South American Indians Research Articles

The Chilean COVID-19 Genomics Network Biorepository: A Resource for Multi-Omics Studies of COVID-19 and Long COVID in a Latin American Population.

Although a lack of diversity in genetic studies is an acknowledged obstacle for personalized medicine and precision public health, Latin American populations remain particularly understudied despite their heterogeneity and mixed ancestry. This gap extends to COVID-19 despite its variability in susceptibility and clinical course, where ethnic background appears to influence disease severity, with non-Europeans facing higher hospitalization rates. In addition, access to high-quality samples and data is a critical issue for personalized and precision medicine, and it has become clear that the solution lies in biobanks. The creation of the Chilean COVID-19 Biorepository reported here addresses these gaps, representing the first nationwide multicentric Chilean initiative. It operates under rigorous biobanking standards and serves as one of South America's largest COVID cohorts. A centralized harmonization strategy was chosen and included unified standard operating procedures, a sampling coding system, and biobanking staff training. Adults with confirmed SARS-CoV-2 infection provided broad informed consent. Samples were collected to preserve blood, plasma, buffy coat, and DNA. Quality controls included adherence to the standard preanalytical code, incident reporting, and DNA concentration and absorbance ratio 260/280 assessments. Detailed sociodemographic, health, medication, and preexisting condition data were gathered. In five months, 2262 participants were enrolled, pseudonymized, and sorted by disease severity. The average Amerindian ancestry considering all participant was 44.0% [SD 15.5%], and this value increased to 61.2% [SD 19.5%] among those who self-identified as Native South Americans. Notably, 279 participants self-identified with one of 12 ethnic groups. High compliance (>90%) in all assessed quality controls was achieved. Looking ahead, our team founded the COVID-19 Genomics Network (C19-GenoNet) focused on identifying genetic factors influencing SARS-CoV-2 outcomes. In conclusion, this bottom-up collaborative effort aims to promote the integration of Latin American populations into global genetic research and welcomes collaborations supporting this endeavor. Interested parties are invited to explore collaboration opportunities through our catalog, accessible online.

Extraction of anti-hyperglycaemic bioactive compounds from Phyllanthus niruri L. through solvent mixture design: In vitro and in vivo evaluation

BackgroundSpecies within Phyllanthus genus exhibit a diverse range of experimentally validated pharmacological activities. Notably, Phyllanthus niruri Linneo(Phyllanthaceae), commonly referred to as stonebreaker, is a native Central and South American species with a rich history of use in traditional ethnomedicine for treating gastrointestinal and renal disorders. PurposeThe aim of this study was to investigate the application of various solvent mixtures to optimize the extraction of anti-hyperglycemic secondary metabolites from P. niruri. MethodsTo optimize the extraction of anti-hyperglycemic compounds from P. niruri, a solvent mixture design strategy was employed. The optimized extracts were subjected to chemical characterization using spectrophotometric methods and HPLC-DAD analysis. Also, the influence of edaphoclimatic conditions on the composition of extracts was investigated. The anti-hyperglycaemic potential of the extracts was evaluated through both in vitro and in vivo assays. The in vitro studies included enzyme inhibition assays targeting α-glucosidase from two sources (yeast and pig). For in vivo studies, a rat model with oral starch overload was used to confirm the anti-hyperglycaemic activity of the extracts. ResultsAn optimal solvent mixture (70 % methanol and 30 % ethyl acetate) was found as effective for extracting compounds with anti-hyperglycemic potential from P. niruri. All the extracts obtained using this solvent inhibited both, yeast and pig α-glucosidase, with greater selectivity for inhibiting the yeast-derived enzyme. Extracts from aerial parts (AP) exhibited the strongest inhibitory activity. These extracts contained phenolic compounds, specifically flavonoids, but no condensed tannins were detected. Chromatographic analysis of profile revealed a major peak consistent with corilagin. In vivo studies using a dose of 500 mg kg-1 demonstrated that this extract significantly reduced blood sugar levels after starch overload in rats. ConclusionThis study demonstrates the importance of selecting appropriate solvent mixtures to extract bioactive compounds with anti-hyperglycemic properties from P. niruri. Our findings support the traditional use of this plant as a anti-hyperglycaemic agent in ethnomedicine.

