54 research outputs found

    Influence of Silver Nitrate on Somatic Embryogenesis Induction in Arabica Coffee (Coffea arabica L.).

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    Plant somatic embryogenesis (SE) has been defined as the formation of embryos from a single or group of haploid or somatic cells [1, 2]. Low frequency (LFSE) and high frequency somatic embryogenesis (HFSE) have been described. In the first type, somatic embryos are induced directly from pro-embryogenic cells of explants, while in the second, they originate from embryogenic callus [1]. It has been suggested that in LFSE the origin of somatic embryos is unicellular, whereas in HFSE has been described as unicellular or multicellular [3]. SE is a powerful biotechnological tool used to propagate elite plants or to conserve important genotypes [4]. Moreover, SE offers an efficient in vitro regeneration approach as a fundamental step in plant genetic improvement for studying basic aspects of ontogenesis of somatic embryos [5]. In Coffea spp., the first studies of SE have been reported at the beginning of 1970 [6]. Since then, a large quantity of LFSE and HFSE protocols have been optimized demonstrating that coffee is not a recalcitrant species for SE [4]. In the LFSE the somatic embryos are obtained faster (approximately 70 days) using only one medium meanwhile in HFSE several media are used and somatic embryo formation takes 9-10 months [4]. Although, in LFSE small number of somatic embryos are obtained (around 10 per explant) compared to hundreds of somatic embryos obtained per gram of embryogenic calli [4], the unicellular origin of somatic embryos in LFSE represents an advantage for the chemical and physical mutagenesis, genetic transformation and genetic editing, since prevents or reduces the appearance of chimeras [7]. In C. arabica and C. canephora many factors (such as genotype, explant type, the physiological state, age and growth conditions of the donor plants, the season of collection, nutrient composition of the medium, the volume of dissolved CO2 or O2 in the culture flask, and plant growth regulators) that affect LFSE induction have been studied [3, 8, 9, 10, 11, 12, 13]. However, few studies reported the effect of silver nitrate on LFSE using leaf explants of C. arabica L. and to the best of our knowledge it has not been analyzed using Caturra and Catuaí, which are two economic important producer cultivars in Costa Rica. Since SE is genotype dependent, the culture medium need to be modified for the different genotypes [7].Therefore, the objective of this study was to determine the influence of the benzyladenine (BAP), indole-3-acetic acid (IAA), and silver nitrate (AgNO3) on low frequency somatic embryogenesis using leaf explants of Coffea arabica L. cultivars Caturra and Catuaí

    Experimental and quantum chemical studies of a novel synthetic prenylated chalcone

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    BACKGROUND: Chalcones are ubiquitous natural compounds with a wide variety of reported biological activities, including antitumoral, antiviral and antimicrobial effects. Furthermore, chalcones are being studied for its potential use in organic electroluminescent devices; therefore the description of their spectroscopic properties is important to elucidate the structure of these molecules. One of the main techniques available for structure elucidation is the use of Nuclear Magnetic Resonance Spectroscopy (NMR). Accordingly, the prediction of the NMR spectra in this kind of molecules is necessary to gather information about the influence of substituents on their spectra. RESULTS: A novel substituted chalcone has been synthetized. In order to identify the functional groups present in the new synthesized compound and confirm its chemical structure, experimental and theoretical (1)H-NMR and (13)C-NMR spectra were analyzed. The theoretical molecular structure and NMR spectra were calculated at both the Hartree-Fock and Density Functional (meta: TPSS; hybrid: B3LYP and PBE1PBE; hybrid meta GGA: M05-2X and M06-2X) levels of theory in combination with a 6-311++G(d,p) basis set. The structural parameters showed that the best method for geometry optimization was DFT:M06-2X/6-311++G(d,p), whereas the calculated bond angles and bond distances match experimental values of similar chalcone derivatives. The NMR calculations were carried out using the Gauge-Independent Atomic Orbital (GIAO) formalism in a DFT:M06-2X/6-311++G(d,p) optimized geometry. CONCLUSION: Considering all HF and DFT methods with GIAO calculations, TPSS and PBE1PBE were the most accurate methods used for calculation of (1)H-NMR and (13)C-NMR chemical shifts, which was almost similar to the B3LYP functional, followed in order by HF, M05-2X and M06-2X methods. All calculations were done using the Gaussian 09 software package. Theoretical calculations can be used to predict and confirm the structure of substituted chalcones with good correlation with the experimental data

