6 research outputs found

    Long-term annual and monthly changes in mysids and caridean decapods in a macrotidal estuarine environment in relation to climate change and pollution

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    © 2018 Elsevier B.V. A 26-year time series of monthly samples from the water intake of a power station has been used to analyse the trends exhibited by number of species, total abundance, and composition of the mysids and caridean decapods in the inner Bristol Channel. During this period, annual water temperatures, salinities and the North Atlantic Oscillation Index (NAOI) in winter did not change significantly, whereas annual NAOI declined. Annual mean monthly values for the number of species and total abundance both increased over the 26 years, but these changes were not correlated with any of the measured physico-chemical/climatic factors. As previous studies demonstrated that, during a similar period, metal concentrations in the Severn Estuary and Bristol Channel (into which that estuary discharges) declined and water quality increased, it is proposed that the above changes are due to an improved environment. The fauna was dominated by the mysids Mesopodopsis slabberi and Schistomysis spiritus, which collectively contributed 94% to total abundance. Both species, which were represented by juveniles, males, non-brooding females and brooding females, underwent statistically-indistinguishable patterns of change in abundance over the 26 years. When analysis was based on the abundances of the various species, the overall species composition differed significantly among years and changed serially with year. When abundances were converted to percentage compositions, this pattern of seriation broke down, demonstrating that changes in abundance and not percentage composition were responsible for the seriation. As with the number and abundance of species, changes in composition over the 26 years were not related to any of the physico-chemical/climatic factors tested. Species composition changed monthly in a pronounced cyclical manner throughout the year, due to statistically different time-staggered changes in the abundance of each species. This cyclicity was related most strongly to salinity

    Summary Document

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    This summary is based on the following larger document: Sauchyn, Dave; Barrow, Elaine; Fang, X; Henderson, Norm; Johnston, Mark; Pomeroy, John; Thorpe, Jeff; Wheaton, Elaine; Williams, B. 2009. Saskatchewan’s Natural Capital in a Changing Climate: An Assessment of Impacts and Adaptation, PARC, Regina, 162pp. The full report is viewable on the PARC website at www.parc.caSummary edited by Dave Sauchyn and Norm Henderson.PARC acknowledges the funding support of Saskatchewan Environment.Non-Peer ReviewedClimate change impacts in Saskatchewan are already evident and will become increasing significant over time. This report draws on the expertise of top climate change researchers and a large body of previous work to create a state-of-knowledge synthesis of key biophysical impacts and adaptation options specific to Saskatchewan. The focus is Saskatchewan’s ecosystems and water resources and the sectors of our economy, agriculture, and forestry, which are most dependent on these natural resources. The purpose of this report is to 1) document the expected impacts of climate change on Saskatchewan’s natural resources and dependent industries, and 2) outline options for adaptation of resource management practices, policies and infrastructure to minimize the risks associated with the impacts of climate change and to take advantage of opportunities provided by a warming climate

    Searches for rare B-s(0) and B-0 decays into four muons

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    Searches for rare Bs0B_s^0 and B0B^0 decays into four muons are performed using proton-proton collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 9 fb−1\text{fb}^{-1}. Direct decays and decays via light scalar and J/ψJ/\psi resonances are considered. No evidence for the six decays searched for is found and upper limits at the 95% confidence level on their branching fractions ranging between 1.8×10−101.8\times10^{-10} and 2.6×10−92.6\times10^{-9} are set

    Characterizing CO and NO y Sources and Relative Ambient Ratios in the Baltimore Area Using Ambient Measurements and Source Attribution Modeling.

