bluuebunny/crossref_metadata_2025 huggingface dataset:
An Experimental Examination of Cantilevered and Shrouded Stators in a Multistage Axial Compressor
Authors: Swoboda M. , Ivey P. C. , Wenger U. , Gümmer V.
Published: December 2014

This paper presents experimental investigations on a large-scale low-speed compressor facility with four repeating stages equipped with CDA-profiles (Controlled Diffusion Airfoils). Two different builds were investigated. Both builds used identical rotors, but had stators configured either in cantilevered or in shrouded form.

Traverse measurements of total pressure and flow angle at six axial locations (IGV, two rotor and three stator exit planes) were performed between 1% and 99% annulus height and across two blade pitches. Circumferentially mass-averaged radial profiles were used in a through-flow code for reconstruction analysis of the measurements. In addition to the traverse measurements surface static pressures on stage 3 rotor and stator were measured. The effect of the “free-end” configuration on an embedded stage of this multistage compressor is described and compared to the shrouded configuration. The objective of this study was to investigate the differences of these two configurations and especially the effects caused by the hub clearance vortex in the cantilevered case.

The entire set of measurements and through-flow analysis was performed at two operating points of the compressor i.e. at peak efficiency and near stall condition. Thus also the effects of the hub clearance vortex which influences the stall margin of the compressor are described. The analysis of the results shows slightly higher pressure rise coefficients for shrouded stators, but slightly higher stall margin in the cantilevered case. This is due to a stabilizing effect of the hub clearance vortex (cleans up separation on hub) in the cantilevered configuration because its direction is opposite to the secondary flow in the passage.
Micro Gas Turbine for Combined Heat and Power in Distributed Generation
Authors: Carnö Johanna , Cavani Adrin , Liinanki Leif
Published: December 2014

Micro gas turbine units are becoming popular for on-site combined heat and power production (CHP). CHP units based on gas turbines have several advantages; low emissions, compactness, low maintenance costs and fuel flexibility. The successful development of a small high-speed turbogenerator gives major opportunities to meet the customers’ demands in a deregulated and competitive market.

Vattenfall, together with Volvo Aero Turbines and ABB, has actively participated in development of a future concept of micro gas turbines. The first demonstration plant in Northern Europe for small scale heat and power co-generation, a 40 kWe turbogenerator was installed by Vattenfall at Pappersgruppen in Gothenburg, Sweden.

A first evaluation phase of the demonstration plant has been performed. The electricity and heat output showed to be 38 kWe and 70 kW respectively at full load. The net plant efficiency was 28.2% and the overall efficiency was 80%, based on the lower heating value. The emissions from the unit were very low due to low emission combustion chamber. The evaluation period will continue during 97/98. The influence of outdoor temperature, degree of loading, as well as the required maintenance and manned operation will be investigated.
Experimental Evaluation of the High-to-Low Speed Transformation Process for a Highly Loaded Core Compressor Stage
Authors: Lyes P. A. , Ginder R. B.
Published: December 2014

A set of low speed blading has been designed to represent an embedded stage from the DERA C147 high speed research compressor. The aim of the design was to undertake a careful high-to-low speed transformation of the geometry of a high speed stage and evaluate the transformation process through comparing detailed flow measurements taken in both the high and low speed environments.

The high-to-low speed transformation process involves compromises due to both geometric and aerodynamic constraints. Geometric constraints include the parallel annulus of the low speed compressor and also its size and power which restrict the Reynolds number that can be achieved. Aerodynamically the high speed blades have to be subsonic and the effects of Mach number on loss buckets and boundary layer development limit the extent to which a full high-to-low speed match is possible.

The low speed blading has been tested at Cranfield University’s 4-stage research compressor facility. Detailed traverse measurements were taken at rotor and stator exit along with blade surface static pressure measurements and oil flow visualisation. These, along with previous traverse measurements from the C147 compressor, have been used to show that a good comparison of pressure, flow angle, and endwall loss distributions can be achieved despite the compromises inherent in the transformation process. However some interesting differences were apparent and these are discussed.

In addition, 3D flow calculations have been performed on both the rotor and stator using measured inlet conditions. These predictions model the endwall corner flow well. However, further work is needed to obtain better modelling of the clearance flow of both blade rows.
Improved Pt Aluminide Coatings Using CVD and Novel Platinum Electroplating
Authors: Warnes Bruce Michael
Published: December 2014

Chemical vapor deposition (CVD) is an old coating technology, but it was not successfully utilized to aluminize gas turbine hardware until recently (1989). In CVD aluminizing, the use of multiple, independently controlled, low temperature, external, metal halide generators combined with computer control of all process variables gives flexibility and consistent quality that is not possible with any other aluminizing process.

It has been shown that harmful coating impurities (such as sulfur and boron etc.) can be transported to a coating from a high temperature aluminum source in the coating chamber during aluminizing. Representative processes include: pack cementation, above the pack, SNECMA, and high activity CVD. In contrast, it has also been demonstrated that CVD low activity aluminizing removes harmful impurities (S, P, B & W etc.) from the coating during deposition. Furthermore, clean, low activity coatings (simple aluminide MDC-210 or platinum modified MDC-150L) have been shown to exhibit superior oxidation resistance compared to similar coatings made by other aluminizing processes. A second significant source of impurities in platinum modified aluminide diffusion coatings is electroplating, that is, plating bath components (S, P, CI, K, Ca etc.) are codeposited with the platinum, and these impurities can have either a beneficial (K&Ca) or a detrimental (S,P&Cl) influence upon the oxidation resistance of the product coating.

