Search Results (67)

Although it is the wettest continent, droughts are a regular occurrence in South America. As the effects of anthropogenic influences, including climate change, become more pronounced, droughts are expected to increase in frequency and severity. The purpose of this study is to assess the relative drought vulnerability of the countries in South America. Each country is evaluated for drought exposure, sensitivity, adaptive capacity, and overall vulnerability. Sixteen drought-related indicators were used to measure the relative vulnerability of each country and to measure separate scores for exposure, sensitivity, and adaptive capacity to identify what factor(s) contributed to a country’s vulnerability. The results indicate that Ecuador, a country with a high population and limited water resources, is the most vulnerable to drought in South America, followed by Colombia and Uruguay. Conversely, the country least vulnerable to drought is Guyana, followed by Suriname and Chile. Our analysis suggests that there are both geographic and as well as economic factors influencing the relative drought vulnerability of countries in South America. Full article

In recent decades, the keeping of exotic animals has gained popularity among enthusiasts worldwide. However, alongside the development of exotic animal husbandry, issues related to health status and adequate veterinary care are coming to the forefront. The introduction of new snakes into a collection and shared enclosures should always be preceded by an assessment of their parasitic status. In our study, we present an overview of the screening for the presence of Cryptosporidium spp. in individuals captured in regions of Indonesia and Suriname, intended for further trade. Out of 40 tested fecal samples, the presence of cryptosporidial oocysts was confirmed in 6 samples. Detection was performed by molecular methods, namely Nested PCR targeting the GP60 gene region (60 kDa glycoprotein). By sequencing, we confirmed the presence of C. parvum in Oligodon octolineatus (n = 1) and Trimeresurus insularis (n = 1), C. tyzzeri in Corallus spp. (n = 2), and C. hominis in Boiga dendrophila spp. gemmicincta (n = 2), which is the very first time that this species has been detected in snakes in captivity. Although the presence of Cryptosporidium species, typical for snakes, was not detected, the identified species may pose a health risk to humans, especially workers who come into direct contact with animals. Full article

Magnaporthe oryzae serves as a model organism for studying the molecular biology of filamentous fungi and the pathogenic mechanisms of fungal pathogens. It also poses a significant threat to rice production in China. Bax inhibitor-1 (Bi-1), a protein with evolutionary conservation, functions as an inhibitor of programmed cell death induced by the proapoptotic protein Bax. Despite the widespread presence of Bi-1 proteins in hyphal fungi, their biological functions have not been extensively characterized. Here, we characterized the function of MoBI-1, a putative Bax-inhibitor protein in M. oryzae, which is located in the mitochondria and participates in conidiation, stress adaptation, and pathogenicity. Further investigations revealed that MoBi-1 is also essential for the regulation of mitochondrial energy metabolism. Remarkably, experimental evidence indicates that MoBi-1 does not seem to function in inhibiting Bax-induced programmed cell death, thus lacking inherent Bax inhibitory function, which broadens the existing understanding of Bax inhibitor-1’s function and provides significant new insights into the disease-causing mechanisms of M. oryzae. Full article

Snakebite represents a significant public health challenge in Central and South America, with Lachesis (Bushmaster) species posing unique clinical challenges due to their severe envenomation effects arising from a combination of potent venom and copious venom yields. Using in vitro coagulation assays, we analyzed the coagulotoxic venom effects from four distinct localities: L. muta from Surinam and French Guiana and L. stenophrys from Costa Rica and Panama. This study examined the venom’s impact on human plasma and fibrinogen and evaluated the efficacy of two regionally available antivenoms (PoliVal-ICP and Antivipmyn-Tri) in neutralizing the pathophysiological effects. Our results demonstrated a remarkable consistency in the pseudo-procoagulant venom activity (also known as: thrombin-like) across different species and localities. Antivenom efficacy testing revealed that both the PoliVal-ICP and Antivipmyn-Tri antivenoms effectively neutralized the venom effects across localities for both species, with the ICP antivenom showing the highest neutralization capacity. These toxicology findings highlight the biochemical conservation of venom composition across Lachesis species which underpins effective cross-neutralization in antivenom treatment. Full article

