Mesoamerican Region Research Articles

Niche conservatism and convergence in birds of three cenocrons in the Mexican Transition Zone.

The niche conservatism hypothesis postulates that physiological and phylogenetic factors constrain species distributions, creating richness hotspots with older lineages in ancestral climatic conditions. Conversely, niche convergence occurs when species successfully disperse to novel environments, diversifying and resulting in areas with high phylogenetic clustering and endemism, low diversity, and lower clade age. The Mexican Transition Zone exhibits both patterns as its biotic assembly resulted from successive dispersal events of different biotic elements called cenocrons. We test the hypothesis that biogeographic transitionallity in the area is a product of niche conservatism in the Nearctic and Typical Neotropical cenocrons and niche convergence in the Mountain Mesoamerican cenocron. We split the avifauna into three species sets representing cenocrons (sets of taxa that share the same biogeographic history, constituting an identifiable subset within a biota by their common biotic origin and evolutionary history). Then, we correlated richness, endemism, phylogenetic diversity, number of nodes, and crowning age with environmental and topographic variables. These correlations were then compared with the predictions of niche conservatism versus niche convergence. We also detected areas of higher species density in environmental space and interpreted them as an environmental transition zone where birds' niches converge. Our findings support the expected predictions on how niches evolved. Nearctic and Typical Neotropical species behaved as predicted by niche conservatism, whereas Mountain Mesoamerican species and the total of species correlations indicated niche convergence. We also detected distinct ecological and evolutionary characteristics of the cenocrons on a macroecological scale and the environmental conditions where the three cenocrons overlap in the Mesoamerican region.

Mexican Biobank advances population and medical genomics of diverse ancestries.

Latin America continues to be severely underrepresented in genomics research, and fine-scale genetic histories and complex trait architectures remain hidden owing to insufficient data1. To fill this gap, the Mexican Biobank project genotyped 6,057 individuals from 898 rural and urban localities across all 32 states in Mexico ata resolution of 1.8 million genome-wide markers with linked complex trait and disease information creating a valuable nationwide genotype-phenotype database. Here, using ancestry deconvolution and inference of identity-by-descent segments, we inferred ancestral population sizes across Mesoamerican regions over time, unravelling Indigenous, colonial and postcolonial demographic dynamics2-6. We observed variation in runs of homozygosity among genomic regions with different ancestries reflecting distinct demographic histories and, in turn, different distributions of rare deleterious variants. We conducted genome-wide association studies (GWAS) for 22 complex traits and found that several traits are better predicted using the Mexican Biobank GWAS compared to the UK Biobank GWAS7,8. We identified genetic and environmental factors associating with trait variation, such as the length of the genome in runs of homozygosity as a predictor for body mass index, triglycerides, glucose and height. This study provides insights into the genetic histories of individuals in Mexico and dissects their complex trait architectures, both crucial for making precision and preventive medicine initiatives accessible worldwide.

Agri-silvicultures of Mexican Arid America

BackgroundAgri-silvicultures (ASC) are biocultural practices procuring either the maintenance of wild diversity in predominantly agricultural spaces or introducing agrobiodiversity into forests. In the Mesoamerican region, ASC contribute to food sovereignty and territorial conservation and provide strategies for dealing with global changes. Previous inventories of ASC identified gaps in information about these systems in the Mexican Arid America region. This article raises the general question: How have human interactions between cultural, wild, and domesticated biodiversity in this territory? The particular questions in this paper are: (i) How have historical processes shaped human interactions between wild and domesticated biodiversity in the region? and (ii) What types of agri-silvicultures have emerged in Mexican Arid America since these relationships?MethodsWe trace a methodological border where archaeologists have identified the Mesoamerican region to define our study area as Arid America northern of this line in Mexico. We analyzed agriculturalization processes in Arid America through a historical review. Then, we carry out an inventory of Arid America ASC based on academic papers and other documented experiences. We constructed a spatial database and a typology to understand what kinds of agri-silviculture occur in the region.ResultsWe identified several pre-Hispanic agri-silvicultural practices in the region, like hunting, fishing, terraces, gathering, and irrigation systems. The cultivation of native species of maize, beans, and squash even was registered. The Spanish colonization forced the agriculturization in arid northern Mexico, where itinerant hunting-gathering patterns predominated. In the twentieth century, the Green Revolution adopted this area as the principal setting for industrialized agriculture. The industrialized irrigated systems expansion and other political strategies provoked the simplification of productive landscapes. The practices that integrate wild and agricultural diversity systems were marginalized and invisibilized in such a context. Our research group proposes seven types of agri-silvicultural systems (natives agrisilvicultures, the oases agroforestry, Mesquite and Huisache ASC, homegardens and other traditional forms of agroforestry or agri-silvicultures). These agri-silvicultures provide food, medicine, fodder, and other contributions, as income to the families that practice them and protect native and exotic species.Discussion and conclusionThe agriculturization of the arid environments initiated during Spanish colonization and the subsequent modernizing projects shaped dominant actors and ideologies in the arid north of Mexico. However, aridity has favored ancestral and agroecological relationships between cultures and biodiversity, emerging and subsisting Arid American agri-silvicultures. These agri-silvicultures deserve to be understood, adopted, and adapted to new contexts. They could be essential alternatives in the context of environmental changes.

