Southern Guatemala Research Articles

Place and Person at Pre-Hispanic Teotihuacan, Mexico

There are significant societal differences evident in the material remains of the Classic period (ca. AD 250-600) city of Teotihuacan in central Mexico compared to contemporary Maya kingdoms in southern Mexico and Guatemala, despite both being part of the larger Mesoamerican civilization, sharing many cultural features. One proposed explanation for these differences derives from an analytical social science dichotomy that contrasts groups and individuals. According to this approach, Maya art and architecture indicate a society centered on individuals, particularly the rivalrous semi-divine rulers. Teotihuacan’s depersonalized art, lack of royal tombs, and gridded city plan are believed to indicate a corporate ethos in which individuals were subsumed by the societal collective. However, archaeological evidence for these interpretations is not compelling; moreover, the dichotomy itself is misleading. The key to these differences may lie in conceptions of embodied versus emplaced personae. The identity of Teotihuacanos was shaped by living within the city itself, and their concepts of personhood were entwined with their built environment in ways different from their Maya counterparts.

Combining spectral analysis and geochemical tracers to investigate surface water–groundwater interactions: A case study in an intensive agricultural setting (southern Guatemala)

An increase in the frequency of severe hydrological events has highlighted the importance of sustainable water management in intensive agricultural regions. In a warming climate, improved understanding and stewardship of water resources are needed to guarantee water supply, ensure food security, and build resilience against extreme events. In this study, we evaluate a framework that combines spectral analysis and geochemical tracers as a potential tool for (1) gaining valuable insights into surface water (SW)–groundwater (GW) interactions, and (2) providing guidance for improved water management in an intensive agricultural basin in southern Guatemala. The framework proves to be useful in revealing important water dynamics, exposing key feedback mechanisms for water availability and quality. With the use of power density functions and hydrochemistry (T, pH, EC, and major ions), two specific interaction regimes (influent and effluent) were identified and delimited for the main watercourse. These segments are estimated to interact at high rates with the shallow aquifer in the river channel proximities and would lose influence towards the basin flanks. Furthermore, the δ2H and δ18O values indicate that regional groundwater flow systems play an essential role in the basin groundwater recharge. Lastly, we established three influence zones that depict the spatial extent of the SW-GW interactions within the basin. With these zones, we provide recommendations that will allow for further investigation and application into better water management strategies regulating groundwater development and land use activities within the agricultural context of the area.

Abstract 4221: Aflatoxin exposure in a population-based representative sample of adults in Mexico in 2018

Abstract Importance: Southern Mexico and Guatemala, together represent the region with the highest liver cancer burden in the Americas. There is a higher burden of liver cancer in rural regions in eastern and southern Mexico and remarkably there is an equal number of cases in men and women. Reasons for this increased burden are not clear, but previous studies of food samples have found that contamination of maize with aflatoxin B1 (AFB1), a potent liver carcinogen, is common in the region while HBV and HCV seroprevalence is less than 0.5%. Few examinations of AFB1 levels in persons have been conducted. Objective: To estimate the prevalence of exposure and circulating levels AFB1 in a representative sample of adults living in five regions across Mexico. Study Design: We randomly selected a subsample of 955 adults ≥40 years who participated in Mexico’s National Health and Nutrition Survey 2018 (ENSANUT). These residents were from five states in eastern and southern Mexico and all provided a venous blood sample. We assessed AFB1 levels as pg AFB1-lys/µL in serum using mass spectrometry. The limits of detection and quantification were both 0.010 pg/μL. Results: The mean age of participants was 56 years (± SD 11.7) and 54% were female. The overall prevalence of AFB1-lys detection was 92% (95% confidence intervals; 95%CI 88, 94%). The region with the lowest prevalence, 88% (95%CI 78, 94%), was Chiapas and the region with the highest prevalence was Veracruz 95% (95%CI 84, 98). Median AFB1 was 0.127 pg AFB1-lys/µL (interquartile range; IQR 0.054, 0.446) with a range from 0.066 (IQR, 0.033, 0.147) in Yucatán to 0.476 (IQR, 0.199, 1.355) in Veracruz. AFB1 exposure levels were higher in persons aged ≥60 years, men, and participants living in rural areas. We observed decreasing levels of AFB1 exposure with increasing socioeconomic status. Conclusions: In a representative sample of adults in eastern and southern Mexico we observed a high prevalence of exposure to AFB1. For certain regions, AFB1 levels are comparable to those in Guatemala. These results suggest that AFB1 may be related to the increased burden of liver cancer in eastern and southern Mexico. Citation Format: Adriana Monge, Katherine McGlynn, Luis Santiago-Ruiz, Jose Maria Remes-Troche, Karina Hernandez-Flores, Salvador Villapando-Hernandez, Martin Romero, John Groopman, Martin Lajous. Aflatoxin exposure in a population-based representative sample of adults in Mexico in 2018. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4221.

