Reptilia, Squamata, Iguanidae, Stenocercus aculeatus: distribution extension and first record for Ecuador

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On the monotonicity of the correction term in Ramanujan's factorial approximation

We present two new proofs of the monotonicity of the correction term $\theta_n$ in Ramanujan's refinement of Stirling's formula.Comment: Latex, 5 page

Gonatodes caudiscutatus (Günther, 1859) (Squamata: Sphaerodactylidae): distribution extension in Ecuador

Gonatodes caudiscutatus is currently known from the Pacific coast of Ecuador, the Galapagos Archipelago and Peru (all west of the Andes). Here we provide the first records of this species from the Upper Amazon Basin east of the Andes in Ecuador. We found no morphometric or meristic differences between populations east and west of the Andes except in the number of loreals (fewer on eastern populations), and in the number of supraciliary spines (more individuals with higher number of supraciliary spines on western populations)

Characterization of Aspergillus section Flavi: molecular markers as tools to unmask cryptic species

Certains champignons, notamment des Ascomycètes, peuvent synthétiser des métabolites secondaires toxiques pour les hommes et les vertébrés, appelés mycotoxines. Étant donné que la présence de ces champignons dans les aliments de base constitue un risque potentiel pour la santé humaine et animale, les aliments de base sont éliminés lorsqu'ils sont contaminés. La section Flavi est un des groupes de champignons les plus importants du point de vue économique et sanitaire car il comprend des espèces productrices de mycotoxines. Parmi les mycotoxines produites par ce groupe se trouvent les aflatoxines (AF), considérées comme une préoccupation majeure en raison de leurs effets délétères chez les vertébrés. Les espèces de la section Flavi se développent principalement dans les régions tropicales et subtropicales car elles bénéficient de conditions environnementales optimales. De plus, les conditions de récolte et de stockage sont souvent inappropriées, favorisant ainsi leur développement. Dans les régions tempérées, ces espèces se rencontrent moins fréquemment. Cependant, le réchauffement climatique pourrait favoriser leur colonisation. L'identification des espèces d'Aspergillus de la section Flavi est un défi, en raison de l'inter- et intra-variabilité des caractères. Par conséquent, l'utilisation d'une seule méthode d'identification (caractérisation morphologique, moléculaire ou du profil des métabolites secondaires) est insuffisante. Inversement, le développement d'outils moléculaires a facilité la tâche. Le but de notre étude était de déterminer les relations entre les espèces d'Aspergillus de la section Flavi à partir de différents marqueurs moléculaires (ITS, benA, cmdA, amdS, préA, perB, ppgA, aflP, gènes Mat1), puis d'identifier ceux qui permettent une classification des espèces par inférence phylogénétique. L'utilisation de l'inférence phylogénétique dans cette étude a montré qu'il s'agit d'une approche robuste pour identifier les espèces d'Aspergillus de la section Flavi, notamment en confirmant certaines hypothèses déjà proposées pour les espèces de la section Flavi. En effet, l'ajout de marqueurs moléculaires a permis de confirmer le placement phylogénétique des espèces dans la section Flavi. De plus, une nouvelle espèce cryptique a pu être décrite : Aspergillus korhogoensis (appartenant au clade A. flavus). Notre étude a également pu mettre en évidence que les marqueurs moléculaires sélectionnés (benA, cmdA, mcm7, rpb1, preB, preA et ppgA) sont de bons candidats pour l'étude d'autres sections d'Aspergillus. L'utilisation de l'inférence phylogénétique est une méthode élégante permettant d'identifier de façon précise les espèces. Sur la base de nos résultats, il est recommandé d'utiliser des matrices concaténées pour effectuer une inférence phylogénétique dans cette section, et la meilleure combinaison inclut les gènes benA, cmdA, et l'inclusion d'un autre gène : mcm7, rpb1, preB, preA ou ppgA. A l'inverse, l'utilisation du gène ITS chez Aspergillus peut conduire à une sous-estimation de la diversité car le gène est très fortement conservé. L'étude des gènes du loci Mat1 dans la section est utile pour accroître les connaissances sur la reproduction sexuée chez les ascomycètes. De plus, plusieurs fonctions de la machinerie biologique fongique sont liées aux gènes du loci Mat1. La caractérisation du profil métabolique secondaire chez les souches d'Aspergillus de la section Flavi doit être utilisée, non seulement comme outil d'identification, mais également pour discriminer les souches toxinogènes et atoxinogènes. La section Flavi renferme des espèces capables de produire à la fois de mycotoxines et de composés bénéfiques. Parmi les mycotoxines qui devraient faire l'objet d'une attention particulière figurent les AF, l'acide cyclopiazonique, les versicolorines a et b, la stérigmatocystine. Une étude plus approfondie du métabolisme secondaire sera également utile pour la recherche de nouveaux composés bénéfiques.Some fungi, mostly Ascomycota, are able to synthesize secondary metabolites that are toxic to humans and vertebrates, called mycotoxins. Since the presence of these fungi in staples represents a potential risk to human and livestock health, staples are eliminated when they are contaminated. The section Flavi is one most important group of fungi from an economic and public health point of view because it comprises several mycotoxin producer species. Amongst the mycotoxins produced by this group are aflatoxins (AFs), considered a main concern because of their deleterious effects on humans and vertebrates. Species from section Flavi grow mainly in tropical and subtropical regions where environmental conditions are optimal, and harvest and storage conditions are not always appropriate to avoid production of mycotoxins, which enhance their growth. In temperate regions, these species are less frequent; however, climate changes can favor their colonization. Species identification in Aspergillus section Flavi is challenging because of inter- and intra- variability of traits. Therefore, the use of one identification method (morphological, molecular or secondary metabolite profile characterization) is futile. Conversely, the development of molecular tools has facilitated the task. The aim of this study was to screen the species relationships in Aspergillus section Flavi based on different molecular markers (ITS, benA, cmdA, amdS, preA, preB, ppgA, aflP, Mat1 genes), and subsequently identify which ones allow a fine species classification in the section Flavi by phylogenetic inference. The use of phylogenetic inference in the present study showed that it is a robust approach to identify Aspergillus section Flavi species. The use of this technique confirmed some of the hypotheses proposed in the Flavi section, since more genetic information was added, thus strengthening the placement of the species in the Flavi section. In addition, we described a new cryptic species in this section Aspergillus korhogoensis that is nested in A. flavus clade as the sister taxon of A. parvisclerotigenus. Likewise, the molecular markers (benA, cmdA, mcm7, rpb1, preB, preA or ppgA) were good candidates for studying other sections in Aspergillus. The use of phylogenetic inference is a good method for fine-scale species identification; however, it should be used carefully, and the morphological approach and characterization of secondary metabolites should also be carried out. Based on our results, concatenated matrices are recommended to perform phylogenetic inference in this section, and the best combination includes benA, cmdA, and the inclusion of at least one another gene (preB, mcm7, rpb1, preA or ppgA). Conversely, the use of ITS in Aspergillus may lead to an underestimation of the diversity because the gene is highly conserved. Studying mating type MAT1 loci in the section is helpful to increase the knowledge of sexual reproduction in ascomycetes. In addition, several functions of fungal biological machinery are linked to Mat1 loci genes. Secondary metabolic profile characterization of Aspergillus section Flavi strains should be performed, not only as an identification tool, but also to discriminate toxinogenic and atoxinogenic strains. Section Flavi encloses species able to produce a mixture of mycotoxins and beneficial compounds. Amongst mycotoxins that should be screened are AFs, cyclopiazonic acid, A and B versicolorin, sterigmatocystin, tenuazonic acid. An exhaustive study of the secondary metabolism can also be useful to investigate novel beneficial products

