46 research outputs found

    Sublittoral soft bottom communities and diversity of Mejillones Bay in northern Chile (Humboldt Current upwelling system)

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    The macrozoobenthos of Mejillones Bay (23°S; Humboldt Current) was quantitatively investigated over a 7-year period from austral summer 1995/1996 to winter 2002. About 78 van Veen grab samples taken at six stations (5, 10, 20 m depth) provided the basis for the analysis of the distribution of 60 species and 28 families of benthic invertebrates, as well as of their abundance and biomass. Mean abundance (2,119 individuals m-2) was in the same order compared to a previous investigation; mean biomass (966 g formalin wet mass m-2), however, exceeded prior estimations mainly due to the dominance of the bivalve Aulacomya ater. About 43% of the taxa inhabited the complete depth range. Mean taxonomic Shannon diversity (H', Log e) was 1.54 ± 0.58 with a maximum at 20 m (1.95 ± 0.33); evenness increased with depth. The fauna was numerically dominated by carnivorous gastropods, polychaetes and crustaceans (48%). About 15% of the species were suspensivorous, 13% sedimentivorous, 11% detritivorous, 7% omnivorous and 6% herbivorous. Cluster analyses showed a significant difference between the shallow and the deeper stations. Gammarid amphipods and the polychaete family Nephtyidae characterized the 5-mzone, the molluscs Aulacomya ater, Mitrella unifasciata and gammarids the intermediate zone, while the gastropod Nassarius gayi and the polychaete family Nereidae were most prominent at the deeper stations. The communities of the three depth zones did not appear to be limited by hypoxia during non-El Niño conditions. Therefore, no typical change in community structure occurred during El Niño 1997–1998, in contrast to what was observed for deeper faunal assemblages and hypoxic bays elsewhere in the coastal Humboldt Current system

    Depletion of abscisic acid levels in roots of flooded Carrizo citrange (Poncirus trifoliata L. Raf. x Citrus sinensis L. Osb.) plants is a stress-specific response associated to the differential expression of PYR/PYL/RCAR receptors

