209 research outputs found
A phytosociological investigation on the mixed hemycryptophitic and therophitic grasslands of the Cornicolani mountains (Lazio Region – central Italy)
Abstract
In this paper a phytosociological study on the dry grasslands of the Cornicolani mountains is presented. The Cornicolani are a group of isolated limestone
hills which emerge from the slightly ondulating grounds of the Rome countryside in the Tyrrhenian side of the central Italy. Eighty-nine relevés
were performed using the Braun-Blanquet phytosociological approach. These were further subjected to hierarchical classification and to NMDS
ordination. Five major types of grasslands were distinguished: short therophytic grasslands developed on shallow soils dominated, in turns, by Hypochaeris
achyrophorus, Plantago lagopus and Plantago bellardii; sub-nitrophilous detriticolous perennial grasslands dominated by Dittrichia viscosa
and Helichrysum italicum; Dasypyrum villosum and Vulpia ligustica lawn and fallow annual tall-grasslands; Ampelodesmos mauritanicus grasslands
of the rocky S-facing slopes and sub-mesophilous Lolium perenne and Cynodon dactylon grasslands of the flat and pastured areas. From a syntaxonomical
standpoint a new associations named Plantaginetum afrae-bellardii was proposed and included in the class Stipo-Trachynetea. In addition the
association Helichryso italici-Inuletum viscosae Trinajstić 1965 (nom. inval.) was here validated
Geometric morphometric analysis as a tool to explore covariation between shape and other quantitative leaf traits in European white oaks
In this study, 2-Block Partial Least-Squares analysis was used to
explore the pattern of covariation between two sets of leaf morphological data
(landmarks and traditional measures), sampled on 273 trees in a mixed forest
of Quercus frainetto, Q. petraea and Q. pubescens, in southern-central Italy.
Two groups of related variables were detected and the three oak species were
highly significant discriminated by CVA computed on dimensions extracted by
2B-PLS analysis. Q. frainetto was characterized by obovate leaf blade with a
short petiole and leaves were greater than in the other species. Q. petraea
was differentiated by acute basal and apical regions, while Q. pubescens has
higher values of leaf compactness, pubescence and length of trichomes. The
high degree of classification accuracy of this combined approach advocates
its extension to other problematic species and highlights its importance as an
exploratory tool in plant ecology, physiology and taxonomy
Base excision repair intermediates are mutagenic in mammalian cells
Base excision repair (BER) is the main pathway for repair of DNA damage in mammalian cells. This pathway leads to the formation of DNA repair intermediates which, if still unsolved, cause cell lethality and mutagenesis. To characterize mutations induced by BER intermediates in mammalian cells, an SV-40 derived shuttle vector was constructed carrying a site-specific lesion within the recognition sequence of a restriction endonuclease. The mutation spectra of abasic (AP) sites, 5′-deoxyribose-5-phosphate (5′dRp) and 3′-[2,3-didehydro-2,3-dideoxy-ribose] (3′ddR5p) single-strand breaks (ssb) in mammalian cells was analysed by RFLP/PCR and mutation frequency was estimated by quantitative PCR. Point mutations were the predominant events occurring at all BER intermediates. The AP site-induced mutation spectrum supports evidence for the ‘A-rule’ and is also consistent with the use of the 5′ neighbouring base to instruct nucleotide incorporation (5′-rule). Preferential adenine insertion was also observed after in vivo replication of 5′dRp or 3′ddR5p ssb. We provide original evidence that not only the abasic site but also its derivatives ‘faceless’ BER intermediates are mutagenic, with a similar mutation frequency, in mammalian cells. Our findings support the hypothesis that unattended BER intermediates could be a constant threat for genome integrity as well as a spontaneous source of mutations
The main plant community types of the alpine belt of the Apennine chain
