Search results for " Sediment"
showing 10 items of 762 documents
Type V collagen-induced upregulation of capn2 (large subunit of m-calpain) gene expression and DNA fragmentation in 8701-BC breast cancer cells
2011
Abstract Type V collagen is known to be over-deposited in the stroma of ductal infiltrating carcinomas of the breast. When used as a substrate, type V collagen restrains growth and invasion, and affects gene expression of 8701-BC ductal infiltrating carcinomas cells. Here we supplement existing data by demonstrating type V collagen dependent upregulation of capn2 gene expression in 8701-BC cells through differential display-PCR and Western blot assays. Furthermore, we suggest that our data obtained by centrifugal sedimentation and electrophoresis strongly suggest a correlation between calpain overproduction and DNA fragmentation, since the incubation with calpain inhibitor partly reverts th…
IMPIEGO DEL RADIONUCLIDE 137CS PER LA STIMA DEI PROCESSI EROSIVI IN UN BACINO FORESTATO
2008
Il radionuclide cesio-137 (137Cs) è uno dei traccianti più utilizzati per stimare la perdita di suolo per erosione idrica. L'applicazione di questa tecnica alla scala di bacino richiede anzitutto l'acquisizione delle misure del radionuclide in punti distribuiti sulla superficie e l'utilizzo di modelli di conversione idonei a trasformare i valori di 137Cs in quantità di erosione netta o di deposito. La presente memoria si pone l'obiettivo di verificare l'affidabilità del modello di conversione esponenziale per stimare i processi erosivi in terreni interessati da coperture forestali. L'applicazione è stata condotta in un bacino sperimentale della Sila Greca per il quale sono disponibili alcun…
EXPERIMENTAL ANALYSIS OF RELATION BETWEEN COHERENT TURBULENT STRUCTURES AND BED-FORMS FORMATION
2008
The present paper describes an experimental investigation on the interactions between flow turbulence and sediment motion. During the experiments, detailed measures of flow velocity components have been carried out using an Acoustic Doppler Velocimeter (ADV). The occurrence of turbulent events (inward interaction, ejection, sweep and burst) has been verified through the conditioned quadrant analysis. The quantitative information about the spatial and temporal evolution of turbulent events has been obtained through the space-time correlations of the conditioned data. As the primary objective was to analyse how turbulent structures influence the bed-forms formation, the spatial scale of turbu…
COMPOSITION AND QUALITY OF FRESHWATER LAKE SEDIMENTS (BALVU AND PĒRKONU LAKES)
2019
Water quality, watershed basin and urbanization are key factors from the perspective of freshwater management; however, actual depth of waterbodies is often an overlooked element. Actual depth represents the overall depth of lake bed and depth of sediments. Some cases have been reported, where with increase of average depth of lake , it is possible to expect improvements of water quality when sediments are removed. If lakes are eutrophic, shallow, overgrown with macrophytes and contain high concentrations of biogenic elements water and lake ecosystem quality can be endangered. Removal of sediments can be an expensive procedure and also depends on the composition, structure, local conditions…
Chemical speciation of polycyclic aromatic hydrocarbons in sediments: partitioning and extraction of humic substances.
2010
The primary objective of this study was to examine the chemical speciation of polycyclic aromatic hydrocarbons (PAHs) found in sediments endowed with different characteristics. To achieve this purpose and because the nature of the sediments influences the distribution of PAHs, we have analyzed four different types of sediments. To study the role of organic matter in the sequestration of PAHs, we fractionated humic substances into humic acids and humin–mineral fractions. After their separation and purification, the humic components were examined for their sorptive reactivity by extracting them with organic solvents; these extracts were subsequently subjected to GC/MS analysis. Our results sh…
Polycyclic Aromatic Hydrocarbons in Sediments of Marine Coastal Lagoons in Messina, Italy: Extraction and GC/MS Analysis, Distribution and Sources
2004
The content of 21 polycyclic aromatic hydrocarbons (PAHs) has been determined in 16 samples of sediments collected from Ganzirri and Faro marine coastal lagoons in Messina (Italy). Analysis was performed by gas chromatography/mass spectrometry (GC/MS) in selected ion monitoring (SIM) mode. The total concentration of polycyclic aromatic hydrocarbons (PAHs) ranged from 74 to 5755 ...g/Kg of dry matrix. The resulting distributions and molecular ratios of specific compounds have been discussed in terms of sampling location and origin of organic matter. The results obtained show that levels of contamination are not homogeneous throughout the stations, while the relative distributions of PAH are…
Use of stable isotopes to investigate dispersal of waste from fish farm as a function of hydrodynamics.
2006
Stable isotopes were used to examine differential effects of fish farm waste on the water column and sediments. To achieve this objective, we chose 3 marine fish farms located along the coast of Sicily (Mediterranean Sea) as point-source disturbances, and a control area. The hypothesis that carbon and nitrogen isotope composition of particulate (POM) and sedimentary (SOM) organic matter varied with increasing distance (from cages to 1000 m) was tested at 3 levels of hydrodynam- ics: low (mean velocity of current (MVC) ~12 cm s -1 ), intermediate (MVC ~22 cm s -1 ), and high (MVC ~40 cm s -1 ). Different isotopic signals from allochthonous (fish waste) over natural (phytoplankton, terrigenou…
Influence of anthropogenic activity on the lead isotope signature of Thau Lake sediments (southern France): origin and temporal evolution
2000
Lead concentrations and isotopic compositions were determined on both bulk sediments deposited in the Thau lake in southern France during the last 200 years, and leachates derived from a series of sequential leachings of the sediments, making it possible to identify the sources, natural (i.e. indigenous lithologic) or anthropogenic, and to quantify the different inputs of Pb. Two distinct inputs of Pb could be distinguished. One of these corresponds to the terrigenous material entering the basin, representative of the local natural Pb ‘background’. Its supply remained steady most of the time with 206Pb/207Pb ratios of 1.200±0.003, except at the time of heavy storms producing voluminous and …
Orbitally induced limestone/marlstone rhythms in the Albian—Cenomanian Cismon section (Venetian region, northern Italy): Sedimentology, calcareous an…
1996
Abstract A multidisciplinary study of the upper Albian—Cenomanian portion of the Cismon section (Venetian region, northern Italy) was undertaken in order to characterize the cyclic alternations of carbonate-rich and carbonate-poor layers and to investigate their possible origin and cyclic patterns. Limestone semicouplets are characterized by abundant radiolarians and micarbs (micron-sized calcitic fragments), common planktonic foraminifera, strong bioturbation, good oxygenation as expressed by the Mn* and V/(V+Ni) parameters, high Si/Al ratio, low K/Al, in the absence of pyrite and organic matter. The marlstone semicouplets are, on the contrary, frequently laminated, rich in pyrite and orga…
Use of biological and sedimentation models for designing Peñíscola WWTP.
2004
This paper presents Peñíscola wastewater treatment plant design. Peñíscola is a tourist city in Castellón (Spain), whose population changes significantly between summer and the rest of the year. The design of the biological and settling treatment units has been confirmed by computer model simulations and provided for biological organic matter, nitrogen and phosphorus removal. Two different treatment schemes have been proposed in order to optimize the plant performance during both seasonal operations. During low-load season, the plant will be operated under extended aeration conditions, so further sludge stabilization will not be needed. During high-load season, the plant will be operated un…