The results of investigations on the transport of impurities during aluminizing and electroplating, plus the influence of these impurities on oxidation resistance of the product coatings will be presented and discussed.
Development of a 50-kW, Low-Emission Turbogenerator for Hybrid Electric Vehicles
Authors: O’Brien Patrick
Published: December 2014

This paper describes the development of a low-emission, 50-kW turbine-driven generator called a turbogenerator. It gives a detailed description of the key design features that benefit hybrid electric vehicles driven in various driving cycles. Although the turbogenerator is designed for hybrid electric vehicles, other applications such as standby and primary electric power generation will benefit from its characteristics. These include very-low-exhaust emissions, low cost, high reliability, high fuel efficiency, compact design, and low noise levels. The turbogenerator is relatively unique in that the turbine wheel, compressor impeller, and electrical generator are all mounted on a single, common shaft which is supported on air bearings. These features eliminate the need for both the gearbox and oil lubrication commonly found on conventional automotive and gas turbine engines. AlliedSignal developed the 50-kW turbogenerator for Ford Motor Company under the DOE Hybrid Electric Vehicle Propulsion Program. The turbogenerator is designed to fit into the engine compartment of a Mercury Sable. AlliedSignal originally proved this innovative concept in an APU development program for the U.S. Army. The unit developed for that program has accumulated over 600 hours of operation in laboratory and Army vehicle tests.
A Risk Based Approach to the Potential for CCGT Enclosure Explosions: A Study on Teesside Power Station
Authors: Hunt Peter J. , Beanland Michael G.
Published: December 2014

The potential for an explosion inside a Gas Turbine Combined Heat and Power (CHP) plant or a Combined Cycle Gas Turbine (CCGT) plant enclosure from a fuel leak has been widely addressed in the industry and reviewed at a number of seminars. Enron, the Teesside Power Station operators, contracted Eutech to undertake a study into the explosion potential inside the gas turbine (GT) enclosure and to recommend solutions to achieve an acceptable level of risk.
Effects of Inlet Flow Field Conditions on the Performance of Centrifugal Compressor Diffusers: Part 1 — Discrete-Passage Diffuser
Authors: Filipenco Victor G. , Deniz Sabri , Johnston J. Mark , Greitzer Edward M. , Cumpsty Nicholas A.
Published: December 2014

This is Part 1 of a two-part paper considering the performance of radial diffusers for use in a high performance centrifugal compressor. Part 1 reports on discrete-passage diffusers (shown in Fig. 1) while Part 2 describes a test of a straight-channel diffuser designed for equivalent duty. Two builds of discrete-passage diffuser were tested, with 30 and 38 separate passages. Both the 30 and 38 passage diffusers investigated showed comparable range of unstalled operation and similar level of overall diffuser pressure recovery.

The paper concentrates on the influence of inlet flow conditions on the pressure recovery and operating range of radial diffusers for centrifugal compressor stages. The flow conditions examined include diffuser inlet Mach number, flow angle, blockage, and axial flow non-uniformity. The investigation was carried out in a specially built test facility, designed to provide a controlled inlet flow field to the test diffusers. The facility can provide a wide range of diffuser inlet velocity profile distortion and skew with Mach numbers up to unity and flow angles of 63° to 75° from the radial direction.

The consequences of different averaging methods for the inlet total pressure distributions, which are needed in the definition of diffuser pressure recovery coefficient for non-uniform diffuser inlet conditions were also assessed. The overall diffuser pressure recovery coefficient, based on suitably averaged inlet total pressure, was found to correlate well with the momentum-averaged flow angle into the diffuser. Furthermore the pressure recovery coefficient was found to be essentially independent of the axial distortion at diffuser inlet, and the Mach number, over the wide flow range (from maximum flow to the beginning of flow instabilities) investigated. It is thus shown that the generally accepted sensitivity of diffuser pressure recovery performance to inlet flow distortion and boundary layer blockage can be largely attributed to inappropriate quantification of the average dynamic pressure at diffuser inlet. Use of an inlet dynamic pressure based on availability or mass-averaging in combination with definition of inlet flow angle based on mass average of the radial and tangential velocity at diffuser inlet removes this sensitivity.
PM2000 Honeycomb Structures
Authors: Brown C. , Verghese E. , Sporer D. , Sellors R.
Published: December 2014

The use of oxide dispersion strengthened (ODS) superalloys for excellent high temperature oxidation resistance has been well established. This is achieved by the formation of a dense, slowly growing and tightly adherent alumina scale on Fe-Cr-Al and Ni-Cr-Al ODS alloys. The addition of oxide dispersion strengthening confers a structural capability for operation temperatures of up to 1350°C. Traditionally these materials have been used in relatively thick sections where the core “reservoir” of aluminium is adequate to provide a continuous replenishment of the protective oxide coating.

