Food intake and nutrition in children 1-4 years of age in Yucatan, Mexico.

Science.gov (United States)

Cuanalo de la Cerda, Heriberto E; Ochoa Estrada, Ernesto; Tuz Poot, Felipe R; Datta Banik, Sudip

2014-01-01

The National Health and Nutrition Survey 2006 (ENSANUT in Spanish) reported high rates of under-nutrition in children of Yucatan. Is food intake the main cause of under-nutrition in children of the state of Yucatan, Mexico? Identify the primary causes of under-nutrition in pre-school children in Yucatan. A sample of 111 children (59 girls and 52 boys) aged 1-4 years representing Yucatan was taken from a database of ENSANUT 2006 and another national survey, a federal poverty mitigation programme for the state of Yucatan, Mexico entitled "Oportunidades". A human ecology approach together with life history theory was used to analyse anthropometric indices and food intake data from the ENSANUT 2006 and "Oportunidades". Height and weight were significantly correlated to age and total food intake. No correlations were found between age and anthropometric indices or food intake rates. The children in the sample had adequate protein intake but deficient energy intake. No correlation was identified between nutritional status and food intake rates. Pre-schoolers with higher weight-for-height values achieved greater height-for-age. These relationships can be explained by life history theory in that energy intake was used either for maintenance (combating and recovering from infections) or growth. The poor relationship between food intake rates and nutritional status is probably explained by the interaction between high disease incidence and insufficient energy intake. These conditions are endemic in Yucatan due to widespread poor housing, water and sanitation conditions.

Celebrating the diversity of biogeographical research

DEFF Research Database (Denmark)

Nogues-Bravo, D.; Rahbek, C.

2010-01-01

Biogeography Society took place in Merida on the Yucatan Peninsula, Mexico. Ecography provided financial support, acting as the sponsor of the Symposium of Extinction Biogeography and contributing to student travel awards. In addition, Ecography was the officially designated journal for publishing some...

Leishmania spp. Epidemiology of Canine Leishmaniasis in the Yucatan Peninsula

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A. López-Céspedes

2012-01-01

Full Text Available Canine Leishmaniasis is widespread in various Mexican states, where different species of Leishmania have been isolated from dogs. In the present study, we describe the detection of L. braziliensis, L. infantum, and L. mexicana in serum of dogs from the states of Yucatan and Quintana Roo in the Yucatan Peninsula (Mexico. A total of 412 sera were analyzed by ELISA using the total extract of the parasite and the iron superoxide dismutase excreted by different trypanosomatids as antigens. We found the prevalence of L. braziliensis to be 7.52%, L. infantum to be 6.07%, and L. mexicana to be 20.63%, in the dog population studied. The results obtained with ELISA using iron superoxide dismutase as the antigen were confirmed by western blot analysis with its greater sensitivity, and the agreement between the two techniques was very high.

Leishmania spp. epidemiology of canine leishmaniasis in the Yucatan Peninsula.

Science.gov (United States)

López-Céspedes, A; Longoni, S S; Sauri-Arceo, C H; Sánchez-Moreno, M; Rodríguez-Vivas, R I; Escobedo-Ortegón, F J; Barrera-Pérez, M A; Bolio-González, M E; Marín, C

2012-01-01

Canine Leishmaniasis is widespread in various Mexican states, where different species of Leishmania have been isolated from dogs. In the present study, we describe the detection of L. braziliensis, L. infantum, and L. mexicana in serum of dogs from the states of Yucatan and Quintana Roo in the Yucatan Peninsula (Mexico). A total of 412 sera were analyzed by ELISA using the total extract of the parasite and the iron superoxide dismutase excreted by different trypanosomatids as antigens. We found the prevalence of L. braziliensis to be 7.52%, L. infantum to be 6.07%, and L. mexicana to be 20.63%, in the dog population studied. The results obtained with ELISA using iron superoxide dismutase as the antigen were confirmed by western blot analysis with its greater sensitivity, and the agreement between the two techniques was very high.

New administrative center of the councils in Merida; Nuevo centro administrativo de las consejerias en Merida

Energy Technology Data Exchange (ETDEWEB)

Gamero, E.; Montero, E.

2008-07-01

The set of buildings of the new Administrative Center of the Consejerias of the Junta de Extremadura will be located in Merida. The design of the building has been realized bearing aspects of sustainability in mind, like cultural, environmental and the technical one; as well as it has looked for the fulfill diverse criteria of energetic efficiency guaranteeing suitable levels of thermal and visual comfort, acoustic quality and of the internal air. For what it has been necessary to developed strategies like the installation of an air-to-ground heat interchanges, conduits of the Sun, photovoltaic panels, control of the solar radiation and of the contribution of artificial light, air conditioning of high performance, domotics and monitoring. The incorporation of these systems supposes considerable reductions in the energetic consumption, cost of functioning and emissions of CO{sub 2} and greenhouse gases. (Author)

ESTABLISHMENT OF TREE ASSOCIATION WITH CAOBA AND RAMON IN AN ABANDONED QUARRY IN YUCATAN, MEXICO

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Patricia Montañez Escalante

2009-02-01

Full Text Available The influence of the association trees on the height and diameter growth  of mahogany (Swietenia macrophylla King and ramón (Brosimum alicastrum Sw. plantations during the establishment period in an quarry near the city of Merida, Yucatan, Mexico, was evaluated. Associated trees to mahogany were  tamarindo (Tamarindus indica L. and achiote (Bixa orellana L.. Associated trees to ramón were huaxin (Leucaena leucocephala (Lam de Wit. and pixoy (Guazuma ulmifolia Lam.. Tree association effects on the growth in height and diameter of mahogany and ramón were analyzed. The production of fruits and forage in the associated tree species was determined. There were no significant differences in mahogany and ramón diameter and height growth (p> 0.05 among treatments. To associate the ramón with other species of fast growth like huaxin and pixoy pruning was repeatedly conducted on this species to obtain the light levels required for ramón. The forage production of haxin and pixoy was 2 t dry matter ha-1 y-1 and there were not significant differences (p>0.05. The time required to get productive age in the species like ramon and mahogany offer opportunities to use the interspaces during growth period.

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

Science.gov (United States)

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

Measuring the Wavelength of a Diode Laser and the Birefringence of Mica: The Experimental Examination of the IPHO 40 Held in Mexico

Science.gov (United States)

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…

Influenza seasonality goes south in the Yucatan Peninsula: The case for a different influenza vaccine calendar in this Mexican region.

Science.gov (United States)

Ayora-Talavera, Guadalupe; Flores, Gerardo Montalvo-Zurbia; Gómez-Carballo, Jesus; González-Losa, Refugio; Conde-Ferraez, Laura; Puerto-Solís, Marylin; López-Martínez, Irma; Díaz-Quiñonez, Alberto; Barrera-Badillo, Gisela; Acuna-Soto, Rodolfo; Livinski, Alicia A; Alonso, Wladimir J

2017-08-24

While vaccination may be relatively straightforward for regions with a well-defined winter season, the situation is quite different for tropical regions. Influenza activity in tropical regions might be out of phase with the dynamics predicted for their hemispheric group thereby impacting the effectiveness of the immunization campaign. To investigate how the climatic diversity of Mexico hinders its existing influenza immunization strategy and to suggest that the hemispheric vaccine recommendations be tailored to the regional level in order to optimize vaccine effectiveness. We studied the seasonality of influenza throughoutMexico by modeling virological and mortality data.De-trended time series of each Mexican state were analyzed by Fourier decomposition to describe the amplitude and timing of annual influenza epidemic cycles and to compare with each the timing of the WHO's Northern and Southern Hemispheric vaccination schedule. The timings of the primary (major) peaks of both virological and mortality data for most Mexican states are well aligned with the Northern Hemisphere winter (December-February) and vaccine schedule. However, influenza peaks in September in the three states of the Yucatan Peninsula. Influenza-related mortality also peaks in September in Quintana Roo and Yucatan whereas it peaks in May in Campeche. As the current timing of vaccination in Mexico is between October and November, more than half of the annual influenza cases have already occurred in the Yucatan Peninsula states by the time the Northern Hemispheric vaccine is delivered and administered. The current Northern Hemispheric influenza calendar adopted for Mexico is not optimal for the Yucatan Peninsula states thereby likely reducing the effectiveness of the immunization of the population. We recommend that Mexico tailor its immunization strategy to better reflect its climatologic and epidemiological diversity and adopt the WHO Southern Hemisphere influenza vaccine and schedule for the

Seroprevalence of antibodies against the excreted antigen superoxide dismutase by Trypanosoma cruzi in dogs from the Yucatan Peninsula (Mexico).

Science.gov (United States)

López-Cespedes, A; Longoni, S S; Sauri-Arceo, C H; Rodríguez-Vivas, R I; Villegas, N; Escobedo-Ortegón, J; Barrera-Pérez, M A; Sánchez-Moreno, M; Bolio González, M E; Marín, C

2013-06-01

Numerous studies have shown the role of dogs as a reservoir for the American trypanosomiasis, as the bridge connecting sylvatic and peridomestic cycles. The objective of this study was to determine the prevalence of American trypanosomiasis in the dog population (630 sera) from seven localities in the Yucatan Peninsula (city of Mérida and the towns of Molas, Playa del Carmen, Akumal, Xcalacoop, Xcalac and Xahuachol). These data are key for developing control measures for the disease. The sera were analysed to detect antibodies against Trypanosoma cruzi, using Fe-SOD excreted as the antigenic fraction by ELISA and Western blot as confirmation. The total prevalence found in the Yucatan Peninsula was some 14.76%, with 10.74% in the state of Yucatan (city of Mérida, towns of Molas and Xcalacoop) and 21.34% in the state of Quintana Roo (towns of Playa del Carmen, Akumal, Xcalac and Xahuachol). However, a more thorough epidemiological study of the dog population, both wild and urban, in the Yucatan Peninsula will be required to design a control strategy for these diseases, paying particular attention to the population affected and even broadening the study to other Mexican states as well as neighbouring countries. These results again confirm that iron-superoxide dismutase excreted by T. cruzi constitutes a good source of antigen for serodiagnosis in epidemiological studies. © 2012 Blackwell Verlag GmbH.

The Orphans of Cholera Morbus in Yucatan, 1833

OpenAIRE

Elsa Malvido; Paola Peniche Moreno

2013-01-01

This essay discusses the phenomenon of orphanhood which affected a large number of children after the cholera epidemic that struck Yucatan in July 1833. Moreover, it inquires into the fate of children whose parents died of cholera, the role played by kinship networks to provide them with shelter, and the influence of the Church and the State on the situation. Based on first hand sources, the author suggests that the orphanhood produced by cholera served as a pretext for economically and socia...

Detection of different Leishmania spp. and Trypanosoma cruzi antibodies in cats from the Yucatan Peninsula (Mexico) using an iron superoxide dismutase excreted as antigen.

Science.gov (United States)

Longoni, Silvia S; López-Cespedes, Angeles; Sánchez-Moreno, Manuel; Bolio-Gonzalez, Manuel E; Sauri-Arceo, Carlos H; Rodríguez-Vivas, Roger I; Marín, Clotilde

2012-09-01

Although human leishmaniasis has been reported in 20 states in Mexico, no case of leishmaniasis has been reported in cats to date. In the Yucatan Peninsula, it has been found that dogs may act as reservoirs for at least three Leishmania species (Leishmania mexicana, Leishmania braziliensis, and Leishmania panamensis). In this study we identified specific antibodies against these three Leishmania spp. and Trypanosoma cruzi in the sera from 95 cats from two States on the Yucatan Peninsula, namely Quintana Roo and Yucatan, by ELISA and Western blot techniques using whole extract and an iron superoxide dismutase excreted by the parasites as antigens. As well as demonstrating the presence of trypanosomatid antibodies in the feline population on the Yucatan Peninsula, we were also able to confirm the high sensitivity and specificity of the iron superoxide dismutase antigen secreted by them, which may prove to be very useful in epidemiological studies. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Merida Initiative: Security-Surveillance Harmonization in Latin America

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Nelson Arteaga Botello

2009-10-01

Full Text Available This work analyses the Merida Initiative, whose objective is to coordinate the information systems used against terrorism, organized crime, and drug and arms trafficking between the United States, Mexico and Central America. This implies the introduction of communication equipment, data bases and surveillance technology, which not only reinforces the security policies of the ‘western hemisphere’, but also consolidates and broadens the spaces of exception in Mexico and Central America, thus eroding their already weakened democratic institutions.  Resumen: La Iniciativa Mérida: la armonización de seguridad y vigilancia en América LatinaEl trabajo analiza la Iniciativa Mérida, que tiene por objetivo coordinar los sistemas de información contra el terrorismo, el crimen organizado, el tráfico de drogas y de armas entre Estados Unidos, México y Centroamérica. Esto implica la introducción de equipos de comunicación, bases de datos y tecnología de vigilancia, las que no sólo refuerzan las políticas de seguridad del ‘hemisferio occidental’, sino también consolidan los espacios de excepción en México y Centroamérica, erosionando las ya debilitadas instituciones democráticas.

The Orphans of Cholera Morbus in Yucatan, 1833

Directory of Open Access Journals (Sweden)

Elsa Malvido

2013-07-01

Full Text Available This essay discusses the phenomenon of orphanhood which affected a large number of children after the cholera epidemic that struck Yucatan in July 1833. Moreover, it inquires into the fate of children whose parents died of cholera, the role played by kinship networks to provide them with shelter, and the influence of the Church and the State on the situation. Based on first hand sources, the author suggests that the orphanhood produced by cholera served as a pretext for economically and socially privileged groups to get hold of free labor force both for domestic service and hacienda work.

Association between overweight and obesity with school performance in secondary students in Merida, Mexico.

Science.gov (United States)

Salazar-Rendón, Juan Carlos; Méndez, Nina; Azcorra, Hugo

2018-01-01

Some studies have found a negative relationship between obesity and school performance in scholars. However, this topic has not been studied in depth in Mexico. The aim of this study was to analyze the association between overweight and obesity with school performance in secondary school students from Merida. Weight and height were measured, and body mass index was calculated in a sample of 566 secondary students in Merida. Nutritional status was classified in normal weight (-2- + 2 SD) according to the World Health Organization criteria. The scores in language, mathematics and sciences were used as indicators of school performance. Good performance was considered when the scores were ≥8 points, and poor performance when scores were <8 points. Logistic regression models were used to analyse the association between the variables. The 44% of the sample met the criteria for overweight and obesity. After adjusting for school grade, type of school, number of absences, and Mayan surnames, we found that girls classified as obese had a significant risk of a poor performance in mathematics (odds ratio [OR]: 3.07; 95% confidence interval [CI]: 1.39-6.80) and language (OR: 2.55; 95% CI: 1.14-5.71) compared with those with healthy weight. Our results suggest that obesity represents a risk of having a lower school performance in girls but not in boys. Copyright: © 2018 Permanyer.

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

Science.gov (United States)

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

1 Sunday November 30, 2008 Merida, Yucatan, Mexico Fiesta ...

International Development Research Centre (IDRC) Digital Library (Canada)

Jayne Bergeron

2008-11-30

Nov 30, 2008 ... Higher Education and Scientific Research in Rwanda. He then became the ...... availability of protective clothing and masks and alter- ...... count on collection services for used pesticide containers, bags and packaging. Fair.

PRESENCE OF PESTICIDES IN THE KARSTIC AQUIFER BETWEEN THE MUNICIPALITIES OF MÉRIDA TO PROGRESO, YUCATÁN, MÉXICO

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Germán Giácoman Vallejos

2017-07-01

Full Text Available Pollution by pesticides has become relevant worldwide due to its serious effects on living organisms. Pesticides act as endocrine disrupters, affect the immune system, decrease the reproductive capacity and some are potentially carcinogenic for human beings. For the characteristicsmentioned, their high environmental persistence and bioacumulation potential in fat tissues,since 1970, some of the organochlorade pesticides have been restricted in many countries, and it is necessary their monitoring. In the Yucatan State, the predominant karstic nature of soil enables the infiltration of a wide range of substances to the underground hydric resources, polluting them. Particularly, it can be observed the north occidental state region, which is characterized by the presence of human settlements, agricultural activity and ground water flows oriented towards the north coast. The present study presents the results of a research carried outin the north occidental region of the Yucatan State (between the municipalities of Merida and Progreso about the groundwater pollution by the presence of4,4´-DDT, 4,4´-DDD, 4,4´-DDE, lindane, endosulphan I and endosulphansulfate. The DDT concentrations and its derivatives as well as the endosulphan found in the area represent a risk for human water consumption, according to the mexican regulatory NOM-127-SSA1-1994.

A cross sectional study of leptospirosis and fetal death in Yucatan, Mexico

OpenAIRE

Cárdenas-Marrufo, MaríaFidelia; Vado-Solis, Ignacio; Pérez-Osorio, Carlos; Peniche-Lara, Gaspar; Segura-Correa, José

2016-01-01

Introduction: Leptospirosis is a zoonotic disease affecting mainly to low income human population. Acute leptospiral infection during pregnancy has been associated with spontaneous abortion and fetal death during the first trimester and the abortion may occur as consequence of systemic failure. Objective: To estimate the frequency of Leptospira interrogans infection in women with spontaneous abortion in the state of Yucatan, Mexico. Methods: A cross sectional study on women with spontaneous a...

El cuidado de enfermería en pacientes con ventilación mecánica asistida

OpenAIRE

Vega Morales, Elsy Guadalupe

2013-01-01

This qualitative study had as objectives to describe and analyze the styles of care / caring performed by nurses on the adult patient with mechanical ventilation. Maturana, Figueiredo and Boff were the authors who gave support to the theoretical and philosophical study. A total of ten nurses at the intensive care unit of Dr. Augustine O’Horán General Hospital in Merida, Yucatan, Mexico, participated in the study. Data were obtained through profound interviews and participant observation. The ...

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

Science.gov (United States)

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.

Low prevalence of high risk human papillomavirus in normal oral mucosa by hybrid capture 2 Baixa prevalência de papilomavírus humano de alto risco na mucosa oral normal através de Captura Híbrida 2

Directory of Open Access Journals (Sweden)

Maria del Refugio González-Losa

2008-03-01

Full Text Available 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. HR-HPV is present in low rate among healthy oral mucosa. Hybrid capture 2 could be a good methodology for large epidemiology studies.Papilomavírus humano de alto risco (HR-HPV é um fator reconhecido como necessário para o desenvolvimento de câncer cervical. Na última década vários estudos encontraram HR-HPV em OSCC (oral squamous cell carcinoma e em mucosa oral normal, mas a associação entre HR-HPV e OSCC não é bem conhecida. O objetivo desse estudo foi determinar DNA de HR-HPV na cavidade oral normal de adultos saudáveis. Realizou-se um estudo cross-sectional com amostras da cavidade oral normal de 77 pacientes da Escola de Odontologia da Autonomous University of Yucatan, Merida, Yucatan, México. HR-HPV foi detectado através de Captura Híbrida 2. Uma amostra em 77 (1,2% foi positiva para HR-PVH e era proveniente de um homem de 50 anos de idade. Concluiu-se que HR-HPV tem baixa prevalência na mucosa oral normal e a Captura Híbrida 2 pode ser um método adequado para estudos epidemiológicos.

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

Science.gov (United States)

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.

Chemical constraints of groundwater management in the Yucatan peninsula, Mexico

Science.gov (United States)

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.

Emissions from Biomass Burning in the Yucatan

Science.gov (United States)

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

Prefeasibility of the project for repowering the Nachi Cocom thermal station in Merida, Yucatan state; Prefactibilidad del proyecto de repotenciacion de la central termoelectrica de Nachi- Cocom, en Merida estado de Yucatan

Energy Technology Data Exchange (ETDEWEB)

Sanchez Perez, J.L. [Comision Federal de Electricidad (CFE) (Mexico)

1995-12-31

This paper presents an alternative to the solution of the more efficient use of energy and for the solution on environmental pollution at a reduced cost, satisfying the electric energy demand with additional capacity three times as much greater than the installed capacity and utilizing evaluation of projects techniques for the prefeasibility analysis of the project. The investment for this type of projects results are feasible and attractive because of the short amortization term. The summary of results is given in Table 4. [Espanol] El presenta trabajo da una alternativa de solucion al uso mas eficiente de la energia y solucion a los problemas de contaminacion ambiental a un costo reducido, satisfaciendo la demanda de energia electrica con capacidad adicional de tres veces mayor a la capacidad instalada. Empleando tecnicas de evaluacion de proyectos para analisis de la prefactibilidad del proyecto. La inversion para este tipo de proyectos resulta factible y atractiva por el corto tiempo de amortizacion. El resumen de los resultados se muestra en la tabla 4.

Prefeasibility of the project for repowering the Nachi Cocom thermal station in Merida, Yucatan state; Prefactibilidad del proyecto de repotenciacion de la central termoelectrica de Nachi- Cocom, en Merida estado de Yucatan

Energy Technology Data Exchange (ETDEWEB)

Sanchez Perez, J L [Comision Federal de Electricidad (CFE) (Mexico)

1996-12-31

This paper presents an alternative to the solution of the more efficient use of energy and for the solution on environmental pollution at a reduced cost, satisfying the electric energy demand with additional capacity three times as much greater than the installed capacity and utilizing evaluation of projects techniques for the prefeasibility analysis of the project. The investment for this type of projects results are feasible and attractive because of the short amortization term. The summary of results is given in Table 4. [Espanol] El presenta trabajo da una alternativa de solucion al uso mas eficiente de la energia y solucion a los problemas de contaminacion ambiental a un costo reducido, satisfaciendo la demanda de energia electrica con capacidad adicional de tres veces mayor a la capacidad instalada. Empleando tecnicas de evaluacion de proyectos para analisis de la prefactibilidad del proyecto. La inversion para este tipo de proyectos resulta factible y atractiva por el corto tiempo de amortizacion. El resumen de los resultados se muestra en la tabla 4.

Frequency of Varroa destructor, Nosema spp and Acarapis woodi in commercial colonies of bees (Apis mellifera in Yucatan, Mexico

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Martínez-Puc Jesús Froylán

2015-10-01

Full Text Available Today it has been observed that diseases affecting bees (Apis mellifera have caused significant economic losses in the European continent and in parts of the United States due to high mortality in honey bee colonies without a cause apparent, which is known as the syndrome of depopulation of hives. It is noteworthy that this mortality is not yet presented in Yucatan. In order to determine the frequency and levels of infestation Acarapis woodi and Varroa destructor, and the frequency and levels of infection Nosema spp. commercial colonies of bees (A. mellifera in Yucatan, was collected from June to December 2006, a total of 165 samples distributed in 13 towns of Yucatan. V. destructor frequency was 63.6%, with an average level of infestation of 2.85 ± 0.79 (mites / 100 bees. The frequency of Nosema spp. was 81.8%, with an average infection level = 1'234000 ± 118000 (spores / bee, the presence of A. woodi in the samples analyzed was detected. The existence of an association between V. destructor and Nosema spp was observed. (X2 = 6.53, df = 1, p = 0.01.

Structure and Variability of the Loop Current along the Yucatan Slope and Shelf Break.

Science.gov (United States)

Sheinbaum, J.; Athie, G.; Candela, J.; Ochoa, J.; Romero, A.

2016-02-01

Yucatan Current and Loop Current variability is investigated using data from an array of moorings that was deployed during 2006-2011 at the western Yucatan Channel and two other strategic cross-sections further north over the Campeche Bank, where the core and western edge of the currents are usually located. Measurements show the cores of the Yucatan Current and Loop Current have a more offshore (onshore) position in summer (winter-spring) suggesting seasonality and a relation to transport variations. Some eastward displacements of the currents are associated with periods of positive horizontal shear (cyclonic vorticity anomalies) propagating northward from the Caribbean coast of Mexico into the Gulf. Ten of the thirteen Loop Current eddies released between 2006 and 2011 were found to be clearly related to these propagating cyclonic anomalies that after crossing the Yucatan Channel produce intense pulses of eddy kinetic energy in the mooring sections downstream. Current structure and variability above and below 1000 m depth have very different characteristics. Diffferences are also found between western and eastern mooring measurements at similar depths. Wind forcing, coastally trapped waves and small scale frontal eddies appear to be the source of this east-west asymmetry.

Education and neoliberalism in Yucatan, Mexico

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Gabriela Vargas-Cetina

2016-08-01

Full Text Available Under neoliberalism, at least in Mexico, education has been recast as a service that is to be sold for money, and not as a right of all Mexicans. The economy itself is now seen as a services economy, where everything is expected to make money. Here we reflect on some of the implications of current education reforms on our work at the Autonomous University of Yucatan.

Differences in coastal and oceanic SST trends north of Yucatan Peninsula

Science.gov (United States)

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.

Restoring the environment, revitalizing the culture: cenote conservation in Yucatan, Mexico

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Yolanda Lopez-Maldonado

2017-12-01

Full Text Available Cenotes are sinkholes through which groundwater may be accessed from the Yucatan Peninsula Aquifer. Historically and culturally, cenotes are also important cultural and spiritual natural sites for the Maya, but they have been contaminated and degraded. We ask the following: What are the present-day meanings, understanding, and values of cenotes for the Maya? Is it possible to adopt a cultural approach for conservation of cenotes in Yucatan? Participant observation, interviews with stakeholders, and underwater exploration in cenotes were used to obtain data. Results indicate that cenotes often retain some spiritual meaning for people but not as important cultural, spiritual, or sacred sites. Little consensus was found regarding the significance of cenotes and how best to protect them. Informants noted changes in water quality, and identified the threats to cenotes including tourism, poor solid waste management, contamination, and deficiency of interest in preservation. Lack of accurate knowledge was a problem: informants did not seem to understand that cenotes are interconnected through the groundwater system. The Yucatan case illustrates how loss of cultural values can be linked to environmental quality and resource degradation. Conversely, it can be argued that cultural revitalization in indigenous communities has the potential to bring back community-based conservation.

Tuluweckelia cernua, a new genus and species of stygobiont amphipod crustacean (Hadziidae) from anchialine caves on the Yucatan Peninsula in Mexico

NARCIS (Netherlands)

Holsinger, John R.

1990-01-01

Tuluweckelia cernua, a new genus and species of stygobiont amphipod is described from six anchialine caves near the northeastern coast of the state of Quintana Roo on the Yucatan Peninsula in Mexico. The new genus is closely allied morphologically with Mayaweckelia Holsinger, which is also recorded

Wind characteristics on the Yucatan Peninsula based on short term data from meteorological stations

International Nuclear Information System (INIS)

Soler-Bientz, Rolando; Watson, Simon; Infield, David

2010-01-01

Due to the availability of sparsely populated and flat open terrain, the Yucatan Peninsula located in eastern Mexico is a promising region from the perspective of wind energy development. Study of the diurnal and seasonal wind resource is an important stage in the move towards commercial exploitation of wind power in this Latin American region. An analysis of the characteristics of the wind resource of the Yucatan Peninsula is presented in this paper, based on 10 min averaged wind speed data from nine meteorological stations, between 2000 and 2007. Hourly and monthly patterns of the main environmental parameters have been examined. Highly directional behaviour was identified that reflects the influence of winds coming from the Caribbean Sea and the Gulf of Mexico. The characteristics of the wind speed variation observed at the studied sites reflected their proximity to the coast and whether they were influenced by wind coming predominantly from over the land or predominantly from over the sea. The atmospheric stability over the eastern seas of the Yucatan Peninsula was also analysed to assess thermal effects for different wind directions. The findings were consistent with the variation in average wind speeds observed at the coastal sites where winds came predominantly from over the sea. The research presented here is to be used as a basis for a wind atlas for the Yucatan Peninsula.

The Securing of a Precarious Commerce: Exchanges between Seville and Yucatan (1590- 1600

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Manuela Cristina García Bernal

2000-10-01

Full Text Available This work underlines the importance of Yucatan's commercial relations across the Atlantic Ocean, as opposed to the traditional belief  that  these exchanges were small and  infrequent. Due to the margination and poverty of the province, in 1590 the Span­ish Crown granted Yucatan a license  to send two small  ships each year, with the necessary products. This license  allowed the securing of a trade that until  then had  been quite  precarious. This is why the quantitative and qualitative analyses of the move­ments of ships and merchandise between 1590 and 1600 lets us understand why, despite being considered secondary, this re­gion's commerce occupied, as seen from Seville, a considerable position among the  great amount of Atlantic trade. These analy­ses also reveal  why  during the  seventeenth  century Yucatan would come  to be  the  most  favored of the smaller posts along the Spain-Indies trading route.

CONTRIBUTION TO THE KNOWLEDGE OF THE ARACHNIDS IN THE YUCATAN PENINSULA, MEXICO (EXCLUDING ARANAE AND ACARI

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Hugo Delfin Gonzalez

2017-08-01

Full Text Available The Chelicerata are the second group of arthropods with the highest diversity after insects and they can inhabit almost all types of environments. The most current classification recognizes 11 orders and estimates in the number of species vary from 52,000 to 100,000. We have made an extensive literature review on the diversity of arachnids in the Yucatan Peninsula (YP (excluding spiders and ticks. In Mexico there are 834 known species which represent 6% of the worldwide diversity. In the YP 63 records were found (58 species and 5 genera of arachnids, which represent 6.8% of the Mexican species. According to our research, 28 of the 58 species (48% in the YP were also record in other parts of Mexico, the continent and the world. Undoubtedly, the state of Yucatan is the best represented of the YP. In order to have a better understanding of the diversity of arachnid species is important to promote biological compendiums and sampling programs, which will improve the representation of this group and probably increasing the number of local species.

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

Science.gov (United States)

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.

Spatio-temporal coherence of dengue, chikungunya and Zika outbreaks in Merida, Mexico.

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Donal Bisanzio

2018-03-01

Full Text Available Response to Zika virus (ZIKV invasion in Brazil lagged a year from its estimated February 2014 introduction, and was triggered by the occurrence of severe congenital malformations. Dengue (DENV and chikungunya (CHIKV invasions tend to show similar response lags. We analyzed geo-coded symptomatic case reports from the city of Merida, Mexico, with the goal of assessing the utility of historical DENV data to infer CHIKV and ZIKV introduction and propagation. About 42% of the 40,028 DENV cases reported during 2008-2015 clustered in 27% of the city, and these clustering areas were where the first CHIKV and ZIKV cases were reported in 2015 and 2016, respectively. Furthermore, the three viruses had significant agreement in their spatio-temporal distribution (Kendall W>0.63; p<0.01. Longitudinal DENV data generated patterns indicative of the resulting introduction and transmission patterns of CHIKV and ZIKV, leading to important insights for the surveillance and targeted control to emerging Aedes-borne viruses.

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

Science.gov (United States)

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.

Science.gov (United States)

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.

Elements of success in cooperatives conformed by Maya women in the Yucatan Peninsula, Mexico

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Maria Cristina Osorio Vázquez

2016-05-01

Full Text Available This paper describes different elements leading to the success of cooperatives formed by indigenous Maya women of the Yucatan Peninsula in Mexico. These elements have shown to facilitate the sustainability (permanence over time of the cooperatives and their presence in the market, while improving the work environment and enhancing the practice of honesty. All these elements have generated an increase in the number of clients and beneficiaries due to their trustable relationships. As can be appreciated in this study, indigenous Maya women living in the Yucatan Peninsula are demonstrating an innovative way to do business, which has resulted in greater social benefits and profitability through social capital, ethical leadership and monitoring of actions.

Treating leachate by Fenton oxidation

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Roger Iván Méndez Novelo

2010-01-01

Full Text Available Leachates are formed from liquids, mainly rainwater, percolating through solid wastes during stabilisation. Their composition is variable and highly toxic; leachate treatment is therefore a complex task. Leachates represent a high risk to health due to the Yucatan Peninsula’s highly permeable soil. The results are presented from applying the Fenton process to treating leachate from the sanitary Merida landfill, Yucatan, Mexico. The Fenton process consists of treating the contaminant load with an H2O2 and FeSO4 combination in acidic conditions. Optimal reaction time, pH value, Fenton reagent dose, post treatment coagulation – flocculation doses and increased biodegradability index were all determined. Optimal oxidation conditions and doses were 202+ minute contact time, 4 pH, 600 mg/L H2O2 concentration and 1,000 mg/L Fe. Average organic matter removal rate, measured as CODS and TOC, were 78% and 87% respectively. The biodegradability index increased from 0.07 to 0.11 during the Fenton process and up to 0.13 when the Fenton process was followed by coagulation-flocculation.

Preliminary study of long-term wind characteristics of the Mexican Yucatan Peninsula

International Nuclear Information System (INIS)

Soler-Bientz, Rolando; Watson, Simon; Infield, David

2009-01-01

Mexico's Yucatan Peninsula is one of the most promising areas for wind energy development within the Latin American region but no comprehensive assessment of wind resource has been previously published. This research presents a preliminary analysis of the meteorological parameters relevant to the wind resource in order to find patterns in their long-term behaviour and to establish a foundation for subsequent research into the wind power potential of the Yucatan Peninsula. Three meteorological stations with data measured for a period between 10 and 20 years were used in this study. The monthly trends of ambient temperature, atmospheric pressure and wind speed data were identified and are discussed. The directional behaviour of the winds, their frequency distributions and the related Weibull parameters are presented. Wind power densities for the study sites have been estimated and have been shown to be relatively low (wind power class 1), though a larger number of suitable sites needs to be studied before a definitive resource evaluation can be reported.

Indoor-outdoor relationship of fungal aerosols in domestic homes situated in humid-warm climate

International Nuclear Information System (INIS)

ACeron Palma, I. M.; Lopez Pacheco, M.; Perez Sanchez, M. M.; Quintal Franco, C.; Giacoman Vallejos, G.; Ponce Caballero, C.

2009-01-01

Among the different kinds of bio aerosols, fungi represent a heterogeneous group, which plays an important role in human pathology. These microorganisms can be the cause of a variety of infectious diseases as well as allergic and toxic effects. Therefore, it is necessary to assess their composition and concentrations indoors, outdoors and in domestic environments. The study of indoor-air quality is a relatively new activity in the world, and very recent in Mexico. The aim of this study was to establish the relation between indoors and outdoors fungal aerosols in domestic homes. Air samples were collected, using the 6-stage Andersen impactor, inside and outside thirty domestic homes of Merida city, in Yucatan, Mexico. (Author)

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

Science.gov (United States)

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.

Some helminth parasites of Epinephelus morio (Pisces: Serranidae) from the peninsula of Yucatan, Mexico

NARCIS (Netherlands)

Moravec, F.; Vidal-Martínez, V.M.; Aguirre-Macedo, M.L.

1995-01-01

Moravec, F., V.M. Vidal-Martinez & M.L. Aguirre-Macedo, 1995. Some helminth parasites of Epinephelus morio (Pisces: Serranidae) from the Peninsula of Yucatan, Mexico. Studies Nat. Hist. Caribbean Region 72: 55-68. One nematode species, Hysterothylacium eurycheilum, the acanthocephalan Gorgorhynchus

Elements of success in cooperatives conformed by Maya women in the Yucatan Peninsula, Mexico

NARCIS (Netherlands)

Osorio Vazqez, Maria Cristina; Bressers, Johannes T.A.; Franco Garcia, Maria Laura; Boer, C.L.; Reyes Maya, Oscar Ivan

2016-01-01

This paper describes different elements leading to the success of cooperatives formed by indigenous Maya women of the Yucatan Peninsula in Mexico. These elements have shown to facilitate the sustainability (permanence over time) of the cooperatives and their presence in the market, while improving

CALIDAD DEL SERVICIO DE COMIDA RÁPIDA A PARTIR DE LA PARTICIPACIÓN DEL EMPLEADO DE VANGUARDIA, MUNICIPIO LIBERTADOR, ESTADO MÉRIDA, VENEZUELA | QUALITY OF FAST FOOD SERVICE FROM VANGUARD EMPLOYEE PARTICIPATION, LIBERTADOR MUNICIPALITY, MERIDA STATE, VENEZUELA

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Marysela Coromoto Morillo Moreno

2015-11-01

Full Text Available Currently, the service quality is the biggest distinguishing factor and the most powerful competitive advantage of service companies, where the performance of the human factor is fundamental. For the study of service quality two fundamental props exist: the internal and the external clients. The present investigation analyzes the service quality of fast food businesses from the participation of the avant-garde employee, in the specific case of businesses located in Libertador Municipality of Merida State, Venezuela. For this purpose, the integral model of quality breaches of the service and the scale of Dineserv were applied during the second semester of 2014. In this regards, a representative sample of the population of managers, employees and external customers of fast food businesses was selected, and a survey was applied to each of them. Compliance with the standards of the service employees was verified, as well as the positive correspondence between this performance and the levels of quality of service perceived by the user. To confront the low perception of the performance of the employee, rewards, recognition and multiple and varied stimulus should be implemented in order to motivate for a continuous improvement of the quality of service.

Infection by Trypanosoma cruzi in mammals in Yucatan, Mexico: a serological and parasitological study Infecção pelo Trypanosoma cruzi em mamíferos em Yucatan, México: estudo sorológico e parasitológico

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J Zavala-Velázquez

1996-08-01

Full Text Available In order to determine Trypanosoma cruzi infection among mammals in Yucatan, Mexico, 372 animals, both wild and synanthropic including carnivores, marsupials and rodents were studied. Serological studies by indirect haemagglutination (IHA were carried out to detect antibodies to T. cruzi and a parasitological study was also performed (blood smear and histopathology. Of all the animals tested 18.54% were serologically positive, with a significantly higher frequency among the wild ones (33.33% compared to the synanthropic ones (17.79%. To determine T. cruzi in positive animals, blood was inoculated into a white mouse (webster type to prove myocardium colonization. The serological and parasitological positivity of these animals, as well as their behavior in the environment, taken together with the socioeconomic and cultural characteristics of the population, suggest that in Yucatan, Mexico, Canis familiaris, Didelphis marsupialis and Rattus rattus act as a link with the wild cycle.Para determinar a infecção pelo Trypanosoma cruzi em mamíferos em Yucatan, México, foram estudados 372 animais selvagens e sinantrópicos incluindo carnívoros, marsupiais e roedores. Estudos sorológicos pela hemaglutinação indireta (IHA foram realizados para detectar anticorpos contra o T. cruzi e estudos parasitológicos (esfregaços de sangue e histopatologia. De todos os animais testados 18,54% foram sorologicamente positivos com freqüência significativamente maior entre os silvestres (33,3% em comparação com os sinantrópicos (11,79%. Para determinação do T. cruzi nos animais positivos, o sangue foi inoculado em camundongos brancos (tipo Webster para provar a colonização miocárdica. Através da sua positividade sorológica e parasitológica, bem como seu comportamento no meio ambiente acompanhado pelas características sociais, econômicas e culturais da população, deduz-se que em Yucatan, México, Canis familiaris, Didelphis marsupialis e Rattus

Length-weight relationships of coral reef fishes from the Alacran Reef, Yucatan, Mexico

OpenAIRE

Gonzalez-Gandara, C.; Perez-Diaz, E.; Santos-Rodriguez, L.; Arias-Gonzalez, J.E.

2003-01-01

Length-weight relationships were computed for 42 species of coral reef fishes from 14 families from the Alacran Reef (Yucatan, Mexico). A total of 1 892 individuals was used for this purpose. The fish species were caught by different fishing techniques such as fishhooks, harpoons, gill and trawl nets. The sampling period was from March 1998 to January 2000.

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

Science.gov (United States)

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.

Science.gov (United States)

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.

Salinity proxy comparison in four tropical biogenic carbonates for suitability in paleohydrologic reconstruction

Science.gov (United States)

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

2014-12-01

Climate change is expected to increasingly stress water resources in drought-prone areas such as the American Southwest or Central America. Understanding patterns in precipitation frequency and intensity in the recent past are critical to accurately modeling groundwater recharge potential and managing diminishing resources in conjunction with rapid urbanization (e.g. Yucatan, Mexico). Wet and dry seasons on the Yucatan Peninsula are affected by the Intertropical Convergence Zone (ITCZ) which can exacerbate drought as the climate warms. This study focuses on precipitation patterns during the late Holocene recorded in foraminifera (Ammonia beccarii, Elphidium sp., Quinqueloculina sp.) and ostracods (suspected Hemicyprideis nichuptensis) along a transect in Celestun Lagoon near Merida, Yucatan, Mexico. Submarine groundwater springs feed the north terminus of the lagoon resulting in δ18O and Mg gradients toward the ocean which oscillate in response to increased or decreased precipitation. Mg/Ca ratios from the north (4.59) and south (3.08) lagoon suggest warmer waters in the shallow northern end, resulting in evaporation and confounding the δ18O values there (upper lagoon = 2.1‰, middle lagoon = 0.3‰, lower lagoon = 1.5‰). B/Ca ratios remain fairly constant (average range 27.3-33.2) despite increasing B concentrations toward the southern mouth, suggesting a concurrent increase in dissolved calcium down the lagoon and thus a lower Ca signal in spite of the karst source of springs. Of the four species tested, A. beccarii and H. nichuptensis yielded the most similar results ([Ca] ~ 150 ppm). Replicate analyses are needed for Elphidium sp. and Quinqueloculina sp. due to their low sample size and signal variability which suggests they may not be ideal candidates for paleoenvironmental reconstruction in Celestun Lagoon and possible other marginal environments around the Yucatan Peninsula.