Background/Objectives: Follow-up studies in very preterm infants are common, but fewer studies are situated in low- or middle-income countries. In a prospective cohort study, we explored longitudinal motor performance trajectories and influencing factors, including an early motor intervention program. Very preterm infants (gestational age < 32 weeks and/or very-low-birth-weight < 1500 g) in the middle-income country of Suriname were included. Methods: We assessed 149 (49.7% boys) infants (mean gestational age 29⁺⁶, mean birth weight 1271 g) at 3, 12, and 24 months with the Bayley Scales of Infant and Toddler Development for fine motor (FM), gross motor (GM), and composite scores (CSs). Influencing perinatal and environmental factors were explored. Delayed-scoring infants were referred to a motor intervention program. Data were analyzed using mixed-model linear regression. Results: The Bayley mean FM and GM scores decreased between 3 and 12 months and stabilized at 24 months. The mean CS at 3, 12, and 24 months was 102.3, 92.7, and 92.2, respectively. The latter two were significantly below the reference values (100, SD 15, p < 0.01). Birth weight z-scores significantly influenced FM (p = 0.013) and CS (p = 0.009); a lower birth weight was associated with initially lower scores and a smaller decline over time than a higher birth weight. The motor intervention program (n = 54) showed no significant interaction effects at all time points after correction for frequency of interventions (no; 1–5; >5 interventions). Conclusions: Motor performance was normal at 3 months and delayed at 12 and 24 months. Birth weight, but not the early intervention program, influenced longitudinal motor trajectories. We recommend follow-up of motor performance and suggest adding the Prechtl General Movement assessment at 3 months of age. The clinical implementation of the early motor invention program needs additional studies to reach an adequate training level. Full article

Contemporary ART as Dolutegravir (DTG) has significantly advanced antiretroviral therapy, but relatively few data are available on its impact on the emergence of HIV-1 drug resistance mutations (DRMs). Monitoring the emergence of INSTI-associated DRMs following the introduction of DTG in Suriname will provide general insight and guide national HIV treatment strategies. All people living with HIV (PLHIV) in Suriname, for whom an INSTI drug resistance test was requested between September 2019 and February 2024 (n = 20), were included. HIV-1 integrase gene sequences were determined using Sanger sequencing. INSTI-associated mutations were identified using the Stanford HIV Drug Resistance Database program. The majority of the participants (66.7%) harbored HIV-1 subtype B, and 33.3% were B-recombinant forms. In addition to the INSTI wildtype, a strain was revealed carrying E157EQ and one person harbored a highly INSTI-resistant strain (E138K, G140S, Q148H and N155H). The emergence of a highly INSTI-resistant HIV-1 strain in Suriname, with unusual mutations for ART-experienced PLHIV exposed to DTG as the only INSTI, accentuates the need for continuous monitoring of the emergence of INSTI drug resistance mutations, not only to enable timely interventions and optimized treatment outcomes for PLHIV, but also to steer the decision making for ART protocols, especially for second generation INSTIs. Full article

This study presents a numerical investigation on the heat transfer and pressure drop characteristics of silver/water nanofluids (0.1–0.5 vol.%) flowing in tubes with four distinct expansion–contraction ratios (ECR = 1.25, 1.50, 1.75, and 2). Additionally, the impact of the distance between expansion and contraction (DEC) within the tubes was examined. The analysis was conducted under turbulent flow conditions and three-dimensional thermal convection in tubes subjected to a constant heat flux of 20 kW/m², with the inlet Reynolds number maintained at approximately 20,000. The nanofluids were considered as single-phase and modeled in the Ansys Fluent 16 software through the finite volume method, and the equations were discretized through the second-order upwind scheme. The nanofluids demonstrated significant potential in enhancing thermal performance, particularly in tubes where the convective heat transfer coefficient was affected by abrupt expansion–contraction ratio (ECR). A maximum increase of up to 24.90% in the average convective heat transfer coefficient compared to the base fluid was observed. Exergy efficiency showed a tendency to increase by up to 29.97% with the use of nanofluids. The findings indicate that the convective heat transfer coefficient can both increase and decrease with the expansion–contraction ratio (ECR) of the tube, as can the pressure drop. Consequently, the application of this passive technique, incorporating silver/water nanofluids, holds promise for use in cooling systems, nuclear reactors, and other similar applications, provided they are meticulously designed. Full article

The carambola fruit fly, Bactrocera carambolae Drew & Hancock, is native to Southeast Asia, infests about 150 plant species, and is considered a quarantine pest insect in several regions of the world. Bactrocera carambolae has invaded Suriname, French Guyana, and northern Brazil. In Brazil, it was first recorded in 1996 and has been restricted to the states of Amapá and Roraima due to official control efforts of the Ministry of Agriculture and Food Supply (Ministério da Agricultura e Pecuária—MAPA). This is the first study to estimate the genetic structure and diversity of South American populations of B. carambolae. A total of 116 individuals from 11 localities in Brazil and 7 localities in Suriname were analyzed. Additional sequences available at GenBank from Indonesia (Lampung) and Thailand (San Pa Tong and Muang District) were also used in the analysis. We sequenced a fragment of the mitochondrial gene cytochrome oxidase subunit I. A total of 35 haplotypes were found. Haplotypes from Indonesia were closest to the haplotypes from South America, separated only by a few mutational steps. This suggests that Indonesia is the likely source for the introduction of B. carambolae into South America. The Southeast Asian populations appeared as the most ancestral group in the phylogenetic trees. The high similarity and sharing of several haplotypes among populations within South America indicate a lack of genetic structure. The mismatch distribution and neutrality tests suggest that South American populations have undergone a rapid growth and expansion following a single founder event. The low genetic diversity and the population expansion evidenced by the neutrality tests lend support to the hypothesis of a recent introduction of a single lineage of the carambola fruit fly into South America. Full article