Editorial: Neurodegeneration: From Genetics to Molecules (Part II)

Among non-transmissible chronic diseases, neurodegenerative complications have become a big challenge in public health. Elongation of human lifespan, due in part to better health services, lifestyle changes, and improvements in medicine and nutrition, has brought up in consequence, an emergence in growing scientific knowledge on fields related to aging and longevity physiology. This new social context faces human medicine to novel concerns that includes coping with chronic diseases that affect life quality at elderly and that increasingly, appear earlier in mid-age and young people

Editorial: Neurodegeneration: from Genetics to Molecules

Chronic degenerative diseases are one of the major public health problems, particularly those affecting the nervous system. They are characterized by the degeneration of specific cell populations that include several pathologies which contribute significantly to morbidity and mortality in the elderly population. Therefore, in recent years, the study of neuroscience has gained significant importance. Most of these neurodegenerative disorders are the result of a complex interaction between genetic and environmental factors that generate progression and can even determine its severity. The presence of mutations in genes as LRRK2, SNCA, PARK7, PARK2 or PINK1 is associated with Parkinson's disease. Mutations in genes such as APP, PS1 and PS2 are associated with familial Alzheimer's disease; while HTT gene mutations are the cause of Huntington's disease. In most cases, this condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. It is known that these mutations can also alter the proteins function; however, it has not yet been possible to fully understand how some genetic changes cause the disease or influence the risk of developing these disorders. Most symptoms seen in these conditions occurs when specific nerve cells are damaged or die generating a loss in brain communication. Also many of these mutations generate aggregation of intracellular or extracellular proteins affecting cell function and eventually causing neuronal death. It is unclear whether the presence of these aggregates play an important role in nerve cell death during the development of neurodegenerative diseases, or if they are simply part of the response of cells to the disease. Other mutations affect the mitochondrial function generating alterations in energy production and promoting the formation of unstable molecules such as free radicals. Under normal conditions, the harmful effects caused by free radicals, are offset within the cell. However, in pathological conditions, the presence of mutations can alter this process by allowing the accumulation of radicals and damaging or killing cells. On the other hand, we also know that these diseases may not have a direct genetic component, thus, the study of sporadic type neurodegenerative diseases is much more complex. Histopathological lesions as well as the cellular and molecular alterations are generally indistinguishable from familial cases. For this reason, it is important to understand the genetic and molecular mechanisms associated with this type of pathologies. In this sense, this issue aims to understand the molecular processes that occur in the brain, and how these are influenced by the environment, genetics and behavior

