Implementación de un componente para el préstamo de material bibliográfico digital para la biblioteca virtual en el cib-ESPOL

En el presente artículo se resume cómo se ha elaborado un componente para la Biblioteca Virtual de la ESPOL, que busca facilitar la lectura, por medio de libros digitales, completos y de manera legal a través del préstamo de los mismo, de manera online, usando la tecnología de hoy en día, que se encuentra cada vez mas al alcance de todos, haciendo uso de la misma con mayor frecuencia gracias a su accesibilidad, rapidez e interactividad. El componente constará de dos módulos, el administrador en donde se administrará el material bibliográfico y el módulo usuario que permitirá a los estudiantes de la comunidad politécnica acceder mediante su usuario y contraseña para así poder realizar el préstamo del material que necesite. Para el desarrollo de este componente se han utilizado tecnologías modernas como Responsive Web Design Calibre, eCub y las tecnologías clásicas como MySQL, PHP, JavaScript, Jquery, entre otros

Multivector Field Formulation of Hamiltonian Field Theories: Equations and Symmetries

We state the intrinsic form of the Hamiltonian equations of first-order Classical Field theories in three equivalent geometrical ways: using multivector fields, jet fields and connections. Thus, these equations are given in a form similar to that in which the Hamiltonian equations of mechanics are usually given. Then, using multivector fields, we study several aspects of these equations, such as the existence and non-uniqueness of solutions, and the integrability problem. In particular, these problems are analyzed for the case of Hamiltonian systems defined in a submanifold of the multimomentum bundle. Furthermore, the existence of first integrals of these Hamiltonian equations is considered, and the relation between {\sl Cartan-Noether symmetries} and {\sl general symmetries} of the system is discussed. Noether's theorem is also stated in this context, both the ``classical'' version and its generalization to include higher-order Cartan-Noether symmetries. Finally, the equivalence between the Lagrangian and Hamiltonian formalisms is also discussed.Comment: Some minor mistakes are corrected. Bibliography is updated. To be published in J. Phys. A: Mathematical and Genera

Pathogenicity of Entomopathogenic Fungi on the Weevil of the Andes (Premnotrypes vorax Hustache) of the Potato (Solanum tuberosum L.) in Chimborazo Province, Ecuador

From thirty native isolates of entomopathogenic fungi, which were obtained from corpses of larvae and adults of Andean weevil (Premnotrypes vorax Hustache); two fungi with entomopathogenic characteristics were selected through laboratory tests, which will be used in a program of integrated management of this pest in the Ecuadorian inter-Andean region. The pathogenicity of the 30 isolates was determined by the mortality that they caused in larvae and adults and it was expressed in percentage; for this, a complete randomized design (CRD) was used. The LC50 and TL50 were determined by Probit analysis. The two selected isolates corresponded to: Metarhizium anisopliae (Metschnikoff 1879) Sorokin 1883 (A13) and  Beauveria bassiana (Bals.-Criv.) Vuill. 1912 (A21), which proved to be the best, because they caused the highest mortality in larvae of the fourth instar and adults of P. vorax. The Probit analysis showed that LC50 for A21 isolate (B. bassiana) in fourth instar larvae was obtained with a concentration of 1,75x109 spores/ml and 1,08x109 spores/ml for adults. Instead for A13 isolate (M. anisopliae), the LC50 was obtained with a concentration of 1,65x109 spores/ml for larvae and 2,42x109 spores/ml for adults. The LT50 for the selected isolates at the indicated concentrations, was 4,84 and 4,32 days for larvae with A13 and A21 isolates respectively, while, for adults, the shortest time was obtained with A21 isolate in 4.36 days, compared with A13 isolate, that delayed 20,70 days. The larval stage of P. vorax was the most susceptible to A13 isolate, on the other hand, larvae and adults were equally susceptible to A21 isolate at the indicated concentrations. According to the results obtained, the two selected isolates can be used as an alternative to the use of conventional agrochemicals, which will contribute to a more ecological production

