18 research outputs found

    Review on hard coral recruitment (Cnidaria: Scleractinia) in Colombia

    Get PDF
    Recruitment, defined and measured as the incorporation of new individuals (i.e. coral juveniles) into a population, is a fundamental process for ecologists, evolutionists and conservationists due to its direct effect on population structure and function. Because most coral populations are self-feeding, a breakdown in recruitment would lead to local extinction. Recruitment indirectly affects both renewal and maintenance of existing and future coral communities, coral reef biodiversity (bottom-up effect) and therefore coral reef resilience. This process has been used as an indirect measure of individual reproductive success (fitness) and is the final stage of larval dispersal leading to population connectivity. As a result, recruitment has been proposed as an indicator of coral-reef health in marine protected areas, as well as a central aspect of the decision-making process concerning management and conservation. The creation of management plans to promote impact mitigation,rehabilitation and conservation of the Colombian coral reefs is a necessity that requires firstly, a review and integration of existing literature on scleractinian coral recruitment in Colombia and secondly, larger scale field studies. This motivated us to summarize and analyze all existing information on coral recruitment to determine the state of knowledge, isolate patterns, identify gaps, and suggest future lines of research

    Clinical Presentation and Outcomes of Kawasaki Disease in Children from Latin America: A Multicenter Observational Study from the REKAMLATINA Network

    Get PDF
    Objetivos: Describir la presentación clínica, el manejo y los resultados de la enfermedad de Kawasaki (EK) en Latinoamérica y evaluar los indicadores pronósticos tempranos de aneurisma de la arteria coronaria (AAC). Diseño del estudio: Se realizó un estudio observacional basado en el registro de la EK en 64 centros pediátricos participantes de 19 países latinoamericanos de forma retrospectiva entre el 1 de enero de 2009 y el 31 de diciembre de 2013, y de forma prospectiva desde el 1 de junio de 2014 hasta el 31 de mayo de 2017. Se recopilaron datos demográficos, clínicos y de laboratorio iniciales. Se utilizó una regresión logística que incorporaba factores clínicos y la puntuación z máxima de la arteria coronaria en la presentación inicial (entre 10 días antes y 5 días después de la inmunoglobulina intravenosa [IGIV]) para desarrollar un modelo pronóstico de AAC durante el seguimiento (>5 días después de la IGIV). Resultados: De 1853 pacientes con EK, el ingreso tardío (>10 días tras el inicio de la fiebre) se produjo en el 16%, el 25% tuvo EK incompleta y el 11% fue resistente a la IGIV. Entre los 671 sujetos con puntuación z de la arteria coronaria notificada durante el seguimiento (mediana: 79 días; IQR: 36, 186), el 21% presentaba AAC, incluido un 4% con aneurismas gigantes. Un modelo pronóstico simple que utilizaba sólo una puntuación z de la arteria coronaria máxima ≥2,5 en la presentación inicial fue óptimo para predecir la AAC durante el seguimiento (área bajo la curva: 0,84; IC del 95%: 0,80, 0,88). Conclusiones: De nuestra población latinoamericana, la puntuación z de la arteria coronaria ≥2,5 en la presentación inicial fue el factor pronóstico más importante que precedió a la AAC durante el seguimiento. Estos resultados resaltan la importancia de la ecocardiografía temprana durante la presentación inicial de la EK. © 2023 Los autoresObjectives: To describe the clinical presentation, management, and outcomes of Kawasaki disease (KD) in Latin America and to evaluate early prognostic indicators of coronary artery aneurysm (CAA). Study design: An observational KD registry-based study was conducted in 64 participating pediatric centers across 19 Latin American countries retrospectively between January 1, 2009, and December 31, 2013, and prospectively from June 1, 2014, to May 31, 2017. Demographic and initial clinical and laboratory data were collected. Logistic regression incorporating clinical factors and maximum coronary artery z-score at initial presentation (between 10 days before and 5 days after intravenous immunoglobulin [IVIG]) was used to develop a prognostic model for CAA during follow-up (>5 days after IVIG). Results: Of 1853 patients with KD, delayed admission (>10 days after fever onset) occurred in 16%, 25% had incomplete KD, and 11% were resistant to IVIG. Among 671 subjects with reported coronary artery z-score during follow-up (median: 79 days; IQR: 36, 186), 21% had CAA, including 4% with giant aneurysms. A simple prognostic model utilizing only a maximum coronary artery z-score ≥2.5 at initial presentation was optimal to predict CAA during follow-up (area under the curve: 0.84; 95% CI: 0.80, 0.88). Conclusion: From our Latin American population, coronary artery z-score ≥2.5 at initial presentation was the most important prognostic factor preceding CAA during follow-up. These results highlight the importance of early echocardiography during the initial presentation of KD. © 2023 The Author(s

    Time to Switch to Second-line Antiretroviral Therapy in Children With Human Immunodeficiency Virus in Europe and Thailand.

