North Brazil Research Articles

Western boundary current in relation to Atlantic Subtropical Gyre dynamics during abrupt glacial climate fluctuations

Ocean-atmosphere simulations corroborate the relationship between tropical Atlantic subsurface heat and salt storage driven by Salinity Maximum Water (SMW) and deglacial perturbations of the Atlantic Meridional Overturning Circulation (AMOC). Whether AMOC variability of the last glacial cycle affected SMW export into the tropical West Atlantic remained yet elusive. In order to assess the sensitivity of the tropical hydrography during abrupt and rapid glacial climatic and oceanic perturbations, we present century-resolving foraminifera-based subsurface (~200 m water depth) temperature and salinity reconstructions from Tobago Basin core M78/1–235-1. The proxy records were interpreted in terms of the closely related development of the North Brazil Current (NBC) and the North Atlantic Subtropical Gyre (STG) from ~37 to 30 ka BP, and in relation to their deglacial developments. Prior to ~32.8 ka BP, the cyclic variations in subsurface conditions were attributed to the NBC, which acted in line with a recurrent intensification and relaxation of the trade winds, subtle migrations of the Intertropical Convergence Zone, and the related moisture transport across Central America. Major and rapid re-organizations of the tropical Atlantic upper ocean-atmosphere system took place at ~32.8 ka BP and ~ 21.8 ka BP, unmirrored by major AMOC changes. Thresholds for sufficient heat and salinity accumulation in the STG to allow for formation and intensified subsurface dispersal of SMW were not achieved before late HS1, when AMOC weakening, according tropical heat backlog and surface warming by maximum Northern Hemisphere insolation acted together.

Surface Circulation and Vertical Structure of Upper Ocean Variability Around Fernando de Noronha Archipelago and Rocas Atoll During Spring 2015 and Fall 2017

Using current, hydrographic and satellite observations collected off Northeast Brazil around the Fernando de Noronha Archipelago and Rocas Atoll during two oceanographic cruises (spring 2015 and fall 2017), we investigated the general oceanic circulation and its modifications induced by the islands. In spring 2015, the area was characterized by lower SST (26.6°C) and deep mixed-layer (∼90 m). At this depth, a strong current shear was observed between the central branch of the eastward flowing near-surface South Equatorial Current and the westward flowing South Equatorial Undercurrent. In contrast, in fall 2017, SST was higher (∼28.8°C) and the mixed-layer shallower (∼50 m). The shear between the central South Equatorial Current and the South Equatorial Undercurrent was weaker during this period. Interestingly, no oxygen-rich water from the south (retroflection of the North Brazil undercurrent) was observed in the region in fall 2017. In contrast, we revealed the presence of an oxygen-rich water entrained by the South Equatorial Undercurrent reaching Rocas Atoll in spring 2015. Beside these global patterns, island wake effects were noted. The presence of islands, in particular Fernando de Noronha, strongly perturbs central South Equatorial Current and South Equatorial Undercurrent features, with an upstream core splitting and a reorganization of single current core structures downstream of the islands. Near islands, flow disturbances impact the thermohaline structure and biogeochemistry, with a negative anomaly in temperature (−1.3°C) and salinity (−0.15) between 200 and 400 m depth in the southeast side of Fernando Noronha (station 5), where the fluorescence peak (>1.0 mg m–3) was shallower than at other stations located around Fernando de Noronha, reinforcing the influence of flow-topography. Satellite maps of sea-surface temperature and chlorophyll-a confirmed the presence of several submesoscale features in the study region. Altimetry data suggested the presence of a cyclonic mesoscale eddy around Rocas Atoll in spring 2015. A cyclonic vortex (radius of 28 km) was actually observed in subsurface (150–350 m depth) southeast of Rocas Atoll. This vortex was associated with topographically induced South Equatorial Undercurrent flow separation. These features are likely key processes providing an enrichment from the subsurface to the euphotic layer near islands, supplying local productivity.

