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Le ulteriori dimensioni della politica comunitaria per la coesione economica, sociale e territoriale
No full textLo scopo del paper è quello di dimostrare che il rilievo della politica comunitaria di coesione è cresciuto anche in termini demografici e territoriali, in seguito all'allargamento dell'Unione europea, tanto da superare quello misurato in termini economico-finanziari.
Avvalendosi di dati ufficiali si effettua una puntuale ricostruzione dell'andamento fatto registrare dalle diverse "dimensioni" di tale politica dal suo avvio (1975) fino al periodo di programmazione 2007-2013 attualmente in corso
PCBS AND ORGANOCHLORINATED PESTICIDES IN EELS (ANGUILLA ANGUILLA L.) FROM THE PO DELTA.
No full textEels (Anguilla anguilla L.) live in the brackish waters vallis of the Mediterranean, where the elvers enter the lagoons and estuaries and grow in the sheltered areas, feeding on natural food available in the bottom sediments. Eels are therefore exposed to persistent pollutants, such as polychlorinated biphenyls (PCBs) and organochlorine pesticides. These lipophilic xenobiotics tend to accumulate in high concentrations in this species because of its considerable fat amount. Alarming concentrations form heavily polluted areas have been reported in eels; for example, 91% of this species of fish from the lower Elbe River contained levels exceeding the regulatory limits. Moreover, studies from the river Rhine have suggested that the high levels of organochlorine residues found in eels, are due to biomagnification through the food chain. PCBs and chlorinated pesticides have also been detected in different species of fish in the final stretch of the River Po, which is considered a land based source of pollution in the Adriatic Sea. In order to find out whether contamination by PCBs and organochlorine pesticides in the Po Delta poses a risk to human and animal health, studies on the content of the above pollutants in eels were carried out. Twenty eels of 548 +- 126 g weight and 43 +- cm length, were caught twice a year, in March and October 1994. Fish muscles were homogenized in a mixer and freeze-dried. A 30 g sample of the above mixture was dissolved in 20 ml of acetonitrile and placed in an ultrasonic bath for 5 minutes. After sedimentation the supernatant was centrifuged at 1400 rpm for 10 minutes, following which the volume was reduced by means of a rotavapor to about 5 ml and the resulting extract passed through a liquid chromatography LC-18 (octadecyl) column in order to remove lipids and hydrocarbons. Subsequently, this extract was passed through a LC-NH2 (aminopropil) column to remove polar substances such as amines and organic acids and then it was further concentrated under a gentle stream of N2 at room temperature. A gas chromatography-mass spectrometry (Hewlett Packard 5890 GC with a 5989 mass selective detector) equipped with a fused silica capillary column (Alltech SE 30 m x 0.25 mm) was used for the quantification of the pesticides. The operating conditions were as follows: injection port temperature 260 °C, column initial temperature 100 °C, rate of temperature increase 10 °C/min. With a final temperature of 300 °C, helium was used as the carrier gas (25 cm/sec at 200 °C). The mass spectrometer was used in SIM mode (Selected Ion Monitoring) under the following conditions: electron energy 70 eV, source temperature 200 °C, quadrupole temperature 100 °C, electron multiplier voltage 2200 V. The SIM programmes used for the analysis of chlorinated pesticides and PCBs were selected to enable the simultaneous determination of more than fifty compounds. Confirmation and quantification of the various pesticides and PCBs, were carried out by comparison with standard of 99-100% purity (Cambridge Isotope Lab., Woburn, MA, USA). The levels of pollutants found in fish muscle demonstrate the continuing presence of p,p’-DDT (4.16 +- 0.76 μg/kg dry weight) and some metabolites (p,p’-DDE and p,p’-DDD) although it has been banned in Italy since 1978. Contamination with other organochlorinated pesticides was significant, whereas for PCBs high values were found (23.80 +- 8.15 μg/kg dry weight). However, this levels do not present risk for the survival and normal development of fish living in this area. Therefore, there is no real health hazard for people consuming eels caught in waterways form the River Po
PCBS AND ORGANOCHLORINATED PESTICIDES IN EEL (ANGUILLA ANGUILLA L.) FROM THE PO DELTA.
