1000 resultados para Enterobacter species
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This account concentrates on the six species of crayfish found in Austria, and the current state of knowledge on their distribution and laws affecting conservation. In general the occurrence and distribution of crayfish in Austria is poorly known, although information obtained by researchers and the general public, after careful checking, is increasing. Three native crayfish species occur in Austria: Austropotamobius torrentium which is relatively widespread, A. pallipes with a restricted distribution, and Astacus astacus which is widespread. Three species of non-native (alien) crayfish have been recorded from a total of 158 localities in Austria. They are Astacus leptodactylus from eastern Europe, and two Nearctic species: Pacifastacus leniusculus and Orconectes limosus. The introduction of alien species causes considerable problems as they act as vectors of crayfish plague and are able to outcompete native species by higher reproductive capacities.
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Ponds are unjustly neglected habitats. This paper aims to raise awareness of the potential interaction between angling and the macrophyte vegetation of ponds. The work described by the author followed on from a study of 57 ponds in East Yorkshire, northeast England, by Linton & Goulder (2000). They found that the species richness of aquatic vascular plants (macrophytes) is greater in ponds that are used for angling and suggest that to some extent there are more species because disturbance by anglers leads to greater habitat diversity. This article describes how the hypothesis was tested by comparing species richness at fished sites with that at non-fished sites around the margins of ponds in two localities in East Yorkshire. The localities were investigated during August-September 1999.
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Lough Erne in Northern Ireland has been the subject of much research over the last 30 years by, amongst others, the Department of Agriculture and Rural Development (DARD). In this article, the authors provide a summary of a workshop held on the 16–17th October 2003 in Enniskillen, on the shores of Lough Erne, which gave an opportunity to step back and take a holistic look at the Erne lakes. Ecological change has been driven by many factors, including land use changes and species invasions. The workshop consisted of five sessions which are summarised in this article: Session 1 – Invasive species, nutrients, phytoplankton and macrophytes; Session 2 – Zooplankton, benthic macroinvertebrates and fish; Session 3 – An ecosystem approach – relating the previous sessions; Session 4 – How does Lough Erne fit into lake classifications? Implications of the Water Framework Directive; Session 5 – Using new techniques to examine food webs and species invasions. Identifying a future research programme for Lough Erne.
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Widespread pollution by heavy metals generated by various industries has serious adverse effects on human health and the environment. Cadmium is a heavy metal recognised as one of the most hazardous environmental pollutants. It is a non-essential and non-beneficial element to organisms, causing toxicity and other deleterious effects on various components of the aquatic environment. The ability of algal periphyton to concentrate cadmium from fresh water is well known. Moreover, periphyton communities are able to accumulate large amounts of cadmium despite its low concentration in fresh water. Many researchers use algal periphyton as an indicator of water quality in aquatic environments. In the present study, the authors ask two basic questions: Does cadmium accumulate along a food chain consisting of the periphyton community and a grazer species (Physa sp.) under semi-natural conditions provided by artificial streams? If not, which one can better indicate the water quality?
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This translation includes selected passages of a longer paper on Mastigophora and Rhizopoda found in saline lakes Weissovo and Repnoie. The translation focuses on describing taxonomy and morphology of Ochromonas species and Pedinella. Plates and figures of the original paper are not included in the translation.
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Eudiaptomus vulgaris Schmeil is the most abundant copepod in Lake Maggiore and forms also, in respect to other entomostraca, the most important element, through its average biomass and because it is fairly numerous throughout the year. Plankton samples collected in a systematic and quantitative way, gave the opportunity to study some aspects of the dynamics of the population of this copepod, in safety in view of the uncertainty which in this kind of study can ensue when samples are taken only at a single station - in consequence of the changes in size of population between different water masses. The results of the biometrical observations are of the population of Eudiaptomus vulgaris is presented.
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In the waterbodies of central Russia, the Urals and western Siberia four species of Crustacea, related to the genus Mesocyclops, are widely distributed: M. (s.str.) leuckarti (Claus), M. (Thermocyclops) oithonoides Sars, [M.](Th.) crassus (Fisch.) and M. (Th.) dybowskii (Lande). Numbers and biomass of Mesocyclops oithonoides in the pelagic water of various water-bodies of the Urals are presented and observations on the above mentioned species are discussed.
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This thesis describes applications of cavity enhanced spectroscopy towards applications of remote sensing, chemical kinetics and detection of transient radical molecular species. Both direct absorption spectroscopy and cavity ring-down spectroscopy are used in this work. Frequency-stabilized cavity ring-down spectroscopy (FS-CRDS) was utilized for measurements of spectral lineshapes of O2 and CO2 for obtaining laboratory reference data in support of NASA’s OCO-2 mission. FS-CRDS is highly sensitive (> 10 km absorption path length) and precise (> 10000:1 SNR), making it ideal to study subtle non-Voigt lineshape effects. In addition, these advantages of FS-CRDS were further extended for measuring kinetic isotope effects: A dual-wavelength variation of FS-CRDS was used for measuring precise D/H and 13C/12C methane isotope ratios (sigma>0.026%) for the purpose of measuring the temperature dependent kinetic isotope effects of methane oxidation with O(1D) and OH radicals. Finally, direct absorption spectroscopic detection of the trans-DOCO radical via a frequency combs spectrometer was conducted in collaboration with professor Jun Ye at JILA/University of Colorado.
