very large AD 535 eruption at or near Krakatau. We find no evidence for ash from such an eruption, and although this is negative evidence, we consider it sufficiently strong to rule out any possibility that one took place.

Seawater carbonate chemistry and community calcification during Reunion Island coral reef community study, 2007

To assess the contribution of soft-bottoms to the carbon cycle in coral reefs, the net community production (p) was measured in winter at 3 stations on La Saline inner reef flat (Reunion Island). Changes in pH and total alkalinity at different irradiances (I) were assessed using benthic chambers (0.2 m2) during a 1-h incubation. Mean grain size, the silt and clay load and chlorophyll a content of the sediments were analysed in each chamber. Daily community production (P), gross community production (Pg) and community respiration (R) were estimated from p-I curves and daily irradiance variations (PAR, 400-700 nm). Sediment characteristics and chlorophyll a contents did not differ between the three sites, except for the silt and clay fraction at one station. R being higher than Pg (84.88 ± 7.36 and -62.29 ± 3.34 mmolC m-2 d-1 respectively), P value reached 22.59 ± 5.66 mmolC m-2 d-1. The sediments were therefore heterotrophic with a mean Pg/R lower than 1 (0.74 ± 0.05) and appear to be a carbon source. Our data suggested the importance of the degradation process in the functioning of near-reef sediments.

Seawater carbonate chemistry and calcification during a tropical lagoon study at SW lagoon of New Caledonia, 1994

Carbon dioxide and oxygen fluxes were measured in 0.2 m2 enclosures placed at the water sediment interface in the SW lagoon of New Caledonia. Experiments, performed at several stations in a wide range of environments, were carried out both in darkness to estimate respiration and at ambient light, to assess the effects of primary production. The community respiratory quotient (CRQ = CO2 production rate/02 consumption rate) and the community photosynthetic quotient (CPQ= gross O2 production rate/gross CO2 consumption rate) were calculated by functional regressions. The CRQ value, calculated from 61 incubations, was 1.14 (S.E. 0.05) and the CPQ value, obtained from 18 incubations, was 1.03 (S.E. 0.08). The linearity of the relationship between the O2 and the CO2 fluxes suggests that these values are representative for the whole lagoon

Who is in charge? An L2 Discourse Intonation Study on Four Prosodic Parameters to Exert the Pragmatic Function of Dominance and Control in the Context of L2 Non-specialist Public Speaking

This paper reports the findings from a study of the learning of English intonation by Spanish speakers within the discourse mode of L2 oral presentation. The purpose of this experiment is, firstly, to compare four prosodic parameters before and after an L2 discourse intonation training programme and, secondly, to confirm whether subjects, after the aforementioned L2 discourse intonation training, are able to match the form of these four prosodic parameters to the discourse-pragmatic function of dominance and control. The study designed the instructions and tasks to create the oral and written corpora and Brazil’s Pronunciation for Advanced Learners of English was adapted for the pedagogical aims of the present study. The learners’ pre- and post-tasks were acoustically analysed and a pre / post- questionnaire design was applied to interpret the acoustic analysis. Results indicate most of the subjects acquired a wider choice of the four prosodic parameters partly due to the prosodically-annotated transcripts that were developed throughout the L2 discourse intonation course. Conversely, qualitative and quantitative data reveal most subjects failed to match the forms to their appropriate pragmatic functions to express dominance and control in an L2 oral presentation.