196 research outputs found
Semiring and semimodule issues in MV-algebras
In this paper we propose a semiring-theoretic approach to MV-algebras based
on the connection between such algebras and idempotent semirings - such an
approach naturally imposing the introduction and study of a suitable
corresponding class of semimodules, called MV-semimodules.
We present several results addressed toward a semiring theory for
MV-algebras. In particular we show a representation of MV-algebras as a
subsemiring of the endomorphism semiring of a semilattice, the construction of
the Grothendieck group of a semiring and its functorial nature, and the effect
of Mundici categorical equivalence between MV-algebras and lattice-ordered
Abelian groups with a distinguished strong order unit upon the relationship
between MV-semimodules and semimodules over idempotent semifields.Comment: This version contains some corrections to some results at the end of
Section
A Comparison of Some Fuzzy Relation-based Linguistic Preference Models for Multiple-Factor Project Assessment
Some approaches to the use of linguistic-preference models based on fuzzy relations in the context of multiple factor project assessment are considered. Projects are characterized in terms of linguistic expressions of 'performance' with respect to factors or impacts and the 'importance' of those factors and impacts. Some variations of methods by Wilhelm and Parsaei (1991) and Eldukair and Ayyub (1992) are considered with some possible analogous methods. A simple illustrative, hypothetical example is developed to compare methods in the context of a proposed bridge river crossing in the city of Brisbane, Queensland, Australia, assessed against six factors: (1) cost, (2) lifespan, (3) usage, (4) aesthetics, (5) construction time, and (6) environmental impact
Molecular dynamics with coupling to an external bath
In molecular dynamics (MD) simulations the need often arises to maintain such parameters as temperature or pressure rather than energy and volume, or to impose gradients for studying transport properties in nonequilibrium MD. A method is described to realize coupling to an external bath with constant temperature or pressure with adjustable time constants for the coupling. The method is easily extendable to other variables and to gradients, and can be applied also to polyatomic molecules involving internal constraints. The influence of coupling time constants on dynamical variables is evaluated. A leap‐frog algorithm is presented for the general case involving constraints with coupling to both a constant temperature and a constant pressure bath
Interval valued (\in,\ivq)-fuzzy filters of pseudo -algebras
We introduce the concept of quasi-coincidence of a fuzzy interval value with
an interval valued fuzzy set. By using this new idea, we introduce the notions
of interval valued (\in,\ivq)-fuzzy filters of pseudo -algebras and
investigate some of their related properties. Some characterization theorems of
these generalized interval valued fuzzy filters are derived. The relationship
among these generalized interval valued fuzzy filters of pseudo -algebras
is considered. Finally, we consider the concept of implication-based interval
valued fuzzy implicative filters of pseudo -algebras, in particular, the
implication operators in Lukasiewicz system of continuous-valued logic are
discussed
Hyperstates of Involutive MTL-Algebras that Satisfy
States of MV-algebras have been the object of intensive study and attempts of
generalizations. The aim of this contribution is to provide a preliminary
investigation for states of prelinear semihoops and hyperstates of algebras in
the variety generated by perfect and involutive MTL-algebras (IBP0-algebras for
short). Grounding on a recent result showing that IBP0-algebras can be
constructed from a Boolean algebra, a prelinear semihoop and a suitably defined
operator between them, our first investigation on states of prelinear semihoops
will support and justify the notion of hyperstate for IBP0- algebras and will
actually show that each such map can be represented by a probability measure on
its Boolean skeleton, and a state on a suitably defined abelian l-group.Comment: 12 page
Efficacy and safety of therapies for COVID-19 in pregnancy: a systematic review and meta-analysis
Background: Clinical evidence suggests that pregnant women are more vulnerable to COVID-19, since they are at increased risk for disease progression and for obstetric complications, such as premature labor, miscarriage, preeclampsia, cesarean delivery, fetal growth restriction and perinatal death. Despite this evidence, pregnant women are often excluded from clinical trials, resulting in limited knowledge on COVID-19 management. The aim of this systematic review and meta-analysis is to provide better evidence on the efficacy and safety of available COVID-19 treatment in pregnant women. Methods: Four authors searched major electronic databases from inception until 1 st November-2022 for controlled trials/observational studies, investigating outcomes after the administration of anti-SARS-CoV-2 treatments in pregnant women affected by COVID-19. The analyses investigated the cumulative incidence of delivery and maternal outcomes in pregnant women, comparing those taking active medication vs standard care. Risk ratios (RRs) with 95% confidence intervals were calculated. Statistical