This paper examines the use of one of these materials, PM2000, in thin section structures. In particular it addresses the problem of using thin foils in the manufacture of a typical engineering structure, seal honeycomb. Thin foils in the thickness range 90 to 150μm were tested to explore the oxidation limit under extreme temperature conditions. The results indicate that material life is determined by foil thickness and aluminium content of the alloy. Comparison is drawn with existing typical materials for these applications e.g. Haynes 214.
Thermodynamic Analysis of Advanced Power Cycles Based Upon Solid Oxide Fuel Cells, Gas Turbines and Rankine Bottoming Cycles
Authors: Campanari S. , Macchi E.
Published: December 2014

This paper investigates the thermodynamic potential of the integrated Solid Oxide Fuel Cell - Gas Turbine technology for medium and large scale electric power production. After detailed description of the adopted calculation model, the performances of a variety of plant configurations are presented. The obtained results show the possibility of achieving very high efficiencies with pressurized SOFC-gas turbine cycles with heat recovery bottoming cycles: net LHV efficiencies exceeding 70% with almost zero-NOx emissions.
Confocal sputtering of conformal α-β phase W films on etched Al features
Authors: Kreikebaum John Mark , Cabrera Blas , Yen Jeffrey J. , Brink Paul L. , Cherry Matt , Tomada Astrid , Young Betty A.
Published: December 2014

The authors report on thin-film processing improvements in the fabrication of superconducting quasiparticle-trap-assisted electrothermal-feedback transition-edge sensors used in the design of cryogenic dark matter search detectors. The work was performed as part of a detector upgrade project that included optimization of a new confocal sputtering system and development of etch recipes compatible with patterning 40 nm-thick, α-β mixed-phase W films deposited on 300–600 nm-thick, patterned Al. The authors found that their standard exothermic Al wet etch recipes provided inadequate W/Al interfaces and led to poor device performance. The authors developed a modified Al wet-etch recipe that effectively mitigates geometrical step-coverage limitations while maintaining their existing device design. Data presented here include scanning electron microscope and focused ion beam images of films and device interfaces obtained with the new Al etch method. The authors also introduce a method for quantitatively measuring the energy collection efficiency through these interfaces.
Balanced polarimeter: A cost-effective approach for measuring the polarization of light
Authors: Patterson Luke H. C. , Kihlstrom Kenneth E. , Everest Michael A.
Published: December 2014

We have designed and built a fast and precise balanced polarimeter from components commonly found in undergraduate physics laboratories. Balanced polarimetry measures the orientation of linearly polarized light by splitting the beam into orthogonal polarization components and detecting each separately. Our polarimeter is capable of measuring the orientation of linearly polarized light with a precision of approximately 0.001°/Hz. The apparatus cost less than $1000. Measurements of the specific rotation of sucrose and of the Faraday effect were performed, both of which produced results that were comparable to previously reported values.
“We Can Talk While We’re Walking”: Seeking the Views of Adults With Intellectual Disability to Inform a Walking and Social-Support Program
Authors: Brooker Katie , Mutch Allyson , McPherson Lyn , Ware Robert , Lennox Nick , Van Dooren Kate
Published: December 2014

To better understand how physical activity programs may contribute to improved health and social-support outcomes for people with intellectual disability, the authors conducted semistructured interviews with 11 people with intellectual disability and community-based volunteers in Brisbane, Australia. Three broad themes emerged: individual factors that generally facilitated activity, external factors that posed barriers to participation, and broader normative factors that directed participation. A key reflection arising out of the thematic analysis was that participants with intellectual disability and volunteers highlighted subtle but pervasive differences in barriers and facilitators to being active. Recommendations are provided for interventions aiming to improve physical activity and social support among those with intellectual disability. The authors’ research process demonstrates the utility of seeking the views of potential participants before program rollout to inform implementation and demonstrates the usefulness of a qualitative, actively inclusive approach to health interventions.
Pharmacokinetics of LFF571 and Vancomycin in Patients with Moderate Clostridium difficile Infections
Authors: Bhansali Suraj G. , Mullane Kathleen , Ting Lillian S. L. , Leeds Jennifer A. , Dabovic Kristina , Praestgaard Jens , Pertel Peter
Published: December 2014

Clostridium difficile
infection causes diarrheal disease with potentially fatal complications. Although treatments are available, including vancomycin, metronidazole, and fidaxomicin, the recurrence of disease after therapy remains a problem. LFF571 is a novel thiopeptide antibacterial that shows
in vitro
potency against
C. difficile
that is comparable to or greater than that of other clinically used antibiotics. Here, we compare the pharmacokinetics (PK) of LFF571 and vancomycin in patients with
C. difficile
infection as part of an early efficacy study. This multicenter, randomized, evaluator-blind, and active-controlled study evaluated the safety, efficacy, and pharmacokinetics of LFF571 in adults with primary episodes or first relapses of moderate
C. difficile
infections. Patients were randomized to receive 200 mg of LFF571 or 125 mg of vancomycin four times daily for 10 days. The PK parameters were calculated from drug concentrations measured in serum and fecal samples. The systemic exposure following oral administration of 200 mg of LFF571 four times per day for 10 days in patients with
C. difficile
infection was limited. The highest LFF571 serum concentration observed was 41.7 ng/ml, whereas the levels in feces at the end of treatment were between 107 and 12,900 μg/g. In comparison, the peak vancomycin level observed in serum was considerably higher, at 2.73 μg/ml; the levels of vancomycin in feces were not measured. Similar to healthy volunteers, patients with
C. difficile
infections exhibited high fecal concentrations and low serum levels of LFF571. These results are consistent with the retention of LFF571 in the lumen of the gastrointestinal tract. (This study has been registered at ClinicalTrials.gov under registration no. NCT01232595.)
Characterization of the Novel DNA Gyrase Inhibitor AZD0914: Low Resistance Potential and Lack of Cross-Resistance in Neisseria gonorrhoeae
Authors: Alm Richard A. , Lahiri Sushmita D. , Kutschke Amy , Otterson Linda G. , McLaughlin Robert E. , Whiteaker James D. , Lewis Lisa A. , Su Xiaohong , Huband Michael D. , Gardner Humphrey , Mueller John P.
Published: December 2014