This paper deals with the occurrence of the main plant community types occurring within the alpine bioclimatic belt in the Central Apennines. The study area was represented by three mountain groups, the Gran Sasso, Maiella and Laga mountains. These three mountain chains are those in which, out of the entire Apennine area, alpine vegetation is best expressed. The vegetation has been investigated following the Braun-Blanquet phytosociological approach. During the field work 135 releves were collected. The raw data were further treated with multivariate analysis procedures to find objective clusters on a statistical basis. Several plant community types, belonging to different phytosociological classes, such as Elyno-Seslerietea, Salicetea herbaceae, Thlaspietea rotundifolii, Asplenietea trichomanis, were identified. In particular two new phytosociological associations, Galio-Silenetum acaulis and Potentillo-Festucetum alfredianae, and several new sub-associations are described in this paper. In order to express the occurrence and autonomy of the Apennine alpine bioclimatic belt also in coenological terms, a new Seslerion apenninae sub-alliance, named Leontopodio-Elynenion, is here proposed
Evidence from multivariate morphometric study of the quercus pubescens complex in southeast Italy
The name Quercus pubescens s.l. encompasses a complex of deciduous oak taxa with mainly southeastEuropean
distribution and a large ecological niche. As the easternmost region of Italy, Apulia is
rather isolated from a geographical and physiographical viewpoint and counts the highest number
of oak species (10). In the taxonomic and phytosociological literature, the occurrence of several
species belonging to the Quercus pubescens collective group is reported for this region. In order to
verify if different sets of morphological characters are associated with different taxa, 24 populations
of Quercus pubescens s.l. located in different ecological-geographical areas of Apulia were sampled.
A total of 367 trees, 4254 leaves and 1120 fruits were collected and morphologically analysed.
Overall, 25 morphological characters of oak leaves and fruits were statistically treated using both
univariate and multivariate analysis. Nested ANOVA showed that leaves collected from a single tree
exhibited a degree of morphological variability higher than that observed when comparing leaves
coming from different trees of the same population and from different trees of different populations
as well. Almost all the morphological characters analysed exhibited a continuous trend of variation
so that none of them can be used as a character to discriminate between populations. Only leaf
and fruit “size” and fruit petiole length emerged as slightly discriminating characters. Our results
suggest that it is unlikely that more than one species belonging to the Quercus pubescens complex
occurs in the Apulia region. Comparison between the Apulian populations and a genetically
pure Q. pubescens population coming from a different area (the Molise region) strengthened the
assumption as to the existence of a single species that can provisionally be classified under the name
of Q. pubescens s.
The type of DNA glycosylase determines the base excision repair pathway in mammalian cells.
The base excision repair (BER) of modified nucleotides is initiated by damage-specific DNA glycosylases. The repair of the resulting apurinic/apyrimidinic site involves the replacement of either a single nucleotide (short patch BER) or of several nucleotides (long patch BER). The mechanism that controls the selection of either BER pathway is unknown. We tested the hypothesis that the type of base damage present on DNA, by determining the specific DNA glycosylase in charge of its excision, drives the repair of the resulting abasic site intermediate to either BER branch. In mammalian cells hypoxanthine (HX) and 1,N6-ethenoadenine (epsilonA) are both substrates for the monofunctional 3-methyladenine DNA glycosylase, the ANPG protein, whereas 7,8-dihydro-8-oxoguanine (8-oxoG) is removed by the bifunctional DNA glycosylase/beta-lyase 8-oxoG-DNA gly- cosylase (OGG1). Circular plasmid molecules containing a single HX, epsilonA, or 8-oxoG were constructed. In vitro repair assays with HeLa cell extracts revealed that HX and epsilonA are repaired via both short and long patch BER, whereas 8-oxoG is repaired mainly via the short patch pathway. The preferential repair of 8-oxoG by short patch BER was confirmed by the low efficiency of repair of this lesion by DNA polymerase beta-deficient mouse cells as compared with their wild-type counterpart. These data fit into a model where the intrinsic properties of the DNA glycosylase that recognizes the lesion selects the branch of BER that will restore the intact DNA template
Emotional management and biological markers of dietetic regimen in chronic kidney disease patients
