An Analytic Method for SS-Expansion involving Resonance and Reduction

In this paper we describe an analytic method able to give the multiplication table(s) of the set(s) involved in an $S$-expansion process (with either resonance or $0_S$-resonant-reduction) for reaching a target Lie (super)algebra from a starting one, after having properly chosen the partitions over subspaces of the considered (super)algebras. This analytic method gives us a simple set of expressions to find the partitions over the set(s) involved in the process. Then, we use the information coming from both the initial (super)algebra and the target one for reaching the multiplication table(s) of the mentioned set(s). Finally, we check associativity with an auxiliary computational algorithm, in order to understand whether the obtained set(s) can describe semigroup(s) or just abelian set(s) connecting two (super)algebras. We also give some interesting examples of application, which check and corroborate our analytic procedure and also generalize some result already presented in the literature.Comment: v3, 47 pages, misprints corrected in Fortschritte der Physik, Published online 7 November 201

Chern-Simons and Born-Infeld gravity theories and Maxwell algebras type

Recently was shown that standard odd and even-dimensional General Relativity can be obtained from a $(2n+1)$-dimensional Chern-Simons Lagrangian invariant under the $B_{2n+1}$ algebra and from a $(2n)$-dimensional Born-Infeld Lagrangian invariant under a subalgebra $\cal{L}^{B_{2n+1}}$ respectively. Very Recently, it was shown that the generalized In\"on\"u-Wigner contraction of the generalized AdS-Maxwell algebras provides Maxwell algebras types $\cal{M}_{m}$ which correspond to the so called $B_{m}$ Lie algebras. In this article we report on a simple model that suggests a mechanism by which standard odd-dimensional General Relativity may emerge as a weak coupling constant limit of a $(2p+1)$-dimensional Chern-Simons Lagrangian invariant under the Maxwell algebra type $\cal{M}_{2m+1}$, if and only if $m\geq p$. Similarly, we show that standard even-dimensional General Relativity emerges as a weak coupling constant limit of a $(2p)$-dimensional Born-Infeld type Lagrangian invariant under a subalgebra $\cal{L}^{\cal{M}_{2m}}$ of the Maxwell algebra type, if and only if $m\geq p$. It is shown that when $m<p$ this is not possible for a $(2p+1)$-dimensional Chern-Simons Lagrangian invariant under the $\cal{M}_{2m+1}$ and for a $(2p)$-dimensional Born-Infeld type Lagrangian invariant under $\cal{L}^{\cal{M}_{2m}}$ algebra.Comment: 30 pages, accepted for publication in Eur.Phys.J.C. arXiv admin note: text overlap with arXiv:1309.006

Generalized Poincare algebras and Lovelock-Cartan gravity theory

We show that the Lagrangian for Lovelock-Cartan gravity theory can be re-formulated as an action which leads to General Relativity in a certain limit. In odd dimensions the Lagrangian leads to a Chern-Simons theory invariant under the generalized Poincar\'{e} algebra $\mathfrak{B}_{2n+1},$ while in even dimensions the Lagrangian leads to a Born-Infeld theory invariant under a subalgebra of the $\mathfrak{B}_{2n+1}$ algebra. It is also shown that torsion may occur explicitly in the Lagrangian leading to new torsional Lagrangians, which are related to the Chern-Pontryagin character for the $B_{2n+1}$ group.Comment: v2: 18 pages, minor modification in the title, some clarifications in the abstract, introduction and section 2, section 4 has been rewritten, typos corrected, references added. Accepted for publication in Physic letters

Nutrition is Perceived as an Ecosystem Service of the Mangrove by Rural People in Ecuador

