Ocean data manager: practical software for oceanographic sensors

Peer Reviewe

MicroRNA Profiling and Bioinformatics Target Analysis in Dorsal Hippocampus of Chronically Stressed Rats: Relevance to Depression Pathophysiology

Indexación: Scopus.1Laboratory of Neuroplasticity and Neurogenetics, Faculty of Chemical and Pharmaceutical Sciences, Department of Biochemistry and Molecular Biology, Universidad de Chile, Santiago, Chile, 2National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Durham, NC, United States, 3Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago, Chile, 4Millennium Institute for Integrative Biology (iBio), FONDAP Center for Genome Regulation, Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Santiago, Chile, 5Department of Kinesiology, Faculty of Health Sciences, Universidad Católica del Maule, Talca, Chile, 6Escuela de Química y Farmacia, Facultad de Medicina, Universidad Andres Bello, Santiago, Chile.This study was supported by the following grants: FONDECYT 1120528 (JLF), Fondo Central de Investigación, Universidad de Chile ENL025/16 (JLF), ES090079 (JAC). Research in RG and EV laboratories is funded by Instituto Milenio iBio – Iniciativa Científica Milenio MINECON.Studies conducted in rodents subjected to chronic stress and some observations in humans after psychosocial stress, have allowed to establish a link between stress and the susceptibility to many complex diseases, including mood disorders. The studies in rodents have revealed that chronic exposure to stress negatively affects synaptic plasticity by triggering changes in the production of trophic factors, subunit levels of glutamate ionotropic receptors, neuron morphology, and neurogenesis in the adult hippocampus. These modifications may account for the impairment in learning and memory processes observed in chronically stressed animals. It is plausible then, that stress modifies the interplay between signal transduction cascades and gene expression regulation in the hippocampus, therefore leading to altered neuroplasticity and functioning of neural circuits. Considering that miRNAs play an important role in post-transcriptional-regulation of gene expression and participate in several hippocampus-dependent functions; we evaluated the consequences of chronic stress on the expression of miRNAs in dorsal (anterior) portion of the hippocampus, which participates in memory formation in rodents. Here, we show that male rats exposed to daily restraint stress (2.5 h/day) during 7 and 14 days display a differential profile of miRNA levels in dorsal hippocampus and remarkably, we found that some of these miRNAs belong to the miR-379-410 cluster. We confirmed a rise in miR-92a and miR-485 levels after 14 days of stress by qPCR, an effect that was not mimicked by chronic administration of corticosterone (14 days). Our in silico study identified the top-10 biological functions influenced by miR-92a, nine of which were shared with miR-485: Nervous system development and function, Tissue development, Behavior, Embryonic development, Organ development, Organismal development, Organismal survival, Tissue morphology, and Organ morphology. Furthermore, our in silico study provided a landscape of potential miRNA-92a and miR-485 targets, along with relevant canonical pathways related to axonal guidance signaling and cAMP signaling, which may influence the functioning of several neuroplastic substrates in dorsal hippocampus. Additionally, the combined effect of miR-92a and miR-485 on transcription factors, along with histone-modifying enzymes, may have a functional relevance by producing changes in gene regulatory networks that modify the neuroplastic capacity of the adult dorsal hippocampus under stress. © 2018 Muñoz-Llanos, García-Pérez, Xu, Tejos-Bravo, Vidal, Moyano, Gutiérrez, Aguayo, Pacheco, García-Rojo, Aliaga, Rojas, Cidlowski and Fiedler.https://www.frontiersin.org/articles/10.3389/fnmol.2018.00251/ful

Exact relativistic models of thin disks around static black holes in a magnetic field

The exact superposition of a central static black hole with surrounding thin disk in presence of a magnetic field is investigated. We consider two models of disk, one of infinite extension based on a Kuzmin-Chazy-Curzon metric and other finite based on the first Morgan-Morgan disk. We also analyze a simple model of active galactic nuclei consisting of black hole, a Kuzmin-Chazy-Curzon disk and two rods representing jets, in presence of magnetic field. To explain the stability of the disks we consider the matter of the disk made of two pressureless streams of counterrotating charged particles (counterrotating model) moving along electrogeodesic. Using the Rayleigh criterion we derivate for circular orbits the stability conditions of the particles of the streams. The influence of the magnetic field on the matter properties of the disk and on its stability are also analyzed.Comment: 17 pages, 14 figures. arXiv admin note: text overlap with arXiv:gr-qc/0409109 by other author

