Time filter

Source Type

Puebla de Zaragoza, Mexico

Platas-Neri D.,Autonomous University of the State of Morelos | Hidalgo-Tobon S.,Hospital Infantil de Mexico Federico Gomez | Hidalgo-Tobon S.,Metropolitan Autonomous University | Da Celis Alonso B.,Benemerita University Puebla | And 4 more authors.
PLoS ONE | Year: 2015

The objective of this research was to describe the organization, connectivity and microstructure of the corpus callosum of the spider monkey (Ateles geoffroyi). Non-invasive magnetic resonance imaging and diffusion-tensor imaging were obtained from three subjects using a 3T Philips scanner. We hypothesized that the arrangement of fibers in spider monkeys would be similar to that observed in other non-human primates. A repeated measure (n = 3) of fractional anisotropy values was obtained of each subject and for each callosal subdivision. Measurements of the diffusion properties of corpus callosum fibers exhibited a similar pattern to those reported in the literature for humans and chimpanzees. No statistical difference was reached when comparing this parameter between the different CC regions (p = 0.066). The highest fractional anisotropy values corresponded to regions projecting from the corpus callosum to the posterior cortical association areas, premotor and supplementary motor cortices. The lowest fractional anisotropy corresponded to projections to motor and sensory cortical areas. Analyses indicated that approximately 57% of the fibers projects to the frontal cortex and 43% to the post-central cortex. While this study had a small sample size, the results provided important information concerning the organization of the corpus callosum in spider monkeys. © 2015 Platas-Neri et al.

Lucio-Ortiz C.J.,Autonomous University of Nuevo Leon | De la Rosa J.R.,Autonomous University of Nuevo Leon | Hernandez-Ramirez A.,Autonomous University of Nuevo Leon | Lopez-Cuellar E.M.,Autonomous University of Nuevo Leon | And 3 more authors.
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2010

Catalysts of pure zirconia and novel zirconia materials doped with combinations of La, Mn and Fe at 0.5 wt% of each metal were synthesized by a sol-gel method and characterized by transmission electron microscopy (TEM). The crystallite size was determined by the Scherrer equation from the main peak of the tetragonal phase of ZrO2 observed in X-ray diffraction (XRD) patterns; the size thus determined coincided with the crystallite size observed in the TEM images. The structures were revealed to be porous and the dopant metals La, Mn and Fe were distributed on the surfaces of the zirconia crystallite with metal particle sizes ranging from a few to 13nm. Different morphologies were adopted by the metal doping agents and caused different crystal aggregation modes in the doped samples during the xerogel annealing process. Agglomerates of the crystallites provided an average particle diameter of 23.67μm for the catalyst loaded into the experimental reactor, resulting in low mass-transfer effects during the combustion of trichloroethylene in air. The mass-transfer effect was evaluated using the Yoshida correlation under the catalytic test of trichloroethylene combustion. A Langmuir-Hinshelwood model was proposed to describe the inhibition phenomenon seen in the reaction rate data for trichloroethylene combustion over the catalysts. © 2010 Elsevier B.V.

Bussiere Y.D.,Benemerita University Puebla | Torres I.E.,University of the Humanities | Collomb J.-L.,SETEC | Ravalet E.,Certu
WIT Transactions on Ecology and the Environment | Year: 2010

Cycling in the city, a practice which had been lost progressively since the 1960s with the rapid expansion of the use of the automobile, has recently become common practice in many cities of the North where the bicycle had almost disappeared. Urban speedways and viaducts built in the 1960s are being reconsidered and even destroyed to give place to boulevards and a friendlier urban environment for pedestrians. Many examples are available: Lyon with the introduction of Velo'V in 2005, Paris with the introduction of Veli'b in 2007 and Montreal with the introduction of BIXI in 2009 are recent experiences which may be cited as best practices. Could similar policies be applicable to Latin American cities where the use of the bicycle has been progressively abandoned but seems to have now a regaining image? What could be its potential impact on diminishing greenhouse gas emissions? What could be its potential impact on tourism? After a rapid review of various experiences in Europe, Canada and Latin America, we will focus on the example of Puebla, a city of 1.5 million inhabitants in the Centre-East of Mexico, for which we collected data in an opinion survey (2007-8) on non motorized modes. This case study leads to conclusions on the feasibility of such policies in a South American context and its potential impact in terms of sustainability as well as in economic benefits via the tourist industry. An approximation of the emissions in urban transportation that can be saved by the practice of the bicycle for utilitarian an leisure purposes and multimodality Bike-Public Transport, facilitated by the rent-a-bike systems, gives us a tangible reduction of the emissions of around 3% of urban transport of persons and 0.5% of total emissions in conservative scenarios. Furthermore these environment friendly policies, in cities like Puebla, a UNESCO World Monument city with strong tourist activity, could induce enormous economic benefits (in the range of 500 million US$ a year) by prolonging the average stay of tourists of a few days. © 2010 WIT Press.