Small-scale fishing has affected abundance and size distributions of deepwater snappers and groupers in the MesoAmerican region

Deepwater fisheries in the Caribbean Sea are poorly studied and mostly unmanaged, despite their importance to local economies and food security. In the MesoAmerican region, deepwater fisheries are nearshore and easily accessible in many locations by small vessels, but historical and contemporary fishing effort varies by country. We used standardized fishery-independent methods, including vertical longlines and baited remote underwater video (BRUV) to assess the relative abundance and distribution of deepwater (100–550 m) snappers and groupers in Belize and Honduras. Fishery-dependent samples were used to supplement spatial distribution and body length data. Gathered data revealed that Belize, with a smaller fishing population and shorter history of deepwater fishing, had overall higher abundance of groupers and snappers and that fish were significantly larger than those in Honduras, which has a well-established and larger deepwater fishery. Water temperature was found to influence the abundance and occurrence of deepwater snappers more than depth. Deepwater snappers were widely-distributed throughout available habitat in both countries, but groupers were more patchy, and rarely encountered in the more heavily fished areas off Honduras. Our results suggest that a precautionary approach to fisheries management and targeted biological research of these stocks is required, which is particularly relevant for Belize, where climate change and overfishing mitigation measures are focused on an expansion of the deepwater fishery.

Settlement, trade, and subsistence in coastal Mesoamerica: An introduction

Over the past several decades, a large corpus of studies has been published on the relationship between resource availability and settlement in coastal Mesoamerica, particularly regarding the prevalence of mixed subsistence systems early in the Formative Period (ca.1800–850 BC). Few recent comparative works, however, are available which draw together research on coastal human–environment interactions from several Mesoamerican regions. This article endeavors to contribute toward interregional comparisons by highlighting findings from case studies in this special section of The Journal of Island and Coastal Archaeology. I explore broadly relevant themes, including geomorphic impacts on the archaeological record and the significance of coastal resources to coastal settlement, subsistence, and trade. While common patterns illuminate archaeological debates, it is important to identify the distinctive environmental characteristics of different regions which impact the visibility of archaeological data as well as the resources available to local populations. I emphasize the utility of conducting high-resolution interdisciplinary research to capture such ecological variability.

Gossypium purpurascens genome provides insight into the origin and domestication of upland cotton

IntroductionAllotetraploid upland cotton (Gossypium hirsutum L.) is native to the Mesoamerican and Caribbean regions, had been improved in the southern United States by the mid-eighteenth century, was then dispersed worldwide. However, a Hainan Island Native Cotton (HIC) has long been grown extensively on Hainan Island, China. ObjectivesExplore HIC’s evolutionary relationship and genomic diversity with other tetraploid cottons, its origin and whether it was used for YAZHOUBU (Yazhou cloth, World Intangible Cultural Heritage) weaving, and the role of structural variations (SVs) in upland cotton domestication. MethodsWe assembled a high-quality genome of one HIC plant. We performed phylogenetic analysis, divergence time estimation, principal component analysis and population differentiation estimation using cotton assemblies and/or resequencing data. SVs were detected by whole-genome comparison. A F2 population was used for linkage analysis and to study effects of SVs. Buoyancy and salt water tolerance tests for seeds were conducted. ResultsWe found that the HIC belongs to G. purpurascens. G. purpurascens is best classified as a primitive race of G. hirsutum. The potential for long range transoceanic dispersal of G. purpurascens seeds was proved. A set of SVs, selective sweep regions between G. hirsutum races and cultivars, and quantitative trait loci (QTLs) of eleven agronomic traits were obtained. SVs, especially large-scale SVs, were found to have important effects on cotton domestication and improvement. Of them, eight large-scale inversions strongly associated with yield and fiber quality have probably undergone artificial selection in domestication. ConclusionG. purpurascens including HIC is a primitive race of G. hirsutum, probably disperse to Hainan from Central America by floating on ocean currents, may have been partly domesticated, planted and was likely used for YAZHOUBU weaving in Hainan much earlier than the Pre-Columbian period. SV plays an important role in cotton domestication and improvement.

