Biogenic coastal aerosol production and its influence on aerosol radiative properties

Coastal zones have been shown to provide a massive source of new, tidal-related, aerosol particles in the atmospheric boundary layer with concentrations exceeding 1,000,000 cm(-3) during nucleation bursts sustained over many hours [O Dowd, 2000]. While coastal regions are very strong sources of natural aerosol particles, hithertofore, it has not been demonstrated that these particles contribute to aerosol-related radiative flux. In this brief report, evidence is presented Fur growth of these new particles, following tidal-related particle formation, into radiatively active particle sizes (i.e. radius>50 nm) where an increase in concentration of more than 300% can be seen. This increase of radiatively active particles concomitantly results in more than a threefold enhancement in both aerosol scattering ability (thereby influencing direct radiative flux) and cloud condensation nuclei (CCN) availability (thereby influencing indirect radiative flux). These results provide direct evidence for coastal biogenic emissions significantly enhancing the radiative flux potential of atmospheric aerosols

Biogenic coastal aerosol production and its influence on aerosol radiative properties

Coastal zones have been shown to provide a massive source of new, tidal-related, aerosol particles in the atmospheric boundary layer with concentrations exceeding 1,000,000 cm(-3) during nucleation bursts sustained over many hours [O Dowd, 2000]. While coastal regions are very strong sources of natural aerosol particles, hithertofore, it has not been demonstrated that these particles contribute to aerosol-related radiative flux. In this brief report, evidence is presented Fur growth of these new particles, following tidal-related particle formation, into radiatively active particle sizes (i.e. radius>50 nm) where an increase in concentration of more than 300% can be seen. This increase of radiatively active particles concomitantly results in more than a threefold enhancement in both aerosol scattering ability (thereby influencing direct radiative flux) and cloud condensation nuclei (CCN) availability (thereby influencing indirect radiative flux). These results provide direct evidence for coastal biogenic emissions significantly enhancing the radiative flux potential of atmospheric aerosols

Volcanic sulphate and arctic dust plumes over the North Atlantic Ocean

High time resolution aerosol mass spectrometry measurements were conducted during a field campaign at Mace Head Research Station, Ireland, in June 2007. Observations on one particular day of the campaign clearly indicated advection of aerosol from volcanoes and desert plains in Iceland which could be traced with NOAA Hysplit air mass back trajectories and satellite images. In conjunction with this event, elevated levels of sulphate and light absorbing particles were encountered at Mace Head. While sulphate concentration was continuously increasing, nitrate levels remained low indicating no significant contribution from anthropogenic pollutants. Sulphate concentration increased about 3.8 µg m-3 in comparison with the background conditions. Corresponding sulphur flux from volcanic emissions was estimated to about 0.3 TgS yr-1, suggesting that a large amount of sulphur released from Icelandic volcanoes may be distributed over distances larger than 1000 km. Overall, our results corroborate that transport of volcanogenic sulphate and dust particles can significantly change the chemical composition, size distribution, and optical properties of aerosol over the North Atlantic Ocean and should be considered accordingly by regional climate models.SF

Can bacterial virulence factors predict antibiotic resistant Helicobacter pylori infection?

AIM: To evaluate the association between virulence factor status and antibiotic resistance in Helicobacter pylori (H. pylori)-infected patients in Ireland. METHODS: DNA was extracted from antral and corpus biopsies obtained from 165 H. pylori-infected patients. Genotyping for clarithromycin and fluoroquinolone-mediating mutations was performed using the Genotype HelicoDR assay. cagA and vacA genotypes were investigated using PCR. RESULTS: Primary, secondary and overall resistance rates for clarithromycin were 50.5% (n = 53/105), 78.3% (n = 47/60) and 60.6% (n = 100/165), respectively. Primary, secondary and overall resistance rates for fluoroquinolones were 15.2% (n = 16/105) and 28.3% (n = 17/60) and 20% (n = 33/165), respectively. Resistance to both antibiotics was 12.4% (n = 13/105) in treatment-na?ve patients, 25% (n = 15/60) in those previously treated and 17% (n = 28/165) overall. A cagA-positive genotype was detected in 22.4% (n = 37/165) of patient samples. The dominant vacA genotype was S1/M2 at 44.8% (n = 74/165), followed by S2/M2 at 26.7% (n = 44/165), S1/M1 at 23.6% (n = 39/165) and S2/M1 at 4.8% (n = 8/165). Primary clarithromycin resistance was significantly lower in cagA-positive strains than in cagA-negative strains [32% (n = 8/25) vs 56.3% (n = 45/80) P = 0.03]. Similarly, in patients infected with more virulent H. pylori strains bearing the vacA s1 genotype, primary clarithromycin resistance was significantly lower than in those infected with less virulent strains bearing the vacA s2 genotype, [41% (n = 32/78) vs 77.8% (n = 21/27) P = 0.0001]. No statistically significant association was found between primary fluoroquinolone resistance and virulence factor status. CONCLUSION: Genotypic H. pylori clarithromycin resistance is high and cagA-negative strains are dominant in our population. Less virulent (cagA-negative and vacA S2-containing) strains of H. pylori are associated with primary clarithromycin resistance