Deep structure of the Pará-Maranhão/Barreirinhas passive margin in the equatorial Atlantic (NE Brazil)

The Pará-Maranhão/Barreirinhas margin, North Brazil, is a pull-apart passive margin, with two strike-slip borders, formed during the opening of the Equatorial Atlantic Ocean during Cretaceous time. Its geometry and evolution are speculative due to the lack of information on the crustal structure and the crustal nature. We present here the E-W profiles of the MAGIC (Margins of brAzil, Ghana and Ivory Coast) deep seismic experiment, a joint project between French and Brazilian universities, research institutes and the industry. Fifty-six Ocean Bottom Seismometers (OBS) and a 4.5 seismic streamer were deployed at sea along 2 of the 5 MAGIC profiles. One profile was extended onshore by installing 8 land stations. We perform forward modelling through combined interpretation of the multichannel seismic and of the main reflected and refracted of these phases recorded by the OBSs. The final P-wave velocity models reveal distinct structural domains from onshore Brazil towards the Atlantic Ocean characterized by variations of the crustal thicknesses and velocities: (1) an unthinned continental crust below the São Luís Craton, where the crust is 33 km thick, (2) a 60 km wide necking domain below the Ilha de Santana Platform; (3) offshore, east of the continental slope, a 10 km-thick deep sedimentary basin underlain by a 5 km thick crust with velocity of 6.2–6.9 km/s that we interpret as an exhumed lower continental crust, on the top of an Anomalous Velocity Layer (AVL) probably made of intrusions of mantle-derived melts into the lower continental crust, or a mixture of them; (4) eastwards, the limit of the previous domain is marked by NW-SE aligned volcanoes and the disappearance of the AVL. The sedimentary succession becomes thinner (6 km) overlaying a proto-oceanic crust characterized by seismic velocities higher than “normal” oceanic crust in its upper part, but in continuity with the velocity described in the previous domain; (5) followed by a more characteristic but thin oceanic crust.The middle/lower continental crust seems not only to have a crucial role in the genesis of the passive margin but also to be involved in the genesis of the first oceanic crust. The passage to a typical oceanic crust seems to have occurred progressively by steps: first in the deeper layer by the setup of more and more intrusions of mantle-derived melts at the base of the crust or mixture of exhumed lower crust and mantle, producing a domain of proto-oceanic crust, then by the emplacement of an upper 1-2 km-thick layer with typical oceanic characteristics.

The Benefits of Combining Global and Local Data—A Showcase for Valuation and Mapping of Mangrove Climate Regulation and Food Provisioning Services within a Protected Area in Pará, North Brazil

Mangrove forests provide a large variety of ecosystem services (ES) to coastal societies. Using a case study focusing on the Ajuruteua peninsula in Northern Brazil and two ES, food provisioning (ES1) and global climate regulation (ES2), this paper proposes a new framework for quantifying and valuing mangrove ES and allow for their small-scale mapping. We modelled and spatialised the two ES from different perspectives, the demand (ES1) and the supply (ES2) side respectively. This was performed by combining worldwide databases related to the global human population (ES1) or mangrove distribution and canopy height (ES2) with locally derived parameters, such as crab catches (ES1) or species-specific allometric equations based on local estimates of tree structural parameters (ES2). Based on this approach, we could estimate that the area delivers the basic nutrition of about 1400 households, which equals 2.7 million USD, and that the mangrove biomass in the area contains 2.1 million Mg C, amounting to 50.9 million USD, if it were paid as certificates. In addition to those figures, we provide high-resolution maps showing which areas are more valuable for the two respective ES, information that could help inform management strategies in the future.

Formation and Evolution of a Freshwater Plume in the Northwestern Tropical Atlantic in February 2020

