A comparison between ultraviolet disinfection and copper alginate beads within a vortex bioreactor for the deactivation of bacteria in simulated waste streams with high levels of colour, humic acid and suspended solids.

We show in this study that the combination of a swirl flow reactor and an antimicrobial agent (in this case copper alginate beads) is a promising technique for the remediation of contaminated water in waste streams recalcitrant to UV-C treatment. This is demonstrated by comparing the viability of both common and UV-C resistant organisms in operating conditions where UV-C proves ineffective - notably high levels of solids and compounds which deflect UV-C. The swirl flow reactor is easy to construct from commonly available plumbing parts and may prove a versatile and powerful tool in waste water treatment in developing countries

High-dose clevudine impairs mitochondrial function and glucose-stimulated insulin secretion in INS-1E cells

<p>Abstract</p> <p>Background</p> <p>Clevudine is a nucleoside analog reverse transcriptase inhibitor that exhibits potent antiviral activity against hepatitis B virus (HBV) without serious side effects. However, mitochondrial myopathy has been observed in patients with chronic HBV infection taking clevudine. Moreover, the development of diabetes was recently reported in patients receiving long-term treatment with clevudine. In this study, we investigated the effects of clevudine on mitochondrial function and insulin release in a rat clonal β-cell line, INS-1E.</p> <p>Methods</p> <p>The mitochondrial DNA (mtDNA) copy number and the mRNA levels were measured by using quantitative PCR. MTT analysis, ATP/lactate measurements, and insulin assay were performed.</p> <p>Results</p> <p>Both INS-1E cells and HepG2 cells, which originated from human hepatoma, showed dose-dependent decreases in mtDNA copy number and cytochrome c oxidase-1 (Cox-1) mRNA level following culture with clevudine (10 μM-1 mM) for 4 weeks. INS-1E cells treated with clevudine had reduced total mitochondrial activities, lower cytosolic ATP contents, enhanced lactate production, and more lipid accumulation. Insulin release in response to glucose application was markedly decreased in clevudine-treated INS-1E cells, which might be a consequence of mitochondrial dysfunction.</p> <p>Conclusions</p> <p>Our data suggest that high-dose treatment with clevudine induces mitochondrial defects associated with mtDNA depletion and impairs glucose-stimulated insulin secretion in insulin-releasing cells. These findings partly explain the development of diabetes in patients receiving clevudine who might have a high susceptibility to mitochondrial toxicity.</p

Protocol for Project FACT: a randomised controlled trial on the effect of a walking program and vitamin B supplementation on the rate of cognitive decline and psychosocial wellbeing in older adults with mild cognitive impairment [ISRCTN19227688]

BACKGROUND: the prevalence of individuals with cognitive decline is increasing since the number of elderly adults is growing considerably. The literature provides promising results on the beneficial effect of exercise and vitamin supplementation on cognitive function both in cognitively healthy as well as in the demented elderly. METHODS/DESIGN: the design is a two-by-two factorial randomised controlled trial. The study population consists of independently living elderly, between 70 and 80 years old, with mild cognitive impairment (MCI). In the RCT the effect of two interventions, a walking program and vitamin supplementation, is examined. The walking program (WP) is a group-based program aimed at improving cardiovascular endurance; frequency two lessons a week; lesson duration one hour; program duration one year. Non-walking groups receive a placebo activity program (PAP) (i.e. low intensive non-aerobic group exercises, like stretching) with the same frequency, lesson and program duration. Vitamin supplementation consists of a single daily vitamin supplement containing 50 mg B6, 5 mg folic acid and 0,4 mg B12 for one year. Subjects not receiving vitamin supplements are daily taking an identically looking placebo pill, also for a year. Participants are randomised to four groups 1) WP and vitamin supplements; 2) WP and placebo supplements; 3) PAP and vitamin supplements; 4) PAP and placebo supplements. Primary outcome measures are measures of cognitive function. Secondary outcomes include psychosocial wellbeing, physical activity, cardiovascular endurance and blood vitamin levels. DISCUSSION: no large intervention study has been conducted yet on the effect of physical activity and vitamin supplementation in a population-based sample of adults with MCI. The objective of the present article is to describe the design of a randomised controlled trial examining the effect of a walking program and vitamin B supplementation on the rate of cognitive decline in older adults with MCI

The USDA Barley Core Collection:Genetic Diversity, Population Structure, and Potential for Genome-Wide Association Studies

