5,341 research outputs found
Nomenclature adjustments and new syntaxa of the arctic, alpine and oro-Mediterranean vegetation
Proposte sintassonomiche e nomenclaturali per la vegetazione della Tundra alpina. Il capitolo riguardante l'alta quota appenninica è il più corposo e propone il nuovo syntaxon Leontopodio-Elynion a livello di alleanza. La grande novità sta nel fatto che questa alleanza è da considerarsi anfi-Adriatica e unsice Appennino e balcani, differenziandosi dall'alleanza già definita da altri per le Alpi. i Pirenei e i Carpazi.During preparation of the European checklist of vegetation units (EuroVegChecklist), it became clear that some earlier described syntaxa need to be typified in order to stabilize nomenclature and some new syntaxa need to be described. Here we propose nomenclature adjustments and formal description of four new alliances
for the Arctic, alpine and oro-Mediterranean vegetation of Europe, Greenland and Anatolia. First, we typify the class Juncetea trifidi. Second, we describe four new alliances, such as the Puccinellion nuttallianae (Low-Arctic salt steppes of Greenland; class Saxifrago tricuspidatae-Calamagrostietea purpurascentis), Dryado octopetalae-
Caricion arctisibiricae (Arctic tundra vegetation of north-eastern European Russia; class Carici rupestris-Kobresietea bellardii), Leontopodio nivalis-Elynion myosuroidis (southern European alpine tundra vegetation; class Carici rupestris-Kobresietea bellardii) and Lagotido uralensis-Caricion ensifoliae (alpine tundra vegetation of the Southern Ural Mountains; class Juncetea trifidi). Two new associations are described within the first two of these alliances. Finally, we present an interpretation of the alliance Muscario-Scillion nivalis
Olea europaea L-derived secoiridoids: Beneficial health effects and potential therapeutic approaches
Over the years, health challenges have become increasingly complex and global and, at the beginning of the 21st century, chronic diseases, including cardiovascular, neurological, and chronic respiratory diseases, as well as cancer and diabetes, have been identified by World Health Organization as one of the biggest threats to human health. Recently, antimicrobial resistance has also emerged as a growing problem of public health for the management of infectious diseases. In this scenario, the exploration of natural products as supplementation or alternative therapeutic options is acquiring great importance, and, among them, the olive tree, Olea europaea L, specifically leaves, fruits, and oil, has been increasingly investigated for its health promoting properties. Traditionally, these properties have been largely attributed to the high concentration of monounsaturated fatty acids, although, in recent years, beneficial effects have also been associated to other components, particularly polyphenols. Among them, the most interesting group is represented by Olea europaea L secoiridoids, comprising oleuropein, oleocanthal, oleacein, and ligstroside, which display anti-inflammatory, antioxidant, cardioprotective, neuroprotective and anticancer activities. This review provides an overview of the multiple health beneficial effects, the molecular mechanisms, and the potential applications of secoiridoids from Olea europaea L
Ionizing Radiation-Induced Apoptosis and DNA Repair in Murine Erythroleukemia Cells
A morphological study of DNA repair and apoptotic patterns in relationship with cell cycle events was performed on murine erythroleukemia cells. The presence and distribution of DNA replicon sites were evaluated through the BrdU-anti BrdU immunofluorescence and immunogold techniques in light and electron microscopy. Different patterns of labelling and percentages of BrdU positive cells were observed depending on irradiation dose (up to 60 Gy) and time in post-irradiation culture (up to 24 hours). An enlargement of the S phase of the cell cycle was evidenced 18 hours post-irradiation as determined by flow cytometry analysis. The high resolution approach showed that, in spite of several morphological alterations, BrdU labelling was present even in cells displaying early and late apoptotic features
On the semiclassical treatment of Hawking radiation
In the context of the semiclassical treatment of Hawking radiation we prove
the universality of the reduced canonical momentum for the system of a massive
shell self gravitating in a spherical gravitational field within the Painlev\'e
family of gauges. We show that one can construct modes which are regular on the
horizon both by considering as hamiltonian the exterior boundary term and by
using as hamiltonian the interior boundary term. The late time expansion is
given in both approaches and their time Fourier expansion computed to reproduce
the self reaction correction to the Hawking spectrum.Comment: 18 pages, LaTeX, Corrected typo
A revised phytosociological nomenclature for the Italian Quercus cerris woods