    Get PDF
    Background: Data on durability of first-line antiretroviral therapy (ART) in children with human immunodeficiency virus (HIV) are limited. We assessed time to switch to second-line therapy in 16 European countries and Thailand. Methods: Children aged <18 years initiating combination ART (≥2 nucleoside reverse transcriptase inhibitors [NRTIs] plus nonnucleoside reverse transcriptase inhibitor [NNRTI] or boosted protease inhibitor [PI]) were included. Switch to second-line was defined as (i) change across drug class (PI to NNRTI or vice versa) or within PI class plus change of ≥1 NRTI; (ii) change from single to dual PI; or (iii) addition of a new drug class. Cumulative incidence of switch was calculated with death and loss to follow-up as competing risks. Results: Of 3668 children included, median age at ART initiation was 6.1 (interquartile range (IQR), 1.7-10.5) years. Initial regimens were 32% PI based, 34% nevirapine (NVP) based, and 33% efavirenz based. Median duration of follow-up was 5.4 (IQR, 2.9-8.3) years. Cumulative incidence of switch at 5 years was 21% (95% confidence interval, 20%-23%), with significant regional variations. Median time to switch was 30 (IQR, 16-58) months; two-thirds of switches were related to treatment failure. In multivariable analysis, older age, severe immunosuppression and higher viral load (VL) at ART start, and NVP-based initial regimens were associated with increased risk of switch. Conclusions: One in 5 children switched to a second-line regimen by 5 years of ART, with two-thirds failure related. Advanced HIV, older age, and NVP-based regimens were associated with increased risk of switch

    Mesophotic Gorgonian Corals Evolved Multiple Times and Faster Than Deep and Shallow Lineages

    Get PDF
    Mesophotic Coral Ecosystems (MCEs) develop on a unique environment, where abrupt environmental changes take place. Using a time-calibrated molecular phylogeny (mtDNA: mtMutS), we examined the lineage membership of mesophotic gorgonian corals (Octocorallia: Cnidaria) in comparison to shallow and deep-sea lineages of the wider Caribbean-Gulf of Mexico and the Tropical Eastern Pacific. Our results show mesophotic gorgonians originating multiple times from old deep-sea octocoral lineages, whereas shallow-water species comprise younger lineages. The mesophotic gorgonian fauna in the studied areas is related to their zooxanthellate shallow-water counterparts in only two clades (Gorgoniidae and Plexauridae), where the bathymetrical gradient could serve as a driver of diversification. Interestingly, mesophotic clades have diversified faster than either shallow or deep clades. One of this groups with fast diversification is the family Ellisellidae, a major component of the mesophotic gorgonian coral assemblage worldwide

    Revisão sobre o recrutamento de corais pétreos (Cnidaria: Scleractinia) na Colômbia.