Serosurvey of Canine Dirofilariasis in a Population of Southern Guatemala

Introduction: Canine dirofilariasis, is a vector-borne disease caused by the parasitic filarial nematode named Dirofilaria immitis. Cardiopulmonary dirofilariasis is a worldwide distributed disease affecting domestic and wild canines as well as felines, causing pulmonary or cutaneous infections in humans. In recent years, scientists have reported the importance of investigating human cases of dirofilariasis since it can be easily confused with lung disease. Guatemala has a high-density of the canine population. Few studies have reported a high prevalence of canine dirofilariasis; nevertheless, knowledge in Guatemala of Dirofilaria immitis is scarce and practically inexistent. Given this, the current study aimed to explore the circulation of antibodies against D. immitis in dogs in the southern part of Guatemala.
 Materials and methods: Data were recollected from 110 male and female dogs aged more than a year from various breeds in the village “El Brito”, Escuintla, Guatemala. One milliliter of blood was collected from each dog. The samples were analyzed using ELISA test to examine the presence of antibodies in adult worms.
 Results: The prevalence determined for antibodies against Dirofilaria immitis of sampled canines was 2.7%, and the most frequent age of the canines was 1-3 years old (85%).
 Conclusions: According to the obtained data, the prevalence of canine dirofilariasis in a southern region of Guatemala was low.

Evolution and Introductions of Influenza A Virus H1N1 in a Farrow-to-Finish Farm in Guatemala.

Commercial swine farms provide unique systems for interspecies transmission of influenza A viruses (FLUAVs) at the animal-human interface. Bidirectional transmission of FLUAVs between pigs and humans plays a significant role in the generation of novel strains that become established in the new host population. Active FLUAV surveillance was conducted for 2 years on a commercial pig farm in Southern Guatemala with no history of FLUAV vaccination. Nasal swabs (n = 2,094) from fattening pigs (6 to 24 weeks old) with respiratory signs were collected weekly from May 2016 to February 2018. Swabs were screened for FLUAV by real-time reverse transcriptase PCR (RRT-PCR), and full virus genomes of FLUAV-positive swabs were sequenced by next-generation sequencing (NGS). FLUAV prevalence was 12.0% (95% confidence interval [CI], 10.6% to 13.4%) with two distinct periods of high infection. All samples were identified as FLUAVs of the H1N1 subtype within the H1 swine clade 1A.3.3.2 and whose ancestors are the human origin 2009 H1N1 influenza pandemic virus (H1N1 pdm09). Compared to the prototypic reference segment sequence, 10 amino acid signatures were observed on relevant antigenic sites on the hemagglutinin. The Guatemalan swine-origin FLUAVs show independent evolution from other H1N1 pdm09 FLUAVs circulating in Central America. The zoonotic risk of these viruses remains unknown but strongly calls for continued FLUAV surveillance in pigs in Guatemala. IMPORTANCE Despite increased surveillance efforts, the epidemiology of FLUAVs circulating in swine in Latin America remains understudied. For instance, the 2009 H1N1 influenza pandemic strain (H1N1 pdm09) emerged in Mexico, but its circulation remained undetected in pigs. In Central America, Guatemala is the country with the largest swine industry. We found a unique group of H1N1 pdm09 sequences that suggests independent evolution from similar viruses circulating in Central America. These viruses may represent the establishment of a novel genetic lineage with the potential to reassort with other cocirculating viruses and whose zoonotic risk remains to be determined.