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

Science.gov (United States)

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.

Science.gov (United States)

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.

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

NARCIS (Netherlands)

Kampichler, C.; Calmé, S.; Weissenberger, H.; Arriaga-Weiss, S.

2010-01-01

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

First molecular evidence of Toxoplasma gondii in opossums (Didelphis virginiana) from Yucatan, Mexico

OpenAIRE

Torres-Castro, M.; Noh-Pech, H.; Puerto-Hern?ndez, R.; Reyes-Hern?ndez, B.; Panti-May, A.; Hern?ndez-Betancourt, S.; Yeh-Gorocica, A.; Gonz?lez-Herrera, L.; Zavala-Castro, J.; Puerto, F.I.

2016-01-01

Toxoplasma gondii is an obligate intracellular parasite recognized as a causal agent of toxoplasmosis; zoonotic disease endemic in many countries worldwide, including Mexico. Different species of animals participate in the wild cycle infection, including opossums of the species Didelphis virginiana. Thirteen D. virginiana were captured in Yucatan, Mexico. Detection of T. gondii was achieved by Polymerase Chain Reaction, which determined an infection of 76.9% (10/13) in brains. Positive amplic...

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

Science.gov (United States)

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

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

International Nuclear Information System (INIS)

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

2011-01-01

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. - Research highlights: → Intensive land development as a result of the rapidly growing tourism industry in the 'Riviera Maya' region of the Yucatan Peninsula, Mexico is contaminating groundwater resources that discharge into Caribbean coastal ecosystems. → Passive sampling devices deployed in groundwater flowing through cave systems below two communities in the Riviera Maya accumulated: pharmaceuticals and personal care products originating from domestic sewage. → PAHs originating from runoff from highways and other impermeable surfaces; chlorophenoxy herbicides originating from pesticide applications to lawns and turf. → Prevention and mitigation measures are needed to ensure that expanding development does not impact the marine environment and human health in the region. - Contaminants accumulated in passive samplers deployed in flooded cave systems in the Yucatan Peninsula in Mexico indicate contamination by domestic sewage, runoff and applications of pesticides

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

Energy Technology Data Exchange (ETDEWEB)

Metcalfe, Chris D., E-mail: cmetcalfe@trentu.ca [Worsfold Water Quality Centre, Trent University, Peterborough, ON, K9J 7B8 (Canada); Beddows, Patricia A. [Department of Earth and Planetary Sciences, Northwestern University, Evanston, IL (United States); Bouchot, Gerardo Gold [Departemento de Recursos del Mar, CINVESTAV Unidad Merida, Yucatan (Mexico); Metcalfe, Tracy L.; Li Hongxia [Worsfold Water Quality Centre, Trent University, Peterborough, ON, K9J 7B8 (Canada); Van Lavieren, Hanneke [UN University Institute for Water, Environment and Health (UNU-INWEH), Hamilton, ON (Canada)

2011-04-15

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. - Research highlights: > Intensive land development as a result of the rapidly growing tourism industry in the 'Riviera Maya' region of the Yucatan Peninsula, Mexico is contaminating groundwater resources that discharge into Caribbean coastal ecosystems. > Passive sampling devices deployed in groundwater flowing through cave systems below two communities in the Riviera Maya accumulated: pharmaceuticals and personal care products originating from domestic sewage. > PAHs originating from runoff from highways and other impermeable surfaces; chlorophenoxy herbicides originating from pesticide applications to lawns and turf. > Prevention and mitigation measures are needed to ensure that expanding development does not impact the marine environment and human health in the region. - Contaminants accumulated in passive samplers deployed in flooded cave systems in the Yucatan Peninsula in Mexico indicate contamination by domestic sewage, runoff and applications of

Recovery of Biomass Following Shifting Cultivation in Dry Tropical Forests of the Yucatan

OpenAIRE

Read, L; Lawrence, Deborah; Foster, David Russell

2003-01-01

Land-use change in the tropics is creating secondary forest at an unprecedented rate. In the tropical Americas, mature dry tropical forest is rapidly being converted to secondary forest during the fallow period of shifting cultivation. This study addresses changes in forest biomass during forest recovery following shifting cultivation of maize (corn) in the Southern Yucatan Peninsular Region (SYPR), Mexico. We sampled stems .1 cm diameter at breast height at 36 study sites in t...

Tidal currents in the Yucatan Channel

Energy Technology Data Exchange (ETDEWEB)

Carrillo Gonzalez, Fatima [Centro Universitario de la Costa, Universidad de Guadalajara, Guadalajara, Jalisco (Mexico); Ochoa, Jose; Candela, Julio; Badan, Antonio; Sheinbaum; Gonzalez Navarro, Juan Ignacio [Departamento de Oceanografia Fisica, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Ensenada, Baja California (Mexico)

2007-07-15

Currents data from a ten-month period at 197 measuring points covering all Yucatan Channel were processed by harmonic analysis to estimate tidal parameters for the O{sub 1}, K{sub 1}, M{sub 2} and S{sub 2} components. The highly detailed coverage confirms the known dominance for the O{sub 1} and K{sub 1} diurnal components, but also showed, for the first time, their intensification in the deep eastern margin of the channel where maximum amplitudes in main axis are 17 and 19 cm.s{sup -}1. The data also confirms weak semi-diurnal components, of which the most intense, M{sub 2} and S{sub 2}, have amplitudes only up to 2 cm.s{sup -}1. The tidal ellipses were elongated (i.e. with eccentricities close to one) in the NNW direction. The O{sub 1}, K{sub 1}, M{sub 2} and S{sub 2} contributions in transport variability through the channel have amplitudes of 11.7, 12.5, 1.2 and 1.0 Sv, all well determined above noise. [Spanish] Se presentan, a detalle sin precedente, las caracteristicas de las corrientes de marea O{sub 1}, K{sub 1}, M{sub 2} y S{sub 2} en el canal de Yucatan. Mapas de los parametros que definen las elipses, como son las amplitudes en los ejes principales, la orientacion, la fase y la razon-senal-ruido se obtienen, por el clasico analisis armonico en mediciones de 10 meses en duracion, en 197 puntos que cubren ampliamente un plano vertical del canal. En acuerdo con reportes anteriores, las senales diurnas O{sub 1} y K{sub 1} dominan, demostrandose aqui que sus amplitudes alcanzan, en la parte profunda y Este, 17 y 19 cm.s{sup -}1. El analisis tambien revela senales semidiurnas M{sub 2} y S{sub 2} muy debiles con amplitudes maximas de 2 y 1cm.s{sup -}1. Las elipses son muy alargadas (i.e. con excentricidad cercana a uno) y orientadas al nornoroeste. Los valores de la razon senal a ruido indican que los parametros de las dos constituyentes diurnas se encuentran bien determinados, mientras que las semidiurnas quedan muy contaminadas por el ruido. El rasgo mas

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

Science.gov (United States)

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

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

Directory of Open Access Journals (Sweden)

Santos-Fita Dídac

2012-10-01

Full Text Available Abstract 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

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

Science.gov (United States)

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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 shade

Hydrogeology of the south-eastern Yucatan Peninsula: New insights from water level measurements, geochemistry, geophysics and remote sensing

DEFF Research Database (Denmark)

Gondwe, Bibi Ruth Neuman; Lerer, Sara Maria; Stisen, S.

2010-01-01

The Yucatan Peninsula is one of the world’s largest karstic aquifer systems. It is the sole freshwater source for human users and ecosystems. The region hosts internationally important groundwater-dependent ecosystems (GDEs) in the 5280km2 Sian Ka’an Biosphere Reserve. The GDEs are threatened by ...

Validation of an indirect ELISA for the diagnosis of Babesia bovis in cattle in Yucatan, Mexico

International Nuclear Information System (INIS)

Dominguez, A.J.L.; Rodriguez, V.R.I.; Oura, C.; Cob, G.L.A.

1998-01-01

The ELISA kit provided by the FAO/IAEA for the diagnosis of Babesia bovis was validated. In order to determine the appropriate ELISA cut-off point that would serve as the threshold between positive and negative samples, 119 serum samples from a Mexican Babesia-free zone were analyzed. The optimal cut-off point chosen was at 12% of the reactivity of the high positive control serum sample (PP) which resulted in a specificity of 97%. One hundred and ninety-six cattle from Wisconsin, USA, were introduced into Yucatan, Mexico, of which 181 were vaccinated with an attenuated live Babesia bovis vaccine; 15 animals remained as unvaccinated controls. Before and after vaccination all animals were bled and tested by enzyme linked immunosorbent assay (ELISA) and indirect fluorescence antibody test (IFAT). Both tests showed a high degree of correlation in their results. To evaluate an immune response to vaccination the optimal cut-off point chosen was 12% PP resulting in a sensitivity 99% and a specificity 95%. We concluded that the ELISA test has proved to be useful in Yucatan, Mexico for serological surveys and monitoring the efficiency o vaccination programmes. (author)

Preliminary study of the offshore wind and temperature profiles at the North of the Yucatan Peninsula

International Nuclear Information System (INIS)

Soler-Bientz, Rolando; Watson, Simon; Infield, David; Ricalde-Cab, Lifter

2011-01-01

Highlights: → This is the first study that reports the properties of the vertical wind resources for the offshore conditions of the North coast of the Yucatan Peninsula. → A significant and detailed analysis of the thermal patterns has revealed a complex structure of the atmospheric boundary layer close to the shore. → The structure of the diurnal wind patterns was assessed to produce an important reference for the wind resource availability in the study region. → It was identified that the sea breeze blows in directions almost parallel to the shoreline of the North of the Yucatan Peninsula during the majority of the 24 h cycle. → The analysis of the offshore data revealed a persistent non-uniform surface boundary layer developed as result of the advection of a warn air over a cold sea. - Abstract: The stability conditions in the atmospheric boundary layer, the intensity of the wind speeds and consequently the energy potential available in offshore conditions are highly influenced by the distance from the coastline and the differences between the air and sea temperatures. This paper presents a preliminary research undertook to study the offshore wind and temperature vertical profiles at the North-West of the Yucatan Peninsula coast. Ten minute averages were recorded over approximately 2 years from sensors installed at two different heights on a communication tower located at 6.65 km from the coastline. The results have shown that the offshore wind is thermally driven by differential heating of land and sea producing breeze patterns which veer to blow parallel to the coast under the action of the Coriolis force. To investigate further, a dataset of hourly sea surface temperatures derived from GEOS Satellite thermal maps was combined with the onsite measured data to study its effect on the vertical temperature profile. The results suggested largely unstable conditions and the potentially development of a shallow Stable Internal Boundary Layer which occurs

HYDROGEOLOGY AND CONCEPTUAL MODEL OF THE KARSTIC COASTAL AQUIFER IN NORTHERN YUCATAN STATE, MEXICO

Directory of Open Access Journals (Sweden)

Miguel J Villasuso-Pino

2011-04-01

Full Text Available The coastal zone of northern Yucatan Peninsula (YP is mainly constituted by Tertiary limestones, covered by Pleistocen limestones, where there exist swamps and estuary systems, locally called “rías”, with mouths connecting them to the sea and hence being a way for an important amount of groundwater to discharge, like in Ría Lagartos and Celestún. These limestones have karstic layers located at depths from 8 to 16 meters below terrain surface.  It is in these layers where groundwater mainly flows toward coast, passing below the sand dune and discharging in the sea in the form of submarine springs which in many cases manifest themselves on the marine surface depending on the hydraulic or piezometric fresh water head. The width of the superficial limestone within this coastal fringe, called “caliche”, varies from 5 to 10 kilometers in the study zone (Chuburna-Progreso-Chicxulub.  Its permeability is extremely low, so it constitutes a confining layer that impedes superficial waters to percolate toward groundwater.  The hydraulic head of the groundwater below this confining layer is over the mean sea level and also over the swamp water level, coastal lagoons and estuaries. There are two important hydrological phenomena that occur in this coastal fringe: 1 There is no recharge to the aquifer (groundwater due to limestone rock outcrops is impermeable or semipermeable; and 2 groundwater pressure is not lost, nor saline interfase is rised if the superficial layer is broken.  The groundwater pollution vulnerability within this coastal fringe is less than that for the superficial saline waters of swamps and estuaries, because of caliche’s low intrinsic permeability that impedes percolation.

Frecuencia de anticuerpos contra el virus C de la hepatitis en pacientes con cirrosis hepática en Yucatán, México Frequency of antibodies against the hepatitis C virus in patients with hepatic cirrhosis in Yucatan, Mexico

Directory of Open Access Journals (Sweden)

Renán A Góngora-Biachi

2003-10-01

Full Text Available OBJETIVO: En este estudio reportamos la prevalencia de anticuerpos contra el virus C de la hepatitis (Ac-VCH en un grupo de pacientes con cirrosis hepática (CH. MATERIAL Y MÉTODOS: Se hizo un estudio prospectivo, transversal y descriptivo, de marzo de 1998 a mayo de 1999. Se estudiaron a 153 pacientes (117 (76% hombres y 36 (24% mujeres con diagnóstico de CH, que eran atendidos en el Hospital General Agustín O' Horan y en el Centro de Investigaciones Regionales Doctor Hideyo Noguchi, en la ciudad de Mérida, Yucatán, México. Se aplicó un cuestionario con datos clínico-epidemiológicos y se determinó la presencia de Ac-VCH (ELISA de 2ª generación y RIBA-2 para confirmar el diagnóstico a cada paciente. Se determinó también el antígeno de superficie de la hepatitis B (AgsHB y anticuerpos contra el antígeno central de la hepatitis B (Anti-HBc mediante el método de ELISA. La presencia de Ac-VCH fue relacionada con las variables epidemiológicas de los sujetos. La prevalencia de anti-HCV y la frecuencia de características se compararon entre los pacientes positivos y negativos con las pruebas de c² y exacta de Fisher. RESULTADOS: El 32% de los pacientes con CH (35/117 (30% hombres y 14/36 (39% mujeres fueron positivos para los Ac-VCH. El alcoholismo estuvo presente en todos los hombres serorreactivos y en ninguna de las mujeres positivas (pOBJECTIVE: To report the prevalence of antibodies against the hepatitis C virus (anti-HCV in a group of patients with hepatic cirrhosis (HC. MATERIAL AND METHODS: A prospective transversal and descriptive study was carried out from March 1998 to May 1999. Study subjects were 153 patients; 117 (76% male and 36 (24% female, diagnosed with HC. They were attended at the General Hospital Agustín O' Horan and at Regional Research Center Doctor Hideyo Noguchi, in Merida, Yucatan, Mexico. A clinical-epidemiologic questionnaire completed by interview was used for data collection. Anti-HCV were detected

Beyond the colours: discovering hidden diversity in the Nymphalidae of the Yucatan Peninsula in Mexico through DNA barcoding.

Directory of Open Access Journals (Sweden)

Blanca R Prado

Full Text Available 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

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

Science.gov (United States)

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

Pigging the unpiggable: a total integrated maintenance approach of the Progreso Process Pipelines in Yucatan, Mexico

Energy Technology Data Exchange (ETDEWEB)

Sanchez Graciano, Luis [PEMEX Refinacion, Mexico, MX (Mexico); Gonzalez, Oscar L. [NDT Systems and Services, Stutensee (Germany)

2009-07-01

Pemex Refinacion and NDT Systems and Services, executed a Total Integrated Maintenance Program of the Process Pipeline System in the Yucatan Peninsula in Mexico, in order to modernize, enhance and bring the pipeline system up to the best industry standards and ensure the integrity, reliability and safe operation of the system. This approach consisted in using multi-diameter ultrasonic inspection technology to determine the current status of the pipelines, repair every 'integrity diminishing' feature present on the system and establish a Certified Maintenance Program to ensure the future reliability and safety of the pipelines. Due to the complex nature of the pipeline construction, dated from 1984, several special modifications, integrations and solutions were necessary to improve the in line inspection survey as for all traditionally unpiggable systems. The Progreso Pipeline System consists in 3 major pipelines which transport diesel, jet fuel and gasoline respectively. The outside diameter of two pipelines varies along its length between 12 inches - 14 inches - 16 inches, making the inspection survey more difficult and particularly demanding an Inspection Tool solution. It is located on the coast of the Yucatan Peninsula, at the Mexican Caribbean, and its main purpose is to transport the product from the docked tanker ships to the Pemex Storage and Distribution Terminal. (author)

MaritimeMaya2011: The Costa Escondida Project: Exploring the Hidden World of the Maritime Maya on the Yucatan Peninsula between 20110509 and 20110531

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The northeast tip of the Yucatan Peninsula is a largely unexplored coastline where ancient Maya traders traveled in massive dugout canoes filled with goods from...

Application of Artificial Neural Networks for Dengue Fever Outbreak Predictions in the Northwest Coast of Yucatan, Mexico and San Juan, Puerto Rico

Directory of Open Access Journals (Sweden)

Abdiel E. Laureano-Rosario

2018-01-01

Full Text Available Modelling dengue fever in endemic areas is important to mitigate and improve vector-borne disease control to reduce outbreaks. This study applied artificial neural networks (ANNs to predict dengue fever outbreak occurrences in San Juan, Puerto Rico (USA, and in several coastal municipalities of the state of Yucatan, Mexico, based on specific thresholds. The models were trained with 19 years of dengue fever data for Puerto Rico and six years for Mexico. Environmental and demographic data included in the predictive models were sea surface temperature (SST, precipitation, air temperature (i.e., minimum, maximum, and average, humidity, previous dengue cases, and population size. Two models were applied for each study area. One predicted dengue incidence rates based on population at risk (i.e., numbers of people younger than 24 years, and the other on the size of the vulnerable population (i.e., number of people younger than five years and older than 65 years. The predictive power was above 70% for all four model runs. The ANNs were able to successfully model dengue fever outbreak occurrences in both study areas. The variables with the most influence on predicting dengue fever outbreak occurrences for San Juan, Puerto Rico, included population size, previous dengue cases, maximum air temperature, and date. In Yucatan, Mexico, the most important variables were population size, previous dengue cases, minimum air temperature, and date. These models have predictive skills and should help dengue fever mitigation and management to aid specific population segments in the Caribbean region and around the Gulf of Mexico.

José Martí, Viajes y Apreciación del Pueblo Maya

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Carlos Eduardo Bojórquez Urzaiz

2015-09-01

Full Text Available Este trabajo expone y examina los cambios de percepción que experimentó José Martí sobre el papel de los pueblos originarios de América, entre 1875 y 1878, años en los que vivió en México y Guatemala, con intensa escala en Yucatán, lugares donde conoció directamente la cultura y el pueblo maya. Martí resume una visión inicial de nuestra América en la figura lítica de Chacmool cuando después de ser expropiada por el gobierno yucateco, el Apóstol cubano la admira en la ciudad de Mérida y expresa que es la síntesis de las culturas americanas. Aspecto poco estudiado en la obra de Martí es este acercamiento etnográfico a la realidad maya de Yucatán y Guatemala.   This paper aims at presenting and examining the change of perception José Martí underwent in relation to the role of the native peoples of America between 1875 and 1878, the years he lived in Mexico and Guatemala, during which he spent a large amount of time in Yucatan, where he was able to get to know the Mayan culture and its people first hand. Martí summarized his initial vision of our America in the lithic figure of Chacmool, which he was able to admire in the city of Merida, after it had been expropriated by the government of Yucatan. The Cuban apostle described this as a synthesis of American cultures. This ethnographic insight into the Mayan reality in Yucatan and Guatemala represents a scarcely explored aspect of Martí's work.

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

Science.gov (United States)

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.

Regional-scale airborne electromagnetic surveying of the Yucatan karst aquifer (Mexico): geological and hydrogeological interpretation

DEFF Research Database (Denmark)

Gondwe, Bibi Ruth Neuman; Ottowitz, David; Supper, Robert

2012-01-01

-spectral remote sensing imagery, shuttle radar topography data and frequency-domain airborne electromagnetic (AEM) survey data were used to map karst-aquifer structure on the Yucatan Peninsula, Mexico. Anomalous AEM responses correlated with topographic features and anomalous spectral reflectance of the terrain...... as ejecta from the Chicxulub impact (Cretaceous/Paleogene boundary), based on similar resistivity signatures found in borehole logs. Due to limited sensitivity of the AEM survey, the subsurface configuration beneath the low-resistivity layer could not be unambiguously determined. AEM measurements combined...

PES Impact and Leakages over Several Cohorts: The Case of PSA-H in Yucatan, Mexico

OpenAIRE

LE VELLY , Gwenole; Sauquet , Alexandre; CORTINA-VILLAR , Sergio

2015-01-01

We assess the impact of a payment for environmental services scheme implemented in Mexico, the PSA-H, over the 2005-2012 period. By studying several cohorts of program beneficiaries we are able to shed lights on the permanence of the program's impact. Based on the exploitation of 2.5 to 20m resolution SPOT images and ejido-surveys carried out in 76 ejidos located in the Cono Sur of Yucatan, we find that the program's effects are cancelled after communities choose to withdraw from the program,...

First molecular evidence of Toxoplasma gondii in opossums (Didelphis virginiana) from Yucatan, Mexico.

Science.gov (United States)

Torres-Castro, M; Noh-Pech, H; Puerto-Hernández, R; Reyes-Hernández, B; Panti-May, A; Hernández-Betancourt, S; Yeh-Gorocica, A; González-Herrera, L; Zavala-Castro, J; Puerto, F I

2016-01-01

Toxoplasma gondii is an obligate intracellular parasite recognized as a causal agent of toxoplasmosis; zoonotic disease endemic in many countries worldwide, including Mexico. Different species of animals participate in the wild cycle infection, including opossums of the species Didelphis virginiana. Thirteen D. virginiana were captured in Yucatan, Mexico. Detection of T. gondii was achieved by Polymerase Chain Reaction, which determined an infection of 76.9% (10/13) in brains. Positive amplicons were sequenced for analysis, this produced results similar to T. gondii with identity and coverage values of 98% and 96-100%, respectively. This study presents the first molecular evidence of the circulation of T. gondii in D. virginiana from Mexico.

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

Science.gov (United States)

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 limestone bedrock. This reflector is flat-lying and undisturbed throughout the survey area. Therefore, none of these dissolution pits appear to be underlain by a cenote or sink hole. The NW sector of the survey area exhibits a more complex morphology than the alternating ribbon/bare rock morphology elsewhere, including linear scarps (up to ~1 m relief), deeper pitting (up to ~1 m relief), and sinuous, dendritic channeling (up to ~2 m relief). The geologic origin of these features will require further investigation. Sand drifts are present in this region, but are thinner and cover less area. These observations show the dominant modern sediment formation and transport processes on this starved platform are from large storms and hurricanes that place large regions of the platform at wave base. Remaining observed features were generated during times of lower sea level.

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

Science.gov (United States)

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 (Pevaluated 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.

CONTRIBUTION TO THE KNOWLEDGE OF THE ARACHNIDS IN THE YUCATAN PENINSULA, MEXICO (EXCLUDING ARANAE AND ACARI)

OpenAIRE

Hugo Delfin Gonzalez; Virginia Meléndez-Ramírez; Pablo C. Manrique-Saide; Abdiel Martin-Park; Carlos Arisqueta-Chablé

2017-01-01

The Chelicerata are the second group of arthropods with the highest diversity after insects and they can inhabit almost all types of environments. The most current classification recognizes 11 orders and estimates in the number of species vary from 52,000 to 100,000. We have made an extensive literature review on the diversity of arachnids in the Yucatan Peninsula (YP) (excluding spiders and ticks). In Mexico there are 834 known species which represent 6% of the worldwide diversity. In the YP...

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

Science.gov (United States)

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.

[Prevalence of high blood pressure and their association with body mass index in children between 5 and 11 years of Nahbalam, Yucatan].

Science.gov (United States)

Saury-Paredes, Leonel Alejandro

To determine the prevalence of high blood pressure in children aged between 5-11 years in the community of Nahbalam, Yucatan, and its association with the body mass index. A transversal study with children of the primary school "Lazaro Cardenas del Rio" was performed, measuring blood pressure, height, and weight of 259 girls and boys; systolic and/or diastolic blood pressure equal or greater than percentile 95 for gender, age, and height at three measures was considered as hypertension; prehypertension was considered as blood pressure equal or greater than percentile 90 but lower than percentile 95. A prevalence of 11.9% prehypertension and 6.1% hypertension was found. There is an association between hypertension and overweight and obesity (p ≤ 0.001). The prevalence of high blood pressure in children of the community of Nahbalam, Yucatan, is 18%. The children with overweight and obesity have an almost tenfold greater risk of hypertension than the eutrophic children (OR: 9.896; 95% CI: 2.738-35.764).

Henequén'ın Dönüşü, Bir Yeşil Lif İle Yucatan'da Karmaşık Bir Tarih

OpenAIRE

ANAYA, Yosi

2014-01-01

Meksika Mayaları ve Orta Amerika'nın önde gelen liflerinden birisi, sisal olarak bilinen Henequéndir. Sömürgecilik döneminin üretim merkezlerinden birisi olan Yucatan'ınadını alan Henequén, yüzyıllarca Yucatan Yarımadasının “Yeşil Altın”ı olarak bilindi. Yucatek ekonomisi, 20. yüzyıl boyunca ihtiyaç duyulan her türlü ip, halı,çuval ve kaba kumaşları sağlayan henequén tarlaları etrafında gelişti, yerleşti ve serpildi. 20. yüzyılda henequén lifi, daha ucuz fiyatlarla Madagaskar ve Ken...

First molecular evidence of Toxoplasma gondii in opossums (Didelphis virginiana from Yucatan, Mexico

Directory of Open Access Journals (Sweden)

M. Torres-Castro

2016-03-01

Full Text Available Toxoplasma gondii is an obligate intracellular parasite recognized as a causal agent of toxoplasmosis; zoonotic disease endemic in many countries worldwide, including Mexico. Different species of animals participate in the wild cycle infection, including opossums of the species Didelphis virginiana. Thirteen D. virginiana were captured in Yucatan, Mexico. Detection of T. gondii was achieved by Polymerase Chain Reaction, which determined an infection of 76.9% (10/13 in brains. Positive amplicons were sequenced for analysis, this produced results similar to T. gondii with identity and coverage values of 98% and 96-100%, respectively. This study presents the first molecular evidence of the circulation of T. gondii in D. virginiana from Mexico.

Petrography of the Nimun and Baca pottery (Ware Celestun Roja): Canbalam Ceramic Sphere of the Yucatan Peninsula, Mexico

International Nuclear Information System (INIS)

Obando, Luis G.; Jimenez Alvarez, Socorro del Pilar

2016-01-01

The ware Celestun Red (of the Nimun and Baca ceramic typologies) is one of the most diagnosis ceramics of the northwestern coast of Mexico's Yucatan Peninsula and subject of ongoing debate regarding its distribution and origin. Although ceramics from coastal Campeche and Yucatan have been the focus of years of investigation, scholars still do not know if Celestun Red was manufactured locally during the Late Classic (A.D. 600-900) or was made and exchanged by the regional elite. The first petrographic description of Celestun Red are provide, and use to contribute to a formal definition of the Cambalan Ceramic Sphere. These petrographic observations show that the detrital components were rhyolite fragments, vitroclastic tuffs, pumice, shards of glass, quartzes, plagioclase, calcite, hematite, magnetite and other minor contributors. The clay matrix is phyllomorphic, with a parallel, rectilinear fabric of fine grains. granulometricaly, the detrital components have been characterized as fine to medium sands. The pastes pastes present evidence of diagenetic processes, most notably porosity in the primary ceramic matrix. These space are in some cases filled by secondary calcite deposits. Evidence of manufacturing was also observed, such as the fracture and bending of the paste that took place to produce the rims of these ceramic objects. (author) [es

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

NARCIS (Netherlands)

Val-Laillet, David; Besson, M.; Guérin, S.; Coquery, N.; Randuineau, G.; Kanzari, A.; Quesnel, H.; Bonhomme, N.; Bolhuis, J.E.; Kemp, B.; Blat, S.; Huërou-Luron, Le I.; Clouard, C.M.

2017-01-01

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 (SD) vs.

Seasonal abundance of crustaceans associated with artisanal fishery of blue crab (Callinectes sapidus) in Sisal, Yucatan, Mexico

OpenAIRE

Celis-Sánchez, José Alfredo; Estrella-Canto, Arely de Jesús; Poot-López, Gaspar Román; González-Salas, Carlos; López-Rocha, Jorge Alberto

2014-01-01

Seasonal abundance and selectivity of the main crustacean species associated with blue crab fishing was studied at the port of Sisal, Yucatan, Mexico. For this purpose, 52 crab traps were used, which were divided into four parallel transects placed 100, 150, 200 and 250 m of the shoreline. Each transect consisted of 13 traps 20 m from each other. Traps were set at dusk and checked at dawn, standardizing the fishing effort to 17 hours/trap/day. A total of 832 organisms from eight species were ...

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

Science.gov (United States)

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.

Merida and Integrated Strategic Solutions

Science.gov (United States)

2011-10-28

organization), are primarily responsible for the concentration of crime in the three northern Mexican states of Chihuahua , Sinaloa and Baja and control...creation of fifteen Module Police Units (MPUs) in the Mexican States of Nuevo Leon, Chihuahua , and Tamaulipas.lvii These MPUs have approximately 422

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

Science.gov (United States)

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 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.

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

Science.gov (United States)

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.

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

Directory of Open Access Journals (Sweden)

Gaspar PENICHE-LARA

2016-01-01

Full Text Available 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.

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

Science.gov (United States)

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.

Science.gov (United States)

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...

Prevalencia y factores de riesgo en Yucatán, México, para litiasis urinaria Urolithiasis prevalence and risk factors in Yucatan, Mexico

Directory of Open Access Journals (Sweden)

Martha Medina-Escobedo

2002-11-01

Full Text Available Objetivo. Determinar la prevalencia de urolitiasis en el estado de Yucatán, México, y una posible asociación de ésta con antecedentes familiares de la enfermedad y la dureza del agua. Material y métodos. Durante 1996 se efectuó una encuesta transversal en población abierta mayor de un año de edad, del estado de Yucatán. Los sujetos se clasificaron como litiasis definitiva (LD, litiasis probable (LP y sin litiasis (SL. Se determinó dureza total, dureza de calcio y dureza de magnesio a las muestras de agua empleadas para el consumo humano. Se emplearon ji cuadrada y t de student para comparación de medias de muestras independientes en el análisis. Resultados. De un total de 5 832 encuestas, 323 sujetos (5.5% se catalogaron como LD, y 282 (4.8% como LP. La prevalencia de litiasis se incrementó con la edad, partiendo de 1% en población de 18 años o menor, hasta 11.3% en los mayores de 50. El 44% del grupo LD y 34% del LP tuvieron antecedente familiar de urolitiasis, comparado con 28% del grupo SL (pObjective. To measure the prevalence of urolithiasis in Yucatan, and to establish a possible association of the disease with family history and water hardness. Material and Methods. During 1996, a survey was conducted on the population over one year of age in the State of Yucatan. Subjects were classified as having definite lithiasis (DL, probable lithiasis (PL, or no lithiasis (NL. Total hardness, calcium hardness, and magnesium hardness, were determined in drinking water samples. Results. From a total of 5 832 questionnaires, 323 subjects (5.5% were found to have DL, and 282 (4.8% PL. The prevalence of lithiasis increased sharply with age, ranging from 1% in the population 18 years or younger, to 11.3% in those over 50 years. A family history of urolithiasis was positive in 44% of subjects with DL and in 34 % of those with PL, compared to 28% of those with NL (OR=2.8, 95% CI=2.2-3.4, p<0.0001, and OR=1.8, 95% CI=1.4-2.4, p<0

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

Science.gov (United States)

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

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

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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.

In vitro culture and characterization of putative porcine embryonic germ cells derived from domestic breeds and yucatan mini pig embryos at days 20-24 of gestation

DEFF Research Database (Denmark)

Petkov, Stoyan Gueorguiev; Marks, Hendrik; Klein, Tino

2011-01-01

Embryonic germ cells (EGC) are cultured pluripotent cells derived from primordial germ cells (PGC). This study explored the possibility of establishing porcine EGC from domestic breeds and Yucatan mini pigs using embryos at Days 17-24 of gestation. In vitro culture of PGC from both pooled...

Groundwater-flow modeling in the Yucatan karstic aquifer, Mexico

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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

Presence of Toxoplasma gondii in Drinking Water from an Endemic Region in Southern Mexico.

Science.gov (United States)

Hernandez-Cortazar, Ivonne B; Acosta-Viana, Karla Y; Guzman-Marin, Eugenia; Ortega-Pacheco, Antonio; Segura-Correa, Jose C; Jimenez-Coello, Matilde

2017-05-01

Toxoplasmosis can be acquired through the ingestion of contaminated drinking water with oocysts of Toxoplasma gondii, highly resistant to the routinely disinfection processes; based on chlorination commonly used in the water supply industry. The aim of this study was to determine the presence of T. gondii DNA in samples of public drinking water from an endemic region of southern Mexico. In total 74 samples of water (5 L each) were collected from the three well fields (I, II, and III) and 71 independent wells, distributing public drinking water to the city of Merida Yucatan, after passing through the chlorination process. Water samples were filtered and concentrated by a sucrose solution, then DNA was extracted and evaluated through a nested-PCR (nPCR) specific for T. gondii. Positive samples were detected in 5.4% (4/74) of the water samples. This is the first report of the presence of T. gondii DNA in public drinking water from a large city in southern Mexico, where their consumption without any postpurification treatment could pose a risk for acquiring the infection in the urban population.

Climate and cultural history of the Northeastern Yucatan Peninsula, Quintana Roo, Mexico

Energy Technology Data Exchange (ETDEWEB)

Hodell, D.A. [Department of Geological Sciences, University of Florida, 241 Williamson Hall, P.O. Box 112120, Gainesville, FL 32611 (United States); Brenner, M.; Curtis, J.H. [Land Use and Environmental Change Institute (LUECI), University of Florida, Gainesville, FL (United States)

2007-07-15

We inferred the Holocene paleoclimate history of the northeastern Yucatan Peninsula, Mexico, by studying stratigraphic variations in stable isotopes (d 18O and d 13C) and lithologic properties (organic matter and carbonate content) in sediment cores taken in 6.3 and 16.2 m of water from Lake Punta Laguna. We present a simple model to explain the lithologic and isotopic variations, and discuss the inferred paleoclimate history in terms of its relation to ancient Maya cultural development. We find evidence for lower lake level and drier climate at about the same time as each major discontinuity in Maya cultural history: Preclassic Abandonment (150-250 A.D.), Maya Hiatus (534 to 593 A.D.), Terminal Classic Collapse (750-1050 A.D.), and Postclassic Abandonment (mid-fifteenth century). Although these broad temporal correlations suggest climate played a role in Maya cultural evolution, chronological uncertainties preclude a detailed analysis of climate changes and archaeologically documented cultural transformations.

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

Science.gov (United States)

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

Shaded Relief with Height as Color, Yucatan Peninsula, Mexico

Science.gov (United States)

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 image: 1.5 m

Price, Virtues, Principles: How to Discern What Inspires Best Practices in Water Management? A Case Study about Small Farmers in the Yucatan Peninsula of Mexico

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Rafael R. Ramírez

2016-04-01

Full Text Available Improving water practices among small farmers in a water scarce area like the Yucatan Peninsula in Mexico is a complex task. Despite government attempts to enforce regulations and question the possibility of adjusting prices, the misuse of this scarce resource continues. Most farmers are, at best, motivated to aim for a minimum level of compliance, with very few striving to engage in best practices. This article seeks to make a proposal about the best drivers for inspiring best practices in an effort to improve the use of water management in the area. It proposes that a virtue ethics approach that explicitly focuses on the cultivation of an attitude of respect for water founded on three key principles (participation, hydrosolidarity and proactive engagement is the best solution for Yucatan. This hypothesis is the result of developing a singular methodology based on Partial Least Squares (PLS, according to structural equation modeling (SEM, that could be replicated anywhere to ascertain which measures are best suited in a particular context. Using a small sample size, this research ascertains what is required to achieve best practices with regards to the management of water in that particular area.

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

Science.gov (United States)

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

Climate Change Scenarios in the Yucatan Peninsula to the year 2020

Science.gov (United States)

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

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

Science.gov (United States)

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.

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.

Science.gov (United States)

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.

Science.gov (United States)

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.

Science.gov (United States)

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.

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

Science.gov (United States)

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

Science.gov (United States)

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

Microbial deterioration of Mayan stone buildings at Uxmal, Yucatan, Mexico

International Nuclear Information System (INIS)

Ortega-Morales, O.; Guezennec, J.; Hernandez D, G.; Jozsa, P.; Sand, W.; Crassous, P.

1998-01-01

The microbial communities associated to Uxmal Mayan monuments (Yucatan, Mexico) and their role in stone deterioration were preliminary characterized by chemical, biochemical, microbiological, microscopical and surface analysis methods under two climatic seasons (1997). The organic matter and organic carbon and nitrogen were in the range of those reported for other stone buildings, indicating that oligo trophic conditions prevail at Uxmal. Quantitative differences in microbial biomass was higher at indoor section were the organic matter content was the highest and micro-environmental conditions (availability of water and protection to direct sunlight) are more suitable for microbial growth. The microbiological analysis underestimated the microbial biomass, as revealed by biochemical approaches. Nitrate and nitrite-oxidizing, metilotrophic and heterotrophic bacteria and fungi were detected in most surfaces. The heterotrophic bacteria were the most abundant microbial group (microbiological data). However, the chlorophyll profiles and Scanning Electron Microscopy showed that the microalgae are the most abundant colonizers in Uxmal stone buildings. EDAX analysis showed that the most surfaces were covered by an organic layer (cells and exo polymers). Gypsum was found in few samples. The large photo trophic biomass seems to play a role in stone bio deterioration by supporting growth of heterotrophic microorganisms (bacteria and fungi) which are known to produce organic acids leading to calcite dissolution and cations chelation. Further studies are being carried out in order to determine the role of exo polysaccharides which are thought to play a role in chemical degradation of limestone substrates in Uxmal. (Author)

Occurrence of Sciadicleithrum mexicanum Kritsky, Vidal-Martinez et Rodríguez-Canul, 1994 (Monogenea: Dactylogyridae) in the Cichlid Cichlasoma urophthalmus from a flooded quarry in Yucatan, Mexico

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Mendoza-Franco,E. F.; Vidal-Martínez,V.; Simá-Álvarez,R.; Rodríguez-Canul,R.; Vivas-Rodríguez,C.; Scholz,T.

1995-01-01

Cichlids, Cichlasoma urophthalmus, collected in a flooded quarry in the Yucatan Peninsula, Mexico, from January through June 1992, had high levels of infection with the ancyrocephaline Sciadicleithrum mexicanum (Monogena: Dactylogyridade) in all montlhly samples. Neither occurrence nor maturation of the worms eshibited any pronounced monthly fluctuation. The infection rate was found to be sizedependent, greater in longer fish. The worms occurred on primary lamellae of gill filaments of all ar...

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

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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.

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

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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.

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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.

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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.

Prevalence of the metabolic syndrome, insulin resistance index, leptin and thyroid hormone levels in the general population of Merida (Venezuela).

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Uzcátegui, Euderruh; Valery, Lenin; Uzcátegui, Lilia; Gómez Pérez, Roald; Marquina, David; Baptista, Trino

2015-06-01

The metabolic syndrome (MetSyn) is a significant risk factor for cardiovascular events, but scarce information exists about its frequency in Venezuela. In this cross-sectional study, we quantified the prevalence of the MetSyn in a probabilistic, stratified sample of 274 subjects aged > or =18 years from the Libertador district in Merida, Venezuela. Secondary outcomes were the measurement of thyroid hormones (free T4 and TSH), leptin levels, and insulin resistance index (HOMA2-IR). The frequency of MetSyn (percentage +/- 95% confidence interval) according to several diagnostic criteria was as follows: National Cholesterol Education Panel (NCEP, original): 27.4% (22.1-32.7); modified NCEP: 31.8% (26.3-37.3); International Diabetes Federation: 40.9% (35.1-46.7); Latin American Diabetes Association: 27% (21.7-32.3), and Venezuelan criteria: 31.8% (26.3-37.3). The MetSyn was more frequent in males than in females with most diagnostic criteria. The estimated prevalence of type 2 diabetes mellitus was 2.9% either according to the patients' self reports or to fasting glucose level found to be above 126 mg/dL. Abnormal HOMA2-IR index, free T4 and TSH (above the 95th percentile) were detected in 4.5%, 4.4% and 5.1% of the sample, respectively. Free T4 and TSH levels below the 5th percentile were detected in 4.4% and 4.7% of subjects respectively. These values are presented for comparisons with forthcoming studies in specific clinical populations. While studies are being conducted about the different definitions of the MetSyn in Venezuela, we recommend analyzing and publishing local research data with all the available criteria so as to allow comparisons with the results already reported in the literature.

