Search results for " Heavy"
showing 10 items of 447 documents
Sometimes Sperm Whales (Physeter macrocephalus) Cannot Find Their Way Back to the High Seas: A Multidisciplinary Study on a Mass Stranding
2011
BackgroundMass strandings of sperm whales (Physeter macrocephalus) remain peculiar and rather unexplained events, which rarely occur in the Mediterranean Sea. Solar cycles and related changes in the geomagnetic field, variations in water temperature and weather conditions, coast geographical features and human activities have been proposed as possible causes. In December 2009, a pod of seven male sperm whales stranded along the Adriatic coast of Southern Italy. This is the sixth instance from 1555 in this basin.Methodology/principal findingsComplete necropsies were performed on three whales whose bodies were in good condition, carrying out on sampled tissues histopathology, virology, bacter…
Trace element accumulation and elutriate toxicity in surface sediment in northernTunisia (Tunis Gulf, southern Mediterranean)
2017
International audience; Metal concentrations in sediments were investigated in the Gulf of Tunis, Tunisia, in relation to anthropic activities along the Mejerda River and Ghar El Melh Lagoon, with effluents discharged into the gulf. Distribution of grain size showed that the silty fraction is dominant with 53%, while sand and clay averages are 34 and 12% respectively. Zn concentration increased in the vicinity of the Mejerda River while Pb was at its highest levels at the outlet of Ghar El Mehl Lagoon. Sediment elutriate toxicity, as measured by oyster embryo bioassays, ranged from 10 to 45% abnormalities after 24 h, but no relation was found between metal concentration and sediment toxicit…
Constraining the ship contribution to the aerosol of the central Mediterranean
2017
Particulate matter with aerodynamic diameters lower than 10 µm, (PM10) aerosol samples were collected during summer 2013 within the framework of the Chemistry and Aerosol Mediterranean Experiment (ChArMEx) at two sites located north (Capo Granitola) and south (Lampedusa Island), respectively, of the main Mediterranean shipping route in the Straight of Sicily. The PM10 samples were collected with 12 h time resolutions at both sites. Selected metals, main anions, cations and elemental and organic carbon were determined. The evolution of soluble V and Ni concentrations (typical markers of heavy fuel oil combustion) was related to meteorology and ship traffic intensity in the Straight of Sicily…
Occurrence of Antibiotic Resistance in the Mediterranean Sea
2022
Seawater could be considered a reservoir of antibiotic-resistant bacteria and antibiotic resistance genes. In this communication, we evaluated the presence of bacterial strains in seawater collected from different coasts of Sicily by combining microbiological and molecular methods. Specifically, we isolated viable bacteria that were tested for their antibiotic resistance profile and detected both antibiotic and heavy metal resistance genes. Both antibiotic-resistant Gram-negative bacteria, Vibrio and Aeromonas, and specific antibiotic resistance genes were found in the seawater samples. Alarming levels of resistance were determined towards cefazolin, streptomycin, amoxicillin/clavulanic aci…
Synthesis of Tetrasubstituted 4,4'-Biimidazoles
2012
Highly substituted 4,4'-biimidazoles were synthesized, in good to excellent yields, through a multicomponent imidazole ring synthesis by using imidazol-4-yl-ethane-1,2-diones as starting materials. The obtained compounds were preliminarily tested as chromogenic and fluorescent sensors for heavy metals.
Role of calcium carbonate in the process of heavy metal biosorption from solutions: synergy of metal removal mechanisms.
2022
AbstractThe effect of calcium carbonate on the removal efficiency of cations of the selected heavy metals Cu, Zn and Pb from aqueous solutions using various biosorbents (BS) was investigated under laboratory static conditions. The main mechanism of biosorption of heavy metal cations is ion exchange, whereas the reaction with calcium carbonate results in precipitation of poorly soluble carbonates and hydroxides of the examined heavy metals. Studies conducted under static conditions have shown that the effect of Cu and Zn cations removal from solutions is better when using a mixture of BS and CaCO3 as compared to the effect of process, in which these two components were used separately. Remov…
Trends and potential human health risk of trace elements accumulated in transplanted blue mussels during restoration activities of Flekkefjord fjord …
2022
AbstractThe monitoring of contaminants represents a priority to preserve the integrity of marine ecosystems, as well as to plan and to manage restoration activities in order to protect environmental and human health. In the present study, a 6-months active biomonitoring was performed to explore the levels of eighteen trace and toxic elements, including heavy metals (TEs; i.e. Al, As, Ca, Cd, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Sr, Ti, and Zn), accumulated in soft tissues of blue mussel (Mytilus edulis Linnaeus, 1758) individuals transplanted at different depths (5- and 15-m depth) in five locations within the Flekkefjord fjord (Southern Norway). As this area suffered a long-lasting co…
Zvaigžņotā Debess: 2018, Vasara (240)
2018
Jauna hipotēze par I tipa pārnovu izcelšanos ; No 108 minūtēm līdz 96 dienām ; Maiņzvaigznes (astronomija skolā) ; O.Dumbrājs. Nēteres teorēmai 100 gadu ; K.Švarcs. Jauni novērojumi tālā un tuvā kvazārā ; I.P. Īsumā: ALMA un VLT iegūst liecību par zvaigžņu veidošanos tikai 250 miljonus gadu pēc Lielā Sprādziena ; I.Pundure. Lagūnas miglājs – zvaigžņu bērnistaba Habla skatījumā ; I.Pundure. ALMA un APEX atklāj veidojošos galaktiku megasaplūšanu agrīnajā Visumā ; K.Salmiņš. LU Astronomijas institūts pirmais veicis nanopavadoņa S-NET lāzermērījumus ; J.Jaunbergs. Zeme atpakaļskata spogulī ; J.Jaunbergs. Sniegotā Helēne un mazais Polideiks ; R.Misa. Latvijas uzņēmums Eventech piedalīsies Luna-2…
Improving the Design of Ion Track-Based Biosensors
2018
In the last decade we had developed new types of biosensors, by cladding the inner walls of transparent etched swift heavy ion tracks in thin polymer foils with enzymes. The enzymatic reaction products of appropriate analytes penetrating into narrow tracks are enriched in the track’s confinement, and they change the electrical track properties if their charge states differ from those of the analytes. It was yet unknown how to design these sensors so that their best efficiency and highest possible sensitivity is achieved. This requires the accurate knowledge of the optimum track radius and the degree of product enrichment within the tracks. These questions were answered by appropriate experi…
Effect of in vitro exposure to cadmiumand copper on sea bass blood cells
2009
Blood cells freshly collected from sea bass (Dicentrarchus labrax) were exposed in vitro to different concentrations of cadmium (Cd) and copper (Cu) at 10-7 M, 10-5 M, 10-3 M, and exam- ined for neutral red retention capacity and for cell vitality with MTT assay. A relationship between heavy metal exposure and alteration in responses of blood cells in a dose-time-dependent was found. Our results showed that fish blood cells may constitute an interesting biological model for experimen- tal and applied toxicology, especially in the case of environmental pollution.