Assessing the lidar revolution in the Maya lowlands: A geographic approach to understanding feature classification accuracy

It has been well over a decade since lidar-based research began in earnest in the Maya Lowlands of southern Mexico, Guatemala, Belize, and Honduras. Most investigations have an archaeological focus, with a few integrating studies of the ancient Maya with analyses of local ecology and land-use. A review of frequently cited publications reveals a lack of consistency in assessing the accuracy of archaeological feature classifications in lidar data with variables such as sensor type, class definitions, and ground-truthing methods differentially affecting assessment results across the Lowlands. In general, area-based ground-truthing approaches to classifications of full waveform lidar data present the most comprehensive accuracy assessments. New assessment data from the Buenavista Valley of north-central Guatemala are presented to compare against existing studies and to demonstrate how a geographic approach (a comprehensive, landscape-scale study of features over space and time) to classification error assessment can enhance understanding of classification accuracy. Results show that meaningful comparisons of archaeological features across lidar datasets cannot be considered reliable without more uniform and detailed presentations of accuracy assessment methods, analyses, and results. The article concludes with recommendations for how such collaborations might proceed.

Chia (Salvia hispanica L.) Seed Germination: a Brief Review.

Chia (Salvia hispanica L.) is a seed native to northern Mexico and southern Guatemala that has started to be consumed in recent years in other regions of the world owing to its nutritional and functional properties. Germination of chia seeds seems to be able to further improve these properties, and it has been the subject of some studies. In general, germination has proven to be a simple and inexpensive process capable of improving the content of phenolic compounds and the antioxidant capacity of foods, as well as reducing antinutritional factors that interfere with nutrient absorption. A particular characteristic of chia seeds is that they produce mucilage when they are hydrated. For this reason, the germination conditions of the seed need to be adapted. The nutritional guidelines of some countries, such as Brazil, Germany and Sweden, recommend that the diet of the population should be more plant-based, thus encouraging the consumption of foods with a high content of bioactive compounds and nutrients, e.g., germinated seeds. This review briefly explored the germination conditions of chia seeds as well as the changes in phytonutrient content and antinutritional factors after their germination process. The main information available in the literature is that germination of chia seeds can increase the contents of protein, fiber, and total phenolic compounds. As a conclusion, germination of chia seeds is favorable for increasing their health benefits and nutritional value. However, chia germination parameters should be adjusted and microbiological risks should be properly evaluated.

Potential Distribution and Connectivity for Two Plethodontid Salamanders: Conservation Areas and Landscape Corridors for Two Endemic Species of México and Guatemala.

Habitat loss is one of the most important threats to biodiversity; it alters the habitat connectivity of species and is among the main causes of the global amphibian extinction crisis. Identifying the potential areas of distribution and connectivity of species is of the utmost importance so that informed decisions can be made for the conservation of vulnerable amphibian populations. In this study, we performed species distribution models and used circuit theory to model omnidirectional connectivity for two plethodontid salamanders of conservation concern distributed in the forests of Chiapas, Mexico, and Guatemala (Bolitoglossa franklini and Bolitoglossa lincolni). Potential distribution maps show an affinity for well-preserved montane forests for both species. Likewise, we found that the niches of the species are not similar. The connectivity models show that the main areas of connectivity are in the Meseta Central de Chiapas, Sierra Madre de Chiapas, and the Cordillera Volcánica Guatemalense, in this last range, important areas of connectivity were located, as well as least-cost paths and barriers to the movement of both species. We identified that important areas of climatic suitability and connectivity are not within the protected natural areas and may be threatened by the increasing influence of anthropogenic activities. The results of our study show the importance of preserving the regional forests to ensure the persistence of species with arboreal habits and high sensitivity to habitat transformation, as well as to recognize and prioritize potential areas for management and protection in both southern Mexico and Guatemala.

