America Research Articles

Corruption and neo-colonialism in Latin America

Corruption is deemed one of the main drivers of development challenges in many countries, mainly in those territories that drag the shackles of colonialism. The roots of corruption in underdeveloped countries can be traced from Colonial times from South America, Asia to Africa the pattern seems to be repeated: populations subjugated to new masters, disenfranchised indigenous people, labour and sexual exploitation, brutal punishments for those who resisted colonial power were commune features for countries that experienced colonialism. Many of those power excesses have been recognised historically, however one of the most persistent element of Colonialism that survives until nowadays is corruption. The present text aims to shine a light on the relation of colonialism and corruption in Latin America. The hypothesis raised suggests that corruption was installed through colonialism in the Latin America region. The text is presented in three parts; the first one offers some historical considerations about European colonialism, the second one describes the strategies used by colonisers and the use of corruption as a tool to impose their rule and consolidate their power, and the third one exposes the new colonial form of corruption carried out by the West, led today by the United States.

Urban Parrots in Southern South America: Challenges and Opportunities

Data on the interactions between the order Psittaciformes and the anthropogenic environment are still insufficient and have not been systematized, especially in the Neotropical region. As a consequence of this coexistence, the volume of accumulated knowledge is probably significantly greater than the formal scientific contributions on the subject. In this survey, information was compiled on the wild parrots inhabiting cities in the Southern Cone of South America, based on surveys with key informants. The results obtained highlighted the presence of a large number of parrot species that form part of the urban avifauna of the region, between 67% and 90% of the total number of species of the order cited for each territory evaluated. The greatest species richness and the number of breeding species were associated with the large cities located in middle and low latitudes. We confirmed breeding within the cities for more than 40% of the species mentioned. Seventy-five percent of the species reported are native to the study area, the rest originating from other regions of South America or other continents. A quarter of the reported species are considered threatened and almost 50% have declining populations. Urban parrots represent a challenge in the search for urban models compatible with biodiversity conservation, and in the designing of innovative conservation strategies that respond to the new challenges posed by a constantly growing human population.

Cross-equatorial extension of the Pacific-South American wave train enabled by Southeastern South American rainfall

The Pacific–South American (PSA) pattern is a key mode of climate variability in the mid-to-high latitudes of the Southern Hemisphere, impacting circulation and rainfall anomalies over South America. However, the effect of South American rainfall on the PSA has not been previously explored. This study focuses on the impact of rainfall over southeastern South American (SESA) during the austral summer (December–February). Observational analyses reveal that the PSA pattern remains confined to higher southern latitudes when SESA rainfall anomalies are weak. In contrast, strong SESA rainfall anomalies can generate a quasi-stationary Rossby wave train, which represents a cross-equatorial extension of the PSA. This wave train propagates along a southwest–northeast great circle path from higher latitudes, crosses the equator, and reaches the tropical Atlantic, southern Europe, and northern Africa, inducing a wet and cool weather condition over western and southern Europe. The observed wave train can be reproduced by the linear baroclinic model (LBM) simulations. Given the PSA’s connection to tropical forcing over the central Pacific, we examine differences in the wave response to central Pacific forcing alone versus combined central Pacific and SESA forcings. By incorporating SESA forcing, the wave train originally triggered by central Pacific forcing is amplified and extended. Our findings confirm the significant role of SESA rainfall anomalies in extending the PSA pattern to the Northern Hemisphere and highlight the South American continent as a land bridge that links circulation anomalies across the Pacific and Atlantic Oceans and the Southern and Northern Hemispheres.

The Ciboney and the Taino in the Context of Craniometric Variation in Native American Population

The article examines two cranial samples representing the pre-Columbian population of Cuba (the Ciboney and the Taino), in the general context of craniometric variation in the indigenous population of the American continent. Published craniometric data from various sources were used for comparison by the canonical discriminant analysis and calculation of pairwise squared Mahalanobis distances. The question is raised about the possibility of including artificially deformed crania (of which the Taino and many other American samples are entirely composed) in the analyses using only the metrics of the facial skeleton. When analyzing samples without artificial deformation, similarities were found between the Ciboney and South American groups, mainly from the West, which may indicate their origin from an ancient and less differentiated type that inhabited Central and northwestern South America in ancient times. The results of the analysis combining deformed and non-deformed samples are more difficult to interpret, which may indicate a significant influence of cranial vault deformation on the morphology of the facial skeleton, but they do not contradict the conclusions of studies of related sciences about the South American origin of the Taino.

