82 research outputs found

    Spatio-temporal distribution of spinetail devil ray (Mobula mobular) in the eastern tropical Atlantic Ocean.

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    The distribution of the spinetail devil ray Mobula mobular in the eastern tropical Atlantic remains poorly known compared to the Pacific and Indian Oceans. We used fisherydependent data and generalized additive models to examine the environmental characteristics associated with the presence of M. mobular in the eastern Atlantic Ocean. Results revealed that the distribution of M. mobular is significantly associated with seasonal upwelling systems in coastal and pelagic areas. Our model predicted the presence of the species in areas where there is evidence of its occurrence, such as the Angolan upwelling system and the coast of Ghana. In addition, our model predicted new hotspot areas, including locations around the Mauritanian upwelling system, the Guinea coast, offshore Ghana and the south coast of Angola and Brazil, where sample sizes are limited. Those areas, as well as the environmental preferences depicted by the model, provide valuable information about the habitat and ecology of the spinetail devil ray. Future research lines derived from this study, as well as its limitations, are discussed. Furthermore, in light of our results we discuss the improvements that are needed to contribute to the conservation and management of this vulnerable species.Versión del edito

    Experimental transmission of Corn Stunt Spiroplasma Present In Different Regions of Argentina

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    The aim was to transmit Corn stunt spiroplasma (Spiroplasma kunkelii Whitcomb) using field-collected Dalbulus maidis insects (Hemiptera-Cicadellidae), and diseased plants from places in the subtropical and temperate regions of Argentina. Field-collected D. maidis populations transmitted the spiroplasma in 39% of the cases when a density of five insects per plant was used. Transmissions were obtained from diseased plants collected in two subtropical locations. In all the symptomatic plants, the presence of spiroplasma was detected by serology and confirmed with PCR. The development of the symptoms and the pathogen titer varied between plants infected with insects from the same location, leading to the identification of two plant groups: one with severe symptoms and high pathogen titer, and the other with mild symptoms and lower titer, showing a direct relation between pathogen titer and the severity of symptomsFacultad de Ciencias Naturales y MuseoInstituto Nacional de Tecnología Agropecuari

    Natural Distribution of Parasitoids of Larvae of the Fall Armyworm, Spodoptera frugiperda, in Argentina

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    To develop a better understanding of the natural distribution of the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), and to update the knowledge of the incidence of its complex of parasitoids. S. frugiperda, samplings in whorl-stage corn were carried out in provinces of Argentina from 1999 to 2003. S. frugiperda larvae were collected from corn in localities of the provinces of Tucumán, Salta, Jujuy, Santiago del Estero, La Rioja, Córdoba, San Luis, Chaco and Misiones. In each locality 30 corn plants were sampled and only larvae located in those plants were collected. The parasitoids that emerged from S. frugiperda larvae were identified and counted. The abundance of the parasitoids and the parasitism rate were estimated. The S. frugiperda parasitoids collected were Campoletis grioti (Blanchard) (Hymenoptera: Ichneumonidae), Chelonus insularis (Cresson) (Hymenoptera: Braconidae), Archytas marmoratus (Townsend) (Diptera Tachinidae) and/or A. incertus (Macquart), Ophion sp. (Hymenoptera: Ichneumonidae), Euplectrus platyhypenae Howard (Hymenoptera: Eulophidae), and Incamyia chilensis (Aldrich) (Diptera Tachinidae). C. grioti was the most abundant and frequent during the five-year survey. Similar diversity of parasitoids was obtained in all the provinces, with the exception of I. chilensis and E. platyhypenae that were recovered only in the province of Salta. In the Northwestern region, in Tucumán, C. grioti and species of Archytas were the most abundant and frequent parasitoids. On the contrary, in Salta and Jujuy Ch. insularis was the parasitoid most abundant and frequently recovered. The parasitism rate obtained in Tucumán, Salta and Jujuy provinces were 21.96%, 17.87% and 6.63% respectively with an average of 18.93%. These results demonstrate that hymenopteran and dipteran parasitoids of S. frugiperda occurred differentially throughout the Argentinian provinces and played an important role on the natural control of the S. frugiperda larval population

    Does ICCAT need ecosystem plans? a pilot ecosystem plan for the Atlantic tropical ecoregion.

