Here, an epidemiological model considering pro and anti-vaccination groups is proposed and analyzed. In this model, susceptible individuals can migrate between these two groups due to the influence of false and true news about safety and efficacy of vaccines. From this model, written as a set of three ordinary differential equations, analytical expressions for the disease-free steady state, the endemic steady state, and the basic reproduction number are derived. It is analytically shown that low vaccination rate and no influx to (...) the pro-vaccination group have similar impacts on the long-term amount of infected individuals. Numerical simulations are performed with parameter values of the COVID-19 pandemic to illustrate the analytical results. The possible relevance of this work is discussed from a public health perspective. (shrink)

We determine the number of non‐isomorphic semi‐Heyting algebras on an n‐element chain, where n is a positive integer, using a recursive method. We then prove that the numbers obtained agree with those determined in [1]. We apply the formula to calculate the number of non‐isomorphic semi‐Heyting chains of a given size in some important subvarieties of the variety of semi‐Heyting algebras that were introduced in [5]. We further exploit this recursive method to calculate the numbers of non‐isomorphic semi‐Heyting chains with (...) n elements such that removing the mth element () we are left with a subalgebra. We also solve a related problem posed in [1] of determining the number of ways a semi‐Heyting chain with elements can be extended to a n element semi‐Heyting chain by adding a new element in the mth place. Finally we combine these results by finding a second way to calculate the numbers that provides some extra information. (shrink)

This article’s assumption is that ordinary aesthetics does not necessarily imply a distancing from art and artists; rather, it can benefit from the input of creators when they use everyday scenes or objects as their theme. This approach focuses on the practice of twentieth-century Italian painter Giorgio Morandi, who depicted compositions of common objects such as bottles, jars, and vases. Through Morandi’s meditative and artistic search, these objects are given value and aesthetic elevation in his paintings. Thomas Leddy’s aesthetics of (...) everyday life will also be called upon in my analysis, insofar as the author recognizes a continuity between the ordinary and the extraordinary, through auratic experiences. If Morandi discovers the extraordinary in the trivial, this is achieved through a gradual process of selection regarding the objects he favoured, which allows for the interaction of various levels of aesthetic intensity. Morandi’s objects and models and their preparation suggest a circulation between aesthetic degrees that, in turn, suggests a timeless “language of things” fixed through the discourse of the paintings. Along these lines, it will be necessary to address the enchantment related to common things, a mesmerizing presence of which we became more aware through Morandi compositions. (shrink)

For each integer n ≥ 2, MVn denotes the variety of MV-algebras generated by the MV-chain with n elements. Algebras in MVn are represented as continuous functions from a Boolean space into a n-element chain equipped with the discrete topology. Using these representations, maximal subalgebras of algebras in MVn are characterized, and it is shown that proper subalgebras are intersection of maximal subalgebras. When A ∈ MV3, the mentioned characterization of maximal subalgebras of A can be given in terms of (...) prime filters of the underlying lattice of A, in the form that was conjectured by A. Monteiro. (shrink)

For each integer n ≥ 2, MVn denotes the variety of MV-algebras generated by the MV-chain with n elements. Algebras in MVn are represented as continuous functions from a Boolean space into a n-element chain equipped with the discrete topology. Using these representations, maximal subalgebras of algebras in MVn are characterized, and it is shown that proper subalgebras are intersection of maximal subalgebras. When A ∈ MV3, the mentioned characterization of maximal subalgebras of A can be given in terms of (...) prime filters of the underlying lattice of A, in the form that was conjectured by A. Monteiro. (shrink)

The increase in women’s labor market participation emphasizes the importance of understanding maternal separation anxiety, that is, the unpleasant maternal emotional state, due to the actual or anticipated short-term separation from the child. Drawing on the insights of the attachment and psychoanalytic perspectives, the Maternal Separation Anxiety Scale was developed to overcome existing measurement gaps. However, prior research did not replicate its original three-factor structure in the contemporary context and in other cultural settings, using large samples composed of mothers of (...) preschool children. This study aimed to examine the factorial structure of the MSAS in a sample of 597 Portuguese mothers of children aged 5–84 months who completed the questionnaire. The exploratory factor analysis conducted in subsample 1 revealed a four-factor structure: Maternal Negative Feelings, Beliefs about Exclusive Maternal Care, Need of Proximity, and Perceptions of Separation Benefits for Children. Confirmatory factor analyses conducted in subsample 2 revealed that the original three-factor structure revealed a poor fit, whereas the four-factor solution revealed an acceptable fit. As in previous studies, our findings report deviations from the original three-factor structure of the MSAS. Three of the newly identified factors seem to reflect specific sub-dimensions that originally guided item development in the MSAS, namely, maternal negative feelings, maternal attitudes about the value of exclusive maternal care, and the need of proximity with the child. The last factor appears to represent a refinement of original items pertaining to perceptions about separation effects for children. (shrink)

The notion of monadic three-valued ukasiewicz algebras was introduced by L. Monteiro ([12], [14]) as a generalization of monadic Boolean algebras. A. Monteiro ([9], [10]) and later L. Monteiro and L. Gonzalez Coppola [17] obtained a method for the construction of a three-valued ukasiewicz algebra from a monadic Boolea algebra. In this note we give the construction of a monadic three-valued ukasiewicz algebra from a Boolean algebra B where we have defined two quantification operations and * such that *x=*x (where (...) *x=-*-x). In this case we shall say that and * commutes. If B is finite and is an existential quantifier over B, we shall show how to obtain all the existential quantifiers * which commute with .Taking into account R. Mayet [3] we also construct a monadic three-valued ukasiewicz algebra from a monadic Boolean algebra B and a monadic ideal I of B. (shrink)

Due to the pandemic and the suspension of in-person school classes, there was an interruption in the meals served to approximately 40 million students who benefited from the Brazilian National School Feeding Program (PNAE). This article describes two case studies, comparing the strategies adopted by two municipalities for maintaining school feeding during the Covid-19 pandemic in the northern region of the state of Rio de Janeiro, Brazil, and discuss possible impacts of these strategies on food and nutrition security. These municipalities (...) together cover about 81% of the population in the region. In July 2020, we conducted interviews with PNAE municipal managers, following a qualitative approach. We discuss the results in relation to existing Brazilian guidance on food and nutrition security. The municipalities have developed distinct strategies to overcome operational obstacles and maintain PNAE goals, such as distributing food kits and making cash transfers to students’ families. The main determinants of these strategies are financial availability, the relationship between municipal teams and school communities, and the pre-pandemic PNAE logistics and management. Depending on the strategy and duration of the pandemic, the impacts on food and nutrition security can be wide-ranging, affecting food quality and local farmers who sell products to PNAE. It is necessary to acknowledge that this is not a short-term pandemic and find ways to perform school feeding in accordance with PNAE criteria. (shrink)

Let the individuals of a population be divided into two groups with different personal habits. The core group is associated with health risk behaviors; the non-core group avoids unhealthy activities. Assume that the infected individuals of the core group can spread a contagious disease to the whole population. Also, assume that cure does not confer immunity. Here, an epidemiological model written as a set of ordinary differential equations is proposed to investigate the infection propagation in this population. In the model, (...) migrations between these two groups are allowed; however, the transitions from the non-core group into the core group prevail. These migrations can be either spontaneous or stimulated by social pressure. It is analytically shown that, in the scenario of spontaneous migration, the disease is either naturally eradicated or chronically persists at a constant level. In the scenario of stimulated migration, in addition to eradication and constant persistence, self-sustained oscillations in the number of sick individuals can also be found. These analytical results are illustrated by numerical simulations and discussed from a public health perspective. (shrink)