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

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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

The United Nations Convention against Corruption. A Primer for Development Practitioners

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Schultz, Jessica

2007-01-01

The United Nations Convention against Corruption (UNCAC), adopted in Merida, Mexico in 2003, represents a remarkable achievement for international anti-corruption efforts. With endorsements from more than 140 state signatories representing every region of the world, the UNCAC offers a comprehensive, global framework for combating corruption.

Apicultura y organizaciones de apicultores entre los mayas de Yucatán Beekeeping and Apicultural Organizations Among the Mayas of Yucatan

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Margarita Rosales González

2010-01-01

Full Text Available En las comunidades mayas la apicultura continúa siendo una actividad relevante pero complementaria, cuya lógica y condiciones de producción se contraponen a las nuevas normas del mercado internacional. La integración de organizaciones apícolas se considera una estrategia para la "modernización" de la apicultura y la comercialización de la miel en mejores condiciones. Este trabajo se refiere al sentido que tanto la apicultura como estas organizaciones tienen para sus integrantes, a sus expectativas, intereses, aprendizajes y a la forma en que se relacionan con instituciones y agentes externos. El escrito se basa en entrevistas y observaciones realizadas en 12 organizaciones apícolas durante 2005 y 2006 en el marco del proyecto de investigación del centro INAH Yucatán "Organizaciones indígenas y procesos de desarrollo en comunidades mayas del sur de Yucatán".In Mayan communities, beekeeping continues to be an important but complementary activity, whose logic and conditions of production are opposed to the new norms of the international market. The integration of apicultural organizations is considered as a strategy for the "modernization" of beekeeping and the commercialization of the honey in better quality. The present research deals with the meaning that beekeeping has for the members of such organizations, and it explores the expectations, interests and training processes of the members, analyzing finally how are the relationships between these organizations and external agents and institutions. The research is based on interviews and observations made in 12 apicultural organizations between 2005 and 2006, as part of the research project of the INAH Regional Center Yucatan, entitled "Indigenous Organizations and Processes of Development in Mayan Communities in Southern Yucatan".

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

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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.

Effects of Trichoderma harzianum Rifai over Plasmodiophora brassicae Woronin in broccoli, in Escagüey, municipality of Rangel, Mérida state

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Mirna Labrador Morales

2014-04-01

Full Text Available The effectiveness of Trichoderma harzianum in suppressing clubroot of brassicas, which is caused by Plasmodiophora brassicae, was tested on broccoli (Brassica oleracea var. italica Plenck, in field conditions, in Escagüey, municipality of Rangel, Merida State, Venezuela. The experiment showed that the applications of a biopesticide based on this antagonist had a significant effect on the percentage of health plants and the crop yields, in dependence of the dose used. In addition, the relation benefits/cost was also favorable. These results showed that, for these particular conditions, P. brassicae is an adequate biological alternative to control the clubroot of brassicas, no aggressive to environment and human beings, useful for the transition phase toward a sustainable agriculture, without chemical pesticides.

Effects of Trichoderma harzianum Rifai over Plasmodiophora brassicae Woronin in broccoli, in Escagüey, municipality of Rangel, Mérida State

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Mirna Labrador Morales

2016-03-01

Full Text Available The effectiveness of Trichoderma harzianum in suppressing clubroot of brassicas, which is caused by Plasmodiophora brassicae, was tested on broccoli (Brassica oleracea var. italica Plenck, in field conditions, in Escagüey, municipality of Rangel, Merida State, Venezuela. The experiment showed that the applications of a biopesticide based on this antagonist had a significant effect on the percentage of health plants and the crop yields, in dependence of the dose used. In addition, the relation benefits/cost was also favorable. These results showed that, for these particular conditions, P. brassicae is an adequate biological alternative to control the clubroot of brassicas, no aggressive to environment and human beings, useful for the transition phase toward a sustainable agriculture, without chemical pesticides.

Merida Initiative: Insight Into U.S. Mexico Relations

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2016-09-01

LEGISLATION IN THE UNITED STATES ....................................................................................................33 E. MEXICO AS...United States and Mexico go far beyond sheer geography.” She goes on to say, “Bound by economic, environmental , cultural, familial, security, and...attribute the rise in prevalence of Mexican cartels to U.S. seizures of drugs in the Caribbean, essentially closing this route down and forcing Colombian

Evaluation of depressive symptoms and sleep alterations in college students.

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Moo-Estrella, Jesús; Pérez-Benítez, Hugo; Solís-Rodríguez, Francisco; Arankowsky-Sandoval, Gloria

2005-01-01

Increasing evidence suggests that sleep alterations could favor subsequent depression development. In order to identify the simultaneous occurrence of these parameters in young people, in this work we evaluated the prevalence of depressive symptoms, sleep habits, and possible sleep disturbances in college students. Beck Depression Inventory (BDI), Epworth Sleepiness Scale (ESS), and a Sleep Habits Questionnaire were applied to students registered at the Autonomous University of Yucatan, Merida (mean age 20.2 +/- 2.6 years). The final sample was composed of 340 (53%) women and 298 (47%) men. Reliability of the BDI and ESS was assessed by Cronbach's alpha method. Taking 10 as ESS cut-off point, it was found that 31.6% of the students had a high level of sleepiness. Students with depressive symptoms had a greater number of days with somnolence during class (p students without symptoms. In comparison to subjects without depressive symptoms, students with those symptoms rated their sleep quality as poor (p sleep after going to bed (p sleep alterations in a large proportion of the studied subjects, which were more severe in those who showed depressive symptoms. Educating students for appropriate sleep hygiene and encouraging them to seek professional advice to treat sleep disturbances may be useful to prevent depression.

Never judge an iguana by its spines: Systematics of the Yucatan spiny tailed iguana, Ctenosaura defensor (Cope, 1866).

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Malone, Catherine L; Reynoso, Víctor Hugo; Buckley, Larry

2017-10-01

Spiny tailed iguanas are highly diverse clade of lizards in Mesoamerica, ranging from northern Mexico through Panama. Utilizing 2 regions of mitochondrial DNA (1948bp) and 4 nuclear loci (2232bp) we explored the relationships between these species and the phylogeographic history of the major clades. We discovered that the lineage endemic to the Yucatan Peninsula renders the genus Ctenosaura paraphyletic. To resolve this non-monophyly, we resurrect the taxon Cachryx Cope, 1866, and provide a new diagnosis for the genus. We also find that small body-size and highly spinose tails in the species previously referred to the subgenus Enyaliosaurus, have evolved independently 3 times. Cachryx were recovered as sister to the lineage of iguanines endemic to the Galapagos Islands, and we discuss biogeographic scenarios to explain this relationship as well as those among the primary clades of Ctenosaura in Mesoamerica. Copyright © 2017 Elsevier Inc. All rights reserved.

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

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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.

The Blue-gray Tanager (Thraupis episcopus in the state of Guerrero, Mexico

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Epifanio Blancas-Calva

2017-10-01

Full Text Available We recorded the Blue-gray Tanager (Thraupis episcopus on the southeastern coastal plain of the state of Guerrero, Mexico, in urban areas with cover of scattered trees of native and introduced species. The current range known for this taxon comprises lowlands of eastern Mexico, from south-central Nuevo Leon to the Yucatan peninsula, including eastern Oaxaca and the Pacific slope on the coastal plain of Chiapas. However, there are no published previous records of the species in Guerrero. Possibly T. episcopus is a species that has expanded its range in episodes of active dispersal.

Comparison of small mammal prevalence of Leishmania (Leishmania) mexicana in five foci of cutaneous leishmaniasis in the State of Campeche, Mexico.

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Van Wynsberghe, N R; Canto-Lara, S B; Sosa-Bibiano, E I; Rivero-Cárdenas, N A; Andrade-Narváez, F J

2009-01-01

In the Yucatan Peninsula of Mexico, 95% of the human cases of Cutaneous Leishmaniasis are caused by Leishmania (Leishmania) mexicana with an incidence rate of 5.08 per 100,000 inhabitants. Transmission is limited to the winter months (November to March). One study on wild rodents has incriminated Ototylomys phyllotis and Peromyscus yucatanicus as primary reservoirs of L. (L.) mexicana in the focus of La Libertad, Campeche. In the present study, the prevalence of both infection and disease caused by L. (L.) mexicana in small terrestrial mammals were documented during five transmission seasons (1994-2004) in five foci of Leishmaniasis in the state of Campeche. Foci separated by only 100 km, with similar relative abundances of small mammals, were found to differ significantly in their prevalence of both symptoms and infection. Transmission rates and reservoir species seemed to change in space as well as in time which limited the implementation of effective control measures of the disease even in a small endemic area such as the south of the Yucatan Peninsula.

Health and nutritional status in Mérida, México: A population-based study

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Enrique Efraín Barbosa-Martín

2016-09-01

Full Text Available Introduction: The Health and Nutrition National Survey (ENSANUT reports the panorama of the national and state nutritional epidemiology in Mexico. However, there are no reports of the capital cities of the country. The objective of this report was to evaluate the health and nutritional condition in a sample of the population of Merida, Yucatan, Mexico. Material and Methods: Transversal, retrospective and descriptive study that used the methodological and diagnostic guidelines of ENSANUT, WHO and Official Mexican Standards. To know malnutrition, normal weight and overweight prevalence, hypertension probable cases (CPHA and diabetes mellitus probable cases (CPDM were determined and anthropometric measurements were performed. SPSS 20.0 and Excel 2013 were used to calculate proportions and the results were expressed in prevalence. Results: 4,324 subjects were evaluated (644 pre-school pupils, 1,881 school pupils, 133 adolescents and 1,666 adults. In adults the prevalence of CPHA and CPDM were 11.8% and 10.2%, respectively. For pre-school pupils the prevalence of low weight, emaciation and low height were 0.4%, 0.7% and 2.7%, respectively. For school pupils, adolescents and adults malnutrition prevalence was 3.3%, 2.2% and 1.2% respectively. The prevalence of normal weight and overweight in pre-school pupils, school pupils, adolescents and adults was 54.6%, 45.5%, 48.1%, 20.7% and 16.1%, 51%, 49.5% y 77.9%, respectively. Conclusions: High prevalence of diabetes mellitus probable cases in men and low prevalence of malnutrition in all ages were observed. The prevalence of overweight in pre-school pupils, school pupils and adolescents was higher than the national and estate average.

A Three-Dimensional Sustainability Evaluation of Jatropha Plantations in Yucatan, Mexico

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Julio C. Sacramento Rivero

2016-12-01

Full Text Available This paper presents a unique sustainability analysis of one of the first attempts to establish a biodiesel industry in Mexico. From 2008, several companies established medium to large-sized Jatropha curcas plantations in Yucatan, hiring local peasants to carry out the agricultural work. After five years, the plantations were abandoned due to poor seed yields and a lack of key knowledge for large-scale cultivation. Based on a multidisciplinary approach, we performed a three-dimensional sustainability evaluation of the potential biodiesel production chain, which included household interviews, a socioeconomic survey, and a life-cycle assessment (LCA. We identified both negative and positive effects in the three dimensions analyzed. Socially and culturally, the local peasant families understood sustainability as their ability to preserve their traditional lifestyle, and associated environmental services with their sense of identity. They therefore considered the jatropha plantations to be positive for sustainability, since they brought income, even though some perceived damage to the natural resources of the surrounding areas. Economically, peasants’ annual household income increased by approximately $1080 USD due to the increased salaries paid by the jatropha companies. The LCA predicted large savings of greenhouse gas emissions (>50% compared to fossil diesel, but also potential negative impacts in some categories (human/ecological toxicity and eutrophication potentials associated with the use of mineral fertilizers, insecticides, and pesticides applied during the cultivation stage. Biodiesel production would be potentially energetically self-sufficient, in addition to producing a 40% energy surplus. Finally, even though the sustainability indicators suggested a positive overall assessment, the reality was that the jatropha projects failed because they were predicated on unrealistically optimistic projections and poor agronomic knowledge of the

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

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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.

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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.

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

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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.

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

Science.gov (United States)

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 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.

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

Science.gov (United States)

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.

Use of enzyme linked immunosorbent assay (ELISA) for the diagnosis of brucellosis in cattle in Yucatan, Mexico

International Nuclear Information System (INIS)

Dajer, A.; Gutierrez, E.; Zapata, D.

1998-01-01

Sera (247) from non-vaccinated brucellosis negative herds, 328 negative sera from Brucella abortus strain 19 vaccinated herds (brucellosis free), and 95 sera positive to the Rose Bengal test (RBT) and Complement Fixation test (CFT) from Brucella abortus-infected herds, were used to determine the relative sensitivity and specificity of a FAO/IAEA I-ELISA kit and the Rivanol Agglutination Test (RAT), using the CFT as a 'gold standard'. A threshold value for the I-ELISA was determined to be 37 PP using the mean plus 3 standard deviations of the negative sera from vaccinated animals. The I-ELISA showed a high relative sensitivity (100%) and a good relative specificity (92.5%), using the threshold determined for local conditions. The RAT gave a lower sensitivity value than the CFT (97.8%) and good specificity (99.3%). The I-ELISA could be used as a screening test under Yucatan conditions or as a confirmatory test in places where vaccination is not carried out. The RAT lacks sensitivity and is therefore not recommended for use in final stages of eradication programs but could be used in control programmes or early stages of eradication campaigns as a confirmatory test. (author)

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

Science.gov (United States)

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.

Resistance of Mayan Women against Obstetric Violence

OpenAIRE

Gonzalez-Flores, Marina

2015-01-01

Mayan women are often victims of obstetric violence in the Yucatan Peninsula. Obstetric violence is defined as violence women experience by health officials or midwives during birth. This article will examine five different communities within the states of Yucatan, Campeche, and Quintana Roo in Mexico and compare and contrast activism efforts against obstetric violence among Mayan women. Mayan women are organizing to create unions for midwives, workshops on reproductive rights and health care...

An optical laser device for mapping 3D geometry of underwater karst structures: first tests in the Ox BelHa system, Yucatan, Mexico; Un dispositivo laser optico para la cartografia 3D de la geometria de estructuras karsticas submarinas: primeros resultados en el sistema de Ox BelHa, Yucatan, Mexico

Energy Technology Data Exchange (ETDEWEB)

Schiller, A.; Renard, P.

2016-07-01

In the course of extended hydrological studies in the coastal Karst plain of Yucatan, near the town of Tulum amongst others, a novel laser scanning device was developed and applied for the acquisition of the 3d-geometry of ground water conduits. The method is derived from similar industrial systems and for the first time adapted to the specific measurement conditions in underwater cave systems. The device projects a laser line over the whole perimeter at a certain position. This line represents the intersection of a plane with the cave walls. The line is imaged with a wide angle camera system. Through proper design and calibration of the device it is possible to derive the true scale geometry of the perimeter via special image processing techniques. By acquiring regularly spaced images it is possible to reconstruct the true scale and 3 d-shape of a tunnel through the incorporation of location and attitude data. In a first test in the Ox Bel Ha under-water cave system, about 800 metres of tunnels have been scanned down to water depths of 20 metres. The raw data is further interpolated using the ODSIM-algorithm in order to delineate the 3D geometry of the cave system. The method provides easy, operable acquisition of the 3-D geometry of caves in clear water with superior resolution and speed and significantly facilitates the measurement in underwater tunnels as well as in dry tunnels. The data gathered represents crucial input to the study of the state, dynamics and genesis of the complex karst water regime. (Author)

Uranium exploration in Venezuela: Situation at the end of 1978

International Nuclear Information System (INIS)

Pasquali, J.

1981-01-01

Uranium exploration started in Venezuela in 1951. The activities began with enthusiasm but interest waned because of the unfavourable economic conditions of the uranium market. In 1975, with the establishment of the National Council for the Development of the Nuclear Industry, emphasis was once again placed on exploration for radioactive minerals. Systematic exploration began 18 months ago, and so far exploratory targets have been found in phosphate rocks in Tachira state and in Palaeozoic granites at El Baul (Cojedes state); very favourable occurrences have been encountered in the Precambrian in Merida and Bolivar states, and in continental Tertiary rocks in Trujillo state. (author)

Characterization of constitutive materials and technology of the mural painting of the acropolis of the archaeological zone of Ek Balam, Yucatan, Mexico; Caracterizacion de materiales constitutivos y tecnologia de la pintura mural de la acropolis de la zona arquelogica de Ek Balam, Yucatan, Mexico

Energy Technology Data Exchange (ETDEWEB)

Alonso O, A.; Vazquez N, J.; Ruiz M, C. [INAH, 11000 Mexico D.F. (Mexico); Mendoza A, D.; Espinosa P, M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Ruvalcaba, J.L. [IFUNAM, 04510 Mexico D.F. (Mexico); Vandenabeele, P. [Universidad de Ghent, Belgica (Belgium)]. e-mail: alealonsolvera@yahoo.com

2005-07-01

The conservation project of Ek'Balam is one of the few experiences of systematic conservation applied in an archaeological Maya site at the Yucatan Peninsula in Mexico. The project started in the year 2001 when important stone, stucco and painting decorations were discovered during archaeological excavations. Being a recently discovered site, the conservation program includes a research program based on particular conservation issues detected as potential risk of archaeological data losses. One of the research topics is based on deter- mining the ancient painting technology used in mural and stucco decorations through the characterization of building and decorative composite materials. Archaeometric techniques have been used to fulfil the proposed goal. Raman, X-ray Fluorescence, Light and Electron Microscopy were practiced on a set of 35 wall painting samples. Preliminary results obtained on pigments characterization have partially revealed general features of wall painting technique at Ek'Balam during the late Classic period. Some particular pigments, not reported ever for mural paintings, have been identified in Ek'Balam samples. (Author)

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

Directory of Open Access Journals (Sweden)

Eric Dumonteil

Full Text Available 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.

U.S. Coast Guard Addendum to the United States National Search and Rescue Supplement (NSS) to the International Aeronautical and Maritime Search and Rescue Manual (IAMSAR)

Science.gov (United States)

2009-09-01

Oaxaca (7) U.S. Consulates (C) and Consulates General (CG) in Mexico: Ciudad Juarez (CG) Matamoros (C) Nogales (C) Guadalajara (CG) Merida (C) Nuevo...recommendations should always be carefully reviewed for practicality and sensibility . 3 - 7 COMDTINST M16130.2E Section 3.2 Search Planning...in some sensible pattern. The number of corner points will be determined by the number of SLDMBs readily available, and the shape and disposition of

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

Science.gov (United States)

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.

Development and Calibration of a Model for the Determination of Hurricane Wind Speed Field at the Peninsula of Yucatan

Directory of Open Access Journals (Sweden)

L.E. Fernández–Baqueiro

2009-01-01

Full Text Available In this work a model to calculate the wind speed field produced by hurricanes that hit the Yucatan Peninsula is developed. The model variables are calculated using equations recently developed, that include new advances in meteorology. The steps in the model are described and implemented in a computer program to systematize and facilitate the use of this model. The model and the program are calibrated using two data bases; the first one includes trajectories and maximum wind velocities of hurricanes; the second one includes records of wind velocities obtained from the Automatic Meteorology Stations of the National Meteorology Service. The hurricane wind velocity field is calculated using the model and information of the first data base. The model results are compared with field data from the second data base. The model is calibrated adjusting the Holland's pressure radial profile parameter B; this is carried out for three hurricane records: Isidore, Emily and Wilma. It is concluded that a value of B of 1.3 adjusts globally the three hurricane records and that the developed model is capable of reproducing satisfactorily the wind velocity records.

PREVALENCE AND RISK FACTORS ASSOCIATED WITH THE PRRS VIRUS IN SEMEN OF BOARS IN PIG FARMS OF YUCATAN

Directory of Open Access Journals (Sweden)

Aremi Jordan-Craviotto

2009-07-01

Full Text Available The objectives of the present study were to estimate the prevalence of and to determine the risk factors associated with the porcine reproductive and respiratory syndrome virus (PRRSV, American strain in semen of boars in pig herds of Yucatan, Mexico. Ninety two boars from 26 herds were ejaculated once. Semen samples were processed by the RT-nPCR test using the ORF7 primer to detect the PRRS virus. The true prevalence estimated was 10.1% (95% CI = 4.1-16.1%. Significance of risk factors was determined by Fisher-exact test. The odds of detecting genetic material of the PRRSV was greater (OR = 9.2 in semen of boars used under natural mating than those used in artificial insemination. In herds where boar’s acclimatization was not practiced the odds of a positive boar was 4.3. Another risk factor (P < 0.05 was the origin of the animals. In conclusion, the prevalence of the PRRSV in boar semen was smaller to the notified in the literature and determinate in blood serum. Management practices, such as the use of the artificial insemination and acclimatization of the boar, could be useful in reducing the prevalence of the PRRS virus in the pig farms.

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

Science.gov (United States)

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.

Obesidad, morfología corporal y presión arterial en grupos urbanos y rurales de Yucatán Obesity, body morphology, and blood pressure in urban and rural population groups of Yucatan

Directory of Open Access Journals (Sweden)

Pedro Arroyo

2007-08-01

Full Text Available OBJETIVO: Caracterizar la antropometría y presión arterial de adultos del estado de Yucatán, México. MATERIAL Y MÉTODOS: Se evaluaron diferencias rural-urbanas por grupos sexo-edad en peso, talla, circunferencias de cintura y cadera, y presión arterial en 313 adultos de origen urbano y 271 del rural, de Yucatán. RESULTADOS: No hubo diferencias rural-urbanas en prevalencias de obesidad y sobrepeso, y en hipertensión los urbanos tuvieron valores marginalmente mayores. Se encontró mayor prevalencia rural de cintura anormal sólo en mujeres y hombres jóvenes. La comparación con dos encuestas nacionales y una regional (mixtecos rurales mostró obesidad similar a la notificada en la Encuesta Nacional de Salud 2000 (ENSA y mayor que mixtecos y la informada en la Encuesta Nacional de Enfermedades Crónicas 1993 (ENEC. La prevalencia de cintura anormal fue intermedia entre la indicada en la Encuesta Nacional de Salud y Nutrición 2006 (ENSANUT y mixtecos, y la de hipertensión intermedia entre la notificada en la ENEC y mixtecos. CONCLUSIONES: Las poblaciones maya y mestiza de Yucatán presentaron alta prevalencia de obesidad y cintura anormal que no se acompañaron de prevalencia mayor de hipertensión. Esta observación requiere confirmación.OBJECTIVE: To characterize body morphology and blood pressure of adults of the Mexican state of Yucatan. MATERIAL AND METHODS: Rural-urban differences in weight, height, waist, and hip circumferences, and blood pressure were analyzed in 313 urban and 271 rural subjects. RESULTS: 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

Characterization of constitutive materials and technology of the mural painting of the acropolis of the archaeological zone of Ek Balam, Yucatan, Mexico

International Nuclear Information System (INIS)

Alonso O, A.; Vazquez N, J.; Ruiz M, C.; Mendoza A, D.; Espinosa P, M.; Ruvalcaba, J.L.; Vandenabeele, P.

2005-01-01

The conservation project of Ek'Balam is one of the few experiences of systematic conservation applied in an archaeological Maya site at the Yucatan Peninsula in Mexico. The project started in the year 2001 when important stone, stucco and painting decorations were discovered during archaeological excavations. Being a recently discovered site, the conservation program includes a research program based on particular conservation issues detected as potential risk of archaeological data losses. One of the research topics is based on deter- mining the ancient painting technology used in mural and stucco decorations through the characterization of building and decorative composite materials. Archaeometric techniques have been used to fulfil the proposed goal. Raman, X-ray Fluorescence, Light and Electron Microscopy were practiced on a set of 35 wall painting samples. Preliminary results obtained on pigments characterization have partially revealed general features of wall painting technique at Ek'Balam during the late Classic period. Some particular pigments, not reported ever for mural paintings, have been identified in Ek'Balam samples. (Author)

Representación gráfica del riesgo de mortalidad neonatal en un centro perinatal regional en Mérida, Yucatán, México The graphical display of neonatal mortality risk at a regional perinatal center in Merida, Yucatan, Mexico: The joint effect of birth weight and gestational age

Directory of Open Access Journals (Sweden)

Lorenzo Osorno-Covarrubias

2002-07-01

Full Text Available Objetivo. Determinar el riesgo de mortalidad neonatal por edad gestacional y el peso al nacer. Material y métodos. Se estudió una cohorte de 19 668 neonatos que egresaron entre el 1 de enero de 1995 y el 31 de octubre de 1999 del Centro Médico Nacional Ignacio García Téllez, del tercer nivel de atención perinatal del Instituto Mexicano del Seguro Social de la Península de Yucatán. Se registraron el peso al nacer, edad gestacional y condición de egreso. Se calculó el riesgo absoluto (RA de mortalidad para cada semana de edad gestacional y grupo de peso. Resultados. El RA de mortalidad observado en neonatos de entre 34 a 44 semanas y peso mayor o igual a 2 250 g fue de 0.4%, de 15% para aquellos de entre 26 a 32 semanas con peso mayor o igual a 1000 g, y de 73% para los de entre las 26 a las 34 semanas, con peso al nacimiento de entre 750 y 1 000 g. Conclusione. El RA de mortalidad neonatal aumentó a menor. edad gestacional y peso. Los datos pueden ser utilizados como valores de referencia para nuestro hospital y para comparación con otros hospitales.Objective. To determine the neonatal mortality risk according to gestational age and birth weight. Material and Methods. The cohort consisted of 19 668 newborns of Centro Médico Nacional (National Medical Center Ignacio García Téllez, a tertiary level healthcare institution of the Instituto Mexicano del Seguro Social (Mexican Institute of Social Security, IMSS of the Yucatan Peninsula. All new-borns discharged from the hospital between January 1 st , 1995 and October 31 st , 1999 were included in the study. Birth weight, gestational age, and conditions upon discharge were recorded. Absolute risk (AR of mortality was calculated for each week-of-gestation- and birth group. Results. Observed AR in newborns 34 to 44 weeks of gestational age and weighing at least 2 250 g was 0.4, while that for those 26 to 32 weeks of gestational age and weighing between 1000 g was 15%. Conclusions. AR of

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

Science.gov (United States)

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.

Interaction of landscape varibles on the potential geographical distribution of parrots in the Yucatan Peninsula, Mexico

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Plasencia–Vázquez, A. H.

2014-12-01

Full Text Available The loss, degradation, and fragmentation of forested areas are endangering parrot populations. In this study, we determined the influence of fragmentation in relation to vegetation cover, land use, and spatial configuration of fragments on the potential geographical distribution patterns of parrots in the Yucatan Peninsula, Mexico. We used the potential geographical distribution for eight parrot species, considering the recently published maps obtained with the maximum entropy algorithm, and we incorporated the probability distribution for each species. We calculated 71 metrics/variables that evaluate forest fragmentation, spatial configuration of fragments, the ratio occupied by vegetation, and the land use in 100 plots of approximately 29 km², randomly distributed within the presence and absence areas predicted for each species. We also considered the relationship between environmental variables and the distribution probability of species. We used a partial least squares regression to explore patterns between the variables used and the potential distribution models. None of the environmental variables analyzed alone determined the presence/absence or the probability distribution of parrots in the Peninsula. We found that for the eight species, either due to the presence/absence or the probability distribution, the most important explanatory variables were the interaction among three variables, particularly the interactions among the total forest area, the total edge, and the tropical semi–evergreen medium– height forest. Habitat fragmentation influenced the potential geographical distribution of these species in terms of the characteristics of other environmental factors that are expressed together with the geographical division, such as the different vegetation cover ratio and land uses in deforested areas.

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

Science.gov (United States)

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.

Occurrence of Sciadicleithrum mexicanum Kritsky, Vidal-Martinez et Rodríguez-Canul, 1994 (Monogenea: Dactylogyridae in the Cichlid Cichlasoma urophthalmus from a flooded quarry in Yucatan, Mexico

Directory of Open Access Journals (Sweden)

E. F. Mendoza-Franco

1995-06-01

Full Text Available Cichlids, Cichlasoma urophthalmus, collected in a flooded quarry in the Yucatan Peninsula, Mexico, from January through June 1992, had high levels of infection with the ancyrocephaline Sciadicleithrum mexicanum (Monogena: Dactylogyridade in all montlhly samples. Neither occurrence nor maturation of the worms eshibited any pronounced monthly fluctuation. The infection rate was found to be sizedependent, greater in longer fish. The worms occurred on primary lamellae of gill filaments of all arches, with lower numbers of parasites attached to the fourth gill arch. Otherwise, there was no significant site preference of worms. Only minor histopathological changes were found at the sites of attachment, and these were restricted to the epithelial cells of the primary lamellae of thegill filaments. The lack of seasonal periodicity in this tropical monogenean is compared to seasonal cycles typical of temperate species.

77 FR 58088 - Submission for OMB Review; Comment Request

Science.gov (United States)

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...

U.S.-Mexican Security Cooperation: the Merida Initiative and Beyond

Science.gov (United States)

2010-08-16

2010, those funds had yet to be transferred from the State Department to USAID for implementation. 71 “Cárteles Perturban al Sistema Carcelario,” El...Quejas a Web .” Milenio. July 28, 2010. U.S.-Mexican Security Cooperation: the Mérida Initiative and Beyond Congressional Research Service 27

Geosciences Information for Teachers (GIFT) Workshops held in Conjunction with Alexander von Humboldt (AvH) EGU Conferences

Science.gov (United States)

Laj, Carlo; Cifelli, Francesca

2015-04-01

The Alexander von Humboldt Conference Series of the European Geosciences Union are a series of meetings held outside of Europe, in particular in South America, Africa or Asia, on selected topics of geosciences with a socio-economic impact for regions on these continents, jointly organised with the scientists and their institutes and the institutions of these regions. Given the increasing success of the GIFT workshops held in conjunction with the General Assemblies, since 2010 EGU has also developed a series of GIFT workshops held in conjunction with AvH conferences. Associated GIFT workshops were held in Merida, Yucatan, on the theme of Climate Change, Natural Hazards and Societies (March 2010), then in Penang, Malaysia (June 2011) on the theme of Ocean Acidification, in November 2012 in Cusco (Peru) on the theme of Natural Disasters, Global Change and the Preservation of World Heritage Sites, finally in Istanbul (March 2014) on "High Impact Natural Hazards Related to the Euro-Mediterranean Region. The next GIFT workshop is already planned for October 2015 in Adis Ababa (Ethiopia) on the theme "Water". In each case, the GIFT workshop was held on the last two days of the AvH conference and reunited 40-45 teachers from the nation where the AvH was held. Keynote speakers from AvH were speakers to the GIFT workshops which also included hands-on activities animated by sciences educators. These GIFT workshops represented the first workshops specifically aimed at teachers held in the country, and therefore represents a significant Earth Sciences contribution to secondary education in non European countries.

A new species of predaceous midge of the genus Monohelea Kieffer from Mexico (Diptera: Ceratopogonidae).

Science.gov (United States)

Felippe-Bauer, M L; Huerta, H; Bernal, S I

2000-01-01

A description and illustrations of Monohelea maya, new species, based on male and female characteristics are provided. The specimens were collected in the special biosphere Reserves of Ria Lagartos and Ria Celestun, Yucatan State, Mexico.

Merida Initiative and Effectiveness: An Analysis of Supply-Side Policy

Science.gov (United States)

2013-06-01

found in anti-narcotics efforts by the United States to combat “organizations [that] constitute a threat to regional security and to U.S. national...Agreement ( NAFTA ), as well as politically sensitive issues like immigration. The progression of these discussions eventually led to policy changes in... constitution of the MI, leading to its formal approval in 2007. Finally, the chapter provided an overview of the MI’s final structure, including its four

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

Science.gov (United States)

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

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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.

A new species of predaceous midge of the genus Monohelea Kieffer from Mexico (Diptera: Ceratopogonidae

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Maria Luiza Felippe-Bauer

2000-12-01

Full Text Available A description and illustrations of Monohelea maya, new species, based on male and female characteristics are provided. The specimens were collected in the special biosphere Reserves of Ria Lagartos and Ria Celestun, Yucatan State, Mexico.

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

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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

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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...

Kesk-Ameerika võitleb uimastimaffia vastu / Allan Espenberg

Index Scriptorium Estoniae

Espenberg, Allan

2008-01-01

USA parlament andis rohelise tee Merida initsiatiivile, mis näeb ette Mehhikole, Kesk-Ameerika riikidele ja Kariibi maadele organiseeritud kuritegevuse vastu võitlemiseks majanduslikku ja tehnilist abi

Workshop on Singularities in Geometry, Topology, Foliations and Dynamics

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Lê, Dung; Oka, Mutsuo; Snoussi, Jawad

2017-01-01

This book features state-of-the-art research on singularities in geometry, topology, foliations and dynamics and provides an overview of the current state of singularity theory in these settings. Singularity theory is at the crossroad of various branches of mathematics and science in general. In recent years there have been remarkable developments, both in the theory itself and in its relations with other areas. The contributions in this volume originate from the “Workshop on Singularities in Geometry, Topology, Foliations and Dynamics”, held in Merida, Mexico, in December 2014, in celebration of José Seade’s 60th Birthday. It is intended for researchers and graduate students interested in singularity theory and its impact on other fields.

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

Science.gov (United States)

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.

BOVINE RESPIRATORY SYNCYTIAL VIRUS EPIDEMIOLOGY AND RISK FACTORS ON CATTLE HERDS OF CAMPECHE STATE, MEXICO

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Lisandro Alberto Encalada Mena

2016-12-01

Full Text Available High seroprevalence in Yucatan and proximity to the state of Campeche make it necessary to determine the seroprevalence and risk factors of bovine respiratory syncytial virus (VRSB in the state of Campeche, Mexico. Thus the objective of the present work was to determine the seroprevalence and risk factors bovine respiratory syncytial virus (BRSV of the state of Campeche, Mexico. The sampled of 36 cattle herds (842 sera were analyzed by indirect ELISA kit, in the 11 municipalities of Campeche. A survey to obtain risk factors (sex, age of animals, number of animals grazing density, management system, presence of sheep on the farm and access to the roadside was applied and calculated X2 for each variable considered. Of the total number of samples analyzed (842, 273 were positive (32.47%. The prevalence ranges found ranged from 0% to 84%, so in 9 of the herds there were no positive samples, indicating a 75% (27/36 of dispersion of this virus. X2 analysis indicated that all variables were significant and are risk factors regarding with respect to the variable seroprevalence of BRSV. The results indicate a wide circulation of BRSV and we suggest implement recommendations that will enable a lower spread of this virus in the cattle population.

75 FR 49454 - Submission for OMB Review; Comment Request

Science.gov (United States)

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...

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

Science.gov (United States)

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.

Science.gov (United States)

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.

Spinal Cord Swelling and Alterations in Hydrostatic Pressure After Acute Injury

Science.gov (United States)

2016-10-01

management ! of! such! patients.! However,! this! swelling! has! largely! been! neglected! in! SCI,! despite! being! consistently!observed.!!Even!after... management !of!acute!SCI.!As!an!example!of!how!swelling,!increased!intraparenchymal! pressure,! and! its! effects! on! perfusion! are! factored! into! clinical...Yucatan! 22=Jul=15! 2014! 18.5! duraplasty! Completed! 7743! Football ! Yucatan! 22=Jul=15! 3482! 18.5! SCI!only! Completed! 7730! Golf! Yucatan! 29=Jul=15

Reef demise and back-stepping during the last interglacial, northeast Yucatan

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Blanchon, Paul

2010-06-01

The elevation of reefs and coastal deposits during the last Interglaciation (MIS-5e) indicates that sea level reached a highstand of as much as 6 m above the present, but it is uncertain how rapidly this level was attained and how it impacted reef development. To investigate this problem, I made a detailed sedimentological analysis of a well-dated reef from the northeast coast of the stable Yucatan Peninsula. Two linear reef tracts were delineated which are offset and at different elevations. The lower reef tract crops out along northern shore for 575 m and extends from below present mean sea level to +3 m. The reef crest facies consists of large Acropora palmata colonies dispersed within a coral boulder-gravel and is flanked by an A. cervicornis-dominated reef-front and a large area of lagoonal framework formed by coalesced patches of A. cervicornis and Montastraea spp. Constituents in the upper centimetre of the lower tract are heavily encrusted by a cap of crustose corallines and, in places, are levelled by a discontinuous marine-erosion surface. The upper reef tract crops out ~150 m inland up to an elevation of +5.8 m and parallels the southern section of shore for ~400 m. It also consist of an A. palmata-dominated crest facies flanked by reef-front, back-reef and lagoonal frameworks. In this case, however, lagoonal frameworks are dominated by a sediment-tolerant assemblage of branching coralline algae. Also different is the lack of encrustation by corallines, and the infiltration of upper tract facies by beach-derived shell-gravels from regressive shoreface deposits above. These results indicate that the lower reef tract and lagoonal patch-reefs formed at a sea level of +3 m. Final capping by crustose corallines and discontinuous marine erosion indicates that the lower tract was terminated by the complete demise of corals on the crest but only patchy demise in the lagoon. Areas of continuous framework accretion between the lagoonal patch reefs and the upper

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

Science.gov (United States)

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.

Science.gov (United States)

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

Palaeoenvironmental Evolution of Cenote Aktun Ha (Carwash) on the Yucatan Peninsula, Mexico and its Response to Holocene Sea-Level Rise

Science.gov (United States)

Gabriel, J. J.; Reinhardt, E. G.; Peros, M. C.; Davidson, D. E.; van Hengstum, P. J.; Beddows, P. A.

2008-12-01

A 61-cm core was obtained from 4 metres below the water table in Cenote Aktun Ha, on the Yucatan Peninsula, Mexico. The cenote is 8.6 km from the Caribbean coast and its formation and evolution have been largely affected by sea-level change. The base of the core dates to 6940 - 6740 cal yr BP and overlying sediments were deposited rapidly over the subsequent ~200 years. The pollen record shows that the cenote evolved from a marsh dominated by red mangrove (Rhizophora mangle) and fern (Polypodiaceae) to an open-water system. These vegetation changes were controlled by water level and salinity and are thus useful indicators of past sea level. At the base, the d13C isotopic ratios reveal the influence of terrestrial vegetation (-29‰), but shift to more negative values up-core (-33‰), indicating an influence from particulate matter in the flooded cenote pool. Although microfossil populations were nearly absent through most of the core, the microfossil assemblage in the upper 6 cm of the core is dominated by juvenile Ammonia tepida and the thecamoebian genus Centropyxis. These populations indicate open-water conditions in the cenote and a major environmental shift around 6600 cal yr BP, which is related to sea-level rise in the Caribbean basin. These data fit well with previously established sea-level curves for the Caribbean Sea. Our reconstruction of the environmental history of Cenote Aktun Ha helps elucidate the floral and hydrological history of the region, and highlights the utility of cenote sediments for studying the Holocene sea-level history of the Caribbean Sea.

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

Science.gov (United States)

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.

Science.gov (United States)

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.