Thelyphonida Blanchard, 1852, also known as vinegaroons or whip-scorpions, is a small arachnid order with 140 described species contained in a single family, Thelyphonidae Lucas, 1835. Despite being conspicuous and widely distributed across the tropics and subtropics on four continents, knowledge of the order has been slow to advance. Hypoctoninae Pocock, 1899, one of four subfamilies currently recognized and one of two represented in the New World, comprises five genera. Since its inception, Thelyphonellus Pocock, 1894 has remained the only hypoctonine genus occurring in South America, with only four species described prior to the present contribution. The first detailed morphological study and phylogenetic analysis of Thelyphonellus is presented herein. The morphological phylogenetic analysis—the first for Thelyphonida—includes all except one of the previously described species of Thelyphonellus in addition to two new species described herein; the species of Ravilops Víquez and Armas, 2005 (from the Caribbean island of Hispaniola); and the monotypic Old World genus Etienneus Heurtault, 1984 (from West Africa) scored for 45 morphological characters. A single, most parsimonious phylogenetic hypothesis revealed that Thelyphonellus is paraphyletic with respect to Ravilops. The New World Hypoctoninae comprises four clades with disjunct distributions and well supported by a combination of morphological characteristics, on the basis of which four genera, two of which are new, are recognized: Ravilops, with two species, endemic to Hispaniola; Thelyphonellus, herein restricted to Thelyphonellus amazonicus (Butler, 1872) and Thelyphonellus ruschii Weygoldt, 1979, occurring in Guyana, Suriname, French Guiana, and northern Brazil; Wounaan, gen. n., containing Wounaan vanegasae (Giupponi and Vasconcelos, 2008), comb. n. and Wounaan yarigui, sp. n. from Colombia; and Yekuana, gen. n., containing Yekuana venezolensis (Haupt, 2009), comb. n. and Yekuana wanadi, sp. n. from Venezuela. The two new species are described and illustrated. A key to the identification of the Neotropical genera of Hypoctoninae and a map plotting the known distribution of its species are also presented. Full article

Stroke is the second leading cause of death and disability in Latin America; however, few epidemiological studies have been conducted in South America. An observational study was conducted to analyze trends in stroke mortality in South American (SA) countries. Age-standardized mortality rates and proportional mortality due to stroke in the populations of SA countries between 1990 and 2019 were assessed by extracting data from the Global Burden of Disease 2019 study. Joinpoint regression models were employed to identify trends in the annual percentage change in mortality rates for each segment. Considering the data collected over the 30 years that were studied, the age-standardized stroke mortality trend decreased in Argentina (−1.6%), Uruguay (−0.6%), Brazil (−0.5%), Guyana (−0.5%), and Bolivia (−0.4%), while Venezuela (+1.6%) and Suriname (+1.0%) showed an increasing trend. The proportional stroke mortality trend decreased in Argentina (−1.7%), Paraguay (−0.9%), Uruguay (−0.7%), Guyana (−0.7%), Brazil (−0.5%), and Chile (−0.5%), whereas Bolivia (+1.0%), Suriname (+0.6%), and Peru (+0.4%) exhibited an increasing trend. The trends in stroke mortality between 1990 and 2019 demonstrated considerable variability. While most SA countries experienced significant decreases in stroke mortality trends, Venezuela and Suriname showed increases in age-standardized mortality rates, and Bolivia, Suriname, and Peru exhibited increases in proportional mortality rates. No decreasing stroke mortality trend was observed in the segment after the last joinpoint, highlighting the need for improvement in prevention and treatment. Full article

Exposure to mercury (Hg) and lead (Pb), in combination with liver and kidney impairment, may result in adverse birth outcomes. From 408 women in the age range of 16 to 46 years, living in rural and urban areas in the interior of Suriname, we looked at the association between adverse birth outcomes and exposure to Hg and Pb in combination with liver and kidney function. This group of women represented a subcohort of pregnant women who participated in the Caribbean Consortium for Research in Environmental and Occupational Health (CCREOH)—Meki Tamara study. Liver function was assessed by measuring aspartate amino transferase (AST), alanine amino transferase (ALT), and gamma-glutamyl transferase (GGT). Kidney function was assessed by measuring creatinine, urea, and cystatin C. We defined preterm births as birth before 37 weeks of gestation, low birthweight as birthweight < 2500 g, and low Apgar score as a score < 7 at 5 min, and these were used as indicators for adverse birth outcomes. Small size for gestational age was defined as gestational age < −2SD weight for GA. We found significant statistical associations between biomarkers for liver and kidney functions and adverse birth outcomes Apgar score and gestational age. No significant association was found between heavy metals Hg and lead and adverse birth outcomes. Full article