Top-down proteomics of venoms from five Micrurus species from Costa Rica: Comparative composition of phospholipase A2-rich vs three-finger toxin-rich phenotypes

Coralsnakes of the genus Micrurus include more than 80 species distributed in the American continent. They produce potent neurotoxic venoms acting at the neuromuscular junction and potentially leading to respiratory paralysis and death. The vast majority of proteins in coralsnake venoms belong to the three-finger toxin (3FTx) and the group I phospholipase A2 (PLA2) families. Previous studies using ‘bottom-up’ proteomic strategies have revealed a compositional dichotomy of toxin expression by which different Micrurus species display a predominance of either 3FTx or PLA2 proteins in their venoms, possibly linked to the phylogeographic structure of the genus radiation. ‘Top-down’ proteomics (TDP) allows the direct analysis of intact proteins in a high resolution mass spectrometer, circumventing the limitations of the ‘peptide-to-protein inference problem’ inherent to the bottom-up approach. Here, we analyzed the venoms of five out of the six Micrurus species that inhabit Costa Rica, by using a TDP approach. Results unveil venom proteoforms that are shared between these species, and provide additional insights into the variable compositional complexity of these venoms and relationships to their 3FTx/PLA2 dichotomy.

Environmental and Life Cycle Assessment of Lithium(I) Carbonate Production from Lithium(I) Containing Brines

Lithium(I) consumption is predicted to continue growing exponentially to support the rapidly expanding lithium-ion battery (LIB) market. Extracting Li(I) from lithium(I)-containing brine is commonly used for production of battery-grade Li2CO3, an essential component in LIB production. Lithium(I)-containing brine resources are abundant in a specific region in South America, often referred to as the Lithium Triangle, including the Chilean Atacama Desert.This study aims to establish a detailed and up-to-date life cycle inventory (LCI) of battery-grade Li2CO3 production from brine in Chile’s Atacama Desert based on parameter modelling, literature, technical reports, and Ecoinvent database. The comprehensive analysis of the environmental impacts conducted includes brine production and modelling evaporation through three scenarios: engineering calculations, Penman equation and measured data. Rates of evaporation of brine are influenced by weather and salinity changes, so corrections to data are necessary. Process modelling was conducted in Aspen Plus and the modelling method was set as ELECNRTL. The northern Chile electricity grid was modelled, as was the water footprint (WF) of the production process. Once emissions are estimated, the LCA modelling software Sphera is used, according to ISO 14040, with the functional unit set to the production of 1 kg of battery-grade Li2CO3. Based on the ReCiPe 2016 v1.1 midpoint characterisation method and AWARE method, the environmental impacts and water scarcity footprint (WSF) have been analysed and will be presented.The results showed that most of the environmental impacts arose from sodium hydroxide (NaOH), sodium carbonate (Na2CO3), water and electrical energy consumption for the entire Li2CO3 production process. Solvent extraction is used to remove borates from the brines, requiring aqueous NaOH for re-extraction from the organic solvent. The major contribution is from the chlor-alkali electrolytic process for NaOH production. Na2CO3 is required for removal of MgII and CaII aqueous species as corresponding carbonate precipitates, and for Li2CO3 formation. The required process water was used as a solvent and as wash water. The northern Chile electricity grid is powered by 48.46 % natural gas and 34.8 % hard coal, as well as 8.7 % photovoltaic energy. The overall global warming potential (GWP) of the process was 5.82 kg CO2 (kg Li2CO3)-1. 75.84 % of the GWP was incurred by NaOH production, 14.01 % by Na2CO3 production and 8.30 % by electrical energy generation; other components contributed < 5 %. The environmental impacts of the mining and evaporation processes were caused primarily by electricityconsumption, whereas the GWP of the Li2CO3 chemical production process was determined mainly by the chemicals used.The results also showed that in waste management, the infiltration caused by waste piles accumulated near the production site and surface impoundments has an insignificant impact, although large areas of land are occupied. For WF and WSF, the blue WF, which is the consumption of surface and ground water, was 0.16 m3 (kg Li2CO3)-1 and the chemical production process blue WF accounted for 87.50 %. NaOH production in chlor-alkali processes consumes water by the reaction 2H2O + 2e- → H2 + 2OH-, accounting for 74.8 % of the blue WF of the chemical production process. Hence, oxygen diffusion cathodes are advocated to decrease specific electrical energy consumptions by ca. a third by substituting the above cathode reaction by: O2 + 2H2O + 4e- → 4OH-, so decreasing CO2 emissions and enabling GWP savings of 24.1 %. Additionally, comparison of H2O to OH- ratios between conventional membrane chlor-alkali processes (H2O : OH- = 1) and those utilizing oxygen reduction cathodes (H2O : OH- = 0.5) indicates water consumption could be decreased.Despite the small amount of WF, the impact on water scarcity was 13.1 m3 world equivalent per kg Li2CO3 in this arid desert, so it is essential to decrease water consumption and increase its recycling. The comparative performance of different modelling approaches for the LCI parameters, combined with the borate re-extraction overlooked in previous such LCA studies, has enabled a more detailed LCI and environmental assessment which can identify hotspots and decrease water consumption and environmental impacts. However, further work is needed to simulate and compare the environmental impacts, water consumption, and economic benefits of selective lithium(I) recovery from brines by electrochemical processes and by conventional evaporation methods.

