Host-Feeding Preference of the Mosquito, Culex quinquefasciatus, in Yucatan State, Mexico

PubMed Central

Garcia-Rejon, Julian E.; Blitvich, Bradley J.; Farfan-Ale, Jose A.; Loroño-Pino, Maria A.; Chi Chim, Wilberth A.; Flores-Flores, Luis F.; Rosado-Paredes, Elsy; Baak-Baak, Carlos; Perez-Mutul, Jose; Suarez-Solis, Victor; Fernandez-Salas, Ildefonso; Beaty, Barry J.

2010-01-01

Studies were conducted to determine the host-feeding preference of Culex quinquefasciatus Say (Diptera: Culicidae) in relation to the availability of human and domestic animals in the city of Merida, Yucatan State, Mexico. Mosquitoes were collected in the backyards of houses using resting wooden boxes. Collections were made five times per week from January to December 2005. DNA was extracted from engorged females and tested by PCR using universal avian- and mammalian-specific primers. DNA extracted from avian-derived blood was further analyzed by PCR using primers that differentiate among the birds of three avian orders: Passeriformes, Columbiformes and Galliformes. PCR products obtained from mammalian-derived blood were subjected to restriction enzyme digestion to differentiate between human-, dog-, cat-, pig-, and horse-derived blood meals. Overall, 82% of engorged mosquitoes had fed on birds, and 18% had fed on mammals. The most frequent vertebrate hosts were Galliformes (47.1%), Passeriformes (23.8%), Columbiformes (11.2%) birds, and dogs (8.8%). The overall human blood index was 6.7%. The overall forage ratio for humans was 0.1, indicating that humans were not a preferred host for Cx. quinquefasciatus in Merida. PMID:20578953

Host-feeding preference of the mosquito, Culex quinquefasciatus, in Yucatan State, Mexico.

PubMed

Garcia-Rejon, Julian E; Blitvich, Bradley J; Farfan-Ale, Jose A; Loroño-Pino, Maria A; Chi Chim, Wilberth A; Flores-Flores, Luis F; Rosado-Paredes, Elsy; Baak-Baak, Carlos; Perez-Mutul, Jose; Suarez-Solis, Victor; Fernandez-Salas, Ildefonso; Beaty, Barry J

2010-01-01

Studies were conducted to determine the host-feeding preference of Culex quinquefasciatus Say (Diptera: Culicidae) in relation to the availability of human and domestic animals in the city of Merida, Yucatan State, Mexico. Mosquitoes were collected in the backyards of houses using resting wooden boxes. Collections were made five times per week from January to December 2005. DNA was extracted from engorged females and tested by PCR using universal avian- and mammalian-specific primers. DNA extracted from avian-derived blood was further analyzed by PCR using primers that differentiate among the birds of three avian orders: Passeriformes, Columbiformes and Galliformes. PCR products obtained from mammalian-derived blood were subjected to restriction enzyme digestion to differentiate between human-, dog-, cat-, pig-, and horse-derived blood meals. Overall, 82% of engorged mosquitoes had fed on birds, and 18% had fed on mammals. The most frequent vertebrate hosts were Galliformes (47.1%), Passeriformes (23.8%), Columbiformes (11.2%) birds, and dogs (8.8%). The overall human blood index was 6.7%. The overall forage ratio for humans was 0.1, indicating that humans were not a preferred host for Cx. quinquefasciatus in Merida.

Prevalence of obesity and diabetes in the socioeconomic transition of rural Mayas of Yucatan from 1962 to 2000.

PubMed

Loria, Alvar; Arroyo, Pedro; Fernandez, Victoria; Pardio, Jeanette; Laviada, Hugo

2018-02-20

The Mayas of the State of Yucatan in Mexico are the only aboriginal group with obesity and diabetes data before 1997. To analyze socioeconomic trends associated with the increase in obesity and diabetes seen in rural Yucatan from 1962 to 2000. Body weight, height and venous Fasting Blood Glucose (FBG) were measured in 263 rural Maya adults participating in a 2000 nutrition survey. Diabetes (FBG > 125 mg/dL) and obesity (BMI ≥ 30 kg/m 2 ) were 10.6% and 35.7%, respectively. These results contrast with those of a 1962 survey where diabetic prevalence was 2.3% and 0% in women and men respectively, with widespread adult pellagra and malnutrition. An important socioeconomic transition that took place in Yucatan during this lapse appeared to be associated to the obesity and diabetes increase. Rural Yucatan evolved from malnutrition conditions to high prevalence of obesity and diabetes in less than 40 years. This change was associated with the transition from an agroindustry-based economy, characterized by high-energy expenditure and low protein intake, to lower energy requirements of a Government-subsidized economy with larger food supply.

Antibodies to West Nile virus in asymptomatic mammals, birds, and reptiles in the Yucatan Peninsula of Mexico.

PubMed

Farfán-Ale, José A; Blitvich, Bradley J; Marlenee, Nicole L; Loroño-Pino, María A; Puerto-Manzano, Fernando; García-Rejón, Julián E; Rosado-Paredes, Elsy P; Flores-Flores, Luis F; Ortega-Salazar, Andres; Chávez-Medina, Jaidy; Cremieux-Grimaldi, Juan C; Correa-Morales, Favián; Hernández-Gaona, Gerson; Méndez-Galván, Jorge F; Beaty, Barry J

2006-05-01

Surveillance for evidence of West Nile virus (WNV) infection in taxonomically diverse vertebrates was conducted in the Yucatan Peninsula of Mexico in 2003 and 2004. Sera from 144 horses on Cozumel Island, Quintana Roo State, 415 vertebrates (257 birds, 52 mammals, and 106 reptiles) belonging to 61 species from the Merida Zoo, Yucatan State, and 7 farmed crocodiles in Ciudad del Carmen, Campeche State were assayed for antibodies to flaviviruses. Ninety (62%) horses on Cozumel Island had epitope-blocking enzyme-linked immunosorbent assay (ELISA) antibodies to flaviviruses, of which 75 (52%) were seropositive for WNV by plaque reduction neutralization test (PRNT). Blocking ELISA antibodies to flaviviruses also were detected in 13 (3%) animals in the Merida Zoo, including 7 birds and 2 mammals (a jaguar and coyote) seropositive for WNV by PRNT. Six (86%) crocodiles in Campeche State had PRNT-confirmed WNV infections. All animals were healthy at the time of serum collections and none had a history of WNV-like illness.

Uses of Mayan and Spanish in Bilingual Elementary Schools in Yucatan, Mexico

ERIC Educational Resources Information Center

Mijangos-Noh, Juan Carlos; Romero-Gamboa, Fabiola

2008-01-01

In this paper we present our study of the use of Mayan and Spanish in nine groups of pupils in bilingual elementary schools in the Mayan area of the Yucatan State, Mexico. Michael Cole's, as well as Guillermo Bonfil's, perspectives were used for the data analysis, in the sense of considering language as a cultural artifact, and an element of…

Nematodes parasitic in fishes of cenotes (= sinkholes) of the Peninsula of Yucatan, Mexico. Part 1. Adults.

PubMed

Moravec, F; Vivas-Rodríguez, C; Scholz, T; Vargas-Vázquez, J; Mendoza-Franco, E; González-Solís, D

1995-01-01

The present paper comprises a systematic survey of adult nematodes collected from fishes from cenotes (= sinkholes) of the Peninsula of Yucatan, southeastern Mexico, in 1993-1994. Examinations of a total of 533 fishes (17 species) originating from 39 cenotes from the Mexican states of Yucatan and Quintana Roo revealed the presence of the following nine nematode species: Rhabdochona (Rhabdochona) kidderi, Procamallanus (Spirocamallanus) rebecae, P. (S.) neocaballeroi, Philometroides caudata, Hysterothylacium cenotue. Pseudocapillaria yucatanensis, Paracapillaria rhamdiae, P. teixerafreitasi and Capillostrongyloides sp. (only females). Four species (R. kidderi, P. rebecae, P. neocaballeroi and Capillostrongyloides sp.) are briefly described and illustrated and some problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. Taxonomic changes include Procamallanus (Spirocamallanus) neocaballeroi (Caballero-Deloya. 1977) comb. n. and Procamallanus (Spirocamallanus) rebecae (Andrade-Salas, Pineda-López et García-Magaña, 1994) comb. n. The nematode fauna of fishes in cenotes of the Yucatan Peninsula shows its appurtenance to the Neotropical fauna with close affinities with that of fish nematodes from South America, but with a considerable degree of endemism.

Growth and nutritional status of school age children of three communities from Yucatan, Mexico.

PubMed

Azcorra, Hugo; Vaizquez-Vdzquez, Adriana; Baqueiro Ctirdenas, Josi Enrique; Salazar-Rendon, Juan Carlos

2016-06-01

In Mexico, the nutritional status of school age children it is still a public health problem, particularly in the country southeast where malnutrition is alarming. Yucatan state, in Mexico, has one of the highest chronic undernutrition (stunting) and overweight/obesity prevalences. The aim of this study was to describe the growth and nutritional status of a sample of school children (6 - 12 years old) from three rural communities in Yucatan. Between November and December 2014 we obtained height, sitting height, weight, waist circumference (WC) and tricipital skinfold, and calculate leg length, body mass index (BMI) and body fat percentage of a sample of 144 children (6 - 12 years old) in three communities in Yucatan. The 14% of the total sample showed low height for age and 16% and 21% showed exceeded BMI and WC respectively. These data show the coexistence of both extremes of malnutrition. Significant differences in measures of growth and nutritional status categories were found between communities. Factors such as the production and merchandising of local foods, migration (rural-to-urban, regional and international) as well as differences in infraestructure investment in social support appear to be associated with variaticins in the growth and nutritional stattus of school age children analyzed.

Chicxulub Impact Crater and Yucatan Carbonate Platform - PEMEX Oil Exploratory Wells Revisited

NASA Astrophysics Data System (ADS)

Pérez-Drago, G.; Gutierrez-Cirlos, A. G.; Pérez-Cruz, L.; Urrutia-Fucugauchi, J.

2008-12-01

Geophysical oil exploration surveys carried out by PEMEX in the 1940's revealed occurrence of an anomalous pattern of semi-circular concentric gravity anomalies. The Bouguer gravity anomalies covered an extensive area over the flat carbonate platform in the northwestern Yucatan Peninsula; strong density contrasts were suggestive of a buried igneous complex or basement uplift beneath the carbonates, which was referred as the Chicxulub structure. The exploration program carried out afterwards included a drilling program, starting with Chicxulub-1 well in 1952 and comprising eight deep boreholes through the 1970s. An aeromagnetic survey in late 1970's showed high amplitude anomalies in the gravity anomaly central sector. Thus, research showing Chicxulub as a large complex impact crater formed at the K/T boundary was built on the PEMEX decades-long exploration program. Despite frequent reference to PEMEX information and samples, original data and cores have not been openly available for detailed evaluation and integration with results from recent investigations. Core samples largely remain to be analyzed and interpreted in the context of recent marine, aerial and terrestrial geophysical surveys and the drilling/coring projects of UNAM and ICDP. In this presentation we report on the stratigraphy and paleontological data for PEMEX wells: Chicxulub- 1 (1582m), Sacapuc-1 (1530m), Yucatan-6 (1631m), Ticul-1 (3575m) Yucatan-4 (2398m), Yucatan-2 (3474m), Yucatan-5A (3003m) and Yucatan-1 (3221m). These wells remain the deepest drilled in Chicxulub, providing samples of impact lithologies, carbonate sequences and basement, which give information on post- and pre-impact stratigraphy and crystalline basement. We concentrate on stratigraphic columns, lateral correlations and integration with UNAM and ICDP borehole data. Current plans for deep drilling in Chicxulub crater target the peak ring and central sector, with offshore and onshore boreholes proposed to the IODP and ICDP

Cocaine-induced microvascular vasoconstriction but differential systemic haemodynamic responses in Yucatan versus Yorkshire varieties of swine.

PubMed Central

Miao, L.; Núñez, B. D.; Susulic, V.; Wheeler, S.; Carrozza, J. P.; Ross, J. N.; Morgan, J. P.

1996-01-01

1. Systemic and coronary haemodynamics were measured in 6 Yorkshire swine and 6 Yucatan miniature swine under isoflurane anaesthesia to investigate the influence of cocaine following its intravenous administration at 1, 3 and 7 mg kg-1. 2. Cocaine in Yorkshire swine decreased mean arterial pressure and rate pressure product (systolic pressure x heart rate), suggesting a cardiac depressant effect, whereas cocaine in Yucatan miniature swine increased these parameters, consistent with a hyperadrenergic state. 3. Cocaine in both Yorkshire swine and Yucatan miniature swine decreased coronary blood flow and coronary flow reserve, and increased coronary vascular resistance. 4. A modest generalized epicardial coronary artery constriction was observed by angiography, without evidence of focal spasm. 5. Our results confirm a marked vasoconstrictor effect of cocaine on the coronary arterial circulation, predominantly distal to the epicardial coronary arteries, but also indicate important differences in the systemic cardiovascular responses to the drug between two closely related strains of animals within the same species. Due to the similarities between the swine and human coronary arterial vasculature, we suggest that vasoconstriction in the coronary microcirculation may produce cardiac toxicity in man. PMID:8821549

[Comparison of climacteric symptoms among women in Mexico City and women of a Mayan community of Yucatan].

PubMed

Carranza-Lira, Sebastián; Quiroz González, Byanca Nerea; Alfaro Godinez, Hugo César; May Can, Ana María

2012-10-01

to compare the climacteric symptoms between women from Mexico City and those from a Mayan community of the state of Yucatan. In two groups of women, Group I) Spanish-speaking women from Mexico City and Group II) Maya speaking women from the state of Yucatan, 22 climacteric symptoms were evaluated using an analog visual scale (AVS) and the SUMEVA index. For statistical analysis t student test was used as well as Chi squared. 105 women, 50 of Mexico City and 55 of Maxcanu, Yucatan were studied. When comparing the groups no difference was found in age (52.5 +/- 6.5 vs 53.7 +/- 6.2, for group I and II respectively), the body mass index was significantly smaller in group I (29.7 +/- 5.0 vs 34.0 +/- 6.0, p < 0.001). In group 1, 15 of the 22 evaluated symptoms were significantly more intense in Group I, as well as the SUMEVA (Sum of Analog Visual Scale) index (71.4 +/- 44.5 vs 45.8 +/- 24.8, p < 0.001). The proportion of symptomatic women for each one of the symptoms was similar in both groups except for hair fall that was significantly greater in group I (74% vs 52%). climacteric symptoms were perceived with more intensity by Mexico City women, which allows suppose that western culture influence can be the responsible.

Maternal maya ancestry and birth weight in Yucatan, Mexico.

PubMed

Azcorra, Hugo; Vázquez-Vázquez, Adriana; Mendez, Nina; Carlos Salazar, Juan; Datta-Banik, Sudip

2016-05-01

The purpose of this study was to analyze the association between maternal Maya ancestry and the birth weight of infants born in Yucatan, Mexico, during 2013. A total of 30,435 singletons born at term (≥37 weeks) in Yucatan during 2013 were analyzed. Birth weights, gestational ages, and maternal socioeconomic data were provided by the Ministry of Health of Yucatan. Maternal Maya ancestry was defined by the presence of Maya surnames in: (1) non-Maya surnames (NM-NM), (2) one Maya surname (NM-M), and (3) two Maya surnames (M-M). Biological and socioeconomic parameters were compared between the categories of ancestry through one-way analysis of variance (ANOVA) and a multiple regression model was used to analyze the association between ancestry and infants' birth weight controlling for influence of covariates. Mean birth weight was 3,114 g (SD = 406) (NM-NM: 3,150 g [SD = 404], NM-M: 3,106 g [SD = 402], M-M: 3,088 g [SD = 408]). With the biological and socioeconomic variables statistically adjusted for, the presence of one and two maternal Maya surnames was associated with decreases in birth weight of 42 g and 63 g, respectively. None of the interactions between ancestry and other predictors was statistically significant. The lower mean birth weights of Maya infants are consistent with studies reporting poor growth and nutritional status of Maya children from Yucatan. Historically adverse socioeconomic conditions experienced by the Maya population are probably linked to the relatively lower birth weights of their infants. Am. J. Hum. Biol. 28:436-439, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Water management by early people in the Yucatan, Mexico

USGS Publications Warehouse

Back, W.

1995-01-01

The Yucatan Peninsula is a coastal plain underlain by permeable limestone and receives abundant rainfall. Such hydrogeologic conditions should provide major supplies of water; however, factors of climate and hydrogeology have combined to form a hydrologic system with chemical boundaries that limits the amount of fresh water available. Management of water resources has long had a major influence on the cultural and economic development of the Yucatan. The Mayan culture of the northern Yucatan developed on extensive use of groundwater. The religion was water oriented and the Mayan priests prayed to Chac, the water god, for assistance in water management, primarily to decrease the severity of droughts. The Spaniards arrived in 1517 and augmented the supply by digging wells, which remained the common practice for more than 300 years. Many wells now have been abandoned because of serious problems of pollution. A historical perspective of a paper such as this provides insight into the attitudes concerning water of early people and perhaps provides insight into current attitudes concerning water. Hydrogeologists possess the expertise to generate relevant information required by water managers to arrive at management programs to achieve sustainable development. ?? 1995 Springer-Verlag.

Water management by early people in the Yucatan, Mexico

NASA Astrophysics Data System (ADS)

Back, W.

1995-06-01

The Yucatan Peninsula is a coastal plain underlain by permeable limestone and receives abundant rainfall. Such hydrogeologic conditions should provide major supplies of water; however, factors of climate and hydrogeology have combined to form a hydrologic system with chemical boundaries that limits the amount of fresh water available. Management of water resources has long had a major influence on the cultural and economic development of the Yucatan. The Mayan culture of the northern Yucatan developed on extensive use of groundwater. The religion was water oriented and the Mayan priests prayed to Chac, the water god, for assistance in water management, primarily to decrease the severity of droughts. The Spaniards arrived in 1517 and augmented the supply by digging wells, which remained the common practice for more than 300 years. Many wells now have been abandoned because of serious problems of pollution. A historical perspective of a paper such as this provides insight into the attitudes concerning water of early people and perhaps provides insight into current attitudes concerning water. Hydrogeologists possess the expertise to generate relevant information required by water managers to arrive at management programs to achieve sustainable development.

[Obesity, body morphology, and blood pressure in urban and rural population groups of Yucatan].

PubMed

Arroyo, Pedro; Fernández, Victoria; Loría, Alvar; Pardío, Jeannette; Laviada, Hugo; Vargas-Ancona, Lizardo; Ward, Ryk

2007-01-01

To characterize body morphology and blood pressure of adults of the Mexican state of Yucatan. Rural-urban differences in weight, height, waist, and hip circumferences, and blood pressure were analyzed in 313 urban and 271 rural subjects. No rural-urban differences in prevalence of obesity and overweight were found. Hypertension was marginally higher in urban subjects. Rural abnormal waist circumference was higher in young men and young women. Comparison with two national surveys and a survey in the aboriginal population (rural mixtecos) showed similar prevalence of obesity as ENSA-2000 and higher than mixtecos and ENEC-1993. Abnormal waist circumference was intermediate between ENSANUT-2006 and mixtecos and hypertension was intermediate between ENEC and mixtecos. The Maya and mestizo population of Yucatan showed a high prevalence of obesity and abnormal waist circumference not accompanied by a comparable higher hypertension frequency. This finding requires further confirmation.

Mechanisms of the 40-70 Day Variability in the Yucatan Channel Volume Transport

NASA Astrophysics Data System (ADS)

van Westen, René M.; Dijkstra, Henk A.; Klees, Roland; Riva, Riccardo E. M.; Slobbe, D. Cornelis; van der Boog, Carine G.; Katsman, Caroline A.; Candy, Adam S.; Pietrzak, Julie D.; Zijlema, Marcel; James, Rebecca K.; Bouma, Tjeerd J.

2018-02-01

The Yucatan Channel connects the Caribbean Sea with the Gulf of Mexico and is the main outflow region of the Caribbean Sea. Moorings in the Yucatan Channel show high-frequent variability in kinetic energy (50-100 days) and transport (20-40 days), but the physical mechanisms controlling this variability are poorly understood. In this study, we show that the short-term variability in the Yucatan Channel transport has an upstream origin and arises from processes in the North Brazil Current. To establish this connection, we use data from altimetry and model output from several high resolution global models. A significant 40-70 day variability is found in the sea surface height in the North Brazil Current retroflection region with a propagation toward the Lesser Antilles. The frequency of variability is generated by intrinsic processes associated with the shedding of eddies, rather than by atmospheric forcing. This sea surface height variability is able to pass the Lesser Antilles, it propagates westward with the background ocean flow in the Caribbean Sea and finally affects the variability in the Yucatan Channel volume transport.

Merida, Yucatan Peninsula, Mexico

NASA Technical Reports Server (NTRS)

1992-01-01

This rare cloud free view of the city of Merida (21.0N, 90.0W) on the Yucatan Peninsula of Mexico was taken as an experiment with color infrared film to determine the best applications of this unique film. Color film presents an image as it appears to the eye but color infrared film eliminates haze and better defines vegetation and its vitality by the shade of red or pink. Note that much of the native forests have been cut down for farm lands.

Chemical constraints of groundwater management in the Yucatan peninsula, Mexico

NASA Astrophysics Data System (ADS)

Back, W.; Lesser, J. M.

1981-05-01

Two critical objectives of water management in the Yucatan are: (1) to develop regional groundwater supplies for an expanding population and tourism based on the Mayan archeological sites and excellent beaches; and (2) to control groundwater pollution in a chemically sensitive system made vulnerable by geologic conditions. The Yucatan peninsula is a coastal plain underlain by permeable limestone and has an annual rainfall of more than 1000 mm. Such a setting should provide abundant supplies of water; however, factors of climate and hydrogeology have combined to form a hydrologic system with chemical boundaries that decrease the amount of available fresh water. Management of water resources has long had a major influence on the cultural and economic development of the Yucatan. The Mayan culture of the northern Yucatan developed by extensive use of groundwater. The religion was water-oriented and the Mayan priests prayed to Chac, the water god, for assistance in water management primarily to decrease the severity of droughts. The Spaniards arrived in 1517 and augmented the supplies by digging wells, which remained the common practice for more than 300 years. Many wells now have been abandoned because of serious problems of pollution resulting from the use of a sewage disposal well adjacent to each supply well. The modern phase of water management began in 1959 when the Secretaría de Recursos Hidráulicos (S.R.H.) was charged with the responsibility for both scientific investigations and development programmes for water-supply and sewage-disposal systems for cities, villages and islands.

Chemical constraints of groundwater management in the Yucatan peninsula, Mexico

USGS Publications Warehouse

Back, W.; Lesser, J.M.

1981-01-01

Two critical objectives of water management in the Yucatan are: (1) to develop regional groundwater supplies for an expanding population and tourism based on the Mayan archeological sites and excellent beaches; and (2) to control groundwater pollution in a chemically sensitive system made vulnerable by geologic conditions. The Yucatan peninsula is a coastal plain underlain by permeable limestone and has an annual rainfall of more than 1000 mm. Such a setting should provide abundant supplies of water; however, factors of climate and hydrogeology have combined to form a hydrologic system with chemical boundaries that decrease the amount of available fresh water. Management of water resources has long had a major influence on the cultural and economic development of the Yucatan. The Mayan culture of the northern Yucatan developed by extensive use of groundwater. The religion was water-oriented and the Mayan priests prayed to Chac, the water god, for assistance in water management primarily to decrease the severity of droughts. The Spaniards arrived in 1517 and augmented the supplies by digging wells, which remained the common practice for more than 300 years. Many wells now have been abandoned because of serious problems of pollution resulting from the use of a sewage disposal well adjacent to each supply well. The modern phase of water management began in 1959 when the Secretari??a de Recursos Hidra??ulicos (S.R.H.) was charged with the responsibility for both scientific investigations and development programmes for water-supply and sewage-disposal systems for cities, villages and islands. ?? 1981.

Metabolic Syndrome and Coronary Artery Disease in Ossabaw Compared with Yucatan Swine

PubMed Central

Neeb, Zachary P; Edwards, Jason M; Alloosh, Mouhamad; Long, Xin; Mokelke, Eric A; Sturek, Michael

2010-01-01

Metabolic syndrome (MetS), a compilation of associated risk factors, increases the risk of type 2 diabetes and coronary artery disease (CAD, atherosclerosis), which can progress to the point of artery occlusion. Stents are the primary interventional treatment for occlusive CAD, and patients with MetS and hyperinsulinemia have increased restenosis. Because of its thrifty genotype, the Ossabaw pig is a model of MetS. We tested the hypothesis that, when fed high-fat diet, Ossabaw swine develop more features of MetS, greater native CAD, and greater stent-induced CAD than do Yucatan swine. Animals of each breed were divided randomly into 2 groups and fed 2 different calorie-matched diets for 40 wk: control diet (C) and high-fat, high-cholesterol atherogenic diet (H). A bare metal stent was placed in the circumflex artery, and pigs were allowed to recover for 3 wk. Characteristics of MetS, macrovascular and microvascular CAD, in-stent stenosis, and Ca2+ signaling in coronary smooth muscle cells were evaluated. MetS characteristics including, obesity, glucose intolerance, hyperinsulinemia, and elevated arterial pressure were elevated in Ossabaw swine compared to Yucatan swine. Ossabaw swine with MetS had more extensive and diffuse native CAD and in-stent stenosis and impaired coronary blood flow regulation compared with Yucatan. In-stent atherosclerotic lesions in Ossabaw coronary arteries were less fibrous and more cellular. Coronary smooth muscle cells from Ossabaw had impaired Ca2+ efflux and intracellular sequestration versus cells from Yucatan swine. Therefore, Ossabaw swine are a superior model of MetS, subsequent CAD, and cellular Ca2+ signaling defects, whereas Yucatan swine are leaner and relatively resistant to MetS and CAD. PMID:20819380

Emissions from Biomass Burning in the Yucatan

NASA Technical Reports Server (NTRS)

Yokelson, R.; Crounse, J. D.; DeCarlo, P. F.; Karl, T.; Urbanski, S.; Atlas, E.; Campos, T.; Shinozuka, Y.; Kapustin, V.; Clarke, A. D.;

Hematologic values of the yucatan miniature pig.

PubMed

Parsons, A H; Wells, R E

1998-01-01

Mean values and ranges for 16 hematological parameters for healthy, young, sexually-mature Yucatan miniature swine are presented. No significant differences were observed between sexes with regard to hemograms. Comparison of observed values with those published in the literature for standard domestic and other breeds of miniature swine reveals no major differences.

Shaded Relief with Height as Color, Yucatan Peninsula, Mexico

NASA Image and Video Library

2003-03-06

This shaded relief image of Mexico Yucatan Peninsula show a subtle, but unmistakable, indication of the Chicxulub impact crater. Most scientists now agree that this impact was the cause of the Cretatious-Tertiary Extinction.

Effective and Safe Anesthesia for Yorkshire and Yucatan Swine with and without Cardiovascular Injury and Intervention

PubMed Central

Linkenhoker, Jan R; Burkholder, Tanya H; Linton, CG Garry; Walden, April; Abusakran-Monday, Kim A; Rosero, Ana P; Foltz, Charmaine J

2010-01-01

The goal of this study was to identify an injectable anesthetic protocol that provides sedation sufficient for peripheral vascular catheterization, intubation, and transport while minimizing cardiovascular changes in Yorkshire and Yucatan pigs with and without cardiovascular injury and intervention (CI). Phase 1 examined the safety and efficacy of acepromazine–ketamine, diazepam–ketamine, midazolam–ketamine, and medetomidine–ketamine in 5 healthy Yorkshire pigs. For each drug combination, we obtained multiple measurements of heart rate, blood pressure, respiratory rate, temperature, sedation score, ability to catheterize and intubate, and recovery score. Phase 2 evaluated and refined the dose of the most effective Phase 1 anesthetic combination (midazolam–ketamine) in healthy and CI Yorkshire pigs (n = 53 trials). Phase 3 mirrored Phase 2 but tested midazolam–ketamine in healthy and CI Yucatan pigs (n = 34 trials). Midazolam (0.5 mg/kg)–ketamine (25 to 27 mg/kg) was the most effective anesthetic combination in healthy Yorkshire pigs, but this dose was less effective in healthy Yucatan pigs and CI Yorkshire and Yucatan pigs. Midazolam–ketamine resulted in tachycardia and apnea more frequently in CI pigs than healthy pigs. This combination also caused vomiting in one CI Yucatan pig. Overall, midazolam–ketamine provided safe and effective sedation for catheterization and intubation of both healthy and CI pigs. This study suggests Yucatan pigs may require a higher dose midazolam–ketamine to achieve the same level of sedation as that in Yorkshire pigs. Although anesthetic complication rates were higher in CI pigs, our results indicate that midazolam–ketamine can be safely used for sedation of both pig breeds with and without CI. PMID:20587167

The potential application of hairless guinea pigs as a replacement for the Yucatan mini-pig in animal studies

NASA Astrophysics Data System (ADS)

Jindra, Nichole M.; Imholte, Michelle L.

2008-02-01

The Yucatan mini-pig (Sus scrofa) is one of the most widely used animal models for skin damage studies because it shares many of the same physical properties as human skin. While the Yucatan is ideal for laser exposure studies using a large spot size, its size and cost are excessive for projects using smaller beams. This experiment performed histological analysis of skin biopsies from pigmented Hairless Guinea Pigs (Cavia porcellus) for epidermal thickness and melanin concentration. That data was then compared to similar information on the Yucatan.

Differences in coastal and oceanic SST trends north of Yucatan Peninsula

NASA Astrophysics Data System (ADS)

Varela, R.; Costoya, X.; Enriquez, C.; Santos, F.; Gómez-Gesteira, M.

2018-06-01

The coastal area north of Yucatan has experienced a cooling SST trend from 1982 to 2015 during the upwelling season (May-September) that contrasts with the warming observed at the adjacent ocean area. Different drivers were analyzed to identify the possible causes of that unusual coastal cooling. Changes in coastal upwelling and in sea-atmosphere heat fluxes are not consistent with the observed coastal cooling. The eastward shift of the Yucatan Current observed over the last decades is hypothesized as the most probable cause of coastal cooling. This shift enhances the vertical transport of cold deeper water to the continental shelf from where it is pumped to the surface by upwelling favorable westerly winds.

An innovative ecohealth intervention for Chagas disease vector control in Yucatan, Mexico.

PubMed

Waleckx, Etienne; Camara-Mejia, Javier; Ramirez-Sierra, Maria Jesus; Cruz-Chan, Vladimir; Rosado-Vallado, Miguel; Vazquez-Narvaez, Santos; Najera-Vazquez, Rosario; Gourbière, Sébastien; Dumonteil, Eric

2015-02-01

Non-domiciliated (intrusive) triatomine vectors remain a challenge for the sustainability of Chagas disease vector control as these triatomines are able to transiently (re-)infest houses. One of the best-characterized examples is Triatoma dimidiata from the Yucatan peninsula, Mexico, where adult insects seasonally infest houses between March and July. We focused our study on three rural villages in the state of Yucatan, Mexico, in which we performed a situation analysis as a first step before the implementation of an ecohealth (ecosystem approach to health) vector control intervention. The identification of the key determinants affecting the transient invasion of human dwellings by T. dimidiata was performed by exploring associations between bug presence and qualitative and quantitative variables describing the ecological, biological and social context of the communities. We then used a participatory action research approach for implementation and evaluation of a control strategy based on window insect screens to reduce house infestation by T. dimidiata. This ecohealth approach may represent a valuable alternative to vertically-organized insecticide spraying. Further evaluation may confirm that it is sustainable and provides effective control (in the sense of limiting infestation of human dwellings and vector/human contacts) of intrusive triatomines in the region. © The author 2015. The World Health Organization has granted Oxford University Press permission for the reproduction of this article.

Detection of Rickettsia felis in Wild Mammals from Three Municipalities in Yucatan, Mexico.

PubMed

Panti-May, Jesús Alonso; Torres-Castro, Marco; Hernández-Betancourt, Silvia; Dzul-Rosado, Karla; Zavala-Castro, Jorge; López-Avila, Karina; Tello-Martín, Raúl

2015-09-01

The aim of this study was to provide information of the occurrence of Rickettsia felis in wild mammals from three municipalities in Yucatan, Mexico. The reactivity of rodent serum to Rickettsia antigens was detected in 80.9% (17 of 21) samples using immunofluorescence assay. Polymerase chain reaction identified rickettsial DNA in spleens of 43.5% (10 of 23) rodents and 57.1% (4 of 7) opossums. The identification of the rickettsial DNA was confirmed as R. felis by restriction fragment length polymorphism and DNA sequencing. This study comprises the first report of R. felis detection in wild mammals in Yucatan.

Regeneration of mahogany (Swietenia macrophylla) in the Yucatan

Treesearch

M.B. Dickinson; D.F. Whigham; D.F. Whigham

1999-01-01

Low rates of natural regeneration of big-leaf mahogany were found in gaps due to felling and natural treefalls in the Yucatan. This finding is consistent with low post-logging abundances of reproductive-sized trees as well as relatively low growth rates of planted mahogany seedlings in small felling gaps. High growth rates of seedlings in large felling gaps and...

Comparison of current and paleorecharge on the Yucatan Peninsula, Mexico

NASA Astrophysics Data System (ADS)

Van Pelt, S.; Allen, D. M.; Kohfeld, K. E.

2016-12-01

During the Terminal Classic Period (TCP) 800-1000 AD, the Yucatan Peninsula is thought to have experienced a 150-year long series of droughts that contributed to the demise of the Mayan civilization. The occurrence of this type of event suggests that similar precipitation extremes could occur again, and severely impact water supplies. Studying the past occurrence of droughts may provide more insight into the possible timing and intensity of droughts. However, observed data of the past climate is limited to proxy records, which are not detailed enough for groundwater modeling. The goals of this study were two-fold: (a) to generate a daily paleoclimate time series for use in a recharge model, and (b) to compare current and past recharge on the Yucatan Peninsula. Past temperature and precipitation were reconstructed using a novel backwards shift factor approach using output from two experiments of the Community Climate System Model Version 4 (CCSM4). Shift factors were applied using two approaches: (1) application of shift factors to a stochastic weather series based on the observed climate, and (2) application of shift factors directly to the observed climate. The second method (direct shift factor approach) was found to be more suitable for the Yucatan Peninsula, as the observed median annual precipitation was poorly reproduced in the stochastic data. The reconstructed precipitation was used in the recharge model, which used the unsaturated component of the modeling program MIKE SHE. The comparison of the TCP and the current climate models indicated that on average, 1.74% more recharge occurred annually during the TCP. The seasonal water balance components showed that the majority of this higher recharge occurred during the wet season, with little to no increase in recharge during the dry season. Due to issues with the CCSM4 model data, changes in climate variability were not able to be incorporated into this study. If variability were incorporated, the TCP climate

Chicxulub Impact Crater and Yucatan Carbonate Platform - Stratigraphy and Petrography of PEMEX Borehole Cores

NASA Astrophysics Data System (ADS)

Gutierrez-Cirlos, A. G.; Perez-Drago, G.; Perez-Cruz, L.; Urrutia-Fucugauchi, J.

2008-12-01

Chicxulub impact crater is the best preserved of the three large multi-ring structures documented in the terrestrial record. Chicxulub, formed 65 Ma ago, is associated with the Cretaceous/Tertiary (K/T) boundary layer and the impact related to the organism extinctions and events marking the boundary. The crater is buried under Tertiary sediments in the Yucatan carbonate platform in the southern Gulf of Mexico. The structure was initially recognized from gravity and magnetic anomalies in the PEMEX exploration surveys of the northwestern Yucatan peninsula. The exploration program included eight deep boreholes completed from 1952 through the 1970s. The investigations showing Chicxulub as a large complex impact crater formed at the K/T boundary have relayed on the PEMEX decades-long exploration program. However, despite frequent use of PEMEX information and core samples, significant parts of the database and cores remain to be evaluated, analyzed and incorporated with results from recent efforts. Access to PEMEX Core Repository has permitted to study the cores and collect new samples from some of the boreholes. We analyzed cores from Yucatan-6, Chicxulub-1, Sacapuc-1, Ticul-1, Yucatan-1 and Yucatan-4 boreholes to make new detailed stratigraphic correlations and petrographic characterization, using information from PEMEX database and the recent studies. In C-1 cores, breccias show 4-8 cm clasts of fine grained altered melt dispersed in a medium to coarse grained matrix composed of pyroxene and feldspar with little macroscopic alteration. Clasts contain 0.2 to 0.1 cm fragments of silicate material (basement) that show variable degrees of digestion. Melt samples from C-1 N10 comes from interval 1,393-1,394 m, and show a fine-to-medium grained coherent microcrystalline groundmass. Melt and breccias in Y-6 extend from about 1,100 m to more than 1,400 m. Sequence is well sorted, with an apparent gradation in both the lithic and melt clasts. In this presentation we report on

West Nile Virus in Resident Birds from Yucatan, Mexico.

PubMed

Chaves, Andrea; Sotomayor-Bonilla, Jesus; Monge, Otto; Ramírez, Abigaíl; Galindo, Francisco; Sarmiento-Silva, Rosa Elena; Gutiérrez-Espeleta, Gustavo A; Suzán, Gerardo

2016-01-01

West Nile virus (WNV) in the Americas is thought to be transported at large spatial scales by migratory birds and locally spread and amplified by resident birds. Local processes, including interspecific interactions and dominance of passerine species recognized as competent reservoirs, may boost infection and maintain endemic cycles. Change in species composition has been recognized as an important driver for infection dynamics. Due to migration and changes in species diversity and composition in wintering grounds, changes in infection prevalence are expected. To these changes, we used PCR to estimate the prevalence of WNV in wild resident birds during the dry and rainy seasons of 2012 in Yucatan, Mexico. Serum samples were obtained from 104 wild birds, belonging to six orders and 35 species. We detected WNV in 14 resident birds, representing 11 species and three orders. Prevalences by order was Passeriformes (27%), Columbiformes (6%), and Piciformes (33%). Resident birds positive to WNV from Yucatan may be indicative of local virus circulation and evidence of past virus transmission activity.

Shaded Relief with Height as Color and Landsat, Yucatan Peninsula, Mexico

NASA Image and Video Library

2003-03-06

The top picture is a shaded relief image of the northwest corner of Mexico Yucatan Peninsula generated from NASA Shuttle Radar Topography Mission SRTM data, and shows a subtle, but unmistakable, indication of the Chicxulub impact crater.

Pumas and Prepositions: Training Nature Guides in the Yucatan Peninsula.

ERIC Educational Resources Information Center

Brown, Cynthia

2000-01-01

In the Yucatan Peninsula (Mexico), the 10-week Nature Guide Training Program integrates English immersion with natural history and environmental interpretation to train rural adults as nature guides and conservation leaders. Most graduates have found work as ecotourism guides or in conservation-related activities, and many have provided English…

Targeted disruption of LDLR causes hypercholesterolemia and atherosclerosis in Yucatan miniature pigs.

PubMed

Davis, Bryan T; Wang, Xiao-Jun; Rohret, Judy A; Struzynski, Jason T; Merricks, Elizabeth P; Bellinger, Dwight A; Rohret, Frank A; Nichols, Timothy C; Rogers, Christopher S

2014-01-01

Recent progress in engineering the genomes of large animals has spurred increased interest in developing better animal models for diseases where current options are inadequate. Here, we report the creation of Yucatan miniature pigs with targeted disruptions of the low-density lipoprotein receptor (LDLR) gene in an effort to provide an improved large animal model of familial hypercholesterolemia and atherosclerosis. Yucatan miniature pigs are well established as translational research models because of similarities to humans in physiology, anatomy, genetics, and size. Using recombinant adeno-associated virus-mediated gene targeting and somatic cell nuclear transfer, male and female LDLR+/- pigs were generated. Subsequent breeding of heterozygotes produced LDLR-/- pigs. When fed a standard swine diet (low fat, no cholesterol), LDLR+/- pigs exhibited a moderate, but consistent increase in total and LDL cholesterol, while LDLR-/- pigs had considerably elevated levels. This severe hypercholesterolemia in homozygote animals resulted in atherosclerotic lesions in the coronary arteries and abdominal aorta that resemble human atherosclerosis. These phenotypes were more severe and developed over a shorter time when fed a diet containing natural sources of fat and cholesterol. LDLR-targeted Yucatan miniature pigs offer several advantages over existing large animal models including size, consistency, availability, and versatility. This new model of cardiovascular disease could be an important resource for developing and testing novel detection and treatment strategies for coronary and aortic atherosclerosis and its complications.

Performance and genetic variation of big-leaf mahogany (Swietenia macrophylla King) in provenance and progeny trials in the Yucatan Peninsula of Mexico.

Treesearch

Kevyn E. Wightman; Sheila E. Ward; Jeremy P. Haggar; Bartolo Rodriguez Santiago; Jonathan P. Cornelius

2008-01-01

Stocks of the valuable big-leaf mahogany (Swietenia macrophylla King) are declining, and trials for growth and pest resistance are needed to select material for plantations. Seeds were collected from 67 open-pollinated trees from five provenances in the Yucatan Peninsula of Mexico and planted in three provenance/progeny trials in the state of Quintana Roo, Mexico, in...

Wind-driven coastal upwelling and westward circulation in the Yucatan shelf

NASA Astrophysics Data System (ADS)

Ruiz-Castillo, Eugenio; Gomez-Valdes, Jose; Sheinbaum, Julio; Rioja-Nieto, Rodolfo

2016-04-01

The wind-driven circulation and wind-induced coastal upwelling in a large shelf sea with a zonally oriented coast are examined. The Yucatan shelf is located to the north of the Yucatan peninsula in the eastern Gulf of Mexico. This area is a tropical shallow body of water with a smooth sloping bottom and is one of the largest shelves in the world. This study describes the wind-driven circulation and wind-induced coastal upwelling in the Yucatan shelf, which is forced by easterly winds throughout the year. Data obtained from hydrographic surveys, acoustic current profilers and environmental satellites are used in the analysis. Hydrographic data was analyzed and geostrophic currents were calculated in each survey. In addition an analytical model was applied to reproduce the currents. The results of a general circulation model were used with an empirical orthogonal function analysis to study the variability of the currents. The study area is divided in two regions: from the 40 m to the 200 m isobaths (outer shelf) and from the coast to the 40 m isobath (inner shelf). At the outer shelf, observations revealed upwelling events throughout the year, and a westward current with velocities of approximately 0.2 m s-1 was calculated from the numerical model output and hydrographic data. In addition, the theory developed by Pedlosky (2007) for a stratified fluid along a sloping bottom adequately explains the current's primary characteristics. The momentum of the current comes from the wind, and the stratification is an important factor in its dynamics. At the inner shelf, observations and numerical model output show a wind-driven westward current with maximum velocities of 0.20 m s-1. The momentum balance in this region is between local acceleration and friction. A cold-water band is developed during the period of maximum upwelling.

Extensive Gravity Sliding of Late Jurassic-Cretaceous Age along the Northern Yucatan Margin of the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Steier, A.; Mann, P.

2017-12-01

Gravity slides on salt or shale detachment surfaces linking updip extension with down dip compression have been described from several margins of the Gulf of Mexico (GOM). In a region 250 km offshore from the southwestern coast of Florida, the late Jurassic section near Destin Dome and Desoto Canyon has undergone late Jurassic to Cretaceous gravity sliding and downdip dispersion of rigid blocks along the top of the underlying Louann salt. Yet there has been no previous study of similar structural styles on the slope and deep basin of its late Jurassic conjugate margin located 200 km offshore of the northern margin of the Yucatan Peninsula. This study describes an extensive area of Mesozoic gravity sliding from the northern Yucatan slope using a grid of 2D seismic data covering a 134,000 km2 area of the northern Yucatan margin tied to nine wells. These data allow the northern Yucatan margin to be divided into three slope and basinal provinces: 1) a 225 km length of the northeastern margin consisting of late Jurassic-Cretaceous section that is not underlain by salt, exhibits no gravity sliding features, and has sub-horizontal dips; 2) a 120 km length of the north-central Yucatan margin with gravity slide features characterized by an 80-km-wide updip zone of normal faults occupying the shelf edge and upper slope and a 50-km-wide downdip zone of folds and thrust faults at the base of the slope; the slide area exhibits multiple detached slide blocks composed of late Jurassic sandstones and marine mudstones separated by intervening salt rollers; growth wedges adjacent to listric, normal faults suggest a gradual and long-lived downdip motion of rigid fault blocks throughout much of the late Jurassic and Cretaceous rather than a catastrophic and instantaneous collapse of the shelf edge; the basal, normal detachment fault averages 3° in dip and is overlain by salt that varies from 0-500 ms in time thickness; by the end of the Cretaceous, most gravity sliding and vertical

Changes in stature, weight, and nutritional status with tourism-based economic development in the Yucatan.

PubMed

Leatherman, Thomas L; Goodman, Alan H; Stillman, Tobias

2010-07-01

Over the past 40 years, tourism-based economic development has transformed social and economic conditions in the Yucatan Peninsula, Mexico. We address how these changes have influenced anthropometric indicators of growth and nutritional status in Yalcoba, a Mayan farming community involved in the circular migration of labor in the tourist economy. Data are presented on stature and weight for children measured in 1938 in the Yucatan Peninsula and from 1987 to 1998 in the Mayan community of Yalcoba. In addition, stature, weight and BMI are presented for adults in Yalcoba based on clinic records. Childhood stature varied little between 1938 and 1987. Between 1987 and 1998 average male child statures increased by 2.6cm and female child statures increased by 2.7cm. Yet, 65% of children were short for their ages. Between 1987 and 1998, average child weight increased by 1.8kg. Child BMIs were similar to US reference values and 13% were considered to be above average for weight. Forty percent of adult males and 64% of females were overweight or obese. The anthropometric data from Yalcoba suggest a pattern of stunted children growing into overweight adults. This pattern is found elsewhere in the Yucatan and in much of the developing world where populations have experienced a nutrition transition toward western diets and reduced physical activity levels. 2010 Elsevier B.V. All rights reserved.

Acremonium camtosporum isolated as an endophyte of Bursera simaruba from Yucatan Peninsula, Mexico

USDA-ARS?s Scientific Manuscript database

Bursera simaruba (Burseraceae) is a frequent and co-dominant tree of tropical sub-caducifolious forest in the Yucatan Peninsula. This species is important ecologically because it can grow in poor, clay or sandy, saline soils. The Mayan communities use this plant medicinally for its analgesic, antimy...

SUBACTUTE HEMATOLOGICAL RESPONSES OF THE YUCATAN SAILFIN MOLLY (POECILIA VELIFERA) EXPOSED TO CADMIUM CHLORIDE

EPA Science Inventory

This study focuses on the subacute hematological responses of the Yucatan sailfin molly, Poecilia velifera, exposed to cadmium chloride. Previous studies in other teleosts and mammals have suggested that exposure to cadmium chloride results in a leucocytic response. Fish were exp...

SUBACUTE HEMATOLOGICAL RESPONSES OF THE YUCATAN SAILFIN MOLLY (POECILIA VELIFERA) EXPOSED TO CADMIUM CHLORIDE

EPA Science Inventory

This study focuses on the subacute hematological responses of the Yucatan sailfin molly, Poecilia velifera, exposed to cadmium chloride. Previous studies in other teleosts and mammals have suggested that exposure to cadmium chloride results in a leucocytic response. Fish were exp...

Increased Precipitation over the Yucatan Peninsula Inferred from the Spatial and Temporal Distribution of Late Holocene Foram Assemblages

NASA Astrophysics Data System (ADS)

Rachmallu, M.; Broach, K.; Paytan, A.; Street, J. H.

2014-12-01

As global climate warms, IPCC predictions suggest dry and seasonally dry regions will become dryer, increasing stress on water resources by growing urban populations (e.g. Southern California; Yucatan, Mexico). This study aims to reconstruct paleohydrologic trends during the late Holocene using foraminifera assemblages in Yucatan, Mexico to determine drought susceptibility in a region affected by migration of the Intertropical Convergence Zone (ITCZ). The ITCZ affects precipitation over the Yucatan Peninsula, potentially decreasing groundwater infiltration and thus reducing discharge in submarine springs at the peninsula margins. The field site Celestun Lagoon near Merida, Yucatan, Mexico, is dominated by spring and groundwater inputs at the northern terminus and opens to the Gulf of Mexico at the southern end resulting in a strong salinity gradient dependent on freshwater influx. We analyzed the foram assemblage in the top 6 cm of a set of 7 cores collected along a lagoonal transect (from the mouth to the head) and plotted the relative abundances of Ammonia beccarii, Elphidium sp., Quinqueloculina sp., and the ostracod Hemicyprideis cf. nichuptensis against site location. A. beccarii abundance increases from 40% near the head to 70% near the middle of the lagoon before dropping to <10% toward the saline lagoon mouth (high abundance in brackish salinity). Quinqueloculina sp. increases from 0% at the upper lagoon to nearly 40% near the mouth showing an opposite trend along the same transect. Elphidium sp. showed no clear trend (abundance range 10-28% throughout), and lowest H. nichuptensis abundance occurred at the middle of the lagoon (10%) increasing to the north and south (up to 60%). The inversely correlated spatial distribution between A. beccarii and Quinqueloculina sp. occurs vertically in an upper lagoon long core from 125-96 cm below sediment-water interface (14C age dates 3968-2820 ka), implying a decreasing salinity over ~1000 yrs and increased

Urban Modelling with Typological Approach. Case Study: Merida, Yucatan, Mexico

NASA Astrophysics Data System (ADS)

Rodriguez, A.

2017-08-01

In three-dimensional models of urban historical reconstruction, missed contextual architecture faces difficulties because it does not have much written references in contrast to the most important monuments. This is the case of Merida, Yucatan, Mexico during the Colonial Era (1542-1810), which has lost much of its heritage. An alternative to offer a hypothetical view of these elements is a typological - parametric definition that allows a 3D modeling approach to the most common features of this heritage evidence.

Reverse Polarity Magnetized Melt Rocks from the Cretaceous/Tertiary Chicxulub Structure, Yucatan Peninsula, Mexico

NASA Technical Reports Server (NTRS)

Urrutia-Fucugauchi, J.; Marin, Luis; Sharpton, Virgil L.

1994-01-01

We report paleomagnetic results for core samples of the breccia and andesitic rocks recovered from the Yucatan-6 Petrolcos Mexicanos exploratory well within the Chicxulub structure (about 60 km SSW from its center), northern Yucatan, Mexico. A previous study has shown that the rocks studied contain high iridium levels and shocked breccia clasts and an Ar/Ar date of 65.2 +/- 0.4 Ma. Andesitic rocks are characterized by stable single-component magnetizations with a mean inclination of -42.6 deg +/- 2.4 deg. Breccias present a complex paleomagnetic record characterized by multivectorial magnetizations with widely different initial NRM inclinations. However, after alternating field demagnetization, well defined characteristic components with upward inclinations are defined. IRM acquisition experiments, comparison of IRM and NRM coercivity spectra and the single component magnetization of the andesitic rocks indicate the occurrence of iron-rich titanomagnetites of single or pseudo-single domain states as the dominant magnetic carriers. Mean inclinations from the andesitic rocks and most of the breccia samples give a mean inclination of about -40 deg to -45 deg, indicating a reverse polarity for the characteristic magnetization that is consistent with geomagnetic chron 29R, which spans the Cretaceous/Tertiary (K/T) boundary. The inclination is also consistent with the expected value (and corresponding paleolatitude) for the site estimated from the reference polar wander curve for North America. We suggest that the characteristic magnetizations for the andesitic and breccia rocks are the result of shock heating at the time of formation of the impact structure and that the age, polarity and pateolatitude are consistent with a time at the K/T boundary.

Anaglyph, Yucatan Peninsula, Mexico

NASA Technical Reports Server (NTRS)

2003-01-01

This anaglyph (stereoscopic view) of Mexico's Yucatan Peninsula was generated entirely from Shuttle Radar Topography Mission (SRTM) data, and shows a subtle but distinctive indication of the Chicxulub impact crater. Most scientists now agree that this impact was the cause of the Cretatious-Tertiary extinction, the event 65 million years ago that marked the demise of the dinosaurs as well as the majority of life then on Earth. The crater's rim is marked by a shallow semicircular depression arcing about an offshore center point in the upper left of the picture. (The arcing depression is just above the blue line, when viewed with the naked eye.) This depression, or trough, only about 3 to 5 meters (10 - 15 feet) deep and about 5 kilometers (3 miles) wide, was likely caused by collapse of limestone caverns preferentially above the crater rim, resulting in an arcing chain of sinkholes. The limestone that covers most of the Yucatan Peninsula post-dates the impact crater. However, the crater pattern apparently controls the subsidence pattern just enough to show through.

This anaglyph was created by deriving a shaded relief image from the SRTM data, draping it back over the SRTM elevation model, and then generating two differing perspectives, one for each eye. Illumination is from the north (top). When viewed through special glasses, the anaglyph is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter. The total relief (range of elevations) across this entire image is less than 300 meters (1000 feet).

Elevation data used in this image were acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM

Leishmanicidal evaluation of extracts from native plants of the Yucatan peninsula.

PubMed

Peraza-Sánchez, S R; Cen-Pacheco, F; Noh-Chimal, A; May-Pat, F; Simá-Polanco, P; Dumonteil, E; García-Miss, M R; Mut-Martín, M

2007-06-01

Methanol extracts were prepared from different parts of 18 plants collected in the Yucatan peninsula and evaluated in an in vitro bioassay for leishmanicidal activity against Leishmania mexicana promastigotes. The ten most potent plant extracts (IC(50)<50 microg/ml) were Aphelandra scabra leaves, Byrsonima bucidaefolia bark, Byrsonima crassifolia bark, Clusia flava leaves, Cupania dentata bark, Diphysa carthagenensis leaves, Dorstenia contrajerva whole plant, Milleria quinqueflora roots, Tridax procumbens whole plant, and Vitex gaumeri bark.

Gulf of Mexico, coast of Yucatan, as seen from the Apollo 7 spacecraft

NASA Image and Video Library

1968-10-13

AS07-05-1635 (13 Oct. 1968) --- Gulf of Mexico, coast of Yucatan, Mexico, as seen from the Apollo 7 spacecraft during its 33rd revolution of Earth. Note road leading to city of Merida which is under cloud cover. Photographed from an altitude of 123 nautical miles, at ground elapsed time of 52 hours and 37 minutes.

Mercury levels assessment and its relationship with oxidative stress biomarkers in children from three localities in Yucatan, Mexico.

PubMed

Rangel-Méndez, Jorge A; Arcega-Cabrera, Flor E; Fargher, Lane F; Moo-Puc, Rosa E

2016-02-01

Mercury (Hg) is a global pollutant that is released into the environment from geologic and anthropogenic sources. Once it enters an organism, it generates several toxicity mechanisms and oxidative stress has been proposed as the main one. Metal susceptibility is greater in children, which is a result of their physiology and behavior. In Yucatan, Mexico, burning of unregulated garbage dumps and household trash, ingestion of top marine predators, and pottery manufacturing are among the conditions that could promote Hg exposure. However, for Yucatan, there are no published studies that report Hg levels and associated oxidative stress status in children. Therefore, this study aimed to assess Hg levels in blood and urine and oxidative stress biomarkers levels in a sample of 107 healthy children from three localities in Yucatan, Mexico, as well as investigate the relationship between these parameters. Hg was detected in 11 (10.28%) of blood samples and 38 (35.51%) of urine samples collected from the participating children. Fourteen subjects showed Hg above recommended levels. The oxidative stress biomarkers were slightly elevated in comparison with other studies and were statistically different between the sampling sites. No linear correlation between Hg levels and oxidative stress biomarkers was found. Nevertheless, exploratory univariate and multivariate analysis showed non-linear relations among the measured variables. Globally, the study provides, for the first time, information regarding Hg levels and their relationship with oxidative stress biomarkers in a juvenile population from Mexico's southeast (Yucatan) region. In agreement with worldwide concern about Hg, this study should stimulate studies on metal monitoring in humans (especially children) among scientists working in Mexico, the establishment of polices for its regulation, and the reduction of human health risks. Copyright © 2015 Elsevier B.V. All rights reserved.

A third case of amelia in Morelet's crocodile from the Yucatan Peninsula.

PubMed

Charruau, Pierre; Niño-Torres, Carlos A

2014-07-03

Congenital defects in crocodilians have received little interest. In the context of global change and increasing threats to biodiversity, data on birth defects occurring in wildlife could be of importance for estimating the health of species populations and their ecosystems. Herein, we report the first case of amelia (i.e. absence of limbs) in Morelet's crocodiles Crocodylus moreletii from Mexico and the third on the southern Yucatan Peninsula. The crocodile in question was a juvenile (41 cm total length) captured in July 2012 in the Río Hondo, the river that forms the border between Mexico and Belize south of the state of Quintana Roo. The prevalence of this malformation in the C. moreletii population of Río Hondo (0.35%) is similar to that reported in 2 previous cases in Belize. Several causes of birth defects in crocodilians have previously been cited in the literature. Although we do not have relevant information to elucidate this case, we discuss some plausible explanations for this birth defect.

Brominated Flame Retardants in Sediments of Four Coastal Lagoons of Yucatan, Mexico.

PubMed

Valenzuela-Sánchez, I S; Gold-Bouchot, G; Hernández-Núñez, E; Barrientos-Medina, R C; Garza-Gisholt, E; Zapata-Pérez, O

2018-05-02

We examined the sediments of four coastal lagoons (Ria Lagartos, Bocas de Dzilam, Laguna de Chelem and Ria Celestun) from the state of Yucatan, Mexico, for three widely used commercial polybrominated diphenyl ethers formulations (penta-, octa- and deca-BDE). The most commonly found congeners in all four lagoons were BDEs 47, 99 and 100 (all in the penta-BDE formulation) and BDE209 (deca-BDE formulation). The greatest variety and highest concentrations of brominated flame retardants were found in Ria Lagartos, which also showed the highest BDE 100 concentration (24.129 ng/g). Hexabromocyclododecane was found in all lagoons, but at lower concentrations than those of the various polybrominated diphenyl ethers. Dispersal routes of these compounds are discussed, such as a ring of sinkholes (cenotes) adjacent to the lagoons. Moreover, electronic waste is a serious problem because municipal landfills have been the primary disposal method for these wastes and therefore represent a reservoir of brominated fire retardants.

Indication of a species in an extinction vortex: The ocellated turkey on the Yucatan peninsula, Mexico

NASA Astrophysics Data System (ADS)

Kampichler, Christian; Calmé, Sophie; Weissenberger, Holger; Arriaga-Weiss, Stefan Louis

2010-11-01

The ocellated turkey Meleagris ocellata (OT) is a large, unmistakable endemic bird of the Yucatan peninsula. The species has suffered a considerable loss of distributional area as well as local abundance between 1980 and 2000 and is classified as endangered according to Mexican norms. We applied Classification Trees and Random Forests in order to determine the factors that most closely explain the observed patterns of distribution and abundance loss, and to develop hypotheses that may guide measures for the protection of the OT. Among the most important predictors of change were variables corresponding to aspects of forest cover and variables on human population and small settlements. OT abundance in 1980, however, was by far the most important predictor for OT abundance change. This is an indication that the OT dynamics are governed by internal rather than by external factors. Medium and low abundances in 1980 inevitably led to a further decrease during the following years, which gives rise to the conclusion that the OT might find itself in an extinction vortex. We suggest the following hypothetical scenario for OT decline: migrant people from other Mexican states colonise forested regions in Yucatan; they establish small settlements; bushmeat hunting is important for their survival; the naïve OT is easy prey; hunting—together with beginning deforestation—reaches a certain level, and local OT abundance falls below a critical threshold; OT continues declining regardless of current social and environmental changes except where there is total protection of both the species and its habitat.

Modeling carbon stocks in a secondary tropical dry forest in the Yucatan Peninsula, Mexico

Treesearch

Zhaohua Dai; Richard A. Birdsey; Kristofer D. Johnson; Juan Manuel Dupuy; Jose Luis Hernandez-Stefanoni; Karen Richardson

2014-01-01

The carbon balance of secondary dry tropical forests of Mexico’s Yucatan Peninsula is sensitive to human and natural disturbances and climate change. The spatially explicit process model Forest-DeNitrification-DeComposition (DNDC) was used to estimate forest carbon dynamics in this region, including the effects of disturbance on carbon stocks. Model evaluation using...

Multivariate Statistical Analysis: a tool for groundwater quality assessment in the hidrogeologic region of the Ring of Cenotes, Yucatan, Mexico.

NASA Astrophysics Data System (ADS)

Ye, M.; Pacheco Castro, R. B.; Pacheco Avila, J.; Cabrera Sansores, A.

2014-12-01

The karstic aquifer of Yucatan is a vulnerable and complex system. The first fifteen meters of this aquifer have been polluted, due to this the protection of this resource is important because is the only source of potable water of the entire State. Through the assessment of groundwater quality we can gain some knowledge about the main processes governing water chemistry as well as spatial patterns which are important to establish protection zones. In this work multivariate statistical techniques are used to assess the groundwater quality of the supply wells (30 to 40 meters deep) in the hidrogeologic region of the Ring of Cenotes, located in Yucatan, Mexico. Cluster analysis and principal component analysis are applied in groundwater chemistry data of the study area. Results of principal component analysis show that the main sources of variation in the data are due sea water intrusion and the interaction of the water with the carbonate rocks of the system and some pollution processes. The cluster analysis shows that the data can be divided in four clusters. The spatial distribution of the clusters seems to be random, but is consistent with sea water intrusion and pollution with nitrates. The overall results show that multivariate statistical analysis can be successfully applied in the groundwater quality assessment of this karstic aquifer.

Preliminary Geochemical and Rock Magnetic Study of a Stalagmite From Quintana Roo, Northeastern Yucatan Peninsula

NASA Astrophysics Data System (ADS)

Urrutia-Fucugauchi, J.; Perez-Cruz, L.; Zhao, X.; Rebolledo-Vieyra, M.; Rodriguez, A.

2012-04-01

We present the preliminary results of geochemical, stable isotopes and rock magnetic studies of a stalagmite from a cave in eastern Quintana Roo, northern Yucatan peninsula. In the past years, there has been increased interest in understanding the paleoclimatic and paleoenvironmental evolution of the Yucatan peninsula and northern Central America, investigating the relationships between climate variations and the development of the Maya civilization. In particular, the variations in regional precipitation and occurrence of several drought periods, which might have been related to the collapse of the Classic Maya period. Stable isotope data on speleothems from different sites in Yucatan and Central America have provided evidence on changes in precipitation, which have affected the Maya region. The stalagmite is ~47 cm long and about 4-5 cm wide at its base. It was collected from the Hilariós Well cave in Tulum, Quintana Roo. Magnetic susceptibility and geochemical analyses have been completed as part of the initial characterization of the stalagmite, with measurements taken every centimeter. Geochemical analyses have been carried out for x-ray fluorescence, with a Niton XRF analyzer. Magnetic susceptibility was determined with a Bartington MS2 instrument using the high resolution surface probe. Additional rock magnetic analyses include magnetic hysteresis loops and isothermal remanent magnetization (IRM) acquisition, and saturation IRM demagnetization, which have been measured with a MicroMag instrument. Hysteresis loops are diamagnetic, with small varying low-coercivity ferromagnetic components. The elemental compositions of major oxides and trace elements vary with depth. Calcium is the major element and displays a pattern of small amplitude fluctuations with a trend to lower values at the bottom, which are also shown in other elements such as barium. Silica and elements such as titanium and strontium are positively correlated and show an apparent cyclic pattern

Comparison of multi-proxy data with past1000 model output over the Terminal Classic Period (800-1000 A.D.) on the Yucatan Peninsula.

NASA Astrophysics Data System (ADS)

Van Pelt, S.; Kohfeld, K. E.; Allen, D. M.

2015-12-01

The decline of the Mayan Civilization is thought to be caused by a series of droughts that affected the Yucatan Peninsula during the Terminal Classic Period (T.C.P.) 800-1000 AD. The goals of this study are two-fold: (a) to compare paleo-model simulations of the past 1000 years with a compilation of multiple proxies of changes in moisture conditions for the Yucatan Peninsula during the T.C.P. and (b) to use this comparison to inform the modeling of groundwater recharge in this region, with a focus on generating the daily climate data series needed as input to a groundwater recharge model. To achieve the first objective, we compiled a dataset of 5 proxies from seven locations across the Yucatan Peninsula, to be compared with temperature and precipitation output from the Community Climate System Model Version 4 (CCSM4), which is part of the Coupled Model Intercomparison Project Phase 5 (CMIP5) past1000 experiment. The proxy dataset includes oxygen isotopes from speleothems and gastropod/ostrocod shells (11 records); and sediment density, mineralogy, and magnetic susceptibility records from lake sediment cores (3 records). The proxy dataset is supplemented by a compilation of reconstructed temperatures using pollen and tree ring records for North America (archived in the PAGES2k global network data). Our preliminary analysis suggests that many of these datasets show evidence of drier and warmer climate on the Yucatan Peninsula around the T.C.P. when compared to modern conditions, although the amplitude and timing of individual warming and drying events varies between sites. This comparison with modeled output will ultimately be used to inform backward shift factors that will be input to a stochastic weather generator. These shift factors will be based on monthly changes in temperature and precipitation and applied to a modern daily climate time series for the Yucatan Peninsula to produce a daily climate time series for the T.C.P.

Cellular and biochemical features of skeletal muscle in obese Yucatan minipigs.

PubMed

Guillerm-Regost, Christelle; Louveau, Isabelle; Sébert, Sylvain P; Damon, Marie; Champ, Martine M; Gondret, Florence

2006-10-01

To examine cellular and biochemical features of skeletal muscle in response to dietary-induced obesity in a novel Yucatan minipig model of childhood obesity. From 4 to 16 months of age, minipigs were fed either a recommended human-type diet (NF; n = 4) or were overfed a western-type diet with saturated fat and high-glycemic index carbohydrates (OF, n = 4). Muscle samples (biceps femoris) were histochemically stained for the identification of intramuscular adipocytes, intramyocellular lipid aggregates (oil red O), and myofiber types (myosin ATPase, succinate dehydrogenase). Gene expressions and/or activities of factors involved in lipogenesis, lipolysis, or energetic metabolism were quantified in muscle. Cross-sectional areas of myofibers paralleled pig body weight (r = 0.86, p < 0.01). The size of intramuscular adipocytes, the relative proportion of oil red O-stained fibers, and total muscle lipid content tended (p < or = 0.10) to increase in response to OF diet. Hormone-sensitive lipase, carnitine palmityl transferase-I, and uncoupling protein 2 mRNA levels were lower (p < 0.05) in OF pigs than in NF pigs. Activities of beta-hydroxyacyl-coenzyme A dehydrogenase and citrate synthase assessing post-carnitine palmityl transferase I events and the proportion of oxidative myofibers were not altered by OF diet. Activity and gene expression of fatty acid synthase were lower (p < 0.02) in OF pigs than in NF pigs. Overfeeding in Yucatan minipigs reduced the expression levels of three catabolic steps in skeletal muscle that are involved also in the etiology of human obesity.

