Statistical tools for the improvement and optimization of electrochemical sensors

The response of electrochemical sensors for substance detection critically depends on the sensing potential, the value of which is often selected by the visual inspection of the sensor's response, as given by, for example, electrochemical methods like cyclic voltammetry (CV). Using experimental data from CV, we show how the selection of the sensing potential can affect the sensitivity and linear range of the measurements. Whenever the magnitude of the sensor's response is crucial, it can be better to optimize the sensor for its sensitivity; however, if the testing conditions involve a variable range of concentrations, with putative very small or high concentrations, a reliable response can be obtained if the sensor is optimized for the linear range.ITESO, A.C

Global characterization and target identification of piRNAs and endo-siRNAs in mouse gametes and zygotes

44 p.-1 tab.-10 fig.A set of small RNAs known as rasRNAs (repeat-associated small RNAs) have been related to the down-regulation of Transposable Elements (TEs) to safeguard genome integrity. Two key members of the rasRNAs group are piRNAs and endo-siRNAs. We have performed a comparative analysis of piRNAs and endo-siRNAs present in mouse oocytes, spermatozoa and zygotes, identified by deep sequencing and bioinformatic analysis. The detection of piRNAs and endo-siRNAs in the spermatozoa and revealed also in zygotes, hints to their potential delivery to oocytes during fertilization. However, a comparative assessment of the three cell types indicates that both piRNAs and endo-siRNAs are mainly maternally inherited. Finally, we have assessed the role of the different rasRNA molecules in connection with amplification processes by way of the "ping-pong cycle". Our results suggest that the ping-pong cycle can act on other rasRNAs, such as tRNA- and rRNA-derived fragments, thus not only being restricted to TEs during gametogenesis. © 2014 Elsevier B.V.This work was funded by grants from The European Chemical Industry Council Long-range Research Initiative (CEFIC-LRi), from the MEDDTL (11-MRESPNRPE-9-CVS-072), France, from the CSIC (PIE 201020E016), Spain.Peer reviewe

Influencia de temperatura y luz sobre la toxicidad del DNBP en postemergencia en trigo (Triticum vulgare L.).

Trigo-Triticum aestiv

SHALE PLAYS: PRONÓSTICOS DE PRODUCCIÓN A PARTIR DE SIMULACIÓN NUMÉRICA PREDICTIVA

RESUMEN El Shale gas es simplemente gas natural, compuesto generalmente de 90% de metano. Su nombre se debe a su procedencia, el esquisto (o Shale en inglés). Durante la última década este recurso se ha convertido en una fuente de energía cada vez más importante en los Estados Unidos, y el interés se ha extendido a Canadá, Europa, Asia, Australia y ahora, Latinoamérica. Debido a que los Shales no tienen suficiente permeabilidad para permitir el flujo de fluidos de forma significativa, la mayoría de estos Shales no son fuentes comerciales de gas natural y se denominan recursos no convencionales, al igual que el gas asociado a mantos de carbón, las arenas apretadas y los hidratos de gas. Debido a las condiciones que presentan este tipo de yacimientos, la viabilidad económica de su explotación económica requiere necesariamente la implementación de tecnologías de pozos horizontales combinadas con técnicas de fracturamiento hidráulico. Con el fin de optimizar los parámetros operacionales, los cuales son indispensables para garantizar el éxito de la explotación y evaluar el desempeño de este tipo de reservorios, es muy usual realizar pronósticos de producción a partir de la simulación de yacimientos. El conocimiento del posible comportamiento futuro de un yacimiento de Shale gas permite determinar la viabilidad de los proyectos, las estimaciones económicas y el incremento de la producción esperada. En este artículo se realiza el modelado numérico y analítico para un Single Well Model de shale gas con el fin de cuantificar el gas in place, el EUR de estos yacimientos y determinar la viabilidad económica al momento de explotar estos plays. Palabras claves: Shale Plays, EUR, Modelado, fracturamiento hidráulico, pozos horizontales.  SHALE PLAYS: PRODUCTION FORECASTS FROMNUMERICAL SIMULATION PREDICTIVE.  ABSTRACT The Shale gas is natural gas produced from Shales. Over the last decade, this resource has become an increasingly important source of energy in the United States, and interest has spread to Canada, Europe, Asia, Australia and now Latin America. Due to extremely low permeability to permit fluid flow significantly, most Shale are not commercial sources of natural gas and qualify as unconventional resources, as well as the coal bed methane, the tight sands and gas hydrates. To make the development of this resource economically feasible is necessary to implement horizontal wells technology combined with hydraulic fracturing techniques. In order to optimize the operational parameters, which are essential for the success of the operation, is very common production forecasting from reservoir simulation. A knowledge of the future behavior of shale gas reservoir to determine the viability of the projects, the economic estimates and expected production increase. In this paper shows the numerical and analytical modeling for a Single Well Model of shale gas in order to quantify the gas in place, the EUR of these deposits and determine the economic feasibility to produce these plays. Keywords: Shale Plays, EUR, modeling, hydraulic fracturing, horizontal wells.