AbstractIn February 2020, a 120‐km‐wide freshwater plume was documented by satellite and in situ observations near the Demerara Rise (7°N/54°W‐56°W). It was initially stratified in the upper 10 m with a freshwater content of 2–3 m of Amazon water distributed down to 40 m. On February 2nd, ship transects indicate an inhomogeneous shelf structure with a propagating front in its midst, whereas minimum salinity close to 30 pss was observed close to the shelf break on February 5th. The salinity minimum eroded in time but was still observed 13–16 days later with 33.3 pss minimum value up to 400 km from the shelf break. At this time, the mixed layer depth was close to 20 m. The off‐shelf flow lasted 10 days, contributing to a plume area extending over 100,000 km2 and associated with a 0.15 Sv (106 m3 s−1) freshwater transport. The off‐shelf plume was steered northward by a North Brazil Current ring up to 12°N and then extended westward toward the Caribbean Sea. Its occurrence followed 3 days of favorable wind direction closer to the Amazon estuary, which contributed to north‐westward freshwater transport on the shelf. Other such events of freshwater transport in January–March are documented since 2010 in salinity satellite products in 7 out of 10 years, and in 6 of those years, they were preceded by a change in wind direction between the Amazon estuary and the Guianas favoring the north‐westward freshwater transport toward the shelf break.

Phylogenetic structure of lichen metacommunities in Amazonian and Northeast Brazil

AbstractAmazon, Atlantic forest, Brejos de Altitude, Caatinga, Carrasco, Cerradão and Restinga are major vegetation units in North and Northeast Brazil. Little is known about lichen metacommunity structure in these habitats. While species richness and composition generally depend on climatic factors, in azonal vegetation edaphic factors may have a filtering effect on tree bark structure and hence the composition of epiphytic lichen communities. We hypothesized that climatic stress and a tree bark filtering effect would result in reduced richness and phylogenetic clustering in Caatinga, Carrasco, Cerradão and Restinga, whereas high richness and phylogenetic overdispersion were predicted for Amazon and Atlantic Forest. To test this, we analyzed 2,090 lichenized species in the study area, with a supertree to assess phylogenetic metacommunity structure. Amazon and Atlantic forest exhibited high richness and phylogenetic diversity, with phylogenetic overdispersion only in the Amazon. The zonal Caatinga with drought stress and the extrazonal Brejos both exhibited phylogenetic clustering. Among the azonal, edaphic vegetation units, Cerradão exhibited phylogenetic overdispersion, whereas Restinga showed phylogenetic clustering. Nearest taxon phylogenetic distance indicated a close relationship between Amazon and Atlantic forest, Atlantic forest and Brejos and Atlantic forest and Caatinga. Carrasco was mostly closely related to Cerradão, and Restinga was distantly related to any other unit. These findings indicate more complex patterns in the phylogenetic structure of lichen metacommunities, partly reflecting those of plant metacommunities, as a result of concurrent macroecological evolutionary histories. Our data supported floristic evidence that Carrasco is part of the Cerrado complex and not related to Caatinga.

Early Report on COVID-19 Infections in Pediatric Heart Transplant Recipients and Candidates

PurposeReports focused on adult heart transplant (HT) recipients with COVID-19 suggest an increased risk of severe disease. It is unclear if this holds true for pediatric HT patients, given the reported milder course of illness in children in general with COVID-19. We sought to rapidly implement a system for multi-center data collection on pediatric HT recipients and candidates, with the aim of describing the patient population and infection related outcomes.MethodsThe Pediatric Heart Transplant Society (PHTS) is a multi-center collaboration whose main goal is to improve the outcomes of children who are listed and undergo HT. The society consists of pediatric HT centers in North America (n=53), UK (n=2), and Brazil (n=1). In response to the pandemic, PHTS developed a web-based platform to collect COVID-19 specific data in pediatric HT candidates and recipients. Non-PHTS centers were also invited to submit data. Data fields included pre-and post-HT patient characteristics, presumed vs. documented infection, need for hospitalization (including ICU and ventilator use), treatments administered, and 30-day outcome (death, resolution, sequelae, ongoing treatment).ResultsData collection was initiated on 4/30/20. As of 9/28/20, there were 72 patients (7 pre-HT and 65 post-HT, median age 13 years) reported from 27 centers. Of these, 67 were PCR+ by nasal swab and 5 were presumed positive. Complete data with 30-day follow-up was available for 60 patients (7 pre and 53 post HTx). Hospitalization was common and occurred in 71% of the pre-HT and 32% of the post HTx patients. Of the pre-Tx patients, 43% required ICU and 14% were ventilated. In the post HTx group, 13% required ICU and 4% were ventilated. At 30 days a majority of pre-Tx had resolution of symptoms (n=6/7). Among post HTx patients, resolution occurred in 87%% (46/53) with 1 death at 30 days.ConclusionThe PHTS remains the most robust source of data on pediatric HT and this effort shows the adaptability of the registry. Although likely limited by reporting bias, these data represent the first known report of characteristics and early outcomes for pediatric HT candidates and recipients with COVID-19. As data collection continues, we aim to better understand the characteristics of patients with more severe disease in order to improve risk characterization and decrease the knowledge gap that currently exists in this unique population.