STRUCTURAL AND HYDROGEOLOGIC APPLICATIONS OF REMOTE SENSING DATA, EASTERN YUCATAN PENINSULA, MEXICO.

USGS Publications Warehouse

Southworth, C. Scott; ,

1984-01-01

Landsat and Seasat satellite images and aerial photographs of eastern Yucatan Peninsula, Mexico, were analyzed to delineate geologic controls of ground water. Significant interpretation results include the delineation of linear topographic swales, interpreted as fractures, extending more than 50 km along strike from the previously known limit of the Holbox fracture system; the alignment of sink holes (cenotes) and inlets (caletas) on strike with existing faults and fracture systems; and the identification of tonal anomalies in Ingles Lagoon suggesting fresh-water discharge from a submarine spring.

[Effectiveness of commercial repellents against Aedes aegypti (L.) in Yucatan, México].

PubMed

Uc-Puc, Valentín; Herrera-Bojórquez, Josué; Carmona-Carballo, Carolina; Che-Mendoza, Azael; Medina-Barreiro, Anuar; Chablé-Santos, Juan; Arredondo-Jiménez, Juan I; Flores-Suárez, Adriana E; Manrique-Saide, Pablo

2016-08-01

We assessed the efficacy of commercial repellents available in Yucatan against Aedes aegypti, vector of dengue, Chikungunya and Zika. Protection time was determined based on WHO/CTD/ WHOPES/IC y la NOM-032-SSA2-20I4. Products with DEET (N, N-diethyl-3-methylbenzamide) at 25% met the recommended protection. Efficacy was directly proportional to the concentration of DEET; botanicals repellents resulted no protective. Repellents with DEET provided more protection against Ae. aegypti and botanical repellents, including impregnated wristbands, provided no protection.

The checkered puffer (Spheroides testudineus) and its helminths as bioindicators of chemical pollution in Yucatan coastal lagoons.

PubMed

Pech, Daniel; Vidal-Martínez, Víctor M; Aguirre-Macedo, M Leopoldina; Gold-Bouchot, Gerardo; Herrera-Silveira, Jorge; Zapata-Pérez, Omar; Marcogliese, David J

2009-03-15

The suitability of using helminth communities as bioindicators of environmental quality of the Yucatan coastal lagoons status was tested on the checkered puffer (Spheroides testudineus) in four coastal lagoons along the Yucatan coast. The concentration of chemical pollutants in sediments, water quality parameters, helminth infracommunity characteristics, as well as fish physiological biomarkers, including EROD (7-ethoxyresorufin-O-deethylase) and catalase activities, were measured. Results from sediment analyses demonstrated the presence of hydrocarbons, organochlorine pesticides and polychlorinated biphenyls at varying concentrations, some of which exceeded the Probability Effect Level (PEL). Significant negative associations among organochlorine pesticides, infracommunity characteristics and fish physiological responses were observed in most of the lagoons. Results suggest that EROD activity and parasite infracommunity characteristics could be useful tools to evaluate the effects of chemical pollutants on the fish host and in the environment. Importantly, certain parasites appear to influence biomarker measurements, indicating that parasites should be considered in ecotoxicological studies.

Wildlife uses and hunting patterns in rural communities of the Yucatan Peninsula, Mexico

PubMed Central

2012-01-01

Background Subsistence hunting is a traditional practice providing food and many other goods for households in the Yucatan Peninsula, southeast Mexico. Economic, demographic, and cultural change in this region drive wildlife habitat loss and local extinctions. Improving our understanding about current practices of wildlife use may support better management strategies for conserving game species and their habitat. We aimed to evaluate if wildlife use remained relevant for the subsistence of rural residents of the Yucatan Peninsula, as well as if local hunting practices were related to environmental, geographical, and cultural factors. Methods Fieldwork was done between March 2010 and March 2011. Information was obtained through conversations, interviews, and participant observation. Record forms allowed recording animals hunted, biomass extracted, distance intervals to hunting sites, habitat types and seasonality of wildlife harvests. Data were analyzed using one-way Analysis of Variance, and Generalized Linear Models. Results Forty-six terrestrial vertebrate species were used for obtaining food, medicine, tools, adornments, pets, ritual objects, and for sale and mitigating damage. We recorded 968 animals taken in 664 successful hunting events. The Great Curassow, Ocellated Turkey, paca, white-tailed deer, and collared peccary were the top harvested species, providing 80.7% of biomass (10,190 kg). The numbers of animals hunted and biomass extracted declined as hunting distances increased from villages. Average per capita consumption was 4.65 ± 2.7 kg/person/year. Hunting frequencies were similar in forested and agricultural areas. Discussion Wildlife use, hunting patterns, and technologies observed in our study sites were similar to those recorded in previous studies for rural Mayan and mestizo communities in the Yucatan Peninsula and other Neotropical sites. The most heavily hunted species were those providing more products and by-products for residents. Large

Wildlife uses and hunting patterns in rural communities of the Yucatan Peninsula, Mexico.

PubMed

Santos-Fita, Dídac; Naranjo, Eduardo J; Rangel-Salazar, José Luis

2012-10-02

Subsistence hunting is a traditional practice providing food and many other goods for households in the Yucatan Peninsula, southeast Mexico. Economic, demographic, and cultural change in this region drive wildlife habitat loss and local extinctions. Improving our understanding about current practices of wildlife use may support better management strategies for conserving game species and their habitat. We aimed to evaluate if wildlife use remained relevant for the subsistence of rural residents of the Yucatan Peninsula, as well as if local hunting practices were related to environmental, geographical, and cultural factors. Fieldwork was done between March 2010 and March 2011. Information was obtained through conversations, interviews, and participant observation. Record forms allowed recording animals hunted, biomass extracted, distance intervals to hunting sites, habitat types and seasonality of wildlife harvests. Data were analyzed using one-way Analysis of Variance, and Generalized Linear Models. Forty-six terrestrial vertebrate species were used for obtaining food, medicine, tools, adornments, pets, ritual objects, and for sale and mitigating damage. We recorded 968 animals taken in 664 successful hunting events. The Great Curassow, Ocellated Turkey, paca, white-tailed deer, and collared peccary were the top harvested species, providing 80.7% of biomass (10,190 kg). The numbers of animals hunted and biomass extracted declined as hunting distances increased from villages. Average per capita consumption was 4.65 ± 2.7 kg/person/year. Hunting frequencies were similar in forested and agricultural areas. Wildlife use, hunting patterns, and technologies observed in our study sites were similar to those recorded in previous studies for rural Mayan and mestizo communities in the Yucatan Peninsula and other Neotropical sites. The most heavily hunted species were those providing more products and by-products for residents. Large birds such as the Great Curassow and

Evaluation of a commercial vaccine against avian poxvirus in turkeys kept in the backyard system in the state of Yucatan, Mexico.

PubMed

Estrella-Tec, J E; Gutiérrez-Ruiz, E J; Ramírez-González, S; Aranda-Cirerol, F; Santos-Ricalde, R; Puerto-Nájera, J L

2013-12-01

One hundred and sixty 1-month-old turkey poults were delivered to 40 households in four communities of the State of Yucatan, Mexico. The poults were divided into two populations, one vaccinated and the other non-vaccinated against avian pox. During three months, monthly visits were carried out in order to monitor the appearance of lesions suggesting avian pox in the birds delivered. Each turkey was clinically examined, searching for characteristic avian pox lesions that were classified according to the degree of severity observed. The true incidence rate and the cumulative incidence rate of avian pox were determined and the true incidence and cumulative incidence rates of mortality were determined and the relative risks calculated. The true incidence rates for avian pox in vaccinated and non-vaccinated birds were 1.5 and 1.47 respectively. The cumulative incidence rates were 0.94 and 0.90 for vaccinated and non-vaccinated birds, respectively. The comparison for the whole period between vaccinated and non-vaccinated groups did not show a significant statistical difference for mortality. However, when mortality was compared between vaccinated and non-vaccinated turkeys for each month of the study, there was a statistically significant difference for the first month (relative risk = 0.216, confidence interval 0.069 to 0.676). In addition, when the severity of pox lesions between groups was compared, statistically significant differences were found in favour of the vaccinated birds (P < 0.0001).

Groundwater geochemistry of the Yucatan Peninsula, Mexico: Constraints on stratigraphy and hydrogeology

NASA Astrophysics Data System (ADS)

Perry, Eugene; Paytan, Adina; Pedersen, Bianca; Velazquez-Oliman, Guadalupe

2009-03-01

SummaryWe report 87Sr/ 86Sr and ion concentrations of sulfate, chloride, and strontium in the groundwater of the northern and central Yucatan Peninsula, Mexico. Correlation between these data indicates that ejecta from the 65.95 m.y. old Chicxulub impact crater have an important effect on hydrogeology, geomorphology, and soil development of the region. Ejecta are present at relatively shallow subsurface depths in north-central Yucatan and at the surface along the Rio Hondo escarpment in southeast Quintana Roo, where they are referred to as the Albion Formation. Anhydrite/gypsum (and by inference celestite) are common in impact ejecta clasts and in beds and cements of overlying Paleocene and Lower Eocene rocks cored around the margin of the crater. The sulfate-rich minerals that are found in rocks immediately overlying the impact ejecta blanket, may either be partially mobilized from the ejecta layer itself or may have been deposited after the K/T impact event in an extensive pre-Oligocene shallow sea. These deposits form a distinctive sedimentary package that can be easily traced by the Eocene-Cretaceous 87Sr/ 86Sr signal. A distinct Sr isotopic signature and high SO 4/Cl ratios are observed in groundwater of northwestern and north-central Yucatan that interacts with these rocks. Moreover, the distribution of the gypsum-rich stratigraphic unit provides a solution-enhanced subsurface drainage pathway for a broad region characterized by dissolution features (poljes) extending from Chetumal, Quintana Roo to Campeche, Campeche. The presence of gypsum quarries in the area is also consistent with a sulfate-rich stratigraphic "package" that includes ejecta. The distinctive chemistry of groundwater that has been in contact with evaporite/ejecta can be used to trace flow directions and confirms a groundwater divide in the northern Peninsula. Information about groundwater flow directions and about deep subsurface zones of high permeability is useful for groundwater and

Nature of the Yucatan Block Basement as Derived From Study of Granitic Clasts in the Impact Breccias of Chicxulub Crater

NASA Astrophysics Data System (ADS)

Vera-Sanchez, P.; Rebolledo-Vieyra, M.; Perez-Cruz, L.; Urrutia-Fucugauchi, J.

2008-05-01

The tectonic and petrologic nature of the basement of the Yucatan Block is studied from analyses of basement clasts present in the impact suevitic breccias of Chicxulub crater. The impact breccias have been sampled as part of the drilling projects conducted in the Yucatan peninsula by Petroleos Mexicanos, the National University of Mexico and the Chicxulub Scientific Drilling Project. Samples analyzed come mainly from the Yaxcopoil-1, Tekax, and Santa Elena boreholes, and partly from Pemex boreholes. In this study we concentrate on clasts of the granites, granodiorites and quartzmonzonites in the impact breccias. We report major and trace element geochemical and petrological data, which are compared with data from the granitic and volcanic rocks from the Maya Mountains in Belize and from the Swannee terrane in Florida. Basement granitic clasts analyzed present intermediate to acidic sub-alkaline compositions. Plots of major oxides (e.g., Al2O3, Fe2O3, TiO2 and CaO) and trace elements (e.g., Th, Y, Hf, Nb and Zr) versus silica allow separation of samples into two major groups, which can be compared to units in the Maya Mountains and in Florida basement. The impact suevitic breccia samples have been affected by alteration likely related to the hydrothermal processes associated with the crater melt sheet. Cloritization, seritization and fenitization alterations are recognized, due to the long term hydrothermalism. Krogh et al. (1993) reported U-Pb dates on zircons from the suevitic breccias, which gave dates of 545 +/- 5 Ma and 418 +/- 6 Ma, which were interpreted in terms of the deep granitic metamorphic Yucatan basement. The younger date correlates with the age for the Osceola Granite and the St. Lucie metamorphic complex of the Swannee terrane in the Florida peninsula. The intrusive rocks in the Yucatan basement may be related to approx. 418 Ma ago collisional event in the Late Silurian.

Regional reduction in paleogroundwater discharge and rainfall in the Late Holocene Yucatan Peninsula reconstructed from trace metals in benthic foraminifera

NASA Astrophysics Data System (ADS)

Broach, K. H.; Chapman, B. L.; Paytan, A.; Street, J.

2017-12-01

As climate change progresses, droughts are predicted to become more common in regions dominated by seasonal precipitation, a problem compounded where precipitation provides significant freshwater resources. The Yucatan Peninsula relies on rain-recharged groundwater for potable water, and regional development due to tourism will further strain supply. Historical and geochemical evidence suggest extensive droughts harmed Mayan Civilization and may again impact the Yucatan in the near future, but proxies around the Yucatan and Caribbean region are complicated by variability and even opposing interpretations. An integrated rainfall signal is needed to smooth variability and separate local aberrations from long-term regional trends that can be used for risk assessment. Here we present a 5,000 year record of rainfall sourced from a broad swath of the peninsula and recorded as trace metal ratios in the foram Ammonia parkinsoniana. Rainwater percolation across the western peninsula forms a groundwater lens that discharges as brackish springs in our field site Celestun Lagoon resulting in trace metal gradients (Li, B, Sr, Ba, Nd) along the lagoon that oscillate with discharge. Sr/Ca and Ba/Ca ratios in the forams suggest a long-term decrease in spring water discharge for the western Yucatan during the last 2,500 years with notable drops coinciding with known droughts (e.g. 800-950 CE) and more variability on a regional scale to 5,000 years. B/Ca ratios appear to depend on proximity to springs and may respond to low-pH discharge water while Nd/Ca ratios suggest sporadic incursions of seawater into the lagoon, possibly related to severely reduced spring water discharge or large hurricane events. We interpret these results to mean that periods of decreased rainfall broadly affect the western peninsula which may pose problems for large population centers like Merida. Future work will focus on periodicity of such rainfall changes and impact on the ecological environment of

The Yucatan miniature swine as an in vivo model for screening skin depigmentation.

PubMed

Nair, X; Tramposch, K M

1991-12-01

The usefulness of the Yucatan miniature pig as a screen for skin dipigmenting activity by topical application was evaluated with standard compounds. This is a naturally occurring breed of swine with light brown to dark brown skin that is relatively hairless. The skin morphology, including the pattern of pigment distribution, in this breed of swine closely resembles the human skin. Test compounds examined in this study included the three standard compounds with known clinical depigmenting activity, hydroquinone (HQ), 4-hydroxyanisole (4HA) and tert-butyl catechol (TBC), each at a 5% concentration. Test materials in 25 microliters of propylene glycol/ethanol (50:50) were applied topically twice daily, 7 days a week for 90 days to test sites on each side of the dorsal mid-line. Test sites were graded weekly for variation in pigmentation and local irritation. After 90 days of test material application, skin biopsies of the test sites were taken for histological evaluation. Topical application of HQ, 4HA and TBC promoted marked skin depigmentation which was substantiated by reductions of pigment and melanocytes observed on microscopic examination. While both HQ and TBC produced marked local irritation, 4HA was only mildly irritating. These results suggest that the Yucatan pig, could be a potentially useful model for screening compounds with skin depigmenting activity.

Origin of honeybees (Apis mellifera L.) from the Yucatan peninsula inferred from mitochondrial DNA analysis.

PubMed

Clarke, K E; Oldroyd, B P; Javier, J; Quezada-Euán, G; Rinderer, T E

2001-06-01

Honeybees (Apis mellifera L.) sampled at sites in Europe, Africa and South America were analysed using a mitochondrial DNA restriction fragment length polymorphism (RFLP) marker. These samples were used to provide baseline information for a detailed analysis of the process of Africanization of bees from the neotropical Yucatan peninsula of Mexico. Radical changes in mitochondrial haplotype (mitotype) frequencies were found to have occurred in the 13-year period studied. Prior to the arrival of Africanized bees (1986) the original inhabitants of the Yucatan peninsula appear to have been essentially of southeastern European origin with a smaller proportion having northwestern European ancestry. Three years after the migration of Africanized bees into the area (1989), only very low levels of maternal gene flow from Africanized populations into the resident European populations had occurred. By 1998, however, there was a sizeable increase in the proportion of African mitotypes in domestic populations (61%) with feral populations having 87% of mitotypes classified as African derived. The results suggest that the early stages of Africanization did not involve a rapid replacement of European with African mitotypes and that earlier studies probably overestimated the prevalence of African mitotypes.

Validation of a preclinical model of diethylnitrosamine-induced hepatic neoplasia in Yucatan miniature pigs

PubMed Central

Mitchell, Jennifer; Tinkey, Peggy T.; Avritscher, Rony; Van Pelt, Carolyn; Eskandari, Ghazaleh; George, Suraj Konnath; Xiao, Lianchun; Cressman, Erik; Morris, Jeffrey S.; Rashid, Asif; Kaseb, Ahmed O.; Amin, Hesham M.; Uthamanthil, Rajesh

2016-01-01

Objective The purpose of this study was to reduce time to tumor onset in a diethylnitrosamine (DEN)-induced hepatocellular carcinoma (HCC) swine model via partial liver embolization (PLE) and to characterize the model for use in translational research. Methods Eight Yucatan miniature pigs were injected intraperitoneally with either saline (n=2) or DEN (n=6) solution weekly for 12 weeks. Three of the DEN-treated pigs underwent PLE. Animals underwent periodic radiological evaluation, liver biopsy, and blood sampling, and full necropsy was performed at study termination (~29 months). Results All DEN-treated pigs developed hepatic adenoma and HCC. PLE accelerated the time to adenoma development but not to HCC development. Biomarker analysis results showed that IGF1 levels decreased in all DEN-treated pigs, as functional liver capacity decreased with progression of HCC. VEGF and IL-6 levels were positively correlated with disease progression. Immunohistochemical probing of HCC tissues demonstrated the expression of several important survival-promoting proteins. Conclusion To our knowledge, we are the first to demonstrate accelerated development of hepatic neoplasia in Yucatan miniature pigs. Our HCC swine model closely mimics the human condition (i.e., progressive disease stages and expression of relevant molecular markers) and is a viable translational model. PMID:27305144

Prevalence and risk factors of Toxoplasma gondii in fattening pigs farm from Yucatan, Mexico.

PubMed

Ortega-Pacheco, A; Acosta Viana, K Y; Guzmán-Marín, E; Segura-Correa, J C; Alvarez-Fleites, M; Jiménez-Coello, M

2013-01-01

The objective of this study was to estimate the prevalence and identify risk factors associated with the presence of Toxoplasma gondii in pig-fattening farms from Yucatan, Mexico. A cross-sectional study was conducted with a two-stage sampling. There were 429 pigs sampled from 39 farms randomly selected. Blood samples were collected to obtain DNA and serum. The presence of IgM and IgG antibodies was determined by indirect ELISA. Prevalence was estimated by diagnostic test. Potential risk factors to be included in a marginal logistic regression were tested by chi-square or Fisher. The prevalence of IgM and IgG was 92.5% (397/429) (CI 89.9-95.1%) and 95.8% (411/429) (CI 93.7-97.8%), respectively. Regarding PCR, a prevalence of 50.8% (218/429) (CI 45.9-55.6%) was found. The logistic regression showed an association with herd size and type of feeder (P < 0.05). The risk of a case in farms with ≤400 pigs was 27.9 times higher than in farms with >400 pigs. The manual feeder was a significant protective factor associated with the seropositive against T. gondii. Results indicate a high circulation of T. gondii in pig-fattening farms from Yucatan, finding an increased risk of infection for those farms with less than 400 animals and automatic feeders.

Beyond the Colours: Discovering Hidden Diversity in the Nymphalidae of the Yucatan Peninsula in Mexico through DNA Barcoding

PubMed Central

Prado, Blanca R.; Pozo, Carmen; Valdez-Moreno, Martha; Hebert, Paul D. N.

2011-01-01

Background Recent studies have demonstrated the utility of DNA barcoding in the discovery of overlooked species and in the connection of immature and adult stages. In this study, we use DNA barcoding to examine diversity patterns in 121 species of Nymphalidae from the Yucatan Peninsula in Mexico. Our results suggest the presence of cryptic species in 8 of these 121 taxa. As well, the reference database derived from the analysis of adult specimens allowed the identification of nymphalid caterpillars providing new details on host plant use. Methodology/Principal Findings We gathered DNA barcode sequences from 857 adult Nymphalidae representing 121 different species. This total includes four species (Adelpha iphiclus, Adelpha malea, Hamadryas iphtime and Taygetis laches) that were initially overlooked because of their close morphological similarity to other species. The barcode results showed that each of the 121 species possessed a diagnostic array of barcode sequences. In addition, there was evidence of cryptic taxa; seven species included two barcode clusters showing more than 2% sequence divergence while one species included three clusters. All 71 nymphalid caterpillars were identified to a species level by their sequence congruence to adult sequences. These caterpillars represented 16 species, and included Hamadryas julitta, an endemic species from the Yucatan Peninsula whose larval stages and host plant (Dalechampia schottii, also endemic to the Yucatan Peninsula) were previously unknown. Conclusions/Significance This investigation has revealed overlooked species in a well-studied museum collection of nymphalid butterflies and suggests that there is a substantial incidence of cryptic species that await full characterization. The utility of barcoding in the rapid identification of caterpillars also promises to accelerate the assembly of information on life histories, a particularly important advance for hyperdiverse tropical insect assemblages. PMID:22132140

The occurrence of the larval cestode Cysticercus fasciolaris in rodent populations from the Cuxtal ecological reserve, Yucatan, Mexico.

PubMed

Rodríguez-Vivas, R I; Panti-May, J A; Parada-López, J; Hernández-Betancourt, S F; Ruiz-Piña, H A

2011-12-01

Cysticercus fasciolaris is the larval stage of the cestode Taenia taeniaeformis, whose definitive hosts are mainly cats. This larval stage uses a wide variety of small rodents, and occasionally birds and humans, as intermediate hosts. In the Yucatan, there are no reports of the presence of this cestode in animal populations. The aim of this study was to evaluate the occurrence of C. fasciolaris in rodent populations from the Cuxtal ecological reserve, Yucatan, Mexico. Trapping of rodents was conducted from October 2009 to April 2010 in 40 households in Molas, in which Sherman traps were placed both inside and outside backyards. Rodents were dissected to inspect the liver for the presence of the worm. To determine risk factors associated with infection, univariate analysis was performed using sex, age, species, trapping site, and season as independent variables. Variables with a P value <  0.2 were analysed using a logistic regression model. In this study, 411 individuals of six rodent species were trapped; Mus musculus was the most abundant (78%), followed by Rattus rattus (13%) and the wild species Peromyscus yucatanicus, Ototylomys phyllotis, Heteromys gaumeri and Reithrodontomys gracilis (9%). Only 7.5% (n = 31) of M. musculus and R. rattus were infected with C. fasciolaris (demonstrated by the presence of liver cysts) with a prevalence of 9.0% and 3.5%, respectively. Both adults and male mice were 4.33 and 3.46 (OR values) times more likely to have C. fasciolaris than juveniles and females respectively. We can conclude that in the Cuxtal Reserve, Yucatan, Mexico, the prevalence of C. fasciolaris is higher in M. musculus, and that adult males had a higher probability of infection. Wild species, mainly P. yucatanicus, were not found to be infected with the cestode, but its presence in the backyards of households could result in a potential risk of acquiring this infection.

Sources and distribution of organic matter along the Ring of Cenotes, Yucatan, Mexico: sterol markers and statistical approaches.

PubMed

Derrien, Morgane; Cabrera, Flor Arcega; Tavera, Nadia Libertad Velazquez; Kantún Manzano, Cristian A; Vizcaino, Santiago Capella

2015-04-01

The Yucatan Peninsula is a large low lying platform of limestone, dolomite and evaporite deposits, forming an extensive and mature karst aquifer with many sinkholes locally called cenotes. In Yucatan, the only source of drinking water is groundwater and its quality could be impaired by: (i) infiltration of contaminants and (ii) saltwater intrusion. To investigate the sources of organic matter in this aquifer, sediment samples (46) were collected from cenotes and analysed using gas chromatography-mass spectrometry. Sterol analysis, coupled with principal component analysis (PCA), allowed us to distinguish three sources of natural organic matter (e.g. marine, autotrophic and terrigenous) and to detect an anthropogenic input (e.g. fecal contamination). Good consistency was observed between the source assignment and the land use context (forest, agricultural, rural or urban areas) and the season, except for some of the samples where a direct correlation could not be made. The latter cases are most likely a result of the karstic character of the system. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of a Diet High in Salt, Fat, and Sugar on Telemetric Blood Pressure Measurements in Conscious, Unrestrained Adult Yucatan Miniature Swine (Sus scrofa)

PubMed Central

Myrie, Semone B; McKnight, Leslie L; King, J Christopher; McGuire, John J; Vliet, Bruce N Van; Bertolo, Robert F

2012-01-01

Radiotelemetry was used to evaluate diet-related elevation of blood pressure in adult Yucatan miniature swine. Systolic arterial blood pressure (SAP), diastolic atrial blood pressure (DAP), heart rate, and locomotor activity were assessed in 9- or 11-mo-old Yucatan miniature pigs fed a standard diet or a North American-type diet high in salt, fat, and sugar (HSFS). Compared with pigs fed standard diet, pigs fed HSFS diet showed markedly elevated SAP (132 ± 3 compared with 156 ± 6 mm Hg), whereas DAP was unchanged (92 ± 2 compared with 99 ± 5 mm Hg). In addition, all pigs were modestly sensitive to short-term changes in dietary salt, as indicated by a 6% to 7% response in blood pressure parameters. According to these data, the increase in SAP for pigs on the HSFS diet was too large to be explained by the NaCl content of the diet alone. We found no evidence of endothelial dysfunction, and the relaxation responses of isolated coronary arteries actually were enhanced in the HSFS group. In conclusion, in a Yucatan miniature pigs model chronically fed a HSFS diet, DAP did not increase, but SAP and pulse pressure appeared to be affected by high dietary levels of fat or sugar (or both). PMID:23043781

The malleability of infant motor development: cautions based on studies of child-rearing practices in Yucatan.

PubMed

Solomons, H C

1978-11-01

Tests with the Bayley Motor Scale were given to 288 infants, equally divided by sex, in Yucatan, Mexico. These were 2 to 54 weeks in age and came from three sociocultural levels. In comparison to USA infants, early acceleration of motor development was followed by a marked downward trend. This phenomenon, if observed in a single child, may indicate progressive neurologic disease. Child-rearing practices would appear to account for the difference in pattern of test performance.

Coca-colonization of diets in the Yucatan.

PubMed

Leatherman, Thomas L; Goodman, Alan

2005-08-01

Over the past three decades, tourism-based economic development has transformed social and economic conditions in the Yucatan Peninsula, Mexico. Mayan communities have become directly involved in the changing economy as the main source of inexpensive labor for construction and service jobs at tourism centers, and as sites of ecotourism and archeotourism. In this paper, we address how these macro-processes of change intersect locally with the commoditization of food systems, diets and nutrition in four Yucatec Mayan communities with differing relationships to the tourist economy. Yucatec Mayan diets have become increasingly dependent on purchased foods, and reflect a greater consumption of commercialized processed foods. Coca-Cola, an international icon of US culture, along with other local and internationally owned calorie-dense but nutrient-poor snack foods, is now a common element of Mayan diets, leading to what we call "coca-colonization." The consequences of this diet, likely exacerbated by the increased consumption of snack foods, include an apparent increase in overweight and obese adults as well as signs of growth stunting in children. The Maya we talked with recognize both the potential disruption that tourism brings to all aspects of their lives and the necessity of jobs that tourism creates to meet their families' basic needs.

Dietary fat saturation and endurance exercise alter lipolytic sensitivity of adipocytes isolated from Yucatan miniature swine.

PubMed

Meservey, C M; Carey, G B

1994-12-01

This study examined the effects of dietary fat saturation and endurance exercise on lipolytic sensitivity of adipocytes isolated from Yucatan miniature swine. Twenty-four female swine had free access to a high fat diet with a polyunsaturated to saturated fat ratio (P:S) of 0.3 or 1.0, and were treadmill-exercised or remained sedentary. After 3 months, biopsies were taken, adipocytes were isolated and lipolytic activity was determined. Adipocytes were incubated with adenosine deaminase followed by epinephrine, isoproterenol, or epinephrine plus phenylisopropyladenosine, and glycerol release was measured. Backfat thickness was measured by ultrasonography. Our findings revealed that 1) adipocytes from 1.0 P:S diet-fed swine released 30% more glycerol than adipocytes from 0.3 P:S diet-fed swine when stimulated by 1 micromol/L isoproterenol; 2) adipocytes from exercised swine released 45% more glycerol than adipocytes from sedentary swine when stimulated by 1 micromol/L epinephrine; 3) body weight of exercised swine was significantly lower than sedentary swine; and 4) backfat thickness was less in exercised swine than in sedentary swine (2.39 vs. 2.95 cm, P = 0.002). We conclude that ad libitum consumption of diet with a P:S of 1.0, combined with endurance exercise, increases lipolytic sensitivity, lowers body weight gain, and reduces fat accumulation in female Yucatan miniature swine.

Effectiveness of a regional self-study perinatal education programme: a successful adaptation in Yucatan, Mexico.

PubMed

Osorno, Lorenzo R; Campos, Miriam C; Cook, Lynn J; Vela, Gabriela R; Dávila, Jorge R

2006-08-01

To evaluate the effectiveness of the Perinatal Continuing Education Programme (PCEP) in a Latin American country. We carried out a study within secondary and tertiary care, and rural Mexican Institute of Social Security (IMSS) hospitals on the Yucatan Peninsula. Participants were doctors, nurses and nursing assistants working with pregnant women and newborns at each hospital. The PCEP was translated into Spanish and then implemented between January 1998 and December 2001. Two nurses at each hospital were trained to co-ordinate the programme and the personnel were invited to participate. Participation involved purchasing the self-teaching books, study outside work hours and participation in skills demonstration and practice sessions. Evaluation included the percentage of personnel who participated in and those who completed the programme, an opinion survey of the programme, level of pre- and post-intervention knowledge, and the quality of neonatal care according to expert-recommended routines. Results were analysed with chi-square and Student's t-tests. A total of 65.3% of the 1421 people in the study population began the programme and 72% of those completed it. Improvement was observed in 14 of 23 (P<0.05) evaluated neonatal care practices. Participants rated the written material as very clear and useful in daily practice. The PCEP is an effective strategy for improving the level of knowledge and perinatal care in all regional hospitals on the Yucatan Peninsula, Mexico. This initial application of the PCEP in a Spanish-speaking country was successful.

A case for archaeological reconnaissance of the Cabo Catoche-Porvenir region of the northeastern Yucatan Peninsula

NASA Technical Reports Server (NTRS)

Duller, Charles E.

1990-01-01

Satellite remote sensing technology is a tool with which archaeologists can, with relative ease, survey a region that is otherwise inaccessible. The northeast corner of the Yucatan Peninsula is such an area: it is isolated and sparsely inhabited, with dense forest and extensive swamps. From Cabo Catoche inland to Cancun, this remote corner of the ancient Maya world is virtually unexplored. Recent satellite images disclose evidence of past human activity in this unexplored region and offer a compelling argument for an archaeological reconnaissance.

Copy Number Variation of TLR-7 Gene and its Association with the Development of Systemic Lupus Erythematosus in Female Patients from Yucatan Mexico

PubMed Central

Pacheco, Guillermo Valencia; Cruz, Darig Cámara; González Herrera, Lizbeth J; Pérez Mendoza, Gerardo J; Adrián Amaro, Guadalupe I; Nakazawa Ueji, Yumi E; Angulo Ramírez, Angélica V

2014-01-01

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by the production of autoantibodies against self-antigens, which occurs most often in women between 15 and 40 years of age. The innate immunity is involved in the pathogenesis of SLE through TLR- 7. Genetic factors such as copy number variation (CNV) of target genes may contribute to disease development, but this possible risk has not yet been studied in SLE patients from Yucatan, Mexico. The CNV of TLR-7 gene was determined by quantitative polymerase chain reaction assay using TaqMan probes in 80 SLE women and 150 control subjects. The results showed that 10% of SLE patients exhibited more than two copies of TLR-7 gene, whereas no mRNA overexpression was detected. These data suggested that increased CNV of the TLR-7 gene in Yucatan SLE women can be a risk factor for this disease. PMID:25512712

Education, fish consumption, well water, chicken coops, and cooking fires: Using biogeochemistry and ethnography to study exposure of children from Yucatan, Mexico to metals and arsenic.

PubMed

Arcega-Cabrera, Flor; Fargher, Lane F

2016-10-15

Around the world, the nocuous health effects of exposure to environmental contaminants, especially metals and Arsenic, are a growing health concern. This is especially the case in Mexico, where corruption and ineffective political administration are contributing to increasing deterioration in the environment. Importantly, shallow soils and the karstic nature of bedrock in Yucatan, Mexico make the subterranean aquifer especially susceptible to contamination because contaminates are carried to it with little resistance. Given these environmental conditions, we developed a multi/interdisciplinary project to evaluate the impact of metal and Arsenic pollution on a sample of 107 children, ages 6 to 9years, living in the urban areas of Progreso, Merida, and Ticul, in the State of Yucatan using urine and blood samples. In addition, ethnographic research was carried out in the homes of the children that participated in the study to identify potential exposure pathways. This research proved invaluable because the complexity of human social organization, lifestyles, and geographical patterning create an intricate array of exposure pathways that vary across social sectors and geographic space. In the following article, we use nonparametric univariate statistical analysis to reveal potential exposure pathways among sub-populations included in our sample. These analyses show that children from poor/marginal families tend to be exposed to Copper, Lead, and Nickel; whereas, children, from wealthier families, tend to be exposed to Cadmium, Arsenic, and inorganic Copper (Copper Sulfate). Copyright © 2016 Elsevier B.V. All rights reserved.

Surficial Geology of the Chicxulub Impact Crater, Yucatan, Mexico

NASA Technical Reports Server (NTRS)

Pope, Kevin O.; Ocampo, Adriana C.; Duller, Charles E.

1993-01-01

The Chicxulub impact crater in northwestern Yucatan, Mexico is the primary candidate for the proposed impact that caused mass extinctions at the end of the Cretaceous Period. The crater is buried by up to a kilometer of Tertiary sediment and the most prominent surface expression is a ring of sink holes, known locally as cenotes, mapped with Landsat imagery. This 165 +/- 5 km diameter Cenote Ring demarcates a boundary between unfractured limestones inside the ring, and fractured limestones outside. The boundary forms a barrier to lateral ground water migration, resulting in increased flows, dissolution, and collapse thus forming the cenotes. The subsurface geology indicates that the fracturing that created the Cenote Ring is related to slumping in the rim of the buried crater, differential thicknesses in the rocks overlying the crater, or solution collapse within porous impact deposits. The Cenote Ring provides the most accurate position of the Chicxulub crater's center, and the associated faults, fractures, and stratigraphy indicate that the crater may be approx. 240 km in diameter.

Surficial geology of the Chicxulub impact crater, Yucatan, Mexico

NASA Technical Reports Server (NTRS)

Pope, Kevin O.; Ocampo, Adriana C.; Duller, Charles E.

1993-01-01

The Chicxulub impact crater in northwestern Yucatan, Mexico is the primary candidate for the proposed impact that caused mass extinctions at the end of the Cretaceous Period. The crater is buried by up to a kilometer of Tertiary sediment and the most prominent surface expression is a ring of sink holes, known locally as cenotes, mapped with Landsat imagery. This 165 +/- 5 km diameter Cenote Ring demarcates a boundary between unfractured limestones inside the ring, and fractured limestones outside. The boundary forms a barrier to lateral ground water migration, resulting in increased flows, dissolution, and collapse thus forming the cenotes. The subsurface geology indicates that the fracturing that created the Cenote Ring is related to slumping in the rim of the buried crater, differential thicknesses in the rocks overlying the crater, or solution collapse within porous impact deposits. The Cenote Ring provides the most accurate position of the Chicxulub crater's center, and the associated faults, fractures, and stratigraphy indicate that the crater may be approximately 240 km in diameter.

Rickettsia lusitaniae associated with Ornithodoros yumatensis (Acari: Argasidae) from two caves in Yucatan, Mexico.

PubMed

Sánchez-Montes, Sokani; Guzmán-Cornejo, Carmen; Martínez-Nájera, Yecenia; Becker, Ingeborg; Venzal, José M; Labruna, Marcelo B

2016-10-01

The genus Rickettsia includes obligate intracellular bacteria transmitted by several hematophagous arthropods such as ticks, fleas and sucking lice. In particular hard ticks (Ixodidae) have been cited as the main vectors of pathogenic rickettsiae in Mexico. However, there have been only two records of a single Rickettsia species associated with Mexican soft ticks (Argasidae). In this study, we searched for rickettsial DNA in argasid ticks (13 adults and eight nymphs of Ornithodoros yumatensis) from two bat caves in the state of Yucatan, Mexico. Additionally one larva collected in a cave from Chiapas, Mexico, and associated with Desmodus rotundus was used to corroborate the tick taxonomic determination. Of these, nine ticks (43%) yielded expected PCR products for the rickettsial gltA gene. These PCR-positive ticks were tested with additional PCR protocols targeting the rickettsial genes gltA, ompA and ompB. DNA partial sequences from these genes showed 99-100% identities with Rickettsia lusitaniae, an agent isolated from O. erraticus in Portugal, and closely related to R. felis and R. hoogstraalii. Based on the results from this study, the inventory of rickettsiae distributed in Mexico increases from six to seven species. Copyright © 2016 Elsevier GmbH. All rights reserved.

Endothelial dysfunction occurs independently of adipose tissue inflammation and insulin resistance in ovariectomized Yucatan miniature-swine.

PubMed

Jurrissen, Thomas J; Olver, T Dylan; Winn, Nathan C; Grunewald, Zachary I; Lin, Gabriela S; Hiemstra, Jessica A; Edwards, Jenna C; Gastecki, Michelle L; Welly, Rebecca J; Emter, Craig A; Vieira-Potter, Victoria J; Padilla, Jaume

2018-01-02

In rodents, experimentally-induced ovarian hormone deficiency increases adiposity and adipose tissue (AT) inflammation, which is thought to contribute to insulin resistance and increased cardiovascular disease risk. However, whether this occurs in a translationally-relevant large animal model remains unknown. Herein, we tested the hypothesis that ovariectomy would promote visceral and perivascular AT (PVAT) inflammation, as well as subsequent insulin resistance and peripheral vascular dysfunction in female swine. At sexual maturity (7 months of age), female Yucatan mini-swine either remained intact (control, n = 9) or were ovariectomized (OVX, n = 7). All pigs were fed standard chow (15-20 g/kg), and were euthanized 6 months post-surgery. Uterine mass and plasma estradiol levels were decreased by ∼10-fold and 2-fold, respectively, in OVX compared to control pigs. Body mass, glucose homeostasis, and markers of insulin resistance were not different between control and OVX pigs; however, OVX animals exhibited greater plasma triglycerides and triglyceride:HDL ratio. Ovariectomy enhanced visceral adipocyte expansion, although this was not accompanied by brachial artery PVAT adipocyte expansion, AT inflammation in either depot, or increased systemic inflammation assessed by plasma C-reactive protein concentrations. Despite the lack of AT inflammation and insulin resistance, OVX pigs exhibited depressed brachial artery endothelial-dependent vasorelaxation, which was rescued with blockade of endothelin receptor A. Together, these findings indicate that in female Yucatan mini-swine, increased AT inflammation and insulin resistance are not required for loss of ovarian hormones to induce endothelial dysfunction.

Infection levels of intestinal helminths in two commensal rodent species from rural households in Yucatan, Mexico.

PubMed

Panti-May, J A; Hernández-Betancourt, S F; Rodríguez-Vivas, R I; Robles, M R

2015-01-01

The aim of the present study was to calculate the prevalence and intensity of intestinal helminths in the house mouse (Mus musculus) and the black rat (Rattus rattus) trapped in rural households of Yucatan, Mexico. Sampling was conducted during the rainy season from October to December 2011 and the dry season from January to March 2012. A total of 154 M. musculus and 46 R. rattus were examined, with 84.2% of M. musculus being infected with helminths compared with a significantly lower prevalence of 52.2% in R. rattus (P< 0.01). Adult M. musculus were more likely to be infected with helminths (89%) than subadults (63%) (P< 0.01). Four helminth species were identified: Taenia taeniaeformis larvae, Nippostrongylus brasiliensis, Syphacia muris and Trichuris muris. Nippostrongylus brasiliensis was present more frequently in M. musculus than in R. rattus (P< 0.01) and in adult mice compared to subadults (P< 0.01). Trichuris muris was present only in adult mice. This is the first report of N. brasiliensis, S. muris and T. muris in Yucatan, Mexico, as well as the first to report the presence of N. brasiliensis in M. musculus from Mexico. The helminth fauna of commensal rodents present in households appears to constitute a low potential health risk to local inhabitants; however, it would be advisable to conduct further studies to better understand the public health risk posed by these rodent intestinal helminths.

Science and stewardship to protect and sustain wilderness values: Ninth World Wilderness Congress symposium; November 6-13, 2009; Merida, Yucatan, Mexico

Treesearch

Alan Watson; Joaquin Murrieta-Saldivar; Brooke McBride

2011-01-01

The Ninth World Wilderness Congress (WILD9) met in Merida, Yucatan, Mexico in 2009. The symposium on science and stewardship to protect and sustain wilderness values was the largest of multiple symposia held in conjunction with the Congress. The papers contained in this proceedings were generated at this symposium or submitted by the author or authors for consideration...

[Identification of rotavirus associated to serotype G2 in Yucatan, Mexico].

PubMed

Gonzales-Loza, M del R; Polanco-Marín, G G; Puerto-Solis, M

2000-01-01

In the present study, rotavirus G2 serotype was identified from fecal samples of children with gastroenteritis from the city of Merida, Yucatan, Mexico. Virological diagnosis of disease was performed using polycrylamide gel electrophoresis and immunoenzymatic assay. Out of 149 analyzed samples 25 (16.7%) gave positive reaction to rotavirus groups A, of these 23 (92%) were identified as serotype g2, subgroup i and electrophoretic short pattern, whereas 2 (8%) were identified as subgroups II and electrophoretic long pattern, however, the G serotype was not possible to determine. Rotavirus G serotype has not been detected in more than 90% of samples since 1985. This indicates that the number of people susceptible to G2 serotype within the population has increased over recent years, which perhaps indicates that an important outbreak of acute infectious diarrhea caused by the rotavirus G2 serotype may be forthcoming.

Prevalence of pediculosis capitis in children from a rural school in Yucatan, Mexico.

PubMed

Manrique-Saide, Pablo; Pavía-Ruz, Norma; Rodríguez-Buenfil, Jorge C; Herrera Herrera, Roodeth; Gómez-Ruiz, Pilar; Pilger, Daniel

2011-01-01

We conducted an analytical cross-sectional survey to estimate the prevalence of and factors associated with active head lice infestation. In total 140 children, aged 6 to 16-years, from a public school in rural Yucatan, Mexico, were examined by wet-combing. A structured questionnaire was used to collect information on individuals and the conditions in the surrounding environment. Head lice infestation was found in 19 out of the 140 children tested (13.6%) and this was associated with both lower income (OR 9.9, 95% CI 2.15-45.79, p = 0.003) and a higher frequency of hair washing (OR 8, 95% CI 1.58-50, p = 0.012). Intersectoral control programs that take into account the socioeconomic differences of children should be implemented.

Levels of persistent organic pollutants in breast milk of Maya women in Yucatan, Mexico.

PubMed

Polanco Rodríguez, Ángel G; Inmaculada Riba López, M; Angel DelValls Casillas, T; León, Jesús Alfredo Araujo; Anjan Kumar Prusty, B; Álvarez Cervera, Fernando J

2017-02-01

In this study, 24 breast milk samples, obtained from rural Maya women, from municipalities of Yucatan, Mexico, were analyzed for organochlorine pesticide (OCP) residues by gas chromatography. Recent studies have shown that Maya communities have a poor perception about the proper usage and handling of OCP. The karstic soil in this area has a high vulnerability to groundwater pollution by the use of OCP in agriculture and livestock activities. The impact of the ecosystem on human health is much more critical due to the prevailing poverty and a very low educational level of these communities. About 30% of the Maya population consumes water directly from contaminated wells and sinkholes, resulting in a chronic exposure to OCP. The samples served to identify and quantify high levels of OCP residues (18.43 mg/kg of heptachlor epoxide and 1.92 mg/kg of endrin in the metropolitan zone; 2.10 mg/kg of dieldrin, 0.117 mg/kg of endosulfan II, 0.103 mg/kg of heptachlor, 0.178 mg/kg of endrin, and 0.127 mg/kg of endrin aldehyde in the main agricultural zone and on the west coast). The detected levels of OCP residues are a major concern and represent a potential risk to women and children in the region. This could be associated with the high rates of cervical uterine and breast cancer mortality in Yucatan. Thus, regulations on the usage of OCP and their enforcement are necessary, and it is important to establish a yearly monitoring program for OCP residues in breast milk and groundwater, as well as to implement health promotion programs for women in particular and the general population in general.

[Nucleotidic variations of two captive groups of tepezcuintle, Agouti paca (Rodentia: Agoutidae), from two sites in Yucatan, Mexico].

PubMed

Montes-Pérez, Rubén C; García, Adán W Echeverría; Castro, Jorge Zavala; Gamboa, Militza G Alfaro

2006-09-01

The objective of this work was to estimate the nucleotidic variation between two groups of tepezcuintles (Agouti paca) from the states of Campeche and Quintana Roo, Mexico and within members of each group. Blood samples were collected from eleven A. paca kept in captivity. DNA from leukocytic cells was used for Ramdom Amplification of DNA Polimorphism (RAPD). The primers three 5'-d(GTAGACCCGT)- 3' and six 5'-d(CCCGTCAGCA)- 3' were selected from de Amersham kit (Ready.To.Go. RAPD Analysis Beads, Amersham Pharmacia Biotech), because they produced an adequate number of bands. The electrophoretic pattern of bands obtained was analyzed using software for phylogenetic analysis based on the UPGMA method, to estimate the units of nucleotidic variation. The phylogenetic tree obtained with primer three reveals a dicotomic grouping between the animals from both states in the Yucatan Peninsula showing a divergent value of 1.983 nucleotides per hundred. Animals from Quintana Roo show a grouping with primer six; an additional grouping was observed with animals from Campeche. Nucleotidic variation between both groups was 2.118 nucleotides per hundred. The nucleotidic variation for the two primers within the groups from both states, showed fluctuating values from 0.46 to 1.68 nucleotides per hundred, which indicates that nucleotidic variation between the two groups of animals is around two nucleotides per hundred and, within the groups, less than 1.7 nucleotides per hundred.

Trace gas emissions from tropical biomass fires: Yucatan Peninsula, Mexico

NASA Astrophysics Data System (ADS)

Cofer, Wesley R.; Levine, Joel S.; Winstead, Edward L.; Stocks, Brian J.; Cahoon, Donald R.; Pinto, Joseph P.

Mixing ratios for carbon dioxide (CO 2), carbon monoxide (CO), hydrogen (H 2), methane (CH 4) and total non-methane hydrocarbons (TNMHC) were determined from the smoke plumes of two small (˜0.25 ha) prescribed biomass fires conducted on the Yucatan Peninsula in Mexico. In the region of these fires the combination of climate and shallow soils produces a scrubby and stunted forest with species composition similar to the Brazilian rain forest, but at a noticeably reduced size. Aircraft collections of smoke from these fires were analysed and used to determine CO 2-normalized emission ratios ( ΔX/ ΔCO 2; v/v; where Δ = in-plume specie concentration less background concentration) for CO, H 2, CH 4 and TNMHC produced and released into the atmosphere from these fires. Suprisingly, high mean emission ratios for TNMHCs (˜1.7% of CO 2 release) and H 2 (˜2.5% of CO 2) were determined. Emission ratios for CO (˜7%) and CH 4 (˜0.7%), however, were found to fall within expected bounds.

INFECTION BY Rickettsia felis IN OPOSSUMS (Didelphis sp.) FROM YUCATAN, MEXICO

PubMed Central

PENICHE-LARA, Gaspar; RUIZ-PIÑA, Hugo A.; REYES-NOVELO, Enrique; DZUL-ROSADO, Karla; ZAVALA-CASTRO, Jorge

2016-01-01

Rickettsia felis is an emergent pathogen and the causative agent of a typhus-like rickettsiosis in the Americas. Its transmission cycle involves fleas as biological vectors (mainly Ctenocephalides felis) and multiple domestic and synanthropic mammal hosts. Nonetheless, the role of mammals in the cycle of R. felis is not well understood and many efforts are ongoing in different countries of America to clarify it. The present study describes for the first time in Mexico the infection of two species of opossum (Didelphis virginiana and D. marsupialis) by R. felis. A diagnosis was carried out from blood samples by molecular methods through the gltAand 17 kDa genes and sequence determination. Eighty-seven opossum samples were analyzed and 28 were found to be infected (32.1%) from five out of the six studied localities of Yucatan. These findings enable recognition of the potential epidemiological implications for public health of the presence of infected synanthropic Didelphis in households. PMID:27074326

INFECTION BY Rickettsia felis IN OPOSSUMS (Didelphis sp.) FROM YUCATAN, MEXICO.

PubMed

Peniche-Lara, Gaspar; Ruiz-Piña, Hugo A; Reyes-Novelo, Enrique; Dzul-Rosado, Karla; Zavala-Castro, Jorge

2016-01-01

Rickettsia felis is an emergent pathogen and the causative agent of a typhus-like rickettsiosis in the Americas. Its transmission cycle involves fleas as biological vectors (mainly Ctenocephalides felis) and multiple domestic and synanthropic mammal hosts. Nonetheless, the role of mammals in the cycle of R. felis is not well understood and many efforts are ongoing in different countries of America to clarify it. The present study describes for the first time in Mexico the infection of two species of opossum (Didelphis virginiana and D. marsupialis) by R. felis. A diagnosis was carried out from blood samples by molecular methods through the gltA and 17 kDa genes and sequence determination. Eighty-seven opossum samples were analyzed and 28 were found to be infected (32.1%) from five out of the six studied localities of Yucatan. These findings enable recognition of the potential epidemiological implications for public health of the presence of infected synanthropic Didelphis in households.

Chemical and biological tracers to determine groundwater flow in karstic aquifer, Yucatan Peninsula

NASA Astrophysics Data System (ADS)

Lenczewski, M.; Leal-Bautista, R. M.; McLain, J. E.

2013-05-01

Little is known about the extent of pollution in groundwater in the Yucatan Peninsula; however current population growth, both from international tourism and Mexican nationals increases the potential for wastewater release of a vast array of contaminants including personal care products, pharmaceuticals (Rx), and pathogenic microorganisms. Pathogens and Rx in groundwater can persist and can be particularly acute in this region where high permeability of the karst bedrock and the lack of top soil permit the rapid transport of contaminants into groundwater aquifers. The objective of this research is to develop and utilize novel biological and chemical source tracking methods to distinguish between different sources of anthropogenic pollution in degraded groundwater. Although several methods have been used successfully to track fecal contamination sources in small scale studies, little is known about their spatial limitations, as source tracking studies rarely include sample collection over a wide geographical area and with different sources of water. In addition, although source tracking methods to distinguish human from animal fecal contamination are widely available, this work has developed source tracking distinguish between separate human populations is highly unique. To achieve this objective, we collected water samples from a series of drinking wells, cenotes (sinkholes), wastewater treatment plants, and injection wells across the Yucatan Peninsula and examine potential source tracers within the collected water samples. The result suggests that groundwater sources impacted by tourist vs. local populations contain different chemical stressors. This work has developed a more detailed understanding of the presence and persistence of personal care products, pharmaceuticals, and fecal indicators in a karstic system; such understanding will be a vital component for the protection Mexican groundwater and human health. Quantification of different pollution sources

Early results from genetic trials on the growth of Spanish cedar and itssusceptibility to the shoot borer moth in the Yucatan Peninsula, Mexico.

Treesearch

Sheila E. Ward; Kevyn E. Wightman; Bartolo Rodriguez Santiago

2008-01-01

Cedrela odorata (Spanish cedar) is a neotropical broadleaf tree species that is in high demand for furniture and interior fittings. In 1998, seed collections were made from Spanish cedar in the Yucatan Peninsula, Mexico, for genetic conservation and tree improvement projects. Progeny from these collections were established in genetic trials at Bacalar, Noh Bec, and Zoh...

High-Resolution Aeromagnetic Survey over the Yucatan Peninsula - Implications for Chicxulub Impact, Secondary Craters and Regional Crustal Structures

NASA Astrophysics Data System (ADS)

Fucugauchi, J. U.; Lopez-Loera, H.; Rebolledo-Vieyra, M.

2011-12-01

We present the initial results of a low-altitude high-resolution aeromagnetic study over the Yucatan peninsula. Area surveyed extends from 86W to 91W and 18N to 21N, covering the peninsula and adjacent continental margin of Gulf of Mexico and Caribbean Sea. Aeromagnetic surveys are integrated into a regional map, and regional and residual anomalies are separated using spectral and least-squares methods. For the study, aeromagnetic field was reduced to the pole and several data filtering techniques were used, including first and second vertical derivatives, analytical signal, and upward and downward analytical continuations. The region is characterized by large amplitude broad elongated magnetic anomalies oriented north-south in the northern sector of the continental shelf, and northwest-southeast and northeast-southwest over the western and eastern sides of the peninsula, respectively. Major regional anomalies extend from the continental shelf into the peninsula, whereas other anomaly trends in the central northern sector, at northeast limit of Chicxulub crater, are restricted to the shelf. Largest anomaly on the east extends over the Holbox fracture zone. At its southern end, south of Chetumal a parallel trend extends over the Rio Hondo fault zone between Quintana Roo and Belize. On the western peninsula the anomaly is characterized by two parallel trends offset between Yucatan and Campeche. The central zone of Chicxulub is characterized by a semi-circular anomaly pattern, surrounded by long wavelength small amplitude anomalies extending to the east on the peninsula and shelf, isolated from the regional broad anomalies. To the south of Chicxulub anomaly, there is an elongated low with a central high extending southward from the terrace zone inside the crater rim. The elongated magnetic anomaly correlates with a broad gravity low, which is apparent south of the concentric zone of anomalies. To the north of Chicxulub anomaly, a magnetic high inside the crater is

Assessing Impacts of Disturbances and Climate Change on Carbon Stocks in Mexican Semidry Forests of the Yucatan Peninsula

NASA Astrophysics Data System (ADS)

Dai, Z.; Birdsey, R.; Johnson, K.; Dupuy, J. M.; Hernandez-Stefanoni, J. L.; Richardson, K.

2014-12-01

The spatially explicit biogeochemical model Forest-DNDC was used to estimate carbon dynamics with disturbances and climate change in secondary semidry forests in Yucatan Peninsula. The model was validated using observations from 276 field plots in a 350 km2 region of semi-deciduous forest surrounding the intensive monitoring site at Kaxil Kiuic, and it performed well with high performance efficiency (E=0.79, R2=0.83). The simulation results showed substantial spatial differences in biomass in the forests due to historical disturbance patterns and heterogeneous forest environments. The simulated impacts of the disturbances that occurred from 1998-2010 revealed an estimated loss of total biomass carbon storage of 154.7 Gg due mainly to about 12 km2 of forestland loss. The results from disturbance scenarios indicate that disastrous storms, which are not uncommon in the Yucatan Peninsula, can substantially impact carbon storage in a short time. However, warming can produce a long-term impact on carbon sequestration, due principally to the decrease in biomass carbon at a mean rate of over 100 kg ha-1yr-1 with an increase in temperature by 1 degree Celsius. The forests in this area are highly sensitive to warming due to a semidry climate where the evapotranspiration is higher than precipitation. Even if each degree of warming increase is accompanied by an increase in precipitation of 10%, the significant impact of warming cannot be dismissed.

Bartonella Infection in Hematophagous, Insectivorous, and Phytophagous Bat Populations of Central Mexico and the Yucatan Peninsula.

PubMed

Stuckey, Matthew J; Chomel, Bruno B; Galvez-Romero, Guillermo; Olave-Leyva, José Ignacio; Obregón-Morales, Cirani; Moreno-Sandoval, Hayde; Aréchiga-Ceballos, Nidia; Salas-Rojas, Mónica; Aguilar-Setién, Alvaro

2017-08-01

Although emerging nonviral pathogens remain relatively understudied in bat populations, there is an increasing focus on identifying bat-associated bartonellae around the world. Many novel Bartonella strains have been described from both bats and their arthropod ectoparasites, including Bartonella mayotimonensis , a zoonotic agent of human endocarditis. This cross-sectional study was designed to describe novel Bartonella strains isolated from bats sampled in Mexico and evaluate factors potentially associated with infection. A total of 238 bats belonging to seven genera were captured in five states of Central Mexico and the Yucatan Peninsula. Animals were screened by bacterial culture from whole blood and/or polymerase chain reaction of DNA extracted from heart tissue or blood. Bartonella spp. were isolated or detected in 54 (22.7%) bats, consisting of 41 (38%) hematophagous, 10 (16.4%) insectivorous, and three (4.3%) phytophagous individuals. This study also identified Balantiopteryx plicata as another possible bat reservoir of Bartonella . Univariate and multivariate logistic regression models suggested that Bartonella infection was positively associated with blood-feeding diet and ectoparasite burden. Phylogenetic analysis identified a number of genetic variants across hematophagous, phytophagous, and insectivorous bats that are unique from described bat-borne Bartonella species. However, these strains were closely related to those bartonellae previously identified in bat species from Latin America.

Localized thermal anomalies in haloclines of coastal Yucatan sinkholes.

PubMed

Stoessell, Ronald K; Coke, James G; Easley, Dale H

2002-01-01

A temperature spike is reported in the haloclines of three Yucatan sinkholes along a 1 km NW-SE transect from 5 to 4 km inland from the Caribbean coast. The temperature spike decreases in magnitude from 3.5 degrees C to 0.2 degrees C, approaching the coast. The anomaly does not vary diurnally and does not extend down into the underlying sea water. These conditions are inconsistent with explanations such as radiation absorption within the halocline, in situ microbially mediated sulfate reduction within the halocline and the underlying sea water, and sulfide oxidation by photosynthetic purple and green bacteria within the halocline. One explanation consistent with the shape and halocline location of the temperature spike involves a localized sea water convection cell operating near the coast. Cold sea water from the Caribbean Sea enters the coastal limestone at depths of a few hundred meters and heats up because of the geothermal gradient, buoyantly rising in vertical fractures within the unconfined aquifer. Blocked by the less dense fresh water, the movement stops in the halocline where the warm sea water mixes with brackish water. The convection cycle would be completed by the coastward movement of cooling brackish water. The observed temperature anomalies could possibly be snapshots of this warm layer moving coastward.

Groundwater-flow modeling in the Yucatan karstic aquifer, Mexico

NASA Astrophysics Data System (ADS)

González-Herrera, Roger; Sánchez-y-Pinto, Ismael; Gamboa-Vargas, José

2002-09-01

The current conceptual model of the unconfined karstic aquifer in the Yucatan Peninsula, Mexico, is that a fresh-water lens floats above denser saline water that penetrates more than 40 km inland. The transmissivity of the aquifer is very high so the hydraulic gradient is very low, ranging from 7-10 mm/km through most of the northern part of the peninsula. The computer modeling program AQUIFER was used to investigate the regional groundwater flow in the aquifer. The karstified zone was modeled using the assumption that it acts hydraulically similar to a granular, porous medium. As part of the calibration, the following hypotheses were tested: (1) karstic features play an important role in the groundwater-flow system; (2) a ring or belt of sinkholes in the area is a manifestation of a zone of high transmissivity that facilitates the channeling of groundwater toward the Gulf of Mexico; and (3) the geologic features in the southern part of Yucatan influence the groundwater-flow system. The model shows that the Sierrita de Ticul fault, in the southwestern part of the study area, acts as a flow barrier and head values decline toward the northeast. The modeling also shows that the regional flow-system dynamics have not been altered despite the large number of pumping wells because the volume of water pumped is small compared with the volume of recharge, and the well-developed karst system of the region has a very high hydraulic conductivity. Résumé. Le modèle conceptuel classique de l'aquifère karstique libre de la péninsule du Yucatan (Mexique) consiste en une lentille d'eau douce flottant sur une eau salée plus dense qui pénètre à plus de 40 km à l'intérieur des terres. La transmissivité de l'aquifère est très élevée, en sorte que le gradient hydraulique est très faible, compris entre 7 et 10 mm/km dans la plus grande partie du nord de la péninsule. Le modèle AQUIFER a été utilisé pour explorer les écoulements souterrains régionaux dans cet

Final Environmental Assessment for Advanced Littoral Reconnaissance Technologies (ALRT) Project at Eglin Air Force Base, Florida

DTIC Science & Technology

2008-05-28

the Gulf of Mexico, Bahamas, Greater Antilles, and Yucatan . Most loggerhead hatchlings originating from U.S. beaches are believed to spend their...beaches near Panama City; and (5) Yucatan Subpopulation occurring on the eastern Yucatan Peninsula, Mexico (Bowen et at. , 1993; Encalada et at. , 1998...be detected from the State of Florida’s Index Nesting Beach Survey program from 1989 to 2002. Nesting surveys in the Northwest Florida and Yucatan

Physiological levels and action of dehydroepiandrosterone in Yucatan miniature swine.

PubMed

Tagliaferro, A R; Ronan, A M

2001-07-01

The biological role of dehydroepiandrosterone (DHEA) and its less active sulphated conjugate DHEAS was investigated in two experiments using Yucatan miniature swine. In experiment 1, plasma levels of both DHEA(S) among males were greater than female pigs that ranged in age from 0.3 to 84 mo old (P < 0.0001). In males, DHEA(S) were related inversely to serum triglycerides; DHEA was positively related to triglycerides in females (P < 0.01). In experiment 2, four 2-yr old male pigs, used as their own control, showed a 5% decrease in body weight, 11% increase in energy expenditure, 88% increase in lipid, and 100% decrease in glucose utilization (P < 0.0001) in response to DHEA vs. placebo treatments when adjusted for body weight. Plasma DHEA(S) were not different between treatment conditions. Glucose tolerance and plasma insulin levels were not different from controls. In vivo response to norepinephrine indicated beta-adrenergic sensitivity was altered by DHEA. Present findings suggest DHEA and/or its hormone products are important in modulating energy expenditure and lipid utilization for energy in male animals. The role of DHEA in energy metabolism and the difference between sexes warrant further investigation.

Development of induced glioblastoma by implantation of a human xenograft in Yucatan minipig as a large animal model.

PubMed

Khoshnevis, Mehrdad; Carozzo, Claude; Bonnefont-Rebeix, Catherine; Belluco, Sara; Leveneur, Olivia; Chuzel, Thomas; Pillet-Michelland, Elodie; Dreyfus, Matthieu; Roger, Thierry; Berger, François; Ponce, Frédérique

2017-04-15

Glioblastoma is the most common and deadliest primary brain tumor for humans. Despite many efforts toward the improvement of therapeutic methods, prognosis is poor and the disease remains incurable with a median survival of 12-14.5 months after an optimal treatment. To develop novel treatment modalities for this fatal disease, new devices must be tested on an ideal animal model before performing clinical trials in humans. A new model of induced glioblastoma in Yucatan minipigs was developed. Nine immunosuppressed minipigs were implanted with the U87 human glioblastoma cell line in both the left and right hemispheres. Computed tomography (CT) acquisitions were performed once a week to monitor tumor growth. Among the 9 implanted animals, 8 minipigs showed significant macroscopic tumors on CT acquisitions. Histological examination of the brain after euthanasia confirmed the CT imaging findings with the presence of an undifferentiated glioma. Yucatan minipig, given its brain size and anatomy (gyrencephalic structure) which are comparable to humans, provides a reliable brain tumor model for preclinical studies of different therapeutic METHODS: in realistic conditions. Moreover, the short development time, the lower cyclosporine and caring cost and the compatibility with the size of commercialized stereotactic frames make it an affordable and practical animal model, especially in comparison with large breed pigs. This reproducible glioma model could simulate human anatomical conditions in preclinical studies and facilitate the improvement of novel therapeutic devices, designed at the human scale from the outset. Copyright © 2017 Elsevier B.V. All rights reserved.

An epidemiological study of intestinal parasites of dogs from Yucatan, Mexico, and their risk to public health.

PubMed

Rodríguez-Vivas, Roger Ivan; Gutierrez-Ruiz, Edwin; Bolio-González, Manuel Emilio; Ruiz-Piña, Hugo; Ortega-Pacheco, Antonio; Reyes-Novelo, Enrique; Manrique-Saide, Pablo; Aranda-Cirerol, Francisco; Lugo-Perez, J A

2011-08-01

The prevalence of intestinal parasites in dogs and factors associated were studied in a rural community of Yucatan (southern Mexico), with special attention to those gastrointestinal parasites potentially transmitted to man. One hundred thirty dogs from 91 households were studied. Fecal samples were processed by the centrifugation-flotation and the McMaster techniques. To determine factors associated with zoonotic parasites in dogs, univariate analysis was performed, using sex, age, and body condition as independent variables. Variables with p < 0.2 were analyzed by a logistic regression. Of 130 dogs, 104 were positive for the presence of intestinal parasites, representing a prevalence of 80%. Eggs of four species of helminths (Ancylostoma caninum, Thichuris vulpis, Toxocara canis, and Dipylidium caninum) and coccidian oocysts were detected. A. caninum was the most prevalent parasite (73.8%), followed by T. vulpis (25.4%), T. canis (6.2%), D. caninum (2.3%), and coccidian oocysts (2.3%). The majority of dogs were infected by only one species of parasite (70/130, 53.8%). Mixed infection caused by two or three zoonotic parasites were discovered in 21.3% (30/130) and 3.1% (4/130), respectively. A. caninum showed the highest egg output (42.3% of dogs had ≥ 500 eggs per gram). Factors associated with zoonotic parasites were age (<2 years old; odds ratio = 5.30, p = 0.029) and body condition (poor body condition; odds ratio = 6.69, p = 0.026). In conclusion, young dogs from rural Yucatan, Mexico, with poor body condition had a higher prevalence of intestinal zoonotic parasites as these factors were associated with a higher risk of becoming infected.