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    [EN] Soil flooding reduces root abscisic acid (ABA) levels in citrus, conversely to what happens under drought. Despite this reduction, microarray analyses suggested the existence of a residual ABA signaling in roots of flooded Carrizo citrange seedlings. The comparison of ABA metabolism and signaling in roots of flooded and water stressed plants of Carrizo citrange revealed that the hormone depletion was linked to the upregulation of CsAOG, involved in ABA glycosyl ester (ABAGE) synthesis, and to a moderate induction of catabolism (CsCYP707A, an ABA 8'-hydroxylase) and buildup of dehydrophaseic acid (DPA). Drought strongly induced both ABA biosynthesis and catabolism (CsNCED1, 9-cis-neoxanthin epoxycarotenoid dioxygenase 1, and CsCYP707A) rendering a significant hormone accumulation. In roots of flooded plants, restoration of control ABA levels after stress release was associated to the upregulation of CsBGLU18 (an ABA beta-glycosidase) that cleaves ABAGE. Transcriptional profile of ABA receptor genes revealed a different induction in response to soil flooding (CsPYL5) or drought (CsPYL8). These two receptor genes along with CsPYL1 were cloned and expressed in a heterologous system. Recombinant CsPYL5 inhibited Delta NHAB1 activity in vitro at lower ABA concentrations than CsPYL8 or CsPYL1, suggesting its better performance under soil flooding conditions. Both stress conditions induced ABA-responsive genes CsABI5 and CsDREB2A similarly, suggesting the occurrence of ABA signaling in roots of flooded citrus seedlings. The impact of reduced ABA levels in flooded roots on CsPYL5 expression along with its higher hormone affinity reinforce the role of this ABA receptor under soil-flooding conditions and explain the expression of certain ABA-responsive genes.This work was supported by Ministerio de Economia y Competitividad (MINECO), Fondo Europeo de Desarrollo Regional (FEDER) and Universitat Jaume I through grants No. AGL201676574-R, UJI-B2016-23/UJI-B2016-24 to A.G-C. and V.A. and MINECO, FEDER and Consejo Superior de Investigaciones Cientificas (CSIC) through grant BIO2014-52537-R to P.L.R. S.I.Z. and M.M. were supported by predoctoral grants from Universitat Jaume I and Generalitat Valenciana, respectively. M.G.G. was recipient of a "JAE-DOC" contract from the CSIC. Mass spectrometry analyses were performed at the central facilities (Servei Central d'Instrumentacio Cientifica, SCIC) of Universitat Jaume I.Arbona, V.; Zandalinas, SI.; Manzi, M.; González Guzmán, M.; Rodríguez Egea, PL.; Gómez-Cadenas, A. (2017). Depletion of abscisic acid levels in roots of flooded Carrizo citrange (Poncirus trifoliata L. Raf. x Citrus sinensis L. Osb.) plants is a stress-specific response associated to the differential expression of PYR/PYL/RCAR receptors. Plant Molecular Biology. 93(6):623-640. https://doi.org/10.1007/s11103-017-0587-7S623640936Agarwal PK, Jha B (2010) Transcription factors in plants and ABA dependent and independent abiotic stress signalling. Biol Plant 54:201–212Agustí J, Merelo P, Cercós M, Tadeo FR, Talón M (2008) Ethylene-induced differential gene expression during abscission of citrus leaves. J Exp Bot 59:2717–2733. doi: 10.1093/jxb/ern138Antoni R, Gonzalez-Guzman M, Rodriguez L, Rodrigues A, Pizzio G, Rodriguez PL (2012) Selective inhibition of clade a phosphatases type 2 C by PYR/PYL/RCAR abscisic acid receptors. Plant Physiol 158:970–980. doi: 10.1104/pp.111.188623Antoni R, Gonzalez-Guzman M, Rodriguez L, Peirats-Llobet M, Pizzio G, Fernandez M, De Winne N, De Jaeger G, Dietrich D, Bennett MJ, Rodriguez PL (2013) PYRABACTIN RESISTANCE1-LIKE8 plays an important role for the regulation of abscisic acid signaling in root. Plant Physiol 161:491–931. doi: 10.1104/pp.112.208678Arbona V, Gómez-Cadenas A (2008) Hormonal modulation of citrus responses to flooding. J Plant Growth Regul 27:241–250. doi: 10.1007/s00344-008-9051-xArbona V, López-climent MF, Pérez-Clemente RM, Gómez-cadenas A (2009) Maintenance of a high photosynthetic performance is linked to flooding tolerance in citrus. 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    Analysis of the functional conservation of ethylene receptors between maize and Arabidopsis

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    Ethylene, a regulator of plant growth and development, is perceived by specific receptors that act as negative regulators of the ethylene response. Five ethylene receptors, i.e., ETR1, ERS1, EIN4, ETR2, and ERS2, are present in Arabidopsis and dominant negative mutants of each that confer ethylene insensitivity have been reported. In contrast, maize contains just two types of ethylene receptors: ZmERS1, encoded by ZmERS1a and ZmERS1b, and ZmETR2, encoded by ZmETR2a and ZmETR2b. In this study, we introduced a Cys to Tyr mutation in the transmembrane domain of ZmERS1b and ZmETR2b that is present in the etr1-1 dominant negative mutant and expressed each protein in Arabidopsis. Mutant Zmers1b and Zmetr2b receptors conferred ethylene insensitivity and Arabidopsis expressing Zmers1b or Zmetr2b were larger and exhibited a delay in leaf senescence characteristic of ethylene insensitive Arabidopsis mutants. Zmers1b and Zmetr2b were dominant and functioned equally well in a hemizygous or homozygous state. Expression of the Zmers1b N-terminal transmembrane domain was sufficient to exert dominance over endogenous Arabidopsis ethylene receptors whereas the Zmetr2b N-terminal domain failed to do so. Neither Zmers1b nor Zmetr2b functioned in the absence of subfamily 1 ethylene receptors, i.e., ETR1 and ERS1. These results suggest that Cys65 in maize ZmERS1b and ZmETR2b plays the same role that it does in Arabidopsis receptors. Moreover, the results demonstrate that the mutant maize ethylene receptors are functionally dependent on subfamily 1 ethylene receptors in Arabidopsis, indicating substantial functional conservation between maize and Arabidopsis ethylene receptors despite their sequence divergence

