40 research outputs found
Relationships between methansulfononic acid in PM10 sampled at two Arctic sites (Ny Ålesund, Thule) and primary production and marginal ice zone in the surrounding seas.
α-Synuclein Heterocomplexes with β-Amyloid Are Increased in Red Blood Cells of Parkinson's Disease Patients and Correlate with Disease Severity
Neurodegenerative disorders (NDs) are characterized by abnormal accumulation/misfolding of specific proteins, primarily α-synuclein (α-syn), β-amyloid1-42(Aβ1-42) and tau, in both brain and peripheral tissues. In addition to oligomers, the role of the interactions of α-syn with Aβ or tau has gradually emerged. Nevertheless, despite intensive research, NDs have no accepted peripheral markers for biochemical diagnosis. In this respect, Red Blood Cells (RBCs) are emerging as a valid peripheral model for the study of aging-related pathologies. Herein, a small cohort (N= 28) of patients affected by Parkinson's disease (PD) and age-matched controls were enrolled to detect the content of α-syn (total and oligomeric), Aβ1-42and tau (total and phosphorylated) in RBCs. Moreover, the presence of α-syn association with tau and Aβ1-42was explored by co-immunoprecipitation/western blotting in the same cells, and quantitatively confirmed by immunoenzymatic assays. For the first time, PD patients were demonstrated to exhibit α-syn heterocomplexes with Aβ1-42and tau in peripheral tissues; interestingly, α-syn-Aβ1-42concentrations were increased in PD subjects with respect to healthy controls (HC), and directly correlated with disease severity and motor deficits. Moreover, total-α-syn levels were decreased in PD subjects and inversely related to their motor deficits. Finally, an increase of oligomeric-α-syn and phosphorylated-tau was observed in RBCs of the enrolled patients. The combination of three parameters (total-α-syn, phosphorylated-tau and α-syn-Aβ1-42concentrations) provided the best fitting predictive index for discriminating PD patients from controls. Nevertheless further investigations should be required, overall, these data suggest α-syn hetero-aggregates in RBCs as a putative tool for the diagnosis of PD
Size distribution and ion composition of aerosol collected at Ny-Ålesund in the spring–summer field campaign 2013
Characterization of PM10 sources in the central Mediterranean
The Mediterranean Basin atmosphere is influenced by both strong natural and
anthropogenic aerosol emissions and is also subject to important climatic
forcings. Several programs have addressed the study of the Mediterranean
basin; nevertheless important pieces of information are still missing. In
this framework, PM10 samples were collected on a daily basis on the
island of Lampedusa (35.5° N, 12.6° E; 45 m a.s.l.),
which is far from continental pollution sources (the nearest coast, in
Tunisia, is more than 100 km away). After mass gravimetric measurements,
different portions of the samples were analyzed to determine the ionic
content by ion chromatography (IC), the soluble metals by inductively
coupled plasma atomic emission spectrometry (ICP-AES), and the total
(soluble + insoluble) elemental composition by particle-induced x-ray
emission (PIXE). Data from 2007 and 2008 are used in this study.