Anaplasma marginale Yucatan (Mexico) Strain. Assessment of low virulence and potential use as a live vaccine.

PubMed

Rodríguez Camarillo, Sergio D; García Ortiz, Miguel Angel; Rojas Ramírez, Edmundo E; Cantó Alarcón, Germinal J; Preciado de la Torre, Jesús F; Rosario Cruz, Rodrigo; Ramos Aragón, Juan A; Aboytes Torres, Ramón

2008-12-01

Anaplasma marginale Yucatan strain was found to have low virulence in cattle. We studied the virulence of this isolate by experimental inoculation of 113 susceptible cattle at increasing doses, after which only one animal required treatment for clinical disease. Subsequently, 104 cattle received a live vaccine of this strain by inoculation, which induced immunoprotection after heterologous challenged exposure with a different A. marginale isolate. In this study 14% of the immunized cattle required treatment as compared with the control nonimmunized cattle, in which 56% required treatment. The A. marginale vaccine strains used for the immunization studies had MSP1a variable regions that were different from those used for the challenge exposure.

Ancient shoreline reconstruction at a Maritime Maya Port in Yucatan, Mexico

NASA Astrophysics Data System (ADS)

Jaijel, Roy; Goodman, Beverly; Glover, Jeffrey; Rissolo, Dominique; Beddows, Patricia; Carter, Alice; Smith, Derek; Ben Avraham, Zvi

2017-04-01

Throughout history, worldwide, a major part of the human experience has been to adapt to changing landscapes, and environments. These adaptations can take many forms, sometimes as innovation, manipulation of the conditions, behavioral or technological changes; and in some cases the decision to abandon the area. The northeastern Yucatan peninsula, home of the Maritime maya port site Vista-Alegre, shows signs of such human changes, though little is known about the corresponding landscape and environment. Vista Alegre is located on the meeting point of the Caribbean Sea and the Gulf of Mexico, at the north-eastern tip of the Yucatan peninsula, in the back of the Holbox lagoon. The site was inhabited from the 9th century B.C until the mid 16th century A.D., with an apparent two century abandonment phase from the mid 7th to 9th century A.D. A multidisciplinary effort ("Costa Escondida project") has been investigating the life of past Mayan inhabitants and the broader connections of the site to the Maritime Maya trade network. One of the questions that has arisen is what were the mutual influences between the inhabitants to their surrounding environment. In order to answer that question the site's shoreline geomorphology and climate history is being reconstructed for the past 2-3000 years. The reconstruction is based on multiproxy analysis of marine sediment cores and surface samples, combined with archaeological data. The study presented focuses on the shoreline shifts at the site, revealing the complexity, and significant affect of sea level rise on the marine environment of Vista Alegre. This study contributes to our understanding of the site's possible functions, the environmental challenges the local inhabits contended with, and the identification of ancient harboring locations. The results show five depositional phases over the past 2-3000 years. The ancient shoreline maps show a general trend of sea level rise, though with varying rates over time that relates well

Pseudocapillaria yucatanensis sp. n. (Nematoda: Capillariidae) from the bagre Rhamdia guatemalensis (Pisces) from cenotes in Yucatan, Mexico.

PubMed

Moravec, F; Scholz, T; Vivas Rodríguez, C

1995-01-01

A new nematode species, Pseudocapillaria yucatanensis sp. n., is described from the intestine of the freshwater pimelodid catfish Rhamdia guatemalensis (Günther) from cenotes (= sinkholes) in Yucatan, Mexico. It differs from other three related species parasitizing freshwater fishes mainly in possessing the spicule with a simple rim of its proximal end and a non-expanded distal end, in the length of the spicule (0.218-0.295 mm), and the size (0.050-0.060 x 0.025-0.030 mm), shape and structure of eggs, and also in the host types and geographical distribution. Pseudocapillaria yucatanensis is the first known autochtonous species of Pseudocapillaria parasitizing freshwater fishes in Mexico.

Taxocoenosis of epibenthic dinoflagellates in the coastal waters of the northern Yucatan Peninsula before and after the harmful algal bloom event in 2011-2012.

PubMed

Aguilar-Trujillo, Ana C; Okolodkov, Yuri B; Herrera-Silveira, Jorge A; Merino-Virgilio, Fany Del C; Galicia-García, Citlalli

2017-06-15

Eutrophication causes the major impact in the coastal waters of the state of Yucatan. In general, loss of water quality and biological communities and massive development of toxic microorganisms are some of the consequences of this phenomenon. To reveal changes in species composition and cell abundance of the taxocoenosis of epibenthic dinoflagellates before and after a harmful algal bloom event in the water column that lasted about 150days (August-December 2011) in the Dzilam - San Crisanto area (northern Yucatan Peninsula, southeastern Gulf of Mexico) were the main objectives of the present study. In August 2011 and September 2012, sampling along 20 transects perpendicular to the coastline along the entire northern Yucatan coast, starting from 20 sampling sites from El Cuyo in the east to Celestún in the west, at a distance of 50, 150 and 250m from the coast, was carried out. Physicochemical characteristics measured before and after the bloom were within the ranges previously reported in the study area. Salinity was the most stable characteristic, with mean values of 36.25 and 36.42 in 2011 and 2012, respectively. Phosphates were the only parameter that showed a wide range with higher values before the bloom (0.03-0.54μM/l). A total of 168 macrophyte (seaweeds and seagrasses), sponge and sediment samples (105 in 2011 and 63 in 2012) that included associated microphytobenthos were taken by snorkeling from 0.7 to 5m depth. Six substrate types were distinguished: Chlorophyta, Phaeophyceae, Rhodophyta, Angiospermae (seagrasses), Demospongiae (sponges) and sediment. Chlorophytes dominated the collected samples: 38 samples in 2011 and 23 in 2012. Avrainvillea longicaulis f. laxa predominated before the bloom and Udotea flabellum after it. In total, 25 epibenthic dinoflagellate species from 11 genera were found. The genus Prorocentrum was the most representative in terms of the number of species. The highest total dinoflagellate cell abundances were observed in the

Shaded Relief with Height as Color, Yucatan Peninsula, Mexico

NASA Technical Reports Server (NTRS)

2003-01-01

This shaded relief image of Mexico's Yucatan Peninsula show a subtle, but unmistakable, indication of the Chicxulub impact crater. Most scientists now agree that this impact was the cause of the Cretatious-Tertiary Extinction, the event 65 million years ago that marked the sudden extinction of the dinosaurs as well as the majority of life then on Earth.

Most of the peninsula is visible here, along with the island of Cozumel off the east coast. The Yucatan is a plateau composed mostly of limestone and is an area of very low relief with elevations varying by less than a few hundred meters (about 500 feet.) In this computer-enhanced image the topography has been greatly exaggerated to highlight a semicircular trough, the darker green arcing line at the upper left corner of the peninsula. This trough is only about 3 to 5 meters (10 to 15 feet) deep and is about 5 km. wide (3 miles), so subtle that if you walked across it you probably would not notice it, and is a surface expression of the crater's outer boundary. Scientists believe the impact, which was centered just off the coast in the Caribbean, altered the subsurface rocks such that the overlying limestone sediments, which formed later and erode very easily, would preferentially erode on the vicinity of the crater rim. This formed the trough as well as numerous sinkholes (called cenotes) which are visible as small circular depressions.

Two visualization methods were combined to produce the image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast direction, so that northwestern slopes appear bright and southeastern slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations.

For a smaller, annotated version of this image, please select Figure 1, below: [figure removed for brevity, see original site] (Large

Mineralogy of Cretaceous/Tertiary boundary clays in the Chicxulub structure in northern Yucatan

NASA Technical Reports Server (NTRS)

Ming, D. W.; Sharpton, Virgil L.; Schuraytz, B. C.

1991-01-01

The Cretaceous/Tertiary (K/T) boundary clay layer is thought to be derived from ejecta material from meteorite impact, based on the anomalous concentrations of noble metals in the layer. Because of recent findings of a half-meter thick ejecta deposit at the K/T boundary in Haiti, efforts have focused on locating a large impact feature in the Caribbean and the Gulf of Mexico. One of the leading candidates for the site of a large impact is the Chicxulub structure located on the northern Yucatan Peninsula in Mexico. The Chicxulub structure is a subsurface zone of upper Cretaceous igneous rocks, carbonates, and breccias. The structure has been interpreted to be a 200 km diameter; however, there is some question to the size of the structure or to the fact that it even is an impact feature. Little is known about the mineralogy of this structure; the objective of this study was to determine the clay mineralogy of core samples from within the Chicxulub structure.

The role of the white-eyed vireo in the dispersal of bersera fruit on the Yucatan Peninsula

USGS Publications Warehouse

Greenberg, R.; Foster, M.S.; Marquez-Valdelamar, L.

1995-01-01

White-eyed vireos (Vireo griseus) winter in the forests and secondary growth of the Yucatan Peninsula where Bursera simaruba (Burseraceae) is an abundant tree Twenty-five per cent of all white-eyed vireos observed foraging visited Bursera trees In addition, presence and abundance of territorial white-eyed vireos in small forest patches were correlated with the size of the Bursera crop Vireos were the most reliable dispersers of Bursera seeds These birds visited 32 of 35 trees observed for at least three hours. They accounted for approximately half of all bird visits, and two-thirds of the seeds dispersed. Most of the other species rarely visited (<5% of visits) or failed to remove seeds from the tree. Peculiarities of phenology and fruit structure may contribute to the tendency of Bursera to be dispersed by relatively few species The capsules of Bursera fruits do not open when the fruit ripens; birds apparently locate ripe fruit using visual cues, although these are few In addition, only a small portion of the crop ripens daily over a 7- or 8-month period. The vireo-Bursera simaruba relationship, found regionally on the Yucatan Peninsula, may result from the prolonged fruit ripening period (October-March), the relatively depauperate frugivore community and the relatively high density of small Bursera trees in the hurricane-disturbed dry forests. Small trees at all times, and all trees from October to February, depend upon territorial vireos for continuous, highly efficient local dispersal of a small number of fruits In March and April residual fruits ripen rapidly and synchronously, attracting a greater variety of visitors for broad spectrum dispersal during a period of food scarcity. Thus, Bursera has an unusual two-phase phenological pattern, perhaps alternately to take advantage of both specialized and opportunistic dispersers.

78 FR 17999 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Northwest...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-25

... Carolina (United States), Quintana Roo and Yucatan (Mexico), Brazil, Cape Verde Islands (Cape Verde.... Additional nesting beaches are found along the eastern Mexico coast, particularly the eastern Yucatan...

Diversity of Vibrio spp in Karstic Coastal Marshes in the Yucatan Peninsula

PubMed Central

2015-01-01

Coastal bodies of water formed by the combination of seawater, underground rivers and rainwater comprise the systems with the greatest solar energy flow and biomass production on the planet. These characteristics make them reservoirs for a large number species, mainly microorganisms. Bacteria of the genus Vibrio are natural inhabitants of these environments and their presence is determined by variations in the nutrient, temperature and salinity cycles generated by the seasonal hydrologic behavior of these lagoon systems. This study determined the diversity of the genus Vibrio in 4 coastal bodies of water on the Yucatan Peninsula (Celestun Lagoon, Chelem Lagoon, Rosada Lagoon and Sabancuy Estuary). Using the molecular technique of 454 pyrosequencing, DNA extracted from water samples was analyzed and 32,807 reads were obtained belonging to over 20 culturable species of the genus Vibrio and related genera. OTU (operational taxonomic unit) richness and Chao2 and Shannon Weaver diversity indices were obtained with the database from this technique. Physicochemical and environmental parameters were determined and correlated with Vibrio diversity measured in OTUs. PMID:26252792

Bioeconomic modeling for a small-scale sea cucumber fishery in Yucatan, Mexico

PubMed Central

Hernández-Flores, Alvaro; Cuevas-Jiménez, Alfonso; Condal, Alfonso; Espinoza-Méndez, Juan Carlos

2018-01-01

Due to the heavy exploitation of holothurians over the last few decades, it is necessary to implement fishing regulations aimed at reversing this situation. Holothurians require specific regulations that take into account their biology and ecology. Their behavior to group and form patches as a strategy for feeding, defense and reproduction, makes them vulnerable to overfishing. The higher the population density, the higher the catchability coefficient, and because they are sedentary organisms, the catchability does not change significantly until the density is very low. Hence, the stock assessment of holothurians can be improved by analyzing their spatial distribution. This paper proposes a stock assessment technique that considers the spatial distribution pattern of the sea cucumber Isostichopus badionotus from Yucatan, Mexico. A bioeconomic spatial model was developed to explain the interactions between fishing effort allocation, quasi-profits and the population in the short term. Because of the high price of the species and the low production costs, artisanal fishers preferred to maximize short-term quasi-profits, rather than the long-term benefits they could gain with low fishing mortality rates. PMID:29315339

Bioeconomic modeling for a small-scale sea cucumber fishery in Yucatan, Mexico.

PubMed

Hernández-Flores, Alvaro; Cuevas-Jiménez, Alfonso; Poot-Salazar, Alicia; Condal, Alfonso; Espinoza-Méndez, Juan Carlos

2018-01-01

Due to the heavy exploitation of holothurians over the last few decades, it is necessary to implement fishing regulations aimed at reversing this situation. Holothurians require specific regulations that take into account their biology and ecology. Their behavior to group and form patches as a strategy for feeding, defense and reproduction, makes them vulnerable to overfishing. The higher the population density, the higher the catchability coefficient, and because they are sedentary organisms, the catchability does not change significantly until the density is very low. Hence, the stock assessment of holothurians can be improved by analyzing their spatial distribution. This paper proposes a stock assessment technique that considers the spatial distribution pattern of the sea cucumber Isostichopus badionotus from Yucatan, Mexico. A bioeconomic spatial model was developed to explain the interactions between fishing effort allocation, quasi-profits and the population in the short term. Because of the high price of the species and the low production costs, artisanal fishers preferred to maximize short-term quasi-profits, rather than the long-term benefits they could gain with low fishing mortality rates.

Nematodes parasitic in fishes of cenotes (= sinkholes) of the Peninsula of Yucatan, Mexico. Part 2. Larvae.

PubMed

Moravec, F; Vivas-Rodríguez, C; Scholz, T; Vargas-Vázquez, J; Mendoza-Franco, E; Schmitter-Soto, J J; González-Solís, D

1995-01-01

This paper comprises a systematic survey of larval nematodes collected from fishes from cenotes (= sinkholes) of the Peninsula of Yucatan, southern Mexico, in 1993-1994. Larvae of the following nine species were recorded: Physocephalus sexalatus, Acuariidae gen. sp., Spiroxys sp., Falcaustra sp., Hysterothylacium cenotae, Contracaecum sp. Type 1, Contracaecum sp. Type 2, Goezia sp., and Eustrongylides sp. Larvae of P. sexalatus are recorded from fishes (Rhamdia guatemalensis) for the first time. The larvae are briefly described and illustrated and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. Adults of these larvae are parasitic in piscivorous fishes, reptiles, birds and mammals (definitive hosts). Fishes harbouring the larvae of these parasites serve as paratenic hosts, being mostly an important source of infection for the definitive hosts.

Bothriocephalus pearsei n. sp. (Cestoda: Pseudophyllidea) from cenote fishes of the Yucatan Peninsula, Mexico.

PubMed

Scholz, T; Vargas-Vázquez, J; Moravec, F

1996-10-01

The cestode Bothriocephalus pearsei n. sp. is described from the intestine of the cichlid Cichlasoma urophthalmus (Günther) from cenote (= sinkhole) Zaci near Valladolid, Yucatan, Mexico. The pimelodid catfish Rhamdia guatemalensis Günther, which also harbored conspecific cestodes, seems to represent accidental or postcyclic host of B. pearsei. The new species differs from congeners mainly by the morphology of the scolex, which is clavate, with the maximum width in its middle part, has a distinct but weakly muscular apical disc; 2 short and wide bothria distinctly demarcated in their anterior part, becoming indistinct posteriorly in the middle part of the scolex, and 2 elongate, lateral grooves. In addition to the scolex morphology, the new species can be differentiated from Bothriocephalus species parasitizing North American freshwater fishes as follows: B. claviceps (Goeze, 1782), a specific parasite of eels in the Holarctic, B. cuspidatus Cooper, 1917, occurring mostly in perciform fishes in North America, B. musculosus Baer, 1937 found in the cichlid Cichlasoma biocellata (Regan) (= C. octofasciatum (Regan)), and B. texomensis Self, 1954, described from Hiodon alosoides (Rafinesque), are much larger, with strobilae consisting of relatively short and very wide proglottids versus small-sized strobila (length 26-32 mm) composed of about 70 proglottids, which are only slightly wider than they are long (ratio 1:1-3), rectangular, or even longer than wide in the last proglottids in B. pearsei. Bothriocephalus formosus Mueller and Van Cleave, 1932, described from Percopsis omiscomaycus (Walbaum) in the USA, can be distinguished from B. pearsei, besides the different shape of the scolex, by the distribution of vitelline follicles, which are not separated into 2 lateral fields and are present along the midline of proglottids in the former species. Bothriocephalus acheilognathi, a widely distributed parasite of fishes of many families, in particular of cyprinids

76 FR 58867 - Endangered and Threatened Species; Determination of Nine Distinct Population Segments of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-22

... through North Carolina (United States), Quintana Roo and Yucatan (Mexico), Brazil, Cape Verde Islands... beaches are found along the northern and western Gulf of Mexico, eastern Yucatan Peninsula, at Cay Sal...

ISVEE 14 Yucatan 2015 14th Symposium of the International Society for Veterinary Epidemiology and Economics.

PubMed

de Anda, Jorge Hernández

2017-02-01

The 14th Symposium of the International Society for Veterinary Epidemiology and Economics (ISVEE 14) was held in Merida, Yucatan, Mexico during 3-7 November. 2015. The purpose of ISVEE 14 Yucatan 2015 was to provide a global forum for graduate students, postdoctoral fellows, junior and senior investigators, as well as health policymakers to exchange information that can advance the fields of veterinary epidemiology and economics, and other disciplines in the health and social sciences. The main theme of ISVEE 14 was Planning Our Future. Human population growth is predicted to increase nearly 50% to 11 billion by 2050, and climate change and changing land use can have an impact on local and global food systems, interactions among humans, wildlife and domestic animals, as well as local, regional, and global public health alerts. How can we help our systems of education, research, and public policy adapt? Are new veterinary graduates and epidemiology practitioners prepared to become active protagonists in the solution of health issues that affect humans and animal populations in a changing environment? What innovative research is needed to understand and enhance the food systems of the future? What are the expected roles or contributions of veterinarians or epidemiology practitioners on future climate change, food systems, and health? Is our profession or discipline leading One Health initiatives? Are there current or new models that make national veterinary services more efficacious and efficient for disease control and eradication? To help us answer these questions, the organizing committee of ISVEE 14 invited five distinguished keynote speakers to share their vision and innovative ideas on education, technological developments, research, and public policy of our future with a concentration in the following five areas: (i) One Health (Jonna Mazet), (ii) climate change (Bernard Bett), (iii) animal health economics (Jonathan Rushton), (iv) national veterinary services

Detection of groundwater conduits in limestones with gravity surveys: data from the area of the Chicxulub Impact crater, Yucatan Peninsula, Mexico.

PubMed

Kinsland, G L; Hurtado, M; Pope, K O

2000-04-15

Small negative gravity anomalies are found in gravity data from along the northwestern shoreline of the Yucatan Peninsula. These anomalies are shown to be due to elongate, shallow anomalous porosity zones in the Tertiary carbonates. These zones are caused primarily by groundwater solution and are presently active conduits for groundwater flow. The association of these small gravity anomalies with known topographic and structural features of the area, which partially overlies the Chicxulub Impact crater, indicates their development was influenced by structures, faults and/or fractures, within the Tertiary and pre-Tertiary carbonates.

Detection of groundwater conduits in limestones with gravity surveys: data from the area of the Chicxulub Impact crater, Yucatan Peninsula, Mexico

NASA Technical Reports Server (NTRS)

Kinsland, G. L.; Hurtado, M.; Pope, K. O.; Ocampo, A. C. (Principal Investigator)

2000-01-01

Small negative gravity anomalies are found in gravity data from along the northwestern shoreline of the Yucatan Peninsula. These anomalies are shown to be due to elongate, shallow anomalous porosity zones in the Tertiary carbonates. These zones are caused primarily by groundwater solution and are presently active conduits for groundwater flow. The association of these small gravity anomalies with known topographic and structural features of the area, which partially overlies the Chicxulub Impact crater, indicates their development was influenced by structures, faults and/or fractures, within the Tertiary and pre-Tertiary carbonates.

Characterization of Motor and Somatosensory Evoked Potentials in the Yucatan Micropig Using Transcranial and Epidural Stimulation.

PubMed

Benavides, Francisco D; Santamaria, Andrea J; Bodoukhin, Nikita; Guada, Luis G; Solano, Juan P; Guest, James D

2017-09-15

Yucatan micropigs have brain and spinal cord dimensions similar to humans and are useful for certain spinal cord injury (SCI) translational studies. Micropigs are readily trained in behavioral tasks, allowing consistent testing of locomotor loss and recovery. However, there has been little description of their motor and sensory pathway neurophysiology. We established methods to assess motor and sensory cortical evoked potentials in the anesthetized, uninjured state. We also evaluated epidurally evoked motor and sensory stimuli from the T6 and T9 levels, spanning the intended contusion injury epicenter. Response detection frequency, mean latency and amplitude values, and variability of evoked potentials were determined. Somatosensory evoked potentials were reliable and best detected during stimulation of peripheral nerve and epidural stimulation by referencing the lateral cortex to midline Fz. The most reliable hindlimb motor evoked potential (MEP) occurred in tibialis anterior. We found MEPs in forelimb muscles in response to thoracic epidural stimulation likely generated from propriospinal pathways. Cranially stimulated MEPs were easier to evoke in the upper limbs than in the hindlimbs. Autopsy studies revealed substantial variations in cortical morphology between animals. This electrophysiological study establishes that neurophysiological measures can be reliably obtained in micropigs in a time frame compatible with other experimental procedures, such as SCI and transplantation. It underscores the need to better understand the motor control pathways, including the corticospinal tract, to determine which therapeutics are suitable for testing in the pig model.

Climate Change Scenarios in the Yucatan Peninsula to the year 2020

NASA Astrophysics Data System (ADS)

Orellana, R.; Espadas, C.; Conde, C.; Gay, C.

2010-03-01

A topic that has not been sufficiently analyzed is that the global warming is already affecting, and that it will have worst consequences in those regions with transitional climates, which have more sensibility to changes. This is the case of the Yucatan Peninsula which is semi-arid in their northern portion, and toward the south is subhumid, with a tendency to be more rainy toward the south. To have an estimation of what could happen in the future, the Intergovernmental Panel of Climatic Change (IPCC) has promoted the use of General Circulation Models (GCM), as well as the construction of possible emission scenarios that integrate different global and regional socioeconomic and demographic conditions, which project then a possible increase of emissions of greenhouse gases. These conditions are recognized as the decisive forces that will determine the variations of temperature and of precipitation. These projections are useful for the analysis of climatic change, and in particular for the assessments of the possible impacts and of the initiatives of adaptation and of mitigation that should be implemented in every country or region. In Mexico, most of those evaluations of climate change have been carried out generally at country level. For that reason, it is necessary to direct the research at regional level. In this work, we evaluated the potential climatic changes on the Yucatan Peninsula, considering the different changes of temperature and precipitation as a consequence for different emission scenarios and for the horizon 2020. To project the environmental responses of the region, we used as a base scenario the available temperature and precipitation information of the period 1961-1990, registered in 85 meteorological stations of the peninsula. With these data, we generated climate change scenarios using the outputs of four General Circulation Models: HADLEY, ECHAM, GFDL and CGCM, and the emission scenarios A1FI, A2, B1 and B2. The outputs of these models were

Oceanographic implications of the Cabo Catoche (Northeast Yucatan) upwelling and its effects on the coastal ecosystem

NASA Astrophysics Data System (ADS)

Reyes-Mendoza, O.; Marino-Tapia, I.; Herrera Silveira, J.; Cárdenas-Palómo, N.; Ruiz, G.

2013-05-01

The coasts of the world where upwelling events occur are intrinsically related to the human population, mainly because of their large fisheries, socioeconomic repercussion and implications concerning the health of the ecosystem. In the northeast of the Yucatan Peninsula occurs an upwelling event known as the Yucatan upwelling (YU) associated with the current of the same name. The mechanisms that generate the YU are still under discussion. In terms of seasonality it is agreed that this is annual, occurring between April and September. During spring and summer, the northeast coast of the Peninsula between CaboCatoche and Isla Contoy becomes a productive and diverse pelagic ecosystem, unique to the region. It is classified as a priority marine zone host to close to 59 species protected by the national laws. It is also recognized as an important priority marine site because of its fishery. Also, the largest global aggregation of whale sharks, the world's biggest fish, is found at this site. There is a strong connection between the physical and the biological components of the system, however the coastal extent, seasonality, and magnitude of these processes need to be determined. Therefore an in-situ study was designed in the coastal region of CaboCatoche, where a 50 km transect was positioned along shelf and another across shelf 20 km, where water was collected to determine nutrient concentrations and CTD profiles were casted during the summer of 2007, 2008 and 2011. Two acoustic profilers were installed 12 km from the coast, which recorded currents and temperature by 2 years. Another profiler located 17 km from the coast to recorded data by 8 years. Atmospheric pressure and temperature were measured, as a wind fields from NOAA. Maps were created for the vertical distribution of temperature (18-31°C), salinity (35-38 psu), density (22-27 kg/m3) and chlorophyll (0.05-12.7 mg/m3). Frequency periods were estimated for temperature, currents, wind and atmospheric pressure

Reverse polarity magnetized melt rocks from the Chicxulub impact structure, Yucatan Peninsula, Mexico

NASA Astrophysics Data System (ADS)

Urrutia-Fucugauchi, Jaime; Marin, Luis E.; Sharpton, Virgil L.; Quezada, Juan Manuel

1993-03-01

Further paleomagnetic data for core samples of melt rock recovered in the Petroleos Mexicanos (PEMEX) exploratory wells within the Chicxulub structure, northern Yucatan peninsula, Mexico are reported. A previous report by Sharpton showed that the rocks studied contain high iridium levels and shocked breccia clasts, and an Ar-40/Ar-39 age of 65.2 plus or minus 0.4 Ma. The geomagnetic polarity determined for two samples is reverse (R) and was correlated with chron 29R that includes the K/T boundary. Our present analysis is based on two samples from each of three clasts of the melt rock from PEMEX well Y6-N17 (1295 to 1299 m b.s.l.). This study concentrates on the vectorial nature and stability of the remanence (NRM), the magnetic mineralogy and remanence carriers (i.e., the reliability and origin of the record), and on the implications (correlation with expected paleolatitude and polarity). The relative orientation of the drill core samples with respect to the horizontal is known. Samples were stable under alternating field (AF) and thermal treatments, and after removal of a small component they exhibited single-vectorial behavior. The characteristic remanence inclinations show small dispersion and a mean value (-43 deg) in close agreement with the expected inclination and paleolatitude (derived from the North American apparent polar wander path). Isothermal remenence (IRM) acquisition experiments, Lowrie-Fuller tests, coercivity and unblocking temperature spectra of NRM and saturation IRM, susceptibility and Q-coefficient analyses, and the single-component nature indicate a dominant mineralogy of iron-rich titanomagnetites with single or pseduo-single domain states. The stable characteristic magnetization may be interpreted as a result of shock heating of the rock at the time of formation of the inpact structure and its polarity, age, and paleolatitude are consistent with a time about the K/T boundary.

Reverse polarity magnetized melt rocks from the Chicxulub impact structure, Yucatan Peninsula, Mexico

NASA Technical Reports Server (NTRS)

Urrutia-Fucugauchi, Jaime; Marin, Luis E.; Sharpton, Virgil L.; Quezada, Juan Manuel

1993-01-01

Further paleomagnetic data for core samples of melt rock recovered in the Petroleos Mexicanos (PEMEX) exploratory wells within the Chicxulub structure, northern Yucatan peninsula, Mexico are reported. A previous report by Sharpton showed that the rocks studied contain high iridium levels and shocked breccia clasts, and an Ar-40/Ar-39 age of 65.2 plus or minus 0.4 Ma. The geomagnetic polarity determined for two samples is reverse (R) and was correlated with chron 29R that includes the K/T boundary. Our present analysis is based on two samples from each of three clasts of the melt rock from PEMEX well Y6-N17 (1295 to 1299 m b.s.l.). This study concentrates on the vectorial nature and stability of the remanence (NRM), the magnetic mineralogy and remanence carriers (i.e., the reliability and origin of the record), and on the implications (correlation with expected paleolatitude and polarity). The relative orientation of the drill core samples with respect to the horizontal is known. Samples were stable under alternating field (AF) and thermal treatments, and after removal of a small component they exhibited single-vectorial behavior. The characteristic remanence inclinations show small dispersion and a mean value (-43 deg) in close agreement with the expected inclination and paleolatitude (derived from the North American apparent polar wander path). Isothermal remenence (IRM) acquisition experiments, Lowrie-Fuller tests, coercivity and unblocking temperature spectra of NRM and saturation IRM, susceptibility and Q-coefficient analyses, and the single-component nature indicate a dominant mineralogy of iron-rich titanomagnetites with single or pseduo-single domain states. The stable characteristic magnetization may be interpreted as a result of shock heating of the rock at the time of formation of the inpact structure and its polarity, age, and paleolatitude are consistent with a time about the K/T boundary.

The Disruption of Subsistence Agricultural Systems in Rural Yucatan, Mexico may have Contributed to the Coexistence of Stunting in Children with Adult Overweight and Obesity.

PubMed

Gurri, Francisco D

2015-12-01

This paper attempts to link last century's disruption of local agricultural systems to today's presence of childhood under nutrition and adult overweight and obesity in the Yucatan Peninsula. It first compares Height for Age (H/A), Weight for Age (W/A) and Body Mass Index (BMI) of children from three rural populations in Yucatan and Campeche, Mexico whose subsistence strategy had been altered to different degrees since 1970. It then compares BMI in adults, in the same regions, born before and after the alteration of their environment in the 1970's. Children in the least disrupted zone were taller and had lower BMI than children in the other two, but were not heavier than children from the richest disrupted zone. Children in the poorest disrupted zone were shorter and lighter than the rest. BMI in adult men was higher in the two most disrupted zones only in those cohorts that grew up after the traditional agricultural regime was altered. It is concluded that disruptions of staple-based subsistence agriculture promoted a stockier phenotype in children and a tendency to accumulate body fat. Persistence of these conditions in the twenty first century has favored the coexistence of stunting during childhood with adults who easily become overweight.

Cytotoxic diterpenes from roots of Crossopetalum gaumeri, a Celastraceae species from Yucatan Peninsula.

PubMed

Miron-Lopez, Gumersindo; Bazzocchi, Isabel L; Jimenez-Diaz, Ignacio A; Moujir, Laila M; Quijano-Quiñones, Ramiro; Quijano, Leovigildo; Mena-Rejon, Gonzalo J

2014-05-01

Four new diterpenes, crossogumerins A-D (1-4) along with six known ones (5-10) were isolated from the root bark of Crossopetalum gaumeri, an endemic medicinal plant from the Yucatan Peninsula. Their structures were elucidated on the basis of 1D and 2D NMR techniques, including HMQC, HMBC, and ROESY experiments. Compounds 1-5, 8-10 were evaluated for cytotoxicity against HeLa (carcinoma of the cervix) and Hep-2 (lung carcinoma) human tumor cells lines and against normal Vero cells (African green monkey kidney) in lag and log phase of growth. Podocarpane diterpenes, crossogumerin B (2) and nimbiol (10), exhibited the highest activity against HeLa cells (IC50 values of 3.1 and 8.1 μM, respectively), but also selectivity on Vero cells (SI 22.6 and 7.5, respectively). The preliminary SAR studies suggest that an epoxy moiety in ring B and a hydrogen bond-donor group strategically positioned in the diterpene core are important requirements for cytotoxicity and selectivity. Copyright © 2014. Published by Elsevier Ltd.

Monogeneans of freshwater fishes from cenotes (sinkholes) of the Yucatan Peninsula, Mexico.

PubMed

Mendoza-Franco, E F; Scholz, T; Vivas-Rodríguez, C; Vargas-Vázquez, J

1999-01-01

During a survey of the parasites of freshwater fishes from cenotes (sinkholes) of the Yucatan Peninsula the following species of monogeneans were found on cichlid, pimelodid, characid and poeciliid fishes: Sciadicleithrum mexicanum Kritsky, Vidal-Martinez et Rodriguez-Canul, 1994 from Cichlasoma urophthalmus (Günther) (type host), Cichlasoma friedrichsthali (Heckel), Cichlasoma octofasciatum (Regan), and Cichlasoma synspilum Hubbs, all new host records; Sciadicleithrum meekii Mendoza-Franco, Scholz et Vidal-Martínez, 1997 from Cichlasoma meeki (Brind); Urocleidoides chavarriai (Price, 1938) and Urocleidoides travassosi (Price, 1938) from Rhamdia guatemalensis (Günther); Urocleidoides costaricensis (Price et Bussing, 1967), Urocleidoides heteroancistrium (Price et Bussing, 1968), Urocleidoides anops Kritsky et Thatcher, 1974, Anacanthocotyle anacanthocotyle Kritsky et Fritts, 1970, and Gyrodactylus neotropicalis Kritsky et Fritts, 1970 from Astyanax fasciatus; and Gyrodactylus sp. from Gambusia yucatana Regan. Urocleidoides chavarriai, U. travassosi, U. costaricensis, U. heteroancistrium, U. anops, Anacanthocotyle anacanthocotyle and Gyrodactylus neotropicalis are reported from North America (Mexico) for the first time. These findings support the idea about the dispersion of freshwater fishes and their monogenean parasites from South America through Central America to southeastern Mexico, following the emergence of the Panamanian isthmus between 2 and 5 million years ago.

Cenotes (sinkholes) of the Yucatan Peninsula, Mexico, as a habitat of adult trematodes of fish.

PubMed

Scholz, T; Vargas-Vázquez, J; Moravec, F; Vivas-Rodríguez, C; Mendoza-Franco, E

1995-01-01

Examination of a total of 581 fish specimens of 15 species from 39 cenotes (sinkholes) in the Yucatan Peninsula, southeastern Mexico, revealed the presence of 10 species of adult trematodes. These were as follows: Saccocoelioides sogandaresi Lumsden, 1963, Saccocoelioides sp. (family Haploporidae), Cichlasotrema ujati Pineda et Andrade, 1989 (Angiodictyidae), Crassicutis cichlasomae Manter, 1936 (Homalometridae), Magnivitellinum simplex Kloss, 1966 (Macroderoididae), Stunkardiella minima (Stunkard, 1938) (Acanthostomidae), Oligogonotylus manteri Watson, 1976 (Cryptogonimidae), Genarchella tropica (Manter, 1936), G. astyanactis (Watson, 1976), and G. isabellae (Lamothe-Argumedo, 1977) (Derogenidae). Saccocoelioides sogandaresi is reported from Mexico for the first time. Poecilia velifera and P. latipunctata for S. sogandaresi, Cichlasoma octofasciatum for C. cichlasomae, Cichlasoma friedrichstahli and C. meeki for O. manteri, and C. meeki, C. octofasciatum and Gobiomorus dormitor for G. isabellae represent new host records. Most species found are described and figured and their host range and distribution are discussed.

Composition and fluxes of submarine groundwater along the Caribbean coast of the Yucatan Peninsula

NASA Astrophysics Data System (ADS)

Null, Kimberly A.; Knee, Karen L.; Crook, Elizabeth D.; de Sieyes, Nicholas R.; Rebolledo-Vieyra, Mario; Hernández-Terrones, Laura; Paytan, Adina

2014-04-01

Submarine groundwater discharge (SGD) to the coastal environment along the eastern Yucatan Peninsula, Quintana Roo, Mexico was investigated using a combination of tracer mass balances and analytical solutions. Two distinct submarine groundwater sources including water from the unconfined surficial aquifer discharging at the beach face and water from a deeper aquifer discharging nearshore through submarine springs (ojos) were identified. The groundwater of nearshore ojos was saline and significantly enriched in short-lived radium isotopes (223Ra, 224Ra) relative to the unconfined aquifer beach face groundwater. We estimated SGD from ojos using 223Ra and used a salinity mass balance to estimate the freshwater discharge at the beach face. Analytical calculations were also used to estimate wave set-up and tidally driven saline seepage into the surf zone and were compared to the salinity-based freshwater discharge estimates. Results suggest that average SGD from ojos along the Yucatan Peninsula Caribbean coast is on the order of 308 m3 d-1 m-1 and varies between sampling regions. Higher discharge was observed in the southern regions (568 m3 d-1 m-1) compared to the north (48 m3 d-1 m-1). Discharge at the beach face was in the range of 3.3-8.5 m3 d-1 m-1 for freshwater and 2.7 m3 d-1 m-1 for saline water based on the salinity mass balance and wave- and tidally-driven discharge, respectively. Although discharge from the ojos was larger in volume than discharge from the unconfined aquifer at the beach face, dissolved inorganic nitrogen (DIN) was significantly higher in beach groundwater; thus, discharge of this unconfined beach aquifer groundwater contributed significantly to total DIN loading to the coast. DIN fluxes were up to 9.9 mol d-1 m-1 from ojos and 2.1 mol d-1 m-1 from beach discharge and varied regionally along the 500 km coastline sampled. These results demonstrate the importance of considering the beach zone as a significant nutrient source to coastal waters

Fecal sterols, seasonal variability, and probable sources along the ring of cenotes, Yucatan, Mexico

NASA Astrophysics Data System (ADS)

Arcega-Cabrera, F.; Velázquez-Tavera, N.; Fargher, L.; Derrien, M.; Noreña-Barroso, E.

2014-11-01

Rapid development in Yucatan has had a dramatic impact on the environment, especially the water supply. Groundwater is the only source of water in Yucatan, since surface water is virtually absent due to the karstic nature of the soil. The ring of cenotes (RC) is a geological feature which functions as a source of water and as nodes in the underground river system that canalizes water towards the coast. Numerous productive and domestic activities take place around the RC in the absence of wastewater treatment or sewage systems. Consequently, a number of researchers have hypothesized that pollutants could migrate from the land surface to the underlying aquifer and, eventually, to the coast. Therefore, the present study investigates the relationship among sources of fecal sterols and their levels in cenotes, using the expected levels of fecal sterols obtained by a spatial analysis of the sources and a Pollution Source Index. Accordingly, expected levels are compared with the detected levels of fecal sterols in 5 areas around the RC. Regarding levels, observed during a sampling campaign carried out along the RC during September 2011 (rainy season) and May 2012 (dry season), varied from low to high concentrations of sterols (0.5-2396.42 μg g- 1) and fecal sterols (0.3-1690.18 μg g- 1). These concentrations showed no relationship between neighboring cenotes, where similar fecal sterol concentrations or gradients were expected. When comparing expected fecal sterols levels with the detected ones, only two of the five analyzed areas concur, suggesting that no clear relationship exists among sources and fecal sterols levels at the regional scale. Multivariate analysis showed that fecal sterols were associated with sterols and fine grain particulates during the rainy season, which suggests co-transport. During the dry season, fecal sterols associated with fine grain particulate and organic matter, which indicates a change to a deposition phenomenon. These findings indicate

Fecal sterols, seasonal variability, and probable sources along the ring of cenotes, Yucatan, Mexico.

PubMed

Arcega-Cabrera, F; Velázquez-Tavera, N; Fargher, L; Derrien, M; Noreña-Barroso, E

2014-11-01

Rapid development in Yucatan has had a dramatic impact on the environment, especially the water supply. Groundwater is the only source of water in Yucatan, since surface water is virtually absent due to the karstic nature of the soil. The ring of cenotes (RC) is a geological feature which functions as a source of water and as nodes in the underground river system that canalizes water towards the coast. Numerous productive and domestic activities take place around the RC in the absence of wastewater treatment or sewage systems. Consequently, a number of researchers have hypothesized that pollutants could migrate from the land surface to the underlying aquifer and, eventually, to the coast. Therefore, the present study investigates the relationship among sources of fecal sterols and their levels in cenotes, using the expected levels of fecal sterols obtained by a spatial analysis of the sources and a Pollution Source Index. Accordingly, expected levels are compared with the detected levels of fecal sterols in 5 areas around the RC. Regarding levels, observed during a sampling campaign carried out along the RC during September 2011 (rainy season) and May 2012 (dry season), varied from low to high concentrations of sterols (0.5-2396.42 μg g(-1)) and fecal sterols (0.3-1690.18 μg g(-1)). These concentrations showed no relationship between neighboring cenotes, where similar fecal sterol concentrations or gradients were expected. When comparing expected fecal sterols levels with the detected ones, only two of the five analyzed areas concur, suggesting that no clear relationship exists among sources and fecal sterols levels at the regional scale. Multivariate analysis showed that fecal sterols were associated with sterols and fine grain particulates during the rainy season, which suggests co-transport. During the dry season, fecal sterols associated with fine grain particulate and organic matter, which indicates a change to a deposition phenomenon. These findings

Microbial Threats to Health. Emerging Infections: Microbial Threats to Health in the United States.

DTIC Science & Technology

1992-10-01

enzootic in much of the rodent population in the western United States, Mexico , and Canada. Thanks to modem sanitation and the availability of...pandemic, as explorers, soldiers, and others ini acted by the smallpox virus traveled to all parts of the globe. Smallpox was introduced into Mexico 6y...Caribbean and on the Yucatan Peninsula of Mexico . Although the disease is concentrated in a small number of areas, world- wide incidence rates for DHF

Intrauterine growth-restricted Yucatan miniature pigs experience early catch-up growth, leading to greater adiposity and impaired lipid metabolism as young adults.

PubMed

Myrie, Semone B; McKnight, Leslie L; King, J Christopher; McGuire, John J; Van Vliet, Bruce N; Cheema, Sukhinder K; Bertolo, Robert F

2017-12-01

Early nutrition has critical influences on cardiovascular disease risk in adulthood. The study objectives were to evaluate the impact of low birth weight on fasting and postprandial lipid metabolism and endothelium function in Yucatan miniature pigs. Intrauterine growth-restricted (IUGR) piglets (n = 6; 3 days old, 0.73 ± 0.04 kg) were paired with normal-weight (NW) same-sex littermates (n = 6; 1.11 ± 0.05 kg) and fed milk replacer ad libitum for 4 weeks. Thereafter, all pigs were fed a standard diet ad libitum for 5 h/day with growth, intakes, and blood samples collected for 8 months. At 9 months old, pigs were surgically fitted with venous catheters and an oral fat tolerance test was performed. At 10 months old, pigs were killed and endothelium-dependent and -independent vasodilations of isolated coronary arteries were measured using wire-myographs. IUGR pigs demonstrated catch-up growth (P < 0.05) in body weight and abdominal circumference prior to sexual maturity (<7 months old) and had more (P < 0.05) subcutaneous fat at 10 months old compared with NW pigs. IUGR pigs had consistently higher fasting plasma triglyceride concentrations from 5 to 10 months old and higher liver triglyceride and total cholesterol concentrations at 10 months old (P < 0.05). The fat tolerance test revealed delayed postprandial triglyceride clearance in IUGR pigs, but no differences in plaque formation or vascular reactivity. To conclude, IUGR and early postnatal catch-up growth are associated with increased overall body fat deposition and altered triglyceride metabolism in adult Yucatan miniature swine.

Contaminants in the coastal karst aquifer system along the Caribbean coast of the Yucatan Peninsula, Mexico.

PubMed

Metcalfe, Chris D; Beddows, Patricia A; Bouchot, Gerardo Gold; Metcalfe, Tracy L; Li, Hongxia; Van Lavieren, Hanneke

2011-04-01

Intensive land development as a result of the rapidly growing tourism industry in the "Riviera Maya" region of the Yucatan Peninsula, Mexico may result in contamination of groundwater resources that eventually discharge into Caribbean coastal ecosystems. We deployed two types of passive sampling devices into groundwater flowing through cave systems below two communities to evaluate concentrations of contaminants and to indicate the possible sources. Pharmaceuticals and personal care products accumulated in the samplers could only have originated from domestic sewage. PAHs indicated contamination by runoff from highways and other impermeable surfaces and chlorophenoxy herbicides accumulated in samplers deployed near a golf course indicated that pesticide applications to turf are a source of contamination. Prevention and mitigation measures are needed to ensure that expanding development does not impact the marine environment and human health, thus damaging the tourism-based economy of the region. Copyright © 2010 Elsevier Ltd. All rights reserved.

Final Environmental Assessment for Continued Personnel Recovery Training Operations Within the Gulf of Mexico WTA Moody Air Force Base, Georgia

DTIC Science & Technology

2010-06-01

when Caribbean oceanic water flows northward into the Gulf of Mexico via the Yucatan Channel. After penetrating the Gulf, the current turns east and...the Gulf of Mexico from Florida to the Yucatan . It inhabits most coastal shores and estuaries and offshore areas to a depth of 115 ft. Blue crabs... Yucatan Peninsula of Mexico (Garduno-Andrade et al. 1999). With respect to the United States, nesting occurs in Puerto Rico, the U.S. Virgin Islands, and

Fish community structure in freshwater karstic water bodies of the Sian Ka'an Reserve in the Yucatan peninsula, Mexico

USGS Publications Warehouse

Zambrano, L.; Vazquez-Dominguez, E.; Garcia-Bedoya, D.; Loftus, W.F.; Trexler, J.C.

2006-01-01

We evaluated the relationship between limnetic characteristics and fish community structure (based on species richness, abundance and individual size) in contrasting but interconnected inland aquatic habitats of freshwater karstic wetlands in the Yucatan peninsula, Mexico. In the western hemisphere, freshwater karstic wetlands are found in south-eastern Mexico, northern Belize, western Cuba, Andros Island, Bahamas and the Everglades of southern Florida. Only in the Everglades have fish communities been well described. Karstic wetlands are typically oligotrophic because calcium carbonate binds phosphorus, making it relatively unavailable for plants. Fourteen permanent and seasonally flooded water bodies were sampled in both wet and dry seasons in Sian Ka'an Biosphere Reserve, in the Mexican state of Quintana Roo. Water systems were divided by morphology in four groups: cenotes with vegetation (CWV), cenotes without vegetation (CNV), wetlands (WTL), and temporal cenotes (TPC). Discriminant analysis based on physical characteristics such as turbidity, temperature, depth and oxygen confirmed that these habitats differed in characteristics known to influence fish communities. A sample-based rarefaction test showed that species richness was significantly different between water systems groups, showing that WTL and CWV had higher richness values than CNV and TPC. The most abundant fish families, Poeciliidae, Cichlidae and Characidae, differed significantly in average size among habitats and seasons. Seasonal and inter-annual variation, reflecting temporal variation in rainfall, strongly influenced the environmental differences between shallow and deep habitats, which could be linked to fish size and life cycles. Five new records of species were found for the reserve, and one new record for Quintana Roo state. ?? 2006 by Verlag Dr. Friedrich Pfeil.

Hydrogeothermal Convective Circulation Model for the Formation of the Chicxulub Ring of Cenotes in the Yucatan Peninsula, Mexico.

NASA Astrophysics Data System (ADS)

Monroy-Rios, E.; Beddows, P. A.

2015-12-01

Despite being deeply buried, the topography and geophysical characteristics of the multi-ring Chicxulub impact structure are reflected on the now subaerial Yucatan Peninsula with aligned arcs of cenotes (sinkholes), forming the "Ring of Cenotes". A pending question is the determination of the geological, geochemical, structural features and associated processes that have led to void development, and the upwards propagation of the voids, cross cutting over 1000 m of super-deposited carbonate sequences. Drawing from the published literature on drill core and geophysical surveys undertaken by Pemex, UNAM, and IODP/ICDP, numerical modeling, and general carbonate platform hydrothermal reactive transport models, we provide a conceptual model for the genesis of the Ring of Cenotes. In horizontally bedded carbonate platforms, geothermal gradients will drive convective flow, with strong vertical components specifically in the platform center. In the Yucatan Platform, a high occurrence of anhydrite and dolomite at depth evokes early burial dolomitization and anhydritization, sourcing Mg from seawater. The Chicxulub impact near the center of the platform produced a low permeability and high thermal conductivity melt rock that arguably extends to the basement rock at 3.5 km below surface. Heat of impact enforced the pre-existing geothermal circulation pattern, and even with depletion of the heat of impact, the high thermal conductivity of the crystalline melt would lead to enhanced geothermal gradients in the center of the platform. The cenotes overlying the crater are deep (150+ m) vertical shafts with most (but not all) breaching the surface. The pit geomorphology suggests a bottom-up formation. Excess Si in the shallow groundwater points to a convective circulation with strong vertical components geochemically linking the granodioritic basement rock to the surface. Water temperature and conductivity profiles support ongoing vertical flux in some deep pit cenotes. Within

Capillaria (Hepatocapillaria) cichlasomae (Nematoda: Capillariidae) from the liver of the cichlid fish Cichlasoma urophthalmus from Yucatan, Mexico.

PubMed

Moravec, F; Scholz, T; Mendoza Franco, E

1995-01-01

Capillaria (Hepatocapillaria) cichlasomae sp. n., parasitic in the liver of the cichlid Cichlasoma urophthalmus (Günther) from a small freshwater lake ("aguada") Xpoc in Yucatan, Mexico, is described. The parasite is characterized mainly by its small body size (male 1.8 mm, female 4.5 mm), the structure of the stichosome (markedly short stichocytes in one row) and the male (the presence of a pair of small subventral postanal papillae) and female (anus distinctly subterminal) caudal ends, and by the size and structure of the spicule (spicule 0.068-0.085 mm long, with marked transverse grooves on surface) and eggs (size 0.053-0.058 x 0.023 mm, with protruding polar plugs). This is the second known Capillaria species from the liver of fish and the first one from the liver of a freshwater fish.

High-resolution speleothem record of precipitation from the Yucatan Peninsula spanning the Maya Preclassic Period

NASA Astrophysics Data System (ADS)

Medina-Elizalde, Martín; Burns, Stephen J.; Polanco-Martínez, Josué M.; Beach, Timothy; Lases-Hernández, Fernanda; Shen, Chuan-Chou; Wang, Hao-Cheng

2016-03-01

We produced a new high-resolution absolute U-Th dated stalagmite oxygen isotope record (δ18O) from Río Secreto, Playa del Carmen, Yucatan Peninsula (YP). This new 1434-year stalagmite record (named Itzamna after the Maya god of creation) spans the time interval between BCE 1037 and CE 397 with an average resolution of 8 ± 2 years. It provides a novel view of climate evolution over the Preclassic and early Classic periods in Maya history. To understand the controls of regional precipitation δ18O on seasonal time scales, we characterized the amount effect between precipitation amount (P) and precipitation δ18O (δP). We found that precipitation δ18O in the Yucatan Peninsula is controlled by the amount effect on seasonal scales (δP/ΔP = - 0.0137 ± 0.0031‰ per mm, r = 0.9), as suspected but never before demonstrated. Cave drip δ18O is consistent with the annual amount-weighted δ18O composition of precipitation. Multiple lines of evidence suggest that stalagmite δ18O reflects isotopic equilibrium conditions and thus stalagmite δ18O changes are interpreted to reflect precipitation amount. We determined quantitative precipitation changes from the stalagmite δ18O record following previous methods (Medina-Elizalde and Rohling, 2012). The stalagmite precipitation record suggests twelve periods of anomalous precipitation reductions ranging between about 30 and 70% below mean conditions at the time and with durations from 6 years to 31 years. Between BCE 520 and 166, the speleothem precipitation record suggests that the YP experienced an interval of high precipitation labeled the Late Preclassic Humid Period (LPHP) with precipitation maxima of up to + 86 ± 20%. Preclassic Maya cultural expansion in El Mirador Basin, located in northern Guatemala, took place while the peninsula transitioned from the LPHP to an interval with below average precipitation. We find that the Preclassic abandonment of major centers in the Mirador Basin and others around the Maya

Is There any Relationship Between the Santa Elena Depression and Chicxulub Impact Crater, Northwestern Yucatan Peninsula, Mexico?

NASA Astrophysics Data System (ADS)

Lefticariu, L.

2005-05-01

The Terminal Cretaceous Chicxulub Impact Crater had a strong control on the depositional and diagenetic history of the northern Yucatan Platform during most of the Cenozoic Era. The Chicxulub Sedimentary Basin (henceforth Basin), which approximately coincides with the impact crater, is circumscribed by a concentration of karstic sinkholes known as the Ring of Cenotes. Santa Elena Depression (henceforth Depression) is the name proposed for the bowl-shaped buried feature, first contoured by geophysical studies, immediately south of the Basin, in the area where the Ticul 1 and UNAM 5 wells were drilled. Lithologic, petrographic, and biostratigraphic data on PEMEX, UNAM, and ICDP cores show that: 1) Cenozoic deposits are much thicker inside the Basin than inside the Depression, 2) in general, the Cenozoic formations from inside the Depression are the thickest among those outside the Basin, 3) variably dolomitized pelagic or outer-platform wackestone or mudstone occur both inside the Basin and Depression, 4) the age of the deeper-water sedimentary carbonate rocks is Paleocene-Eocene inside the Basin and Paleocene?-Early Eocene inside the Depression, 5) the oldest formations that crop out are of Middle Eocene age at the edge of the Basin and Early-Middle Eocene age inside the Depression, 6) saline lake deposits, that consist chiefly of anhydrite, gypsum, and fine carbonate, and also contain quartz, chert, clay, zeolite, potassium feldspar, pyrite, and fragments of wood, are present in the Cenozoic section of the UNAM 5 core between 282 and 198 m below the present land surface, 7) the dolomite, subaerial exposure features (subaerial crusts, vugs, karst, dedolomite), and vug-filling cement from the Eocene formations are more abundant inside the Depression than inside the Basin. The depositional environments that are proposed for explaining the Cenozoic facies succession within the Santa Elena Depression are: 1) deeper marine water (Paleocene?-Early Eocene), 2) relatively

Space Radar Image of the Yucatan Impact Crater Site

NASA Image and Video Library

1999-01-27

This is a radar image of the southwest portion of the buried Chicxulub impact crater in the Yucatan Peninsula, Mexico. The radar image was acquired on orbit 81 of space shuttle Endeavour on April 14, 1994 by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR). The image is centered at 20 degrees north latitude and 90 degrees west longitude. Scientists believe the crater was formed by an asteroid or comet which slammed into the Earth more than 65 million years ago. It is this impact crater that has been linked to a major biological catastrophe where more than 50 percent of the Earth's species, including the dinosaurs, became extinct. The 180-to 300-kilometer-diameter (110- to 180-mile) crater is buried by 300 to 1,000 meters (1,000 to 3,000 feet) of limestone. The exact size of the crater is currently being debated by scientists. This is a total power radar image with L-band in red, C-band in green, and the difference between C-band L-band in blue. The 10-kilometer-wide (6-mile) band of yellow and pink with blue patches along the top left (northwestern side) of the image is a mangrove swamp. The blue patches are islands of tropical forests created by freshwater springs that emerge through fractures in the limestone bedrock and are most abundant in the vicinity of the buried crater rim. The fracture patterns and wetland hydrology in this region are controlled by the structure of the buried crater. Scientists are using the SIR-C/X-SAR imagery to study wetland ecology and help determine the exact size of the impact crater. http://photojournal.jpl.nasa.gov/catalog/PIA01723

Maternal Western diet during gestation and lactation modifies adult offspring's cognitive and hedonic brain processes, behavior, and metabolism in Yucatan minipigs.

PubMed

Gautier, Yentl; Luneau, Isabelle; Coquery, Nicolas; Meurice, Paul; Malbert, Charles-Henri; Guerin, Sylvie; Kemp, Bas; Bolhuis, J Elizabeth; Clouard, Caroline; Le Huërou-Luron, Isabelle; Blat, Sophie; Val-Laillet, David

2018-06-13

This study explores the long-term effects of exposure to a maternal Western diet (WD) vs. standard diet (SD) in the Yucatan minipig, on the adult progeny at lean status ( n = 32), and then overweight status. We investigated eating behavior, cognitive abilities, brain basal glucose metabolism, dopamine transporter availability, microbiota activity, blood lipids, and glucose tolerance. Although both groups demonstrated similar cognitive abilities in a holeboard test, WD pigs expressed a higher stress level than did SD pigs (immobility, P < 0.05) and lower performance in an alley maze ( P = 0.06). WD pigs demonstrated lower dopamine transporter binding potential in the hippocampus and parahippocampal cortex ( P < 0.05 for both), as well as a trend in putamen ( P = 0.07), associated with lower basal brain activity in the prefrontal cortex and nucleus accumbens ( P < 0.05) compared with lean SD pigs. Lean WD pigs demonstrated a lower glucose tolerance than did SD animals (higher glucose peak, P < 0.05) and a tendency to a higher incremental area under the curve of insulin from 0 to 30 minutes after intravenous glucose injection ( P < 0.1). Both groups developed glucose intolerance with overweight, but WD animals were less impacted than SD animals. These results demonstrate that maternal diet shaped the offspring's brain functions and cognitive responses long term, even after being fed a balanced diet from weaning, but behavioral effects were only revealed in WD pigs under anxiogenic situation; however, WD animals seemed to cope better with the obesogenic diet from a metabolic standpoint.-Gautier, Y., Luneau, I., Coquery, N., Meurice, P., Malbert, C.-H., Guerin, S., Kemp, B., Bolhuis, J. E., Clouard, C., Le Huërou-Luron, I., Blat, S., Val-Laillet, D. Maternal Western diet during gestation and lactation modifies adult offspring's cognitive and hedonic brain processes, behavior, and metabolism in Yucatan minipigs.

Global Mercury Observatory System (GMOS): measurements of atmospheric mercury in Celestun, Yucatan, Mexico during 2012.

PubMed

Velasco, Antonio; Arcega-Cabrera, Flor; Oceguera-Vargas, Ismael; Ramírez, Martha; Ortinez, Abraham; Umlauf, Gunther; Sena, Fabrizio

2016-09-01

Within the Global Mercury Observation System (GMOS) project, long-term continuous measurements of total gaseous mercury (TGM) were carried out by a monitoring station located at Celestun, Yucatan, Mexico, a coastal site along the Gulf of Mexico. The measurements covered the period from January 28th to October 17th, 2012. TGM data, at the Celestun site, were obtained using a high-resolution mercury vapor analyzer. TGM data show values from 0.50 to 2.82 ng/m(3) with an annual average concentration of 1.047 ± 0.271 ng/m(3). Multivariate analyses of TGM and meteorological variables suggest that TGM is correlated with the vertical air mass distribution in the atmosphere, which is influenced by diurnal variations in temperature and relative humidity. Diurnal variation is characterized by higher nighttime mercury concentrations, which might be influenced by convection currents between sea and land. The back trajectory analysis confirmed that local sources do not significantly influence TGM variations. This study shows that TGM monitoring at the Celestun site fulfills GMOS goals for a background site.

Molecular characterization and phylogenetic relationships of Desmodium leaf distortion virus (DeLDV): a new begomovirus infecting Desmodium glabrum in Yucatan, Mexico.

PubMed

Hernández-Zepeda, Cecilia; Argüello-Astorga, Gerardo; Idris, Ali M; Carnevali, Germán; Brown, Judith K; Moreno-Valenzuela, Oscar A

2009-12-01

The complete DNA-A component sequence of Desmodium leaf distortion virus (DeLDV, Begomovirus) isolated in Yucatan was determined to be 2569 nucleotides (nt) in length, and it was most closely related to Cotton leaf crumple virus-California (CLCrV-[Cal]), at 76%. The complete DNA-B component sequence was 2514 nt in length, and shared its highest nucleotide identity (60%) with Potato yellow mosaic Trinidad virus (PYMTV). Phylogenetic analyses group the DeLDV DNA-A component in the SLCV clade, whereas, the DeLDV DNA-B was grouped with the Abutilon mosaic virus clade, which also contains PYMV, suggesting that the DeLDV components have distinct evolutionary histories, possibly as the result of recombination and reassortment.

Trace-element composition of Chicxulub crater melt rock, K/T tektites and Yucatan basement

NASA Technical Reports Server (NTRS)

Hildebrand, A. R.; Gregoire, D. C.; Attrep, M., Jr.; Claeys, P.; Thompson, C. M.; Boynton, W. V.

1993-01-01

The Cretaceous/Tertiary (K/T) boundary Chicxulub impact is the best preserved large impact in the geologic record. The Chicxulub crater has been buried with no apparent erosion of its intracrater deposits, and its ejecta blanket is known and is well preserved at hundreds of localities globally. Although most of the molten material ejected from the crater has been largely altered, a few localities still preserve tektite glass. Availability of intra- and extracrater impact products as well as plausible matches to the targeted rocks allows the comparison of compositions of the different classes of impact products to those of the impacted lithologies. Determination of trace-element compositions of the K/T tektites, Chicxulub melt rock, and the targeted Yucatan silicate basement and carbonate/evaporite lithologies have been made using instrumental neutron activation analysis (INAA) and inductively coupled plasma mass spectrometry (ICP-MS). Some sample splits were studied with both techniques to ensure that inter-laboratory variation was not significant or could be corrected. The concentration of a few major and minor elements was also checked against microprobe results. Radiochemical neutron activation analysis (RNAA) was used to determine Ir abundances in some samples.

Diabetic dyslipidemia and exercise alter the plasma low-density lipoproteome in Yucatan pigs

PubMed Central

Richardson, Matthew R.; Lai, Xianyin; Dixon, Joseph L.; Sturek, Michael; Witzmann, Frank A.

2010-01-01

Although low-density lipoprotein (LDL) plays a predominant role in atherogenesis, the low-density lipoproteome has not been fully characterized. Moreover, alterations from a Western diet, diabetes, and physical inactivity on this proteome have yet to be determined. Accordingly, relative quantification was determined in LDL proteins from male Yucatan diabetic dyslipidemic (DD) swine in the early stages of atherosclerosis compared to healthy control (C) and non-diabetic hyperlipidemic (H) swine. Importantly, coronary vascular dysfunction was prevented by aerobic exercise training in these animals (DDX) without altering total LDL concentration. Using 2-DE, Western blot, label-free quantitative MS, and selected reaction monitoring, alterations in the abundance of apolipoproteins A-I, B, C-III, D, E, and J and noncovalently associated proteins were determined in LDL isolated using fast protein liquid chromatography. At least 28 unique proteins, many of which were novel, were identified with high confidence. An apolipoprotein E isoform demonstrated stronger correlation to disease (percent of coronary artery segments with intimal thickening) than some traditional risk factors (total cholesterol, LDL cholesterol, and LDL/HDL cholesterol). Taken together, this work identifies new possible biomarkers, potential therapeutic targets for atherosclerosis, and generates new hypotheses regarding the role of LDL in atherogenesis. PMID:19402046

Environmental Exposure of Children to Toxic Trace Elements (Hg, Cr, As) in an Urban Area of Yucatan, Mexico: Water, Blood, and Urine Levels.

PubMed

Arcega-Cabrera, F; Fargher, L; Quesadas-Rojas, M; Moo-Puc, R; Oceguera-Vargas, I; Noreña-Barroso, E; Yáñez-Estrada, L; Alvarado, J; González, L; Pérez-Herrera, N; Pérez-Medina, S

2018-05-01

Merida is the largest urban center in the Mexican State of Yucatan. Here domestic sewage is deposited in poorly built septic tanks and is not adequately treated. Because of contamination from such waste, water from the top 20 m of the aquifer is unsuitable for human consumption. Given this situation and because children are highly vulnerable to environmental pollution, including exposure to toxic trace elements, this study focused on evaluating the exposure of children to arsenic (As), chromium (Cr), and mercury (Hg) in water. It also evaluated the relationship between the levels of these elements in water and their concentrations in urine and blood. Among the 33 children monitored in the study, arsenic surpassed WHO limits for blood in 37% of the cases, which could result from the ingestion of poultry contaminated with organoarsenic compounds. In the case of WHO limits for Mercury, 65% of the water samples analyzed, 28% of urine samples, and 12% of blood samples exceeded them. Mercury exposure was correlated with biological sex, some lifestyle factors, and the zone in Merida in which children live. These data suggest that the levels of some toxic metals in children may be affected by water source, socioeconomic factors, and individual behavior.

Disease Occurrence - Worldwide, July - December 1983. Compilation of Unclasssified Articles.

DTIC Science & Technology

1983-12-01

hardest hit. Manuel Campuzano, Director of the National Institute of Nutrition , has announced the diagnosis of four cases of acquired immune deficiency...other than the United States has been reported in a visitor to Cancun on the Yucatan Peninsula. Hemolytic Vibrio cholerae O-group 1, biotype El Tor...from the states of Oaxaca (759), Guerrero (725) and Michoacan (542) on the Pacific coast and from Yucatan (592) and Veracruz (286) on the east coast

A computationally simplistic poly-phasic approach to explore microbial communities from the Yucatan aquifer as a potential sources of novel natural products.

PubMed

Marfil-Santana, Miguel David; O'Connor-Sánchez, Aileen; Ramírez-Prado, Jorge Humberto; De Los Santos-Briones, Cesar; López-Aguiar; Lluvia, Korynthia; Rojas-Herrera, Rafael; Lago-Lestón, Asunción; Prieto-Davó, Alejandra

2016-11-01

The need for new antibiotics has sparked a search for the microbes that might potentially produce them. Current sequencing technologies allow us to explore the biotechnological potential of microbial communities in diverse environments without the need for cultivation, benefitting natural product discovery in diverse ways. A relatively recent method to search for the possible production of novel compounds includes studying the diverse genes belonging to polyketide synthase pathways (PKS), as these complex enzymes are an important source of novel therapeutics. In order to explore the biotechnological potential of the microbial community from the largest underground aquifer in the world located in the Yucatan, we used a polyphasic approach in which a simple, non-computationally intensive method was coupled with direct amplification of environmental DNA to assess the diversity and novelty of PKS type I ketosynthase (KS) domains. Our results suggest that the bioinformatic method proposed can indeed be used to assess the novelty of KS enzymes; nevertheless, this in silico study did not identify some of the KS diversity due to primer bias and stringency criteria outlined by the metagenomics pipeline. Therefore, additionally implementing a method involving the direct cloning of KS domains enhanced our results. Compared to other freshwater environments, the aquifer was characterized by considerably less diversity in relation to known ketosynthase domains; however, the metagenome included a family of KS type I domains phylogenetically related, but not identical, to those found in the curamycin pathway, as well as an outstanding number of thiolases. Over all, this first look into the microbial community found in this large Yucatan aquifer and other fresh water free living microbial communities highlights the potential of these previously overlooked environments as a source of novel natural products.

