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Shewanella species are frequently selected as model strains to investigate microbially influenced steel corrosion. This selection is due to their relevance for corrosion, but also because of their easy cultivation in aerobic media. Unfortunately, these cultivation advantages do not lead to a straight-forward interpretation of their corrosion inducing or inhibiting mechanisms. The metabolic versatility of Shewanellae indeed enables a wide variety of corrosion mechanisms. This work reviews the metabolic capacities and the extracellular electron transfer mechanisms of Shewanellae and explains how these abilities lead to the various mechanisms by which Shewanellae induce and inhibit corrosion. It should be emphasized that the medium composition (presence of electron donor, acceptor, carbon source) strongly affects which mechanism is in play. Overall, this work concludes that Shewanellae model strains offer great opportunities to study corrosion, thanks in part due to genetic engineering options, but the full complexity of their corrosion processes should always be kept mind. [ABSTRACT FROM AUTHOR]

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) amplifies tissue glucocorticoid levels and is a pharmaceutical target in diabetes and cognitive decline. Clinical translation of inhibitors is hampered by lack of in vivo pharmacodynamic biomarkers. Our goal was to monitor substrates and products of 11β-HSD1 non-invasively in liver via 19Fluorine magnetic resonance spectroscopy (19F-MRS). Interconversion of mono/poly-fluorinated substrate/product pairs was studied in Wistar rats (male, n = 6) and healthy men (n = 3) using 7T and 3T MRI scanners, respectively. Here we show that the in vitro limit of detection, as absolute fluorine content, was 0.625 μmole in blood. Mono-fluorinated steroids, dexamethasone and 11-dehydrodexamethasone, were detected in phantoms but not in vivo in human liver following oral dosing. A non-steroidal polyfluorinated tracer, 2-(phenylsulfonyl)-1-(4-(trifluoromethyl)phenyl)ethanone and its metabolic product were detected in vivo in rat liver after oral administration of the keto-substrate, reading out reductase activity. Administration of a selective 11β-HSD1 inhibitor in vivo in rats altered total liver 19F-MRS signal. We conclude that there is insufficient sensitivity to measure mono-fluorinated tracers in vivo in man with current dosage regimens and clinical scanners. However, since reductase activity was observed in rats using poly-fluorinated tracers, this concept could be pursued for translation to man with further development. [ABSTRACT FROM AUTHOR]

Microaerophilic veils of swimming microorganisms form at oxic-anoxic interfaces, mostly described in sediments where sulfide from below meets oxygen diffusing in from the water phase. However, microaerophilic veils form even when these gradients do not overlap, for example when cable bacteria activity leads to a suboxic zone. This suggests that veil microorganisms can use electron donors other than sulfide. Here we describe the extraction of microorganisms from a microaerophilic veil that formed in cable-bacteria-enriched freshwater sediment using a glass capillary, and the subsequent isolation of a motile, microaerophilic, organoheterotrophic bacterium, strain R2-JLT, unable to oxidize sulfide. Based on phenotypic, phylogenetic, and genomic comparison, we propose strain R2-JLT as a novel Phyllobacterium species, P. calauticae sp. nov.. The type strain is R2-JLT (= LMG 32286T = DSM 112555T). This novel isolate confirms that a wider variety of electron donors, including organic compounds, can fuel the activity of microorganisms in microaerophilic veils. [ABSTRACT FROM AUTHOR]