The unmet medical need for novel intervention strategies to treat
Neisseria gonorrhoeae
infections is significant and increasing, as rapidly emerging resistance in this pathogen is threatening to eliminate the currently available treatment options. AZD0914 is a novel bacterial gyrase inhibitor that possesses potent
in vitro
activities against isolates with high-level resistance to ciprofloxacin and extended-spectrum cephalosporins, and it is currently in clinical development for the treatment of
N. gonorrhoeae
infections. The propensity to develop resistance against AZD0914 was examined in
N. gonorrhoeae
and found to be extremely low, a finding supported by similar studies with
Staphylococcus aureus
. The genetic characterization of both first-step and second-step mutants that exhibited decreased susceptibilities to AZD0914 identified substitutions in the conserved GyrB TOPRIM domain, confirming DNA gyrase as the primary target of AZD0914 and providing differentiation from fluoroquinolones. The analysis of available bacterial gyrase and topoisomerase IV structures, including those bound to fluoroquinolone and nonfluoroquinolone inhibitors, has allowed the rationalization of the lack of cross-resistance that AZD0914 shares with fluoroquinolones. Microbiological susceptibility data also indicate that the topoisomerase inhibition mechanisms are subtly different between
N. gonorrhoeae
and other bacterial species. Taken together, these data support the progression of AZD0914 as a novel treatment option for the oral treatment of
N. gonorrhoeae
infections.
Exopolysaccharide Production and Ropy Phenotype Are Determined by Two Gene Clusters in Putative Probiotic Strain Lactobacillus paraplantarum BGCG11
Authors: Zivkovic Milica , Miljkovic Marija , Ruas-Madiedo Patricia , Strahinic Ivana , Tolinacki Maja , Golic Natasa , Kojic Milan
Published: December 2014

Lactobacillus paraplantarum
BGCG11, a putative probiotic strain isolated from a soft, white, artisanal cheese, produces a high-molecular-weight heteropolysaccharide, exopolysaccharide (EPS)-CG11, responsible for the ropy phenotype and immunomodulatory activity of the strain. In this study, a 26.4-kb region originating from the pCG1 plasmid, previously shown to be responsible for the production of EPS-CG11 and a ropy phenotype, was cloned, sequenced, and functionally characterized. In this region 16 putative open reading frames (ORFs), encoding enzymes for the production of EPS-CG11, were organized in specific loci involved in the biosynthesis of the repeat unit, polymerization, export, regulation, and chain length determination. Interestingly, downstream of the
eps
gene cluster, a putative transposase gene was identified, followed by an additional
rfb
gene cluster containing the
rfbACBD
genes, the ones most probably responsible for dTDP-
l
-rhamnose biosynthesis. The functional analysis showed that the production of the high-molecular-weight fraction of EPS-CG11 was absent in two knockout mutants, one in the
eps
and the other in the
rfb
gene cluster, as confirmed by size exclusion chromatography analysis. Therefore, both
eps
and
rfb
genes clusters are prerequisites for the production of high-molecular-weight EPS-CG11 and for the ropy phenotype of strain
L. paraplantarum
BGCG11.
Community Structure and Biogeochemical Impacts of Microbial Life on Floating Pumice
Authors: Elser J. J. , Bastidas Navarro M. , Corman J. R. , Emick H. , Kellom M. , Laspoumaderes C. , Lee Z. M. , Poret-Peterson A. T. , Balseiro E. , Modenutti B.
Published: December 2014

Volcanic eruptions are a widespread force of geological and ecological disturbance and present recurrent opportunities for the study of biological responses to novel habitat formation. However, scientific study of such events is difficult given their short duration and often distant location. Here we report results from opportunistic sampling of unique volcano-generated habitats formed during the 2011 explosive eruption in the Puyehue-Cordón Caulle complex (Chile), when massive amounts of pumice were ejected, creating novel floating substrata that have never before been characterized from a microbiological perspective. DNA sequencing revealed a dynamic community of microbes that came to inhabit the pumice, with a unique composition distinct from that of the lakes' surface waters and with suggestions of ecological convergence across lakes and sampling times. Furthermore, biogeochemical studies of net nutrient fluxes showed that, while the fresh pumice arriving to the lakes was an initial source of phosphorus (P), colonized pumice had high rates of nitrogen (N) and P uptake and was sufficiently abundant to represent a significant lake-wide nutrient sink. These findings highlight the remarkable versatility of microbes in exploiting novel environments and are consistent with a recent proposal of floating pumice as a favorable environment for the initial origins of life on early Earth.
Genetic Engineering Activates Biosynthesis of Aromatic Fumaric Acid Amides in the Human Pathogen Aspergillus fumigatus
Authors: Kalb Daniel , Heinekamp Thorsten , Lackner Gerald , Scharf Daniel H. , Dahse Hans-Martin , Brakhage Axel A. , Hoffmeister Dirk
Published: December 2014