Storm-generated bedforms and relict dissolution pits and channels on the Yucatan carbonate platform

NASA Astrophysics Data System (ADS)

Gulick, S. P.; Goff, J. A.; Stewart, H. A.; Perez-Cruz, L. L.; Davis, M. B.; Duncan, D.; Saustrup, S.; Sanford, J. C.; Fucugauchi, J. U.

2013-12-01

The Yucatan 2013 (cruise number 2013/4_ECORD) geophysical and geotechnical hazard site survey took place aboard the R/V Justo Sierra in April 2013. Our study was conducted within the Chicxulub impact crater, encompassing three potential IODP drilling sites. The survey was located ~32 km northwest of Progreso, Mexico; data acquired included ~15.6 km2 of complete multibeam bathymetry coverage, ~435 line km of side scan sonar and CHIRP data, 204 line kilometers of magnetometer data, and 194 line kilometers of surface tow boomer profiles. Based on these data, this portion of the Yucatan Shelf consists of flat-lying, hard limestone rock overlain by isolated ribbons of carbonate sand <1.0 m thick. These ribbons are oriented along NE-SW trends and have smaller scale orthogonal sand-waves (~20-100 m wavelengths and relief of ~0.2-0.6 m) on them. The sand waves are anisotropic with steeper slopes facing the NE. The larger scale morphology can be classified as longitudinal bedforms (ribbons), and the smaller scale transverse bedforms formed in response to a NE-directed flow. This flow direction is inconsistent with the ambient west-directed current conditions, and may therefore be indicative of storm-driven currents. Numerous dissolution pits, ~5-50m in diameter, ~0.2-0.5 m deep with steep (0.1-0.5 gradient) walls, are present in the bare rock regions of most of the study area. These occasionally are floored by rippled, highly reflective (coarse) sediments. We interpret these pits as representing karstic morphology formed during the last sub-aerial exposure of the study area interpreted to have occurred during Holocene times given the present day ~17 m average water depth. A sub-surface reflector imaged on the surface tow boomer data lies 1-3 m below the hard seafloor reflection (sand ribbons are below the vertical resolution of the surface tow boomer), which we interpret as a layer within the limestone bedrock. This reflector is flat-lying and undisturbed throughout the

Seroprevalence of Dengue Antibodies in Three Urban Settings in Yucatan, Mexico.

PubMed

Pavía-Ruz, Norma; Diana Patricia Rojas; Salha Villanueva; Granja, Pilar; Balam-May, Angel; Longini, Ira M; Halloran, M Elizabeth; Manrique-Saide, Pablo; Gómez-Dantés, Hector

2018-04-01

Dengue transmission in Mexico has become a major public health problem. Few epidemiological studies have examined the seroprevalence of dengue in Mexico, and recent estimates are needed to better understand dengue transmission dynamics. We conducted a dengue seroprevalence survey among 1,668 individuals including all age groups in three urban settings in Yucatan, Mexico. Children (< 19 years old) were selected randomly from schools. The adults (≥ 19 years old) were selected from healthcare facilities. Participants were asked to provide a venous blood sample and to answer a brief questionnaire with demographic information. Previous exposure to dengue was determined using indirect immunoglobulin G enzyme-linked immunosorbent assay. The overall seroprevalence was 73.6%. The age-specific seroprevalence increased with age, going from 51.4% (95% confidence interval [CI] = 45.0-57.9%) in children ≤ 8 years to 72% (95% CI = 66.3-77.2%) in the 9- to 14-years old. The highest seroprevalence was 83.4% (95% CI = 77-82.2%) in adults greater than 50 years. The seroprevalence in Merida was 68.6% (95% CI = 65-72%), in Progreso 68.7% (95% CI = 64.2-72.8%), and in Ticul 85.3% (95% CI = 81.9-88.3%). Ticul had the highest seroprevalence in all age groups. Logistic regression analysis showed that age and city of residence were associated with greater risk of prior dengue exposure. The results highlight the level of past exposure to dengue virus including young children. Similar studies should be conducted elsewhere in Mexico and other endemic countries to better understand the transmission dynamics of dengue.

Impacts of geochemical and environmental factors on seasonal variation of heavy metals in a coastal lagoon Yucatan, Mexico.

PubMed

Arcega-Cabrera, F; Garza-Pérez, R; Noreña-Barroso, E; Oceguera-Vargas, I

2015-01-01

This study investigated the influence of geochemical and environmental factors on seasonal variation in metals in Yucatan's Chelem lagoon. Anthropogenic activities discharge non-treated wastewater directly into it with detrimental environmental consequences. Accordingly, this study established the spatial and temporal patterns of fine grain sediments and concentrations of heavy metals. Multivariate analyses showed fine grain facies deposition, transition sites dominated by fine grain transport, and fine grain erosion sites. Spatial and temporal variations of heavy metals concentration were significant for Cd, Cu, Cr, and Pb. As, Cd, and Sn were as much as 12 times higher than SQuiRTs standards (Buchman 2008). The results indicate that aquifer water is bringing metals from relatively far inland and releasing them into the lagoon. Thus, it appears that the contamination of this lagoon is highly complex and must take into account systemic connections with inland anthropogenic activates and pollution, as well as local factors.

Removal of organic matter and electricity generation of sediments from Progreso, Yucatan, Mexico, in a sediment microbial fuel cell.

PubMed

González-Gamboa, Nancy Karina; Valdés-Lozano, David Sergio; Barahona-Pérez, Luis Felipe; Alzate-Gaviria, Liliana; Domínguez-Maldonado, Jorge Arturo

2017-02-01

Sediment microbial fuel cells (SMFCs) are devices that generate electrical energy through sediments rich in organic matter (OM). The present study assessed the potential of sediments collected at two sites in Yucatan, Mexico, (the swamp of Progreso port and Yucalpetén dock) to be used in these electrochemical devices. Sediments were collected during the rainy and winter seasons and were monitored in the SMFC for 120 days through electrochemical and physicochemical characterization. OM removal in the SMFC ranged from 8.1-18.01%, generating a maximum current density of 232.46 mA/cm 2 and power density of 95.85 mW/cm 2 . SUVA analysis indicated that with a young soil, the ratio E4/E6 presented evidence directly related to the degradation of aromatic and aliphatic compound formation, implying humification and, therefore, sediment enrichment.

Antioxidant compounds, antioxidant activity and phenolic content in peel from three tropical fruits from Yucatan, Mexico.

PubMed

Moo-Huchin, Víctor M; Moo-Huchin, Mariela I; Estrada-León, Raciel J; Cuevas-Glory, Luis; Estrada-Mota, Iván A; Ortiz-Vázquez, Elizabeth; Betancur-Ancona, David; Sauri-Duch, Enrique

2015-01-01

The aim of this study was to determine the antioxidant compounds, antioxidant activity and content of individual phenolic compounds of freeze-dried peel from three tropical fruits grown in Yucatan, México: purple star apple (Chrysophyllum cainito L.), yellow cashew and red cashew (Anacardium occidentale). The freeze-dried peels were good source of antioxidant compounds. ABTS and DPPH values in the peel from each fruit were 3050.95-3322.31 μM Trolox/100g dry weight (DW) or 890.19-970.01 mg of vitamin C/100 g DW, and 1579.04-1680.90 μM Trolox/100 g DW or 340.18-362.18 mg of vitamin C/100 g DW, respectively. Six phenolic compounds were identified in the peel from the tropical fruits studied: ferulic, caffeic, sinapic, gallic, ellagic and myricetin. This study demonstrated that freeze-dried peels from purple star apple, yellow cashew and red cashew, could serve as potential sources of antioxidants for use in food and pharmaceutical industries. Copyright © 2014 Elsevier Ltd. All rights reserved.

Determination of some physicochemical characteristics, bioactive compounds and antioxidant activity of tropical fruits from Yucatan, Mexico.

PubMed

Moo-Huchin, Víctor M; Estrada-Mota, Iván; Estrada-León, Raciel; Cuevas-Glory, Luis; Ortiz-Vázquez, Elizabeth; Vargas y Vargas, María de Lourdes; Betancur-Ancona, David; Sauri-Duch, Enrique

2014-01-01

The aim to the study was to determine the physicochemical composition, bioactive compounds and antioxidant activity of fruits from Yucatan, Mexico such as star apple, cashew, mombin, mamey sapote, white sapote, sugar apple, sapodilla, dragon fruit, nance, ilama, custard apple, mamoncillo and black sapote. The physicochemical characteristics were different between fruits and were good sources of bioactive compounds. The edible part with the highest values of antioxidant activity were mamoncillo, star apple, mombin, cashew, white sapote, ilama, custard apple, sugar apple, and nance. Total soluble phenols content showed a correlation with antioxidant activity by ABTS (R=0.52, P⩽0.05) and DPPH (R=0.43, P⩽0.05). A high correlation was obtained between the two assays (ABTS and DPPH) used to measure antioxidant activity in the tropical fruit species under study (R=0.82, P⩽0.05). The results show promising perspectives for the exploitation and use of tropical fruits studied with significant levels of nutrients and antioxidant activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

High Frequency of Human Blood in Triatoma dimidiata Captured Inside Dwellings in a Rural Community in the Yucatan Peninsula, Mexico, but Low Antibody Seroprevalence and Electrocardiographic Findings Compatible with Chagas Disease in Humans

PubMed Central

Monteon, Victor; Alducin, César; Hernández, Jorge; Ramos-Ligonio, Angel; Lopez, Ruth

2013-01-01

We studied a small rural community of 411 inhabitants localized in the state of Campeche in the Yucatan Peninsula, Mexico. In 44 collected triatomines captured inside the houses, human feeding source was revealed in 23 of 44 (52%) samples, and chicken feeding source was revealed in 16 of 44 (36%) samples. In a set of 29 triatomines, mouse was the feeding source in 13 (44%) samples, and dog was the feeding source in 7 (24%) samples. Infection index with Trypanosoma cruzi in collected triatomines was 38%, and all parasites belonged to discrete type unit I. Inhabitants referred high contact with triatomine's bite in 60 of 128 (47%) samples, but seroprevalence was 2.3% (3/128). Evidence of electrocardiographic alteration compatible with Chagas disease was observed only in one asymptomatic seropositive subject. In conclusion, Triatoma dimidiata in this region are preferentially infected with T. cruzi I and feed on human beings with relative high frequency, but seroprevalence and Chagas disease in humans is relatively low. PMID:23296447

Porosity Gradient Development Around Karst Features due to Tidal Pumping in Eastern Yucatan Peninsula

NASA Astrophysics Data System (ADS)

Maqueda, A.; Renard, P.

2016-12-01

Water exchange between karst features and the porous matrix around them has been observed in karst aquifers by previous research. The exchange is driven by hydraulic head gradients caused by stormwater runoff or sea tides and may cause mineral dissolution. The authors of this work proposed a conceptual model of porosity development under tidal variations of hydraulic head is proposed. Simulations of reactive transport and porosity evolution were conducted to explore the porosity gradient development around a karst feature. Simulations account for petrophysical properties of porous media and groundwater geochemical characteristics. Data used in simulations corresponds to an eogenetic karst aquifer found on the eastern coast of Yucatan Peninsula in Mexico. Simulations include both analytical and numerical solutions of porosity increase caused by mineral dissolution. The estimated rate of porosity development and associated wall retreat (3-30 cm/100 yr) are large enough to develop karst cavities on time periods relevant to karst formation in the study area (10K yr). The analytical solution could be used to assess porosity increase in rock samples and can be also applied to model slow reactions in porous media under flow driven by sinusoidal hydraulic boundary conditions. The results show a possible alternative mechanism of karst cavity development in a high conductive limestone rock matrix aquifer.

Height Growth and Percentage of Body Fat in Relation to Early Menarche in Girls from Merida, Yucatan, Mexico.

PubMed

Datta Banik, Sudip; Mendez, Nina; Dickinson, Federico

2015-01-01

Early menarche (EM) (i.e., age at menarche [AAM] <12 years of age) is related to short height and higher body fatness. In a mixed-longitudinal study done in Merida, Yucatan, height, body mass index (BMI), and percentage of body fat (BF%) were recorded at a one-year interval among 258 postmenarcheal (EM = 94) girls. Anthropometric measurements were recorded of the age cohorts in 2008-09 when participants were 13-17 years of age (baseline), and in the one-year follow-up study (± 6 days) the girls were 14-18 years of age. The BF% was estimated through bioelectrical impedance analysis. Mean AAM was 10.59 years in EM girls and 12.54 years in not early menarche (NEM) girls. Height growth (cm/year) was greater in NEM girls. Mean values of BMI, BF%, and frequencies of stunting (low height-for-age) and excess weight (overweight + obesity) were higher in EM girls than in their NEM age peers.

Seroprevalence of Dengue Antibodies in Three Urban Settings in Yucatan, Mexico

PubMed Central

Pavía-Ruz, Norma; Diana Patricia Rojas; Salha Villanueva; Granja, Pilar; Balam-May, Angel; Longini, Ira M.; Halloran, M. Elizabeth; Manrique-Saide, Pablo; Gómez-Dantés, Hector

2018-01-01

Abstract. Dengue transmission in Mexico has become a major public health problem. Few epidemiological studies have examined the seroprevalence of dengue in Mexico, and recent estimates are needed to better understand dengue transmission dynamics. We conducted a dengue seroprevalence survey among 1,668 individuals including all age groups in three urban settings in Yucatan, Mexico. Children (< 19 years old) were selected randomly from schools. The adults (≥ 19 years old) were selected from healthcare facilities. Participants were asked to provide a venous blood sample and to answer a brief questionnaire with demographic information. Previous exposure to dengue was determined using indirect immunoglobulin G enzyme-linked immunosorbent assay. The overall seroprevalence was 73.6%. The age-specific seroprevalence increased with age, going from 51.4% (95% confidence interval [CI] = 45.0–57.9%) in children ≤ 8 years to 72% (95% CI = 66.3–77.2%) in the 9- to 14-years old. The highest seroprevalence was 83.4% (95% CI = 77–82.2%) in adults greater than 50 years. The seroprevalence in Merida was 68.6% (95% CI = 65–72%), in Progreso 68.7% (95% CI = 64.2–72.8%), and in Ticul 85.3% (95% CI = 81.9–88.3%). Ticul had the highest seroprevalence in all age groups. Logistic regression analysis showed that age and city of residence were associated with greater risk of prior dengue exposure. The results highlight the level of past exposure to dengue virus including young children. Similar studies should be conducted elsewhere in Mexico and other endemic countries to better understand the transmission dynamics of dengue. PMID:29460714

Metazoan parasite infracommunities of Florida pompano (Trachinotus carolinus) from the coast of the Yucatan Peninsula, Mexico.

PubMed

Sánchez-Ramírez, Claudia; Vidal-Martínez, Victor M

2002-12-01

Metazoan parasite infracommunities of the Florida pompano (Trachinotus carolinus) were studied in terms of species composition, species richness, diversity, numerical dominance, and similarity. Seventy-five fishes were collected from 4 localities along the Yucatan Peninsula coast and 24 parasite species recovered. Most were digeneans (8 species) and nematodes (7). Other species were monogeneans (3). aspidogastreans (2), cestodes (1), acanthocephalans (1), and crustaceans (2). Only 4 species were common in at least I locality. Mean values for species richness, abundance, diversity, numerical dominance, and similarity in total (all species in the individual fish), gastrointestinal, and ectoparasite infracommunities were within ranges observed for most helminth infracommunities of marine fishes from temperate and tropical latitudes. These infracommunities had low species richness, abundance, diversity, and predictability (except ectoparasite infracommunities) and high dominance. Within the predictable element (common species), the specialist monogenean Pseudobicotylophora atlantica was the main reason for the increase in predictability because it was the only common species at all 4 localities. Host feeding habits, the distribution of intermediate hosts and infective stages, the local species pool, and a phylogenetic component seem to be determining the characteristics of these metazoan parasite infracommunities.

Bioarchaeological investigation of ancient Maya violence and warfare in inland Northwest Yucatan, Mexico.

PubMed

Serafin, Stanley; Lope, Carlos Peraza; Uc González, Eunice

2014-05-01

This study investigates evidence of changes and continuities in ancient Maya violence and warfare in inland northwest Yucatan, Mexico from the Middle Preclassic (600-300 BC) to the Postclassic (AD 1050-1542) through bioarchaeological analysis of cranial and projectile trauma. It is hypothesized that the frequency of violence increases before the Classic Maya collapse and remains high during the Postclassic period. It is also hypothesized that the flat, open terrain was conducive to warfare and resulted in higher trauma frequencies than in other parts of the Maya area. Results show that the frequency of cranial trauma decreases before the Classic collapse and increases in the Postclassic, partially matching the expected chronological trends. The frequency of cranial trauma does not differ significantly from other Maya regions but the pattern does: for all periods, males have more healed injuries than females and they are concentrated on the left side of the anterior of the skull. Some injuries appear to be from small points hafted in wooden clubs. In addition, projectile trauma is evident in a scapula with an embedded arrowhead tip, the first such case reported in a Maya skeleton. Overall, these results suggest greater reliance on open combat and less on raids in this region compared with other parts of the Maya area, possibly due to the flat, open terrain, though the identification of perimortem trauma in both women and men indicates surprise raids on settlements were also practiced. Copyright © 2014 Wiley Periodicals, Inc.

Age and tectonic implications of some low-grade metamorphic rocks from the Yucatan Channel

USGS Publications Warehouse

Vedder, J.G.; MacLeod, N.S.; Lanphere, M.A.; Dillon, William P.

1973-01-01

Phyllite and marble dredged from the lower part of the continental slope between Cuba and the Yucatan Peninsula seem to support the contention that a pre-early Tertiary metamorphic belt extends from the western Greater Antilles into northern Central America. The minimum K-Ar ages derived from the samples suggest that the metamorphic event was pre-Late Cretaceous, and evaluation of the K-Ar data implies that this metamorphic event is not older than Late Jurassic. Greater antiquity, however, is inferred from structural and stratigraphic relations in British Honduras, where the latest regional metamorphic event was post-Early Permian and pre-Middle Jurassic.  Rifting and extension related to plate motions along the British Honduras Quintana Roo margin through Mesozoic and earliest Cenozoic time presumably would preclude extensive regional metamorphism, permitting only limited development of schistose rocks there during that interval. The timing of metamorphic events in western Cuba is uncertain, but a pre-Middle Jurassic episode possibly is reflected in the phyllite and marble terranes of Isla de Pinos and Sierra de Trinidad. Local incipient metamorphism of Early and Middle Jurassic strata in the Sierra de los Organos may have resulted from severe tectonism that began in Late Cretaceous time and diminished in the Eocene.

Two new species of dicyemid mesozoans (Dicyemida: Dicyemidae) from Octopus maya Voss & Solis-Ramirez (Octopodidae) off Yucatan, Mexico.

PubMed

Castellanos-Martinez, Sheila; Aguirre-Macedo, M Leopoldina; Furuya, Hidetaka

2016-07-01

Two new dicyemid species are described from the endemic cephalopod Octopus maya Voss & Solis-Ramirez collected off Yucatan, Mexico. The renal sacs of 40 juvenile and adult octopuses from four localities were examined. Dicyema hochbergi n. sp. is a medium-sized species that reaches 2,245 µm in length. The vermiform stages consist of 18-24 peripheral cells, a conical calotte and the extension of the axial cell between the base and middle of the metapolar cells. Infusoriform embryos consist of 39 cells with urn cell containing one germinal cell, two nuclei and solid refringent bodies. Dicyema mexcayae n. sp. is a relatively small species that reaches 1,114 µm in length. The vermiform stages are constituted by 14-16 peripheral cells, an elongate calotte and the axial cell extending forward to the middle of the metapolar cells. The infusoriform embryos consist of 37 cells, two solid refringent bodies and urn cells with two nuclei each. The present study represents the first description of a dicyemid species from O. maya and increases the number of described species from Mexican waters to 11.

Use of Amynthas gracilis (Oligochaeta, Megascolecidae) and Bougainvillea litter for rehabilitation of overexploited soils, in Campeche, Yucatan Peninsula, Mexico.

NASA Astrophysics Data System (ADS)

Huerta, Esperanza; Alonso Gongora, Erick

2014-05-01

Yucatan peninsula is one of the recent emerged lands in Mexico; where more of the soils have low organic matter content, and/or the organic horizon is thin (2-5cm). The industry of material extraction for construction purposes is well developed in Yucatan Peninsula, due to the fact of the calcareous material that can be obtained by the maternal rock. Therefore, the material extraction promotes the desertification of the areas, and soil erosion. Bougainvillea sp is a tropical and subtropical woody, evergreen, shrubby vine (Kobayashi et al. 2007), it has a wide range of distribution and it roots are superficial, what allows the plant to inhabit soils with a thin layer of soil organic matter. Earthworms as ecosystem engineers (Jones et al. 1994) can modify their environment, forming borrows and incorporation organic matter into the soil. The aim of this study was to rehabilitate soils without organic matter horizon by the use of earthworms and Bougainvillea litter. The study was developed at mesocosmos level in the laboratory of soils at El Colegio de la Frontera Sur, Unidad Campeche, Mexico. Individual of anecic earthworms were collected and reproduced previously, anecic worms can better incorporate organic matter in to the soil than epigeics or endogeics worms, in Mexican tropical terrestrial ecosystems, anecic worms are almost absent or scarce. In this study we used the exotic earthworm Amynthas gracilis (native in Taiwan),that used to inhabit banana plantations with low technology in southeast Mexico, as exotic has a wide range of tolerance to different amounts of soil organic matter and pH. Four treatments with 4 replicas were established: a) calcareous soil without organic matter horizon+earthworms+litter, b) calcareous soil with organic matter horizon+ earthworms+litter, c) calcareous soil without organic matter horizon+litter, d) calcareous soil with organic matter horizon+litter. After 60 days of study, we observed how earthworms developed successfully in

Water Consumption as Source of Arsenic, Chromium, and Mercury in Children Living in Rural Yucatan, Mexico: Blood and Urine Levels.

PubMed

Arcega-Cabrera, F; Fargher, L F; Oceguera-Vargas, I; Noreña-Barroso, E; Yánez-Estrada, L; Alvarado, J; González, L; Moo-Puc, R; Pérez-Herrera, N; Quesadas-Rojas, M; Pérez-Medina, S

2017-10-01

Studies investigating the correlation between metal content in water and metal levels in children are scarce worldwide, but especially in developing nations. Therefore, this study investigates the correlation between arsenic, chromium, and mercury concentrations in drinking and cooking water and in blood and urine samples collected from healthy and supposedly non-exposed children from a rural area in Yucatan, Mexico. Mercury in water shows concentrations above the recommended World Health Organization (WHO) value for drinking and cooking water. Also, 25% of the children show mercury in urine above the WHO recommended value. Multivariate analyses show a significant role for drinking and cooking water as a vector of exposure in children. Also, the factor analysis shows chronic exposure in the case of arsenic, as well as an ongoing detoxification process through urine in the case of mercury. Further studies should be done in order to determine other potential metal exposure pathways among children.

Eco-bio-social determinants for house infestation by non-domiciliated Triatoma dimidiata in the Yucatan Peninsula, Mexico.

PubMed

Dumonteil, Eric; Nouvellet, Pierre; Rosecrans, Kathryn; Ramirez-Sierra, Maria Jesus; Gamboa-León, Rubi; Cruz-Chan, Vladimir; Rosado-Vallado, Miguel; Gourbière, Sébastien

2013-01-01

Chagas disease is a vector-borne disease of major importance in the Americas. Disease prevention is mostly limited to vector control. Integrated interventions targeting ecological, biological and social determinants of vector-borne diseases are increasingly used for improved control. We investigated key factors associated with transient house infestation by T. dimidiata in rural villages in Yucatan, Mexico, using a mixed modeling approach based on initial null-hypothesis testing followed by multimodel inference and averaging on data from 308 houses from three villages. We found that the presence of dogs, chickens and potential refuges, such as rock piles, in the peridomicile as well as the proximity of houses to vegetation at the periphery of the village and to public light sources are major risk factors for infestation. These factors explain most of the intra-village variations in infestation. These results underline a process of infestation distinct from that of domiciliated triatomines and may be used for risk stratification of houses for both vector surveillance and control. Combined integrated vector interventions, informed by an Ecohealth perspective, should aim at targeting several of these factors to effectively reduce infestation and provide sustainable vector control.

Eco-Bio-Social Determinants for House Infestation by Non-domiciliated Triatoma dimidiata in the Yucatan Peninsula, Mexico

PubMed Central

Dumonteil, Eric; Nouvellet, Pierre; Rosecrans, Kathryn; Ramirez-Sierra, Maria Jesus; Gamboa-León, Rubi; Cruz-Chan, Vladimir; Rosado-Vallado, Miguel; Gourbière, Sébastien

2013-01-01

Background Chagas disease is a vector-borne disease of major importance in the Americas. Disease prevention is mostly limited to vector control. Integrated interventions targeting ecological, biological and social determinants of vector-borne diseases are increasingly used for improved control. Methodology/principal findings We investigated key factors associated with transient house infestation by T. dimidiata in rural villages in Yucatan, Mexico, using a mixed modeling approach based on initial null-hypothesis testing followed by multimodel inference and averaging on data from 308 houses from three villages. We found that the presence of dogs, chickens and potential refuges, such as rock piles, in the peridomicile as well as the proximity of houses to vegetation at the periphery of the village and to public light sources are major risk factors for infestation. These factors explain most of the intra-village variations in infestation. Conclusions/significance These results underline a process of infestation distinct from that of domiciliated triatomines and may be used for risk stratification of houses for both vector surveillance and control. Combined integrated vector interventions, informed by an Ecohealth perspective, should aim at targeting several of these factors to effectively reduce infestation and provide sustainable vector control. PMID:24086790

Fish community structure and dynamics in a coastal hypersaline lagoon: Rio Lagartos, Yucatan, Mexico

NASA Astrophysics Data System (ADS)

Vega-Cendejas, Ma. Eugenia; Hernández de Santillana, Mireya

2004-06-01

Rio Lagartos, a tropical coastal lagoon in northern Yucatan Peninsula of Mexico, is characterized by high salinity during most of the year (55 psu annual average). Even though the area has been designated as a wetland of international importance because of its great biodiversity, fish species composition and distribution are unknown. To determine whether the salinity gradient was influencing fish assemblages or not, fish populations were sampled seasonally by seine and trawl from 1992 to 1993 and bimonthly during 1997. We identified 81 fish species, eight of which accounted for 53.1% considering the Importance Value Index ( Floridichthys polyommus, Sphoeroides testudineus, Eucinostomus argenteus, Eucinostomus gula, Fundulus majalis, Strongylura notata, Cyprinodon artifrons and Elops saurus). Species richness and density declined from the mouth to the inner zone where extreme salinity conditions are prominent (>80) and competitive interactions decreased. However, in Coloradas basin (53 average sanity) and in the inlet of the lagoon, the highest fish density and number of species were observed. Greater habitat heterogeneity and fish immigration were considered as the best explanation. Multivariate analysis found three zones distinguished by fish occurrence, abundance and distribution. Ichthyofaunal spatial differences were attributed to selective recruitment from the Gulf of Mexico due to salinity gradient and to changing climatic periods. Estuarine and euryhaline marine species are abundant, with estuarine dependent ones entering the system according to environmental preferences. This knowledge will contribute to the management of the Special Biosphere Reserve through baseline data to evaluate environmental and anthropogenic changes.

An 8700 Year Record of Holocene Climate Variability from the Yucatan Peninsula

NASA Astrophysics Data System (ADS)

Wahl, D.; Byrne, R.; Anderson, L.

2013-12-01

Our understanding of Holocene climate change in the Maya lowlands of Central America has improved significantly during the last several decades thanks to the development of proxy climate records from lake cores and speleothems. One important finding is that longer-term climate changes (i.e., millennial scale) were driven primarily by precessional forcing; less clear, however, are the causes of abrupt shifts and higher frequency (centennial to decadal) change recognized in many Holocene climate reconstructions. The mechanisms driving climate change on these time scales have been difficult to identify in the region, in part because the Yucatan peninsula is influenced by climatic conditions linked to both the tropical Atlantic and Pacific oceans. Additional complications arise from the development of dense human populations following the initial introduction of agriculture ~5000 cal yr BP, which had significant impact on the environment as a whole. Here we present the results of analyses (stable isotope, pollen, magnetic susceptibility, and physical properties) of a 7.25 m sediment core from Lago Puerto Arturo, a closed basin lake in the northern Peten, Guatemala. An age-depth model, based on 6 AMS radiocarbon determinations and created using CLAM, indicates the record extends to 8700 cal yr BP. Proxy data suggest that, similar to other low latitude sites, millennial scale climate at Lago Puerto Arturo was driven by changes in insolation. Higher frequency variability is associated with El Niño/Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO) dynamics, reflecting latitudinal shifts in the Intertropical Convergence Zone in both the tropical North Atlantic and North Pacific. Solar forcing may also play a role in short-term climate change. The pollen and isotope records show that the entire period of prehispanic settlement and agricultural activity, i.e. ~5000-1000 cal yr B.P., was characterized by relatively dry conditions compared to before or after.

CHICKEN COOPS, Triatoma dimidiata INFESTATION AND ITS INFECTION WITH Trypanosoma cruzi IN A RURAL VILLAGE OF YUCATAN, MEXICO.

PubMed

Koyoc-Cardeña, Edgar; Medina-Barreiro, Anuar; Escobedo-Ortegón, Francisco Javier; Rodríguez-Buenfil, Jorge Carlos; Barrera-Pérez, Mario; Reyes-Novelo, Enrique; Chablé-Santos, Juan; Selem-Salas, Celia; Vazquez-Prokopec, Gonzalo; Manrique-Saide, Pablo

2015-01-01

This study longitudinally investigated the association between Triatoma dimidiata infestation, triatomine infection with Trypanosoma cruzi and household/backyard environmental characteristics in 101 homesteads in Molas and Yucatan, Mexico, between November 2009 (rainy season) and May 2010 (dry season). Logistic regression models tested the associations between insect infestation/infection and potential household-level risk factors. A total of 200 T. dimidiata were collected from 35.6% of the homesteads, mostly (73%) from the peridomicile. Of all the insects collected, 48% were infected with T. cruzi. Infected insects were collected in 31.6% of the homesteads (54.1% and 45.9% intra- and peridomiciliary, respectively). Approximately 30% of all triatomines collected were found in chicken coops. The presence of a chicken coop in the backyard of a homestead was significantly associated with both the odds of finding T. dimidiata (OR = 4.10, CI 95% = 1.61-10.43, p = 0.003) and the presence of triatomines infected with T. cruzi (OR = 3.37, CI 95% = 1.36-8.33, p = 0.006). The results of this study emphasize the relevance of chicken coops as a putative source of T. dimidiata populations and a potential risk for T. cruzi transmission.

CHICKEN COOPS, Triatoma dimidiata INFESTATION AND ITS INFECTION WITH Trypanosoma cruzi IN A RURAL VILLAGE OF YUCATAN, MEXICO

PubMed Central

KOYOC-CARDEÑA, Edgar; MEDINA-BARREIRO, Anuar; ESCOBEDO-ORTEGÓN, Francisco Javier; RODRÍGUEZ-BUENFIL, Jorge Carlos; BARRERA-PÉREZ, Mario; REYES-NOVELO, Enrique; CHABLÉ-SANTOS, Juan; SELEM-SALAS, Celia; VAZQUEZ-PROKOPEC, Gonzalo; MANRIQUE-SAIDE, Pablo

2015-01-01

This study longitudinally investigated the association between Triatoma dimidiata infestation, triatomine infection with Trypanosoma cruzi and household/backyard environmental characteristics in 101 homesteads in Molas and Yucatan, Mexico, between November 2009 (rainy season) and May 2010 (dry season). Logistic regression models tested the associations between insect infestation/infection and potential household-level risk factors. A total of 200 T. dimidiata were collected from 35.6% of the homesteads, mostly (73%) from the peridomicile. Of all the insects collected, 48% were infected with T. cruzi. Infected insects were collected in 31.6% of the homesteads (54.1% and 45.9% intra- and peridomiciliary, respectively). Approximately 30% of all triatomines collected were found in chicken coops. The presence of a chicken coop in the backyard of a homestead was significantly associated with both the odds of finding T. dimidiata (OR = 4.10, CI 95% = 1.61-10.43, p = 0.003) and the presence of triatomines infected with T. cruzi (OR = 3.37, CI 95% = 1.36-8.33, p = 0.006). The results of this study emphasize the relevance of chicken coops as a putative source of T. dimidiata populations and a potential risk for T. cruzi transmission. PMID:26200970

[Susceptibility and insecticide resistance mechanisms in Anopheles albimanus from the southern Yucatan Peninsula, Mexico].

PubMed

Dzul, Felipe A; Patricia Penilla, R; Rodríguez, Américo D

2007-01-01

To diagnose susceptibility levels and insecticide resistance mechanisms in Anopheles albimanus from the southern Yucatan Peninsula (YP), Mexico. F1 generation of An. albimanus females, collected from November to December 2005 in six villages in the Othon P. Blanco municipality in Quintana Roo and the Calakmul municipality in Campeche, were exposed to deltamethrin, DDT, pirimiphos-methyl and bendiocarb in susceptibility tests, as well as to biochemical assays in order to calculate the enzyme levels related to insecticide resistance. High levels of DDT and deltamethrin resistance were found in An. albimanus collected from the six villages, and a high resistance to pirimiphos-methyl was found in those from La Union, Quintana Roo. Biochemical assays showed high levels of glutathione S-transferase (GST), cytochrome P450 and esterases (with pNPA substrate) in all villages. The frequency of An. albimanus with altered acetylcholinesterase (AChE) was high in La Union (33%). The An. albimanus populations collected in the south of the YP are resistant to DDT and deltamethrin, whereas resistance to pirimiphos-methyl was significant only in those collected from La Union. The mechanisms explaining this resistance are based on high concentrations of GST, cytochrome P450 and esterasas, the former being responsible for DDT metabolism and the others for pyrethroid metabolism. The altered AChE was the mechanism correlated to pirimiphos-methyl resistance in La Union. The results of the present study have important practical consequences for the chemical control of An. albimanus in the south of the YP.

Diving behavior and fishing performance: the case of lobster artisanal fishermen of the Yucatan coast, Mexico.

PubMed

Huchim-Lara, Oswaldo; Salas, Silvia; Chin, Walter; Montero, Jorge; Fraga, Julia

2015-01-01

An average of 209 cases of decompression sickness (DCS) have been reported every year among artisanal fishermen. divers of the Yucatan Peninsula, Mexico. DCS is a major problem among fishermen divers worldwide. This paper explores how diving behavior and fishing techniques among fishermen relate to the probability of experiencing DCS (Pdcs). Fieldwork was conducted in two communities during the 2012-2013 fishing season. Fishermen were classified into three groups (two per group) according to their fishing performance and followed during their journeys. Dive profiles were recorded using Sensus Ultra dive recorders (Reefet Inc.). Surveys were used to record fishing yields from cooperative and individual fishermen along with fishing techniques and dive behavior. 120 dives were recorded. Fishermen averaged three dives/day, with an average depth of 47 ± 2 feet of sea water (fsw) and an average total bottom time (TBT) of 95 ± 11 minutes. 24% of dives exceeded the 2008 U.S. Navy no-decompression limit. The average ascent rate was 20 fsw/minute, and 5% of those exceeded 40 fsw/minute. Inadequate decompression was observed in all fishermen. Fishermen are diving outside the safety limits of both military and recreational standards. Fishing techniques and dive behavior were important factors in Pdcs. Fishermen were reluctant to seek treatment, and symptoms were relieved with analgesics.

Adsorption of organophosphorus pesticides in tropical soils: The case of karst landscape of northwestern Yucatan.

PubMed

Alfonso, Lorenzo-Flores; Germán, Giácoman Vallejos; María Del Carmen, Ponce Caballero; Hossein, Ghoveisi

2017-01-01

This article discusses the adsorption of four organophosphorus pesticides-diazinon, dimethoate, methyl parathion, and sulfotep-in soil samples from four sites-Komchén, Xcanatún, Chablekal and Mocochá- in the northwest of Yucatan, Mexico. These pesticides have been detected in groundwater at concentrations greater than 5 (μg/L) during recent monitoring campaigns in the study area. In this region, groundwater contamination is exacerbated by its karst aquifer, which is susceptible to contamination and is considered very vulnerable. The experimental work was carried out using the batch equilibrium technique. Pesticide analyses by solid-phase extraction and gas chromatography were performed. The equilibrium adsorption data were analyzed by Henry, Langmuir and Freundlich models. The results indicate that the Freundlich model provides the best correlation of the experimental data. Freundlich adsorption coefficients K f were in the range of 1.62-2.35 for sulfotep, 2.43 to 3.25 for dimethoate, from 5.54 to 9.27 for methyl parathion, and 3.22 to 5.17 for diazinon. Freundlich adsorption coefficients were normalized to the content of organic carbon in the soil to estimate the sorption coefficient of organic carbon (K OC ). K OC values were in the range of 9.45-71.80, indicated that four pesticides have low adsorption on the four studied soils, which represents a high risk of contamination to the aquifer. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ecohydrology of the coastal wetlands of Yucatan Peninsula are related with the submarine groundwater discharges?

NASA Astrophysics Data System (ADS)

Herrera Silveira, J. A.; Morales-Ojeda, S. M.; Medina Gomez, I.; Kantun Manzano, C.; Caamal Sosa, J.; Marino-Tapia, I.; Adame, F.; Teutli Hernandez, C.

2013-05-01

Submarine groundwater discharge (SGD) contributes significantly in the structure and function of coastal ecosystems favoring nutrients and salinity gradients, and with these spatial variability of wetland types and rates of primary production. However, the connectivity between SGD and coastal wetlands remains largely unexplored, especially in the tropics and karstic regions. On the other hand, coastal wetlands could represents exceptionally large carbon (C) stocks, whose protection and restoration can constitute an effective mitigation strategy for climate change. The Yucatán Peninsula is a low-relief carbonate platform and karst geology that permits fast rainfall infiltration, minimal surface flow, and high SGD., which is characterized by a continuum of freshwater wetland, mangroves, seagrasses meadows and coral reefs. Our studies around the Yucatan coastal wetlands related with the ecohydrology, suggest strong connectivity between SGD and mangrove and seagrasses structure and function. Some of the results indicate that SGD are the main source of nitrate and silicate favoring salinity gradient along the coastal lagoons and bays like estuaries. Mangrove forests show the best structural developments where a spring of groundwater is located, these types of mangroves are called locally "petenes" and show large C stocks. Respect to seagrasses, high shoots density has been observed at sites characterized by low salinity and peak nutrients concentration. Further research on groundwater flows among human activities on inland activities, coastal wetlands and marine ecosystems are required in order to develop management strategies for mitigation and adaptation to global climate change

A maternal Western diet during gestation and lactation modifies offspring's microbiota activity, blood lipid levels, cognitive responses, and hippocampal neurogenesis in Yucatan pigs.

PubMed

Val-Laillet, David; Besson, Marie; Guérin, Sylvie; Coquery, Nicolas; Randuineau, Gwénaëlle; Kanzari, Ameni; Quesnel, Hélène; Bonhomme, Nathalie; Bolhuis, J Elizabeth; Kemp, Bas; Blat, Sophie; Le Huërou-Luron, Isabelle; Clouard, Caroline

2017-05-01

A suboptimal early nutritional environment ( i.e., excess of energy, sugar, and fat intake) can increase susceptibility to diseases and neurocognitive disorders. The purpose of this study was to investigate in nonobese Yucatan minipigs ( Sus scrofa ) the impact of maternal diet [standard diet (SD) vs. Western diet (WD)] during gestation and 25 d of lactation on milk composition, blood metabolism, and microbiota activity of sows ( n = 17) and their piglets ( n = 65), and on spatial cognition ( n = 51), hippocampal plasticity ( n = 17), and food preferences/motivation ( n = 51) in the progeny. Milk dry matter and lipid content, as well as plasma total cholesterol and free fatty acid (FFA) concentrations ( P < 0.05) were higher in WD than in SD sows. Microbiota activity decreased in both WD sows and 100-d-old piglets ( P < 0.05 or P < 0.10, depending on short-chain FAs [SCFAs]). At weaning [postnatal day (PND) 25], WD piglets had increased blood triglyceride and FFA levels ( P < 0.01). Both SD and WD piglets consumed more of a known SD than an unknown high-fat and -sucrose (HFS) diet ( P < 0.0001), but were quicker to obtain HFS rewards compared with SD rewards ( P < 0.01). WD piglets had higher working memory ( P = 0.015) and reference memory ( P < 0.001) scores, which may reflect better cognitive abilities in the task context and a higher motivation for the food rewards. WD piglets had a smaller hippocampal granular cell layer ( P = 0.03) and decreased neurogenesis ( P < 0.005), but increased cell proliferation ( P < 0.001). A maternal WD during gestation and lactation, even in the absence of obesity, has significant consequences for piglets' blood lipid levels, microbiota activity, gut-brain axis, and neurocognitive abilities after weaning.-Val-Laillet, D., Besson, M., Guérin, S., Coquery, N., Randuineau, G., Kanzari, A., Quesnel, H., Bonhomme, N., Bolhuis, J. E., Kemp, B., Blat, S., Le Huërou-Luron, I., Clouard, C. A maternal Western diet during gestation and

A new genus of speleophriid copepod (Copepoda: Misophrioida) from a cenote in the Yucatan, Mexico with a phylogenetic analysis at the species level.

PubMed

Boxshall, Geoff A; Zylinski, Sarah; Jaume, Damià; Iliffe, Thomas M; Suárez-Morales, Eduardo

2014-06-23

A new genus and species of speleophriid copepod, Mexicophria cenoticola gen. et sp. nov., is described based on material collected from a cenote in the Yucatan Peninsula of Mexico. It is characterised by relatively reduced fifth legs that are located adjacent to the ventral midline in both sexes, by the possession of a bulbous swelling on the first antennulary segment in both sexes, and by the reduced setation of the swimming legs. The presence of just one inner margin seta on the second endopodal segment of legs 2 to 4 is a unique feature for the family. A phylogenetic analysis places the new genus on a basal lineage of the family together with its sister taxon, Boxshallia Huys, 1988, from Lanzarote in the Canary Islands, and recovers the existing genera as monophyletic units. The zoogeography is discussed at local, regional, ocean basin  and global scales.

[Post-surgical morbidity in paediatric patients undergoing surgery for congenital heart disease in the UMAE of Yucatan, Mexico].

PubMed

Castillo-Espínola, Addy; Velázquez-Ibarra, Ana; Zetina-Solórzano, Aurea; Bolado-García, Patricia; Gamboa-López, Gonzalo

To describe the clinical course of paediatric patients undergoing surgery for congenital heart disease in UMAE of Yucatan. Descriptive review was performed on the records of paediatric patients undergoing surgery for congenital heart disease from 1 November 2011 to 30 November 2013. The most frequent heart diseases were persistent ductus arteriosus (37.6%) and transposition of the great vessels. The median intensive care stay was 3 days. Mortality was 11.76%, with septic shock (44.4%) in most cases. The most frequent complications were sepsis (5.9%), low cardiac output syndrome (4.7%), cardiac arrest, and AV block and ventricular tachycardia (2.4% each). There was a moderate positive correlation between surgical complications and survival or death. The number of surgical patients is lower compared to reference centres for cardiovascular surgery. There is a marked tendency to perform corrective and palliative surgeries in specific disease in patients with added risk or 'bad' cardiac anatomy that prevent full correction at the first attempt. Prospective epidemiological and clinical studies should be conducted to understand the behaviour of congenital heart diseases treated in the region. Copyright © 2016 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

A dataset on the species composition of amphipods (Crustacea) in a Mexican marine national park: Alacranes Reef, Yucatan

PubMed Central

Simões, Nuno; Pech, Daniel

2018-01-01

Abstract Background Alacranes Reef was declared as a National Marine Park in 1994. Since then, many efforts have been made to inventory its biodiversity. However, groups such as amphipods have been underestimated or not considered when benthic invertebrates were inventoried. Here we present a dataset that contributes to the knowledge of benthic amphipods (Crustacea, Peracarida) from the inner lagoon habitats from the Alacranes Reef National Park, the largest coral reef ecosystem in the Gulf of Mexico. The dataset contains information on records collected from 2009 to 2011. Data are available through Global Biodiversity Information Facility (GBIF). New information A total of 110 amphipod species distributed in 93 nominal species and 17 generic species, belonging to 71 genera, 33 families and three suborders are presented here. This information represents the first online dataset of amphipods from the Alacranes Reef National Park. The biological material is currently deposited in the crustacean collection from the regional unit of the National Autonomous University of Mexico located at Sisal, Yucatan, Mexico (UAS-Sisal). The biological material includes 588 data records with a total abundance of 6,551 organisms. The species inventory represents, until now, the richest fauna of benthic amphipods registered from any discrete coral reef ecosystem in Mexico. PMID:29416428

A dataset on the species composition of amphipods (Crustacea) in a Mexican marine national park: Alacranes Reef, Yucatan.

PubMed

Paz-Ríos, Carlos E; Simões, Nuno; Pech, Daniel

2018-01-01

Alacranes Reef was declared as a National Marine Park in 1994. Since then, many efforts have been made to inventory its biodiversity. However, groups such as amphipods have been underestimated or not considered when benthic invertebrates were inventoried. Here we present a dataset that contributes to the knowledge of benthic amphipods (Crustacea, Peracarida) from the inner lagoon habitats from the Alacranes Reef National Park, the largest coral reef ecosystem in the Gulf of Mexico. The dataset contains information on records collected from 2009 to 2011. Data are available through Global Biodiversity Information Facility (GBIF). A total of 110 amphipod species distributed in 93 nominal species and 17 generic species, belonging to 71 genera, 33 families and three suborders are presented here. This information represents the first online dataset of amphipods from the Alacranes Reef National Park. The biological material is currently deposited in the crustacean collection from the regional unit of the National Autonomous University of Mexico located at Sisal, Yucatan, Mexico (UAS-Sisal). The biological material includes 588 data records with a total abundance of 6,551 organisms. The species inventory represents, until now, the richest fauna of benthic amphipods registered from any discrete coral reef ecosystem in Mexico.

Shift from ecosystem P to N limitation at precipitation gradient in tropical dry forests at Yucatan, Mexico

NASA Astrophysics Data System (ADS)

Campo, Julio

2016-09-01

The effect of precipitation regime on N and P cycles in tropical forests is poorly understood, despite global climate models project total precipitation reductions during the 21st Century. I investigated the influence of variation in annual precipitation (1240-642 mm yr-1) on N and P intra-system cycling along a precipitation regime gradient at Yucatan including 12 mature, tropical dry forests (TDFs) growing under otherwise similar conditions (similar annual temperature, rainfall seasonality and geological substrate). I analyzed N and P storage and turnover in the forest floor and mineral soil and explored the dependence of these processes and pools on precipitation level. The study findings indicate that with decreasing precipitation the litterfall decreases slightly (10%), while nutrient use efficiency increases by 20% for N, and by 40% for P. Decomposition rate and nutrient release was smallest in the dry extremity of precipitation regime. The difference between N and P turnover times in the forest floor and in organic matter indicates that different nutrients control the ecosystem function across the precipitation gradient. The data from this study reveals a pattern of limitation shifting from P towards N with decreasing annual precipitation. I suggest that the long-term consequences of the expected decrease in precipitation in many tropical dry regions would changes N and P supply could have long-term negative effects on primary productivity and future carbon storage in TDFs.

Obesity induced during sexual maturation is linked to LDL-triacylglycerols in Yucatan miniature swine.

PubMed

Sébert, Sylvain P; Lecannu, Gérard; Sené, Sandrine; Hucteau, Séverine; Chetiveaux, Maud; Ouguerram, Khadija; Champ, Martine M-J

2005-08-01

The incidence of childhood obesity is rising dramatically throughout industrialised countries. To evaluate and study the impact of childhood obesity on lipoprotein metabolism, we developed a new animal model of premature obesity. Yucatan mini-pigs aged 4 months were studied over a 12-month period from childhood to adulthood. Animals were divided into two groups: the first group were overfed a Western misbalanced diet; the second group were normally fed a recommended human-type diet. Cholesterol and triacylglycerol concentrations in VLDL-, LDL- and HDL-lipoproteins were followed from baseline to adulthood by fast protein liquid chromatography. At 10 (the end of sexual maturation) and 16 months old (adulthood), liver, visceral and subcutaneous adipose tissues were sampled. Real-time RT-PCR was performed in order to compare apo AI, apo B, apo C-III, PPAR-alpha, insulin receptor and lipoprotein lipase gene expression between groups and ages. Differences between groups were observed only after sexual maturity. Adult overfed mini-pigs had a higher LDL-cholesterol:HDL-cholesterol ratio (P < 0.05; 0.55 (SE 0.06) for overfed v. 0.42 (SE 0.04) for normally fed pigs at the tenth month of the study). In both groups, VLDL-triacylglycerol decreased (P < 0.05). VLDL-triacylglycerol evolution in the overfed group was associated with an increase in LDL-triacylglycerol plasma concentrations (P < 0.05) after sexual maturation. LDL-triacylglycerol concentration in overfed mini-pigs went from an average of 0.28 mmol/l before sexual maturation to reach an average concentration of 0.56 mmol/l afterwards. This phenomenon has never been observed in similar studies when obesity is induced in adult mini-pigs and may represent a specific hallmark of an obesity induced during sexual maturity.

The Africanization of honeybees (Apis mellifera L.) of the Yucatan: a study of a massive hybridization event across time.

PubMed

Clarke, Kylea E; Rinderer, Thomas E; Franck, Pierre; Quezada-Euán, Javier G; Oldroyd, Benjamin P

2002-07-01

Until recently, African and European subspecies of the honeybee (Apis mellifera L.) had been geographically separated for around 10,000 years. However, human-assisted introductions have caused the mixing of large populations of African and European subspecies in South and Central America, permitting an unprecedented opportunity to study a large-scale hybridization event using molecular analyses. We obtained reference populations from Europe, Africa, and South America and used these to provide baseline information for a microsatellite and mitochondrial analysis of the process of Africanization of the bees of the Yucatan Peninsula, Mexico. The genetic structure of the Yucatecan population has changed dramatically over time. The pre-Africanized Yucatecan population (1985) comprised bees that were most similar to samples from southeastern Europe and northern and western Europe. Three years after the arrival of Africanized bees (1989), substantial paternal gene flow had occurred from feral Africanized drones into the resident European population, but maternal gene flow from the invading Africanized population into the local population was negligible. However by 1998, there was a radical shift with both African nuclear alleles (65%) and African-derived mitochondria (61%) dominating the genomes of domestic colonies. We suggest that although European mitochondria may eventually be driven to extinction in the feral population, stable introgression of European nuclear alleles has occurred.

Spinal Cord Swelling and Alterations in Hydrostatic Pressure After Acute Injury

DTIC Science & Technology

2017-10-01

finalized and reported on the metabolite responses data over a 7-day period with or without duraplasty surgery. Eight female Yucatan pigs, weighing 29-34...Control 8371 Badminton Yucatan Contusion: 50gr/20cm Compression : 150gr/5min 3227.00 33.0 2016-09-06 Control 8372 Diving Yucatan 2154.00 34.0 2016...09-21 Control 8437 Gymnastics Yucatan 2538.00 32.0 2016-09-27 Control 8400 Heptathlon Yucatan 2539.00 34.0 SX date Group ID# Name Species Injury

Effect of exercise on postprandial lipemia following a higher calorie meal in Yucatan miniature swine.

PubMed

Rector, R Scott; Thomas, Tom R; Liu, Ying; Henderson, Kyle K; Holiman, Denise A; Sun, Grace Y; Sturek, Michael

2004-08-01

Exercise has been shown to attenuate the postprandial lipemic (PPL) response to a modest kcal high-fat meal in numerous human studies, but has not been fully examined in swine. In addition, the effects of exercise on a high-fat meal of larger magnitude have not been examined in humans or in swine. Thus, the purpose of this study was to examine the PPL response to a single, high-fat/cholesterol (HFC) meal (approximately 3,000 kcal, 1,300 kcal from fat) and determine if exercise attenuates the PPL response. Sedentary, female Yucatan miniature swine (n = 10) completed 3 PPL trials: (1) pre diet (PRE); (2) post HFC diet (POST); and (3) post HFC diet plus exercise (EX, 45 minutes at 75% heart rate maximum). Blood samples were collected before (0 hour) and at 2, 4, 6, and 8 hours after the single HFC meal for PPL analysis. Postheparin lipoprotein lipase (LPL) activity was assessed at 8 hours. While fasting LPL activity was significantly increased with the HFC diet, the PPL response to the HFC meal did not differ depending on diet. Furthermore, the PPL response was not significantly altered with a single session of exercise, perhaps because of the severity of the HFC meal, the sedentary nature of the swine, or because LPL activity was not elevated after exercise. These findings suggest that administration of a HFC meal of this magnitude (approximately 3,000 kcal, 1,300 kcal from fat) will promote significant elevations in postprandial triglyceride (TG) concentrations, overwhelm the adaptive response to a HFC diet (elevated LPL activity), and attenuate the beneficial effects of a single exercise session on this system. Copyright 2004 Elsevier Inc.

Effect of alcohol on skin permeation and metabolism of an ester-type prodrug in Yucatan micropig skin.

PubMed

Fujii, Makiko; Ohara, Rieko; Matsumi, Azusa; Ohura, Kayoko; Koizumi, Naoya; Imai, Teruko; Watanabe, Yoshiteru

2017-11-15

We studied the effect that three alcohols, ethanol (EA), propanol (PA), and isopropanol (IPA), have on the skin permeation of p-hydroxy benzoic acid methyl ester (HBM), a model ester-type prodrug. HBM was applied to Yucatan micropig skin in a saturated phosphate buffered solution with or without 10% alcohol, and HBM and related materials in receptor fluid and skin were determined with HPLC. In the absence of alcohol, p-hydroxy benzoic acid (HBA), a metabolite of HBM, permeated the skin the most. The three alcohols enhanced the penetration of HBM at almost the same extent. The addition of 10% EA or PA to the HBM solution led to trans-esterification into the ethyl ester or propyl ester of HBA, and these esters permeated skin as well as HBA and HBM did. In contrast, the addition of 10% IPA promoted very little trans-esterification. Both hydrolysis and trans-esterification in the skin S9 fraction were inhibited by BNPP, an inhibitor of carboxylesterase (CES). Western blot and native PAGE showed the abundant expression of CES in micropig skin. Both hydrolysis and trans-esterification was simultaneously catalyzed by CES during skin permeation. Our data indicate that the alcohol used in dermal drug preparations should be selected not only for its ability to enhance the solubility and permeation of the drug, but also for the effect on metabolism of the drug in the skin. Copyright © 2017 Elsevier B.V. All rights reserved.

Thermal biology of prey (Melongena corona bispinosa, Strombus pugilis, Callinectes similis, Libinia dubia) and predators (Ocyurus chrysurus, Centropomus undecimalis) of Octopus maya from the Yucatan Peninsula.

PubMed

Noyola Regil, Javier; Mascaro, Maite; Díaz, Fernando; Denisse Re, Ana; Sánchez-Zamora, Adolfo; Caamal-Monsreal, Claudia; Rosas, Carlos

2015-10-01

On the Yucatan Peninsula there is an upwelling which allows access to a body of cold water that controls temperature in this area. This modulates the ecology and distribution of organisms that inhabit the continental shelf. The objective of this study was to determine the effect of different acclimation temperatures on the thermal biology of prey as mollusc, crustacean (Melongena corona bispinosa, Strombus pugilis, Callinectes similis, Libinia dubia) and predators as fish (Ocyurus chrysurus, Centropomus undecimalis) of Octopus maya. Octopus prey preferred temperatures between 23.5°C and 26.0°C, while predators preferred temperatures 26.4-28.5°C. The species with largest thermal windows were M. corona bispinosa (328.8°C(2)), C. similis (322.8°C(2)), L. dubia (319.2°C(2)), C. undecimalis (288.6°C(2)), O. chrysurus (237.5°C(2)), while the smallest thermal window was for S. pugilis (202.0°C(2)). The acclimation response ratios (ARR) estimated for prey ranged from 0.24-0.55 in animals exposed to CTMax and 0.21-0.65 in those exposed to CTMin. Amongst predators, ARR ranged from 0.30 to 0.60 and 0.41 to 0.53 for animals exposed to CTMax and CTMin, respectively. Correlating the optimal temperature limits of prey and predators with surface temperatures on the continental shelf and those 4m deep showed that the main prey, Callinectes similis and L. dubia, shared a thermal niche and that an increase in temperature could force these species to migrate to other sites to find optimal temperatures for their physiological functions. As a consequence the continental shelf community would undergo a structural change. Predators were found to be near their optimal temperatures in surface temperatures on the continental shelf. We conclude that they would remain in the area in a warming scenario. The size of the thermal window was related to the type of ecosystem inhabited by these species. These ARR intervals allowed us to categorize the species as temperate or tropical

77 FR 58088 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-19

... live poultry from Argentina and the Mexican States of Campeche, Quintana Roo, and Yucatan under certain... forms will provide APHIS with critical information concerning the origin and history of the items... from Argentina and certain Mexican States. Description of Respondents: Federal Government; Business or...

Optimizing Hemodynamic Support of Acute Spinal Cord Injury Based on Injury Mechanism

DTIC Science & Technology

2016-10-01

lnJury Specifics Force Weig Tre.tment Notes ht (k&) 8178 Andrew the Giant Yucatan 1-Apr-16 2585.52 25.0 CNTR PILOTTING: unst1ble MAP 8177 Brett...Hart Yucatan 6-Apr-16 3210.77 26.0 CNTR MAP inf11sion: 8202 Coco B. Ware Yucatan 24-Apr-16 2967.00 26.5 NEQJmp(30 min) 60-min Norepinephrine 20...mmHg above BSL 8192 Diamond D. Page Yucatan 27-Apr-16 3609.00 25.0 CNTR 8179 Edge Yucatan 3-May-16 Contusion: 3423.00 26.0 CNTR Groups: - CNTR: no

Space Radar Image of the Yucatan Impact Crater Site

NASA Technical Reports Server (NTRS)

1999-01-01

This is a radar image of the southwest portion of the buried Chicxulub impact crater in the Yucatan Peninsula, Mexico. The radar image was acquired on orbit 81 of space shuttle Endeavour on April 14, 1994 by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR). The image is centered at 20 degrees north latitude and 90 degrees west longitude. Scientists believe the crater was formed by an asteroid or comet which slammed into the Earth more than 65 million years ago. It is this impact crater that has been linked to a major biological catastrophe where more than 50 percent of the Earth's species, including the dinosaurs, became extinct. The 180-to 300-kilometer-diameter (110- to 180-mile)crater is buried by 300 to 1,000 meters (1,000 to 3,000 feet) of limestone. The exact size of the crater is currently being debated by scientists. This is a total power radar image with L-band in red, C-band in green, and the difference between C-band L-band in blue. The 10-kilometer-wide (6-mile) band of yellow and pink with blue patches along the top left (northwestern side) of the image is a mangrove swamp. The blue patches are islands of tropical forests created by freshwater springs that emerge through fractures in the limestone bedrock and are most abundant in the vicinity of the buried crater rim. The fracture patterns and wetland hydrology in this region are controlled by the structure of the buried crater. Scientists are using the SIR-C/X-SAR imagery to study wetland ecology and help determine the exact size of the impact crater. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community

Site Fidelity in Space Use by Spider Monkeys (Ateles geoffroyi) in the Yucatan Peninsula, Mexico

PubMed Central

Ramos-Fernandez, Gabriel; Smith Aguilar, Sandra E.; Schaffner, Colleen M.; Vick, Laura G.; Aureli, Filippo

2013-01-01

Animal home ranges may vary little in their size and location in the short term but nevertheless show more variability in the long term. We evaluated the degree of site fidelity of two groups of spider monkeys (Ateles geoffroyi) over a 10- and 13-year period, respectively, in the northeastern Yucatan peninsula, Mexico. We used the Local Convex Hull method to estimate yearly home ranges and core areas (defined as the 60% probability contour) for the two groups. Home ranges varied from 7.7 to 49.6 ha and core areas varied from 3.1 to 9.2 ha. We evaluated the degree of site fidelity by quantifying the number of years in which different areas were used as either home ranges or core areas. Large tracts were used only as home ranges and only for a few years, whereas small areas were used as either core area or home range for the duration of the study. The sum of the yearly core areas coincided partially with the yearly home ranges, indicating that home ranges contain areas used intermittently. Home ranges, and especially core areas, contained a higher proportion of mature forest than the larger study site as a whole. Across years and only in one group, the size of core areas was positively correlated with the proportion of adult males in the group, while the size of home ranges was positively correlated with both the proportion of males and the number of tree species included in the diet. Our findings suggest that spider monkey home ranges are the result of a combination of long-term site fidelity and year-to-year use variation to enable exploration of new resources. PMID:23675427

Hydrochemistry of waters from five cenotes and evaluation of their suitability for drinking-water supplies, northeastern Yucatan, Mexico

NASA Astrophysics Data System (ADS)

Alcocer, Javier; Lugo, Alfonso; Marín, Luis E.; Escobar, Elva

Waters from five cenotes that are currently being used for aquatic recreational activities and that lie along the Cancun-Tulum touristic corridor, Mexico, were evaluated hydrochemically to determine whether the cenotes may be considered as potential drinking-water sources. Several parameters exceed the Mexican Drinking Water Standards (MDWS), but since they do not pose a significant health threat, four of the five cenotes may be used as drinking-water sources. The common contaminants in the Yucatan Peninsula, fecal coliforms and nitrate, are in most cases below the MDWS (0-460 MPN/100ml and 0.31-1.18mg/L, respectively). Although these four cenotes meet the MDWS, a careful groundwater management policy needs to be developed to avoid contamination (fecal and nitrates) and salt-water intrusion. Résumé Les eaux de cinq cénotés, qui sont normalement utilisées pour des activités de plein air, dans la région touristique de Cancun-Tulum (Mexique), ont été soumises à analyses chimiques pour savoir si les cénotés peuvent être considérés comme des sources d'eau potable. Plusieurs paramètres dépassent les normes mexicaines en matière d'eau potable; mais comme ceux-ci ne posent pas de problème réel de santé, quatre des cinq cénotés peuvent être captés pour l'eau potable. Les contaminants habituels dans les eaux de la presqu'île du Yucatan, coliformes fécaux et concentrations élevées en nitrate, sont la plupart du temps au-dessous des normes (respectivement 0 à 460 germes/100ml et 0,31 à 1,18mg/l). Bien que ces quatre cénotés satisfassent aux normes, il est nécessaire de mettre en place des règles précises de l'utilisation de l'eau souterraine, afin d'éviter la contamination par les germes fécaux et par les nitrates, ainsi que l'intrusion marine. Resumen Se analizó hidroquímica y bacteriológicamente el agua de algunos cenotes localizados a lo largo del corredor turístico Cancun-Tulum, que actualmente se utilizan para diversas actividades

Geochemical variability of the Yucatan basement: Constraints from crystalline clasts in Chicxulub impactites

NASA Astrophysics Data System (ADS)

Kettrup, B.; Deutsch, A.

2003-07-01

The 65 Ma old Chicxulub impact structure with a diameter of about 180 km is again in the focus of the geosciences because of the recently commenced drilling of the scientific well Yaxcopoil- 1. Chicxulub is buried beneath thick post-impact sediments, yet samples of basement lithologies in the drill cores provide a unique insight into age and composition of the crust beneath Yucatan. This study presents major element, Sr, and Nd isotope data for Chicxulub impact melt lithologies and clasts of basement lithologies in impact breccias from the PEMEX drill cores C-1 and Y-6, as well as data for ejecta material from the K/T boundaries at La Lajilla, Mexico, and Furlo, Italy. The impact melt lithologies have an andesitic composition with significantly varying contents of Al, Ca, and alkali elements. Their present day 87Sr/86Sr ratios cluster at about 0.7085, and 143Nd/144Nd ratios range from 0.5123 to 0.5125. Compared to the melt lithologies that stayed inside the crater, data for ejecta material show larger variations. The 87Sr/86Sr ratios range from 0.7081 for chloritized spherules from La Lajilla to 0.7151 for sanidine spherules from Furlo. The 143Nd/144Nd ratio is 0.5126 for La Lajilla and 0.5120 for the Furlo spherules. In an tCHUR(Nd)-tUR(Sr) diagram, the melt lithologies plot in a field delimited by Cretaceous platform sediments, various felsic lithic clasts and a newly found mafic fragment from a suevite. Granite, gneiss, and amphibolite have been identified among the fragments from crystalline basement gneiss. Their 87Sr/86Sr ratios range from 0.7084 to 0.7141, and their 143Nd/144Nd ratios range from 0.5121 to 0.5126. The TNdDM model ages vary from 0.7 to 1.4 Ga, pointing to different source terranes for these rocks. This leads us to believe that the geological evolution and the lithological composition of the Yucatàn basement is probably more complex than generally assumed, and Gondwanan as well as Laurentian crust may be present in the Yucatàn basement.

Merida virus, a putative novel rhabdovirus discovered in Culex and Ochlerotatus spp. mosquitoes in the Yucatan Peninsula of Mexico.

