First evidence of microplastics in Antarctic snow

In recent years, airborne microplastics have been identified in a range of remote environments. However, data throughout the Southern Hemisphere, in particular Antarctica, are largely absent to date. We collected snow samples from 19 sites across the Ross Island region of Antarctica. Suspected microplastic particles were isolated and their composition confirmed using micro-Fourier transform infrared spectroscopy (μFTIR).We identified microplastics in all Antarctic snow samples at an average concentration of 29 particles L−1, with fibres the most common morphotype and polyethylene terephthalate (PET) the most common polymer. To investigate sources, backward air mass trajectories were run from the time of sampling. These indicate potential long-range transportation of up to 6000 kilometers, assuming a residence time of 6.5 days. Local sources were also identified as potential inputs into the environment, as the polymers identified were consistent with those used in clothing and equipment from nearby research stations. This study adds to the growing body of literature regarding microplastics as a ubiquitous airborne pollutant, and establishes their presence in Antarctica.

Online Chemical Characterization and Sources of Submicron Aerosol in the Major Mediterranean Port City of Piraeus, Greece

Port cities are affected by a wide array of emissions, including those from the shipping, road transport, and residential sectors; therefore, the characterization and apportionment of such sources in a high temporal resolution is crucial. This study presents measurements of fine aerosol chemical composition in Piraeus, one of the largest European ports, during two monthly periods (winter vs. summer) in 2018–2019, using online instrumentation (Aerosol Chemical Speciation Monitor—ACSM, 7-λ aethalometer). PMF source apportionment was performed on the ACSM mass spectra to quantify organic aerosol (OA) components, while equivalent black carbon (BC) was decomposed to its fossil fuel combustion and biomass burning (BB) fractions. The combined traffic, shipping and, especially, residential emissions led to considerably elevated submicron aerosol levels (22.8 μg m−3) in winter, which frequently became episodic late at night under stagnant conditions. Carbonaceous compounds comprised the major portion of this submicron aerosol in winter, with mean OA and BC contributions of 61% (13.9 μg m−3) and 16% (3.7 μg m−3), respectively. The contribution of BB to BC concentrations was considerable and spatially uniform. OA related to BB emissions (fresh and processed) and hydrocarbon-like OA (from vehicular traffic and port-related fossil fuel emissions including shipping) accounted for 37% and 30% of OA, respectively. In summer, the average PM1 concentration was significantly lower (14.8 μg m−3) and less variable, especially for the components associated with secondary aerosols (such as OA and sulfate). The effect of the port sector was evident in summer and maintained BC concentrations at high levels (2.8 μg m−3), despite the absence of BB and improved atmospheric dispersion. Oxygenated components yielded over 70% of OA in summer, with the more oxidized secondary component of regional origin being dominant (41%) despite the intensity of local sources, in the Piraeus environment. In general, with respect to local sources that can be the target of mitigation policies, this work highlights the importance of port-related activities but also reveals the extensive wintertime impact of residential wood burning. While a separation of the BB source is feasible, more research is needed on how to disentangle the short-term effects of different fossil-fuel combustion sources.

Kenya

On 4 March 2013, when Kenyans participated in national presidential and legislative elections, there was wide-spread concern that the underling grievances that erupted during the 2007 and 2008 post-election violence would remerge. However, the polls were relatively peaceful in comparison. This case study will interrogate how mass atrocities were prevented in 2013 in Kenya, despite the prevalence of risk factors which could spark tensions and fuel violence. This article interrogates the local sources of resilience and inhibitors of atrocity crimes and considers the preventive actions that were undertaken and by whom, with a view to understanding what they achieved. In addition, it will assess the outcomes that were achieved as a result of these preventive actions. Through an evaluation of the preventive actions the article will examine which actions proved to be most effective in affecting the risks dynamics of the country in the short, medium and long-term. Kenya’s history of violence and failure to uphold accountability and redress for victims, meant that in 2013, it was significantly prone to the scourge of atrocity crimes. This analysis will draw out a number of key lessons for enhancing the prevention of atrocity crimes in the future.

Annual exposure to polycyclic aromatic hydrocarbons in urban environments linked to wintertime wood-burning episodes

Polycyclic aromatic hydrocarbons (PAHs) are organic pollutants in fine particulate matter (PM) long known to have mutagenic and carcinogenic effects, but much is unknown about the importance of local and remote sources for PAH levels observed in population-dense urban environments. A year-long sampling campaign in Athens, Greece, where more than 150 samples were analyzed for 31 PAHs and a wide range of chemical markers, was combined with positive matrix factorization (PMF) to constrain the temporal variability, sources, and carcinogenic risk associated with PAHs. It was found that biomass burning (BB), a source mostly present during wintertime intense pollution events (observed for 18 % of measurement days in 2017), led to wintertime PAH levels that were 7 times higher than in other seasons and was as important for annual mean PAH concentrations (31 %) as diesel and oil (33 %) and gasoline (29 %) sources. The contribution of non-local sources, although limited on an annual basis (7 %), increased during summer, becoming comparable to that of local sources combined. The fraction of PAHs (12 members that were included in the PMF analysis) that was associated with BB was also linked to increased health risk compared to the other sources, accounting for almost half the annual PAH carcinogenic potential (43 %). This can result in a large number of excess cancer cases due to BB-related high PM levels and urges immediate action to reduce residential BB emissions in urban areas facing similar issues.