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Identification keys to families of Cladocera and to subfamilies, genera, species and subspecies of Macrothricidae and Moinidae are given. This translation does not include ecological notes or illustrations.
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This document is a partial translation of taxonomic notes on two Diptera species (Acalcarella Shilova, Acalcarrella nucus) which were abundant in a survey of Tendipedid species (Diptera, Tendipedidae) of the Amu Darya drainage basin. These taxonomic notes of the larva, pupa and adults include drawings of the Acalcarella nucus larva.
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Taxonomic observations are given on Dangeardia sporapiculata n. sp. Furthermore the term 'apiculus' and the species limitation of some chytrids are being discussed. It is concluded that the newly described species Dangeardia sporapiculata does not fit satisfactorily into the present system of phlyctidiacee, because their characteristics do not agree exactly with any genus.
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Recent surveys have indicated an increase in haplochromine biomass recorded from the bottom trawl and in the beam trawl. The haplochromines recovering in the offshore waters belong to three species in the zooplanktivorous trophic group: Yssichromis laparogramma (Greenwood and Gee), Yssichromis fusiformis (Greenwood and Gee) and Astatotilapia lacrimosa (Boulenger). In this paper, the species composition and relative abundance of the zooplanktivorous haplochromines recorded from the bottom and frame trawl surveys in the various parts of the Ugandan waters of Lake Victoria are discussed.
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In a tagging experiment carried out in the Kenyan waters of Lake Victoria, an annual growth increment of 29 cm yr was obtained for Lates niloticus (L.). Growth parameters obtained using the von Bertalanffy model on the growth curve fitted by eye were L (inf.) = 122 cm yr and k = 0.26 yr. Data for other species tagged were inadequate to obtain meaningful results.
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Albacore and Atlantic Bluefin tuna are two pelagic fish. Atlantic Bluefin tuna is included in the IUCN red list of threatened species and albacore is considered to be near threatened, so conservation plans are needed. However, no genomic resources are available for any of them. In this study, to better understand their transcriptome we functionally annotated orthologous genes. In all, 159 SNPs distributed in 120 contigs of the muscle transcriptome were analyzed. Genes were predicted for 98 contigs (81.2%) using the bioinformatics tool BLAST. In addition, another bioinformatics tool, BLAST2GO was used in order to achieve GO terms for the genes, in which 41 sequences were given a biological process, and 39 sequences were given a molecular process. The most repeated biological process was metabolism and it is important that no cellular process was given in any of the sequences. The most abundant molecular process was binding and very few catalytic activity processes were given. From the initial 159 SNPs, 40 were aligned with a sequence in the database after BLAST2GO was run, and were polymorphic in Atlantic Bluefin tuna and monomorphic in albacore. From these 40 SNPs, 24 were located in an open reading frame of which four were non-synonymous and 20 were synonymous and 16 were not located in a known open reading frame,. This study provides information for better understanding the ecology and evolution of these species and this is important in order to establish a proper conservation plan and an appropriate management.
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Em estudo anterior, as espécies de enterobactérias apresentando perfis variados de resistência aos antimicrobianos foram detectadas em 20% dos sítios com lesões periodontais de pacientes sadios do ponto de vista sistêmico. Tais cepas microbianas foram submetidas a investigações com o intuito de determinar à expressão de enzimas hidrolíticas para substratos diversos, a multirresistência aos agentes antimicrobianos e os mecanismos de resistência aos antimicrobianos da classe dos β lactâmicos. A maioria das amostras expressou atividade de gelatinase (65%), caseinase (30%) e elastase (10%). Lipase, lecitinase e DNase foram observadas apenas para Serratia marcescens. A multirresistência (considerado como a resistência a pelo menos dois agentes antimicrobianos de famílias diferentes) foi observada em 56% das amostras isoladas. A maioria das cepas foi resistentes à ampicilina (93,75%) e amoxicilina/ácido clavulânico (81,25%). Investigações sobre a resistência aos antibióticos β-lactâmicos mostraram que três amostras resistentes à cefalosporinas de 2 geração, apresentaram perfis plasmidiais de diferentes pesos moleculares. A expressão fenotípica de β-lacatamases, foi detectada nas cepas de Enterobacter cloacae (PcOM46 e PcOM5) e S. marcescens (PcOM63). No entanto, na análise molecular, não foi possível confirmar a expressão fenotípica de diferentes β-lactamases, com exceção do E. cloacae PcOM46, que apresentou amplificação para AmpC e blaTEM. Embora sensível à maioria dos antibióticos β-lactâmicos (exceção feita à ampicilina e amoxicilina / ácido clavulânico), amostra de S. marcescens PcOM68 apresentou amplificação para o gene blaSHV. Os experimentos de conjugação não detectaram a transferência de plasmídios para uma cepa de Escherichia coli K12 sensívei aos β-lactâmicos, o mesmo ocorreu nos procedimentos de transformação por eletroporação e por CaCl2, sugerindo uma resistência dependente de genes cromossomiais. A expressão de diferentes atividades enzimáticas, juntamente com a resistência aos antimicrobianos, aponta estes grupos de bactérias como agentes patogênicos potenciais capazes de contribuir para a patogênese e resposta à quimioterapia antimicrobiana nas doenças periodontais, além da disseminação sistêmica para outros locais do corpo, especialmente em indivíduos imunocomprometidos. A colonização prévia de lesões periodontais por espécies resistentes aos β-lactâmicos, pode contribuir para a disseminação destes genes relacionados à resistência aos antimicrobianos em ambientes hospitalares.