Chilled Pacu (Piaractus mesopotamicus) fillets: Modeling Pseudomonas spp. and psychrotrophic bacteria growth and monitoring spoilage indicators by 1H NMR and GC–MS during storage

This study aimed to assess the growth of Pseudomonas spp. and psychrotrophic bacteria in chilled Pacu (Piaractus mesopotamicus), a native South American fish, stored under chilling conditions (0 to 10 °C) through the use of predictive models under isothermal and non-isothermal conditions. Growth kinetic parameters, maximum growth rate (μmax, 1/h), lag time (tLag, h), and (Nmax, Log10 CFU/g) were estimated using the Baranyi and Roberts microbial growth model. Both kinetic parameters, growth rate and lag time, were significantly influenced by temperature (P < 0.05). The square root secondary model was used to describe the bacteria growth as a function of temperature. Secondary models, √μ = 0.016 (T + 10.13) and √μ =0.017 (T + 9.91) presented a linear correlation with R2 values >0.97 and were further validated under non-isothermal conditions. The model's performance was considered acceptable to predict the growth of Pseudomonas spp. and psychrotrophic bacteria in refrigerated Pacu fillets with bias and accuracy factors between 1.24 and 1.49 (fail-safe) and 1.45–1.49, respectively. Fish biomarkers and spoilage indicators were assessed during storage at 0, 4, and 10 °C. Volatile organic compounds, VOCs (1-hexanol, nonanal, octenol, and indicators 2-ethyl-1-hexanol) showed different behavior with storage time (P > 0.05). 1H NMR analysis confirmed increased enzymatic and microbial activity in Pacu fillets stored at 10 °C compared to 0 °C. The developed and validated models obtained in this study can be used as a tool for decision-making on the shelf-life and quality of refrigerated Pacu fillets stored under dynamic conditions from 0 to 10 °C.

Can the Herbicide Dicamba Produce Oxidative Stress in the Native South American fish Jenynsia lineata at Environmentally Relevant Concentrations?

Dicamba (DIC) is one of the most applied auxin herbicides worldwide. Sublethal effects in the South American native fish Jenynsia lineata exposed to DIC concentrations close to environmental concentrations (0.03-30µg/L) during 48h were analysed thorough the evaluation of catalase (CAT), glutathione S-transferase (GST), superoxide dismutase (SOD) activities and malondialdehyde (MDA) and H2O2 levels for detecting potential oxidative stress. In gills MDA increased showing oxidative damage probably because of an inefficient antioxidant defense. This response evidenced the important role of gills as an organ of direct contact with waterborne contaminants. In addition, other changes in the biomarkers of oxidative stress were observed such as the inhibition of SOD activities in brain and the inhibition of GST in liver. These results show that short- term exposures to environmentally relevant concentrations of DIC could induce sublethal effects in native fish.

Gallbladder Cancer Risk and Indigenous South American Mapuche Ancestry: Instrumental Variable Analysis Using Ancestry-Informative Markers.

A strong association between the proportion of indigenous South American Mapuche ancestry and the risk of gallbladder cancer (GBC) has been reported in observational studies. Chileans show the highest incidence of GBC worldwide, and the Mapuche are the largest indigenous people in Chile. We set out to assess the confounding-free effect of the individual proportion of Mapuche ancestry on GBC risk and to investigate the mediating effects of gallstone disease and body mass index (BMI) on this association. Genetic markers of Mapuche ancestry were selected based on the informativeness for assignment measure, and then used as instrumental variables in two-sample Mendelian randomization analyses and complementary sensitivity analyses. Results suggested a putatively causal effect of Mapuche ancestry on GBC risk (inverse variance-weighted (IVW) risk increase of 0.8% per 1% increase in Mapuche ancestry proportion, 95% CI 0.4% to 1.2%, p = 6.7 × 10-5) and also on gallstone disease (3.6% IVW risk increase, 95% CI 3.1% to 4.0%), pointing to a mediating effect of gallstones on the association between Mapuche ancestry and GBC. In contrast, the proportion of Mapuche ancestry showed a negative effect on BMI (IVW estimate -0.006 kg/m2, 95% CI -0.009 to -0.003). The results presented here may have significant implications for GBC prevention and are important for future admixture mapping studies. Given that the association between the individual proportion of Mapuche ancestry and GBC risk previously noted in observational studies appears to be free of confounding, primary and secondary prevention strategies that consider genetic ancestry could be particularly efficient.

