4,243 research outputs found
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
From Judgment to Justice: Implementing International and Regional Human Rights Decisions
Examines the European, Inter-American, and African human rights systems and United Nations treaty bodies; how well court decisions are implemented; and what monitoring mechanisms exist. Suggests ways to strengthen implementation and, in turn, legitimacy
Novel catalysts for the conversion of phenol to anilines
In this thesis the direct conversion of phenol to anilines is catalyzed with Pd supported on Carbon, which adsorbs H2 gas, the phenols and the amines. This make the contact between the reactives easier. The mecanism runs through cyclohexanone and finish into a secondary or tertiary N,substituted-aniline and the correspondant cyclohexyl-R-amine, the hydrogenated analogous. Other metals, as Pb, and other supporters, as CeO, for example, were used in the investigation. It has been studied the kinetics and the thermodinamyc properties of the reaction. It was regarded that the reaction finished with the cyclohexylamine and the N,substituted-aniline in the reaction with H2 gas pressure. As we wanted to obtain the maximum amount of the dehydrogenated molecule, a second step in the reaction was added: Dehydrogenation step. It worked in the same conditions as the main reaction, but with any H2 pressure. It was observed that for both steps the best catalysts were Pd/CaCo3 and Pd/BaSO4. The analysis of the samples were performed into a GC and GC-MS machines
Pathways of change : shifting connectivities in the world city network, 2000-08
This is an empirical paper that measures and interprets changes in intercity relations at the global scale in the period 2000-08. It draws on the network model devised by the Globalization and World Cities (GaWC) research group to measure global connectivities for 132 cities across the world in 2000 and 2008. The measurements for both years are adjusted so that a coherent set of services/cities is used. A range of statistical techniques is used to explore these changes at the city level and the regional scale. The most notable changes are: the general rise of connectivity in the world city network; the loss of global connectivity of US and sub-Saharan African cities (Los Angeles, San Francisco and Miami in particular); and, the gain in global connectivity of south Asian, Chinese and eastern European cities (Shanghai, Beijing and Moscow in particular)
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
The smallest worthwhile effect of primary care physiotherapy did not differ across musculoskeletal pain sites
Objectives: To determine and compare estimates of the smallest worthwhile effect (SWE) for physiotherapy in neck, shoulder, and low-back pain patients and to investigate the influence of sociodemographic, clinical, and psychological factors on these estimates. Methods: A structured telephone interview was conducted before treatment was commenced in 160 patients referred for primary care physiotherapy. The benefit-harm trade-off method was used to estimate the SWE of physiotherapy for the following outcomes; pain, disability, and time to recovery, compared with the improvement achieved without any treatment (natural course). Regression analyses were used to assess the influence of sociodemographics, clinical variables, and intake scores on pain, disability, and psychological scales. Results: The median SWE for improvements on pain and disability was 20% (interquartile range 10%–30%), and the SWE for time to recovery was 10 days (interquartile range 7–14 days) over a period of 6 weeks. These estimates did not differ with respect to pain location (neck, shoulder, or back) and were generally unaffected by sociodemographic, clinical, and psychological factors. Conclusion: People with neck, shoulder, and low-back pain need to see at least 20% of additional improvement on pain and disability compared with natural recovery to consider that the effect of physiotherapy is worthwhile, given its costs, potential side effects, and inconveniences
Epidemiologic Questions from Anthrax Outbreak, Hunter Valley, Australia
Anthrax was introduced into Australia in 1847 near Sydney, New South Wales, and spread along stock routes throughout New South Wales and southern Queensland. Anthrax was considered endemic to the Hunter Valley, New South Wales, during the 1890s. The last recorded anthrax-related stock losses there occurred on 3 properties in the Upper Hunter Valley in 1939. During the past 4 decades, anthrax has become uncommon in Australia. However, our experience is a timely reminder that veterinary public health authorities should be on high alert for possible anthrax when unexpected livestock deaths follow flooding in areas where anthrax has historically occurred
Combination toceranib and lomustine shows frequent high grade toxicities when used for treatment of non-resectable or recurrent mast cell tumours in dogs: A European multicentre study
Reply to Hancock and Kent. Clinical important differences:a step toward a more intervention-specific approach
Analysis of bacterial fatty acids by flow modulated comprehensive two dimensional gas chromatography with parallel flame ionization detector/mass spectrometry
Comprehensive two-dimensional gas chromatography (GC×GC) offers an interesting tool for profiling bacterial fatty acids. Flow modulated GC×GC using a commercially available system was evaluated, and different parameters such as column flows and modulation time were optimized. The method was tested on bacterial fatty acid methyl esters (BAMEs) from Stenotrophomonas maltophilia by using parallel flame ionization detector (FID)/mass spectrometry (MS). The GC×GC plots obtained for a reference sample of bacterial fatty acid esters and a bacteria sample (S. maltophilia) were very similar to those obtained by using thermal modulated GC×GC. The parallel FID/MS set-up is useful since the MS allows identification and confirmation, while the FID allows comparison of the relative fatty acid composition with existing databases. The data show that flow modulated GC×GC-FID/MS method can be applied in a routine environment and offers interesting perspectives for chemotaxonomy of bacteria
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