French Guyana Research Articles

Subjective Nature

Science, thought and art meet within the limits of reality, in how reality is understood and represented.. This is where the art-techne binomial materialises graphics, which in turn facilitate the faithful or fictionalised reproduction of our environment. The vocation of science is to advance explanations of the world through a supposedly objective gaze, and the vocation of art is to broaden this understanding by evoking other sensitive and unexpected perspectives. Given the historical relationship between printmaking and the dissemination of knowledge in all fields and the natural sciences in particular, we would like to present the graphic derivations of a collaborative experience between a printmaking artist-cum-researcher and a researcher in forestry science. The experience: A multidimensional approach to the plant: An art and science project started at the end of 2021 when the author, Antía Iglesias, an art student from the interdisciplinary PhD programme in Creativity, Social Innovation and Sustainability (Universidade de Vigo, Spain) (Fig. 1) collaborated with another student, Marion Boisseaux, a PhD student in Tropical Ecology (Université de Guyane) during a research stay in French Guyana. The two students began a joint project to analyse and represent tropical tree seedling species (that Marion had selected in her DRYER project, which observed the effect of drought due to climate change) using their respective technical, numerical and graphical languages, and to provide multiple representations of the plants. This paper aims to present this common experience through the description and analysis of the process that was followed, from a botanical illustration to obtaining graphic digressions from these plants. We will now focus on the derivations obtained from the digital biomimetic record, laser engraving, and printing experimentation.

Sound propagation modeling in forests using the transmission line matrix method: Comparison with experimental in situ measurements

We present efforts to adapt the time-domain Transmission Line Matrix (TLM) method for modeling sound propagation in forests. It is relevant to professionals and researchers in environmental acoustics and to those interested in studying sound propagation in outdoor environments using numerical modeling techniques. The study aims to demonstrate the applicability of the method in complex media where sound waves undergo multiple reflections combined with ground effects during their propagation from a sound source to a receiver point. The TLM method is used to numerically model sound propagation in a 3D forest geometry generated based on a real tree distribution case. Data from an experimental campaign conducted in the rainforest of French Guyana are used as a reference. The results show an encouraging comparison between them and the in situ measurements, even if the hypotheses made to adapt the input data in the model were strong. We find that more measurement points and more specifications (ground impedance measurements, canopy density, etc.) about the experimental site are needed for further simulations, even if obtaining them presents technical difficulties.

Larvicidal properties of terpenoid-based nanoemulsions against the dengue vector Aedes aegypti L. and their potential toxicity against non-target organism.

The development of insecticide resistance in mosquitoes of public health importance has encouraged extensive research into innovative vector control methods. Terpenes are the largest among Plants Secondary Metabolites and have been increasingly studied for their potential as insecticidal control agents. Although promising, terpenes are insoluble in water, and they show low residual life which limits their application for vector control. In this study, we developed and evaluated the performances of terpenoid-based nanoemulsions (TNEs) containing myrcene and p-cymene against the dengue vector Aedes aegypti and investigated their potential toxicity against non-target organisms. Our results showed that myrcene and p-cymene showed moderate larvicidal activity against mosquito larvae compared to temephos an organophosphate widely used for mosquito control. However, we showed similar efficacy of TNEs against both susceptible and highly insecticide-resistant mosquitoes from French Guyana, hence suggesting an absence of cross-resistance with conventional insecticides. We also showed that TNEs remained effective for up to 45 days in laboratory conditions. The exposure of zebrafish to TNEs triggered behavioral changes in the fish at high doses but they did not alter the normal functioning of zebrafish organs, suggesting a good tolerability of non-target organisms to these molecules. Overall, this study provides new insights into the insecticidal properties and toxicity of terpenes and terpenoid-based formulations and confirms that TNE may offer interesting prospects for mosquito control as part of integrated vector management.

Redescription du genre Lampethusa Distant, 1884, et description d’un genre et d’une espèce nouvelle de Guyane française (Hemiptera, Miridae, Mirinae)

Redescription of the genus Lampethusa Distant, 1884, with description of a new genus and a new species from French Guiana (Hemiptera, Miridae, Mirinae). The genus Lampethusa Distant, 1884, is redescribed. A new genus, Lampethusoides, is described to accommodate four nominal species: Lampethusoides diamantina (Carvalho, 1984) n. comb. described from Brazil, L. vianai (Carvalho, 1947) n. comb. described from Argentina, L. vingtuni (Carvalho, 1990) n. comb. described from Brazil and L. gorczycai n. sp. described from French Guyana. A new synonymy is suggested Lampethusa vingtuni Carvalho, 1990, n. syn. of Lampethusa vianai Carvalho, 1947.