Tourism and Indigenous peoples in South America: reflections on experiences in Argentina and Chile

ABSTRACT Since the 1990s, the participation of Indigenous peoples in tourism has been fostered as part of global development policies to address rural poverty in Latin America. In this article, our aim is to examine the promotion of indigenous tourism in relation to multicultural transformations and local inter-ethnic relations in South America, taking two experiences, one in southern Chile’s Araucanía Region and the other in the General San Martín Department of northern Argentina’s Salta Province. We reflect on the relevance of institutions – state and non-state – which promote these development perspectives and the links that Indigenous people establish with them for the understanding of indigenous tourism. First, we consider the promotion of indigenous tourism in both countries within the particular dynamics of multiculturalism transformations in each one. Then we focus on the two experiences of indigenous tourism, to think about the relations between Indigenous people, institutions and interethnic relationships in these projects. We suggest that the definition of community tourism should not be considered as a reified field, but rather as a definition that is determined through negotiations and inter-ethnic disputes.

Human genetics: Rich genomic history of two isolated Indigenous peoples of South America.

Genome-wide data from two Indigenous South American groups reveal their dynamic population history. The Mapuche from Southern Chile and the Ashaninka from Amazonian Peru remained largely isolated over time. Yet, both groups interacted with other South American peoples sporadically.

Violence and human rights

The decisions taken by Jair Bolsonaro’s government since the first day of his mandate, in January 2019, have weakened the country’s environmental control policies and contributed to reduced inspection, increased deforestation on public lands and, consequently, the violation of the rights of indigenous peoples. There is a great diversity of contexts for isolated indigenous peoples in Brazil, from small groups to a single individual. These groups are the survivors of successive massacres and are threatened by the spread of disease, and for these reasons avoid contact with other agents at any cost. In addition to the need to ensure that their territories remain protected, the decision itself to live in isolation must be guaranteed in accordance with the already established instruments, including the United Nations Declaration on the Rights of Indigenous Peoples and Convention No. 169 of the International Labor Organization (ILO). Despite the traumatic history of contact, Brazil is the country with the largest number of isolated indigenous peoples in South America, as well as has the oldest public policy in terms of guaranteeing the rights of these peoples to self-determination. The measures presented in this article substantially undermine the protection of the rights of isolated indigenous peoples and obstruct the possibility of advancing or enforcing human rights which are internationally recognised and provided for in domestic law.

Americana bei Jean Bodin und Johann Fischart, Hexen bei Jean de Léry

Abstract The scope of Early Modern Demonology is universal, for the perceived threat of the devil is omnipresent, stretching through time and space. This article examines various utilizations of the description of central and south American indigenous peoples in demonological discourse. By means of three closely related examples, I will demonstrate the discursive conflation of deviant behavior in Europe and in America through comparisons and transferences: Jean Bodin’s Démonomanie des Sorciers (1580), its German translation by Johann Fischart (1581/1586), and Jean de Léry’s writings, especially his Histoire d’un voyage (1578/1585). Within this discursive nexus, Léry compares the American Indigenes to European Catholics, whereas Bodin compares them to European witches - and Fischart completes this argumentative triangle by calling for European Catholics to be held accountable for comparable acts in the same way as European witches.

The genus Aphis (Hemiptera, Aphididae) living on Asteraceae species in southern South America: Argentina and Chile, with five new species.

In the whole of Argentina and Chile, southern South America in this paper, 20 species of the genus Aphis hosted in species of Asteraceae were known; eleven of them are native South American, and those introduced are mostly polyphagous and widespread. The Chilean regions and the Argentine provinces in which each one of them is known, as well as the host plants on which it has been recorded, are listed. New data of 15 of them are presented, with several first records in different Argentine provinces or hosted on diverse plants: The knowledge of A. conspicua and A. fuentesi, which were recently described living on species of Baccharis, is improved from specimens respectively collected on Senecio and Gutierrezia. A. rogerblackmani Nieto Nafra, Ortego Mier Durante sp. n. is described from apterous and alate viviparous females, oviparous females and males collected on Baccharis in Argentina. Other four species are described from apterous and alate viviparae: A. gutierreziae Ortego, Mier Durante Nieto Nafra sp. n., collected on species of Gutierrezia in Argentina, A. hyalis Mier Durante, Nieto Nafra Ortego sp. n., collected on Hyalis argentea in Argentina, A. pulverea Nieto Nafra, Moreno-Gonzlez Ortego sp. n., collected on species of Senecio in Chile and Argentina, and A. sanrafaelina Ortego, Mier Durante Nieto Nafra sp. n., collected on Tagetes mendocina, Thymophylla pentachaeta and Pectis odorata in Argentina. The intraspecific diversity of Aphis pulverea has been analysed by a principal component analysis followed by hierarchical clustering of principal components. An identification key to viviparous females of the species of Aphis hosted in Asteraceae and known in southern South America is presented.