Thymidylate synthase and methylenetetrahydrofolate reductase polymorphisms and breast cancer susceptibility in a Brazilian population

Breast cancer (BC) is the most diagnosed cancer and the leading cause of cancer death in women worldwide. Polymorphisms in genes involved in the folate pathway are suggested as possible BC etiological factors. Among them, Thymidylate synthase (TYMS) has two polymorphisms related to BC: TSER and 1494del6. Methylenetetrahydrofolate reductase (MTHFR) has two SNPs, C677T and A1298C, that also could increase breast cancer risk. This work aimed to determine if TYMS and MTHFR genes polymorphisms are related to BC risk in a population of North Brazil. A total of 124 DNA samples, obtained from BC patients and control women, were genotyped utilizing PCR and automatic sequencing. Chi-square, G-test, Fisher's exact test, and odds ratio were applied to analyse the data. Significant associations with BC risk were observed for TYMS 3R allele carriers. Besides, patients with the −6 allele of 1494del6 polymorphism were more likely to develop aggressive BC molecular tumor types (Luminal B, HER2-positive, and Triple-Negative). In conclusion, TYMS polymorphisms are related to BC risk in the studied population, as the 3R allele is associated with BC susceptibility and the presence of the 1494del6–6 allele increases the development risk of more aggressive BC subtypes. Those findings may be useful for predicting the efficacy of anti-TS drugs in BC patients.

Future carbon emissions from global mangrove forest loss.

Mangroves have among the highest carbon densities of any tropical forest. These ‘blue carbon’ ecosystems can store large amounts of carbon for long periods, and their protection reduces greenhouse gas emissions and supports climate change mitigation. Incorporating mangroves into Nationally Determined Contributions to the Paris Agreement and their valuation on carbon markets requires predicting how the management of different land‐uses can prevent future greenhouse gas emissions and increase CO2 sequestration. We integrated comprehensive global datasets for carbon stocks, mangrove distribution, deforestation rates, and land‐use change drivers into a predictive model of mangrove carbon emissions. We project emissions and foregone soil carbon sequestration potential under ‘business as usual’ rates of mangrove loss. Emissions from mangrove loss could reach 2391 Tg CO2 eq by the end of the century, or 3392 Tg CO2 eq when considering foregone soil carbon sequestration. The highest emissions were predicted in southeast and south Asia (West Coral Triangle, Sunda Shelf, and the Bay of Bengal) due to conversion to aquaculture or agriculture, followed by the Caribbean (Tropical Northwest Atlantic) due to clearing and erosion, and the Andaman coast (West Myanmar) and north Brazil due to erosion. Together, these six regions accounted for 90% of the total potential CO2 eq future emissions. Mangrove loss has been slowing, and global emissions could be more than halved if reduced loss rates remain in the future. Notably, the location of global emission hotspots was consistent with every dataset used to calculate deforestation rates or with alternative assumptions about carbon storage and emissions. Our results indicate the regions in need of policy actions to address emissions arising from mangrove loss and the drivers that could be managed to prevent them.

Soil macrofauna in Brazil: a bibliometric review and state of the art

Macrofauna individuals' knowledge and their environmental functions is essential to seek more conservationist forest management practices. Understanding how the publications are being distributed in Brazil, and what knowledge need to be discussed to direct future research. The purpose of this review was to compile and analyze all publications on soil macrofauna in Brazil until 2019, conducting a bibliometric and state of the art review. 60 documents were evaluated, it was analyzing institutions and authors, citations networks and terms used, forest sciences areas that encompass the most explored biomes, crop systems or natural environmental and the most studied soil macrofauna individuals. Since 2002, every year, publications on the topic indexed in the Scopus database. The Atlantic Forest was the most studied biome and although the North region has the largest number of states that have not yet developed works on the subject, the Amazon forest is in second place in terms of publications, together with Savannah/Cerrado. The largest gap in studies and areas of natural fields is found in the Brazilian North. The macrofauna individuals studied, the highlights are from the orders Coleoptera, Hymenoptera, Blattodea, Araneae and Hemiptera. Vegetation type was carried out predominantly in native forests, followed by pasture.