Molecular systematics of the genus Acidithiobacillus:insights into the phylogenetic structure and diversification of the taxon

The acidithiobacilli are sulfur-oxidizing acidophilic bacteria that thrive in both natural and anthropogenic low pH environments. They contribute to processes that lead to the generation of acid rock drainage in several different geoclimatic contexts, and their properties have long been harnessed for the biotechnological processing of minerals. Presently, the genus is composed of seven validated species, described between 1922 and 2015: Acidithiobacillus thiooxidans, A. ferrooxidans, A. albertensis, A. caldus, A. ferrivorans, A. ferridurans, and A. ferriphilus. However, a large number of Acidithiobacillus strains and sequence clones have been obtained from a variety of ecological niches over the years, and many isolates are thought to vary in phenotypic properties and cognate genetic traits. Moreover, many isolates remain unclassified and several conflicting specific assignments muddle the picture from an evolutionary standpoint. Here we revise the phylogenetic relationships within this species complex and determine the phylogenetic species boundaries using three different typing approaches with varying degrees of resolution: 16S rRNA gene-based ribotyping, oligotyping, and multi-locus sequencing analysis (MLSA). To this end, the 580 16S rRNA gene sequences affiliated to the Acidithiobacillus spp. were collected from public and private databases and subjected to a comprehensive phylogenetic analysis. Oligotyping was used to profile high-entropy nucleotide positions and resolve meaningful differences between closely related strains at the 16S rRNA gene level. Due to its greater discriminatory power, MLSA was used as a proxy for genome-wide divergence in a smaller but representative set of strains. Results obtained indicate that there is still considerable unexplored diversity within this genus. At least six new lineages or phylotypes, supported by the different methods used herein, are evident within the Acidithiobacillus species complex. Although the diagnostic characteristics of these subgroups of strains are as yet unresolved, correlations to specific metadata hint to the mechanisms behind econiche-driven divergence of some of the species/phylotypes identified. The emerging phylogenetic structure for the genus outlined in this study can be used to guide isolate selection for future population genomics and evolutionary studies in this important acidophile model

Analysis of the Yield of Radish (Raphanus Sativus L.) Fertilized with Compost Based on Organic Waste from Markets and its Relationship with its Stomatal Density

For higher yields in vegetable cultivation, the availability of soil nutrients must be improved. Therefore, the aim of this research was to establish the relationship between stomatal density and the yield of the radish crop fertilized with compost made from organic market waste. A completely randomized block design was used, which consisted of 3 blocks and 5 treatments, which were T1, T2, T3, T4 and T5 with 00, 10, 15, 15, 20 and 25 g compost/plant respectively. The physical characteristics of the plants were evaluated from sowing to harvest and the data obtained were processed by analysis of variance and Duncan's test. Chemical analysis of the compost and soil was carried out, as well as a foliar analysis to determine the nutrient concentration by treatment. The results determined that the treatment (T4) stood out in plant length with 28.96 cm, plant weight with 43.33 g, yield of 10.82 t/ha and bulb diameter of 3.92 cm; likewise, in the concentration of nutrients in the leaves, the treatment (T5) highlighted in N with 5.94%, Ca 4.84%, Mg 1.29%, Zn 64.58 ppm and a stomatal density of 642 stomas/mm2. It is concluded that, at an adequate dose of compost, the concentration of nutrients increases, as well as the stomatal density, resulting in higher yields

Stomatal Density and its Relationship with Yield of Radish (Raphanus Sativus L.) Fertilized with Biol Produced from Sugar Cane Residues

The impact of agro-industrial waste can be reduced by using it in crop fertilization. The aim of this study was to evaluate the stomatal density and yield of radish (Raphanus Sativus L.) fertilized with biol at different concentrations, produced from sugar cane residues. A completely randomized blocks design statistical model was used, which consisted of 5 tests with 3 repetitions for each one, being T1 the control trial, and T2, T3, T4 and T5 the treatments using 2, 3, 4 and 5 L of biol in 200 L of water respectively. In terms of crop physical characteristics, the T5 treatment excelled in plant length, equatorial diameter, plant weight, as well as yield with 12.71 t/ha. Likewise, in the chemical analysis of the radish leaves, the T5 treatment showed an increase in K, Ca, Zn and MN, while the T2 did it in N, P and Cu, the T3 in Fe and the T4 in Mg. In terms of stomatal density, T5 stood out with 122 stomatal/mm2. Based on this, it is concluded that the increase in the dose of biol influences the increase in nutrient and stomatal density and hence the yield of the radish crop