Neonatal hemolytic disease due to anti-Diegoa antibody: a case report

BackgroundThe Diegoa antigen commonly occurs in certain Asian and South American Indian populations. In general, hemolysis caused by anti-Diegoa antigen is not severe, and exchange transfusion is rarely needed. Here, we report a neonate with moderate hemolytic disease caused by anti-Diegoa antigen in the Baoji area of China.Case presentationA 39-week gestation male newborn of Han nationality was delivered by second cesarean section because of scarred uterus. The newborn’s birth weight was 3700 g with an Apgar score of 9. Four hours after delivery, transcutaneous bilirubin test revealed a level of 17 mg/dl. After 23 hours, the neonate developed anemia and hyperbilirubinemia. Bacterium, virus and other pathogens, as well as tests for arcuate and glucose-6-phosphate dehydrogenase, were all negative. Direct antiglobulin test of the neonate was positive. Diegoa antigens of the baby and his father were positive, while his mother was negative. The newborn was successfully cured with phototherapy and one-dose intravenous injection of human albumin.ConclusionsIt is important to consider and test for the anti-Diegoa antibody in cases of hemolytic disease of the newborn of the Han ethnicities of China.

INITIAL HUMAN COLONIZATION OF THE AMERICAS, REDUX

ABSTRACTThe study of the peopling of the Americas has been transformed in the past decade by astonishing progress in paleogenomic research. Ancient genomes now show that Native American ancestors were formed in Siberia or the Amur region by admixture of ca. 15–30% Ancient North Eurasian genes with those of East Asians. The Anzick infant, buried with Clovis bifaces at 12,900 cal BP, belonged to a group that was ancestral to later Native Central and South Americans. Fishtail points, derived from Clovis, mark the arrival and rapid expansion of Clovis-descended Paleoindians across South America, also evident in the sharp increase of radiocarbon dates, continent-wide, at 13,000–12,500 cal BP. In both North and South America, extinction of most genera of megafauna was virtually simultaneous with Paleoindian expansion. Human hunting must have been involved, perhaps in concert with other indirect impacts. Contrary to the alternative bolide impact theory, there is no evidence of a dramatic human population decline after 12,800 cal BP. Ancient genomes show that divergent lithic traditions after 13,000 cal BP need not be attributed to a separate Pacific Rim migration stream. Several recent finds raise the possibility that pre-Clovis people might have reached the Americas before 20,000 cal BP, but these precursors must have either failed to thrive, or were ultimately replaced by proto-Clovis or Clovis people. Consilient paleogenomic and archaeological data indicate that initial colonization by Paleoindian ancestors of living Native Americans occurred after 14,500 cal BP.

Oxidative stress responses after exposure to triclosan sublethal concentrations: an integrated biomarker approach with a native (Corydoras paleatus) and a model fish species (Danio rerio)

ABSTRACT Triclosan (TCS) is a synthetic broad-spectrum antimicrobial agent commonly used world-wide in a range of personal care and sanitizing products detected frequently in aquatic ecosystems. The aim of this study was to examine biochemical markers responses triggered by TCS in Danio rerio and in a native South American fish species (Corydoras paleatus). Further, an integrated approach comparing both test fish species was undertaken. These fish organisms were exposed to 100 or 189 µg TCS/L for 48 h. The activities of catalase (CAT), glutathione-s-transferase (GST), superoxide dismutase (SOD), and lipid peroxidation levels (LPO) and total antioxidant capacity against peroxyl radicals (ACAP) were determined in liver, gills, and brain. Acetylcholinesterase activity (AChE) was measured in the brain. Multivariate analysis showed that the most sensitive hepatic parameters were activities of GST and SOD for C. paleatus while LPO levels were for D. rerio. In gills the same parameters were responsive for C. paleatus but CAT in D. rerio. ACAP and GST activity were responsive parameters in brain of both species. Integrated biomarker responses (IBR) index demonstrated similar trends in both species suggesting this parameter might serve as a useful tool for quantification of integrated responses induced by TCS.