Proposed Extension of the U.S.–Caribbean Super Grid to South America for Resilience during Hurricanes

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.

Brazil towards malaria elimination: A time-series analysis of imported cases from 2007 to 2022.

Malaria is a global health challenge, and international efforts are underway to alleviate its impact by 2035. Within the 249 million global cases, 0.6 million occur in the Americas, mainly in Venezuela, Brazil, and Colombia. Considering Brazil's geographical proximity to malaria-endemic countries in South America, this study objective is to analyze the epidemiological characteristics and time trends of imported malaria cases in Brazil from 2007 to 2022, discussing their influence on the elimination process. This is an ecological time-series study that analyses malaria imported cases (infected in other countries) notified in Brazil, from 2007 to 2022. Brazil's Ministry of Health data were used. Descriptive statistics were employed to analyze sociodemographic and spatial patterns, while the impact of the Covid-19 pandemic on imported malaria trends was assessed using Prais-Winsten regression methods. In the study period there was a total of 109,914 imported cases (2.6% of Brazil's total malaria burden). There was an annual reduction of 515.3 cases (p = 0.001) prior to the Covid-19 pandemic. During the pandemics there was an overall reduction of -3,301.8 cases (p = 0.001). In the Amazon region P. vivax imported infections predominated, whereas in the extra-Amazon region P. falciparum imported infections were more prevalent. Most imported cases were males (67.8%), of Black ethnicity (47.5%), with incomplete primary education (45.1%), aged 20-39 (61.1%), and primarily gold miners (54.0%). Most cases are from French Guiana (31.7%), Venezuela (30.0%), and Guyana (17.9%). African nations, notably Angola and Nigeria, were primary sources of imported cases to the extra-Amazon region. The imported cases flux, predominantly from Latin America, threatens Brazil's elimination goals by potentially reintroducing the disease into previously cleared areas and sustaining the transmission in endemic areas. Strengthening epidemiological surveillance at the borders and fostering international cooperation are imperative steps in addressing this challenge.

Investigating Abiotic Sources of Spectral Variability From Multitemporal Hyperspectral Airborne Acquisitions Over the French Guyana Canopy

Investigating Abiotic Sources of Spectral Variability From Multitemporal Hyperspectral Airborne Acquisitions Over the French Guyana Canopy

Fetal Macrosomia and Postpartum Hemorrhage in Latin American and Caribbean Region: Systematic Review and Meta-analysis.

To determine the association between fetal macrosomia (FM) and postpartum hemorrhage (PPH) in Latin American and Caribbean (LAC) women. Studies evaluating the association between FM and PPH (≥ 500 ml) and severe PPH (≥ 1,000 ml) until November 4, 2021, indexed in CINHAL, Scopus, Embase, Cochrane Library, MEDLINE, LILACS, and SciELO. Inclusion criteria were cohort and case-control studies that provided the number of PPH and FM cases. Exclusion criteria were studies lacking information about the number of cases, with a population of women who were not from LAC; published in a language other than English, Spanish, or Portuguese, and with a different design. Data extraction was performed independently by two authors, and discrepancies were resolved with a third author. Data regarding FM and PPH cases were retrieved. Of the 1,044 articles evaluated, 5 studies were included, from 6 different countries: Argentina and Uruguay (multi-country), West Indies, Antigua and Barbuda, French Guyana, and Suriname. The pooled odds ratio (OR) for FM and PPH in the meta-analysis (five studies) was 2.10 (95% confidence interval [CI]: 1.79-2.47; I2: 0%), with estimates within this 95% CI in the sensitivity analysis. The combined OR for severe PPH (3 studies) was 1.61 (95% CI: 0.40-6.48; I2: 91.89%), showing high heterogeneity. There was a positive association between FM and PPH in the LAC, increasing the risk of the presence of this event 2-fold. The high heterogeneity of the studies that measured severe PPH does not allow drawing conclusions about the estimates obtained.

Covid-19 crisis in french Guyana: logistical and societal challenges for pharmacy

Covid-19 crisis in french Guyana: logistical and societal challenges for pharmacy

A new and unusual Digonocryptus Viereck (Hymenoptera, Ichneumonidae,Cryptinae), with notes on two other rare species.