A new species of Deamia (Cactaceae) from Nicaragua

Deamia funis sp. nov. (Cactaceae) from Nicaragua, in the Mesoamerican region, is described and illustrated based on morphological data. The new species is characterized by its often long, dangling (ropey), and relatively narrow, multiribbed stems with relatively small flowers like those of D. chontalensis, but with the stigma exerted among or slightly beyond the anthers as occurs in D. montalvoae and D. testudo.

Occurrence of contact organs and sexual dimorphism in fishes of the family Profundulidae (Actinopterygii: Cyprinodontiformes)

The family Profundulidae is one of the few families of freshwater fishes endemic to the Mesoamerican region, and one of the least speciose within the order Cyprinodontiformes, with only 13 valid species. Sexual dimorphism is poorly developed and sparsely studied in this family. Herein, we report the presence of spicule-like organs of contact in scales and fins (anal and dorsal) in fishes of the family Profundulidae and discuss the use of spicules as a means to facilitate the identification of male and female in this family. Data from museum specimens of the 13 species of profundulid fishes were analyzed. We studied the following species: Tlaloc labialis (Günther, 1866); Tlaloc candalarius (Hubbs, 1924); Tlaloc hildebrandi (Miller, 1950); Tlaloc portillorum (Matamoros et Schaefer, 2010); Profundulus punctatus (Günther, 1866); Profundulus guatemalensis (Günther, 1866); Profundulus oaxacae (Meek, 1902); Profundulus balsanus Ahl, 1935; Profundulus kreiseri Matamoros, Schaefer, Hernández et Chakrabarty, 2012; Profundulus parentiae Matamoros, Domínguez-Cisneros, Velázquez-Velázquez et McMahan, 2018; Profundulus mixtlanensis Ornelas-García, Martínez-Ramírez et Doadrio, 2015; Profundulus adani Dominguez-Cisneros, Velázquez-Velázquez, McMahan, et Matamoros, 2021; Profundulus chimalapensis Del Moral-Flores, López-Segovia et Hernández-Arellano, 2020. Scales were observed and photographed with a Hitachi VP-MEB SU1510 scanning electron microscope; the spicules in fins were observed from specimens cleared and double-stained. This study revealed the presence of 1–10 spicules on the surface of the scales in males and its absence in females of all species analyzed. Numerous, small and thin spicules were also observed and they were restricted to the middle rays of the anal and dorsal fins of the males. The observation of spicules in the anal fins for the sexual identification of profundulid fishes constitutes an advantage of operational simplicity, speed, and potential for its application in taxonomic and ecological studies.

Monograph of Ceratozamia (Zamiaceae, Cycadales): an endangered genus.

Ceratozamia (Zamiaceae, Cycadales), is a member one of the most endangered seed plant groups. Species of Ceratozamia grow from near sea level up to 2,100 meters in Mexico and Mesoamerica. We present a modern taxonomic treatment of Ceratozamia, based on fieldwork combined with detailed study of herbarium specimens in and from Mexico and Central America. This new revision is based on incorporation of morphological, molecular and biogeographic data that have been previously published in circumscriptions of species complexes by our group. Detailed morphological descriptions of the 36 species of Ceratozamia are provided and relevant characters for the genus are discussed and described. A majority are endemic to Mexico and are concentrated at high elevations in mountainous areas. Synonymies, lectotypifications, etymologies, taxonomic notes, distribution maps, illustrations and detailed species-level comparisons are included, as well as a dichotomous key for identification of all species. Data on distributional ranges and habitats of all species are summarized. Ceratozamiaosbornei D.W.Stev., Mart.-Domínguez & Nic.-Mor., sp. nov. is described from evergreen tropical forests of Belize and we highlight new populations and distributional ranges for C.subroseophylla Mart.-Domínguez & Nic.-Mor. and C.vovidesii Pérez-Farr. & Iglesias in the Mesoamerican region.

