153 research outputs found
Influenza della cementazione sulla compressibilità di depositi pelitici lacustri pliocenici dell'Italia centrale
No full textThe role of calcium carbonate in the geomechanical behaviour of Pliocene lacustrine deposits.
No full textThe results of a study on the influence of calcium carbonate content on the physical characteristics and compressibility parameters of Pliocene lacustrine deposits are discussed. The origin of CaCO3 has been investigated and it is thought to have been precipitated, after consolidation, as cement which partially filled the void spaces between soil particles. Average CaCO3 content was about 22% along a 116.5 m deep vertical profile. The CaCO3 in the clay and silt fractions (CaCO3*) was considered the best available estimate of that acting as cement. The relationships reported in the literature between Atterberg limits and CaCO3 content have been statistically confirmed by the tests performed on decalcified laboratory samples, but not by those performed on natural samples due to lithological heterogeneities. Yield stress, constrained modulus, swelling index and microstructure resistance were affected by CaCO3* content in the stress range lower than yield stress. In the stress range higher than sigma'(vy), no relationship was observed between C-c and CaCO3, while an inverse relationship between C-s and CaCO, was observed in both the natural and remoulded samples and thus is thought to be due to the presence of inactive calcite. Moreover, the remoulded samples also show an increase in C-s with respect to the natural ones. From these findings it follows that the yield stress for cemented materials corresponds to the partial disruption of the structure
Weathering of Valle Ricca stiff and jointed clay
No full textThe study proposes a weathering model of Pliocene-Pleistocene stiff and jointed blue-grey clay transforming into yellow clay. Physical, mineralogical, chemical and textural changes, as well as the weathering profile were investigated in a quarry of central Italy. Based on geological records and inferences, these changes are likely to have occurred within a time-span of about 50,000 years BP, upon overburden stress unloading and in a stress regime that is locally controlled by suction. Weathering propagated into the clay at a rate of about 0.3 mm/year and was enhanced by the enlargement of the pre-existing tectonic discontinuities and by the fori-nation of new joints. A mass loss of about 22-25 wt.% was calculated. Considering Fe and P as immobile elements, the individual oxides contribute to mass loss in the following order: SiO2 > CaO = CO2 > Al2O3 > MgO > K2O > S > Na2O > TiO2 > MnO. The Fe2O3/(Fe2O3+FeO) ratio varies from 9-29% in the blue-grey clay to 75-82% in the yellow one. Oxidation and/or dissolution of 7 angstrom-Fe2+-bearing clay minerals, mica-like minerals and calcite and parallel increase of smectite and Fe-hydroxides play a critical role in the chemical changes and explain the higher plasticity of the yellow clay with respect to the blue-grey one. The role of water during the weathering process was inferred to occur in cyclical steps: 1) seepage of meteoric water; 2) dissemination of highly oxidizing meteoric water; 3) triggering of oxidation and dissolution of minerals; 4) water evaporation; 5) partial migration of the elements contained in the aqueous solution and consequent deposition of minerals in the joints. (C) 2005 Elsevier B.V. All rights reserved
Food components and contaminants as (anti)androgenic molecules.
No full textAndrogens, the main male sex steroids, are the critical factors responsible for the development of the male phenotype during embryogenesis and for the achievement of sexual maturation and puberty. In adulthood, androgens remain essential for the maintenance of male reproductive function and behavior. Androgens, acting through the androgen receptor (AR), regulate male sexual differentiation during development, sperm production beginning from puberty, and maintenance of prostate homeostasis. Several substances present in the environment, now classified as endocrine disruptors (EDCs), strongly interfere with androgen actions in reproductive and non-reproductive tissues. EDCs are a heterogeneous group of xenobiotics which include synthetic chemicals used as industrial solvents/lubricants, plasticizers, additives, agrochemicals, pharmaceutical agents, and polyphenols of plant origin. These compounds are even present in the food as components (polyphenols) or food/water contaminants (pesticides, plasticizers used as food packaging) rendering the diet as the main route of exposure to EDCs for humans. Although huge amount of literature reports the (anti)estrogenic effects of different EDCs, relatively scarce information is available on the (anti)androgenic effects of EDCs. Here, the effects and mechanism of action of phytochemicals and pesticides and plasticizers as possible modulators of AR activities will be reviewed taking into account that insight derived from principles of endocrinology are required to estimate EDC consequences on endocrine deregulation and disease
Signal analysis in gravitational wave data
No full textIn this thesis, I study the gravitational wave signals coming from compact objects on both present-stage, and future gravitational wave detectors.