    Get PDF
    AbstractRecruitment, defined and measured as the incorporation of new individuals (i.e. coral juveniles) into a population, is a fundamental process for ecologists, evolutionists and conservationists due to its direct effect on population structure and function. Because most coral populations are self-feeding, a breakdown in recruitment would lead to local extinction. Recruitment indirectly affects both renewal and maintenance of existing and future coral communities, coral reef biodiversity (bottom-up effect) and therefore coral reef resilience. This process has been used as an indirect measure of individual reproductive success (fitness) and is the final stage of larval dispersal leading to population connectivity. As a result, recruitment has been proposed as an indicator of coral-reef health in marine protected areas, as well as a central aspect of the decision-making process concerning management and conservation. The creation of management plans to promote impact mitigation, rehabilitation and conservation of the Colombian coral reefs is a necessity that requires firstly, a review and integration of existing literature on scleractinian coral recruitment in Colombia and secondly, larger scale field studies. This motivated us to summarize and analyze all existing information on coral recruitment to determine the state of knowledge, isolate patterns, identify gaps, and suggest future lines of research.Key words: Recruitment, juvenile, coral, Scleractinia, structure, reef, Colombia, density, richness, monitoring. El reclutamiento, definido y medido como la incorporación de nuevos individuos (ej. juveniles de coral) a la población, es considerado en arrecifes coralinos como un proceso fundamental por parte de ecólogos, evolucionistas y conservacionistas debido a que determina de forma directa la estructura y función de las poblaciones. Además, debido a que la mayor parte de las poblaciones coralinas se auto-abastecen (self-seeding), fallas en el reclutamiento conducirían a extinción local. Indirectamente, el reclutamiento afecta la renovación y el mantenimiento de las comunidades coralinas presentes y futuras, la biodiversidad (efecto bottom-up) y por lo tanto, la capacidad de resiliencia del ecosistema arrecifal. Este proceso ha sido empleado como una medida del éxito reproductivo de individuos (fitness) y representa la etapa final del proceso de dispersión que conlleva a la conectividad poblacional. Es por lo anterior, que esta variable ha sido propuesta como un indicador del estado de salud de los arrecifes en áreas marinas protegidas y es un elemento fundamental para la toma de decisiones de manejo y conservación. Generar planes de manejo que propendan a minimizar impactos, rehabilitar y conservar los arrecifes del país es una necesidad que requiere en primera instancia de una revisión e integración de la literatura existente sobre reclutamiento de corales escleractínios en Colombia, al igual que estudios de campo a mayor escala. Lo anterior nos motivó a analizar y sintetizar la literatura existente con el ánimo de determinar el estado del conocimiento, extraer patrones, identificar vacíos y sugerir líneas de investigación. Palabras clave: Reclutamiento, juvenil, coral, escleractinia, estructura, arrecife, Colombia, densidad, riqueza, monitoreo.O recrutamento, definido e medido como a entrada de novos indivíduos para a população (exemplo juvenis do coral), tem sido considerado como um processo fundamental pelos ecólogos, os evolucionistas e conservacionistas que trabalham em recifes de coral, ja que determina diretamente a estrutura e a função das populações. Além disso, dado que a maioria das populações de coral produz seus próprios juvenis (self-seeding), falhas no recrutamento levam à extinção local. Indiretamente, o recrutamento afeta a renovação-manutenção das comunidades de corais presentes e futuras, a biodiversidade (efeito bottom-up) e, portanto, da resiliência do ecossistema recifal. Este processo tem sido utilizado como uma medida de sucesso reprodutivo dos indivíduos (fitness) e representa o estágio final do processo de dispersão que leva a conectividade populacional. Pelo exposto, esta variável tem sido proposta como um indicador da saúde dos recifes nas áreas marinhas protegidas e é um elemento chave na tomada de decisões de gestão e conservação. Gerar planos de ação que tendem a minimizar impactos, recuperar e preservar os recifes do país é uma necessidade que requer, em primeira instância, uma revisão e integração da literatura existente sobre o recrutamento dos corais escleractíneos na Colômbia; assim mesmo, estudos de campo a escala maior. Isso levou a analisar e sintetizar a literatura existente com o objetivo de determinar o estado do conhecimento, abstrair padrões, identificar vazios e sugerir linhas de pesquisa. Palavras-chave: Recrutamento, juvenil, coral, escleractíneos, estrutura, recifes, Colômbia, densidade, riqueza, monitoramento

    Remarkable population structure in the tropical Atlantic lace corals Stylaster roseus (Pallas, 1766) and Stylaster blatteus (Boschma, 1961)

