685 research outputs found

    Gorceixia decurrens (Compositae: Vernonieae): nova espécie para o estado da Bahia, Brasil

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    Recent fieldwork and collections have added a new genus to the Compositae flora of Bahia State, Brazil. Gorceixia decurrens is newly recorded for the State from Caatinga woodland along the lower part of the Estrada Real, in the municipality of Rio de Contas. A full description is provided, its distribution and conservation status discussed; likely affinities in the Vernonieae are discussed with the conclusion that it belongs to the subtribe Piptocarphinae.Trabalhos de campo e coletas recentes na Bahia, Brasil, permitiram adicionar mais um gênero para a flora do Estado. Gorceixia decurrens foi coletada em 2001, em área de Caatinga Arbórea, na base da Estrada Real no município a Rio de Contas. É fornecida uma completa descrição da espécie e discussão sobre sua distribuição e estado de conservação. Também, é apresentada discussão do posicionamento do gênero monotípico nas Vernonieae concluindo-se que o mesmo pertence à subtribo Piptocarphinae

    Population genetic structure of the parasite Anisakis simplex (s. s.) collected in Clupea harengus L. from North East Atlantic fishing grounds

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    The Atlantic herring is a schooling, pelagic species that inhabits both sides of the North Atlantic Ocean. Herring stock identification is usually based on several approaches, including fish meristic characters, population genetic analysis and the use of parasite species composition. A total of 654 Anisakis spp. larvae collected from herring of four fishing grounds in the Norwegian Sea, Baltic Sea, North Sea, and the English Channel off the French coast, was identified to species level using diagnostic allozymes and sequence analysis of EF1 α−1 nDNA and the mtDNA cox2 genes. Population genetic differentiation of Anisakis simplex (s. s.) among the different fishing areas was estimated, at the intraspecific level, on the basis of mtDNA cox2 sequences analysis. Spatial comparison based on molecular variance analysis and Fst values was performed for the collected specimens (among regions). Haplotype network construction showed relevant differences in haplotype frequencies between samples of A. simplex (s. s.) from the different geographical areas. Results indicate a genetic sub-structuring of A. simplex (s. s.) obtained from herring in different areas, with the population from the Norwegian Sea being the most differentiated one, and with North Sea and Baltic Sea populations being most similar. The population genetic structure of A. simplex (s. s.) was in accordance with the herring population genetic structure throughout the host’s geographical range in the NE Atlantic. Results suggest that mtDNA cox2 is a suitable genetic marker for A. simplex (s. s.) population genetic structure analysis and a valuable tool to elucidate the herring stock structure in the NE Atlantic Ocean

    Explicaciones en argumentación rebatible

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    En la literatura es usual encontrar acuerdo, en que un sistema experto o de recomendación debe responder con un nivel comparable a los humanos expertos, pero también debe tener la capacidad de explicar, en una forma entendible por el usuario, el proceso de razonamiento que empleó para resolver el problema y generar una recomendación. En general, cuando un usuario es responsable por la toma de decisiones, normalmente tiende a descartar una recomendación que no entiende completamente. Por ejemplo, aunque una recomendación efectuada por el sistema sea técnicamente correcta, la pérdida de confianza en ella puede deberse simplemente a que esté basada en alternativas que el usuario no había previsto. El objetivo principal de esta línea de investigación es intentar avanzar sobre el desarrollo de explicaciones que resulten aceptables para el usuario que recibe una recomendación de un sistema.Eje: Agentes y Sistemas InteligentesRed de Universidades con Carreras en Informática (RedUNCI

    Long-term investigation of the ‘soft flesh’ condition in Northeast Atlantic mackerel induced by the myxosporean parasite Kudoa thyrsites (Cnidaria, Myxozoa). Temporal trends and new molecular epidemiological observations

