1,721,289 research outputs found
Peat bog records of dust deposition over the last 2000 years in the Dolomites (NE Italian Alps)
No full textPeat bog records of dust deposition over the last 2000 years in the Dolomites (NE Italian Alps)
No full textMapping environmental suitability for anthrax reemergence in the Arctic
Full text linkRecent studies have raised concerns about the potential reemergence of infectious diseases in Arctic regions associated with warming temperatures. Among these, particular attention has been devoted to anthrax, as a consequence of the outbreak that occurred in the Russian Yamalo-Nenets peninsula in 2016. Understanding how environmental change might influence the diffusion of this pathogen could allow informed decisions to prevent further zoonotic or epidemic episodes. To that end, the present study aims to identify and investigate the driving variables that may favor anthrax transmission within the Arctic, in order to build environmental niche maps describing the future suitability of these regions for the pathogen. To do so, we use the MaxEnt statistical learning tool informed by Arctic-specific variables, such as reindeer herd distribution and active-layer variation. Because of the relative lack of reliable georeferenced information in these regions, the resulting potential distribution maps are to be considered preliminary, but they can already provide a first assessment tool for local communities living in potential risk areas. They also indicate areas in which additional investigation is needed to improve the reliability of environmental niche modeling, hence the accuracy of risk mapping and the usefulness to Arctic communities
Fire and climate: Biomass burning recorded in ice and lake cores
Full text linkHuman activities including fossil fuel burning are currently altering the global climate system at rates faster than ever recorded in geologic time. Biomass burning causes carbon dioxide emissions equal to 50% of those from fossil-fuel combustion and so are highly likely to influence future climate change. However, aerosols continue to be one of the least understood aspects of the modern climate system and even less is known about their past influence. Ice and lake core proxy records provide quantifiable data on past fire regimes across most spatial and temporal scales. Some monosaccharide anhydrides such as levoglucosan, mannosan and galactosan are used as specific molecular markers for biomass burning as they can only be produced by combustion processes at temperatures greater than 300 °C and are present in both ice and lake cores. Other paleofire tracers such as microcharcoal, polycyclic aromatic hydrocarbons, and pollen records augment the fire history derived at single sites or across regions. As both pyrochemical and climate parameters are determined from the same depth and time within the ice or sediment matrix, the multi-proxy nature of ice and lake cores presents an ideal material to investigate the links between fires and climate change
Organic pollutants in protected plain areas: The occurrence of PAHs, musks, UV-filters, flame retardants and hydrocarbons in woodland soils
Full text linkProtected woodlands are rare and small portions of the plain territory of northern Italy, where agricultural, industrial and urban activities strongly dominate the landscape. Such natural areas are frequently set on river floodplains and are therefore potentially conditioned by the contamination brought by the surface waters. We investigated the occurrence of multiple categories of organic pollutants, including Polycyclic Aromatic Hydrocarbons (PAHs), Musk fragrances, UV-filters, organophosphorus and novel brominated Flame Retardants (FRs) and Total Petroleum Hydrocarbons (TPH) in woodland soils of eight different protected areas. The samples collected in the floodplains of the Po, Adige and Fratta rivers resulted more contaminated, with levels of PAHs up to 633 ng g−1. Moreover, these samples for the first time revealed the presence of personal care products, primarily 2-ethylhexyl-4-methoxycinnamate (EHMC) and tonalide (AHTN), in soils of protected woodlands, reaching respectively 3.4 ng g−1 and 5.0 ng g−1, together with the occurrence of both organophosphorus and brominated FRs, with total concentrations up to 15 ng g−1. Higher concentrations of hydrocarbons, with TPH in the range 5–65 μg g−1, were instead reflecting the inputs of long chain n-alkanes from epicuticular waxes more than petrogenic contamination
Permafrost dynamics and the risk of anthrax transmission: a modelling study
Full text linkA recent outbreak of anthrax disease, severely affecting reindeer herds in Siberia, has been reportedly associated to the presence of infected carcasses or spores released from the active layer over permafrost, which is thawing and thickening at increasing rates, thus underlying the re-emerging nature of this pathogen in the Arctic region because of warming temperatures. Anthrax is a global zoonotic and epizootic disease, with a high case-fatality ratio in infected animals. Its transmission is mediated by environmental contamination through highly resistant spores which can persist in the soil for several decades. Here we develop and analyze a new epidemiological model for anthrax transmission that is specifically tailored to the Arctic environmental conditions. The model describes transmission dynamics including also herding practices (e.g. seasonal grazing) and the role of the active layer over permafrost acting as a long-term storage of spores that could be viable for disease transmission during thawing periods. Model dynamics are investigated through linear stability analysis, Floquet theory for periodically forced systems, and a series of simulations with realistic forcings. Results show how the temporal variability of grazing and active layer thawing may influence the dynamics of anthrax disease and, specifically, favor sustained pathogen transmission. Particularly warm years, favoring deep active layers, are shown to be associated with an increase risk of anthrax outbreaks, and may also foster infections in the following years. Our results enable preliminary insights into measures (e.g. changes in herding practice) that may be adopted to decrease the risk of infection and lay the basis to possibly establish optimal procedures for preventing transmission; furthermore, they elicit the need of further investigations and observation campaigns focused on anthrax dynamics in the Arctic environment
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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