bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic diversity and clonal characteristics of ciprofloxacin-resistant meningococcal strains in China
Authors: Zhu Bingqing , Fan Yaochun , Xu Zheng , Xu Li , Du Pengcheng , Gao Yuan , Shao Zhujun
Published: August 2014

The purpose of the present study was to identify the clonal characteristics and gyrA gene diversity of ciprofloxacin-resistant meningococcal strains in China. One hundred and forty-one ciprofloxacin-resistant and 103 ciprofloxacin-susceptible meningococcal strains were selected for multilocus sequence typing. Of these, 54 ciprofloxacin-resistant and 42 ciprofloxacin-susceptible strains were selected for gyrA gene sequencing. Of the three clonal complexes prevalent in China, serogroup A of ST-5 complex (CC5) and serogroup C/B strains of CC4821 had a high proportion of ciprofloxacin resistance, whereas CC11 serogroup W strains were all susceptible. Nucleotide and amino acid sequences of the gyrA gene among ciprofloxacin-resistant strains showed more diversity than those among ciprofloxacin-susceptible strains. All ciprofloxacin-resistant strains had a T91I mutation and the ciprofloxacin-susceptible strains had no T91I mutation. Phylogenetic analysis showed that the gyrA gene sequences of CC4821 serogroup B/C strains, CC11 serogroup W, CC1 serogroup A, ciprofloxacin-susceptible CC5 serogroup A and reference strains had high similarity. By contrast, the ciprofloxacin-resistant CC5 serogroup A strains had a highly conserved gyrA gene sequence which was different (94.8 % similarity) from that in the above strains. The results of our investigation showed that the high proportion of ciprofloxacin resistance in Neisseria meningitidis is associated with certain sequence types (STs) or clonal complexes (CCs). The prevalence of certain CCs with a high proportion of ciprofloxacin resistance can facilitate the spread of ciprofloxacin resistance.
Evolutionary dynamics and genetic diversity from three genes of Anguillid rhabdovirus
Authors: Bellec Laure , Cabon Joelle , Bergmann Sven , de Boisséson Claire , Engelsma Marc , Haenen Olga , Morin Thierry , Olesen Niels Jørgen , Schuetze Heike , Toffan Anna , Way Keith , Bigarré Laurent
Published: August 2014

Wild freshwater eel populations have dramatically declined in recent past decades in Europe and America, partially through the impact of several factors including the wide spread of infectious diseases. The anguillid rhabdoviruses eel virus European X (EVEX) and eel virus American (EVA) potentially play a role in this decline, even if their real contribution is still unclear. In this study, we investigate the evolutionary dynamics and genetic diversity of anguiillid rhabdoviruses by analysing sequences from the glycoprotein, nucleoprotein and phosphoprotein (P) genes of 57 viral strains collected from seven countries over 40 years using maximum-likelihood and Bayesian approaches. Phylogenetic trees from the three genes are congruent and allow two monophyletic groups, European and American, to be clearly distinguished. Results of nucleotide substitution rates per site per year indicate that the P gene is expected to evolve most rapidly. The nucleotide diversity observed is low (2–3 %) for the three genes, with a significantly higher variability within the P gene, which encodes multiple proteins from a single genomic RNA sequence, particularly a small C protein. This putative C protein is a potential molecular marker suitable for characterization of distinct genotypes within anguillid rhabdoviruses. This study provides, to our knowledge, the first molecular characterization of EVA, brings new insights to the evolutionary dynamics of two genotypes ofAnguillid rhabdovirus, and is a baseline for further investigations on the tracking of its spread.
Controlling Shareholder‐Manager Collusion and Tunneling: Evidence from China
Authors: Zhang Min , Gao Shenghao , Guan Xinjiao , Jiang Fuxiu
Published: August 2014

Manuscript Type

Empirical

Research Question/Issue

This study examines whether and how controlling shareholders collude with managers with respect to tunneling.