PubMed

Charles, Jermilia; Firth, Andrew E; Loroño-Pino, Maria A; Garcia-Rejon, Julian E; Farfan-Ale, Jose A; Lipkin, W Ian; Blitvich, Bradley J; Briese, Thomas

2016-04-01

Sequences corresponding to a putative, novel rhabdovirus [designated Merida virus (MERDV)] were initially detected in a pool of Culex quinquefasciatus collected in the Yucatan Peninsula of Mexico. The entire genome was sequenced, revealing 11 798 nt and five major ORFs, which encode the nucleoprotein (N), phosphoprotein (P), matrix protein (M), glycoprotein (G) and RNA-dependent RNA polymerase (L). The deduced amino acid sequences of the N, G and L proteins have no more than 24, 38 and 43 % identity, respectively, to the corresponding sequences of all other known rhabdoviruses, whereas those of the P and M proteins have no significant identity with any sequences in GenBank and their identity is only suggested based on their genome position. Using specific reverse transcription-PCR assays established from the genome sequence, 27 571 C. quinquefasciatus which had been sorted in 728 pools were screened to assess the prevalence of MERDV in nature and 25 pools were found positive. The minimal infection rate (calculated as the number of positive mosquito pools per 1000 mosquitoes tested) was 0.9, and similar for both females and males. Screening another 140 pools of 5484 mosquitoes belonging to four other genera identified positive pools of Ochlerotatus spp. mosquitoes, indicating that the host range is not restricted to C. quinquefasciatus. Attempts to isolate MERDV in C6/36 and Vero cells were unsuccessful. In summary, we provide evidence that a previously undescribed rhabdovirus occurs in mosquitoes in Mexico.

Merida virus, a putative novel rhabdovirus discovered in Culex and Ochlerotatus spp. mosquitoes in the Yucatan Peninsula of Mexico

PubMed Central

Charles, Jermilia; Firth, Andrew E.; Loroño-Pino, Maria A.; Garcia-Rejon, Julian E.; Farfan-Ale, Jose A.; Lipkin, W. Ian; Briese, Thomas

2016-01-01

Sequences corresponding to a putative, novel rhabdovirus [designated Merida virus (MERDV)] were initially detected in a pool of Culex quinquefasciatus collected in the Yucatan Peninsula of Mexico. The entire genome was sequenced, revealing 11 798 nt and five major ORFs, which encode the nucleoprotein (N), phosphoprotein (P), matrix protein (M), glycoprotein (G) and RNA-dependent RNA polymerase (L). The deduced amino acid sequences of the N, G and L proteins have no more than 24, 38 and 43 % identity, respectively, to the corresponding sequences of all other known rhabdoviruses, whereas those of the P and M proteins have no significant identity with any sequences in GenBank and their identity is only suggested based on their genome position. Using specific reverse transcription-PCR assays established from the genome sequence, 27 571 C. quinquefasciatus which had been sorted in 728 pools were screened to assess the prevalence of MERDV in nature and 25 pools were found positive. The minimal infection rate (calculated as the number of positive mosquito pools per 1000 mosquitoes tested) was 0.9, and similar for both females and males. Screening another 140 pools of 5484 mosquitoes belonging to four other genera identified positive pools of Ochlerotatus spp. mosquitoes, indicating that the host range is not restricted to C. quinquefasciatus. Attempts to isolate MERDV in C6/36 and Vero cells were unsuccessful. In summary, we provide evidence that a previously undescribed rhabdovirus occurs in mosquitoes in Mexico. PMID:26868915

The stress response and exploratory behaviour in Yucatan minipigs (Sus scrofa): Relations to sex and social rank.

PubMed

Adcock, Sarah J J; Martin, Gerard M; Walsh, Carolyn J

2015-12-01

According to the coping styles hypothesis, an individual demonstrates an integrated behavioural and physiological response to environmental challenge that is consistent over time and across situations. Individual consistency in behavioural responses to challenge has been documented across the animal kingdom. Comparatively few studies, however, have examined inter-individual variation in the physiological response, namely glucocorticoid and catecholamine levels, the stress hormones secreted by the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system, respectively. Variation in coping styles between individuals may be explained in part by differences in social rank and sex. Using 20 Yucatan minipigs (Sus scrofa) we: (1) investigated the existence of consistent inter-individual variation in exploratory behaviour and the hormonal stress response, and tested for correlations as predicted by the coping styles hypothesis; and (2) evaluated whether inter-individual behavioural and hormonal variation is related to social rank and sex. Salivary stress biomarkers (cortisol, alpha-amylase, chromogranin A) were assessed in the presence and absence of a stressor consisting of social isolation in a crate for 10 min. Principal components analysis on a set of behavioural variables revealed two traits, which we labelled exploratory tendency and neophobia. Neither exploratory tendency nor neophobia predicted the physiological stress response. Subordinate pigs exhibited higher catecholamine levels compared to dominant conspecifics. We observed sex differences in the repeatability of salivary stress markers and reactivity of the stress systems. The results do not provide support for the existence of behavioural-physiological coping styles in pigs. Sex is an important determinant of the physiological stress response and warrants consideration in research addressing behavioural and hormonal variation. Copyright © 2015 Elsevier Inc. All rights reserved.

Conservative nutrient use by big-leaf mahogany (Swietenia macrophylla King) planted under contrasting environmental conditions

Treesearch

E. Medina; E. Cuevas; A.E. Lugo; E. Terezo; J. Jimenez-Osornio; P.A. Macario-Mendoza; P. Montanez

2014-01-01

We analyzed the nutritional composition and isotope ratios (C and N) of big-leaf mahogany (Swietenia macrophylla King) leaves in plantations established on contrasting soils and climates in Central America (State of Quintana Roo, Yucatan, Mexico) and South America (State of Para, Brazil). The objective was to determine the adaptability of this species to large...

Identification of NAFTA-induced opportunities for Louisiana's ports and waterways.

DOT National Transportation Integrated Search

1996-06-01

The implementation of the North American Free Trade Agreement (NAFTA) on January 1, 1994, created a trading region extending from the Yucatan Peninsula in Mexico to the Yukon region of Alaska with trade between the United States, Canada, and Mexico t...

Opportunities for Improved Chagas Disease Vector Control Based on Knowledge, Attitudes and Practices of Communities in the Yucatan Peninsula, Mexico

PubMed Central

Rosecrans, Kathryn; Cruz-Martin, Gabriela; King, Ashley; Dumonteil, Eric

2014-01-01

Background Chagas disease is a vector-borne parasitic disease of major public health importance. Current prevention efforts are based on triatomine vector control to reduce transmission to humans. Success of vector control interventions depends on their acceptability and value to affected communities. We aimed to identify opportunities for and barriers to improved vector control strategies in the Yucatan peninsula, Mexico. Methodology/principal findings We employed a sequence of qualitative and quantitative research methods to investigate knowledge, attitudes and practices surrounding Chagas disease, triatomines and vector control in three rural communities. Our combined data show that community members are well aware of triatomines and are knowledgeable about their habits. However, most have a limited understanding of the transmission dynamics and clinical manifestations of Chagas disease. While triatomine control is not a priority for community members, they frequently use domestic insecticide products including insecticide spray, mosquito coils and plug-in repellents. Families spend about $32 US per year on these products. Alternative methods such as yard cleaning and window screens are perceived as desirable and potentially more effective. Screens are nonetheless described as unaffordable, in spite of a cost comparable to the average annual spending on insecticide products. Conclusion/Significance Further education campaigns and possibly financing schemes may lead families to redirect their current vector control spending from insecticide products to window screens. Also, synergism with mosquito control efforts should be further explored to motivate community involvement and ensure sustainability of Chagas disease vector control. PMID:24676038

Carious lesions and maize consumption among the Prehispanic Maya: an analysis of a coastal community in northern Yucatan.

PubMed

Cucina, Andrea; Cantillo, Cristina Perera; Sosa, Thelma Sierra; Tiesler, Vera

2011-08-01

Patterns of carious lesions were analyzed in the Classic period coastal Maya population of Xcambó, a salt production and administration center in northern Yucatan. To this end, the study investigated caries in the permanent dentitions of 163 adult skeletons, 23 from the Early Classic (AD 250-550) and 140 from the Late Classic period (AD 550-750), equally distributed between sexes. The archaeological and bioarchaeological evidence indicates a wealthy and socially homogeneous population dedicated to salt production and administration in the Early Classic that switched to pure administrative functions in the Late Classic. The results indicate an increase in caries from 7.4% and 21.2% (males and females respectively) from the Early Classic to 14.0% in males and 27.4% in females from the Late Classic period. The rate of caries in the Early and in the Late Classic phases of continuous occupation is not consistent with a simple interpretation of a heavier reliance on maize during the latter phase, characterized by a sedentary lifestyle, particularly for the male segment of the society now dedicated completely to the administration of the salt mines. Rather, the increase in caries rates in both sexes is best explained within a broader context of overall food habits, new cariogenic foods for both sexes, and the changes in lifestyle imposed by the increased socioeconomic role of the site. Our conclusions stress the limitations imposed by interpreting carious lesions solely in terms of single dietary components, such as maize consumption, without taking into account broader aspects of cultural and socioeconomic relevance. Copyright © 2011 Wiley-Liss, Inc.

The Geology of Haiti: An Annotated Bibliography of Haiti’s Geology, Geography and Earth Science

DTIC Science & Technology

2010-07-01

Yucatan Peninsula. Abstract: The stratigraphy and age of breccia containing Chicxulub impact glass spherules is documented in late Maastrichtian-early...Tertiary; tsunamis; turbidite; turbidity current structures; Upper Cretaceous; West Indies; Yucatan Peninsula. Notes: SP: USGSOP, Non-USGS...Chichancanab, and Coba, Yucatan Peninsula, Bibliography of Haitian Earth Science Army Geospatial Center June 2010 70 Mexico; Lake Peten-Itza, Peten

Chesapeake Bay Future Conditions Report. Volume 6. Water Quality

DTIC Science & Technology

1977-12-01

Bay ecosystem. Beginning as a tropical depression off the Yucatan "Coast on I5 June 1972, Agnes moved from the Gulf of Mexico, across the Southern...ultimately assumes a completely terres- trial state and disappears. During eu- trophication, the lake becomes so rich in nutritive compounds

Deepening Democracy: Explaining Variations in the Levels of Democracy

DTIC Science & Technology

2010-06-01

life such as health, nutrition , and employment. In either case, the term “development” suggests some type of advancement. Some refer to this...Mexico is concentrated in Mexico City, the seven northern states (manufacturing, services, trade), and the Yucatan (oil and tourism). Four of the six

75 FR 49454 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-13

... live poultry from Argentina and the Mexican States of Campeche, Quintana Roo, and Yucatan under certain... will provide APHIS with critical information concerning the origin and history of the items destined... effective defense against the incursion of END from poultry and poultry products imported from Argentina and...

Environmental Assessment for Beach Shoreline Protection at Patrick Air Force Base, Florida

DTIC Science & Technology

2012-02-27

3) a Florida Panhandle nesting subpopulation, occurring at Eglin Air Force Base and the beaches near Panama City, Florida; (4) a Yucatan nesting...subpopulation, occurring on the Eastern Yucatan Peninsula, Mexico (Marquez 1990 and Turtle Expert Working Group or TEWG 2000); and (5) a Dry Tortugas...the Yucatan Peninsula. Additional important foraging areas in the western Atlantic include the Mosquito Lagoon and Indian River Lagoon systems and

First Detection of the Kdr Mutation T929I in Head Lice (Phthiraptera: Pediculidae) in Schoolchildren of the Metropolitan Area of Nuevo Leon and Yucatan, Mexico.

PubMed

Ponce-Garcia, Gustavo; Villanueva-Segura, Karina; Trujillo-Rodriguez, Gerardo; Rodriguez-Sanchez, Iram P; Lopez-Monroy, Beatriz; Flores, Adriana E

2017-07-01

The head louse Pediculus humanus capitis (De Geer) is a hematophagous ectoparasite that inhabits the human scalp. Infestations by this insect are commonly known as pediculosis, which is more common in younger groups. These infestations are asymptomatic; however, skin irritation from scratching occasionally may cause secondary bacterial infections. In recent years, the prevalence of pediculosis has increased in children; this increase has been attributed to louse resistance to the insecticides used as a control measure for infestation. The aim of the present study was to determine the presence and frequency of the knockdown resistance mutation (kdr) T929I in 468 head lice collected from 32 elementary schools in the metropolitan area of Nuevo Leon (24) and Yucatan (8), Mexico. This is the first report of a knockdown resistance (kdr) mechanism in head lice from Mexico. The T929I mutation was present in all of the sampled schools, with variability observed in its allelic and genotypic frequencies. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of precipitation regime and soil nitrogen on leaf traits in seasonally dry tropical forests of the Yucatan Peninsula, Mexico.

PubMed

Roa-Fuentes, Lilia L; Templer, Pamela H; Campo, Julio

2015-10-01

Leaf traits are closely associated with nutrient use by plants and can be utilized as a proxy for nutrient cycling processes. However, open questions remain, in particular regarding the variability of leaf traits within and across seasonally dry tropical forests. To address this, we considered six leaf traits (specific area, thickness, dry matter content, N content, P content and natural abundance (15)N) of four co-occurring tree species (two that are not associated with N2-fixing bacteria and two that are associated with N2-fixing bacteria) and net N mineralization rates and inorganic N concentrations along a precipitation gradient (537-1036 mm per year) in the Yucatan Peninsula, Mexico. Specifically we sought to test the hypothesis that leaf traits of dominant plant species shift along a precipitation gradient, but are affected by soil N cycling. Although variation among different species within each site explains some leaf trait variation, there is also a high level of variability across sites, suggesting that factors other than precipitation regime more strongly influence leaf traits. Principal component analyses indicated that across sites and tree species, covariation in leaf traits is an indicator of soil N availability. Patterns of natural abundance (15)N in foliage and foliage minus soil suggest that variation in precipitation regime drives a shift in plant N acquisition and the openness of the N cycle. Overall, our study shows that both plant species and site are important determinants of leaf traits, and that the leaf trait spectrum is correlated with soil N cycling.

The Coast Artillery Journal. Volume 85, Number 6, November-December 1942

DTIC Science & Technology

1942-12-01

knowledge of this subject, all phases of mess management are con- sidered, including nutrition , menus, kitchen manage- ment, mess accounting for both...Newspaper accounts state much storm damage was done on the Yucatan peninsula. This may have been the starting place for the many coconuts that were found in

Environmental Analysis of U.S. Navy Shipboard Solid Waste Discharges: Addendum to the Report of Findings.

DTIC Science & Technology

1999-02-01

numbering in the billions of individuals. Joiris (1991) has estimated that, based on the nutritional requirements of the top predators of the Antarctic, a...east ( Yucatan and East Florida) and by terrigenous sediment to the north (Mississippi and Rio Grande deltas). The Yucatan Basin, between Cuba and the... Yucatan Gulf and Eastern Florida, continental shelves are narrow and much of the eastern margin in the Lesser Antilles Archipelago lacks a shelf

Joint Distraction Treatments of Intra-Articular Fracture-Induced Posttraumatic Osteoarthritis in a Large Animal Model

DTIC Science & Technology

2017-10-01

that was developed this Year for use in the upcoming Aim 2 studies. 15. SUBJECT TERMS External Fixator, Fracture Fixation Delay, Yucatan Minipig 16... Yucatan minipig model of PTOA after IAF that was developed during our previous work (W81XWH-10-1-0864) to investigate the use of joint distraction to...proactive treatment for PTOA. 2. KEYWORDS Post-traumatic Osteoarthritis Intra-articular Fracture Yucatan Miniature Pig Impact Ankle Cartilage

A method for the stochastic modeling of karstic systems accounting for geophysical data: an example of application in the region of Tulum, Yucatan Peninsula (Mexico)

NASA Astrophysics Data System (ADS)

Vuilleumier, C.; Borghi, A.; Renard, P.; Ottowitz, D.; Schiller, A.; Supper, R.; Cornaton, F.

2013-05-01

The eastern coast of the Yucatan Peninsula, Mexico, contains one of the most developed karst systems in the world. This natural wonder is undergoing increasing pollution threat due to rapid economic development in the region of Tulum, together with a lack of wastewater treatment facilities. A preliminary numerical model has been developed to assess the vulnerability of the resource. Maps of explored caves have been completed using data from two airborne geophysical campaigns. These electromagnetic measurements allow for the mapping of unexplored karstic conduits. The completion of the network map is achieved through a stochastic pseudo-genetic karst simulator, previously developed but adapted as part of this study to account for the geophysical data. Together with the cave mapping by speleologists, the simulated networks are integrated into the finite-element flow-model mesh as pipe networks where turbulent flow is modeled. The calibration of the karstic network parameters (density, radius of the conduits) is conducted through a comparison with measured piezometric levels. Although the proposed model shows great uncertainty, it reproduces realistically the heterogeneous flow of the aquifer. Simulated velocities in conduits are greater than 1 cm s-1, suggesting that the reinjection of Tulum wastewater constitutes a pollution risk for the nearby ecosystems.

Worldwide Report, Epidemiology

DTIC Science & Technology

1985-10-28

California, Yucatan AIDS 36 AIDS Contracted in U.S. 36 MOZAMBIQUE Briefs NETHERLANDS I o7 Polio, Measles Vaccinations J/ Government on Spread of AIDS...CALIFORNIA, YUCATAN AIDS—It has been confirmed that three persons have died in Baja California and Yucatan as a result of acquired Immune deficiency...breeds and nutrition . Grazing schemes could be initiated. Fridges would hold vaccines for rabies, anthrax, quarter evil and fowl pox and the list

Our Changing Planet: The U.S. Climate Change Science Program for Fiscal Year 2009

DTIC Science & Technology

2008-07-01

forests of the southern Yucatan Peninsula form the largest expanse of this ecosystem type remaining in Mexico. It forms an ecocline between a drier...Calakmul Biosphere Reserve to preserve this unique forested area. The Southern Yucatan Peninsular Region Project is currently engaged in an assessment of the...Eastman, B.L. Turner II, S. Calme, R. Dickson, C. Pozo, and F. Sangermano, 2007: Land Change in the southern Yucatan and Calamul biosphere reserve

The molecular characterisation of a Sida-infecting begomovirus from Jamaica.

PubMed

Stewart, Cheryl; Kon, Tatsuya; Rojas, Maria; Graham, André; Martin, Darren; Gilbertson, Robert; Roye, Marcia

2014-02-01

The complete DNA sequence of both genome components of a new begomovirus (Sida golden mosaic Buckup virus-[Jamaica:St. Elizabeth:2004]; SiGMBuV-[JM:SE:04]) was determined from a field-infected Sida sp. sample from Buckup, St. Elizabeth, Jamaica. Phylogenetically, both genome components of SiGMBuV-[JM:SE:04] are most closely related to malvaceous weed-infecting Floridian and Mexican begomoviruses. Its DNA-B is a recombinant molecule, the majority of which was derived from a virus resembling Sida yellow mosaic Yucatan virus-[Mexico:Yucatan:2005] (SiYMYuV-[MX:Yuc:05]), while nucleotides 43-342 were derived from a virus resembling Sida golden mosaic virus-[United States of America:Florida] (SiGMV-[US:Flo]). Symptomatic infectivity of our cloned SiGMBuV-[JM:SE:04] components was confirmed in Nicotiana benthamiana.

Are the London Declaration's 2020 goals sufficient to control Chagas disease?: Modeling scenarios for the Yucatan Peninsula.

PubMed

Lee, Bruce Y; Bartsch, Sarah M; Skrip, Laura; Hertenstein, Daniel L; Avelis, Cameron M; Ndeffo-Mbah, Martial; Tilchin, Carla; Dumonteil, Eric O; Galvani, Alison

2018-03-01

The 2020 Sustainable Development goals call for 100% certified interruption or control of the three main forms of Chagas disease transmission in Latin America. However, how much will achieving these goals to varying degrees control Chagas disease; what is the potential impact of missing these goals and if they are achieved, what may be left? We developed a compartmental simulation model that represents the triatomine, human host, and non-human host populations and vector-borne, congenital, and transfusional T. cruzi transmission between them in the domestic and peridomestic settings to evaluate the impact of limiting transmission in a 2,000 person virtual village in Yucatan, Mexico. Interruption of domestic vectorial transmission had the largest impact on T. cruzi transmission and prevalence in all populations. Most of the gains were achieved within the first few years. Controlling vectorial transmission resulted in a 46.1-83.0% relative reduction in the number of new acute Chagas cases for a 50-100% interruption in domestic vector-host contact. Only controlling congenital transmission led to a 2.4-8.1% (30-100% interruption) relative reduction in the total number of new acute cases and reducing only transfusional transmission led to a 0.1-0.3% (30-100% reduction). Stopping all three forms of transmission resulted in 0.5 total transmission events over five years (compared to 5.0 with no interruption); interrupting all forms by 30% resulted in 3.4 events over five years per 2,000 persons. While reducing domestic vectorial, congenital, and transfusional transmission can successfully reduce transmission to humans (up to 82% in one year), achieving the 2020 goals would still result in 0.5 new acute cases per 2,000 over five years. Even if the goals are missed, major gains can be achieved within the first few years. Interrupting transmission should be combined with other efforts such as a vaccine or improved access to care, especially for the population of already

Occurrence of Pepper Mild Mottle Virus (PMMoV) in Groundwater from a Karst Aquifer System in the Yucatan Peninsula, Mexico.

PubMed

Rosiles-González, Gabriela; Ávila-Torres, Gerardo; Moreno-Valenzuela, Oscar A; Acosta-González, Gilberto; Leal-Bautista, Rosa María; Grimaldo-Hernández, Cinthya D; Brown, Judith K; Chaidez-Quiroz, Cristóbal; Betancourt, Walter Q; Gerba, Charles P; Hernández-Zepeda, Cecilia

2017-12-01

The Yucatan Peninsula of Mexico hosts a karst aquifer system that is the only source of freshwater for the area; however, it is vulnerable to human-mediated contamination. Pepper mild mottle virus (PMMoV) is one of the most abundant RNA viruses associated with human feces, making it a viable indicator for tracking fecal pollution in aquatic environments, including groundwater. In this study, groundwater samples collected from a karst aquifer from fresh and brackish water locations were analyzed for fecal indicator bacteria, somatic and male F+ specific coliphages, and PMMoV during the rainy and dry seasons. Total coliform bacteria were detected at all sites, whereas Escherichia coli were found at relatively low levels <40 MPN/100 ml. The highest average concentrations of somatic and male F+ specific coliphages were 920 and 330 plaque forming units per 100 ml, respectively, detected in freshwater during the rainy season. PMMoV RNA was detected in 85% of the samples with gene sequences sharing 99-100% of nucleotide identity with PMMoV sequences available in GenBank. Quantification of PMMoV genome copies (GC) by quantitative real-time PCR indicated concentrations ranging from 1.7 × 10 1 to 1.0 × 10 4 GC/L, with the highest number of GC detected during the rainy season. No significant correlation was observed between PMMoV occurrence by season or water type (p > 0.05). Physicochemical and indicator bacteria were not correlated with PMMoV concentrations. The abundance and prevalence of PMMoV in the karst aquifer may reflect its environmental persistence and its potential as a fecal indicator in this karst aquifer system.

Settlement patterns and communication routes of the western Maya wetlands: An archaeological and remote-sensing survey, Chunchucmil, Yucatan, Mexico

NASA Astrophysics Data System (ADS)

Hixson, David R.

This dissertation investigates the role of the seasonal wetlands in the political economy and subsistence strategies of the ancient Maya of Chunchucmil, Yucatan, Mexico. A combination of pedestrian surveys and remote-sensing tasks were performed in order to better understand the settlement patterns and potential communication routes in and through the wetlands between Chunchucmil and the Gulf of Mexico. These western wetlands had been proposed as the principal avenue for interregional trade between coastal merchants and inland consumers, yet were thought to be uninhabited and uncultivable. Following the survey tasks outlined in this dissertation, these wetlands were found to contain an abundance of archaeological settlements and features indicating habitation, utilization, and trade throughout this diverse ecological zone. The remote-sensing platforms utilized in this study include both multispectral (Landsat) and synthetic aperture radar (AirSAR), combined with additional remotely sensed resources. One of the goals of this survey was to test the capabilities of these two sensors for the direct detection of archaeological features from air and space. The results indicate that Landsat can be highly successful at detecting site location and measuring site size under certain environmental conditions. The Airborne Synthetic Aperture Radar proved to be adept at detecting large mounded architecture within the Yucatecan karstic plain, but its further utility is hampered by limitations of resolution, scale, and land cover. One of the salient features of the landscape west of Chunchucmil is a network of stone pathways called andadores. These avenues through the wetlands outline a dendritic network of communication, trade, and extraction routes. The following dissertation places this network and its associated settlements (from suburban centers to diminutive camps) within their regional context, examining the roles they may have played in supporting a large mercantile

Begomovirus diversity in tomato crops and weeds in Ecuador and the detection of a recombinant isolate of rhynchosia golden mosaic Yucatan virus infecting tomato.

PubMed

Paz-Carrasco, Lenin C; Castillo-Urquiza, Gloria P; Lima, Alison T M; Xavier, Cesar A D; Vivas-Vivas, Leticia M; Mizubuti, Eduardo S G; Zerbini, F Murilo

2014-08-01

Viral diseases caused by begomoviruses are of economic importance due to their adverse effects on the production of tropical and subtropical crops. In Ecuador, despite reports of significant infestations of Bemisia tabaci in the late 1990s, only very recently has a begomovirus, tomato leaf deformation virus (ToLDeV, also present in Peru), been reported in tomato. ToLDeV is the first monopartite begomovirus discovered that originated in the Americas, and its presence in Ecuador highlights the need for a wider survey of tomato-infecting begomoviruses in this country. Tomato and weed samples were collected in 2010 and 2011 in six provinces of Ecuador, and begomovirus genomes were cloned and sequenced using a rolling-circle-amplification-based approach. Most tomato samples from the provinces of Guayas, Loja, Manabi and Santa Elena were infected with tomato leaf deformation virus (ToLDeV). One sample from Manabi had a triple infection with ToLDeV, rhynchosia golden mosaic Yucatan virus (RhGMYuV) and an isolate that was a recombinant between the two. A new begomovirus was detected in another tomato sample from Manabi. Samples of Rhynchosia sp. from the provinces of Guayas and Manabi were infected by RhGMYuV. These results indicate not only the prevalence of ToLDeV in tomato in Ecuador but also the presence of other viruses, albeit at a much lower frequency.

Research Program in Tropical Infectious Diseases

DTIC Science & Technology

1990-12-14

of the Yucatan Peninsula, surrounded on the west and north by Guatemala and Mexico and on the east by the Caribbean Sea. The jungle covered Maya...infectious diseases are common. Yellow fever has been known to occur in the Yucatan 1 , dengue and malaria are endemic in Belize 2, and cutaneous leishmaniasis...cietifico truncado en 1912, et de la fiebre amarilla de la serva en Yucatan . 1986, Gac. Med. Mex. 122:263-272. 2. Freeman, K. American cutaneous

For Love of Family and Family Values: How Immigrant Motivations Can Inform Immigration Policy

ERIC Educational Resources Information Center

Piacenti, David

2009-01-01

This article consists of more than fifty interviews with Spanish and Yucatec-Mayan men from Yucatan, Mexico, to the United States. Based on interview responses, I contend that Yucatec-Mayan immigrants support Jeffrey Cohen's (2004) "household model" and use a ch'i'ibal-centered, or family-centered, decision-making process to frame…

Shaded Relief with Height as Color and Landsat, Yucatan Peninsula, Mexico

NASA Technical Reports Server (NTRS)

2003-01-01

The top picture is a shaded relief image of the northwest corner of Mexico's Yucatan Peninsula generated from Shuttle Radar Topography Mission (SRTM) data, and shows a subtle, but unmistakable, indication of the Chicxulub impact crater. Most scientists now agree that this impact was the cause of the Cretatious-Tertiary Extinction, the event 65 million years ago that marked the sudden extinction of the dinosaurs as well as the majority of life on Earth. The pattern of the crater's rim is marked by a trough, the darker green semicircular line near the center of the picture. This trough is only about 3 to 5 meters (10 - 15 feet) deep and is about 5 km (3 miles) wide; so subtle that if you walked across it you probably would not notice it. It is the surface expression of the buried crater's outer boundary. Scientists believe the impact, which was centered just off the coast in the Caribbean, altered the subsurface rocks such that the overlying limestone sediments, which formed later and erode very easily, would preferentially erode along the crater rim. This formed the trough as well as numerous sinkholes (called cenotes) which are visible as small circular depressions.

The bottom picture is the same area viewed by the Landsat satellite, and was made by displaying the Thematic Mapper's Band 7 (mid-infrared), Band 4 (near-infrared) and Band 2 (green) as red, green and blue. These colors were chosen to maximize the contrast between different vegetation and land cover types, with native vegetation and cultivated land showing as green, yellow and magenta, and urban areas as white. The circular white area near the center of the image is Merida, a city of about 720,000 population. Notice that in the SRTM image, which shows only topography, the city is not visible, while in the Landsat image, which does not show elevations, the trough is not visible.

Two visualization methods were combined to produce the SRTM image: shading and color coding of topographic height. The

Meemul Tziij: An Indigenous Sign Language Complex of Mesoamerica

ERIC Educational Resources Information Center

Tree, Erich Fox

2009-01-01

This article examines sign languages that belong to a complex of indigenous sign languages in Mesoamerica that K'iche'an Maya people of Guatemala refer to collectively as Meemul Tziij. It explains the relationship between the Meemul Tziij variety of the Yukatek Maya village of Chican (state of Yucatan, Mexico) and the hitherto undescribed Meemul…

Effect of oral contraceptive use on the erythrocytic glutathione reductase and aspartate aminotransferase activities in women with or without clinical signs of vitamin deficiency.

PubMed

Tovar, A; Bourges, H; Canto, T; Torres, N; Lopez-castro, B R

1985-07-01

The effect of the chronic use of combined oral contraceptives (OCs) on the "activity coefficients" (alpha = coenzyme-stimulated activity/basal activity) of erythrocytic glutathione reductase and aspartate aminotransferase was studied in 2 groups of 90 female volunteers each; 1 of the groups, from the state of Yucatan in southeast Mexico, presented clinical lesions of vitamin deficiency, while the other group, from Mexico City, did not have any clinical evidence of vitamin deficiency. One half of the women (45) in each group were chronic OC users and the other half were not. The results were analyzed comparing OC users with non-users in each location. For both glutathione reductase and aspartate aminotransferase, the Mexico City OC users had significantly higher (p 0.001) alpha values than nonusers, while in the Yucatan women, the alpha values were similarly high independent of OC use.

Reconstruction of precipitation variability in the Strait of Yucatan associated with latitudinal shifts in the position of the Intertropical Convergence Zone since the Last Glacial Maximum

NASA Astrophysics Data System (ADS)

Staines-Urías, Francisca; Seidenkrantz, Marit-Solveig; Fischel, Andrea; Kuijpers, Antoon

2017-04-01

The elemental composition of sediments from gravity core HOLOVAR11-03 provides a ca. 40 ka record of past climate variability in the Strait of Yucatan, between the Caribbean Sea and the Gulf of Mexico, a region where precipitation variability is determined by the seasonal position of the Intertropical Convergence Zone (ITCZ). Within this region, sea level pressure decreases and rainfall increases as the ITCZ moves north of the equator in response to increased solar insolation in the Northern Hemisphere during boreal summer. In contrast, as the ITCZ retracts southward towards the equator during boreal winter, rainfall diminishes and the regional sea level pressure gradient strengthens. On interannual, multidecadal and millennial timescales, fluctuations in the average latitudinal position of the ITCZ in response to insolation forcing modulate the intensity and duration of the seasonal regimens, determining average regional precipitation and, ultimately, the elemental composition of the marine sedimentary record. Regionally, higher titanium and iron content in marine sediments reflect greater terrigenous input from inland runoff, indicating greater precipitation, hence a more northerly position of the ITCZ. Correspondingly, Ti and Fe concentration data were used to reconstruct regional rainfall variability since the Last Glacial Maxima (LGM ˜24 cal ka BP). HOLOVAR11-03 age model (based on 4 AMS 14C dates obtained from multi-specific samples of planktic foraminifera) shows stable sedimentation rates in the area throughout the cored period. Nonetheless, higher terrestrial mineral input is observed since the LGM and all through the last glacial termination (24 to 12 cal ka BP), indicating a period of increased precipitation. In contrast, lower Ti and Fe values are typical for the period between 12 and 8 cal ka BP, indicating reduced precipitation. A positive trend characterizes the following interval, showing a return to wetter conditions lasting until 5 cal ka BP

Are the London Declaration’s 2020 goals sufficient to control Chagas disease?: Modeling scenarios for the Yucatan Peninsula

PubMed Central

Bartsch, Sarah M.; Skrip, Laura; Hertenstein, Daniel L.; Ndeffo-Mbah, Martial; Dumonteil, Eric O.; Galvani, Alison

2018-01-01

Background The 2020 Sustainable Development goals call for 100% certified interruption or control of the three main forms of Chagas disease transmission in Latin America. However, how much will achieving these goals to varying degrees control Chagas disease; what is the potential impact of missing these goals and if they are achieved, what may be left? Methods We developed a compartmental simulation model that represents the triatomine, human host, and non-human host populations and vector-borne, congenital, and transfusional T. cruzi transmission between them in the domestic and peridomestic settings to evaluate the impact of limiting transmission in a 2,000 person virtual village in Yucatan, Mexico. Results Interruption of domestic vectorial transmission had the largest impact on T. cruzi transmission and prevalence in all populations. Most of the gains were achieved within the first few years. Controlling vectorial transmission resulted in a 46.1–83.0% relative reduction in the number of new acute Chagas cases for a 50–100% interruption in domestic vector-host contact. Only controlling congenital transmission led to a 2.4–8.1% (30–100% interruption) relative reduction in the total number of new acute cases and reducing only transfusional transmission led to a 0.1–0.3% (30–100% reduction). Stopping all three forms of transmission resulted in 0.5 total transmission events over five years (compared to 5.0 with no interruption); interrupting all forms by 30% resulted in 3.4 events over five years per 2,000 persons. Conclusions While reducing domestic vectorial, congenital, and transfusional transmission can successfully reduce transmission to humans (up to 82% in one year), achieving the 2020 goals would still result in 0.5 new acute cases per 2,000 over five years. Even if the goals are missed, major gains can be achieved within the first few years. Interrupting transmission should be combined with other efforts such as a vaccine or improved access to

Educating Bilingual/ESL Teachers in a Language/Culture Exchange Field School: A Collaborative Model in Teacher Education.

ERIC Educational Resources Information Center

Guadarrama, Irma N.

This paper describes a program that brings bilingual and English-as-a-Second-Language (ESL) teachers from the United States to a Mexican ESL school to teach in the Tetiz (Yucatan, Mexico) field school and in exchange, learn Mayan language and culture. The theoretical base for the project is drawn from the work of major theorists in second language…

Obesogenic diets have deleterious effects on fat deposits irrespective of the nature of dietary carbohydrates in a Yucatan minipig model.

PubMed

Ochoa, Melissa; Val-Laillet, David; Lallès, Jean-Paul; Meurice, Paul; Malbert, Charles-Henri

2016-09-01

The effects of digestible carbohydrates, fructose in particular, on the development of metabolic disturbances remain controversial. We explored the effects of prolonged consumption of high-fat diets differing in their carbohydrate source on fat deposits in the adult Yucatan minipig. Eighteen minipigs underwent computed tomographic imaging and blood sampling before and after 8 weeks of three isocaloric high-fat diets with different carbohydrate sources (20% by weight for starch in the control diet, glucose or fructose, n=6 per diet). Body adiposity, liver volume, and fat content were estimated from computed tomographic images (n=18). Liver volume and lipid content were also measured post mortem (n=12). We hypothesized that the quantity and the spatial distribution of fat deposits in the adipose tissue or in the liver would be altered by the nature of the carbohydrate present in the obesogenic diet. After 8 weeks of dietary exposure, body weight (from 26±4 to 58±3 kg), total body adiposity (from 38±1 to 47±1%; P<.0001), liver volume (from 1156±31 to 1486±66 mL; P<.0001), plasma insulin (from 10±1 to 14±2 mIU/L; P=.001), triacylglycerol (from 318±37 to 466±33 mg/L; P=.005), and free-fatty acids (from 196±60 to 396±59 μmol/L; P=.0001) increased irrespective of the carbohydrate type. Similarly, the carbohydrate type did not induce changes in the spatial repartition of the adipose tissue. Divergent results were obtained for fat deposits in the liver depending on the investigation method. In conclusion, obesogenic diets alter adipose tissue fat deposits and the metabolic profile independently of the nature of dietary carbohydrates. Copyright © 2016 Elsevier Inc. All rights reserved.

Land-use change, deforestation, and peasant farm systems: A case study of Mexico's Southern Yucatan Peninsular Region

NASA Astrophysics Data System (ADS)

Vance, Colin James

This dissertation develops spatially explicit econometric models by linking Thematic Mapper (TM) satellite imagery with household survey data to test behavioral propositions of semi-subsistence farmers in the Southern Yucatan Peninsular Region (SYPR) of Mexico. Covering 22,000 km2, this agricultural frontier contains one of the largest and oldest expanses of tropical forests in the Americas outside of Amazonia. Over the past 30 years, the SYPR has undergone significant land-use change largely owing to the construction of a highway through the region's center in 1967. These landscape dynamics are modeled by exploiting a spatial database linking a time series of TM imagery with socio-economic and geo-referenced land-use data collected from a random sample of 188 farm households. The dissertation moves beyond the existing literature on deforestation in three principal respects. Theoretically, the study develops a non-separable model of land-use that relaxes the assumption of profit maximization almost exclusively invoked in studies of the deforestation issue. The model is derived from a utility-maximizing framework that explicitly incorporates the interdependency of the household's production and consumption choices as these affect the allocation of resources. Methodologically, the study assembles a spatial database that couples satellite imagery with household-level socio-economic data. The field survey protocol recorded geo-referenced land-use data through the use of a geographic positioning system and the creation of sketch maps detailing the location of different uses observed within individual plots. Empirically, the study estimates spatially explicit econometric models of land-use change using switching regressions and duration analysis. A distinguishing feature of these models is that they link the dependent and independent variables at the level of the decision unit, the land manager, thereby capturing spatial and temporal heterogeneity that is otherwise

Is Change Required? An Economic Case Study of the Rise and Fall of Empires, and Why a National Strategic Narrative Could Change the Fate of the United States Empire

DTIC Science & Technology

2011-12-01

able to account for desertion of the Southern Maya Lowlands.”267 He points to the invasion in the Yucatan Peninsula to the north and says that “even...including differences in skeletal sizes, which denotes differing levels of nutrition , recruitment or capture of rival tribesman to maintain the economic

A new anchialine Stephos Scott from the Yucatan Peninsula with notes on the biogeography and diversity of the genus (Copepoda, Calanoida, Stephidae)

PubMed Central

Suárez-Morales, Eduardo; Gutiérrez-Aguirre, Martha A.; Cervantes-Martínez, Adrián; Iliffe, Thomas M.

2017-01-01

Abstract Surveys of the anchialine crustacean fauna of the Yucatan Peninsula (YP), Mexico, have revealed the occurrence of calanoid copepods. The genus Stephos Scott, 1892, belonging to the family Stephidae is among the most frequent and widely distributed groups in anchialine caves but has not been hitherto recorded from the YP. Recent collections from an anchialine cave in an island off the northern coast of the YP yielded many specimens of a new species of Stephos. The new taxon, S. fernandoi sp. n., is described here based on male and female specimens. The new species is clearly distinguished from its congeners by the following characters: male left fifth leg with three terminal lamellae plus subdistal process, right leg with distal row of peg-like elements; female fifth leg with single long, acute apical process; genital double-somite with two rows each of 4 long spinules adjacent to operculum; legs 2-4 with articulated setae. The diversity of the genus shows regional differences; the Australia-Western Pacific region is the most diverse (eleven species), followed by the Mediterranean (seven species) and the Northeastern Atlantic (six species); only four species are known from the Northwestern Tropical Atlantic (NWTA). The morphology of the female fifth leg was examined to explore possible biogeographic trends in the genus; patterns suggest multiple colonization events in the highly diverse regions and a relatively recent radiation in the NWTA, characterized by anchialine forms. The introduction of stephid copepods in the region may be a relatively recent event derived from colonization of benthopelagic ancestral forms and subsequent invasion onto cave habitats. The new species appears to be linked to the strictly anchialine Miostephos. PMID:28769658

A new anchialine Stephos Scott from the Yucatan Peninsula with notes on the biogeography and diversity of the genus (Copepoda, Calanoida, Stephidae).

PubMed

Suárez-Morales, Eduardo; Gutiérrez-Aguirre, Martha A; Cervantes-Martínez, Adrián; Iliffe, Thomas M

2017-01-01

Surveys of the anchialine crustacean fauna of the Yucatan Peninsula (YP), Mexico, have revealed the occurrence of calanoid copepods. The genus Stephos Scott, 1892, belonging to the family Stephidae is among the most frequent and widely distributed groups in anchialine caves but has not been hitherto recorded from the YP. Recent collections from an anchialine cave in an island off the northern coast of the YP yielded many specimens of a new species of Stephos . The new taxon, S. fernandoi sp. n. , is described here based on male and female specimens. The new species is clearly distinguished from its congeners by the following characters: male left fifth leg with three terminal lamellae plus subdistal process, right leg with distal row of peg-like elements; female fifth leg with single long, acute apical process; genital double-somite with two rows each of 4 long spinules adjacent to operculum; legs 2-4 with articulated setae. The diversity of the genus shows regional differences; the Australia-Western Pacific region is the most diverse (eleven species), followed by the Mediterranean (seven species) and the Northeastern Atlantic (six species); only four species are known from the Northwestern Tropical Atlantic (NWTA). The morphology of the female fifth leg was examined to explore possible biogeographic trends in the genus; patterns suggest multiple colonization events in the highly diverse regions and a relatively recent radiation in the NWTA, characterized by anchialine forms. The introduction of stephid copepods in the region may be a relatively recent event derived from colonization of benthopelagic ancestral forms and subsequent invasion onto cave habitats. The new species appears to be linked to the strictly anchialine Miostephos .

Blood Feeding Status, Gonotrophic Cycle and Survivorship of Aedes (Stegomyia) aegypti (L.) (Diptera: Culicidae) Caught in Churches from Merida, Yucatan, Mexico.

PubMed

Baak-Baak, C M; Ulloa-Garcia, A; Cigarroa-Toledo, N; Tzuc Dzul, J C; Machain-Williams, C; Torres-Chable, O M; Navarro, J C; Garcia-Rejon, J E

2017-12-01

Blood-feeding status, gonotrophic cycle, and survival rates of Aedes (Stegmyia) aegypti (L.) was investigated in catholic churches from Merida, Yucatan. Female Ae. aegypti were caught using backpack aspirator during 25 consecutive days in rainy (2015) and dry season (2016). Blood-feeding status was determined by external examination of the abdomen and classified as unfed, fed, and gravid. Daily changes in the parous-nulliparous ratio were recorded, and the gonotrophic cycle length was estimated by a time series analysis. Also, was observed the vitellogenesis to monitoring egg maturity. In total, 408 females Ae. aegypti were caught, and there was a significant difference in the number of females collected per season (Z = -6.729, P ≤ 0.05). A great number was caught in the rainy season (n = 329). In the dry season, 79 females were caught, which the fed females were twice greatest than the unfed. The length of gonotrophic cycle was estimated on the base of a high correlation coefficient value appearing every 4 days in rainy at 26.7 ± 1.22°C, and 3 days in dry season at 29.8 ± 1.47°C. The daily survival rate of the Ae. aegypti population was higher in both seasons, 0.94 and 0.93 for the rainy and dry season, respectively. The minimum time estimated for developing mature eggs after blood feeding was similar in both seasons (3.5 days in rainy versus 3.25 days in dry). The measurement of the vectorial capacity of Ae. aegypti in catholic churches could help to understand the dynamics of transmission of arboviruses in sites with high human aggregation.

Meat and Fish Entree Item Production Guides Prepared for Walter Reed Army Medical Center

DTIC Science & Technology

1977-04-01

Onion, powdered 0.43 Coriander, ground 0.29 Pepper, white 0.04 Starch, Col-Flo 67 0. 67 PERCH YUCATAN F-4 Pounds 26.45 0.62 8,89 1. 78 1.29...formula weight or volume. 10. Chill to 50°F (l0°C). 11. Pour 22 oz (624 g) over perch in half-size steam table pans. PERCH YUCATAN Can’t Ingredients...yield of perch. Weight or cooked perch equals 20.63 pounds (9358 g). 47 PERCH YUCATAN Fish 1. Perch 1 f’rozen, f’illets - NSN-8905-00-164-0485, Fed

A Kinematic Model for Opening of the Gulf of Mexico between 169-150 Ma

NASA Astrophysics Data System (ADS)

Harry, D. L.; Jha, S.

2016-12-01

Lineated magnetic anomalies interpreted to be seafloor spreading isochrons are identified in the central and eastern Gulf of Mexico. The southernmost of these anomalies coincides with a strong positive vertical gravity gradient interpreted to mark the location of the extinct spreading ridge in the Gulf. Together, the magnetic and gravity anomalies reveal a concave-south fossil spreading system that accommodated counterclockwise rotation of Yucatan away from North America during Jurassic opening of the Gulf. Magnetic models show that the magnetic lineations correlate with geomagnetic time scale chrons M22n (150 Ma), M33n (161 Ma), M39n (165 Ma), and Toar-Aal N (174 Ma). M22n lies astride the fossil ridge and defines the age at which seafloor spreading ended. M33n lies between the ridge and the Florida shelf. M39n lies close to the shelf edge in the eastern Gulf. Taor-Aal N is the oldest recognized seafloor spreading anomaly and is present only in the central Gulf, laying near the ocean-continent transition (OCT). The magnetic anomalies define an Euler pole located at 22°N, 82ºW. Rotating Yucatan clockwise 29° about this pole places the northeast Yucatan shelf edge tightly against the southwestern Florida shelf, closing the southeastern Gulf. An additional 12° clockwise rotation juxtaposes the OCT on the northwestern Yucatan margin against the North American OCT in the central Gulf. These constraints on Yucatan's past position indicate that continental extension propagated from the western into the eastern Gulf between 215-174 Ma as Yucatan began to rotate away from North America. Seafloor spreading began 174 Ma and was asymmetric, with all extension occurring north of the spreading ridge. Symmetric seafloor spreading was established by 165 Ma and continued until 150 Ma. A total of 41°counterclockwise rotation of Yucatan relative to North America is predicted to have occurred during continental extension and seafloor spreading.

Proline supplementation to parenteral nutrition results in greater rates of protein synthesis in the muscle, skin, and small intestine in neonatal Yucatan miniature piglets.

PubMed

Brunton, Janet A; Baldwin, Mark P; Hanna, Rodney A; Bertolo, Robert F

2012-06-01

Proline and arginine are each indispensable during parenteral feeding due to limited interconversion by an atrophied gut. Commercial amino acid parenteral products designed for neonates contain proline concentrations that differ by almost 4-fold. To assess the adequacy of the lowest concentration of proline provided in commercial total parenteral nutrition (TPN) products, we compared rates of tissue-specific protein synthesis and nitrogen balance in neonatal piglets provided TPN at 2 different proline concentrations. Yucatan miniature piglets (9-11 d old, n = 12) were randomized to complete isonitrogenous TPN diets with low proline (LP; L-proline as 3% of amino acids) or proline supplemented (PS; 9%). After 7 d of receiving TPN, rates of protein synthesis in liver, gastrocnemius muscle, jejunal mucosa, and skin were determined by the flooding dose technique and tissue free amino acids were measured. Nitrogen balance was assessed during the last 3 d. The LP TPN resulted in lower free proline concentrations in plasma, muscle, and skin (P < 0.05) and lower rates of protein synthesis in the jejunum (by 25%; P = 0.02), muscle (by 45%; P = 0.015), and skin (by 60%; P = 0.01); there was no difference in liver. Nitrogen retention was 20% lower in the LP group (P = 0.01). In conclusion, muscle and skin protein synthesis was profoundly sensitive to parenteral proline supply and the reduced protein synthesis in the intestine could affect intestinal integrity. Low-proline TPN solutions that are currently in wide use in neonatal care may result in impaired tissue growth.

Voices of Mayan Women in Plaza Comunitaria: Poética y Educación Desde Yucatán

ERIC Educational Resources Information Center

Ceballos Zapata, Abraham

2017-01-01

This study took place in a village in Yucatan, Mexico in the context of two adult education programs in Yucatan [Plaza Comunitaria and Preparatoria Abierta]. I interacted in "convivencia" with bilingual (Mayan-Spanish) Yucatec Mayan women who took on the challenge of completing their formal schooling through those adult education…

Ex Vivo Pharmacodynamics of Amoxicillin-Clavulanate against β-Lactamase-Producing Escherichia coli in a Yucatan Miniature Pig Model That Mimics Human Pharmacokinetics

PubMed Central

Bronner, Stéphane; Murbach, Valérie; Peter, Jean-Daniel; Levêque, Dominique; Elkhaïli, Hassan; Salmon, Yves; Dhoyen, Nathalie; Monteil, Henri; Woodnutt, Gary; Jehl, François

2002-01-01

The objective of the present study was to investigate the potential bactericidal activity of amoxicillin-clavulanate against β-lactamase-producing Escherichia coli strains and to elucidate the extent to which enzyme production affects the activity. Six adult Yucatan miniature pigs received a single intravenous dose of 1.1 g of amoxicillin-clavulanate as an intravenous infusion over 30 min. The pharmacokinetic parameters were determined for the serum samples and compared to the published data for humans (2.2-g intravenous dose). The parameters were comparable for the two species, and therefore, the miniature pig constitutes a good model for pharmacodynamic study of amoxicillin-clavulanate. Therefore, the model was used in an ex vivo pharmacodynamic study of amoxicillin-clavulanate against four strains of Escherichia coli producing β-lactamases at different levels. The E. coli strains were cultured with serial dilutions (1:2 to 1:256) of the serum samples from the pharmacokinetic study, and the number of surviving bacteria was determined after 1, 3, and 6 h of exposure. Amoxicillin-clavulanate at concentrations less than the MIC and the minimal bactericidal concentration had marked bactericidal potency against the strain that produced low levels of penicillinase. For high-level or intermediate-level β-lactamase-producing strains, the existence of a clavulanate concentration threshold of 1.5 to 2 μg/ml, below which there was no bactericidal activity, was demonstrated. The index of surviving bacteria showed the existence of mixed concentration- and time-dependent actions of amoxicillin (in the presence of clavulanate) which varied as a function of the magnitude of β-lactamase production by the test strains. This study shows the effectiveness of amoxicillin-clavulanate against low- and intermediate-level penicillinase-producing strains of E. coli. These findings are to be confirmed in a miniature pig experimental infection model. PMID:12435677

Surf Zone Sediment Size Variation, Morphodynamics, and Hydrodynamics During Sea/Land Breeze and El-Norte Storm in Sisal, Yucatan, Mexico

NASA Astrophysics Data System (ADS)

Alrushaid, T.; Figlus, J.; Torres-Freyermuth, A.; Puleo, J. A.; Dellapenna, T. M.

2016-02-01

Coastlines around the world are under ever-increasing pressure due to population trends, commerce, and geophysical processes like tropical storms and erosion. This multi-institutional field campaign was conducted to improve our understanding of complex nearshore processes under varying forcing conditions on a microtidal, sandy beach located in Sisal, Yucatan from 3/27 to 4/12/2014. Hydrodynamics, morphodynamics, and textural variability were investigated during: (1) a cold front event (referred to as El-Norte); (2) land breeze (LB); and (3) sea breeze (SB). The instrumentation layout included three surf/swash zone cross-shore transects where water elevation, suspended sediment concentration, bed load, and current velocities were measured, as well as several offshore ADCP for hydrodynamic measurements. TKE, τb, ɛ and were estimated using the data obtained from surf zone ADV. In addition, Hs and Tsin the surf zone were computed using measurements from ADV pressure sensors, while a separate pressure transducer was used to obtain water free-surface elevation within the swash zone. During SB cycles the study area experienced wind velocities reaching up to 12ms-1, and 15ms-1 during El-Norte. Elevated wind stress during El-Norte resulted in Hs of 1.5m and 0.6m in water depths of 10m and 0.4m, respectively. Surface sediment grab samples during SB/LB cycles showed that the swash zone had a moderately well sorted distribution with a mean grain size of 0.5mm, while poor sorting and a mean grain size of 0.7mm were found during El-Norte. Additionally, measured bathymetry data showed evidence for offshore sandbar migration during strong offshore currents (0.4ms-1) during El-Norte, while onshore sandbar migration was evident during SB/LB periods (0.3ms-1 and 0.1ms-1, respectively). This study highlights how different weather forcing conditions affect hydrodynamics, morphodynamics, and textural variability on a sandy beach. Aside from furthering our knowledge on these complex

Sedimentology, Petrography and Microfacies of the Paleogene Carbonate Sequence - Yaxcopoil-1 Borehole (Chicxulub, Yucatan)

NASA Astrophysics Data System (ADS)

Escobar-Sanchez, E.; Fucugauchi, J. U.

2013-05-01

Chicxulub crater is one the three largest known impact craters on Earth, formed 66 Ma-old, with multi-ring basin morphology. Crater is located in northwestern Yucatan, southern Gulf of Mexico, with rim diameter of 200 km and crater center at Chicxulub Perto in the coastline. It is buried beneath the carbonate and evaporitic Cenozoic sequence. Study of the structure requires geophysics and drilling, with several boreholes drilled in the peninsula. The Yaxcopoil-1 borehole was drilled south of Merida, about 62 km from center, as part of the Chicxulub Scientific Drilling Program. One of the main objectives was to determine the role of the Chicxulub impact event in the K/Pg mass extinction and boundary events. We present a sedimentological and petrological study of the carbonate sequence in the interval from 404 m to 792 m overlying the K/Pg boundary. The well reached a depth of 1510.6 m. In this interval, we identified twelve units marked by different lithological and sedimentological changes, and supplemented by thin section analysis. Facies are composed mainly of marls, argillaceous, limestones, dolomitized limestones, calcareous breccias and calcarenites with shales thin beds. From the microfacies study we observed several major changes in the microfacies. From bottom of the sequence several textural changes cyclic from mudstone to bioclastic planktic foraminiferal wackestone, bioclastic packstone and some bioclastic grainstone. Two textures dominated in the calcareous sequence: bioclastic wackestone and packstone microfacies. From the microfacies study, we derived inferences on stable environmental conditions. We observed benthic and planktic foraminiferal layers. The benthic foraminifera strongly depend on environmental parameters, such as nutrient supply or oxygenation of the sea bottom water in the Paleocene and Eocene. Changes suggest occurrence of a progradational event, with a relative increase in sea level very slowly, with the sediment enough to overcome

Arriba! Building Teamwork and a Ropes Course in Mexico.

ERIC Educational Resources Information Center

Fullerton, Jim; Davis, Scot G.

A staff member of the Outdoor Adventures Program at the University of Nebraska-Lincoln relates his experience in supervising the construction of the first low ropes course in Yucatan, Mexico. During 1994, two staff members visited Yucatan to explore trip possibilities for the program and to inquire about a future conference location. While leading…

An Alternative Method of Evaluating 1540NM Exposure Laser Damage using an Optical Tissue Phantom

DTIC Science & Technology

2006-11-01

experimentation at this wavelength. Most experiments have been done using Yucatan and Yorkshire pig skin since it is very similar to human skin. Alexei...3.82 Guinea Pig 9 3.0 Domestic Pig - (Lukashev) 5, 6 3.2 Yucatan Mini-Pig (Zohner) 22 6.1 Figure 5. Laser exposure damage (8.39 J/cm 2) to resin, viewed

Yucatan Subsurface Stratigraphy from Geophysical Data, Well Logs and Core Analyses in the Chicxulub Impact Crater and Implications for Target Heterogeneities

NASA Astrophysics Data System (ADS)

Canales, I.; Fucugauchi, J. U.; Perez-Cruz, L. L.; Camargo, A. Z.; Perez-Cruz, G.

2011-12-01

Asymmetries in the geophysical signature of Chicxulub crater are being evaluated to investigate on effects of impact angle and trajectory and pre-existing target structural controls for final crater form. Early studies interpreted asymmetries in the gravity anomaly in the offshore sector to propose oblique either northwest- and northeast-directed trajectories. An oblique impact was correlated to the global ejecta distribution and enhanced environmental disturbance. In contrast, recent studies using marine seismic data and computer modeling have shown that crater asymmetries correlate with pre-existing undulations of the Cretaceous continental shelf, suggesting a structural control of target heterogeneities. Documentation of Yucatan subsurface stratigraphy has been limited by lack of outcrops of pre-Paleogene rocks. The extensive cover of platform carbonate rocks has not been affected by faulting or deformation and with no rivers cutting the carbonates, information comes mainly from the drilling programs and geophysical surveys. Here we revisit the subsurface stratigraphy in the crater area from the well log data and cores retrieved in the drilling projects and marine seismic reflection profiles. Other source of information being exploited comes from the impact breccias, which contain a sampling of disrupted target sequences, including crystalline basement and Mesozoic sediments. We analyze gravity and seismic data from the various exploration surveys, including multiple Pemex profiles in the platform and the Chicxulub experiments. Analyses of well log data and seismic profiles identify contacts for Lower Cretaceous, Cretaceous/Jurassic and K/Pg boundaries. Results show that the Cretaceous continental shelf was shallower on the south and southwest than on the east, with emerged areas in Quintana Roo and Belize. Mesozoic and upper Paleozoic sediments show variable thickness, possibly reflecting the crystalline basement regional structure. Paleozoic and Precambrian

Lead from hunting activities and its potential environmental threat to wildlife in a protected wetland in Yucatan, Mexico.

PubMed

Arcega-Cabrera, Flor; Noreña-Barroso, Elsa; Oceguera-Vargas, Ismael

2014-02-01

This study provides insights into the status of lead in the protected wetland of El Palmar, located on the northwestern littoral of the Yucatan Peninsula. This reserve is ecologically and economically important because it provides feeding and breeding habitats for many species, as well as being an ecotourism destination (especially for bird watching). Although it is a protected area, duck species are heavily hunted within the reserve during the winter. As a result, animals feeding or living in sediments could be exposed to anthropogenic lead. Total lead and its geochemical fractionated forms were measured in sediment cores from six selected sites in "El Palmar" wetland, during pre- and post-hunting seasons, to approximate the potential environmental threat (especially for benthonic living/feeding organisms). Anthropogenic lead concentrations detected in soil cores ranged from below the minimum infaunal community effect level (30.24 μg g(-1)) during the pre-hunting season, to bordering the probable infaunal community effect level (112.18 μg g(-1)) during the post-hunting season, according to SquiiRTs NOAA guidelines. Yet, these results were lower than expected based on the intensity of hunting. Consequently, this article explores the possibility that the lower than expected lead concentration in sediments results from (1) degradation of shot and transformation to soluble or particulate forms; or (2) ingestion of lead shot by benthic and other lacustrine species living in the protected area. Geochemical fractionation of lead demonstrated that in the top 6 cm of the soil column at heavily active hunting sites (EP5 and EP6), lead was associated with the lithogenic fraction (average 45 percent) and with the organic fraction (average 20 percent). Bioavailable lead (sum of lead adsorbed to the carbonates, Fe/Mn oxyhydroxides and organic fractions) in sediments was lower than 50 percent for the heavily active hunting areas and higher for the rest of the sites

Childhood obesity and insulin resistance in a Yucatan mini-piglet model: putative roles of IGF-1 and muscle PPARs in adipose tissue activity and development.

PubMed

Sébert, S P; Lecannu, G; Kozlowski, F; Siliart, B; Bard, J M; Krempf, M; Champ, M M-J

2005-03-01

To explore metabolic and cellular modifications induced during childhood obesity, in a novel animal model of obese mini-piglets. A total of 10 four-month old Yucatan mini-pigs were followed from prepuberty to adulthood. Animals were divided into two groups. The first one had been overfed (OF) a western-type diet and the second one had been normally fed a control recommended human-type diet (NF). Plasma insulin-like growth factor 1 (IGF-1), insulin, leptin, nonesterified fatty acids, triglycerides (TGs) and glucose were determined at sexual maturity and at young adulthood. Quantitative gene expressions of peroxysome-proliferator-activated receptors (PPARs), glucose transporter 4, insulin receptor, IGF-1, leptin and interleukin-6 (IL-6) in skeletal muscle, adipose tissue and liver were also measured at both stages. Adult insulin sensitivity was measured via euglycaemic-hyperinsulinaemic clamps. Increased body weight in adult OF pigs was associated with increased body size and low insulin sensitivity. Sexually mature OF pigs had higher IGF-1 plasma concentrations than their lean littermates (P < 0.05). In the OF group, TGs and glucose were both decreased (P < 0.05). Muscle PPARgamma and alpha in OF pubescent pigs as compared to NF pigs were 11 times higher and 20 times lower, respectively (P < 0.01). Obesity and insulin resistance induced by overfeeding mini-pigs during development and puberty were not associated with the cluster of metabolic modifications frequently observed in their adult littermates. Increased IGF-1 concentrations and modifications of skeletal muscle PPAR (alpha and gamma) expressions may help the young obese pig to partially regulate its glycaemia and triglyceridaemia through an increase of fat mass, which maintains its high insulin sensitivity.

[Knowledge of vector-borne diseases (dengue, rickettsiosis and Chagas disease) in physicians].

PubMed

Lugo-Caballero, César I; Dzul-Rosado, Karla; Dzul-Tut, Irving; Balam-May, Ángel; Zavala-Castro, Jorge

2017-01-01

The ecological conditions of Yucatan made it a suitable region for the acquisition of vector-borne diseases such as dengue, rickettsiosis, and Chagas disease. As the epidemiological burden of these diseases shows an alarming increase of severe cases, the early establishment of diagnosis and therapeutics by first-contact physicians is a critical step that is not being fulfilled due to several reasons, including poor knowledge. To determine the level of knowledge related to dengue, Chagas disease, and rickettsiosis among rural first-contact physicians of Yucatan. A survey was applied to 90 first-contact physicians from rural clinics of Yucatan, which included 32 items related to the diagnosis, treatment, and prevention of dengue, rickettsiosis, and Chagas disease. Answers were analyzed by central tendency statistics. Differences were observed among every category, however; diagnosis and therapeutics showed the lower values. Globally, 62.5% of respondents showed moderate knowledge, 37.5% poor knowledge, and 0% adequate knowledge. Results suggest that a strong campaign for a continuous diffusion of knowledge regarding these diseases is needed. In regions with high prevalence of these kinds of diseases, like Yucatan, the impact of these results on the epidemiological burden of these diseases must be evaluated.

Military Review: The Professional Journal of the U.S. Army, July-August 2008

DTIC Science & Technology

2008-08-01

do you want the united States to make war on one man? Suppose he should get on the train and go to Guatemala, yucatan , or South america; are you...educated. In addition, educated women tend to meet their families’ nutrition and health needs. as Stephen C. Smith and Michael Todaro have found...later marriage, lower fertility, and greatly improved child health and nutrition .”11 In fact, “studies from around the developing world consistently

Influence of maternal stature, pregnancy age, and infant birth weight on growth during childhood in Yucatan, Mexico: a test of the intergenerational effects hypothesis.

PubMed

Varela-Silva, Maria Inês; Azcorra, Hugo; Dickinson, Federico; Bogin, Barry; Frisancho, A R

2009-01-01

In developing nations, obesity has increased dramatically in the last decade, but a high prevalence of stunting still coexists. The intergenerational influences hypothesis (IIH) is one explanation for this. We test the IIH regarding variation in maternal stature, mother's age at pregnancy, and infant birth weight in relation to risk for overweight and stunting in 206 Maya children (4-6 years old) from Mérida, Yucatan, Mexico. The Maya children are compared with growth references (Frisancho 2008: Anthropometric Standards: An Interactive Nutritional Reference of Body Size and Body Composition for Children and Adults. Ann Arbor, MI: The University of Michigan Press. 335 pp) for height, weight, and body mass index (BMI). Almost 70% of the mothers are shorter than 150 cm. Mothers' height and child's birth weight predict overweight. Children with a mother shorter than 150 cm are less than half as likely (OR = 0.44) to be overweight compared to children whose mothers are equal to or taller than 150 cm. Children with birth weights below 3,000 g are only a third as likely to be overweight (OR = 0.28) than their peers within the range of normal birth weight (3,000-3,500 g). Sex of the child, mother's height, and birth weight predict stunting. Girls are only 40% as likely as boys to be stunted. Children with a mother below 150 cm are 3.6 times more likely of being stunted. Children with birth weights below 3000 g are over 3 times more likely to be stunted relative to children with birth weights within the normal range. Mother's age at pregnancy is not a predictor of overweight or stunting. Our findings conform the IIH and with similar studies of populations undergoing nutritional/epidemiological transitions from traditional to globalized lifestyles.

Interannual variability in the extent and intensity of tropical dry forest deciduousness in the Mexican Yucatan (2000-2016): Drivers and Links to Regional Atmospheric Conditions

NASA Astrophysics Data System (ADS)

Cuba, Nicholas Joseph

The dry topical forests of the southern Yucatan Peninsula experience multiple natural and anthropogenic disturbances, as well as substantial interannual climate variability that can result in stark interannual differences in vegetation phenology. Dry season deciduousness is a typical response to limit tree water loss during prolonged periods of hot and dry conditions, and this behavior has both direct implications for ecosystem functioning, and the potential to indicate climate conditions when observed using remotely-sensed data. The first research paper of this dissertation advances methods to assess the accuracy of remotely-sensed measurements of canopy conditions using in-situ observations. Linear regression models show the highest correlation (R2 = 0.751) between in-situ canopy gap fraction and Landsat NDWISWIR2. MODIS time series NDWISWIR2 are created for the period March 2000-February 2011, and exhibit stronger correlation with time series of TRMM precipitation data than do MODIS EVI time series (R2= 0.48 vs. R2 = 0.43 in deciduous forest areas). The second paper examines differences between the deciduous phenology of young forest stands and older forest stands. Land-cover maps are overlaid to determine whether forested areas are greater than or less than 22 years old in 2010, and metrics related to deciduous phenology are derived from MODIS EVI2 time series in three years, 2008 to 2011. Statistical tests that compare matched pairs of young (12-22 years) and older (>22 years) forest stand age class samples are used to detect significant differences in metrics related to the intensity and timing of deciduousness. In all three years, younger forests exhibit significantly more intense deciduousness, measured as total seasonal change of EVI2 normalized by annual maximum EVI2 (p<0.001), and exhibit larger EVI2 declines at successive 32-day periods during dry season months (p<0.02), than nearby older forests that are assumed to share similar environmental

Women in Insurgent Groups in Latin America

DTIC Science & Technology

2014-03-01

Yucatan region by Spaniards went through a strong inquisition to convert indigenous souls, who struggled unsuccessfully to keep their identity and...the God through the representatives of the Crown. 109 Inga Clendinnen, Ambivalent Conquest: Maya and Spaniard in Yucatan , 1517–1570 (Cambridge...health and nutritional standards among the children of indigenous peoples; it must also support, on an egalitarian basis, the training of women

Clinical Investigation Program Annual Progress Report

DTIC Science & Technology

1993-09-30

272 93/200A 0 Comparison of Healing Rates of Bones Plated Following Fracture, Among Yucatan Swine Having Open and Closed Physes...Study Objective: Compare two enteral formulas in respect to nutritional aspects. (16) Technical Approach: Protocol will take place in SICU. (17...Protocol #: 93/200A (3) Status: Ongoing (4) Title: Comparison of Healing Rates of Bones Plated Following Fractures, Among Yucatan Swine Having Open and

Advanced Medical Countermeasures Consortium

DTIC Science & Technology

2010-10-01

acid, gamma-linolenic acid, and antioxidants in patients with acute respiratory distress syndrome. Enteral Nutrition in ARDS Study Group. Crit Care Med...molecular mechanism of action, and (3) efficacy of countermeasures for HD injury. Studies on the Yucatan mini-pig have demonstrated that laminin in...Lindsay CD, Rice P. Changes in connective tissue macromolecular components of Yucatan mini-pig skin following application of sulphur mustard vapour. Hum

Revisiting the Mesozoic opening of the Southeastern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Marton, G.; Pascoe, R. P.

