3126019 documents found, page 312302 of 312602
Monitorização psicoterapêutica com crianças e adolescentes em situação de vulne...
Gonçalves, Beatriz AlvesO presente estudo tem como principal objetivo analisar a relação entre a sintomatologia e o consumo iniciais e a evolução observada ao longo do processo terapêutico de crianças e adolescentes em situação de vulnerabilidade psicossocial, recorrendo a indicadores sistemáticos de monitorização. No estudo participaram 193 crianças e jovens com idades compreendidas entre os 6 e os 18 anos, em acompanhamento psicológ...
Another note on effective descent morphisms of topological spaces and relationa...
Clementino, Maria Manuel; Janelidze, GeorgeWe make three independent observations on characterizing effective descent morphisms in the category of topological spaces. The first of them proposes a new modification of known characterizations of effective descent morphisms of general spaces, while the other two are devoted to locally finite and Hausdorff spaces, respectively. The Hausdorff case is considered, as far as we could, at the more general level o...
Strict monadic topology I: First separation axioms and reflections
Janelidze, George; Sobral, ManuelaGiven a monad T on the category of sets, we consider reflections of Alg(T) into its full subcategories formed by algebras satisfying natural counterparts of topological separation axioms T_0, T_1, T_2, T_ts, and T_ths; here ts stands for totally separated and ths for what we call totally homomorphically separated, which coincides with ts in the (compact Hausdorff) topological case. We ask whether these reflecti...
On difunctionality of class relations
Hoefnagel, Michael; Janelidze, Zurab; Rodelo, DianaFor a given variety V of algebras, we define a class relation to be a binary relation R ⊆ S^2 which is of the form R = S^2 ∩ K for some congruence class K on A^2, where A is an algebra in V such that S ⊆ A. In this paper we study the following property of V: every reflexive class relation is an equivalence relation. In particular, we obtain equivalent characterizations of this property analogous to well-known e...
Facets of congruence distributivity in Goursat categories
Gran, Marino; Rodelo, Diana; Nguefeu, Idriss TchoffoWe give new characterisations of regular Mal'tsev categories with distributive lattice of equivalence relations through variations of the so-called Triangular Lemma and Trapezoid Lemma in universal algebra. We then give new characterisations of equivalence distributive Goursat categories (which extend 3-permutable varieties) through variations of the Triangular and Trapezoid Lemmas involving reflexive and posit...
Intrinsic Schreier Split Extensions
Montoli, Andrea; Rodelo, Diana; Van der Linden, TimIn the context of regular unital categories we introduce an intrinsic version of the notion of a Schreier split epimorphism, originally considered for monoids. We show that such split epimorphisms satisfy the same homological properties as Schreier split epimorphisms of monoids do. This gives rise to new examples of S-protomodular categories, and allows us to better understand the homological behaviour of monoi...
Goursat completions
Rodelo, Diana; Nguefeu, Idriss TchoffoWe characterize categories with weak finite limits whose regular completions give rise to Goursat categories.
Cancellative conjugation semigroups and monoids
Garrão, Ana Paula; Martins-Ferreira, Nelson; Raposo, Margarida; Sobral, ManuelaWe show that the category of cancellative conjugation semigroups is weakly Mal’tsev and give a characterization of all admissible diagrams there. In the category of cancellative conjugation monoids we describe, for Schreier split epimorphisms with codomain B and kernel X, all morphisms h:X→B which induce a reflexive graph, an internal category or an internal groupoid. We describe Schreier split epimorphisms in ...
Split extensions and semidirect products of unitary magmas
Gran, Marino; Janelidze, George; Sobral, ManuelaWe develop a theory of split extensions of unitary magmas, which includes defining such extensions and describing them via suitably defined semidirect product, yielding an equivalence between the categories of split extensions and of (suitably defined) actions of unitary magmas on unitary magmas. The class of split extensions is pullback stable but not closed under composition. We introduce two subclasses of it...
On the classification of Schreier extensions of monoids with non-abelian kernel
Martins-Ferreira, Nelson; Montoli, Andrea; Patchkoria, Alex; Sobral, ManuelaWe show that any regular (right) Schreier extension of a monoid M by a monoid A induces an abstract kernel \Phi: M \rightarrow\frac{End(A)}{Inn(A)}. If an abstract kernel factors through \frac{SEnd(A)}{Inn(A)}, where SEnd(A) is the monoid of surjective endomorphisms of A, then we associate to it an obstruction, which is an element of the third cohomology group of M with coeffcients in the abelian group U(Z(A)) ...