Evidence of the genetic and spatial structure of Nasua narica in Central America and northern South America from mitogenomic analysis

Carnivores are extremely important in ecosystem dynamics. Coatis (Procyonidae) are a group of Neotropical species with highly developed social behavior. One coati species is the Central American or white-nosed coati (Nasua narica). This work describes the analysis of two sets of mitochondrial data for a sample of N. narica covering most of the geographic distribution range of the species. The first data set analyzed 74 specimens for three mitochondrial loci; the second, 59 specimens for complete mitochondrial genomes. Our phylogenetic analyses revealed six distinct genetic groups of N. narica in southern México, Central America, and South America, which, together with three additional groups found in northern México and southern USA in a previous study, resulted in a total of nine genetically distinct groups of N. narica. The first genetic group (G1), which began to differentiate 4.1 to 3.2 million years ago, was located on the Pacific coast of Ecuador and northern Colombia. A second genetic group (G6) was detected in northern Colombia, Panama, and southern Costa Rica, being introgressed by mitochondrial DNA from the mountain coati (Nasuella olivacea). The third genetic group (G3) was located in Costa Rica, Nicaragua, El Salvador, Honduras, and southern Guatemala. The fourth genetic group (G4) was located in north-central Guatemala and Belize. The fifth genetic group (G5) was distributed in southern México (Chiapas, Tabasco, Campeche, Quintana Roo, and Yucatán) and northern Guatemala. Finally, the sixth genetic group (G2) was found only in Mérida (Yucatán, México). Groups G2 to G5 became mitochondrially diversified over 1.9 to 1.1 million years. All groups showed high mitochondrial genetic diversity, although the South American genetic group (G1) had the highest diversity. The northern genetic groups (G4, G5) had lower genetic diversity, except for the Merida group, which is likely composed of other undetected subgroups. The existence of six (nine, considering another study) well-developed groups in N. narica is related to female phylopatry and climatic changes during the Pleistocene. A spatial autocorrelation analysis showed a very high structure, well in line with the south-to-north colonization of the American continent by N. narica.

Seismicity and seismically active faulting of Guatemala: A review

We present a review of the main sources of seismicity of Guatemala. The largest seismically active faults are related to the transform, left-lateral, North America-Caribbean plate boundary zone, the most prominent of which are the Motagua and Polochic faults, both exceeding 350 km in length. Additionally, the Ixcán fault, a 150-200-km-long left-lateral structure, is located north of the Polochic and Motagua faults. Other seismically active faults associated to the Polochic-Motagua system and smaller in length are the Seleguá, Nentón and Las Conchas.The Jocotán and Chamelecón faults are located south of and parallel to, the Polochic-Motagua, with a combined length of about 300 km. These faults are not active at present but probably were part of the plate boundary zone in the geologic past. A system of North-South-trending grabens is located immediately south of the Jocotán-Chamelecón fault system, and cutting through it. These grabens are seismically active. South-southwest of the grabens, there is a system of conjugate faults, called the Arco Volcánico fault system, whose main structure is the Jalpatagua fault, a right-lateral strike-slip structure parallel to the volcanic arc. There are other minor faults along this system striking perpendicular to the Jalpatagua with left-lateral displacement. These faults are partially covered by volcanic deposits and have only been identified by their seismic activity. Finally, the Middle America trench offshore southern Guatemala is the plate boundary between the overriding Caribbean and the subducting Cocos plates.All these structures have produced large earthquakes. Historical data show that epicenters of great earthquakes have indeed been located along one of these faults, such as the July 22, 1816 (Magnitude 7.6) along the Polochic fault. More recently, on February 4, 1976, a Magnitude 7.5 earthquake took place, with epicenter on the Motagua fault. This event caused severe damages to the infrastructure of the country, and about 23,000 deaths. The rest of the faults and grabens have also been the site of destructive earthquakes, such as the seismic sequence of December 1917–January 1918, which caused severe damages in Guatemala City. The Cocos-Caribbean convergent boundary is also seismically active, producing events of magnitude 7.0 or larger, the latest of which took place on November 2012, damaging towns and cities along the coastal plain of southern Guatemala.