    Borderline Personality Disorder With Cocaine Dependence: Impulsivity, Emotional Dysregulation and Amygdala Functional Connectivity

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    Background: Borderline personality disorder is present in 19% of cocaine dependence cases; however, this dual pathology is poorly understood. We wished to characterize the dual pathology and find its functional connectivity correlates to better understand it.Methods: We recruited 69 participants divided into 4 groups: dual pathology (n = 20), cocaine dependence without borderline personality disorder (n = 19), borderline personality without cocaine dependence (n = 10) and healthy controls (n = 20). We used self-reported instruments to measure impulsivity and emotional dysregulation. We acquired resting state fMRI and performed seed-based analyses of the functional connectivity of bilateral amygdala.Results: Borderline personality disorder and cocaine dependence as factors had opposing effects in impulsivity and emotional dysregulation, as well as on functional connectivity between left amygdala and medial prefrontal cortex. On the other hand, in the functional connectivity between right amygdala and left insula, the effect of having both disorders was instead additive, reducing functional connectivity strength. The significant functional connectivity clusters were correlated with impulsivity and emotional dysregulation.Conclusions: In this study, we found that clinical scores of dual pathology patients were closer to those of borderline personality disorder without cocaine dependence than to those of cocaine dependence without borderline personality disorder, while amygdala-medial prefrontal cortex functional connectivity patterns in dual pathology patients were closer to healthy controls than expected

    Transcriptional portrait of M. bovis BCG during biofilm production shows genes differentially expressed during intercellular aggregation and substrate attachment.

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    Mycobacterium tuberculosis and M. smegmatis form drug-tolerant biofilms through dedicated genetic programs. In support of a stepwise process regulating biofilm production in mycobacteria, it was shown elsewhere that lsr2 participates in intercellular aggregation, while groEL1 was required for biofilm maturation in M. smegmatis. Here, by means of RNA-Seq, we monitored the early steps of biofilm production in M. bovis BCG, to distinguish intercellular aggregation from attachment to a surface. Genes encoding for the transcriptional regulators dosR and BCG0114 (Rv0081) were significantly regulated and responded differently to intercellular aggregation and surface attachment. Moreover, a M. tuberculosis H37Rv deletion mutant in the Rv3134c-dosS-dosR regulon, formed less biofilm than wild type M. tuberculosis, a phenotype reverted upon reintroduction of this operon into the mutant. Combining RT-qPCR with microbiological assays (colony and surface pellicle morphologies, biofilm quantification, Ziehl-Neelsen staining, growth curve and replication of planktonic cells), we found that BCG0642c affected biofilm production and replication of planktonic BCG, whereas ethR affected only phenotypes linked to planktonic cells despite its downregulation at the intercellular aggregation step. Our results provide evidence for a stage-dependent expression of genes that contribute to biofilm production in slow-growing mycobacteria

    Ancient DNA analysis suggests negligible impact of the Wari Empire expansion in Peru's Central Coast during the Middle Horizon