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

Science.gov (United States)

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…

Copro-necrophagous beetle (Coleoptera: Scarabaeidae diversity in an agroecosystem in Yucatan, Mexico

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Enrique Reyes Novelo

2007-03-01

Full Text Available Scarabaeinae are sensitive to structural habitat changes caused by disturbance. We compared copronecrophagous beetle (Scarabaeinae community structure in three differently managed zones within an agroecosystem of the northern Yucatan Peninsula, Mexico. We placed dung and carrion traps once a month from June 2004 through May 2005. The beetle community included 17 species from the genera Canthon, Canthidium, Deltochilum, Pseudocanthon, Malagoniella, Onthophagus, Phanaeus, Copris, Uroxys, Sisyphus and Ateuchus. The secondary vegetation had a higher beetle diversity than the other two zones. Species richness was highest in the Brosimum alicastrum plantation. The pasture had the lowest species diversity and richness, but exhibited the highest abundance of Scarabaeinae in the dry season. The two zones with extensive tree cover were the most diverse. Roller beetles were dominant over burrower species and small-sized species outnumbered large species. Our data show two important issues: beetle species in the pasture extended their activity to the beginning of the dry season, while abundances dropped in the other, unirrigated zones; and the possibility that the Scarabaeinae living in neotropical forests are opportunistic saprophages and have specialized habits for resources other than dung. The B. alicastrum plantation is beneficial to the entire ranch production system because it functions as a dispersion and development area for stenotopic species limited to tree cover. Rev. Biol. Trop. 55 (1: 83-99. Epub 2007 March. 31.Este estudio describe y compara la estructura de la comunidad de escarabajos copronecrófagos (Scarabaeinae en tres zonas con diferente manejo al interior de un agroecosistema localizado en el norte de la Península de Yucatán. A lo largo de un año de muestreo sistemático se encontraron 17 especies de los géneros Canthon, Canthidium, Deltochilum, Pseudocanthon, Malagoniella, Onthophagus, Phanaeus, Copris, Uroxys, Sisyphus y Ateuchus

Agujeros negros clasicos y cuanticos en teoria de cuerdas

OpenAIRE

Ortin, Tomas

2004-01-01

Introductory lectures on classical and quantum string black holes (supergravity, branes and dualities) given at the VII School "La Hechicera" of Relativity, Fields and Astrophysics, held in the University of Los Andes, Merida (Venezuela) 2001. Fully in Spanish.

Study of the Thermal Behaviour of Water for Residential Use in Tanks of Concrete and Polyethylene in Humid Subtropical Climate

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Diego-Ayala Ulises

2015-09-01

Full Text Available This article presents a comparative study of the thermal behavior of residential water tanks of polyethylene and concrete exposed to the sun over a year in the state of Yucatan. The energy for radiation and their corresponding temperatures in each system were measured. Daily patterns of elevation and reduction of temperature were identified and the amount of energy acquired during the day as well as the heat dissipated overnight were determined, aiming to determine the possibility of using residential water tanks as a source of hot water in residential homes in the Yucatan region. Based on this study it has been found that the periods of the day with hot water temperature for showering with comfort is limited and that, interestingly, both systems show similar temperatures at the bottom of the tanks throughout the year.

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

Science.gov (United States)

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

Science.gov (United States)

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.

Science.gov (United States)

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…

Kakskümmend üheksa / Juhapekka Tukiainen

Index Scriptorium Estoniae

Tukiainen, Juhapekka

2013-01-01

TMi test: 29tollised maastikurattad, hinnaklass 1500 eurot. Bianchi Jab 29.2; Canyon Grand Canyon 8.9 AL 29; Corratec Superbow Team 29; Cube LTD SL 29; Felt Nine 30; Kona Kahuna DL; KTM Ultra Race 29; Merida Big Nine TFS XT Edition

Epidemiology of Streptococcus pneumoniae and Staphylococcus aureus colonization in healthy Venezuelan children

NARCIS (Netherlands)

Quintero, B.; Araque, M.; Gaast-de Jongh, C.E. van der; Escalona, F.; Correa, M.; Morillo-Puente, S.; Vielma, S.; Hermans, P.W.M.

2011-01-01

Streptococcus pneumoniae and Staphylococcus aureus cause significant morbidity and mortality worldwide. We investigated both the colonization and co-colonization characteristics for these pathogens among 250 healthy children from 2 to 5 years of age in Merida, Venezuela, in 2007. The prevalence of

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

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Eduardo Suárez-Morales

2017-04-01

Full Text Available 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.

Crisis in Mexico: Assessing the Merida Initiative and its Impact on Us-Mexican Security

Science.gov (United States)

2009-04-01

strategic narcotics transportation routes in seven Mexican states. 14 The Sinaloa Cartel, headed by Joaquin “El Chapo” Guzman Loera, operates from...Fingerprint Exchange (CAFÉ) that will be linked to the FBI. Two million dollars went to refurbish 65- and 82-foot patrol boats for Costa Rica‟s Coast

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

Science.gov (United States)

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…

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

Science.gov (United States)

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

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

Science.gov (United States)

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.

Science.gov (United States)

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

Intoxicación aguda por plaguicidas Acute poisoning from pesticides

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Jaime Jesús Durán-Nah

2000-02-01

Full Text Available OBJETIVO: Describir la epidemiología de la intoxicación aguda por plaguicidas (IAP en el Hospital General O'Horán de Mérida, Yucatán, México. MATERIAL Y MÉTODOS: Se revisaron los expedientes de 33 pacientes ³ 13 años, tratados en una unidad de cuidados intensivos (UCI, entre 1994 y 1998. Se recopilaron variables demográficas y clínicas relevantes, y se aplicó estadística descriptiva. RESULTADOS: En la población estudiada predominó el sexo masculino (82% del medio rural (70%, y la edad media fue de 34 ± 15.8 años. El intento de suicidio fue causa frecuente de IAP (79%, y en 33% de los casos la intoxicación se produjo por la utilización de organofosforados. La mortalidad fue de 12%. CONCLUSIONES: La IAP fue baja entre los sujetos del medio rural, por lo que los resultados de este estudio parecen no reflejar la realidad del problema. Es importante añadir que los plaguicidas son utilizados con relativa frecuencia para el intento de suicidio.OBJECTIVE: To describe the epidemiologic pattern of acute pesticide poisoning (APP in a general hospital in Merida, Yucatan, Mexico. MATERIAL AND METHODS: From 1994 to 1998, 33 patients 13 years of age or older with diagnosis of APP were studied. Descriptive statistics were used to analyze information. RESULTS: Males were frequently affected (82%, specially those coming from rural areas (60%. The mean age of the group was 34 ± 15.8 years. In 79% of the cases, pesticides were used to commit suicide and 33% of poisoning cases were due to organophospate pesticides. The mortality rate was 12%. CONCLUSIONS: In this small sample, acute poisoning from pesticides in the agricultural setting may be underestimated, since it was less frequent than in the general population. APP was more commonly used by indigent people to commit suicide.

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

Science.gov (United States)

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.

Fishery of the Goliath grouper, Epinephelus itajara (Teleostei: Epinephelidae based on local ecological knowledge and fishery records in Yucatan, Mexico

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Alfonso Aguilar-Perera

2009-09-01

Full Text Available The Goliath grouper, Epinephelus itajara, a large-bodied (~ 2.5 m TL, > 400 kg and critically endangered fish (Epinephelidae, is highly vulnerable to overfishing. Although protected from fishing in many countries, its exploitation in Mexico is unregulated; a situation that puts its populations at risk. Fishery records of E. itajara are scarce, which prevents determination of its fishery status. This work aimed to elucidate the E. itajara fishery in the northern Yucatan Peninsula by 1 analyzing available catch records and 2 interviewing veteran fishermen (local ecological knowledge from two traditional landing sites: Dzilam de Bravo and Puerto Progreso. Historic fishery records from two fishing cooperatives were analyzed in order to elucidate the current situation and offer viable alternatives for conservation and management. Catches have decreased severely. Local knowledge obtained from fishermen represented a very important source of information for reconstructing the fisheries history of this species. Conservation measures that incorporate regional and international regulations on critically endangered fish species are suggested. Rev. Biol. Trop. 57 (3: 557-566. Epub 2009 September 30.La cherna, Epinephelus itajara, un mero (Epinephelidae corpulento (~ 2.5 m TL, > 400 kg y amenazado, es altamente vulnerable a la sobrepesca. Si bien es protegido en varios países, en México su explotación no está regulada; situación que pone a su población en riesgo. Sus registros pesqueros son escasos, lo que impide determinar su condición pesquera. Este trabajo intentó ilustrar la pesquería en el norte de la Península de Yucatán usando procedimientos que involucraron analizar registros y entrevistar a pescadores veteranos (conocimiento ecológico tradicional de dos sitios de desembarque: Dzilam de Bravo y Puerto Progreso. Se analizaron registros pesqueros históricos de dos cooperativas pesqueras para determinar la situación actual y ofrecer

ARBUSCULAR MYCORRHIZAL ASSOCIATION IN Coccothrinax readii Quero

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Gerardo Emmanuel Polanco Hernández

2013-08-01

Full Text Available Coccothrinax readii, is a palm endemic to the Yucatan coast, its successful establishment in stressful environments suggests that factors such as mycorrhizal association may determine its success, the question arose in this work, assess environmental conditions which states and to describe their particular characteristics related to the anatomy of their roots and mycorrhizal colonization in three different seasons over a year. The study site was the coastal dune scrub of San Benito, Yucatan, where he placed a data logger that measurements performed ambient temperature (T, relative humidity (HR and photosynthethic photon flux (PPF for five days in dry, rainy and windy, also determined  the total phosphorus and extractable of the soil. The results indicate significant fluctuations of environmental variables throughout the year, on the other hand, the presence of the velamen on the roots of C. readii not restrict arbuscular mycorrhizal colonization. This association is affected by microenvironmental conditions, as during the dry season, when environmental conditions are unfavorable, the colonization percentage is higher than in the windy season, when microenvironmental conditions are more favorable.

EXTRAPOLATING THE SUITABILITY OF SOILS AS NATURAL REACTORS USING AN EXISTING SOIL MAP: APPLICATION OF PEDOTRANSFER FUNCTIONS, SPATIAL INTEGRATION AND VALIDATION PROCEDURES

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Yameli Guadalupe Aguilar Duarte

2011-04-01

Full Text Available The aim of this study was the spatial identification of the suitability of soils as reactors in the treatment of swine wastewater in the Mexican state of Yucatan, as well as the development of a map with validation procedures. Pedotransfer functions were applied to the existing soils database. A methodological approach was adopted that allowed the spatialization of pedotransfer function data points. A map of the suitability of soil associations as reactors was produced, as well as a map of the level of accuracy of the associations using numerical classification technique, such as discriminant analysis. Soils with the highest suitability indices were found to be Vertisols, Stagnosols, Nitisols and Luvisols. Some 83.9% of the area of Yucatan is marginally suitable for the reception of swine wastewater, 6.5% is moderately suitable, while 6% is suitable. The percentages of the spatial accuracy of the pedotransfer functions range from 62% to 95% with an overall value of 71.5%. The methodological approach proved to be practical, accurate and inexpensive.

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

Science.gov (United States)

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

On the phylogenetic position of Pseudophilomedinae within Sarsielloidea (Ostracoda, Myodocopida), with a description of one new Harbansus from Ningaloo Reef and redescription of H. paucichelatus from Yucatan

Science.gov (United States)

Karanovic, Ivana; Orduña-Martínez, Lorena; Ardisson, Pedro-Luis

2015-03-01

Previous studies have suggested incongruence between current systematics and molecular phylogenies of Sarsielloidea, with a possible polyphyly of the family Philomedidae. Here, we provide molecular phylogenetic analyses based on 18S rDNA and 28S rDNA. The former includes five new sequences and 12 from the GenBank, and the latter two new and six sequences from the GenBank. We use three methods, maximum likelihood, maximum parsimony, and neighbor joining, and all reconstructed phylogenies support previously suggested polyphyly, indicating a closer relationship of the subfamily Pseudophilomedinae with one subfamily of Sarsiellidae than with the nominotypical subfamily of Philomedidae. Morphological characters that may be key indicators of the phylogenetic relationships between three Sarsielloidea families are discussed. We also describe the 21st representative of the Pseudophilomedinae genus, Harbansus Kornicker, (Smith Contrib Zool 260:75, 1978), Harbansus ningalooi n. sp., from the Ningaloo Reef, Western Australia. This is the first Harbansus reported from the Australian west coast and the second from the Australian coral reef systems. It differs from all other congeners by peculiar claw-like processes on the posterior infold. Most Harbansus species have relatively restricted distributions, except Harbansus paucichelatus (Kornicker, in Inst Mar Sci 5:195-300, 1958), which has also been postulated to represent a species complex. We present a detailed morphological redescription of this species, based on the freshly collected material from the Yucatan Peninsula, as well as four mitochondrial COI sequences. These become the first COI sequences of the entire superfamily Sarsielloidea available on the GenBank. To facilitate future identification, we include a key to species of Harbansus.

Research Program In Tropical Infectious Diseases

Science.gov (United States)

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

Seroprevalence of feline leukemia virus, feline immunodeficiency virus and heartworm infection among owned cats in tropical Mexico.

Science.gov (United States)

Ortega-Pacheco, Antonio; Aguilar-Caballero, Armando J; Colin-Flores, Rafael F; Acosta-Viana, Karla Y; Guzman-Marin, Eugenia; Jimenez-Coello, Matilde

2014-06-01

Several infectious agents may be distributed within a healthy population of cats where diverse risk factors predispose them to come into contact with pathogens. Blood samples from 227 owned cats in Merida, Mexico, were collected with the objective of determining the seroprevalence and associated risk factors of feline leukemia virus (FeLV) and Dirofilaria immitis antigen, and feline immunodeficiency virus (FIV) antibody. Serological detection of FeLV and D immitis antigens, and FIV antibodies was performed using the commercial kit SNAP Feline Triple Test. The prevalence was found to be 7.5% for FeLV, 2.5% for FIV and 0% for D immitis. Adult cats were at a higher risk of coming into contact with FeLV (P <0.01) than younger cats. Owing to its low prevalence, a risk factor analysis was not performed for FIV. The prevalence of retroviral infections found in this study was low, but within the limits reported in the different geographical areas of the world. Cases of filariosis in the domestic cats of Merida, Mexico, may be absent or very low; however, the low sample size may have influenced these results. © ISFM and AAFP 2013.

NIVELES SÉRICOS DE MAGNESIO, HIERRO Y COBRE EN POBLACIÓN DE ADULTOS DE CIUDAD BOLÍVAR, ESTADO BOLÍVAR, VENEZUELA I SERUM LEVELS OF MAGNESIUM , IRON AND COPPER IN ADULT POPULATION FROM CIUDAD BOLIVAR, BOLIVAR STATE, VENEZUELA

Directory of Open Access Journals (Sweden)

María Caride

2014-02-01

Full Text Available Determination of bioelements concentrations in serum are considered very important, since they allow to establish reference levels that can be used to detect essential elements deficiency or poisoning by their excess. The aim of this study was to identify the serum levels of magnesium, iron and copper in a population of apparently healthy adults, residents of an urban area of Ciudad Bolivar, Bolivar State, The sample consisted of 57 individuals (28 men and 29 women that were not occupationally exposed residents in Ciudad Bolivar, aged between 25 and 60 years. Bioelements were determined by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES after acid digestion of serum samples. The average concentration values (± SD of magnesium, iron and copper obtained were, respectively, 22 ± 3 mg.L-1, 1.1 ± 0.2 mg.L-1 y 1.0 ± 0.2 mg.L-1. Regarding the studied bioelement levels, only magnesium levels of men were significantly higher (p < 0.05 than the levels of women. The mean concentrations of bioelements were within ranges of reference values reported in the literature for healthy people, but significantly different (p < 0,05 to those from Merida, another region from Venezuela, and a possible consequence of changes in eating habits and environment conditions among these two Venezuelan regions.

Amphibians and reptiles of the Calakmul Biosphere Reserve, México, with new records

OpenAIRE

Colston, Timothy; Barão-Nóbrega, José António; Manders, Ryan; Lett, Alice; Wilmott, Jamie; Cameron, Gavin; Hunter, Sidony; Radage, Adam; Littlefair, Etienne; Williams, Robert; Lopez Cen, Antonio; Slater, Kathy

2015-01-01

We provide a list of amphibians and reptiles of the Calakmul Biosphere Reserve in the southern half of the Mexican Yucatan, in the state of Campeche. The study area was sampled through opportunistic, transect and pitfall trap surveys conducted for three successive years. These surveys resulted in a total of 2,359 amphibian and reptile encounters, belonging to 20 amphibian and 69 reptile species from 24 total families. We present herein the records for one snake, one chelonian and two salamand...

The Balloon Effect and Mexican Homeland Security: What it Means to be the Weakest Link in the Americas’ Security Chain

Science.gov (United States)

2011-12-01

Direccion de Comunicacion Social SEMAR, 2011b), arresting 19 cartel members and seizing guns, money, and communication systems (Direccion de... Comunicacion Social SEMAR, 2011a). 51 Table 1. Selected Equipment and Training Delivered to Mexico and Central America Under the Merida...history (3rd ed.). New York: Algora Publishing. Direccion de Comunicacion Social SEMAR. (2011a). Asegura la Armada a 19 Presuntos Integrantes del

Extremadura (Spain): a case to be considered as Global Heritage Stone Province

Science.gov (United States)

Mota, Maribel; Tejado, Juanjo; Pereira, Dolores

2015-04-01

Extremadura is geologically located in the Iberian Massif, belonging part of the Central Iberian Zone, in the north of the region, and the Ossa Morena zone, in the south of it. The Central Iberian Zone is characterized by the abundance of clastic metasedimentary rocks and greywacke, sandstones, shales, conglomerates, quartzites and lesser amounts of carbonate materials such as limestone and dolomite (600-300 Ma). Also featured are Hercynian granitic intrusions. The rocks from the Ossa-Morena zone are metamorphic, intrusive igneous and volcanic (650-300 Ma). Extremadura, given its strategic geographical position, has been the site of human settlement since ancient times, and this civilisation has left its influence on the building materials used in buildings and monuments. The rocks used in building, are directly related to the geology of the immediate area, since rock outcrops, near the construction are mostly granites, slates and marbles. The historic and artistic heritage from Extremadura includes Roman treasures (like the bridges located in the Via de la Plata, dams, walls and milestones), Islamic and Christian treasures as well as medieval and Renaissance Jewish treasures. Extremadura has three World Heritage Sites declared by UNESCO: the old town of Cáceres, the archaeological site at Merida and the monastery of Guadalupe. The latter is built mainly of bricks and masonry. In Merida, granites and diorites of various facies of the batholiths located north of the city are used together with Sierra Carija's marble and quartzite alluvial gravels from the river Guadiana. Among the constructions in Merida, granite utilisation in the theater and amphitheater, aqueduct of Miracles and the Proserpina dam, are remarkable. The old town of Cáceres is characterised by the presence of narrow streets and monuments, medieval churches and Renaissance palaces, built with granite and flanked by a wall constructed during the Muslim period. This granite comes from the quarries

Evaluation of the health status of a coastal ecosystem in southeast Mexico: Assessment of water quality, phytoplankton and submerged aquatic vegetation.

Science.gov (United States)

Herrera-Silveira, Jorge A; Morales-Ojeda, Sara M

2009-01-01

The coastal environment of the Yucatan Peninsula (SE, Mexico) includes a wide variety of ecosystems ranging from mangroves to coral reefs, resulting in a heterogeneous landscape. Specifically, the marine system is characterized by environmental differences which respond to regional and local forcing functions such as marine currents and groundwater discharges (GD). Such functional characteristics were used here to define four subregions across the Yucatan coast and diagnose the health status of this coastal marine ecosystem. To achieve this goal, we conducted an analysis and integration of water quality variables, an eutrophic assessment, evaluated changes in submerged aquatic vegetation (SAV), and analyzed the community structure and distribution of harmful phytoplankton. The first step was to determine the reference values for each subregion based on data previously collected from 2002 to 2006 along the coast of Yucatan, 200m offshore. The trophic index (TRIX) and Canadian index for aquatic life (CCMEWQI) were used to diagnose each subregion and then the ASSETS approach was conducted for Dzilam and Progreso, sampling localities on each end of the health status continuum (those with the best and worst conditions). Overall, results indicated that the marine coastal ecosystem of Yucatan is in good condition; however, differences were observed between subregions that can be attributed to local forcing functions and human impacts. Specifically, the central region (zone HZII, Progreso-Telchac) showed symptoms of initial eutrophication due to nutrient inputs from human activities. The eastern region (zone HZ III, Dzilam-Las Bocas) showed a meso-eutrophic condition linked to natural groundwater discharges, while the other two subregions western (zone HZI Celestun-Palmar) and caribbean (zone HZ IV Ria Lagartos-El Cuyo) exhibited symptoms of oligo-mesotrophic condition. These findings may be considered baseline information for coastal ecosystem monitoring programs in

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

Science.gov (United States)

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.

Comparación de la atención del parto normal en los sistemas hospitalario y tradicional A comparison of vaginal delivery care between hospital and traditional systems

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Rosa María Méndez-González

2002-04-01

Full Text Available Objetivo. Comparar la atención del parto por vía vaginal entre los sistemas hospitalario y tradicional, para identificar recursos y procedimientos utilizados, y la aparición de complicaciones maternas y neonatales derivadas del tipo de atención. Material y métodos. Estudio transversal realizado en tres hospitales de la ciudad de Mérida y cuatro municipios del estado de Yucatán, México, entre 1989 y 1990. La muestra estuvo constituida por 205 mujeres que tuvieron parto por vía vaginal. Se observó la atención del parto y, a los 15 días posparto, se les entrevistó para detectar complicaciones maternas y neonatales. Se calcularon proporciones y se aplicó ji cuadrada para compararlas. Resultados. Se presentaron complicaciones en ambos sistemas. Sin embargo, en el hospitalario predominaron las maternas y en el tradicional, las neonatales. El número total de complicaciones fue similar. Conclusiones. La calidad de la atención fue similar en ambos servicios. Las complicaciones observadas pueden atribuirse a los recursos y acciones utilizados en cada sistema. Se requieren más estudios de este tipo para contar con evaluaciones objetivas de las ventajas y desventajas de ambos sistemas y contribuir a mejorar la calidad de la atención materno-infantil.Objective. To compare vaginal delivery hospital and traditional care systems to identify resources and practices, as well as maternal and neonatal complications related to each system. Material and Methods. Between 1989 and 1990, a cross-sectional study was conducted in three hospitals of Merida City and four municipalities of the state of Yucatan. The study sample consisted of 205 women who had a normal vaginal delivery. Delivery procedures were observed and a questionnaire to identify complications was applied 15 days after childbirth. Data analysis consisted in comparison of proportions with the chi-squared test. Results. Maternal and neonatal complications were identified in both systems

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

Science.gov (United States)

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.

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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.

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

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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 (pmediating environmental factors that drive the spatial and temporal variability in the intensity of deciduousness, and point toward analyzing deciduousness to reveal information about other

Fine Resolution Termohaline Structure Of The Yuctatan Coastal Sea

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Marino-Tapia, I.; Enriquez-Ortiz, C.; Capurro, L.; Euan-Avila, J.

2007-05-01

In the Yucatan peninsula there are a variety processes that drastically affect the thermohaline structure of the coastal seas. Some of these include hyperhaline lagoons that export salt to the ocean, upwelling events that propagate to the coast, persistent submarine groundwater discharges, and very high evaporation rates caused by the intense solar radiation. On July 2006 a fine resolution oceanographic campaign was performed on the Yucatan coast to study the detailed structure of thermohaline processes and currents from the shore to the 10 m isobath. A total of sixty nine transects that cover the entire northern stretch of the Yucatan coast were made. The transects extend seven kilometers in the offshore direction and have an alongshore spacing of 5 km. The temperature and salinity characteristics of the water column were monitored with a SEABIRD SBE 19 CTD performing profiles every 500 m along each transect. Ocean currents were measures along the same transect using a 1.5 MHz Acoustic Doppler Profiler (Sontek). The results clearly show the effects of coastal lagoons on the adjoining sea, with net salt export associated with hyperhaline lagoons (e.g. Ria Lagartos) or more estuarine influence of lagoons such as Celestun, where groundwater discharges play the role of rivers on the estuary. An assessment of this influence on the coastal ocean will be presented. It is well known the meteor impact at the end of the Cretacic era at Chicxulub, Yucatan, generated a crater with multiple rings which is evident from horizontal gravity gradients of the Yucatan mainland, and that associated with the outer ring there is a high concentration of cenotes (sinkholes) (Pope et al. 1991; Hildebrand, et al. 1995). It has also been shown that groundwater flows along this cenote ring towards the ocean, and the zones where the ring intersects the coast (Celestun and Dzilam Bravo) have impressive geologic features known as `submarine water springs' where freshwater springs as a fountain

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

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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.

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.

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Aurélia Revel

Full Text Available 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.

Spanish Patriotic Groups in Mexico and the 98: Patriotism, Dissidence, and Political Proselytism

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Aimer Granados

2000-01-01

Full Text Available This paper reviews the political activities of the Spanish colony in Mexico during the Porfiriato, regarding the 1895-1898 war be­tween Spain and Cuba and the United States. The author focu­ses on three urban centers with Spanish residents -Mexico City, Veracruz and Merida- and analyzes the subject in relation with the colony's complex ideological, social and material interests. The patriotic activities carried out by the colony until the defeat of 1898 is not explained from the diplomatic viewpoint, which is the most common, but from the creation of  patriotic groups (juntas patrióticas, encouraged by the Spanish embassy and  by institutions such as the Casino, the interests of which were often contrary to those of the Mexican government and even entailed conflicts with Cuban secessionist groups also active in Mexico.

Spatial and temporal characterization of fish assemblages in a tropical coastal system influenced by freshwater inputs: northwestern Yucatan peninsula

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Daniel Arceo-Carranza

2009-06-01

Full Text Available Coastal lagoons are important systems for freshwater, estuarine and marine organisms; they are considered important zones of reproduction, nursery and feeding for many fish species. The present study investigates the fish assemblages of the natural reserve of Dzilam and their relationship with the hydrologic variables. A total of 6 474 individuals (81 species were collected, contributing with more than 50% considering the Importance Value Index (IVI, Sphoeroides testudineus, Fundulus persimilis, Anchoa mitchilli, Eucinostomus gula, Eucinostomus argenteus and Mugil trichodon. Differences in species composition were found between seasons the highest during the cold fronts. Spatially, differences were related with the presence of freshwater seeps, the highest in the ecological characterized eastern part and the lowest with higher difference in specific composition located in the western part of the internal zone, due to a higher abundance and dominance of L. rhomboides. Salinity and temperature were the variables that presented a higher influence in the distribution of some pelagic species such as A. mitchilli and A. hepsetus. Because of the abundant freshwater seeps characteristic of the coastal lagoons of Yucatan Peninsula their community structure and fish assemblage display spatial and temporal differences in specific composition. Rev. Biol. Trop. 57 (1-2: 89-103. Epub 2009 June 30.Las lagunas costeras son sistemas importantes para muchas especies de organismos dulceacuícolas, estuarinos y marinos, ya que son consideradas zonas de reproducción, refugio y alimentación de muchas especies de peces. El presente estudio analizó los ensamblajes de la comunidad íctica de la reserva de Dzilam y su relación con las variables hidrológicas. Se capturaron un total de 6 474 individuos (81 especies, en donde Sphoeroides testudineus, Fundulus persimilis, Anchoa mitchilli, Eucinostomus gula, Eucinostomus argenteus and Mugil trichodon contribuyeron con m

Epidemiology of Streptococcus pneumoniae and Staphylococcus aureus colonization in healthy Venezuelan children

OpenAIRE

Quintero, B.; Araque, M.; van der Gaast-de Jongh, C.; Escalona, F.; Correa, M.; Morillo-Puente, S.; Vielma, S.; Hermans, P. W. M.

2010-01-01

Streptococcus pneumoniae and Staphylococcus aureus cause significant morbidity and mortality worldwide. We investigated both the colonization and co-colonization characteristics for these pathogens among 250 healthy children from 2 to 5?years of age in Merida, Venezuela, in 2007. The prevalence of S. pneumoniae colonization, S. aureus colonization, and S. pneumoniae?S. aureus co-colonization was 28%, 56%, and 16%, respectively. Pneumococcal serotypes 6B (14%), 19F (12%), 23F (12%), 15 (9%), 6...

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

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Cesar Valdovinos-Flores

Full Text Available 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.

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

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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

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

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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

EL FOGÓN ABIERTO DE TRES PIEDRAS EN LA PENÍNSULA DE YUCATÁN: TRADICIÓN Y TRANSFERENCIA TECNOLÓGICA

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Citlalli Cantú Gutiérrez

2012-06-01

In Mexico and particularly on the Yucatan peninsula, the use of the three-stone open fire cook stove and fire wood fuel is a phenomenon of great importance due to the number of people using it, its historical-cultural background and its meaning within the complex of traditional technologies. Its current existence represents a process of autonomy of the indigenous, peasant and poor populations with respect to the hegemonic networks of conventional sources of energy. Based on observations of 4000 households in 39 locations in Yucatan and Quintana Roo, Mexico, this article describes the characteristics of the open fire cook stove as well as the preferred types of firewood. It analyzes the transfer of technology and describes the process of delivery of open fire cook stoves by the federal government in Yucatan, interpreting it as a carbon subsidy policy for both local capitalist industry and developed countries, and as a way of neutralizing traditional autonomy and the efforts of organized civil society to promote participatory and community development.

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

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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.

The Two Subduction Zones of the Southern Caribbean: Lithosphere Tearing and Continental Margin Recycling in the East, Flat Slab Subduction and Laramide-Style Uplifts in the West

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Levander, A.; Bezada, M. J.; Niu, F.; Schmitz, M.

2015-12-01

The southern Caribbean plate boundary is a complex strike-slip fault system bounded by oppositely vergent subduction zones, the Antilles subduction zone in the east, and a currently locked Caribbean-South American subduction zone in the west (Bilham and Mencin, 2013). Finite-frequency teleseismic P-wave tomography images both the Atlanic (ATL) and the Caribbean (CAR) plates subducting steeply in opposite directions to transition zone depths under northern South America. Ps receiver functions show a depressed 660 discontinuity and thickened transition zone associated with each subducting plate. In the east the oceanic (ATL) part of the South American (SA) plate subducts westward beneath the CAR, initiating the El Pilar-San Sebastian strike slip system, a subduction-transform edge propagator (STEP) fault (Govers and Wortel, 2005). The point at which the ATL tears away from SA as it descends into the mantle is evidenced by the Paria cluster seismicity at depths of 60-110 km (Russo et al, 1993). Body wave tomography and lithosphere-asthenosphere boundary (LAB) thickness determined from Sp and Ps receiver functions and Rayleigh waves suggest that the descending ATL also viscously removes the bottom third to half of the SA continental margin lithospheric mantle as it descends. This has left thinned continental lithosphere under northern SA in the wake of the eastward migrating Antilles subduction zone. The thinned lithosphere occupies ~70% of the length of the El Pilar-San Sebastian fault system, from ~64oW to ~69oW, and extends inland several hundred kilometers. In northwestern SA the CAR subducts east-southeast at low angle under northern Colombia and western Venezuela. The subducting CAR is at least 200 km wide, extending from northernmost Colombia as far south as the Bucaramanga nest seismicity. The CAR descends steeply under Lake Maracaibo and the Merida Andes. This flat slab is associated with three Neogene basement cored, Laramide-style uplifts: the Santa Marta

De miasmas a mosquitos: el pensamiento médico sobre la fiebre amarilla en Yucatán, 1890-1920 From miasmas to mosquitoes: medical thought on yellow fever in Yucatan, 1890-1920

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Carlos Alcalá Ferráez

2012-03-01

Full Text Available La fiebre amarilla fue un problema de salud pública desde la época colonial debido a la frecuencia con que se presentaba en forma epidémica y a su alta letalidad. El objetivo de este trabajo es analizar el pensamiento médico y su evolución con respecto al vómito prieto entre 1890 y 1921 en Yucatán. Dos aspectos serán abordados: algunos antecedentes con respecto a la enfermedad y las ideas predominantes hasta 1881; y la propuesta de Carlos Finlay para vencer el escepticismo ante su teoría por parte de la comunidad médica. En segundo lugar se analizará la mezcla de las ideas miasmáticas y bacterianas. En tercer lugar, se mostrará cómo, a partir de la demostración de sus postulados, la mirada médica se dirigió al exterminio del mosquito transmisor de este padecimiento.Yellow fever has been a public health concern since colonial days because of its frequent epidemics and high mortality rate. This analysis of medical thought about "the black vomit" in the Yucatan and the evolution of this thinking from 1890 through 1921 first addresses some of the disease's antecedents and preponderant ideas prior to 1881 as well as Carlos Finlay's efforts to convince the medical community that his theory was right. The article goes on to analyze the co-existence of miasmatic and bacterial ideas and to show how medical initiatives began focusing on eradication of the mosquito transmitter once Finlay's postulates had been demonstrated.

Resistencia indígena y discursos racistas: una lectura biopolítica de los mayas yucatecos

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Izaskun Álvarez Cuartero

2012-06-01

Full Text Available In this article I propose to analyse the history of Yucatec Maya people from a biopolitical perspective. I study two periods of great importance in Mayan history: first, during the colonial period, the politics of population control and the peculiar geography of Yucatan guide us to explain how the colony was settled there; while the second part discusses the lack of instability of Mayan Indians during Independence, the indigenous resistance that will eventually lead to the 1847 Caste War and its consequence: the sale of Mayan Indians as slaves to Cuba as an alternative to eliminate Indian rebels and to create an imagined nation of Yucatan.

Caracterización de los paisajes terrestres actuales de la península de Yucatán

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Carlos Chiappy

2000-04-01

Full Text Available This work presents the characterization of current landscapes in the Yucatan peninsula. To this end the physico-geographical landscape method was used, based on an integrated scheme of the following natural components: geomorphology, altitude, climate, soils, land use and vegetation. These components were derived from digitalized maps, and afterwards they were analyzed using a geographic information system, which resulted in new combinations of components. For the landscape classification process the suggestions of Mateo (1984 were followed regarding diagnose Indexes and taxonomic levels, From the landscape maps so obtained six different landscape types were identified for Quintana Roo, three for Campeche and four for Yucatan.

La realidad comunicable como discurso histórico decimonónico:los indígenas mayas durante la guerra de castas en Yucatán

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Miriam Edith León Méndez

2017-12-01

Full Text Available This study focuses on the historical discourse in 4 books by Justo Sierra O ́Reilly, Serapio Baqueiro and Eligio Ancona. leading historians in the XIX centuryo Yucatan Peninsula. We aim to understand the use of the adjective bárbaro (“barbarian”, to refer to native Mayan people partaking in The Caste War, a conflict that developed in the Yucatan. Thisanalysis is performed within the historiographical methodology to account for the fact that the comunicable reality about the native Maya, described as barbarian, is the main connotation identifying this population as outcasts with respect to the sociopolitical and cultural norms of their time.

Riesgo de transmisión de Leishmania (Kinetoplastida: Trypanosomatidae en Mérida Venezuela

Directory of Open Access Journals (Sweden)

Elsa Nieves

2014-09-01

Full Text Available La leishmaniasis es una enfermedad causada por la infección de un parásito protozoario del género Leishmania, transmitido por la picada de insectos hematófagos conocidos como flebotominos. El estudio tiene como objetivo determinar la presencia de flebotominos en los Distritos Sanitarios del estado Mérida y diseñar un mapa de riesgo de transmisión entomológico. Se utilizaron cuatro métodos de captura de flebotominos, los ejemplares se identificaron y se les determinó la infección natural por Leishmania. Se estimó la riqueza de especies, y se realizó un proceso analítico Jerárquico. Los resultados muestran la presencia de diversas especies de flebotominos en los Distritos Sanitarios del estado Mérida, siendo las especies de mayor frecuencia L. youngi, L. gomezi, L. ovallesi y L. walkeri. Se detectó 2,1% de infección natural con Leishmania, la cual se encontró en las 4 especies más frecuentes. Se presenta un mapa de riesgo de transmisión entomológico para el estado Mérida. El conocimiento de la situación actual de los vectores de Leishmania en el estado Mérida y el riesgo de transmisión son relevantes a la hora de considerar la prevención y posible surgimiento de nuevos brotes de leishmaniasis. Abstract (english The leishmaniasis is a disease caused by infection with a protozoan parasite of the genus Leishmania, transmitted by the bite of blood-sucking insects known as sandflies. The study aims to determine the presence of sandflies in Merida state health districts and design a map of entomological risk of transmission. Four methods capture sandflies were used, the specimens were identified and natural Leishmania infection was determined. The richness species was estimated and analityc Hierarchie procesess was performed. The results show the presence of various species of sandflies in Merida state health districts, L. youngi, L. gomezi, L. ovallesi and L. walkeri were most abundant species. The 2.1% of natural infection

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

Directory of Open Access Journals (Sweden)

Jaime Rendon-von Osten

2017-06-01

Full Text Available 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.

Science.gov (United States)

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.

U.S. Economic Assistance to Colombia: A Model for U.S. Economic Assistance to Mexico?

Science.gov (United States)

2013-12-01

chronologically and territorially speaking); with Plan Colombia (2000– 2006) as the major program for U.S.-Colombia relations and the Merida Initiative...Ecuador 24.3 19.8 21.3 Peru 96.6 83.6 73.7 Venezuela 5.0 5.0 3.0 Total 621.0 519.7 452.0 Table 2. U.S. assistance to the Andean Region, FY2011–FY2013...Office of National Drug Control (ONDC) policy, Colombia’s potential cocaine production capabilities have once again fallen below those of Peru and

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

Science.gov (United States)

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.

[Distribution of Ecteinascidia turbinata (Ascidiacea: Perophoridae) in mangroves of the Yucatán Peninsula, Mexico].

Science.gov (United States)

Carballo, J L

2000-01-01

The ascidian Ecteinascidia turbinata synthesizes some of the most promising substances against solid-type tumors, but the only available source are the natural populations of this tunicate, which is reared or collected in different parts of the world. A total of 33 locations were sampled in the Gulf of Mexico and the Yucatan Peninsula. The tunicate was not found in Veracruz, Tabasco and Campeche, but it was well established on mangrove roots in the Yucatan Peninsula where we estimated densities more or less equal to one colony and an average production of 115 g of biomass per lineal meter of mangrove coastline in one location (Río Lagartos). Sustainable management appears to be possible.

Rickettsia rickettsii isolation from naturally infected Amblyomma parvum ticks by centrifugation in a 24-well culture plate technique

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K. Dzul-Rosado

2013-09-01

Full Text Available Rocky Mountain spotted fever is an acute illness caused by Rickettsia rickettsii (R. rickettsii and is transmitted by the bite of ticks of the genera Dermacentor, Amblyomma and Rhipicephalus. The illness results in a high mortality rate and may be easily confused with other febrile syndromes. In Yucatan State, Mexico, childhood cases with a high mortality have been reported. In this work we report the isolation of a Mexican R. rickettsii strain from a tick egg mass using an alternative method for Rickettsia isolation with 24-well plates. We also identified a potential vector of R. rickettsii in the southeast of Mexico, which is Amblyomma parvum.

Urban invation of sandflies transmition of leishmania in merida venezuela

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Elsa Nieves Blanco

2018-05-01

Full Text Available Urban development together with uncontrolled construction in endemic areas of leishmaniasis has resulted in a series of environmental transformations that have promoted the spread of cutaneous leishmaniasis, with the adaptation sandflies transmitters to these urban environments. This study aims to determine the presence of sandflies and the epidemiological factors associated with the transmission of leishmaniasis in an urban area of Zea, Venezuela. Five methods of catching sandflies were used indoors in two urbanizations in Zea, Venezuela. Through a survey-type instrument, the epidemiological variables associated with the transmission of leishmaniasis in the housing estates were determined. The presence in the urban dwellings of Lutzomyia youngi, Lutzomyia spinicrassa, Lutzomyia migonei, Lutzomyia ovallesi, Lutzomyia walkeri, Lutzomyia venezuelensis, Lutzomyia atroclavata and Lutzomyia lichyi were demonstrated. 62.5% of the species caught in urbanized areas have antropohematophagy habits. A 67% and 80% of infestation was determined in the dwellings of the studied urbanizations. It was evidenced a low level of knowledge in the inhabitants mainly on the sandflies, which increases the risk of domiciliation and transmission of leishmaniasis, the control entities are warned to implement preventive and educational measures.

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

Science.gov (United States)

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.

( Didelphis virginiana ) from Yucatan, Mexico

African Journals Online (AJOL)

Toxoplasma gondii is an obligate intracellular parasite recognized as a causal agent of toxoplasmosis; zoonotic disease endemic in many countries worldwide, including Mexico. Different species of animals participate in the wild cycle infection, including opossums of the species Didelphis virginiana. Thirteen D. virginiana ...

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

Science.gov (United States)

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.

Science.gov (United States)

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.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

The Sac Actun System, Quintana Roo, Mexico; Sistema Sac Actun, Quintana Roo, Mexico

Energy Technology Data Exchange (ETDEWEB)

Kambesis, P. N.; Coke, J. G.