The Positive Matrix Factorization (PMF) model was applied to the 2-year long
data set of PM10 mass concentration and chemical composition to assess
the aerosol sources affecting the central Mediterranean basin. Seven sources
were resolved: sea salt, mineral dust, biogenic emissions, primary
particulate ship emissions, secondary sulfate, secondary nitrate, and
combustion emissions. Source contributions to the total PM10 mass were
estimated to be about 40 % for sea salt, around 25 % for mineral dust,
10 % each for secondary nitrate and secondary sulfate, and 5 % each for
primary particulate ship emissions, biogenic emissions, and combustion
emissions. Large variations in absolute and relative contributions are found
and appear to depend on the season and on transport episodes. In addition,
the secondary sulfate due to ship emissions was estimated and found to
contribute by about one-third to the total sulfate mass. Results for the
sea-salt and mineral dust sources were compared with estimates of the same
contributions obtained from independent approaches, leading to an estimate
of the water content bound to the sea salt in the marine source
P2‐239: POTENTIAL DIAGNOSTIC VALUE OF RED BLOOD CELLS α‐SYNUCLEIN HETEROAGGREGATES IN ALZHEIMER'S DISEASE
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A social and ecological assessment of tropical land uses at multiple scales: the Sustainable Amazon Network
Science has a critical role to play in guiding more sustainable development trajectories. Here, we present the Sustainable Amazon Network (Rede Amazonia Sustentavel, RAS): a multidisciplinary research initiative involving more than 30 partner organizations working to assess both social and ecological dimensions of land-use sustainability in eastern Brazilian Amazonia. The research approach adopted by RAS offers three advantages for addressing land-use sustainability problems: (i) the collection of synchronized and co-located ecological and socioeconomic data across broad gradients of past and present human use; (ii) a nested sampling design to aid comparison of ecological and socioeconomic conditions associated with different land uses across local, landscape and regional scales; and (iii) a strong engagement with a wide variety of actors and non-research institutions. Here, we elaborate on these key features, and identify the ways in which RAS can help in highlighting those problems in most urgent need of attention, and in guiding improvements in land-use sustainability in Amazonia and elsewhere in the tropics. We also discuss some of the practical lessons, limitations and realities faced during the development of the RAS initiative so far.Keywords: Social–ecological systems, Tropical forests, Land use, Interdisciplinary research, Sustainability, Trade-off
One-million year Rare Earth Element stratigraphies along an Antarctic marine sediment core
Abstract
An integrated system, based on Inductively Coupled Plasma-Sector Field Mass Spectrometry (ICP-SFMS) and Inductively Coupled Plasma-Atomic Emission Spectrophotometry (ICP-AES) techniques, was optimised for the geochemical characterisation of soils and marine sediments. Sample mineralization was carried out with HF, HNO3 and HClO4. Operative blanks were at least two orders of magnitude lower than the lowest concentration measured in real samples. For ICP-SFMS, the detection power of the method in high resolution mode was sufficient for an accurate quantification of metals, yet avoiding REEs' (Rare Earth Elements) isobaric interferences. Once tested the accuracy on six certified materials, the methods were applied to the analysis of 39 major and trace metals on the top 90 m of sediments from the ANDRILL AND-1B core, covering the last million years.
Stratigraphies of REEs and of normalised markers from this core clearly highlight a discontinuity at about 660,000 years before present. This pattern is well shown by the results of a PMF (Positive Matrix Factorization) statistical analysis, revealing two different sources for the sedimentary material, whose relative contribution changed around that time. Such a result is consistent with previous studies and confirms the net change in the provenance of glacial fluxes in the McMurdo region (Ross Ice Shelf, Antarctica) in the last million years
Insights on nitrate sources at Dome C (East Antarctic Plateau) from multi-year aerosol and snow records
Here we present the first multi-year record of nitrate in the atmospheric aerosol (2005–2008) and surface snow (2006–08) from central Antarctica. PM10 and size-segregated aerosol, together with superficial snow, have been collected all year-round at high resolution (daily for all the snow samples and for most of aerosol samples) at Dome C since the 2004/05 field season and analysed for main and trace ionic markers. The suitability of the sampling location in terms of possible contamination from the base is shown in detail. In spite of the relevance of nitrate in Antarctic atmosphere, both for better understanding the chemistry of N cycle in the plateau boundary layer and for improving the interpretation of long-term nitrate records from deep ice core records, nitrate sources in Antarctica are not well constrained yet, neither in extent nor in timing. A recurring seasonal pattern was pointed out in both aerosol and snow records, showing summer maxima and winter minima, although aerosol maxima lead the snow ones of 1–2 months, possibly due to a higher acidity in the atmosphere in mid-summer, favouring the repartition of nitrate as nitric acid and thus its uptake by the surface snow layers. On the basis of a meteorological analysis of one major nitrate event, of data related to PSC I extent and of irradiance values, we propose that the high nitrate summer levels in aerosol and snow are likely due to a synergy of enhanced source of nitrate and/or its precursors (such as the stratospheric inputs), higher solar irradiance and higher oxidation rates in this season. Moreover, we show here a further evidence of the substantial contribution of HNO3/NOx re-emission from the snowpack, already shown in previous works, and which can explain a significant fraction of atmospheric nitrate, maintaining the same seasonal pattern in the snow. As concerning snow specifically, the presented data suggest that nitrate is likely to be controlled mainly by atmospheric processes, not on the daily timescale but rather on the seasonal one