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    Northeast Atlantic (NEA) mackerel (Scomber scombrus, Scombridae) represents an economically important target for the Norwegian pelagic fishing industry. Despite the commercial significance of NEA mackerel, little is known about the infections with the myxosporean parasite Kudoa thyrsites (Kudoidae). The parasite may cause post-mortem myoliquefaction of the fish skeletal muscle and therefore reduce the quality of the fish product. In this study, we examined 'soft flesh' occurrence in commercial size groups of NEA 'autumn mackerel' caught between 2007 and 2020, and investigated the prevalence and density of K. thyrsites (qPCR) and how they related to the occurrence of 'soft flesh'. The present study is the first long-term investigation of the occurrence of K. thyrsites-induced 'soft flesh' in NEA mackerel. After appearing stable for over a decade, the 'soft flesh' occurrence increased three-to six-fold in 2019 and 2020. This increase, together with the findings that 'soft flesh' seems primarily to affect the commercially most valuable mackerel size group (>400 g), may have important implications for the fishing industry and the fishery management. Molecular analysis (qPCR) suggests that the prevalence of K. thyrsites is substantially higher than 'soft flesh' occurrence. The majority (87.4%, n = 76/87) of infected mackerel did not develop 'soft flesh' and only individuals with high parasite density in the musculature (12.6%, n = 11/87) showed the condition. Therefore, qPCR analyses should be used for estimating the prevalence of K. thyrsites in fish. The method may also be used to assess the risk of NEA mackerel to develop post-mortem 'soft flesh'

    Generation of ultra-short light pulses by a rapidly ionizing thin foil

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    A thin and dense plasma layer is created when a sufficiently strong laser pulse impinges on a solid target. The nonlinearity introduced by the time-dependent electron density leads to the generation of harmonics. The pulse duration of the harmonic radiation is related to the risetime of the electron density and thus can be affected by the shape of the incident pulse and its peak field strength. Results are presented from numerical particle-in-cell-simulations of an intense laser pulse interacting with a thin foil target. An analytical model which shows how the harmonics are created is introduced. The proposed scheme might be a promising way towards the generation of attosecond pulses. PACS number(s): 52.40.Nk, 52.50.Jm, 52.65.RrComment: Second Revised Version, 13 pages (REVTeX), 3 figures in ps-format, submitted for publication to Physical Review E, WWW: http://www.physik.tu-darmstadt.de/tqe

    On generation-integrated energy storage

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    Generation-integrated energy storage (GIES) systems store energy at some point along the transformation between the primary energy form and electricity. Instances exist already in natural hydro power, biomass generation, wave power, and concentrated solar power. GIES systems have been proposed for wind, nuclear power and they arise naturally in photocatalysis systems that are in development. GIES systems can compare very favourably in both performance and total cost against equivalent non-integrated systems comprising both generation and storage. Despite this, they have not hitherto been recognised as a discrete class of systems. Consequently policy decisions affecting development or demonstration projects and policy approaches concerning low-carbon generation are not fully informed. This paper highlights that policy structures exist militating against the development and introduction of GIES systems-probably to the detriment of overall system good

    Optimization of the precipitation of clavulanic acid from fermented broth using t-octylamine as intermediate

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    This work describes the use of clavulanic acid (CA) precipitation as the final step in the process of purification of CA from fermentation broth as an alternative to conventional methods employed traditionally. The purpose of this study was to use a stable intermediate (t-octylamine) between the conversion of CA to its salt form (potassium clavulanate), thereby enabling the resulting intermediate (amine salt of clavulanic acid) to improve the purification process and maintain the stability of the resulting potassium clavulanate. To this end, response surface methodology was employed to optimize the precipitation step. For the first reaction, five temperatures (6.6 to 23.4 ºC), concentrations of clavulanic acid in organic solvent (6.6 to 23.4 mg/mL) and t-octylamine inflow rates (0.33 to 1.17 drop/min) were selected based on a central composite rotatable design (CCRD). For the second reaction, five temperatures (11.6 to 28.4 ºC), concentrations of clavulanic acid amine salt in organic solvent (8.2 to 41.8 mg/mL) and concentrations of potassium 2-ethylhexanoate (0.2 to 1.2 molar) were also selected using CCRD. From these results, precipitation conditions were selected and applied to the purification of CA from the fermentation broth, obtaining a yield of 72.37%.23124
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