Digonocryptus magnus sp. nov., from French Guyana, is described and illustrated, and new records, morphological and morphometric data are presented for two other rare species, D. coloratus (Szpligeti, 1916), registered for the first time from Colombia, and D. zatheos Aguiar & Santos, 2012. The new species is characterized by having the apical margin of the clypeus straight, medially with a small tooth, propodeal apophyses stout, scale-shaped, fore wing with ramellus, areolet about as wide as high, nearly quadrate, 2r-m as long as the mostly spectral 3r-m, T1basally with a distinct lateral rounded flange, and the longest ovipositor of the genus. The study employs morphological character coding combined with a reanalysis of published molecular data to investigate the phylogenetic placement of D. magnus. The results suggest that it may represent a borderline species within Digonocryptus or potentially a new genus, although further investigation is required due to limited available material and inconclusive data.

37. Herd practices and pathogen analysis on 10 pig farms in French Guyana

37. Herd practices and pathogen analysis on 10 pig farms in French Guyana

Distributions, range extensions and host list update for four phoretic mite genera (Acari: Klinckowstroemiidae) on Passalidae (Coleoptera)

Mites of the family Klinckowstroemiidae are phoretic on passalid beetles in the New World. The family includes 37 species distributed in 4 genera, Klinckowstroemia (28 spp.), Similantennurella (2 spp.), Klinckowstroemiella (5 spp.) y Antennurella (2 spp.). Little is known about the true distribution and species diversity of these genera, especially the latter 3. We examined specimens of Antennurella, Similantennurella and Klinckowstroemiella collected from passalids from several entomological collections. We added Ecuador, French Guyana, Guatemala and Mexico to the distribution range of Similantennurella, Belize, Bolivia, Ecuador, Guatemala, Trinidad and Venezuela for Antenurella, and Bolivia, Ecuador, Honduras and Peru for Klinckowstroemiella. We report 8 new passalid host species previously unknown for these genera. Our study suggests a broad distribution range of the 3 genera, probably encompassing Mesoamerica and South America except Chile and Patagonia, where passalids are not found. Antennurella, Similantennurella and Klinckowstroemiella apparently occur primarily below 1500m altitude, while Klinckowstroemia has been repeatedly found above this limit. All genera have been found mostly on large passalids (>22 mm, long). We also cite the family for the first time from El Salvador.

Factors related to mortality in critically ill histoplasmosis: a multicenter retrospective study in Guadeloupe and French Guyana

PurposeTo describe clinical and biological features and the outcomes of patients admitted for histoplasmosis in two intensive care units (ICU) in French Guyana and in the French West Indies (Guadeloupe).MethodsAll patients admitted to these two ICUs for culture-proven histoplasmosis between January 2014 to August 2022 were included in the study. Using univariate and multivariate analysis, we assessed risk factors at ICU admission that were associated with death.ResultsForty patients were included (65% men). Median age was 56 years and simplified acute physiologic score (SAPS) II was 65. HIV was found in 58%, another immunodeficiency was identified in 28%, and no underlying immunodeficiency could be identified in 14% of patients. Within the first 24 h of ICU admission, 85% of patients had acute respiratory failure, 78% had shock, 30% had coma, and 48% had hemophagocytic lymphohistiocytosis. Mechanical ventilation was instituted in 78% of patients and renal replacement therapy in 55%. The 30-day mortality was 53%. By multivariate analysis, factors independently associated with 30-day mortality were SOFA score (odds ratio [OR] 1.5, 95% confidence interval [CI] [1.1–2.1]), time between symptom onset and treatment per day (OR 1.1, 95% CI 1.0–1.1), and hemophagocytic lymphohistiocytosis (OR 6.4, 95% CI 1.1–47.5).ConclusionHistoplasmosis requiring ICU admission is a protean disease with multiple and severe organ involvement. Immunodeficiency is found in most patients. The prognosis remains severe despite appropriate treatment and is worsened by late treatment initiation.