2016-07-01

The Sac Actun system, located in northeast Quintana Roo, Mexico, is among the most extensive underwater cave systems located along the Caribbean coast of the Yucatan Peninsula. The cave is composed of linear phreatic conduits that have two forms. The coastal sections of the Sac Actun system are characterized by low horizontal tunnels that form mazes paralleling the coast and rudimentary conduits broken by fracture-controlled rooms. Inland passages are fault/fracture controlled, have a linear, anastomotic configuration, and align perpendicular to the coast. Access to the cave system is gained through cenotes which are the portals into the Yucatan underwater cave systems. The occurrence of drowned speleothems in many parts of the cave system, and sections of air-filled upper level passages are indicative of major fluctuations in sea level. The Sac Actun system is part of one of the most extensive and significant eogenetic karst aquifers in the world. The development of the Sac Actun system, as well as the many other caves systems along the Yucatan Caribbean Coast is controlled by the coastal hydrologic regime, driven by glacio-eustatics, and influenced by stratigraphic and structural controls. The karstic permeability of the aquifer makes it and the Sac Actun system vulnerable to the anthropogenic impacts of increased population growth, quarries, and infrastructure development associated with the burgeoning tourist industry that dominates land use in the region. (Author)

Overview of the Chicxulub impactite and proximal ejecta

Science.gov (United States)

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.

The Sac Actun System, Quintana Roo, Mexico

International Nuclear Information System (INIS)

Kambesis, P. N.; Coke, J. G.

2016-01-01

The Sac Actun system, located in northeast Quintana Roo, Mexico, is among the most extensive underwater cave systems located along the Caribbean coast of the Yucatan Peninsula. The cave is composed of linear phreatic conduits that have two forms. The coastal sections of the Sac Actun system are characterized by low horizontal tunnels that form mazes paralleling the coast and rudimentary conduits broken by fracture-controlled rooms. Inland passages are fault/fracture controlled, have a linear, anastomotic configuration, and align perpendicular to the coast. Access to the cave system is gained through cenotes which are the portals into the Yucatan underwater cave systems. The occurrence of drowned speleothems in many parts of the cave system, and sections of air-filled upper level passages are indicative of major fluctuations in sea level. The Sac Actun system is part of one of the most extensive and significant eogenetic karst aquifers in the world. The development of the Sac Actun system, as well as the many other caves systems along the Yucatan Caribbean Coast is controlled by the coastal hydrologic regime, driven by glacio-eustatics, and influenced by stratigraphic and structural controls. The karstic permeability of the aquifer makes it and the Sac Actun system vulnerable to the anthropogenic impacts of increased population growth, quarries, and infrastructure development associated with the burgeoning tourist industry that dominates land use in the region. (Author)

Valoración, partición y distribución de la tierra de los resguardos indígenas en una localidad andina venezolana. Santa Bárbara de Chachopo

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Samudio A., Edda O.

2010-12-01

Full Text Available The article examines the process of the establishment of Indian reserves (resguardos in the Venezuelan Andes in the late sixteenth century, and the experiences of their dissolution three centuries later. The main objective of the study is to analyze the appraisal, partition and distribution of the Indian reserves of Merida, assessing the role of the factors that were key elements in that process. The study includes aspects of the extinction of lands that were given with common and non-transferable title to the Indians settlements of Merida. The case of the pueblo of Santa Barbara de Chachopo is here offered as an example.

El artículo examina el proceso mediante el cual los Resguardos indígenas que fueron establecidos en la región andina venezolana en el tardío siglo XVI experimentaron su disolución tres centurias más tarde. El objetivo central de este trabajo es analizar la valoración, partición y distribución de esos Resguardos Indígenas de Mérida, tratando de apreciar la intervención de los factores que participan en ese hecho; para el estudio de los aspectos contemplados en el proceso de extinción de las tierras que fueron otorgadas, con carácter común e intransferible, a los pueblos de indios de Mérida; en esta ocasión, se tomó como ejemplo el caso de Santa Bárbara de Chachopo.

Los intérpretes generales de Yucatán: hombres entre dos mundos

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Mark Lentz

2009-01-01

Full Text Available Este artículo se centra en un tipo importante de intermediarios en el Yucatán colonial, los intérpretes generales del Juzgado Privado de Indios de Yucatán. Desde la época de Gaspar Antonio Chi en 1580 hasta la desaparición de esta corte en la década de 1820, estos hombres mediaron directamente en disputas de propiedades, quejas contra las autoridades, y tradujeron decretos inicialmente publicados en español para la mayoría maya hablante de la provincia. Sus actividades demuestran que Yucatán poseyó un alto número de individuos que dominaron tanto el maya como el español hasta finales del periodo colonial. Además, la cantidad de individuos calificados sirviendo extra oficial mente como intérpretes durante finales del siglo dieciocho, y el sorprendente número de no-mayas que necesitaron sus servicios, muestran también que el periodo colonial fue una época en la que el maya se extendió como lenguaje predominante en Yucatán, en lugar de una época de declive para ese idioma.This paper focuses one type of important intermediaries of colonial Yucatan, the general interpreters of Yucatan's Juzgado Privado de Indios. From the time of Gaspar Antonio Chi in 1580 until the demise of this court in the 1820s, these men mediated directly in land disputes, complaints against priests and other officials, and translated decrees initially published in Spanish for the province's Maya-speaking majority. The activities of the interpreters demonstrate that Yucatan had a high number of individuals literate and fluent in both Maya and Spanish until the close of the colonial period. Furthermore, the quantity of qualified individuals serving unofficially as interpreters during the late eighteenth century and the surprising number of non-Mayas in need of their services also shows that the colonial period was a time in which Maya spread as the predominant language of Yucatan rather than a time of decline for the region's native language.

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

Directory of Open Access Journals (Sweden)

Francisco Valadez

2013-06-01

Full Text Available 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 42.7µM and low concentrations of SRP (mean value of 1.0µM promoted the enhanced growth and bloom formation of cyanobacteria. The mean biovolume was 3.22X10(8µm³/mL, and two biovolume peaks were observed; the first was dominated by Microcystis panniformis in November 2007 (7.40X10(8µm³/mL, and the second was dominated by Oscillatoria princeps in April 2008 (6.55X10(8µm³/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.

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

Science.gov (United States)

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

Use of water-Cherenkov detectors to detect Gamma Ray Bursts at the Large Aperture GRB Observatory (LAGO)

International Nuclear Information System (INIS)

Allard, D.; Allekotte, I.; Alvarez, C.; Asorey, H.; Barros, H.; Bertou, X.; Burgoa, O.; Gomez Berisso, M.; Martinez, O.; Miranda Loza, P.; Murrieta, T.; Perez, G.; Rivera, H.; Rovero, A.; Saavedra, O.; Salazar, H.; Tello, J.C.; Ticona Peralda, R.; Velarde, A.; Villasenor, L.

2008-01-01

The Large Aperture GRB Observatory (LAGO) project aims at the detection of high energy photons from Gamma Ray Bursts (GRB) using the single particle technique in ground-based water-Cherenkov detectors (WCD). To reach a reasonable sensitivity, high altitude mountain sites have been selected in Mexico (Sierra Negra, 4550 m a.s.l.), Bolivia (Chacaltaya, 5300 m a.s.l.) and Venezuela (Merida, 4765 m a.s.l.). We report on detector calibration and operation at high altitude, search for bursts in 4 months of preliminary data, as well as search for signal at ground level when satellites report a burst

Use of water-Cherenkov detectors to detect Gamma Ray Bursts at the Large Aperture GRB Observatory (LAGO)

Energy Technology Data Exchange (ETDEWEB)

Allard, D. [APC, CNRS et Universite Paris 7 (France); Allekotte, I. [Centro Atomico Bariloche, Instituto Balseiro (Argentina); Alvarez, C. [Facultad de Ciencias Fisico-Matematicas de la BUAP (Mexico); Asorey, H. [Centro Atomico Bariloche, Instituto Balseiro (Argentina); Barros, H. [Laboratorio de Fisica Nuclear, Universidad Simon Bolivar, Caracas (Venezuela, Bolivarian Republic of); Bertou, X. [Centro Atomico Bariloche, Instituto Balseiro (Argentina)], E-mail: bertou@cab.cnea.gov.ar; Burgoa, O. [Instituto de Investigaciones Fisicas, UMSA (Bolivia); Gomez Berisso, M. [Centro Atomico Bariloche, Instituto Balseiro (Argentina); Martinez, O. [Facultad de Ciencias Fisico-Matematicas de la BUAP (Mexico); Miranda Loza, P. [Instituto de Investigaciones Fisicas, UMSA (Bolivia); Murrieta, T.; Perez, G. [Facultad de Ciencias Fisico-Matematicas de la BUAP (Mexico); Rivera, H. [Instituto de Investigaciones Fisicas, UMSA (Bolivia); Rovero, A. [Instituto de Astronomia y Fisica del Espacio (Argentina); Saavedra, O. [Dipartimento di Fisica Generale and INFN, Torino (Italy); Salazar, H. [Facultad de Ciencias Fisico-Matematicas de la BUAP (Mexico); Tello, J.C. [Laboratorio de Fisica Nuclear, Universidad Simon Bolivar, Caracas (Venezuela, Bolivarian Republic of); Ticona Peralda, R.; Velarde, A. [Instituto de Investigaciones Fisicas, UMSA (Bolivia); Villasenor, L. [Facultad de Ciencias Fisico-Matematicas de la BUAP (Mexico); Instituto de Fisica y Matematicas, Universidad de Michoacan (Mexico)

2008-09-21

The Large Aperture GRB Observatory (LAGO) project aims at the detection of high energy photons from Gamma Ray Bursts (GRB) using the single particle technique in ground-based water-Cherenkov detectors (WCD). To reach a reasonable sensitivity, high altitude mountain sites have been selected in Mexico (Sierra Negra, 4550 m a.s.l.), Bolivia (Chacaltaya, 5300 m a.s.l.) and Venezuela (Merida, 4765 m a.s.l.). We report on detector calibration and operation at high altitude, search for bursts in 4 months of preliminary data, as well as search for signal at ground level when satellites report a burst.

Contamination des eaux de puits traditionnels par les nitrates sur le ...

African Journals Online (AJOL)

SARAH

30 juin 2014 ... Objectif : La contamination des eaux souterraines par les nitrates est un ... Methodology and Results: the origin of nitrate water from traditional wells of Lobo's watershed was ...... 12 water supply wells, Yucatan, Mexico.

Difference in optimum temperature for growth and reproduction in benthic foraminifer Rosalina globularis: Implications for paleoclimatic studies

Digital Repository Service at National Institute of Oceanography (India)

Saraswat, R.; Nigam, R.; Pachkhande, S.

, P.A., Gabriel, J.J. 2010. Linkages between Holocene paleoclimate and paleohydrogeology preserved in a Yucatan underwater cave. Quat. Sci. Rev. 29, 2788-2798. 9 Leorri, E., Martin, R., McLaughlin, P. 2006. Holocene environmental and parasequence...

Phosphatised limestones and associated sediments from the western continental shelf of India

Digital Repository Service at National Institute of Oceanography (India)

Rao, V.P.; Natarajan, R.; Parthiban, G.; Mascarenhas, A.

Quaternary carbonate sediments: Rao, Ch.M., Paropkari~ A.L., Mascarenhas, A. and Murty, carbonate sediments and reefs, Yucatan shelf, Mexico. Am. P.S.N., 1987. Distribution of phosphorus and phosphatisa- Assoc. Pet. Geol. Mem., 11: 1-128. tion along...

Post-drilling destabilization of temperature profile in borehole Yaxcopoil-1, Mexico

Czech Academy of Sciences Publication Activity Database

Šafanda, Jan; Heidinger, P.; Wilhelm, H.; Čermák, Vladimír

2007-01-01

Roč. 15, č. 2 (2007), s. 423-428 ISSN 1431-2174 Institutional research plan: CEZ:AV0Z30120515 Keywords : Karst * thermal conditions * Yucatan Peninsula Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.122, year: 2007

Gender Mainstreaming or Instrumentalization of Women?

Directory of Open Access Journals (Sweden)

Marie France Labrecque

2010-09-01

Full Text Available This question is discussed on the basis of first hand data collected in Mexico between 2004 and 2007. The research aimed at examining how gender equity policies elaborated at the international level using an approach known as “gender mainstreaming” are transformed within national and local contexts. In a first step, the context of the emergence of the gender mainstreaming approach is reconstituted, and in a second step we try to clarify how and under what circumstances, in a country like Mexico, women can be instrumentalized within this approach, as for example, when gender mainstreaming is applied without any critical vision as it is so under neoliberalism. The main example rests on the case of microcredit for maya women in the state of Yucatan.

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

Science.gov (United States)

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.

The Praxis Teacher from Continuing Training

Directory of Open Access Journals (Sweden)

Yuraima Margelis Matos

2017-05-01

Full Text Available Related with the demands and policies that the Venezuelan system is setting, it´s necessary to make emphasis in the need for continuing formation of teachers in order to optimize their educational practice; even more when teachers now day have to be in constant process of formation and transformation. It´s necessary to mention that this study is part of a macro research that has been done in the U.E.B. The Paramito, Merida State, which presents one of its research purposes: to reveal through the voices of teachers conception of teaching practice from continuing training they receive. Methodologically it was addressed from the qualitative paradigm directed by the Participatory Action, which emerged from a diagnosis made and led to describe a phase research study. In this case they were made work tables, where dialogue prevailed between the actors involved, emerging categories such as were made: practice and experience for action, sharing knowledge, professional skills, which when put into practice can optimize the educational process in the as they strengthen the continuing education of teachers and thus a better quality education.

Lime muds and their genesis off-Northwestern India during the late Quaternary

Digital Repository Service at National Institute of Oceanography (India)

Rao, V.P.; AnilKumar, A.; Naqvi, S.W.A.; Chivas, A.R.; Sekar, B.; Kessarkar, P.M.

Dryas event and deep ocean circulation; Nature 342 637–642. Gischler E and Lomando A 1999 Recent sedimentary facies of isolated carbonate platforms, Belize-Yucatan system, Central America; J. Sedim. Res. 69 747–763. Gischler E and Zingeler D 2002...

Isolation of Salmonella enterica and serologic reactivity to Leptospira interrogans in opossums (Didelphis virginiana) from Yucatán, México.

Science.gov (United States)

Ruiz-Pina, Hugo Antonio; Puc-Franco, Miguel Angel; Flores-Abuxapqui, Javier; Vado-Solis, Ignacio; Cardenas-Marrufo, María Fidelia

2002-01-01

The presence of Salmonella enterica and serologic evidence of infection by Leptospira interrogans, were detected in the opossum Didelphis virginiana in a semi-urban locality of the Yucatán State, México. Ninety-one opossums were captured during the period April 1996 and May 1998. From a total of 17 feces samples, four Salmonella enterica subsp. enterica serotypes (Sandiego, Newport, Anatum, and Minnesota), and one Salmonella enterica subsp. arizonae serovar O44:Z4,Z23:- were isolated. Some opossums presented mixed infections. From 81 sera samples, four (4.9%) were positive to antibodies to Leptospira serovars pomona and wolfii. Both animals infected with Salmonella enterica and those serologically positive to Leptospira interrogans were captured in peridomestic habitat. Opossums infected with Salmonella enterica, were captured in dry season, and those seropositive to Leptospira interrogans during the rainy season. The implications of infection and reactivity of these zoonotic pathogens in D. virginiana in the Yucatan state are briefly discussed.

Postmortem findings in cloned and transgenic piglets dead before weaning

DEFF Research Database (Denmark)

Schmidt, Mette; Winther, K.D.; Secher, Jan Ole Bertelsen

2015-01-01

Important factors contributing to the well-known high mortality of piglets produced by SCNT are gross malformations of vital organs. The aim of the present retrospective study was to describe malformations found in cloned piglets, transgenic or not, dying or culled before weaning on Day 28. Large...... White (LW) embryos were transferred to 78 LW recipients, while 72 recipients received Göttingen embryos (67 transgenic and five not transgenic) and 56 received Yucatan embryos (43 transgenic and 13 not transgenic). Overall pregnancy rate was 76%, and there were more abortions in recipients with minipig...... in 152 piglets, but several piglets showed two (n = 58) or more (n = 23) malformations (7.4% and 2.8% of all born, respectively). A significantly higher malformation rate was found in transgenic Göttingen and Yucatan piglets (32% and 46% of all born, respectively) than in nontransgenic LW (17...

Molecular characterization of atypical antigenic variants of canine rabies virus reveals its reintroduction by wildlife vectors in southeastern Mexico.

Science.gov (United States)

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.

Dinámica regional de Yucatán 1980-2000

Directory of Open Access Journals (Sweden)

Ana García de Fuentes

2000-04-01

Full Text Available Amidst a long structural crisis, globalization has promoted deep regional transformations in Yucatan that have moved the axis of its economic production, which during the 20th Century rested exclusively in the production of henequén for export. Three axes of the neoliberal policy are applied in the region: privatization of public businesses, opening to foreign investment, and reorientation of production toward the external market. These axes affect the whole economic structure of the region, while, at the same time, there is a consolidation in the re-accommodation of regional capitals in line with the re-composition that is taking place within capitals at a national level. The new axes of regional dynamics, namely swine raising, contract manufacturing industry, and the renovation of the communications and transportation infrastructure, modify the territorial processes in Yucatan, imprinting new features to the international insertion of this border zone.

Familial hypercholesterolemia and atherosclerosis in cloned minipigs created by DNA transposition of a human PCSK9 gain-of-function mutant

DEFF Research Database (Denmark)

Al-Mashhadi, Rozh Husain; Sørensen, Charlotte Brandt; Kragh, Peter M.

2013-01-01

dominant hypercholesterolemia and accelerates atherosclerosis in humans. Using Sleeping Beauty DNA transposition and cloning by somatic cell nuclear transfer, we created Yucatan minipigs with liver-specific expression of human D374Y-PCSK9. D374Y-PCSK9 transgenic pigs displayed reduced hepatic low...

91 Évaluation de l'activité inhibitrice des extraits d'une algue brune ...

African Journals Online (AJOL)

AKA BOKO

OLIVERA-ROCHA, E. LISBOA -LEITE, Antioxydant activity of sulfated polysaccarides from brown and red seaweeds, Journal of applied Phycology, 19 (2007) 153-160. [14] - D. ZUBIA, D. ROBLEDO, Y. FREILE-PELEGRIN, Antioxidant activities in tropical marine macroalgae from the Yucatan peninsula Mexico, Journal of ...

A new species of Eutrachytes (Acari: Uropodina: Eutrachytidae) associated with the indian mangrove (Avicennia officinalis)

Digital Repository Service at National Institute of Oceanography (India)

Moraza, M.L.; Kontschan, J.; Sahoo, G.; Ansari, Z.A.

. Prague, Academia and The Hague, SPB Academic Publishing bv. pp. 349-356. Krantz G.W. 1969 — The Mites of Quintana Roo. I. A new species of Eutrachytes from the Yucatan Peninsula, with observations on the classification of the genus — Ann. Entomol. Soc. Am...

Enhancing maya women's development through cooperative associations : what factors support or restrict the contribution of cooperatives?

NARCIS (Netherlands)

Osorio Vazquez, Maria Cristina

2017-01-01

With the aim of contributing to the development of Mayan women living in the Yucatan Peninsula, this research focused on determine the factors that support or inhibit the sustainability of micro-businesses cooperatives, which are organizations with innovative elements that allow Mayan women to work

An Environmental Expedition Course in Search of the Maya.

Science.gov (United States)

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…

Student Travel to Pan-Am Congress of Plants & Biofuels in Merida, Mexico

Energy Technology Data Exchange (ETDEWEB)

Kimberly, Kimnach [American Society of Plant Biologists, Rockville, MD (United States)

2014-04-01

The Pan American Congress on Plants and BioEnergy convened in Mérida, Mexico, June 22 to 25, 2008. The program was organized by Steve Long (University of Illinois) and Nick Carpita (Purdue University), along with co-organizers Marcos Buckeridge (University of São Paulo, Brazil) and Federico Sánchez (Universidad Nacional Autónoma de México). More than 200 scientists from over a dozen nations around the world gathered to discuss key issues surrounding the development of biofuel feedstocks and to report on their research in this area. This three day conference had invited speakers surrounding developing renewable and sustainable energy resources which are typically propelled by three important drivers – security, cost and environmental impact.

Determination of 137Cs and 60Co pollution in the area of the Laguna Verde Nuclear Power Plant, Mexico

International Nuclear Information System (INIS)

Salas Mar, Bernardo

2015-01-01

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 hyper-pure 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. (authors)

Patterns and correlates of plant diversity differ between common and rare species in a neotropical dry forest

NARCIS (Netherlands)

Tetetla-Rangel, Erika; Dupuy, Juan Manuel; Hernández-Stefanoni, José Luis; Hoekstra, Paul H.

2017-01-01

Determining which factors affect species richness is important for conservation theory and practice. However, richness of common and rare species may be affected by different factors. We use an extensive inventory of woody plants from a tropical dry forest landscape in Yucatan, Mexico to assess the

[ANTIOXIDANT POTENTIAL OF MELIPONA BEECHEII HONEY AND ITS RELATIONSHIP TO HEALTH: A REVIEW].

Science.gov (United States)

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.

Distribución del zooplancton durante flujos de marea opuestos en el complejo lagunar de Chelem, Yucatán, México

Directory of Open Access Journals (Sweden)

J.B. Escamilla

2001-03-01

Full Text Available Zooplankton was surveyed in a tropical lagoon system of the northern coast of the Yucatan Peninsula in high tide, December (1998 and low tide, March 1999 (northerlies season. Zooplankton biomass was measured, zooplankters were counted, and copepods were identified and quantified. Despite the fact that both months were influenced by winds from the North, they showed a different salinity gradient which developed a particular structure of the zooplankton community. Biomass tended to be accumulated in certain areas apparently because of the high residence time of water in Chelem, the forcing effect of the northerlies, and of the tidal current. Biomass values suggest a relatively high secondary production when compared with other systems of the Yucatan Peninsula. The distribution of the copepods Acartia lilljeborgii and A. tonsa is related to saline conditions and tidal flow. The overall faunistic and hydrologic data suggest that even during a single climatic season, the zooplankton community shows strong changes due to mesoscale hydrological processes.

Metabolic syndrome in children and adolescents from Mérida city, Venezuela: Comparison of results using local and international reference values (CREDEFAR study).

Science.gov (United States)

Villalobos Reyes, Marjorie; Mederico, Maracelly; Paoli de Valeri, Mariela; Briceño, Yajaira; Zerpa, Yajaira; Gómez-Pérez, Roald; Camacho, Nolis; Martínez, José Luis; Valeri, Lenín; Arata-Bellabarba, Gabriela

2014-11-01

To obtain local reference values for blood lipids and blood pressure (BP), and to determine the prevalence of metabolic syndrome (MS) in children and adolescents from Mérida, Venezuela, and to compare results using local and international cut-off values. The study enrolled 916 participants of both sexes aged 9-18 years of age from educational institutions. Demographic, anthropometric, and BP data were collected. Fasting blood glucose and lipid profile were measured. Percentile distribution of lipid and BP values was done by age group and sex. Prevalence of MS was estimated based on the NCEP-ATPIII classification (as modified by Cook et al.) and the classification of the International Diabetes Federation, using percentiles of Mérida and the USA as cut-off points. Agreement between both classifications was estimated using the kappa test (κ). Prevalence of MS was 2.2% by Cook-Merida percentiles, as compared to 1.8% by Cook-USA percentiles, a moderate agreement (κ=0.54). Agreement between Cook et al. and IDF using Merida percentiles was weak (κ=0.28). There was a higher frequency of abdominal obesity, hypertriglyceridemia and hypertension, and a lower frequency of low HDL-C using Mérida percentiles. The risk (odds ratio) of having MS is greater if abdominal obesity exists (OR: 98.63, CI: 22.45-433.35, p=0.0001). MS was significantly more common in obese subjects (18.3%, p=0.0001). Prevalence of MS in this sample of children and adolescents was 2.2%. Lipid and BP values were lower in Venezuelan as compared to US, European, and Asian children and adolescents, and similar to those in Latin-American references. Own reference values are required for accurate diagnosis of MS, as well as a worldwide consensus on its diagnostic criteria. Copyright © 2014 SEEN. Published by Elsevier Espana. All rights reserved.

ETHNICITY AND INCOME IMPACT ON BMI AND STATURE OF SCHOOL CHILDREN LIVING IN URBAN SOUTHERN MEXICO.

Science.gov (United States)

Mendez, Nina; Barrera-Pérez, The Late Mario; Palma-Solis, Marco; Zavala-Castro, Jorge; Dickinson, Federico; Azcorra, Hugo; Prelip, Michael

2016-03-01

Obesity affects quality of life and increases the risk of morbidity and mortality. Mexico, a middle-income country, has a high prevalence of overweight and obesity among urban children. Merida is the most populated and growing city in southern Mexico with a mixed Mayan and non-Maya population. Local urbanization and access to industrialized foods have impacted the eating habits and physical activity of children, increasing the risk of overweight and obesity. This study aimed to contribute to the existing literature on the global prevalence of overweight and obesity and examined the association of parental income, ethnicity and nutritional status with body mass index (BMI) and height in primary school children in Merida. The heights and weights of 3243 children aged 6-12 from sixteen randomly selected schools in the city were collected between April and December 2012. Multinomial logistic regression models were used to examine differences in the prevalence of BMI and height categories (based on WHO reference values) by ethnicity and income levels. Of the total students, 1648 (50.9%) were overweight or obese. Stunting was found in 227 children (7%), while 755 (23.3%) were defined as having short stature. Combined stunting and overweight/obesity was found in 301 students (9.3%) and twelve (0.4%) were classified as stunted and of low weight. Having two Mayan surnames was inversely associated with having adequate height (OR=0.69, pobese. Overweight, obesity and short stature were frequent among the studied children. A significant proportion of Meridan children could face an increased risk of developing cardiovascular disease and its associated negative economic and social outcomes unless healthier habits are adopted. Action is needed to reduce the prevalence of obesity among southern Mexican families of all ethnic groups, particularly those of lower income.

European Virtual Atomic And Molecular Data Center - VAMDC

Science.gov (United States)

Dimitrijevic, M. S.; Sahal-Brechot, S.; Kovacevic, A.; Jevremovic, D.; Popovic, L. C.

2010-07-01

); 14) Corporacion Parque tecnologico de Merida - IVIC (Merida, Venezuela); 15) Institute for Astronomy RAS - INASAN (Moscow, Russia). This review describes the VAMDC project and its objectives.

e-Science initiatives in Venezuela

Energy Technology Data Exchange (ETDEWEB)

Chaves, J. L.; Diaz, G.; Hamar, V.; Isea, R.; Rojas, F.; Ruiz, N.; Torrens, R.; Uzcategui, M.; Florez-Lopez, J.; Hoeger, H.; Mendoza, C.; Nunez, L. A.

2007-07-01

Within the context of the nascent e-Science infrastructure in Venezuela, we describe several webbased scientific applications developed at the Centro Nacional de Calculo Cientifico Universidad de Los Andes (CECALCULA), Merida, and at the Instituto Venezolano de Investigaciones Cientificas (IVIC), Caracas. The different strategies that have been followed for implementing quantum chemistry and atomic physics applications are presented. We also briefly discuss a damage portal based on dynamic, nonlinear, finite elements of lumped damage mechanics and a biomedical portal developed within the framework of the E-Infrastructure shared between Europe and Latin America (EELA) initiative for searching common sequences and inferring their functions in parasitic diseases such as leishmaniasis, chagas and malaria. (Author)

Prevalence of Dyslipidemias in Three Regions in Venezuela: The VEMSOLS Study Results

Science.gov (United States)

González-Rivas, Juan P.; Nieto-Martínez, Ramfis; Brajkovich, Imperia; Ugel, Eunice; Rísquez, Alejandro

2018-01-01

Background The prevalence of dyslipidemia in multiple regions of Venezuela is unknown. The Venezuelan Metabolic Syndrome, Obesity and Lifestyle Study (VEMSOLS) was undertaken to evaluate cardiometabolic risk factors in Venezuela. Objective To determine the prevalence of dyslipidemia in five populations from three regions of Venezuela. Methods During the years 2006 to 2010, 1320 subjects aged 20 years or older were selected by multistage stratified random sampling from all households in five municipalities from 3 regions of Venezuela: Lara State (Western region), Merida State (Andean region), and Capital District (Capital region). Anthropometric measurements and biochemical analysis were obtained from each participant. Dyslipidemia was defined according to the NCEP/ATPIII definitions. Results Mean age was 44.8 ± 0.39 years and 68.5% were females. The prevalence of lipids abnormalities related to the metabolic syndrome (low HDL-c [58.6%; 95% CI 54.9 - 62.1] and elevated triglycerides [39.7%; 36.1 - 43.2]) were the most prevalent lipid alterations, followed by atherogenic dyslipidemia (25.9%; 22.7 - 29.1), elevated LDL-c (23.3%; 20.2 - 26.4), hypercholesterolemia (22.2%; 19.2 - 25.2), and mix dyslipidemia (8.9%; 6.8 - 11.0). Dyslipidemia was more prevalent with increasing body mass index. Conclusion Dyslipidemias are prevalent cardiometabolic risk factors in Venezuela. Among these, a higher prevalence of low HDL is a condition also consistently reported in Latin America. PMID:29538522

Publications | Page 609 | IDRC - International Development ...

International Development Research Centre (IDRC) Digital Library (Canada)

Results 6081 - 6090 of 6341 ... For small-scale farmers who maintain genetically diverse crop populations, aspects of the storage of their seeds and harvest may be just as important for successful farming as those related to productivity. The community of Yaxcaba, Yucatan, Mexico was studied to understand how the conditions ...

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African Journals Online (AJOL)

komla

seven soils: Yucatan (from Mexico), San Isidro or low; shape as flat or raised; and colour as. (Costa Rica), Itabela ..... (Mexico) soil, isolates did not form clusters either according to host or geographical origin. Isolates obtained ... Biodiversity of rhizobia which nodulate fast-growing tree legumes in tropical soils. PhD thesis,.

Arctic Carbon Sinks: Present and Future.

Science.gov (United States)

1989-12-01

R. Ruedy, and R. Rohan, Antarctic Salps II, J. Lerner, Climate sensitivity: Trophodynamics in the Scotia Sea and Analysis of feedback mechanisms, in...Over a longer travel distance of -1500km for water parcels observed in the 6-7 and 14 November 1976 sections across Yucatan and Florida Straits (Fig

Comparison of small mammal prevalence of Leishmania (Leishmania mexicana in five foci of cutaneous leishmaniasis in the State of Campeche, Mexico Comparación de las prevalencias de Leishmania (Leishmania mexicana en mamíferos pequeños en cinco focos de leishmaniosis cutánea en el estado de Campeche, México

Directory of Open Access Journals (Sweden)

N.R. Van Wynsberghe

2009-04-01

Full Text Available In the Yucatan Peninsula of Mexico, 95% of the human cases of Cutaneous Leishmaniasis are caused by Leishmania (Leishmania mexicana with an incidence rate of 5.08 per 100,000 inhabitants. Transmission is limited to the winter months (November to March. One study on wild rodents has incriminated Ototylomys phyllotis and Peromyscus yucatanicus as primary reservoirs of L. (L. mexicana in the focus of La Libertad, Campeche. In the present study, the prevalence of both infection and disease caused by L. (L. mexicana in small terrestrial mammals were documented during five transmission seasons (1994-2004 in five foci of Leishmaniasis in the state of Campeche. Foci separated by only 100 km, with similar relative abundances of small mammals, were found to differ significantly in their prevalence of both symptoms and infection. Transmission rates and reservoir species seemed to change in space as well as in time which limited the implementation of effective control measures of the disease even in a small endemic area such as the south of the Yucatan Peninsula.En la Península de Yucatán, México, la Leishmaniosis Cutánea es causada por Leishmania (L. mexicana en 95% de los casos humanos, con una incidencia de 5.08% por cada 100,000 habitantes. El ciclo de transmisión se limita a la estación de invierno (noviembre- marzo. Un estudio de mamíferos silvestres incrimina a Ototylomys phyllotis y Peromyscus yucatanicus como reservorios primarios de L. (L. mexicana en el foco de infección de La Libertad, Campeche. En el presente estudio, se documenta la prevalencia de infección/enfermedad causada por L. (L. mexicana en pequeños mamíferos, durante cinco estaciones de transmisión (1994-2004 en cinco focos de CL del estado de Campeche. Los focos separados por solamente 100 km. de distancia, aún cuando tienen abundancias relativas de pequeños roedores similares, fueron significativamente diferentes en relación a la prevalencia de síntomas así como de

Emissions from biomass burning in the Yucatan

Science.gov (United States)

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...

Crossing Pedagogical Borders in the Yucatan Peninsula

Science.gov (United States)

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…

Author Details - AJOL

African Journals Online (AJOL)

Yeh-Gorocica, A. Vol 6, No 1 (2016) - Articles First molecular evidence of Toxoplasma gondii in opossums (Didelphis virginiana) from Yucatan, Mexico Abstract PDF. ISSN: 2218-6050. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's ...

The U.S. Navy, the Neutrality Patrol, and Atlantic Fleet Escort Operations, 1939-1941

Science.gov (United States)

1991-05-13

Hereward in the Yucatan Channel, watching as the British ship refueled from a G- 3 class cruiser.3 3 Later that month, two American destroyers and the...4 0 On 14 December, the German freighter Arauca put out of Veracruz, and shaped a course for Hamburg. The ship’s cargo included " sisal , phosphate

Migrant songbirds, habitat change, and conservation prospects in northern Peten, Guatemala: some initial results

Science.gov (United States)

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...

Fish as paratenic hosts of Serpinema trispinosum (Leidy, 1852) (Nematoda: Camallanidae).

Science.gov (United States)

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.

Science.gov (United States)

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

Determination of 137Cs and 60Co pollution in the area of the Laguna Verde Nuclear Power Plant, Mexico.

Science.gov (United States)

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.

Chitons (Mollusca, Polyplacophora from Alacranes Reef, Yucatan, Mexico

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Adriana Reyes-Gómez

2017-04-01

Full Text Available 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.

Emissions from biomass burning in the Yucatan [Discussions

Science.gov (United States)

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...

Chitons (Mollusca, Polyplacophora) from Alacranes Reef, Yucatan, Mexico

Science.gov (United States)

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

Conservation in Context: A Comparison of Conservation Perspectives in a Mexican Protected Area

Directory of Open Access Journals (Sweden)

Martha Bonilla-Moheno

2012-09-01

Full Text Available The conservation of biodiversity in protected areas depends on the interests and agendas of stakeholders involved in the planning and enforcing of management actions. The challenge, therefore, has been to identify and include the perspectives of multiple participants important to local conservation. This paper describes the social context in which local conservation is conducted in a natural protected area in Yucatan, Mexico. In particular, it examines the agreement and expectations among local stakeholders on the main goals the reserve should achieve. Through participatory observation and semi-structured interviews, we analyzed the perceptions on conservation of the five groups relevant to the area management: 1 local people; 2 conservation government agency; 3 scientists; 4 non-governmental organization, and 5 a tourist agency. All actors agreed that the protected area should fulfill two main goals: i to conserve biodiversity and, ii to improve local welfare and development. In general, ecotourism is perceived as the best option for protecting the forest and promoting local development. Traditional agriculture, on the other hand, is perceived as the main conservation threat, but recognized as a crucial component of local wellbeing. We discuss these results in the context of the Yucatan Peninsula.

Participation of Parents of Elementary School Students in their Children’s Academic Activities

Directory of Open Access Journals (Sweden)

Ángel Alberto Valdés Cuervo

2009-05-01

Full Text Available This article describes the degree of parental involvement in the educational activities of elementary school children in the State of Yucatán. Based on the opinion of experts and references in the relevant literature, a Likert-type scale with 36 items was designed and applied to 106 parents of students at a public elementary school in the city of Mérida, capital of the state of Yucatan, in order to evaluate their involvement. The results show that the scale has an acceptable reliability coefficient (Cronbach’s alpha = .92 and its underlying structure, after a factor analysis with varimax rotation, consists of three unit factors: 1 Communication with the school; 2 Communication with the child, and 3 Knowledge of the school. Generally, the results show that parent involvement in children’s educational activities is low or precarious, especially in regard to the factors of Communication and Knowledge of the school, although mothers have a considerably higher level of involvement than fathers in these factors. The implications of these findings for the school as well as for research on parental participation in the educational process are discussed in light of the results.

Endurance and Adaptation of Community Forest Management in Quintana Roo, Mexico

Directory of Open Access Journals (Sweden)

Edward A. Ellis

2015-11-01

Full Text Available Despite regional deforestation threats, the state of Quintana Roo has maintained over 80% of its territory in forests. Community forest management (CFM has played a pivotal role in forest cover and biodiversity conservation in the region. In this article, we present the institutional, socioeconomic and environmental conditions under which community-based forest management has been consolidated in the tropical state of Quintana Roo, which occupies the eastern half of Mexico’s Yucatan Peninsula. With a focus on management for timber and other market-based development strategies, we then examine the institutional and socioeconomic factors, as well as biophysical shocks, that have constrained community forestry development in the past 25 years, challenging its persistence. Following, we discuss how forest communities and institutions have responded and adapted to changing forest policies and markets as well as major environmental shocks from hurricanes and fires. CFM in Quintana Roo has shown resiliency since its institutionalization 30 years ago. Future challenges and opportunities include biodiversity conservation, carbon management through Reducing Emissions from Deforestation and Forest Degradation (REDD+ initiatives, market strengthening, business management training as well as the implementation of alternative silvicultural systems, particularly to manage sustainable populations of commercial timber species.

Effect of temperature increments in septic tank efficiency

International Nuclear Information System (INIS)

Chi-Tec, M.; Caballero-Arzapalo, N.; Giacoman Vallejo, G.; Mendez-Novelo, R.; Quintal-Franco, C.

2009-01-01

Septic tanks are the main sewage disposal system used in Yucatan, Mexico. Septic tank content is stabilized under anaerobic conditions and is considered the temperature has a significant effect on the efficiency. This work was developed in order asses the feasibility to improve communal septic tanks efficiency by increasing content temperature. Temperatures inside the tank were increased using a hybrid heater system (solar and electricity). (Author)

El vigía de la costa: funcionario olvidado de la historia de Yucatán, siglos XVI al XIX

Directory of Open Access Journals (Sweden)

Jorge Victoria Ojeda

2015-09-01

This article presents an official who worked on the beaches of Yucatan, whose presence in regional history goes from colonial to independent times (XVI century-1867. Its role had not been studied in Hispanic America. In this research we give you to know the legal and illegal affairs that the watchtower (vigía performed in his job and waht that employment had implied.

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

Science.gov (United States)

2010-06-01

occurring on the Eastern Yucatan Peninsula, Mexico (Marquez 1990 and TEWG 2000); and (5) a Dry Tortugas nesting subpopulation, occurring in the...islands of the Dry Tortugas , near Key West, Florida (NMFS SEFSC 2001). The recently published recovery plan for the Northwest Atlantic population of...southern Virginia); (2) the Peninsular Florida Recovery Unit (Florida/Georgia border through Pinellas County, Florida); (3) the Dry Tortugas Recovery

Six new and one previously described species of pseudorhabdosynochus (Monogenoidea, Diplectanidae) infecting the gills of groupers (Perciformes, Serranidae) from the Pacific Coasts of Mexico and Panama

Czech Academy of Sciences Publication Activity Database

Mendoza-Franco, Edgar F.; Violante-González, J.; Rojas Herrera, A.A.

2011-01-01

Roč. 97, č. 1 (2011), 20-35 ISSN 0022-3395 R&D Projects: GA MŠk LC522 Institutional research plan: CEZ:AV0Z60220518 Keywords : N. SP MONOGENEA * SOUTH CHINA SEA * EPINEPHELUS-MACULATUS PERCIFORMES * E-MERRA PERCIFORMES * SP-NOV MONOGENEA * NEW-CALEDONIA * CYCLOPLECTANUM OLIVER * DAPENG BAY * YUCATAN PENINSULA * YAMAGUTI Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.405, year: 2011

Nearshore circulation on a sea breeze dominated beach during intense wind events

Science.gov (United States)

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

State of the States 2016: Arts Education State Policy Summary

Science.gov (United States)

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…

Assessment of intravenous pbi-shRNA PDX1 nanoparticle (OFHIRNA-PDX1) in yucatan swine.