The Barreirinhas Eddies: Stable Energetic Anticyclones in the Near-Equatorial South Atlantic

We explore the Barreirinhas Eddies, submesoscale vortices generated by the North Brazil Current (NBC) off the Barreirinhas Bight (Brazil, centered at 1.75°S), using vessel-mounted and moored ADCP data, and a Global HYCOM reanalysis. These double-stacked anticyclones with incredibly high Rossby Number O (10)] occur independently at different depths (high Burger number). Anticyclones with Rossby number greater than unity are unstable according to inviscid linear theory, and hence these submesoscale features are not easily observable at mid latitudes. At these low latitudes, they last about a week, allowing characterization by oceanographic surveys. Our analyses suggest this increased stability is due to the joint effect of strong winds, stratification, proximity to the equator, and topography. Heretofore hypothesized via analytical studies and seen in numerical models, our study confirms this stabilization process in observations, and is also a starting point for the description of the submesoscale dynamics in the NBC domain.

Back from the past: Molecular and morphological support for Simulium mutucuna Nunes de Mello & Vieira da Silva, 1974 (Diptera: Simuliidae) as a valid species

Simulium mutucuna, a species described based on a single female from Roraima state, was previously synonymized with Simulium paynei and currently is considered a synonym of Simulium rubrithorax. In the present paper we present morphological and molecular evidence supporting the validity of S. mutucuna based on analysis of specimens from Brazil, Venezuela and Mexico. We redescribe the female and describe, for the first time, the male, pupa and larva of S. mutucuna and discuss the morphological differences between this species and the others that are already considered as its senior synonyms. Currently, the distribution of S. mutucuna is restricted to Roraima state. The distribution record for S. rubrithorax in Brazil's North region needs to be removed, since the previous records were based on occurrence of S. mutucuna. Finally, we present new evidence of cryptic diversity in the S. paynei complex based on molecular information.

Rural development and the expansion of non‑agricultural activities in the Brazilian Amazon

Abstract This paper analyzes the employment and income dynamics of rural families in Brazil's North Region, the main representative of the Brazilian Amazon. We use information from the National Household Sample Survey between 2004 and 2015 to create a typology of families based on the members' occupation in agricultural and non-agricultural activities. We hypothesize that the recent increase in employment and income was strongly associated with non-agricultural activities, reproducing the dynamics observed in other developing countries and Brazil's more developed regions. The results highlight that, differently from the rural exodus observed in the other regions of the country, the number of rural households increased in the North Region, attracted by the expanding non-agricultural occupations. As a result, the importance of earnings from non-agricultural activities and non-labor (pensions, cash transfers, among others) to family income has increased considerably, especially among self-employed family farmers. The final discussion highlights the relevance of non-agricultural activities for public policies to increase income in less developed rural areas.

Holocene diatoms from Xingu river: new records for the Brazilian Amazon and Brazil

ABSTRACT Present study is the floristic survey and the distribution of diatoms observed in two sediment cores of the Xingu river, Pará State, north Brazil, and represents the past ~6,000 cal yr BP. Thirty-eight taxa distributed in twenty genera were recorded, among which five were new records for Brazil and nineteen new for the Brazilian Amazon. The most representative genus based on species number was Gomphonema Ehrenberg with six species. In brief, present new records represent a 75% increase in the total number of records for the Brazilian Amazon, and indicates that this region has not only been poorly investigated, but also suggests that its biodiversity assessment is underestimated. These findings highlight the efficacy of the paleolimnological approach as a tool for assessing biodiversity before the human impacts begin to affect the pristine conditions of the area.