Evolution and Biogeographic History of Rubyspot Damselflies (Hetaerininae: Calopterygidae: Odonata)

The damselflies Hetaerininae, a subfamily of Calopterygidae, comprise four genera distributed from North to South America: Hetaerina, Mnesarete, Ormenophlebia and Bryoplathanon. While several studies have focused on the intriguing behavioral and morphological modifications within Hetaerina, little of the evolutionary history of the group is well understood. Understanding the biogeographical history of Hetaerininae is further complicated by uncertainty in important geological events, such as the closure of the Central American Seaway (CAS). We generated a phylogenetic hypothesis to test the relationships and divergence times within Hetaerininae using IQtree and BEAST2 and found that Mnesarete and Ormenophlebia render Hetaerina paraphyletic. Reclassification of the genera within Hetaerininae is necessary based on our results. We also tested the fit to our dataset of two different hypotheses for the closure of CAS. Our results supported a gradual closure, starting in the Oligocene and ending in the Pliocene. Using Ancestral Character State Reconstruction, we found that the rubyspot, which is associated with higher fecundity in several species, was ancestral for Hetaerininae and subsequently lost four times. Estimates of diversification in association with the rubyspot are needed to understand the plasticity of this important character. Forest habitat was the ancestral state for Hetaerininae, with transitions to generalist species of Hetaerina found primarily in the Mesoamerican region. These results add to our understanding of the relationship between morphology, biogeography and habitat in a charismatic group of damselflies.

HOME GARDENS IN LATIN AMERICA: WILD FOODS IN THE MESOAMERICAN EKUARO OF P'URÉPECHAS, MEXICO AND THE ANDEAN CHAKRA OF KICHWAS, ECUADOR

Agroforestry systems comprise important spaces for biodiversity involving traditional ecological knowledge in their management. In Latin America, within Mesoamerican region as well as Andean exists a prominent kind of agroforestry system called home gardens, distinguished by the presence of domesticated plants and animals, coexisting with wild foods. In this paper, we addressed a comparative view on home gardens between p’urhépecha ekuaro and kichwa chakra to document qualitatively the relationship between diversity of wild food and food sovereignty in Mesoamerica and Andean regions, within a context of cultural change, and to contribute to the discussion of wild-domesticated continuum related to plants in different home gardens. The ethnographic research shows three main elements: 1) that the diversity of forms of lives domesticated and wild that coexist in the home gardens form part of a food sovereignty system; 2) cultural change does not just affect home gardens in negative ways; 3) wild foods are in a very complex process of domestication in which it is difficult to define the lines between wild and domesticated. Wild food studies have to consider a broad approach to how wild food relates to human cultures.

Chronic kidney disease of nontraditional causes in central Panama

BackgroundOver the last three decades, the mesoamerican region has seen an increase in the frequency of patients diagnosed with Chronic Kidney Disease of nontraditional causes (CKDnt) also known as Meso-American Nephropathy (MeN). A region with an increased frequency of patients with Chronic Kidney Disease (CKD) has been identified in central Panama. The present study aims to characterize the clinical presentation of patients with CKDnt in an understudied population of the central region of Panama and to compare them with patients with traditional chronic kidney disease (CKDt).MethodsA retrospective descriptive study was conducted in a nephrology reference hospital in the central provinces of Herrera and Los Santos, comparing a group of 15 patients with CKDnt to 91 patients with CKDt. Sociodemographic variables, personal history, laboratory parameters, and of renal ultrasound were compared.ResultsPatients with CKDnt had a median age of 58 years (IQR: 52–61), significantly lower (P < 0.001) than patients with CKDt with a median age of 71 years (IQR: 64–78). Patients with CKDnt had a history of being agricultural (60%) and transportation (20%) workers, significantly higher than patients with CKDt (15%, P < 0.001 and 0%, P < 0.01 respectively). Renal atrophy and hyperuricemia are significant clinical markers of CKDnt (P < 0.001 and P < 0.05 respectively).ConclusionTo our knowledge, this is the first study in Panama to investigate the clinical presentation of patients with CKDnt and one of the few in Central America and the world that compares them with patients with CKDt. In central Panama the typical CKDnt patient is a male in his 50 s who is primarily engaged in agriculture or as a public transport driver. Renal atrophy and hyperuricemia are significant clinical markers of CKDnt. Further studies are needed to help understand the common determinants and risk factors for CKDnt development in Panama and Mesoamerica.

