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Marine regulations aim to reduce sulfur and nitrogen exhaust emissions from maritime shipping. Here, two compliance pathways for reducing sulfur dioxide emissions, fuel sulfur content reduction and exhaust wet scrubbing, are studied for their effects on physicochemical properties and cloud forming abilities of engine exhaust particles. A test‐bed diesel engine was utilized to study fresh exhaust emissions from combustion of non‐compliant, high sulfur content fuel with (WS) and without (HiS) the usage of a wet scrubber as well as a regulatory compliant, low sulfur content fuel (LoS). Particle number emissions are decreased by ≈99% when switching to LoS due to absence of 20–30 nm sulfate rich particles. While number emissions for WS are also decreased, a shift in the sulfate mode toward larger sizes was found to increase particle mass emission factors by at least 31%. Changes in the mixing state induced by the compliance measures are reflected in the hygroscopicity of the exhaust particles. Fuel sulfur reduction decreased cloud condensation nuclei emissions by at least 97% due to emissions of primarily hydrophobic soot particles. Wet scrubbing increased those emissions, mainly driven by changes in particle size distributions. Our results indicate that both compliance alternatives have no obvious impact on the ice forming abilities of 200 nm exhaust particles. These detailed results are relevant for atmospheric processes and might be useful input parameters for cloud‐resolving models to investigate ship aerosol‐cloud interactions and to quantify the impact of shipping on radiative budgets from local to global scales. Plain Language Summary: We investigate how two pathways to comply with international regulations, aiming to reduce emissions of atmospheric pollutants from ships, alter properties of exhaust particles. Both investigated compliance measures (i.e., combustion of cleaner, low sulfur content fuels and aftertreatment of exhaust from a high sulfur content fuel via wet scrubbing) have substantial impacts on the chemical and physical properties of these particles. We find that, while both alternatives reduce the total number of emitted particles substantially, the effect on emissions of cloud forming particles is path dependent. While fuel sulfur content reduction decreased the number of cloud forming particles by about 97%, wet scrubbing led to a strong increase in emissions, suggesting that the measures can have substantial and opposing impacts on local cloud formation and evolution. Key Points: Low sulfur content fuels can reduce emissions of ultrafine particulate matter significantlyExhaust wet scrubbing can lead to shifts in particle size distributions and reduce soot emissionsUsage of low sulfur content fuels or exhaust wet scrubbing have opposing effects on CCN activity of ship exhaust particles [ABSTRACT FROM AUTHOR]

Emission factors of SO2, NOx and size-distributed particle numbers were measured for approximately 300 different ships in the Gulf of Finland and Neva Bay area during two campaigns in August/September 2011 and June/July 2012. The measurements were carried out from a harbor vessel and from an Mi-8 helicopter downwind of passing ships. Other measurements were carried out from shore sites near the island of Kronstadt and along the Neva River in the urban area of Saint Petersburg. Most ships were running at reduced speed (10 kn), i.e., not at their optimal load. Vessels for domestic and international shipping were monitored. It was seen that the distribution of the SO2 emission factors is bi-modal, with averages of 4.6 and 18.2 gSO2 kgfuel-1 for the lower and the higher mode, respectively. The emission factors show compliance with the 1% fuel sulfur content Sulfur Emission Control Areas (SECA) limit for 90% of the vessels in 2011 and 97% in 2012. The distribution of the NOx emission factor is mono-modal, with an average of 58 gNOx kgfuel-1. The corresponding emission related to the generated power yields an average of 12.1 gNOx kWh-1. The distribution of the emission factors for particulate number shows that nearly 90% of all particles in the 5.6 nm to 10 µm size range were below 70 nm in diameter. The distribution of the corresponding emission factors for the mass indicates two separated main modes, one for particles between 30 and 300 nm and the other for above 2 µm. The average particle emission factors were found to be in the range from 0.7 to 2.7×1016 particles kgfuel-1 and 0.2 to 3.4 gPM kgfuel-1, respectively. The NOx and particulate emissions are comparable with other studies. The measured emission factors were compared, for individual ships, to modeled ones using the Ship Traffic Emission Assessment Model (STEAM) of the Finnish Meteorological Institute. A reasonably good agreement for gaseous sulfur and nitrogen emissions can be seen for ships in international traffic, but significant deviations are found for inland vessels. Regarding particulate mass, the values of the modeled data are about 2-3 times higher than the measured results, which probably reflects the assumptions made in the modeled fuel sulfur content. The sulfur contents in the fuel retrieved from the measurements were lower than the previously used assumptions by the City of Saint Petersburg when carrying out atmospheric modeling, and using these measurements it was possible to better assess the impact of shipping on air quality. [ABSTRACT FROM AUTHOR]