School efficiency in Latin America before and after the COVID-19 pandemic: New evidence from PISA 2018 and 2022

The efficiency of schools can be measured as the ratio between the outputs produced (achievement) and the inputs utilised (human and technical resources). Once efficiency levels are obtained for each school through Data Envelopment Analysis (DEA) techniques, one can assess how an education system as a whole is either far or close to a maximum efficient educational frontier given available resources. Further, one can rely on this estimated frontier to gauge the importance of students, family and school factors pushing efficiency in different directions, and whether the efficiency-equality trade holds. This exercise is relevant to the realities of education systems of the global south where resources are limited and inequalities are vast. In this paper, we present novel evidence for the Latin America region (9 countries) by using the latest two waves of data from PISA (years: 2018 and 2022), a pooled sample of 4969 schools. Importantly, given the surveys’ timing, we are able to compare efficiency before and after the COVID-19 pandemic, contrasting leading determinants. We find that, at regional level, efficiency slightly increased from 0.75 to 0.78, and only being constant in three (Brazil, Chile and Colombia) out of the nine countries. Barriers of efficiency hold across the two waves overall, with systemic factors such as ICT access and school type and location being more empirical relevant post-pandemic. Also, the link between low access to minimum knowledge and efficiency, as well as inclusion, worsened post pandemic in half of the countries. During the pandemic, school efficiency was found to be boosted −among others− by higher school support, better stock of ICT at home and communication with teachers, whereas lack of coordination with education authorities was found to be a barrier.

Genome-Wide Identification and Stress Responses of Cowpea Thaumatin-like Proteins: A Comprehensive Analysis.