2016-12-01

The Southeastern Gulf of Mexico (SEGOM) is defined here as the seaway between Yucatan and Florida, south of the Tampa Embayment. This area is regarded as a southward propagating rift in the Gulf of Mexico. There is an overwhelming amount of previous evidence that the Yucatan block rotated counterclockwise about 42 degrees around a pole located just north of present-day Cuba (23oN, 84oW) during the Late Jurassic to Earliest Cretaceous oceanic spreading phase. North of the pole in the SEGOM the rotational movement of Yucatan was accommodated by a uniformly increasing amount of SW-NE extension. The degree of extension north of 25oN was large enough to result in rifting and oceanic spreading. Lack of salt in the area south of the Tampa embayment indicates that the SEGOM was not affected by the large amount of NW-SE continental extension as observed in the rest of the Gulf of Mexico. Thus, the area between Yucatan and the Sarasota arch remained a land bridge between the proto- GOM and the Proto-Caribbean and formed a barrier to salt deposition. During the period of late Jurassic oceanic crust formation (and Yucatan rotation), the southern tip of the oceanic spreading center propagated south from 27oN to 25oN, or about 220 km. In the 220 km long zone from 25oN to the pole (23oN) the rotation of Yucatan was accommodated by continental rifting only. The validity of the above outlined propagating rift model in the SEGOM is also supported by the age differences in the observed post-rift unconformities along its margins. At the edge of the salt basin to the north, the post-rift unconformity in the upper crust occurs at the base of the Louann salt and thus is Callovian in age. In the southern continental rift segment of the SEGOM, a seismic to well tie at the DSDP Site 535 shows that the post-rift unconformity is no younger than Late Berriasian to Early Valanginian. This latter age bracket constrains a) the cessation of continental rifting in the SEGOM, b) the time when the

The Annual Meeting of the American Society of Tropical Medicine and Hygiene (38th) Held in Honolulu, Hawaii on 10-14 December 1989

DTIC Science & Technology

1991-01-01

FOR IgG ANTIBODIES TO LEISHMANIA MEXICANA MEXICANA. M.R. Garcia*, F. Andrade, R. Esquivel, E. Simmonds, S. Canto, and A.L. Cruz. University of Yucatan ...Baltimore, MD; Universidad Peruana Cayetano Heredia; and Instituto de Investigacin Nutricional .?? 4:15 437 CHICKENPOX IN THE U.S. ARMY: A DEVELOPING... Yucatan (Mexico) Tropical Diseases Research Unit. Reference Center for Leishmaniasis Control. A total of 223 sera from human beings were processed by

The Proceedings of the Hypobaric Decompression Sickness Workshop Held in Armstrong Laboratory, Brooks AFB, Texas on 16-18 October 1990.

DTIC Science & Technology

1992-06-01

exhibited by humans, ostium secundum (15) and, like humans with PFO, are generally a3ymptomatic. Yucatan Miniature Swine exhibited an incidence of 8...W. Corin; A. Fazel; W.W.R. Biederman; F.G. Spinale and P.C. Gillette. Heritable Ventricular Septal Defect In Yucatan Miniature Swine. Laboratory...of sleep, poor nutrition , and recent illness; exercising prior to flight (two separate cases of bends); dehydration. 448 Immediately following are 7

Research in Biological and Medical Sciences, Including Biochemistry, Communicable Disease and Immunology, Internal Medicine, Nuclear Medicine, Physiology, Psychiatry, Surgery, and Veterinary Medicine. Volume 1

DTIC Science & Technology

1975-07-01

Preparation of immunoglobulins for lodonation. Goat anti-rabbit gamma globulin (GARG) was obtained from Nutritional Biochemlcals as the 7S fraction of the...upon the parasite of the Yucatan peninsula - British Honduras area, primarily upon the basis of its apparent failure to ever cause mucocutaneous...to Texas is Yucatan , where only L. mexicana is known to occur. With no intent to imply an argument for subspecies status, this isolate will

Development of an Injectable Salmon Fibrinogen-Thrombin Matrix to Enhance Healing of Compound Fractures of Extremities

DTIC Science & Technology

2012-09-01

first responder. Many factors may contribute to non-union of fractures, including nutritional or hormonal status, age of the patient, and presence of...of transdermal 420 fentanyl (100 µg/h) in Yucatan minipigs, plasma fentanyl concentration peaked within 48 hours, 421 with peak concentrations...3rd, Morse BC. 2001. Evaluation of a transdermal fentanyl system in 612 yucatan miniature pigs. Contemp Top Lab Anim Sci 40:12-16. 613 50. Wolfe

The Development of Therapeutic and Diagnostic Countermeasures to WMD by the Advanced Medical Countermeasures Consortium

DTIC Science & Technology

2008-09-01

and antioxidants in patients with acute respiratory distress syndrome. Enteral Nutrition in ARDS Study Group. Crit Care Med 27: 1409–1420, 1999. 30...mechanism of action, and (3) efficacy of countermeasures for HD injury. Studies on the Yucatan mini-pig have demonstrated that laminin in the dermo...Rice P. Changes in connective tissue macromolecular components of Yucatan mini-pig skin following application of sulphur mustard vapour. Hum Exp Toxicol

Theater Missile Defense Extended Test Range Supplemental Environmental Impact Statement - Eglin Gulf Test Range. Volume 1

DTIC Science & Technology

1998-07-01

facilities No existing infrastructure or utilities Yucatan Peninsula, Mexico Not on DOD property Expense due to logistics Matagorda Island... nutritive or harmful substances from the soil by percolation of a liquid Lead—a heavy metal which can accumulate in the body and cause a variety of negative...THE YUCATAN PENINSULA, MEXICO ............ 2-74 2.3.3 LAUNCH FROM MATAGORDA ISLAND, TEXAS ..................... 2-74 2.3.4 LAUNCH FROM BOCA CHICA KEY

Complex Population Patterns of Eunica tatila Herrich-Schäffer (Lepidoptera: Nymphalidae), with Special Emphasis on Sexual Dimorphism.

PubMed

Cavanzón-Medrano, L; Pozo, C; Hénaut, Y; Legal, L; Salas-Suárez, N; Machkour-M'Rabet, S

2016-04-01

The species Eunica tatila (Herrich-Schäffer) is present in the Neotropical region and comprises three subspecies. In Mexico, only one subspecies is reported: E. t. tatila (Herrich-Schäffer). The Yucatan Peninsula, in southeastern Mexico, is located in a transitional geographical position, between southern Florida, the West Indies and Central America. It is part of a transitional region, important for the dispersion of insects from southern Florida via Cuba and the Yucatan Peninsula. Considering the possibility of the overlapping and delimitation of described subspecies, we sampled different populations in the Yucatan Peninsula to possibly assign a subspecies name and evaluate the magnitude of sexual dimorphism. We collected 591 individuals (♀284, ♂307) in conserved areas. The study of male genitalia led to the identification of Eunica tatila tatilista (Kaye) as a subspecies; however, hypandrium structure and wing pattern analysis suggest a mix of E. t. tatila and E. t. tatilista characteristics. The analysis of sexual dimorphism provided evidence of more complex wing morphs for females, with 12 patterns instead of four as previously described. Our results demonstrate the complexity of characterizing E. tatila and suggest that the Yucatan Peninsula is a transitional zone for subspecies of some butterflies.

Research Program In Tropical Infectious Diseases

DTIC Science & Technology

1991-12-15

Central America at the base of the Yucatan Peninsula, surrounded on the west and north by Guatemala and Mexico and on the east by the Caribbean Sea...inferred that in Belize, 2 tropical infectious diseases are common. Yellow fever has been known to occur in the Yucatan ,1 dengue and malaria are...Centro Americano) representatives in Belize City. Two ERC technologists and two CML technicians attended an INCAP (Instituto de Nutricion de Centro

The Susceptibility and Behavioral Response of Anopheles Albimanus Weidemann and Anopheles Vestitipennis Dyar and Knab (Diptera: Culicidae) to Insecticides in Northern Belize, Central America

DTIC Science & Technology

1999-01-01

modem existence. Withoutth~ the general lifestyle we enjoy today with regards to our health and nutrition would probably be different in many respects...Palacios (1956) described it occurring in the coastal zones ofthe GulfofMexico in southern Mexico and the Yucatan ; however, it is also found commonly...located on the southeastern part of the Yucatan peninsula ofCentral America (Fig. 5). Belize has a total land area of21,400 square kilometers and a

Commerce Raiding: Historical Case Studies, 1755-2009

DTIC Science & Technology

2013-10-01

Ariel proceed under bond.26 On 23 December, Alabama met Agrippina at the Arcas Islands off Yucatan and spent a week there taking on supplies and...as the population on the home islands. In particular, the U.S. unrestricted campaign dra- matically reduced the nutritional intake of most Japanese...See Jeune École Yucatan 80 Yusuf, Abdullahi 260, 262–63 Z Z, Operation 182 Zanzibar 128 Zeebrugge 140 Zhili Province 105, 108 The Newport

Development of a Toxin Knowledge System

DTIC Science & Technology

1990-11-12

HYPERTENSIVE 1379, 1977 YUCATAN MINIATURE SWINE, PROC SOC EXP BIOL MED 178:591-598,1985 (1329) Campbell RL, Bomeyer BE, Yam J: EFFECTS OF MIXED...BF, I-bu I-C_ DEOXYCORTICOSTERONE ACETATEHYPERTENSIVE IN VITRO BINDING OF AFLATOXIN BI AND 2- YUCATAN MINIATURE SWINE. CAN J PI-YSIOL PHARMACOL...Hamilton RMG,Trenholm HL- OBSERVATIONSCN (465) Hear LP, Graseltn WE JR,, Stebbins TC. PRODUC- THE CHEMICAL AND NUTRITIVE CONTENT OF WHITE WIN- lION OF

Topical Application of Liposomal Antioxidants for Protection Against CEES Induced Skin Damage

DTIC Science & Technology

2008-06-01

The DSM Nutritional Products (www.dsm.com ) supplied us with 100 g quantities of mixed tocopherols (with a very high content of γ-tocopherol) for...Studies on the Yucatan mini-pig have demonstrated that laminin in the dermo-epithelial junction is a target for partial protease degradation following HD...therapies. J Burns Wounds. 2005;4:e1. 14. Lindsay CD, Rice P. Changes in connective tissue macromolecular components of Yucatan mini-pig skin

The Development of Therapeutic and Diagnostic Countermeasures to WMD by the Advanced Medical Countermeasures Consortium

DTIC Science & Technology

2007-09-01

pantothenate mixture. J. Ocul. Pharmacol. Ther. 1998; 14: 423–428. 14. Brown RFR, Rice P. Histopathological changes in Yucatan minipig skin following...antioxidants in patients with acute respiratory distress syndrome. Enteral Nutrition in ARDS Study Group. Crit Care Med 27: 1409–1420, 1999. 30. Galley HF...countermeasures for HD injury. Studies on the Yucatan mini-pig have demonstrated that laminin in the dermo-epithelial junction is a target for partial

Calling Behavior, Copulation Time, and Reproductive Compatibility of Corn-Strain Fall Armyworm (Lepidoptera: Noctuidae) From Populations in Mexico.

PubMed

Cruz-Esteban, Samuel; Rojas, Julio C; Malo, Edi A

2017-08-01

The calling behavior, mating time, and the reproductive compatibility of virgin adults of fall armyworms, Spodoptera frugiperda (J. E. Smith), were studied in this work. Larvae were collected on maize (Zea mays L.) from six states located on the Pacific coast (Chiapas, Michoacán, and Sinaloa), on the Gulf of Mexico (Veracruz and Yucatan), and in central Mexico (Morelos). Before the experiments, insects were reared under laboratory conditions for one generation. We recorded the age at which females called for the first time, the onset time of calling, the duration of calling, the onset time of copulation, and the duration of copulation. The calling rhythms of the six populations were dissimilar. Females from all populations began to call in the second or third scotophase. The time for onset of calling and the duration of calling were significantly different among the S. frugiperda populations studied. Spodoptera frugiperda pairs from Sinaloa, Veracruz, Yucatan, and Morelos started to copulate earlier than the pairs from Chiapas and Michoacán. Pairs from Veracruz and Yucatan copulated longer than those from Michoacán, Morelos, Chiapas, and Sinaloa. Our crossing experiment using females and males from the six populations showed that individuals from different populations could copulate and produce fertile offspring. Thus, although the S. frugiperda populations showed variability in the timing of reproduction, the populations were not reproductively incompatible, which indicated that geographic distance has not led to reproductive isolation in corn-strain populations of S. frugiperda in Mexico. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of income supplementation on health of the poor elderly: the case of Mexico.

PubMed

Aguila, Emma; Kapteyn, Arie; Smith, James P

2015-01-06

We use an income supplementation experiment we designed in the state of Yucatan in Mexico for residents 70 y and older to evaluate health impacts of additional income. Two cities in the State of Yucatan, Valladolid (treatment) and Motul (control), were selected for the income supplementation experiment. Elderly residents of Valladolid were provided the equivalent of an additional $67 per month, a 44% increase in average household income. We designed a survey given to residents of both cities before and 6 mo after the income supplement about their health and other aspects of overall well-being. Both baseline and follow-up surveys collect self-reported data on health, physical functioning, and biomarkers. Anthropometric measurements for every age-eligible respondent, including height, weight, and waist circumference, were collected. We also collected lung capacity, grip strength, a series of balance tests, and a timed walk. Our results show significant health benefits associated with the additional income. Relative to the control site, there was a statistically significant improvement in lung function and an improvement in memory. These improvements are equivalent to a reduction in age of 5-10 y. Residents used their extra income to go to the doctor, buy their medications, and alleviate their hunger. The fear that this extra income could be undone by reduced transfers from other family members or unwise expenditures by the poor elderly appears to be unfounded.

Chicxulub's Cretaceous-Tertiary Boundary Twin Crater. Was There a Double Impact in the Yucatan Peninsula?

NASA Astrophysics Data System (ADS)

Camargo, A. Z.; Juarez, J. S.

2004-05-01

In 1980, Alvarez and co-authors proposed that the K/T extinctions were caused by the effects of a celestial body falling on Earth. After a long search for the impact site, the 1981 work by Penfield and Camargo on a 170 km structure in the Yucatan Peninsula got the attention of the specialists, and it was later proved that it was the crater created by the impact of that celestial body. New data suggests the existence of a second impact crater close to Chicxulub, both being of the same age and created by two fragments of the same celestial boby. A new magnetic map plotted as a color-coded shaded relief surface, reveals a feature not evident before: two interlaced ringed anomalies of about 100 and 50 km diameters, the larger one related to the magnetic signature of the Chicxulub Crater, and the second located at its E-SE edge. The 50 km anomaly, with morphology similar to Chicxulub's, is interpreted as also corresponding to an impact crater, centered at about 89 Deg. Long. W and 21 Deg. Lat. N, close to the city of Izamal. The anomaly size indicates that the diameter of the IZAMAL CRATER is about 85 km. The Chicxulub Crater, being buried under several hundred meters of Tertiary carbonate rocks, is not visible from the surface or from space; although some surface expression of its morphology has been reported. The best known is the ring of cenotes (sink holes) at the crater's rim, visible on satellite images and photographs. The JPL/NASA image PIA03379, is a color-coded shaded relief image of terrain elevation in which the topography was exagerated to highlight the Chicxulub Crater rim. On this image, a semi circular arc of dark spots is also visible immediately to the E-SE of the Chicxulub Crater rim. These spots are interpreted as large irregular karstic depressions, similar to the ones along the cenote ring of Chicxulub. On the evidence of the spatial relationship of the magnetic anomalies and the satellite image features, we tested how well the proposed Izamal

Bibliography of Leishmania and Leishmanial Diseases. Volume 1

DTIC Science & Technology

1980-06-01

Sea 7 Rev. Med.- Yucatan Paulo, REVISTA MEDICA DE YUCATAN . Merida. Rev, Paliclin, Caracas Rev. Menn. Med. , Brazil REVISTA DE LA POLICLINICA, CARACAc...Parasit., 41(2):126-136. 799 pp. CHAKG, P. Y.; TENG, L. T.; SUNG, Y. (1957A) Interactions T. & LIU, Y. C. (1958A) Kala-azar between nutrition and...of nutrition in experimental Infectivan. Bact. Rev. , 13:99-134. CLINTON, B. A.; STAUBER, L. A.& CLRT .(1959A) Comparative PALCZUK, N. C. (1969A

Circulatory Shock. Volume 27, Number 4, 1989

DTIC Science & Technology

1990-02-01

Bacte- rial Translocation" Carol Wells, Ph.D. University of Minnesota 2) "Burn, Trauma, Nutrition and Bac- terial Translocation" J. Wesley Alexander...effects of alpha and beta adrenergic agents on Oz utilization. The day after instrumentation, ten Yucatan minipigs (18-29kg) were given 2-4x010 K...The day after invasive vascular lines were insert- ed, sixteen male Yucatan minature swine received 1-4XIO t 0 E. coli/kg through an intraperitoneal

Advanced Chemical Measurements of Smoke from DoD-prescribed Burns

DTIC Science & Technology

2014-04-01

and in the Yucatan Peninsula of Mexico. Keene et al. [2006] 72 observed ΔHONO/ΔNOx ratios (50th percentile) for African samples of grass (0.048...h from a plume in the Yucatan . In context, O3 formation is probably ubiquitous in tropical biomass burning plumes, but O3 destruction, as well as...via two dimensional heteronuclear NMR spectroscopy,” Phys. Chem. Chem. Phys., 11, 7810–7818, (2009). Marschner, H. 1986. Mineral Nutrition of

Earth observations taken during STS-77

NASA Image and Video Library

1996-05-21

STS077-704-010 (19-29 May 1996) --- The northeastern tip of the Yucatan Peninsula is visible in this Earth scene. The eastern coast of the Yucatan Peninsula is characterized by bluffs, bays, and islands. Isla Mujeres is one of the larger islands off the eastern coast where a tourism industry is being developed. The different shades of blue along the coast is an indication of water depth, with the lighter shades representing more shallow water.

[Analysis of the impact of mortality due to suicides in Mexico, 2000-2012].

PubMed

Dávila Cervantes, Claudio Alberto; Ochoa Torres, María del Pilar; Casique Rodríguez, Irene

2015-12-01

The objective of this study was to analyze the burden of disease due to suicide in Mexico using years of life lost (YLL) between 2000 and 2012 by sex, age group (for those under 85 years of age) and jurisdiction. Vital statistics on mortality and population estimates were used to calculate standardized mortality rates and years of life lost due to suicide. Between 2000 and 2012 a sustained increase in the suicide mortality rate was observed in Mexico. The age group with the highest rate was 85 years of age or older for men, and 15-19 years of age for women. The highest impact in life expectancy due to suicide occurred at 20 to 24 years of age in men and 15 to 19 years of age in women. The states with the highest mortality due to suicide were located in the Yucatan Peninsula (Yucatan, Quintana Roo and Campeche). Mortality due to suicide in Mexico has increased continually. As suicides are preventable, the implementation of health public policies through timely identification, integral prevention strategies and the detailed study of associated risk factors is imperative.

Scoping Summary Report, Los Angeles AFB, California. Air Force Base Closure and Realignment Environmental Impact Analysis Process Support

DTIC Science & Technology

1990-07-01

Mexico 87123 Dayton, Ohio 45402 * Richard A. Lampson Butch Maki Hydro Conduit Corp. Congressman Bill Richardson - 4801 Yucatan N.E. 548 Agua Fria...some chile con queso; however, that would be too much, and I think that might be considered a bribe. The Mayor asked me to convey his regrets. He’s tied...that God sends you here. Also, the small momento that Loretta is giving you, which is our state symbol, has a chile on it; and that’s to remind you

A serological survey for avian infectious bronchitis virus and Newcastle disease virus antibodies in backyard (free-range) village chickens in Mexico.

PubMed

Gutierrez-Ruiz, E J; Ramirez-Cruz, G T; Camara Gamboa, E I; Alexander, D J; Gough, R E

2000-12-01

The commercial flocks in Yucatan, Mexico are free of Newcastle disease virus (NDV) in its velogenic viscerotropic form, but little is known about the disease status of backyard poultry. A seroprevalence survey in 30 villages using haemagglutination inhibition (HI) tests for infectious bronchitis virus (IBV) and NDV antibodies was carried out from December 1997 to June 1998. The seroprevalences were 56.5% (95% CI 50-63%) for IBV and 2.2% (95% CI 0.5-3.8%) for NDV. All the villages had chickens that were positive for antibodies to IBV and nine of the villages had chickens that were positive for antibodies to NDV. This suggests that IBV may be responsible for a large proportion of the respiratory disease observed in backyard chickens in Yucatan. The implications of these findings are discussed, including the highly susceptible status of the backyard chickens in Yucatan to NDV and the possibility of this virus being one cause of the syndrome known as mortandad by the local people.

[Migration from a rural zone to an urban one is associated with android distribution of body fat in obese women].

PubMed

González-Barranco, J; López-Alvarenga, J C; Roiz-Simancas, M; Bravo-García, A L; Fanghänel-Salmón, G; Laviada Arrigunaga, E; Castaño, L R; García Tapia, M P

2001-01-01

Studies about migration to industrialized countries have shown an increased prevalence of diabetes, obesity and dyslipidaemias, all of them related to android body fat distribution. Migration status might be influence body fat distribution but it has not been sufficiently investigated. The aim of this study is to determine the relationship between body fat distribution and migration from rural to urban areas in Mexico. This sequential sample of 433 women were seen in the outpatient obesity clinic of four federal states: Tabasco (n = 81), Mexico City (n = 166), Coahuila (n = 80), and Yucatan (n = 106). Migration history from rural to urban area, familial history of diabetes, ages of onset of obesity, height and weight circumferences were obtained. A regression logistic model was used and maintained as dependent variable body fat distribution. Age and federal state were considered as confounders and they adjusted the model. Migrating women from rural to urban area were 121 (27.9%). The waist circumference was higher in Tabasco (102.2 +/- 12 cm), and lesser in Yucatan (93.6 +/- 15 cm, p < 0.001); no differences were found for hip circumference. The logistic regression model showed that body fat distribution is associated to migration from rural to urban area, and also to diabetes of mother and age of onset of obesity. Migrating from rural to urban area is a risk factor for android body fat distribution and this risk increases with age, history of diabetes in mother and adulthood onset o obesity.

Early evolution of the Gulf of Mexico and the origin of the pervasive salt

NASA Astrophysics Data System (ADS)

Lawver, L. A.; Norton, I. O.; Gahagan, L.

2016-12-01

The final stage of formation of the Gulf of Mexico (GOM) is fairly well constrained, while the earlier evolution is still debated. During the final stage, Yucatan rotated about a Florida Straits Euler pole that created most of the oceanic crust in the GOM. From observations of salt overlying seaward-dipping reflectors (diagnostic of volcanism during the rift to drift transition) in the northeast GOM we suggest that salt was deposited at the onset of sea floor spreading, which coincides with initiation of the rotational motion of Yucatan. Salt is Callovian or earliest Oxfordian in age, and the next oldest rocks known from the northern GOM are Late Triassic redbeds found in what are generally regarded as grabens formed during early rifting. Since there was a long-lived, strikingly linear, continental margin arc in Mexico that lasted from the Permian through the Middle Jurassic (Barboza-Gudino et al., 2012), a lot of the rocks of this age seen in Mexico that are linked to GOM rifting are in fact associated with this earlier arc. This arc places major constraints on a pre-rift reconstruction involving North America, Africa, South America, Yucatan and the Tampico block of Mexico and defines the space available for Yucatan. In this presentation we will review reconstructions of the region and develop a tectonic model that forms the basis for further understanding of rifting in the GOM. A consequence of our new model involves a back-arc basin that is represented by the compressed Juarez or Cuicateco terrane of southeastern Mexico. The opening of this basin, coupled with the early opening of the Central Atlantic and the motion of South America away from Yucatan, not only allowed Yucatan to begin its rotation but may also be part of the "western" seaway that brought the necessary sea water into the Gulf to form the thick salt deposits. Barboza-Gudino, J.R., Molina-Garza. R.S., and Lawton, T.E., 2012. Sierra de Cato-: Remnants of the ancient western equatorial margin of

At same leucine intake, a whey/plant protein blend is not as effective as whey to initiate a transient post prandial muscle anabolic response during a catabolic state in mini pigs.

PubMed

Revel, Aurélia; Jarzaguet, Marianne; Peyron, Marie-Agnès; Papet, Isabelle; Hafnaoui, Noureddine; Migné, Carole; Mosoni, Laurent; Polakof, Sergio; Savary-Auzeloux, Isabelle; Rémond, Didier; Dardevet, Dominique

2017-01-01

Muscle atrophy has been explained by an anabolic resistance following food intake and an increase of dietary protein intake is recommended. To be optimal, a dietary protein has to be effective not only to initiate but also to prolong a muscle anabolic response in a catabolic state. To our knowledge, whether or not a dairy or a dairy/plant protein blend fulfills these criterions is unknown in a muscle wasting situation. Our aim was, in a control and a catabolic state, to measure continuously muscle anabolism in term of intensity and duration in response to a meal containing casein (CAS), whey (WHEY) or a whey/ plant protein blend (BLEND) and to evaluate the best protein source to elicit the best post prandial anabolism according to the physio-pathological state. Adult male Yucatan mini pigs were infused with U-13C-Phenylalanine and fed either CAS, WHEY or BLEND. A catabolic state was induced by a glucocorticoid treatment for 8 days (DEX). Muscle protein synthesis, proteolysis and balance were measured with the hind limb arterio-venous differences technique. Repeated time variance analysis were used to assess significant differences. In a catabolic situation, whey proteins were able to initiate muscle anabolism which remained transient in contrast to the stimulated muscle protein accretion with WHEY, CAS or BLEND in healthy conditions. Despite the same leucine intake compared to WHEY, BLEND did not restore a positive protein balance in DEX animals. Even with WHEY, the duration of the anabolic response was not optimal and has to be improved in a catabolic state. The use of BLEND remained of lower efficiency even at same leucine intake than whey.

Facies dimensions within carbonate reservoirs - guidelines from satellite images of modern analogs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harris, P.M.; Kowalik, W.S.

1995-08-01

Modern analogs illustrate the distribution of carbonate facies within an overall depositional setting and can be an integral part of a subsurface geologic model in indicating the dimensions, trend, and interrelationships of facies that might be related to reservoir and non-reservoir distribution. Satellite images from several modern carbonate areas depict the geologic characteristics that can be expected in ancient shallow-water settings. Isolated carbonate platforms- the Bahamas, Caicos Platform in the British West Indies, Chinchorro Bank offshore of Yucatan, and portions of the Belize area; Ramp-style shelf-to-basin transitions - Abu Dhabi and northern Yucatan; Rimmed shelf margins - South Florida, portionsmore » of Belize, and the Great Barrier Reef of Australia; Broad, deep shelf lagoons - the Great Barrier Reef and Belize; Reef variability - South Florida, the Bahamas, Caicos, Northern Yucatan, and Abu Dhabi; Shallow lagoon/tidal flat settings - South Florida, the Bahamas, Caicos, Northern Yucatan, Shark Bay in Western Australia, Abu Dhabi; Mixed carbonate and siliciclastic depostion - South Florida, Belize, the Great Barrier Reef, Shark Bay and Abu Dhabi. The geologic framework as illustrated by these areas is important at the development scale where lateral variation of porosity and permeability, i.e. reservoir quality, is commonly tied to facies changes and facies dimensions are required as input to reservoir models. The geologic framework is essential at the exploration scale for reservoir facies prediction and stratigraphic play concepts which are related directly to depositional facies patterns.« less

Effects of Exercise Intensity and Pre-Exercise Feeding on Splanchnic Tissue Blood Flow

DTIC Science & Technology

1988-08-23

Department of the Nivy, NIT! SCOFn iant .!HL176F,?. and the U. S. Aim’, Nutrition Task For(e (Work 1’!i0 0141). Ih . pt’sentevi in thi. paper are those of...prior to the EX tests to evaluate the effect! of pre-exercise feeding on gastrointestinal (GI) BF. Subjects. Thirty, 9-12 month old Yucatan miniature...thirty Q-12 mont old Yucatan miniature swine subjected to a ’progressive exercise treddmill run after an overnight fast (FST) or one to three hours post

Boron and Coumaphos Residues in Hive Materials Following Treatments for the Control of Aethina tumida Murray.

PubMed

Valdovinos-Flores, Cesar; Gaspar-Ramírez, Octavio; Heras-Ramírez, María Elena; Lara-Álvarez, Carlos; Dorantes-Ugalde, José Antonio; Saldaña-Loza, Luz María

2016-01-01

In the search of alternatives for controlling Aethina tumida Murray, we recently proposed the BAA trap which uses boric acid and an attractant which mimics the process of fermentation caused by Kodamaea ohmeri in the hive. This yeast is excreted in the feces of A. tumida causing the fermentation of pollen and honey of infested hives and releasing compounds that function as aggregation pheromones to A. tumida. Since the boron is the toxic element in boric acid, the aim of this article is to assess the amount of boron residues in honey and beeswax from hives treated with the BAA trap. For this aim, the amount of bioaccumulated boron in products of untreated hives was first determined and then compared with the amount of boron of products from hives treated with the BAA trap in two distinct climatic and soil conditions. The study was conducted in the cities of Padilla, Tamaulipas, and Valladolid, Yucatan (Mexico) from August 2014 to March 2015. The quantity of boron in honey was significantly less in Yucatan than in Tamaulipas; this agrees with the boron deficiency among Luvisol and Leptosol soils found in Yucatan compared to the Vertisol soil found in Tamaulipas. In fact, the honey from Yucatan has lower boron levels than those reported in the literature. The BAA treatment was applied for four months, results show that the BAA trap does not have any residual effect in either honey or wax; i.e., there is no significant difference in boron content before and after treatment. On the other hand, the organophosphate pesticide coumaphos was found in 100% of wax samples and in 64% of honey samples collected from Yucatan. The concentration of coumaphos in honey ranges from 0.005 to 0.040 mg/kg, which are below Maximum Residue Limit (MRL) allowed in the European Union (0.1 mg/kg) but 7.14% of samples exceeded the MRL allowed in Canada (0.02 mg/kg).

Boron and Coumaphos Residues in Hive Materials Following Treatments for the Control of Aethina tumida Murray

PubMed Central

Valdovinos-Flores, Cesar; Gaspar-Ramírez, Octavio; Heras–Ramírez, María Elena; Dorantes-Ugalde, José Antonio; Saldaña-Loza, Luz María

2016-01-01

In the search of alternatives for controlling Aethina tumida Murray, we recently proposed the BAA trap which uses boric acid and an attractant which mimics the process of fermentation caused by Kodamaea ohmeri in the hive. This yeast is excreted in the feces of A. tumida causing the fermentation of pollen and honey of infested hives and releasing compounds that function as aggregation pheromones to A. tumida. Since the boron is the toxic element in boric acid, the aim of this article is to assess the amount of boron residues in honey and beeswax from hives treated with the BAA trap. For this aim, the amount of bioaccumulated boron in products of untreated hives was first determined and then compared with the amount of boron of products from hives treated with the BAA trap in two distinct climatic and soil conditions. The study was conducted in the cities of Padilla, Tamaulipas, and Valladolid, Yucatan (Mexico) from August 2014 to March 2015. The quantity of boron in honey was significantly less in Yucatan than in Tamaulipas; this agrees with the boron deficiency among Luvisol and Leptosol soils found in Yucatan compared to the Vertisol soil found in Tamaulipas. In fact, the honey from Yucatan has lower boron levels than those reported in the literature. The BAA treatment was applied for four months, results show that the BAA trap does not have any residual effect in either honey or wax; i.e., there is no significant difference in boron content before and after treatment. On the other hand, the organophosphate pesticide coumaphos was found in 100% of wax samples and in 64% of honey samples collected from Yucatan. The concentration of coumaphos in honey ranges from 0.005 to 0.040 mg/kg, which are below Maximum Residue Limit (MRL) allowed in the European Union (0.1 mg/kg) but 7.14% of samples exceeded the MRL allowed in Canada (0.02 mg/kg). PMID:27092938

Floristic affinities of the lowland savannahs of Belize and southern Mexico.

PubMed

Canché-Estrada, Idalia Arely; Ortiz-Díaz, Juan Javier; Tun-Garrido, Juan

2018-01-01

Environmental heterogeneity of Belize and southern Mexico savannahs as well as their geographical location suggest that these plant communities share floristic elements, making them conducive to a phytogeographical analysis. The aim of this study was to analyse the floristic affinities of nine savannahs of Belize and southern Mexico and to explain the similarities and differences amongst them. A binary data matrix containing 915 species was built based on the authors' own collections and on nine floristic lists already published. A second data matrix, consisting of 113 species representing trees, was also used since most literature on neotropical savannahs has focused on this life form. In addition, the ten most species-rich families as well as the characteristic species present in more than five savannahs were analysed. Floristic similarities were calculated using the Jaccard index. Dendrograms obtained in both types of analysis showed clusters with low similarity values, corresponding to geographic locations formed by the savannahs of Belize-Tabasco and the Yucatan Peninsula. The floristic affinities of the savannahs may be explained in terms of heterogeneity in climate and physiography. The Yucatan Peninsula and Belize-Tabasco groups have differences in climate type and the amount of rainfall. In addition, the Yucatan Peninsula savannahs are established at the bottom of karstic valleys, while the Belize and Tabasco savannahs develop on extensive flatlands. The savannahs of Oaxaca have the same climate type and amount of rainfall as those of the Yucatan Peninsula but they are distributed along peaks and the slopes of shale hills. Fabaceae and Poaceae mainly dominated the local floras with 121 and 116 species each; remarkably, Melastomataceae was absent in the Yucatan Peninsula and Oaxaca. Nine species occurred in five to seven savannahs, confirming that they are widespread in both Belize and southern Mexico, and the Neotropics. Geographic location and floristic

Gene expression in caged fish as indicators of contaminants exposure in tropical karstic water bodies.

PubMed

Rodríguez-Fuentes, Gabriela; Luna-Ramírez, Karen S; Soto, Mélina; Richardson, Kristine L

2012-04-01

Karstic areas in Yucatan are very permeable, which allows contaminants to move rapidly into the aquifer. In the present study, we evaluated gene expression of vitellogenin (VTG) and cytochrome P-450 1A (CYP1A) in caged juvenile zebrafish deployed for 15 days in 13 different water bodies, cenotes and aguadas, throughout karstic region of the Yucatan peninsula. Gene expression was evaluated using qRT-PCR. Results indicated induction of VTG in 7 water bodies with respect to reference cage. The highest relative VTG expression, about 3000 times higher than reference cage, was found in an aguada close to a cattle farm. CYP1A induction with respect to reference cage was observed in 3 water bodies, all of them located near villages or used for tourist activities. Pollutants and biomarkers of effect should be monitored in these water bodies in order to have a better understanding of the actual levels of pollutants that are present at Yucatan's aquifer and the potential risk to human and environmental health. Copyright © 2011 Elsevier Ltd. All rights reserved.

Comparison of in-vivo skin models for near-infrared laser exposure

NASA Astrophysics Data System (ADS)

Eggleston, Thomas A.; Mitchell, Michael A.; Johnson, Thomas E.; Becker, Robert L., Jr.; Roach, William P.

1999-06-01

Current safety standards for lasers operating in the 1400 to 10,000 nm wavelength region are based on few observations at specific wavelengths using in vivo models that may not represent an accurate correlation to human integument. Based on experimental results conducted with Yorkshire pigs, these standards may not accurately reflect the potential for laser injury when humans are exposed to these wavelengths. It is our belief that one of the primary damage mechanisms involved in these laser injuries is due to energy absorption by skin pigmentation, or melanin. Qualitatively, Yorkshire pigs lack melanin in their skin when compared to a more highly pigmented animal, such as the Yucatan minipig. It is hypothesized that the Yucatan minipig is a more appropriate model for pigmented human skin. By comparing histologic samples taken from various locations on Yucatan minipigs and Yorkshire pigs, and comparing these to potential locations of skin exposure on humans, we present a discussion for the establishment of more appropriate locations for in vivo laser exposure studies.

Species composition and abundance of Brevipalpus spp. on different citrus species in Mexican orchards.

PubMed

Salinas-Vargas, D; Santillán-Galicia, M T; Valdez-Carrasco, J; Mora-Aguilera, G; Atanacio-Serrano, Y; Romero-Pescador, P

2013-08-01

We studied the abundance of Brevipalpus spp. in citrus orchards in the Mexican states of Yucatan, Quintana Roo and Campeche. Mites were collected from 100 trees containing a mixture of citrus species where sweet orange was always the main species. Eight collections were made at each location from February 2010 to February 2011. Mites from the genus Brevipalpus were separated from other mites surveyed and their abundance and relationships with the different citrus species were quantified throughout the collection period. A subsample of 25% of the total Brevipalpus mites collected were identified to species level and the interaction of mite species and citrus species were described. Brevipalpus spp. were present on all collection dates and their relative abundance was similar on all citrus species studies. The smallest number of mites collected was during the rainy season. Brevipalpus phoenicis (Geijskes) and Brevipalpus californicus (Banks) were the only two species present and they were found in all locations except Campeche, where only B. phoenicis was present. Yucatan and Campeche are at greater risk of leprosis virus transmission than Quintana Roo because the main vector, B. phoenicis, was more abundant than B. californicus. The implications of our results for the design of more accurate sampling and control methods for Brevipalpus spp. are discussed.

At same leucine intake, a whey/plant protein blend is not as effective as whey to initiate a transient post prandial muscle anabolic response during a catabolic state in mini pigs

PubMed Central

Revel, Aurélia; Jarzaguet, Marianne; Peyron, Marie-Agnès; Papet, Isabelle; Hafnaoui, Noureddine; Migné, Carole; Mosoni, Laurent; Polakof, Sergio; Savary-Auzeloux, Isabelle; Rémond, Didier

2017-01-01

Background Muscle atrophy has been explained by an anabolic resistance following food intake and an increase of dietary protein intake is recommended. To be optimal, a dietary protein has to be effective not only to initiate but also to prolong a muscle anabolic response in a catabolic state. To our knowledge, whether or not a dairy or a dairy/plant protein blend fulfills these criterions is unknown in a muscle wasting situation. Objective Our aim was, in a control and a catabolic state, to measure continuously muscle anabolism in term of intensity and duration in response to a meal containing casein (CAS), whey (WHEY) or a whey/ plant protein blend (BLEND) and to evaluate the best protein source to elicit the best post prandial anabolism according to the physio-pathological state. Methods Adult male Yucatan mini pigs were infused with U-13C-Phenylalanine and fed either CAS, WHEY or BLEND. A catabolic state was induced by a glucocorticoid treatment for 8 days (DEX). Muscle protein synthesis, proteolysis and balance were measured with the hind limb arterio-venous differences technique. Repeated time variance analysis were used to assess significant differences. Results In a catabolic situation, whey proteins were able to initiate muscle anabolism which remained transient in contrast to the stimulated muscle protein accretion with WHEY, CAS or BLEND in healthy conditions. Despite the same leucine intake compared to WHEY, BLEND did not restore a positive protein balance in DEX animals. Conclusions Even with WHEY, the duration of the anabolic response was not optimal and has to be improved in a catabolic state. The use of BLEND remained of lower efficiency even at same leucine intake than whey. PMID:29045496

The Unique Dorsal Brood Pouch of Thermosbaenacea (Crustacea, Malacostraca) and Description of an Advanced Developmental Stage of Tulumella unidens from the Yucatan Peninsula (Mexico), with a Discussion of Mouth Part Homologies to Other Malacostraca

PubMed Central

Olesen, Jørgen; Boesgaard, Tom; Iliffe, Thomas M.

2015-01-01

The Thermosbaenacea, a small taxon of crustaceans inhabiting subterranean waters, are unique among malacostracans as they brood their offspring dorsally under the carapace. This habit is of evolutionary interest but the last detailed report on thermosbaenacean development is more than 40 years old. Here we provide new observations on an ovigerous female of Tulumella unidens with advanced developmental stages in its brood chamber collected from an anchialine cave at the Yucatan Peninsula, which is only the third report on developmental stages of Thermosbaenacea and the first for the genus Tulumella. Significant in a wider crustacean context, we report and discuss hitherto unexplored lobate structures inside the brood chamber of the female originating at the first (maxilliped) and second thoracic segments, which are most likely modified epipods, perhaps serving as gills. At the posterior margin of carapace of the female are rows of large spines preventing the developing stages from falling out. The external morphology of the advanced developmental stages is described in much detail, providing information on e.g., carapace formation and early limb morphology. Among the hitherto unknown structures in the advanced developmental stages provided by this study are the presence of an embryonic dorsal organ and rudimentary ‘naupliar processes’ of the second antennae. Since most hypotheses on crustacean (and malacostracan and peracaridan) relationship rest on external limb morphology, we use early limb bud morphology of Tulumella to better establish thermosbaenacean limb homologies to those of other crustaceans, which is a necessary basis for future morphology based phylogenetic considerations. PMID:25901753

The Unique Dorsal Brood Pouch of Thermosbaenacea (Crustacea, Malacostraca) and Description of an Advanced Developmental Stage of Tulumella unidens from the Yucatan Peninsula (Mexico), with a Discussion of Mouth Part Homologies to Other Malacostraca.

PubMed

Olesen, Jørgen; Boesgaard, Tom; Iliffe, Thomas M

2015-01-01

The Thermosbaenacea, a small taxon of crustaceans inhabiting subterranean waters, are unique among malacostracans as they brood their offspring dorsally under the carapace. This habit is of evolutionary interest but the last detailed report on thermosbaenacean development is more than 40 years old. Here we provide new observations on an ovigerous female of Tulumella unidens with advanced developmental stages in its brood chamber collected from an anchialine cave at the Yucatan Peninsula, which is only the third report on developmental stages of Thermosbaenacea and the first for the genus Tulumella. Significant in a wider crustacean context, we report and discuss hitherto unexplored lobate structures inside the brood chamber of the female originating at the first (maxilliped) and second thoracic segments, which are most likely modified epipods, perhaps serving as gills. At the posterior margin of carapace of the female are rows of large spines preventing the developing stages from falling out. The external morphology of the advanced developmental stages is described in much detail, providing information on e.g., carapace formation and early limb morphology. Among the hitherto unknown structures in the advanced developmental stages provided by this study are the presence of an embryonic dorsal organ and rudimentary 'naupliar processes' of the second antennae. Since most hypotheses on crustacean (and malacostracan and peracaridan) relationship rest on external limb morphology, we use early limb bud morphology of Tulumella to better establish thermosbaenacean limb homologies to those of other crustaceans, which is a necessary basis for future morphology based phylogenetic considerations.

Designing Cash Transfer Programs for an Older Population: The Mexican Case

PubMed Central

Kapteyn, Arie; Tassot, Caroline

2016-01-01

Aging populations and the prevalence of poverty in old age have led to the introduction of noncontributory pensions in many countries. We consider a number of alternative targeting approaches and simulate their effects in an empirical application in the State of Yucatan, Mexico. We compare the approaches with respect to leakage, under-coverage, and their effects on government budgets. We are also able to compare the simulated effects of one alternative with the observed effect of a recently introduced demogrant and find that the simulation is a close approximation of the empirical outcomes. We discuss issues of implementation and political feasibility. PMID:28752042

The 8th Century Megadrought Across North America

NASA Astrophysics Data System (ADS)

Stahle, D. W.; Therrell, M. D.; Cleaveland, M. K.; Fye, F. K.; Cook, E. R.; Grissino-Mayer, H. D.; Acuna-Soto, R.

2002-12-01

Tree-ring data suggest that the 8th and 16th century megadroughts may have been the most severe and sustained droughts to impact North America in the past 1500 years. The 16th century megadrought may have persisted for up to 40 years, and extended from the tropics to the boreal forest and from the Pacific to Atlantic coasts. Evidence for the 8th century drought is sparse, but tree-ring and lake sediment data indicate that this drought extended from the northern Great Plains, across the southwestern United States, and into central Mexico and the Yucatan peninsula. Tree-ring data from Colorado and New Mexico document severe drought from A.D. 735-765, and may provide accurate and precise dating for the onset of the epic droughts reconstructed during the late first millennium A.D. with sedimentary data from Elk Lake, Minnesota; Moon Lake, South Dakota; La Piscina de Yuriria, Guanajuato; and Lake Chichancanab, Yucatan. If these chronological refinements are correct, then the sedimentary records suggest much greater persistence to the 8th century megadrought than indicated by the very high resolution tree-ring data, and a strong second pulse of prolonged drought late in the first millennium. Analyses of instrumental precipitation and drought indices during the 20th century, along with tree-ring reconstructions of climate in Mexico and the Southwest, indicate that annual and decadal droughts can both simultaneously impact the entire region from New Mexico and Texas down into central Mexico. The intensity and large-scale impact of drought across this region seem to be greatest when La Nina conditions and the low phase of the North Pacific oscillation prevail. The tree-ring dated 8th century megadrought occurred near the decline of the Classic Period civilizations at Teotihuacan in central Mexico and in the Mayan region of the Yucatan. The 8th century megadrought may have interacted with anthropogenic environmental degradation, epidemic disease, and social upheaval to

DO COMMERCIAL SEROLOGIC TESTS FOR TRYPANOSOMA CRUZI INFECTION DETECT MEXICAN STRAINS IN WOMEN AND NEWBORNS?

PubMed Central

Gamboa-León, Rubi; Gonzalez-Ramirez, Claudia; Padilla-Raygoza, Nicolas; Sosa-Estani, Sergio; Caamal-Kantun, Alejandra; Buekens, Pierre; Dumonteil, Eric

2012-01-01

We sought to determine the serological test that could be used for Trypanosoma cruzi seroprevalence studies in Mexico, where lineage I predominates. In a previous study among pregnant women and their newborns in the states of Yucatan and Guanajuato, we reported a 0.8–0.9% of prevalence for T. cruzi–specific antibodies by Stat-Pak and Wiener ELISA. We have expanded this study here by performing an additional non-commercial ELISA and confirming the seropositives with Western blot, using whole antigens of a local parasite strain. We found a seroprevalence of 0.6% (3/500) in Merida and 0.4% in Guanajuato (2/488). The 5 seropositive umbilical cord samples reacted to both non-commercial ELISA and Western blot tests, and only 1 of the maternal samples was not reactive to non-commercial ELISA. A follow-up of the newborns at 10 mo was performed in Yucatan to determine the presence of T. cruzi antibodies in children as evidence of congenital infection. None of the children was seropositive. One newborn from an infected mother died at 2 wk of age of cardiac arrest, but T. cruzi infection was not confirmed. The T. cruzi seroprevalence data obtained with both commercial tests (Stat-Pak and ELISA Wiener) are similar to those from non-commercial tests using a local Mexican strain of T. cruzi. PMID:21506787

Glyphosate Residues in Groundwater, Drinking Water and Urine of Subsistence Farmers from Intensive Agriculture Localities: A Survey in Hopelchén, Campeche, Mexico.

PubMed

Rendon-von Osten, Jaime; Dzul-Caamal, Ricardo

2017-06-03

The use of pesticides in Mexican agriculture creates an interest in learning about the presence of these substances in different environmental matrices. Glyphosate (GLY) is an herbicide widely used in the state of Campeche, located in the Mayan zone in the western Yucatan peninsula. Despite the fact that GLY is considered a non-toxic pesticide to humans, its presence in water bodies through spillage, runoff, and leaching are a risk to human health or biota that inhabit these ecosystems. In the present study, glyphosate residues were determined in groundwater, bottled drinking water, and the urine of subsistence farmers from various localities of the Hopelchén municipality in Campeche. Determination of GLY was carried out using Enzyme-Linked Immunosorbent Assay (ELISA). The highest concentrations of GLY were observed in the groundwater (1.42 μg/L) of Ich-Ek and urine (0.47 μg/L) samples of subsistence farmers from the Francisco J. Mújica communities. The glyphosate concentrations in groundwater and bottled drinking water indicate an exposure and excessive use of glyphosate in these agricultural communities. This is one of the first studies that reports glyphosate concentration levels in human urine and bottled drinking water in México and in the groundwater in the Yucatan Peninsula as part of a prospective pilot study, to which a follow-up will be performed to monitor this trend over time.

Glyphosate Residues in Groundwater, Drinking Water and Urine of Subsistence Farmers from Intensive Agriculture Localities: A Survey in Hopelchén, Campeche, Mexico

PubMed Central

Rendón-von Osten, Jaime; Dzul-Caamal, Ricardo

2017-01-01

The use of pesticides in Mexican agriculture creates an interest in learning about the presence of these substances in different environmental matrices. Glyphosate (GLY) is an herbicide widely used in the state of Campeche, located in the Mayan zone in the western Yucatan peninsula. Despite the fact that GLY is considered a non-toxic pesticide to humans, its presence in water bodies through spillage, runoff, and leaching are a risk to human health or biota that inhabit these ecosystems. In the present study, glyphosate residues were determined in groundwater, bottled drinking water, and the urine of subsistence farmers from various localities of the Hopelchén municipality in Campeche. Determination of GLY was carried out using Enzyme-Linked Immunosorbent Assay (ELISA). The highest concentrations of GLY were observed in the groundwater (1.42 μg/L) of Ich-Ek and urine (0.47 μg/L) samples of subsistence farmers from the Francisco J. Mújica communities. The glyphosate concentrations in groundwater and bottled drinking water indicate an exposure and excessive use of glyphosate in these agricultural communities. This is one of the first studies that reports glyphosate concentration levels in human urine and bottled drinking water in México and in the groundwater in the Yucatan Peninsula as part of a prospective pilot study, to which a follow-up will be performed to monitor this trend over time. PMID:28587206

Phenotypic differentiation between wild and domesticated varieties of Crescentia cujete L. and culturally relevant uses of their fruits as bowls in the Yucatan Peninsula, Mexico

PubMed Central

2013-01-01

Background Selection criteria are important for analyzing domestication of perennial plant species, which experience a selection pressure throughout several human generations. We analyze the preferred morphological characteristics of Crescentia cujete fruits, which are used as bowls by the Maya of Yucatan, according to the uses they are given and the phenotypic consequences of artificial selection between one wild and three domesticated varieties. Methods We performed 40 semi-structured interviews in seven communities. We calculated Sutrop’s salience index (S) of five classes of ceremonial and daily life uses, and of each item from the two most salient classes. We sampled 238 bowls at homes of people interviewed and compared their shape, volume and thickness with 139 fruits collected in homegardens and 179 from the wild. Morphology of varieties was assessed in fruit (n = 114 trees) and vegetative characters (n = 136 trees). Differences between varieties were evaluated through linear discriminant analysis (LDA). Results Use of bowls as containers for the Day of the Dead offerings was the most salient class (S = 0.489) with chocolate as its most salient beverage (S = 0.491), followed by consumption of daily beverages (S = 0.423), especially maize-based pozol (S = 0.412). The sacred saka’ and balche' are offered in different sized bowls during agricultural and domestic rituals. Roundness was the most relevant character for these uses, as bowls from households showed a strong selection towards round shapes compared with wild and homegarden fruits. Larger fruits from domesticated varieties were also preferred over small wild fruits, although in the household different sizes of the domesticated varieties are useful. LDA separated wild from domesticated trees (p < 0.001) according to both fruit and vegetative variables, but domesticated varieties were not different among themselves. Conclusions The association between C. cujete bowls and

Strengthening and Fostering Science and Technology Programs in Latinamerica and the Caribbean

NASA Astrophysics Data System (ADS)

Fucugauchi, J. U.

2013-05-01

An overview and discussion of the status of research and education in Latinamerica and the Caribbean is used for developing a proposal for a research foundation or agency in the region and establishing initiatives for capacity building and promoting and strengthening scientific programs and cooperation. Scientific research increasingly requires global multi- and inter-disciplinary approaches and infrastructure. Developing countries face challenges resulting from small academic communities, limited economic resources, and pressing social and political issues. Science and education are not major priorities as compared with more pressing issues related to poverty, diseases, conflicts, drugs and famine. However, solving major problems require improved educational and research programs. International research collaboration, north-south and south-south, has an immense potential, but basic infrastructure and internal organization at national and regional levels are required. For the analysis we concentrate on current situation, size and characteristics of research community, education programs, facilities, economic support, and bilateral and multinational collaborations. Analysis also includes the São Paulo Research Foundation (FAPESP) and the Yucatan Science and Technology System (SIIDETEY). FAPESP is a highly successful public foundation started more than 50 years ago, dedicated to foster scientific and technological development in the State of São Paulo and which has had a major impact in Brazil. SIIDETEY is a more recent effort of the Yucatan Government, also dedicated to support research and technology innovation within the state. We then move to discussion on perspectives for future development and capacity building in regional and international contexts, including international collaboration programs. We propose to establish a Science Foundation for the Latinamerica and Caribbean and develop an agenda for strengthening scientific programs in the region.

Assessment of human activities impact on groundwater quality discharging into a reef lagoon

NASA Astrophysics Data System (ADS)

Rebolledo-Vieyra, M.; Hernandez, L.; Paytan, A.; Merino-Ibarra, M.; Lecossec, A.; Soto, M.

2010-03-01

The Eastern coast of the Yucatan Peninsula has the fastest growth rate in Mexico and groundwater is the only source of drinking water in the region. The consequences of the lack of proper infrastructure to collect and treat wastewater and the impact of human activities on the quality of groundwater are addressed. The groundwater in the coastal aquifer of Quintana Roo (SE Mexico) discharges directly into the ocean (Submarine Groundwater Discharges). In addition, the coral reef of the Eastern Yucatan Peninsula is part of the Mesoamerican Coral Reef System, one of the largest in the world. The interaction of the reef-lagoon hydraulics with the coastal aquifer of Puerto Morelos (NE Yucatan Peninsula), and a major input of NH4, SO4, SiO2, as a consequence of the use of septic tanks and the lack of modern wastewater treatment plants are presented. A conceptual model of the coastal aquifer was developed, in order to explain how the human activities are impacting directly on the groundwater quality that, potentially, will have a direct impact on the coral reef. The protection and conservation of coral reefs must be directly related with a policy of sound management of coastal aquifers and wastewater treatment.

Probabilistic Seismic Hazard Assessment of the Chiapas State (SE Mexico)

NASA Astrophysics Data System (ADS)

Rodríguez-Lomelí, Anabel Georgina; García-Mayordomo, Julián

2015-04-01

The Chiapas State, in southeastern Mexico, is a very active seismic region due to the interaction of three tectonic plates: Northamerica, Cocos and Caribe. We present a probabilistic seismic hazard assessment (PSHA) specifically performed to evaluate seismic hazard in the Chiapas state. The PSHA was based on a composited seismic catalogue homogenized to Mw and was used a logic tree procedure for the consideration of different seismogenic source models and ground motion prediction equations (GMPEs). The results were obtained in terms of peak ground acceleration as well as spectral accelerations. The earthquake catalogue was compiled from the International Seismological Center and the Servicio Sismológico Nacional de México sources. Two different seismogenic source zones (SSZ) models were devised based on a revision of the tectonics of the region and the available geomorphological and geological maps. The SSZ were finally defined by the analysis of geophysical data, resulting two main different SSZ models. The Gutenberg-Richter parameters for each SSZ were calculated from the declustered and homogenized catalogue, while the maximum expected earthquake was assessed from both the catalogue and geological criteria. Several worldwide and regional GMPEs for subduction and crustal zones were revised. For each SSZ model we considered four possible combinations of GMPEs. Finally, hazard was calculated in terms of PGA and SA for 500-, 1000-, and 2500-years return periods for each branch of the logic tree using the CRISIS2007 software. The final hazard maps represent the mean values obtained from the two seismogenic and four attenuation models considered in the logic tree. For the three return periods analyzed, the maps locate the most hazardous areas in the Chiapas Central Pacific Zone, the Pacific Coastal Plain and in the Motagua and Polochic Fault Zone; intermediate hazard values in the Chiapas Batholith Zone and in the Strike-Slip Faults Province. The hazard decreases

Finds in Belize document Late Classic Maya salt making and canoe transport

PubMed Central

McKillop, Heather

2005-01-01

How did people in preIndustrial ancient civilizations produce and distribute bulk items, such as salt, needed for everyday use by their large urban populations? This report focuses on the ancient Maya who obtained quantities of salt at cities in the interior of the Yucatan peninsula of Mexico, Belize, and Guatemala in an area where salt is scarce. I report the discovery of 41 Late Classic Maya saltworks (anno Domini 600–900) in Punta Ycacos Lagoon on the south coast of Belize, including one with the first-known ancient Maya canoe paddle. The discoveries add important empirical information for evaluating the extent of surplus salt production and river transport during the height of Late Classic civilization in the southern Maya lowlands. The discovery of the saltworks indicates that there was extensive production and distribution of goods and resources outside the cities in the interior of the Yucatan. The discovery of a wooden canoe paddle from one of the Punta Ycacos saltworks, Ka'k' Naab', ties the production of salt to its inland transport by rivers and documents the importance of canoe trade between the coast and the interior during the Late Classic. Archaeological discovery of multiple saltworks on the Belizean coast represents surplus production of salt destined largely for the inland Peten Maya during their Late Classic peak, underscoring the importance of non-state-controlled workshop production in preIndustrial societies. PMID:15809426

New records of ectoparasitic Acari (Arachnida) and Streblidae (Diptera) from bats in Jalisco, Mexico.

PubMed

Martínez, Maria M Ramírez; Lopez, M Pilar Ibarra; Iñiguez-Dávalos, Luis Ignacio; Yuill, Thomas; Orlova, Maria V; Reeves, Will K

2016-12-01

Ectoparasites of bats in the Neotropics are diverse and play numerous ecological roles as vectors of microbial pathogens and endoparasites and as food sources for other cave fauna living both on their hosts and in bat roosts. The ectoparasites of bats in Jalisco State of western Mexico have not been as well described as those of other states with recent checklists that have focused primarily on the Yucatan Peninsula. We captured bats from 2011-2015 on the south coast and Sierra de Amula, Jalisco using mist nets, and we removed ectoparasites by hand. We identified 24 species of streblid bat flies and six ectoparasitic mites from bats caught in mist nets. There were an additional eight possibly undescribed species of Streblidae. Our collections extend the known range of species into Jalisco. © 2016 The Society for Vector Ecology.

Methane and Dissolved Organic Carbon Sustain an Ecosystem within a Density Stratified Coastal Aquifer of the Yucatan Peninsula, Mexico. Evidence for a Subterranean Microbial Loop?

NASA Astrophysics Data System (ADS)

Brankovits, David; Pohlman, John W.; Niemann, Helge; Leigh, Mary Beth; Casso, Michael; Alvarez Noguera, Fernando; Lehmann, Moritz F.; Iliffe, Thomas M.

2016-04-01

In coastal karst terrains, anchialine caves that meander in density stratified aquifers provide an exceptional opportunity for scientists to study in situ biogeochemical processes within the groundwater. The Caribbean coast of Mexico's Yucatan Peninsula contains over 1000 km of mapped cave passages, the densest known accumulation of anchialine caves in the world. A decades-old study based on the simple observation of 13C-depleted biomass in the cave-adapted fauna suggested biogeochemical processes related to methane-linked carbon cycling and/or other chemoautotrophic pathways as a source of energy and carbon. In this study, we utilized cave diving and a novel sampling device (the Octopipi) to obtain cm-scale water column profiles of methane, DOC and DIC concentrations and stable carbon isotope ratios to identify the energy sources and microbial processes that sustain life in these subterranean estuaries. High concentrations (up to 9522 nM) low-δ13C (as low as -67.5 permil) methane near the ceiling of the cave (in the fresh water section of the stratified water column) and evidence for methane oxidation in the brackish water portion of the water column suggest methane availability and consumption. Profiles obtained by the Octopipi demonstrate that virtually all of the methane (˜99%) is oxidized at the interface of anoxic freshwater and hypoxic brackish water masses. The high-methane water mass near the ceiling also contained elevated concentrations of DOC (851 μM) that displayed comparatively high δ13C (-27.8 to -28.2 permil), suggesting terrestrial organic matter input from the overlying soils. Low-methane brackish and saline water was characterized by lower DOC concentration (15 to 97 μM), yet with similar δ13C (-25.9 to -27.2 permil), suggesting significant terrestrial organic matter consumption or removal with increasing depth, from fresh to saline water, within the water column. The presence of 13C-depleted fatty acids (e.g., C16:1ω7c with δ13C

Planktonic cyanobacteria of the tropical karstic lake Lagartos from the Yucatan Peninsula, Mexico.

PubMed

Valadez, Francisco; Rosiles-González, Gabriela; Almazán-Becerril, Antonio; Merino-Ibarra, Martin

2013-06-01

The tropical karstic lakes on the Mexican Caribbean Sea coast are numerous. However, there is an enormous gap of knowledge about their limnological conditions and micro-algae communities. In the present study, surface water samples were collected monthly from November 2007 to September 2008 to provide taxonomical composition and biovolume of planktonic cyanobacteria of the lake Lagartos from State of Quintana Roo, Mexico. Water temperature, pH, conductivity, salinity, soluble reactive phosphorus (SRP), dissolved inorganic nitrogen (DIN), and soluble reactive silica (SRSi) levels were also analyzed. A total of 22 species were identified. Chroococcales and Oscillatoriales dominated the phytoplankton assemblages during the study period. Chroococcus pulcherrimus, Coelosphaerium confertum, Cyanodyction iac, Phormidium pachydermaticum and Planktolyngbya contorta were recorded for the first time in Mexico. A surplus of DIN (mean value of 42.7 microM) and low concentrations of SRP (mean value of 1.0 microM) promoted the enhanced growth and bloom formation of cyanobacteria. The mean biovolume was 3.22 x 10(8) microm3/mL, and two biovolume peaks were observed; the first was dominated by Microcystis panniformis in November 2007 (7.40 x 10(8) microm3/mL), and the second was dominated by Oscillatoriaprinceps in April 2008 (6.55 x 10(8) microm3/mL). Water quality data, nitrates enrichment, and trophic state based on biovolume, indicated that Lagartos is a hyposaline, secondarily phosphorus-limited, and eutrophic lake, where the cyanobacteria flora was composed mainly by non-heterocystous groups.

Overview of the Chicxulub impactite and proximal ejecta

NASA Astrophysics Data System (ADS)

Claeys, Ph

2003-04-01

Several types of impactites have now been recovered from the various wells drilled in the Chicxulub crater in Yucatan. The old Pemex wells (Yucatan 6 and Chicxulub 1) contain a highly heterogeneous and stratified suevite, which upper unit is unusually rich in carbonates, impact breccia and a possibly an impact melt at the very bottom of C1. They are located towards the crater center (C1), on the flank of the peak ring (Y6). The thickness of impactite in this zone exceeds 250 m. The UNAM wells just outside the crater rim reveal sedimentary breccia and a fall-out suevite richer in silicate melt and basement fragments, than its crater equivalent. There, the thickness of the impactite was probably several hundred meters, considering that its top might have been eroded. It can also be speculated that a cover of fall-back suevite extended over the ejecta blanket in Yucatan, all the way to Belize and perhaps even to the region of Tabasco, in Southern Mexico. The recently drilled Yaxcopoil contains about 100 m of impactites, which is currently under study. Preliminary data seem to show less variability than the material recovered from Y6. As in the UNAM well, the impactite is dominated by basement material, and shows alternating severely altered and better preserved horizons.

Evaluating the human impact on groundwater quality discharging into a coastal reef lagoon

NASA Astrophysics Data System (ADS)

Rebolledo-Vieyra, M.; Hernandez-Terrones, L.; Soto, M.; Lecossec, A.; Monroy-Rios, E.

2008-12-01

The Eastern coast of the Yucatan Peninsula has the fastest growth rate in Mexico and groundwater is the only source of drinking water in the region. The consequences of the lack of proper infrastructure to collect and treat wastewater and the impact of human activities on the quality of groundwater are addressed. The groundwater in the coastal aquifer of Quintana Roo (SE Mexico) discharges directly into the ocean. In addition, the coral reef of the Eastern Yucatan Peninsula is part of the Mesoamerican Coral Reef System, one of the largest in the world. The interaction of the reef-lagoon hydraulics with the coastal aquifer of Puerto Morelos (NE Yucatan Peninsula), and a major input of NH4, SO4, SiO2, as a consequence of the use of septic tanks and the lack of modern wastewater treatment plants are presented. No seasonal parameters differences were observed, suggesting that groundwater composition reaching the reef lagoon is not changing seasonally. A conceptual model of the coastal aquifer was developed, in order to explain how the human activities are impacting directly on the groundwater quality that, potentially, will have a direct impact on the coral reef. The protection and conservation of coral reefs must be directly related with a policy of sound management of coastal aquifers and wastewater treatment.

MISR High-Resolution, Cross-Track Winds for Hurricane Ida

NASA Image and Video Library

2009-11-10

This image shows JPL Multi-angle Imaging SpectroRadiometer instrument onboard NASA Terra satellite on Sunday, Nov. 8, 2009 as it passed over Hurricane Ida while situated between western Cuba and the Yucatan Peninsula.

