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Tabasco, Mexico

Universidad Juárez Autónoma de Tabasco is a public institution of higher learning located in Villahermosa, Tabasco, Mexico. The mission of the university is "to prepare professionals with broad and deep expertise in their area of study to fill the needs of Tabasco and the country at large." UJAT is the largest and most prominent university in the state of Tabasco. During the 2007-2008 academic year the University enrolled 35,271 students and had a teaching staff of over 2,000. For the same school year the University offered bachelor's degrees in 36 disciplines, master's degrees in 26 areas, three doctoral degrees, and post-graduate Certificates in 17 graduate areas of specialization . The University grants law, education, management, engineering, medicine, architecture, nursing, and dentistry degrees, plus some 30 additional degrees in other fields of study. Wikipedia.

Valdes-Manzanilla A.,Juarez Autonomous University of Tabasco
Natural Hazards | Year: 2016

It is presented a chronology of historical floods during sixteenth–twentieth centuries in the Mexican states of Tabasco and Chiapas. There were 41 historical flooding events during 1528–1948, 16 of them were catastrophic flooding and 25 were extraordinary ones. There were periods of historical floods between 1651–1652, 1676–1677, 1679–1680, 1888–1889, 1927–1929, 1931–1933 and 1940–1944. During the instrumental period (1949–1999) there were only four extraordinary flood events in the Usumacinta River. Most of flood periods coincided with the warm phase of the Atlantic Multidecadal Oscillation (AMO). The flood period of 1940–1944 was as long as the most recent one (2007–2011). Wavelet analysis found flood periodicities of 2.5, 52 and 83 years, but only the last one was statistical significant and their occurrence was in phase with the AMO. Logistic regression showed that AMO index was the most correlated index with flood events. In fact, the odds ratio showed that floods were 1.90 times more likely to occur when AMO index was positive. This regression model predicted correctly 64.70 % of flood occurrences during twentieth century using its flood information only as validation data. © 2015, Springer Science+Business Media Dordrecht. Source

Corzo C.A.,Juarez Autonomous University of Tabasco | Waliszewski K.N.,Instituto Tecnologico De Veracruz | Welti-Chanes J.,Monterrey Institute of Technology
Food Chemistry | Year: 2012

Optimal pH and temperature conditions for proteolytic activity of pineapple fruit bromelain were determined using five different substrates: azocasein and azoalbumin (pH 3-10 at 20-70°C), casein and sodium caseinate (pH 2-10 at 20-70°C), and haemoglobin (pH 2-6.5 at 30-60°C). Fruit bromelain has shown optimum activity at pH 7.5 for azoalbumin and at 6.5 for azocasein, all at 55°C. Fruit bromelain activity determined with casein and sodium caseinate has shown optimum activity at 59°C, while the optimum pH was 7.7 for casein and 6.5 for sodium caseinate. Optimum hydrolysis conditions of fruit bromelain towards haemoglobin showed a sharp peak at an acidic pH 2.9 at 37°C. The lowest results of K m and the highest results of V max/ K m were found for azocasein and azoalbumin. These substrates are highly recommended for fruit bromelain activity determination. © 2012 Elsevier Ltd. All rights reserved. Source

The aim of this study was to evaluate the actions of coenzyme Q10 (CoQ10) on rats with a cholesterol-rich diet (HD) and high doses of atorvastatin (ATV, 0.2, 0.56 or 1.42 mg/day). Two experiments were done, the first one without coenzyme Q10 supplementation. On the second experiment all groups received coenzyme Q10 0.57 mg/day as supplement. After a 6-week treatment animals were sacrificed, blood and liver were analyzed and liver mitochondria were isolated and its oxygen consumption was evaluated in state 3 (phosphorylating state) and state 4 (resting state) in order to calculate the respiratory control (RC). HD increased serum and hepatic cholesterol levels in rats with or without CoQ10. ATV reduced these values but CoQ10 improved even more serum and liver cholesterol. Triacylglycerols (TAG) were also lower in blood and liver of rats with ATV + CoQ10. HDL-C decreased in HD rats. Treatment with ATV maintained HDL-C levels. However, these values were lower in HD + CoQ10 compared to control diet (CD) + CoQ10. RC was lessened in liver mitochondria of HD. The administration of ATV increased RC. All groups supplemented with CoQ10 showed an increment in RC. In conclusion, the combined administration of ATV and CoQ10 improved biochemical parameters, liver function and mitochondrial respiration in hypercholesterolemic rats. Our results suggest a potential beneficial effect of CoQ10 supplementation in hypercholesterolemic rats that also receive atorvastatin. This beneficial effect of CoQ10 must be combined with statin treatment in patient with high levels of cholesterol. Source

Yang C.-S.,University College London | Mora-Fonz J.M.,Juarez Autonomous University of Tabasco | Catlow C.R.A.,University College London
Journal of Physical Chemistry C | Year: 2013

The nucleation mechanism of zeolite A is investigated by means of Density Functional Theory (DFT) calculations. We calculated the Gibbs free energy change for the polymerization and cyclization reactions involved in the nucleation of zeolite A in the gas phase and solution between 298 and 450 K. Our analysis reveals that the four-ring species formed could be the most likely to participate in the nucleation of zeolite A, and its nucleation mechanism could proceed by a reaction route which involves the formation of the double-four-ring. © 2013 American Chemical Society. Source

Hernandez-Franyutti A.,Juarez Autonomous University of Tabasco | Uribe M.C.,National Autonomous University of Mexico
Journal of Morphology | Year: 2012

We describe seasonal variations of the histology of the seminiferous tubules and efferent ducts of the tropical, viviparous skink, Mabuya brachypoda, throughout the year. The specimens were collected monthly, in Nacajuca, Tabasco state, Mexico. The results revealed strong annual variations in testicular volume, stages of the germ cells, and diameter and height of the epithelia of seminiferous tubules and efferent ducts. Recrudescence was detected from November to December, when initial mitotic activity of spermatogonia in the seminiferous tubules were observed, coinciding with the decrease of temperature, photoperiod and rainy season. From January to February, early spermatogenesis continued and early primary and secondary spermatocytes were developing within the seminiferous epithelium. From March through April, numerous spermatids in metamorphosis were observed. Spermiogenesis was completed from May through July, which coincided with an increase in temperature, photoperiod, and rainfall. Regression occurred from August through September when testicular volume and spermatogenic activity decreased. During this time, the seminiferous epithelium decreased in thickness, and germ cell recruitment ceased, only Sertoli cells and spermatogonia were present in the epithelium. Throughout testicular regression spermatocytes and spermatids disappeared and the presence of cellular debris, and scattered spermatozoa were observed in the lumen. The regressed testes presented the total suspension of spermatogenesis. During October, the seminiferous tubules contained only spermatogonia and Sertoli cells, and the size of the lumen was reduced, giving the appearance that it was occluded. In concert with testis development, the efferent ducts were packed with spermatozoa from May through August. The epididymis was devoid of spermatozoa by September. M. brachypoda exhibited a prenuptial pattern, in which spermatogenesis preceded the mating season. The seasonal cycle variations of spermatogenesis in M. brachypoda are the result of a single extended spermiation event, which is characteristic of reptilian species. © 2012 Wiley Periodicals, Inc. Source

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