Science.gov (United States)

Jay, C M; Ruoff, C; Kumar, P; Maass, H; Spanhel, B; Miller, M; Arrington, A; Montalvo, N; Gresham, V; Rao, D D; Evans, C; Wang, Z; Brunicardi, F C; Liu, S-H; Zhou, G; Senzer, N; Nemunaitis, J; King, L; Weeks, B; Clubb, F J; Fossum, T W; Maples, P B

2013-12-01

PDX1 (pancreatic and duodenal homeobox 1) is overexpressed in pancreatic cancer, and its reduction results in tumor regression. Bi-functional pbi-shRNA PDX1 nanoparticle (OFHIRNA-PDX1) utilizes the endogenous micro-RNA biogenesis pathway to effect cleavage- and non-cleavage-dependent degradation of PDX1 mRNA. We have shown that OFHIRNA-PDX1 reduces pancreatic tumor volume in xenograft models. Thus, we are now exploring biorelevant large animal safety of OFHIRNA-PDX1. Mini pigs were chosen as the biorelevant species based on the similarity of human and pig PDX1 target sequence. In the initial study, animals developed fever, lethargy, hyporexia and cutaneous hyperemia following administration of OFHIRNA-PDX1. Twenty-one days later, the same animals demonstrated less toxicity with a second OFHIRNA-PDX1 infusion in conjunction with a prophylactic regimen involving dexamethasone, diphenhydramine, Indocin and ranitidine. In a new group of animals, PDX1 protein (31 kDa) expression in the pancreas was significantly repressed at 48 and 72 h (85%, P=0.018 and 88%, P=0.013; respectively) following a single infusion of OFHIRNA-PDX1 but recovered to normal state within 7 days. In conclusion, a single intravenous infusion of OFHIRNA-PDX1 in conjunction with premedication in pigs was well tolerated and demonstrated significant PDX1 knockdown.

State of the States, 2012: Arts Education State Policy Summary

Science.gov (United States)

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.

Reproductive biology of Hechtia schottii, a dioecious Bromeliaceae, in Mexico

Directory of Open Access Journals (Sweden)

Ivón M Ramírez Morillo

2008-03-01

Full Text Available Hechtia schottii is a terrestrial, rosetofilous, dioecious, polycarpic succulent herb, that grows mainly in shrubby associations, and less frequently, in secondary low caducifolious forests, both on calcareous soils or limestone outcrops in Yucatan and Campeche States, Mexico. We studied phenology, floral and pollination biology, and breeding system at Calcehtok, Yucatan, during two flowering seasons. Plants bloom mainly during the dry season (November-April and disperse seeds during the rainy season (May-October. Both floral morphs have diurnal anthesis; pollen is removed ca. 1 h after anthesis starts and both floral morphs are visited by several insect species, especially bees, but results suggest that the introduced honey bee, Apis mellifera, is the pollinator. Controlled crossings show that the species is functionally dioecious and requires to be serviced by pollinators based on fruit setting only in unassisted cross pollination crosses. Rev. Biol. Trop. 56 (1: 279-289. Epub 2008 March 31.Hechtia schottii es una hierba terrestre, suculenta, rosetófila, dioica y policárpica, que crece en asociaciones arbustivas y selva baja caducifolia secundaria, ambos en suelos calcáreos o limosos. Estudiamos la fenología, la biología floral, reproductiva y de la polinización en una población en Calcehtok, Yucatán, México, durante dos estaciones de floración. Las plantas florecen principalmente en la época de secas (noviembre-abril y la dispersión de semillas es durante la estación de lluvias (mayo-octubre. Ambas formas (morphs florales tienen antesis diurna; el polen es removido ca. 1 h después del comienzo de la antesis y ambas formas florales son visitadas por varias especies de insectos, especialmente abejas, pero los resultados sugieren que la abeja introducida, Apis mellifera, es el polinizador. Cruces controlados muestran que la especie es funcionalmente dioica y que requiere de un polinizador, ya que solo produce frutos por polinizaci

[Population estimates and conservation of felids (Carnivora: Felidae) in Northern Quintana Roo, Mexico].

Science.gov (United States)

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.

Acoustic Signal Characteristics Measured with the LAMBDA III During CHURCH STROKE III

Science.gov (United States)

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

Noncorrelated effects of seed predation and pollination on the perennial herb Ruellia nudiflora remain spatially consistent

OpenAIRE

Abdala-Roberts, Luis; Parra-Tabla, Víctor; Salinas-Peba, Luis; Herrera, Carlos M.

2009-01-01

By simultaneously manipulating both seed predator and pollinator effects on the perennial herb Ruellia nudiflora at two sites in Yucatan (Mexico), the present study evaluated (1) whether a correlation (interaction) existed between seed predator and pollinator effects on R. nudiflora seed production and (2) whether such an interaction varied geographically. We used three populations per site, and a total of 20 plants per population (N = 120). Groups of five plants wer...

Neural-Network Quantum States, String-Bond States, and Chiral Topological States

Science.gov (United States)

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.

State-to-state and state-to-all-states reactive scattering angular distributions: F+H 2→HF+H

International Nuclear Information System (INIS)

Emmons, R.W.; Suck, S.H.

1983-01-01

How each state-to-state reactive transition determines nonundulatory ''state-to-all-states'' angular distribution has not yet been investigated. Here we present a complete exposure of state-to-state distorted-wave Born-approximation angular distributions in order to examine how the nonoscillatory and backward-peaked state-to-all-states reactive scattering angular distribution occurs

Development of in vivo impedance spectroscopy techniques for measurement of micropore formation following microneedle insertion.

Science.gov (United States)

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 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.

Effect of cutting intervals and heights in forage productivity of Moringa oleifera.

Directory of Open Access Journals (Sweden)

Ramos-Trejo O.

2015-07-01

Full Text Available The use of Moringa oleifera as fodder is due to its good nutritional characteristics and high yield of fresh biomass. Eastern Yucatan, Mexico has favorable soil and climatic conditions for its establishment. The aim of this work was to estimate forage productivity of Moringa oleifera in two cutting intervals and three different heights. The experiment was conducted at the Experimental Site of Tizimín fron the National Institute of Forest, Agricultural and lLvestock Researches (INIFAP. The experimental units were placed in a completely randomized design with a 2 x 3 factorial arrangement and four replications. Forage yield was quantified and foliage samples were taken for DM content. Significant differences (p0.05 were found. In conclusion, during the evaluation of Moringa oleifera, it was found that the best performance in this work is obtained when the cuts on the soles are made every 60 days at a height of 40 cm (1.9119 t ha-1 cut-1; however, more agronomic studies of this plant are recommended in the eastern Yucatan, such as: planting density, arrangement, partnerships with other shrub species in the region, rain and dry periods, in order to have a viable and profitable option forage productivity of this plant.

State of the States

Science.gov (United States)

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…

Quantum State Engineering Via Coherent-State Superpositions

Science.gov (United States)

Janszky, Jozsef; Adam, P.; Szabo, S.; Domokos, P.

1996-01-01

The quantum interference between the two parts of the optical Schrodinger-cat state makes possible to construct a wide class of quantum states via discrete superpositions of coherent states. Even a small number of coherent states can approximate the given quantum states at a high accuracy when the distance between the coherent states is optimized, e. g. nearly perfect Fock state can be constructed by discrete superpositions of n + 1 coherent states lying in the vicinity of the vacuum state.

Local adaptation of Ruellia nudiflora (Acanthaceae) to biotic counterparts: complex scenarios revealed when two herbivore guilds are considered

OpenAIRE

Ortegón-Campos, I.; Parra-Tabla, Víctor; Abdala-Roberts, Luis; Herrera, Carlos M.

2009-01-01

This study evaluated whether the herb Ruellia nudiflora is locally adapted to a specialist insect seed predator (SP) and insect folivores, and if plant local adaptation (LA) to the former is more likely. A reciprocal transplant experiment was conducted using three sites in Yucatan (Mexico) (n = 864 plants). A third of the plants of each origin were placed at each site, and we recorded the following during a 9-month period: fruit number, leaf ...

Interpretation and mathematical modeling of temporal changes of temperature observed in borehole Yaxcopoil-1 within the Chicxulub impact structure, Mexico

Czech Academy of Sciences Publication Activity Database

Šafanda, Jan; Wilhelm, H.; Heidinger, P.; Čermák, Vladimír

2009-01-01

Roč. 372, č. 1-4 (2009), s. 9-16 ISSN 0022-1694 R&D Projects: GA ČR(CZ) GA205/06/1181 Grant - others:Deutsche Forschungsgemeinschaft(DE) W1 687/17-1,2,3 Institutional research plan: CEZ:AV0Z30120515 Keywords : repeated borehole temperature logging * karstic environment * Yucatan * groundwater convection * heat transport numerical simulation * fluid dynamics Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 2.433, year: 2009

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

Science.gov (United States)

2016-10-01

amounts for those were based on a 60 kg animal. We have identified another approved vendor of Yucatan minipigs who offers animals at an intermediate ...Activity in Acute Cartilage Injury Sponsor Agency: Orthopaedic Trauma Association 9400 W. Higgins Road, Suite 305 Rosemont IL 60018-4226 01/01...Orthopaedic Foot & Ankle Society 9400 West Higgins Road, Suite 220 Rosemont IL 60018 05/12/2015 – 10/31/2016, $20,000 Total Costs Nathan A

Diffusion Of Indigo Molecules Inside The Palygorskite Clay Channels

OpenAIRE

Dejoie , Catherine; Martinetto , Pauline; Dooryhee , Eric; Van Eslande , Elsa; Blanc , Sylvie; Bordat , Patrice; Brown , Ross; Porcher , Florence; Anne , Michel

2011-01-01

International audience; The search for durable dyes led several past civilizations to develop artificial pigments. Maya Blue (MB), manufactured in pre-Columbian Mesoamerica, is one of the best known examples of an organic-inorganic hybrid material. Its durability is due to the unique association of indigo molecule and palygorskite, a particular fibrous clay occurring in Yucatan. Despite 50 years of sustained interest, the microscopic structure of MB and its relation to the durability remain o...

Detecting Near-Earth Objects Using Cross-Correlation with a Point Spread Function

Science.gov (United States)

2009-03-01

impact in the Yucatan Peninsula caused the extinction of the dinosaurs in the Cretaceous Period [Fix, 1995]. Even the Moon is pot marked by many...the atmosphere that the light traverses. For this reason , it is typically better to be at higher elevations to decrease the amount of atmosphere the...detection on average for the Rayleigh sampling with cross-correlation of a PSF than the Rayleigh sampling without cross- correlation. For this reason

Infección por Chlamydia trachomatis en usuarias de dos clínicas de planificación familiar Chlamydia trachomatis infection in users of two family planning clinics

Directory of Open Access Journals (Sweden)

Thelma Canto-de Cetina

2003-01-01

Full Text Available OBJETIVO: Determinar la prevalencia de infección por Chlamydia trachomatis en mujeres que acuden a dos clínicas de planificación familiar. MATERIAL Y MÉTODOS: Se llevó a cabo un estudio transversal en 1 100 mujeres sexualmente activas, aparentemente sanas, de Mérida, Yucatán, México, quienes acudieron a dos clínicas de planificación familiar en el periodo comprendido de enero a diciembre de 1998. Las mujeres incluidas en el estudio tuvieron entre 15 y 45 años de edad, y habían estado libres de tratamiento antibacteriano al menos durante el mes previo a su inclusión. Se obtuvieron muestras endocervicales y datos epidemiológicos. La detección de bacterias fue realizada por el método inmunoenzimático de marca Wellcozyme. Los datos fueron procesados en el programa EPI Info. Como métodos estadísticos se utilizaron la prueba de Z, ji cuadrada y como medida de asociación, la razón de prevalencias. RESULTADOS: Setenta y cuatro mujeres (6.7 % fueron positivas a infección por Chlamydia trachomatis. Cerca de 50% de las mujeres estuvo asintomática. No se encontró diferencia estadística entre la proporción de mujeres con y sin Chlamydia que tuvieron síntomas vulvovaginales; por el contrario, los cambios relacionados con cervicitis fueron más frecuentes en las pacientes infectadas. C trachomatis fue más frecuente en usuarias de anticonceptivos orales (8.3% comparadas con mujeres que no tenían método anticonceptivo (5.4%. CONCLUSIONES: Los resultados de este estudio confirman la alta prevalencia de infecciones asintomáticas y pone énfasis en la importancia de un diagnóstico oportuno para evitar secuelas.OBJECTIVE: To determine the prevalence of Chlamydia trachomatis in women attending two family planning clinics in Merida, Yucatan, Mexico. MATERIAL AND METHODS: From January to December 1998, a cross-sectional study was conducted in 1 100 sexually active women between 15 and 45 years of age. Study subjects had not received

Beekeeping, environment and modernity in localities in Yucatan, Mexico

Directory of Open Access Journals (Sweden)

Enrique Rodríguez Balam

2015-05-01

Full Text Available http://dx.doi.org/10.5007/2175-7925.2015v28n3p143 In this paper, we reflect on the local knowledge about the European honey bee  Apis mellifera scutellata, namely its biology, behavior, social structure, communication, and the relationships that these organisms maintain with the environment and their natural enemies. We also discuss the impacts that land use has on this economic activity. The empirical knowledge of beekeepers converges quite well with the scientific knowledge concerning this group of organisms.

Beekeeping, environment and modernity in localities in Yucatan, Mexico

Directory of Open Access Journals (Sweden)

Enrique Rodríguez Balam

2015-09-01

Full Text Available In this paper, we reflect on the local knowledge about the European honey bee Apis mellifera scutellata, namely its biology, behavior, social structure, communication, and the relationships that these organisms maintain with the environment and their natural enemies. We also discuss the impacts that land use has on this economic activity. The empirical knowledge of beekeepers converges quite well with the scientific knowledge concerning this group of organisms.

Interoceanic occurrence of species of Aristocleidus Mueller, 1936 (Monogenoidea: Dactylogyridae) parasitizing the gills of gerreid fishes in the Neotropics.

Science.gov (United States)

Mendoza Franco, Edgar F; Violante-González, Juan; Roche, Dominique G

2009-09-01

During investigations of fish parasites in the Neotropics (including the state of Veracruz and the Yucatán Peninsula in the Gulf of Mexico, the Chautengo Lagoon on the Pacific coast of the state of Guerrero in Mexico, and Lake Gatun in the Panama Canal), three monogenoidean (Dactylogyridae) species were found parasitizing the gills of gerreids (Gerreidae): Aristocleidus hastatus Mueller, 1936, was recovered from Eugerres plumieri (Cuvier) and Diapterus auratus Ranzani in Veracruz, from D. auratus and Diapterus rhombeus (Cuvier) in Yucatán, from Eugerres brasilianus (Cuvier) in Panama (all new hosts and geographical records), and from D. peruvianus (Cuvier) and Gerres cinereus (Walbaum) in Guerrero; Aristocleidus lamothei Kritsky and Mendoza-Franco, 2008, was recovered from E. plumieri in Veracruz and from D. rhombeus in Yucatan (new hosts and geographical records), and Aristocleidus sp. was recovered from G. cinereus in Guerrero. Results from this study suggest that species of Aristocleidus exhibit wide host specificity within gerreid fishes and that geminate species within this parasite genus may have originated with the formation of the Isthmus of Panama (3.1 to 3.5 ma). Evidence is also presented suggesting the potential role of the Panama Canal as a passageway allowing the interoceanic dispersal of Aristocleidus species across the isthmus.

Responsabilidad Social Empresarial en el Sector Servicios de Mérida, Yucatán (Corporate social responsability for the service industry sector in Mérida, Yucatán

Directory of Open Access Journals (Sweden)

Ruth Noemí Ojeda López

2012-11-01

Full Text Available El objetivo del presente trabajo fue describir el gradode Responsabilidad Social Empresarial (RSE de las empresasde servicios afiliadas a la Confederación Patronal de laRepública Mexicana (COPARMEX de Mérida, Yucatán,mediante el análisis de cuatro dimensiones: ética empresarial,preservación del medio ambiente, calidad de vida enel trabajo y vinculación empresa-sociedad. Se puede afirmarque, aunque la ética empresarial es la dimensión con mayordesarrollo, la RSE no es una práctica cotidiana.   ABSTRACT This work aims to describe the entrepreneurial socialresponsibility reach (RSE of service companies affiliated tothe Mexican Management Confederation (COPARMEX inMerida, Mexico, by considering four aspects: entrepreneurialethics, environmental preservation, work quality of lifeand company-society interaction. Although entrepreneurialethic is the most developed of the above four, RSE is not awidespread practice.

7 CFR 1220.615 - State and United States.

Science.gov (United States)

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...

7 CFR 1220.129 - State and United States.

Science.gov (United States)

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 1209.21 - State and United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false State and United States. 1209.21 Section 1209.21... Definitions § 1209.21 State and United States. (a) State means any of the several States, the District of Columbia, and the Commonwealth of Puerto Rico. (b) United States means collectively the several States of...

Optimal resource states for local state discrimination

Science.gov (United States)

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.

Research Program in Tropical Infectious Diseases

Science.gov (United States)

1992-12-01

171-177. 9. Glass, R. I. (1991) Personal communication. 1% ’ 10. Organizascion Panamericana de la Salud (1989). XXXIV Reunion. Situacion de los...PREFEENCES 1. Bustamante, M.E. (1986) Un descubrimiento cietifico truncado en 1912, et de la fiebre amarilla de la serva en Yucatan. Gac. Med. Mex. 122...programas de malaria en las Americas. XXXVII Informe. CD34/INF/2, 4 Agosto 11. Krieg, R., Lopez, J., Reyes, L., Jaramillo, R. and Duncan, J. (1992

La arqueofauna de Xcambó, Yucatán, México

Directory of Open Access Journals (Sweden)

Christopher M Gôtz

2011-12-01

Full Text Available This article discusses the faunal use pattern of the pre-Hispanic Mayas of the Yucatan coast (Mexico, based on a zooarchaeological sample from the site of Xcambo. The discussion addresses the use of a wide and diverse spectrum of fauna, emphasizing the discovery of remains of the tropical seal (Monachhus tropicalss a species currently extinct. Tropical seal specimens are extremely rare in Mesoamerica, but they show that these animals were occasionally used by pre-Columbian inhabitants.

FINANCIAL MANAGEMENT IN THE FAMILY AND NON-FAMILY SME´S IN THE TEXTILE INDUSTRY IN MEXICO

OpenAIRE

Martha Isabel Bojorquez Zapata; Antonio Emmanuel Perez Brito; Jorge Humberto Basulto Triay

2014-01-01

In this paper, we analyze differences in financial management practices between family and non-family Small and Medium Enterprises (SMEs) in the textile industry. We hypothesize that family SMEs use different sources of funding for new investments, tend to have less debt, are more profitable and use less financial and accounting information for decision making than non-family SMEs. We survey 24 textile SMEs located in Yucatan, Mexico. The results show that family SMEs rely more heavily on int...

Earth observations during Space Shuttle flight STS-41 - Discovery's mission to planet earth

Science.gov (United States)

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.

Feeding malnourished children with corn tortilla fortified with amino acids in Yucatán, México

OpenAIRE

Ramón Canul, L. G.; Betancur Ancona, D. A.; Castellanos Ruelas, A. F.; Chel Guerrero, L. A.

2012-01-01

Caloric and protein malnutrition in children has led to the development of programs that design and distribute nutritionally enhanced products in México. That is why this study was conducted in order to evaluate the effect of consumption of corn tortillas fortified with lysine and tryptophan, on growth of malnourished preschool children in two rural areas of Yucatan. An original population of 156 pre-school children originated from two rural communities, Canicab and Ticopó, with ages between ...

Octopus - Red Rouper Interaction in the Exploited Ecosystem of the Northern Continental Shel of Yucatán, México

OpenAIRE

Arreguín Sánchez, Francisco

2000-01-01

Octopus (Octopus maya) and red grouper (Epinephelus morio) are the most important fisheries resources on the northern continental shelf of Yucatan, Mexico, with annual yields fluctuating between 9000 and 16[punctuation space]000 t. Octopus is an important component of the diet of red grouper, particularly when the abundance of octopus increases during summer and autumn in shallow waters. A previous mass-balanced model using the Ecopath program described the main flows of biomass in this ecosy...

On NEO Threat Mitigation (Preprint)

Science.gov (United States)

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

[Trend analysis of acquired syphilis in Mexico from 2003 to 2013].

Science.gov (United States)

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?

Science.gov (United States)

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.

Science.gov (United States)

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

Redefining Secondary Forests in the Mexican Forest Code: Implications for Management, Restoration, and Conservation

Directory of Open Access Journals (Sweden)

Francisco J. Román-Dañobeytia

2014-05-01

Full Text Available The Mexican Forest Code establishes structural reference values to differentiate between secondary and old-growth forests and requires a management plan when secondary forests become old-growth and potentially harvestable forests. The implications of this regulation for forest management, restoration, and conservation were assessed in the context of the Calakmul Biosphere Reserve, which is located in the Yucatan Peninsula. The basal area and stem density thresholds currently used by the legislation to differentiate old-growth from secondary forests are 4 m2/ha and 15 trees/ha (trees with a diameter at breast height of >25 cm; however, our research indicates that these values should be increased to 20 m2/ha and 100 trees/ha, respectively. Given that a management plan is required when secondary forests become old-growth forests, many landowners avoid forest-stand development by engaging slash-and-burn agriculture or cattle grazing. We present evidence that deforestation and land degradation may prevent the natural regeneration of late-successional tree species of high ecological and economic importance. Moreover, we discuss the results of this study in the light of an ongoing debate in the Yucatan Peninsula between policy makers, non-governmental organizations (NGOs, landowners and researchers, regarding the modification of this regulation to redefine the concept of acahual (secondary forest and to facilitate forest management and restoration with valuable timber tree species.

Impact-generated Hydrothermal Activity at the Chicxulub Crater

Science.gov (United States)

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.

Transcriptome States Reflect Imaging of Aging States.

Science.gov (United States)

Eckley, D Mark; Coletta, Christopher E; Orlov, Nikita V; Wilson, Mark A; Iser, Wendy; Bastian, Paul; Lehrmann, Elin; Zhang, Yonqing; Becker, Kevin G; Goldberg, Ilya G

2018-06-14

In this study, we describe a morphological biomarker that detects multiple discrete subpopulations (or "age-states") at several chronological ages in a population of nematodes (Caenorhabditis elegans). We determined the frequencies of three healthy adult states and the timing of the transitions between them across the lifespan. We used short-lived and long-lived strains to confirm the general applicability of the state classifier and to monitor state progression. This exploration revealed healthy and unhealthy states, the former being favored in long-lived strains and the latter showing delayed onset. Short-lived strains rapidly transitioned through the putative healthy state. We previously found that age-matched animals in different age-states have distinct transcriptome profiles. We isolated animals at the beginning and end of each identified state and performed microarray analysis (principal component analysis, relative sample to sample distance measurements, and gene set enrichment analysis). In some comparisons, chronologically identical individuals were farther apart than morphologically identical individuals isolated on different days. The age-state biomarker allowed assessment of aging in a novel manner, complementary to chronological age progression. We found hsp70 and some small heat shock protein genes are expressed later in adulthood, consistent with the proteostasis collapse model.

Bio-screening of a few green seaweeds from India for their cytotoxic and antioxidant potential

Digital Repository Service at National Institute of Oceanography (India)

Vinayak, R.C.; Sabu, A.S.; Chatterji, A.

, cataractogenesis, pulmonary dysfunction, muscular dystrophy, ischemia perfusion, tissue damage and neu- rological disorders, such as Alzheimer’s disease. 1 Additionally, ROS are known to be the predominant cause of food decay, leading to rancidity, toxicity... extract. J Agric Food Chem 48:1466–1472 (2000). 34 Zubia M, Robledo D and Freile-Pelegrin Y, Antioxidant activities in tropical marine macroalgae from the Yucatan Peninsula, Mexico. J Appl Phycol 19:449–458 (2007). 35 Meir S, Kanner J, Akiri B...

Natural inactivation of phosphorus by aluminum in preindustrial lake sediments

Czech Academy of Sciences Publication Activity Database

Kopáček, Jiří; Marešová, M.; Hejzlar, Josef; Norton, S. A.

2007-01-01

Roč. 52, č. 3 (2007), s. 1147-1155 ISSN 0024-3590. [Keele Meeting on Aluminium /7./. Yucatan, 24.02.2007-28.02.2007] R&D Projects: GA ČR(CZ) GA206/06/0410 Grant - others:NSF(US) DEB-0415348; EU(XE) GOCE-CT-2003-505540 Institutional research plan: CEZ:AV0Z60170517 Source of funding: R - rámcový projekt EK Keywords : freshwaters * acidification * climate change Subject RIV: DJ - Water Pollution ; Quality Impact factor: 3.277, year: 2007

Influence of multiple factors on plant local adaptation: soil type and folivore effects in Ruellia nudiflora (Acanthaceae)

OpenAIRE

Ortegón-Campos, I.; Abdala-Roberts, Luis; Parra-Tabla, Víctor; Cervera, J. Carlos; Marrufo-Zapata, Denis; Herrera, Carlos M.

2011-01-01

Different environmental factors can have contrasting effects on the extent of plant local adaptation (LA). Here we evaluate the influence of folivory and soil type on LA in Ruellia nudiflora by performing reciprocal transplants at two sites in Yucatan (Mexico) while controlling for soil source and folivory level. Soil samples were collected at each site and half of the plants of each source at each site were grown with one soil source and half with the other. After transplanting, we reduced f...

Feeding ecology of juvenile marine fish in a shallow coastal lagoon of southeastern Mexico

OpenAIRE

Daniel Arceo-Carranza; Xavier Chiappa-Carrara

2015-01-01

Many species of marine fish use coastal lagoons during early stages of their life cycles due to the protection provided by their turbid waters and complex structure of the environment, such as mangroves and mudflats, and the availability of food derived from the high productivity of these sites. In this study, we analyzed the diet of six species of juvenile marine fishes that use a karstic lagoon system in the northwest portion of the Yucatan Peninsula, Mexico. Through stomach contents analys...

Competing States in the t-J Model: Uniform d-Wave State versus Stripe State versus Stripe State

NARCIS (Netherlands)

Corboz, P.R.; Rice, T.M.; Troyer, M.

2014-01-01

Variational studies of the t-J model on the square lattice based on infinite projected-entangled pair states confirm an extremely close competition between a uniform d-wave superconducting state and different stripe states. The site-centered stripe with an in-phase d-wave order has an equal or only

The association between state attachment security and state Mindfulness.

Directory of Open Access Journals (Sweden)

Christopher A Pepping

Full Text Available Recent research suggests that attachment and mindfulness are related, though the nature of this association is unclear. Here we present two studies examining whether there is a causal relationship between state attachment and state mindfulness. Study 1 investigated the effects of experimentally increasing state mindfulness on state attachment security. State mindfulness was successfully enhanced, but this led to no change in state attachment security. Study 2 investigated the effects of experimentally enhancing state attachment security on state mindfulness. State attachment security was successfully enhanced, but this did not lead to any change in state mindfulness. These findings suggest that there is not a direct, immediate causal relationship between state attachment and state mindfulness as a result of brief experimental manipulations. Future research should examine these associations in longer term interventions.

Physicochemical characterization of pigments and supports in mural paints: Mayapan, Yucatan case; Caracterizacion fisicoquimica de pigmentos y soportes en pinturas murales: caso Mayapan, Yucatan

Energy Technology Data Exchange (ETDEWEB)

Silva V, Y. [FIME-UANL, Pedro A. del Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon (Mexico); Peraza L, C.A. [Centro INAH Yucatan (Mexico); Bautista M, J.P. [DRPMZA/INAH. Direccion de Registro Publico de Monumentos y Zonas Arqueologicas, Victoria 110, Copilco El Bajo, 04340 Mexico D.F. (Mexico); Arenas A, J. [IFUNAM, Circuito de la Investigacion Cientifica s/n, Ciudad Universitaria, 04510 Mexico D.F. (Mexico)

2006-07-01

The present work is focused in the study of pigments and supports located in mural paintings belonging to the archaeological site of Mayapan. The raw materials utilized by the pre hispanic are revealed by means of the use of different techniques of characterization such as Scanning and Transmission Electron Microscopy (SEM and TEM, respectively), Energy Dispersive X-Ray Spectroscopy (EDS), X-Ray Diffraction and Fourier Transform Infrared Spectroscopy (FTIR). The pigments analyzed cover the following colors: yellow, blue, white, orange, black, red, olive and aqua green. In general, the elements O, Ca and C were the main elements present, as well as quantities of Si and Fe were very significant in all the cases. The manufacture techniques for the production of pigments and supports coincided with all those reported in literature for the Maya culture; however, influence from the Central Altiplane could be appreciated. The results obtained by XRD show the phases of calcite (CaCO{sub 3}) and dolomite ferroan (Ca(Mg,Fe)(CO{sub 3}){sub 2}) in all the support. The analyses by FTIR indicated the presence of some agglutinating, but it has not been identified yet. (Author)

Teleportations of Mixed States and Multipartite Quantum States

Institute of Scientific and Technical Information of China (English)

YU Chang-Shui; WANG Ya-Hong; SONG He-Shan

2007-01-01

In this paper, we propose a protocol to deterministically teleport an unknown mixed state of qubit by utilizing a maximally bipartite entangled state of qubits as quantum channel. Ifa non-maximally entangled bipartite pure state is employed as quantum channel, the unknown mixed quantum state of qubit can be teleported with 1 - √1 - C2 probability, where C is the concurrence of the quantum channel. The protocol can also be generalized to teleport a mixed state of qudit or a multipartite mixed state. More important purpose is that, on the basis of the protocol, the teleportation of an arbitrary multipartite (pure or mixed) quantum state can be decomposed into the teleportation of each subsystem by employing separate entangled states as quantum channels. In the case of deterministic teleportation,Bob only needs to perform unitary transformations on his single particles in order to recover the initial teleported multipartite quantum state.

Aprovechamiento de desechos orgánicos: 1. Extracción y caracterización del aceite de semillas de naranja colectadas en expendios ambulantes de jugos

Directory of Open Access Journals (Sweden)

María Escalante

2012-12-01

Full Text Available The Soxhlet extraction, using n-hexane as solvent, of the orange seed oil from waste residues obtained in street sales of fruit juices of Merida, Venezuela, was studied. Yields of 5.1% oil (w/w and 42.7% (w/w relative to the initial mass of the residue and dry seeds, respectively, were obtained. The oil was subjected to a transesterification process with methanol and the main components of the mixture of methyl esters achieved were quantified by gas chromatography coupled to mass spectrometry (GC-MS, which turned out to be: linoleate (311%, oleate (311%, palmitate (303% and magnesium stearate (7.10.5%. The mixture of methyl esters was subjected to the hydrolysis reaction in aqueous alkaline medium yielding the respective acid mixture which, after a precipitation process in HCl aqueous solution and its re-crystallization in n-hexane, generated an acid mixture with a higher content of unsaturated acids.

Supersqueezed states from squeezed states

International Nuclear Information System (INIS)

Nieto, M.M.

1992-01-01

Using super-Baker-Campbell-Hausdorff relations on the elements of the supergroup OSP(2/2), we derive the supersqueeze operator and the supersqueezed states, which are the supersymmetric generalization of the squeezed states of the harmonic oscillator

Quantum States Transfer by Analogous Bell States

International Nuclear Information System (INIS)

Mei Di; Li Chong; Yang Guohui; Song Heshan

2008-01-01

Transmitting quantum states by channels of analogous Bell states is studied in this paper. We analyze the transmitting process, constructed the probabilitic unitary operator, and gain the largest successful transfer quantum state probability.

State-to-State Mode Specificity: Energy Sequestration and Flow Gated by Transition State.

Science.gov (United States)

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.

Noisy teleportation of qubit states via the Greenberger–Horne–Zeilinger state or the W state

International Nuclear Information System (INIS)

Yan-Ling, Li; Mao-Fa, Fang; Xing, Xiao; Chao, Wu; Li-Zhen, Hou

2010-01-01

The effects of distributing entanglement through the amplitude damping channel or the phase damping channel on the teleportation of a single-qubit state via the Greenberger–Horne–Zeilinger state and the W state are discussed. It is found that the average fidelity of teleportation depends on the type and rate of the damping in the channel. For the one-qubit affected case, the Greenberger–Horne–Zeilinger state is as robust as the W state, i.e., the same quantum information is preserved through teleportation. For the two-qubit affected case, the W state is more robust when the entanglement is distributed via the amplitude damping channel; if the entanglement is distributed via the phase damping channel, the W state is more robust when the noisy parameter is small while the Greenberger–Horne–Zeilinger state becomes more robust when it is large. For the three-qubit affected case, the Greenberger–Horne–Zeilinger state is more robust than the W state. (general)

A Regional-Scale Groundwater Model Supporting Management of the Sian Ka'an Biosphere Reserve and its Catchment, Quintana Roo, Mexico

Science.gov (United States)

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 nuclear initiatives in the United States

International Nuclear Information System (INIS)

Strauss, P.L.; Stoiber, C.R.

1977-01-01

The paper deals with State nuclear initiatives regarding the role of nuclear power in the energy future of the United States. The question of whether and under what circumstances nuclear facilities should be used to generate electricity was put to the popular vote in several States in 1976. Some general principles of Federal-State relations are discussed with specific reference to nuclear regulations. The initiative mechanism itself is described as well as its legal form and background. The parallel developments in the State and Federal legislative consideration of nuclear issues is reviewed and the suggested reasons for the defeat of the proposals in the seven States concerned are discussed. Finally, the author draws some conclusions on the effects of the 1976 initiatives on future decision-making in the US on energy policy in general and nuclear power in particular. (NEA) [fr

Expectations and Perceptions of the Educational Service at the Universidad Nacional Abierta (Local Center Merida, Venezuela

Directory of Open Access Journals (Sweden)

Teresa de Jesús Molina Gutiérrez

2017-08-01

Full Text Available The objective of this study was to interpret the relationship between the expectations and the perceptions that the staff has about the quality of the educational service offered at the Mérida Local Center (Universidad Nacional Abierta, then the conceptual model of quality of service SERVQUAL, complemented with the qualitative approach. The informants were 15 advisors, 20 students and 5 administrative staff, the data were collected through the semi-structured interview and interpreted with the content analysis. The results indicate that there is no satisfaction with the educational service or that satisfaction is very low, because the expectations that are generated before receiving it are not surpassed by the perceived value, which is an indicator of the absence of quality of service. On the other hand, achieving quality in the service provided is the responsibility of all involved since the complexity of the roles fulfilled in the educational dialectic means that the staff act simultaneously as clients and as service providers.

Persistent organic pollutant concentrations in first birth mothers across Mexico.

Science.gov (United States)

Rodríguez-Dozal, Sandra; Riojas Rodríguez, Horacio; Hernández-Ávila, Mauricio; Van Oostdam, Jay; Weber, Jean Philippe; Needham, Larry L; Trip, Luke

2012-01-01

This project was initiated by the North America Commission for Environmental Cooperation (CEC). Its main purpose was to obtain an initial profile on pregnant woman's exposure to persistent organic pollutants (POPs) in North America (Canada, the United States and Mexico). Persistent organic pollutants are transferred to the fetus via the placenta during the pregnancy or to the infant via maternal milk; therefore, the pregnant woman's body burden is important because of the higher exposures and potential health effects in the fetus and infant. This paper presents the results from 240 pregnant women in 10 Mexican cities, and includes the concentrations of various POPs such as polychlorinated biphenyls (PCBs), organochlorine pesticides and polychlorinated dibenzo dioxins and furans (PCDDs and PCDFs) in maternal plasma. We found concentrations of p,p'-DDE in maternal samples from Coatzacoalcos to be ∼60% higher than those found in Ciudad Obregon, which had the second highest concentration. Pregnant women from Merida had higher mean concentrations of PCBs than all women in other regions. Results for PCDDs and PCDFs plus dioxin-like PCBs data were only available on the basis of composite samples, and their concentrations are similar in most cities except for Coatzacoalcos, which had more than double the concentration found in other cities. Although this study provides useful information on the variability of POPs in specific populations and possible regional/local differences, these results cannot be generalized to the entire Mexican population because of differences in age, gender, sources of exposure and nonrandom nature of the sample.

Parameter and State Estimator for State Space Models

Directory of Open Access Journals (Sweden)

Ruifeng Ding

2014-01-01

Full Text Available This paper proposes a parameter and state estimator for canonical state space systems from measured input-output data. The key is to solve the system state from the state equation and to substitute it into the output equation, eliminating the state variables, and the resulting equation contains only the system inputs and outputs, and to derive a least squares parameter identification algorithm. Furthermore, the system states are computed from the estimated parameters and the input-output data. Convergence analysis using the martingale convergence theorem indicates that the parameter estimates converge to their true values. Finally, an illustrative example is provided to show that the proposed algorithm is effective.

Migración contemporánea mexicana: redes sociales transnacionales y políticas migratorias : la experiencia migratoria de la comunidad de Tunkás, Yucatán en el sur de California

OpenAIRE

Martell Gámez, Alpha Iliana Guadalupe

2016-01-01

This research explores the impacts of the most recent U.S. economic crisis on the Mexican immigrant labour market, specifically from the town of Tunkás, Yucatan. Based on Bourdieu.’s theory of Capital production, and the transnational theoretical perspective, this study aims to build a conceptual frame for the migrant’s social capital in modern societies. A key element of this analysis is that a pioneer migrant-woman has initiated the tunkaseño social network in Los Angeles and Orange County,...

Tales from the Paleoclimate Underground: Lessons Learned from Reconstructing Extreme Events

Science.gov (United States)

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.

Prevention of Blast-Related Injuries

Science.gov (United States)

2013-07-01

influence of cerebrospinal fluid (CSF) on the shock wave response 3. Development of the geometric model for the head of a 23 55-kg Yucatan pig 4...of Tissue-Tek® optimum cutting compound and 20% sucrose (w/v) and frozen in a stream of liquid nitrogen (Saljo et al, 2008). The frozen blocks will...review of current models of the pig head under air blast loading 2. Development of a 2-D pig head FE model to study the influence of cerebrospinal fluid

31 CFR 515.321 - United States; continental United States.

Science.gov (United States)

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 500.321 - United States; continental United States.

Science.gov (United States)

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 535.321 - United States; continental United States.

Science.gov (United States)

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...

Transdermal delivery of flurbiprofen from surfactant-based vesicles: particle characterization and the effect of water on in vitro transport.

Science.gov (United States)

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

Science.gov (United States)

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.

Quantum Teleportation of Tripartite Arbitrary State via W State

Institute of Scientific and Technical Information of China (English)

XUE Zheng-Yuan; YI You-Min; CAO Zhuo-Liang

2005-01-01

A scheme of teleportation of a tripartite state via W state is suggested. The W state serves as quantum channels. Standard Bell-state measurements and Von Neumann measurements are performed. After the sender operates the measurements and informs the receiver her results, he can reconstruct the original state by the corresponding unitary transformation. The probability of the successful teleportation is also obtained.

Genetic, ecological and morphological divergence between populations of the endangered Mexican Sheartail hummingbird (Doricha eliza.

Directory of Open Access Journals (Sweden)

Yuyini Licona-Vera

Full Text Available 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.

Overlaps of partial Néel states and Bethe states

International Nuclear Information System (INIS)

Foda, O; Zarembo, K

2016-01-01

Partial Néel states are generalizations of the ordinary Néel (classical anti-ferromagnet) state that can have arbitrary integer spin. We study overlaps of these states with Bethe states. We first identify this overlap with a partial version of reflecting-boundary domain-wall partition function, and then derive various determinant representations for off-shell and on-shell Bethe states. (paper: quantum statistical physics, condensed matter, integrable systems)

Preface

Science.gov (United States)

Mallamace, Francesco; Quintana, Jacqueline

2002-03-01

Complex systems represent one of the richest and more fascinating fields of current scientific research. The reason behind this is the important role that the properties of complex systems and materials play in a variety of different but overlapping areas in physics, chemistry, biology, mathematics, and social sciences, like medicine and economy. Such unusually broad research field is, therefore, of primary interest nowadays in pure science and technology. The role of statistical physics in this new field of complex systems has been present since its onset and it has been accelerating recently. Methods developed for studying ordering phenomena in simple systems have been generalized for application to more complex forms of matter (polymers, biological macromolecules, glasses, etc) and complex processes (e.g. chaos, turbulence, economy, jamming, biological processes). In particular, many different phenomena (considered in the past to belong to separate research fields) have now a common description. Pillars of such a description are the concepts of scaling and universality. The International Conference on `Scaling Concepts and Complex Systems' (a satellite meeting of STATPHYS21) was devoted to give an overview on recent developments around these two concepts. The Conference took place in Merida, Yucatan, Mexico, in July 9-14 2001. The meeting was held in the Gordon Conference style and was attended by about 100 scientists, it covered a large variety of theoretical and experimental research topics of current interest in complex systems and materials. The meeting consisted of a total number of about 40 invited and contributed talks and a poster session. The topics covered included: scaling behaviour, supra-molecular systems, aggregation, aggregation kinetics, growth mechanisms, disordered systems, soft condensed matter (polymers, biological polymers, bio-colloids, gels, colloids, membranes and interfacial phenomena), granular matter, phase separation and out

State cigarette minimum price laws - United States, 2009.

