Molecular methods allow an extremely fine strain typing that can be used to establish the population structure of bacterial species. This methodology has been used to characterize a collection of 74 ...uropathogenic
Escherichia coli obtained from three hospitals located in geographically distant towns in Spain, some representatives of the ECOR collection and other reference strains. Genomic DNA was analyzed by RAPD (Random Amplified Polymorphic DNA) that can characterize a bacterial strain to the level of defining individual clones. The 16S rDNA-23S rDNA spacers were amplified by PCR and submitted to restriction analysis. Finally, the presence or absence of G adhesins in
Escherichia coli as well as the type of adhesin (three types are known) have been shown by PCR amplification followed by digestion with restriction enzymes. As expected a wide diversity was shown by RAPD and identical patterns were only found in the case of strains isolated from the same individual, an obvious case of relapse. Analysis of the spacers' restriction patterns showed the presence of two markedly differentiated clusters that we have named α and ß. Both RAPD and spacer restriction patterns originated similar clusters of strains showing a consistency in the evolution of the global genome with the sequence variation of the ribosomal spacers. Furthermore, most of the strains having G-adhesin, with only a few exceptions, corresponded to the α rRNA spacer group. The two spacer types detected were also consistent with some phenotypic markers such as sucrose and raffinose utilization. The α and β clusters could be intraspecific groups produced by partial sexual isolation or other barriers that are originating a divergent evolution.
BackgroundSurface waters of aquatic environments have been shown to both evolve and consume hydrogen and the ocean is estimated to be the principal natural source. In some marine habitats, H2 ...evolution and uptake are clearly due to biological activity, while contributions of abiotic sources must be considered in others. Until now the only known biological process involved in H2 metabolism in marine environments is nitrogen fixation.Principal FindingsWe analyzed marine and freshwater environments for the presence and distribution of genes of all known hydrogenases, the enzymes involved in biological hydrogen turnover. The total genomes and the available marine metagenome datasets were searched for hydrogenase sequences. Furthermore, we isolated DNA from samples from the North Atlantic, Mediterranean Sea, North Sea, Baltic Sea, and two fresh water lakes and amplified and sequenced part of the gene encoding the bidirectional NAD(P)-linked hydrogenase. In 21% of all marine heterotrophic bacterial genomes from surface waters, one or several hydrogenase genes were found, with the membrane-bound H2 uptake hydrogenase being the most widespread. A clear bias of hydrogenases to environments with terrestrial influence was found. This is exemplified by the cyanobacterial bidirectional NAD(P)-linked hydrogenase that was found in freshwater and coastal areas but not in the open ocean.SignificanceThis study shows that hydrogenases are surprisingly abundant in marine environments. Due to its ecological distribution the primary function of the bidirectional NAD(P)-linked hydrogenase seems to be fermentative hydrogen evolution. Moreover, our data suggests that marine surface waters could be an interesting source of oxygen-resistant uptake hydrogenases. The respective genes occur in coastal as well as open ocean habitats and we presume that they are used as additional energy scavenging devices in otherwise nutrient limited environments. The membrane-bound H2-evolving hydrogenases might be useful as marker for bacteria living inside of marine snow particles.
Abstract Background Saturated brines are extreme environments of low diversity. Salinibacter ruber is the only bacterium that inhabits this environment in significant numbers. In order to establish ...the extent of genetic diversity in natural populations of this microbe, the genomic sequence of reference strain DSM 13855 was compared to metagenomic fragments recovered from climax saltern crystallizers and obtained with 454 sequencing technology. This kind of analysis reveals the presence of metagenomic islands, i.e. highly variable regions among the different lineages in the population. Results Three regions of the sequenced isolate were scarcely represented in the metagenome thus appearing to vary among co-occurring S. ruber cells. These metagenomic islands showed evidence of extensive genomic corruption with atypically low GC content, low coding density, high numbers of pseudogenes and short hypothetical proteins. A detailed analysis of island gene content showed that the genes in metagenomic island 1 code for cell surface polysaccharides. The strain-specific genes of metagenomic island 2 were found to be involved in biosynthesis of cell wall polysaccharide components. Finally, metagenomic island 3 was rich in DNA related enzymes. Conclusion The genomic organisation of S. ruber variable genomic regions showed a number of convergences with genomic islands of marine microbes studied, being largely involved in variable cell surface traits. This variation at the level of cell envelopes in an environment devoid of grazing pressure probably reflects a global strategy of bacteria to escape phage predation.
