Colonia del Valle, Mexico

University of Tlaxcala
Colonia del Valle, Mexico

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Lara C.,University of Tlaxcala | Martinez-Garcia V.,University of Tlaxcala | Ornelas J.F.,Institute Ecologia
Acta Ornithologica | Year: 2015

Hummingbird vocalizations are usually displayed in two contexts. When foraging or defending territories, males and females usually display relative simple calls as territorial advertisement, while during courtship males perform individually elaborate songs to mate attraction or through singing assemblies (leks). About 15% of all described hummingbird species form leks or singing assemblies during the breeding season. However, the vocal repertoire displayed by males in these arenas has been rarely described. Here we studied the songs of Green Violetear Colibri thalassinus in a temperate forest from central Tlaxcala, Mexico, to document structure and variation within and between singing assemblies established over 3 years. We found 41 well differentiated and structurally complex syllable types across eleven recorded singing groups of Green Violetears (≈12 syllable types per singing group). The songs of most birds were repeats of the same 3-4 syllables, but the syllables types emitted can vary. Birds from the same lek tend to have similar song. Comparison of syllable sharing within-groups showed a Jaccard'similarity coefficient averaging 0.51 ± 0.09 (mean ± SD), and 0.24 ± 0.01 for among groups comparisons. These differences were corroborated by bootstrapping tests finding no significant similarity among males from different leks. However, significant similarity in syllable sharing was found between males from the same lek. No significant correlation was found between song similarity and geographic distances between leks. We have documented that static songs of lekking Green Violetears are more complex than had previously suggested. The variation of vocal repertoire among leks indicates the apparent presence of "vocal dialects" that are variable across time and space. The song variation in the context of discrimination ability in vocal neighborhoods requires further research.

Netzahuatl-Munoz A.R.,National Polytechnic Institute of Mexico | Netzahuatl-Munoz A.R.,University of Tlaxcala | Del Carmen Cristiani-Urbina M.,Autonomous University of Chiapas | Cristiani-Urbina E.,National Polytechnic Institute of Mexico
PLoS ONE | Year: 2015

The present study investigated the kinetics, equilibrium and thermodynamics of chromium (Cr) ion biosorption from Cr(VI) aqueous solutions by Cupressus lusitanica bark (CLB). CLB total Cr biosorption capacity strongly depended on operating variables such as initial Cr(VI) concentration and contact time: as these variables rose, total Cr biosorption capacity increased significantly. Total Cr biosorption rate also increased with rising solution temperature. The pseudo-second-order model described the total Cr biosorption kinetic data best. Langmuir's model fitted the experimental equilibrium biosorption data of total Cr best and predicted a maximum total Cr biosorption capacity of 305.4 mg g-1. Total Cr biosorption by CLB is an endothermic and non-spontaneous process as indicated by the thermodynamic parameters. Results from the present kinetic, equilibrium and thermodynamic studies suggest that CLB biosorbs Cr ions from Cr(VI) aqueous solutions predominantly by a chemical sorption phenomenon. Low cost, availability, renewable nature, and effective total Cr biosorption make CLB a highly attractive and efficient method to remediate Cr(VI)-contaminated water and wastewater. Copyright: © 2015 Netzahuatl-Muñoz et al.

Jimenez-Aguilar D.M.,Monterrey Institute of Technology | Ortega-Regules A.E.,University of Tlaxcala | Lozada-Ramirez J.D.,Universidad de Las Americas Puebla | Perez-Perez M.C.I.,Celaya Institute of Technology | And 2 more authors.
Journal of Food Composition and Analysis | Year: 2011

Blueberry is an important source of anthocyanins, which are highly colored substances recognized for their antioxidant activity. One of the drawbacks of using anthocyanins as food colorant is their low stability. The objective of this study was to evaluate the variations found in color and concentration of the compounds (which produce the color) on spray-dried powders, obtained from blueberry extracts with added mesquite gum. Ethanolic blueberry extracts were concentrated until reaching 35% of soluble solids. They were then spray-dried using mesquite gum as an encapsulating agent at 140 and 160 °C of air inlet temperature and 8.5, 9.1 and 9.6. mL/min of feeding rates. The lowest losses in the content of total phenolics, total anthocyanins, and color of the samples were found in samples dried at 140 °C and 9.1. mL/min. The microencapsulates that were stored for 4 weeks at 4 °C in the absence of light presented low degradation of phenolics (10%), anthocyanins (7%) and antioxidant activity (15%). Final color values were L= 39.87, C= 47.83 and H° = 28.59, with a total color difference Δ E= 5. © 2011 Elsevier Inc.