Mooring observations of the near-inertial wave wake of Hurricane Ida (2009)

NASA Astrophysics Data System (ADS)

Pallàs-Sanz, Enric; Candela, Julio; Sheinbaum, Julio; Ochoa, José

2016-12-01

The near-inertial wave wake of Hurricane Ida is examined of the basis of horizontal velocity observations acquired from 7 moorings instrumented with acoustic Doppler current profilers deployed across the shelf break, slope, and at the abyssal plain of the Yucatan Peninsula, from 130 m to ∼3300 m. During the forced stage, background mean-flow consisted on a dominant cyclonic circulation of ∼100 km of diameter intensified toward the Yucatan's shelf (topographic constraint) and bounded by anticyclonic vorticity northeastward (north 25° N). In the low frequency band, subinertial signals of ∈ [5.5-7.5] day period propagating along the Yucatan shelf break. After the passage of Hurricane Ida, energetic near-inertial oscillations spread away from the storm's track over cyclonic vorticity. The wave's Eulerian frequency increases shoreward and toward the Yucatan's shelf. After Ida's passage, mooring data show a contrasting velocity response: semi-diurnal and diurnal tides are enhanced at the shelf break of the Yucatan Peninsula and near-inertial oscillations at the slope and abyssal plain. The near-inertial kinetic energy is largest to the right of the storm track because of the asymmetric wind-stress and amplified due to vorticity trapping near z =-500 m, which is a proxy of the base of the mesoscale structure and where the mean-flow is nearly zero. The blue frequency shifted wave wake propagates downward at ∼57-70 m day-1 and horizontally at 23-28 km day-1 leading a downward vertical energy flux of [1.3-1.6] × 10-2 W m-2. This represents a 7-9% of the total wind power input to near-inertial oscillations that, ultimately, became available for interior ocean mixing. The results suggest that the most energetic wave packet propagated poleward and downward from a broad upwelling region located near the Hurricane's track. The vertical structure of the near-inertial kinetic energy is described as a sum of the first 12 standing vertical modes and as vertically

Relationships among charcoal particles from modern lacustrine sediments and remotely sensed fire events

NASA Astrophysics Data System (ADS)

López-Pérez, M.; Correa-Metrio, A.

2013-05-01

Analysis of charcoal particles from lacustrine sediments is a useful tool to understand fire regimes through time, and their relationships with climate and vegetation. However, the extent of the relationship between charcoal particles and their origin in terms of the spatial and temporal extent of the fire events is poorly known in the tropics. Modern sediments were collected from lakes in the Yucatan Peninsula and Central Mexico, 51 and 22 lakes respectively, to analyze their charcoal concentration and its relationships with modern fire events. Number of modern fire events was derived from the public source Fire Information for Resource Management System (FIRMS) for concentric spatial rings that ranged from 1 to 30 km of radius. The association between charcoal and fires was evaluated through the construction of linear models to explain charcoal concentration as a function of the number of fires recorded. Additionally, charcoal particles were stratified according to size to determine the association between fire distance and charcoal size classes. The relationship between total charcoal concentration and fire events was stronger for central Mexico than for the Yucatan Peninsula, which is probably the result of differences in vegetation cover. The highest determination coefficients were obtained for charcoal particle sizes ranging between 0.2 and 0.8 mm2, and for fire event distances of between 0 and 15 km from the lake. Overall, the analyses presented here offer useful tools to quantitatively and spatially reconstruct past regional fire dynamics in Central Mexico and the Yucatan Peninsula.

Corneal and skin laser exposures from 1540-nm laser pulses

NASA Astrophysics Data System (ADS)

Johnson, Thomas E.; Mitchell, Michael A.; Rico, Pedro J.; Fletcher, David J.; Eurell, Thomas E.; Roach, William P.

2000-06-01

Mechanisms of tissue damage are investigated for skin and cornea exposures from 1540 nm ('eye safe') laser single pulses of 0.8 milli-seconds. New skin model data point out the advantages of using the Yucatan mini-pig versus the Yorkshire pig for in-vivo skin laser exposures. Major advantages found include similarities in thickness and melanin content when compared with human skin. Histology from Yucatan mini-pig skin exposures and the calculation of an initial ED50 threshold indicate that the main photon tissue interaction may not be solely due to water absorption. In-vitro corneal equivalents compared well with in-vivo rabbit cornea exposure under similar laser conditions. In-vivo and in-vitro histology show that initial energy deposition leading to damage occurs intrastromally, while epithelial cells show no direct injury due to laser light absorption.

Water quality assessment in the Mexican Caribbean: Impacts on the coastal ecosystem

NASA Astrophysics Data System (ADS)

Hernández-Terrones, Laura M.; Null, Kimberly A.; Ortega-Camacho, Daniela; Paytan, Adina

2015-07-01

Coastal zones are dominated by economically important ecosystems, and excessive urban, industrial, agricultural, and tourism activities can lead to rapid degradation of those habitats and resources. Groundwater in the Eastern Yucatan Peninsula coastal aquifer discharges directly into the coastal ocean affecting the coral reefs, which are part of the Mesoamerican Coral Reef System. The composition and impacts of groundwater were studied at different coastal environments around Akumal (SE Yucatan Peninsula). Radium isotopes and salinity were used to quantify fresh groundwater and recirculated seawater contributions to the coastal zone. Excess Ra distribution suggests spatially variable discharge rates of submarine groundwater. High NO3- levels and high coliform bacteria densities indicate that groundwater is polluted at some sites. Dissolved phosphorous content is elevated in the winter and during the high tourism season, likely released from untreated sewage discharge and from aquifer sediments under reducing conditions.

Solar forcing of drought frequency in the Maya lowlands.

PubMed

Hodell, D A; Brenner, M; Curtis, J H; Guilderson, T

2001-05-18

We analyzed lake-sediment cores from the Yucatan Peninsula, Mexico, to reconstruct the climate history of the region over the past 2600 years. Time series analysis of sediment proxies, which are sensitive to the changing ratio of evaporation to precipitation (oxygen isotopes and gypsum precipitation), reveal a recurrent pattern of drought with a dominant periodicity of 208 years. This cycle is similar to the documented 206-year period in records of cosmogenic nuclide production (carbon-14 and beryllium-10) that is thought to reflect variations in solar activity. We conclude that a significant component of century-scale variability in Yucatan droughts is explained by solar forcing. Furthermore, some of the maxima in the 208-year drought cycle correspond with discontinuities in Maya cultural evolution, suggesting that the Maya were affected by these bicentennial oscillations in precipitation.

Interstitial water studies on small core samples, Deep Sea Drilling Project: Leg 10

USGS Publications Warehouse

Manheim, Frank T.; Sayles, Fred L.; Waterman, Lee S.

1973-01-01

Leg 10 interstitial water analyses provide new indications of the distribution of rock salt beneath the floor of the Gulf of Mexico, both confirming areas previously indicated to be underlain by salt bodies and extending evidence of salt distribution to seismically featureless areas in the Sigsbee Knolls trend and Isthmian Embayment. The criterion for presence of salt at depth is a consistent increase in interstitial salinity and chlorinity with depth. Site 86, on the northern margin of the Yucatan Platform, provided no evidence of salt at depth. Thus, our data tend to rule out the suggestion of Antoine and Bryant (1969) that the Sigsbee Knolls salt was squeezed out from beneath the Yucatan Scarp. Cores from Sites 90 and 91, in the central Sigsbee Deep, were not obtained from a great enough depth to yield definite evidence for the presence of buried salt.

Experimental infection of Contracaecum multipapillatum (Nematoda: Anisakinae) from Mexico in the domestic cat.

PubMed

Vidal-Martínez, V M; Osorio-Sarabia, D; Overstreet, R M

1994-08-01

Juveniles of Contracaecum multipapillatum infected the Mayan cichlid (Cichlasoma urophthalmus) and adults infected the olivaceous cormorant (Phalacrocorax olivaceus) and the great egret (Casmerodius albus) in the coastal lagoon at Celestun, State of Yucatan, Mexico. All are new host records, and, even though the geographic locality record of Mexico for the species has not been published, unidentified but presumably conspecific specimens have been reported from there. When juveniles of C. multipapillatum were fed to a kitten, but not rats, ducks, or chickens, they developed into adults. Measurements and morphological data are provided on the specimens from the kitten. Development of an avian ascaridoid in the intestine of a mammal increases the potential of this widespread species to infect other mammals, including humans.

Methionine metabolism in Yucatan miniature swine.

PubMed

McBreairty, Laura E

2016-06-01

Methionine is an essential amino acid which when not incorporated into protein, can be converted to S-adenosylmethionine, the universal methyl donor in over 200 transmethylation reactions, which include creatine and phosphatidylcholine (PC) synthesis, as well as deoxyribonucleic acid (DNA) methylation. Following transmethylation, homocysteine is formed, which can be converted to cysteine via transsulfuration or remethylated to methionine by receiving a methyl group from folate or betaine. Changes to methyl group availability in utero can lead to permanent changes in epigenetic patterns of DNA methylation, which has been implicated in "fetal programming", a phenomenon associated with poor nutrition during fetal development that results in low birth weight and disease in later life. It has been shown that programming can also occur in the neonate. Our global objective was to understand how the variability of nutrients involved in methionine metabolism can affect methionine and methyl group availability. We hypothesize that nutrients that converge on methionine metabolism can affect methionine availability for its various functions. In this thesis, we used intrauterine growth restricted (IUGR) piglets to investigate whether a global nutritional insult in utero can lead to a perturbed methionine metabolism. Our results demonstrate that IUGR piglets have a lower capacity to dispose of homocysteine via both transsulfuration and remethylation pathways, as well as a lower incorporation of methyl groups into PC. The second objective of this thesis was to determine whether variation in methionine supply and demand can affect methionine availability. We demonstrated that stimulating either acute or chronic creatine synthesis leads to lower methyl incorporation into protein and PC in pigs. Furthermore, when methionine is limiting, supplementation with either folate or betaine leads to higher methionine availability for protein synthesis. Finally, because creatine is increasingly being utilized as an ergogenic and neuroprotective supplement, we wanted to determine whether provision of the creatine precursor, guanidinoacetate (GAA), could effectively increase tissue creatine stores. We showed that 2.5 weeks of supplementation with GAA is more effective than creatine at increasing hepatic and muscle creatine stores. The results of this thesis demonstrate that the presence of IUGR, an increased demand for creatine synthesis, or the supplementation with remethylation nutrients can each affect methionine availability; all are important when considering neonatal nutrient requirements. Furthermore, although GAA is effective at increasing levels of tissue creatine, higher GAA methylation can limit methionine availability for growth and synthesis of PC.

Hurricane Isidore

Atmospheric Science Data Center

2013-04-18

... 20, 2002. After bringing large-scale flooding to western Cuba, Isidore was upgraded (on September 21) from a tropical storm to a ... Yucatan Peninsula, the hurricane caused major destruction and left hundreds of thousands of people homeless. Although weakened after ...

A Blast from the Past.

ERIC Educational Resources Information Center

Sharp, Len

1998-01-01

Describes how teaching a lesson on the discovery of a crater in the Yucatan Peninsula and the rock strata deep in the ocean can help students explain the demise of dinosaurs. Discusses the impact theory and the core model. (DDR)

Chicxulub impact basin: Gravity characteristics and implications for basin morphology and deep structure

NASA Technical Reports Server (NTRS)

Sharpton, Virgil L.; Burke, Kevin; Hall, Stuart A.; Lee, Scott; Marin, Luis E.; Suarez, Gerardo; Quezada-Muneton, Juan Manuel; Urrutia-Fucugauchi, Jaime

1993-01-01

The K-T-aged Chicxulub Impact Structure is buried beneath the Tertiary carbonate rocks of the Northern Yucatan Platform. Consequently its morphology and structure are poorly understood. Reprocessed Bouguer (onshore) and Free Air (offshore) gravity data over Northern Yucatan reveal that Chicxulub may be a 200-km-diameter multi-ring impact basin with at least three concentric basin rings. The positions of these rings follow the square root of 2 spacing rule derived empirically from analysis of multi-ring basins on other planets indicating that these rings probably correspond to now-buried topographic basin rings. A forward model of the gravity data along a radial transect from the southwest margin of the structure indicates that the Chicxulub gravity signature is compatible with this interpretation. We estimate the basin rim diameter to be 204 +/- 16 km and the central peak ring diameter (D) is 104 +/- 6 km.

Molecular characterization of atypical antigenic variants of canine rabies virus reveals its reintroduction by wildlife vectors in southeastern Mexico.

PubMed

Garcés-Ayala, Fabiola; Aréchiga-Ceballos, Nidia; Ortiz-Alcántara, Joanna M; González-Durán, Elizabeth; Pérez-Agüeros, Sandra I; Méndez-Tenorio, Alfonso; Torres-Longoria, Belem; López-Martínez, Irma; Hernández-Rivas, Lucía; Díaz-Quiñonez, José Alberto; Ramírez-González, José Ernesto

2017-12-01

Rabies is an infectious viral disease that is practically always fatal following the onset of clinical signs. In Mexico, the last case of human rabies transmitted by dogs was reported in 2006 and canine rabies has declined significantly due to vaccination campaigns implemented in the country. Here we report on the molecular characterization of six rabies virus strains found in Yucatan and Chiapas, remarkably, four of them showed an atypical reaction pattern when antigenic characterization with a reduced panel of eight monoclonal antibodies was performed. Phylogenetic analyses on the RNA sequences unveiled that the three atypical strains from Yucatan are associated with skunks. Analysis using the virus entire genome showed that they belong to a different lineage distinct from the variants described for this animal species in Mexico. The Chiapas atypical strain was grouped in a lineage that was considered extinct, while the others are clustered within classic dog variants.

Low prevalence of high risk human papillomavirus in normal oral mucosa by hybrid capture 2

PubMed Central

González-Losa, Maria del Refugio; Manzano-Cabrera, Luis; Rueda-Gordillo, Florencio; Hernández-Solís, Sandra E.; Puerto-Solís, Luis

2008-01-01

High risk human papillomavirus (HR-HPV) are recognized as a necessary factor to development cervical cancer. During the last decade many studies have found HR-HPV in oral squamous cell carcinoma (OSCC) and normal oral mucosa, however the association between HR-HPV and OSCC is still uncertain. The aim of the study was to determine DNA HR-HPV in normal oral cavity of healthy adults. A cross-sectional study was performed; samples from 77 patients with normal oral cavity were collected at the Dentistry school, Autonomous University of Yucatan, Merida, Yucatan, México. HR-HPV was detected by hybrid capture 2. One sample out of 77(1.2%) was positive for HR-PVH. It was from a man of 50 years old. HRHPV is present in low rate among healthy oral mucosa. Hybrid capture 2 could be a good methodology for large epidemiology studies. PMID:24031173

Ballistic Missile Defense System (BMDS) Programmatic Environmental Impact Statement

DTIC Science & Technology

2007-01-01

upon the fish for their nutrition , health, and economy. Additional studies need to be done to assess this potential threat to the Alaska...the Yucatan . (Lincoln et al., 1998) Several studies of bird migrations using NEXRAD (weather radar) have allowed researchers to estimate the

Protection by Purines in Toxin Models of Parkinson’s Disease

DTIC Science & Technology

2014-08-01

Nucleoside transport and metabolism in erythrocytes from the Yucatan miniature pig. Evidence that inosine functions as an in vivo energy substrate...BJ, Choi HK. Prevalence of gout and hyperuricemia in the us general population: The national health and nutrition examination survey 2007–2008

Modern African, Asian, Latin American, and Middle Eastern Military History: A Bibliography of English-Language Books and Articles Published From 1960-2013

DTIC Science & Technology

2014-03-01

Nutrition , Sanitation, Hygiene, and the Likelihood of Death: The British Army in India c. 1870-1920.” Population Studies XLVII 3 (November 1993...77    Reed, Nelson. The Caste War of Yucatan . Stanford: Stanford University Press, 1964. Rodriguez, Linda Alexander, ed. Rank and Privilege

Pesticide Avoidance Behavior in Anopheles albimanus, a Malaria Vectorin Central and South America

DTIC Science & Technology

1995-07-11

Clements, A.N. 1992. The Bjoloey of MOSQuitoes. Volume 1. Development, nutrition , and reproduction. Chapman & Hall, 509 pp. EL-Khatib. Z.l...WHO 29(suppl): 121-126. Hoffman, C.C. 1934. Contribucion al conocimiento del paludismo en Ja peninsula de Yucatan . Boletia dellnstituto de

Drug and Immigration Issues in the Mexico-US Relationship

DTIC Science & Technology

1994-06-01

and Yucatan . 89 Confederation) and the CNOC (National worker-peasants Confederation) which make really a strong party because the quantity of secure... nutrition , and housing; greatly broadened opportunities for all individuals to realize their full potential through education; and a strong voice for all

Our Changing Planet. The U.S. Climate Change Science Program for Fiscal Year 2007

DTIC Science & Technology

2006-11-01

soil food webs and the mineral nutrition of vascular plants. Biological crusts also contribute to soil stability (reducing erosion) and water...In Mexico’s Yucatan Peninsula, the network studied the decline of corn productivity after the second year of cultivation, and determined that corn

An Environmental Expedition Course in Search of the Maya.

ERIC Educational Resources Information Center

Loret, John

1978-01-01

Sponsoring an interdisciplinary program (over 30 lecture hours of geology, ecology, anthropology, ethnology, and agriculture of the Yucatan and Meso-America), Queens College and the University of Connecticut provide expeditions to Mexico and study of local geomorphology, stratigraphy, climate, topography, soils, archeological sites, flora, and…

Modelling dengue fever risk in the State of Yucatan, Mexico using regional-scale satellite-derived sea surface temperature.

PubMed

Laureano-Rosario, Abdiel E; Garcia-Rejon, Julian E; Gomez-Carro, Salvador; Farfan-Ale, Jose A; Muller-Karger, Frank E

2017-08-01

Accurately predicting vector-borne diseases, such as dengue fever, is essential for communities worldwide. Changes in environmental parameters such as precipitation, air temperature, and humidity are known to influence dengue fever dynamics. Furthermore, previous studies have shown how oceanographic variables, such as El Niño Southern Oscillation (ENSO)-related sea surface temperature from the Pacific Ocean, influences dengue fever in the Americas. However, literature is lacking on the use of regional-scale satellite-derived sea surface temperature (SST) to assess its relationship with dengue fever in coastal areas. Data on confirmed dengue cases, demographics, precipitation, and air temperature were collected. Incidence of weekly dengue cases was examined. Stepwise multiple regression analyses (AIC model selection) were used to assess which environmental variables best explained increased dengue incidence rates. SST, minimum air temperature, precipitation, and humidity substantially explained 42% of the observed variation (r 2 =0.42). Infectious diseases are characterized by the influence of past cases on current cases and results show that previous dengue cases alone explained 89% of the variation. Ordinary least-squares analyses showed a positive trend of 0.20±0.03°C in SST from 2006 to 2015. An important element of this study is to help develop strategic recommendations for public health officials in Mexico by providing a simple early warning capability for dengue incidence. Copyright © 2017 Elsevier B.V. All rights reserved.

Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Mid-Atlantic). Bay Anchovy

DTIC Science & Technology

1989-02-01

Mexico coasts, from Cape Cod, species of anchovies have been Massachusetts, to Yucatan , Mexico recorded from the Mid-Atlantic Region, (Hildebrand 1963...bay anchovies were food web (Figure 3). It is an apparently unaffected by water important source of nutrition for many temperatures exceeding 32 0 C

Adapting, Transforming, and Modernizing Under Fire: The Mexican Military 2006-11

DTIC Science & Technology

2011-09-01

Quin- tana Roo, and Yucatan , respectively. • In June 2007, a SEMAR plan to stand up a total of 30 marine infantry battalions (BIM) report- 2007 2008...disaster relief operations as part of its mission portfolio and participated in national vaccination, lit- eracy, nutrition , and reforestation campaigns

Geothermal Energy

DTIC Science & Technology

1975-11-15

temperature conditions, etc. It is also engaged on physiological studies, on studies of nutrition for increasing plants and studies on the agricultural...activity, especially in the Acapulco region. The zones known as Sierra Madre del Sur, Sierra de Chiapas, the Gulf coastal plain and the Yucatan

Archeological Data Recovery of the Camino Site (16JE223), A Spanish Colonial Period Site Near New Orleans, Louisiana

DTIC Science & Technology

1996-03-01

Barataria Basin. Byrd (1976) examined the nutritional and caloric value of this brackish water mollusk in order to determine its relative importance to... Yucatan ) received 149 settlers in the period 1733-1735; the future San Antonio, Texas, received 56 Islefios in 1730; St. Augustine received 707

Mississippi River, Baton Rouge to the Gulf, Louisiana, Project. Supplement II.

DTIC Science & Technology

1984-04-01

include portions of the west coast of Florida and the northern coast of Yucatan as major feeding areas for green turtles. Hildebrand (1979) has...D. Seneca. 1973. An investigation of propagation and mineral nutrition of Spartina alterniflora. Sea Grant Publication UNC-SG-73-14. North Carolina

Revision of the amphiamerican Neotetraonchus Bravo-Hollis, 1968 (Monogenoidea: Dactylogyridae), with a description of N. vegrandis n. sp. from the gill lamellae of the blue sea catfish Ariopsis guatemalensis (Siluriformes: Ariidae) off the Pacific Coast of Mexico.

PubMed

Kritsky, Delane C; Mendoza-Franco, Edgar F; Bullard, Stephen A; Vidal-Martínez, Victor M

2009-09-01

Neotetraonchus Bravo-Hollis, 1968 is revised and reassigned to the Dactylogyridae Bychowsky, 1933 based on examinations of specimens representing four species from the gill lamellae of sea catfishes (Ariidae). The monotypic Neotetraonchidae Bravo-Hollis, 1968 is placed in synonymy with the Dactylogyridae. Neotetraonchus bychowskyi Bravo-Hollis, 1968 (type-species), is redescribed from the tete sea catfish Ariopsis seemanni (Günther) (type-host) in the eastern Pacific Ocean off Panama (new geographical record). Neotetraonchus vegrandis n. sp. is described from the blue sea catfish A. guatemalensis (Günther) off the Pacific Coast of Mexico. Neotetraonchus bravohollisae Paperna, 1977 is redescribed from the hardhead sea catfish A. felis (L.) in the Gulf of Mexico off the Yucatan Peninsula. Neotetraonchus felis (Hargis, 1955) Paperna, 1977 is redescribed from A. felis in the Gulf of Mexico off Mississippi and the Yucatan Peninsula (new geographical record). Morphological similarities between species of Neotetraonchus suggest the likely presence of geminate species pairs flanking the Isthmus of Panama.

[ANTIOXIDANT POTENTIAL OF MELIPONA BEECHEII HONEY AND ITS RELATIONSHIP TO HEALTH: A REVIEW].

PubMed

Cauich Kumul, Roger; Ruiz Ruiz, Jorge Carlos; Ortíz Vázquez, Elizabeth; Segura Campos, Maira Rubi

2015-10-01

The present article provides a literature review about the biological potential of Melipona beecheii. The objective is to project some tendecies in research about nutraceutical aspects related to the bioactive compounds presents in the honey of this stingless bee species, known for its medicinal properties traditional, in the Yucatan Peninsula. Currently, there is strong evidence that M. beecheii honey has bioactive compounds such as proteins, flavonoids and polyphenols with high antioxidant activity. The scientific evidence allows to propose to the honey of stingless bee species as a potential alternative for the obtention of bioactive compounds with antioxidant activity in the Yucatan Peninsula and natural food being proposed to reduce some diseases associated with stress oxidative physiological human cells. However, there is still information that explains such antioxidant activity, therefore, according to the literature reviewed, sees the need to address nutraceuticals and functional aspects correlated with the bioactive compounds present in this honey bee. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Archaeointensity and rock magnetism on Maya locations pottery, Southeast Mexico, from Preclassic to Posclassic

NASA Astrophysics Data System (ADS)

Rodriguez Trejo, A.; Alva-Valdivia, L. M.; Nieto Calleja, R.; Jimenez, S.

2016-12-01

Archeointensity results are presented from 7 archeological sites of the Maya Zone, southeast Mexico: Chiapas, Yucatan and Quintana Roo, distributed geographically over a 500,000 Km2 area over the Yucatan Peninsula. The sites corresponds to over 250 samples from Palenque, Chichén-Itzá, Flor de Mayo, El Mirador, Oxtancah, Busiljá and Mensabak. All the artifact sites correspond from the Preclasic to Posclasic period (1000 b.C. to 1600 a.C.), which represent the most important period in Mesoamerica. The laboratory experiments for rock magnetism includes the suscpetibility vs. temperature curves (KT), hysteresis loop, first order reversal curves analysis (FORC), IRM coercivity unmixing and thermal and AF demagnetization. Archaeointensity were carried out using previously selected samples that accomplish the quality criteria, using the Thellier - Thellier methology and the Coe check modification. These results will be used to construct a secular variation curve for intensity in this region, which eventually could be used for dating many archeological materials of unknown age.

Mexico's Luna discoveries are more than moonshine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stewart-Gordon, T.J.; Baker, G.T.

1987-05-01

Just when it seemed that Mexico's petroleum reserves may have been overstated, the state oil company opened a new province. Petroleos Mexicanos (Pemex) geologists think the Luna area of Tabasco State and the Gulf of Mexico could add the condensate and gas equivalent of 20 billion bbl of light oil to Mexico's proven reserves. If true, this would be the largest discovery in Mexico since the Campeche Sound fields in 1976. To date, the new province stretches about 50 miles between the Caribbean coastal towns of Frontera and Puerto Ceiba in Tabasco State, and extends some 31 miles offshore (seemore » map). Since the early 1970s, Pemex geologists have postulated that the entire Yucatan platform will prove productive. Luna finds reduce the distance between Campeche fields and onshore production to 93 miles. The Luna area is ideally suited for rapid development - it is about 40 miles northeast of Villahermosa, Tabasco, and within 60 miles of the export terminal at Dos Bocas near the border between Tabasco and Vera Cruz states. It is also less than 50 miles from the Cactus gas-processing and petrochemical plants in Chiapas State, which means that gas can be put into the country's trunk line that extends to the U.S. grid at Reynosa.« less

Low-Level Sarin (GB) Vapor Exposure in the Gottingen Minipig: Effect of Exposure Concentration and Duration on Pupil Size

DTIC Science & Technology

2006-09-01

Macary, G. Comparative Study of the Opthalmological Observations in the Yucatan Micropig and the Gottingen Minipig. Scand. J Lab. Anim. Sci. 1998, 25...2002, 28(8), pp 1433-1438. 25. Yoss, R.E.; Moyer, N.J.; Hollenhorst, R.W. Hippus and Other Spontaneous Rhythmic Pupillary Waves. American J. Opthalmology

Hurricane Ida

Atmospheric Science Data Center

2013-04-18

article title:  Hurricane Ida Cross-Track Winds       ... (MISR) instrument on NASA's Terra satellite passed over Hurricane Ida while it was situated between western Cuba and the Yucatan Peninsula. According to the National Hurricane Center, at 15:00 UTC, the hurricane had an estimated minimum central ...

77 FR 30819 - Endangered and Threatened Wildlife and Plants; Final Rule To Remove the Morelet's Crocodile From...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-23

... may vary by habitat, nutrition, etc. Our Response: We revised that section to reflect this correction..., nutrition, and other environmental factors (Rainwater 2011, pers. comm.) A growth rate of 0.63 inches (in... crocodile comprised the eastern coastal plain of Mexico, most of the Yucatan Peninsula, Belize, and northern...

Clinical Investigation Program: Annual Progress Report

DTIC Science & Technology

1992-09-30

Academy of Surgical Research, Chicago, Illinois; Yucatan Miniature Swine as a Model System for the Studyt of Vocal Fold Vibratory Function; 6th Annual...34(14)e". (15) Study Objective: Compare two enteral formulas in respect to nutritional aspects. (16) Technical Approach: Protocol will take place in

Species Profiles. Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Gulf of Mexico). American Oyster.

DTIC Science & Technology

1986-07-01

valves when fully oyster (Butler 1954). Its range closed. extends to the Yucatan Peninsula of Mexico and to Venezuela. Along the Shel. shape is... nutritional factors which affect report on the 1950 opening. Pubi. the growth and setting of the Inst. Mar. Sci. Univ. Texas. larvae of the oyster

Missile Defense Agency Ballistic Missile Defense System (BMDS): Programmatic Environmental Impact Statement. Volume 3 Appendices K - N

DTIC Science & Technology

2007-01-01

Bering Sea through direct affects on the fish, as well as the thousands of people dependent upon the fish for their nutrition , health, and economy...Newfoundland to British Columbia; however, the width of the migratory path narrows to 400 miles from east-west at the latitude of the Yucatan . (Lincoln et

The Role of Physical-Chemical Factors in Structuring Subtidal Marine and Estuarine Benthos.

DTIC Science & Technology

1983-06-01

Yucatan and West Indies (Bahr 1981), and has even been 29 reported from Brazil (Gunter 1951). The Pacific oyster (Oystrea lurida) replaces the Atlantic...N. T. 1970. "The Role of Zooplankton in the Nutrition of Scleractinian Corals," Limnol. Oceanogr., 15:579-586. Johnson, R. G. 1970. "Variations in

Multidisciplinary Strategies in the Prevention and Early Detection of Ovarian Cancer

DTIC Science & Technology

2001-09-01

J. Obstet. Gynecol., 64. Beyene, Y., and Martin, M. C. Menopausal experiences and bone density of Mayan 161: 905-910, 1989. women in Yucatan , Mexico...USA, 95, 12334-12339 40 Sasagawa, T., Suzuki, K., Shiota, T., Kondo, T. and Okita, M. (1998) Journal of Nutritional Science & Vitaminology 44, 809-818

Belize Area Study

DTIC Science & Technology

1983-11-20

plains. It ’is generally similar . to the entire Yucatan Penisula of which it is a part. If the drainage is sufficient, land use there is intensive...and reported. Dental disease is rather prevalent affecting 90% of the pcpulation and is primarily treated by extractions. Nutrition Energy-protein...8217 ............................................................................................................................................................. . . ._. .- -" nutritionally

Crossing Pedagogical Borders in the Yucatan Peninsula

ERIC Educational Resources Information Center

Willhauck, Susan

2009-01-01

A challenging intercultural teaching experience provided an opportunity for engaging embodied pedagogies that facilitated border crossings of language, age, gender, and experience. Influenced by the work of Augusto Boal, the author describes how improvisation, role-play, music, and drawing led seminary students in Mexico into sacred time and space…

Emissions from biomass burning in the Yucatan

Treesearch

R. J. Yokelson; J. D. Crounse; P. F. DeCarlo; T. Karl; S. Urbanski; E. Atlas; T. Campos; Y. Shinozuka; V. Kapustin; A. D. Clarke; A. Weinheimer; D. J. Knapp; D. D. Montzka; J. Holloway; P. Weibring; F. Flocke; W. Zheng; D. Toohey; P. O. Wennberg; C. Wiedinmyer; L. Mauldin; A. Fried; D. Richter; J. Walega; J. L. Jimenez; K. Adachi; P. R. Buseck; S. R. Hall; R. Shetter

2009-01-01

In March 2006 two instrumented aircraft made the first detailed field measurements of biomass burning (BB) emissions in the Northern Hemisphere tropics as part of the MILAGRO project. The aircraft were the National Center for Atmospheric Research C-130 and a University of Montana/ US Forest Service Twin Otter. The initial emissions of up to 49 trace gas or particle...

Fertility, Infant Feeding, and Change in Yucatan.

ERIC Educational Resources Information Center

Howrigan, Gail A.

1988-01-01

Although the Yucatec pattern of child care conforms on the whole to the pattern seen in other agrarian societies, it is currently becoming destabilized as the society becomes more modern. Some of the developing customs, such as bottle-feeding, are maladaptive, at least in the short run. (RH)

Journey to the end of the dinosaur era: A society expedition to Belize

NASA Technical Reports Server (NTRS)

Ocampo, Adriana

1995-01-01

The impact of the extraterrestrial object that formed the Chicxulub crater in the northwestern Yucatan peninsula of Mexico is the leading suspect for the extinction of the dinosaurs. This article reports on a Planetary Society expedition to Albion Island in the Rio Hondo region of Belize to investigate evidence supporting the impact theory.

ARC-1991-AC91-0257

NASA Image and Video Library

1991-05-07

Prehistoric Yucatan Impact Crater: 'The infamous K-T impact event 65 million years ago (64.98 plus or minus 50,000 years), imagined here just as the bolide strikes, as seen by some high flying Pteranodons. Artwork for NASA by Don Davis. Acrylics and airbrush inks on board.' (nicknamed the Dino Killer)

The Fourth Gospel as Contextualized by Yucatecan Assemblies of God Pastors

ERIC Educational Resources Information Center

Kazim, Paul S.

2017-01-01

Most of the training material that Assemblies of God educators use in Latin America was originally written in English. Almost without exception nationals or missionaries translated the approved theology texts from English. While everyone contextualizes, the gospel message will not ever be completely at home in the Yucatan until the pastors think…

Mexican Trends: The Next Five Years,

DTIC Science & Technology

1985-12-12

nutrition and euployment in rural areas and restoring *the ountry to IMOIX-miiciency in basic grdu. 2he latest in this prcession are PF40NAL, an...traditionally, with the exception of Yucatan . give overwhelming support to the PRI. The Right will continued to be limited in its ,7 appeal as a national

Teaching Beliefs and Teaching Styles of Mathematics Teachers and Their Relationship with Academic Achievement

ERIC Educational Resources Information Center

Canto-Herrera, Pedro; Salazar-Carballo, Humberto

2010-01-01

The purpose of this study was to study the relationship between beliefs and teaching styles of teachers of mathematics and their students' academic performance in high schools of Yucatan. For this purpose, a questionnaire was administered to 72 high school mathematics teachers and the student academic achievement score of 1241 were used. A…

Are there trends towards drier hydrological conditions in Central America?

NASA Astrophysics Data System (ADS)

Hidalgo, H. G.

2013-12-01

A summary of hydrological projections at the end of the century from 30 General Circulation Models (GCMs) is presented; and several hydrometeorological parameters are analyzed to validate if there are hydroclimatological trends during the observational period (1982-2005) consistent with the GCMs results. At the end of the century the median of 30 GCM simulations projects a drier future for Tegucigalpa and San Jose, with a marked increment in evapotranspiration in the first half of the rainy season along with reductions of soil moisture. With respect to the observations (1982-2005): 1) the Normalized Difference Vegetation Index showed negative trends in the North Pacific coast of Costa Rica, the border of Honduras and Nicaragua, and especially in southern Mexico (except the Yucatan Peninsula). Positive trends were found in the several parts of Central America, 2) the Palmer Drought Severity Index showed strong and consistent trends from Nicaragua to the North of Central America and southern Mexico (not including Yucatan), consistent with the direction of GCM projections; 3) negative precipitation trends in satellite data were found in Nicaragua, with strong trends in its Caribbean coast; 4) NCEP/NCAR Reanalysis precipitation showed strong negative trends in northern Central America, the Central Valley, the Dry Pacific of Costa Rica and the South-Pacific coast of Nicaragua, all consistent with the direction of GCM projections; and 5) station data showed no significant trends however, and 6) Reanalysis' temperature showed positive trends in southern Mexico (not including Yucatan) and negative trends in El Salvador. It can be concluded that several trends in drought indexes and precipitation are consistent with the future projected by the GCMs; that is, with some exceptions some of the trends were validated towards a drier future for the region, especially in the northern part.

Response of pigmented porcine skin (Sus scrofa domestica) to single 3.8-micron laser radiation pulses

NASA Astrophysics Data System (ADS)

Bostick, Anthony C.; Johnson, Thomas E.; Randolph, Donald Q.; Winston, Golda C. H.

2005-04-01

Background and purpose: The purpose of this study is to determine the impact of melanin on skin response to single 3.8 micron, eight microsecond laser pulses and the difference in lesion formation thresholds for input into laser safety standards. Williams et al., performed a study examining laser tissue interaction from 3.8-micron lasers in lightly pigmented Yorkshire pigs (Sus scrofa domestica). However, studies performed by Eggleston et al comparing pigmented and lightly pigmented skin with human skin found that the Yucatan mini-pig is a superior model for laser skin exposures. Methods: Five Yucatan mini-pigs under general anesthesia were exposed to 3.8 micron laser pulses ranging from 0.8 J/cm2 to 93 J/cm2. Gross examinations were done acutely and 24 hours after laser exposure. Skin biopsies were then collected at various times post exposure, and histologic examinations were conducted. Results: The 24 hour ED50 was determined to be 4.5 J/cm2 with fiducial limits of 6.2 and 2.2 J/cm2. As deposited energy was increased, the lesion presentation ranged from whitening of the epidermis (4 J/cm2) to whitening with inflammatory centers (14 J/cm2), and at the highest energy levels inflammatory areas were replaced with an epidermal ulcerated central area (>21 J/cm2). Conclusion: Preliminary findings suggest pigmentation or melanin may play a minor role in the mechanism of laser-tissue damage. The ED50 of Yorkshire pigs was 2.6 J/cm2. The ED50 of the Yucatan mini-pig was found to be 3.6 J/cm2, and although it was higher, it is still within the 95% fiducial limits.

Analysis of Thiopurine S-Methyltransferase Deficient Alleles in Acute Lymphoblastic Leukemia Patients in Mexican Patients.

PubMed

Jiménez-Morales, Silvia; Ramírez-Florencio, Mireya; Mejía-Aranguré, Juan Manuel; Núñez-Enríquez, Juan Carlos; Bekker-Mendez, Carolina; Torres-Escalante, José Luis; Flores-Lujano, Janet; Jiménez-Hernández, Elva; Del Carmen Rodríguez-Zepeda, María; Leal, Yelda A; González-Montalvo, Pablo Miguel; Pantoja-Guillen, Francisco; Peñaloza-Gonzalez, José Gabriel; Gutiérrez-Juárez, Erick Israel; Núñez-Villegas, Nora Nancy; Pérez-Saldivar, Maria Luisa; Guerra-Castillo, Francisco Xavier; Flores-Villegas, Luz Victoria; Ramos-Cervantes, María Teresa; Fragoso, José Manuel; García-Escalante, María Guadalupe; Del Carmen Pinto-Escalante, Doris; Ramírez-Bello, Julián; Hidalgo-Miranda, Alfredo

2016-11-01

It has been demonstrated that heterozygote and homozygote thiopurine S-methyltransferase (TPMT) mutant allele carriers are at high risk to develop severe and potentially fatal hematopoietic toxicity after treatment with standard doses of 6-mercaptopurine (6-MP) and methotrexate (MX). Those drugs are the backbone of acute lymphoblastic leukemia (ALL) and several autoimmune disease treatments. We undertook this study to determine the frequency of the TPMT deficient alleles in children with ALL and non-ALL subjects from Mexico City and Yucatan, Mexico. We included 849 unrelated subjects, of which 368 ALL children and 342 non-ALL subjects were from Mexico City, and 60 ALL cases and 79 non-ALL individuals were from Yucatan. Genotyping of the rs1800462, rs1800460 and rs1142345 SNPs was performed by 5'exonuclease technique using TaqMan probes (Life Technologies Foster City, CA). The mutant TPMT alleles were present in 4.8% (81/1698 chromosomes) and only 0.2% were homozygote TPMT*3A/TPMT*3A. We did not find statistically significant differences in the distribution of the mutant alleles between patients from Mexico City and Yucatan in either ALL cases or non-ALL. Nonetheless, the TPMT*3C frequency in ALL patients was higher than non-ALL subjects (p = 0.03). To note, the null homozygous TPMT*3A/TPMT*3A genotype was found in 2.5% of the non-ALL subjects. TPMT mutant alleles did not exhibit differential distribution between both evaluated populations; however, TPMT*3C is overrepresented in ALL cases in comparison with non-ALL group. Assessing the TPMT mutant alleles could benefit the ALL children and those undergoing 6-MP and MX treatment. Copyright © 2016 IMSS. Published by Elsevier Inc. All rights reserved.

Migrant songbirds, habitat change, and conservation prospects in northern Peten, Guatemala: some initial results

Treesearch

David F. Whitacre; Julio Madrid M.; Ciriaco Marroquín; Mark Schulze; Laurin Jones; Jason Sutter; Aaron J. Baker

1993-01-01

A recently-created complex of reserves spanning the Guatemala, Mexico, Belize borders in the southern Yucatan Peninsula constitutes 5.5 million acres of contiguous, protected lowland forest. Information is needed on compatibility of various land-uses and biodiversity protection in multiple-use zones of these reserves. To address these and other needs related to...

Creative Problem Solving How Do Undergraduates Perceive the Teaching Practice of Their Professors?

ERIC Educational Resources Information Center

Briceño, Efrain Duarte; Diaz-Mohedo, Maria Teresa; Chan, Jorge Carlos Aguayo; Ballote, Guillermo Baeza

2018-01-01

The research question was inquiring the undergraduates' perception of their professors' practice regarding whether they make use of the creative problem solving (CPS) as a competence for teaching. The study was performed in a public university located in the urban area of Merida City, Yucatan, Mexico, where a total of 247 undergraduates from the…

The Road to 2012: Looking Towards the Next Two Decades

DTIC Science & Technology

1993-03-01

Carolina in 1989 and was rated a 4 on the 5-point scale measuring storm intensity? And what about Gilbert, which ravaged Jamaica and Mexico’s Yucatan ...the nutritional 237 The Road to 2012: Looking Tozvai, the Next Two Decades and neuroendo,:rine aspects of aging, and if we develop ways to re- pair

The Development of Short-Term and Incidental Memory: A Cross-Cultural Study.

ERIC Educational Resources Information Center

Wagner, Daniel A.

This study investigated developmental changes in memory performance for two contrasting populations in Urban and Rural Yucatan, Mexico. Subjects were divided into five groups defined by age, including children and adults. All urban S's were in school, while only the two younger rural groups were in school, and older rural S's had little or no…

Computed tomography-based tissue-engineered scaffolds in craniomaxillofacial surgery.

PubMed

Smith, M H; Flanagan, C L; Kemppainen, J M; Sack, J A; Chung, H; Das, S; Hollister, S J; Feinberg, S E

2007-09-01

Tissue engineering provides an alternative modality allowing for decreased morbidity of donor site grafting and decreased rejection of less compatible alloplastic tissues. Using image-based design and computer software, a precisely sized and shaped scaffold for osseous tissue regeneration can be created via selective laser sintering. Polycaprolactone has been used to create a condylar ramus unit (CRU) scaffold for application in temporomandibular joint reconstruction in a Yucatan minipig animal model. Following sacrifice, micro-computed tomography and histology was used to demonstrate the efficacy of this particular scaffold design. A proof-of-concept surgery has demonstrated cartilaginous tissue regeneration along the articulating surface with exuberant osseous tissue formation. Bone volumes and tissue mineral density at both the 1 and 3 month time points demonstrated significant new bone growth interior and exterior to the scaffold. Computationally designed scaffolds can support masticatory function in a large animal model as well as both osseous and cartilage regeneration. Our group is continuing to evaluate multiple implant designs in both young and mature Yucatan minipig animals. 2007 John Wiley & Sons, Ltd.

Measuring the Wavelength of a Diode Laser and the Birefringence of Mica: The Experimental Examination of the IPHO 40 Held in Mexico

ERIC Educational Resources Information Center

Moran-Lopez, J. L.; Ortiz, M. E.; Rodriguez, L. F.; Romero-Rochin, V.

2010-01-01

The experimental examination applied in the 40th International Physics Olympiad held in Merida, Yucatan, Mexico, is presented. The examination consisted of two parts: (1) based on the measurements of a diffraction pattern produced by a diode laser impinging on a sharp edge of a razor blade, the students were asked to estimate the wavelength of the…

Science and stewardship to protect and sustain wilderness values: Proceedings of the Ninth World Wilderness Congress Symposium

Treesearch

Brooke B. McBride

2011-01-01

WILD9 convened in Merida, Yucatan, Mexico, in 2009 with a challenging agenda. For more than eight days, 1,800 delegates from more than 50 nations gathered to feel, think, and act (siente, piensa, actua) on many important conservation issues requiring international cooperation. The compilation of papers from the Symposium on Science and Stewardship to Protect and...

A Source Manual of Raptors Occurring on Corps of Engineers Lands in the Pacific Northwest Region.

DTIC Science & Technology

1986-10-01

From Ibis 107(1), 1965.) In Norwegian with English summary. Pasanen, S., and S. Sulkava. 1971. On the nutritional biology of the rough- legged buzzard...Nebraska. Nebraska Bird Review 43(4): 78-79. lon"g, W. S. 1934. The western pigeon hawk in Yucatan and Kansas. Auk 51(4): 515-516. Lowery, G. H., Jr

Research Stanchion and Transporter for Small Ruminants

DTIC Science & Technology

1988-03-30

L, Plumlee V P, Hobbs C S, at al. The Design and Operation of Metabolism Units for Nutritional Studies With Swine. J Anin Sci 1951; 10:88-98. 12...Restraint for Yucatan Miniature Swine. Lab Anim Sci 1983; 33(1):95-97. i . I ൖ ----------. A . APPEM4IX I UATEITLS LIST I. Stainless Steel Tubing: a

Science and Technology Text Mining: Mexico Core Competencies

DTIC Science & Technology

2002-01-01

leaf represents germination nutrient comparative recovered juvenile nutritional winter_spring white difficult spring_summer segment requirements eggs... nutritional ) focuses on diets for small shrimp, emphasizing impact on feed consumption, weight increase, and nutrition . Factor 4 (patients, patient...species, Yucatan , dry season, Campeche, feeding, sex, reproduction) focuses on reproductive and feeding habits of species of both sexes as a function

Fish as paratenic hosts of Serpinema trispinosum (Leidy, 1852) (Nematoda: Camallanidae).

PubMed

Moravec, F; Mendoza-Franco, E; Vivas-Rodríguez, C

1998-04-01

Third-stage larvae of the nematode Serpinema trispinosum (Leidy, 1852) were collected from the intestine of the freshwater cichlid, Cichlasoma urophthalmus (Günther), from a small lake in Yucatan, Mexico. This is the first record of Serpinema larvae from fishes, and their presence may reflect the importance of fishes as paratenic hosts of turtle parasites in this genus.

Genetic Affiliation of Pre-Hispanic and Contemporary Mayas Through Maternal Linage.

PubMed

Ochoa-Lugo, Mirna Isabel; Muñoz, María de Lourdes; Pérez-Ramírez, Gerardo; Beaty, Kristine G; López-Armenta, Mauro; Cervini-Silva, Javiera; Moreno-Galeana, Miguel; Meza, Adrián Martínez; Ramos, Eduardo; Crawford, Michael H; Romano-Pacheco, Arturo

2016-04-01

Maya civilization developed in Mesoamerica and encompassed the Yucatan Peninsula, Guatemala, Belize, part of the Mexican states of Tabasco and Chiapas, and the western parts of Honduras and El Salvador. This civilization persisted approximately 3,000 years and was one of the most advanced of its time, possessing the only known full writing system at the time, as well as art, sophisticated architecture, and mathematical and astronomical systems. This civilization reached the apex of its power and influence during the Preclassic period, from 2000 BCE to 250 CE. Genetic variation in the pre-Hispanic Mayas from archaeological sites in the Mexican states of Yucatan, Chiapas, Quintana Roo, and Tabasco and their relationship with the contemporary communities in these regions have not been previously studied. Consequently, the principal aim of this study was to determine mitochondrial DNA (mtDNA) variation in the pre-Hispanic Maya population and to assess the relationship of these individuals with contemporary Mesoamerican Maya and populations from Asia, Beringia, and North, Central, and South America. Our results revealed interactions and gene flow between populations in the different archaeological sites assessed in this study. The mtDNA haplogroup frequency in the pre-Hispanic Maya population (60.53%, 34.21%, and 5.26% for haplogroups A, C, and D, respectively) was similar to that of most Mexican and Guatemalan Maya populations, with haplogroup A exhibiting the highest frequency. Haplogroup B most likely arrived independently and mixed with populations carrying haplogroups A and C based on its absence in the pre-Hispanic Mexican Maya populations and low frequencies in most Mexican and Guatemalan Maya populations, although this also may be due to drift. Maya and Ciboneys sharing haplotype H10 belonged to haplogroup C1 and haplotype H4 of haplogroup D, suggesting shared regional haplotypes. This may indicate a shared genetic ancestry, suggesting more regional interaction

Checklist of fishes from madagascar reef, campeche bank, méxico.

PubMed

Zarco Perello, Salvador; Moreno Mendoza, Rigoberto; Simões, Nuno

2014-01-01

This study presents the first list of fish species from Madagascar Reef, Campeche Bank, Gulf of México. Field surveys and literature review identified 54 species belonging to 8 orders, 30 families and 43 genera, comprising both conspicuous and cryptic fishes. Species richness was lower at this reef site compared to reefs in the Mexican Caribbean, Veracruz or Tuxpan, but was similar to other reefs in the same region. Species composition was a mixture of species present in all the reef systems of the Mexican Atlantic. Hypoplectrusecosur was recorded here for the first time in the Gulf of Mexico, Mycteropercamicrolepis, Equetuslanceolatus and Chaetodipterusfaber were new records for the reefs of the Campeche Bank, Elacatinusxanthiprora was recorded for the second time in Mexico and expanded its known distribution westwards from Alacranes Reef and Sanopusreticulatus, endemic of the Yucatan state, was recorded here for the first time on a reef.

Determination of 137Cs and 60Co pollution in the area of the Laguna Verde Nuclear Power Plant, Mexico.

PubMed

Salas Mar, Bernardo

2015-11-01

The project 'Radiological Analysis of Environmental Samples in the Gulf of Mexico and the coast of Quintana Roo', had the aim of identifying and quantifying anthropogenic radionuclides in environmental samples consisting of silt, sand and sea water. This paper presents the results of the radiological analysis of these samples, which was made in the multichannel system for gamma spectrometry with hyperpure germanium detector in the Laboratory of Radiological Analysis of Environmental Samples, located at the Physics Department, Faculty of Sciences, of the Autonomous National University of Mexico (UNAM). The sampled points are along the coast of the contiguous states of Tamaulipas, Veracruz, Tabasco, Campeche, Yucatan and Quintana Roo. This paper presents the qualitative and quantitative concentrations of the main identified anthropogenic radionuclides (60)Co and (137)Cs. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Well-being changes in response to 30 years of regional integration in Maya populations from Yucatan, Mexico.

PubMed

Gurri, F D; Pereira, G B; Moran, E F

2001-01-01

Infant mortality rate (IMR), overall frequency of linear enamel hypoplasia (LEH), sexual dimorphism in LEH, age of onset of LEH, and age at menarche were used as indicators to test the hypothesis that the origin and development of the tourist industry and increased state participation on Maya subsistence agriculturists in the early 1970s had improved the well-being of the Maya. Two historical moments where inferred from the data. The first was derived from cheap and effective immunization and sanitation campaigns that reduced IMR from 143.4/1,000 live births in the early 1960s to 97.4 in the early 1970s. State participation broke the undernutrition-disease cycle enough to reduce LEH frequencies significantly (from 71.9% in individuals born before 1971 to 51.5% in those born in 1971 or after, chi(2) = 55.72; 1 df; alpha = 0.00001) and to eliminate the sex difference in LEH expression (from a 14.8% LEH difference between men and women before 1971 [Male/Female Odds Radio = 0.45, alpha significant at 0.05] to a nonsignificant 2% difference). Improvement in overall living conditions reflected in a "modern stage" infant mortality regime and an almost disappearance of LEHs, resulted from gradual improvements in living conditions that did not become apparent until the 1980s. Trends in the age at menarche are not statistically significant, probably due to methodological limitations. However, if overall living conditions continue to improve or stay as they are today, accelerations in maturation should become noticeable.

The Geology of Yemen: An Annotated Bibliography of Yemen’s Geology, Geography and Earth Science

DTIC Science & Technology

2012-01-01

pneumonia by improving maternal nutrition , health education, promoting breastfeeding, and preventing rickets and nutritional anaemia among the...Monitoring, Modeling, and Management. Merida, Yucatan , Mexico. Bauman, Paul, Sallomy, Janan, Lyness, Lucien, et al. 1996. “The Exploration for a Deep...shopping must also be educated on health and nutrition matters. Due to the traditional segregation of the sexes, this training will have to be

Chitons (Mollusca, Polyplacophora) from Alacranes Reef, Yucatan, Mexico

PubMed Central

Reyes-Gómez, Adriana; Ortigosa, Deneb; Simões, Nuno

2017-01-01

Abstract This study represents the first comprehensive chiton study from Alacranes Reef, the largest reef system in the Gulf of Mexico. Nine chiton species were found in seven localities within the area, in the intertidal and subtidal to 12 m depth. SEM examination of C. janeirensis, A. hemphilli, T. schrammi and C. floridanus, showed variations in the sculpture and radular teeth morphology when compared to specimens of the same species from Florida Keys, Bahamas and Puerto Rico. The distribution ranges of T. schrammi, L. liozonis and S. floridana are extended into the south-western area of the Gulf of Mexico. Altogether, combining previous literature and the present survey, reports eleven chiton species which have now been recorded within the Alacranes reef area. PMID:28769624

Emissions from biomass burning in the Yucatan [Discussions

Treesearch

R. Yokelson; J. D. Crounse; P. F. DeCarlo; T. Karl; S. Urbanski; E. Atlas; T. Campos; Y. Shinozuka; V. Kapustin; A. D. Clarke; A. Weinheimer; D. J. Knapp; D. D. Montzka; J. Holloway; P. Weibring; F. Flocke; W. Zheng; D. Toohey; P. O. Wennberg; C. Wiedinmyer; L. Mauldin; A. Fried; D. Richter; J. Walega; J. L. Jimenez; K. Adachi; P. R. Buseck; S. R. Hall; R. Shetter

2009-01-01

In March 2006 two instrumented aircraft made the first detailed field measurements of biomass burning (BB) emissions in the Northern Hemisphere tropics as part of the MILAGRO project. The aircraft were the National Center for Atmospheric Research C-130 and a University of Montana/US Forest Service Twin Otter. The initial emissions of up to 49 trace gas or particle...

Pre- and Post-Columbian Land Cover Changes and Associated Climate Impacts

NASA Astrophysics Data System (ADS)

Cook, B. I.; Puma, M. J.; Kaplan, J. O.; Anchukaitis, K. J.

2011-12-01

Central America experienced extensive expansion of agricultural land during development of the major Central American societies, followed by widespread abandonment and regrowth of natural vegetation after the European conquest. Here we use a high resolution climate model, in combination with a new land cover reconstruction, to investigate the impact of pre- (1490 C.E.) and post- (1650 C.E.) Columbian land cover change on climate in this region. Pre-Columbian land cover causes significant precipitation reductions over coastal Mexico, the Yucatan, and southern Mexico during the wet season, as replacement of forests with agricultural land reduces evapotranspiration fluxes to the atmosphere. Conversely, precipitation over the Yucatan increases during the dry season, as increased surface warming moves additional moisture into this region from the surrounding oceans. With the post-Columbian period, during which major population declines led to large scale agricultural abandonment, the forest recovery results in a partial, though not complete, return to wetter conditions. Our study finds support for previous work speculating that land cover change associated with the Mayan civilizations may have amplified major droughts in the region, and points to the possibility of a direct biogeophysical response to the forest recovery following the arrival of Europeans.

Inventorying and Monitoring of Tropical Dry Forests Tree Diversity in Jalisco, Mexico Using a Geographical Information System

Treesearch

Efren Hernandez-Alvarez; Dieter R. Pelz; Carlos Rodriguez Franco

2006-01-01

Tropical dry forests in Mexico are an outstanding natural resource, due to the large surface area they cover. This ecosystem can be found from Baja California Norte to Chiapas on the eastern coast of the country. On the Gulf of Mexico side it grows from Tamaulipas to Yucatan. This is an ecosystem that is home to a wide diversity of plants, which include 114 tree...

Porcine (Sus scrofa) Chronic Myocardial Infarction Model Development

DTIC Science & Technology

2015-04-03

Change from 8 mini pigs to 6 farm pigs and 2 mini pigs 3 Personnel added: Southard, Riddock 4 Personnel added: Julian 2 FDGXXX 6. FUNDING...models. Methods: Eight Yucatan miniature pigs underwent percutaneous embolization of the D1-LAD via injection of 90 µm polystyrene micro-spheres...myocardial structure and extracellular matrix composition respectively. Results: Overall procedural survival rate was 83% (5/6) with one pig

Major Rehabilitation of the Jetty System at the Mouth of the Columbia River

DTIC Science & Technology

2012-06-01

reduced rates of body growth that were consistent with nutritional limitation (Calkins and Goodwin 1988; Pitcher et al. 1998; Calkins et al. 1998...fishing grounds, duration of fishing season, and monitoring have been established to prevent Steller sea lion nutritional deficiencies as a result of...at Quintana Roo (Mexico’s Yucatan Peninsula), along Brazil’s shores, and at additional rookeries in Caribbean Central America, Bahamian Archipelago

Frontiers of Karst Research: Proceedings and recommendations of the workshop held in San Antonio, Texas on 3-5 May 2007. Karst Waters Institute Special Publication 13

DTIC Science & Technology

2009-01-08

a rich and abundant food source provided by chemolithoautotrophy may reduce nutritional stress to subsurface fauna because members of the...sulfide oxidation on coastal limestone dissolution in Yucatan cenotes: Ground Water, v. 31, p. 566-575. Symk, B., and Drzal, M., 1964, Research on...the nutritional status and availability (i.e. quality and quantity of carbon substrates) and the energetic base of cave ecosystems. The base of

Intra-Articular Lubricin Gene Therapy for Post-Traumatic Arthritis

DTIC Science & Technology

2015-09-01

recreational activities. In our previously funded work, we developed the Yucatan minipig as a large animal model of PTOA following an intra-articular...65% in the deep zone. Water allows load-dependent deformation of the cartilage. It provides nutrition and medium for lubrication, creating a low...spread within the matrix. Chondrocytes receive their nutrition by diffusion through the matrix. Chondrocytes are specialized cells for synthesizing

Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (South Atlantic). Brown Shrimp

DTIC Science & Technology

1989-01-01

northwest coast of crest well developed as far back as the Yucatan Peninsula. In the South adrostral grooves; gastrofrontal Atlantic Region, brown shrimp are...1969). Turbidity may the abundance and type of commercially reflect the nutritive potential of the important penaeids is directly related water, and...Couch (1979) reviewed the major (Jones and Sholar 1981). The disposal parasites and diseases affecting brown of dredged material covers nutritive

Bronzed cowbird taken in Florida

USGS Publications Warehouse

Matteson, R.E.

1970-01-01

On 8 November 1968 in Gainesville, Florida, I removed a male Bronzed Cowbird (Tangavius a. aeneus) from a blackbird decoy trap containing a large number of Brown-headed Cowbirds (Malothrus ater). Oliver L. Austin, Jr., at the Florida State Museum, verified the species identification by noting the notched inner webs of the outer three primaries, a characteristic of the genus. The subspecific identification was made at the U. S. National Museum where the bird is now specimen number 531666. The subspecies normally ranges from southcentral Texas and the Yucatan Peninsula south through Central America to Panama (Check-list of North American birds, fifth ed., Baltimore, Amer. Ornithol. Union, 1957, p. 542). This Gainesville specimen apparently is the first Bronzed Cow- bird taken in Florida. Alexander Sprunt, Jr., (Florida bird life. In Addendum to Florida bird life, New York, Coward-McCann, 1963, p. 18) lists three photographed sightings at Sarasota, Florida, in April 196

Gene frequencies and admixture estimates in four Mexican urban centers.

PubMed

Lisker, R; Ramirez, E; Briceño, R P; Granados, J; Babinsky, V

1990-12-01

We studied 202 individuals from the city of Leon in Guanajuato state, 228 from Merida, Yucatan, 220 from Oaxaca, Oaxaca, and 257 from Saltillo, Coahuila, to learn the distribution of the ABO, MN, Rh, and Duffy blood groups, serum haptoglobin, albumin, and factor Bf types, and red cell hemoglobin and glucose-6-phosphate dehydrogenase types. With the gene frequencies obtained, we performed admixture measurements with a maximum likelihood method, obtaining a trihybrid model for black, Indian, and white ancestry with the following proportions: 0.084, 0.513, and 0.403 in Leon: 0.059, 0.512, and 0.429 in Merida; 0.018, 0.676, and 0.306 in Oaxaca; and 0.073, 0.547, and 0.380 in Saltillo. The general pattern has high Indian ancestry followed by white and black ancestry. This pattern is congruent with most other studies performed in Mexico, including the east coast, where Indian ancestry predominates despite a clear increase in the black contribution.

Checklist of Fishes from Madagascar Reef, Campeche Bank, México

PubMed Central

2014-01-01

Abstract This study presents the first list of fish species from Madagascar Reef, Campeche Bank, Gulf of México. Field surveys and literature review identified 54 species belonging to 8 orders, 30 families and 43 genera, comprising both conspicuous and cryptic fishes. Species richness was lower at this reef site compared to reefs in the Mexican Caribbean, Veracruz or Tuxpan, but was similar to other reefs in the same region. Species composition was a mixture of species present in all the reef systems of the Mexican Atlantic. Hypoplectrus ecosur was recorded here for the first time in the Gulf of Mexico, Mycteroperca microlepis, Equetus lanceolatus and Chaetodipterus faber were new records for the reefs of the Campeche Bank, Elacatinus xanthiprora was recorded for the second time in Mexico and expanded its known distribution westwards from Alacranes Reef and Sanopus reticulatus, endemic of the Yucatan state, was recorded here for the first time on a reef. PMID:24891834

Nearshore circulation on a sea breeze dominated beach during intense wind events

NASA Astrophysics Data System (ADS)

Torres-Freyermuth, Alec; Puleo, Jack A.; DiCosmo, Nick; Allende-Arandía, Ma. Eugenia; Chardón-Maldonado, Patricia; López, José; Figueroa-Espinoza, Bernardo; de Alegria-Arzaburu, Amaia Ruiz; Figlus, Jens; Roberts Briggs, Tiffany M.; de la Roza, Jacobo; Candela, Julio

2017-12-01

A field experiment was conducted on the northern Yucatan coast from April 1 to April 12, 2014 to investigate the role of intense wind events on coastal circulation from the inner shelf to the swash zone. The study area is characterized by a micro-tidal environment, low-energy wave conditions, and a wide and shallow continental shelf. Furthermore, easterly trade winds, local breezes, and synoptic-scale events, associated with the passage of cold-fronts known as Nortes, are ubiquitous in this region. Currents were measured concurrently at different cross-shore locations during both local and synoptic-scale intense wind events to investigate the influence of different forcing mechanisms (i.e., large-scale currents, winds, tides, and waves) on the nearshore circulation. Field observations revealed that nearshore circulation across the shelf is predominantly alongshore-directed (westward) during intense winds. However, the mechanisms responsible for driving instantaneous spatial and temporal current variability depend on the weather conditions and the across-shelf location. During local strong sea breeze events (W > 10 m s-1 from the NE) occurring during spring tide, westward circulation is controlled by the tides, wind, and waves at the inner-shelf, shallow waters, and inside the surf/swash zone, respectively. The nearshore circulation is relaxed during intense land breeze events (W ≈ 9 m s-1 from the SE) associated with the low atmospheric pressure system that preceded a Norte event. During the Norte event (Wmax≈ 15 m s-1 from the NNW), westward circulation dominated outside the surf zone and was correlated to the Yucatan Current, whereas wave breaking forces eastward currents inside the surf/swash zone. The latter finding implies the existence of large alongshore velocity shear at the offshore edge of the surf zone during the Norte event, which enhances mixing between the surf zone and the inner shelf. These findings suggest that both sea breezes and Nortes play

Connectivity of the South Florida Coral Reef Ecosystem to Upstream Waters of the Western Caribbean and Gulf of Mexico

NASA Astrophysics Data System (ADS)

Johns, E. M.; Smith, R. H.; Lamkin, J. T.; Birbriezca, L. C.; Vasquez-Yeomans, L.; Cordero, E. S.

2008-05-01

The coastal waters of south Florida, including the coral reefs of NOAA's Florida Keys National Marine Sanctuary (FKNMS), are directly connected by means of strong ocean currents with upstream waters of the western Caribbean Sea and the Gulf of Mexico. The Caribbean Current and the Loop Current provide a rapid conduit for transport from Mexican and Belizean coral reefs, located off the eastern shore of the Yucatan Peninsula, to nearshore regions of northern Cuba, Florida, and the Bahamas. Interdisciplinary cruise data collected in August 2002, March 2006 and January 2007 aboard the NOAA Ship Gordon Gunter, in combination with satellite-tracked surface drifter trajectories and remote sensing imagery, clearly show the highly variable and dynamic nature of the regional current regimes and provide a means of quantifying the potential pathways and transport rates of the coastal waters and their biological and chemical constituents from one region to another. Results from these cruises and ancillary data show that the study areas are connected with rapid transport time scales, and that frontal eddies and gyres play an important role in establishing the time and length scales of this connectivity. Such direct physical connectivity between the coral reef biota of these geographically separated spawning grounds via ocean currents may have an important influence on the degree of biological connectivity between regional larval populations. Initial analyses of ichthyoplankton surveys and inshore collections along the Yucatan mesoamerican reef suggest large scale variability in both local recruitment and large scale spatial distribution. Despite strong northward flowing currents, inshore collections indicate that local recruitment in some areas is strongly influenced by small scale circulation patterns. However, the distribution of spawning aggregations along the Yucatan coast suggests a larger role for the Caribbean Current. Determining the interactions between the larger scale

State of the States 2016: Arts Education State Policy Summary

ERIC Educational Resources Information Center

Aragon, Stephanie

2016-01-01

The "State of the States 2016" summarizes state policies for arts education identified in statute or administrative code for all 50 states and the District of Columbia. Information is based on a comprehensive search of state education statute and codes on each state's relevant websites. Complete results from this review are available in…

State of the States, 2012: Arts Education State Policy Summary

ERIC Educational Resources Information Center

Arts Education Partnership (NJ1), 2012

2012-01-01

The "State of the States 2012" summarizes state policies for arts education identified in statute or code for all 50 states and the District of Columbia. Information is based primarily on results from the AEP Arts Education State Policy Survey conducted in 2010-11, and updated in April 2012.

[Population estimates and conservation of felids (Carnivora: Felidae) in Northern Quintana Roo, Mexico].

