Niche differentiation in nitrogen metabolism among methanotrophs within an operational taxonomic unit

Background: The currently accepted thesis on nitrogenous fertilizer additions on methane oxidation activity assumes niche partitioning among methanotrophic species, with activity responses to changes in nitrogen content being dependent on the in situ methanotrophic community structure Unfortunately, widely applied tools for microbial community assessment only have a limited phylogenetic resolution mostly restricted to genus level diversity, and not to species level as often mistakenly assumed. As a consequence, intragenus or intraspecies metabolic versatility in nitrogen metabolism was never evaluated nor considered among methanotrophic bacteria as a source of differential responses of methane oxidation to nitrogen amendments. Results: We demonstrated that fourteen genotypically different Methylomonas strains, thus distinct below the level at which most techniques assign operational taxonomic units (OTU), show a versatile physiology in their nitrogen metabolism. Differential responses, even among strains with identical 16S rRNA or pmoA gene sequences, were observed for production of nitrite and nitrous oxide from nitrate or ammonium, nitrogen fixation and tolerance to high levels of ammonium, nitrate, and hydroxylamine. Overall, reduction of nitrate to nitrite, nitrogen fixation, higher tolerance to ammonium than nitrate and tolerance and assimilation of nitrite were general features. Conclusions: Differential responses among closely related methanotrophic strains to overcome inhibition and toxicity from high nitrogen loads and assimilation of various nitrogen sources yield competitive fitness advantages to individual methane-oxidizing bacteria. Our observations proved that community structure at the deepest phylogenetic resolution potentially influences in situ functioning

The identity of the recipients of the Fourth Gospel in the light of the purpose of the Gospel

The purpose of this article is to explore the identity of the recipients at the time of the completion of the Gospel. An effort is made to determine to whom John wrote this Gospel and how he adapted his theological message to reach this aim. It will be argued that John did not only focus on a specific group of people, but had a wide variety of people (i.e., Jews, Hellenists, Samaritans) in mind, which leads to the conclusion that the Fourth Gospel was written with both evangelistic and didactic aims

Methanotrophic microbiomes as drivers for environmental biotechnology

Since the industrial revolution, the average temperature on Earth has risen considerably, mainly due to the enormous emissions of greenhouse gases. This doctoral research focused on microbial mitigation strategies for methane (CH4), the second most important greenhouse gas after CO2. Therefore, methanotrophic microbiomes were used, the latter being entire microbial communities depending on CH4 for their activity. In a first phase, the effects of external growth parameters on the activity and structure of such communities were evaluated. Thereafter, research was done on the interactions taking place within the methanotrophic microbiomes, thereby proving that carbon fluxes take place between methanotrophs and associated microorganisms. Lastly, the methalgae concept was developed; by cocultivation of methanotrophs and algae, it was possible to treat CO2 and CH4 simultaneously under anoxic conditions

The Performance of ECMWF sub-seasonal forecasts to predict the Rainy Season Onset Dates in Vietnam

The onset of the rainy season is an important date for the mostly rain-fed agricultural practices in Vietnam. Sub-seasonal to seasonal (S2S) ensemble hindcasts from the European Centre for Medium-Range Weather Forecasts (ECMWF) are used to evaluate the predictability of the rainy season onset dates (RSODs) over five climatic sub-regions of Vietnam. The results show that the ECMWF model reproduces well the observed inter-annual variability of RSODs, with a high correlation ranging from 0.60 to 0.99 over all sub-regions at all lead times (up to 40 days) using five different RSOD definitions. For increasing lead times, forecasted RSODs tend to be earlier than the observed ones. Positive skill score values for almost all cases examined in all sub-regions indicate that the model outperforms the observed climatology in predicting the RSOD at sub-seasonal lead times (~28–35 days). However, the model is overall more skilful at shorter lead times. The choice of the RSOD criterion should be considered because it can significantly influence the model performance. The result of analysing the highest skill score for each sub-region at each lead time shows that criteria with higher 5-day rainfall thresholds tend to be more suitable for the forecasts at long lead times. However, the values of mean absolute error are approximately the same as the absolute values of the mean error, indicating that the prediction could be improved by a simple bias correction. The present study shows a large potential to use S2S forecasts to provide meaningful predictions of RSODs for farmers

Endovascular treatment of intractable epistaxis — results of a 4-year local audit

