Structure of the testis and spermatogenesis of the viviparous teleost Poecilia mexicana (Poeciliidae) from an active sulfur spring cave in Southern Mexico

2019 ◽  
Vol 280 (10) ◽  
pp. 1537-1547
Author(s):  
Aarón Torres‐Martínez ◽  
Liliana Ruiz de Dios ◽  
Arlette Hernández‐Franyutti ◽  
Mari Carmen Uribe ◽  
Wilfrido Contreras Sánchez
Keyword(s):  
Southern Mexico ◽  
Poecilia Mexicana

scholarly journals Epigenetic inheritance of DNA methylation changes in fish living in hydrogen sulfide–rich springs

2021 ◽  
Vol 118 (26) ◽  
pp. e2014929118
Author(s):  
Joanna L. Kelley ◽  
Michael Tobler ◽  
Daniel Beck ◽  
Ingrid Sadler-Riggleman ◽  
Corey R. Quackenbush ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Hydrogen Sulfide ◽  
Epigenetic Inheritance ◽  
Natural Environments ◽  
Environmental Stressor ◽  
Southern Mexico ◽  
Poecilia Mexicana ◽  
Two Generations ◽  
Laboratory Populations ◽  
Males And Females

Environmental factors can promote phenotypic variation through alterations in the epigenome and facilitate adaptation of an organism to the environment. Although hydrogen sulfide is toxic to most organisms, the fish Poecilia mexicana has adapted to survive in environments with high levels that exceed toxicity thresholds by orders of magnitude. Epigenetic changes in response to this environmental stressor were examined by assessing DNA methylation alterations in red blood cells, which are nucleated in fish. Males and females were sampled from sulfidic and nonsulfidic natural environments; individuals were also propagated for two generations in a nonsulfidic laboratory environment. We compared epimutations between the sexes as well as field and laboratory populations. For both the wild-caught (F0) and the laboratory-reared (F2) fish, comparing the sulfidic and nonsulfidic populations revealed evidence for significant differential DNA methylation regions (DMRs). More importantly, there was over 80% overlap in DMRs across generations, suggesting that the DMRs have stable generational inheritance in the absence of the sulfidic environment. This is an example of epigenetic generational stability after the removal of an environmental stressor. The DMR-associated genes were related to sulfur toxicity and metabolic processes. These findings suggest that adaptation of P. mexicana to sulfidic environments in southern Mexico may, in part, be promoted through epigenetic DNA methylation alterations that become stable and are inherited by subsequent generations independent of the environment.

scholarly journals Habitat characteristics and environmental parameters influencing fish assemblages of karstic pools in southern Mexico

2013 ◽  
Vol 11 (4) ◽  
pp. 859-870 ◽  
Author(s):  
María Eugenia Vega-Cendejas ◽  
Mirella Hernandez de Santillana ◽  
Steven Norris
Keyword(s):  
Fish Assemblages ◽  
Anthropogenic Impacts ◽  
Conservation Status ◽  
Monitoring Program ◽  
Biosphere Reserve ◽  
Fish Diversity ◽  
Fish Assemblage Structure ◽  
Southern Mexico ◽  
Calakmul Biosphere Reserve ◽  
Poecilia Mexicana

Fish assemblage structure was evaluated and compared among 36 karstic pools located within protected areas of the Calakmul Biosphere Reserve (southern Mexico) and unprotected adjacent areas beyond the Reserve. Nonmetric multidimensional scaling (MDS), indicator species analysis (ISA), and canonical correspondence analysis (CCA) were used to identify which environmental factors reflected local influences and to evaluate the correlation of these variables with fish assemblages structure. Thirty-one species were encountered in these karstic pools, some for the first time within the Reserve. These aquatic environments were separated into three groups based on physico-chemical characteristics. Although CCA identified significant associations between several fish species (based on their relative abundance) and environmental variables (K, NH4, NO3, and conductivity), the most abundant species (Astyanax aeneus, Poecilia mexicana, and Gambusia sexradiata ) occur in most pools and under several environmental conditions. Baseline data on fish diversity along with a continued monitoring program are essential in order to evaluate the conservation status of fish assemblages and their habitats, as well as to measure the influence of anthropogenic impacts on pristine habitats such as the karstic pools of the Calakmul Biosphere Reserve.

Overcoming Challenges of International Migration Research: A Case Study Approach in Southern Mexico

2016 ◽  
Vol 13 (1) ◽  
pp. 131-143
Author(s):  
Julie Boyles
Keyword(s):  
International Migration ◽  
Common Ground ◽  
Data Gathering ◽  
Ethnographic Case Study ◽  
Case Study Approach ◽  
Southern Mexico ◽  
Mixed Methods Approach ◽  
Study Approach ◽  
Migration Research

An ethnographic case study approach to understanding women’s actions and reactions to husbands’ emigration—or potential emigration—offers a distinct set of challenges to a U.S.-based researcher.  International migration research in a foreign context likely offers challenges in language, culture, lifestyle, as well as potential gender norm impediments. A mixed methods approach contributed to successfully overcoming barriers through an array of research methods, strategies, and tactics, as well as practicing flexibility in data gathering methods. Even this researcher’s influence on the research was minimized and alleviated, to a degree, through ascertaining common ground with many of the women. Research with the women of San Juan Guelavía, Oaxaca, Mexico offered numerous and constant challenges, each overcome with ensuing rewards.

The value, costs, and meaning of transnational migration in rural Oaxaca, Mexico

2006 ◽  
Vol 3 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Jeffrey H. Cohen ◽  
Bernardo Rios ◽  
Lise Byars
Keyword(s):  
Social Networks ◽  
Sense Of Belonging ◽  
Southern California ◽  
Transnational Migration ◽  
Urban Centers ◽  
Cultural Economic ◽  
Southern Mexico ◽  
Shared Identity ◽  
The Social

Rural Oaxacan migrants are defined as quintessential transnational movers, people who access rich social networks as they move between rural hometowns in southern Mexico and the urban centers of southern California.  The social and cultural ties that characterize Oaxacan movers are critical to successful migrations, lead to jobs and create a sense of belonging and shared identity.  Nevertheless, migration has socio-cultural, economic and psychological costs.  To move the discussion away from a framework that emphasizes the positive transnational qualities of movement we focus on the costs of migration for Oaxacans from the state’s central valleys and Sierra regions.   

GEOCHRONOLOGY AND PETROGENESIS OF THE PUERTO ESCONDIDO-HUATULCO INTRUSIONS IN SOUTHERN MEXICO AND STRUCTURAL ANALYSIS OF THE WESTERN CHACALAPA FAULT SYSTEM

2019 ◽  
Author(s):  
Samantha Yahel García Hernández ◽  
◽  
Dante J. Morán-Zenteno ◽  
Barbara M. Martiny ◽  
Gustavo Tolson
Keyword(s):  
Structural Analysis ◽  
Fault System ◽  
Southern Mexico

GEOCHRONOLOGY AND PETROGENESIS OF THE JAMILTEPEC – PUERTO ESCONDIDO BATHOLITHS: NEW INSIGHTS ON SOUTHERN MEXICO CENOZOIC MAGMATISM

2019 ◽  
Author(s):  
Hermes Martín García Rodríguez ◽  
◽  
Dante J. Morán-Zenteno ◽  
Barbara M. Martiny
Keyword(s):  
Southern Mexico ◽  
Cenozoic Magmatism

Tongues of Fire

2018 ◽  
Author(s):  
Nancy Farriss
Keyword(s):  
Cultural Difference ◽  
Language Contact ◽  
Social Contexts ◽  
Culture Contact ◽  
Rhetorical Strategies ◽  
Southern Mexico ◽  
Fine Grained ◽  
Indigenous Church ◽  
Cultural Gaps

Language and translation governed the creation of Mexican Christianity during the first centuries of colonial rule. Spanish missionaries collaborated with indigenous intellectuals to communicate the gospel in dozens of local languages that had previously lacked grammars, dictionaries, or alphabetic script. The major challenge to translators, more serious than the absence of written aids or the great diversity of languages and their phonetic and syntactical complexity, was the vast cultural difference between the two worlds. The lexical gaps that frustrated the search for equivalence in conveying fundamental Christian doctrines derived from cultural gaps that separated European experiences and concepts from those of the Indians. This study focuses on the Otomangue languages of Oaxaca in southern Mexico, especially Zapotec, and relates their role in the Dominican evangelizing program to the larger frame of culture contact in postconquest Mesoamerica. Fine-grained analysis of translated texts is used to reveal the rhetorical strategies of missionary discourse and combines with an examination of language contact in different social contexts. A major aim is to spotlight the role of the native elites in shaping what emerged as a new form of Christianity. As translators, chief catechists, and parish administrators they made evangelization in many respects an indigenous enterprise and the Mexican church it created an indigenous church.

scholarly journals Evidence for Designing Public Policies Aimed at Reducing Food Waste and Food Insecurity in Mexico

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1727-1727
Author(s):  
Verónica Mundo-Rosas
Keyword(s):  
Public Policy ◽  
Food Insecurity ◽  
Food Waste ◽  
Scientific Evidence ◽  
Public Policies ◽  
Southern Mexico ◽  
Funding Sources ◽  
National Production ◽  
Development Goals ◽  
Food Residues

Abstract Objectives To analyze the magnitude and distribution of food waste and insecurity in Mexico as a first step in designing public policies to counteract these problems. Methods Based on methodology proposed by Subirats et al. (2008), we analyzed the magnitude and distribution of food waste and insecurity in Mexico. Using scientific evidence and official data, we responded to the following guiding questions: What is the problem? What is the magnitude of the problem? Who are the population groups most affected by the problem and where do they reside? To what extent does coverage under current public policies address these problems? Results Problem: By 2050, the Mexican population will have grown by 22.9 million with respect to 2015. The country's capacity to produce the amount of food required in the future will depend largely on what proportion of the population has the necessary financial resources to acquire the food it needs, and whether food is equitably distributed. Magnitude of the problem: Mexico loses and wastes approximately 34% of the national production of items in the basic food basket while 26.4 million Mexicans lack sufficient income to acquire the quantity and quality of food they need. Those affected the most: From an environmental viewpoint, the larger cities in Mexico constitute the principal production centers of food waste, among other residues. This causes air, land and water pollution at the regional level, as well as serious health problems in the population. From an ethical and nutritional perspective, food waste indirectly affects those experiencing food insecurity. Location of the affected population: In 2012, central Mexico was the largest generator of urban solid waste including organic and, specifically, food residues. Conversely, southern Mexico was the region most affected by food insecurity. Public policy coverage: Despite the magnitude of the problem, several Mexican states have no public policy in place to combat food waste or insecurity. Conclusions The evidence provided by our study contributes to decision making in the formulation of public policies aimed at reducing food loss and waste as well as food insecurity. It also serves to monitor progress towards the 2030 Sustainable Development Goals. Funding Sources None.

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