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    The analysis of ancient human DNA from South America allows the exploration of pre-Columbian population history through time and to directly test hypotheses about cultural and demographic evolution. The Middle Horizon (650-1100 AD) represents a major transitional period in the Central Andes, which is associated with the development and expansion of ancient Andean empires such as Wari and Tiwanaku. These empires facilitated a series of interregional interactions and socio-political changes, which likely played an important role in shaping the region's demographic and cultural profiles. We analyzed individuals from three successive pre-Columbian cultures present at the Huaca Pucllana archaeological site in Lima, Peru: Lima (Early Intermediate Period, 500-700 AD), Wari (Middle Horizon, 800-1000 AD) and Ychsma (Late Intermediate Period, 1000-1450 AD). We sequenced 34 complete mitochondrial genomes to investigate the potential genetic impact of the Wari Empire in the Central Coast of Peru. The results indicate that genetic diversity shifted only slightly through time, ruling out a complete population discontinuity or replacement driven by the Wari imperialist hegemony, at least in the region around present-day Lima. However, we caution that the very subtle genetic contribution of Wari imperialism at the particular Huaca Pucllana archaeological site might not be representative for the entire Wari territory in the Peruvian Central Coast.Guido Valverde, María Inés Barreto Romero, Isabel Flores Espinoza, Alan Cooper, Lars Fehren-Schmitz, Bastien Llamas, Wolfgang Haa

    4to. Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad. Memoria académica

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    Este volumen acoge la memoria académica de la Cuarta edición del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad, CITIS 2017, desarrollado entre el 29 de noviembre y el 1 de diciembre de 2017 y organizado por la Universidad Politécnica Salesiana (UPS) en su sede de Guayaquil. El Congreso ofreció un espacio para la presentación, difusión e intercambio de importantes investigaciones nacionales e internacionales ante la comunidad universitaria que se dio cita en el encuentro. El uso de herramientas tecnológicas para la gestión de los trabajos de investigación como la plataforma Open Conference Systems y la web de presentación del Congreso http://citis.blog.ups.edu.ec/, hicieron de CITIS 2017 un verdadero referente entre los congresos que se desarrollaron en el país. La preocupación de nuestra Universidad, de presentar espacios que ayuden a generar nuevos y mejores cambios en la dimensión humana y social de nuestro entorno, hace que se persiga en cada edición del evento la presentación de trabajos con calidad creciente en cuanto a su producción científica. Quienes estuvimos al frente de la organización, dejamos plasmado en estas memorias académicas el intenso y prolífico trabajo de los días de realización del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad al alcance de todos y todas

    Food intake, growth and anxiety, after overcrowding or isolation-induced stress in rats [Consumo de alimento, crecimiento y ansiedad, tras estrés por hacinamiento o aislamiento de ratas]

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    The overcrowding and isolation conditions are often experienced by people living in big cities around the world, the literature suggest that under certain conditions it could promote stress-induced anxiety and obesity. The goal of this study was to investigate the effects of post-weaning overcrowding or isolation over the food intake, growth and anxiety in rats. 30 male rats were housed from weaning (21 days old) till 60 days old on three different conditions: 1) optimal recommended for lab rodents with at least 168 cm2 per rat (control group), 2) with no more than 50.4 cm2 per rat (overcrowding group) and 3) individual housed (isolation group). Were recorded daily food intake, weight gain and increased size. On days 58, 59 and 60 was assessed the anxiety level in elevated plus-maze followed by recorded of food intake. Our results shown anxiety in adulthood and food intake was altered in the beginning of dark cycle

    A brain connectivity characterization of children with different levels of mathematical achievement based on graph metrics.

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    Recent studies aiming to facilitate mathematical skill development in primary school children have explored the electrophysiological characteristics associated with different levels of arithmetic achievement. The present work introduces an alternative EEG signal characterization using graph metrics and, based on such features, a classification analysis using a decision tree model. This proposal aims to identify group differences in brain connectivity networks with respect to mathematical skills in elementary school children. The methods of analysis utilized were signal-processing (EEG artifact removal, Laplacian filtering, and magnitude square coherence measurement) and the characterization (Graph metrics) and classification (Decision Tree) of EEG signals recorded during performance of a numerical comparison task. Our results suggest that the analysis of quantitative EEG frequency-band parameters can be used successfully to discriminate several levels of arithmetic achievement. Specifically, the most significant results showed an accuracy of 80.00% (α band), 78.33% (δ band), and 76.67% (θ band) in differentiating high-skilled participants from low-skilled ones, averaged-skilled subjects from all others, and averaged-skilled participants from low-skilled ones, respectively. The use of a decision tree tool during the classification stage allows the identification of several brain areas that seem to be more specialized in numerical processing
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