Anaerobic biofilm enriched with an ammonia tolerant methanogenic consortium to improve wastewater treatment in the fishing industry.

The digestion efficiency of liquid industrial wastes increases when using bioreactors colonized by microbial biofilms. High concentrations of proteins derived from the fish processing industry lead to the production of ammonia, which inhibits methane production. Two bioreactors were constructed to compare methanogenic activity: one enriched with mMPA (methylaminotrofic methane production archaea) consortia (control bioreactor), and the second with NH3 tolerant consortia (treatment bioreactor). Ammonia tolerant activity was assessed by applying an ammonia shock (755 mg NH3/L). Methane production, consumption of total organic carbon (TOC) and the taxonomic composition of bacteria and archaea was evaluated using 16S rDNA in the acclimatization, ammonia shock, and recovery phases.The ammonia shock significantly affected both methane production and the consumption of TOC in the control reactor (p < 0.05) and taxonomical composition of the microbial consortia (OTU). These values remained constant in the treatment reactor. The analysis of biofilm composition showed a predominance of Methanosarcinaceae (Methanomethylovorans sp., and probably two different species of Methanosarcina sp.) in bioreactors. These results demonstrate that using acclimated biofilms enriched with ammonia tolerant methanogens control the inhibitory effect of ammonia on methanogenesis.

Assessing signals of selection and historical demography to develop conservation strategies in the Chilean emblematic Araucaria araucana.

Loss of genetic diversity reduces the ability of species to evolve and respond to environmental change. Araucaria araucana is an emblematic conifer species from southern South America, with important ethnic value for the Mapuche people (Pehuenche); the Chilean Government has catalogued its conservation status as vulnerable. Climatic fluctuations were potentially a major impact in the genetic variation within many tree species. In this context, the restricted geographic distribution of A. araucana in Chile appears to be a consequence of the Last Glacial Maximum (LGM). During the past two centuries, strong human intervention has also affected the geographical distribution and population sizes of A. araucana. Reduction of population size may cause loss of genetic diversity, which could affect frequency of adaptive loci. The aims of this study were to know the existence of potential loci under selection and populations with genetic, demographic disequilibrium in the Chilean distribution of A. araucana. Based on 268 polymorphic AFLP loci, we have investigated potential loci under selection and genetic, demographic disequilibrium within seven Chilean populations of Araucaria araucana. Correlation of 41 outlier loci with the environmental variables of precipitation and temperature reveals signatures of selection, whereas 227 neutral loci provide estimates of demographic equilibrium and genetic population structure. Three populations are recommended as priorities for conservation.

Perfiles de estilos de aprendizaje y rendimiento académico en estudiantes de primer año de enfermería / Learning style profiles and academic improvement in the first year of nursing

Objetivo: Identificar los perfiles de estilos de aprendizaje y relacionarlos con el rendimiento académico en dos asignaturas de primer año de Enfermería. Método: Se aplicó el Cuestionario de Honey-Alonso de Estilos de Aprendizaje (CHAEA) disponible a los estudiantes en una planilla electrónica que respondieron y enviaron por correo electrónico 193 estudiantes, quienes respondieron de acuerdo a normas éticas establecidas. Los análisis comparativos, puntajes de los estilos de aprendizaje y las calificaciones de las evaluaciones parciales de cada asignatura, se realizaron usando el programa estadístico Infostat. Se analizaron dos cohortes sucesivas (20092010). Resultados: La mayor parte de los estudiantes presentan 3 o más estilos de aprendizaje con puntaje superior o igual a moderado, con evaluaciones parciales con notas igual o superior al promedio de cada año. Conclusión: Se sugiere que con el fin de obtener un mejor rendimiento, los docentes conozcan los estilos de aprendizaje de los estudiantes y diseñen herramientas pedagógicas para fomentar estilo de aprendizaje y que los estudiantes tomen conciencia de su propio estilo.

Objective: To identify nursing students' learning styles profiles and statistically relate them to their academic performance in two courses in the first year of Nursing. Method: Honey-Alonso Learning Styles Questionnaire (CHAEA) was applied. It was available to 193 students who responded it on an electronic spreadsheet and sent it via e-mail, according to established ethic rules. Comparative analyses, scores of learning styles and grades of evaluations of each course were carried out using the Infostat program. Two successive cohorts (2009-2010) were analysed. Results: Most of the students present 3 or more learning styles with moderate to higher than moderate scores, who showed test results with grades that were average or higher each year. Conclusion: It is suggested that in order to get better academic performance, teachers must know the students' learning styles and design pedagogical tools to promote the different learning styles so students can become aware of their own style.

Hsp70 localizes differently from chaperone Hsc70 in mouse mesoangioblasts under physiological growth conditions.

Mouse A6 mesoangioblasts express Hsp70 even in the absence of cellular stress. Its expression and its intracellular localization were investigated under normal growth conditions and under hyperthermic stress. Immunofluorescence assays indicated that without any stress a fraction of Hsp70 co-localized with actin microfilaments, in the cell cortex and in the contractile ring of dividing cells, while the Hsc70 chaperone did not. Hsp70 immunoprecipitation assays confirmed that a portion of Hsp70 binds actin. Immunoblot assays showed that both proteins were present in the nucleus. After heat treatment Hsp70 and actin continued to co-localize in the leading edge of A6 cells but not on microfilaments. Although Hsp70 and Hsc70 are both basally synthesized they showed different cellular distribution, suggesting an Hsp70 different activity respect to the Hsc70 chaperone. Moreover, we found Hsp70 in the culture medium as it has been described in other cell types.

Genetic diversity in Nothofagus alessandrii (Fagaceae), an endangered endemic tree species of the coastal maulino forest of Central Chile.

BACKGROUND AND AIMS: The endemic tree Nothofagus alessandrii (Fagaceae) has been historically restricted to the coastal range of Region VII of central Chile, and its forests have been increasingly destroyed and fragmented since the end of the 19th century. In this study, the patterns of within- and among-population genetic diversity in seven fragments of this endangered narrowly endemic tree were examined. METHODS: Allozyme electrophoresis of seven loci of N. alessandrii was used to estimate genetic diversity, genetic structure and gene flow. KEY RESULTS: High levels of genetic diversity were found as shown by mean expected heterozygosity (H(e) = 0.182 +/- 0.034), percentage of polymorphic loci (P(p) = 61.2 %), mean number of alleles per locus (A = 1.8) and mean number of alleles per polymorphic locus (A(p) = 2.3). Genetic differentiation was also high (G(ST) = 0.257 and Nm = 0.7). These values are high compared with more widespread congeneric species. CONCLUSIONS: Despite its endemic status and restricted geographical range N. alessandrii showed high levels of genetic diversity. The observed patterns of diversity are explained in part by historical processes and more recent human fragmentation.

Electronic evaluation for freshmen nursing students: Advantages and disadvantages.

An electronic evaluation was applied to freshmen nursing students who are taking Biology and Nursing Introduction. Questions and alternatives were randomly ordered. Evaluation took place simultaneously for all the students. Students preferred multiple choice questions with no more than two lines of headings and requested about three minutes for test timing. Test scores from electronic evaluation were higher than the ones obtained with written evaluation. This result implies that information technology can be used for evaluating large group of students.