Chemotaxonomic profiling of fungal endophytes of Solanum mauritianum (alien weed) using gas chromatography high resolution time-of-flight mass spectrometry (GC-HRTOF-MS)

IntroductionSince ancient times medicinal plants have been used as medicine in many parts of the world to promote human health and longevity. In recent years many novel secondary metabolites of plants have been isolated and reported to provide lead compounds for new drug discoveries. Solanum mauritianum Scopoli is native to South America. It is reported to be used by native South Americans during famine as a vegetable and as medicine to cure various diseases. In South Africa the plant is viewed as weed and is facing eradication, however, this plant is a valuable subject for research into its potential pharmaceutical and chemical uses. This study elucidated the metabolic profile of fungal endophytes that have promising bioactive secondary metabolites against pathogenic microorganisms, including mycobacterium species.Material and methodsFungal endophytes from a weed Solanum mauritianum Scop. were used to synthesize secondary metabolites. Gas chromatograph high-resolution time-of-flight mass spectrometry (GC-HRTOF-MS) was used to analyse volatile compounds to prove that potentially fungal endophytes could be extracted from this weed. Extracts obtained with ethyl acetate were screened for phytochemicals and analyzed using a gas chromatograph high-resolution time-of-flight mass spectrometry system. Principal component analysis was used to compare the gas chromatograph high-resolution time-of-flight mass spectrometry data for differences/similarities in their clustering. Phytochemical screening was conducted on the crude extracts of fungal endophytes obtained from different parts of Solanum mauritianum Scopoli (leaves, ripe fruit, unripe fruit and stems).ResultsPhytochemical screening indicated the presents of alkaloids, flavonoids, glycosides, phenols, quinones and saponins. Quinones were not present in the crude extracts of Fusarium sp. A total of 991 compounds were observed in the fungal endophytes, and Cladosporium sp. (23.8%) had the highest number of compounds, compared to Paracamarosporium leucadendri (1.7%) and Talaromyces sp. (1.5%). Some volatile compounds such as eicosane, 2-pentadecanone, 2-methyloctacosane, hexacosane and tridecanoic acid methyl ester with antibacterial activity were also observed.ConclusionCompositional variations between the plant and fungal endophyte phytochemicals were observed. The results of this study indicate that fungal endophytes from Solanum mauritianum Scop. contain compounds that can be exploited for numerous pharmaceutical and medicinal applications.

Origin of the green iguana (Iguana iguana) invasion in the greater Caribbean Region and Fiji

Invasive populations of green iguanas (Iguanidae: Iguana iguana) are widely established beyond their native Central, South American, and Lesser Antillean range in various islands of the Pacific, Florida USA, and in the Greater Caribbean Region. Although widespread, information about these invasions is scarce. Here we determine the origin of invasive populations of green iguanas in Puerto Rico, Fiji, The Caymans, Florida USA, The Dominican Republic, the US Virgin Islands (USVI) of St. Thomas and St. Croix, and a U.S.A pet store. We sampled 120 individuals from these locations and sequenced one mitochondrial (ND4) and two nuclear (PAC and NT3) loci. We also include a preliminary characterization of population structure throughout Puerto Rico using six microsatellite loci to genotype individuals across 10 sampling sites. Comparing the genealogical relationships of all our samples to published sequencing data from the native range, we found that sampled populations were largely a product of populations from Colombia and El Salvador; two countries with multiple, industrial-size pet iguana farming operations. Notably, we found that haplotypes detected exclusively in the USVI and Puerto Rico’s outlying island of Vieques are closely linked to green iguanas native to Saba and Montserrat (Lesser Antilles); a clade not reported in the pet trade. Our population genetic analyses did not reveal isolation among sampling sites in Puerto Rico, rather the evidence supported admixture across the island. This study highlights the roles of the pet trade and lack of regulation in the spread of green iguanas beyond their native range.

