Reacções ião-molécula em fase gasosa de aminas biologicamente activas

Estudaram-se as reacções químicas, em fase gasosa, de um grupo de aminas biogénicas, de alguns dos seus metabolitos e de outras aminas estruturalmente relacionadas com as primeiras, com diversos reagentes positivos e um reagente negativo, numa fonte de ionização química de um espectrómetro de massa de geometria EBEqQ. Entre os primeiros reagentes destacam-se o catião t-butilo, o catião propilo, o catião etilo, o catião metoximetileno, o catião dimetoxiborínio, o catião nitrosilo e outros iões produzidos num plasma de nitrometano, e o reagente negativo foi o anião-radical oxigénio. O estudo é acompanhado de uma revisão da bibliografia relativa aos vários tópicos envolvidos. Com base nos dados experimentais (espectros de ionização química, espectros de MIKE, espectros de varrimento ligado de B2/E, espectros de CID e marcação dos substratos com deutério) foram deduzidos os mecanismos de muitas das reacções observadas, e os resultados globais põem em evidência os modos variados como as características estruturais dos substratos determinam o género e a abundância dos produtos formados nessas reacções.The chemical reactions, in the gas-phase, of several biogenic amines and some of their metabolites, as well as of other amines with close structural relations with the former ones, were studied by chemical ionization mass spectrometry in a mass spectrometer of EBEqQ geometry, employing as reagents, in the positive mode, the ethyl, propyl and t-butyl cations, the methoxymethylene and dimethoxyborinium cations, the nitrosonium ion and other ions produced in a nitromethane plasma, and, in the negative mode, the oxygen radical anion produced in a plasma of N2/N2O. As an introduction to these topics, a comprehensive review of the pertinent scientific literature was made. On the ground of the results obtained from chemical ionization mass spectra, MIKE and CID spectra, linked-scanning B2/E spectra and isotopic labelling with deuterium, mechanisms for most of the reactions observed could be proposed, and the ways in which the structural features of the substrates influence the outcome of the reactions were established

Follicular Development of Beef Heifers Exposed to Bulls During an Estrus Synchronization Protocol that Included a 14-D CIDR, PGF2 ALPHA and Timed Artificial Insemination (AI) and GNRH (Poster)

The objective was to evaluate the effect of presence of a bull on ovarian follicular development and its relationship to fertility in beef heifers using an estrus synchronization protocol that included a progesterone (P4)-containing, controlled internal drug release devices (CIDR) for 14 days, PGF 2alpha (PG, and, timed AI (TAI) and GnRH.  Heifers were then assigned randomly to be exposed to bulls (BE; n = 41) or not exposed to bulls (NE; n = 38). Heifers were exposed to bulls on the day of CIDR insertion (d -32) and remained with bulls until day 3 (d 0 = day of PG injection). The heifer bull ratio was 20 to 1. CIDRs were removed 14 days (d -18) after insertion. On day 0 each heifer was injected with PG and bulls removed from BE heifers. Ovaries of each heifer were imaged ultrasonically.  Heifers were observed for estrus during the next 60 h, 2x daily.  Diameters of the DF at the time of CIDR removal and PG injection (d 0) did not differ between BE and NE heifers and averaged 10.3 ± 0.3 mm (mean ± SE) and 10.9 ± 0.3 mm, respectively. There was no difference in number of antral follicles between BE- and NE-treated heifers (1.7 ± 0.1 and 1.5 ± 0.1, respectively).  Diameter of DF did not affect the proportion of heifers that showed estrus or time to estrus of heifers in either treatment. Diameter of DF increased (P < 0.05) linearly as body condition score (BSC) increased. Presence of mature bulls during an estrus synchronization protocol that included a CIDR for 14 days does not appear to influence ovarian follicular dynamics or the expression of estrus after PG in beef heifers.  This may not be the mechanism whereby the presence of bulls increases fertility in the bovine.  However, the relationship between DF diameter and BCS supports the concept that “more fit” females ovulate larger follicles which in turn improve fertility

Differences between CO- and calcium triplet-derived velocity dispersions in spiral galaxies: evidence for central star formation?