Science.gov (United States)

2010-04-09

Cigarette price increases reduce the demand for cigarettes and thereby reduce smoking prevalence, cigarette consumption, and youth initiation of smoking. Excise tax increases are the most effective government intervention to increase the price of cigarettes, but cigarette manufacturers use trade discounts, coupons, and other promotions to counteract the effects of these tax increases and appeal to price-sensitive smokers. State cigarette minimum price laws, initiated by states in the 1940s and 1950s to protect tobacco retailers from predatory business practices, typically require a minimum percentage markup to be added to the wholesale and/or retail price. If a statute prohibits trade discounts from the minimum price calculation, these laws have the potential to counteract discounting by cigarette manufacturers. To assess the status of cigarette minimum price laws in the United States, CDC surveyed state statutes and identified those states with minimum price laws in effect as of December 31, 2009. This report summarizes the results of that survey, which determined that 25 states had minimum price laws for cigarettes (median wholesale markup: 4.00%; median retail markup: 8.00%), and seven of those states also expressly prohibited the use of trade discounts in the minimum retail price calculation. Minimum price laws can help prevent trade discounting from eroding the positive effects of state excise tax increases and higher cigarette prices on public health.

Functional State Modelling of Cultivation Processes: Dissolved Oxygen Limitation State

Directory of Open Access Journals (Sweden)

Olympia Roeva

2015-04-01

Full Text Available A new functional state, namely dissolved oxygen limitation state for both bacteria Escherichia coli and yeast Saccharomyces cerevisiae fed-batch cultivation processes is presented in this study. Functional state modelling approach is applied to cultivation processes in order to overcome the main disadvantages of using global process model, namely complex model structure and a big number of model parameters. Alongwith the newly introduced dissolved oxygen limitation state, second acetate production state and first acetate production state are recognized during the fed-batch cultivation of E. coli, while mixed oxidative state and first ethanol production state are recognized during the fed-batch cultivation of S. cerevisiae. For all mentioned above functional states both structural and parameter identification is here performed based on experimental data of E. coli and S. cerevisiae fed-batch cultivations.

Inter-state coupling and definitions of bright and dark states

International Nuclear Information System (INIS)

Mensik, Miroslav; Nespurek, Stanislav

2007-01-01

Contrary to a standard definition of diabatic states (i.e., those without momentum-dependent coupling), based on the construction from adiabatic ones, we defined diabatic states as bright and dark states of a given experiment. Namely, they are defined as states providing maximum, respectively, zero value of electronic transition dipole moments projected to a given polarization vector. Second, the state from (or to) which the optical transition is performed is not from the space of investigated electronic excited state manifold, but it is chosen by the observer. It is shown, for this case, that the inter-state coupling is a general function of vibrational coordinates. The explicit dependence of the inter-state coupling on vibrational coordinates is particularly important for system with strong Stokes shift. The role of exact definitions of bright and dark states as well as the inter-state coupling is discussed with respect to the coherent structure of electronic population observed in optical spectroscopy

FAILED STATE

African Journals Online (AJOL)

Dr. Miles R. Cone

The state and society are mutual symbionts as far as their political, economic and social relationships .... consequences have played a role in the African state's deviation from the 'strong state' ideal. .... International Olympic Committee (IOC).

Matrix product state description of Halperin states

Science.gov (United States)

Crépel, V.; Estienne, B.; Bernevig, B. A.; Lecheminant, P.; Regnault, N.

2018-04-01

Many fractional quantum Hall states can be expressed as a correlator of a given conformal field theory used to describe their edge physics. As a consequence, these states admit an economical representation as an exact matrix product state (MPS) that was extensively studied for the systems without any spin or any other internal degrees of freedom. In that case, the correlators are built from a single electronic operator, which is primary with respect to the underlying conformal field theory. We generalize this construction to the archetype of Abelian multicomponent fractional quantum Hall wave functions, the Halperin states. These can be written as conformal blocks involving multiple electronic operators and we explicitly derive their exact MPS representation. In particular, we deal with the caveat of the full wave-function symmetry and show that any additional SU(2) symmetry is preserved by the natural MPS truncation scheme provided by the conformal dimension. We use our method to characterize the topological order of the Halperin states by extracting the topological entanglement entropy. We also evaluate their bulk correlation lengths, which are compared to plasma analogy arguments.

Remote state preparation through hyperentangled atomic states

Science.gov (United States)

Nawaz, Mehwish; ul-Islam, Rameez-; Ikram, Manzoor

2018-04-01

Hyperentangled states have enhanced channel capacity in quantum processing and have yielded` evident increased communication speed in quantum informatics as a consequence of excessively high information content coded over each quantum entity. In the present article, we intend to demonstrate this fact by utilizing atomic states simultaneously entangled both in internal as well as external degrees of freedom, i.e. the de Broglie motion for remote state preparation (RSP). The results clearly demonstrate that we can efficiently communicate two bit information while manipulating only a single quantum subsystem. The states are prepared and manipulated using atomic Bragg diffraction as well as Ramsey interferometry, both of which are now considered as standard, state of the art tools based on cavity quantum electrodynamics. Since atomic Bragg diffraction is a large interaction time regime and produces spatially well separated, decoherence resistant outputs, the schematics presented here for the RSP offer important perspectives on efficient detection as well as unambiguous information coding and readout. The article summarizes the experimental feasibility of the proposal, culminating with a brief discussion.

Microstructural study of pre hispanic and colonial pigments of diverse sites of Mexico

International Nuclear Information System (INIS)

Arenas A, J.; Espinosa P, M.; Fernandez, M.E.; Mondragon G, G.; Perez H, R.; Mendoza A, D.; Rodriguez L, V.; Martinez, G.

2004-01-01

The aim of this work is to show some studies about the pre hispanic paintings, blue paint, green and red colors found in several archaeological sites located in the southeast and center of Mexico, also were analyzed clays samples from Sacalum mine localized in Yucatan state. The samples were analyzed by X Ray Diffraction (XRD), Scanning Electron Microscopy (Sem) and Transmission Electron Microscopy both equipped with a microprobe for chemical elemental analysis by Energy Dispersive Spectroscopy (EDS). The results obtained by Sem showed that all the pre hispanic paintings are made of fiber-like structures of micrometers order. In other zones of the samples were identified irregular morphologies in which the fibers are supported. The EDS analysis identified the elements C, O, Na, Mg, Al, Si, Ca and Fe. The XRD and High Resolution Transmission Electron Microscopy (HREM) results showed fiber crystalline structures at nanoscopic level corresponding to paligorskite clay. Other particles were identified as calcite phase. In the red pigments were identified paligorskite fibers in some of them and another sample was identified cinnabar phase. In these last sample no was identify the paligorskite. (Author) 14 refs., 13 figs

Student-Centred Teaching Strategies by Gender, Grade Level, and Teacher’s Self-Concept in Mexico

Directory of Open Access Journals (Sweden)

PEDRO SÁNCHEZ-ESCOBEDO

2018-05-01

Full Text Available This study examined the student-centred teaching strategies of Mexican teachers by gender, grade level, and self-concept as an instructor. A conventional sample of 573 teachers from diverse school settings in the state of Yucatan in Mexico responded to a paper and pencil questionnaire. Results indicated, in general, that teachers prioritized classroom management and independent learning activities, in contrast with teaching strategies emphasized by policies and teacher´s training programs in the country, such as cooperative learning, differentiation, or promoting critical thinking. There were some gender and grade level differences. In general, female teachers promoted more independent activities than males. As expected, primary school teachers were more concerned with using differentiation teaching strategies than secondary education teachers, considering the greatest variance in younger students. Teachers self-concept had differential effects. Whilst self-efficacy feelings had no influence in the use of specific student-centred teaching strategies, high self-esteem teachers used more student-centred teaching strategies. The importance of asking teachers what they did, and how they felt as teachers was argued in light of results. Future research avenues regarding self-concept and teaching strategies are posited.

State diagrams of tokamaks and state transitions

International Nuclear Information System (INIS)

Minardi, E.

1992-01-01

In a simple one-fluid cylindrical model of transport and of dissipative effects, the family of the magnetic states of the Tokamak which correspond to a vanishing entropy production in the confinement region is characterized by a define relation or ''state equation'' involving the relevant parameters of the discharge. An investigation is made as to how the entropy production changes when the current density profile is rearranged by a perturbation which conserves the poloidal magnetic flux. It is shown that for a sufficiently short time interval, that is to say t 2 E τ s where τ E is the energy confinement time and τ s is the resistive time, neighbouring bifurcating equilibria exist which can be reached with a flux-conserving transition and with increase of the magnetic entropy. The family of these new states can also be characterized by a state equation involving the relevant discharge parameters. When the state equations of the two families are simultaneously satisfied by the same set of parameter values, a flux-conserving, entropy-increasing transition may take place between states of the two families. The modifications of the current density and of the temperature profiles involved in the transition and the conditions that the discharge parameters should satisfy in order that the transition could occur are investigated. (author)

A state comparison amplifier with feed forward state correction

Science.gov (United States)

Mazzarella, Luca; Donaldson, Ross; Collins, Robert; Zanforlin, Ugo; Buller, Gerald; Jeffers, John

2017-04-01

The Quantum State Comparison AMPlifier (SCAMP) is a probabilistic amplifier that works for known sets of coherent states. The input state is mixed with a guess state at a beam splitter and one of the output ports is coupled to a detector. The other output contains the amplified state, which is accepted on the condition that no counts are recorded. The system uses only classical resources and has been shown to achieve high gain and repetition rate. However the output fidelity is not high enough for most quantum communication purposes. Here we show how the success probability and fidelity are enhanced by repeated comparison stages, conditioning later state choices on the outcomes of earlier detections. A detector firing at an early stage means that a guess is wrong. This knowledge allows us to correct the state perfectly. The system requires fast-switching between different input states, but still requires only classical resources. Figures of merit compare favourably with other schemes, most notably the probability-fidelity product is higher than for unambiguous state discrimination. Due to its simplicity, the system is a candidate to counteract quantum signal degradation in a lossy fibre or as a quantum receiver to improve the key rate of continuous variable quantum communication. The work was supported by the QComm Project of the UK Engineering and Physical Sciences Research Council (EP/M013472/1).

Developing State Level Approaches under the State Level Concept

International Nuclear Information System (INIS)

Budlong Sylvester, K.; Murphy, C.L.; Boyer, B.; Pilat, J.F.

2015-01-01

With the pursuit of the State-Level Concept (SLC), the IAEA has sought to further evolve the international safeguards system in a manner which maintains (or improves) the effectiveness of the system in an environment of expanding demands and limited resources. The IAEA must not remain static and should continuously examine its practices to ensure it can capture opportunities for cost reductions while adapting to, and staying ahead of, emerging proliferation challenges. Contemporary safeguards have been focused on assessing the nuclear programme of the State as a whole, rather than on the basis of individual facilities. Since the IAEA's integrated safeguards program, State-level Approaches (SLAs) have been developed that seek to optimally combine the measures provided for by the Additional Protocol with those of traditional safeguards. This process resulted in facility specific approaches that, while making use of a State's broader conclusion, were nonetheless prescriptive. Designing SLAs on a State-by-State basis would avoid the shortcomings of a one-size-fits-all system. It would also enable the effective use of the Agency's information analysis and State evaluation efforts by linking this analysis to safeguards planning efforts. Acquisition Path Analysis (APA), along with the State Evaluation process, can be used to prioritize paths in a State in terms of their attractiveness for proliferation. While taking advantage of all safeguards relevant information, and tailoring safeguards to individual characteristics of the State, paths of the highest priority in all States will necessarily meet the same standard of coverage. Similarly, lower priority paths will have lower performance targets, thereby promoting nondiscrimination. Such an approach would improve understanding of safeguards implementation under the SLC and the rational for safeguards resource allocation. The potential roles for APA and performance targets in SLA development will be reviewed

State of the States. Fuel Cells in America 2012

Energy Technology Data Exchange (ETDEWEB)

Curtin, Sandra [Fuel Cells 2000, Washington, DC (United States); Gangi, Jennifer [Fuel Cells 2000, Washington, DC (United States); Skukowski, Ryan [Fuel Cells 2000, Washington, DC (United States)

2012-09-01

This report, written by Fuel Cells 2000 and partially funded by the U.S. Department of Energy's Fuel Cell Technologies Program, continues to build on the April 2010 State of the States report that provided a snapshot of fuel cell and hydrogen activity in the 50 states and District of Columbia. This update report provides more details on the progress and activities that happened since the second report, issued in June 2011. Details reported for each state include new policies and funding, recent and planned fuel cell and hydrogen installations, and recent activity by state industry and universities.

Controlled Remote State Preparation via General Pure Three-Qubit State

Directory of Open Access Journals (Sweden)

Yuebo Zha

2015-07-01

Full Text Available The protocols for controlled remote state preparation of a single qubit and a general two-qubit state are presented in this paper. The general pure three-qubit states are chosen as shared quantum channel, which are not Local operations and classical communication (LOCC equivalent to the mostly used GHz state. This is the first time that general pure three-qubit states have been introduced to complete remote state preparation. The probability of successful preparation is presented. Moreover, in some special cases, the successful probability could reach a unit value.

Rethinking State Politics: The Withering of State Dominant Machines in Brazil

Directory of Open Access Journals (Sweden)

André Borges

2007-03-01

Full Text Available Research on Brazilian federalism and state politics has focused mainly on the impact of federal arrangements on national political systems, whereas comparative analyses of the workings of state political institutions and patterns of political competition and decision-making have often been neglected. The article contributes to an emerging comparative literature on state politics by developing a typology that systematizes the variation in political competitiveness and the extent of state elites’ control over the electoral arena across Brazilian states. It relies on factor analysis to create an index of “electoral dominance”, comprised of a set of indicators of party and electoral competitiveness at the state level, which measures state elites’ capacity to control the state electoral arena over time. Based on this composite index and on available case-study evidence, the article applies the typological classificatory scheme to all 27 Brazilian states. Further, the article relies on the typological classification to assess the recent evolution of state-level political competitiveness. The empirical analysis demonstrates that state politics is becoming more competitive and fragmented, including in those states that have been characterized as bastions of oligarchism and political bossism. In view of these findings, the article argues that the power of state political machines rests on fragile foundations: in Brazil’s multiparty federalism, vertical competition between the federal and state governments in the provision of social policies works as a constraint on state bosses’ machine-building strategies. It is concluded that our previous views on state political dynamics are in serious need of re-evaluation.

The State of Preschool 2012: State Preschool Yearbook. Executive Summary

Science.gov (United States)

Barnett, W. Steven; Carolan, Megan E.; Fitzgerald, Jen; Squires, James H.

2012-01-01

The 2012 "State Preschool Yearbook" profiles state-funded prekindergarten programs in the United States. The "Yearbook" compares each state program's standards against a checklist of 10 research-based quality standards benchmarks. Although the benchmarks against which the National Institute for Early Education Research (NIEER)…

Parent di-nuclear quasimolecular states as exotic resonant states

International Nuclear Information System (INIS)

Grama, N.

2002-01-01

It in shown that the parent di-nuclear quasimolecular state is an exotic resonant state that corresponds to a S-matrix pole in the neighbourhood of an attractor in the k-plane. The properties of the parent quasimolecular states i.e. energy, widths, deviation from the linear dependence of the energy on l(l + 1) doorway character and criteria for observability, result naturally from the general properties of the exotic resonant states. (author)

SwingStates: adding state machines to the swing toolkit

OpenAIRE

Appert , Caroline; Beaudouin-Lafon , Michel

2006-01-01

International audience; This article describes SwingStates, a library that adds state machines to the Java Swing user interface toolkit. Unlike traditional approaches, which use callbacks or listeners to define interaction, state machines provide a powerful control structure and localize all of the interaction code in one place. SwingStates takes advantage of Java's inner classes, providing programmers with a natural syntax and making it easier to follow and debug the resulting code. SwingSta...

steady – state performance of induction and transfer state

African Journals Online (AJOL)

eobe

This paper presents paper presents paper presents the steady the steady the steady–state performance state performance state performance comparison comparison comparison between polyphase induction motor and polyphase between polyphase induction motor and polyphase. TF motor operating in. TF motor ...

Multi-state Quantum Teleportation via One Entanglement State

International Nuclear Information System (INIS)

Guo Ying; Zeng Guihua; Lee, Moon Ho

2008-01-01

A multi-sender-controlled quantum teleportation scheme is proposed to teleport several secret quantum states from different senders to a distance receiver based on only one Einstein-Podolsky-Rosen (EPR) pair with controlled-NOT (CNOT) gates. In the present scheme, several secret single-qubit quantum states are encoded into a multi-qubit entangled quantum state. Two communication modes, i.e., the detecting mode and the message mode, are employed so that the eavesdropping can be detected easily and the teleported message may be recovered efficiently. It has an advantage over teleporting several different quantum states for one scheme run with more efficiency than the previous quantum teleportation schemes

State of the States: Fuel Cells in America

Energy Technology Data Exchange (ETDEWEB)

None

2011-06-15

This 2011 report, written by Fuel Cells 2000 and partially funded by the U.S. Department of Energy's Fuel Cell Technologies Program, provides an update of fuel cell and hydrogen activity in the 50 states and District of Columbia. State activities reported include new policies and funding, recent and planned fuel cell and hydrogen installations, and recent activities by state industries and universities.

Readings and Questions Around the Topographic Map of Merida 1864-1867. Solitary Construction of a Local History

OpenAIRE

Arana López, Gladys Noemí; Universidad Autónoma de Yucatán

2014-01-01

The main objective of this paper was to make a reading of a nineteenth century topographic map, considering that: a)The map is the territory, implying that a representation is made according to its own conventions of geosciences atthe time in question; b) The map is not the territory, but only a picture of it in paper, where there are different sets ofcultural codes and symbols; and finally, c) The territory is the map (plan) and therefore should be known from what isrepresented. The study to...

Trip Generation by Transportation Mode of Private School, Semi-private and Public. Case Study in Merida-Venezuela

Energy Technology Data Exchange (ETDEWEB)

Quintero Petit, A.M.; Diaz Gallardo, M.I.; Moreno Gonzalez, E.G.

2016-07-01

The trip generation model (TGM) is the first step in transportation forecasting, this is useful for estimating travel demand because it can predict travel from or to a particular land use. Typically, the analysis focuses in residential trip generation as a function of the social and economic attributes of households, but nonresidential land use suggests others variables. Travel generator poles such as: Private school, Semi-private and Public, have not been studied in Venezuela. The TGMs that shows the Institute of Transportation Engineers (ITE), EE.UU, are used typically and could be not appropriate. By using stepwise regression and transformation of data, high correlation coefficients and substantial improvements in the variability of data from several schools they were found. The trip generation rates (TGRs) by transportation mode: walking, motorcycle, public transport and cars, can be compared and be included in the Ibero-American Network of travel attractors poles. (Author)

Multiparty Quantum Secret Sharing of Quantum States Using Entanglement States

International Nuclear Information System (INIS)

Ying, Guo; Da-Zu, Huang; Gui-Hua, Zeng; Ho, Lee Moon

2008-01-01

A multi-partite-controlled quantum secret sharing scheme using several non-orthogonal entanglement states is presented with unconditional security. In this scheme, the participants share the secret quantum state by exchanging the secret polarization angles of the disordered travel particles. The security of the secret quantum state is also guaranteed by the non-orthogonal multi-partite-controlled entanglement states, the participants' secret polarizations, and the disorder of the travelling particles. Moreover, the present scheme is secure against the particle-number splitting attack and the intercept-and-resend attack. It may be still secure even if the distributed quantum state is embedded in a not-so-weak coherent-state pulse

States Moving from Accreditation to Accountability. Accreditation: State School Accreditation Policies

Science.gov (United States)

Wixom, Micah Ann

2014-01-01

Accreditation policies vary widely among the states. Since Education Commission of the States last reviewed public school accreditation policies in 1998, a number of states have seen their legislatures take a stronger role in accountability--resulting in a move from state-administered accreditation systems to outcomes-focused state accountability…

Influence of Noises on Remote State Preparation Using GHZ State

International Nuclear Information System (INIS)

Liang Huaqiu; Liu Jinming

2008-01-01

Using a quantum channel consisting of a GHZ state exposed to noisy environment, we investigate how to remotely prepare an entangled state and a qubit state, respectively. By solving the master equation in the Lindblad form, the influence of the various types of noises on the GHZ state is first discussed. Then we use the fidelity to describe how close the remotely prepared state and the initial state are. Our results show that the fidelity is a function of the decoherence rates and the angles of the initial state. It is found that for each of the two RSP schemes, the influence of the noise acting simultaneously in x, y, and z directions on the average fidelity is the strongest while the influence of the noise acting in x or z direction on the average fidelity is relatively weaker

Generalized Choi states and 2-distillability of quantum states

Science.gov (United States)

Chen, Lin; Tang, Wai-Shing; Yang, Yu

2018-05-01

We investigate the distillability of bipartite quantum states in terms of positive and completely positive maps. We construct the so-called generalized Choi states and show that it is distillable when it has negative partial transpose. We convert the distillability problem of 2-copy n× n Werner states into the determination of the positivity of an Hermitian matrix. We obtain several sufficient conditions by which the positivity holds. Further, we investigate the case n=3 by the classification of 2× 3× 3 pure states.

Classic Maya civilization collapse associated with reduction in tropical cyclone activity

Science.gov (United States)

Medina, M. A.; Polanco-Martinez, J. M.; Lases-Hernández, F.; Bradley, R. S.; Burns, S. J.

2013-12-01

In light of the increased destructiveness of tropical cyclones observed over recent decades one might assume that an increase and not a decrease in tropical cyclone activity would lead to societal stress and perhaps collapse of ancient cultures. In this study we present evidence that a reduction in the frequency and intensity of tropical Atlantic cyclones could have contributed to the collapse of the Maya civilization during the Terminal Classic Period (TCP, AD. 800-950). Statistical comparisons of a quantitative precipitation record from the Yucatan Peninsula (YP) Maya lowlands, based on the stalagmite known as Chaac (after the Mayan God of rain and agriculture), relative to environmental proxy records of El Niño/Southern Oscillation (ENSO), tropical Atlantic sea surface temperatures (SSTs), and tropical Atlantic cyclone counts, suggest that these records share significant coherent variability during the TCP and that summer rainfall reductions between 30 and 50% in the Maya lowlands occurred in association with decreased Atlantic tropical cyclones. Analysis of modern instrumental hydrological data suggests cyclone rainfall contributions to the YP equivalent to the range of rainfall deficits associated with decreased tropical cyclone activity during the collapse of the Maya civilization. Cyclone driven precipitation variability during the TCP, implies that climate change may have triggered Maya civilization collapse via freshwater scarcity for domestic use without significant detriment to agriculture. Pyramid in Tikal, the most prominent Maya Kingdom that collapsed during the Terminal Classic Period (circa C.E. 800-950) Rainfall feeding stalagmites inside Rio Secreto cave system, Yucatan, Mexico.

Groundwater Quality: Analysis of Its Temporal and Spatial Variability in a Karst Aquifer.

Science.gov (United States)

Pacheco Castro, Roger; Pacheco Ávila, Julia; Ye, Ming; Cabrera Sansores, Armando

2018-01-01

This study develops an approach based on hierarchical cluster analysis for investigating the spatial and temporal variation of water quality governing processes. The water quality data used in this study were collected in the karst aquifer of Yucatan, Mexico, the only source of drinking water for a population of nearly two million people. Hierarchical cluster analysis was applied to the quality data of all the sampling periods lumped together. This was motivated by the observation that, if water quality does not vary significantly in time, two samples from the same sampling site will belong to the same cluster. The resulting distribution maps of clusters and box-plots of the major chemical components reveal the spatial and temporal variability of groundwater quality. Principal component analysis was used to verify the results of cluster analysis and to derive the variables that explained most of the variation of the groundwater quality data. Results of this work increase the knowledge about how precipitation and human contamination impact groundwater quality in Yucatan. Spatial variability of groundwater quality in the study area is caused by: a) seawater intrusion and groundwater rich in sulfates at the west and in the coast, b) water rock interactions and the average annual precipitation at the middle and east zones respectively, and c) human contamination present in two localized zones. Changes in the amount and distribution of precipitation cause temporal variation by diluting groundwater in the aquifer. This approach allows to analyze the variation of groundwater quality controlling processes efficiently and simultaneously. © 2017, National Ground Water Association.

Distribution of some Calanoida (Crustacea: Copepoda from the Yucatán Peninsula, Belize and Guatemala

Directory of Open Access Journals (Sweden)

Gerd-Oltmann Brandorff

2012-03-01

Full Text Available Southern Mexico and Central America have many water bodies of different morphology and water chemistry with an interesting zooplankton fauna, originating from North or South America. A set of 63 samples, taken in 2005 and 2008, from water bodies of the Yucatan Peninsula karst, Belize and Guatemala, were studied for the content of calanoid copepods. Old and recent literature was used to determine animals to species level. Drawings were prepared with a microscope and a camera lucida. A total of 32 samples with totally six species contained calanoid copepods: one estuarine pseudodiaptomid and five freshwater diaptomids. Pseudodiaptomus marshi was found at different salinities. It is confirmed that the commonest diaptomids in the Yucatan Peninsula are Arctodiaptomus dorsalis and Mastigodiaptomus nesus. The former was also recorded from Lake Amatitlan. Mastigodiaptomus nesus is as widespread as A. dorsalis but it is absent from the Lake Peten area in Guatemala. Mastigodiaptomus reidae was found in two shallow habitats, these specimens differ from those from the type locality by having a set of peculiar large spine-like processes on the last thoracic and the urosome segments of the females. Leptodiaptomus siciloides was found only in Lake Ayarza with high salinity. Prionodiaptomus colombiensis occurred in the highlands of Guatemala in Lago de Güija and in the Peten area in Laguna Sacpuy. We contributed with our occurrence records to a better knowledge of the geographic distribution of some calanoid copepods. Morphological findings in some species are of value for taxonomic differentiation between species.

Tektite-bearing, deep-water clastic unit at the Cretaceous-Tertiary boundary in northeastern Mexico

Science.gov (United States)

Smit, J.; Montanari, A.; Swinburne, N. H.; Alvarez, W.; Hildebrand, A. R.; Margolis, S. V.; Claeys, P.; Lowrie, W.; Asaro, F.

1992-01-01

The hypothesis of Cretaceous-Tertiary (K-T) boundary impact on Yucatan, Mexico, predicts that nearby sites should show evidence of proximal impact ejecta and disturbance by giant waves. An outcrop along the Arroyo el Mimbral in northeastern Mexico contains a layered clastic unit up to 3 m thick that interrupts a biostratigraphically complete pelagic-marl sequence deposited at more than 400 m water depth. The marls were found to be unsuitable for determining magnetostratigraphy, but foraminiferal biostratigraphy places the clastic unit precisely at the K-T boundary. We interpret this clastic unit as the deposit of a megawave or tsunami produced by an extraterrestrial impact. The clastic unit comprises three main subunits. (1) The basal "spherule bed" contains glass in the form of tektites and microtektites, glass spherules replaced by chlorite-smectite and calcite, and quartz grains showing probable shock features. This bed is interpreted as a channelized deposit of proximal ejecta. (2) A set of lenticular, massive, graded "laminated beds" contains intraclasts and abundant plant debris, and may be the result of megawave backwash that carried coarse debris from shallow parts of the continental margin into deeper water. (3) At the top, several thin "ripple beds" composed of fine sand are separated by clay drapes; they are interpreted as deposits of oscillating currents, perhaps a seiche. An iridium anomaly (921 +/- 23 pg/g) is observed at the top of the ripple beds. Our observations at the Mimbral locality support the hypothesis of a K-T impact on nearby Yucatan.

23 CFR 1.3 - Federal-State cooperation; authority of State highway departments.

Science.gov (United States)

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Federal-State cooperation; authority of State highway... MANAGEMENT AND ADMINISTRATION GENERAL § 1.3 Federal-State cooperation; authority of State highway departments... State in all matters relating to, and to enter into, on behalf of the State, all contracts and...

Teleportation of Two-Particle Entangled State via Cluster State

Institute of Scientific and Technical Information of China (English)

LI Da-Chuang; CAO Zhuo-Liang

2007-01-01

In this paper,two schemes for teleporting an unknown two-particle entangled state from the sender (Alice)to the receiver (Bob) via a four-particle entangled cluster state are proposed.In these two schemes,the unknown twoparticle entangled state can be teleported perfectly.The successful probabilities and fidelities of the schemes can reach unity.

State-Dependent Resource Harvesting with Lagged Information about System States.

Directory of Open Access Journals (Sweden)

Fred A Johnson

Full Text Available Markov decision processes (MDPs, which involve a temporal sequence of actions conditioned on the state of the managed system, are increasingly being applied in natural resource management. This study focuses on the modification of a traditional MDP to account for those cases in which an action must be chosen after a significant time lag in observing system state, but just prior to a new observation. In order to calculate an optimal decision policy under these conditions, possible actions must be conditioned on the previous observed system state and action taken. We show how to solve these problems when the state transition structure is known and when it is uncertain. Our focus is on the latter case, and we show how actions must be conditioned not only on the previous system state and action, but on the probabilities associated with alternative models of system dynamics. To demonstrate this framework, we calculated and simulated optimal, adaptive policies for MDPs with lagged states for the problem of deciding annual harvest regulations for mallards (Anas platyrhynchos in the United States. In this particular example, changes in harvest policy induced by the use of lagged information about system state were sufficient to maintain expected management performance (e.g. population size, harvest even in the face of an uncertain system state at the time of a decision.

State-dependent resource harvesting with lagged information about system states

Science.gov (United States)

Johnson, Fred A.; Fackler, Paul L.; Boomer, G Scott; Zimmerman, Guthrie S.; Williams, Byron K.; Nichols, James D.; Dorazio, Robert

2016-01-01

Markov decision processes (MDPs), which involve a temporal sequence of actions conditioned on the state of the managed system, are increasingly being applied in natural resource management. This study focuses on the modification of a traditional MDP to account for those cases in which an action must be chosen after a significant time lag in observing system state, but just prior to a new observation. In order to calculate an optimal decision policy under these conditions, possible actions must be conditioned on the previous observed system state and action taken. We show how to solve these problems when the state transition structure is known and when it is uncertain. Our focus is on the latter case, and we show how actions must be conditioned not only on the previous system state and action, but on the probabilities associated with alternative models of system dynamics. To demonstrate this framework, we calculated and simulated optimal, adaptive policies for MDPs with lagged states for the problem of deciding annual harvest regulations for mallards (Anas platyrhynchos) in the United States. In this particular example, changes in harvest policy induced by the use of lagged information about system state were sufficient to maintain expected management performance (e.g. population size, harvest) even in the face of an uncertain system state at the time of a decision.

Resting state fMRI: A review on methods in resting state connectivity analysis and resting state networks.

Science.gov (United States)

Smitha, K A; Akhil Raja, K; Arun, K M; Rajesh, P G; Thomas, Bejoy; Kapilamoorthy, T R; Kesavadas, Chandrasekharan

2017-08-01

The inquisitiveness about what happens in the brain has been there since the beginning of humankind. Functional magnetic resonance imaging is a prominent tool which helps in the non-invasive examination, localisation as well as lateralisation of brain functions such as language, memory, etc. In recent years, there is an apparent shift in the focus of neuroscience research to studies dealing with a brain at 'resting state'. Here the spotlight is on the intrinsic activity within the brain, in the absence of any sensory or cognitive stimulus. The analyses of functional brain connectivity in the state of rest have revealed different resting state networks, which depict specific functions and varied spatial topology. However, different statistical methods have been introduced to study resting state functional magnetic resonance imaging connectivity, yet producing consistent results. In this article, we introduce the concept of resting state functional magnetic resonance imaging in detail, then discuss three most widely used methods for analysis, describe a few of the resting state networks featuring the brain regions, associated cognitive functions and clinical applications of resting state functional magnetic resonance imaging. This review aims to highlight the utility and importance of studying resting state functional magnetic resonance imaging connectivity, underlining its complementary nature to the task-based functional magnetic resonance imaging.

Black hole state evolution, final state and Hawking radiation

International Nuclear Information System (INIS)

Ahn, D

2012-01-01

The effect of a black hole state evolution on the Hawking radiation is studied using the final state boundary condition. It is found that the thermodynamic or statistical mechanical properties of a black hole depend strongly on the unitary evolution operator S, which determines the black hole state evolution. When the operator S is random unitary or pseudo-random unitary, a black hole emits thermal radiation as predicted by Hawking three decades ago. In particular, when the black hole mass of the final state vanishes, Hawking’s original result is retrieved. On the other hand, it is found that the emission of the Hawking radiation could be suppressed when the evolution of a black hole state is determined by the generator of the coherent state. Such a case can occur for some primordial black holes with Planck scale mass formed by primordial density fluctuations through the process of squeezing the zero-point quantum fluctuation of a scalar field. Those primordial black holes can survive until the present time and can contribute to cold dark matter. (paper)

Higher USA State Resident Neuroticism Is Associated With Lower State Volunteering Rates.

Science.gov (United States)

McCann, Stewart J H

2017-12-01

Highly neurotic persons have dispositional characteristics that tend to precipitate social anxiety that discourages formal volunteering. With the 50 American states as analytical units, Study 1 found that state resident neuroticism correlated highly ( r = -.55) with state volunteering rates and accounted for another 26.8% of the volunteering rate variance with selected state demographics controlled. Study 2 replicated Study 1 during another period and extended the association to college student, senior, secular, and religious volunteering rates. Study 3 showed state resident percentages engaged in other social behaviors involving more familiarity and fewer demands than formal volunteering related to state volunteering rates but not to neuroticism. In Study 4, state resident neuroticism largely accounted statistically for relations between state volunteering rates and state population density, collectivism, social capital, Republican preference, and well-being. This research is the first to show that state resident neuroticism is a potent predictor of state volunteering rates.

American State Gun Law Strength and State Resident Differences in Neuroticism Levels

Directory of Open Access Journals (Sweden)

Stewart J. H. McCann

2016-04-01

Full Text Available Relations between state gun law strength and state-aggregated levels of Republican leaning, gun ownership, and resident Big Five neuroticism (based on 619,397 residents nationally were determined in a state-level analysis of the 50 American states using multiple regression strategies with state socioeconomic status, white population percent, and urban population percent statistically controlled. In a standard hierarchical model with state gun law strength as the criterion, the three demographic variables accounted for 44.4% of the variance and the Big Five accounted for another 21.9%. When the Big Five entered stepwise after the demographics, neuroticism was the sole significant personality predictor, accounting for another 13.4% of the variance. Greater state gun law strength was associated with higher state resident neuroticism. Further hierarchical regression analyses showed that state Republican leaning and gun ownership could account separately and jointly for significant variance in state gun law strength but not with state resident neuroticism controlled.

Assessing the importance of four sandfly species (Diptera: Psychodidae) as vectors of Leishmania mexicana in Campeche, Mexico.

Science.gov (United States)

Pech-May, A; Peraza-Herrera, G; Moo-Llanes, D A; Escobedo-Ortegón, J; Berzunza-Cruz, M; Becker-Fauser, I; Montes DE Oca-Aguilar, A C; Rebollar-Téllez, E A

2016-09-01

Localized cutaneous leishmaniasis represents a public health problem in many areas of Mexico, especially in the Yucatan Peninsula. An understanding of vector ecology and bionomics is of great importance in evaluations of the transmission dynamics of Leishmania parasites. A field study was conducted in the county of Calakmul, state of Campeche, during the period from November 2006 to March 2007. Phlebotomine sandfly vectors were sampled using Centers for Disease Control light traps, baited Disney traps and Shannon traps. A total of 3374 specimens were captured in the two villages of Once de Mayo (93.8%) and Arroyo Negro (6.1%). In Once de Mayo, the most abundant species were Psathyromyia shannoni, Lutzomyia cruciata, Bichromomyia olmeca olmeca and Psychodopygus panamensis (all: Diptera: Psychodidae). The Shannon trap was by far the most efficient method of collection. The infection rate, as determined by Leishmania mexicana-specific polymerase chain reaction, was 0.3% in Once de Mayo and infected sandflies included Psy. panamensis, B. o. olmeca and Psa. shannoni. There were significant differences in human biting rates across sandfly species and month of sampling. Ecological niche modelling analyses showed an overall overlap of 39.1% for the four species in the whole state of Campeche. In addition, the finding of nine vector-reservoir pairs indicates a potential interaction. The roles of the various sandfly vectors in Calakmul are discussed. © 2016 The Royal Entomological Society.

Quantum-state discrimination

International Nuclear Information System (INIS)

Roa, Luis; Retamal, Juan Carlos; Saavedra, Carlos

2002-01-01

A proposal for a physical implementation of a quantum-state discrimination protocol using an ion in a linear trap is studied, where two nonorthogonal quantum states are codified using two electronic states of the ion. In addition, a protocol is given for discriminating superpositions of nonorthogonal entangled states between ions inside widely separated optical cavities. The discrimination protocol is extended to the case of N linearly independent nonorthogonal quantum states lying in a space of 2N-1 dimensions

Creating cat states in one-dimensional quantum walks using delocalized initial states

International Nuclear Information System (INIS)

Zhang, Wei-Wei; Gao, Fei; Goyal, Sandeep K; Sanders, Barry C; Simon, Christoph

2016-01-01

Cat states are coherent quantum superpositions of macroscopically distinct states and are useful for understanding the boundary between the classical and the quantum world. Due to their macroscopic nature, cat states are difficult to prepare in physical systems. We propose a method to create cat states in one-dimensional quantum walks using delocalized initial states of the walker. Since the quantum walks can be performed on any quantum system, our proposal enables a platform-independent realization of the cat states. We further show that the linear dispersion relation of the effective quantum walk Hamiltonian, which governs the dynamics of the delocalized states, is responsible for the formation of the cat states. We analyze the robustness of these states against environmental interactions and present methods to control and manipulate the cat states in the photonic implementation of quantum walks. (paper)

Sweeping the State Space

DEFF Research Database (Denmark)

Mailund, Thomas

The thesis describes the sweep-line method, a newly developed reduction method for alleviating the state explosion problem inherent in explicit-state state space exploration. The basic idea underlying the sweep-line method is, when calculating the state space, to recognise and delete states...... that are not reachable from the currently unprocessed states. Intuitively we drag a sweep-line through the state space with the invariant that all states behind the sweep-line have been processed and are unreachable from the states in front of the sweep-line. When calculating the state space of a system we iteratively...

Metazoan parasites of fishes from the Celestun coastal lagoon, Yucatan, Mexico.

Science.gov (United States)

Sosa-Medina, Trinidad; Vidal-Martínez, Víctor M; Aguirre-Macedo, M Leopoldina

2015-08-31

The aims of this study were to produce a checklist of the metazoan parasites of fishes from the Celestun coastal lagoon and to determine the degree of faunal similarity among the fishes based on the metazoan parasites they share. A checklist was prepared including all available records (1996-2014) of parasites of marine, brackish water and freshwater fishes of the area. All of these data were included in a presence/absence database and used to determine similarity via Jaccard's index. The results indicate the presence of 62 metazoan parasite species infecting 22 fish species. The number of metazoan parasite species found in the fishes from the Celestún lagoon is apparently the highest reported worldwide for a tropical coastal lagoon. The parasites included 12 species of adult digeneans, 27 digeneans in the metacercarial stage, 6 monogeneans, 3 metacestodes, 9 nematodes, 2 acanthocephalans, 2 crustaceans and 1 annelid. Forty parasite species were autogenic and 23 were allogenic and 1 unknown. The overall similarity among all of the species of fish with respect to the metazoan parasites they share was low (0.08 ± 0.12), with few similarity values above 0.4 being obtained. This low similarity was due primarily to the presence of suites of parasites exclusive to specific species of fish. The autogenic component of the parasite fauna (40 species) dominated the allogenic component (21 species). The most likely explanation for the large number of fish parasites found at Celestún is the good environmental condition of the lagoon, which allows the completion of parasite life cycles and free circulation of euryhaline fishes from the marine environment bringing marine parasites into the lagoon.

3800 Years of Quantitative Precipitation Reconstruction from the Northwest Yucatan Peninsula

Science.gov (United States)

Carrillo-Bastos, Alicia; Islebe, Gerald A.; Torrescano-Valle, Nuria

2013-01-01

Precipitation over the last 3800 years has been reconstructed using modern pollen calibration and precipitation data. A transfer function was then performed via the linear method of partial least squares. By calculating precipitation anomalies, it is estimated that precipitation deficits were greater than surpluses, reaching 21% and <9%, respectively. The period from 50 BC to 800 AD was the driest of the record. The drought related to the abandonment of the Maya Preclassic period featured a 21% reduction in precipitation, while the drought of the Maya collapse (800 to 860 AD) featured a reduction of 18%. The Medieval Climatic Anomaly was a period of positive phases (3.8–7.6%). The Little Ice Age was a period of climatic variability, with reductions in precipitation but without deficits. PMID:24391940

It takes two to tango: self incompatibility in the bromeliad Tillandsia streptophylla (Bromeliaceae) in Mexico.