Transport of microbes in the atmosphere allows them to spread and to colonize new habitats. To survive the harsh environmental conditions encountered in the atmosphere, these microorganisms have to possess properties that allow them to resist atmospheric stress. We combined physiological experiments and genome analysis of Pseudomonas syringae strain R10.79, previously isolated from rain, to decipher the strain's ability to withstand these challenges and identify the mechanisms behind the resistance. We used laboratory experiments to simulate different atmospheric stress factors and evaluated cell survival using fluorescent staining and flow cytometry. We found that while P. syringae R10.79 was resistant to oxidative, osmotic, UVB radiation-induced and freezing stress, it was sensitive to desiccation on surfaces. Strain R10.79 possesses a range of genes that would allow the strain to mitigate atmospheric stresses, such as cold shock and osmotic shock genes as well as genes encoding for properties that relate to UV irradiation resistance. Studying the substrate spectrum of strain R10.79, we uncovered that it can utilize carbon compounds abundant in the atmosphere including acetate, succinate and formate. In addition, strain R10.79 possesses metabolic pathways to utilize formaldehyde and methanol as sole carbon sources. These compounds could support the metabolic activity of strain R10.79 while suspended in the atmosphere during periods with sufficiently high relative humidity. Finally, we found that when growing on acetate, strain R10.79 produces several volatile organic compounds such as isoprene and methanol, for which we propose biochemical pathways and which are relevant for atmospheric chemistry and climate. The results reported in this study will support our general aim at establishing this strain as a model organism to study microbial responses to atmospheric conditions. [ABSTRACT FROM AUTHOR]

Some social arthropods engage in mutualistic symbiosis with antimicrobial compound-producing microorganisms that provide protection against pathogens. Social spiders live in communal nests and contain specific endosymbionts with unknown function. Bacteria are also found on the spiders' surface, including prevalent staphylococci, which may have protective potential. Here we present the genomic and phenotypic characterization of strain i1, isolated from the surface of the social spider Stegodyphus dumicola. Phylogenomic analysis identified i1 as novel strain of Staphylococcus sciuri within subgroup 2 of three newly defined genomic subgroups. Further phenotypic investigations showed that S. sciuri i1 is an extremophile that can grow at a broad range of temperatures (4 °C–45 °C), high salt concentrations (up to 27%), and has antimicrobial activity against closely related species. We identified a lactococcin 972-like bacteriocin gene cluster, likely responsible for the antimicrobial activity, and found it conserved in two of the three subgroups of S. sciuri. These features indicate that S. sciuri i1, though not a specific symbiont, is well-adapted to survive on the surface of social spiders and may gain a competitive advantage by inhibiting closely related species. [ABSTRACT FROM AUTHOR]

Cerebral small vessel disease (SVD) is a major health burden, yet the pathophysiology remains poorly understood with no effective treatment. Since much of SVD develops silently and insidiously, non-invasive neuroimaging such as MRI is fundamental to detecting and understanding SVD in humans. Several relevant SVD rodent models are established for which MRI can monitor in vivo changes over time prior to histological examination. Here, we critically review the MRI methods pertaining to salient rodent models and evaluate synergies with human SVD MRI methods. We found few relevant publications, but argue there is considerable scope for greater use of MRI in rodent models, and opportunities for harmonisation of the rodent-human methods to increase the translational potential of models to understand SVD in humans. We summarise current MR techniques used in SVD research, provide recommendations and examples and highlight practicalities for use of MRI SVD imaging protocols in pre-selected, relevant rodent models. [ABSTRACT FROM AUTHOR]

Proton magnetic resonance spectroscopy yields metabolic information and has proved to be a useful addition to structural imaging in neurological diseases. We applied short-echo time Spectroscopic Imaging in a cohort of 42 patients with secondary progressive multiple sclerosis (SPMS). Linear modelling with respect to brain tissue type yielded metabolite levels that were significantly different in white matter lesions compared with normal-appearing white matter, suggestive of higher myelin turnover (higher choline), higher metabolic rate (higher creatine) and increased glial activity (higher myo-inositol) within the lesions. These findings suggest that the lesions have ongoing cellular activity that is not consistent with the usual assumption of ‘chronic’ lesions in SPMS, and may represent a target for repair therapies. [ABSTRACT FROM AUTHOR]

We develop methods of computation of the Brauer-Picard groups of fusion categories and apply them to compute such groups for several classes of fusion categories of prime power dimension: representation categories of elementary abelian groups with twisted associativity, extra special p-groups, and the Kac-Paljutkin Hopf algebra. We conclude that many finite groups of Lie type occur as composition factors of the Brauer-Picard groups of pointed fusion categories. [ABSTRACT FROM AUTHOR]

Hamiltonian reduction is used to project a trivially integrable system on the Heisenberg double of SU( n, n), to obtain a system of Ruijsenaars type on a suitable quotient space. This system possesses BC symmetry and is shown to be equivalent to the standard three-parameter BC hyperbolic Sutherland model in the cotangent bundle limit. [ABSTRACT FROM AUTHOR]