No full textPolychlorinated biphenyls (PCBs) and organochlorinated pesticides were extracted from samples of muscle from eel (Anguilla anguilla L.) caught in the Po Delta and determined by fused silica capillary gas chromatography/mass spectrometry (GC/MS). The main compound identified were polychlorinated biphenyls, HCB, p,p’-DDT and its metabolites, p,p’-DDE and p,p’-DDD. PCB and DDT concentrations were higher in eel captured in spring than in those fished in autumn and were correlated with fat concentrations in muscle tissue. Mean PCB levels were 265 +- 9 and 211 +- 6.9 microg/kg wet weight, and those of DDT compounds 18.45 +- 12.7 and 15.76 +- 10.6 microg/kg wet weight, respectively. They were also higher than those determined in other species of fish captured in the same body of water, although the data indicate that there is probably no real health risk from irregular consumption of eel containing these xenobiotic concentrations
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
CONCENTRATIONS OF LEAD, MERCURY AND CADMIUM IN TWO SPECIES OF FRESHWATER FISH RAISED IN TEMPERATURE-CONTROLLED WATER TANKS: IMPLICATIONS FOR HUMAN DIET.
No full textIt is known that the bioaccumulation process in fish is influenced by temperature, water-hardness and diet. Particularly, the use of warm water such as that coming from a power station plant after cooling in vapour condensers, besides enhancing the growth of fish, could facilitate accumulation process of xenobiotics with increasing health hazard for human consumers. The concentrations of three heavy metals (Pb, Hg and Cd) were determined in two species of freshwater fishes, the sturgeon (Acipenser naccarii) and the carp (Cyprinus carpio) raised in thermal aquaculture using water from the river Po. One hundred fishes with an initial weight of about 80 g each fed on wet pellets (3% of live weight) and bred for two years at a temperature ranging form a minimum of 15 °C in the winter and a max of 25 °C in the summer. Every three months five fishes were sacrificed and the three elements were determined by AAS in muscle samples. After 24 months of breeding, the following mean levels (mg/kg dry weight) of heavy metals were detected in the muscles of the sturgeon and the carp, respectively: 1.89 +- 1.2 and 1.52 +- 0.6 of Pb; 0.73 +- 0.3 and 0.41 +- 0.2 Hg; 0.26 +- 0.1 and 0.10 +- 0.06 of Cd. Interestingly, the metal concentrations found in these fishes were about ten times lower than in wild ones living of the river Po, in spite of the same aquatic environment. Therefore, the results suggest that the use of the cooling water form thermoelectric plant for aquaculture is a highly efficient system. In fact, it allows considerable fish growth in short time but reducing the bioaccumulation of the heavy metals, so that the raised fish can be considered suitable for human consumption
ACCUMULATION OF TRIBUTYLTIN CHLORIDE BY CARP (CYPRINUS CARPIO L.).
No full textIn these last twenty-five years, tributyltin compounds (TBTs) have been widely used as successful system for the control of growth of fouling organisms on structures submerged in aquatic environment. The TBT compounds are highly toxic to aquatic organisms. The aim of the present work was to evaluate possible uptake of tributyltin chloride (TBTC) by carp (Cyprinus carpio L.) and the subsequent accumulation in organs and tissues. Two groups of 15 fishes of about 1 kg each were fed on wet pellets (3% of live weight) contaminated for one week by TBTC 25 mg/kg and 100 mg/kg, respectively. TBTC levels were measured by high resolution gas chromatography coupled with low resolution mass spectrometry. The concentrations were the highest in kidney and liver, whereas in the brain were less than one filth of renal values. On the other hand, low levels were found in the muscle tissue. However, we believe this represents a great risk for human health through dietary uptake, because TBTs are immunotoxic substances
ACCUMULATION OF ORGANOTIN COMPOUNDS IN MUSSELS FROM NORTHERN ADRIATIC COASTS.
No full textA rapid method (fused silica capillary GC/MS) was developed for quantitative analysis of organotin compounds in mussel tissues and sediments. Samples were homogenized with n-hexane and organotin compounds were pentylated via the Grignard reaction in ethyl ether. Recoveries of organotin compounds were 85-98% from both mussels and sediments samples. High concentrations of TBT were found in sediments from Ravenna harbour, while levels in mussels were generally lower. These preliminary determinations represent the first comparative monitoring of TBT in both types of samples collected in the marine environment of the Northern Adriatic
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