et al.We examine the stellar velocity dispersions (σ) of a sample of 48 galaxies, 35 of which are spirals, from the Palomar nearby galaxy survey. It is known that for ultra-luminous infrared galaxies (ULIRGs) and merger remnants, the σ derived from the near-infrared CO band heads is smaller than that measured from optical lines, while no discrepancy between these measurements is found for early-type galaxies. No such studies are available for spiral galaxies – the subject of this paper. We used cross-dispersed spectroscopic data obtained with the Gemini Near-Infrared Spectrograph, with spectral coverage from 0.85 to 2.5 μm, to obtain σ measurements from the 2.29 μm CO band heads (σCO) and the 0.85 μm calcium triplet (σCaT). For the spiral galaxies in the sample, we found that σCO is smaller than σCaT, with a mean fractional difference of 14.3 per cent. The best fit to the data is given by σopt = (46.0 ± 18.1) + (0.85 ± 0.12)σCO. This ‘σ-discrepancy’ may be related to the presence of warm dust, as suggested by a slight correlation between the discrepancy and the infrared luminosity. This is consistent with studies that have found no σ-discrepancy in dust-poor early-type galaxies, and a much larger discrepancy in dusty merger remnants and ULIRGs. That σCO is lower than σopt may also indicate the presence of a dynamically cold stellar population component. This would agree with the spatial correspondence between low-σCO and young/intermediate-age stellar populations that has been observed in spatially resolved spectroscopy of a handful of galaxies.RAR acknowledges support from FAPERGS (project no. 12/1209-6) and CNPq (project no. 470090/2013-8). LCH acknowledges support from the Kavli Foundation, Peking University, and grant no. XDB09030102 (Emergence of Cosmological Structures) from the Strategic Priority Research Program of the Chinese Academy of Sciences. ARA acknowledges CNPq for partial support to this work through grant 307403/2012-2. LM thanks CNPq through grant 305291/2012-2. LC acknowledges support from the Special Visiting Researcher Fellowship (PVE 313945/2013-6) under the Brazilian Scientific Mobility Program ‘Ciencias sem Fronteiras’. RR acknowledges funding from FAPERGs (ARD 11/1758-5) and CNPq (PeP 304796/2011-5). CRA is supported by a Marie Curie Intra European Fellowship within the 7th European Community Framework Programme (PIEF-GA-2012-327934) and by the Spanish Ministry of Science and Innovation (MICINN) through project PN AYA2010-21887-C04.04.Peer Reviewe

Gestión del trabajo colegiado en la academia de historia en un bachillerato

Proyecto de intervención realizado en la escuela preparatoria No. 9 de la Universidad de Guadalajara. El objetivo fue incrementar la eficacia y la calidad en la organización, funcionamiento y seguimiento del trabajo colegiado de la Academia de Historia del Departamento de Ciencias Histórico-Sociales, mediante la formación y capacitación de sus integrantes, con el propósito de que sean capaces de desarrollar habilidades para replantear sus actividades y rediseñar procesos académicos

Gestión de residuos químicos en instituciones educativas

The present article shows the relation of the educative institutions and the environmental and social responsibilities due to hazardous waste generated in laboratories. Laboratories' hazardous waste should be disposed in a manner meeting local and state regulations. This article sets the standard for the beginning of the development of the project "Dangerous and ordinary design of a plan of handling of the chemical substances, remainders generated in the building of laboratories of Macarena B of the Distrital University"El presente artículo busca la reflexión por parte de las instituciones educativas, en relación con la gran responsabilidad ambiental y social que cada una tiene con la gestión adecuada de los residuos peligrosos generados en sus laboratorios. Gestión esta que debe ser innovadora, económica y de acuerdo a las necesidades propias, pero cumpliendo con las disposiciones legales vigentes. Este artículo es uno de los productos resultado del desarrollo de la investigación Diseño de un plan de manejo de las sustancias químicas, residuos peligrosos y ordinarios generados en el edificio de laboratorios de la Macarena B de la Universidad Distrital

Perspectivas literarias: traducción e intertextualidad

En este libro hemos reunido un conjunto de trabajos que exploran temas relacionados con la traducción literaria y con los estudios literarios desde una perspectiva múltiple y comparada, pues creemos que, en estos tiempos, es valioso detenerse a analizar experiencias complejas con respecto a las prácticas literarias que permiten la comunicación intercultural, ya que ésta es una vía para cuestionar visiones nacionalistas que, en ocasiones, tienden a achatar el panorama en lugar de reconocer la hibridez y la heterogeneidad de los discursos literarios. Se trata de analizar estos temas desde distintos ángulos, tales como la traducción, las intertextualidades temáticas, la formación de traductores, la perspectiva de los lectores, la construcción del canon por distintas instancias culturales y los estudios comparados

Bench checkout equipment for spaceborne laser altimeter systems

This paper addresses the requirements for testing and characterizing spaceborne laser altimeter systems. The Bench Checkout Equipment (BCE) system, test requirements, and flow-down traceability from the instrument system's functional requirements will also be presented. Mars Observer Laser Altimeter (MOLA) and the MOLA BCE are presented as representative of a 'typical' laser altimeter and its corresponding test system. The testing requirements of other or future laser altimeter systems may vary slightly due to the specific spacecraft interface and project requirements. MOLA, the first solid-state interplanetary laser altimeter, was designed to be operational in Mars orbit for two Earth years. MOLA transmits a 7.5 ns pulse at a wavelength of 1.064 microns with a 0.25 mr beam divergence and a pulse repetition rate of 10 Hz. The output energy is specified at 45 mj at the beginning of mapping orbit and 30 mj at the end of one Martian year. MOLA will measure the laser pulse transit time from the spacecraft to the Mars surface and return to a resolution of 1.5 meters