Extension of geographical distribution of three common species of diurnal butterflies (Lepidoptera: Papilionoidea) from the Colombian Caribbean

En este documento se registran tres especies comunes de mariposas diurnas de la región Caribe colombiana (Aides dysoni, Calpodes ethlius y Anteos clorinde). Los especímenes fueron capturados con red entomológica en muestreos realizados en el municipio de Arjona (departamento de Bolívar) en el año de 2015 entre las 8:00 y 16:00 horas. Para cada una de ellas se proporcionan caracteres morfológicos útiles para su reconocimiento y se complementa su distribución en el Neotrópico.In this document we extend the geographical distribution for three common species of diurnal butterflies from the Colombian Caribbean region (Aides dysoni, Calpodes ethlius, and Anteos clorinde). The specimens were captured with an insect net in samplings conducted in the Arjona jurisdiction (Bolivar, Deparment) in 2015, between 8:00 and 16:00 hours. For each of them we provide important morphological characters for their recognition, and complement their distribution in the Neotropic

Diversity and distribution of arbuscular mycorrhizal fungi along a land use gradient in Terceira Island (Azores)

More knowledge of community composition of arbuscular mycorrhizal (AM) fungi in ecosystems in relation to habitat type and land use intensity is needed. We studied AMF in 106 soil samples from pristine natural forests and a gradient of disturbance including semi-natural and intensively managed pastures of Terceira, Azores. Altogether, 42 spore morphotypes were detected from eight AMF families, revealing different fungal community structures among the three land use types. Spore density was highest in native forests and lowest in intensively managed pastures, but fungal richness was highest in semi-natural pastures and lowest in native forests. No significant difference occurred between intensively managed pastures and native forests. Members of Acaulosporaceae and Glomeraceae were dominant in native forests, while fungi from Gigasporaceae and Claroideoglomeraceae were most abundant in semi-natural and intensively managed pastures respectively, indicating family-based ecological preferences. Rarefaction analysis revealed that pastures supported more diverse AMF communities than native forests, because in high elevation pristine forests, a few rare species dominate. It is therefore likely that more species would be found with increasing survey effort. Further research is needed to clarify the influence of land use type on AMF diversity and distribution in remote islands, and the role of native AMF on soil ecosystem processes and the spread of exotic plants.This research was funded by Fundo Regional para a Ciência e Tecnologia–Governo dos Açores (M3.1.a/F/059/2016; M3.1.a/F/012/2016) and by the Development Grant (IF/00462/2013) from the Fundação para a Ciência e a Tecnologia (FCT) Portugal with national funds and co-funded by FEDER and COMPETE 2020 program. The Royal Botanic Garden Edinburgh (RBGE) is supported by the Scottish Government’s Rural and Environmental Science and Analytical Services Division.info:eu-repo/semantics/publishedVersio

Cloning, in silico structural characterization and expression analysis of MfAtr4, an ABC transporter from the banana pathogen Mycosphaerella fijiensis

ABC transporters are membrane proteins that use the energy released from the hydrolysis of ATP to drive the transport of compounds across biological membranes. In some plants, pathogenic fungi ABC transporters play a role as virulence factors by mediating the export of plant defense compounds or fungal virulence factors. Mycosphaerella fijiensis, the causal agent of black Sigatoka disease in banana, is the main constraint for the banana industry worldwide. So far, little is known about molecular mechanism that it uses to infect the host. In this study, degenerated primers designed from fungal ABC transporters known to be involved in virulence were used to isolate homologs from M. fijiensis. Here, we reported the full cloning of MfAtr4 a putative ortholog of MgAtr4, an ABC transporter of the related Mycosphaerella graminicola with a function in virulence. Similarities and differences with its presumed ortholog MgAtr4 are described, and the putative function of MfAtr4 are discussed. Analysis of MfAtr4 gene expression in field banana samples exhibiting visible symptoms of black Sigatoka disease indicated a higher expression of MfAtr4 during the first symptomatic stages in comparison to the late necrotrophic phases, suggesting a role for MfAtr4 in the early stages of pathogenic development of M. fijiensis.Key words: ABC transporters, virulence factors, MgAtr4 ortholog, Mycosphaerella fijiensis, black Sigatoka, Musa sp