The thesis is based on 3 articles, which will be presented after two brief introductory chapters, aimed to guide the reader through some of the main concepts and tools required in the analysis of the presented papers.
In the first article we adopt the Pearson Cross-Correlation analysis, to perform an agnostic search on real detector data of the first four LIGO gravitational wave detections. This work was motivated as a follow-up to some studies carried out by a group at the Niels-Bohr Institute. In their works, they tried to reproduce the detections claimed by the LIGO collaboration using matched filtering, and they discovered that the waveforms used by the LIGO collaboration in their subtractions were not optimal, as some of the signal remained buried in the detector noise after the subtraction. In the paper we used different waveforms, obtained through maximum-likelihood, and we demonstrate that the residual signal found in the noise was just a consequence of the choice of waveforms. Such signal, buried in the residual detector noise, is hence not a result of mismatching on the model but can be removed by using a more accurate waveform description. Furthermore, we show that the LIGO results can be reproduced with statistical significance even by using the Pearson cross-correlation method, even though with this approach the statistical significance will be slightly lower compared to the results obtained using matched filtering.
For the second article we moved to the case of simulated signals, coming from many events, on a future space-based detector datastream. To this extent we analyze the Stochastic Gravitational Wave Background predicted on the LISA detector, which is given by the superposition of all the weak unresolvable signals on the detector strain. We forecast the signal on the LISA detector strain by using the results coming from the latest LVK population inference paper, and produced catalogs representing a Stellar-Origin Black Hole population in our Universe. The Stochastic Gravitational Wave Background is then computed by adopting four different methods, that in order of complexity, range from a simple analytical evaluation to estimating the real detector strain after synthesizing a black hole population and iteratively subtracting all the resolvable sources. We find that, when the assumed SNR threshold is high enough to keep the number of resolvable sources small (∼ 10 over 4 years of observation), all the methods give results well in agreement with each other. This implies that, when working with LISA data, it is possible to use the fast analytical estimation for the stochastic noise component with a small loss of precision. On the other hand, the use of more complex methods like the iterative subtraction of a synthesized population, despite naturally requiring numerical cuts in the population generation phase due to its computational cost, can present both the value of the Stochastic Gravitational Wave Background amplitude as well as the resolvable sources predicted on the LISA strain at the same time. It can hence be useful when both these quantities need to be taken into account in a particular study.
We conclude on the third article by studying the synergy of multiple future gravitational wave detectors (both Earth-based and Space-based), in assessing the presence of secondary population channels in the detectors data stream. To this extent, we investigate the prospects of identifying potential Primordial Black Hole Binary populations over the astrophysical Stellar-Origin Black Hole Binary population of our Universe. We once again assume that our fiducial population follows the latest LVK GWTC-3 inference paper results, and we forecast our analysis on the next generation of gravitational wave detectors. We consider different possibilities both for the merger rate and mass function of the studied Primordial Black Hole subpopulations, and we perform our analysis by focusing on the signatures at higher redshifts than the current LVK detection horizon. We exploit the fact that the astrophysical black holes of our universe are supposed to follow a distribution as a function of redshift closely related to the Star Formation Rate, which is supposed to peak and then slowly die off. At distances beyond the peak of the stellar formation rate, the Stellar-Origin Binary Black Hole contribution will hence become negligible, whereas Primordial Black Hole models predict many sources and will dominate. We generally find that Earth-based and space-based detectors work synergistically, and the value of the Stochastic Gravitational Wave Background measured by LISA will generally be able to improve constraining the presence of additional sub-populations compared to the case when only Earth-based detector observations are considered