Szenczi P.,University of Tlaxcala | Banszegi O.,Institute Investigaciones Biomedicasuniversidad Nacional Autonoma Of Mexicodistrito Federalmexico | Urrutia A.,Institute Investigaciones Biomedicasuniversidad Nacional Autonoma Of Mexicodistrito Federalmexico | Farago T.,MTA ELTE Comparative Ethology Research GroupBudapestHungary | Hudson R.,Institute Investigaciones Biomedicasuniversidad Nacional Autonoma Of Mexicodistrito Federalmexico
Developmental Psychobiology | Year: 2016

Acoustic communication can play an important part in mother-young recognition in many mammals. This, however, has still only been investigated in a small range mainly of herd- or colony-living species. Here we report on the behavioral response of kittens of the domestic cat, a typically solitary carnivore, to playbacks of "greeting chirps" and "meows" from their own versus alien mothers. We found significantly stronger responses to the chirps from kittens' own mother than to her meows or to the chirps or meows of alien mothers. Acoustic analysis revealed greater variation between vocalizations from different mothers than for vocalizations from the same mother. We conclude that chirps emitted by mother cats at the nest represent a specific form of vocal communication with their young, and that kittens learn and respond positively to these and distinguish them from chirps of other mothers and from other cat vocalizations while still in the nest. © 2016 Wiley Periodicals, Inc.

Netzahuatl-Munoz A.R.,University of Tlaxcala | Netzahuatl-Munoz A.R.,National Polytechnic Institute of Mexico | Guillen-Jimenez F.D.M.,National Polytechnic Institute of Mexico | Chavez-Gomez B.,Mexican Institute of Petroleum | And 2 more authors.
Water, Air, and Soil Pollution | Year: 2012

Solution pH is among the most important parameters that influence heavy metal biosorption. This work presents a kinetic study of the effects of pH on chromium biosorption onto Cupressus lusitanica Mill bark from aqueous Cr(VI) or Cr(III) solutions and proposes a mechanism of adsorption. At all assayed contact times, the optimum pH for chromium biosorption from the Cr(III) solution was 5.0; in contrast, optimum pH for chromium biosorption from the Cr(VI) solution varied depending on contact time. The kinetic models that satisfactorily described the chromium biosorption processes from the Cr(III) and Cr (VI) solutions were the Elovich and pseudo second-order models, respectively. Diffuse reflectance infrared Fourier transform spectroscopy studies suggest that phenolic compounds present on C. lusitanica Mill bark play an important role in chromium biosorption from the Cr(III) solution. On the other hand, chromium biosorption from the Cr(VI) solution involved carboxyl groups produced on the bark by redox reactions between oxygen-containing groups and Cr(VI), and these were in turn responsible for the biosorption of Cr (III) produced by Cr(VI) reduction. © Springer Science+Business Media B.V. 2011.

Garcia-Ortiz N.,Metropolitan Autonomous University | Tlecuitl-Beristain S.,University of Tlaxcala | Favela-Torres E.,Metropolitan Autonomous University | Loera O.,Metropolitan Autonomous University
Applied Microbiology and Biotechnology | Year: 2015

Mycoinsecticides application within Integral Pest Management requires high quantities of conidia, with the proper quality and resistance against environmental conditions. Metarhizium anisopliae var. lepidiotum conidia were produced in normal atmospheric conditions (21 % O2) and different concentrations of oxygen pulses (16, 26, 30, and 40 %); conidia obtained under hypoxic conditions showed significantly lower viability, hydrophobicity, and virulence against Tenebrio molitor larvae or mealworm, compared with those obtained under normal atmospheric conditions. Higher concentrations of oxygen (26 and 30 %) improved conidial production. However, when a 30 % oxygen concentration was applied, maximal conidial yields were obtained at earlier times (132 h) relative to 26 % oxygen pulses (156 h); additionally, with 30 % oxygen pulses, conidia thermotolerance was improved, maintaining viability, hydrophobicity, and virulence. Although conidial production was not affected when 40 % oxygen pulses were applied, viability and virulence were diminished in those conidia. In order to find a critical time for mycelia competence to respond to these oxidant conditions, oxygen pulses were first applied either at 36, 48, 60, and 72 h. A critical time of 60 h was determined to be the best time for the M. anisopliae var. lepidiotum mycelia to respond to oxygen pulses in order to increase conidial production and also to maintain the quality features. Therefore, oxygen-enriched (30 %) pulses starting at 60 h are recommended for a high production without the impairment of quality of M. anisopliae var. lepidiotum conidia. © 2014, Springer-Verlag Berlin Heidelberg.

