We study the properties of residual water molecules at different mole fractions in dialkylimidazolium based ionic liquids (ILs), namely 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIM/BF
) and ...1-butyl-3-methylimidazolium tetrafluoroborate (BMIM/BF
) by means of atomistic molecular dynamics (MD) simulations. The corresponding Kirkwood-Buff (KB) integrals for the water-ion and ion-ion correlation behavior are calculated by a direct evaluation of the radial distribution functions. The outcomes are compared to the corresponding KB integrals derived by an inverse approach based on experimental data. Our results reveal a quantitative agreement between both approaches, which paves a way towards a more reliable comparison between simulation and experimental results. The simulation outcomes further highlight that water even at intermediate mole fractions has a negligible influence on the ion distribution in the solution. More detailed analysis on the local/bulk partition coefficients and the partial structure factors reveal that water molecules at low mole fractions mainly remain in the monomeric state. A non-linear increase of higher order water clusters can be found at larger water concentrations. For both ILs, a more pronounced water coordination around the cations when compared to the anions can be observed, which points out that the IL cations are mainly responsible for water pairing mechanisms. Our simulations thus provide detailed insights in the properties of dialkylimidazolium based ILs and their effects on water binding.
Calcific aortic stenosis, a relatively common problem in the elderly, has been found to be associated with atherosclerosis and hypercholesterolemia. This study found that, contrary to expectations, ...intensive lipid-lowering therapy with atorvastatin, which reduced low-density lipoprotein cholesterol levels to a mean of 63±23 mg per deciliter, had no effect on the progression of aortic stenosis (as measured by the aortic-jet velocity) or on aortic-valve calcification (as measured by helical computed tomographic scanning).
Intensive lipid-lowering therapy with atorvastatin had no effect on the progression of aortic stenosis or on aortic-valve calcification.
In the Western world, calcific aortic stenosis is the most common form of valvular heart disease, and its incidence increases with age such that 3 percent of adults over 75 years of age have aortic stenosis.
1
It is a gradually progressive disease, characterized by a long asymptomatic phase, lasting several decades, followed by a shorter symptomatic phase associated with severe narrowing of the orifice of the aortic valve. Once symptoms occur, the prognosis is poor and surgery is usually mandated. Calcific aortic stenosis is now the leading indication for valve replacement in North America and Europe. However, there are currently . . .
The Cold Classical Kuiper Belt, a class of small bodies in undisturbed orbits beyond Neptune, is composed of primitive objects preserving information about Solar System formation. In January 2019, ...the New Horizons spacecraft flew past one of these objects, the 36-kilometer-long contact binary (486958) Arrokoth (provisional designation 2014 MU
). Images from the flyby show that Arrokoth has no detectable rings, and no satellites (larger than 180 meters in diameter) within a radius of 8000 kilometers. Arrokoth has a lightly cratered, smooth surface with complex geological features, unlike those on previously visited Solar System bodies. The density of impact craters indicates the surface dates from the formation of the Solar System. The two lobes of the contact binary have closely aligned poles and equators, constraining their accretion mechanism.
Long‐term monitoring of aerosol optical properties at a boreal forest AERONET site in interior Alaska was performed from 1994 through 2008 (excluding winter). Large interannual variability was ...observed, with some years showing near background aerosol optical depth (AOD) levels (<0.1 at 500 nm) while 2004 and 2005 had August monthly means similar in magnitude to peak months at major tropical biomass burning regions. Single scattering albedo (ω0; 440 nm) at the boreal forest site ranged from ∼0.91 to 0.99 with an average of ∼0.96 for observations in 2004 and 2005. This suggests a significant amount of smoldering combustion of woody fuels and peat/soil layers that would result in relatively low black carbon mass fractions for smoke particles. The fine mode particle volume median radius during the heavy burning years was quite large, averaging ∼0.17 μm at AOD(440 nm) = 0.1 and increasing to ∼0.25 μm at AOD(440 nm) = 3.0. This large particle size for biomass burning aerosols results in a greater relative scattering component of extinction and, therefore, also contributes to higher ω0. Additionally, monitoring at an Arctic Ocean coastal site (Barrow, Alaska) suggested transport of smoke to the Arctic in summer resulting in individual events with much higher AOD than that occurring during typical spring Arctic haze. However, the springtime mean AOD(500 nm) is higher during late March through late May (∼0.150) than during summer months (∼0.085) at Barrow partly due to very few days with low background AOD levels in spring compared with many days with clean background conditions in summer.
