323,441 research outputs found
Induction of EROD activity in European eel (Anguilla anguilla) experimentally exposed to B(a)P and βNP
No full textThe induction of liver ethoxyresorufin O-deethylase (EROD) activity was investigated in the European eel, Anguilla anguilla, collected from a Mediterranean brackish environment and experimentally exposed to benzo[a]pyrene (B[a]P) and h-naphthoflavone (BNF). Eels were injected intraperitoneally at increasing doses (0.1, 1, 10, and 50 mg/kg wet body weight) using corn oil as a carrier and sacrificed after 7 days. The main objectives of the present study are: (1) to assess of the sensitivity of EROD induction as a biomarker to polycyclic aromatic hydrocarbon (PAH) exposure; (2) to determine an EROD dose–response relationship of the contaminants used; and (3) to compare the efficiency of B[a]P and BNF as inducers of EROD activity. Results showed that both chemicals resulted in a dose-dependent EROD induction, but increases were not linear. EROD activity seemed to reach a plateau at the exposure of 10 mg/kg in both treatment groups; B[a]P was a more potent inducer than BNF was at the higher doses (10 and 50 mg/kg), while the opposite result was observed at the lower ones (0.1 and 1 mg/kg). The greatest induction occurred in eels treated with 10 mg/kg B[a]P, in which a 261-fold increase in EROD activity was observed. Results showed that EROD activity in A. anguilla is significantly induced by B[a]P and BNF exposure, responding to a wide range of concentrations of these contaminants. We infer that this tool may be suited as a diagnostic biomarker for biomonitoring PAHs pollution in Mediterranean brackish environments and further field research is suggeste
$FAKE: Evidence of Spam and Bot Activity in Stock Microblogs on Twitter
No full textMicroblogs are increasingly exploited for predicting prices and traded volumes of stocks in financial markets. However, it has been demonstrated that much of the content shared in microblogging platforms is created and publicized by bots and spammers. Yet, the presence (or lack thereof) and the impact of fake stock microblogs has never systematically been investigated before. Here, we study 9M tweets related to stocks of the 5 main financial markets in the US. By comparing tweets with financial data from Google Finance, we highlight important characteristics of Twitter stock microblogs. More importantly, we uncover a malicious practice perpetrated by coordinated groups of bots and likely aimed at promoting low-value stocks by exploiting the popularity of high-value ones. Our results call for the adoption of spam and bot detection techniques in all studies and applications that exploit user-generated content for predicting the stock market
A tale of two layers: The mutual relationship between bitcoin and lightning network
No full textA major concern of the adoption and scalability of Blockchain technologies refers to their efficient use for payments. In this work, we analyze how Lightning Network (LN), which represents a relevant infrastructural novelty, is influenced by the market dynamics of its referring cryptocurrency, namely Bitcoin. In so doing, we focus on how the LN is efficient in performing transactions and we relate this feature to the market conditions of Bitcoin. By applying the Toda–Yamamoto variant of Granger-causality, we note that market conditions of Bitcoin do not significantly influence the topological configuration of the LN. Hence, although the LN represents a second layer on the Bitcoin blockchain, our findings suggest that its efficient functioning does not appear to be related to the simple market performance of its underlying cryptocurrency and, in particular, of its volatile market fluctuations. This result may therefore contribute to shed light on the practical usage of the LN as a blockchain technology to favor transactions
School climate and academic performance of Italian students: the role of disciplinary behaviour and parental involvement
No full textEducational researchers have increasingly recognised the importance of school climate as a malleable factor for improving academic performance. In this perspective, we exploit the data collected by the Italian Institute for the Evaluation of the Education System (INVALSI) to assess the effect of some school climate related factors on academic performance of tenth-grade Italian students. A Multilevel Bayesian Structural Equation Model (MBSEM) is adopted to highlight the effect of some relevant dimensions of school climate (students’ disciplinary behaviour and parents’ involvement) on academic performance and their role on the relationships between student socioeconomic status and achievement. The main findings show that disciplinary behaviour, on the one hand, directly influences the level of competence of the students, and, on the other hand, it partly mediates the effect of socioeconomic background whereas parents’ involvement does not appear to exert any significant effect on students’ performance
Susceptibility to oxidative stress in Adelie and Emperor penguin
No full textThe antioxidant defences in aerobic organisms represent the detoxification pathway against toxicity of reactive oxygen
species (ROS). These highly reactive molecules are normally produced during the 4-electrons reduction of molecular oxygen to
water coupled with oxidative phosphorylation, and during the activity of several enzymatic systems which produce ROS as
intermediates. However, the endogenous generation of oxyradicals may be influenced by different environmental and biological
factors, and the basal efficiency of antioxidant systems generally reflects the normal prooxidant pressure to which organisms are