Biological characteristics and metabolic profile of canine mesenchymal stem cells isolated from adipose tissue and umbilical cord matrix
No full textDespite the increasing demand of cellular therapies for dogs, little is known on the differences between adult and fetal adnexa canine mesenchymal stem cells (MSCs), and data on their metabolic features are lacking. The present study aimed at comparing the characteristics of canine adipose tissue (AT) and umbilical cord matrix (UC) MSCs. Moreover, for the first time in the dog, the cellular bioenergetics were investigated by evaluating the two main metabolic pathways (oxidative phosphorylation and glycolysis) of ATP production. Frozen-thawed samples were used for this study. No differences in mean cell proliferation were found (P>0.05). However, while AT-MSCs showed a progressive increase in doubling time over passages, UC-MSCs showed an initial post freezing-thawing latency. No differences in migration, spheroid formation ability, and differentiation potential were found (P>0.05). RT-PCR analysis confirmed the expression of CD90 and CD44, the lack of CD14 and weak expression of CD34, mostly by AT-MSCs. DLA-DRA1 and DLA-DQA1 were weakly expressed only at passage 0 by UC-MSCs, while they were expressed at different passages for AT-MSCs. There was no difference (P>0.05) in total ATP production between cell cultures, but the ratio between the “mitochondrial ATP Production Rate” and the “glycolytic ATP Production Rate” was higher (P<0.05) in AT- than in UC-MSCs. However, in both MSCs types the mitochondrial respiration was the main pathway of ATP production. Mitochondrial respiration and ATP turnover in UC-MSCs were higher (P<0.05) than in AT-MSCs, but both had a 100% coupling efficiency. These features and the possibility of increasing the oxygen consumption by a spare respiratory capacity of four (AT-MSCSs) and two (UC-MSCs) order of magnitude greater than basal respiration, can be taken as indicative of the cell propensity to differentiate. The findings may efficiently contribute to select the most appropriate MSCs, culture and experimental conditions for transplantation experiments in mesenchymal stem cell therapy for companion animals
DETECTION OF STREPTOCOCCUS EQUI DNA IN RHIPICEPHALUS BURSA TICKS FROM SOUTHERN ITALY
No full textTicks are obligated ecto-parasites of wild and domestic animals and occasionally humans. They have
veterinary interest because vectors of different viruses, bacteria and protozoa. Among the most common
species in Italy and Europe there are Ixodes ricinus and Rhipicephalus spp. The tick-borne diseases
epidemiologically relevant in our country are: Lyme disease, rickettsiosis, relapsing fever, tularemia,
meningoencephalitis and ehrlichiosis.
Recently, the extensive characterization of the tick-associated microbiome faces the possible role of ticks in
the transmission of additional pathogens, which are known to be transmitted by other arthropod vectors.
Through the Denaturing Gradient Gel Electrophoresis (DGGE), we analysed the bacterial community of
seven ticks belonging to three species from different areas of Italy: no. 2 Rhipicephalus sanguineus
(Lombardia), no. 2 Rhipicephalus bursa (Campania) and no. 3 Ixodes ricinus (Marche). The samples were
analysed selecting the highly variable V3 region of the bacterial 16S rRNA gene as target. The dominant
DGGE bands were purified and sequenced allowing the identification of the bacteria present in each
samples.
Burkholderia sp., Coxiella-like endosymbiont, unc. Clostridium, Rickettsia peacockii, unc. Staphylococcus
and Xanthomonas sp. were detected, as already described in ticks. Moreover, Streptococcus equi subsp.
zooepidemicus/ruminatorum was identified in R. bursa collected from buffalos living in rural areas of
Southern Italy (the high genetic identity does not allow the distinction of these subspecies, that is usually
achieved by biochemical tests on cultured bacteria). The DGGE outcome was confirmed by multiplex-PCR in
other R. bursa samples collected from buffalos, ponies and goats from the same area. In particular, no. 6
positive samples over no. 15 analyzed were detected (no. 2 from buffalos and no. 4 from ponies).
