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An endocannabinoid-like system regulates neuronal responses to nicotine in the mesolimbic system: role of N-acylethanolamines and nuclear PPAR-a receptors
Get PDFEffetti dell'isolamento sociale sull'assunzione di etanolo e sulla plasticità neuronale del recettore GABA_a nell'ippocampo di topi C57BL/6J
Get PDFDinamica di popolazione di Ruditapes Decussatus (L) e insediamento di Rudutapes Philippinarum (Adams&Reeve) in Sardegna (Italia)
Get PDFRuditapes decussatus is a traditional resource of fishing activity in Sardinia Island. This species is not cultured, but fishermen picked them up from the bottom of brackish areas.
The distribution and the population structure of Ruditapes decussatus were investigated in six coastal lagoons: Tortolì (OT) S. Giovanni Santa Gilla (CA), Marceddì, Corru S’ittiri (OR), Calich (SS) and in the Olbia gulf. In this last site were also studied the growth and the mortality. In the same area, during the study the settlement of the allochthonous species Ruditapes philippinarum was found, so the population structure of this bivalve mollusc was also studied.
The samplings were seasonally, started in autumn 2008 and finished in summer 2009. Ruditapes were collected using a shellfish rake in different stations for each site (five
repetitions for each of 29 sampling stations). In spring was also collected the sediment in all stations.
With regard to Ruditapes decussatus, the analysis of density demonstrates a highly heterogeneous situation in the different sites. The maximum of density was measured at
San Giovanni (CA), where it has reached 1,315 *m-2 specimens. In the same site, the maximum of density (considering the average between the repetition in each station) was reached equal to 507 * m-2 specimens in summer. This value is close to that observed in the Olbia Gulf and Corru s' Ittiri lagoon in spring. In other sites densities were lower, but the maximum always corresponded to spring or summer, except Marceddì (OR) where the maximum value was detected in the winter sampling. In this case, the excessive rainfall caused very low salinity and the death of almost all Ruditapes in the lagoon.
Also the population structure was very heterogeneous in the sites. The length frequency distribution (oro-aboral length) was statistically different for at least two seasons for all comparisons (χ2 test, P<0,01). The main reason of this difference is the recruitment, very
different among the sites. In all lagoons, except Calich (SS) and Marceddì (OR), the recruitment was evident in spring and often has continued even in the summer. San
Giovanni (CA) was the only case where specimens of shell length below 15 mm were recorded during all year. Several nursery areas were found in different sites. A station of
the Olbia Gulf presented the highest densities of juveniles found during the study (487±368 * m-2 specimens). The cause of this variability, in addiction to the different fishing effort, was the recruitment, which impacted heavily on the distribution and density of juveniles.
The growth of Ruditapes decussatus in the Olbia Gulf has been studied for each station because the analysis of the entire sample did not make possible the identification of
different age groups. The estimates for the Von Bertalanffy model show that growth rates were marginally different in the stations. The function obtained with the average of
parameters in the different station are: K=0.68 ±0.07, L∞ =47.02±4.32 mm, to= -0.17±0.11.
The shell length- high (h= 0.6805*l 0.9853) and length-thickness (s = 0.3876*l 1.1176) relationship has shown a growth not perfectly linear.
The mortality function for the Ruditapes decussatus in the Olbia gulf is N(t+1)=204.27* e (-1.3509 t).
The sediment in all sites was mainly sandy. The granulometry of sites was statistically different for all comparisons (χ2 test, P<0,01). A univocal correlation between density of Ruditapes decussatus and granulometry was not found while exist, in the Olbia Gulf, a strong significant negative correlation between the fraction “fine silt” and the growth constant K.
Ruditapes philippinarum was found in S. Gilla lagoon and in the Olbia gulf. In this site it has reached 19% of the total number of two species. In the gulf Ruditapes philippinarum is distributed everywhere but not in all seasons; the density and the shell length are
statically different in the sampling stations except in winter (Kruskall-Wallis test P<0,01).