Diatom metabarcoding and microscopic analyses from sediment samples at Lake Nam Co, Tibet: The effect of sample-size and bioinformatics on the identified communities

Diatoms (Bacillariophyceae) are characterized by silicified cell walls that favor their long-term preservation in sediments, therefore widely used as bioindicators of present and past water conditions. Alongside with traditional morphological analyses, metabarcoding has become a valuable tool to study the community structures of various organisms, including diatoms. Here, we test whether the quantity of sediment sample used for DNA extraction affects the results obtained from high-throughput sequencing (metabarcoding) of the diatom rbcL region by isolating DNA from 10 g and 0.5 g (wet weight) of lake surface sediment samples. Because bioinformatics processing of metabarcoding data may affect the outcome, we also tested the consistency of the results from three different pipelines: 1) ESVs (exact sequence variants) pipeline; 2) clustering sequences at 95% sequence identity to form OTUs (operational taxonomic units; 95% OTUs); and 3) 97% OTUs pipeline. Additionally, the agreement between metabarcoding data and morphological inventories of corresponding samples were compared. Our results demonstrate highly uniform patterns between the diatom rbcL amplicons from 10 g and 0.5 g of sedimentary DNA (sedDNA) extracts (HTS 10 and HTS 0.5, respectively). Furthermore, after the careful curation of the sequencing data, metabarcoding results were highly consistent among the data sets produced by different bioinformatics pipelines. Comparing results from metabarcoding and microscopy, we identified some taxonomic mismatches: morphological analyses identified 59 diatom genera, whereas metabarcoding 49 to 54 genera. These mismatches are related to incompleteness of the sequence databases, but also to inconsistencies in diatom taxonomy in general and potential dissolution effects of diatom valves caused by high alkalinity of the investigated lake waters. Nevertheless, multivariate community analysis revealed consistent results between data sets identified by microscopy and metabarcoding – water depth and conductivity as the most significant variables in driving diatom communities in Lake Nam Co – further confirming that metabarcoding is a viable method for identifying diatom-environment relationships

Detrended Fluctuation Analysis of Systolic Blood Pressure Control Loop

We use detrended fluctuation analysis (DFA) to study the dynamics of blood pressure oscillations and its feedback control in rats by analyzing systolic pressure time series before and after a surgical procedure that interrupts its control loop. We found, for each situation, a crossover between two scaling regions characterized by exponents that reflect the nature of the feedback control and its range of operation. In addition, we found evidences of adaptation in the dynamics of blood pressure regulation a few days after surgical disruption of its main feedback circuit. Based on the paradigm of antagonistic, bipartite (vagal and sympathetic) action of the central nerve system, we propose a simple model for pressure homeostasis as the balance between two nonlinear opposing forces, successfully reproducing the crossover observed in the DFA of actual pressure signals

On some aspects of the geometry of differential equations in physics

In this review paper, we consider three kinds of systems of differential equations, which are relevant in physics, control theory and other applications in engineering and applied mathematics; namely: Hamilton equations, singular differential equations, and partial differential equations in field theories. The geometric structures underlying these systems are presented and commented. The main results concerning these structures are stated and discussed, as well as their influence on the study of the differential equations with which they are related. Furthermore, research to be developed in these areas is also commented.Comment: 21 page

Cambios microscópicos en ganglios linfáticos de ratones inoculados con veneno de Bothrops alternatus

Echeverría, S.M.; Teibler, G.P.; Maruñak, S.L.; Lértora, W.J.; Leiva, L.C.: Cambios microscópicos en ganglios linfáticos de ratones inoculados con veneno de Bothrops alternatus. Rev. vet. 26: 2, 113-119, 201