Bernaldez J.,CICESE | Jimenez S.,CICESE | Soto E.,Benemerita University Puebla | Salceda E.,Benemerita University Puebla | And 3 more authors.
Toxins | Year: 2016

A novel conotoxin, named as PiVIIA, was isolated from the venom of Conus princeps, a marine predatory cone snail collected in the Pacific Southern Coast of Mexico. Chymotryptic digest of the S-alkylated peptide in combination with liquid chromatography coupled to tandem mass spectrometry, were used to define the sequencing of this peptide. Eleven N-terminal amino acids were verified by automated Edman degradation. PiVIIA is a 25-mer peptide (CDAOTHYCTNYWγCCSGYCγHSHCW) with six cysteine residues forming three disulphide bonds, a hydroxyproline (O) and two gamma carboxyglutamic acid (γ) residues. Based on the arrangement of six Cys residues (C-C-CC-C-C), this conotoxin might belong to the O2-superfamily. Moreover, PiVIIA has a conserved motif (-γCCS-) that characterizes γ-conotoxins from molluscivorous Conus. Peptide PiVIIA has 45% sequence identity with γ-PnVIIA—the prototype of this family. Biological activity of PiVIIA was assessed by voltage-clamp recording in rat dorsal root ganglion neurons. Perfusion of PiVIIA in the μM range produces a significant increase in the Ca2+ currents, without significantly modifying the Na+, K+ or proton-gated acid sensing ionic currents. These results indicate that PiVIIA is a new conotoxin whose activity deserves further studies to define its potential use as a positive modulator of neuronal activity. © 2016 by the authors; licensee MDPI, Basel, Switzerland.

Garcia-Oscos F.,University of Texas at Dallas | Garcia-Oscos F.,Southwestern University | Pena D.,University of Texas at Dallas | Housini M.,University of Texas at Dallas | And 12 more authors.
Journal of Neuroscience Research | Year: 2015

Stress is a potential trigger for a number of neuropsychiatric conditions, including anxiety syndromes and schizophrenic psychoses. The temporal neocortex is a stress-sensitive area involved in the development of such conditions. We have recently shown that aseptic inflammation and mild electric shock shift the balance between synaptic excitation and synaptic inhibition in favor of the former in this brain area (Garcia-Oscos et al., 2012), as well as in the prefrontal cortex (Garcia-Oscos et al., 2014). Given the potential clinical importance of this phenomenon in the etiology of hyperexcitable neuropsychiatric illness, this study investigates whether inactivation of the peripheral immune system by the "anti-inflammatory reflex" would reduce the central response to aseptic inflammation. For a model of aseptic inflammation, this study used i.p. injections of the bacterial toxin lipopolysaccharide (LPS; 5 μM) and activated the anti-inflammatory reflex either pharmacologically by i.p. injections of the nicotinic α7 receptor agonist PHA543613 or physiologically through electrical stimulation of the left vagal nerve (VNS). Patch-clamp recording was used to monitor synaptic function. Recordings from LPS-injected Sprague Dawley rats show that activation of the anti-inflammatory reflex either pharmacologically or by VNS blocks or greatly reduces the LPS-induced decrease of the synaptic inhibitory-to-excitatory ratio and the saturation level of inhibitory current input-output curves. Given the ample variety of pharmacologically available α7 nicotinic receptor agonists as well as the relative safety of clinical VNS already approved by the FDA for the treatment of epilepsy and depression, our findings suggest a new therapeutic avenue in the treatment of stress-induced hyperexcitable conditions mediated by a decrease in synaptic inhibition in the temporal cortex. © 2015 Wiley Periodicals, Inc.

Discover hidden collaborations