    The absence of MyD88 has no effect on the induction of alternatively activated macrophage during Fasciola hepatica infection

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    <p>Abstract</p> <p>Background</p> <p>Alternatively activated macrophages (AAMϕ) play important roles in allergies and responses to parasitic infections. However, whether signaling through toll-like receptors (TLRs) plays any role in AAMϕ induction when young <it>Fasciola hepatica </it>penetrates the liver capsule and migrates through the liver tissue is still unclear.</p> <p>Results</p> <p>The data show that the lack of myeloid differentiation factor 88 (MyD88) has no effect on the AAMϕ derived from the bone marrow (BMMϕ) <it>in vitro </it>and does not impair the mRNA expression of arginase-1, resistin-like molecule (RELMα), and Ym1 in BMMϕs. The Th2 cytokine production bias in splenocytes was not significantly altered in <it>F. hepatica</it>-infected mice in the absence of MyD88 <it>in vitro </it>and in the pleural cavity lavage <it>in vivo</it>. In addition, MyD88-deficiency has no effect on the arginase production of the <it>F. hepatica </it>elicited macrophages (Fe Mϕs), production of RELMα and Ym1 proteins and mRNA expression of Ym1 and RELMα of macrophages in the peritoneal cavity 6 weeks post <it>F. hepatica </it>infection.</p> <p>Conclusions</p> <p>The absence of MyD88 has no effect on presence of AAMϕ 6 weeks post <it>F. hepatica </it>infection.</p

    Marine Biodiversity in the Caribbean: Regional Estimates and Distribution Patterns

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    This paper provides an analysis of the distribution patterns of marine biodiversity and summarizes the major activities of the Census of Marine Life program in the Caribbean region. The coastal Caribbean region is a large marine ecosystem (LME) characterized by coral reefs, mangroves, and seagrasses, but including other environments, such as sandy beaches and rocky shores. These tropical ecosystems incorporate a high diversity of associated flora and fauna, and the nations that border the Caribbean collectively encompass a major global marine biodiversity hot spot. We analyze the state of knowledge of marine biodiversity based on the geographic distribution of georeferenced species records and regional taxonomic lists. A total of 12,046 marine species are reported in this paper for the Caribbean region. These include representatives from 31 animal phyla, two plant phyla, one group of Chromista, and three groups of Protoctista. Sampling effort has been greatest in shallow, nearshore waters, where there is relatively good coverage of species records; offshore and deep environments have been less studied. Additionally, we found that the currently accepted classification of marine ecoregions of the Caribbean did not apply for the benthic distributions of five relatively well known taxonomic groups. Coastal species richness tends to concentrate along the Antillean arc (Cuba to the southernmost Antilles) and the northern coast of South America (Venezuela – Colombia), while no pattern can be observed in the deep sea with the available data. Several factors make it impossible to determine the extent to which these distribution patterns accurately reflect the true situation for marine biodiversity in general: (1) highly localized concentrations of collecting effort and a lack of collecting in many areas and ecosystems, (2) high variability among collecting methods, (3) limited taxonomic expertise for many groups, and (4) differing levels of activity in the study of different taxa

    Mobilidade, acidentes de trânsito e fatores associados entre estudantes universitários da Guatemala