Emission factors of SO2, NOx and size distributed particle numbers were measured for approximately 300 different ships in the Gulf of Finland and Neva Bay area during two campaigns in August/September 2011 and June/July 2012. The measurements were carried out from a harbor vessel and from an MI-8 helicopter downwind of passing ships. Other measurements were carried out from shore sites near the island of Kronstadt and along the river Neva in the city area of Saint Petersburg. Most ships were running at reduced speed (10 knots), i.e. not at their optimal load. Vessels for domestic and international shipping were monitored. It was seen that the distribution of the SO2 emission factors is bi-modal with averages of 4.6 gSO2 kg-1fuel and 18.2 gSO2 kg-1fuel for the lower and the higher mode, respectively. The emission factors show compliance with the 1% fuel sulfur content SECA limit for 90% of the vessels in 2011 and 97% in 2012. The distribution of the NOx emission factor is mono-modal with an average of 58 gNOx kg-1 fuel. The corresponding emission related to the generated power yields an average of 12.1 gNOx 15 kWh-1. The distribution of the emission factors for particulate number shows that nearly 90% of all particles in the 5.6nm to 10 µm size range were below 70nm in diameter. The distribution of the corresponding emission factors for the mass indicates two separated main modes, one for particles between 30 and 300nm the other above 2 µm. The average particle emission factors were found to be in the range from 0.7 to 2.7×1016 particles kg-1fuel and 0.2 to 3.4 gPM kg-1fuel, respectively. The NOx and particulate emissions are comparable with other studies. The measured emission factors were compared, for individual ships, to modeled ones using the Ship Traffic Emission Assessment Model (STEAM) of the Finnish Meteorological Institute. A reasonably good agreement for gaseous sulfur and nitrogen emissions can be seen for ships in international traffic, but significant deviations are found for inland vessels. Considering particulate mass, the modeled data is about two to three times above the measured results, which probably reflects the assumptions made in the modeled fuel sulfur content. The sulfur contents in the fuel retrieved from the measurements were lower than the previously used assumptions by the city of Saint Petersburg when carrying out atmospheric modeling and using these measurements it was possible to better assess the impact of shipping on air quality. [ABSTRACT FROM AUTHOR]

A dedicated system for airborne ship emission measurements of SO2, NOx and particles has been developed and used from several small aircraft. The system has been adapted for fast response measurements at 1 Hz, and the use of several of the instruments is unique. The uncertainty of the given data is about 20% for SO2 and 24% for NOx emission factors. The mean values with one standard deviation for multiple measurements of 158 ships measured from the air on the Baltic and North Sea during 2011 and 2012 show emission factors of 18.8±6.5 g kg-1 fuel, 66.6±23.4 g kg-1 fuel and 1.8±1.3 1016 particles kg-1 fuel for SO2, NOx and particle number, respectively. The particle size distributions were measured for particle diameters between 15 and 560 nm. The mean sizes of the particles are between 45 and 54 nm dependent on the distance to the source, and the number size distribution is monomodal. Concerning the sulfur fuel content, around 85% of the monitored ships comply with the International Maritime Organization (IMO) limits. The reduction of the sulfur emission control area (SECA) limit from 1.5 to 1 % in 2010 appears to have contributed to reduction of sulfur emissions that were measured in earlier studies from 2007 to 2009. The presented method can be implemented for regular ship compliance monitoring. [ABSTRACT FROM AUTHOR]

A dedicated system for airborne ship emission measurements of SO2, NOx and particles has been developed and used from several small aircrafts. The system has been adapted for fast response measurements at 1 Hz and the use of several of the instruments is unique. The uncertainty of the given data is about 20.3% for SO2 and 23.8% for NOx emission factors. Multiple measurements of 158 ships measured from the air on the Baltic and North Sea during 2011 and 2012 show emission factors of 18.8±6.5 g kg-1 fuel, 66.6±23.4 g kg-1fuel, and 1.8±1.3 × 1016 particles kg-1fuel for SO2, NOx and particle number respectively. The particle size distributions were measured for particle diameters between 15 and 560 nm. The mean sizes of the particles are between 50 and 62nm dependent on the distance to the source and the number size distribution is mono-modal. Concerning the sulfur fuel content 85% of the ships comply with the IMO limits. The sulfur emission has decreased compared to earlier measurements from 2007 to 2009. The presented method can be implemented for regular ship compliance monitoring. [ABSTRACT FROM AUTHOR]