Prosulas for Alleluia and Offertories

Alleluia and offertory prosulas are the most numerous (about a hundred, 80% of which are alleluias) in all European manuscripts. They exploit the freely flowing, but at times carefully balanced, contours of the parent chants, so that the structure of the new text often reflects the phrasal structure of melodies. These prosulas also employ textual assonances for which the position of vowels in the prosula often coincides to that of the parent chant. In local sources some of these prosulas display the use of the Latin cursus, which opens a new perspective on the understanding of melodic cadences in chant composition in southern Italy.

How Do California’s Local Governments Fund Surface Transportation? A Guide to Revenue Sources

California local agencies raise the revenue to support high-quality transportation services and infrastructure from a patchwork of federal, state, and local sources. To assist policymakers and transportation experts as they explore options for creating a more sustainable funding system, this report presents an overview of the taxes and fees that currently generate revenue ultimately dedicated to paying for transportation at the sub-state—or “local”—level. The discussion covers federal and state as well as local sources. The report also traces the evolving contribution from each level of government for expenditures on California’s local streets and roads and public transit, looking back two decades. The report concludes with a discussion of options for increasing local transportation revenue

Effect of glass fiber and recycled aggregates on Geopolymer concrete

This study presents the effect of glass fiber and recycled aggregates on the strength properties of Geopolymer Concrete (GPC). The recycled aggregates were incorporated as a partial substitute for the natural coarse aggregates in the geopolymer concrete at 50%, 80%, and 100% by weight, and the results were compared to natural coarse aggregate. Class F fly ash is utilized as the source material for the production of Geopolymer and brought in from local sources. The effect of glass fiber (alkali resistant) with a length of 36 mm is also studied for the content ranging from 0.3, 1, 2, 3, and 3.5% based on the weight of the concrete. The flexural strength and compressive strength were compared at 7 days and 28 days for different cases. The results show that 1%, 1.5%, 2%, and 2.5% of glass fiber have exceeded the flexural strength of the geopolymer concrete by 20%.

The term ‘marble’ in eighteenth-century encyclopaedic literature: from colourful and exclusive to grainy and popular

This article reports on findings concerning the use and understanding of marble in the eighteenth century, as uncovered by a team of geologists and conservators at the Department of Engineering Technology at the Technical University of Munich. While researching a group of marble objects in Bayreuth in order to devise suitable conservation methods, it became apparent that the eighteenth-century understanding of ‘marble’ was different to how we define the stone today. This earlier definition of marble was based on colour, pattern and the ability to shine when polished. However, by the end of the eighteenth century, there was a shift to a focus on the different grain sizes of the stones, while the previously defining quality of colour became less important. Such developments advanced towards the recognition of limestone and marble as two different types, enabling the distinction between sedimentary limestone and its metamorphic product marble to be drawn in the first half of the nineteenth century. At the same time, the exploration of local sources caused the exclusivity of marble to dwindle. Once a building and decorative material for the elite, it now became more widely available. Marble was still the material of sovereigns - proudly presented as locally found - but it simultaneously became accessible to a wider market for household utensils or collectors’ items. This is demonstrated through the exploration of a range of German sources, including encyclopaedias and lexicons with their inherent aim of accumulating the universal knowledge of their time, a ‘marble’ compendium, and a description of the prison and workhouse in St Georgen in Bayreuth, which had marble works on its premises.

Late 19th - Early 20th Century Western Scholars Have Analyzed Data On The Climate, Nature, Flora And Fauna Of Central Asia

In the study of the history of Uzbekistan, in addition to local sources, the study of works and research by foreign authors can be used in a scientific and objective analysis of possible controversies on the subject. The periodic boundaries of our research work cover the late 19th and early 20th centuries. During this period, a number of foreign ambassadors, traders and tourists visited Central Asia. Many of them write about their experiences here and later write about it. Such manuscripts and works also contain a wealth of impressions and information on the nature and climate of Central Asia at that time.

Open Lake Phosphorus Forcing of Cladophora Growth: Modeling the Dual Challenge in Great Lakes Trophic State Management

Stimulated by excess levels of phosphorus, the attached, filamentous green alga Cladophora grows to nuisance proportions in Lake Michigan, one of the Laurentian Great Lakes. While nearshore waters impacted by local sources of the nutrient continue to support nuisance conditions, offshore waters have undergone oligotrophication in response to reductions in phosphorus loading and benthification of phosphorus cycling by invasive dreissenid mussels. A concept termed the Dual Challenge recognizes that implementation of more stringent phosphorus-loading objectives (to control Cladophora in the nearshore) stands in conflict with a foreseen need to mitigate oligotrophication in the offshore (to sustain a healthy fishery). Attention to this nearshore–offshore dynamic calls into play the role of cross-margin phosphorus transport in mediating both endmembers of the conflict. We applied a biophysical model simulating soluble reactive (SRP) and particulate (PP) phosphorus, mussel biokinetics, and cross-margin mass transport in addressing the Dual Challenge. Pre- and post-dreissenid monitoring results suggest that a reduction in offshore PP levels (food web nutrition) in excess of 40% (2.4 to 1.4 mgP×m−3) has driven oligotrophication and attendant food web dysfunction. Yet, in the absence of local sources, model-predicted nearshore SRP levels remain at or below those required to prevent nuisance growth. These findings indicate that there is a margin of ~1 mgP×m−3 over which offshore PP levels could be increased (to the benefit of the food web and the fishery) without hindering efforts to reduce nuisance algal growth through local source control.