High spatiotemporal overlap in the non‐breeding season despite geographically dispersed breeding locations in the eastern whip‐poor‐will (Antrostomus vociferus)

AbstractAimA full annual cycle approach to conservation and understanding of regional population trends requires an understanding of migratory connectivity. We present tracking data on the eastern whip‐poor‐will (Antrostomus vociferus), a Neotropical migrant that has declined by 70% in recent decades. When and where populations of this species are limited throughout the annual cycle is poorly understood.LocationBreeding area: midwestern United States; passage area and winter area: midwestern/southern United States, Mexico, Central America.MethodsWe utilized data from 52 archival GPS tags from five breeding areas covering a 9.5‐degree latitudinal span (~1000 km) of the whip‐poor‐will breeding range in the summers of 2017 and 2019. We identified migratory routes and spatiotemporal bottlenecks, stopover and wintering locations, calculated migratory connectivity throughout migration and on the wintering grounds and tested predictions for three latitudinal connectivity patterns.ResultsWhip‐poor‐wills circumvented the Gulf of Mexico, and populations across a large latitudinal gradient came together in eastern Texas in early October, resulting in decreased connectivity throughout migration. Breeding‐winter migratory connectivity was low (MC = 0.22 ± 0.12), with extensive overlap of core wintering areas in southern Mexico and Guatemala. The overlap of wintering areas by individuals from dispersed breeding latitudes suggests that whip‐poor‐wills most closely resemble telescopic migrants.Main conclusionsCircumventing the Gulf of Mexico influenced connectivity in the whip‐poor‐will, funnelling individuals into a small region in eastern Texas in migration and likely influencing breeding‐winter connectivity. Thus, geographically dispersed breeding populations overlap in space and time during migration and winter, and non‐breeding season conditions affecting populations (both positively and negatively) impact individuals from across the core breeding range. For example, extensive deforestation occurring in the whip‐poor‐will's core wintering area likely impacts individuals from all five deployment locations. We demonstrate that combining multiple indices of spatiotemporal cohesion is critical to fully understand how migratory animals are distributed in the non‐breeding season.

MesoRAD: A New Radiocarbon Data Set for Archaeological Research in Mesoamerica

The Mesoamerican Radiocarbon Database (MesoRAD) compiles radiocarbon dates from the archaeological literature of Mesoamerica. The inaugural data set, ‘Lowland Maya Dates’, includes 1846 radiocarbon dates from 132 sites in 21 distinct environmental zones in the Maya lowlands. These data span the Paleoindian to Colonial Periods (11,670 to 190 uncal BP, 13,740 cal BP to modern) across southern Mexico, Belize, Guatemala, El Salvador, and Honduras. Here, we describe the methods used to compile and organize these dates, including the spatial, chronological, and environmental coverage of the data set.

PATH ANALYSIS OF PHYSICAL ATTRIBUTES OF CHAYOTE FRUIT

Chayote is originally from southern Mexico and Guatemala and has been a staple food highly appreciated in Brazil and worldwide. This study was carried out on a Red Yellow Latosol in 2020 to investigate the relationship between the physical properties of chayote fruit of the variety Cambray and their mass, aiming to indicate criteria for direct selection of more attractive fruits. The fruit parameters evaluated were mass (MAS), largest transverse diameter (LTD), smallest transverse diameter (STD), length (FTL), volume (FTV), area (FTA), and perimeter (FTP), as well as seed area (SDA) and seed perimeter (SDP). Initially, correlations among these morphological variables were assessed by Pearson's correlation coefficient, and a correlation network was used to express the results graphically. A diagnosis of multicollinearity was performed, and a condition number of 6639 (multicollinearity severe) was found. Path analysis considered the fruit mass as the main dependent variable. Our analyses showed that MAS, FTV, FTA, FTP, and STD are physical attributes with the greatest potential for selection and identification of more attractive chayote fruits of the variety Cambray for commercial purposes.