Object: We sought to measure brain metabolite levels in healthy older people. Materials and methods: Spectroscopic imaging at the level of the basal ganglia was applied in 40 participants aged 73-74 years. Levels of the metabolites N-acetyl aspartate (NAA), choline, and creatine were determined in "institutional units" (IU) corrected for T1 and T2 relaxation effects. Structural imaging enabled determination of grey matter (GM), white matter (WM), and cerebrospinal fluid content. ANOVA analysis was carried out for voxels satisfying quality criteria. Results: Creatine levels were greater in GM than WM (57 vs. 44 IU, p < 0.001), whereas choline and NAA levels were greater in WM than GM [13 vs. 10 IU ( p < 0.001) and 76 versus 70 IU ( p = 0.03), respectively]. The ratio of NAA/cre was greater in WM than GM (2.1 vs. 1.4, p = 0.001) as was that of cho/cre (0.32 vs. 0.16, p < 0.001). A low voxel yield was due to brain atrophy and the difficulties of shimming over an extended region of brain. Conclusion: This study addresses the current lack of information on brain metabolite levels in older adults. The normal features of ageing result in a substantial loss of reliable voxels and should be taken into account when planning studies. Improvements in shimming are also required before the methods can be applied more widely. [ABSTRACT FROM AUTHOR]

The aim of our study was to develop a reliable technique for measuring volume of the fibroid uterus using Magnetic Resonance Imaging. We applied the Cavalieri method and standard calliper technique to measure the volume of the uterus and largest fibroid in 26 patients, and results were compared with “gold-standard” planimetry measurements. We found Cavalieri measurements to be unbiased, while calliper measurements systematically underestimated uterine volume (− 13.2%, P < 10−5) and had greater variance. Repeatability was similar for the 2 techniques (standard deviation [SD] = 4.0%-6.9%). Reproducibility of Cavalieri measurements was higher for measurement of uterine (SD = 9.0%) than fibroid volume (SD = 19.1%), whereas the reproducibility of calliper measurements was higher for fibroid (SD = 9.1%) than uterine volume (SD = 15.9%). The additional measurement time for the Cavalieri method was approximately 1 to 2 minutes. In conclusion, the Cavalieri method permits more accurate measurement of uterine and fibroid volumes and is suitable for application in both clinical practice and scientific research. [ABSTRACT FROM PUBLISHER]

Object: We evaluated the use of kt-broad-use linear acquisition speed-up technique (kt-BLAST) acceleration of mouse cardiac imaging in order to reduce scan times, thereby minimising physiological variation and improving animal welfare. Materials and methods: Conventional cine cardiac MRI data acquired from healthy mice ( n = 9) were subsampled to simulate kt-BLAST acceleration. Cardiological indices (left ventricular volume, ejection fraction and mass) were determined as a function of acceleration factor. kt-BLAST threefold undersampling was implemented on the scanner and applied to a second group of mice ( n = 6 healthy plus 6 with myocardial infarct), being compared with standard cine imaging (3 signal averages) and cine imaging with one signal average. Results: In the simulations, sufficient accuracy was achieved for undersampling factors up to three. Cardiological indices determined from the implemented kt-BLAST scanning showed no significant differences compared with the values determined from the standard sequence, and neither did indices derived from the cine scan with only one signal average despite its lower signal-to-noise ratio. Both techniques were applied successfully in the infarcted hearts. Conclusion: For cardiac imaging of mice, threefold undersampling of kt-space, or a similar reduction in the number of signal averages, are both feasible with subsequent reduction in imaging time. [ABSTRACT FROM AUTHOR]

Photosynthetic microbial mats possess extraordinary phylogenetic and functional diversity that makes linking specific pathways with individual microbial populations a daunting task. Close metabolic and spatial relationships between Cyanobacteria and Chloroflexi have previously been observed in diverse microbial mats. Here, we report that an expressed metabolic pathway for the anoxic catabolism of photosynthate involving Cyanobacteria and Chloroflexi in microbial mats can be reconstructed through metatranscriptomic sequencing of mats collected at Elkhorn Slough, Monterey Bay, CA, USA. In this reconstruction, Microcoleus spp., the most abundant cyanobacterial group in the mats, ferment photosynthate to organic acids, CO2 and H2 through multiple pathways, and an uncultivated lineage of the Chloroflexi take up these organic acids to store carbon as polyhydroxyalkanoates. The metabolic reconstruction is consistent with metabolite measurements and single cell microbial imaging with fluorescence in situ hybridization and NanoSIMS. [ABSTRACT FROM AUTHOR]

Type 1 diabetes remains the predominant form of diabetes in the pediatric population, while the incidence of type 2 diabetes has increased, paralleling the increase in obesity. Another form of diabetes, Maturity Onset Diabetes of the Young (MODY), should also be considered especially in those whose clinical presentation is atypical for type 1 and type 2 diabetes. Although testing for MODY is a challenge, testing in appropriate patients and family members should be standard of care. Knowledge of the genetic etiology of the type of diabetes will enable appropriate treatment and optimize outcomes, allow more accurate prediction of disease progression, as well as allow screening for and the diagnosis of MODY in family members. [ABSTRACT FROM AUTHOR]

We developed a broad-ranging method for identifying key hydrogen-producing and consuming microorganisms through analysis of hydrogenase gene content and expression in complex anaerobic microbial communities. The method is based on a tiling hydrogenase gene oligonucleotide DNA microarray (Hydrogenase Chip), which implements a high number of probes per gene by tiling probe sequences across genes of interest at 1.67 × -2 × coverage. This design favors the avoidance of false positive gene identification in samples of DNA or RNA extracted from complex microbial communities. We applied this technique to interrogate interspecies hydrogen transfer in complex communities in (i) lab-scale reductive dehalogenating microcosms enabling us to delineate key H2-consuming microorganisms, and (ii) hydrogen-generating microbial mats where we found evidence for significant H2 production by cyanobacteria. Independent quantitative PCR analysis on selected hydrogenase genes showed that this Hydrogenase Chip technique is semiquantitative. We also determined that as microbial community complexity increases, specificity must be traded for sensitivity in analyzing data from tiling DNA microarrays. [ABSTRACT FROM AUTHOR]

We combine the projective geometry approach to Schroedinger equations on the circle and differential Galois theory with the theory of Poisson Lie groups to construct a natural Poisson structure on the space of wave functions (at the zero energy level). Applications to KdV-like nonlinear equations are discussed. The same approach is applied to 2nd order difference operators on a one-dimensional lattice, yielding an extension of the lattice Poisson Virasoro algebra. [ABSTRACT FROM AUTHOR]

Aedes camptorhynchus (Thom.) collected on the mid-south coast of New South Wales during the winter of 1982 were highly susceptible to infection (ID50 = 102.4 VERO pfu/mosquito) when fed on rat tail skins containing blood and serial dilutions of the T48 strain of Ross River (RR) virus. After 2 d, when no virus was detectable, rapid proliferation allowed transmission from 5 d post ingestion. A maximum transmission rate occurred 9 d post-feeding when 4 of 4 infected mosquitoes transmitted virus. The susceptibility of Ae camptorhynchus to RR virus infection was compared with that of a laboratory colony of Ae aegypti (L.) (ID50 = 103.8 VERO pfu/mosquito) [ABSTRACT FROM AUTHOR]

Examines the antibody responses of rufous night herons and little egrets following infection with Murray Valley encephalitis and Kunjin viruses. Detection of hemugglutinin-inhibiting antibodies; Observation that neutralizing antibody development paralleled that of H1 antibodies; Possibility of determining with which virus a bird had been infected from the pattern of cross-reaction with the antigens.

Reports on the study where rufous night herons, Pacific herons, little egrets and intermediate egrets were experimentally infected with Murray Valley encephalitis, Kunjin or Japanese encephalitis viruses. Detection of viremias of at least one day duration in almost all birds; Absence of viremia in two intermediate egrets inoculated with a very low dose of Kunjin virus and one rufous night heron inoculated with Japanese encephalitis virus.

