Search results for "RACE"

Volatile components from aerial parts of Centaurea gracilenta and C. ovina ssp. besserana growing wild in Bulgaria

2011

The essential oils of Centaurea gracilenta Velen. (CG) and C. ovina Pall. ex Willd. ssp. besserana (DC.) Dostál (COB) growing wild in Bulgaria, were studied by GC and GC-MS. Forty-five compounds for CG, representing the 90.1% of the oil, and 68 compounds for COB, representing the 91.9% of the oil, were identified. The oils were rich in sesquiterpenoids (33.4% for CG and 27.3% for COB), hydrocarbons (28.3% for CG and 10.7% for COB) and carbonylic compounds (12.7% for CG and 13.1% for COB). Fatty acids were abundant only for COB (31.3%). beta-Eudesmol (12.8%), nonacosane (11.8%) and p-vinyl guiacol (7.5%) were recognized as the main constituents for CG, while hexadecanoic acid (21.4%), spathu…

Volcanic signature of volatile trace elements on atmospheric deposition at Mt. Etna, Italy

2009

Volcanic volatiles and aerosol emitted into the atmosphere ultimately fall on the Earth’s surface as wet or dry deposition, and they can influence the environment and the ecosystems at local and regional scales. Therefore, atmospheric deposition plays a key-role in the geochemical cycles, redistributing volcanogenic elements to the ground. For this reason, estimating the volcanogenic trace element fluxes from the atmosphere to the surface is necessary for a better knowledge of the environmental impact of the volcanic emissions. Nevertheless, from a literature review, we have recognized the scarcity of investigation on trace element deposition in the surroundings of active volcanoes. Here, w…

Impact of Volcanic Emissions on Trace Elements Contents Measured in Endemic Plants at Mt. Etna (Italy)

2011

TRACE ELEMENT BEHAVIOUR IN SEAWATER DURING PYROCLASTIC ETNA'S ACTIVITY IN 2001. CONCURRENT EFFECTS OF NUTRIENTS AND FORMATION OF ALTERATION MINERALS

2010

From July 13 2001 began the most intense Etna's eruptive activity in the last 300 years. While this phenomenon occurred the oceanographic cruise ANSIC 01 was carrying out. Therefore the unique opportunity is arisen to investigate the chemical effects on marine system of delivery of large amount of pyroclastic particles (about 1 g m-2) into seawater. Comparing collected trace element data with those analysed during the oceanographic cruise JUVENILE 99, carried out two years before, large enrichments in V, Cr, Mn, Fe, Co, Cu and Pb contents have been recognised and attributed to leaching of freshly-erupted volcanic ash. Further comparison between to-day and previous collected trace element da…

The Cycle of volcanogenic trace elements at Mt Etna (Italy): From volcanic emissions to atmospheric deposition

2009

Volcanogenic particulates and gases from Etna volcano (Italy)

2014

Volcanic emissions represent one of the most relevant natural sources of trace elements to the troposphere. Due to their potential toxicity they may have important environmental impacts from the local to the global scale and they can severely affect the atmospheric and terrestrial environment also at timescales ranging from a few to million years. Etna volcano is known as one of the largest global contributors of magmatic gases (CO2, SO2, and halogens) and particulate matter, including some toxic trace elements. The aim of this study was to characterize the chemical composition and the mineralogical features of the volcanogenic aerosol passively emitted from Mt. Etna. Nine samples were coll…

Geochemistry and isotope composition (Sr, Pb, δ66Zn) of Vulcano fumaroles (Aeolian Islands, Italy)

2018

We present and discuss temperatures, major and trace element gas geochemistry, radiogenic isotopes (Pb, Sr) and the first Zn isotope data of fumarole condensates and altered rocks from the Vulcano fumarolic field. The fumaroles of the La Fossa cone, sampled on 5th May 2015, have temperatures ranging between 233 and 427 °C. They plot compositionally on the mixing trend between the magmatic and hydrothermal end-members defined by previous studies, but are strongly displaced towards the hydrothermal component. Correlations of radiogenic (Sr, Pb) and stable isotopes of Zn with δ13CCO2 and several trace elements of the fumarolic acid condensates support mixing between the above mentioned distinc…

Geochemistry of Chromian Spinels from the Indo-Myanmar Ophiolite Belt of Northeastern India

2015

Chromite is commonly used for deciphering the petrogenesis and geodynamic setting of ultramafic rocks. Chromespinels from the Indo-Myanmar ophiolite belt occurring in the form of podiform chromitites associated with the mantle sequence and associated volcanic rocks are studied to characterise their geochemical composition. We have measured major and trace element concentrations of the chrome-spinels. Cr/(Cr+Al) (Cr#) and Mg/(Mg+Fe 2+ ) (Mg#) range from 66 to 70 and 66 to 69 respectively in the chromitite and 47 to 56 and 67 to 70 in volcanic spinel. The computed crystallization conditions show that the studied samples crystallized in an upper mantle environment. Using the chrome spinel comp…

Metallic nanoparticle enrichment at low temperature, shallow CO2 seeps in Southern Italy

2012

We report on metal enrichment along a natural pH gradient owing to increased CO2 degassing at cold, shallow seeps of Vulcano Island in the Mediterranean Sea, off Sicily. We assessed composition of unfiltered and filtered seawater (<100 nm) along acidic zones ranging between ambient and pH 5, and showed that most seep derived elements are present as nanoclusters which then aggregate into larger colloids while mixing with ambient seawater along a pH gradient. Size and elemental composition of such naturally occurring nanoparticles assessed by modern characterisation methods were in good agreement with the results from conventional analytical methods. We provide analytical evidence for the pre…

Anti-inflammatory Function of High-Density Lipoproteins via Autophagy of IκB Kinase

2015

Background & Aims: Plasma levels of high-density lipoprotein (HDL) cholesterol are frequently found decreased in patients with inflammatory bowel disease (IBD). Therefore, and because HDL exerts anti-inflammatory activities, we investigated whether HDL and its major protein component apolipoprotein A-I (apoA-I) modulate mucosal inflammatory responses in vitro and in vivo. Methods: The human intestinal epithelial cell line T84 was used as the in vitro model for measuring the effects of HDL on the expression and secretion of tumor necrosis factor (TNF), interleukin-8 (IL-8), and intracellular adhesion molecule (ICAM). Nuclear factor-κB (NF-κB)-responsive promoter activity was studied by …