River water is a small percentage of the total freshwater on Earth but represents an essential resource for mankind. Microbes in rivers perform essential ecosystem roles including the mineralization ...of significant quantities of organic matter originating from terrestrial habitats. The Amazon river in particular is famous for its size and importance in the mobilization of both water and carbon out of its enormous basin. Here we present the first metagenomic study on the microbiota of this river. It presents many features in common with the other freshwater metagenome available (Lake Gatun in Panama) and much less similarity with marine samples. Among the microbial taxa found, the cosmopolitan freshwater acI lineage of the actinobacteria was clearly dominant. Group I Crenarchaea and the freshwater sister group of the marine SAR11 clade, LD12, were found alongside more exclusive and well known freshwater taxa such as Polynucleobacter. A metabolism-centric analysis revealed a disproportionate representation of pathways involved in heterotrophic carbon processing, as compared to those found in marine samples. In particular, these river microbes appear to be specialized in taking up and mineralizing allochthonous carbon derived from plant material.
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The sugarcane weevil, Sphenophorus levis, is an important pest in sugarcane culture in São Paulo state, Brazil. To complete its life cycle, S. levis may depends on microorganisms that inhabit its intestinal tract and play an important key in the insect physiology and nutrition.
In this study we report the characterization of the intestinal microbiota from population of insect larvae from field and laboratory. Analysis of 16S rDNA sequences revealed a total of fourteen genera, one group from Candidatus category and two uncultivable groups represented by Alfa-Proteobacteria, Beta-Proteobacteria, Gamma-Proteobacteria, Firmicutes and Bacteroidetes phylum. Microorganisms isolated through culture-dependent methods were classified according morphological parameters and using 16S rDNA molecular marker. In addition to bacteria, four filamentous fungi were isolated. It was observed a slightly higher bacterial diversity in field than in laboratory according to Shannon index (Field H'= 3,36;
Laboratory H'= 3,26). It is also our objective in this work to search for microorganisms capable to degrade cellulose, an important event in the insect attack. From the cultivable
microorganisms, five genera of bacteria and two filamentous fungi presented cellulolytic activity. This is the first study about S. levis microbiota which may contribute to understand the interaction plant-pathogen and also be useful for future development of new strategies for
control of S. levis in sugarcane cultivation.
A cana-de-açúcar é uma das mais importantes culturas no Brasil. No entanto, muitas pragas atacam esta cultura causando prejuízos econômicos. O gorgulho da cana-deaçúcar,
Sphenophorus levis, é uma importante praga na cultura canavieira no Estado de São Paulo. Para completar o seu ciclo de vida, S. levis parece depender de microorganismos que
habitam o seu trato intestinal e desempenham um importante função na fisiologia e nutrição do inseto. Neste estudo, nós realizamos a caracterização da microbiota intestinal de população de larvas de inseto campo e de laboratório. As análises das seqüências de 16S rDNA revelaram um total de catorze gêneros, um grupo da categoria Candidatus e dois grupos nãocultiváveis representados pelos filos Alfa-Proteobacteria, Beta-Proteobacteria, Gamma- Proteobacteria, Firmicutes e Bacteroidetes tanto em larvas do campo quanto nas do laboratório. Os microrganismos isolados através dos métodos dependentes de cultura foram agrupados de acordo com parâmetros morfológicos e através do marcador moléculas 16S rDNA. Além das bactérias também foram isolados quatro fungos filamentosos. Observou-se uma diversidade bacteriana levemente superior no campo do que no laboratório de acordo com o índice de Shannon (Campo H '= 3,36; Laboratório H' = 3,26). É também nosso objetivo
neste trabalho encontrar microorganismos capazes de degradar celulose, um importante evento no ataque do inseto. Dos microorganismos cultiváveis, cinco gêneros de bactérias e
dois fungos filamentosos apresentaram atividade celulolítica. Este é o primeiro estudo sobre a microbiota do S. levis que pode contribuir para a compreensão da interação planta-patógeno e também ser útil para o futuro desenvolvimento de novas estratégias de controle de S. levis no cultivo da cana-de-açúcar.
Eurasian fall snow cover changes have been suggested as a driver for changes in the Arctic Oscillation and might provide a link between sea-ice decline in the Arctic during summer and atmospheric ...circulation in the following winter. However, the mechanism connecting snow cover in Eurasia to sea-ice decline in autumn is still under debate. Our analysis is based on snow observations from 820 Russian land stations, moisture transport using a Lagrangian approach derived from meteorological re-analyses. We show that declining sea-ice in the Barents and Kara Seas (BKS) acts as moisture source for the enhanced Western Siberian snow depth as a result of changed tropospheric moisture transport. Transient disturbances enter the continent from the BKS region related to anomalies in the planetary wave pattern and move southward along the Ural mountains where they merge into the extension of the Mediterranean storm track.
Patients failing antiretroviral treatment for extended periods of time are at risk of accumulating HIV drug resistance mutations (DRMs), which negatively influences second-line treatment. This ...retrospective study assessed the rate of DRM accumulation among South African patients with continued virological failure. Serial genotypic resistance testing was performed and DRMs were scored according to the 2009 IAS-USA list. Among 43 patients, 38 (88.4%) harbored ≥1 DRM. The median time between two sequential resistance tests was 5 months (IQR: 3-10). Thymidine analogue mutations accumulated at a rate of 0.07 mutation per month of drug exposure, which is faster than previously reported. Routine virological monitoring should be implemented in resource-limited settings to preserve susceptibility to second-line regimens.
Abstract Background Access to antiretroviral treatment in resource-limited-settings is inevitably paralleled by the emergence of HIV drug resistance. Monitoring treatment efficacy and HIV drugs ...resistance testing are therefore of increasing importance in resource-limited settings. Yet low-cost technologies and procedures suited to the particular context and constraints of such settings are still lacking. The ART-A (Affordable Resistance Testing for Africa) consortium brought together public and private partners to address this issue. Objectives To develop an automated sequence analysis and editing software to support high throughput automated sequencing. Study design The ART-A Software was designed to automatically process and edit ABI chromatograms or FASTA files from HIV-1 isolates. Results The ART-A Software performs the basecalling, assigns quality values, aligns query sequences against a set reference, infers a consensus sequence, identifies the HIV type and subtype, translates the nucleotide sequence to amino acids and reports insertions/deletions, premature stop codons, ambiguities and mixed calls. The results can be automatically exported to Excel to identify mutations. Automated analysis was compared to manual analysis using a panel of 1624 PR–RT sequences generated in 3 different laboratories. Discrepancies between manual and automated sequence analysis were 0.69% at the nucleotide level and 0.57% at the amino acid level (668,047 AA analyzed), and discordances at major resistance mutations were recorded in 62 cases (4.83% of differences, 0.04% of all AA) for PR and 171 (6.18% of differences, 0.03% of all AA) cases for RT. Conclusions The ART-A Software is a time-sparing tool for pre-analyzing HIV and viral quasispecies sequences in high throughput laboratories and highlighting positions requiring attention.
Reseñas iberoamericanas Fernando Rodríguez Mansilla; José Manuel López De Abiada; Jéromine François ...
Iberoamericana (Madrid, Spain),
07/2022, Letnik:
22, Številka:
80
Journal Article
Latin America: History and Criticism Albert Manke; Stefan Rinke; Josef Opatrný ...
Iberoamericana (Madrid, Spain),
07/2016, Letnik:
16, Številka:
62
Journal Article
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