Contribution of Water-Soluble Organic Matter from Multiple Marine Geographic Eco-Regions to Aerosols around Antarctica

11 pages, 3 figures, supporting information https://doi.org/10.1021/acs.est.0c00695We present shipborne measurements of size-resolved concentrations of aerosol components across ocean waters next to the Antarctic Peninsula, South Orkney Islands, and South Georgia Island, evidencing aerosol features associated with distinct eco-regions. Nonmethanesulfonic acid Water-Soluble Organic Matter (WSOM) represented 6–8% and 11–22% of the aerosol PM1 mass originated in open ocean (OO) and sea ice (SI) regions, respectively. Other major components included sea salt (86–88% OO, 24–27% SI), non sea salt sulfate (3–4% OO, 35–40% SI), and MSA (1–2% OO, 11–12% SI). The chemical composition of WSOM encompasses secondary organic components with diverse behaviors: while alkylamine concentrations were higher in SI air masses, oxalic acid showed higher concentrations in the open ocean air. Our online single-particle mass spectrometry data exclude a widespread source from sea bird colonies, while the secondary production of oxalic acid and sulfur-containing organic species via cloud processing is suggested. We claim that the potential impact of the sympagic planktonic ecosystem on aerosol composition has been overlooked in past studies, and multiple eco-regions act as distinct aerosol sources around AntarcticaThe study was supported by the Spanish Ministry of Economy through project BIO-NUC (CGL2013-49020-R), PI-ICE (CTM2017–89117-R) and the Ramon y Cajal fellowship (RYC-2012-11922), and by the EU though the FP7-PEOPLE-2013-IOF programme (Project number 624680, MANU – Marine Aerosol NUcleations), all to M.D., and PEGASO (CTM2012-37615) to R.S.With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)Peer reviewe

Biogenically driven Organic Contribution of Marine Aerosol.

Abstract not availableJRC.H-Institute for environment and sustainability (Ispra

<i>Fasciola hepatica</i> cathepsin L-like proteases: biology, function and potential in the development of first generation liver fluke vaccines.

Fasciola hepatica secretes cathepsin L proteases that facilitate the penetration of the parasite through the tissues of its host, and also participate in functions such as feeding and immune evasion. The major proteases, cathepsin L1 (FheCL1) and cathepsin L2 (FheCL2) are members of a lineage that gave rise to the human cathepsin Ls, Ks and Ss, but while they exhibit similarities in their substrate specificities to these enzymes they differ in having a wider pH range for activity and an enhanced stability at neutral pH. There are presently 13 Fasciola cathepsin L cDNAs deposited in the public databases representing a gene family of at least seven distinct members, although the temporal and spatial expression of each of these members in the developmental stage of F. hepatica remains unclear. Immunolocalisation and in situ hybridisation studies, using antibody and DNA probes, respectively, show that the vast majority of cathepsin L gene expression is carried out in the epithelial cells lining the parasite gut. Within these cells the enzyme is packaged into secretory vesicles that release their contents into the gut lumen for the purpose of degrading ingested host tissue and blood. Liver flukes also express a novel multi-domain cystatin that may be involved in the regulation of cathepsin L activity. Vaccine trials in both sheep and cattle with purified native FheCL1 and FheCL2 have shown that these enzymes can induce protection, ranging from 33 to 79%, to experimental challenge with metacercariae of F. hepatica, and very potent anti-embryonation/hatch rate effects that would block parasite transmission. In this article we review the vaccine trials carried out over the past 8 years, the role of antibody and T cell responses in mediating protection and discuss the prospects of the cathepsin Ls in the development of first generation recombinant liver fluke vaccines. © 2003 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved