Chiapas Research Articles

Late Pleistocene paleoenvironments and megafauna from the Sierra Madre del Sur flanks and the Central Depression of Chiapas (Southern México)

Pleistocene fluvial sequences have been recognised in some regions of México as an important source of information on past environmental change using a wide range of proxies. However, this has not been attempted in Mexico's southernmost state of Chiapas until the current paper, where the main aim is to describe and date five new Late Pleistocene fossil rich sequences and to interpret their paleoenvironmental record and changes that they indicate. This interpretation is based on the sedimentology, pollen record and stable isotopes from vertebrate fossils together with the radiocarbon dating of the fluvial sediments. At Los Mangos and El Bajión fossil sites the fluvial sediment record reported here includes a conspicuous layer with aerodynamic Fe magnetic microspherules associated with the Younger Dryas (YD) meteorite impact which adds to the type of paleoenvironments in which such meteorite impacts have been recognised. The sediment dating indicates that the fossiliferous sites are Late Pleistocene in age, and they add new locations and information for México for this climatic phase.

Supplying aid products to affected regions by a natural phenomenon in Chiapas, Mexico

Natural phenomena affect differently in the world. It comes first from the geographical location, followed by the economic characteristics of each region. The objective of the case study presented is to design a supply network of essential products to victims in the state of Chiapas, located within the Mexican Republic, which is one of the states most affected by the appearance of natural phenomena. The vehicular routing problem with capacity is applied as a solution for the supply of aid products to 120 of 124 municipalities impacted by natural phenomena of a hydrometeorological type during the period 2015-2022. Evaluating the different municipalities that are home to the state under study through various Infrastructure and service factors, the municipality of Tuxtla Gutiérrez is determined as the origin of the routing, obtaining with it a total of 44 routes with an average of 2.7 municipalities to be supplied per route and an average of 402 km travelled. A second municipality is located, Tapachula, which obtains a second place in evaluating factors, providing the longest route in the distance travelled.

New records of cave-dwelling populations of Rhamdia catfishes (Siluriformes, Heptapteridae) from Chiapas, Mexico

Dedicated ichthyological surveys in four active karstic caves in the Mexican state of Chiapas (Grijalva River drainage basin) resulted in the discovery of the same number of hypogean populations of Rhamdia catfishes assignable to two different species: R. laticauda and R. guatemalensis. The taxonomic identity of these populations was initially determined based on morphological traits and subsequently corroborated with molecular data in a phylogenetic framework. For the most part, these newly discovered populations exhibit partial and variable troglomorphism (vs. fixed), a pattern that has been observed in most other cave-dwelling species/populations of Mexican Rhamdia, and possibly caused by gene flow with and/or incipient speciation from epigean lineages. Since most hypogean forms of Mexican Rhamdia derive from/are part of a larger R. laticauda clade, our discovery of cave-dwelling populations assignable to R. guatemalensis is noteworthy and includes the very first record of a R. guatemalensis population with pronounced and widespread troglomorphism. Our discovery of hitherto unrecorded populations of hypogean Rhamdia highlights the continued importance of exploration in the process of documenting subterranean biodiversity, particularly in regions of the world rich with cave systems. Our findings corroborate the notion that, among Neotropical fishes, the catfish genus Rhamdia is one of the most prone and effective at colonizing subterranean habitats and establishing viable hypogean populations.

First Report of Eratyrus cuspidatus (Hemiptera: Reduviidae) Infected with Trypanosoma cruzi in Peridomestic Environment in Chiapas, Mexico.

Background: Triatomine bugs are natural vectors of Trypanosoma cruzi, which causes Chagas disease or American trypanosomiasis. The role of sylvatic triatomine species as vectors of T. cruzi in Mexico remains to be fully understood. Our research on the epidemiology of Chagas disease in Southeastern Mexico involved sampling triatomines in rural settings. Materials and Methods: A triatomine was collected in a peridomestic environment of a rural dwelling in the state of Chiapas. The triatomine was identified morphologically as an adult female Eratyrus cuspidatus Stal. Results: Microscopic analysis revealed flagellate forms of T. cruzi in the feces of the E. cuspidatus collected. This was confirmed by quantitative polymerase chain reaction. Amplification of the mini-exon gene showed that the T. cruzi infecting E. cuspidatus corresponded to lineage I. Conclusions: This is the first report from Mexico of E. cuspidatus found infected in a human dwelling, which represents an important adaptation process to inhabit human environments.

The Chemical Composition of Scaptotrigona mexicana Honey and Propolis Collected in Two Locations: Similarities and Differences.

The chemical composition of stingless bee honey and propolis depends on the plant sources they are derived from, and thus reflects the flora available in the vicinity of the hives, the preferences of the bee species, and the climate (altitude and temperature). To understand the relative influence of these factors, we studied the composition of honey and propolis of the stingless bee Scaptotrigona mexicana. Samples from 24 colonies were analyzed: 12 each from two S. mexicana meliponaries located in the state of Chiapas in southern Mexico, approximately 8.5 km apart, Tuxtla Chico and Cacahoatán. The chemical composition of honey and propolis was studied using nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometry (GC-MS), respectively. The antioxidant activity of propolis was also studied. Chemometric analyses were applied. The Tuxtla Chico honey samples contained higher concentrations of glucose and fructose, while the Cacahoatán samples displayed a rich composition of di- and trisaccharides. These differences can be attributed to the distinct nectar sources utilized by the bees at each location. Propolis compositions in the two locations also demonstrated qualitative differences, indicating a specific choice of resins by the bees. The observed substantial variations in the chemical composition of propolis and honey of S. mexicana from two locations relatively close to each other supports the assumption that bee species cannot be considered the most important factor in determining their chemistry.

Thoughts on the excessive margins of criminal policy in the state of Chiapas: Case of incest

The evolution of current societies has brought with it the disuse of certain crimes that in the past were conceived with paramount importance in the framework of the healthy order of community life and social coexistence. The object of our deliberation, on this occasion, is the configuration of the criminal type of Incest in the criminal catalog in force in the State of Chiapas. This crime has been chosen as a model for analysis to ponder the trend towards punitive populism that, from our perspective, embraces the state Penal Code, by proscribing a behavior that expresses, with the greatest possible emphasis, the human right to sexual freedom of its practitioners and that is seen as prohibitive even though in special assumptions and hypotheses, it does not transgress any protected legal interest, except that of public morality and good manners. We intend to wield conclusive arguments, in use of sexual self-determination and the free development of personality, that give light to our local legislators so that, in the near future, the penalization conducive to these behaviors in certain specific contexts is suppressed and the normative object of other criminal types that are closely related to it is updated.

Predation of oak acorns by Baird's tapir in one of the last remnants of mountain cloud forest in Southern Mexico

The consumption of fruits and seeds by mammals can have a strong impact on the regeneration of tropical forests. Our knowledge of this biotic interaction has steadily increased recently but it remains fragmentary. This is largely due to most of the studies focusing on a small proportion of the diverse mammals and plants involved in these interactions and to the fact most commonly used methods provide just partial information about the whole seed dispersal/predation process. The use of camera traps has opened the opportunity to greatly improve our knowledge of the intricacies of frugivory and seed predation by increasing the likelihood to record very secretive animal species and providing detailed accounts of their behavior. Based on camera trap data we report acorn consumption of Quercus benthamii and Q. sapotifolia by the threatened Baird's tapir (Tapirus bairdii). This study was conducted in the largest remnant of Mountain cloud forest in Mexico, located in El Triunfo Biosphere Reserve (ETBR) in the state of Chiapas. Despite the fact that ten mammal species were recorded in the focal trees, only two of them (T. bairdii and Sciurus deppei) were documented exhibiting acorn consumption. We obtained 82 videos showing the consumption of Q. benthamii acorns by tapirs (sampling effort = 133 camera trap days, n = 8 trees) with an average of 6.04 ± 3.56 (± sd) minutes spent on this activity. In comparison, we only obtained one video of a tapir consuming Q. sapotifolia acorns (sampling effort = 264 camera trap days, n = 5 trees) during 35 s. Consumption of these Quercus species by tapir was not previously reported. Moreover, our study is the first (to our knowledge) to show video-recorded evidence of the interaction between tapirs and Quercus trees. Due to tapirs' large body size, the consumption of acorns might be an important source of mortality for some Quercus species (e.g., Q. benthamii).

Social determinants of health for moderate and severe periodontal disease in rural and urban populations.

We assessed the prevalence of moderate and severe periodontitis and its association with social determinants of health in rural and urban population from the State of Chiapas, in Southern Mexico. A cross-sectional population-based study was conducted in 2013 comprising people 20 years and older. The determinants were categorized as proximal (age, sex, indigenous origin, diabetes, smoking, diet), intermediate (level of schooling, occupation, medical and dental care), and structural (type of institution of health care provision, residence area). Periodontal status was assessed using the Periodontal Screening and Recording (PSR) Index. In total, 467 persons (72.4% women; mean age 43.0 years [s.d 14.7]) participated. Of them, 76.5% lived in rural areas and 56.7% were of indigenous origin. Participants with moderate and severe periodontitis had a significantly lower toothbrushing frequency (44.1% and 44.8%, respectively), and poorer oral hygiene (90% and 90.3%, respectively) compared with people without periodontitis (29.4% for toothbrushing frequency and 74.5% for oral hygiene). Moderate periodontitis was associated with poor oral hygiene (OR=2.63) and no schooling (OR=1.86). Severe periodontitis was associated with age (OR=1.05), poor oral hygiene (OR=3.99), no schooling (OR=2.08), and the interaction term of rural area and indigenous origin (RM=5.23). Social determinants of health play an important role in the development of periodontitis. Preventive oral health programs should thus focus on the specific social, economic, and geographical context of the population.

Bridges that bind worlds: The emergence of diplomacy from below between Chiapas and Italy (1996–2001)

AbstractFollowing the 2021 Zapatista tour in Europe, this article offers a reconstruction of the genealogy of the practice of diplomacy from below, based on the meeting between the Italian post‐autonomous collectives and the Zapatista rebel communities of the state of Chiapas in southern Mexico, and sets out its continuity after more than two decades. The research hypothesis is that this practice was born as a joint political construction thanks to the collaboration between two collective political subjects, organized and structured in their respective territories as constituent expressions of counterpower and in opposition to the hegemonic neoliberal model. How these collective actors relate to each other demonstrates the existence of two different political identities and cultures that, in the reciprocal encounter, recognize and feed each other—changing, hybridizing and, finally, strengthening each other.

Lifestyle in university students during confinement by COVID-19

The COVID-19 pandemic impacted healthy eating and lifestyles. To determine the impact on diet and lifestyle in university students in the health area of the border areas of Mexico (Tamaulipas and Chiapas) during the confinement by COVID-19. This study was observational, descriptive, analytical, comparative cross-sectional, with convenience sampling with 409 students, 48.7% (199) from Tamaulipas, and 51.3% (210) from Chiapas. A survey with 30 items related to eating behavior and lifestyle was applied. found an increase in obesity in Tamaulipas from 7.5% to 8.5% and in overweight in the state of Chiapas from 21.9% to 24.8% (p=0.001). A decrease in healthy eating was observed during confinement from 61.3% to 52.8% in Tamaulipas (p = 0.05) and from 70.5% to 57.1% in Chiapas (p = 0.001), with consumption of high carbohydrate foods (41.7%) and ultra-high-fat foods predominating on the northern border. processed (13.1%), while for the southern border there was a higher consumption of fruits and vegetables (35.2%) (p = 0.06). On both borders, physical activity decreased during confinement from 61.8% to 60.3% in Tamaulipas (p = 0.09) and 69.5% to 61.0% in Chiapas (p = 0.06). 52.3% and 52.4% of students in Tamaulipas and Chiapas also reported waking up during the night (p = 0.98). The diet and lifestyle of university students from the border areas of Mexico were affected during the confinement by COVID-19 with a decrease in the perception of healthy eating, an increase in the number of meals and a tendency to decrease in the number of meals. consumption of alcohol, tobacco and physical activity.

Chemical analysis and NIR spectroscopy in the determination of the origin, variety and roast time of Mexican coffee

Coffee is a product whose quality and price are associated with its geographical, genetic and processing origin; therefore, the development of analytical techniques to authenticate the above mentioned is important to avoid adulteration. The objective of this study was to compare conventional analytical methods with NIR technology for the authentication of roasted and ground coffee samples from different producing regions in Mexico (origins) and different varieties. A second objective was to determine, under the same processing conditions, if roasting times can be differentiated by using this technology. A total of 120 samples of roasted and ground commercial coffee were obtained from the states of Chiapas, Oaxaca, Tabasco and Veracruz in Mexico, 30 locally available samples per state. Samples from Veracruz included three different varieties, grown on the same farm and processed under the same conditions. One of these varieties was selected to evaluate the chemical composition of samples roasted at 185 °C using four different roasting times (15, 17, 19 and 21 min). Samples from different producing regions showed significant differences (P < 0.05) in fat content (from 7.45 ± 0.42% in Tabasco to 18.40 ± 2.95% in Chiapas), which was associated with the altitude of coffee plantations (Pearson's r = 0.96). The results indicate that NIR technology generates sufficient useful information to authenticate roasted and ground coffee from different geographical origins in Mexico and different varieties from the same coffee plantation, with similar results to those obtained by conventional analytical methods.

Analysis of a Municipal Solid Waste Disposal Site: Use of Geographic Information Technology Tools for Decision Making

In this study, the operation of a final disposal site for municipal solid waste in the state of Chiapas, in Mexico, was evaluated. Several spatial analyses and Geographic Information Technology (GIT) tools were used. It was found that the site’s current operation and location are deficient, partially complying with regulations. The gaseous dispersion is not far-reaching (from 100 to 8725 µg/m3 for landfill gas, and from 0.01 to 0.35 µg/m3 for H2S) but requires attention to avoid olfactory unpleasantness. Liquid emissions (conservative pollutants) move in the east direction of the final disposal site, which can damage the environmental infrastructure (water supply wells) in the long term. The highest and lowest concentrations were found in years 1 (12,270 mg/m3) and 20 (1080 mg/m3), respectively. Thermal emissions around the dumping site are important due to the formation of microclimatic zones. Temperature differences were found during the analysis period, ranging from 8.37 °C in summer to 2.49 °C in winter, which are due to waste decomposition processes and anthropogenic activities. Finally, the change in land use around the dumping site increased at a rate of 5.82% per year, mainly due to the growth of homes, communication routes, and shopping centers.

An updated list of the Mexican herpetofauna: with a summary of historical and contemporary studies.

The growth in our knowledge of the diversity of the herpetofauna of Mexico has occurred over the period of approximately 445 years from the work of Francisco Hernández to that of a broad multinational array of present-day herpetologists. The work of this huge group of people has established Mexico as one of the most significant centers of herpetofaunal biodiversity in the world. This status is the result of a complex orography, in addition to diverse habitats and environments and the biogeographic history of Mexico. The current herpetofauna consists of 1,421 native and introduced species, allocated to 220 genera, and 61 families. This figure is comprised of 1,405 native species and 16 non-native species (as of April 2023). The non-native species include two anurans, 13 squamates, and one turtle. The level of endemism is very high, presently lying at 63%, with this level expected to increase with time. Species richness varies among the 32 federal entities in the country, from a low of 50 in Tlaxcala to a high of 492 in Oaxaca. Amphibian species richness by state-level can be envisioned as comprising three levels of low, medium, and high, with the lowest levels occurring in the Peninsula of Baja California, a group of seven states in north-central and central Mexico, and a group of three states in the Yucatan Peninsula, with the highest levels occupying the southern states of Guerrero, Puebla, Veracruz, Oaxaca, and Chiapas, and the medium level in the remaining states of the country. Reptile species richness also can be allocated to three categories, with the lowest level occupying Baja California Sur, a group of central states, and the states of the Yucatan Peninsula, and the highest level found in a cluster of the states of Veracruz, Guerrero, Oaxaca, and Chiapas. Knowledge of the Mexican herpetofauna will continue to grow with additional studies on systematics, conservation, and the construction of checklists at various levels.

Seroprevalence of HAV and Mandatory Markers of Transfusion- Transmitted Infections in Blood Donors from Chiapas, Mexico: an Exploratory Study

Introduction: Blood transfusion saves millions of lives annually. However, blood transfusion is one of the leading risk factors for Transfusion-Transmitted Infections (TTIs). Therefore, the objective of this study was to explore the seroprevalence of both HAV and mandatory markers of TTIs in blood donors from Chiapas, Mexico. Materials and Methods: The study included 3,067 blood donors from the Dr. Domingo Chanona Rodríguez Blood Bank located in Tuxtla Gutiérrez, Chiapas, and from 9 collection centers located in different regions of Chiapas. Screening was performed using Enzyme immunoassay (anti-HAV IgM) or Chemiluminescent microparticle immunoassay (HBV HBsAg, anti-HCV IgG/IgM, HIV Ag/Ab, anti-T. pallidum IgG/IgM, and anti-T. cruzi IgG). Results: The seroprevalence of T. pallidum was the highest at 1.3%, followed by the seroprevalence of HAV and T. cruzi, both with 0.7%. Regions X and XV of the state of Chiapas presented the six markers of the analyzed TTIs. Blood donors at risk of being TTI reactive donated in regions IX and X. However, donors with qualified and unqualified employment and those who have donated more than 2 times are considered protective factors against TTIs. Conclusion: We observed a high seroprevalence of HAV in this exploratory study. It is indispensable to increase the sample size of blood donors from the state of Chiapas because HAV is endemic to Mexico and it is probably transmitted through blood transfusion. Also, it is necessary to augment voluntary non-remunerated blood donations in the state of Chiapas, mainly in the Southern border regions, to decrease the risk of TTIs.

Transforming care for patients living with diabetes in rural Mexico: a qualitative study of patient and provider experiences and perceptions of shared medical appointments

ABSTRACT Background Global prevalence of diabetes is increasing, causing widespread morbidity, mortality and increased healthcare costs. Providing quality care in a timely fashion to people with diabetes in low-resource settings can be challenging. In the underserved state of Chiapas, Mexico, which has some of the lowest diabetes detection and control rates in the country, there is a need to implement strategies that improve care for patients with diabetes. One such strategy is shared medical appointments (SMAs), a patient-centred approach that has proven effective in fostering patient engagement and comprehensive care delivery among underserved populations. Objective This study aimed to understand the perceptions, experiences and insights of both patients living with diabetes and healthcare providers, who took part in a pilot SMA strategy implemented in five outpatient clinics in rural Chiapas. Methods Following an exploratory qualitative approach, we conducted 50 in-depth interviews with patients and providers involved in diabetes SMAs and five focus group discussions with community health workers providing patient support and education. Results The implementation of an SMA model changed how diabetes care is perceived, structured and delivered. Patients felt sheltered by group interactions based on trust, which allowed for the exchange of experiences, learning and increased engagement in treatment and lifestyle changes. Providers gained insights into their patients’ context and lived experiences, which resulted in improved rapport and quality of care. SMAs also restructured some operational aspects in the clinics and fostered the sharing of power and responsibilities amongst the staff. Conclusions The SMAs model transformed care by providing a patient-centred, collaborative approach to diabetes care, education and support. Additionally, it reshaped the health-care team resulting in power-shifting and role-sharing among members of the interdisciplinary team. We therefore encourage decision-makers to expand the use of SMAs to improve care for patients with diabetes in low-resource settings.

Toxigenic fungi collected in maize fields from four states of Mexico

Maize is the most important crop for the Mexican society. Phytopathogenic fungi pose a major challenge to this cereal. These fungi are harmful to people and animals, mainly as a result of their mycotoxins. The objective of this research was to identify the fungi found in 18 maize genotypes collected in fields from the states of Morelos, Coahuila, Chiapas, and Puebla, Mexico. Pathogens were isolated in potato dextrose agar (PDA) culture medium and identified using morphological criteria. The pathogens were purified using monoconidial cultures and sheltered at 4 °C ± 2 °C. An analysis of variance was carried out using the SAS® 9.1 statistical software. Fungi from the following genus and species were identified: Aspergillus, Penicillium, Alternaria, Bipolaris, Trichothecium roseum, and Fusarium verticillioides. It is worth mentioning that F. verticillioides and Penicillium sp. are the most common pathogens in maize genotypes, with an incidence of 63.68 and 6.57%, respectively. Moreover, along with genus Aspergillus, they are considered to be the most important toxicological fungi, given the harm that they cause to humans and animals. Therefore, management strategies are needed to guarantee that grains can be safely consumed by society

Towards a critical discourse and narratives of resistance in the Mayan Zoque symbolic region. Three cases of alternative identities

This article proposes an analysis of human communication, through a materialist reading of semiotics and culture, capable of accounting for the construction and possibility of critical discourses with which to deal with the emptying of meaning of imposed symbols or degraded in their expressive authenticity by the logic of globalized culture. Through the construction (identification) of the Zoque Mayan symbolic region of the state of Chiapas, we will have the possibility of expanding the horizon of significance of the symbols and alternative interpretations that are available, both in long memory practices, as well as in artistic expressions. Searching with the above, to find the way for the institutionalization of different subjective identities, critical or contrary to what is imposed in societies of postmodern peripheral capitalism, as is the case of the Zoque Mayan region of the state of Chiapas.

Identification and characterization of microsatellites in isolates of Peronospora tabacina collected in tobaccoproducing states of Mexico

Peronospora tabacina is considered the main limiting factor in tobacco production worldwide. In Mexico, information on the genetic diversity of this pathogen is scarce; therefore, the objective of this research was to evaluate 12 microsatellites in 20 isolates collected in the states of Nayarit, Chiapas, and Veracruz. PCR amplification and sequencing of these microsatellites were performed; as well as the alignment and comparison of the sequences deposited in the GenBank database. A total of 19 isolates showed amplification for the 12 microsatellites evaluated, while in one of the isolates, the amplification of two microsatellites was not observed, it being possible to determine that P. tabacina isolates present in Nayarit, Chiapas, and Veracruz are genetically homogeneous. Regions of dinucleotides were observed, most corresponding to (GT)n repeat motifs or (TG)n variations, as well as (AC)n, (CA)n, (AT)n and (AG)n motifs. The isolates analyzed in this study can be considered products of clonal lines, therefore no genetic diversity was found in these isolates.

Molecular detection of Wolbachia and Bartonella as part of the microbiome of phlebotomine sand flies from Chiapas, Mexico

Phlebotomine sand flies are dipterans of relevance due to their role as vectors of several pathogens worldwide. Bacteria in the gut of sand flies possibly affect their vectorial capacity and competence to transmit parasites. A retrospective study was performed in sand fly specimens that had previously been collected in four localities of the state of Chiapas during the period 2009–2011 to detect Wolbachia and Bartonella and their possible coinfection with Leishmania. For the molecular detection of bacteria, we used primers and conditions that had previously been reported. A total of 531 sand fly specimens of 10 species were analyzed. Four Wolbachia strains were detected in five sand fly species, showing a prevalence of 8.6%. All the Wolbachia strains had previously been reported in other taxa. In one sand fly species, we also detected a new lineage of Bartonella evidenced by a phylogenetic analysis. No sand fly specimens showed coinfections of these bacteria and Leishmania. The bacteria found in the phlebotomine sand flies are possibly transmitted by plant-mediated horizontal transmission and during blood meal feeding.

Population genetic structure of the maize weevil, Sitophilus zeamais, in southern Mexico.

The maize weevil, Sitophilus zeamais, is a ubiquitous pest of maize and other cereal crops worldwide and remains a threat to food security in subsistence communities. Few population genetic studies have been conducted on the maize weevil, but those that exist have shown that there is very little genetic differentiation between geographically dispersed populations and that it is likely the species has experienced a recent range expansion within the last few hundred years. While the previous studies found little genetic structure, they relied primarily on mitochondrial and nuclear microsatellite markers for their analyses. It is possible that more fine-scaled population genetic structure exists due to local adaptation, the biological limits of natural species dispersal, and the isolated nature of subsistence farming communities. In contrast to previous studies, here, we utilized genome-wide single nucleotide polymorphism data to evaluate the genetic population structure of the maize weevil from the southern and coastal Mexican states of Oaxaca and Chiapas. We employed strict SNP filtering to manage large next generation sequencing lane effects and this study is the first to find fine-scale genetic population structure in the maize weevil. Here, we show that although there continues to be gene flow between populations of maize weevil, that fine-scale genetic structure exists. It is possible that this structure is shaped by local adaptation of the insects, the movement and trade of maize by humans in the region, geographic barriers to gene flow, or a combination of these factors.