Sulfoxide-Induced Homochiral Folding of ortho-Phenylene Ethynylenes (o-OPEs) by Silver(I) Templating: Structure and Chiroptical Properties

A new family of homochiral silver complexes based on carbophilic interactions with ortho-phenylene ethynylene (o-OPE) scaffolds containing up to two silver atoms are described. These compounds represent a unique class of complexes with chirality at the metal. Chiral induction is based on the inclusion of chiral sulfoxides, which allow efficient transfer of chirality to the helically folded o-OPE, leading to circularly polarized luminescence (CPL)- and vibrational circular dichroism (VCD)-active compounds. In the presence of silver(I) cations, carbophilic interactions dominate, which promote helical structures with a defined helicity. This is one of the very scarce examples of the use of such interactions in the attractive field of abiotic foldamers. The switching event has been extensively studied by using different chiroptical techniques, including circular dichroism, CPL, and VCD, and represents one of the few CPL switches described in the literature.We thank MINECO (FEDER-funded grant CTQ2014-53598-R). Computing Center CINECA, Bologna, Italy; Regione Lombardia for LISA grant no. “ChiPhyto: HPL13POZE1”, and the “Centro de Supercomputación de la UGR” (UGRGRID) are acknowledged for access to computational facilities. S.R. thanks the MECD for an FPU fellowship

Caracterización inmunológica de un grupo familiar colombiano con infección por SARS-CoV-2

Introduction: Immunological markers have been described during COVID-19 and persist after recovery. These immune markers are associated with clinical features among SARSCoV-2 infected individuals. Nevertheless, studies reporting a comprehensive analysis of the immune changes occurring during SARS-CoV-2 infection are still limited.Objective: To evaluate the production of proinflammatory cytokines, the antibody response, and the phenotype and function of NK cells and T cells in a Colombian family cluster with SARS-CoV-2 infection.Materials and methods: Proinflammatory cytokines were evaluated by RT-PCR and ELISA. The frequency, phenotype, and function of NK cells (cocultures with K562 cells) and T-cells (stimulated with spike/RdRp peptides) were assessed by flow cytometry. Anti-SARS-CoV-2 antibodies were determined using indirect immunofluorescence and plaque reduction neutralization assay.Results: During COVID-19, we observed a high proinflammatory-cytokine production and a reduced CD56bright-NK cell and cytotoxic response. Compared with healthy controls, infected individuals had a higher frequency of dysfunctional CD8+ T cells CD38+HLA-DR-. During the acute phase, CD8+ T cells stimulated with viral peptides exhibited a monofunctional response characterized by high IL-10 production. However, during recovery, we observed a bifunctional response characterized by the co-expression of CD107a and granzyme B or perforin.Conclusion: Although the proinflammatory response is a hallmark of SARS-CoV-2 infection, other phenotypic and functional alterations in NK cells and CD8+ T cells couldbe associated with the outcome of COVID-19. However, additional studies are required to understand these alterations and to guide future immunotherapy strategies.Introducción. Se han descrito diferentes marcadores inmunológicos durante la COVID-19, los cuales persisten incluso después de la convalecencia y se asocian con los estadios clínicos de la infección. Sin embargo, aún son pocos los estudios orientados al análisis exhaustivo de las alteraciones del sistema inmunológico en el curso de la infección.Objetivo. Evaluar la producción de citocinas proinflamatorias, la reacción de anticuerpos, y el fenotipo y la función de las células NK y los linfocitos T en una familia colombiana con infección por SARS-CoV-2.Materiales y métodos. Se evaluaron las citocinas proinflamatorias mediante RT-PCR y ELISA; la frecuencia, el fenotipo y la función de las células NK (en cocultivos con células K562) y linfocitos T CD8+ (estimulados con péptidos spike/RdRp) mediante citometría de flujo, y los anticuerpos anti-SARS-CoV-2, mediante inmunofluorescencia indirecta y prueba de neutralización por reducción de placa.Resultados. Durante la COVID-19 hubo una producción elevada de citocinas proinflamatorias, con disminución de las células NK CD56bright y reacción citotóxica. Comparados con los controles sanos, los individuos infectados presentaron con gran frecuencia linfocitos T CD8+ disfuncionales CD38+HLA-DR-. Además, en los linfocitos T CD8+ estimulados con péptidos virales, predominó una reacción monofuncional con gran producción de IL-10 durante la fase aguda y una reacción bifuncional caracterizada por la coexpresión de CD107a y granzima B o perforina durante la convalecencia.Conclusión. Aunque la reacción inflamatoria caracteriza la infección por SARS-CoV-2, hay otras alteraciones fenotípicas y funcionales en células NK y linfocitos T CD8+ que podrían asociarse con la progresión de la infección. Se requieren estudios adicionales para entender estas alteraciones y guiar futuras estrategias de inmunoterapia