Cowpea (Vigna unguiculata (L.) Walp.) is an important legume cultivated mainly in regions with limited water availability across the African and American continents. Its productivity is significantly affected by environmental stresses. Thaumatin-like proteins (TLPs), which belong to the PR-5 (pathogenesis-related 5) protein family, are known to be responsive to both biotic and abiotic stresses. However, their role remains controversial, with some TLPs associated with plant defense (particularly against fungal infections) and others associated with abiotic stresses response. In this study, we evaluated the structural diversity and gene expression of TLPs in cowpea (VuTLPs) under different stress conditions, including biotic [mechanical injury followed by inoculation with Cowpea Aphid-borne Mosaic Virus (CABMV) or Cowpea Severe Mosaic Virus (CPSMV)] and abiotic (root dehydration). Genomic anchoring of VuTLPs revealed 34 loci encoding these proteins. Neighbor- joining analysis clustered the VuTLPs into three distinct groups. We identified 15 segmental duplication and 6 tandem duplication gene pairs, with the majority of VuTLP genes found to be under purifying selection. Promoter analysis associated VuTLPs with bHLH, Dof-type, and MYB- related transcription factors, supporting their diverse roles. Diversity in VuTLP function was also observed in their expression profiles under the studied stress conditions. Gene expression data showed that most VuTLPs are recruited within the first minutes after biotic stress imposition. For the root dehydration assay, the most transcripts were up-regulated 150 min post-stress. Moreover, the gene expression data suggested that VuTLPs exhibit functional specialization depending on the stress condition, highlighting their diverse roles and biotechnological potential.

Carbon farming in the living soils of the Americas

Soil represents Earth’s largest terrestrial reservoir of carbon (C) and is an important sink of C from the atmosphere. However, the potential of adopting best management practices (BMPs) to increase soil C sequestration and offset greenhouse gas (GHG) emissions in agroecosystems remains unclear. Synthesizing available information on soil C sink capacity is important for identifying priority areas and systems to be monitored, an essential step to properly estimate large-scale C sequestration potential. This study brings an overview of thousands of research articles conducted in the Americas and presents the current state-of-the-art on soil C research. Additionally, it estimates the large-scale BMPs adoption impact over soil C dynamics in the region. Results indicated that soil C-related terms are widely cited in the literature. Despite that, from a total of ~13 thousand research articles recovered in the systematic literature review, only 9.2% evaluated soil C (at any depth), and only 4.6% measured soil C for the 0–30 cm soil layer, mostly conducted in North and South America regions. Literature review showed a low occurrence of terms related to BMPs (e.g., cover cropping), suggesting a research gap on the subject. Estimates revealed that upscaling of BMPs over 30% of agricultural land area (334 Mha) of the Americas can lead to soil C sequestration of 13.1 (±7.1) Pg CO2eq over 20 years, offsetting ~39% of agricultural GHG emissions over the same period. Results suggest that efforts should be made to monitor the impact of cropping system on soil C dynamics on the continents, especially in regions where data availability is low (e.g., Central, Caribbean, and Andean regions). Estimating the available degraded area for the continent and the soil C sequestration rates under BMPs adoption for Central, Andean, and Caribbean regions were major shortcomings encountered in our analysis. Thus, it is expected that some degree of uncertainty may be associated with the obtained results. Despite these limitations, upscaling of BMPs across the Americas suggests having great potential for C removal from the atmosphere and represents a global positive impact in terms of climate change mitigation and adaptation.

Disentangling the worldwide invasion process of Halyomorpha halys through approximate Bayesian computation.

Halyomorpha halys is a polyphagous insect pest, which was first found outside its native regions in 1996, and since then it has rapidly spread worldwide causing damage to agriculture. Investigating the genetic diversity among H. halys populations is essential to understand the colonization history out of its native areas. Analyses based on mtDNA indicate multiple invasions from Asia to European and American continents, as well as serial invasions within invaded countries, but the colonization dynamics are still debated. Recently, genome-wide data (ddRAD) have been published to investigate the genomic structure of H. halys, proposing China as a putative source of multiple serial invasion events to Europe and the Americas. In this study we re-analyze published ddRAD sequences from worldwide populations of H. halys to better elucidate the colonization process. We assessed the genetic diversity in native populations identifying genetic differentiation between populations in China. Furthermore, we observed a complex pattern of population structure in the invaded countries, that may have originated from the occurrence of multiple independent colonization waves through time, from sub-populations present in the native range to Europe and the Americas. We tested alternative colonization hypotheses through Approximate Bayesian Computation comparison of demographic scenarios. Our results support multiple waves of migration from East China to invaded territories and the occurrence of European and American bridgehead effects. These results underline the importance of demographic inference through genome-wide data to investigate biological invasions, whose knowledge become fundamental to establish new strategies of management and control of invasive species.