Escolarização básica no Brasil: evoluções, permanências e contrastes entre a população rural e urbana

O texto apresenta, por meio de dados estatísticos, uma reflexão sobre a situação da escolarização básica da população residente no campo, face à população residente na zona urbana, no sentido de compreender avanços e permanências das condições da oferta educacional e seus efeitos no distanciamento e na aproximação da garantia da justiça social e do direito da escolarização. O processo metodológico envolveu a análise de conteúdo e a construção de dados quantitativos realizada com base nas informações disponibilizadas pelo Instituto Brasileiro de Geografia e Estatística (IBGE), pelo Instituto Nacional de Estudos e Pesquisas Educacionais Anísio Teixeira (INEP) e pelo Instituto de Pesquisa Econômica Aplicada (IPEA). Para o estudo, foram selecionadas as categorias: número de escolas no campo, anos de estudo e acesso à escolarização por recortes de localização (rural/urbano). Os dados expressam uma situação desigual em indicadores de escolaridade e escolarização no tocante ao rural e às regiões Norte e Nordeste. Apesar dos avanços, as desigualdades no sistema educacional brasileiro são significativas e fortemente evidenciadas no contraste entre os meios rural e urbano. A persistência de situações desfavoráveis aumenta as condições de desigualdade da população do campo.
 Palavras-chave: educação básica, justiça social, educação do campo, desigualdades educacionais.
 
 Basic schooling in Brazil: advances, continuance, and contrasts between rural e urban populations
 ABSTRACT. The text presents, through statistical data, a reflection on the situation of basic schooling of the population residing in the countryside, vis-à-vis the population residing in the urban area, in order to understand advances and permanence of the conditions of the educational offer and its effects in the distance and in the approximation of the guarantee of social justice and the right to schooling. The methodological process involved content analysis and the construction of quantitative data provided by the Brazilian Institute of Geography and Statistics (IBGE), the National Institute of Educational Studies and Research Anísio Teixeira (INEP) and the Institute for Applied Economic Research (IPEA). For the study, these categories were selected: number of countryside schools, years of study and schooling access by location (rural/urban). The data express an inequality situation in the schooling indicators of rural areas and the Brazilian North and Northeast regions. Despite the advances, the inequalities in the Brazilian educational system are significant and strongly evidenced in the contrast between rural and urban areas. The persistence of unfavorable situations increases the inequality condition of the rural population.
 Keywords: basic education, social justice, rural education, educational inequalities.
 
 Escolarización básica en Brasil: evolución, estancias y contrastes entre población rural y urbana
 RESUMEN. El texto presenta, por medio de datos estadísticos, una reflexión sobre la situación de la escolarización básica de la población que reside en el campo, frente a la población que reside en el área urbana. La finalidad de la reflexión es comprender los avances y la permanencia de las condiciones de la oferta educativa y sus efectos en la distancia y aproximación de la garantía de justicia social y el derecho a la escolarización. El proceso metodológico involucró el análisis de contenido y la construcción de datos cuantitativos basados ​​en información proporcionada por el Instituto Brasileño de Geografía y Estadística (IBGE), por el Instituto Nacional de Estudios e Investigación Anísio Teixeira (INEP) y el Instituto de Investigación Económica Aplicada (IPEA). Para el estudio, se seleccionaron las siguientes categorías: número de escuelas en el campo, años de estudio y acceso a la escuela por ubicación (rural/urbana). Los datos revelan una situación desigual en términos de escolaridad e indicadores de escolaridad con respecto a las regiones rurales y las regiones Norte y Nordeste. Aún con los avances logrados, las desigualdades en el sistema educativo brasileño son significativas y se evidencian fuertemente en el contraste entre los entornos rurales y urbanos. La persistencia de situaciones desfavorables aumenta las condiciones de desigualdad de la población rural.
 Palabras clave: educación básica, justicia social, educación rural, desigualdades educativas.