The
Aspergillus fumigatus
nonribosomal peptide synthetase FtpA is among the few of this species whose natural product has remained unknown. Both FtpA adenylation domains were characterized
in vitro
. Fumaric acid was identified as preferred substrate of the first and both
l
-tyrosine and
l
-phenylalanine as preferred substrates of the second adenylation domain. Genetically engineered
A. fumigatus
strains expressed either
ftpA
or the regulator gene
ftpR
, encoded in the same cluster of genes, under the control of the doxycycline-inducible tetracycline-induced transcriptional activation (tet-on) cassette. These strains produced fumaryl-
l
-tyrosine and fumaryl-
l
-phenylalanine which were identified by liquid chromatography and high-resolution mass spectrometry. Modeling of the first adenylation domain
in silico
provided insight into the structural requirements to bind fumaric acid as peptide synthetase substrate. This work adds aromatic fumaric acid amides to the secondary metabolome of the important human pathogen
A. fumigatus
which was previously not known as a producer of these compounds.
Using a Genome-Scale Metabolic Model of Enterococcus faecalis V583 To Assess Amino Acid Uptake and Its Impact on Central Metabolism
Authors: Veith Nadine , Solheim Margrete , van Grinsven Koen W. A. , Olivier Brett G. , Levering Jennifer , Grosseholz Ruth , Hugenholtz Jeroen , Holo Helge , Nes Ingolf , Teusink Bas , Kummer Ursula
Published: December 2014

Increasing antibiotic resistance in pathogenic bacteria necessitates the development of new medication strategies. Interfering with the metabolic network of the pathogen can provide novel drug targets but simultaneously requires a deeper and more detailed organism-specific understanding of the metabolism, which is often surprisingly sparse. In light of this, we reconstructed a genome-scale metabolic model of the pathogen
Enterococcus faecalis
V583. The manually curated metabolic network comprises 642 metabolites and 706 reactions. We experimentally determined metabolic profiles of
E. faecalis
grown in chemically defined medium in an anaerobic chemostat setup at different dilution rates and calculated the net uptake and product fluxes to constrain the model. We computed growth-associated energy and maintenance parameters and studied flux distributions through the metabolic network. Amino acid auxotrophies were identified experimentally for model validation and revealed seven essential amino acids. In addition, the important metabolic hub of glutamine/glutamate was altered by constructing a glutamine synthetase knockout mutant. The metabolic profile showed a slight shift in the fermentation pattern toward ethanol production and increased uptake rates of multiple amino acids, especially
l
-glutamine and
l
-glutamate. The model was used to understand the altered flux distributions in the mutant and provided an explanation for the experimentally observed redirection of the metabolic flux. We further highlighted the importance of gene-regulatory effects on the redirection of the metabolic fluxes upon perturbation. The genome-scale metabolic model presented here includes gene-protein-reaction associations, allowing a further use for biotechnological applications, for studying essential genes, proteins, or reactions, and the search for novel drug targets.
Prevalence of Carriage of Shiga Toxin-Producing Escherichia coli Serotypes O157:H7, O26:H11, O103:H2, O111:H8, and O145:H28 among Slaughtered Adult Cattle in France
Authors: Bibbal Delphine , Loukiadis Estelle , Kérourédan Monique , Ferré Franck , Dilasser Françoise , Peytavin de Garam Carine , Cartier Philippe , Oswald Eric , Gay Emilie , Auvray Frédéric , Brugère Hubert
Published: December 2014

The main pathogenic enterohemorrhagic
Escherichia coli
(EHEC) strains are defined as Shiga toxin (Stx)-producing
E. coli
(STEC) belonging to one of the following serotypes: O157:H7, O26:H11, O103:H2, O111:H8, and O145:H28. Each of these five serotypes is known to be associated with a specific subtype of the intimin-encoding gene (
eae
). The objective of this study was to evaluate the prevalence of bovine carriers of these “top five” STEC in the four adult cattle categories slaughtered in France. Fecal samples were collected from 1,318 cattle, including 291 young dairy bulls, 296 young beef bulls, 337 dairy cows, and 394 beef cows. A total of 96
E. coli
isolates, including 33 top five STEC and 63 atypical enteropathogenic
E. coli
(aEPEC) isolates, with the same genetic characteristics as the top five STEC strains except that they lacked an
stx
gene, were recovered from these samples. O157:H7 was the most frequently isolated STEC serotype. The prevalence of top five STEC (all serotypes included) was 4.5% in young dairy bulls, 2.4% in young beef bulls, 1.8% in dairy cows, and 1.0% in beef cows. It was significantly higher in young dairy bulls (
P
< 0.05) than in the other 3 categories. The basis for these differences between categories remains to be elucidated. Moreover, simultaneous carriage of STEC O26:H11 and STEC O103:H2 was detected in one young dairy bull. Lastly, the prevalence of bovine carriers of the top five STEC, evaluated through a weighted arithmetic mean of the prevalence by categories, was estimated to 1.8% in slaughtered adult cattle in France.
Deletion of
PHO13
, Encoding Haloacid Dehalogenase Type IIA Phosphatase, Results in Upregulation of the Pentose Phosphate Pathway in Saccharomyces cerevisiae
Authors: Kim Soo Rin , Xu Haiqing , Lesmana Anastashia , Kuzmanovic Uros , Au Matthew , Florencia Clarissa , Oh Eun Joong , Zhang Guochang , Kim Kyoung Heon , Jin Yong-Su
Published: December 2014