PubMed

Ávila-Nájera, Dulce María; Chávez, Cuauhtémoc; Lazcano-Barrero, Marco A; Pérez-Elizalde, Sergio; Alcántara-Carbajal, José Luis

2015-09-01

Wildlife density estimates provide an idea of the current state of populations, and in some cases, reflect the conservation status of ecosystems, essential aspects for effective management actions. In Mexico, several regions have been identified as high priority areas for the conservation of species that have some level of risk, like the Yucatan Peninsula (YP), where the country has the largest population of jaguars. However, little is known about the current status of threatened and endangered felids, which coexist in the Northeastern portion of the Peninsula. Our objective was to estimate the wild cats' density population over time at El Eden Ecological Reserve (EEER) and its surrounding areas. Camera trap surveys over four years (2008, 2010, 2011 and 2012) were conducted, and data were obtained with the use of capture-recapture models for closed populations (CAPTURE + MMDM or 1/2 MMDM), and the spatially explicit capture-recapture model (SPACECAP). The species studied were jaguar (Panthera onca), puma (Puma concolor), ocelot (Leopardus pardalis), jaguarundi (Puma yaguaroundi) and margay (Leopardus wiedii). Capture frequency was obtained for all five species and the density for three (individuals/100km2). The density estimated with The Mean Maximum Distance Moved (MMDM), CAPTURE, ranged from 1.2 to 2.6 for jaguars, from 1.7 to 4.3 for pumas and from 1.4 to 13.8 for ocelots. The density estimates in SPACECAP ranged from 0.7 to 3.6 for jaguars, from 1.8 to 5.2 for pumas and 2.1 to 5.1 for ocelots. Spatially explicit capture recapture (SECR) methods in SPACECAP were less likely to overestimate densities, making it a useful tool in the planning and decision making process for the conservation of these species. The Northeastern portion of the Yucatan Peninsula maintains high populations of cats, the EEER and its surrounding areas are valuable sites for the conservation of this group of predators. Rev. Biol.

A Clinically Realistic Large Animal Model of Intra-Articular Fracture

DTIC Science & Technology

2014-12-01

pendulum system for measuring energy absorption during fracture insult to large animal joints in vivo. J Biomech Eng. 2014 Jun;136(6):064502. PMID:24760051...Model 4. Yucatan Minipig 5. Impact 6. Pendulum 7. Mankin Scoring 8. Inflammatory Cytokines 9. Gait Analysis 10. Incongruity 3. OVERALL...primarily hardware upgrades and ex-vivo experimentation of the pendulum . 3.2.a Device Upgrades The primary hardware upgrade was to instrument the

International Conference on Natural Orifice Transluminal Endoscopic Surgery (NOTES)

DTIC Science & Technology

2006-06-01

causing evisceration. At exploration, a pancreatic stump leak also was noted. Drains were placed, and the patient was placed on total parenteral nutrition ...Department of Surgery. St. Joseph Clinic. Liege, Belgium Hospital Dr. Peset Aleixandre. Valencia. Spain 4 Clinica de Merida. Merida. Yucatan ...pneumonitis (n = 3), and parenteral nutrition (n = 1). There was conversion to laparotomy for 28 patients (2.7%), and surgical time ranged from 32 to 132

Species Profiles. Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Mid-Atlantic). American Oyster.

DTIC Science & Technology

1986-07-01

umbones are usually straight. extends to the Yucatan Peninsula Single oysters from hard substrates of Mexico and the West Indies to are rounded and...season (Merrill and Boss postulated that phytoplankton blooms 1966). Kennedy and Krantz (1982) and nutrition may be responsible for documented the... nutritional factors which affect tidal American oyster Crassostrea the growth and setting of the virygnica (Gmelin). Ph.D. Thesis. larvae of the oyster

Effectiveness of DoD Humanitarian Relief Efforts in Response to Hurricanes Georges and Mitch

DTIC Science & Technology

2001-03-01

31 October (wind speed of 35 mph). The storm’s path then took it across southern Guatemala, over Mexico’s Yucatan Peninsula, back over water in the...standards in sectors like water and sanitation, health care, and nutritional assistance. Incorporation of the work of the Sphere Project and other...their livestock may be a cost-effective mechanism for rebuilding local nutrition and economic capacity, thereby hastening the end of direct relief

Latin America Report

DTIC Science & Technology

1985-09-09

countries’ wealth, good nutritional standards and excellent technique. It would be worth analyzing how many medals have been won by athletes from...the Third World, from those countries that lack sports facilities, physical education and sport« instructors and proper nutrition for the children...as the third political force in San Luis Potosi. 94 In the third district, the leaders from Yucatan and Tamauiipas, Juan, de Dios Colli Mas and

Wound Healing of Cutaneous Sulfur Mustard Injuries: Strategies for the Development of Improved Therapies

DTIC Science & Technology

2005-01-05

nutritional support 5.10 Vacuum Assisted ClosureTM 5.11 Use of non-invasive bioengineering methods to assess treatment efficacy 6. Summary 7...for any therapeutic regimen to be successful, a healthy immunological,8 4 nutritional /metaboliC,81 and psychological 6 status needs to be maintained... Yucatan miniature pigs,91 and young pigs are highly resistant to contamination and infection.92 Furthermore, pigs are amenable to habituation and can be

Marine Mammals Ashore: A Field Guide for Strandings. Second Edition

DTIC Science & Technology

2005-01-01

Cruz, CA (Ch. 9); Diana M. Antochiw-Alonzo, Red de Varamientos, Yucatan (Ch. 2, 6); James Barnett, British Divers Marine Life Rescue, London, UK (Ch...diagnosed in free-ranging ringed seals" at a time when persistent ice interfered with food production. Nutritional stress also has been implicated in...emergency treatment, nutrition , surgery, quarantine, chronic care, and raising orphaned pups. Some operations continue around the clock. It also serves as a

Area Handbook Series: Guyana and Belize: Country Studies

DTIC Science & Technology

1993-01-01

assimi- lated to the Spanish-speaking population of Central America, fled fighting in the Yucatan or forced labor in Guatemala and settled in the...Diet & A Although the 1990 average daily nutritional intake in Guyana, 2,450 calories, exceeded the Food and Agriculture Organization | of the...purchase the food needed for an adequate diet. Also, some foods are not avail- able in sufficient supply to ensure good nutrition . Malnutrition is still

Cedar Grove: An Interdisciplinary Investigation of a Late Caddo Farmstead in the Red River Valley.

DTIC Science & Technology

1983-10-31

a mixed subsistence economy. Nutritional adequacy was is free from problems and potential errors. Each method to be tested by analysis of the...horses. A 1517 slave raid by Hernandez de "wherein Margry made inexcusable alterations, deletions, and Cordoba on the Yucatan was the precursor for the... nutrition , low infection and porotic corresponded closely with the chronological distribution of hyperostosis rates, and a low probability of dying at

Acoustic Signal Characteristics Measured with the LAMBDA III During CHURCH STROKE III

DTIC Science & Technology

1980-09-15

analysis. Dr. William M. Carey and Dr. Richard Doolittle participated in various stages of acquisition, processing and analysis of the information...reported herein. Drs. Carey , Doolittle and Mr. Gereben are the authors of this report. (U) This report: Acoustic Signal Characteristics Measured with... Tortugas Terrace and the East Yucatan Channel,the Catoche Tongue and the Eastern region of the Gulf of Mexico. (U) The exercise was conducted by the Long

Neural-Network Quantum States, String-Bond States, and Chiral Topological States

NASA Astrophysics Data System (ADS)

Glasser, Ivan; Pancotti, Nicola; August, Moritz; Rodriguez, Ivan D.; Cirac, J. Ignacio

2018-01-01

Neural-network quantum states have recently been introduced as an Ansatz for describing the wave function of quantum many-body systems. We show that there are strong connections between neural-network quantum states in the form of restricted Boltzmann machines and some classes of tensor-network states in arbitrary dimensions. In particular, we demonstrate that short-range restricted Boltzmann machines are entangled plaquette states, while fully connected restricted Boltzmann machines are string-bond states with a nonlocal geometry and low bond dimension. These results shed light on the underlying architecture of restricted Boltzmann machines and their efficiency at representing many-body quantum states. String-bond states also provide a generic way of enhancing the power of neural-network quantum states and a natural generalization to systems with larger local Hilbert space. We compare the advantages and drawbacks of these different classes of states and present a method to combine them together. This allows us to benefit from both the entanglement structure of tensor networks and the efficiency of neural-network quantum states into a single Ansatz capable of targeting the wave function of strongly correlated systems. While it remains a challenge to describe states with chiral topological order using traditional tensor networks, we show that, because of their nonlocal geometry, neural-network quantum states and their string-bond-state extension can describe a lattice fractional quantum Hall state exactly. In addition, we provide numerical evidence that neural-network quantum states can approximate a chiral spin liquid with better accuracy than entangled plaquette states and local string-bond states. Our results demonstrate the efficiency of neural networks to describe complex quantum wave functions and pave the way towards the use of string-bond states as a tool in more traditional machine-learning applications.

Development of in vivo impedance spectroscopy techniques for measurement of micropore formation following microneedle insertion

PubMed Central

Brogden, Nicole K.; Ghosh, Priyanka; Hardi, Lucia; Crofford, Leslie J.; Stinchcomb, Audra L.

2013-01-01

Microneedles provide a minimally invasive means to enhance skin permeability by creating micron-scale channels (micropores) that provide a drug delivery pathway. Adequate formation of the micropores is critical to the success of this unique drug delivery technique. The objective of these studies was to develop sensitive and reproducible impedance spectroscopy techniques to monitor micropore formation in animal models and human subjects. Hairless guinea pigs, a Yucatan miniature pig, and human volunteers were treated with 100 microneedle insertions per site following an overnight pre-hydration period. Repeated measurements were made pre- and post-microneedle treatment using dry and gel Ag/AgCl electrodes applied with light vs. direct pressure to hold the electrode to the skin surface. Impedance measurements dropped significantly post-microneedle application at all sites (p < 0.05, irrespective of electrode type or gel application), confirming micropore formation. In the Yucatan pig and human subjects, gel electrodes with direct pressure yielded the lowest variability (demonstrated by lower %RSD), whereas dry electrodes with direct pressure were superior in the guinea pigs. These studies confirm that impedance measurements are suitable for use in both clinical and animal research environments to monitor formation of new micropores that will allow for drug delivery through the impermeable skin layers. PMID:23589356

Fungal spores are transported long distances in smoke from biomass fires

NASA Astrophysics Data System (ADS)

Mims, Sarah A.; Mims, Forrest M.

Viable fungal spores are present in smoke from distant biomass fires. This finding has potentially important implications for prescribed burning, agricultural management and public health. While attempting to find fungal spores in dust blown from China to Texas, one of us (S.A.M.) discovered that smoke from Yucatan contains viable bacteria and fungal spores, including the genera Alternaria, Cladosporium, Fusariella and Curvularia. There was a high correlation ( r2=0.78) of spores and coarse carbon particles collected on microscope slides during 13 days of the 2002 smoke season. To eliminate possible contamination by local spores, an air sampler was flown from a kite at a Texas Gulf Coast beach during and after the 2003 smoke season on days when the NOAA back trajectory showed air arriving from Yucatan. Fifty-two spores and 19 coarse black carbon particles (>2.5 μm) were collected during a 30-min kite flight on the smoke day and 12 spores and four carbons on the day without smoke. We have found spores in smoke from an Arizona forest fire and in Asian smoke at Mauna Loa Observatory, Hawaii. We have tested these findings by burning dried grass, leaves, twigs and flood detritus. The smoke from all test fires contained many spores.

State of the States

ERIC Educational Resources Information Center

Journal of Education Finance, 2017

2017-01-01

In 2016, a group of school finance scholars and public school practitioners gathered in Jacksonville, Florida, for the National Education Finance Academy's annual conference to discuss, among an array of topics, the state of P-20 finance in all 50 states. At the roundtable discussion, 36 states were represented, and scholars representing 30 states…

The Challenge of Violent Drug-Trafficking Organizations: An Assessment of Mexican Security Based on Existing RAND Research on Urban Unrest, Insurgency, and Defense-Sector Reform

DTIC Science & Technology

2011-01-01

Bad Factors Outcome Afghanistan (post-Soviet) 0 10 –10 Loss Somalia 1 10 –9 Loss Chechnya I 2 10 –8 Loss Rwanda 2 10 –8 Loss Zaire (anti-Mobutu) 0...most of Baha California (Norte/Sur), Sonora, Chihuahua, Durango, Sinaloa, Nayarit, Jalisco, Colima, Quintana Roo, Yucatan, Campeche, Zacatecas...Sources of Success in Counterinsurgency and Victory Has a Thousand Fathers: Detailed Counterinsurgency Case Stud- ies . For that study, the research

Area Handbook Series: Cuba; a Country Study,

DTIC Science & Technology

1986-01-01

strategic sea- lanes, and is situated some 150 kilometers south of the Florida keys and 210 kilometers to the east of Mexico’s Yucatan Penin- sula. The...government claimed the nation’s overall health standards had also been raised through measures that improved the nutritional levels of social groups...dairy products, and other items. Other products were available outside the rationing system. There was controversy over how much the nutritional

Animal Models for Testing Antidotes Against an Oral Cyanide Challenge

DTIC Science & Technology

2016-08-01

transport times, and nutrient absorption characteristics, which make them useful in basic nutritional research (Suckow, 2002; Swindle, 2007...paraparesis associated with chronic cyanide intoxication in a cassava staple area of Mozambique. 2. Nutritional factors and hydrocyanic acid content...40.8 ± 3.57 6 Pig (Yorkshire, 8 wks to 1 yr) Not Detected. 13 Pig ( Yucatan age > 1 yr) Not Detected 6 Neutered male beagle dog 18.2 ± 2.12 6 Intact

Protection by Purines in Toxin Models of Parkinson’s Disease

DTIC Science & Technology

2015-08-01

2014. Accepted for publication Sep 23, 2014. Address correspondence to Dr Ascherio, 667 Huntington Ave, Department of Nutrition , Building 2, 3rd floor...Boston, MA 02115. E-mail: aascherio@hsph.harvard.edu From the 1Department of Nutrition , Harvard School of Public Health, Boston, MA; 2Channing... Yucatan miniature pig. Evidence that inosine functions as an in vivo energy substrate. Biochim Biophys Acta 842:214–224. Zai L, Ferrari C, Dice C

Latin American Insurgencies,

DTIC Science & Technology

1985-01-01

Cuba and Iom s arious extension program% in literac\\ , larmn techniques, and healthI and nutrit ion out in AN .acucho’s surrounding countryside. B...mortality rates, health services, nutrition , and education demon- strate the stark differences between the highlands and the capital. By 1968 the judicial...the camps. In an effort to please everybody, a decision was made in June 1984 to move refugees along the Chiapas border to the Yucatan peninsula

Eagel Hill: A Late Quaternary Upland Site in Western Louisiana.

DTIC Science & Technology

1982-01-01

the Florida and Yucatan penin- sulas. The continental shelf is considered to extend to the 200 m contour. The slope is very gradual to the 100 m...it to advantage. It is also counter to dogma on hunter and horticultural nutritional affects on stature. With such a small sample we can at best ask...colluvium-clay interface between, for humans, two nutritionally unproductive sand bodies, which provide the most efficient access to the colluvium-clay

Planetary Defense: Eliminating the Giggle Factor

DTIC Science & Technology

2000-01-01

the coast of the Yucatan Peninsula, and is today credited with ridding the world of the dinosaur menace.1 Since the discovery of these and other...million years, with a less distinct recurrence of larger objects.2 The periodicity of 10 km-size asteroid strikes correlates reasonably well...within the error range of geologic dating) with major global extinction events (as many as ten) recurring on a 26 million year cycle dating back 260

Mixed-layer kaolinite-montmorillonite from the Yucatan Peninsula, Mexico

USGS Publications Warehouse

Schultz, L.G.; Shepard, A.O.; Blackmon, P.D.; Starkey, H.C.

1971-01-01

Clay beds 1–2 m thick and interbedded with marine limestones probably of early Eocene age are composed of nearly pure mixed-layer kaolinite-montmorillonite. Particle size studies, electron micrographs, X-ray diffraction studies, chemical analyses, cation exchange experiments, DTA, and TGA indicate that clays from three different localities contain roughly equal proportions of randomly interlayered kaolinite and montmorillonite layers. The montmorillonite structural formulas average K0·2Na0·2Ca0·2Mg0·2(Al2·5Fe1·03+Mg0·5)(Al0·75Si7.25)O20+(OH)4−, with a deficiency of structural (OH) in either the montmorillonite or kaolinite layers. Nonexchangeable K+ indicates that a few layers are mica-like. Crystals are mostly round plates 1/10 to 1/20 µ across. The feature most diagnostic of the mixed-layer character is an X-ray reflection near 8 Å after heating at 300°C. The clays are inferred to have developed by weathering of volcanic ash and subsequent erosion and deposition in protected nearshore basins.

One State, Two State, Red State, Blue State: Education Funding Accounts for Outcome Differences

ERIC Educational Resources Information Center

Meece, Darrell

2008-01-01

Using publically available data, states coded as "blue" based upon results from the 2004 presidential election were significantly higher in education funding than were states coded as "red." Students in blue states scored significantly higher on outcome measures of math and reading in grades four and eight in 2004 and 2007 than did students in red…

7 CFR 1220.615 - State and United States.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 10 2014-01-01 2014-01-01 false State and United States. 1220.615 Section 1220.615... CONSUMER INFORMATION Procedures To Request a Referendum Definitions § 1220.615 State and United States. State and United States include the 50 States of the United States of America, the District of Columbia...

7 CFR 1220.615 - State and United States.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 10 2013-01-01 2013-01-01 false State and United States. 1220.615 Section 1220.615... CONSUMER INFORMATION Procedures To Request a Referendum Definitions § 1220.615 State and United States. State and United States include the 50 States of the United States of America, the District of Columbia...

7 CFR 1220.129 - State and United States.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 10 2012-01-01 2012-01-01 false State and United States. 1220.129 Section 1220.129... CONSUMER INFORMATION Soybean Promotion and Research Order Definitions § 1220.129 State and United States. The terms State and United States include the 50 States of the United States of America, the District...

7 CFR 1220.129 - State and United States.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 10 2013-01-01 2013-01-01 false State and United States. 1220.129 Section 1220.129... CONSUMER INFORMATION Soybean Promotion and Research Order Definitions § 1220.129 State and United States. The terms State and United States include the 50 States of the United States of America, the District...

7 CFR 1220.129 - State and United States.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 10 2014-01-01 2014-01-01 false State and United States. 1220.129 Section 1220.129... CONSUMER INFORMATION Soybean Promotion and Research Order Definitions § 1220.129 State and United States. The terms State and United States include the 50 States of the United States of America, the District...

7 CFR 1220.129 - State and United States.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 10 2011-01-01 2011-01-01 false State and United States. 1220.129 Section 1220.129... CONSUMER INFORMATION Soybean Promotion and Research Order Definitions § 1220.129 State and United States. The terms State and United States include the 50 States of the United States of America, the District...

7 CFR 1220.129 - State and United States.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false State and United States. 1220.129 Section 1220.129... CONSUMER INFORMATION Soybean Promotion and Research Order Definitions § 1220.129 State and United States. The terms State and United States include the 50 States of the United States of America, the District...

7 CFR 1220.615 - State and United States.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 10 2011-01-01 2011-01-01 false State and United States. 1220.615 Section 1220.615... CONSUMER INFORMATION Procedures To Request a Referendum Definitions § 1220.615 State and United States. State and United States include the 50 States of the United States of America, the District of Columbia...

7 CFR 1220.615 - State and United States.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 10 2012-01-01 2012-01-01 false State and United States. 1220.615 Section 1220.615... CONSUMER INFORMATION Procedures To Request a Referendum Definitions § 1220.615 State and United States. State and United States include the 50 States of the United States of America, the District of Columbia...

7 CFR 1220.615 - State and United States.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false State and United States. 1220.615 Section 1220.615... CONSUMER INFORMATION Procedures To Request a Referendum Definitions § 1220.615 State and United States. State and United States include the 50 States of the United States of America, the District of Columbia...

Review of pre-rift continental fits and plate kinematic models for the Gulf of Mexico opening

NASA Astrophysics Data System (ADS)

Steier, A.; Mann, P.

2016-12-01

We review models for the opening of the Gulf of Mexico (GOM) by: 1) subdividing them into historical groupings; 2) demonstrating their strengths and weaknesses using GPlates; and 3) illustrating the compatibility of models for GOM opening with the surrounding plate mosaic in the Central Atlantic and Caribbean. Tectonic models for GOM opening during the 1970's and 1980's disagreed on whether the Yucatan continental block originated inside or outside the GOM, but difficulties in filling the continental underlap in reconstructions of pre-rift Pangea eventually led to a consensus that the Yucatan block originated inside the GOM. The 1980's saw the advent of the "piggyback model" for GOM evolution based on the assumption that the Jurassic opening of the GOM formed a southwestward extension of the Central Atlantic spreading system and opened about its same pole of rotation. This single-phase model eventually fell out of favor as refraction surveys determined that the existence of a wedge-shaped area of oceanic crust in the deep GOM (widening from east to west) was not compatible with the single, NW-SE opening direction proposed by the piggyback model. The early 2000's saw the appearance of a two-phase opening model as a solution to the existence of a broad zone of NW-SE continental extension in the northern GOM that was succeeded by a more NS-directed phase of extension that in some areas cut at right angles across structures produced during the first rift phase. The second phase of late Jurassic rifting and oceanic crust formation is the outcome of counterclockwise rotation of the Yucatan block that is thought to have been caused by forces acting on the edges of the block. By the earliest Cretaceous rifting in the GOM has ended although tectonic events in Mexico and the northern Caribbean reactivate and influence GOM sedimentation. We provide a GPlates restoration from Triassic to Recent that takes into account all available geologic and geophysical data and illustrates

State Correctional Education Programs. State Policy Update.

ERIC Educational Resources Information Center

Tolbert, Michelle

Secure state correctional facilities currently house more than 1.8 million adults, and nearly 4.4 million adults fall under state-administered community corrections. A state's approach to corrections and the communication between the state correctional components can have a large impact on the state's correctional education program. Decentralized…

Optimal resource states for local state discrimination

NASA Astrophysics Data System (ADS)

Bandyopadhyay, Somshubhro; Halder, Saronath; Nathanson, Michael

2018-02-01

We study the problem of locally distinguishing pure quantum states using shared entanglement as a resource. For a given set of locally indistinguishable states, we define a resource state to be useful if it can enhance local distinguishability and optimal if it can distinguish the states as well as global measurements and is also minimal with respect to a partial ordering defined by entanglement and dimension. We present examples of useful resources and show that an entangled state need not be useful for distinguishing a given set of states. We obtain optimal resources with explicit local protocols to distinguish multipartite Greenberger-Horne-Zeilinger and graph states and also show that a maximally entangled state is an optimal resource under one-way local operations and classical communication to distinguish any bipartite orthonormal basis which contains at least one entangled state of full Schmidt rank.

State of the States 2013

ERIC Educational Resources Information Center

Journal of Education Finance, 2014

2014-01-01

Presenters at the State of the States Roundtable session at the 2014 National Education Finance Conference in Louisville were invited to submit their papers for publication. These papers address the following topics: (1) State issues affecting P-12 and/or higher education funding; (2) Funding priorities/trends for P-12 and/or higher education; (3)…

State of the States 2014

ERIC Educational Resources Information Center

Journal of Education Finance, 2015

2015-01-01

Presenters at the State of the States Roundtable session at the 2014 National Education Finance Conference in Louisville were invited to submit their papers for publication. These papers address the following topics: (1) State issues affecting P-12 and/or higher education funding; (2) Funding priorities/trends for P-12 and/or higher education; (3)…

Compendium of CARDEROCKDIV Articles Published in Navy Domestic Technology Transfer Fact Sheet, January 1990 through December 1992

DTIC Science & Technology

1992-12-01

longer in the Gulf of Mexico and the patrol, in such areas as th(. Florida Straits have learned what Yucatan Peninsula and from naval Ii means to look down...same performed on conventional deep - containing shallow cracks aW/W < J value have markedly different crack specimens The increa-ed 02, are commonly...the Jc values ’for characterization of the crack-tip atW ratio effects on the measured corresponding deep -crack spec- stress field Moreover, these

Canaveral Harbor, Florida, Integrated Section 203 Navigation Study Report and Final Environmental Assessment. Volume 1

DTIC Science & Technology

2012-10-01

source of nutrition for juvenile green sea turtles. The beaches and spoil areas may also be utilized by nesting and foraging shorebirds including the...include the upper west coast of Florida, the northwestern coast of the Yucatan Peninsula, the south coast of Cuba, the Mosquito Coast of Nicaragua...1997. Foraging ecology and nutrition of sea turtles. Pages 199-233 In: Lutz, P.L. and J.A. Musick, eds., The Biology of Sea Turtles. CRC Press, New

The Bionomics and Vector Competence of Anopheles Albimanus and Anopheles Vestitipennis in Southern Belize, Central America

DTIC Science & Technology

2000-11-20

can be found in large numbers throughout the Yucatan , southern Mexico and Guatemala (Kumm et at. 1943, Loyola et a1. 1991, Arredondo-Jimenez et a1...material or detritus as a nutritional source as well as plant cover for shade. Anopheles yestitipennis exhibits its highest numbers during the rainy...species appears to require plant material or detritus as a nutritional source as well as plant cover for shade. Both species also have a clear seasonal

Clinical Investigation Program

DTIC Science & Technology

1990-09-30

with Subretinal Hemorrhage: A Case Report. Ann Ophthalmol, 22:259-262, 1990. Walton WT, Enzenauer RW: " Nutritional Disease" in Levin AV, Enzenauer RW...adequate means of maintaining nutritional status. Publications and Presentations: None. 1 135 FAMC A.P.R. (RCS MED 300) Detail Summary Sheet (HSCR 40-23 as...4) Title: The Effect of Liposucticn on Myocutaneous Flaps in the Yucatan Micro Pig (5) Start Date: (6) Est Compl Date: (7) Principal Investigator: (8

Crew Earth Observations (CEO) by Expedition Five Crew

NASA Image and Video Library

2002-09-16

ISS005- E-15375 (22 September 2002) --- This digital still camera's picture, taken from the International Space Station (ISS) on September 22, 2002, shows the central eye of Hurricane Isidore. The eye become less defined as the hurricane stalled and weakened over the Yucatan Peninsula near Merida. Onboard the orbital outpost for the Expedition Five mission are cosmonauts Valery G. Korzun, commander, and Sergei Y. Treschev, flight engineer, both with Rosaviakosmos; and astronaut Peggy A. Whitson, flight engineer.

On NEO Threat Mitigation (Preprint)

DTIC Science & Technology

2007-10-15

Yucatan event is at least a major contributor, if not the direct cause of the extinction of the dinosaurs . Moreover, it is clear that NEO impacts can... extinction of the human race. The probability of these events decreases with the severity of the impact, and size (mass) of the NEO. Figure 1 and Table 1...thus, it is more reasonable to infer that all the large NEOs can be catalogued within a reasonable time, while smaller and less consequential

Earth observations during Space Shuttle flight STS-41 - Discovery's mission to planet earth

NASA Technical Reports Server (NTRS)

Lulla, Kamlesh P.; Helfert, Michael R.; Amsbury, David L.; Whitehead, Victor S.; Richards, Richard N.; Cabana, Robert D.; Shepherd, William M.; Akers, Thomas D.; Melnick, Bruce E.

1991-01-01

An overview of space flight STS-41 is presented, including personal observations and comments by the mission astronauts. The crew deployed the Ulysses spacecraft to study the polar regions of the sun and the interplanetary space above the poles. Environmental observations, including those of Lake Turkana, Lake Chad, biomass burning in Madagascar and Argentina, and circular features in Yucatan are described. Observations that include landforms and geology, continental sedimentation, desert landscapes, and river morphology are discussed.

[Trend analysis of acquired syphilis in Mexico from 2003 to 2013].

PubMed

Herrera-Ortiz, Antonia; Uribe-Salas, Felipe J; Olamendi-Portugal, Ma Leonidez; García-Cisneros, Santa; Conde-Glez, Carlos Jesús; Sánchez-Alemán, Miguel A

2015-01-01

To identify the population group in which syphilis increase was concentrated. The information was collected from the Mexico health statistical yearbooks. The information disaggregated by sex, age group and state during the period 2003 to 2013 was used to form different databases. Linear regression analysis with confidence interval at 95% was used to evaluate changes over time in different population groups. An increase of 0.67 cases per 100,000 population (95%CI 0.30-1.04) in men was detected from 2010. The increase was concentrated in each group of 20-24 and 25-44. The highest incidence of acquired syphilis was reported in the last two years: 2012 and 2013. The last year reported a 1.85 times higher incidence than reported in 2003. Aguascalientes, Distrito Federal, Durango, Mexico, Oaxaca, Puebla, Quintana Roo, Yucatan and Zacatecas reported that syphilis increased during the study period. Acquired syphilis may be reemerging in our country among young men; this increase is not uniform across the country, it is necessary to focus intervention measures for this sexually transmitted infection.

Minimally conscious state or cortically mediated state?

PubMed

Naccache, Lionel

2018-04-01

Durable impairments of consciousness are currently classified in three main neurological categories: comatose state, vegetative state (also recently coined unresponsive wakefulness syndrome) and minimally conscious state. While the introduction of minimally conscious state, in 2002, was a major progress to help clinicians recognize complex non-reflexive behaviours in the absence of functional communication, it raises several problems. The most important issue related to minimally conscious state lies in its criteria: while behavioural definition of minimally conscious state lacks any direct evidence of patient's conscious content or conscious state, it includes the adjective 'conscious'. I discuss this major problem in this review and propose a novel interpretation of minimally conscious state: its criteria do not inform us about the potential residual consciousness of patients, but they do inform us with certainty about the presence of a cortically mediated state. Based on this constructive criticism review, I suggest three proposals aiming at improving the way we describe the subjective and cognitive state of non-communicating patients. In particular, I present a tentative new classification of impairments of consciousness that combines behavioural evidence with functional brain imaging data, in order to probe directly and univocally residual conscious processes.

State laws on tobacco control--United States, 1998.

PubMed

Fishman, J A; Allison, H; Knowles, S B; Fishburn, B A; Woollery, T A; Marx, W T; Shelton, D M; Husten, C G; Eriksen, M P

1999-06-25

State laws addressing tobacco use, the leading preventable cause of death in the United States, are summarized. Laws address smoke-free indoor air, minors' access to tobacco products, advertising of tobacco products, and excise taxes on tobacco products. Legislation effective through December 31, 1998. CDC identified laws addressing tobacco control by using an on-line legal research database. CDC's findings were verified with the National Cancer Institute's State Cancer Legislative Database. Since a previous surveillance summary on state tobacco-control laws published in November 1995 (covering legislation effective through June 30, 1995), several states have enacted new restrictions or strengthened existing legislation that addresses smoke-free indoor air, minors' access to tobacco, tobacco advertising, and tobacco taxes. Five states strengthened their smoke-free indoor air legislation. All states and Washington, D.C., continued to prohibit the sale and distribution of tobacco products to minors; however, 21 states expanded minors' access laws by designating enforcement authorities, adding license suspension or revocation for sale to minors, or requiring signage. Since the 1995 report, eight additional states (a total of 19 states and Washington, D.C.) now ban vending machines from areas accessible to minors. Thirteen states restrict advertising of tobacco products, an increase of four states since the 1995 report. Although the number of states that tax cigarettes and smokeless tobacco did not change, 13 states increased excise taxes on cigarettes, and five states increased excise taxes on smokeless tobacco products. The average state excise tax on cigarettes is 38.9 cents per pack, an increase of 7.4 cents compared with the average tax in the 1995 report. State laws addressing tobacco control vary in relation to restrictiveness, enforcement and penalties, preemptions, and exceptions. The data summarizing state tobacco-control laws are available through CDC

View of cold water eddies in Falkland Current off southern Argentina

NASA Image and Video Library

1973-12-14

SL4-137-3608 (14 Dec. 1973) --- A view of cold water eddies in the Falkland Current off the South Atlantic coast of southern Argentina as seen from the Skylab space station in Earth orbit. This picture was taken by one of the Skylab 4 crewmen using a hand-held 70mm Hasselblad camera. This land area (left corner) extends south along the coast from Puerto Deseado (center left border) for about 50 miles. Within the ocean, several light blue areas are visible and represent the occurrence of plankton with the Falkland Current. Over the ocean, the cold water eddies are identified by the circular cloud-free areas within the cloud street pattern and bordered by cumulus cloud buildup (white). The cloud streets indicate the wind is from the southwest and do not form over eddies because energy form the atmosphere is absorbed by the cold ocean water. On the downwind side of the eddies, cumulus clouds tend to form as the cold moist air flows over the warmer water. Similar cloud and eddy features have been observed by the Skylab 4 crewmen in the Yucatan Current off Yucatan Peninsula and in some parts of the South Pacific. Studies are underway by Dr. George Maul, NOAA, and Dr. Robert Stevenson, ONR, to determine the significance of the cold water eddies to ocean dynamics. Photo credit: NASA

Impact-generated Hydrothermal Activity at the Chicxulub Crater

NASA Astrophysics Data System (ADS)

Kring, D. A.; Zurcher, L.; Abramov, O.

2007-05-01

Borehole samples recovered from PEMEX exploration boreholes and an ICDP scientific borehole indicate the Chicxulub impact event generated hydrothermal alteration throughout a large volume of the Maya Block beneath the crater floor and extending across the bulk of the ~180 km diameter crater. The first indications of hydrothermal alteration were observed in the crater discovery samples from the Yucatan-6 borehole and manifest itself in the form of anhydrite and quartz veins. Continuous core from the Yaxcopoil-1 borehole reveal a more complex and temporally extensive alteration sequence: following a brief period at high temperatures, impact- melt-bearing polymict breccias and a thin, underlying unit of impact melt were subjected to metasomatism, producing alkali feldspar, sphene, apatite, and magnetite. As the system continued to cool, smectite-series phyllosilicates appeared. A saline solution was involved. Stable isotopes suggest the fluid was dominated by a basinal brine created mostly from existing groundwater of the Yucatan Peninsula, although contributions from down-welling water also occurred in some parts of the system. Numerical modeling of the hydrothermal system suggests circulation occurred for 1.5 to 2.3 Myr, depending on the permeability of the system. Our understanding of the hydrothermal system, however, is still crude. Additional core recovery projects, particularly into the central melt sheet, are needed to better evaluate the extent and duration of hydrothermal alteration.

Development of in vivo impedance spectroscopy techniques for measurement of micropore formation following microneedle insertion.

PubMed

Brogden, Nicole K; Ghosh, Priyanka; Hardi, Lucia; Crofford, Leslie J; Stinchcomb, Audra L

2013-06-01

Microneedles (MNs) provide a minimally invasive means to enhance skin permeability by creating micron-scale channels (micropores) that provide a drug delivery pathway. Adequate formation of the micropores is critical to the success of this unique drug delivery technique. The objective of the current work was to develop sensitive and reproducible impedance spectroscopy techniques to monitor micropore formation in animal models and human subjects. Hairless guinea pigs, a Yucatan miniature pig, and human volunteers were treated with 100 MN insertions per site following an overnight prehydration period. Repeated measurements were made pre- and post-MN treatment using dry and gel Ag/AgCl electrodes applied with light verses direct pressure to hold the electrode to the skin surface. Impedance measurements dropped significantly post-MN application at all sites (p < 0.05, irrespective of electrode type or gel application), confirming micropore formation. In the Yucatan pig and human subjects, gel electrodes with direct pressure yielded the lowest variability (demonstrated by lower %relative standard deviation), whereas dry electrodes with direct pressure were superior in the guinea pigs. These studies confirm that impedance measurements are suitable for use in both clinical and animal research environments to monitor the formation of new micropores that will allow for drug delivery through the impermeable skin layers. Copyright © 2013 Wiley Periodicals, Inc.

Magnetic Mineralogy as Indicator of dry Conditions in Lacustrine Sediments From Santa María del Oro, Nayarit, Central Mexico

NASA Astrophysics Data System (ADS)

Ortega, B.; Vazquez, G.; Rodriguez, A.

2007-05-01

Combined magnetic and geochemical analysis were conducted on laminated sediments from Santa Maria del Oro, a crater lake in Nayarit (Mexico), to build up a model of paleoenvironmental conditions for the late Holocene. The occurrence of a severe drought at the end of the archeological Classic period (100 - 900 AD) has been documented in sites of central Mexico (Zirahuen lake and Lerma basin), the Gulf of Mexico coast (Los Tuxtlas) and the Yucatan peninsula. The effects of this climatic event are considered to have stressed the social and political situation in the Yucatan area and other sites in Mesoamerica, and resulted in the "collapse" of the Maya civilization. Santa Maria del Oro sediments between ca. 600 - 1140 AD are characterized by repeated sequences of ocher silt laminae with high inorganic carbon content, authigenic siderite, and low concentration of SD magnetic minerals, followed upward by an increase of concentrations of fine grained SD and SP ferrimagnetic minerals in brown silt laminae. This sequence is considered to represent dissolution-precipitation cycles of magnetic minerals in low erosion, concentrated waters and anoxic water-sediment interface environments. Dissolution of magnetite occurs in reductive conditions, which are considered as warmer and dryer periods. Above the ocher silt, precipitation of fine grained magnetite occurs when conditions change to oxic environments. Ostracode C and O isotopy document a negative precipitation/evaporation balance during this time period.

Temporal distribution and genetic variants in influenza A(H1N1)pdm09 virus circulating in Mexico, seasons 2012 and 2013.

PubMed

Canche-Pech, Jose Reyes; Conde-Ferraez, Laura; Puerto-Solis, Marylin; Gonzalez-Losa, Refugio; Granja-Pérez, Pilar; Villanueva-Jorge, Salha; Chan-Gasca, Maria; Gómez-Carballo, Jesus; López-Ochoa, Luisa; Jiménez-Delgadillo, Bertha; Rodríguez-Sánchez, Iram; Ramírez-Prado, Jorge; Ayora-Talavera, Guadalupe

2017-01-01

The 2012 and 2013 annual influenza epidemics in Mexico were characterized by presenting different seasonal patterns. In 2012 the A(H1N1)pdm09 virus caused a high incidence of influenza infections after a two-year period of low circulation; whereas the 2013 epidemic presented circulation of the A(H1N1)pdm09 virus throughout the year. We have characterized the molecular composition of the Hemagglutinin (HA) and Neuraminidase (NA) genes of the A(H1N1)pdm09 virus from both epidemic seasons, emphasizing the genetic characteristics of viruses isolated from Yucatan in Southern Mexico. The molecular analysis of viruses from the 2012 revealed that all viruses from Mexico were predominantly grouped in clade 7. Strikingly, the molecular characterization of viruses from 2013 revealed that viruses circulating in Yucatan were genetically different to viruses from other regions of Mexico. In fact, we identified the occurrence of two genetic variants containing relevant mutations at both the HA and NA surface antigens. There was a difference on the temporal circulation of each genetic variant, viruses containing the mutations HA-A141T / NA-N341S were detected in May, June and July; whereas viruses containing the mutations HA-S162I / NA-L206S circulated in August and September. We discuss the significance of these novel genetic changes.

Temporal distribution and genetic variants in influenza A(H1N1)pdm09 virus circulating in Mexico, seasons 2012 and 2013

PubMed Central

Canche-Pech, Jose Reyes; Conde-Ferraez, Laura; Puerto-Solis, Marylin; Gonzalez-Losa, Refugio; Granja-Pérez, Pilar; Villanueva-Jorge, Salha; Chan-Gasca, Maria; Gómez-Carballo, Jesus; López-Ochoa, Luisa; Jiménez-Delgadillo, Bertha; Rodríguez-Sánchez, Iram; Ramírez-Prado, Jorge

2017-01-01

The 2012 and 2013 annual influenza epidemics in Mexico were characterized by presenting different seasonal patterns. In 2012 the A(H1N1)pdm09 virus caused a high incidence of influenza infections after a two-year period of low circulation; whereas the 2013 epidemic presented circulation of the A(H1N1)pdm09 virus throughout the year. We have characterized the molecular composition of the Hemagglutinin (HA) and Neuraminidase (NA) genes of the A(H1N1)pdm09 virus from both epidemic seasons, emphasizing the genetic characteristics of viruses isolated from Yucatan in Southern Mexico. The molecular analysis of viruses from the 2012 revealed that all viruses from Mexico were predominantly grouped in clade 7. Strikingly, the molecular characterization of viruses from 2013 revealed that viruses circulating in Yucatan were genetically different to viruses from other regions of Mexico. In fact, we identified the occurrence of two genetic variants containing relevant mutations at both the HA and NA surface antigens. There was a difference on the temporal circulation of each genetic variant, viruses containing the mutations HA-A141T / NA-N341S were detected in May, June and July; whereas viruses containing the mutations HA-S162I / NA-L206S circulated in August and September. We discuss the significance of these novel genetic changes. PMID:29220381

Benefits of State-by-State Comparisons.

ERIC Educational Resources Information Center

Phillips, Gary W.

1991-01-01

Suggests that the National Assessment of Educational Progress's (NAEP) Trial State Assessment (TSA) will provide reliable and valid state-by-state comparisons of what students have learned and will assess their progress over time. The TSA will also provide information on home learning environments, instructional practices, educational resources,…

Changes in the incidence of intestinal giardiosis in Mexican population during five years (2011-2015).

PubMed

Ibáñez-Cervantes, Gabriela; León-Ávila, Gloria; Bello-López, Juan Manuel; Pérez-Rangel, Armando; León-García, Gregorio; Nogueda-Torres, Benjamín; Hernández, José Manuel

2018-03-26

Giardiosis is a parasitic disease caused by the protozoan Giardia intestinalis, which is distributed worldwide. Most of the data on the prevalence of giardiosis in Mexico comes from research, but it is also necessary to study the data provided by the Mexican Health Ministry and issued by the General Directorate of Epidemiology. The aim of this work was analyse the national surveillance data for human giardiosis in order to update the epidemiological data of this disease in Mexico. A retrospective observational analysis of giardiosis (from January 2011 to December 2015) was performed in the annual reports emitted by the GDE in Mexico. The cases were classified by year, state, age group, gender and seasons of the year. During the period of 2011-2015, a reduction of 38.51% was observed in the total number of new cases of giardiosis reported in the whole country The states of Sinaloa, Yucatan, and Chiapas presented the highest number of new cases reported during the analysed period. Giardiosis rates were always higher among women in all age groups, but the maximum incidence was observed in both sexes in the age group of 1-4 years old (the most susceptible group). On the other hand, the number of cases increased dramatically in southern states during warmer months. Giardiosis is influenced by ambient temperature changes along the year, although this study suggests that tends to decrease in all the analysed states and could be related to the overall improvement of hygienic practices within the Mexican population.

Bibliography of Venomous and Poisonous Marine Animals and Their Toxins

DTIC Science & Technology

1984-02-01

Miami, Florida, 96p., 1975. 909 MILLS, L.3. and KLEIN-MC PHEE, 901 MC LAUGHLIN, 3.3. Euryhaline G. Toxicity of the New England Chrysomonads: nutrition and...8217leau SOLI, L. Nutritional require- rouge," un pdril pour les hifltres ments and toxicity of two marine perliares. Bl.So.Cent.A ic. A rolijum. 3...Comm. Tech. Pap. (141), Nou- cosas de Yucatan " with notes on mea, New Caledonia, Sept., 1963. the probable identification of fishes. Tex. 3. Sci. 4

Protection by Purines in Toxin Models of Parkinson’s Disease

DTIC Science & Technology

2016-04-01

erythrocytes from the Yucatan miniature pig. Evidence that inosine functions as an in vivo energy substrate. Biochim Biophys Acta 842:214–224. Zai L, Ferrari C... nutrition examination survey 2007–2008. Arthritis Rheum 2011; 63: 3136–3141. 28 Ascherio A, LeWitt PA, Xu K, Eberly S, Watts A, Matson WR, Marras C...correspondence to Dr Ascherio, 667 Huntington Ave, Department of Nutrition , Building 2, 3rd floor, Boston, MA 02115. E-mail: aascherio@hsph.harvard.edu From the

State Online College Job Market: Ranking the States

ERIC Educational Resources Information Center

Carnevale, Anthony; Jayasundera, Tamara; Repnikov, Dmitri; Gulish, Artem

2015-01-01

"State Online College Job Market: Ranking the States" analyzes the online college labor market on a state-by-state basis. We examine the geographic distribution of online job ads for college graduates within industries and occupational clusters, and compare the relative strength of the online college labor market across states. We…

Product-State Approximations to Quantum States

NASA Astrophysics Data System (ADS)

Brandão, Fernando G. S. L.; Harrow, Aram W.

2016-02-01

We show that for any many-body quantum state there exists an unentangled quantum state such that most of the two-body reduced density matrices are close to those of the original state. This is a statement about the monogamy of entanglement, which cannot be shared without limit in the same way as classical correlation. Our main application is to Hamiltonians that are sums of two-body terms. For such Hamiltonians we show that there exist product states with energy that is close to the ground-state energy whenever the interaction graph of the Hamiltonian has high degree. This proves the validity of mean-field theory and gives an explicitly bounded approximation error. If we allow states that are entangled within small clusters of systems but product across clusters then good approximations exist when the Hamiltonian satisfies one or more of the following properties: (1) high degree, (2) small expansion, or (3) a ground state where the blocks in the partition have sublinear entanglement. Previously this was known only in the case of small expansion or in the regime where the entanglement was close to zero. Our approximations allow an extensive error in energy, which is the scale considered by the quantum PCP (probabilistically checkable proof) and NLTS (no low-energy trivial-state) conjectures. Thus our results put restrictions on the possible Hamiltonians that could be used for a possible proof of the qPCP or NLTS conjectures. By contrast the classical PCP constructions are often based on constraint graphs with high degree. Likewise we show that the parallel repetition that is possible with classical constraint satisfaction problems cannot also be possible for quantum Hamiltonians, unless qPCP is false. The main technical tool behind our results is a collection of new classical and quantum de Finetti theorems which do not make any symmetry assumptions on the underlying states.

Estimating the geographical distribution of the prevalence of the metabolic syndrome in young Mexicans.

PubMed

Murguía-Romero, Miguel; Jiménez-Flores, Rafael; Villalobos-Molina, Rafael; Méndez-Cruz, Adolfo René

2012-09-01

The geographical distribution of the metabolic syndrome (MetS) prevalence in young Mexicans (aged 17-24 years) was estimated stepwise starting from its prevalence based on the body mass index (BMI) in a study of 3,176 undergraduate students of this age group from Mexico City. To estimate the number of people with MetS by state, we multiplied its prevalence derived from the BMI range found in the Mexico City sample by the BMI proportions (range and state) obtained from the Mexico 2006 national survey on health and nutrition. Finally, to estimate the total number of young people with MetS in Mexico, its prevalence by state was multiplied by the share of young population in each state according to the National Population and Housing Census 2010. Based on these figures, we estimated the national prevalence of MetS at 15.8%, the average BMI at 24.1 (standard deviation = 4.2), and the prevalence of overweight people (BMI ≥25) of that age group at 39.0%. These results imply that 2,588,414 young Mexicans suffered from MetS in 2010. The Yucatan peninsula in the south and the Sonora state in the north showed the highest rates of MetS prevalence. The calculation of the MetS prevalence by BMI range in a sample of the population, and extrapolating it using the BMI proportions by range of the total population, was found to be a useful approach. We conclude that the BMI is a valuable public health tool to estimate MetS prevalence in the whole country, including its geographical distribution.

State-to-State Mode Specificity: Energy Sequestration and Flow Gated by Transition State.

PubMed

Zhao, Bin; Sun, Zhigang; Guo, Hua

2015-12-23

Energy flow and sequestration at the state-to-state level are investigated for a prototypical four-atom reaction, H2 + OH → H + H2O, using a transition-state wave packet (TSWP) method. The product state distribution is found to depend strongly on the reactant vibrational excitation, indicating mode specificity at the state-to-state level. From a local-mode perspective, it is shown that the vibrational excitation of the H2O product derives from two different sources, one attributable to the energy flow along the reaction coordinate into the newly formed OH bond and the other due to the sequestration of the vibrational energy in the OH spectator moiety during the reaction. The analysis provided a unified interpretation of some seemingly contradicting experimental observations. It is further shown that the transfer of vibrational energy from the OH reactant to H2O product is gated by the transition state, accomplished coherently by multiple TSWPs with the corresponding OH vibrational excitation.

Transition States and transition state analogue interactions with enzymes.

PubMed

Schramm, Vern L

2015-04-21

Enzymatic transition states have lifetimes of a few femtoseconds (fs). Computational analysis of enzyme motions leading to transition state formation suggests that local catalytic site motions on the fs time scale provide the mechanism to locate transition states. An experimental test of protein fs motion and its relation to transition state formation can be provided by isotopically heavy proteins. Heavy enzymes have predictable mass-altered bond vibration states without altered electrostatic properties, according to the Born-Oppenheimer approximation. On-enzyme chemistry is slowed in most heavy proteins, consistent with altered protein bond frequencies slowing the search for the transition state. In other heavy enzymes, structural changes involved in reactant binding and release are also influenced. Slow protein motions associated with substrate binding and catalytic site preorganization are essential to allow the subsequent fs motions to locate the transition state and to facilitate the efficient release of products. In the catalytically competent geometry, local groups move in stochastic atomic motion on the fs time scale, within transition state-accessible conformations created by slower protein motions. The fs time scale for the transition state motions does not permit thermodynamic equilibrium between the transition state and stable enzyme states. Isotopically heavy enzymes provide a diagnostic tool for fast coupled protein motions to transition state formation and mass-dependent conformational changes. The binding of transition state analogue inhibitors is the opposite in catalytic time scale to formation of the transition state but is related by similar geometries of the enzyme-transition state and enzyme-inhibitor interactions. While enzymatic transition states have lifetimes as short as 10(-15) s, transition state analogues can bind tightly to enzymes with release rates greater than 10(3) s. Tight-binding transition state analogues stabilize the rare but

Alternative Fuels Data Center: Louisiana State University: The State's

Science.gov Websites

First Workplace Charging Challenge Partner Louisiana State University: The State's First State University: The State's First Workplace Charging Challenge Partner on Facebook Tweet about Alternative Fuels Data Center: Louisiana State University: The State's First Workplace Charging Challenge

A Regional-Scale Groundwater Model Supporting Management of the Sian Ka'an Biosphere Reserve and its Catchment, Quintana Roo, Mexico

NASA Astrophysics Data System (ADS)

Neuman, B. R.; Merediz Alonso, G.; Rebolledo Vieyra, M.; Marin, L.; Supper, R.; Bauer-Gottwein, P.

2007-05-01

The Caribbean Coast of the Yucatan Peninsula is a rapidly developing area featuring a booming tourism industry. The number of hotel rooms in the Riviera Maya has increased from 2600 in 1996 to 26,000 in 2005, while the total population in the Mexican federal state of Quintana Roo has grown from 500,000 in 1990 to 1,115,000 in 2005. This explosive growth threatens the region's water resources, which primarily consist of a less than 50m thick freshwater lens residing in the regional karst aquifer underlying the entire Yucatan Peninsula. The Sian Ka'an Biosphere Reserve, a 6400 km2 combined marine/terrestrial nature protection area is situated south of Tulum (approx. 87.3° - 88° W, 19° - 20° N). The site is listed as a UNESCO world heritage site and is protected under the Ramsar Convention. It includes extensive freshwater wetlands, saline/brackish mangrove swamps, tropical rainforests and parts of the world's second largest coral reef. The freshwater supply to the system occurs primarily via subsurface inflow. Large freshwater springs emerge through vertical sinkholes (cenotes) in the lagoons of Sian Ka'an. Management of this unique ecosystem in view of the rapid development and urbanization of the surrounding areas requires detailed knowledge on the groundwater flow paths in and around the reserve. Moreover, mapping and delineation of its groundwater catchment zone and groundwater traveling time zones is essential. To this end, a regional-scale steady-state groundwater flow model of the Sian Ka'an Biosphere reserve and its catchment was developed. The model is implemented in MIKE SHE with a finite-difference cell size of 1 km2 and is driven with temporally averaged climate forcings. The karst aquifer is treated as an equivalent porous medium. Darcy's law is assumed to be valid over regional scales and the main structural elements of the karst aquifer are included in the model as zones of varying hydraulic conductivity. High conductivity zones in the Sian Ka

State Clean Energy Policies Analysis (SCEPA): State Tax Incentives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lantz, E.; Doris, E.

As a policy tool, state tax incentives can be structured to help states meet clean energy goals. Policymakers often use state tax incentives in concert with state and federal policies to support renewable energy deployment or reduce market barriers. This analysis used case studies of four states to assess the contributions of state tax incentives to the development of renewable energy markets. State tax incentives that are appropriately paired with complementary state and federal policies generally provide viable mechanisms to support renewable energy deployment. However, challenges to successful implementation of state tax incentives include serving project owners with limited statemore » tax liability, assessing appropriate incentive levels, and differentiating levels of incentives for technologies with different costs. Additionally, state tax incentives may result in moderately higher federal tax burdens. These challenges notwithstanding, state tax incentives that consider certain policy design characteristics can support renewable energy markets and state clean energy goals.The scale of their impact though is directly related to the degree to which they support the renewable energy markets for targeted sectors and technologies. This report highlights important policy design considerations for policymakers using state tax incentives to meet clean energy goals.« less

States that are far from being stabilizer states

NASA Astrophysics Data System (ADS)

Andersson, David; Bengtsson, Ingemar; Blanchfield, Kate; Bui Dang, Hoan

2015-08-01

Stabilizer states are eigenvectors of maximal commuting sets of operators in a finite Heisenberg group. States that are far from being stabilizer states include magic states in quantum computation, MUB-balanced states, and SIC vectors. In prime dimensions the latter two fall under the umbrella of minimum uncertainty states (MUSs) in the sense of Wootters and Sussman. We study the correlation between two ways in which the notion of ‘far from being a stabilizer state’ can be quantified. Two theorems valid for all prime dimensions are given, as well as detailed results for low dimensions. In dimension 7 we identify the MUB-balanced states as being antipodal to the SIC vectors within the set of MUS, in a sense that we make definite. In dimension 4 we show that the states that come closest to being MUS with respect to all of the six stabilizer MUBs are the fiducial vectors for Alltop MUBs.

Enzymatic Transition States, Transition-State Analogs, Dynamics, Thermodynamics, and Lifetimes

PubMed Central

Schramm, Vern L.

2017-01-01

Experimental analysis of enzymatic transition-state structures uses kinetic isotope effects (KIEs) to report on bonding and geometry differences between reactants and the transition state. Computational correlation of experimental values with chemical models permits three-dimensional geometric and electrostatic assignment of transition states formed at enzymatic catalytic sites. The combination of experimental and computational access to transition-state information permits (a) the design of transition-state analogs as powerful enzymatic inhibitors, (b) exploration of protein features linked to transition-state structure, (c) analysis of ensemble atomic motions involved in achieving the transition state, (d) transition-state lifetimes, and (e) separation of ground-state (Michaelis complexes) from transition-state effects. Transition-state analogs with picomolar dissociation constants have been achieved for several enzymatic targets. Transition states of closely related isozymes indicate that the protein’s dynamic architecture is linked to transition-state structure. Fast dynamic motions in catalytic sites are linked to transition-state generation. Enzymatic transition states have lifetimes of femtoseconds, the lifetime of bond vibrations. Binding isotope effects (BIEs) reveal relative reactant and transition-state analog binding distortion for comparison with actual transition states. PMID:21675920

Tales from the Paleoclimate Underground: Lessons Learned from Reconstructing Extreme Events

NASA Astrophysics Data System (ADS)

Frappier, A. E.

2017-12-01

Tracing patterns of paleoclimate extremes over the past two millennia is becoming ever more important in the effort to understand and predict costly weather hazards and their varied societal impacts. I present three paleoclimate vignettes from the past ten years of different paleotempestology projects I have worked on closely, illustrating our collective challenges and productive pathways in reconstructing rainfall extremes: temporal, spatial, and combining information from disparate proxies. Finally, I aim to share new results from modeling multiple extremes and hazards in Yucatan, a climate change hotspot.

Space Station Camera Captures New Views of Hurricane Harvey

NASA Image and Video Library

2017-08-24

The National Hurricane Center (NHC) upgraded the remnants of tropical storm Harvey to a tropical depression on August 23, 2017 at 11 a.m. EDT (1500 UTC). Harvey became better organized and was revived after moving from Mexico's Yucatan Peninsula into the Bay of Campeche. The warm waters of the Gulf of Mexico and favorable vertical wind shear promoted the regeneration of the tropical cyclone. This video includes views from The International Space Station recorded on August 24, 2017 at 6:15 p.m. Eastern Time.

States of Consciousness and State-Specific Sciences

ERIC Educational Resources Information Center

Tart, Charles T.

1972-01-01

Proposes the development of state-specific sciences" to overcome the problems of scientifically studying altered states of consciousness induced by drugs or meditation from the paradigm of the ordinary consciousness state. The requirements of good observation, public nature of the observation, logical theorizing, and testing of theories by…

State Budgetary Assumptions. State Fiscal Brief No. 36.

ERIC Educational Resources Information Center

Boyd, Donald J.; Davis, Elizabeth I.

When states prepare their budgets, they usually base revenue and expenditure projections upon forecasts of national and state economic and demographic trends. This brief presents findings of a Center for the Study of the States survey that asked state budget offices what they were assuming for many key variables. The survey obtained 41 state…

31 CFR 515.321 - United States; continental United States.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false United States; continental United... General Definitions § 515.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including the Trust Territory of...

31 CFR 535.321 - United States; continental United States.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false United States; continental United... General Definitions § 535.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof including the Trust Territory of...

31 CFR 535.321 - United States; continental United States.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false United States; continental United... General Definitions § 535.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof including the Trust Territory of...

31 CFR 535.321 - United States; continental United States.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States; continental United... General Definitions § 535.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof including the Trust Territory of...

31 CFR 515.321 - United States; continental United States.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States; continental United... General Definitions § 515.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including the Trust Territory of...

31 CFR 515.321 - United States; continental United States.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false United States; continental United... General Definitions § 515.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including the Trust Territory of...

31 CFR 500.321 - United States; continental United States.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States; continental United... General Definitions § 500.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including U.S. trust territories...

31 CFR 515.321 - United States; continental United States.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false United States; continental United... General Definitions § 515.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including the Trust Territory of...

31 CFR 535.321 - United States; continental United States.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false United States; continental United... General Definitions § 535.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof including the Trust Territory of...

31 CFR 535.321 - United States; continental United States.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false United States; continental United... General Definitions § 535.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof including the Trust Territory of...

31 CFR 515.321 - United States; continental United States.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false United States; continental United... General Definitions § 515.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including the Trust Territory of...

State of the States in Developmental Disabilities

ERIC Educational Resources Information Center

Braddock, David; Hemp, Richard; Rizzolo, Mary Kay

2008-01-01

This is the latest edition of the "State of the States in Developmental Disabilities" study--a thorough and the only one of its kind investigation on public spending, revenues, and programmatic trends of intellectual and developmental programs and services within the United States since 1977. Directed by leading researcher, Dr. David…

Landscape ecology of Trypanosoma cruzi in the southern Yucatan Peninsula.

PubMed

López-Cancino, Sury Antonio; Tun-Ku, Ezequiel; De la Cruz-Felix, Himmler Keynes; Ibarra-Cerdeña, Carlos Napoleón; Izeta-Alberdi, Amaia; Pech-May, Angélica; Mazariegos-Hidalgo, Carlos Jesús; Valdez-Tah, Alba; Ramsey, Janine M

2015-11-01

Landscape interactions of Trypanosoma cruzi (Tc) with Triatoma dimidiata (Td) depend on the presence and relative abundance of mammal hosts. This study analyzed a landscape adjacent to the Calakmul Biosphere Reserve, composed of conserved areas, crop and farming areas, and the human community of Zoh Laguna with reported Chagas disease cases. Sylvatic mammals of the Chiroptera, Rodentia, and Marsupialia orders were captured, and livestock and pets were sampled along with T. dimidiata in all habitats. Infection by T. cruzi was analyzed using mtDNA markers, while lineage and DTU was analyzed using the mini-exon. 303 sylvatic specimens were collected, corresponding to 19 species during the rainy season and 114 specimens of 18 species during dry season. Five bats Artibeus jamaicensis, Artibeus lituratus, Sturnira lilium, Sturnira ludovici, Dermanura phaeotis (Dp) and one rodent Heteromys gaumeri were collected in the three habitats. All but Dp, and including Carollia brevicauda and Myotis keaysi, were infected with predominately TcI in the sylvatic habitat and TcII in the ecotone. Sigmodon hispidus was the rodent with the highest prevalence of infection by T. cruzi I and II in ecotone and domestic habitats. Didelphis viginiana was infected only with TcI in both domestic and sylvatic habitats; the only two genotyped human cases were TcII. Two main clades of T. cruzi, lineages I (DTU Ia) and II (DTU VI), were found to be sympatric (all habitats and seasons) in the Zoh-Laguna landscape, suggesting that no species-specific interactions occur between the parasite and any mammal host, in any habitat. We have also found mixed infections of the two principal T. cruzi clades in individuals across modified habitats, particularly in livestock and pets, and in both haplogroups of T. dimidiata. Results are contradictory to the dilution hypothesis, although we did find that most resilient species had an important role as T. cruzi hosts. Our study detected some complex trends in parasite transmission related to lineage sorting within the matrix. Intriguingly, TcIa is dominant in terrestrial small wildlife in the sylvatic habitat and is the only parasite DTU found in D. virginiana in the domestic habitat, although its frequency remained constant in sylvatic and ecotone vectors. Bats have a key role in TcVI dispersal from the sylvatic habitat, while dogs, sheep, and humans are drivers of TcVI between domestic and ecotone habitats. Overall, our results allow us to conclude that T. cruzi transmission is dependent on host availability within a highly permeable landscape in Zoh Laguna. Copyright © 2015 Elsevier B.V. All rights reserved.

Transdermal delivery of flurbiprofen from surfactant-based vesicles: particle characterization and the effect of water on in vitro transport.

PubMed

Uchino, Tomonobu; Matsumoto, Yuiko; Murata, Akiko; Oka, Toshihiko; Miyazaki, Yasunori; Kagawa, Yoshiyuki

2014-04-10

Flurbiprofen loaded rigid and elastic vesicles comprising the bilayer-forming surfactant sucrose-ester laurate were prepared by the film rehydration and extrusion method. The charge-inducing agent sodium dodecyl sulfate, and the micelle-forming surfactants, sorbitan monolaurate, polyethylene glycol monolaurate, and polysorbate 20, were used to enhance elasticity. Vesicle formulations were evaluated for size, zeta potential, (1)H and (19)F nuclear magnetic resonance (NMR) spectra, and in vitro skin permeation across Yucatan micropig (YMP) skin. Vesicle formulations were stable for 2 weeks and their mean sizes were 95-135 nm. NMR spectroscopy showed that flurbiprofen molecular mobility was restricted by interaction with vesicle components because of entrapment in vesicle bilayers. Moreover, sorbitan monolaurate-containing vesicles strongly retained flurbiprofen molecules. After non-occlusive application to YMP skin, flurbiprofen transport from all vesicle formulations was superior to that of flurbiprofen alone and remarkably decreased after water vaporization. Polarization microscopy and small-angle X-ray diffraction analysis showed that the vesicle formulation was transferred to liquid crystalline state. Suppression of vesicle transition to the liquid crystalline state was observed with applications of both large quantities and diluted samples. The presence of water in the formulations was associated with maintenance of the vesicle structure and greater flurbiprofen transport across YMP skin. Copyright © 2014 Elsevier B.V. All rights reserved.

Rapanos v. United States & Carabell v. United States

EPA Pesticide Factsheets

Documents associated with guidance for implementing the definition of waters of the United States under the Clean Water Act following the Rapanos v. United States, and Carabell v. United States Supreme Court decision.

Differences in liquor prices between control state-operated and license-state retail outlets in the United States.

PubMed

Siegel, Michael; DeJong, William; Albers, Alison B; Naimi, Timothy S; Jernigan, David H

2013-02-01

This study aims to compare the average price of liquor in the United States between retail alcohol outlets in states that have a monopoly ('control' states) with those that do not ('licence' states). A cross-sectional study of brand-specific alcohol prices in the United States. We determined the average prices in February 2012 of 74 brands of liquor among the 13 control states that maintain a monopoly on liquor sales at the retail level and among a sample of 50 license-state liquor stores, using their online-available prices. We calculated average prices for 74 brands of liquor by control versus license state. We used a random-effects regression model to estimate differences between control and license state prices-overall and by alcoholic beverage type. We also compared prices between the 13 control states. The overall mean price for the 74 brands was $27.79 in the license states [95% confidence interval (CI): $25.26-30.32] and $29.82 in the control states (95% CI: $26.98-32.66). Based on the random-effects linear regression model, the average liquor price was approximately $2 lower (6.9% lower) in license states. In the United States monopoly of alcohol retail outlets appears to be associated with slightly higher liquor prices. © 2012 The Authors, Addiction © 2012 Society for the Study of Addiction.

Controlled Remote State Preparation of an Arbitrary Two-Qubit State by Using GHZ States

NASA Astrophysics Data System (ADS)

Huang, Li; Zhao, Hong-xia

2017-03-01

In this paper, we demonstrate that two Greenberger-Horne-Zeilinger (GHZ) states can be used to realize the perfect and deterministic controlled remote state preparation of an arbitrary two-qubit state by performing only the two-qubit projective measurements and appropriate unitary operations.

Genetic, Ecological and Morphological Divergence between Populations of the Endangered Mexican Sheartail Hummingbird (Doricha eliza)

PubMed Central

Licona-Vera, Yuyini; Ornelas, Juan Francisco

2014-01-01

The Mexican Sheartail (Doricha eliza), an endangered hummingbird, is endemic to Mexico where two populations have a disjunct distribution. One population is distributed along the northern tip of the Yucatan Peninsula whereas the other is mostly restricted to central Veracruz. Despite their disjunct distribution, previous work has failed to detect morphological or behavioral differences between these populations. Here we use variation in morphology, mtDNA and nuDNA sequences to determine the degree of morphological and molecular divergence between populations, their divergence time, and historical demography. We use species distribution modeling and niche divergence tests to infer the relative roles of vicariance and dispersal in driving divergence in the genus. Our Bayesian and maximum likelihood phylogenetic analyses revealed that Doricha eliza populations form a monophyletic clade and support their sister relationship with D. enicura. We found marked genetic differentiation, with reciprocal monophyly of haplotypes and highly restricted gene flow, supporting a history of isolation over the last 120,000 years. Genetic divergence between populations is consistent with the lack of overlap in environmental space and slight morphological differences between males. Our findings indicate that the divergence of the Veracruz and Yucatan populations is best explained by a combination of a short period of isolation exacerbated by subsequent divergence in climate conditions, and that rather than vicariance, the two isolated ranges of D. eliza are the product of recent colonization and divergence in isolation. PMID:24992589