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    The implementation of an Ecosystem Approach Fisheries Management (EAFM) in ICCAT has been slow and patchy, as it lacks a long-term plan, vision and guidance on how to operationalize it. Ecosystem plans are needed to formalize the process of operationalizing the EAFM by identifying and formalizing ecosystem goals and objectives, planning actions based on priorities, measuring performance of the whole fishery system, addressing trade-offs, and incorporating them in fisheries management. The Specific Contract N0 2 under the Framework Contract - EASME/EMFF/2016/008 provisions of Scientific Advice for Fisheries Beyond EU Waters has developed a pilot ecosystem plan for the tropical ecoregion of the Atlantic Ocean. In this document, we highlight the main potential benefits of developing ecosystem plans in ICCAT. Second, we briefly describe the main core elements developed in the pilot ecosystem plan for the Tropical ecoregion of the Atlantic Ocean. Third, we summarize our main thoughts and lessons learned in the development of this pilot ecosystem plan for one ecoregion within ICCAT. Last, we propose a list of actions, research activities and capacity building activities to foster the development, use and implementation of ecosystem plans in ICCAT.Versión del edito

    Estudio para la mejora de la calidad del vino albariño

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    Premio de Investigación, Real Academia Galega de Ciencias, convocatoria 2009.[EN]Twenty-two clones from Albariño variety (Vitis vinifera L.), from an initial collection of 115 clones, were selected on the basis of their ampelographic, molecular and sanitary characteristics. These selected clones were studied from the agronomic and oenological point of view, and were also quantified for their levels of susceptibility to Powdery Mildew, Oidium and Botrytis. An ecotypic yeast was selected, its use has been patented and it is being exploited. Musts obtained from the previously selected Albariño clones were fermented with this yeast, essentially by increasing the content in volatile substances of interest (terpens: linalool and geraniol; norisoprenoids: α-ionone and β- damascenone), leading to wines with improved fermentative dynamic and sensorial attributes.[ES]En base a características ampelográficas, moleculares y sanitarias, se seleccionaron 22 clones de la variedad Albariño (Vitis vinifera L.), partiendo de 115 iniciales. Sobre los clones seleccionados se ha llevado a cabo un estudio agronómico y enológico, así como la cuantificación de los niveles de susceptibilidad a Mildiu, Oídio y Botrytis. Se ha seleccionado una levadura ecotípica, cuyo uso ha sido patentado y se encuentra en explotación. Con ella se fermentaron los mostos obtenidos a partir de los clones de Albariño previamente seleccionados, dando lugar a vinos con una dinámica fermentativa xPremio de Investigación, Real Academia Galega de Ciencias, convocatoria 2009 y unos atributos sensoriales mejorados, fundamentalmente en base al aumento del contenido en sustancias volátiles de interés (terpenos: linalool y geraniol; norisoprenoides: α-ionona y β- damascenona).La actividad realizada ha sido financiada, además de por la Bodega Terras Gauda S.A., por la Xunta de Galicia (PGIDIT04TAL035E), y por el propio CSIC (PIE 2004 7 0E 214).Peer reviewe

    Borrelia chilensis, a new member of the Borrelia burgdorferi sensu lato complex that extends the range of this genospecies in the Southern Hemisphere

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    Borrelia burgdorferi sensu lato (s.l.), transmitted by Ixodes spp. ticks, is the causative agent of Lyme disease. Although Ixodes spp. ticks are distributed in both Northern and Southern Hemispheres, evidence for the presence of B. burgdorferi s.l. in South America apart from Uruguay is lacking. We now report the presence of culturable spirochetes with flat-wave morphology and borrelial DNA in endemic Ixodes stilesi ticks collected in Chile from environmental vegetation and long-tailed rice rats (Oligoryzomys longicaudatus). Cultured spirochetes and borrelial DNA in ticks were characterized by multilocus sequence typing and by sequencing five other loci (16S and 23S ribosomal genes, 5S–23S intergenic spacer, flaB, ospC). Phylogenetic analysis placed this spirochete as a new genospecies within the Lyme borreliosis group. Its plasmid profile determined by polymerase chain reaction and pulsed-field gel electrophoresis differed from that of B. burgdorferi B31A3. We propose naming this new South American member of the Lyme borreliosis group B. chilensis VA1 in honor of its country of origin.This work was supported by grant 5R01 AI48856-07 from N.I.H to F.C.C.Peer reviewe

    Viral RNA load in plasma is associated with critical illness and a dysregulated host response in COVID‑19