Effectiveness of conservation agriculture (tillage vs. vegetal soil cover) to reduce water erosion in maize cultivation (Zea mays L.): An experimental study in the sub-humid uplands of Guatemala

Cultivated uplands in tropical latitudes are severely affected by soil water erosion. Conservation agriculture (CA) is specifically intended to control erosion. The aim of the present study is to analyse the effectiveness of CA measures to reduce the erosion in maize cultivation (Zea mays L.) on andosols in the mountains of southern Guatemala. Resolving this question is crucial to the development of sustainable soil policies appropriate to the conditions prevailing in this region. The study was conducted over a three-year period, from 2017 to 2019, on three experimental plots managed under conventional tillage (CT), reduced tillage (RT) and no-tillage (NT). The general-to-specific (GETS) method, based on reduction theory, was used to generate explanatory models of the erosion-affected surface. The study was carried out at two scales, first, with the complete database, and second, the database was segmented according to the agricultural management systems. The results showed different rates of eroded soil surface between the three management systems: 73.2% under CT, 41.3% under RT and 20.4% under NT. Analysis of the complete database (n = 36) showed that the litter cover (ryl.p = –0.86, p < 0.001) and the soil disturbance (ryp.l = 0.57, p < 0.001) were, in that order, the factors with the greatest explanatory power of the eroded surface. The segmented analysis (n = 12) showed that the management system adopted had a decisive influence on the ground cover (litter and weed cover) and, therefore, on the soil erosion. Under CT, the eroded surface was only correlated with the weed cover (ryw.l = –0.68, p < 0.05), under NT only with the litter cover (ryl.w = –0.89, p < 0.001) and under RT the erosion did not correlate with either of the vegetal layers. Three conclusions are derived from this study. First, litter layer was the key explanatory factor of erosion. Second, this factor is highly influenced by the agricultural management system. The proportion and distribution of the litter layer in each management situation were key to explaine the different soil erosion rates between the three management systems. And finally, it is proposed for the area of this study the soil management under NT with a dense and well distributed litter cover.

Chemical characterization of extracts from various parts of Salvia hispanica L. and their antibacterial activity

Plants have been an important source of phytomedicines for thousands of years. Salvia hispanica L. distributed in Central and Southern Mexico and Guatemala has potential medicinal properties. The current research focused on the chemical characterization of the plant extracts from leaf, seed, and flower parts using gas chromatography-mass spectrometry (GC MS) analysis and evaluating its antibacterial effects. Results of antibacterial tests proved that the crude extracts could be potentially utilized in controlling some bacterial strains. The highest zone of inhibition (14.6 mm) was observed against the bacterium Pseudomonas fluorescens at 50 µg/100 μL ethyl acetate flower extract. GC-MS analysis confirmed the occurrence of 49 and 34 different compounds in the ethyl acetate flower and leaf extract respectively. Many of them are used in industry for various applications like flavour and fragrance agent, antioxidant, anti-inflammatory, antimicrobial, antitumor etc. These plant extracts which proved to be potentially effective can be used as natural alternative preventives to control food poisoning diseases and preserve foodstuff avoiding health hazards of chemical antimicrobial agent applications.

Revision of the Pantomorus albosignatus species group (Coleoptera: Curculionidae: Entiminae) from Mexico and Central America.