Molecular characterization and core collection evaluation of Manihot esculenta Crantz

Cassava is one of the most important subsistence crops in tropical regions. It is necessary to preserve and to know the genetic diversity existent for the adequate use of genetic resources. The evaluation of genetic diversity among genotypes results in information about potential parents in breeding programs, allows duplicates identification, and facilitates germplasm exchange between research institutions. The objective of this study was to characterize the genetic diversity of cassava accessions of North Brazil region. A total of 106 accessions were analyzed using ten microsatellite markers. The genetic parameters estimated were: expected heterozygosity (HE), observed heterozygosity (HO) and polymorphic information content (PIC). Clustering was performed using the UPGMA and Neighbor-Joining (NJ) method. Bayesian analysis, analysis of principal coordinates and identification of a core collection were also used. The ten loci amplified 8,40 alleles on average. The average heterozygosity estimates were: HE = 0.71, HO = 0.58 and PIC = 0.72. Genetic distances ranged from 0.158 to 0.908. Six (5,66%) accesses were redundant. Clustering and dispersion analysis didn’t differentiate bitter from sweet cassava, and there wasn’t correlation between groups and collect origin. The core collection consisted of 22 individuals that represented 94% of total allelic diversity and 20,75% of the base collection. The results indicate high dissimilarity between the accessions and allowed the detection of redundant genotypes, showing the use of genetic markers as informative tools for the management of collections.

CRIMINAL RECORDS OF VIOLENCE INVOLVING VENEZUELANS IN NORTH BRAZIL

Introduction: Refugee crisis is a problem faced worldwide. The large borders with neighbouring countries make Brazil a potential destination for most of those seeking for a new life in South America. Venezuela currently fights the worst humanitarian crisis in the history of the country, and migration to Brazil emerges as an option. Living in border regions, these people are more susceptible to violence. Objective: This study aimed to revisit the medico-legal records of a city in North Brazil to calculate rates of Venezuelans involved in situations of violence. Material and methods: Medico-legal records of the city of Pacaraima, Roraima, Brazil, dated from 2013 and 2018, were revisited. The nationality of victims and perpetrators of violent actions were noted as well as the type of crime. Results: In 2013 (n = 86, 39.3%) and 2018 (n = 133, 60.7%), 219 forensic records were documented. Venezuelans were involved in 63 forensic reports (28.7%) – one in 2013 and 62 in 2018. Most of the reports were related to bodily integrity investigations (n = 169, 77.2%). Conclusion: This study highlights the importance of building-up social strategies to support Venezuelans and Brazilians living in the city of Pacaraima, as the number of forensic reports increased 54.7% from 2013 to 2018. This data might reflect the increase of violence in the border region, in which Venezuelans and Brazilians may figure as victims and perpetrators.

Intra‐ and Inter‐Annual Variability of North Brazil Current Rings Using Angular Momentum Eddy Detection and Tracking Algorithm: Observations From 1993 to 2016

AbstractIn order to investigate intra‐ and inter‐annual variability of North Brazil Current (NBC) rings, angular momentum eddy detection and tracking algorithm (AMEDA) was used for identification of their occurrence, trajectories, and parameters. Based on 24 years (1993–2016) of geopotential height and geostrophic current fields reanalysis data from ARMOR 3D (¼°), we identified an average rate of five NBC rings shed by year. The rings present an average lifetime of 15.3 (±5.4) weeks, average speed‐based radius (Rmax) of 139.8 (±23.6) km, and mean sea surface height anomaly (SSHa) of 9.4 (±4.0) cm. The mean observed maximum azimuthal velocity (Vmax) was 0.27 (±0.08) m/s, while the averaged Rossby number (Ro) value was 0.08 (±0.04) and averaged kinetic energy (KE) was of 255.3 (±154.8) cm2/s2. NBC rings have larger dimensions, rotate faster, live less, and transfer more energy in boreal winter months. In contrast, those shed during boreal summer and early fall last longer, have smaller diameters and carry less energy. Besides, the analysis of ring merging pointed that the interaction between NBC rings generated a significantly increase in ring energy (52%), and velocity (22%). Finally, we observed the vertical anomalies temperature and salinity profiles, which indicated a thermocline deepening and sinking of coastal and tropical waters due to NBC rings downwelling. This study emphasizes the robustness and efficiency of AMEDA for studying rings in the ocean and further theorizes possible impacts of NBC ring on ocean physical and biogeochemical features in the Western Tropical North Atlantic.