Abstract Background The cataloging of marine prokaryotic DNA sequences is a fundamental aspect for bioprospecting and also for the development of evolutionary and speciation models. However, large ...amount of DNA sequences used to quantify prokaryotic biodiversity requires proper tools for storing, managing and analyzing these data for research purposes. Description The Micro-Mar database has been created to collect DNA diversity information from marine prokaryotes for biogeographical and ecological analyses. The database currently includes 11874 sequences corresponding to high resolution taxonomic genes (16S rRNA, ITS and 23S rRNA) and many other genes including CDS of marine prokaryotes together with available biogeographical and ecological information. Conclusion The database aims to integrate molecular data and taxonomic affiliation with biogeographical and ecological features that will allow to have a dynamic representation of the marine microbial diversity embedded in a user friendly web interface. It is available online at http://egg.umh.es/micromar/.
Introduction
Aesthetic medicine is characterized by the efficacy and safety of treatments. Although sometimes adverse events could be occurred, in this case vascular occlusion is the most serious of ...them. The tissue is deprived of oxygen and there is a possibility of necrosis, so it is necessary to remove the tissue filler and promote oxygenation.
Objective
We propose the hyperbaric oxygenation treatment to oxygenate the tissue after vascular occlusion generated by a tissue filler such as Hyaluronic Acid.
Results
We show how hyperbaric oxygenation treatment is an adjuvant therapy after vascular occlusion, improving tissue regeneration and prevent or limit scars or sequelae.
Conclusion
Hyperbaric oxygenation treatment is a safe and effective method to treat vascular accident, improving tissue oxygenation in early cases and improving tissue regeneration in cases with necrosis.
Globally, current food consumption and trade are placing unprecedented demand on agricultural systems and increasing pressure on natural resources, requiring tradeoffs between food security and ...environmental impacts especially given the tension between market-driven agriculture and agro-ecological goals. In order to illustrate the wicked social, economic and environmental challenges and processes to find transformative solutions, we focus on the largest concentration of greenhouses in the world located in the semi-arid coastal plain of South-east Spain. Almería family farming, predominantly cooperative, greenhouse intensive production, commenced after the 1960s and has resulted in very significant social and economic benefits for the region, while also having important negative environmental and biodiversity impacts, as well as creating new social challenges. The system currently finds itself in a crisis of diminishing economic benefits and increasing environmental and social dilemmas. Here, we present the outcomes of multi-actor, transdisciplinary research to review and provide collective insights for solutions-oriented research on the sustainability of Almeria's agricultural sector. The multi-actor, transdisciplinary process implemented collectively, and supported by scientific literature, identified six fundamental challenges to transitioning to an agricultural model that aims to ameliorate risks and avoid a systemic collapse, whilst balancing a concern for profitability with sustainability: (1) Governance based on a culture of shared responsibility for sustainability, (2) Sustainable and efficient use of water, (3) Biodiversity conservation, (4) Implementing a circular economy plan, (5) Technology and knowledge transfer, and (6) Image and identity. We conclude that the multi-actor transdisciplinary approach successfully facilitated the creation of a culture of shared responsibility among public, private, academic, and civil society actors. Notwithstanding plural values, challenges and solutions identified by consensus point to a nascent acknowledgement of the strategic necessity to locate agricultural economic activity within social and environmental spheres.This paper demonstrates the need to establish transdisciplinary multi-actor work-schemes to continue collaboration and research for the transition to an agro-ecological model as a means to remain competitive and to create value.
Building a pervasive social gaming experience using SocialPG Valera‐Aranguren, Ramón; Rodriguez, Patricia Paderewski; Vela, Francisco Luis Gutierrez ...
Expert systems,
June 2023, 2023-06-00, 20230601, Letnik:
40, Številka:
5
Journal Article
Recenzirano
Pervasive computing has become a key element to build applications that use fun as a motivating component because it allows exploring new interaction schemes by making the concept of space and time ...ambiguous and confusing. The present research describes a pervasive social gaming experience, using as a reference SocialPG, which is a model that describes social expansion as a strategy to improve gaming experiences supported by pervasive computing. In this article a description of the model is offered, software architecture is proposed to support it and a case study related to the process of error resolution and detection of improvement opportunities in software products is developed, finally, a general idea about the final software product that will support the game experience is offered together with an evaluation performed by a set of users, where some important findings are highlighted, such as the importance of the missions as a unit of cooperative work and the spectator's participation.
COVID-19 has affected education worldwide, in Mexico. In this study, the impact of the extraordinary online modality because of the pandemic on the accreditation of courses for engineering students ...was evaluated, of the 64 students officially registered in three courses of microbiology, only 90% registered on the Moodle platform to take the online course, 71% of the dynamics were delivered, 67% of the final project and 80% of the delivery of the team's activities were not reached, there was an approval of 54%. Some problems were that videoconferences were not attended and assignments were not turned in.
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