Discusses the study on viruses recovered from mosquitoes and wildlife serum collected in the Murray Valley of South-Eastern Australia. Investigation on mosquito species involved in the primary cycle of MVE virus (causative or probable causative agents of encephalitis) during an epidemic; Examination on infection rate arboviruses; Assessment on virus activity in the enzootic tropical regions during pre-epidemic period.

Discusses the study on species composition of mosquitoes collected in the Murray Valley of South-Eastern Australia. Investigation on mosquitoes activities in epidemic situations; Examination on climatic factors affecting increased wildlife and mosquitoes populations; Assessment on methods used in estimating mosquito prevalence during epidemic.

Discusses the result of a serological survey on variation in arbovirus infection rate in species of birds during an encephalitis epidemic in the Murray Valley of South-Eastern Australia. Investigation on species involved in the maintenance cycle and in the transport of virus; Analysis on the incidence rate of viral inhibitors in herons and cormorants; Evaluation on the relation between viruses and species within the Orders Ciconiiformes and Pelecaniformes.

The p× p matrix version of the r-KdV hierarchy has been recently treated as the reduced system arising in a Drinfeld-Sokolov type Hamiltonian symmetry reduction applied to a Poisson submanifold in the dual of the Lie algebra $$\widehat{gl}_{pr} $$ ⊗ℂ[λ,λ−1]. Here a series of extensions of this matrix Gelfand-Dickey system is derived by means of a generalized Drinfeld-Sokolov reduction defined for the Lie algebra $$\widehat{gl}_{pr + s} $$ ⊗ℂ[λ,λ−1] using the natural embedding gl pr ⊂glpr+s for s any positive integer. The hierarchies obtained admit a description in terms of a p× p matrix pseudo-differential operator comprising an r-KdV type positive part and a non-trivial negative part. This system has been investigated previously in the p=1 case as a constrained KP system. In this paper the previous results are considerably extended and a systematic study is presented on the basis of the Drinfeld-Sokolov approach that has the advantage that it leads to local Poisson brackets and makes clear the conformal ( W-algebra) structures related to the KdV type hierarchies. [ABSTRACT FROM AUTHOR]

We study the affine semi-direct product, vECT( S⋉ S, ℝ⊗ℂ( λ, λ)) and show how the coadjoint action on its extended dual leads immediately to a generalisation of the Miura map and also to the existence of several compatible Hamiltonian structures. [ABSTRACT FROM AUTHOR]

This article reports a study investigating aboviral epidemics in coastal South-Eastern Australia. Several successive years of investigations established that Ross River virus (RRV), an alphavirus believed to be the causative agent in Australia of epidemic polyarthritis, is probably enzootic in some coastal areas of temperate southeastern Australia. In an attempt to find direct evidence of RRV activity in more southerly latitudes, mosquitoes and wildlife sera were collected at several sites along the south-east coast of Australia during April 1972. RRV and several strains of another antigenically distinct virus were recovered from mosquitoes collected near Bawley Point on the south coast of New South Wales.

The article focuses on antigenically distinct strains of Ross River virus (RRV)from North Queensland in Queensland and Coastal New South Wales. RRV is euzootic on the east coast of temperate Australia. The drift from a presumed common ancestral virus might be related to different components of the primary cycles available in the two areas, although there is no firm evidence for this. Both Queensland (Q) and Nelson Bay (NB) antigenic types have been recovered from Aedes eigilax and the Q strain isolated from this vector in Townsville on the east coast of Cape York peninsula appears antigenically identical to these subsequently recovered from Culex annulirostris at Kowanyama on the west coast of Cape York.

Preparations from alloxan diabetic rats showed a reduced sensitivity to the neuromuscular blocking action of (+)-tubocurarine but no alteration in sensitivity to the deplolarizing neuromuscular blocking drug decamethonium. Physostigmine was less effective in augmenting twitch height in preparations from alloxan diabetic rats and such preparations had a significantly lowered total cholinesterase activity compared with control preparations. An additional observation was a reduction in the effectiveness of the pre-junctionally active agent β-bungarotoxin in producing neuromuscular blockade in physostigmine-treated preparations from alloxan diabetic rats. All the changes produced by alloxan administration were prevented by treatment with insulin. [ABSTRACT FROM AUTHOR]