Castro-Ramirez J.,University of Tlaxcala | Martinez-Guerra R.,CINVESTAV | Cruz-Victoria J.C.,University of Tlaxcala
Chaos | Year: 2015

This paper deals with the master-slave synchronization scheme for partially known nonlinear chaotic systems, where the unknown dynamics is considered as the master system and we propose the slave system structure which estimates the unknown states. It introduced a new reduced order observer, using the concept of Algebraic Observability; we applied the results to a Sundarapandian chaotic system, and by means of some numerical simulations we show the effectiveness of the suggested approach. Finally, the proposed observer is utilized for encryption, where encryption key is the master system and decryption key is the slave system. © 2015 AIP Publishing LLC.

Lado C.,Real Jardin Botanico de Madrid | Wrigley De Basanta D.,Real Jardin Botanico de Madrid | Estrada-Torres A.,University of Tlaxcala | Stephenson S.L.,University of Arkansas
Fungal Diversity | Year: 2013

The results obtained from two expeditions to survey the biodiversity of myxomycetes in Central Chile are reported in this paper. The surveys were carried out as part of Global Biodiversity of Eumycetozoans project funded by the National Science Foundation (USA) and the Myxotropic project funded by the Spanish Government. The expeditions were made to the temperate zone of the central part of the country between 23 and 39 South latitudes, which is characterized by Mediterranean vegetation, as well as to the transition areas between the arid and semi-arid regions of northern Chile, and the humid, cold Valdivian and Andean-Patagonian forests of the far South. Eight of the fifteen regions of the country, from Antofagasta to Araucanía, in selected areas where the native vegetation is well preserved, were included in these surveys. Over 600 collections were obtained, and a total of 110 species of myxomycetes representing 29 genera have been identified. Two of these (Dianema succulenticola, Didymium chilense) are species new to science and are described in this paper, 12 species (Collaria nigricapillitia, Comatricha alta, Cribraria oregana, Dianema depressum, Didymium eximium, D. nivicolum, Enerthenema melanospermum, Lepidoderma chailletii, Macbrideola ovoidea, Physarum clavisporum, Ph. newtonii and Trichia alpina) were previously unknown for either the Neotropics or South America, and 49 additional species are new records for Chile. Comments are provided on the morphology, distribution and ecology of selected species and light and SEM micrographs of the most significant species are included. An evaluation of the biodiversity of myxomycetes in Chile, with special emphasis on the endemic plants that provided the substrates with which they were associated, and a comparative analysis of our results with those from other countries of South America is presented. © 2012 The Mushroom Research Foundation.

PubMed | University of Tlaxcala and National Autonomous University of Mexico
Type: Journal Article | Journal: Ecology and evolution | Year: 2016

Two patterns commonly emerge when animal body size is analyzed as a function of latitudinal distribution. First, body size increases with latitude, a temperature effect known as Bergmanns rule, and second, the converse to Bergmanns rule, a pattern in which body size decreases with latitude. However, other geographic patterns can emerge when the mechanisms that generate Bergmanns and the converse to Bergmanns clines operate together. Here, we use phylogenetic comparative analysis in order to control for phylogenetic inertia, and we show that bumblebees exhibit the converse to Bergmanns rule. Bumblebee taxa are distributed worldwide in temperate and tropical regions. The largest species are found in places with high water availability during the driest time of the year. Nonetheless, large body size is constrained by extreme temperatures. Bumblebees body size could be related to a higher extent to the size of food rewards to be harvested than to the energetic advantages of thermoregulation. Moreover, we found that the body size of eusocial and cuckoo species responded in the same way to environmental variables, suggesting that they have not diverged due to different selective pressures.

PubMed | University of Tlaxcala, Metropolitan Autonomous University, UPAEP University and Autonomous University of Tlaxcala
Type: | Journal: The Science of the total environment | Year: 2016

Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer widely used in the manufacture of plastics, and it is an environmental contaminant. The specific growth rate (), maximum biomass (Xmax), biodegradation constant of DEHP (k), half-life (t1/2) of DEHP biodegradation and removal efficiency of DEHP, esterase and laccase specific activities, and enzymatic yield parameters were evaluated for Fusarium culmorum grown on media containing glucose and different concentrations of DEHP (0, 500 and 1000mg/L). The greatest and the largest Xmax occurred in media supplemented with 1000mg of DEHP/L. F. culmorum degraded 95% of the highest amount of DEHP tested (1000mg/L) within 60h of growth. The k and t1/2 were 0.024h(-1) and 28h, respectively, for both DEHP concentrations. The removal efficiency of DEHP was 99.8% and 99.9% for 1000 and 500mg/L, respectively. Much higher specific esterase activity than specific laccase activity was observed in all media tested. The compounds of biodegradation of DEHP were identified by GC-MS. A DEHP biodegradation pathway by F. culmorum was proposed on the basis of the intermolecular flow of electrons of the identified intermediate compounds using quantum chemical modeling. DEHP was fully metabolized by F. culmorum with butanediol as the final product. This fungus offers great potential in bioremediation of environments polluted with DEHP.

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