This paper aims to revise the phytosociological nomenclature of the Quercus cerris woods occurring in Italy with particular attention to associations, subassociations, and suballiances. The syntaxa included in this revision were selected based on a physiognomical criterion, i.e., woods with dominance or codominance of Quercus cerris. The nomenclatural revision complied with the International Code of Phytosociological Nomenclature. Correct names and Authors' citations were considered for all the syntaxa analyzed (121), and, in most cases, other information about nomenclatural types, localities, synonyms, classification, and other notes was reported. As regards the alliance level, the correct application of the name Melittio albidae-Quercion frainetto ―whose original diagnosis and type-association occur in Italy― was discussed. In all, 31 syntaxon names were validated or described: two suballiances (Campanulo medii-Ostryenion carpinifoliae and Pulmonario apenninae-Carpinenion betuli), nine associations and 20 subassociations. Five lectotypes were also designated
New syntaxon names for the Italian Quercus cerris woods
Based on the results of a previous nomenclatural revision of the Italian Quercus cerris forests, 31 syntaxon names are here validated or described as new and 5 lectotypes are designated
Differential response to hepatic differentiation stimuli of amniotic epithelial cells isolated from four regions of the amniotic membrane
Human Amniotic Epithelial Cells (hAEC) isolated from term placenta are a promising source for regenerative medicine. However, it has long been debated whether the hAEC population consists of heterogeneous or homogeneous cells. In a previous study, we investigated the characteristics of hAEC isolated from four different regions of the amniotic membrane finding significant heterogeneity. The aim of this study was to evaluate the hepatic differentiation capability of hAEC isolated from these four regions. Human term placentae were collected after caesarean section and hAEC were isolated from four regions of the amniotic membrane (R1-R4, according to their relative distance from the umbilical cord) and treated in hepatic differentiation conditions for 14 days. hAEC-derived hepatocyte-like cells showed marked differences in the expression of hepatic markers: R4 showed higher levels of Albumin and Hepatocyte Nuclear Factor (HNF) 4α whereas R1 expressed higher Cytochrome P450 enzymes, both at the gene and protein level. These preliminary results suggest that hAEC isolated from R1 and R4 of the amniotic membrane are more prone to hepatic differentiation. Therefore, the use of hAEC from a specific region of the amniotic membrane should be taken into consideration as it could have an impact on the outcome of therapeutic applications
Ultrastructural Patterns of Cell Damage and Death Following Gamma Radiation Exposure of Murine Erythroleukemia Cells
Radiation causes damage to cell surface membranes, cytoplasmic organelles, and the nuclear process of DNA synthesis and repair, and this eventually results in different modes of cell death. In this study we examined murine erythroleukemia (MEL) cells, exposed to 15 and 60 Gy of 10 MeV photonic energy, and left in culture for up to 96 hours. Electron microscopical analysis was performed on conventionally embedded samples and freeze-fracture replicas, in order to detect ultrastructural patterns of cell damage and death. Of interest was the observation of chromatin condensates, nuclear membrane associations and nuclear pore redistribution during early apoptosis. Pronounced rearrangements of transmembrane particles during late stages of cellular necrosis were also found. The morphological damage induced by both doses of radiation as a function of time after exposure was only quantitatively but not qualitatively different
ECG monitoring of post-stroke occurring arrhythmias: an observational study using 7-day Holter ECG
Post-stroke arrhythmias represent a risk factor for complications and worse prognosis after cerebrovascular events. The aims of the study were to detect the rate of atrial fibrillation (AF) and other cardiac arrhythmias after acute ischemic stroke, by using a 7-day Holter ECG which has proved to be superior to the standard 24-h recording, and to evaluate the possible association between brain lesions and arrhythmias. One hundred and twenty patients with cryptogenic ischemic stroke underwent clinical and neuroimaging assessment and were monitored with a 7-day Holter ECG. Analysis of the rhythm recorded over 7 days was compared to analysis limited at the first 24 h of monitoring. 7-day Holter ECG detected AF in 4% of patients, supraventricular extrasystole (SVEB) in 94%, ventricular extrasystole (VEB) in 88%, short supraventricular runs (SVRs) in 54%, supraventricular tachycardia in 20%, and bradycardia in 6%. Compared to the first 24 h of monitoring, 7-Holter ECG showed a significant higher detection for all arrhythmias (AF p=0.02; bradycardia p=0.03; tachycardia p=0.0001; SVEB p=0.0002; VEB p=0.0001; SVRs p=0.0001). Patients with SVRs and bradycardia were older (p=0.0001; p=0.035) and had higher CHA(2)DS(2)VASc scores (p=0.004; p=0.026) respectively, in the comparison with patients without these two arrhythmias. An association was found between SVEB and parietal (p=0.013) and temporal (p=0.013) lobe lesions, whereas VEB correlated with insular involvement (p=0.002). 7-day Holter ECG monitoring proved to be superior as compared to 24-h recording for the detection of all arrhythmias, some of which (SVEB and VEB) were associated with specific brain areas involvement. Therefore, 7-day Holter ECG should be required as an effective first-line approach to improve both diagnosis and therapeutic management after stroke
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