Quantum Interference in Single Molecule Electronic Systems

We present a general analytical formula and an ab initio study of quantum interference in multi-branch molecules. Ab initio calculations are used to investigate quantum interference in a benzene-1,2-dithiolate (BDT) molecule sandwiched between gold electrodes and through oligoynes of various lengths. We show that when a point charge is located in the plane of a BDT molecule and its position varied, the electrical conductance exhibits a clear interference effect, whereas when the charge approaches a BDT molecule along a line normal to the plane of the molecule and passing through the centre of the phenyl ring, interference effects are negligible. In the case of olygoynes, quantum interference leads to the appearance of a critical energy $E_c$, at which the electron transmission coefficient $T(E)$ of chains with even or odd numbers of atoms is independent of length. To illustrate the underlying physics, we derive a general analytical formula for electron transport through multi-branch structures and demonstrate the versatility of the formula by comparing it with the above ab-initio simulations. We also employ the analytical formula to investigate the current inside the molecule and demonstrate that large counter currents can occur within a ring-like molecule such as BDT, when the point charge is located in the plane of the molecule. The formula can be used to describe quantum interference and Fano resonances in structures with branches containing arbitrary elastic scattering regions connected to nodal sites.Comment: 12 pages, 11 figure

La formación del concepto de función en alumnos de educación media superior

En este artículo se describe la realización de un taller cuyo diseño responde al marco de una investigación en proceso, que explora los saberes que sobre el concepto de función tienen los alumnos de educación media superior (EMS) y pretende analizar los efectos que presenta la puesta en escena de situaciones didácticas sobre la formación del concepto de función. En la primera etapa de la investigación se están explorando dichos saberes en 30 alumnos de EMS y 10 de los primeros semestres de la licenciatura en matemáticas en Acapulco, Guerrero, México. También se han diseñado situaciones didácticas para abordar este concepto, a fin de que se instrumenten en la escuela. Con estos avances se estructuró el taller para interesados en este campo y realizado en Relme 17 con la participación de siete profesores

Environmental sustainability of cellulose-supported solid ionic liquids for CO2 capture

Solid ionic liquids (SoILs) with cellulose as a support have been demonstrated recently to be effective and low-cost sorbents for CO2 capture. However, at present it is not clear whether they remove more CO2 than is released in the rest of the life cycle, including their manufacture, regeneration and disposal. It is also unknown what other impacts they may have over the whole life cycle while attempting to mitigate climate change. Therefore, this study evaluates for the first time the life cycle environmental sustainability of cellulose-supported SoILs in comparison with unsupported SoILs and some other sorbents. Four SoILs are assessed for 11 life cycle impacts, including global warming potential (GWP), with and without the cellulose support: methyltrioctyl ammonium acetate ([N1888][Ac]), tetraethyl ammonium acetate ([N4444][Ac]), tetra-octylammonium bromide ([N8888]Br) and 1-butyl-4-methylimidazolium bromide ([Bmim]Br). They are compared with one of the ILs in the liquid state (trihexyltetradecylphosphonium 1,2,4-triazolide ([P66614][124Triz])) and with three conventional sorbents: monoethanolamine (MEA), zeolite powder and activated carbon. The results show that SoILs with cellulose loading in the range of 70%–80 wt% have better environmental performance per unit mass of CO2 captured than the unsupported SoILs. The net removal of CO2 eq. over the life cycle ranges from 20% for pure [Bmim]Br to 83% for [N1888][Ac] with 75% cellulose and for [N4444][Ac] with both 75% and 80% loadings. However, pure [N8888]Br generates three times more CO2 eq. over the life cycle than it removes. Among the SoILs, [N4444][Ac] with 80% cellulose has the lowest life cycle impacts for eight out of 11 categories. When compared to the conventional sorbents, it has significantly higher impacts, including GWP. However, it is more sustainable than [P66614][124Triz]. The results of this study can be used to target the hotspots and improve the environmental performance of cellulose-supported SoILs through sustainable design