•Inland fisheries are more prevalent in countries with per capita income below poverty thresholds.•Inland fisheries make substantial contributions to alleviating and preventing poverty.•Inland ...fisheries contribute to resilient livelihood strategies for the poor.•Sustaining inland fisheries requires consideration of external threats to aquatic systems.•Ignoring inland fisheries in development agendas misses a vital tool to address global poverty.
The United Nations’ (UN) 2030 Agenda for Sustainable Development defines the formidable challenge of integrating historically separate economic, social, and environmental goals into a unified ‘plan of action for people, planet, and prosperity.’ We highlight the substantial contribution inland fisheries can make towards preventing increased poverty and, in some cases, alleviating poverty (i.e. addressing Sustainable Development Goal SDG 1: No Poverty) as an opportunity to inform the next set of development agendas and their associated budgets and priorities. Overlooking the contribution of inland fisheries to poverty prevention and alleviation may undermine the capacity to successfully meet the development goals, especially in rural communities in Low-Income Food-Deficit countries. Inland fisheries are essential for food and economic security as the vast majority are small-scale operations or subsistence, predominantly used by poorer groups. Protecting inland fisheries from diverse threats from other water users and associated sectors requires robust, multi-sectoral, and multinational policies that can be brought about by global initiatives like the SDGs. Without such protection, their vital contribution towards sustainable livelihoods and poverty issues becomes uncertain. Further, integrating inland fisheries into sustainable development frameworks strengthens the likelihood of achieving the UN Agenda for Sustainable Development. In this perspective article, we posit that including inland fisheries in national policy statements and programs can prove beneficial to promoting economic and social growth for the poor, preventing further poverty, and achieving SDG 1 and other SDG targets, especially those related to food security.
As a representative site of the southern African biomass‐burning region, sun‐sky data from the 15 year Aerosol Robotic Network (AERONET) deployment at Mongu, Zambia, was analyzed. For the ...biomass‐burning season months (July–November), we investigate seasonal trends in aerosol single scattering albedo (SSA), aerosol size distributions, and refractive indices from almucantar sky scan retrievals. The monthly mean single scattering albedo at 440 nm in Mongu was found to increase significantly from ~0.84 in July to ~0.93 in November (from 0.78 to 0.90 at 675 nm in these same months). There was no significant change in particle size, in either the dominant accumulation or secondary coarse modes during these months, nor any significant trend in the Ångström exponent (440–870 nm; r2 = 0.02). A significant downward seasonal trend in imaginary refractive index (r2 = 0.43) suggests a trend of decreasing black carbon content in the aerosol composition as the burning season progresses. Similarly, burning season SSA retrievals for the Etosha Pan, Namibia AERONET site also show very similar increasing single scattering albedo values and decreasing imaginary refractive index as the season progresses. Furthermore, retrievals of SSA at 388 nm from the Ozone Monitoring Instrument satellite sensor show similar seasonal trends as observed by AERONET and suggest that this seasonal shift is widespread throughout much of southern Africa. A seasonal shift in the satellite retrieval bias of aerosol optical depth from the Moderate Resolution Imaging Spectroradiometer collection 5 dark target algorithm is consistent with this seasonal SSA trend since the algorithm assumes a constant value of SSA. Multi‐angle Imaging Spectroradiometer, however, appears less sensitive to the absorption‐induced bias.