The maximum of density for station was 106±83 specimens in spring. The jouveniles below 15 mm were present mainly in spring and summer, especially in a river mouth.
The research has picked out the good situation of Ruditapes decussatus in Sardinia island in respect to other countries were Ruditapes philippinarum has almost replaced Ruditapes
decussatus. The settlement of Ruditapes philippinarum in some Sardinian sites need some precaution because the allochthonous species are not diffused to avoid a dangerous
competition against the autochthonous species
Degradation of Refractory Organic Compounds in Aqueous Wastes employing a combination of biological and chemical treatments
Get PDFIn this study the removal of refractory organic compounds (ROCs) in
Aqueous Wastes (AW) employing a combination of biological and chemical
treatment were investigated at Department of Chemical Engineering and
Materials Science, University of Cagliari, Italy and Department of Engineering,
Oxford University, UK.
The main objectives were to stimulate and optimise the degradation of
ROCs with efficient removal of them in AW. This project is divided in two
sections, a theoretical section which included a brief literature overview and
subsequently an experimental section which is divided in two parts.
The first part deals with the solubilisation and biodegradation of polycyclic
aromatics hydrocarbons. Phenanthrene was selected as model pollutant in this
study which was solubilised in synthetic aqueous wastes using the mobility
agents like surfactants (Tween80, Triton X100), or organic solvents (Methanol,
Acetone, n-Hexane) and aerobic bacteria mixed cultures.
The second part deals with the degradation of Metal Working Fluids MWFs
in real aqueous wastes employing biological and chemical treatments. Chemical
and/or biological treatments are usually used to destroy the refractory
compounds. The MWFs aqueous waste were provided by Microbial Solution,
Oxford (UK).
The systems used for investigation consist of batch reactors using an aerobic
mixed pure cultures for biological treatment and oxidants, potassium permanganate
KMnO4 and hydrogen peroxide H2O2 for a chemical oxidation treatment.
Results show the influence of both the refractory compounds and
recalcitrant intermediaries on systems
Interazioni trofiche tra Condroitti in Mediterraneo
Get PDFChondrichthyans play an important ecological role, they tend to be high in the food web being
very often predators at the top of marine food webs (Cortés, 1999; Ebert e Bizzarro, 2007). Sharks and
rays appear to be particularly vulnerable to over-exploitation because of their K-selected life-history
strategy (Cailliet et al., 2005). Therefore, given that the consequences of their intense exploitation could
be very dangerous, many authors have stressed their vulnerability (Bonfil, 1994; Cahmi et al., 1998;
Stevens et al., 2000; Fowler & Cavanagh, 2005) and the importance of their protection (Fowler &
Cavanagh, 2005), unfortunately not so effective (Cavanagh e Gibson, 2004).
Currently, many efforts are made in order to clarify and to better understand the functioning of
marine ecosystems, for the purpose of an enhanced management. An exhaustive study of feeding habits
and trophic interactions between species is required to obtain this information (Stevens et al., 2005),
nevertheless data from literature regard a limited number of species.
All that has provided the opportunity to undertake the analysis of feeding habits and trophic
relationships between all the Chondrichthyans caught in Sardinian waters by trawler, in order to
provide an overall view about the interactions that rule the funtcioning of marine ecosystems and
energetic exchanges. Moreover, for the purpose of a better management, we have assessed the fishing
impact on this important taxonomic group.
All of these aims were obtained through stomach content analysis of all the species caught in
the course of three years of study, taking into account some important factors as sex, size and depth
that could influence the diet. Intraspecific and interspecific niche overlap, Trophic index and its trend
were also determined in order to assess state of exploitation of Chondrichthyans.
We analyzed the diet of 27 species M. punctulatus and D. nidarosiensis are new records for
Sardinian waters and Mediterranean Sea respectively.,Among these, 14 species were caught occasionally
or presented a high percentage of empty stomachs, so it was possible to provide only a preys list.
Generally, some similarities could be noticed between all the species. The niche breadth was
larger in the specimens caught at the deepest strata, likely due to their adaptation to oligotrophic
conditions, characteristic of the deepest habitats.