Paleoenvironmental conditions during the Medieval Climatic Anomaly, the Little Ice Age and social impacts in the Oriental Mesoamerican region

The Medieval Climatic Anomaly and the Little Ice Age periods are the most relevant climatic events in the last 1000 yr BP. Although some research describes the effects on Mesoamerican paleoenvironmental conditions and the potential atmospheric-oceanic drivers involved, more studies are needed. While most paleoenvironmental records reveal a Medieval Climatic Anomaly dominated by arid conditions, the paleoclimatic signature of the Little Ice Age seems to be more controversial. Some records display prevailing drought conditions and a minor number of records suggest wetter conditions. Here, we present a new high-resolution paleoenvironmental record from the Serdan Oriental Basin, located in the Oriental Mesoamerican region. We employed the partly laminated sedimentary sequence from the Alchichica crater maar lake. A multi-proxy study by means of microfacies analyses, geochemical analyses, mineralogical composition and magnetic analysis was conducted. Enhanced endogenic calcium carbonate precipitation in the Alchichica lake points to dominant dry conditions during the Medieval Climatic Anomaly. On the other hand, the Little Ice Age represented the rise of predominantly wetter conditions interrupted by short drought intervals. The wetter event is described by increased varve preservation, detrital input, and decreased calcium carbonate precipitation. Furthermore, we argue that the variability of the North Atlantic Oscillation in conjunction with hurricane activity could have influenced the hydrological patterns during both climatic anomalies in the Oriental Mesoamerican sector. Finally, we hypothesize that severe drought conditions registered during the Medieval Climatic Anomaly, which encompasses the Postclassic archeological period, had severe implications in two important landscape elements useful to the agriculture lifestyle: El Salado lacustrine plain and piedmonts.

P-736 Twins, an instant family: beyond the risks and health in Central America

Abstract Study question Why do patients attending fertility centers in Centralamerica consider twins as the best possible outcome? Summary answer In Centralamerica patients expect to have twins after a fertility treatment. Preliminary results show that, from a specialist’s perspective, this expectation might be financially driven. What is known already Twins have fascinated humanity since early times. Every culture in the world has a different reaction to the birth of twins and has myths about them. Some myths are still present in current times and affect our decisions. After a fertility treatment, the likelihood of having twins increases, which has contributed to a worldwide increase of the twin birth rate. In spite of the risks, some patients prefer to have twins. Study design, size, duration This is a qualitative study based on anthropological theory and ethnographic research. Semi-structured interviews were conducted to infertility specialists during July of 2020 in Centralamerica. These six countries are a cultural region that shares historical and economic features which enables a socio-cultural anthropological research. The framework for the interview’s structure is the ecological paradigm from medical anthropology theory. In this paradigm the individual is seen as part of a context that influences their medical decisions. Participants/materials, setting, methods The participants were infertility specialist who had more than 3 years of experience and practice reproductive medicine in Central America. The method was a semi-structured interview via Zoom and was recorded and then transcribed with the software Transcriptions Version 1.2. The results were coded and analyzed with cognitive anthropology methods to identify cultural models in the speech. In ethical aspects, the confidentiality of the interviewee was considered important and was protected through informed consent. Main results and the role of chance The results of the interviews with infertility specialists indicate that they have difficulties explaining patients about the risks and complications of a multiple pregnancy. According to the physicians, many patients expect twins after a treatment. The patients have the idea that they will have “two for one” (“dos de un solo”) and believe that the raising of two babies will require less time and money. The birth of twins is considered a “double blessing” (“doble bendicion”) or a “double price” (“doble premio”). With one single treatment they hope to get the “ideal family” that consist of one girl and one boy (“tener la parejita”). The patients have preconceived ideas that are influenced by their environment, like family members, friends and the media. Central America was part of the mesoamerican region were maya and aztecs myths continue to influence the popular culture and people continued to believe that twins have special connections and could have a good sibling relationship. Physicians are not aware that the media and family have so much weight in the medical decisions of their patients only focus on the fact that patients underestimate the risks. Limitations, reasons for caution The reason for caution is that this is a local study that cannot be generalized in time and place. Wider implications of the findings The results would help to design interviews for patients with the final purpose of understanding their perceptions and attitudes toward twins. In a region with no public health policies regarding infertility treatments, the results can improve communication between the doctors and patients to reduce twin rates. Trial registration number (')