Artisanal and small-scale gold mining (ASGM) has made several environmental impacts, resulting in the significant siltation of water bodies due to the deposition of sediments on riverbanks. Based on this perspective, this study aims to investigate the water bodies and regions most impacted by mining activities, especially in relation to the increase in the Total Suspended Solids (TSS) caused by ASGM, focusing on the territories of Suriname and French Guiana, over the period from 2017 to 2023, through the creation of an algorithm in Google Earth Engine. This research also aims to map and describe active mining in this region using the Classification and Regression Tree (CART) method, which achieved an overall accuracy of 82% and a kappa index of 0.77. The results reveal that from 2017 to 2024, there was an increase of 148.09 km² in mining, with an average increase in TSS of up to 167 mg/L in water bodies most affected by mining activities. Finally, the continued importance of using remote sensing technologies, such as GEE, together with innovative methodological approaches, to monitor and manage natural resources in a sustainable manner is highlighted. Full article

The early detection of sickle cell disease (SCD) is vital to reduce mortality among affected children. Suriname currently lacks a newborn screening programme (NSP) for SCD. We performed a pilot programme to evaluate the scalability of such an initiative. Dried blood spots were collected from five birth centres and subjected to electrophoresis analysis. The programme scalability was evaluated using the non-adoption, abandonment, scale-up, spread, and sustainability framework. Challenges across six domains (illness, technology, value proposition, adopter system, organisation, and societal system), were categorised hierarchically as simple 😊, complicated 😐, or complex 😢. It has been proven that implementing programmes with mainly complicated challenges is difficult and those in mainly complex areas may be unachievable. SCD was detected in 33 of 5185 (0.64%) successfully screened newborns. Most of the domains were classified as simple or complicated. Disease detection and technology suitability for screening in Suriname were confirmed, with favourable parental acceptance. Only minor routine adjustment was required from the medical staff for programme implementation. Complex challenges included a reliance on external suppliers for technical maintenance, ensuring timely access to specialised paediatric care for affected newborns, and securing sustainable financial funding. Scaling up is challenging but feasible, particularly with a targeted focus on identified complex challenges. Full article

The suicide rates in Guyana, Suriname and Trinidad and Tobago are among the highest in the Americas, containing significant Indo-Caribbean populations that are suggested to be most vulnerable to suicide. This systematic review analyzes the existing literature and identifies knowledge gaps in risk and protective factors against suicide in these countries. The literature search conducted followed PRISMA guidelines using the PubMed and APA PsycInfo databases. The PRISMA flow diagram illustrated that eight scholarly papers were eligible for inclusion. Included literature examined stratified data focused on the aforementioned countries, as well as their Indo-Caribbean adolescent populations. Excluded literature did not mention suicidality, adolescents, Indo-Caribbeans, or the focal countries or was focused on the Jonestown mass murder–suicide event. The studies encompassed 6581 individuals. Identified risk factors include social stigma regarding suicide, mental health resource scarcity, and difficult socioeconomic conditions. The identified protective factors for youth include religious/spiritual practices and group activities. Limitations include database quantity, risk of publication bias, and the small sample for each study. A prevailing social stigma regarding suicide was identified. Greater research is needed relating to effects of suicide legislation, bereavement experiences, sociocultural contexts, geography, migration patterns, and culturally compatible interventions to aid future suicide prevention efforts. The protocol was registered with PROSPERO (CRD42023417494). Full article

Climate change mitigation, adaptation to intensifying hurricanes, and decarbonization challenges in developing countries emphasize the urgent need for resilient high-voltage grids to facilitate the expansion of renewables. This research explores the technical feasibility of extending the U.S.–Caribbean Super Grid to include the Virgin Islands, Guadeloupe, Martinique, Trinidad and Tobago, Guyana, Suriname, French Guyana, and the northeastern part of Brazil in South America. This proposed extension aims to capitalize on the recent introduction of a new generation of wind turbines certified for operation under strong hurricane forces. The research utilizes modeling and simulation techniques to evaluate the performance of the proposed extension. A method for modeling and estimating spatiotemporal wind power profiles is applied, and the results demonstrate a reduction in maximum wind power variability within the U.S.–Caribbean Super Grid. Depending on the hurricane trajectory, the variability is reduced from 56.6% to less than 43.2%. This reduction takes effect by distributing peak surplus wind power alongside the proposed U.S.–Caribbean–South America Super Grid (UCASG). The research concludes by acknowledging the merits and limitations of the study and discussing potential directions for future research in this field. Full article