With variable proportions species prey on Crustaceans, Teleosts and Cephalopods, and minorly
on Chondrichthyans too. Two distinct way of feeding, deeply influenced by body morphology. Batoids prey mainly on benthopelagic and benthic organisms, while shark-like species prefer nectonic preys or
organisms more swimming prone.
A few number of preys, characterized by a great abundance in the habitats that inhabit,
represent the core of the diet of all the analyzed species. Mysids, like Gastrosaccus sanctus and Lophogaster
typicus, Brachyurans of the genus Liocarcinus sp, Natantians as Solenocera membranacea, Pasiphaea multidentata
and P. sivado, the euphausiid Meganyctiphanes norvegica and the Cefalopods belonging to the family
Sepiolidae (mainly Heteroteuthis dispar) are the most representative. Moreover, teleostes like
Gymnammodytes cicerelus and Glossanodon leioglossus are exploited by some species.
Ontogenetic variation in feeding habits were noticed: in general small specimens eat small preys,
especially benthic ones (crustaceans, small teleosts and sepiolids). With the growth preys bigger and
more swimming prone become more important in the diet of all the species. Similarly, trophic index
values increase with the growth, maintaining low levels of competition between species and improving
survival rate of juveniles.
Speaking generally, trophic level increase for species that prefer pelagic preys. No differences in
trophic spectrum were observed among sexes that, in fact, are characterized by a high value of niche
overlap.
The analysis of the diet in function of depth does not show any significant difference, except
for species that present a different bathymetric segregation. Niche overlaps analysis points out a greater
interspecific competition between specimens of the deepest strata. These environments are
characterized by oligotrophic conditions that lead to an intensive exploitation of a limited number of
preys, thus maximizing the overlap between diets.
Marine trophic index, estimated for MEDITS target species from 1994 to 2010, showed an
increasing trend, probably related to the change in the Sardinian fishing fleet occurred at the beginning
of the nineties.
Marine trophic index for Chondrichthyans remained stable until 2001, then oscillated and,
finally, tended do decrease slightly.
The study allowed to discover a complex web of trophic interactions. Some results disagree
with those reported in literature, indicating the existence of a big variety, also within the same species,
related to geographical differences. More studies would be necessary to extend knowledge about the
interactions that control the functioning of the ecosystems and to prevent the decline of this taxon,
avoiding the negative effects of its loss.
The final aim will be to provide appropriate management measures very soon, in order to
ensure the protection of Chondrichthyans
L'Italia del secondo dopoguerra attraverso i cinegiornali della "Settimana Incom" (1946-1948)
Get PDFCaratterizzazione dei lipidi in matrici alimentari
Get PDFLa caratterizzazione della frazione lipidica di un alimento comporta diversi passaggi: l’estrazione del grasso dalla matrice, la derivatizzazione, la separazione degli acidi grassi e la loro identificazione e quantificazione. Dall’esito dell’estrazione dipende la qualità del risultato di tutte le analisi successive volte a caratterizzare i lipidi estratti.
L’obiettivo del lavoro è stato quello di confrontare, su carne d’agnello, i principali metodi di estrazione della materia grassa, valutando le performance relativamente alla capacità quantitativa di estrazione e alla composizione acidica delle varie classi lipidiche. Le tecniche analitiche utilizzate nella prima parte del lavoro sono state applicate per determinare le caratteristiche nutrizionali della carne d’agnello prodotta da differenti genotipi con diversi regimi alimentari.
I dati hanno confermato che non esiste un metodo di estrazione “migliore” degli altri. In particolare, le maggiori rese in frazione lipidica sono garantite dai metodi Folch e Folch modificato. La separazione cromatografica (SPE) ha evidenziato che la frazione lipidica estratta con il metodo Hara-Radin contiene una più alta percentuale in frazione apolare. L’estrazione con cloroformio/metanolo ha permesso di ottenere un estratto lipidico con un contenuto in fosfolipidi più elevato rispetto alla miscela esano/isopropanolo.