The mangrove ecosystem is considered as the source of livelihood, particularly for coastal areas. This study explores the perception of the inhabitants of Puerto El Morro and the island of Costa Rica (Ecuador) against the ecosystem services of the mangrove. Seven quantitative variables were used on the Likert scale by performing exploratory factor analysis. The results were based on a sample of 94 participants finding 2 factors, tourism (29.07% of variance) and nutritious food production (25.45% of variance remaining). The reliability of the questionnaire was acceptable according to Cronbach’s Alpha 0.654. A confirmatory factor analysis is necessary to revalidate the items of the factors. Keywords: coastal communities, eating, mangroves, livelihoods, nutrition. Resumen El ecosistema de manglar se considera fuente de medios de vida, en particular para zonas costeras. Este estudio explora la percepción de los habitantes de Puerto El Morro y la isla Costa Rica (Ecuador) frente a los servicios ecosistémicos del manglar. Se utilizaron 7 variables cuantitativas en escala de Likert realizando análisis factorial exploratorio. Los resultados parten de una muestra de 94 participantes, hallando 2 factores: turismo (29,07% de varianza) y producción alimentos nutritivos (25,45% de varianza restante). La confiabilidad del cuestionario fue aceptable según el Alfa de Cronbach 0.654. Es necesario un análisis factorial confirmatorio para revalidar los ítems de los factores. Palabras Clave: comunidades costeras; alimentación; manglares; medios de vida; nutrición

Infinite S-expansion with ideal subtraction and some applications

According to the literature, the S-expansion procedure involving a finite semigroup is valid no matter what the structure of the original Lie (super)algebra is; however, when something about the structure of the starting (super)algebra is known and when certain particular conditions are met, the S-expansion method (with its features of resonance and reduction) is able not only to lead to several kinds of expanded (super)algebras but also to reproduce the effects of the standard as well as the generalized Inönü-Wigner contraction. In the present paper, we propose a new prescription for S-expansion, involving an infinite abelian semigroup S^(∞) and the subtraction of an infinite ideal subalgebra. We show that the subtraction of the infinite ideal subalgebra corresponds to a reduction. Our approach is a generalization of the finite S-expansion procedure presented in the literature, and it offers an alternative view of the generalized Inönü-Wigner contraction. We then show how to write the invariant tensors of the target (super)algebras in terms of those of the starting ones in the infinite S-expansion context presented in this work. We also give some interesting examples of application on algebras and superalgebras

Lean Manufacturing Production Method using the Change Management Approach to Reduce Backorders at SMEs in the Footwear Industry in Peru

This article proposes a production method that aims to increase the manufacturing capacity of a footwear small- and medium-sized enterprise (SME) to reduce backorders. Therefore, an assessment is carried out and delays in production processes, excess product transport time, defective products, and inefficient work methods are identified. This article proposes designing a Lean manufacturing method using the change management approach, whose methodology is composed of six phases. In phase 0, change management is carried out; in phase 1, the company's current situation is reviewed using the Value Stream Mapping (VSM); in phase 2, the work area is reorganized (implementing SLP and 5S); in phase 3, production is balanced (implementing Line Balancing); in phase 4, continual improvement is established using the Kaizen tool; and finally, in phase 5, the results are evaluated. Through validation, it was possible to confirm that Lean manufacturing tools along with change management increased order deliveries by 82%

High prevalence of chigger mite infection in a forest-specialist frog with evidence of parasite-related granulomatous myositis

Amphibians are hosts for a wide variety of micro- and macro-parasites. Chigger mites from the Hannemania genus are known to infect a wide variety of amphibian species across the Americas. In Chile, three species (H. pattoni, H. gonzaleacunae and H. ortizi) have been described infecting native anurans; however, neither impacts nor the microscopic lesions associated with these parasites have been described. Here, we document 70% prevalence of chigger mite infection in Eupsophus roseus and absence of infection in Rhinoderma darwinii in the Nahuelbuta Range, Chile. Additionally, we describe the macroscopic and microscopic lesions produced by H. ortizi in one of these species, documenting previously undescribed lesions (granulomatous myositis) within the host’s musculature. These findings highlight that further research to better understand the impacts of chigger mite infection on amphibians is urgently required in Chile and elsewhere