1359 research outputs found
Sort by
Oligodeossinucleotidi nativi selettivamente attivi in vitro contro il virus dell'immunodeficienza umana di tipo 1: ruolo del G-quartet
Get PDFAmong a series of unmodified phosphodiester (PO)-oligodeoxynucleotides (PO-ODNs) complementary to some of human immunodeficiency virus type 1 (HIV-1) regulatory genes, several PO-ODN sequences complementary to the vpr gene (POODNs-α-vpr, where a-vpr is the antisense vpr sequence) emerged as potent inhibitors(at concentration of 0,8 to 3,3 μM) of HIV-1 multiplication in de novo infected MT-4 cells, while they showed no cytoxicity for uninfected cells at concentration up to 100 μM. Unlike phosphorothioate counterparts, PO-ODN-α-vpr sequences were not inhibitory to HIV-2 multiplication in de novo infected C8166 cells and neither prevented the fusion between chronically infected and bystander CD4+ cells nor inhibited the activity of the HIV-1 reverse transcriptase in enzyme assays. Moreover, they were not inhibitory to HIV-1 multiplication in chronically infected cells. Delayed addition experiments showed that PO-ODNs-α-vpr inhibit an event in the HIV-1 replication cycle following adsorption to the host cell, but preceeding reverse transcription. Structure-activity relationship studies indicated that antiviral activity of the test PO-ODN-α-vpr sequences
is not related to the antisense mechanism but to the presence, within the active sequences, of contiguous guanine residues. Physical characterization of the test POODNs suggested that the active structure is a tetramer stabilized by G quartets (i.e., four G residues connected by eight hydrogen bonds)
Studio dell'attività antiossidante di estratti da piante della flora sarda
Get PDFThe present work was carried out to study the effect of some plant methanol extracts and essential oils on lipid peroxidation in simple in vitro systems. The tested
extracts were obtained from four plants, commonly known in the Mediterranean area, autochthonous in Sardinia, as Artemisia arborescens, Calycotome villosa, Daphne gnidium or exotic naturalised in the island as Eucalyptus globulus. We investigated the activity of the extracts during both the autoxidation and the iron or EDTA-mediated oxidation of linoleic acid at 37°C in absence of solvent, and compared it with that of BHT, a-tocopherol and EDTA. During linoleic acid autoxidation all the extracts were active, showing an antioxidant activity growing in the order: BHT > αtocopherol > Daphne gnidium (methanol extract) > Eucalyptus globulus (essential oil) > Calycotome villosa (essential oil) > Artemisia arborescens (essential oil and methanol extract) > Calycotome villosa (methanol extract). None of them showed any prooxidant activity. During the iron-catalysed oxidation of linoleic acid the oils were not active, while all the methanol extracts showed some efficiency to prevent the oxidation process
Estimation of total factor productivity for regions and sectors in Italy. A panel cointegration approach
Get PDFIn this paper a complete set of estimates of long-run production functions for 20 regions and 17 sectors in Italy is provided over the period 1970-1994. Our approach features two important aspects. First, this paper represents the first attempt to provide such a comprehensive set of estimates for the Italian economy. Moreover, we allow the estimated production functions for heterogeneity across sectors and regions. This is particularly appropriate when analysing the Italian economy since the Italian regions have been experiencing fairly different and, in certain cases, divergent development paths. Secondly, on the basis of specific panel tests, we show that there is a considerable empirical evidence which suggests the presence of unit roots in our series; therefore, we apply panel cointegration tests to guard against the spurious regression problem and to detect long-run relationships. Evidence of long run relationships is found for most of the regions and the sectors on the basis of the cointegration tests; thus, the problem of spurious regressions is ruled out allowing us to offer rigorous inference on the estimation of regional production functions. We find that factor elasticities highly differ across regions and sectors. This is an important result since most previous studies by employing unique national elasticities introduce a serious bias in the productivity comparison
Studio antropologico dei resti rinvenuti in una tomba del sito di Vico III Lanusei a Cagliari
Get PDFThe archaeological excavations in Vico III Lanusei, within the urban area of Cagliari, were carried out between 1996 and 1997. The work was supervised by Donatella Mureddu of the Archaeological Authorities for the Provinces of Cagliari and Oristano. The stratigraphic excavation of the site has brought to light various inhabited and funerary areas, testifying to their use from the late republican period through to the Middle Ages. Differing types of burial have been discovered in the area. In particular,
one was dug directly into the rock, three were in coffins and two were Capuchin type burials. In this paper a description is provided of the results of the anthropological study of the human skeletal remains found in the burial dug directly into the rock. In the grave
there were four infants in a supine position, placed on a later dates
Convergenza e divergenza tra le regioni europee. Implicazioni per lo sviluppo economico in Sardegna
Get PDFThe empirical literature on economic growth has recently devoted increasing attention to the issue of regional disparities. The first part of this paper is devoted to the analysis of the growth process of 110 European regions using an updated version of the database set up by the Centre for North South Economic Research (CRENoS). Applying various statistical tools, it compares the dynamics of both per capita income and labour productivity. The second part of the paper examines more specifically the economic performance of Sardinia, relative to theEuropean regions, and outlines a general interpretation of the economic growth process of this region