exposed. If the antioxidant capacity is exceeded (i.e. as a consequence of enhanced intracellular formation of ROS), a pathological
condition, generally termed oxidative stress, may arise. In this preliminary work, susceptibility to oxidative stress has been
compared in plasma of Adi lie penguin (Pygoscelis adeliae), emperor penguin (Aptenodytes forsteri), south polar skua (Catharacta
maccormicki) and snow petrel (Pagodroma nivea). Within the framework of the Italian Research Program in Antarctica, blood
samples were collected during the austral summer 1998-1999 and the Total Oxyradical Scavenging Capacity (TOSC) analysed. The
TOSC assay, measuring the capability of biological samples to neutralise different oxyradicals, has been recently standardised to
provide a quantifiable value of biological resistance to toxicity of ROS. Penguins exhibited higher scavenging capacity towards
peroxyl radicals than south polar skua and snow petrel. The greater resistance to toxicity of oxyradicals might suggest that penguins
are naturally exposed to a higher basal prooxidant pressure in comparison to other analysed Antarctic birds
An introduction to the EPR-Chameleon experiment
No full textOn September 27 (2001), as a side activity to the "Japan-Italy Joint workshop on: Quantum open systems and quantum measurement", the first; public demonstration of the dynamical EPR-chameleon experiment was performed at Waseda University in order to give an experimental answer to a long standing question in the foundations of quantum theory: do there exist classical macroscopic systems which, by local independent choices, produce sequences of data which reproduce the singlet correlations, hence violating Bell's inequality? The EPR-chameleon experiment gives an affirmative answer to this question by concretely producing an example of such systems in the form of three personal computers which realize a local deterministic dynamical evolution whose mathematical structure is very simple and transparent. In the experiment performed on September 27 the local dynamics used was not a reversible one because the interaction with the degrees of freedom of the apparatus was integrated out giving rise to an effective Markovian dynamics which, although mapping probability measures into probability measures, did not preserve the +/- 1-values of the spin (or polarization) observables. This feature was criticized by some of the partecipants and the following two questions arose: i) is it possible to prove that the Markovian evolution, used in the experiment, is indeed the reduced evolution of a bona fide reversible evolution? ii) if the answer to question (i) is affirmative, is it possible to reproduce the EPR correlations by simply considering empirical averages of +/- 1-values, as one does in usual EPR type experiments? An affirmative answer to these questions was given in the paper [AcImRe01] and it is briefly reviewed in what follows
Identificazione di un agonista parziale del recettore per il neuropeptide S
No full textLa presente invenzione riguarda la sintesi di una molecola di natura peptidica in grado di modulare l’attività del recettore per il neuropeptide S, le composizioni farmaceutiche che la contengono e il loro impiego nel trattamento di disfunzioni, condizioni o stati patologici in cui lo stesso recettore è coinvolto
Susceptibility to oxidative stress in Adélie and Emperor penguin
No full textThe antioxidant defences in aerobic organisms represent the detoxification pathway against toxicity of reactive oxygen species (ROS). These highly reactive molecules are normally produced during the 4-electrons reduction of molecular oxygen to water coupled with oxidative phosphorylation, and during the activity of several enzymatic systems which produce ROS as intermediates. However, the endogenous generation of oxyradicals may be influenced by different environmental and biological factors, and the basal efficiency of antioxidant systems generally reflects the normal prooxidant pressure to which organisms are exposed. If the antioxidant capacity is exceeded (i.e. as a consequence of enhanced intracellular formation of ROS), a pathological condition, generally termed oxidative stress, may arise. In this preliminary work, susceptibility to oxidative stress has been compared in plasma of Adélie penguin (Pygoscelis adeliae), emperor penguin (Aptenodytes forsteri), south polar skua (Catharacta maccormicki) and snow petrel (Pagodroma nivea). Within the framework of the Italian Research Program in Antarctica, blood samples were collected during the austral summer 1998-1999 and the Total Oxyradical Scavenging Capacity (TOSC) analysed. The TOSC assay, measuring the capability of biological samples to neutralise different oxyradicals, has been recently standardised to provide a quantifiable value of biological resistance to toxicity of ROS. Penguins exhibited higher scavenging capacity towards peroxyl radicals than south polar skua and snow petrel. The greater resistance to toxicity of oxyradicals might suggest that penguins are naturally exposed to a higher basal prooxidant pressure in comparison to other analysed Antarctic birds
Le attività artigiane
No full textLa disponibilità di notevoli risorse naturali permette all’Ager Volterranus costiero un precoce sviluppo delle manifatture ceramiche già a partire dal IV-III sec. a.C. La manifattura di ceramiche da mensa e di contenitori da trasporto rimane una delle principali attività produttive del territorio fino alla tarda antichità. Numerose sono le testimonianze sui materiali (bolli) o nel territorio (attraverso la toponomastica) della proprietà di aziende agricole o manifatturiere da parte delle élites locali come i Caecinae o i Rasinii
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