Current production by non-methanotrophic bacteria enriched from an anaerobic methane-oxidizing microbial community.

In recent years, the externalization of electrons as part of respiratory metabolic processes has been discovered in many different bacteria and some archaea. Microbial extracellular electron transfer (EET) plays an important role in many anoxic natural or engineered ecosystems. In this study, an anaerobic methane-converting microbial community was investigated with regard to its potential to perform EET. At this point, it is not well-known if or how EET confers a competitive advantage to certain species in methane-converting communities. EET was investigated in a two-chamber electrochemical system, sparged with methane and with an applied potential of +400 mV versus standard hydrogen electrode. A biofilm developed on the working electrode and stable low-density current was produced, confirming that EET indeed did occur. The appearance and presence of redox centers at -140 to -160 mV and at -230 mV in the biofilm was confirmed by cyclic voltammetry scans. Metagenomic analysis and fluorescence in situ hybridization of the biofilm showed that the anaerobic methanotroph 'Candidatus Methanoperedens BLZ2' was a significant member of the biofilm community, but its relative abundance did not increase compared to the inoculum. On the contrary, the relative abundance of other members of the microbial community significantly increased (up to 720-fold, 7.2% of mapped reads), placing these microorganisms among the dominant species in the bioanode community. This group included Zoogloea sp., Dechloromonas sp., two members of the Bacteroidetes phylum, and the spirochete Leptonema sp. Genes encoding proteins putatively involved in EET were identified in Zoogloea sp., Dechloromonas sp. and one member of the Bacteroidetes phylum. We suggest that instead of methane, alternative carbon sources such as acetate were the substrate for EET. Hence, EET in a methane-driven chemolithoautotrophic microbial community seems a complex process in which interactions within the microbial community are driving extracellular electron transfer to the electrode.

Estudio de validez del mini-examen cognoscitivo de lobo et al para la detección del deterioro cognitivo asociado a demencias / The Mini-Examination Cognitive of Lobo et al to detect mental deterioration associated with dementia: a validative study

Fundamento y objetivos: El Mini-Examen Cognoscitivo (MEC) de Lobo et al constituye uno de los procedimientos de cribado neuropsicológico más utilizados en nuestro país para la evaluación rápida en los casos en los que se sospecha la presencia de deterioro cognitivo debido a demencia. No obstante, todavía no se han realizado los pertinentes análisis de validez en población anciana. Por ello, el objetivo de esta investigación ha sido validar el uso de este instrumento para detectar el deterioro asociado a demencias en personas mayores. Material y métodos: Han participado 95 ancianos, un grupo de ellos pacientes de una consulta de neurología y otro grupo de ancianos sanos, residentes en un Centro del IASS, que han sido evaluados mediante un protocolo de exploración neuropsicológica y el MEC. Resultados: Los resultados demuestran una alta validez de esta prueba para la evaluación del deterioro cognitivo en esta población, tanto por las altas correlaciones con la batería de evaluación neuropsicológica utilizada como en los ANOVA integrupos (con y sin deterioro) utilizados; también reflejan la influencia en las puntuaciones de variables como la edad y el nivel educativo. Conclusiones: Se demuestra la utilidad de este procedimiento para población española de bajo nivel cultural y la necesidad de trabajar con diferentes criterios normativos en función de la edad y/o el nivel educativo de los pacientes evaluados (AU)

[Validity of the Cognitive Mini-Exam of Lobo et al. for the detection of dementia-associated cognitive deterioration] . / Estudio de validez del Mini-Examen Cognoscitivo de Lobo et al para la detección del deterioro cognitivo asociado a demencias.

BACKGROUND AND OBJECTIVES: The Mini-Examination Cognitive (MEC) of Lobo et al is widely used as a screening tool for dementia in epidemiological studies and in clinical context for the rapid evaluation of cases in whom there is a suspicion of cognitive deterioriation due to dementia. Nevertheless, the validity analysis in old people have not been accomplished. The objective of this study has been to validate the use of this instrument to detect cognitive deterioration associated with dementia in elderly people. PATIENTS AND METHODS: Ninety-five old people have participated, one group of patients of a Neurology Service and another group of healthy old people. All of them have been evaluated through a neuropsychological exploration protocol and the MEC. RESULTS: The results show a high validity of this test for the evaluation of the cognitive deterioration in this population, as in the correlation with the neurological tests used as in the ANOVA intergroups (with and without deterioration) executed; they also reflect the influence on the puntuations of variables such as the age and the educational level. CONCLUSIONS: The utility of this procedure for the Spanish population with a low cultural level and the necessity of working with different criteria depending on the age and the educational level of the patients evaluated is shown here.

A self-training program in inductive reasoning for low-education elderly: tutor-guided training vs. self-training.

The main aim of this study was to compare the effectiveness of a self-training program in inductive reasoning run for elderly with low levels of education. Two different training settings were considered, i.e. tutor-guided training and self-training, to ascertain whether results obtained in both settings would be similar. A total of 25 subjects took part in this study (average age = 68.266, range = 60-85 years), all volunteers and residents of the city of Granada. A quasi-experimental design was used with random assignment to either training setting. The design was applied in four stages: pre-test, cognitive training (tutor-guided vs. self-trained inductive reasoning), post-test immediately after training and follow-up at 3 months. Results show considerable gains in inductive reasoning training both in tutor-guided and self-trained groups.