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Differential constraints for hyperbolic systems through k-Riemann invariants
No full textIn this paper we develop a reduction procedure for determining exact wave solutions of first order quasilinear hyperbolic one-dimensional nonhomogeneous systems. The approach is formulated within the theoretical framework of the method of differential constraints and it makes use of the k−Riemann invariants. The solutions obtained permit to characterize rarefaction waves also for nonhomogeneous models so that Riemann problems can be solved. Applications to the Euler system describing an ideal fluid with a source term are given
New thermodynamic aspects and speciation properties of the angiotensin-converting enzyme inhibitor drug, lisinopril with Cu2+, Zn2+, Ca2+, Mg2+ in sodium chloride aqueous solution
No full text(2 S )-1-[(2 S )-6-amino-2-[[(1 S )-1-carboxy-3-phenylpropyl]amino]hexanoyl]pyrrolidine-2- carboxylic acid (Lisinopril) is a drug commonly used to treat hypertension and heart failure. In recent years, it has also been identified as an emerging environmental contaminant. In this study, the thermodynamic behavior of lisinopril in aqueous solution was investigated. The protonation constants of lisinopril were determined potentiometrically at different temperatures (288.15 ≤ T /K ≤ 310.15) and ionic strengths (0.16 ≤ I /mol kg−1(H2O) ≤ 0.97, NaCl). The findings indicate that the first two and the fourth protonation steps are driven by enthalpic contributions, whereas the third is slightly entropy driven. Furthermore, based on the distinct acid-base characteristics of the metal ions and the possible formation of sparingly soluble species, different speciation models were proposed for the various metal/lisinopril systems, including: ZnH2L+2, ZnHL+, CuHL+, CuL, CaL, CaHL+, MgL and MgHL+. The Specific Ion Interaction Theory (SIT) and a modified extended Debye–Hückel equation were employed to model the thermodynamic formation parameters as a function of ionic strength and temperature. Finally, the distribution of lisinopril species (protonation and complex formation constants) under conditions simulating real systems, such as seawater, was evaluated
Preference Modeling and Choice Theory: A Set-Theoretic Approach to Rationality
No full textIn this thesis we explore some classical assumptions in preference modeling and
rational choice theory, and then extend them by means of set-theoretic methods.
The first half of this work mainly focuses on the modelization of the preference
structure of a decision maker by means of binary relations. Our starting point is
the presentation of some very recent approaches to preference modeling. These approaches
employ two or more binary relations in the process of modeling preferences,
thus ensuring a more accurate and realistic description of the agent’s attitude.
The resulting preference structures that we obtain still satisfy the two basic tenets
of economic rationality, namely the two properties of transitivity and completeness,
distributing them along the whole structure rather than requiring that they hold
for a single binary relation. Next, we deal with the properties of transitivity and
completeness on their own: first, we provide an explicit characterizations of various
known properties of possibly intransitive (but complete) structures; then, we study
the representation of possibly incomplete (but transitive) binary relations. Finally,
we extend classical revealed preference theory by introducing a novel paradigm of
rationality.
In the second half of this work, we focus on choice theory. First, we explicitly
represent many known models of bounded rationality as special cases of choice under
‘limited attention’. Next, we introduce a novel notion of choice independence
for multidimensional choices, which captures the possible invariance of some of the
dimensions involved in the decision process. The next chapter deals with the classical
dichotomy between rational and irrational choice behavior, and provides a much
more accurate partition of the family of irrational choices according to their degree
of rationality. The last chapter of this work extends to a stochastic setting the recent
notion of choice resolution, which is an operation that captures types of selection
displaying hierarchical features
Senotherapeutic effects of quercetin against H2O2-induced senescence in SH-SY5Y neuronal cells
No full textStudy of neutron efficiency and cross-talk effects through Monte Carlo simulations for a new neutron detector NArCoS
No full textThe simultaneous detection of neutrons and charged particles is an important goal for the present and future facilities delivering radioactive ion beams (RIBs), especially in the case of neutron-rich ones, to understand structure and dynamics of reactions between systems with high isospin asymmetry. The NArCoS project (Neutron Array for Correlation Studies) is aimed at studying and developing a new modular and versatile array devoted to detecting, at the same time, neutrons and charged particles both with high energy and angular resolution. Final detector prototype will be an array of 64 elementary cells of EJ-276G plastic scintillators, with a dimension of 3×3×3 cm3, individually read by a SiPM matrix. One of the main points of the present work is to evaluate cross-talk phenomena in different conditions. In this contribution the results about cross-talk probability and neutron detection efficiency, obtained using two different Monte Carlo simulation codes, GEANT4 and MCNPX, will be discussed. All these studies will allow to evaluate the better setup for NArCoS array in order to maximize neutrons detection efficiency and to minimize the cross-talk probability
