Molecular analysis of enrichment cultures of ammonia oxidizers from the Salar de Huasco, a high altitude saline wetland in northern Chile

We analyzed enrichment cultures of ammonia-oxidizing bacteria (AOB) collected from different areas of Salar de Huasco, a high altitude, saline, pH-neutral water body in the Chilean Altiplano. Samples were inoculated into mineral media with 10 mM NH4+ at five different salt concentrations (10, 200, 400, 800 and 1,400 mM NaCl). Low diversity (up to three phylotypes per enrichment) of beta-AOB was detected using 16S rDNA and amoA clone libraries. Growth of beta-AOB was only recorded in a few enrichment cultures and varied according to site or media salinity. In total, five 16S rDNA and amoA phylotypes were found which were related to Nitrosomonas europaea/Nitrosococcus mobilis, N. marina and N. communis clusters. Phylotype 1-16S was 97% similar with N. halophila, previously isolated from Mongolian soda lakes, and phylotypes from amoA sequences were similar with yet uncultured beta-AOB from different biofilms. Sequences related to N. halophila were frequently found at all salinities. Neither gamma-AOB nor ammonia-oxidizing Archaea were recorded in these enrichment cultures

Is the meiofauna a good indicator for climate change and anthropogenic impacts?

Our planet is changing, and one of the most pressing challenges facing the scientific community revolves around understanding how ecological communities respond to global changes. From coastal to deep-sea ecosystems, ecologists are exploring new areas of research to find model organisms that help predict the future of life on our planet. Among the different categories of organisms, meiofauna offer several advantages for the study of marine benthic ecosystems. This paper reviews the advances in the study of meiofauna with regard to climate change and anthropogenic impacts. Four taxonomic groups are valuable for predicting global changes: foraminifers (especially calcareous forms), nematodes, copepods and ostracods. Environmental variables are fundamental in the interpretation of meiofaunal patterns and multistressor experiments are more informative than single stressor ones, revealing complex ecological and biological interactions. Global change has a general negative effect on meiofauna, with important consequences on benthic food webs. However, some meiofaunal species can be favoured by the extreme conditions induced by global change, as they can exhibit remarkable physiological adaptations. This review highlights the need to incorporate studies on taxonomy, genetics and function of meiofaunal taxa into global change impact research

Influence of Potamogeton pectinatus and microphytobenthos on benthic metabolism, nutrient fluxes and denitrification in a freshwater littoral sediment in an agricultural landscape: N assimilation versus N removal

No Full Tex

Protocol handbook for NICE - Nitrogen Cycling in Estuaries: a project under the EU research programme: Marine Science and Technology (MAST III)

This protocol handbook has been prepared in order to standardise sampling, analysis and calculations within the project "Nitrogen Cycling in Estuaries" (NICE). The protocol handbook is based on a workshop held from 30 September to 9 October, 1996 at the Aarhus University, Marine Biology Field Station in Rønbjerg, Denmark. The project aimed at investigating benthic nitrogen cycling in shallow coastal European waters with special emphasis on nitrogen removal via denitrification. In order to elucidate the regulating mechanisms for denitrification on a European scale a number of other variables and processes were also measured. Two of the major variables on a European scale affecting nitrogen cycling were expected to be tidal amplitude and climate and sites were selected to represent these differences. The sediments of shallow waters are very often inhabited by benthic primary producers and previous studies indicated that they have the capacity to control the sediment nitrogen cycling. One of the major aims of the project was therefore to investigate the role of benthic primary producers on the sediment nitrogen cycle. The benthic primary producers were divided into three functional groups: the benthic microalgae, the floating macroalgae and the rooted macrophytes. The experimental procedures needed to measure nitrogen cycling and associated variables in these three groups of primary producers are very different. Therefore there is a chapter for each of the groups detailing the experimental procedures. The chemical analysis and calculations are the same for all the groups and they are dealt with in the next chapters

Severe Mental Illness and Clinical Outcome After Primary Percutaneous Coronary Intervention

The mechanisms behind the increased mortality in patients with acute myocardial infarction and co-existing severe mental illness (SMI) compared with non-SMI patients remain unclear. We studied 12,102 patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention, of whom 457 had SMI. The primary outcome was major adverse cardiac events (death, myocardial infarction, target vessel revascularization) at 30 days, 1 year, 2 years, and maximum follow-up. Patients with SMI were younger, more often women, had higher prevalence of active smoking and diabetes, and had a longer duration of symptoms than patients without SMI. There were no substantial differences in the in-hospital treatment of patients with and without SMI. Fewer SMI patients were treated with the recommended medications during follow up; however, the absolute differences were modest. Compared with non-SMI patients, the cumulative risks of major adverse cardiac events after 1 year, 2 years, and maximum follow-up were higher among SMI patients [hazard ratio 1.27 (1.02 to 1.57), hazard ratio 1.32 (1.09 to 1.60), and hazard ratio 1.43 (1.25 to 1.65), respectively]. Even after adjustment for differences in baseline characteristics, the differences in outcome persisted. In conclusion, compared with patients without SMI, primary percutaneous coronary intervention treated patients with SMI had a worse baseline risk profile. No differences in in-hospital treatments were found. Although the absolute differences were small, SMI patients were less likely to receive recommended medical treatment during follow up and they face a worse prognosis, even after adjustment for differences in risk profile. This indicates that SMI per se is likely to have an adverse effect on the prognosis following ST-elevation myocardial infarction.</p