significance was assessed using the random effects model and inverse-variance method. This systematic review and meta-analysis was conducted in accordance with the updated 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The protocol has been registered in Prospero (number registration: CRD42023397445). Results: From initially 937 non duplicate records, we assessed the full texts of 40 articles, finally including ten studies. In six studies, including 1627 patients, the use of casirivimab/imdevimab (CAS/IMD), remdesivir, and IFN-alpha 2b significantly decreased the need of cesarean section ((RR = 0.665; 95%CI: 0.491–0.899; p = 0.008; I 2 = 19.5%;) (Table 1, (Fig. 1). Treatments did not decrease the risk of preterm delivery, admission to neonatal ICU, or stillbirth/perinatal loss (p-values > 0.50 for all these outcomes) and did not prevent the progression of disease towards severe degrees (k = 8; 2,374 pregnant women; RR = 0.778; 95%CI: 0.550–1.099; p = 0.15; I 2 = 0%). Moreover, the use of medications during pregnancy did not modify the incidence of maternal death in two studies (Table 2). Conclusions: To our analysis, CAS/IMD, remdesivir, and IFN alpha 2b reduced the number of cesarean sections but demonstrated no effect on disease progression and other obstetric and COVID-19 related outcomes. The inability to evaluate the influence of viral load on illness development in pregnant women was attributed to lack of data. In our systematic review, no major side effects were reported. Though, it is essential for the medical community to focus more on clinical trials and less on episodic case reports and case series, with standardization of fetal and maternal outcomes
Electron-hole asymmetry in two-terminal graphene devices
A theoretical model is proposed to describe asymmetric gate-voltage
dependence of conductance and noise in two-terminal ballistic graphene devices.
The model is analyzed independently within the self-consistent Hartree and
Thomas-Fermi approximations. Our results justify the prominent role of metal
contacts in recent experiments with suspended graphene flakes. The
contact-induced electrostatic potentials in graphene demonstrate a power-law
decay with the exponent varying from -1 to -0.5. Within our model we explain
electron-hole asymmetry and strong Fabri-Perot oscillations of the conductance
and noise at positive doping, which were observed in many experiments with
submicrometer samples. Limitations of the Thomas-Fermi approximation in a
vicinity of the Dirac point are discussed.Comment: 7 pages, 8 figure
Co-firing of biomass with coals Part 1. Thermogravimetric kinetic analysis of combustion of fir (abies bornmulleriana) wood
The chemical composition and reactivity of fir (Abies bornmulleriana) wood under non-isothermal thermogravimetric (TG) conditions were studied. Oxidation of the wood sample at temperatures near 600 A degrees C caused the loss of aliphatics from the structure of the wood and created a char heavily containing C-O functionalities and of highly aromatic character. On-line FTIR recordings of the combustion of wood indicated the oxidation of carbonaceous and hydrogen content of the wood and release of some hydrocarbons due to pyrolysis reactions that occurred during combustion of the wood. TG analysis was used to study combustion of fir wood. Non-isothermal TG data were used to evaluate the kinetics of the combustion of this carbonaceous material. The article reports application of Ozawa-Flynn-Wall model to deal with non-isothermal TG data for the evaluation of the activation energy corresponding to the combustion of the fir wood. The average activation energy related to fir wood combustion was 128.9 kJ/mol, and the average reaction order for the combustion of wood was calculated as 0.30
Molecular analysis of the apoptotic effects of BPA in acute myeloid leukemia cells
<p>Abstract</p> <p>Background:</p> <p>BPA (bisphenol A or 2,2-bis(4-hydroxy-phenol)propane) is present in the manufacture of polycarbonate plastic and epoxy resins, which can be used in impact-resistant safety equipment and baby bottles, as protective coatings inside metal food containers, and as composites and sealants in dentistry. Recently, attention has focused on the estrogen-like and carcinogenic adverse effects of BPA. Thus, it is necessary to investigate the cytotoxicity and apoptosis-inducing activity of this compound.</p> <p>Methods:</p> <p>Cell cycle, apoptosis and differentiation analyses; western blots.</p> <p>Results:</p> <p>BPA is able to induce cell cycle arrest and apoptosis in three different acute myeloid leukemias. Although some granulocytic differentiation concomitantly occurred in NB4 cells upon BPA treatment, the major action was the induction of apoptosis. BPA mediated apoptosis was caspase dependent and occurred by activation of extrinsic and intrinsic cell death pathways modulating both FAS and TRAIL and by inducing BAD phosphorylation in NB4 cells. Finally, also non genomic actions such as the early decrease of both ERK and AKT phosphorylation were induced by BPA thus indicating that a complex intersection of regulations occur for the apoptotic action of BPA.</p> <p>Conclusion:</p> <p>BPA is able to induce apoptosis in leukemia cells via caspase activation and involvement of both intrinsic and extrinsic pathways of apoptosis.</p
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