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    El objetivo fue identificar y cuantificar la asociación entre la intensidad de exposición (km/año recorridos), la accidentalidad y sus factores asociados en universitarios de Guatemala. Se realizó un estudio trasversal durante el curso 2010-2011, sobre una muestra de 1.016 conductores, quienes cumplimentaron un cuestionario autoadministrado que valoraba: patrones de movilidad, uso de dispositivos de seguridad, estilos de conducción y accidentalidad. Se obtuvieron asociaciones positivas entre la intensidad de exposición y la mayor implicación en circunstancias de riesgo al volante (coeficiente de regresión ajustado de 3,25, IC95%: 2,23-4,27, para las mayores exposiciones). Tanto una mayor implicación en tales circunstancias, como una mayor edad, fueron las variables más fuertemente asociadas con la mayor accidentalidad. Pese a que la intensidad de exposición se asocia positivamente con una mayor accidentalidad, se constató que la mayor parte de dicha asociación está mediada por una mayor implicación en circunstancias de riesgo al volante.The aim of this study was to identify and quantify the association between the amount of driving (km/year), traffic accidents, and other factors among university students in Guatemala. A cross-sectional study was performed during the 2010-2011 school year in a sample of 1,016 drivers who completed a self-administered questionnaire that assessed mobility patterns, use of safety accessories, driving style, and automobile crashes. The results showed a positive association between amount of driving and greater involvement in risky driving (adjusted regression coefficient 3.25, 95%CI: 2.23-4.27, for the highest level of exposure). More frequent involvement in risky driving and older age showed the strongest associations with traffic accidents. Although the amount of driving was positively associated with a higher accident rate, most of this association was found to be mediated by involvement in risky driving practices.O objetivo foi identificar e quantificar a associação entre a intensidade de exposição (km/anos percorridos), a acidentalidade e os seus fatores em universitários da Guatemala. Realizou-se um estudo transversal durante o curso 2010-2011 sobre uma amostra de 1.016 condutores de veículos, que responderam a um questionário autoadministrado que valorizava: padrões de mobilidade, uso de dispositivos de segurança, maneira de condução e acidentalidade. Obtiveram-se associações positivas entre intensidade de exposição e maior implicância em circunstâncias de risco ao conduzir (coeficiente de regressão ajustado a 3,25; IC95%: 2,23-4,27, para as maiores exposições). Tanto a maior implicância em ditas circunstâncias como uma maioridade foram as variáveis mais fortemente associadas com a maior acidentalidade. Apesar de a intensidade de exposição ser associada positivamente com uma maior acidentalidade, estabelecemos que a maior parte da dita associação está mediada pela maior implicância em circunstâncias de risco ao conduzir

    Plant-Mediated Synthesis of Silver Nanoparticles: Their Characteristic Properties and Therapeutic Applications

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    Notes for genera: basal clades of Fungi (including Aphelidiomycota, Basidiobolomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota)

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    Compared to the higher fungi (Dikarya), taxonomic and evolutionary studies on the basal clades of fungi are fewer in number. Thus, the generic boundaries and higher ranks in the basal clades of fungi are poorly known. Recent DNA based taxonomic studies have provided reliable and accurate information. It is therefore necessary to compile all available information since basal clades genera lack updated checklists or outlines. Recently, Tedersoo et al. (MycoKeys 13:1--20, 2016) accepted Aphelidiomycota and Rozellomycota in Fungal clade. Thus, we regard both these phyla as members in Kingdom Fungi. We accept 16 phyla in basal clades viz. Aphelidiomycota, Basidiobolomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota. Thus, 611 genera in 153 families, 43 orders and 18 classes are provided with details of classification, synonyms, life modes, distribution, recent literature and genomic data. Moreover, Catenariaceae Couch is proposed to be conserved, Cladochytriales Mozl.-Standr. is emended and the family Nephridiophagaceae is introduced

    Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

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    Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified
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