I risultati ottenuti nella seconda parte del lavoro hanno mostrato che il regime alimentare cui sono stati sottoposti gli agnelli pesanti incrociati (razza Sarda * Ile de France) non ha influito sulle caratteristiche chimiche della carne. La composizione acidica del grasso intramuscolare degli agnelli pesanti incrociati è stata fortemente influenzata dal tipo di alimentazione. Gli agnelli che venivano allattati dalle madri e gli agnelli alimentati al pascolo hanno presentato un profilo acidico molto simile. Da un punto di vista nutrizionale la carne di questi due gruppi di agnelli è risultata migliore rispetto a quella degli agnelli alimentati con fieno di medica e concentrato.
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The characterization of the lipid fraction in food involves several steps: the extraction of fat from the matrix, derivatization, separation of fatty acids and their identification and quantification. The outcome of the extraction affects the quality of all the subsequent analysis aimed to characterize the lipids extracted.
The aim of this study was to compare different methods for lamb meat lipid extraction, evaluating the performances of quantitative capacity of extraction and of fatty acid composition in various lipid classes. The analytical techniques used in the first part of the work were applied to determine the nutritional value of lamb meat produced by different genotypes with different diets. The data confirmed that the best method of extraction doesn’t exist. In particular, the higher yields in the lipid fraction are guaranteed by Folch and modified Folch methods. Chromatographic separation (SPE) has shown that the lipid fraction extracted by the Hara-Radin method contains a higher percentage in non-polar fraction. We obtained a higher phospholipid content using a chloroform/methanol mixture instead of hexane/isopropanol mixture.
The results obtained in the second part of the work show that the chemical characteristics of meat in heavy cross lamb (Sarda x Ile de France) are not affected by the different diet with which the animals were fed. On the contrary, the acid composition of intramuscolar fat in heavy cross lamb is strongly influenced by diet. Lambs fed by their mothers and lambs fed on pasture had a very similar fatty acid profile. From a nutritional point of view the meat of these two groups of lambs has a higher quality than the meat of lambs fed with alfalfa hay and commercial concentrate
Reaction-Diffusion Processes on Complex Networks
Get PDFThe availability of an unprecedented amount of large-scale data sets has allowed to discover complex features in many real-world networks. This boosted the attention on complex networks in di�erent disciplines: Mathematics, Medicine, Biology, Social Sciences, Computer Sciences and Physics. Recently, a lot of attention has been devoted to the study of dynamical processes occurring on complex networks.
In this work we focused on the general framework of Reaction-Di�usion models on complex topologies. Using this approach we discussed two di�erent problems.
The �rst one is based on the evaluation of the importance or centrality of nodes. In heterogeneous networks not all the nodes are the same. To sort out the di�erences is a relevant problem in data retrieval, biology and in general infrastructure management.
The relative importance of units is not just a local feature. The centrality of a node is in fact related to the importance of the nodes that are connected to it and so on. Therefore we have a di�usion process, the di�usion of importance, which is encoded in the spectral properties of several kinds of matrices. Spectral centrality measures are accordingly de�ned and new results and the interpretations of these measures on directed, undirected and real networks are presented.
The second problem discussed within the same framework is the epidemic spreading in homogeneous and heterogeneous networks. This is an extremely relevant problem for our society as demonstrated by the last H1N1 pandemic in 2009. Complex networks analysis is crucial to get enough insight on the epidemic processes to suggest efficient interventions policies and make forecasts. We introduced the general theory of epidemic spreading on networks. We presented new single population models in order to deal with the e�ects of social disruption due to the epidemic di�usion itself.
We discussed the framework of metapopulation network models in which each population is considered as a node of a network. The populations are coupled by di�usion of individuals. Markovian di�usion is �rst considered and all the known results are reproduced and derived. A more realistic protocol considering origindestination
matrices is introduced and analytically solved.
In the last chapter we show how these models can be used in order to build a realist data driven model, GLEaM, which is a powerful tool to make global epidemic forecasts.
The use of this model during the recent H1N1 pandemic is described and all the new methods and results obtained are discussed in detail