Parallelisms in the morphology and evolutionary transformations of two bones of the visceral skeleton in fossil and recent freshwater sculpins of the genus Triglopsis (Pisces: Cottidae)

The article considers the morphogenesis of two visceral skeleton bones, which are most important for identification, in five freshwater forms of the genus Triglopsis Girard, 1851. These forms evolved as a result of colonization of fresh waters by marine fishes in different geological periods and continents. On American continent, two fossil species, Triglopsis idahoensis (Smith, 1975) and T. antiquus (Smith, 1975), from the Pliocene Lake Idaho and one recent species T. thompsonii Girard, 1851 from Lake Michigan were studied. On European continent, two freshwater populations of one species T. quadricornis (Linnaeus, 1758) from Lakes Ladoga and Onega were investigated. Comparative analysis of the external features of the preopercular and dentary bones showed that all five studied forms have common characters inherent in the genus Triglopsis. The differences are in the size, shape and orientation of the spines; and hollows of the preopercular-mandibular sensory canal. The fossil species T. idahoensis and T. antiquus have wide, slightly curved preopercle with spines of similar length. Significant differences are found in the morphology of the sensory canal. The most primitive state of this canal is observed in T. antiquus. It is characterized by small size of hollows and wide bone bridges between them. Evolutionary transformations in morphology of the canal in fossil and recent species go in the direction of increasing passage of the canal in the bones. In recent forms, passage of the sensory canal occupies almost the entire width of the bone, which is significantly greater than in fossil species. Geographically remote and isolated fossil and recent forms of the genus Triglopsis, each with its own evolutionary fate, have a single trend of evolutionary transformations of the studied bones. Despite the fact that the lake forms were at different stages of differentiation, evolutionary transformations of the morphology of the studied bones proceed in parallel and in the same direction.

Vector SHAP Values for Machine Learning Time Series Forecasting

ABSTRACTWe propose a new vector SHapley Additive exPlanations (SHAP) to interpret machine learning models for forecasting time series using lags of predictor variables. Unlike the standard SHAP measuring the contribution of each lag of each predictor variable, the proposed vector SHAP measures the contribution of the vector of the lags of each variable. The vector SHAP has an advantage of faster computation over the standard SHAP. Some desirable properties of the vector SHAP (vector local accuracy, vector missingness, and vector consistency) are established. A Monte Carlo simulation shows that the vector SHAP has a much faster computing time than the SHAP; the difference of the standard SHAP and the vector SHAP is small; the sampling SHAP is sensitive to the sampling proportion in a range of practical application; the vector SHAP mitigates the sensitivity issue. The vector SHAP is applied to the realized volatility of world major stock price indices of 16 countries for forecasting the realized volatility of South Korea stock price index, KOSPI. Further vectoring by regions of Europe, North America, and Asia yields vector SHAP value for each region which is very close to the sum of vector SHAP values of the countries of the region, illustrating usefulness of the strategy of vectoring.

First report of Trypanosoma microti in Cricetid rodents from Querétaro, Mexico: Expanding the known distribution of Herpetosoma in the Mexican transition zone

Members of the subgenus Herpetosoma are specialized parasites of mammals of the order Lagomorpha and Rodentia. It is estimated that around 50 species within this subgenus are transmitted by several flea species. These parasites have recently gained attention from a public health perspective because several species have been reported to infect humans. Several species of the Herpetosoma subgenus have been recognized on the American continent, although there have been no reports from the Mexican Transition Zone. Therefore, the present study aimed to report the presence of a member of the Herpetosoma subgenus in cricetid rodents from Querétaro, Mexico.A total of 17 rodents belonging to three species, Peromyscus boylii, Peromyscus gratus, and Peromyscus melanophrys, were collected. Genetic material was extracted using the Chelex 100 resin, followed by PCR and sequencing of a fragment of 800 bp of the 18S ribosomal gene of the genus Trypanosoma. Out of these hosts, eight individuals of P. gratus (1♀), P. melanophrys (1♂), and P. boylii (3♂, 3♀) tested positive for Trypanosoma microti DNA, previously detected in the England and Japan. The present study, therefore, provides the first discovery of T. microti in Mexico, thereby increasing the known richness of species of the genus Trypanosoma in rodents from this country and the Mexican Transition Zone.