Key Points
Seasonal trend in particle absorption observed with AERONET retrievals
Trend in imaginary refractive index observed but no trend in particle size
OMI satellite retrievals also observed seasonal SSA trend in southern Africa
Moderate Resolution Imaging Spectroradiometer (MODIS) Deep Blue (DB) collection 5.1 (c5.1) aerosol optical depth (AOD) data were analyzed and evaluated for the first time from an independent research ...group using eight years of Terra (2000–2007) and Aqua (2002–2009). Uncertainties in the DB AOD were identified and studied, and our results show that the performance of DB c5.1 is strongly dependent on surface albedo and aerosol microphysics. Using data with only "very good" quality assurance, the root-mean-square error (RMSE) of the DB Terra (Aqua) AOD is 0.24 (0.19) when validated against AERONET. Expanding upon the uncertainty analysis, the potential of applying the DB products for aerosol assimilation was explored. Empirical corrections and quality assurance procedures were developed for North Africa and the Arabian Peninsula to create a data assimilation (DA)-quality DB product. After applying those procedures, the RMSE is reduced by 18.1% (18.2%) for Terra (Aqua) DB data. Prognostic error models of 0.069 + 0.175 × AODTerra_DB with no noise floor and 0.048 + 0.182 × AODAqua_DB with a noise floor of 0.104 were found for DA-quality Terra and Aqua DB data, respectively. These procedures were also applied to two months of DB collection 6 (c6) AOD data, and reductions in RMSE were found, indicating that the algorithms developed for c5.1 data are applicable to c6 data to some extent.
This investigation examines aerosol dynamics during major fine mode aerosol transboundary pollution events in South Korea primarily during the KORUS-AQ campaign from May 1 – June 10, 2016, ...particularly when cloud fraction was high and/or fog was present to quantify the change in aerosol characteristics due to near-cloud or fog interaction. We analyze the new AERONET Version 3 data that have significant changes to cloud screening algorithms, allowing many more fine-mode observations in the near vicinity of clouds or fog. Case studies for detailed investigation include May 25–26, 2016 when cloud fraction was high over much of the peninsula, associated with a weak frontal passage and advection of pollution from China. These cloud-influenced Chinese transport dates also had the highest aerosol optical depth (AOD), surface PM2.5 concentrations and fine mode particle sizes of the entire campaign. Another likewise cloud/high relative humidity (RH) case is June 9 and 10, 2016 when fog was present over the Yellow Sea that appears to have affected aerosol properties well downwind over the Korean peninsula. In comparison we also investigated aerosol properties on air stagnation days with very low cloud cover and relatively low RH (May 17 & 18, 2016), when local Korean emissions dominated. Aerosol volume size distributions show marked differences between the transport days (with high RH and cloud influences) and the local pollution stagnation days, with total column-integrated particle fine mode volume being an order of magnitude greater on the pollution transport dates. The PM2.5 over central Seoul were significantly greater than for coastal sites on the transboundary transport days yet not on stagnation days, suggesting additional particle formation from gaseous urban emissions in cloud/fog droplets and/or in the high RH humidified aerosol environment. Many days had KORUS-AQ research aircraft flights that provided observations of aerosol absorption, particle chemistry and vertical profiles of extinction. AERONET retrievals and aircraft in situ measurements both showed high single scattering albedo (weak absorption) on the cloudy or cloud influenced days, plus aircraft profile in situ measurements showed large AOD enhancements (versus dried aerosol) at ambient relative humidity (RH) on the pollution transport days, consistent with the significantly larger fine mode particle radii and weak absorption.
•Highest AOD and PM2.5 over S. Korea had significant cloud cover and/or sea fog.•Particle volume was at least 10 times larger on high RH pollution transport days.•Particle SSA was high (0.97–0.99 in mid-visible) on pollution transport days.•The PM2.5 was higher over central Seoul than the coast during pollution transport.
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