Comparing Wild and Cultivated Food Plant Richness Between the Arid American and the Mesoamerican Centers of Diversity, as Means to Advance Indigenous Food Sovereignty in the Face of Climate Change

Climate change is aggravating agricultural crop failures, and the paucity of wild food harvests for Indigenous desert dwellers in Mexico and the U.S. This food production crisis challenges ongoing efforts by Indigenous communities in obtaining greater food security, prompting them to reconsider the value of traditional Indigenous food systems in both Mesoamerica and Arid America, two adjacent centers of crop diversity. While food production strategies in these two centers share many features, the food plant diversity in the Western Mesoamerican region appears to be greater. However, a higher percentage of plants in Arid America have adapted to water scarcity, heat, and damaging radiation. The phytochemical and physiological adaptations of the food plants to abiotic stresses in arid environments offer a modicum of resilience in the face of aggravated climate uncertainties. By comparing food plant genera comprising Western Mesoamerican and Arid American diets, we detected a higher ratio of CAM succulents in the wild and domesticated food plant species in the Arid American food system. We conclude that food plant diversity in the ancestral diets of both centers can provide much of the resilience needed to advance Indigenous food sovereignty and assure food security as climate change advances.

What drives management decisions and grain yield variability in Mesoamerican maize cropping systems? Evidence from small-scale farmers in southern Mexico

CONTEXTSmall-scale cropping systems face enormous challenges in obtaining efficient, stable and predictable responses to grain yields due to their great biophysical, management and socioeconomic complexity. In Mesoamerica, traditional managements have incorporated modern agricultural practices; however, the efficacy of these tools on grain yield and systems´ sustainability is unknown. We explored biophysical, agronomic and socioeconomic drivers determining the maize cropping system and grain yield in Southern Mexico. OBJECTIVESThe specific objectives were i) to investigate the effects of geopedologic soil characteristics on maize grain yield, ii) characterise tropical maize cropping systems and model how agronomic factors determine grain yield variability and iii) identify underlying socioeconomic drivers, which determine the agronomic ones and, consequently, the maize cropping systems. METHODSOn-field interviews and soil data from geopedologic unit maps from maize cropping systems in a Mesoamerican region, Chiapas, Mexico, were used. Structural equation modelling (SEM) and quantitative and qualitative analyses were used to explore the data set. RESULTS AND CONCLUSIONSWe found that cropping systems are differentiated into conventional (CS) and traditional (TS). Soils determined grain yield variability independently from the cropping systems. The most common agronomic inputs expected to positively impact grain yield were not effective in any cropping system. In CS, neither pesticides nor fertilisation determined the crop grain yield; plant density explained 72% of crop grain yield variation. In TS, grain yield was negatively related to plant density, while the fallow period slightly explained grain yield. We identified that cultural practices acquired by the farmers in their birthplace determine the type of the current maize cropping system. SIGNIFICANCEWe highlight inconsistent modern agronomic management of the studied maize cropping systems where agrochemical inputs (fertilisers and pesticides) do not translate into higher grain yields or systems' sustainability. New theoretical models for small-scale maize cropping systems incorporating socioeconomic and cultural drivers might be necessary to predict better maize grain yield.

Operation of research ethics committees in Colombia, Costa Rica, Guatemala, and Mexico: Mesoamerican Project

To attain a better understanding of the structure and processes of Research Ethics Committees (REC) in the low-and middle-income countries of the Mesoamerican region. The objectives are knowing the operational practices of the RECs regarding project evaluation, training needs, and infrastructure. The REC training and needs assessment involved an online survey of all the RECs (n=55) identified in Colombia (n=11), Costa Rica (n=5), Guatemala (n=5), and Mexico (n=34). Participants reported inadequate infrastructure for its proper operation (only 49.1 %, or 27/55, have an exclusive office to safeguard files); insufficient administrative staff (47.3%, 26/55), or financial resources to conduct active site monitoring (85.6%, 47/55) to ensure the protection of rights and welfare of study participants. Investments in REC member training and infrastructure are needed to ensure compliance of REC evaluations with the standards for ethical conduct of research.