Assessing yellow fever outbreak potential and implications for vaccine strategy.

Yellow fever (YF), a vector-borne viral hemorrhagic fever, is endemic in tropical regions of Africa and South America, with large vaccination programmes being used for control. However, significant outbreaks have occurred in recent years. Data on infection rates and seroprevalence is often sparse, requiring robust mathematical models to estimate the burden of yellow fever. In particular, modelling is required to estimate the risk of outbreaks and inform policy decisions regarding the targeting of vaccination. We present a dynamic, stochastic model of YF transmission which uses environmental covariates to estimate the force of infection due to spillover from the sylvatic (non-human primate) reservoir and the basic reproduction number for human-to-human transmission. We examine the potential for targets identified by the World Health Organization EYE Strategy (50%, 60% or 80% vaccination coverage in 1-60 year olds) to achieve different threshold values for the effective reproduction number. Threshold values are chosen to reflect the potential for seasonal and/or climatic variation in YF transmission even in a scenario where vaccination lowers the median reproduction number below 1. Based on parameter estimates derived from epidemiological data, it is found that the 2022 EYE Strategy target coverage is sufficient to reduce the static averaged annual effective reproduction number R below 1 across most or all regions in Africa depending on the effectiveness of reported vaccinations, but insufficient to reduce it below 0.5 and thereby eliminate outbreaks in areas with high seasonal range. Coverage levels aligned with the 2026 targets are found to significantly decrease the proportion of regions where R is greater than 0.5.

Impact of the Belt and Road Initiative on Global Trade and Economic Growth Amid China’s Slowing Growth

Since the inception of the Belt and Road Initiative (BRI), China’s trade relations with participating nations have experienced substantial growth. This study utilises data from the World Trade Organization (WTO) covering the years 2003 to 2021 to explore the dynamics of China’s foreign trade and assess the impact of the BRI on trade interactions with China. One of the central objectives of our research is to determine whether participation in the BRI has significantly contributed to trade growth with China, thereby strengthening economic ties and fostering bilateral cooperation. Another important objective is to analyse the changes in the BRI’s role in driving global economic growth amid China’s slowing growth. Through empirical analysis using data from over 180 countries, we evaluate the heterogeneous effects of the BRI across different continents. Our findings indicate that the BRI has had the most pronounced trade-stimulating impact on the continents of America, Europe and Africa, while trade volumes with Asian countries have seen only marginal increases. The relatively smaller trade growth in Asian countries can be attributed to the already high volume of trade activities due to their geographical proximity to China, which diminishes the marginal impact of the BRI. Additionally, the significant infrastructure investments under the BRI have been predominantly directed towards Africa and Europe, further explaining the smaller trade-enhancing effects observed in Asia compared to other continents. Furthermore, we identified the spillover effects of the BRI on non-participating countries. Moreover, significant differences in the BRI’s impact on global economic growth were observed before and after China’s economic slowdown. This article offers actionable policy recommendations to inform future decisions based on these findings.

Recent Resurgence in Monkeypox Cases: Emerging Trends and Concern for Public Health Authorities

Mpox, was previously known as monkeypox, an infectious zoonotic disease caused by the monkeypox virus, is emerging zoonosis with a significant global concern for health authorities. Initiated in Africa, the disease has now spread its roots into Europe, the American Continent, and the Central Asian Region. Due to recent appearance of few imported cases in Pakistan, Mpox has now become a matter of national concern. As communities may be exposed to combat with its challenges, the need for awareness and immediate measures has now become a matter of urgency. Keywords: Clades, Diagnosis, Mpox, PHEIC, Transmission, Vaccination.