Vernacular Names of Traditional Rice Varieties Reveal the Unique History of Maroons in Suriname and French Guiana

Rice is a keystone crop in all Maroon communities in Suriname and French Guyana today and they cultivate hundreds of traditional varieties. Historically, rice can be considered an indicator crop for successful marronnage in the Guianas. Unraveling local variety names can reveal the history, farming systems, spiritual significance and probably the diversity of rice in Maroon communities. We interviewed 67 rice farmers (96% female), collected over 400 rice specimens and built a database with 284 unique rice names from our own fieldwork and previously collected names. The process of naming a rice variety is complex, but there are recurrent patterns among the five Maroon groups we studied. We categorized names referring to morphology, agronomy, animals, humans, and rice brought from specific regions or by other Maroon and non-Maroon groups. Very few names are shared between Maroon groups. When we showed the farmers six rice varieties from outside their village, all recognized African rice (Oryza glaberrima) and pende (O. sativa with spotted husks). When a variety was unknown, an initial name was given based on its morphology. Maroon rice names are truly unique as they reflect the varieties that were available, the history of plantations and marronnage, climate aspects that influenced the selection of farmers, the many separate groups of runaways joining the Maroons, the adaptation to the Amazonian ecosystem, and their contacts with outsiders. Our results show that unravelling Maroon rice names leads to a better understanding of the close connection between the process of marronage, locally developed agricultural practices, and connections to West Africa. These historical origins continue to exist and form a unique Maroon system of variety exchange, farm management and crop diversity.

Innovation, Integration Enable Success in Guyana-Suriname Basin

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 30946, “Innovation and Integration: Exploration History, ExxonMobil, and the Guyana-Suriname Basin,” by Audrey L. Varga, Matthew R. Chandler, and Worth B. Cotton, ExxonMobil, et al. The paper has not been peer reviewed. Copyright 2021 Offshore Technology Conference. Reproduced by permission. _ Exploration in the Guyana-Suriname Basin has been a decades-long endeavor, including technical challenges and a lengthy history of drilling with no offshore success before the 2015 Liza discovery. The collection of extensive seismic data has been leveraged to enable successful exploration of multiple play types across the basin. Further data collection has enabled the operator to adopt interpretation techniques that are applied across the entire basin to characterize and understand the subsurface better. Historical Context The first wells drilled in the Guyana-Suriname Basin were onshore; the Rose Hall well in Guyana in 1941 first found oil shows. Rumors of oil in the region, and hopes that the prolific hydrocarbon systems present in Venezuela extended into Guyana and Suriname, led geologists from the Standard Oil Company to conduct initial reconnaissance and seismic and geochemical studies. Despite hints—in retrospect—of a favorable basin configuration and hydrocarbon presence, the decision was made to discontinue exploration activities. Through the 1950s and early 1960s, the region saw relatively low levels of activity. In 1960, the first well was drilled offshore Guyana, and, in 1964, the first offshore well was drilled in Suriname; both were dry. In 1965, the Geological and Mining Service of Suriname found heavy oil near the present-day Calcutta Field. This led to the discovery of the Calcutta, Tambaredjo, and Weg naar Zee heavy-oil accumulations, but only a thin reservoir and heavy oil were encountered. In 1975, Esso participated in the North Coronie-1 well in Suriname. The well found oil and gas shows, confirming the presence of immature but rich source rock that was age-equivalent to the prolific La Luna source in Venezuela. A reconnaissance 2D seismic program followed, and, in 1978, Esso drilled the first deepwater well at Demerara A2-1. This well also was dry but did find high-quality, immature source rock and weak oil and gas shows. After another disappointing well at FG-1 in French Guyana in 1978, Esso ultimately relinquished its licenses but noted the presence of excellent-quality source rocks and reservoirs. The onshore Tambaredjo field, discovered in the 1960s, did not start production until 1982. All in all, before the Liza discovery, more than 300 wells were drilled in the basin, with more than 200 of these dry. Of these, all 60 offshore wells were dry. Why, then, did exploration continue? Data Evolution In the mid- to late-1990s, the Guyana deepwater acreage was completely open. The data available to the operator’s geoscientists consisted of one or two seismic lines, approximately four offshore wells, and a Suriname onshore oil sample. At that time, a major change in global coverage and quality of satellite free-air gravity data occurred with the declassification of US military data. An internal project by the operator merged the Sandwell and Smith free-air gravity grid, available in the public domain, with Getech onshore Bouguer gravity grids to create a global gravity compilation. The operator’s researchers recognized the applicability of these data as a key technology enabler to update plate tectonic models and genetic basin analysis.

About some marginelliform gastropods (Marginellidae Cystiscidae and Granulinidae) from French Guyana

About some marginelliform gastropods (Marginellidae Cystiscidae and Granulinidae) from French Guyana

Un proyecto para recolonizar la Guayana francesa con campesinos isleños

The colonization of French Guyana encountered serious difficulties on the part of the administering power due to the impossibility of recruiting white labor. The existing documentation in the overseas archives of Aix-en-Provence and Nantes show the infeasibility of sending Europeans to repopulate Guyana. Before which the French government considered the possibility of resorting to peasants from Madeira and the Canary Islands who were better adapted to the harsh climatic conditions of the colony.