Source waters contribution to the tropical Atlantic central layer: New insights on the Indo-Atlantic exchanges

This study reveals the influence of the Subtropical Mode Water (STMW) varieties and their spatiotemporal variability on the upper thermocline of the tropical Atlantic Ocean. Optimum Multiparameter water mass analysis was applied using the hydrographic and chemical datasets available from the World Ocean Database 2018 and The Global Ocean Ship-Based Hydrographic Investigations Program. Eighteen Degree Water (EDW) and Madeira Mode Water (MMW), sourced in the northwest and northeast North Atlantic, respectively, contribute to the North Atlantic Central Water (NACW) layer, which follows the North Equatorial Current and setting up the limit with the South Atlantic Central Water (SACW) at about 10°N. The contribution of the EDW to the NACW spreads at the surface layer (excluding the first 100 m) until the 26.6 kg m−3 isopycnal (~250 m). MMW contributes to denser levels of the upper layer, mainly between 26.8 and 27.0 kg m−3 (300–700 m). In the southern hemisphere, mode waters formed in the eastern South Atlantic (STMW18) and along the edge of the subtropical front (STMW12) were the main contributors to the surface and denser levels, respectively. The variety formed in the Brazil-Malvinas confluence (STMW14) was restricted to the southwestern side of the South Atlantic gyre, while the Subtropical Indian Mode Water (STIMW; mode water advected from the Indian Ocean into the South Atlantic Ocean) influenced the SACW structure between 20°S and 30°S with an averaged mixing fraction of ~34% ± 20%, mainly at isopycnals of 26.2 and 26.4 kg m−3 (100–400 m). The main source of the STIMW, the Agulhas eddies, act as interocean exchange structures that transport an average of 5.5 ± 3.2 Sv (1 Sv = 106 m3 s−1) of STIMW to the Atlantic, even after they have been altered by splitting and/or merging processes. In addition, a smaller contribution of ~20% of STIMW was associated with the North Brazil Current at ~350 m, showing the interhemispheric connection between the Indian Ocean and the upper branch of the Atlantic Meridional Overturning Circulation. Therefore, due to the previously reported increase of the Agulhas leakage and the dynamic of the southern Equatorial Current bifurcation, the heat and salt fluxes to the northern hemisphere may likely increase in the following years.

Near-surface western boundary circulation off Northeast Brazil

In the tropical Atlantic Ocean, the North Brazil Undercurrent (NBUC) and the North Brazil Current (NBC) play important roles as near-surface northward paths for the Atlantic meridional overturning circulation. To investigate the meridional evolution of the near-surface western boundary circulation in that region, two surveys were carried out off Northeast Brazil during austral spring 2015 and fall 2017, periods that we show to be representative of typical conditions for the spring and fall seasons. Using conductivity temperature depth oxygen probe and ship-mounted acoustic Doppler current profiler measurements, altimetry data, and numerical reanalysis products, we examine the spatiotemporal variability of the NBUC, providing a comprehensive view of the circulation, including NBUC-NBC transition and the potential impact of mesoscale eddies. The NBUC originating south of 10°S flows equatorward over the continental slope. NBUC mean velocity, transport and vertical extent of the velocity core were higher in spring 2015 (0.81 m s−1, 15.6 Sv, and >400 m) than in fall 2017 (0.65 m s−1, 11.0 Sv, and ~300 m). The upper limit of the NBUC velocity core rose slightly from 160 m at 9°S to 105 m depth at 6°S. This pattern is associated with a northward increase in current velocity from 0.7 m s−1 at 9°S to 1 m s−1 at 5°S. The orographic effect shifts the flow from northeastward south of 7.5°S to northwestward north of 7.5°S, following the shoreline. Besides, altimetry data show that this flow can be locally influenced by mesoscale activity. Farther north, at ~4.8°S, data obtained in fall 2017 show that the central branch of the South Equatorial Current (cSEC) enters into the western boundary system where it coalesces with the NBUC to form the NBC, flowing toward the Caribbean Sea. Finally, in fall, the NBUC retroflection does not feed the South Equatorial Undercurrent (SEUC), which, instead originates from retroflections of the cSEC and the equatorial branch of the South Equatorial Current (eSEC).