Urban environments increase generalization of hummingbird–plant networks across climate gradients

Urbanization has reshaped the distribution of biodiversity on Earth, but we are only beginning to understand its effects on ecological communities. While urbanization may have homogenization effects strong enough to blur the large-scale patterns in interaction networks, urban community patterns may still be associated with climate gradients reflecting large-scale biogeographical processes. Using 103 hummingbird-plant mutualistic networks across continental Americas, including 176 hummingbird and 1,180 plant species, we asked how urbanization affects species interactions over large climate gradients. Urban networks were more generalized, exhibiting greater interaction overlap. Higher generalization was also associated with lower precipitation in both urban and natural areas, indicating that climate affects networks irrespective of habitat type. Urban habitats also showed lower hummingbird functional trait diversity and over/underrepresentation of specific clades. From the plant side, urban communities had a higher prevalence of nonnative nectar plants, which were more frequently visited by the hummingbird species occurring in both urban and natural areas. Therefore, urbanization affected hummingbird-plant interactions through both the composition of species and traits, as well as floral resource availability. Taken together, we show that urbanization consistently modifies ecological communities and their interactions, but climate still plays a role in affecting the structure of these novel communities over the scale of continents.

Trends of Climate Extremes and Their Relationships with Tropical Ocean Temperatures in South America

South America has experienced significant changes in climate patterns over recent decades, particularly in terms of precipitation and temperature extremes. This study analyzes trends in climate extremes from 1979 to 2020 across South America, focusing on their relationships with sea surface temperature (SST) anomalies in the Pacific and Atlantic Oceans. The analysis uses precipitation and temperature indices, such as the number of heavy rainfall days (R10mm, R20mm, R30mm), total annual precipitation (PRCPTOT), hottest day (TXx), and heatwave duration (WSDI), to assess changes over time. The results show a widespread decline in total annual precipitation across the continent, although some regions, particularly in the northeast and southeast, experienced an increase in the intensity and frequency of extreme precipitation events. Extreme temperatures have also risen consistently across South America, with an increase in both the frequency and duration of heat extremes, indicating an ongoing warming trend. The study also highlights the significant role of SST anomalies in both the Pacific and Atlantic Oceans in driving these climate extremes. Strong correlations were found between Pacific SST anomalies (Niño 3.4 region) and extreme precipitation events in the northern and southern regions of South America. Similarly, Atlantic SST anomalies, especially in the Northern Atlantic (TNA), exhibited notable impacts on temperature extremes, particularly heatwaves. These findings underscore the complex interactions between SST anomalies and climate variability in South America, providing crucial insights into the dynamics of climate extremes in the region. Understanding these relationships is essential for developing effective adaptation and mitigation strategies in response to the increasing frequency and intensity of climate extremes.

Giants beasts updated: A review of new knowledge about the South American megafauna

ABSTRACTSince the publication of Megafauna: Giant Beasts of Pleistocene South America by Fariña et al. in 2013, much has been published on this fascinating subject. Here, we sum up those contributions according to their aim: taxonomic, geographical and phylogenetic novelty, new approaches to the natural history of those species, and extinction and its aftermath. The traditional centres of interest since the 19th century, especially the Río de la Plata region, have now been complemented as a source of information by many other regions in South America, and the remains are now being studied by biogeochemistry and molecular biology, as well as with finite element analysis and constantly refined statistics. Finally, scholars and the public are becoming more interested in the demise of the megamammals as the starting point of the current process of biodiversity loss.

Population density estimates and conservation status of Aegla jacutinga Marçal &amp; Teixeira, 2020 (Decapoda: Anomura: Aeglidae) from the type locality in Brazil

Abstract Anomuran crabs of the genus AeglaLeach, 1821 are endemic to temperate and subtropical regions of South America and are commonly found in streams and rivers, where they are generally restricted to healthy environments because they are sensitive to environmental changes. The genus presents worrying data regarding its conservation, like the many Brazilian freshwater species classified as being at some level of threat of extinction. We inventoried unexplored watersheds, estimated the population density of Aegla jacutinga Marçal &amp; Teixeira, 2020 in its type locality, updated information on the distribution of the species, and assessed its conservation status using IUCN criteria.