Uso de microRNAS como método diagnóstico para cáncer de colon

Tesis (Tecnología Médica)En Chile, el cáncer colorrectal (CCR) es una patología que ha aumentado su incidencia y mortalidad en los últimos años. Actualmente su diagnóstico es realizado en base a métodos invasivos, costosos o poco confiables. En consecuencia, surge la necesidad de buscar nuevas alternativas para su detección temprana, donde los microRNAs (miRNAs) emergen como una opción viable como biomarcadores diagnósticos de CCR. Los microRNAs son pequeñas moléculas de RNA no codificantes capaces de regular indirectamente la expresión génica y pueden sufrir desregulaciones que en algunos casos promueven la proliferación celular y otros procesos que llevan a la transformación tumoral por sus actividades como oncogenes y/o supresores de tumores. En esta investigación se analizaron 5 microRNAs (miR-21, miR-92a, miR-135b, miR-200c y miR-802) que podrían ser un posible blanco de estudio como nuevas herramientas en el diagnóstico del CCR, también se distinguieron factores que inciden sobre la estandarización de la medición de estos. Como resultado, obtuvimos que miR-21 con miR-92a podrían ser los más aptos para la detección temprana de CCR, pero no específicos de la patología al encontrarse desregulados en distintos cánceres e incluso en otras enfermedades. En cuanto a miR-135b y miR-802 no se pudo llegar a discernir su utilidad clínica pues deben ser estudiados con mayor profundidad y enfoques. Respecto a miR-200c, este fue descartado debido a su actividad contradictoria en CCR, falta de datos sobre su especificidad y sensibilidad y ser estudiado principalmente en cultivos celulares. Además, evidenciamos que actualmente no existe una estandarización universal para la cuantificación de miRNAs que permitan la comparación y reproducibilidad entre estudios relacionados a ello. Complementario a lo anterior, se sugiere la búsqueda de nuevos microRNAs que sean específicos para CCR tomando en cuenta los factores que influyen en sus mediciones, como el tipo de muestra y extracción de RNA, entre otros.Colorectal cancer (CCR) incidence and mortality has increased in Chile in the last few years. CCR diagnosis is normally performed using invasive and expensive methods yet with not total precision. As a consequence, searching for new early detection alternatives has become a must. At this point is where microRNAs (miRNAs) are considered as a viable and reliable option as CCR diagnostic biomarkers. MicroRNAs are small noncoding RNA molecules involved in gene expression regulation. In occasions miRNAs can be dysregulated themselves pathologically promoting cell proliferation and other processes that drive to tumorous cell transformation. miRNAs involved in these diseases are those with oncogene like or tumor suppressor activities. In this job, we focused on 5 microRNAs (miR-21, miR-92a, miR-135b, miR-200c and miR-802) that may be studied as new diagnostic tools in CCR diagnosis. In this study we also distinguished factors that may have an effect on the standardization of these miRNAs’ measurements. As a result, we conclude that both miR-21 and miR-92a might be the most suitable miRNas out of the five selected for early detection of CCR. However, they are not CCR specific because they are also dysregulated in other different cancers or even in other different diseases. In relation to miR-135b and miR-802 we could not reach any conclusion related to its clinical usefulness. More and deeper studies involving these two RNAs are needed. We finally discarded mir-200 as a diagnostic marker because there is contradictory data related to its role in CCR, a lack of knowledge about its specificity and sensitivity and because it has been studied mainly in cell culture lines In general terms we found that there are no clear standard rules about miRNA quantification that may allow to compare among different studies establishing reproducibility of the results. Moreover, we suggest that a search for new CCR specific miRNAs should be done taking into account the factors that influen

Modelo para el diseño de laboratorios virtuales para la Universidad Estatal a Distancia