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. The fetal arterial vasculature of 36 normal human placentas was studied by microangiography. There are two fairly readily distinguishable types of intracotyledonary artery. The first intracotyledonary artery (type A) is long and narrow and runs straight from the chorionic space towards the decidua. Its branches run within the same stem in the same or the opposite direction. The second intracotyledonary artery (type B) is thicker and twisted, and its branches extend perpendicularly from the stem. According to the distribution of these two types of arteries, three different groups of cotyledons were distinguished-those with only type A arteries, those with only type B arteries, and those with both types of intracotyledonary arteries. In these mixed cotyledons the type B arteries were always situated in the middle of the cotyledon. A fourth cotyledonary group was also distinguished; it was composed of an irregular mixture of different types of arteries, which could often only be classified with difficulty. Recurrent anchoring arteries could definitely be demonstrated. These were always branches of type B intracotyledonary arteries. In 5 of the 36 placentas spiralling involved almost all the fetal placental arteries. [ABSTRACT FROM AUTHOR]

A marine test-bed diesel engine was used to study how international fuel sulfur content (FSC) regulations and wet scrubbing can affect physical properties of submicron exhaust particles. Particle size distributions, particle number and mass emission factors as well as effective densities of particulate emissions were measured for three distillate fuels of varying FSC and a laboratory wet scrubber. While particle number concentrations were reduced by up to 9% when switching to low FSC fuels, wet scrubbing led to increased ultrafine particulate emissions (<30 nm). Exhaust processed through the scrubber was also found to have particles with greater effective densities, a result that directly contradicts the particulate characteristics of low FSC fuel emissions. The results demonstrate that alternative pathways to comply with marine FSC regulations can have opposing effects and thus may have very different implications for important atmospheric processes. The relevance for air quality, and the potential implications for cloud and climate interactions are discussed.

The International Maritime Organization (IMO) has gradually applied stricter regulations on the maximum sulphur content permitted in marine fuels and from January 1, 2020, the global fuel sulphur limit was reduced from 3.5% to 0.5%. An attractive option for shipowners is to install exhaust gas cleaning systems, also known as scrubbers, and continue to use high sulphur fuel oil. In the scrubber, the exhausts are led through a fine spray of water, in which sulphur oxides are easily dissolved. The process results in large volumes of acidic discharge water, but while regulations are focused on sulphur oxides removal and acidification, other pollutants e.g. polycyclic aromatic hydrocarbons, metals and nitrogen oxides can be transferred from the exhausts to the washwater and discharged to the marine environment. The aim of the current study was to investigate how different treatments of scrubber discharge water (1, 3 and 10%) affect a natural Baltic Sea summer microplanktonic community. To resolve potential contribution of acidification from the total effect of the scrubber discharge water, "pH controls" were included where the pH of natural sea water was reduced to match the scrubber treatments. Biological effects (e.g. microplankton species composition, biovolume and primary productivity) and chemical parameters (e.g. pH and alkalinity) were monitored and analysed during 14 days of exposure. Significant effects were observed in the 3% scrubber treatment, with more than 20% increase in total biovolume of microplankton compared to the control group, and an even greater effect in the 10% scrubber treatment. Group-specific impacts were recorded where diatoms, flagellates incertae sedis, chlorophytes and ciliates increased in biovolume with increasing concentrations of scrubber water while no effect was recorded for cyanobacteria. In contrast, these effects was not observed in the "pH controls", a suggestion that other parameters/stressors in the scrubber water were responsible for the observed effects., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Syphilis is a globally re-emerging disease, which has marked European history with a devastating epidemic at the end of the 15 th century. Together with non-venereal treponemal diseases, like bejel and yaws, which are found today in subtropical and tropical regions, it currently poses a substantial health threat worldwide. The origins and spread of treponemal diseases remain unresolved, including syphilis' potential introduction into Europe from the Americas. Here, we present the first genetic data from archaeological human remains reflecting a high diversity of Treponema pallidum in early modern Europe. Our study demonstrates that a variety of strains related to both venereal syphilis and yaws-causing T. pallidum subspecies were already present in Northern Europe in the early modern period. We also discovered a previously unknown T. pallidum lineage recovered as a sister group to yaws- and bejel-causing lineages. These findings imply a more complex pattern of geographical distribution and etiology of early treponemal epidemics than previously understood., Competing Interests: Declaration of Interests The authors declare no competing interests., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)

Levänluhta is a unique archaeological site with the remains of nearly a hundred Iron Age individuals found from a water burial in Ostrobothnia, Finland. The strongest climatic downturn of the Common Era, resembling the great Fimbulvinter in Norse mythology, hit these people during the 6th century AD. This study establishes chronological, dietary, and livelihood synthesis on this population based on stable carbon and nitrogen isotopic and radiocarbon analyses on human remains, supported by multidisciplinary evidence. Extraordinarily broad stable isotopic distribution is observed, indicating three subgroups with distinct dietary habits spanning four centuries. This emphasizes the versatile livelihoods practiced at this boundary of marine, freshwater, and terrestrial ecosystems. While the impact of the prolonged cold darkness of the 6th century was devastating for European communities relying on cultivation, the broad range of livelihoods provided resilience for the Levänluhta people to overcome the abrupt climatic decline., Competing Interests: The authors have declared that no competing interests exist.