Research Findings/Insights

Using data from Chinese listed companies, we find evidence consistent with the collusion hypothesis. Specifically, we find that the separation of control and cash flow rights is negatively associated with managerial pay‐performance and turnover‐performance sensitivity. These results suggest that controlling shareholders with excess control rights collude with managers by weakening performance‐based incentives. Further evidence suggests that the negative relation between excess control rights and performance‐based incentives is more pronounced in less profitable and less promising firms. We also find preliminary evidence for rent‐sharing behavior between controlling shareholders and managers.

Theoretic/Academic Implications

We incorporate the influence of managers into the agency framework between controlling and minority shareholders and suggest that controlling shareholders and managers expropriate the minority shareholders. We also propose that excess control rights undermine normal, effective, performance‐based incentives and induce rent‐sharing behavior between controlling shareholders and managers.

Practitioner/Policy Implications

We advise firms' stakeholders, especially minority shareholders, to detect tunneling by observing executive incentives. We suggest that policy makers pay particular attention to the collusion between tunneling participants rather than merely prohibiting certain tunneling tactics. We also recommend that regulators strengthen corporate governance norms and improve the corporate governance environment.
Fetal growth in relation to gestational weight gain in women with Type 2 diabetes: an observational study
Authors: Parellada C. B. , Ásbjörnsdóttir B. , Ringholm L. , Damm P. , Mathiesen E. R.
Published: August 2014

Aims

To evaluate fetal growth in relation to gestational weight gain in women with Type 2 diabetes.

Methods

A retrospective cohort study of 142 consecutive pregnancies in 28 women of normal weight, 39 overweight women and 75 obese women with Type 2 diabetes (pre‐pregnancy BMI  < 25, 25–29.9,  ≥ 30 kg/m2, respectively). Gestational weight gain was categorized as excessive (exceeding the US Institute of Medicine recommendations) or as non‐excessive (within or below the Institute of Medicine recommendations).

Results

Excessive and non‐excessive gestational weight gain were seen in 61 (43%) and 81 women (57%) with a median (range) gestational weight gain of 14.3 (9–32) vs 7.0 (−5–16) kg (P < 0.001), respectively. Infants of women with excessive gestational weight gain were characterized by higher birth weight (3712 vs 3258 g; P = 0.001), birth weight z‐score (1.14 vs ‐0.01, P = 0.001) and prevalence of large‐for‐gestational‐age infants (48 vs 20%; P < 0.001). In normal weight, overweight and obese women with non‐excessive gestational weight gain, the median weight gain in the first half of pregnancy was 371, 114 and 81 g/week, and in the second half of pregnancy 483, 427 and 439 g/week, respectively. In multiple linear regression analysis, gestational weight gain was associated with a higher infant birth weight z‐score independent of pre‐pregnancy BMI, smoking, HbA1c and insulin dose at last visit, ethnicity and parity [β=0.1 (95% CI 0.06–0.14), P < 0.001].

Conclusions

Infant birth weight was almost 0.5 kg higher in women with Type 2 diabetes and excessive gestational weight gain than in women with Type 2 diabetes and non‐excessive weight gain.
A genome‐wide search for quantitative trait loci affecting the cortical surface area and thickness of Heschl's gyrus
Authors: Cai D.‐C. , Fonteijn H. , Guadalupe T. , Zwiers M. , Wittfeld K. , Teumer A. , Hoogman M. , Arias‐Vásquez A. , Yang Y. , Buitelaar J. , Fernández G. , Brunner H. G. , van Bokhoven H. , Franke B. , Hegenscheid K. , Homuth G. , Fisher S. E. , Grabe H. J. , Francks C. , Hagoort P.
Published: August 2014