Border flexibilization, the securitization of migration, and unaccompanied minors’ subjectivity: a case study
No full textIn the Euro-Mediterranean region, the securitization of migration policies operates through the externalization of border controls and the thickening of legal barriers that permit or deny access to rights. These operations can be observed by analyzing unaccompanied foreign minors, whose dual legal status places them both in the condition of foreign migrants as well as minors, and therefore subjects both to border control and extensive legal protection. My empirical research lies at the intersection of these two opposing and changing spheres and is based in the city of Messina (Sicily), where there is a signifcant presence of UAMs. It analyses the most recent Italian securitization legislation in the feld, investigates
the local institutional and policies arena through 20 qualitative interviews with UAMs and institutional and social actors; its aim is to provide a critical account of the securitization of migration policy and how it affects vulnerable subjects such as UAMs
Multi-Criteria Selection of FFF-Printed Gyroid Sandwich Structures in PLA and PLA–Flax Using AHP–TOPSIS
No full textSupercritical Carbon Dioxide Extraction With Dimethyl Carbonate and Bio-Ethanol as Co-Solvents for the Determination of Pesticide Residues in Black Pepper by Low-Pressure Gas Chromatography–Triple Quadrupole Mass Spectrometry
No full textThe determination of pesticide residues in spices is analytically challenging due to their high content of essential oils and secondary metabolites that could interfere with detection and quantification. In this study, supercritical fluid extraction (SFE), using green co-solvents, was evaluated for the extraction of 44 pesticides from black pepper (Piper nigrum). The extraction performance of bio-ethanol (bio-EtOH) and dimethyl carbonate (DMC) was compared under mild operating conditions. Optimal recoveries were obtained with 10% DMC, yielding an average of 92.6% across 44 pesticides, comparable to 93.7% using bio-EtOH. Method performance was assessed by low-pressure gas chromatography–triple quadrupole mass spectrometry (LP-GC-QqQMS). Linearity was achieved over the tested range, with limits of detection (within the range 0.1–17.9 μg kg−1) and quantification (within the range 0.3–59.8 μg kg−1) always below European Union (EU) maximum residue levels (MRLs). Accuracy ranged from 74.4% to 107.7%, with intra-day precision between 0.8% and 16.1%. A pronounced matrix effect was observed (average ionization suppression: −47.6%). The application of the validated method to commercial black pepper samples revealed the presence of diphenylamine, quinalphos, and phosalone, with only quinalphos exceeding EU MRLs. These findings demonstrate that SFE with DMC as a co-solvent provides an efficient, greener, and reliable extraction approach for multi-residue pesticide analysis in a complex spice matrix. The combination of SFE with LP-GC-QqQMS supports the implementation of greener and high-throughput monitoring workflows for complex spice matrices
Proportion of newly diagnosed persons with HIV with HIV-RNA greater than/equal to 500,000 copies/mL in 2018-2023 in Italy: data from the ICONA Foundation Cohort Study
No full textPurpose: To evaluate the prevalence of persons with HIV (PWH) diagnosed with HIV-RNA >= 500,000 copies/mL according to calendar periods and to identify any associated factors.
Method: Inclusion criteria: PWH enrolled in the ICONA cohort between 1997 and 2023 with chronic HIV (acute HIV disease/recent <1 year- seroconversion excluded). Calendar periods examined: 1997-1999, 2000-2003, 2004--2007, 2008-2011, 2012-2015, 2016-2019, 2020-2023.
Logistic regression analyses were performed to identify factors associated with being highly viremic PWH (HV-PWH, HIV-RNA >=500,000 copies/ml) at diagnosis: age, sex, risk behavior, scholarity, occupation, born in Italy, CD4<350 cells/cmm), AIDS, calendar period.
Results: A total of 2092/14682 (14.2%; 95%CI: 13.7% -14.8%) PWH were diagnosed with HIV-RNA >=500,000 copies/ml. Characteristics of the cohort according to HIV-RNA strata are shown in Table 1. Prevalence of HV-PWH were increasing in more recent calendar periods (p-value for trend <.001).
Being diagnosed in more recent calendar periods, being males, with older age, born in Italy, unemployed, with acquired HIV infection by sexual routes, AIDS presenters and with CD4<350 cells/cmm were independent factors of being highly viremic at HIV diagnosis.
We also found evidence for interaction between CD4 count at diagnosis and HV according to calendar period, with a higher and increasing risk of HV in PWH with CD4>350 cells/cmm in more recent years compared to previous periods, after adjustment for socio-demographic and clinical variables (Figure2B).Conclusions: A steep increase in prevalence of HV among newly diagnosed PWH without known acute infection has been identified in recent years, also among PWH with CD4>=350 cells/cmm. The reasons have to be further evaluated, considering also the modification of diagnostic HIV-RNA tests overtime, the circulation of new subtypes and the modulation of the biological characteristics of HIV, whose tendency, as every virus, is to adapt to the host by increasing the replication capacity without increase pathogenicity