Science.gov (United States)

Ramírez Morillo, Ivón M; Chi May, Francisco; Carnevali, Germán; May Pat, Filogonio

2009-09-01

Floral phenology and breeding system of Tillandsia streptophylla (Bromeliaceae) were studied in a low inundated forest in Yucatan, Mexico. During the flowering season, from March to August, terminal scapose 1-branched, paniculate inflorescences are produced with one flower per branch opening per day, over a period of 11-29 days. Flowers are tubular, light violet, with the stigma placed below the anthers, both protruding above the corolla. Flowers are protandrous, with anthers releasing pollen from 0500 hours and stigma becoming receptive around 0900 hours. Controlled experimental crosses suggest that Tillandsia streptophylla is self incompatible and therefore, pollinator-dependent.

Verification of hypergraph states

Science.gov (United States)

Morimae, Tomoyuki; Takeuchi, Yuki; Hayashi, Masahito

2017-12-01

Hypergraph states are generalizations of graph states where controlled-Z gates on edges are replaced with generalized controlled-Z gates on hyperedges. Hypergraph states have several advantages over graph states. For example, certain hypergraph states, such as the Union Jack states, are universal resource states for measurement-based quantum computing with only Pauli measurements, while graph state measurement-based quantum computing needs non-Clifford basis measurements. Furthermore, it is impossible to classically efficiently sample measurement results on hypergraph states unless the polynomial hierarchy collapses to the third level. Although several protocols have been proposed to verify graph states with only sequential single-qubit Pauli measurements, there was no verification method for hypergraph states. In this paper, we propose a method for verifying a certain class of hypergraph states with only sequential single-qubit Pauli measurements. Importantly, no i.i.d. property of samples is assumed in our protocol: any artificial entanglement among samples cannot fool the verifier. As applications of our protocol, we consider verified blind quantum computing with hypergraph states, and quantum computational supremacy demonstrations with hypergraph states.

State distribution and reliability of some multi- state systems with ...

African Journals Online (AJOL)

mn : G series systems and second, the multi-state consecutive kn-out-of-mn : G parallel systems (see denitions 1 and 2).We begin by giving a non recursive formula which calculates the state distribution and the reliability of multi-state ...

Component state-based integrated importance measure for multi-state systems

International Nuclear Information System (INIS)

Si, Shubin; Levitin, Gregory; Dui, Hongyan; Sun, Shudong

2013-01-01

Importance measures in reliability engineering are used to identify weak components and/or states in contributing to the reliable functioning of a system. Traditionally, importance measures do not consider the possible effect of groups of transition rates among different component states, which, however, has great effect on the component probability distribution and should therefore be taken into consideration. This paper extends the integrated importance measure (IIM) to estimate the effect of a component residing at certain states on the performance of the entire multi-state systems. This generalization of IIM describes in which state it is most worthy to keep the component to provide the desired level of system performance, and which component is the most important to keep in some state and above for improving the performance of the system. An application to an oil transportation system is presented to illustrate the use of the suggested importance measure

State Financial Aid: Applying Redesign Principles through State Engagement. Special Report

Science.gov (United States)

Pingel, Sarah

2016-01-01

College is increasingly expensive for students, but states have an important policy tool to help defray the costs: state financial aid programs. However, many states' programs are misaligned with articulated strategic postsecondary education policy goals. Over the past two years, Education Commission of the States has supported a variety of…

Multiqubit W states lead to stronger nonclassicality than Greenberger-Horne-Zeilinger states

International Nuclear Information System (INIS)

Sen, Aditi; Sen, Ujjwal; Zukowski, Marek; Wiesniak, Marcin; Kaszlikowski, Dagomir

2003-01-01

The N-qubit states of the W class, for N>10, lead to more robust (against noise admixture) violations of local realism, than the Greenberger-Horne-Zeilinger (GHZ) states. These violations are most pronounced for correlations for a pair of qubits, conditioned on specific measurement results for the remaining N-2 qubits. The considerations provide us with a qualitative difference between the W state and GHZ state in the situation when they are separately sent via depolarizing channels. For sufficiently high amount of noise in the depolarizing channel, the GHZ states cannot produce a distillable state between two qubits, whereas the W states can still produce a distillable state in a similar situation

Vital Signs: Trends in State Suicide Rates - United States, 1999-2016 and Circumstances Contributing to Suicide - 27 States, 2015.

Science.gov (United States)

Stone, Deborah M; Simon, Thomas R; Fowler, Katherine A; Kegler, Scott R; Yuan, Keming; Holland, Kristin M; Ivey-Stephenson, Asha Z; Crosby, Alex E

2018-06-08

Suicide rates in the United States have risen nearly 30% since 1999, and mental health conditions are one of several factors contributing to suicide. Examining state-level trends in suicide and the multiple circumstances contributing to it can inform comprehensive state suicide prevention planning. Trends in age-adjusted suicide rates among persons aged ≥10 years, by state and sex, across six consecutive 3-year periods (1999-2016), were assessed using data from the National Vital Statistics System for 50 states and the District of Columbia. Data from the National Violent Death Reporting System, covering 27 states in 2015, were used to examine contributing circumstances among decedents with and without known mental health conditions. During 1999-2016, suicide rates increased significantly in 44 states, with 25 states experiencing increases >30%. Rates increased significantly among males and females in 34 and 43 states, respectively. Fifty-four percent of decedents in 27 states in 2015 did not have a known mental health condition. Among decedents with available information, several circumstances were significantly more likely among those without known mental health conditions than among those with mental health conditions, including relationship problems/loss (45.1% versus 39.6%), life stressors (50.5% versus 47.2%), and recent/impending crises (32.9% versus 26.0%), but these circumstances were common across groups. Suicide rates increased significantly across most states during 1999-2016. Various circumstances contributed to suicides among persons with and without known mental health conditions. States can use a comprehensive evidence-based public health approach to prevent suicide risk before it occurs, identify and support persons at risk, prevent reattempts, and help friends and family members in the aftermath of a suicide.

StateGEN/StateNET - A structured method to perform route comparisons

International Nuclear Information System (INIS)

Cashwell, J.W.; Erickson, C.M.

1989-01-01

StateGEN/StateNET is a modeling structure and routing algorithm designed expressly to address the needs of state and local governments to perform analyses of routing alternatives. StateGEN/StateNET is designed to permit the user to construct a network and assign attributes of interest to the network on a personal computer (PC). The completed network is then transferred via a modem to the TRANSNET system and the preferred route is determined based upon attribute weights assigned by the user. This modeling structure permits the state or local government to perform a routing analysis, such as that required by the US Department of Transportation (DOT) for Highway Route-Controlled Quantity shipments of radioactive materials, with a minimum of resources. StateGEN/StateNET provides a computerized version of the DOT guidelines or allows the user to structure their own network parameters. Sandia National Laboratories (SNL) is the Department of Energy (DOE) lead organization for transportation research and development. The DOE Office of Defense Programs has been the prime sponsor of development of models and associated databases used to analyze the impacts of the transportation of radioactive materials. The routing algorithms used in StateGEN/StateNET were based on the existing models on TRANSNET, a system which was developed to enable outside users to access analytical codes and associated data developed for the DOE

StateGEN/StateNET--A structured method to perform route comparisons

International Nuclear Information System (INIS)

Cashwell, J.W.; Erickson, C.M.

1989-01-01

StateGEN/StateNET is a modelling structure and routing algorithm designed expressly to address the needs of state and local governments to perform analyses of routing alternatives. StateGEN/StateNET is designed to permit the user to construct a network and assign attributes of interest to the network on a personal computer (PC). The completed network is then transferred via a modem to the TRANSNET system (Cashwell, 1989) and the preferred route is determined based upon attribute weights assigned by the user. This modelling structure permits the state or local to perform a routing analysis, such as that required by the US Department of Transportation (DOT) for Highway Route-Controlled Quantity shipments of radioactive materials, with a minimum of resources. StateGEN/StateNET provides a computerized version of the DOT guidelines (Cashwell, 1989) or allows the user to structure their own network parameters. Sandia national Laboratories (SNL) is the Department of Energy's (DOE) lead organization for transportation research and development. The DOE Office of Defense Programs has been the prime sponsor of development of models and associated databases used to analyze the impacts of the transportation of radioactive materials. The routing algorithms used in StateGEN/StateNET were based on the existing models on TRANSNET, a system which was developed to enable outside users to access analytical codes and associated data developed for the DOE. 2 refs

Controlled teleportation of high-dimension quantum-states with generalized Bell-state measurement

Institute of Scientific and Technical Information of China (English)

Zhan You-Bang

2007-01-01

In this paper a scheme for controlled teleportation of arbitrary high-dimensional unknown quantum states is proposed by using the generalized Bell-basis measurement and the generalized Hadamard transformation. As two special cases, two schemes of controlled teleportation of an unknown single-qutrit state and an unknown two-qutrit state are investigated in detail. In the first scheme, a maximally entangled three-qutrit state is used as the quantum channel, while in the second scheme, an entangled two-qutrit state and an entangled three-qutrit state are employed as the quantum channels. In these schemes, an unknown qutrit state can be teleported to either one of two receivers, but only one of them can reconstruct the qutrit state with the help of the other. Based on the case of qutrits, a scheme of controlled teleportation of an unknown qudit state is presented.

When Traits Match States: Examining the Associations between Self-Report Trait and State Mindfulness following a State Mindfulness Induction.

Science.gov (United States)

Bravo, Adrian J; Pearson, Matthew R; Wilson, Adam D; Witkiewitz, Katie

2018-02-01

Previous research has found inconsistent relationships between trait mindfulness and state mindfulness. To extend previous research, we sought to examine the unique associations between self-report trait mindfulness and state mindfulness by levels of meditation experience (meditation-naïve vs. meditation-experienced) and by mindfulness induction (experimentally induced mindful state vs. control group). We recruited 299 college students (93 with previous mindfulness meditation experience) to participate in an experiment that involved the assessment of five facets of trait mindfulness (among other constructs), followed by a mindfulness induction (vs. control), followed by the assessment of state mindfulness of body and mind. Correlational analyses revealed limited associations between trait mindfulness facets and facets of state mindfulness, and demonstrated that a brief mindfulness exercise focused on bodily sensations and the breath elicited higher state mindfulness of body but not state mindfulness of mind. We found significant interactions such that individuals with previous meditation experience and higher scores on the observing facet of trait mindfulness had the highest levels of state mindfulness of body and mind. Among individuals with meditation experience, the strengths of the associations between observing trait mindfulness and the state mindfulness facets increased with frequency of meditation practice. Some other interactions ran counter to expectations. Overall, the relatively weak associations between trait and state mindfulness demonstrates the need to improve our operationalizations of mindfulness, advance our understanding of how to best cultivate mindfulness, and reappraise the ways in which mindfulness can manifest as a state and as a trait.

Excited states

CERN Document Server

Lim, Edward C

1974-01-01

Excited States, Volume I reviews radiationless transitions, phosphorescence microwave double resonance through optical spectra in molecular solids, dipole moments in excited states, luminescence of polar molecules, and the problem of interstate interaction in aromatic carbonyl compounds. The book discusses the molecular electronic radiationless transitions; the double resonance techniques and the relaxation mechanisms involving the lowest triplet state of aromatic compounds; as well as the optical spectra and relaxation in molecular solids. The text also describes dipole moments and polarizab

Wind deployment in the United States: states, resources, policy, and discourse.

Science.gov (United States)

Wilson, Elizabeth J; Stephens, Jennie C

2009-12-15

A transformation in the way the United States produces and uses energy is needed to achieve greenhouse gas reduction targets for climate change mitigation. Wind power is an important low-carbon technology and the most rapidly growing renewable energy technology in the U.S. Despite recent advances in wind deployment, significant state-by-state variation in wind power distribution cannot be explained solely by wind resource patterns nor by state policy. Other factors embedded within the state-level socio-political context also contribute to wind deployment patterns. We explore this socio-political context in four U.S. states by integrating multiple research methods. Through comparative state-level analysis of the energy system, energy policy, and public discourse as represented in the media, we examine variation in the context for wind deployment in Massachusetts, Minnesota, Montana, and Texas. Our results demonstrate that these states have different patterns of wind deployment, are engaged in different debates about wind power, and appear to frame the risks and benefits of wind power in different ways. This comparative assessment highlights the complex variation of the state-level socio-political context and contributes depth to our understanding of energy technology deployment processes, decision-making, and outcomes.

Squeezed states of the generalized minimum uncertainty state for the Caldirola-Kanai Hamiltonian

International Nuclear Information System (INIS)

Kim, Sang Pyo

2003-01-01

We show that the ground state of the well-known pseudo-stationary states for the Caldirola-Kanai Hamiltonian is a generalized minimum uncertainty state, which has the minimum allowed uncertainty ΔqΔp = ℎσ 0 /2, where σ 0 (≥1) is a constant depending on the damping factor and natural frequency. The most general symmetric Gaussian states are obtained as the one-parameter squeezed states of the pseudo-stationary ground state. It is further shown that the coherent states of the pseudo-stationary ground state constitute another class of the generalized minimum uncertainty states

State Park Trails

Data.gov (United States)

Minnesota Department of Natural Resources — This data set is a collection of ArcView shapefiles (by park) of trails within statutory boundaries of individual MN State Parks, State Recreation Areas and State...

State Gun Policy and Cross-State Externalities: Evidence from Crime Gun Tracing

OpenAIRE

Brian Knight

2013-01-01

This paper provides a theoretical and empirical analysis of cross-state externalities associated with gun regulations in the context of the gun trafficking market. Using gun tracing data, which identify the source state for crime guns recovered in destination states, we find that firearms in this market tend to flow from states with weak gun laws to states with strict gun laws, satisfying a necessary condition for the existence of cross-state externalities in the theoretical model. We also fi...

Failing States or Failing Models?: Accounting for the Incidence of State Collapse

OpenAIRE

Martin Doornbos

2010-01-01

In recent years the notion and phenomenon of .failingÿ states - states deemed incapable to fulfil the basic tasks of providing security for their populace -, has been rapidly drawing attention. I will start off with a closer look at the inci- dence of fragile states and state failure, more specifically of state collapse. Connected with this, I will raise the question of differential degrees of propensity to failure and collapse among contemporary state systems, and to point to apparent region...

Impossibility criterion for obtaining pure entangled states from mixed states by purifying protocols

International Nuclear Information System (INIS)

Chen Pingxing; Liang Linmei; Li Chengzu; Huang Mingqiu

2002-01-01

Purifying noisy entanglement is a protocol that can increase the entanglement of a mixed state (as a source) at the expense of the entanglement of others (such as an ancilla) by collective measurement. A protocol with which one can get a pure entangled state from a mixed state is defined as purifying mixed states. We address a basic question: can one get a pure entangled state from a mixed state? We give a necessary and sufficient condition of purifying a mixed state by fit local operations and classical communication and show that for a class of source states and ancilla states in arbitrary bipartite systems purifying mixed states is impossible by finite rounds of purifying protocols. For 2x2 systems, it is proved that arbitrary states cannot be purified by individual measurement. The possible application and meaning of the conclusion are discussed

STATE_SYSTEM

Data.gov (United States)

Kansas Data Access and Support Center — This dataset is a single centerline highway network representation of the 10,000 miles Kansas State Highway System (Interstate, U.S., and Kansas routes). The state...

State Machine Framework And Its Use For Driving LHC Operational states

CERN Document Server

Misiowiec, M; Solfaroli Camilloci, M

2011-01-01

The LHC follows a complex operational cycle with 12 major phases that include equipment tests, preparation, beam injection, ramping and squeezing, finally followed by the physics phase. This cycle is modelled and enforced with a state machine, whereby each operational phase is represented by a state. On each transition, before entering the next state, a series of conditions is verified to make sure the LHC is ready to move on. The State Machine framework was developed to cater for building independent or embedded state machines. They safely drive between the states executing tasks bound to transitions and broadcast related information to interested parties. The framework encourages users to program their own actions. Simple configuration management allows the operators to define and maintain complex models themselves. An emphasis was also put on easy interaction with the remote state machine instances through standard communication protocols. On top of its core functionality, the framework offers a transparen...

Electrophysiological difference between mental state decoding and mental state reasoning.

Science.gov (United States)

Cao, Bihua; Li, Yiyuan; Li, Fuhong; Li, Hong

2012-06-29

Previous studies have explored the neural mechanism of Theory of Mind (ToM), but the neural correlates of its two components, mental state decoding and mental state reasoning, remain unclear. In the present study, participants were presented with various photographs, showing an actor looking at 1 of 2 objects, either with a happy or an unhappy expression. They were asked to either decode the emotion of the actor (mental state decoding task), predict which object would be chosen by the actor (mental state reasoning task), or judge at which object the actor was gazing (physical task), while scalp potentials were recorded. Results showed that (1) the reasoning task elicited an earlier N2 peak than the decoding task did over the prefrontal scalp sites; and (2) during the late positive component (240-440 ms), the reasoning task elicited a more positive deflection than the other two tasks did at the prefrontal scalp sites. In addition, neither the decoding task nor the reasoning task has no left/right hemisphere difference. These findings imply that mental state reasoning differs from mental state decoding early (210 ms) after stimulus onset, and that the prefrontal lobe is the neural basis of mental state reasoning. Copyright © 2012 Elsevier B.V. All rights reserved.

Payment - State

Data.gov (United States)

U.S. Department of Health & Human Services — Payment measures – state data. This data set includes state-level data for the payment measures associated with an episode of care for heart attack, heart failure,...

State of the States: Fuel Cells in America 2013

Energy Technology Data Exchange (ETDEWEB)

Curtin, Sandra; Gangi, Jennifer

2013-10-31

This October 2013 report, written by Fuel Cells 2000 and partially funded by the U.S. Department of Energy's Fuel Cell Technologies Office, continues to build on the April 2010 State of the States report that provided a snapshot of fuel cell and hydrogen activity in the 50 states and District of Columbia. This update report provides more details on the progress and activities that happened since the third report, issued in August 2012.

State of the States: Fuel Cells in America, 2010

Energy Technology Data Exchange (ETDEWEB)

Curtin, Sandra; Delmont, Elizabeth; Gangi, Jennifer

2010-04-01

This report, written by Fuel Cells 2000 and partially funded by the U.S. Department of Energy's Fuel Cell Technologies Program, provides a snapshot of fuel cell and hydrogen activity in the 50 states and District of Columbia. It features the top five fuel cell states (in alphabetical order): California, Connecticut, New York, Ohio, and South Carolina. State activities reported include supportive fuel cell and hydrogen policies, installations and demonstrations, road maps, and level of activism.

State and market

Directory of Open Access Journals (Sweden)

Ivan Ferenčak

2014-10-01

Full Text Available The debate about the relationship between state and market, about their relative importance, does not cease to be topical, and there is no end of it in sight. The market (invisible hand does need, more or less, the help of the state (visible hand. Liberal sympathizers of the market prefer a “small” state whose ambitions include only providing an adaptable legal framework in which and by which the market functions, and (re allocation of resources, because of the inherent defects of the market. Proponents of welfare economics will wish for progressive taxation and redistribution of income. Keynes’s mission to save capitalism meant an increase in the importance of the state and appearance of a new, stabilizing role of the state. Excessive unemployment is to be prevented by fine-tuning. Unfortunately, Keynes’s critics from the public choice camp will say that the state (government is not perfect, and, as a rule, falls into the trap of asymmetry. Only and solely in theory will it apply that a perfect state means perfect functioning of an imperfect market.

Remote State Preparation of a Greenberger-Horne-Zeilinger Class State

International Nuclear Information System (INIS)

Zhan Youbang

2005-01-01

In this paper, we propose a scheme for the remote preparation of a three-particle Greenberger-Horne-Zeilinger class state by a two-particle entangled state and a three-particle entangled state. It is shown that, by this scheme, only two classical bits and one two-particle projective measurement are enough for such preparation.

Photon virtual bound state

International Nuclear Information System (INIS)

Inoue, J.; Ohtaka, K.

2004-01-01

We study virtual bound states in photonics, which are a vectorial extension of electron virtual bound states. The condition for these states is derived. It is found that the Mie resonant state which satisfies the condition that the size parameter is less than the angular momentum should be interpreted as a photon virtual bound state. In order to confirm the validity of the concept, we compare the photonic density of states, the width of which represents the lifetime of the photon virtual bound states, with numerical results

Multiquark states

International Nuclear Information System (INIS)

Wang, F.; Ping, J.L.; Quing, D.; Goldman, T.

2005-01-01

The pentaquark state recently discovered has been discussed based on various quark model calculations. Odd parity for the state cannot be ruled out theoretically because the contributions related to nontrivial color structures have not been studied completely. Other multiquark states, especially dibaryons, have been discussed also. A strangeness -3 NΩ dibaryons, have been shown to have a width as small as 12-22 keV and should be detectable in Ω-high-productivity reactions such as at RHIC, COMPAS, and the planned JHF and FAIR projects [ru

Asociación entre la incidencia de leishmaniosis cutánea y el índice de desarrollo humano y sus componentes en cuatro estados endémicos de Venezuela Association between cutaneous leishmaniasis incidence and the human development index and its components in four endemic states of Venezuela

Directory of Open Access Journals (Sweden)

Alfonso J. Rodríguez-Morales

2010-03-01

the linear regression models, it was observed that the relationship between epidemiological and social variables was different at States levels. For Mérida and Trujillo it was observed a significant decrease in the CL regard to the increase of literacy (p<0.05, of the gross combined enrollment (p<0.05, life expectancy (p<0.05, money income (p<0.05 and the HDI (p<0.05. Conclusion. This information reflects the significant influence of socioeconomical indicators on the CL incidence at Trujillo and Merida, being an inverse relationship between both types of variables; with an increase or improvement in the socioeconomical indicators, the disease incidence rate decreased.

State-to-state dynamics of molecular energy transfer

Energy Technology Data Exchange (ETDEWEB)

Gentry, W.R.; Giese, C.F. [Univ. of Minnesota, Minneapolis (United States)

1993-12-01

The goal of this research program is to elucidate the elementary dynamical mechanisms of vibrational and rotational energy transfer between molecules, at a quantum-state resolved level of detail. Molecular beam techniques are used to isolate individual molecular collisions, and to control the kinetic energy of collision. Lasers are used both to prepare specific quantum states prior to collision by stimulated-emission pumping (SEP), and to measure the distribution of quantum states in the collision products by laser-induced fluorescence (LIF). The results are interpreted in terms of dynamical models, which may be cast in a classical, semiclassical or quantum mechanical framework, as appropriate.

Qutrit magic state distillation

International Nuclear Information System (INIS)

Anwar, Hussain; Browne, Dan E; Campbell, Earl T

2012-01-01

Magic state distillation (MSD) is a purification protocol that plays an important role in fault-tolerant quantum computation. Repeated iteration of the steps of an MSD protocol generates pure single non-stabilizer states, or magic states, from multiple copies of a mixed resource state using stabilizer operations only. Thus mixed resource states promote the stabilizer operations to full universality. MSD was introduced for qubit-based quantum computation, but little has been known concerning MSD in higher-dimensional qudit-based computation. Here, we describe a general approach for studying MSD in higher dimensions. We use it to investigate the features of a qutrit MSD protocol based on the five-qutrit stabilizer code. We show that this protocol distils non-stabilizer magic states, and identify two types of states that are attractors of this iteration map. Finally, we show how these states may be converted, via stabilizer circuits alone, into a state suitable for state-injected implementation of a non-Clifford phase gate, enabling non-Clifford unitary computation. (paper)

Quantum chimera states

International Nuclear Information System (INIS)

Viennot, David; Aubourg, Lucile

2016-01-01

We study a theoretical model of closed quasi-hermitian chain of spins which exhibits quantum analogues of chimera states, i.e. long life classical states for which a part of an oscillator chain presents an ordered dynamics whereas another part presents a disordered dynamics. For the quantum analogue, the chimera behaviour deals with the entanglement between the spins of the chain. We discuss the entanglement properties, quantum chaos, quantum disorder and semi-classical similarity of our quantum chimera system. The quantum chimera concept is novel and induces new perspectives concerning the entanglement of multipartite systems. - Highlights: • We propose a spin chain model with long range couplings having purely quantum states similar to the classical chimera states. • The quantum chimera states are characterized by the coexistence of strongly entangled and non-entangled spins in the same chain. • The quantum chimera states present some characteristics of quantum chaos.

Quantum chimera states

Energy Technology Data Exchange (ETDEWEB)

Viennot, David, E-mail: david.viennot@utinam.cnrs.fr; Aubourg, Lucile

2016-02-15

We study a theoretical model of closed quasi-hermitian chain of spins which exhibits quantum analogues of chimera states, i.e. long life classical states for which a part of an oscillator chain presents an ordered dynamics whereas another part presents a disordered dynamics. For the quantum analogue, the chimera behaviour deals with the entanglement between the spins of the chain. We discuss the entanglement properties, quantum chaos, quantum disorder and semi-classical similarity of our quantum chimera system. The quantum chimera concept is novel and induces new perspectives concerning the entanglement of multipartite systems. - Highlights: • We propose a spin chain model with long range couplings having purely quantum states similar to the classical chimera states. • The quantum chimera states are characterized by the coexistence of strongly entangled and non-entangled spins in the same chain. • The quantum chimera states present some characteristics of quantum chaos.

The State, War, and the State of War

African Journals Online (AJOL)

Attempts to offer an understanding of the relationship between war making and state creation in the world have been undertaken by many international relations and strategic studies scholars. In most of these attempts attention has been focused on how state making in Europe differed from that in other parts of the world.

Alaska State Trails Program

Science.gov (United States)

Recreation Search DNR State of Alaska Home Menu Parks Home Alaska State Trails Boating Safety Design and Home / Alaska State Trails Alaska State Trails Program Trails in the Spotlight Glacier Lake and Saddle Trails in Kachemak State Park Glacier Lake A Popular route joins the Saddle and Glacier Lake Trails. The

An Empirical State Error Covariance Matrix for Batch State Estimation

Science.gov (United States)

Frisbee, Joseph H., Jr.

2011-01-01

State estimation techniques serve effectively to provide mean state estimates. However, the state error covariance matrices provided as part of these techniques suffer from some degree of lack of confidence in their ability to adequately describe the uncertainty in the estimated states. A specific problem with the traditional form of state error covariance matrices is that they represent only a mapping of the assumed observation error characteristics into the state space. Any errors that arise from other sources (environment modeling, precision, etc.) are not directly represented in a traditional, theoretical state error covariance matrix. Consider that an actual observation contains only measurement error and that an estimated observation contains all other errors, known and unknown. It then follows that a measurement residual (the difference between expected and observed measurements) contains all errors for that measurement. Therefore, a direct and appropriate inclusion of the actual measurement residuals in the state error covariance matrix will result in an empirical state error covariance matrix. This empirical state error covariance matrix will fully account for the error in the state estimate. By way of a literal reinterpretation of the equations involved in the weighted least squares estimation algorithm, it is possible to arrive at an appropriate, and formally correct, empirical state error covariance matrix. The first specific step of the method is to use the average form of the weighted measurement residual variance performance index rather than its usual total weighted residual form. Next it is helpful to interpret the solution to the normal equations as the average of a collection of sample vectors drawn from a hypothetical parent population. From here, using a standard statistical analysis approach, it directly follows as to how to determine the standard empirical state error covariance matrix. This matrix will contain the total uncertainty in the

Entanglement swapping of a GHZ state via a GHZ-like state

Energy Technology Data Exchange (ETDEWEB)

Tsai, Chia-Wei; Hwang, Tzonelih, E-mail: hwangtl@ismail.csie.ncku.edu.t [National Cheng Kung University, Department of Computer Science and Information Engineering, No. 1 Ta-Hsueh Road, Tainan City 701, Taiwan (China)

2011-10-15

This study uses the Greenberger-Horne-Zeilinger (GHZ)-like state |G>= 1/2 (|001>+|010>+|100>+|111>) to establish an entanglement swapping protocol on a pure GHZ state. A quantum circuit is proposed to assist in teleporting the entanglement of the pure GHZ state. Furthermore, on the basis of the generation of the GHZ-like state, an improved protocol to reduce the number of transmitted photons required in the process of entanglement swapping is proposed.

Accountability. State Implementation of Common Core State Standards

Science.gov (United States)

Anderson, Kimberly; Mira, Mary Elizabeth

2014-01-01

All of the 15 states in this study have recently been involved in school accountability system reform. Since 2011, the states have taken advantage of a federal program to give them flexibility around certain accountability requirements of the "No Child Left Behind Act" of 2001 (NCLB), the most recent reauthorization of the Elementary and…

Error Free Quantum Reading by Quasi Bell State of Entangled Coherent States

Science.gov (United States)

Hirota, Osamu

2017-12-01

Nonclassical states of light field have been exploited to provide marvellous results in quantum information science. Usefulness of nonclassical states in quantum information science depends on whether a physical parameter as a signal is continuous or discrete. Here we present an investigation of the potential of quasi Bell states of entangled coherent states in quantum reading of the classical digital memory which was pioneered by Pirandola (Phys.Rev.Lett.,106,090504,2011). This is a typical example of discrimination for discrete quantum parameters. We show that the quasi Bell state gives the error free performance in the quantum reading that cannot be obtained by any classical state.

SwingStates: Adding state machines to Java and the Swing toolkit

OpenAIRE

Appert , Caroline; Beaudouin-Lafon , Michel

2008-01-01

International audience; This article describes SwingStates, a Java toolkit designed to facilitate the development of graphical user interfaces and bring advanced interaction techniques to the Java platform. SwingStates is based on the use of finite-state machines specified directly in Java to describe the behavior of interactive systems. State machines can be used to redefine the behavior of existing Swing widgets or, in combination with a new canvas widget that features a rich graphical mode...

Effects of the Strategic Prevention Framework State Incentives Grant (SPF SIG) on state prevention infrastructure in 26 states.

Science.gov (United States)

Orwin, Robert G; Stein-Seroussi, Alan; Edwards, Jessica M; Landy, Ann L; Flewelling, Robert L

2014-06-01

The Strategic Prevention Framework State Incentive Grant (SPF SIG) program is a national public health initiative sponsored by the U.S. Substance Abuse and Mental Health Services Administration's Center for Substance Abuse Prevention to prevent substance abuse and its consequences. State grantees used a data-driven planning model to allocate resources to 450 communities, which in turn launched over 2,200 intervention strategies to target prevention priorities in their respective populations. An additional goal was to build prevention capacity and infrastructure at the state and community levels. This paper addresses whether the state infrastructure goal was achieved, and what contextual and implementation factors were associated with success. The findings are consistent with claims that, overall, the SPF SIG program met its goal of increasing prevention capacity and infrastructure across multiple infrastructure domains, though the mediating effects of implementation were evident only in the evaluation/monitoring domain. The results also show that an initiative like the SPF SIG, which could easily have been compartmentalized within the states, has the potential to permeate more broadly throughout state prevention systems.

The State and Corporatism

DEFF Research Database (Denmark)

Kaspersen, Lars Bo; Schmidt-Hansen, Ulrich

in corporatist theory. In particular, we draw upon a conceptualization of the state developed by Michael Mann and Eric Nordlinger's different forms of state autonomy. We propose a state-centered theoretical focus enabling us to grasp the role of the state in the dynamics of the corporatist system. In the second...... to the development of the `Danish model', but that these actors were often orchestrated by the state. At crucial moments the direction of these different actors was even determined by the state. In the first part of the article, it is argued that the state has been under-theorized and to some extent neglected...

Household energy use in urban Venezuela: Implications from surveys in Maracaibo, Valencia, Merida, and Barcelona-Puerto La Cruz

Energy Technology Data Exchange (ETDEWEB)

Figueroa, M.J.; Sathaye, J.

1993-08-01

This report identifies the most important results of a comparative analysis of household commercial energy use in Venezuelan urban cities. The use of modern fuels is widespread among all cities. Cooking consumes the largest share of urban household energy use. The survey documents no use of biomass and a negligible use of kerosene for cooking. LPG, natural gas, and kerosene are the main fuels available. LPG is the fuel choice of low-income households in all cities except Maracaibo, where 40% of all households use natural gas. Electricity consumption in Venezuela`s urban households is remarkably high compared with the levels used in households in comparable Latin American countries and in households of industrialized nations which confront harsher climatic conditions and, therefore, use electricity for water and space heating. The penetration of appliances in Venezuela`s urban households is very high. The appliances available on the market are inefficient, and there are inefficient patterns of energy use among the population. Climate conditions and the urban built form all play important roles in determining the high level of energy consumption in Venezuelan urban households. It is important to acknowledge the opportunities for introducing energy efficiency and conservation in Venezuela`s residential sector, particularly given current economic and financial constraints, which may hamper the future provision of energy services.

State of the States: Fuel Cells in America 2015

Energy Technology Data Exchange (ETDEWEB)

Sandra Curtin and Jennifer Gangi

2015-12-17

This December 2015 report, the sixth in a series, provides a comprehensive analysis of state activities supporting fuel cell and hydrogen technology, profiles of leading states, and a catalog of recent installations, policies, funding, and deployments around the country.

State Standard-Setting Processes in Brief. State Academic Standards: Standard-Setting Processes

Science.gov (United States)

Thomsen, Jennifer

2014-01-01

Concerns about academic standards, whether created by states from scratch or adopted by states under the Common Core State Standards (CCSS) banner, have drawn widespread media attention and are at the top of many state policymakers' priority lists. Recently, a number of legislatures have required additional steps, such as waiting periods for…

Present state of electric power business in United States and Europe

International Nuclear Information System (INIS)

Onishi, Kenichi

2011-01-01

This article reported present state of nuclear power and electric power business in United States and Europe after Fukushima Daiichi Accident. As for the trend of demand and supply of electric power and policy, the accident forced Germany possibly to proceed with phase-out of nuclear power, but France and United States to sustain nuclear power with no great change of energy policy at this moment. As for the trend of electric power market, there was not state in United States with liberalized retail market of electric power after rolling blackouts occurred in California State in the early 2000s. In Germany proceeding with renewable energy introduction, renewable electricity fed into the grid was paid for by the network operators at fixed tariffs and the costs passed on to electricity consumers were increasing. Renewable Portfolio Standards (RPS) in United States forced the state to introduction of renewable energy to some ratio, and Feed-in Tariff (FIT) introduced in EU in 1990s lead to introduction of a large amount of renewable electricity targeted in 2020. Huge amount of wind power introduction brought about several problems to solve such that excess electric power above domestic demand had bad effects on grids in neighboring region. Enforcement of power transmission lines was also needed with increase of maximum electric power as well as introduction of a large amount of renewable electricity. (T. Tanaka)

Excited states v.6

CERN Document Server

Lim, Edward C

1982-01-01

Excited States, Volume 6 is a collection of papers that discusses the excited states of molecules. The first paper discusses the linear polyene electronic structure and potential surfaces, considering both the theoretical and experimental approaches in such electronic states. This paper also reviews the theory of electronic structure and cites some experimental techniques on polyene excitations, polyene spectroscopic phenomenology, and those involving higher states of polyenes and their triplet states. Examples of these experimental studies of excited states involve the high-resolution one-pho

Excited states 2

CERN Document Server

Lim, Edward C

2013-01-01

Excited States, Volume 2 is a collection of papers that deals with molecules in the excited states. The book describes the geometries of molecules in the excited electronic states. One paper describes the geometries of a diatomic molecule and of polyatomic molecules; it also discusses the determination of the many excited state geometries of molecules with two, three, or four atoms by techniques similar to diatomic spectroscopy. Another paper introduces an ordered theory related to excitons in pure and mixed molecular crystals. This paper also presents some experimental data such as those invo

Rotating quantum states

International Nuclear Information System (INIS)

Ambruş, Victor E.; Winstanley, Elizabeth

2014-01-01

We revisit the definition of rotating thermal states for scalar and fermion fields in unbounded Minkowski space–time. For scalar fields such states are ill-defined everywhere, but for fermion fields an appropriate definition of the vacuum gives thermal states regular inside the speed-of-light surface. For a massless fermion field, we derive analytic expressions for the thermal expectation values of the fermion current and stress–energy tensor. These expressions may provide qualitative insights into the behaviour of thermal rotating states on more complex space–time geometries

State and local policies related to sexual orientation in the United States.

Science.gov (United States)

Cramer, Ryan; Hexem, Sarah; LaPollo, Archana; Cuffe, Kendra M; Chesson, Harrell W; Leichliter, Jami S

2017-02-01

Poorer health suffered by lesbian, gay, and bisexual (LGB) populations may be associated with public policies. We collected the laws that in 2013 prohibited discrimination based on sexual orientation from 50 United States (US) states, the District of Columbia (Washington, DC or DC), and the 30 most populous US metropolitan areas. To facilitate future research, we coded certain aspects of these laws to create a dataset. We generated descriptive statistics by jurisdiction type and tested for regional differences in state law using Chi-square tests. Sixteen (31.4 per cent) states prohibited discrimination by all employers based on sexual orientation, 25 states (49.0 per cent) in public employment, 18 states (35.3 per cent) in government contracting, and 21 states (41.2 per cent) in private employment. Twenty-one states prohibited discrimination (41.2 per cent) in housing practices (selling and renting), and 17 (33.3 per cent) in public accommodations. Local (county/city) laws prohibiting discrimination were less common. State laws differed significantly by US census region - West, Midwest, Northeast, and South. Future analyses of these data could examine the impact of these laws on various outcomes, including health among LGB populations.

Employee, State of Alaska

Science.gov (United States)

Business Resources Division of Corporations, Business & Professional Licensing Dept. of Commerce Benefits Resources State Employee Directory State Calendar State Training: LearnAlaska State Travel Manager) Web Mail (Outlook) Login Who to Call Health Insurance Insurance Benefits Health and Optional

Unification of the Two-Parameter Equation of State and the Principle of Corresponding States

DEFF Research Database (Denmark)

Mollerup, Jørgen

1998-01-01

A two-parameter equation of state is a two-parameter corresponding states model. A two-parameter corresponding states model is composed of two scale factor correlations and a reference fluid equation of state. In a two-parameter equation of state the reference equation of state is the two-paramet...

Chemical composition of precipitation in a Mexican Maya region

Science.gov (United States)

Bravo, H. A.; Saavedra, M. I. R.; Sánchez, P. A.; Torres, R. J.; Granada, L. M. M.

The chemical characteristics of wet precipitation in Puerto Morelos, Quintana Roo State, Mexico, were measured from April 1994 to December 1995. Puerto Morelos is located in the Caribbean Mayan coastal region of the Peninsula of Yucatan, and is normally exposed to winds from the Caribbean region. Wetfall was analyzed for pH, conductivity and Cl -, NO 3-, SO 42-, Na +, NH 4+, K +, Mg 2+ and Ca 2+ ion concentrations. Volume-weighted mean pH for the whole sampling period was 5.35, although values as low as 4.6 were measured in several rain samples. Concentrations of all species correlated negatively with rain volume. Sea-salt aerosols contributed with most of the Na +, Cl -, Mg 2+, K + and SO 42- found in wet precipitation. The mean [SO 42-excess] was 9.7 μEq l -1, which agrees with the background hemispheric values of ≈10 μEq l -1 reported elsewhere. The mean [NO 3-] was 11.4 μEq l -1, almost four times higher than the background hemispheric value of ≈2.5 μEq l -1 reported elsewhere. However, a major component causing the slight acidity character of rain in Puerto Morelos seems to be H 2SO 4.

New meaning from old collections- figurines from the Museo de Jonuta, Chapas Mexico

International Nuclear Information System (INIS)

Sears, Erin L.

2001-01-01

Old collections of archaeological ceramics, often with diverse histories can be a rich source of new information when they are linked with new excavation materials through instrumental neutron activation analysis or other comparable analytical technique. INAA has been applied to study of Maya ceramics from southern Mexico for more than forty years, specially in the modern states of Tabasco, Chapas, Campeche and Yucatan and the Guatemala region of El Peten, More than 1.100 analyzes of fine paste orange and gray pottery provides an extensive compositional background against which to view the chemical variation of a recently analyzed collection of Maya figurines from the Museo de Jonuta, Tabasco Mexico. These figurines constitute an important assemblage of archaeological pottery as they reveal stylistic patterns of continuity in artistic traditions and aspects of stylistics change at and immediately before the time of the so called a Maya Collapse. Since the town of Jonuta is located in hypothesized home of non Maya invaders who are thought to be factors in the Maya collapse. INAA data on the figurines sources of production and related patterns of representational style, provide new data to address the social changes that took place in the lowland Maya regions at the end of the 8 th Century