New sources of genetic diversity must be incorporated into plant breeding programs if they are to continue increasing grain yield and quality, and tolerance to abiotic and biotic stresses. Germplasm collections provide a source of genetic and phenotypic diversity, but characterization of these resources is required to increase their utility for breeding programs. We used a barley SNP iSelect platform with 7,842 SNPs to genotype 2,417 barley accessions sampled from the USDA National Small Grains Collection of 33,176 accessions. Most of the accessions in this core collection are categorized as landraces or cultivars/breeding lines and were obtained from more than 100 countries. Both STRUCTURE and principal component analysis identified five major subpopulations within the core collection, mainly differentiated by geographical origin and spike row number (an inflorescence architecture trait). Different patterns of linkage disequilibrium (LD) were found across the barley genome and many regions of high LD contained traits involved in domestication and breeding selection. The genotype data were used to define 'mini-core' sets of accessions capturing the majority of the allelic diversity present in the core collection. These 'mini-core' sets can be used for evaluating traits that are difficult or expensive to score. Genome-wide association studies (GWAS) of 'hull cover', 'spike row number', and 'heading date' demonstrate the utility of the core collection for locating genetic factors determining important phenotypes. The GWAS results were referenced to a new barley consensus map containing 5,665 SNPs. Our results demonstrate that GWAS and high-density SNP genotyping are effective tools for plant breeders interested in accessing genetic diversity in large germplasm collections

Gene probing reveals the widespread distribution, diversity and abundance of isoprene-degrading bacteria in the environment

Background: Approximately 500 Tg of isoprene are emitted to the atmosphere annually, an amount similar to that of methane, and despite its significant effects on the climate, very little is known about the biological degradation of isoprene in the environment. Isolation and characterisation of isoprene degraders at the molecular level has allowed the development of probes targeting isoA encoding the α-subunit of the isoprene monooxygenase. This enzyme belongs to the soluble diiron centre monooxygenase family and catalyses the first step in the isoprene degradation pathway. The use of probes targeting key metabolic genes is a successful approach in molecular ecology to study specific groups of bacteria in complex environments. Here, we developed and tested a novel isoA PCR primer set to study the distribution, abundance, and diversity of isoprene degraders in a wide range of environments. Results: The new isoA probes specifically amplified isoA genes from taxonomically diverse isoprene-degrading bacteria including members of the genera Rhodococcus, Variovorax, and Sphingopyxis. There was no cross-reactivity with genes encoding related oxygenases from non-isoprene degraders. Sequencing of isoA amplicons from DNA extracted from environmental samples enriched with isoprene revealed that most environments tested harboured a considerable variety of isoA sequences, with poplar leaf enrichments containing more phylogenetically diverse isoA genes. Quantification by qPCR using these isoA probes revealed that isoprene degraders are widespread in the phyllosphere, terrestrial, freshwater and marine environments. Specifically, soils in the vicinity of high isoprene-emitting trees contained the highest number of isoprene-degrading bacteria. Conclusion: This study provides the molecular ecology tools to broaden our knowledge of the distribution, abundance and diversity of isoprene degraders in the environment, which is a fundamental step necessary to assess the impact that microbes have in mitigating the effects of this important climate-active gas

Crack growth in stainless steel 304 at 538 degrees C under fatigue loading with and without hold time

The crack growth behavior in stainless steel 304 is investigated at 538 degreesC in air. The effects of frequency (f), load level (P) and hold time on the crack growth rate are examined. It is shown that fracture mechanics parameters DeltaK and DeltaJ can correlate crack growth rates reasonably well beyond the regime of small scale yielding for no hold time tests. Depending on the values of f x P-max, three (f-P-max) domains are suggested for characterization of the da/dN-DeltaK relation. The crack tends to grow faster at low values of f x P-max for DeltaK m. The trend is reversed for DeltaK > 25MPa rootm. The SEM fractographs and optical micrographs of fracture surfaces indicate that oxidation plays a significant role on crack growth. The mode of crack propagation is transgranular for loading without hold time, and it becomes intergranular for loading with hold time. The crack growth rate is found to be much higher for loading with hold time.X11sciescopu

Reciprocal space mapping of phase transformation in epitaxial PbTiO3 thin films using synchrotron x-ray diffraction

Phase transformation in epitaxial PbTiO3 thin films grown on MgO(001) substrates was studied and quantified by two-dimensional reciprocal space mapping technique using synchrotron x-ray diffraction equipped with an in situ high temperature stage. Just below the Curie temperature, a twin-like domain structure was formed with an initial value of c-domain abundance, alpha similar to 0.3, and the value increased continuously during cooling, and eventually the c-domain dominant structure (alpha similar to 0.72) was achieved at room temperature through continuous expansion of the c domains. By investigating the intensity distribution of contour maps, domain tilting and mosaicity were characterized along the q([h00]) direction and the presence of a strain gradient along the growth direction q([001]) was also confirmed from the asymmetric distribution of the contour maps. (C) 1999 American Institute of Physics. [S0021-8979(99)03403-9].open1127sciescopu

Characterization of domain structures in epitaxial PbTiO3 thin films using synchrotron XRD

Ferroelectric twin domain structures of epitaxial PbTiO3 thin films grown on various single crystal substrates were investigated in-detail by reciprocal space mapping techniques using synchrotron X-ray. Direct comparison with one-directional X-ray diffraction scan that is conventionally employed for structural characterization clearly demonstrated that quantitative c-domain abundance and domain-tilt angles could be determined by two-dimensional mapping of PbTiO3 (001) and (100) reflections. Predominant orientation and domain structures of the films strongly depend on the substrate selection. Moreover, it is found that coherency strain across the 90 degrees domain boundary is accommodated mainly by domain-tilt of minor domain.X11sciescopu