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    Modeled source attribution information from the Community Multiscale Air Quality model was coupled with ambient data from the 2011 Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality Baltimore field study. We assess source contributions and evaluate the utility of using aircraft measured CO and NO y relationships to constrain emission inventories. We derive ambient and modeled ΔCO:ΔNO y ratios that have previously been interpreted to represent CO:NO y ratios in emissions from local sources. Modeled and measured ΔCO:ΔNO y are similar; however, measured ΔCO:ΔNO y has much more daily variability than modeled values. Sector-based tagging shows that regional transport, on-road gasoline vehicles, and nonroad equipment are the major contributors to modeled CO mixing ratios in the Baltimore area. In addition to those sources, on-road diesel vehicles, soil emissions, and power plants also contribute substantially to modeled NO y in the area. The sector mix is important because emitted CO:NO x ratios vary by several orders of magnitude among the emission sources. The model-predicted gasoline/diesel split remains constant across all measurement locations in this study. Comparison of ΔCO:ΔNO y to emitted CO:NO y is challenged by ambient and modeled evidence that free tropospheric entrainment, and atmospheric processing elevates ambient ΔCO:ΔNO y above emitted ratios. Specifically, modeled ΔCO:ΔNO y from tagged mobile source emissions is enhanced 5-50% above the emitted ratios at times and locations of aircraft measurements. We also find a correlation between ambient formaldehyde concentrations and measured ΔCO:ΔNO y suggesting that secondary CO formation plays a role in these elevated ratios. This analysis suggests that ambient urban daytime ΔCO:ΔNO y values are not reflective of emitted ratios from individual sources

    Observation of Λb0 {\Lambda}_b^0 → D+pπ−π− and Λb0 {\Lambda}_b^0 → D*+pπ−π− decays

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    AbstractThe multihadron decays Λb0 {\Lambda}_b^0 Λ b 0 → D+pπ−π− and Λb0 {\Lambda}_b^0 Λ b 0 → D*+pπ−π− are observed in data corresponding to an integrated luminosity of 3 fb−1, collected in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV by the LHCb detector. Using the decay Λb0 {\Lambda}_b^0 Λ b 0 → Λc+ {\Lambda}_c^{+} Λ c + π+π−π− as a normalisation channel, the ratio of branching fractions is measured to beB(Λb0→D+pπ−π−)B(Λb0→Λc0π+π−π−)×B(D+→K−π+π+)B(Λc0→pK−π−)=(5.35±0.21±0.16)%, \frac{\mathcal{B}\left({\Lambda}_b^0\to {D}^{+}p{\pi}^{-}{\pi}^{-}\right)}{\mathcal{B}\left({\Lambda}_b^0\to {\Lambda}_c^0{\pi}^{+}{\pi}^{-}{\pi}^{-}\right)}\times \frac{\mathcal{B}\left({D}^{+}\to {K}^{-}{\pi}^{+}{\pi}^{+}\right)}{\mathcal{B}\left({\Lambda}_c^0\to {pK}^{-}{\pi}^{-}\right)}=\left(5.35\pm 0.21\pm 0.16\right)\%, B Λ b 0 → D + p π − π − B Λ b 0 → Λ c 0 π + π − π − × B D + → K − π + π + B Λ c 0 → pK − π − = 5.35 ± 0.21 ± 0.16 % , where the first uncertainty is statistical and the second systematic. The ratio of branching fractions for the Λb0 {\Lambda}_b^0 Λ b 0 → D*+pπ−π− and Λb0 {\Lambda}_b^0 Λ b 0 → D+pπ−π− decays is found to beB(Λb0→D∗+pπ−π−)B(Λb0→D+pπ−π−)×(B(D∗+→D+π0)+B(D∗+→D+γ))=(61.3±4.3±4.0)%. \frac{\mathcal{B}\left({\Lambda}_b^0\to {D}^{\ast +}p{\pi}^{-}{\pi}^{-}\right)}{\mathcal{B}\left({\Lambda}_b^0\to {D}^{+}p{\pi}^{-}{\pi}^{-}\right)}\times \left(\mathcal{B}\left({D}^{\ast +}\to {D}^{+}{\pi}^0\right)+\mathcal{B}\left({D}^{\ast +}\to {D}^{+}\gamma \right)\right)=\left(61.3\pm 4.3\pm 4.0\right)\%. B Λ b 0 → D ∗ + p π − π − B Λ b 0 → D + p π − π − × B D ∗ + → D + π 0 + B D ∗ + → D + γ = 61.3 ± 4.3 ± 4.0 % . </jats:p
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