The aim of the study was to investigate the association between psychological characteristics and biological markers of adherence in chronic kidney disease patients receiving conservative therapy, hemodialysis, peritoneal dialysis (PD), or kidney transplantation. Seventy-nine adult patients were asked to complete the following questionnaires: Toronto Alexithymia scale, Snaith–Hamilton Pleasure Scale, and Short Form Health Survey. Biological markers of adherence to treatment were measured. Peritoneal dialysis patients showed a lower capacity to feel pleasure from sensorial experience (p = .011) and a higher values of phosphorus compared to the other patients’ groups (p = .0001). The inability to communicate emotions was negatively correlated with hemoglobin levels (r = −(0).69; p = .001) and positively correlated with phosphorus values in the PD patients (r = .45; p = .050). Findings showed higher psychological impairments and a lower adherence to the treatment in PD patients and suggest the implication of emotional competence in adherence to treatment.The aim of the study was to investigate the association between psychological characteristics and biological markers of adherence in chronic kidney disease patients receiving conservative therapy, hemodialysis, peritoneal dialysis (PD), or kidney transplantation. Seventy-nine adult patients were asked to complete the following questionnaires: Toronto Alexithymia scale, Snaith-Hamilton Pleasure Scale, and Short Form Health Survey. Biological markers of adherence to treatment were measured. Peritoneal dialysis patients showed a lower capacity to feel pleasure from sensorial experience (p = .011) and a higher values of phosphorus compared to the other patients' groups (p = .0001). The inability to communicate emotions was negatively correlated with hemoglobin levels (r = -(0).69; p = .001) and positively correlated with phosphorus values in the PD patients (r = .45; p = .050). Findings showed higher psychological impairments and a lower adherence to the treatment in PD patients and suggest the implication of emotional competence in adherence to treatment
Notch Signaling Regulates Immune Responses in Atherosclerosis
Atherosclerosis is a chronic autoimmune inflammatory disease that can cause coronary artery disease, stroke, peripheral artery disease, depending on which arteries are affected. At the beginning of atherosclerosis plasma lipoproteins accumulate in the sub-endothelial space. In response, monocytes migrate from the circulation through the endothelium into the intima where they differentiate into macrophages. These early events trigger a complex immune response that eventually involves many cellular subtypes of both innate and adaptive immunity. The Notch signaling pathway is an evolutionary conserved cell signaling system that mediates cell-to-cell communication. Recent studies have revealed that Notch modulate atherosclerosis by controlling macrophages polarization into M1 or M2 subtypes. Furthermore, it is known that Notch signaling controls differentiation and activity of T-helper and cytotoxic T-cells in inflammatory diseases. In this review, we will discuss the role of Notch in modulating immunity in the context of atherosclerosis and whether targeting Notch may represent a therapeutic strategy
A multivariate morphometric analysis of diagnostic traits in southern Italy and Sicily pubescent oaks
Species identification within the species complex
of Q. pubescens is a well-known taxonomic challenge
among European botanists. Some of the specific
pubescent oak binomials currently accepted in various
European floras and checklistswere originally described
in Sicily and southern Calabria. As a consequence,
several species belonging to the pubescent oaks group
(Q. pubescens, Q. amplifolia, Q. congesta,
Q. dalechampii, Q. leptobalana and Q. virgiliana) are
reported in the taxonomic and phytosociological literature.
To verify whether it was possible to associate a
diverse set of morphological characters with each of
these different taxa, thirteen natural populations of pubescent
oak from Sicily and southern Calabria were
sampled. A total of 391 trees, 3,887 leaves and 1,047
fruits were collected. Overall, 28 morphological characters
of oak leaves and fruits were statistically analysed
using univariate and multivariate procedures. The results
showed that neither the groups of morphological
diversity identified by cluster analysis, nor those obtained
by our expert identification through the use of analytical
keys, matched with the current taxonomical
frameworks as proposed by the most recent floras and
checklists. Nearly all of the morphological characters
considered displayed a more or less continuous trend of
variation, both within and among populations. In the
light of these findings it seems unlikely that more than
one biological species of pubescent oak occurs in Sicily
and southern Calabria
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