Human ancient DNA studies have revealed high mobility in Europe's past, and have helped to decode the human history on the Eurasian continent. Northeastern Europe, especially north of the Baltic Sea, however, remains less well understood largely due to the lack of preserved human remains. Finland, with a divergent population history from most of Europe, offers a unique perspective to hunter-gatherer way of life, but thus far genetic information on prehistoric human groups in Finland is nearly absent. Here we report 103 complete ancient mitochondrial genomes from human remains dated to AD 300-1800, and explore mtDNA diversity associated with hunter-gatherers and Neolithic farmers. The results indicate largely unadmixed mtDNA pools of differing ancestries from Iron-Age on, suggesting a rather late genetic shift from hunter-gatherers towards farmers in North-East Europe. Furthermore, the data suggest eastern introduction of farmer-related haplogroups into Finland, contradicting contemporary genetic patterns in Finns.

Although female sex workers are known to be vulnerable to HIV infection, little is known about the epidemiology of HIV infection among this high-risk population in the United States. We systematically identified and critically assessed published studies reporting HIV prevalence among female sex workers in the United States. We searched for and included original English-language articles reporting data on the prevalence of HIV as determined by testing at least 50 females who exchanged sexual practices for money or drugs. We did not apply any restrictions on date of publication. We included 14 studies from 1987 to 2013 that reported HIV prevalence for a total of 3975 adult female sex workers. Only two of the 14 studies were conducted in the last 10 years. The pooled estimate of HIV prevalence was 17.3 % (95 % CI 13.5-21.9 %); however, the prevalence of HIV across individual studies varied considerably (ranging from 0.3 to 32 %) and statistical heterogeneity was substantial (I(2) = 0.89, Q = 123; p < 0.001). Although the variance across the 14 studies was high, prevalence was generally high (10 % or greater in 11 of the 14 included studies). Very few studies have documented the prevalence of HIV among female sex workers in the United States; however, the available evidence does suggest that HIV prevalence among this vulnerable population is high.

Measurements of particle number and mass concentrations and number size distribution of particles from a ship running on liquefied natural gas (LNG) were made on-board a ship with dual-fuel engines installed. Today there is a large interest in LNG as a marine fuel, as a means to comply with sulfur and NOX regulations. Particles were studied in a wide size range together with measurements of other exhaust gases under different engine loads and different mixtures of LNG and marine gas oil. Results from these measurements show that emissions of particles, NOX, and CO2 are considerably lower for LNG compared to present marine fuel oils. Emitted particles were mainly of volatile character and mainly had diameters below 50 nm. Number size distribution for LNG showed a distinct peak at 9-10 nm and a part of a peak at diameter 6 nm and below. Emissions of total hydrocarbons and carbon monoxide are higher for LNG compared to present marine fuel oils, which points to the importance of considering the methane slip from combustion of LNG.

Limonene has a strong tendency to form secondary organic aerosol (SOA) in the atmosphere and in indoor environments. Initial oxidation occurs mainly via ozone or OH radical chemistry. We studied the effect of O(3) concentrations with or without a OH radical scavenger (2-butanol) on the SOA mass and thermal characteristics using the Gothenburg Flow Reactor for Oxidation Studies at Low Temperatures and a volatility tandem differential mobility analyzer. The SOA mass using 15 ppb limonene was strongly dependent on O(3) concentrations and the presence of a scavenger. The SOA volatility in the presence of a scavenger decreased with increasing levels of O(3), whereas without a scavenger, there was no significant change. A chemical kinetic model was developed to simulate the observations using vapor pressure estimates for compounds that potentially contributed to SOA. The model showed that the product distribution was affected by changes in both OH and ozone concentrations, which partly explained the observed changes in volatility, but was strongly dependent on accurate vapor pressure estimation methods. The model-experiment comparison indicated a need to consider organic peroxides as important SOA constituents. The experimental findings could be explained by secondary condensed-phase ozone chemistry, which competes with OH radicals for the oxidation of primary unsaturated products.

The Multiple Chamber Aerosol Chemical Aging Study (MUCHACHAS) tested the hypothesis that hydroxyl radical (OH) aging significantly increases the concentration of first-generation biogenic secondary organic aerosol (SOA). OH is the dominant atmospheric oxidant, and MUCHACHAS employed environmental chambers of very different designs, using multiple OH sources to explore a range of chemical conditions and potential sources of systematic error. We isolated the effect of OH aging, confirming our hypothesis while observing corresponding changes in SOA properties. The mass increases are consistent with an existing gap between global SOA sources and those predicted in models, and can be described by a mechanism suitable for implementation in those models.