S. equi is a complex-species including S. e. equi, S. e. zooepidemicus and S. e. ruminatorum: S. e. equi is the
ethological agent of strangles, a highly contagious and serious infection of horses, whereas S. e.
zooepidemicus and S. e. ruminatorum can cause several infections in both animals and humans. All these
pathogens are known to be transmitted through direct contact.
The DNA detection of S. e. zooepidemicus/ruminatorum in R. bursa is particularly interesting since to our
knowledge this pathogen was not previously detected in any tick species. Thus, in-depth studies are worthy
to assess an effective competence of ticks as vectors of S. equi subspecies, since if a potential role of R.
bursa in their transmission will be confirmed, new perspectives in the control of these zoonoses will be
opened
Genetically Modified Organisms (GMO)-associated herbicides and reproductive tissues: effects on human sperm mitochondria and prostate cell-based assays
No full textSeasonal variations in the chemical composition of particulate matter: a case study in the Po Valley. Part II: concentration and solubility of micro- and trace-elements
No full textSize distribution (fine and coarse fraction) and solubility distribution (extracted and residual fraction) of 20 elements (As, Ba, Be, Cd, Co, Cu, Fe, Li, Mn, Pb, Ni, Rb, S, Sb, Se, Sn, Sr, Ti, Tl, V) in atmospheric particulate matter (PM) were determined during a 5-year field study carried out in the Po Valley (peri-urban area of Ferrara, in Northern Italy). By studying the contribution of the two size fractions and the two solubility fractions to the atmospheric concentration of each element, it was possible to obtain interesting information about the variability of PM sources, to assess the role played by atmospheric stability in determining pollution episodes, and to obtain an estimate of the bio-accessible fraction. Atmospheric stability is confirmed to be one of the main causes of atmospheric pollution in this area and is to be responsible for the pronounced winter increase in both PM and elemental concentration. Long-range transport of natural and polluted air masses caused temporary increases in PM and elemental concentration, while local industrial emission seemed to play a secondary role. Regulated elements were well below their concentration limit, but many toxic elements were in the form of fine particles and soluble chemical species, more accessible to the environment, and the human body
Variazioni stagionali nella concentrazione e nella solubilità di microelementi nel particolato atmosferico
No full textNel presente lavoro viene studiata la variabilità stagionale delle concentrazioni elementari nel particolato atmosferico (PM) nella Pianura Padana (periodo 2008-2012).
L'applicazione di un metodo di frazionamento chimico (frazioni estratta e residua) e dimensionale (frazioni fine e grossolana) ha permesso di suddividere la concentrazione totale di 20 elementi (As, Ba, Be, Cd, Co, Cu, Fe, Li, Mn, Pb, Ni, Rb, S, Sb, Se, Sn, Sr, Ti, Tl, V) in quattro diversi contributi, associati a diverse sorgenti emissive. Sono stati monitorati tre siti, posti a diversa distanza dall'area industriale di Ferrara e le variazioni estate-inverno di ciascun contributo sono state interpretate considerando le diverse condizioni di stabilità atmosferica e la presenza di sorgenti stagionali. In questo modo è stata ottenuta una descrizione piuttosto dettagliata del comportamento degli elementi come traccianti di sorgente.
Alcuni elementi tossici (Cd, As, V, Tl) sono presenti prevalentemente nella frazione fine e come specie chimiche solubili, più accessibili per l’ambiente e per l’uomo.
Le concentrazioni elementari ai tre siti sono risultate estremamente simili, indicando la grande omogeneità spaziale della composizione del PM e lo scarso contributo delle sorgenti locali, incluse quelle di tipo industriale. L'elevata stabilità atmosferica che caratterizza l'area di studio nei mesi invernali si conferma essere una delle cause principali del pronunciato aumento invernale delle concentrazioni elementari, anche se alcuni elementi, come Pb, Sn, Ni, Li e Rb, presentano contributi significativi da sorgenti a carattere stagionale. Le concentrazioni medie di alcuni elementi (Ti, Fe, Mn, S, V, Ni) sono influenzate dal trasporto a lungo raggio di masse d’aria provenienti dall'area sahariana (più frequenti nei mesi estivi) e dai paesi dell'est Europa (più frequenti nei mesi invernali)
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