Pantomorus albosignatus Boheman, 1840 (Entiminae: Naupactini), type species of the genus Pantomorus Schoenherr, 1840, is broadly distributed in Mexico, from Oaxaca and Veracruz to Chihuahua and Coahuila, and is probably related to P. parvulus Sharp 1891 (México: Oaxaca and Veracruz), P. andersoni sp. nov. (México: Guerrero), and P. crinitus (Boheman, 1840) (southern Mexico, El Salvador and Guatemala). The four species are small (5-8 mm), apterous, usually show a characteristic maculation and erect setae on the elytra, short antennae, vestigial to absent humeri, and well-developed, squamose corbels of the metatibiae, and are here referred to as the Pantomorus albosignatus species group. Our study was based on the examination of type material and about 500 specimens from different collections, and provides a dichotomous key, descriptions or redescriptions of the species, habitus photographs, line drawings of female and male genitalia, a map of distribution, new locality records and new plant associations. We propose that Pantomorus nobilis (Boheman 1840) is a new junior subjective synonym of P. crinitus (Boheman, 1840), and we designate lectotypes for the species Pantomorus albosignatus Boheman, P. parvulus Sharp, P. crinitus (Boheman), P. nobilis (Boheman) and P. affinis Sharp, 1891 (the latter is also a junior synonym of P. crinitus). Pantomorus albosignatus usually inhabits Acacia grasslands and cactus deserts of the Mexican Plateau, at higher elevations than remaining species; P. parvulus occurs in cloud forests and tropical deciduous forests of southern Mexico; P. crinitus in open oak pine forests, cloud forests and tropical deciduous forests of southern Mexico, Guatemala and El Salvador; and P. andersoni is endemic to the state of Guerrero, in Acacia-cactus woodlands.

Zoonotic Gastrointestinal Helminths in Rodent Communities in Southern Guatemala.

Rodents are reservoirs and hosts of several pathogens around the world, including zoonotic parasite species. This study aimed to determine the occurrence of zoonotic gastrointestinal helminths in rodents captured inside households in a rural community from southern Guatemala. Sixty-nine rodents were captured in 33% (49/148) of the surveyed households, including Rattus rattus, Rattus norvegicus, Mus musculus, and Sigmodon hispidus. Thirty-six percent (25/69) of these rodents (3 Rattus and 22 Mus musculus), from 45% (22/49) of the households, were parasitized with at least 1 gastrointestinal helminth species. Helminths from 6 species were identified: Hymenolepis diminuta, Moniliformis moniliformis, Heterakis spumosa, Nippostrongylus sp., Strongyloides sp., and Syphacia sp. Two zoonotic species were found in Rattus, H. diminuta in R. rattus (1/6), and M. moniliformis in R. norvegicus (1/1). Coinfection with other non-zoonotic helminth parasites, such as He. spumosa and Strongyloides sp., also was observed in the Rattus genus. Mus musculus had only non-zoonotic helminths: He. spumosa, Nippostrongylus sp., and Syphacia sp. being the most common, and He. spumosa (96%) followed by Nippostrongylus sp. (48%), with a higher presence in males than females, with a similar proportion in adult and young individuals. This is the first report of zoonotic and non-zoonotic helminths parasites in rodents from Guatemala.

&lt;p&gt;&lt;strong&gt;High morphological diversity of &lt;em&gt;Amaranthus cruentus&lt;/em&gt; (Amaranthaceae) and its putative wild ancestor revealed by pistillate floral characterization in the proposed domestication center of origin&lt;/strong&gt;&lt;/p&gt;

