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Matos T.,Research Center tudios Avanzados Del
General Relativity and Gravitation | Year: 2010

Using a new ansatz for solving the Einstein equations with a scalar field with inverted sign in the kinetic term (phantom field), I find a series of formulae to derive axial symmetric stationary exact solutions of the phantom fields in general relativity. I focus on the solutions which represent wormholes. The procedure presented in this work allows to derive new exact solutions up to very simple integrations. Among other results, I find exact rotating solutions containing magnetic monopoles, dipoles, etc., coupled to phantom scalar and to gravitational multipole fields. © 2010 Springer Science+Business Media, LLC. Source


Swanson W.F.,Center or Conservation and Research of Endangered Wildlife | Valle R.R.,Deutches Primatenzentrum DPZ | Valle R.R.,University of Sao Paulo | Carvalho F.M.,University of Sao Paulo | And 6 more authors.
Reproduction in Domestic Animals | Year: 2016

The main objective of this study was to evaluate sperm morphology in four neotropical primate species to compare the sperm morphological traits and the sperm morphometric parameters as a basis for establishing normative sperm standards for each species. Data from 80 ejaculates collected from four primate species, Callithrix jacchus, Callimico goeldii, Alouatta caraya and Ateles geoffroyi, were analysed for detection of sperm morphological alterations using subjective World Health Organization (WHO-2010) standards and Sperm Deformity Index (SDI) criteria, objective computer-assisted sperm morphometry analysis (CASMA) and subpopulation sperm determination (SSD) methods. There were multiple differences (p < 0.01) observed among primate species in values obtained from WHO-2010, SDI, CASMA and SSD sperm analysis methods. In addition, multiple significant positive and negative correlations were observed between the sperm morphological traits (SDI, Sperm Deformity Index Head Defects, Sperm Deformity Index Midpiece Defects, Sperm Deformity Index Tail Defects, Normal Sperm, Head Defects, Midpiece Defects and Tail Defects) and the sperm morphometric parameters (SSD, Area (A), Perimeter (P), Length (L), Width (W), Ellipticity, Elongation and Rugosity) (p ≤ 0.046). In conclusion, our findings using different evaluation methods indicate that pronounced sperm morphological variation exists among these four neotropical primate species. Because of the strong relationship observed among morphological and morphometric parameters, these results suggest that application of objective analysis methods could substantially improve the reliability of comparative studies and help to establish valid normative sperm values for neotropical primates. © 2016 Blackwell Verlag GmbH Source


Rodas-Martinez A.Z.,Research Center tudios Avanzados Del | Rodas-Martinez A.Z.,National Autonomous University of Mexico | Canales D.,Institute Neuroetologia Ac | Brousset D.M.,National Autonomous University of Mexico | And 2 more authors.
Zoo Biology | Year: 2013

The spider monkey (SM) (Ateles geoffroyi) a New World primate species native to Mexican forests, has become endangered in the wild due to environmental perturbations. Little is known about adrenal function and its relationship to reproduction in this species. Our objectives were to assess serum glucocorticoid (GC), mineralocorticoid (MC) and testosterone concentrations in captive SM and evaluate adrenal and testicular responses to potentially stressful animal handling procedures. Seven adult males, housed in a single mixed gender group in an off-exhibit enclosure at the University Park were captured for anesthesia every 2 months over a 1-year period. Blood samples were collected from each male at three time points: (1) ~5-10min after ketamine injection in the outdoor enclosure; (2) ~2hr later following animal transport to the laboratory and immediately after tiletamine-zolazepam injection; and (3) ~20-30min following the second anesthetic injection. Serum samples were frozen and later analyzed for cortisol, corticosterone, aldosterone and testosterone via radioimmunoassay. Cortisol was the primary GC detected in SM serum with much higher mean concentrations than for corticosterone. Capture, restraint and anesthesia resulted in significant increases in both cortisol and corticosterone concentrations. Whereas aldosterone concentrations were unchanged by animal handling procedures, testosterone concentrations significantly declined under anesthesia over time. In summary, these results provide data for the main adrenocortical hormones in male SM and characterize their acute adrenal responses to potentially stressful handling and anesthesia procedures. Our findings also suggest an interaction between acute increases in corticosteroids and decreased concentrations of serum testosterone. © 2013 Wiley Periodicals, Inc. Source


Sanchez-Cabrera G.,Autonomous University of the State of Hidalgo | Zuno-Cruz F.J.,Autonomous University of the State of Hidalgo | Lopez-Ruiz H.,Autonomous University of the State of Hidalgo | Rosales-Hoz M.J.,Research Center tudios Avanzados Del | And 2 more authors.
Journal of Organometallic Chemistry | Year: 2014

The cluster [{Os3(μ-H)(CO)10}3{1,3,5- (μ-SCH2)3C6H3}] has been prepared by the reaction of [Os3(CO)10(NCMe)2] with 1, 3, 5-tris(mercaptomethyl)benzene under mild conditions; the cluster has been fully characterized by IR, NMR spectroscopy, HR-MS, X-ray crystallography and its redox behavior is also described. © 2013 Elsevier B.V. All rights reserved. Source


Hernandez-Cruz M.G.,Autonomous University of the State of Hidalgo | Sanchez-Cabrera G.,Autonomous University of the State of Hidalgo | Hernandez-Sandoval M.,Autonomous University of the State of Hidalgo | Leyva M.A.,Research Center tudios Avanzados Del | And 5 more authors.
Journal of Organometallic Chemistry | Year: 2011

The reaction between [Ru3(CO)10(NCMe)2] and [AuClPPh3] gave compound [Ru3(CO)10(μ- Cl)(μ-AuPPh3)] (1) in quantitative yield under very mild conditions. The reaction of 1 with 4-mercaptopyridine (4-pyS) using ultrasonic reaction conditions gave the heteronuclear compound [Ru3(CO) 10(μ-AuPPh3)(μ-SC5H4N)] (2) in moderate yield. There was no spectroscopic evidence that indicates the formation of the hydride isolobal analog in this reaction. The homonuclear cluster [Ru3(CO)8(μ-H)(μ-SC5H 4N)(μ-dppe)] (3) was prepared by a selective reaction employing the ruthenium-diphosphine derivative [Ru3(CO)10(μ-dppe) ] (dppe = 1,2-bis(diphenylphosphine)ethane) with 4-pyS in THF solution. The isolobal analog to compound 3, compound [Ru3(CO)8(μ- AuPPh3)(μ-SC5H4N)(μ-dppe)] (4) was synthesized by the reaction between compound 2 and dppe in refluxing dichloromethane. Compounds 1-4 were characterized in solution by spectroscopic methods and the molecular structure of compounds 2 and 3 in the solid state was obtained by single crystal X-ray diffraction studies. © 2010 Elsevier B.V. All rights reserved. Source

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