Este documento resume los resultados parciales de investigación titulada “Propuesta técnico pedagógica para la creación de laboratorios virtuales en la UNED”. Esta es una investigación interdisciplinaria que reúne especialistas del Programa de Producción Electrónica Multimedial, de la Escuela de Ciencias de la Educación, de la Escuela de Ciencias Exactas y Naturales, del Sistema de Estudios de Posgrado y de la Dirección de Tecnología, Información y Comunicaciones de la Universidad Estatal a Distancia (UNED). La metodología de esta investigación es cualitativa y de alcance exploratorio. El proceso se llevó a cabo en tres etapas: la revisión preliminar de literatura; la revisión de la propuesta realizada en el año 2011 por la Comisión de Laboratorios Virtuales, nombrada por la Vicerrectoría Académica de la UNED; la revisión de los proyectos llevados a cabo por: University of Colorado at Boulder, Universidad Politécnica de Madrid (UPM), Stanford University, Ecured y Softonic. Derivado de esta investigación se realiza una propuesta del Modelo de Laboratorios Virtuales. Esta integra la posibilidad de la colaboración entre pares y un mayor control de las experiencias de aprendizaje por parte del estudiante. Los resultados obtenidos muestran que la producción e implementación de laboratorios virtuales en los contextos educativos conlleva consideraciones para que cumplan con la función de apoyar el proceso de aprendizaje de los estudiantes, entre los cuales se parte de los niveles de complejidad, el factor experiencial, actividades planteadas, el uso de recursos y nivel de interacción con el estudiante

Insecticide activity of bifenthrin nanoparticles synthesized by laser ablation of solids in liquids

ARTICULO DE INVESTIGACIONARTICULO DE INVESTIGACIO

Representação difusa do limiar de precipitações no desencadeamento de processos de remoção em massa

The main objective of this research is to implement a new methodology for the quantitative representation of metric records on mass removal processes that incorporates the characteristic imprecision consistent with human and/or technical nature. The research used a positivist paradigm with a quantitative scope and longitudinal measurement in a propositive context. The study sample included daily rainfall records of the Punta Ángeles meteorological stations from the Chilean Navy Meteorological Service and Meteorological Laboratory of the Institute of Geography of the Pontifical Catholic University of Valparaiso, between 2008 and 2013. As a result, it is observed that the proposed methodology allows for quick decision-making with formal statistical support, as well as consistency in the precipitation measurements from both stations. In addition, the creation of an alert threshold was improved, and no significant differences were established in the rainfall variability in the meteorological stations studied and the recording years, which leads to the conclusion that this proposal represents a qualitative improvement in generating quantitative results.El objetivo principal de esta investigación es la implementación de una nueva metodología de representación cuantitativa de registros métricos sobre los procesos de remoción en masa que incorpore la imprecisión propia y en coherencia con la naturaleza humana o técnica. La pesquisa se enmarca en un paradigma positivista, con alcance cuantitativo, de medición longitudinal, en un contexto propositivo. La muestra de estudio está caracterizada por los registros diarios de precipitaciones de las estaciones meteorológicas Punta Ángeles del Servicio Meteorológico de la Armada de Chile y Laboratorio de Meteorología del Instituto de Geografía, de la Pontificia Universidad Católica de Valparaíso, entre los años 2008 y 2013. Como resultado, se observa que la metodología propuesta permite tomar decisiones rápidas y con un soporte estadístico formal, además se muestra consistencia en las mediciones de precipitaciones realizadas por ambas estaciones; por otro lado, se mejoró la creación de un umbral de alerta y finalmente, se pudo establecer que la variabilidad de las precipitaciones en las estaciones meteorológicas de estudio y los años de registro no presentan diferencias significativas, por lo que se concluye que la propuesta se transforma en una mejora cualitativa en la generación de resultados cuantitativos.O principal objetivo desta pesquisa é a implementação de uma nova metodologia de representação quantitativa de registros métricos sobre os processos de remoção em massa que integre a imprecisão própria e congruente com a natureza humana ou técnica. A pesquisa se enquadra em um paradigma positivista, com alcance quantitativo, de medição longitudinal, em um contexto propositivo. A amostra de estudo está caracterizada pelos registros diários de precipitações das estações meteorológicas Punta Ángeles do Serviço Meteorológico da Armada do Chile e Laboratório de Meteorologia do Instituto de Geografia, da Pontifícia Universidade Católica de Valparaíso, entre os anos 2008 e 2013. Como resultado, observa-se que a metodologia proposta permite tomar decisões rápidas e com um apoio estatístico formal, além de mostrar consistência nas medições de precipitações realizadas por ambas as estações; por outro lado, a criação de um limiar de alerta melhorou e, finalmente, foi possível estabelecer que a variabilidade das precipitações nas estações meteorológicas de estudo e os anos de registro não apresentam diferenças significativas, razão pela qual a proposta se transforma em uma melhora qualitativa na geração de resultados quantitativos