Objective. Transcatheter embolisation is an accepted and effective treatment for intractable epistaxis. We analysed our success and complication rates and compared these with results from other published series. Design. Retrospective review. Setting. Unitas Interventional Unit, Centurion. Methods. Case record review (57 procedures) and telephonic interviews (36 traceable respondents). Outcome measures. A numerical audit of the success and complication rates for embolisation procedures performed during the 4-year period between July 1999 and June 2003. Results. A total of 57 endovascular embolisation procedures were performed for intractable epistaxis in 51 patients during this period. Eight patients (15.7%) developed a re-bleed between 1 and 33 days after embolisation, of whom 5 were reembolised, giving a primary short-term success rate of 86.3% and secondary assisted success rate of 94.1%. Thirty-five of 36 respondents (97.2%) reported no further epistaxis during the long-term follow-up period of 1 - 47 months. The mortality rate was 0%, the major morbidity rate was 2% (1 stroke) and the minor morbidity rate was 25%. Conclusion. Our success and complication rates are acceptable and compare favourably with those reported in other large series. S Afr Med J 2004; 94: 373-378

Probabilistic linkage without personal information successfully linked national clinical datasets: Linkage of national clinical datasets without patient identifiers using probabilistic methods.

BACKGROUND: Probabilistic linkage can link patients from different clinical databases without the need for personal information. If accurate linkage can be achieved, it would accelerate the use of linked datasets to address important clinical and public health questions. OBJECTIVE: We developed a step-by-step process for probabilistic linkage of national clinical and administrative datasets without personal information, and validated it against deterministic linkage using patient identifiers. STUDY DESIGN AND SETTING: We used electronic health records from the National Bowel Cancer Audit (NBOCA) and Hospital Episode Statistics (HES) databases for 10,566 bowel cancer patients undergoing emergency surgery in the English National Health Service. RESULTS: Probabilistic linkage linked 81.4% of NBOCA records to HES, versus 82.8% using deterministic linkage. No systematic differences were seen between patients that were and were not linked, and regression models for mortality and length of hospital stay according to patient and tumour characteristics were not sensitive to the linkage approach. CONCLUSION: Probabilistic linkage was successful in linking national clinical and administrative datasets for patients undergoing a major surgical procedure. It allows analysts outside highly secure data environments to undertake linkage while minimising costs and delays, protecting data security, and maintaining linkage quality

Miniaturized extinction culturing is the preferred strategy for rapid isolation of fast-growing methane-oxidizing bacteria

Methane-oxidizing bacteria (MOB) have a large potential as a microbial sink for the greenhouse gas methane as well as for biotechnological purposes. However, their application in biotechnology has so far been hampered, in part due to the relative slow growth rate of the available strains. To enable the availability of novel strains, this study compares the isolation of MOB by conventional dilution plating with miniaturized extinction culturing, both performed after an initial enrichment step. The extinction approach rendered 22 MOB isolates from four environmental samples, while no MOB could be isolated by plating. In most cases, extinction culturing immediately yielded MOB monocultures making laborious purification redundant. Both type I (Methylomonas spp.) and type II (Methylosinus sp.) MOB were isolated. The isolated methanotrophic diversity represented at least 11 different strains and several novel species based on 16S rRNA gene sequence dissimilarity. These strains possessed the particulate (100%) and soluble (64%) methane monooxygenase gene. Also, 73% of the strains could be linked to a highly active fast-growing mixed MOB community. In conclusion, miniaturized extinction culturing was more efficient in rapidly isolating numerous MOB requiring little effort and fewer materials, compared with the more widely applied plating procedure. This miniaturized approach allowed straightforward isolation and could be very useful for subsequent screening of desired characteristics, in view of their future biotechnological potential

Higher serum vitamin D3 levels are associated with better cognitive test performance in patients with Alzheimer's disease

Background/Aims: Recent studies suggest that vitamin D metabolites may be important for preserving cognitive function via specific neuroprotective effects. No large studies have examined the association between vitamin D status and cognition. Methods: In this cross-sectional study, we analyzed the serum 25-hydroxyvitamin D3levels and Mini-Mental State Examination (MMSE) test scores of 225 older outpatients who were diagnosed as having probable Alzheimer's disease (AD). In addition to the 25-hydroxyvitamin D3levels, we analyzed the serum vitamin B1, B6and B12levels. Results: An association was found between MMSE test scores and serum 25-hydroxyvitamin D3levels, with a β-coefficient of 0.05 (p = 0.01). Vitamin-D-sufficient patients had significantly higher MMSE scores as compared to vitamin-D-insufficient ones. No association was found with the other serum vitamin levels. Conclusions: These data support the idea that a relationship exists between vitamin D status and cognition in patients with probable AD. However, given the cross-sectional design of this study, no causality can be concluded. Further prospective studies are needed to specify the contribution of vitamin D status to the onset and course of cognitive decline and AD. Copyrigh

Solar System Escape Trajectories Using Solar Sails

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76979/1/AIAA-2354-496.pd