Selecting and characterizing bacterial consortia with the potential of fixing CO2 and removing H2S in a biogas atmosphere

Biogas must be pretreated before its use; thus, both physical and chemical methods have been implemented to remove the fuel's principal pollutants (CO 2and H2S). Additional removal methods that use microorganisms' biological processes to eliminate pollutants have also emerged. A selection was made from six bacterial isolates to obtain consortia that removed CO2and eventually H2S through the enrichment of cultures and the construction of clone libraries of gene 16S ribosomal DNA (rDNA). The results indicate that the principal differences between consortia were determined in the culture medium. C5 and C6 consortia had photosynthetic biomass 1.42 and 1.52 μg/ml, respectively, and concentration of dissolved CO2 100.6 and 99.1 mg/l, respectively. The clone libraries showed that Rhodopseudomonas sp. had percentages 46.6, 42.5, and 86.8 % in C4, C5, and C6, respectively; Xanthobacter sp., 24.5 %, Castellaniella sp., 18 % in C5, and Sphingobium sp., 39.2 % in C4. © Springer International Publ

Investigación basada en diseño para la mejora sostenida del aprendizaje auténtico

The current trends in higher education, as well as the new demands of the working environment call on university teachers to innovate their teaching in order to achieve better learning. Authentic evaluation through strategies such as Project Based Learning (PBL) has proven to be substantive in fostering collaborative work, autonomy and linkage with the professional world. However, many innovations focus on a momen-tary and unsustainable change in time. How, then, can we guarantee the continuous improvement of students’ learning based on an innovation in evaluative design? The course work, evaluation guidelines, the teacher’s field notes and the students’ perception throughout three versions of course implementation were considered. The results show, on the one hand, the relevance of the authentic evaluation design with PBL for the improvement of the student’s learning; on the other hand, the iterative design of the course from the collected evidence shows the importance of teaching reflection to adjust the educational aids to the context.Las actuales tendencias en educación superior, así como las nuevas demandas del medio laboral llaman al profesorado universitario a innovar su enseñanza para lograr mejores aprendizajes. La evaluación auténtica mediante estrategias como el Aprendizaje Basado en Proyectos (ABPy) ha demostrado ser sustantiva en fomentar el trabajo colaborativo, la autonomía y la vinculación con el mundo profesional. Sin embargo, muchas innovaciones se focalizan en un cambio momentáneo y poco sustentable en el tiempo. Entonces, ¿cómo garantizar la mejora continua de los aprendizajes de los estudiantes a partir de una innovación en el diseño evaluativo? Se consideraron los trabajos del curso, pautas de evaluación, notas de campo de la profesora y la percepción de los estudiantes a lo largo de tres versiones de implementación del curso. Los resultados muestran, por una parte, la pertinencia del diseño de evaluación auténtica con ABPy para la mejora de los aprendizajes del estudiantado; por otra, el diseño iterativo del curso a partir de la evidencia recopilada da cuenta de la importancia de la reflexión docente para ajustar las ayudas educativas al contexto.

Occupancy pattern of a long-horned beetle in a variegated forest landscape: linkages between tree quality and forest cover across spatial scales

© 2016, Springer Science+Business Media Dordrecht. Context: Interactions between landscape-scale processes and fine-grained habitat heterogeneity are usually invoked to explain species occupancy in fragmented landscapes. In variegated landscapes, however, organisms face continuous variation in micro-habitat features, which makes necessary to consider ecologically meaningful estimates of habitat quality at different spatial scales. Objectives: We evaluated the spatial scales at which forest cover and tree quality make the greatest contribution to the occupancy of the long-horned beetle Microplophorus magellanicus (Coleoptera: Cerambycidae) in a variegated forest landscape. Methods: We used averaged data of tree quality (as derived from remote sensing estimates of the decay stage of single trees) and spatially independent pheromone-baited traps to model the occurrence probability as a function of multiple cross-scale combinations between forest cover and tree quality (with scales rangin

Unraveling the cavity-nesting network at large spatial scales: The biogeographic role of woodpeckers as ecosystem engineers

<p><strong>Aim</strong>: Cavities are usually a limiting resource for several forest-dwelling vertebrates, with effects that propagate through ecological networks. Although diverse assemblages of primary excavators (e.g., woodpeckers) are assumed to increase cavities, other forest resources can also limit populations of primary excavators and cavity users, thus undermining the ecological role of excavators over different scales. We aim to test the biogeographical-scale relationships between primary excavators and cavity users by distinguishing the contribution of forest characteristics.</p> <p><strong>Location</strong>: Southern South America</p> <p><strong>Methods</strong>: We used species distribution models, which combine bioclimatic and remote sensing derived variables, to map the richness of vertebrates composing the cavity network of temperate and Mediterranean forests of South America. Based on a resampling procedure for ensuring spatial independence, we fitted structural equation models to estimate causal relationships between forest characteristics and cavity-user vertebrates.</p> <p><strong>Results</strong>: Secondary cavity users (obligated, habitat generalists and forest specialists) were positively and strongly influenced by the richness of primary excavators, while mammal richness was more influenced by tree richness. The richness of trees and <em>Nothofagus</em> tree species influenced positively the richness of primary excavators and secondary cavity users. Canopy height and net primary productivity affected positively secondary cavity users.</p> <p><strong>Main conclusions</strong>: Our results confirm the role of primary excavators as ecosystem engineers but highlight the importance of considering large spatial scales when analyzing cavity-nesting networks. Biogeographical patterns of tree diversity and forest structure can be important drivers of cavity-nesting networks that remain hidden when studies are conducted over fine spatial scales. </p><p>Funding provided by: University of Chile<br>Crossref Funder Registry ID: https://ror.org/047gc3g35<br>Award Number: 082375VE_Postdoc</p><p>* Methods of data collection/generation: see manuscript for details.</p&gt