Enhancing Language Services to Native American Children: A Look From the Inside

Enhancing Language Services to Native American Children: A Look From the Inside

Lux et Tenebris? Coloniality and Anglican Missions in Argentine Patagonia in the Nineteenth Century

Within the modern capitalist World-System, Missionary work was mostly developed through the connubiality with colonial powers. The missionary work of the Anglican Church is no exception. This article centers on the missionary enterprise carried out in Argentine Patagonia in the nineteenth century. Missionaries’ reports carefully narrated that venture. However, the language and the notions underlying the missionary work’s narration reveal the dominion of colonial ideologies that imbued how religious agents constructed alterity. Connecting the missionaries’ worldview with the political context and expansion of the British Empire allows us to unfold the complex intersections of religious, ethnic, racial, and geopolitical discourses that traverse the lives of indigenous peoples in South America.

Creole Sketches

New Orleans in 1878 was the most exotic and cosmopolitan city in North America. An international port, with more than 200,000 inhabitants, it was open to French, Spanish, Mexican, South American, and West Indian cultural influences, and home to a thriving population descended from free African Americans. It was also a battleground in the fight against yellow fever (malaria) and in the political upheavals that followed the end of Reconstruction. The continued influx of Anglo-Americans and the renewed ascendancy of white supremacists threatened to overwhelm the local blend of languages, races, and cultures that enlivened the unique Creole character of the city. Writing for an English-language newspaper, Lafcadio Hearn presented the speech, charm, and humor of the Creolized natives on the other side of Canal Street, and illustrated his sketches with woodcut cartoons — the first of their kind in any Southern paper. These vignettes, published in the New Orleans Daily Item during 1878-1880, capture a traditionalist urban world and its colorful characters with a delicate and sympathetic understanding.

Scientific Landscape Related to Mapuche Indigenous Peoples and Wallmapu Territory

Recent international recognition of indigenous peoples, their rights and contributions to solving current challenges has directed academic attention to the way research is conducted in relation to them, what topics are studied, by whom, and using which methodologies. The Mapuche are the most numerous indigenous peoples in South America and have ancestrally inhabited a territory denominated Wallmapu. This study undertook a comprehensive revision and meta-analysis of the scientific literature related to the Mapuche and Wallmapu. Through quantification and visualization of the scientific landscape, the goal was to enhance the understanding of the themes and patterns that have guided research in this field of study. We found 1611 documents in Web of Science and SciELO collections published between 1975 and 2020. Using CiteSpace software, we analyzed the main conceptual hotspots, identified central authors and pivotal works, among other aspects of the scientific knowledge domain. The main research themes found revolve around political and historical aspects of the relationship between Mapuche and the State; ethnobotanical research including plant properties and cultural knowledge transmission; and the indisputable connection between indigenous resistance and environmental depredation. We argue that valuing cultural diversity paves the road for reclaiming indigenous knowledge as a contribution to our understanding of the world.

Tetranychus evansi spider mite populations suppress tomato defenses to varying degrees.

Plant defense suppression is an offensive strategy of herbivores, in which they manipulate plant physiological processes to increase their performance. Paradoxically, defense suppression does not always benefit the defense‐suppressing herbivores, because lowered plant defenses can also enhance the performance of competing herbivores and can expose herbivores to increased predation. Suppression of plant defense may therefore entail considerable ecological costs depending on the presence of competitors and natural enemies in a community. Hence, we hypothesize that the optimal magnitude of suppression differs among locations. To investigate this, we studied defense suppression across populations of Tetranychus evansi spider mites, a herbivore from South America that is an invasive pest of solanaceous plants including cultivated tomato, Solanum lycopersicum, in other parts of the world. We measured the level of expression of defense marker genes in tomato plants after infestation with mites from eleven different T. evansi populations. These populations were chosen across a range of native (South American) and non‐native (other continents) environments and from different host plant species. We found significant variation at three out of four defense marker genes, demonstrating that T. evansi populations suppress jasmonic acid‐ and salicylic acid‐dependent plant signaling pathways to varying degrees. While we found no indication that this variation in defense suppression was explained by differences in host plant species, invasive populations tended to suppress plant defense to a smaller extent than native populations. This may reflect either the genetic lineage of T. evansi—as all invasive populations we studied belong to one linage and both native populations to another—or the absence of specialized natural enemies in invasive T. evansi populations.