Current Interventions to Prevent HTLV-1 Mother-to-Child Transmission and Their Effectiveness: A Systematic Review and Meta-Analysis.

Human T lymphotropic virus 1 (HTLV-1) may be transmitted from mother to child and affects at least 5-10 million individuals worldwide, with severe consequences on health. Strategies to prevent transmission are important, as there is no treatment or vaccine. This systematic review aimed to identify interventions to prevent HTLV-1 mother-to-child transmission and to determine their effectiveness. Exclusive formula feeding, short-term breastfeeding, use of freeze-thaw milk, milk pasteurization, maternal and infant antiretroviral drugs, caesarean section, early clamping of umbilical cord, screening of milk donors and avoidance of cross-breastfeeding were identified as possible strategies. Avoidance of breastfeeding is an intervention that prevents 85% of transmissions. This strategy is recommended in Japan, Brazil, Colombia, Canada, Chile, Uruguay, the USA and some regions of French Guyana. Whilst breastfeeding for <3 months does not increase the risk of transmission compared to exclusive formula-feeding, concerns remain regarding the limited number of studies outside Japan, and the lack of information on women having higher risk of HTLV-1 transmission and on the ability of women to discontinue breastfeeding. Additional interventions are plausible, but data on their effectiveness are limited. The acceptance of interventions is high. These findings may guide healthcare professionals and support policymakers in implementing policies to avoid HTLV-1 mother-to-child transmission.

Assessment of the soil-erosion-sediment for sustainable development of South America

One of the greatest threats to maintaining sustainable agro-ecosystems is mitigating the episodic soil loss from farm operations, further exacerbated by meteorological extremes. The Revised Universal Soil Loss Equation (RUSLE) is a model that combines the effects of rain, soil erodibility, topography, land cover, and conservation practices for estimating the annual average soil losses. This study aims to quantify soil water erosion to continental South America (S.A.) through RUSLE using available datasets and characterizing the average sediment delivery rate (SDR) to the major S.A. basins. Soil erodibility was estimated from the Global Gridded Soil Information soil database. LS-factor's topographical parameter was derived from Digital Elevation Models using the “Shuttle Radar Topography Mission” dataset. The R-factor was estimated from a previous study developed for S.A. and the C-factor from the Global Land Cover (Copernicus Global Land Services) database. We used a modeling study for SDR that simulated the annual average sediment transport in 27 basins in S.A. RUSLE set up presented a satisfactory performance compared to other applications on a continental scale with an estimated averaged soil loss for S.A. of 3.8 t ha−1 year−1. Chile (>20.0 t ha−1 year−1) and Colombia (8.1 t ha−1 year−1) showed the highest soil loss. Regarding SDR, Suriname, French Guyana, and Guyana presented the lowest values (<1.0 t ha−1 year−1). The highest soil losses were found in the Andes Cordillera of Colombia and the Center-South Region of Chile. In the former, the combination of “high” K-factor, “very high” C-factor, and “very high” LS-factor were the leading causes. In the latter, agriculture, livestock, deforestation, and aggressive R-factor explained the high soil loss. Basins with the highest SDR were located in the North Argentina – South Atlantic basin (27.73%), Mar Chiquitita (2.66%), Amazon River basin (2.32%), Magdalena (2.14%) (in Andes Cordillera), and Orinoco (1.83%).

AMICal Sat: A Sparse RGB Imager on Board a 2U CubeSat to Study the Aurora

AMICal sat, a dedicated 2U CubeSat, has been developed, in order to monitor the auroral emissions with a dedicated imager. It aims to help reconstructing the low-energy electron fluxes up to 30 keV in the Earth auroral regions. It includes an imager entirely designed in the Grenoble University Space Center. The imager uses a 1.3-Mpixels sparse RGB CMOS detector and a wide-field objective ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$f=22.5$ </tex-math></inline-formula> mm). The satellite platform has been built by the Polish company Satrevolution. Launched 3 September 2020 from Kuru (French Guyana) on board the Vega flight 16, it produced its first images in October 2020. The aim of this article is to describe the design of the payload, especially the optics and the proximity electronics, and to describe the use of the payload for space weather purpose. A preliminary analysis of a first image showing the relevance of such an instrument for auroral monitoring is performed. This analysis allowed us to reconstruct from one of the first images the local electron input flux at the top of the atmosphere during the exposure time.