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The walking of Salpichroa origanifolia (Lam.) Baill. in Pisa city and surroundings and its dispersal by birds
No full textThe walking of Salpichroa origanifolia in Pisa city and surroundings and its dispersal by birds
No full textSalpichroa origanifolia (Lam.) Baill. (Solanaceae) is native to South America and it is well known as an
invasive species. It is present in Africa, North America, Australia and Europe.
This species is a fruticose chamaephyte, scrambling sub-shrub. It has been abundantly described as an
expanding species in the Canton of Ticino. In Italy it is widespread in almost all regions. For Tuscany it is
reported as naturalized, but we believe it could be defined as invasive.
Several observations are reported for Tuscany. Its presence has been known in the province of Pisa since
1981. According to Wikiplantbase#Tuscany (http://bot.biologia.unipi.it/wpb/toscana/index) has been
widespread in the region since 1999 and it is found in the provinces of Florence (municipalities of
Castelfiorentino, Fiesole, Florence), Grosseto (Castiglione della Pescaia), Livorno (Livorno, Rosignano
Marittimo), Lucca (Pietrasanta), Massa Carrara (Massa, Montignoso), Pisa (Pisa, San Giuliano Terme,
Tirrenia). It colonizes very different environments (synanthropic areas, vegetable gardens, canals, roadsides,
thermophilic woods, holm oak woods with stone pine Pinus pinea L., etc.).
The introduction of S. origanifolia is usually due to cultivation, but it is also caused by animals.
In and around Pisa it is found along roads and in anthropic environments. Its distribution and
development are strictly related to the ruderal environment, where the plant can suffocate even tall trees (see
Tirrenia); birds are thought to be responsible for its spread.
Birds are known to play a key role in the dispersal of the species. The involvement of some species of
passerine birds, such as Zonotrichia capensis and Poospiza whitii, has been highlighted in studies conducted
in the South American countries of origin of S. origanifolia. Seeds of the plant were found in the faeces of
these birds, and their germinability was confirmed.
Occasional observations relating to the city of Pisa proved this attitude in the Italian Sparrow Passer italiae
and the Wood Pigeon Columba palumbus. Further studies are underway to determine which bird species are
attracted to S. origanifolia fruits, in addition to those mentioned
Detection of the centromere in micronuclei by fluorescence in situ hybridization: its application to the human lymphocyte micronucleus assay after treatment with four suspected aneugens
No full textInduction of aneuploidy by the antineoplastic drug estramustine in human lymphocytes.
No full textEstramustine (EM) is an antineoplastic drug used in the therapy of human prostatic carcinoma. The aim of our work was to evaluate the potential aneuploidogenic activity of estramustine, by analysing its cytogenetic effects induced in human lymphocytes. To estimate the ability of EM to induce mitotic spindle disturbances, two parameters were used: the presence of c-mitoses (according to the degree of chromatid spreading and contraction) and mitotic index evaluation (increase after exposure indicating the accumulation of mitoses). EM induced c-mitoses and mitotic index increases starting from the 4 microM dose: statistically significant increases were observed up to the highest dose (40 microM). A strong correlation between c-mitoses and mitotic index increase was found. The micronucleus (MN) assay combined with the fluorescence in situ hybridization technique with a pancentromeric DNA probe was also carried out. Compared to the control, EM induced significant MN increases in binucleated lymphocytes at two doses (8-16 microM). Moreover, we found that estramustine induced significant percentages of MN with positive hybridization signal at the same doses, confirming the presence of entire chromosomes in micronuclei. Additional experiments included induction of numerical and structural chromosome aberrations, and evaluation of sister chromatid exchanges (SCE) and satellited (D- and G-group chromosomes) chromosome associations. The results of numerical chromosome aberration analysis indicated that EM was positive in inducing a statistically significant increase in aneuploid cells and/or polyploid cells at all doses tested. On the basis of these observations, EM may be defined as a typical aneuploidy inducer, whereas it was not found to increase the frequency of structural chromosome aberrations and SCE frequency
Endogenous sex hormones affect the mutagen-induced chromosome damage by altering a caffeine-sensitive checkpoint
No full textIn the present study we analysed the effect of endogenous sex hormones on the SCE frequencies induced in vitro by mitomycin C (MMC), a bifunctional alkylating agent producing high chromosome damage and mitotic arrest. The analysis has been performed on lymphocytes obtained at three different phases of menstrual cycle, from women with regular cycle and hormones dosage. At all phases we further analysed the effect of a post-treatment with caffeine, an agent that it is known to overrride the DNA damage checkpoints. After MMC, the cultures obtained at ovulation and luteal phases have SCE frequencies statistically higher than the cultures obtained at the progestogenic phase, showing increases of 15 and 25%, respectively. After caffeine, the MMC treated cultures which were set up at the progestogenic phase show a high potentiation of SCE frequencies (28%) whereas the treated cultures set up at ovulatory and luteal phases show little or no potentiation. These findings demonstrate that the endogenous hormones greatly modulate the SCE frequencies induced by the mutagen; they also indicate that hormones action competes with the caffeine effect. Caffeine acts by abrogating the mitotic arrest produced by DNA damage and induced cells with a higher chromosome damage into a premature mitosis. Our findings suggest that endogenous hormones could overcome the checkpoint controls activated in cells after mutagenic exposure. This action may be an epigenetic mechanism relevant in hormone carcinogenesis
Il Museo Botanico: un ponte tra collezioni scientifiche e divulgazione
No full textIl Museo botanico pisano è un museo scientifico universitario che si propone come centro attivo per la diffusione della
cultura scientifica. Come esempio di questo ruolo vengono illustrate due modalità di esposizione di una collezione storica
del museo, una rivolta a ricercatori e studenti universitari, l’altra a un pubblico non specialistico
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
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