Physicochemical and Microbiological Standards of Honey Produced by Genus Melipona

Abstract For thousands of years, honey from stingless bees, mainly from Melipona beecheii, has been recognized as part of traditional Mayan medicine in the Mesoamerican region. Currently Melipona honey is the subject of research due to its nutritional, therapeutic and commercial value. Studies have been conducted to characterize Melipona honey produced on Mexico’s Yucatan Peninsula in, but the results have been limited. The low production and botanical-geographical origin of the honey increases the variability of the results and also the real number of Melipona beekeepers in the area is unknown so we are unable to conduct a statistically representative sampling and enough information to establish a generalization of the information. Therefore, we reviewed the published articles that describe the physicochemical and microbiological characteristics of the honey of some species of the genus Melipona. The information analyzed indicated that some of these characteristics are out of the specifications established by the standard that applies to Apis mellifera honey, without this meaning that it is of lesser quality and therefore. Because production and commercialization of this product is prospering, physicochemical and microbiological standards must be established to avoid adulteration and complications to public health, since this product is widely used for therapeutic purposes.

The effect of landscape and human settlement on the genetic differentiation and presence of Paragonimus species in Mesoamerica

Foodborne diseases are a neglected research area, and despite the existence of many tools for diagnosis and genetic studies, very little is known about the effect of the landscape on the genetic diversity and presence of parasites. One of these foodborne disease is paragonimiasis, caused by trematodes of the genus Paragonimus, which is responsible for a high number of infections in humans and wild animals. The main Paragonimus sp reported in Mesoamerica is Paragonimus mexicanus, yet there are doubts about its correct identification as a unique species throughout the region. This, together with a lack of detailed knowledge about their ecology, evolution and differentiation, may complicate the implementation of control strategies across the Mesoamerican region. We had the goal of delimiting the species of P. mexicanus found throughout Mesoamerica and determining the effect of landscape and geology on the diversity and presence of the parasite. We found support for the delimitation of five genetic groups. The genetic differentiation among these groups was positively affected by elevation and the isolation of river basins, while the parasite’s presence was affected negatively only by the presence of human settlements. These results suggest that areas with lower elevation, connected rivers basins, and an absence of human settlements have low genetic differentiation and high P. mexicanus presence, which may increase the risk of Paragonimus infection. These demonstrate the importance of accurate species delimitation and consideration of the effect of landscape on Paragonimus in the proposal of adequate control strategies. However, other landscape variables cannot be discarded, including temperature, rainfall regime, and spatial scale (local, landscape and regional). These additional variables were not explored here, and should be considered in future studies.

Plasmodium vivax Genetic Diversity in Panama: Challenges for Malaria Elimination in Mesoamerica

Panama and all nations within the Mesoamerican region have committed to eliminate malaria within this decade. With more than 90% of the malaria cases in this region caused by Plasmodium vivax, an efficient national/regional elimination plan must include a comprehensive study of this parasite’s genetic diversity. Here, we retrospectively analyzed P. vivax genetic diversity in autochthonous and imported field isolates collected in different endemic regions in Panama from 2007 to 2020, using highly polymorphic markers (csp, msp-1, and msp-3α). We did the analysis using molecular techniques that are cost-effective for malaria molecular surveillance within Mesoamerica. Thus, we used molecular analyses that are feasible for malaria molecular surveillance within the region, and that can provide useful information for policy and decision making about malaria elimination. We also evaluated if haplotypes established by combining the genotypes found in these genes were associated with relevant epidemiological variables and showed structure across the transmission foci that have been observed in Panama. Ten different haplotypes were identified, some of them strongly associated with geographical origin, age, and collection year. Phylogenetic analysis of csp (central repeat domain) revealed that both major variant types (vk210 and vk247) were circulating in Panama. Variant vk247 was restricted to the eastern endemic regions, while vk210 was predominant (77.3%) and widespread, displaying higher diversity (14 alleles) and geographically biased alleles. The regional implications of these molecular findings for the control of P. vivax malaria to achieve elimination across Mesoamerica are discussed.