The haloacid dehalogenase (HAD) superfamily is one of the largest enzyme families, consisting mainly of phosphatases. Although intracellular phosphate plays important roles in many cellular activities, the biological functions of HAD enzymes are largely unknown. Pho13 is 1 of 16 putative HAD enzymes in
Saccharomyces cerevisiae
. Pho13 has not been studied extensively, but previous studies have identified
PHO13
to be a deletion target for the generation of industrially attractive phenotypes, namely, efficient xylose fermentation and high tolerance to fermentation inhibitors. In order to understand the molecular mechanisms underlying the improved xylose-fermenting phenotype produced by deletion of
PHO13
(
pho13
Δ), we investigated the response of
S. cerevisiae
to
pho13
Δ at the transcriptomic level when cells were grown on glucose or xylose. Transcriptome sequencing analysis revealed that
pho13
Δ resulted in upregulation of the pentose phosphate (PP) pathway and NADPH-producing enzymes when cells were grown on glucose or xylose. We also found that the transcriptional changes induced by
pho13
Δ required the transcription factor Stb5, which is activated specifically under NADPH-limiting conditions. Thus,
pho13
Δ resulted in the upregulation of the PP pathway and NADPH-producing enzymes as a part of an oxidative stress response mediated by activation of Stb5. Because the PP pathway is the primary pathway for xylose, its upregulation by
pho13
Δ might explain the improved xylose metabolism. These findings will be useful for understanding the biological function of
S. cerevisiae
Pho13 and the HAD superfamily enzymes and for developing
S. cerevisiae
strains with industrially attractive phenotypes.
Transcriptomic Analysis of Xylan Utilization Systems in Paenibacillus sp. Strain JDR-2
Authors: Sawhney Neha , Crooks Casey , St. John Franz , Preston James F.
Published: December 2014

Xylans, including methylglucuronoxylans (MeGXn) and methylglucuronoarabinoxylans (MeGAXn), are the predominant polysaccharides in hemicellulose fractions of dicots and monocots available for conversion to biofuels and chemicals.Paenibacillussp. strain JDR-2 (Pjdr2) efficiently depolymerizes MeGXnand MeGAXnand assimilates the generated oligosaccharides, resulting in efficient saccharification and subsequent metabolism of these polysaccharides. A xylan utilization regulon encoding a cell-associated GH10 (glycoside hydrolase family 10) endoxylanase, transcriptional regulators, ABC (ATP binding cassette) transporters, an intracellular GH67 α-glucuronidase, and other glycoside hydrolases contributes to complete metabolism. This GH10/GH67 system has been proposed to account for preferential utilization of xylans compared to free oligo- and monosaccharides. To identify additional genes contributing to MeGXnand MeGAXnutilization, the transcriptome of Pjdr2 has been sequenced following growth on each of these substrates as well as xylose and arabinose. Increased expression of genes with different substrates identified pathways common or unique to the utilization of MeGXnor MeGAXn. Coordinate upregulation of genes comprising the GH10/GH67 xylan utilization regulon is accompanied with upregulation of genes encoding a GH11 endoxylanase and a GH115 α-glucuronidase, providing evidence for a novel complementary pathway for processing xylans. Elevated expression of genes encoding a GH43 arabinoxylan arabinofuranohydrolase and an arabinose ABC transporter on MeGAXnbut not on MeGXnsupports a process in which arabinose may be removed extracellularly followed by its rapid assimilation. Further development of Pjdr2 for direct conversion of xylans to targeted products or introduction of these systems into fermentative strains of related bacteria may lead to biocatalysts for consolidated bioprocessing of hemicelluloses released from lignocellulose.
In Situ
Prebiotics for Weaning Piglets:
In Vitro
Production and Fermentation of Potato Galacto-Rhamnogalacturonan
Authors: Strube Mikael Lenz , Ravn Helle Christine , Ingerslev Hans-Christian , Meyer Anne Strunge , Boye Mette
Published: December 2014

Postweaning diarrhea (PWD) in pigs is a leading cause of economic loss in pork production worldwide. The current practice of using antibiotics and zinc to treat PWD is unsustainable due to the potential of antibiotic resistance and ecological disturbance, and novel methods are required. In this study, an
in vitro
model was used to test the possibility of producing prebiotic fiber
in situ
in the gastrointestinal (GI) tract of the piglet and the prebiotic activity of the resulting fiber in the terminal ileum. Soluble fiber was successfully produced from potato pulp, an industrial waste product, with the minimal enzyme dose in a simulated upper GI tract model extracting 26.9% of the initial dry matter. The fiber was rich in galactose and galacturonic acid and was fermented at 2.5, 5, or 10 g/liter in a glucose-free medium inoculated with the gut contents of piglet terminal ileum. Fermentations of 5 g/liter inulin or 5 g/liter of a purified potato fiber were used as controls. The fibers showed high fermentability, evident by a dose-dependent drop in pH and an increase in the organic acid content, with lactate in particular being increased. Deep sequencing showed a significant increase in the numbers of
Lactobacillus
and
Veillonella
organisms and an insignificant increase in the numbers of
Clostridium
organisms as well as a decrease in the numbers of
Streptococcus
organisms. Multivariate analysis showed clustering of the treatment groups, with the group treated with purified potato fiber being clearly separated from the other groups, as the microbiota composition was 60%
Lactobacillus
and almost free of
Clostridium
. For animal studies, a dosage corresponding to the 5-g/liter treatment is suggested.
Genomic Potential for Polysaccharide Deconstruction in Bacteria
Authors: Berlemont Renaud , Martiny Adam C.
Published: December 2014

Glycoside hydrolases are important enzymes that support bacterial growth by enabling the degradation of polysaccharides (e.g., starch, cellulose, xylan, and chitin) in the environment. Presently, little is known about the overall phylogenetic distribution of the genomic potential to degrade these polysaccharides in bacteria. However, knowing the phylogenetic breadth of these traits may help us predict the overall polysaccharide processing in environmental microbial communities. In order to address this, we identified and analyzed the distribution of 392,166 enzyme genes derived from 53 glycoside hydrolase families in 8,133 sequenced bacterial genomes. Enzymes for oligosaccharides and starch/glycogen were observed in most taxonomic groups, whereas glycoside hydrolases for structural polymers (i.e., cellulose, xylan, and chitin) were observed in clusters of relatives at taxonomic levels ranging from species to genus as determined by consenTRAIT. The potential for starch and glycogen processing, as well as oligosaccharide processing, was observed in 85% of the strains, whereas 65% possessed enzymes to degrade some structural polysaccharides (i.e., cellulose, xylan, or chitin). Potential degraders targeting one, two, and three structural polysaccharides accounted for 22.6, 32.9, and 9.3% of genomes analyzed, respectively. Finally, potential degraders targeting multiple structural polysaccharides displayed increased potential for oligosaccharide deconstruction. This study provides a framework for linking the potential for polymer deconstruction with phylogeny in complex microbial assemblages.
A Fungal Sarcolemmal Membrane-Associated Protein (SLMAP) Homolog Plays a Fundamental Role in Development and Localizes to the Nuclear Envelope, Endoplasmic Reticulum, and Mitochondria
Authors: Nordzieke Steffen , Zobel Thomas , Fränzel Benjamin , Wolters Dirk A. , Kück Ulrich , Teichert Ines
Published: December 2014

S
arco
l
emmal
m
embrane-
a
ssociated
p
rotein (SLMAP) is a tail-anchored protein involved in fundamental cellular processes, such as myoblast fusion, cell cycle progression, and chromosomal inheritance. Further,
SLMAP
misexpression is associated with endothelial dysfunctions in diabetes and cancer. SLMAP is part of the conserved
str
iatin-
i
nteracting
p
hosphatase
a
nd
k
inase (STRIPAK) complex required for specific signaling pathways in yeasts, filamentous fungi, insects, and mammals. In filamentous fungi, STRIPAK was initially discovered in
Sordaria macrospora
, a model system for fungal differentiation. Here, we functionally characterize the STRIPAK subunit PRO45, a homolog of human SLMAP. We show that PRO45 is required for sexual propagation and cell-to-cell fusion and that its
f
ork
h
ead-
a
ssociated (FHA) domain is essential for these processes. Protein-protein interaction studies revealed that PRO45 binds to STRIPAK subunits PRO11 and SmMOB3, which are also required for sexual propagation. Superresolution
s
tructured-
i
llumination
m
icroscopy (SIM) further established that PRO45 localizes to the nuclear envelope, endoplasmic reticulum, and mitochondria. SIM also showed that localization to the nuclear envelope requires STRIPAK subunits PRO11 and PRO22, whereas for mitochondria it does not. Taken together, our study provides important insights into fundamental roles of the fungal SLMAP homolog PRO45 and suggests STRIPAK-related and STRIPAK-unrelated functions.
A new screening instrument for disability in low-income and middle-income settings: application at the Iganga-Mayuge Demographic Surveillance System (IM-DSS), Uganda
Authors: Bachani Abdulgafoor M , Galiwango Edward , Kadobera Daniel , Bentley Jacob A , Bishai David , Wegener Stephen , Hyder Adnan A
Published: December 2014

Objective

The measurement of disability in low-income countries is recognised as a major deficiency in health information systems, especially in Africa. The Iganga and Mayuge Demographic Surveillance System (IM-DSS) in Uganda provides a special opportunity to develop population-based data to inform national health policies and evaluate innovations in assessing the burden of disability in Uganda. In this study, we apply a new instrument to screen for physical disabilities at the IM-DSS. The study utilised a modified version of the short set of questions proposed by the Washington Group on Disability Statistics. The instrument was applied at the household level and information was collected on all individuals over the age of 5, who were residents of the IM-DSS.

Setting

The study was based at the IM-DSS, which covers the parts of Iganga and Mayuge districts in Eastern Uganda.

Participants

57 247 individuals were included in the survey, with 51% of the study population being women.

Primary outcomes

Activity limitations

Results

The overall prevalence of physical disability at the IM-DSS was 9.4%, with vision being the most common type of difficulty reported in this population, and communication being least prevalent. Disability was less likely to be observed among males than their female counterparts (OR 0.75; 95% CI 0.71 to 0.81; p<0.001). Statistically significant associations were found between disability and increasing age, as well as disability and decreasing household wealth status.