Hipogonadismo de inicio tardío: revisión de conceptos y pautas diagnósticas

ResumenEl hipogonadismo de inicio tardío es un síndrome clínico y bioquímico cada vez más frecuente entre la población masculina en la edad adulta, sin embargo pocas veces es diagnosticado y por lo tanto cursa sin tratamiento entre la mayoría de los varones afectados. La asociación entre deficiencia de testosterona relacionada con la edad y el diagnóstico de hipogonadismo de inicio tardío continúa siendo un tema controversial, y su asociación con síntomas como pérdida de volumen y fuerza muscular, pérdida de la libido y la función eréctil, así como cambios en el estado afectivo e intelectual del paciente resulta insidiosa ya que en ocasiones las sintomatología es atribuida al proceso «normal» de envejecimiento, o a otras comorbilidades del paciente. El diagnóstico de hipogonadismo de inicio tardío se basa en la coexistencia de bajos niveles séricos de testosterona total o libre y síntomas sugestivos de hipogonadismo. Si bien se han desarrollado cuestionarios de cribado dirigidos a pacientes con sospecha clínica, estos cuestionarios poseen sensibilidad y especificidad limitadas para el diagnóstico de hipogonadismo de inicio tardío. El diagnóstico preciso y oportuno es de crucial importancia ya que permite restablecer los niveles de testosterona y la mejoría clínica significativa mediante la terapia de remplazo hormonal.AbstractLate-onset hypogonadism is a clinical and biochemical syndrome that is increasingly more frequent in the adult male population. However, it is rarely diagnosed and therefore goes untreated in the majority of affected men. The association between age-related testosterone deficiency and late-onset hypogonadism continues to be a subject of debate and its relation to symptoms such as loss of muscle strength and volume, loss of libido, erectile dysfunction, and changes in affective and emotional statuses of the patient are insidious, given that the symptomatology is often attributed to the “normal” aging process or other comorbidities of the patient. The diagnosis of late-onset hypogonadism is based on the coexistence of low total or free testosterone serum levels and symptoms suggestive of hypogonadism. Even though screening questionnaires directed at patients with clinical suspicion of the disease have been developed for late-onset hypogonadism, their diagnostic sensitivity and specificity is limited. Accurate and opportune diagnosis is vitally important because it enables testosterone levels to be reestablished and significant clinical improvement to be made through androgen replacement therapy

The glutamine synthetase gene family in Populus

<p>Abstract</p> <p>Background</p> <p>Glutamine synthetase (GS; EC: 6.3.1.2, L-glutamate: ammonia ligase ADP-forming) is a key enzyme in ammonium assimilation and metabolism of higher plants. The current work was undertaken to develop a more comprehensive understanding of molecular and biochemical features of <it>GS </it>gene family in poplar, and to characterize the developmental regulation of <it>GS </it>expression in various tissues and at various times during the poplar perennial growth.</p> <p>Results</p> <p>The <it>GS </it>gene family consists of 8 different genes exhibiting all structural and regulatory elements consistent with their roles as functional genes. Our results indicate that the family members are organized in 4 groups of duplicated genes, 3 of which code for cytosolic GS isoforms (GS1) and 1 which codes for the choroplastic GS isoform (GS2). Our analysis shows that <it>Populus trichocarpa </it>is the first plant species in which it was observed the complete <it>GS </it>family duplicated. Detailed expression analyses have revealed specific spatial and seasonal patterns of <it>GS </it>expression in poplar. These data provide insights into the metabolic function of GS isoforms in poplar and pave the way for future functional studies.</p> <p>Conclusions</p> <p>Our data suggest that <it>GS </it>duplicates could have been retained in order to increase the amount of enzyme in a particular cell type. This possibility could contribute to the homeostasis of nitrogen metabolism in functions associated to changes in glutamine-derived metabolic products. The presence of duplicated <it>GS </it>genes in poplar could also contribute to diversification of the enzymatic properties for a particular GS isoform through the assembly of GS polypeptides into homo oligomeric and/or hetero oligomeric holoenzymes in specific cell types.</p