Amaranthus (Amaranthaceae) is a widespread genus that includes noxious weeds, economically important species for food, forage, medicinals and ornamentals. Three species of Amaranthus have been cultivated for their grain in the world, i.e. A. hypochondriacus, A. caudatus, and A. cruentus. It has been postulated that A. cruentus was domesticated from the probable wild progenitor A. hybridus, and that the domestication event occurred between southern Mexico and Guatemala, the region where the Mayan civilization flourished. Morphological variation in this grain amaranth and its putative wild progenitor has been poorly documented, even though this area is a possible center of domestication of A. cruentus. Samples of A. cruentus, A. hybridus, hybrids between these two species and aberrant morphotypes collected were studied morphologically using multivariate statistical methods on pistillate floral characters to (1) assess the diversity of grain amaranth A. cruentus and its postulated wild progenitor A. hybridus in the proposed domestication center of origin, (2) test the hypothesis that some hybrids and aberrant morphotypes found in the region can be morphologically differentiated from A. hybridus and A. cruentus based on statistical analyses, and (3) test and review the diagnostic characters traditionally used for assessing species circumscription. Our results showed high morphological diversity for these two species in the study region, indicating differentiation of both species, apparently based primarily on hybridization. Morphological variants on flower, bract, sepal, seed, and fruit characters were significant for confirming and circumscribing species.

Nuclear phylogeography of the temperate tree species Chiranthodendron pentadactylon (Malvaceae): Quaternary relicts in Mesoamerican cloud forests

BackgroundThe Mexican hand tree or Canac (Chiranthodendron pentadactylon) is a temperate tree species of cloud and pine-oak forests of southern Mexico and Guatemala. Its characteristic hand-shaped flower is used in folk medicine and has constituted the iconic symbol of the Sociedad Botánica de México since 1940. Here, the evolutionary history of this species was estimated through phylogeographic analyses of nuclear DNA sequences obtained through restriction site associated DNA sequencing and ecological niche modeling. Total genomic DNA was extracted from leaf samples obtained from a representative number (5 to 10 per sampling site) of individuals distributed along the species geographic range. In Mexico, population is comprised by spatially isolated individuals which may follow the trends of cloud forest fragmentation. By contrast, in Guatemala Chiranthodendron may constitute a canopy dominant species near the Acatenango volcano. The distributional range of this species encompasses geographic provinces separated by the Isthmus of Tehuantepec.The objectives of the study were to: (i) estimate its genetic structure to define whether the observed range disjunction exerted by the Isthmus of Tehuantepec translates into separate populations, (ii) link population divergence timing and demographic trends to historical climate change, and (iii) test hypotheses related to Pleistocene refugia.ResultsPatterns of genetic diversity indicated high levels of genetic differentiation between populations separated by the Isthmus. The western and eastern population diverged approximately 0.873 Million years ago (Ma). Demographic analyses supported a simultaneous split from an ancestral population and rapid expansion from a small stock approximately 0.2 Ma corresponding to a glacial period. The populations have remained stable since the LIG (130 Kilo years ago (Ka)). Species distribution modelling (SDM) predicted a decrease in potential distribution in the Last Interglacial (LIG) and an increase during the Last Glacial Maximum (LGM) (22 Ka), Mid-Holocene (6 Ka) and present times.ConclusionsDivergence time estimations support the hypothesis that populations represent Quaternary relict elements of a species with broader and northernmost distribution. Pleistocene climatic shifts exerted major influence on the distribution of populations allowing dispersion during episodes of suitable climatic conditions and structuring during the first interglacial with a time period length of 100 Kilo years (Kyr) and the vicariant influence of the Isthmus. Limited demographic expansion and population connectivity during the LGM supports the moist forest hypothesis model.

Dengue outbreaks pattern in southern Guatemala

This study analyses time series of dengue occurrence in the southern region of Guatemala. Temporal patterns of epidemic outbreaks in the department of Escuintla were investigated using the official reports from 2001 to 2013. In order to identify underlying associations with climate behavior, the epidemiological data were compared with historical reports available for temperature, rainfall and humidity. Preliminary results reveal that waves of dengue outbreaks exhibit a periodic pattern modulated by climatic conditions. A hierarchical cluster analysis allowed to indirectly estimate the degree of association of each climatic variable with dengue occurrences, showing the dominance of rainfall in dengue outbreaks patterns in three different localities. A further prospective analysis was performed to check whether epidemic trends driven by rainfall are hold in the subsequent years. Results presented here give support to predictive models for dengue incidence driven by climate.