Conclusions

This study shows that the modified short set of questions can be readily applied in a DSS setting to obtain estimates on the prevalence and types of disability at the population level. This instrument could be adapted for use to screen for disability in other LMIC settings, providing estimates that are comparable across different global regions and populations.
Prevalence of work-related musculoskeletal symptoms of the neck and upper extremity among dentists in China
Authors: Feng Beibei , Liang Qi , Wang Yuling , Andersen Lars L , Szeto Grace
Published: December 2014

Objectives

Studies from western countries show that dentists are vulnerable to work-related musculoskeletal disorders (WMSDs) of the neck and upper extremities, but little is known about their epidemiology among members of this rapidly growing profession in China. This study aims to investigate the prevalence of WMSDs and identify potential risk factors associated with their occurrence in the dental profession in China.

Setting and participants

A cross-sectional survey was carried out in 52 different hospitals in a large metropolitan city in China. A total of 304 questionnaires were distributed to respondents identified via stratified random sampling and 272 dentists (121 females and 151 males) completed the survey. The response rate was 89.5%.

Outcomes

Visual analogue score was used to record neck and upper limb musculoskeletal symptoms on a body chart. Work-related risk factors, including physical and psychosocial factors, were accounted for in the regression analysis.

Results

88% of the dentists reported at least one musculoskeletal disorder and 83.8% suffered from neck pain. In the multivariate analyses, working hours per day were associated with neck pain (OR=1.43; 95% CI 1.03 to 1.98). Inability to select the appropriate size of dental instrument was associated with shoulder (OR=2.07; 95% CI 1.00 to 4.32) and wrist/hand (OR=2.47; 95% CI 1.15 to 5.32) pain. As for psychosocial factors, high job demand was associated with symptoms in the shoulder (OR=1.09; 95% CI 1.00 to 1.18), elbow (OR=1.11; 95% CI 1.03 to 1.19) and wrist/hand (OR=1.09; 95% CI 1.02 to 1.17). Regular physical exercise was associated with decreased neck pain (OR=0.37; 95% CI 0.14 to 1.00).

Conclusions

The prevalence of WMSDs among Chinese dentists is high. Specifically, long working hours, inability to select the appropriate size of dental instrument and high job demand are the most significant risk factors.
The effect of the National Essential Medicines Policy on health expenditures and service delivery in Chinese township health centres: evidence from a longitudinal study
Authors: Zhang Xin , Wu Qunhong , Liu Guoxiang , Li Ye , Gao Lijun , Guo Bin , Fu Wenqi , Hao Yanhua , Cui Yu , Huang Weidong , Coyte Peter C
Published: December 2014

Objectives

The government of China has introduced a National Essential Medicines Policy (NEMP) in the new round of health system reform. The objective of this paper is to analyse whether the NEMP can play a role in curbing the rise of medical expenditures without disrupting the availability of healthcare services at township hospitals in China.

Design

This study adopted a pre–post treatment-control study design. A difference-in-differences method and fixed-effects model for panel data were employed to estimate the effect of the NEMP.

Setting

Chongqing, Jiangsu and Henan Province, in China, in 2009 and 2010.

Participants

296 township health centres.

Outcome measures

Outcomes for health expenditures were average outpatient drug expenses per visit, average inpatient drug expenses per discharged patient, average outpatient expenses per visit and average inpatient expenses per discharged patient. Outcomes for care delivery were the numbers of visits per certified doctor per day and the numbers of hospitalised patients per certified doctor per day.

Results

The township health centres that were enrolled in the NEMP reported 26% (p<0.01) lower drug expenditures for inpatient care. An 11% (p<0.05) decrease in average inpatient expenditures per discharged patient was found following the implementation of the NEMP. The impacts of the NEMP on average outpatient expenditures and outpatient drug expenditures were not statistically significant at the 5% level. No statistically significant associations were found between the NEMP and reduction in quantity of health service delivery.

Conclusions

The NEMP was significant in its effect in reducing inpatient medication and health service expenditures. This study shows no evidence that the quantity of healthcare service declined significantly after introduction of the NEMP over the study period, which suggests that if appropriate matching policies are introduced, the side effects of the NEMP can be counteracted to some degree. Further research including a long-term follow-up study is needed.
Translation research: ‘Back on Track’, a multiprofessional rehabilitation service for cancer-related fatigue
Authors: Gracey J H , Watson M , Payne C , Rankin J , Dunwoody L
Published: December 2014

Objectives

To assess the effectiveness and acceptability of an individually tailored rehabilitation intervention for patients with cancer-related fatigue (CRF).

Methods

Eighteen individuals, (16 female, two male, aged 40–83 years), who self-reported CRF (above four on a 10-point Likert scale) took part in an 8 week physical activity intervention weekly review and optional gym-based support. Fifteen participants had a primary diagnosis of breast cancer and along with the other participants had multiple myeloma, colorectal or prostate cancer. All participants took part in a goal-oriented walking and muscle strengthening programme with dietary advice and psychological support based on the Transtheoretical Model (TTM) of behaviour change. Effectiveness was assessed by physical and psychological outcomes. Focus groups with participants and individual interviews with the professionals delivering the intervention explored the feasibility and acceptability of the intervention.

Results

Statistically significant improvements were seen in the primary outcome of fatigue and on the secondary outcomes of physical function, depression and in triceps skin fold thickness reduction. Participants endorsed the intervention as being highly acceptable, holistic and as important as medical treatments for cancer. The importance of team working was highlighted as key to service delivery and success.

Conclusions

A multidisciplinary home-based tailored intervention with optional weekly gym attendance is acceptable to people with CRF, improving physical and psychosocial outcomes. Study limitations and suggestions for further research are discussed.