    No full text
    Biodiversity on coral reefs depends not only on primary reef-builders, but also on associated taxa that create microhabitats for other species. Hydrocorals of the genus Stylaster, commonly known as lace corals, form small branching colonies that enhance three-dimensional complexity on reefs and are known to support a variety of commensal species. Furthermore, the genus is highly speciose, further increasing biodiversity. Despite their important ecological roles, little is known about the evolutionary history and the intraspecific diversity and structure in these broadly distributed hydrocorals. Here, we assessed the phylogenetic relationships among Atlantic species in the genus Stylaster and examined the genetic structure of S. roseus in the Tropical Western Atlantic (Caribbean and Brazil) and of S. blatteus in the Tropical Eastern Atlantic (Africa), using DNA sequences from the 16S ribosomal gene. Time-calibrated phylogenetic analyses showed that S. roseus and S. blatteus diverged at ~ 24.6 Ma. A well-supported Brazilian clade within S. roseus indicates a possible cryptic species that diverged at ~ 11.6 Ma, consistent with the formation of the Amazon River at 9 Ma (Hoorn et al. in Glob Planet Change 153:51–65, 2017). Strong genetic structure was observed even over moderate distances, with ΦST values over all populations being 0.98 for S. roseus and 0.90 for S. blatteus. Nearly, all haplotypes were private (found in a single location) and diverged by many mutational steps from one another. In contrast, genetic diversity was low at the local scale for both species, with most sites showing no variation (a single haplotype). These results are coherent with the reproductive strategy of Stylasteridae, where larvae are brooded and are highly developed at the time of release, often settling near the parental colony. Limited dispersal coupled with possible clonal reproduction have likely contributed to the high levels of genetic differentiation observed here. Lace corals show unusual reproductive and population dynamics compared to other reef inhabiting cnidarians. Future work may reveal additional cryptic diversity in this poorly studied family

    Bacterial Composition and Diversity in Deep-Sea Sediments from the Southern Colombian Caribbean Sea

    No full text
    Deep-sea sediments are considered an extreme environment due to high atmospheric pressure and low temperatures, harboring novel microorganisms. To explore marine bacterial diversity in the southern Colombian Caribbean Sea, this study used 16S ribosomal RNA (rRNA) gene sequencing to estimate bacterial composition and diversity of six samples collected at different depths (1681 to 2409 m) in two localities (CCS_A and CCS_B). We found 1842 operational taxonomic units (OTUs) assigned to bacteria. The most abundant phylum was Proteobacteria (54.74%), followed by Bacteroidetes (24.36%) and Firmicutes (9.48%). Actinobacteria and Chloroflexi were also identified, but their dominance varied between samples. At the class-level, Alphaproteobacteria was most abundant (28.4%), followed by Gammaproteobacteria (24.44%) and Flavobacteria (16.97%). The results demonstrated that some bacteria were common to all sample sites, whereas other bacteria were unique to specific samples. The dominant species was Erythrobacter citreus, followed by Gramella sp. Overall, we found that, in deeper marine sediments (e.g., locality CCS_B), the bacterial alpha diversity decreased while the dominance of several genera increased; moreover, for locality CCS_A, our results suggest that the bacterial diversity could be associated with total organic carbon content. We conclude that physicochemical properties (e.g., organic matter content) create a unique environment and play an important role in shaping bacterial communities and their diversity

    Phylogenomics, origin, and diversification of anthozoans (Phylum Cnidaria)

    No full text
    Anthozoan cnidarians (corals and sea anemones) include some of the world's most important foundation species, capable of building massive reef complexes that support entire ecosystems. Although previous molecular phylogenetic analyses have revealed widespread homoplasy of the morphological characters traditionally used to define orders and families of anthozoans, analyses using mitochondrial genes or rDNA have failed to resolve many key nodes in the phylogeny. With a fully resolved, time-calibrated phylogeny for 234 species constructed from hundreds of ultraconserved elements and exon loci, we explore the evolutionary origins of the major clades of Anthozoa and some of their salient morphological features. The phylogeny supports reciprocally monophyletic Hexacorallia and Octocorallia, with Ceriantharia as the earliest diverging hexacorals; two reciprocally monophyletic clades of Octocorallia; and monophyly of all hexacoral orders with the exception of the enigmatic sea anemone Relicanthus daphneae. Divergence dating analyses place Anthozoa in the Cryogenian to Tonian periods (648-894 Ma), older than has been suggested by previous studies. Ancestral state reconstructions indicate that the ancestral anthozoan was a solitary polyp that had bilateral symmetry and lacked a skeleton. Colonial growth forms and the ability to precipitate calcium carbonate evolved in the Ediacaran (578 Ma) and Cambrian (503 Ma) respectively; these hallmarks of reef-building species have subsequently arisen multiple times independently in different orders. Anthozoans formed associations with photosymbionts by the Devonian (383 Ma), and photosymbioses have been gained and lost repeatedly in all orders. Together, these results have profound implications for the interpretation of the Precambrian environment and the early evolution of metazoans.[Bilateral symmetry; coloniality; coral; early metazoans; exon capture; Hexacorallia; Octocorallia photosymbiosis; sea anemone; ultraconserved elements.]
    corecore