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    Background. COVID-19 can course with respiratory and extrapulmonary disease. SARS-CoV-2 RNA is detected in respiratory samples but also in blood, stool and urine. Severe COVID-19 is characterized by a dysregulated host response to this virus. We studied whether viral RNAemia or viral RNA load in plasma is associated with severe COVID-19 and also to this dysregulated response. Methods. A total of 250 patients with COVID-19 were recruited (50 outpatients, 100 hospitalized ward patients and 100 critically ill). Viral RNA detection and quantification in plasma was performed using droplet digital PCR, targeting the N1 and N2 regions of the SARS-CoV-2 nucleoprotein gene. The association between SARS-CoV-2 RNAemia and viral RNA load in plasma with severity was evaluated by multivariate logistic regression. Correlations between viral RNA load and biomarkers evidencing dysregulation of host response were evaluated by calculating the Spearman correlation coefficients. Results. The frequency of viral RNAemia was higher in the critically ill patients (78%) compared to ward patients (27%) and outpatients (2%) (p < 0.001). Critical patients had higher viral RNA loads in plasma than non-critically ill patients, with non-survivors showing the highest values. When outpatients and ward patients were compared, viral RNAemia did not show significant associations in the multivariate analysis. In contrast, when ward patients were compared with ICU patients, both viral RNAemia and viral RNA load in plasma were associated with critical illness (OR [CI 95%], p): RNAemia (3.92 [1.183–12.968], 0.025), viral RNA load (N1) (1.962 [1.244–3.096], 0.004); viral RNA load (N2) (2.229 [1.382–3.595], 0.001). Viral RNA load in plasma correlated with higher levels of chemokines (CXCL10, CCL2), biomarkers indicative of a systemic inflammatory response (IL-6, CRP, ferritin), activation of NK cells (IL-15), endothelial dysfunction (VCAM-1, angiopoietin-2, ICAM-1), coagulation activation (D-Dimer and INR), tissue damage (LDH, GPT), neutrophil response (neutrophils counts, myeloperoxidase, GM-CSF) and immunodepression (PD-L1, IL-10, lymphopenia and monocytopenia). Conclusions. SARS-CoV-2 RNAemia and viral RNA load in plasma are associated with critical illness in COVID-19. Viral RNA load in plasma correlates with key signatures of dysregulated host responses, suggesting a major role of uncontrolled viral replication in the pathogenesis of this disease.This work was supported by awards from the Canadian Institutes of Health Research, the Canadian 2019 Novel Coronavirus (COVID-19) Rapid Research Funding initiative (CIHR OV2 – 170357), Research Nova Scotia (DJK), Atlantic Genome/Genome Canada (DJK), Li-Ka Shing Foundation (DJK), Dalhousie Medical Research Foundation (DJK), the “Subvenciones de concesión directa para proyectos y programas de investigación del virus SARS‐CoV2, causante del COVID‐19”, FONDO–COVID19, Instituto de Salud Carlos III (COV20/00110, CIBERES, 06/06/0028), (AT) and fnally by the “Convocatoria extraordinaria y urgente de la Gerencia Regional de Salud de Castilla y León, para la fnanciación de proyectos de investigación en enfermedad COVID-19” (GRS COVID 53/A/20) (CA). DJK is a recipient of the Canada Research Chair in Translational Vaccinology and Infammation. APT was funded by the Sara Borrell Research Grant CD018/0123 funded by Instituto de Salud Carlos III and co-fnanced by the European Development Regional Fund (A Way to Achieve Europe programme). The funding sources did not play any role neither in the design of the study and collection, not in the analysis, in the interpretation of data or in writing the manuscript

    Glaciation Effects on the Phylogeographic Structure of Oligoryzomys longicaudatus (Rodentia: Sigmodontinae) in the Southern Andes

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    The long-tailed pygmy rice rat Oligoryzomys longicaudatus (Sigmodontinae), the major reservoir of Hantavirus in Chile and Patagonian Argentina, is widely distributed in the Mediterranean, Temperate and Patagonian Forests of Chile, as well as in adjacent areas in southern Argentina. We used molecular data to evaluate the effects of the last glacial event on the phylogeographic structure of this species. We examined if historical Pleistocene events had affected genetic variation and spatial distribution of this species along its distributional range. We sampled 223 individuals representing 47 localities along the species range, and sequenced the hypervariable domain I of the mtDNA control region. Aligned sequences were analyzed using haplotype network, Bayesian population structure and demographic analyses. Analysis of population structure and the haplotype network inferred three genetic clusters along the distribution of O. longicaudatus that mostly agreed with the three major ecogeographic regions in Chile: Mediterranean, Temperate Forests and Patagonian Forests. Bayesian Skyline Plots showed constant population sizes through time in all three clusters followed by an increase after and during the Last Glacial Maximum (LGM; between 26,000–13,000 years ago). Neutrality tests and the “g” parameter also suggest that populations of O. longicaudatus experienced demographic expansion across the species entire range. Past climate shifts have influenced population structure and lineage variation of O. longicaudatus. This species remained in refugia areas during Pleistocene times in southern Temperate Forests (and adjacent areas in Patagonia). From these refugia, O. longicaudatus experienced demographic expansions into Patagonian Forests and central Mediterranean Chile using glacial retreats
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