Immigrazione, incremento e fluttuazioni della Tortora dal collare orientale (Streptopelia decaocto, Frivaldszky) nella città di Cagliari
Get PDFIn this article the authors examine the expansion of the Collared Dove in the city of Cagliari, where it nested on 1979 for the first time. They took a census in four urban stations, characterized by different arboreous associations, for 7 years and 11 months. The fluctuations demonstrated an increase, and some cyclic movements of the population. After all they examine the causes of the expansion and adaptation of this bird ran away from bondage, and fear the danger of an interspecific competition with the Turtle Dove, very important for the
sardinian hunters
Contributo alla conoscenza dei fitotoponimi del Sulcis(Sardegna sud-occidentale)
Get PDFA first contribution regarding the phytoponimy of the Sulcis area is presented here. 394 vegetal place names have been counted in a census, referred to 89 taxa. Most of these are written in Campidanese dialet and is referred to frequently entities found in the territory. The most recurrent species are shrubs (37,6%) and trees (35,9%)
spontaneus and cultivated, most of them calcifuge. Only in the far western areas is possible to find taxa calcicole linked to sedimentary substrata of carbonated nature. From researches carried out it appears that the IGM plans 1:25.000 with the greater number of phytotoponimy are those in Capoterra (68), Narcao (52), Santadi and Carbonia areas both with 39. It is finally underlined that almost all the censed names are linked to morphological elements of the landscape, particularly the peak areas (21,8%) and the mountains (11,9%)
Analisi esplorativa sulla stima del costo di mantenimento agli studi universitari degli studenti dell'Ateneo di Cagliari
Get PDFIl presente studio ha lo scopo di stimare, sia pure in via approssimativa,
il costo medio di mantenimento agli studi degli studenti
universitari dell'Ateneo di Cagliari, limitatamente ai soli studenti in
corso e fuori sede. Tali limitazioni sono dettate da alcune motivazioni:
a) la necessità di realizzare l'indagine in breve tempo. A tale
scopo si è pensato di limitare la rilevazione ai soli studenti
fuori-sede, in quanto la spesa sostenuta da questi è verosimilmente
più elevata di quelli residenti in sede o pendolari.
In più tale scelta permette di contenere l'ampiezza del campione
e, conseguentemente, la fase di rilevazione dei dati.
b) la necessità di quantificare le spese sostenute dagli studenti
nell'a.a. 1998/99. In questo senso è sembrato più utile limitare
l'indagine ai soli studenti in corso, gli unici, quindi, potenzialmente
in grado di ottenere la borsa di studio oppure
uno dei contributi erogati dall'ERSU1 per l'a.a. 1999/2000.
La necessità di realizzare l'indagine in breve tempo ci ha indotto
a ridurre di molto il campo d'azione, limitandolo quasi esclusivamente
ai soli aspetti quantitativi della vita degli studenti universitari fuorisede.
In questo senso tale ricerca potrebbe assurgere al ruolo di indagine
pilota rispetto ad un'altra ricerca da effettuarsi in un secondo
moment
La vegetazione degli habitats terrestri della riserva marina protetta di Capo Carbonara (Sardegna sud-orientale)
Get PDFThe coastal vegetation of SE Sardinia, near Villasimius, has been studied throught the phytosociological method ad described in relation to taken stations. The syntaxonomical schema of the found vegetational units is presented. Among the several phytosociological associations founded during the field survey a new one is pointed out: Phagnalo saxatili-Calicotometum villosae. In the wole area there are 6 Community Importance Sites (C.I.S.) according to EEC Directive 92/43, with high biodiversity degree
Previsioni demografiche. Alcune note metodologiche e una applicazione al caso dei comuni della Sardegna
Get PDFLe previsioni demografiche rappresentano un importante strumento
analitico e programmatico, in particolare in periodi come questo in cui si rivela
crescente l’attenzione verso sistemi territoriali che non rientrano nelle
aggregazioni amministrative canoniche, comunque ricchi di peculiarità e
sufficientemente omogenei sotto il profilo economico, sociale e geografico.
Proprio per questo motivo essi risultano destinatari di misure politiche di medio
periodo mirate e specifiche, per le quali è utile disporre di possibili scenari futuri.
Il progetto di ricerca del quale questo saggio rappresenta una tappa si inserisce
in tale quadro di riferimento. In particolare, il suo carattere innovativo risiede
nel livello di disaggregazione utilizzato, quello comunale. Ma per fare ciò
occorreva proporre alcuni strumenti metodologici relativamente alle tecniche di
previsione della popolazione. Il modello previsivo da noi messo a punto si basa
su un algoritmo matematico che, partendo dai tassi di fertilità specifici comunali
territorialmente ponderati e seguendo taluni ipotetici andamenti della fertilità
stessa, della mortalità e del fenomeno migratorio, fornisce la popolazione
prevista per sesso e classi di età per ognuno dei 375 comuni sardi. L’arco
temporale nel quale si opera va dal 1995 (periodo osservato) al 2010,
procedendo per successivi quinquenni.
Come corollario dell’apparato metodologico abbiamo intentato un esercizio
applicativo riguardante i comuni della Sardegna. I principali risultati ottenuti
sono così sintetizzabili: in primo luogo, la Sardegna dovrebbe sostanzialmente
stabilizzarsi sulle cifre dell’anno base, con saggi di variazione sempre abbastanza
contenuti. Considerando le dinamiche comunali, si dovrebbe assistere
all’approfondimento di taluni fenomeni del recente passato, con la crescita delle
aree costiere, fra cui spiccano le Baronie e l’Ogliastra, l’hinterland cagliaritano ed
il bacino urbano che ha come fulcro Sassari, e la prosecuzione sul sentiero di
spopolamento di alcuni sistemi interni quali le Barbage, il Sulcis ed i comuni
dell’oristanese non collegati al sistema campidanese. I dati disaggregati per classi
di età farebbero registrare, infine, un ulteriore ispessimento delle classi di età
avanzate, confermato da un incremento costante dei principali indicatori
demografici sintetici