Heschl's gyrus (HG) is a core region of the auditory cortex whose morphology is highly variable across individuals. This variability has been linked to sound perception ability in both speech and music domains. Previous studies show that variations in morphological features of HG, such as cortical surface area and thickness, are heritable. To identify genetic variants that affect HG morphology, we conducted a genome‐wide association scan (GWAS) meta‐analysis in 3054 healthy individuals using HG surface area and thickness as quantitative traits. None of the single nucleotide polymorphisms (SNPs) showed association P values that would survive correction for multiple testing over the genome. The most significant association was found between right HG area and SNP rs72932726 close to gene DCBLD2 (3q12.1; P = 2.77 × 10−7). This SNP was also associated with other regions involved in speech processing. The SNP rs333332 within gene KALRN (3q21.2; P = 2.27 × 10−6) and rs143000161 near gene COBLL1 (2q24.3; P = 2.40 × 10−6) were associated with the area and thickness of left HG, respectively. Both genes are involved in the development of the nervous system. The SNP rs7062395 close to the X‐linked deafness gene POU3F4 was associated with right HG thickness (Xq21.1; P = 2.38 × 10−6). This is the first molecular genetic analysis of variability in HG morphology.
The Effect of Magnesium and Zinc Ions on the Hydration Kinetics of C3S
Authors: Bazzoni Amélie , Ma Suhua , Wang Qianqian , Shen Xiadong , Cantoni Marco , Scrivener Karen L.
Published: August 2014

Impure tricalcium silicate (C3S) in portland cement may contain various foreign ions. These ions can stabilize different polymorphs of C3S at room temperature and may affect its reactivity. In this paper, the effects of magnesium and zinc on the polymorph type, hydration kinetics, and the hydrate morphology of C3S were investigated. The pure C3S has the T1 structure while magnesium and zinc stabilize polymorphs M3 and T2/T3, respectively. The two elements have distinct effects on the hydration kinetics. Zinc increases the maximum heat released. Magnesium increases the hydration peak width. The C–S–H morphology is modified, leading to longer needles in the presence of zinc and thicker needles in the presence of magnesium. Zinc is incorporated into C–S–H, while magnesium is only incorporated slightly, if at all, but rather seems to inhibit nucleation. Implementing experimentally measured parameters for C–S–H nucleation and growth in the μic hydration model captured well the observed changes in hydration kinetics. This supports C–S–H nucleation and growth to be rate controlling in the hydration of C3S.
Well‐being in cross‐cultural transitions: discrepancies between acculturation preferences and actual intergroup and intragroup contact
Authors: Ramos Miguel R. , Cassidy Clare , Reicher Stephen , Haslam S. Alexander
Published: August 2014

Two studies examined the effect of acculturation–contact discrepancies on well‐being. Specifically, we tested the prediction that well‐being will be compromised when cultural minorities' acculturation preferences are not met by the intergroup and intragroup contact in a new society. Study 1 found that for Polish immigrants (n = 55) acculturation–contact discrepancies were associated with compromised well‐being. Study 2 followed a cohort of international students (n = 106) for a period of two academic years. Results suggested that discrepancies in students' acculturation–contact in their first year had harmful consequences for their well‐being 1 year later. Overall, the two studies show that discrepancies between acculturation preferences and actual contact have negative implications for the psychological adaptation of acculturating individuals.
Editorial Perspective: Why is there such a mismatch between traditional heritability estimates and molecular genetic findings for behavioural traits?
Authors: Thapar Anita , Harold Gordon
Published: August 2014

The puzzle of the disparity between molecular‐ and traditional behaviour genetic study findings has prompted widespread discussion. Fundamental questions have been raised across the whole field of complex genetic traits as well as for behavioural traits. We consider explanations for recent findings and discuss what they mean for the field of developmental psychopathology.
A randomised controlled trial of PEGASUS, a psychoeducational programme for young people with high‐functioning autism spectrum disorder
Authors: Gordon Kate , Murin Marianna , Baykaner Ozlem , Roughan Laura , Livermore‐Hardy Vaan , Skuse David , Mandy Will
Published: August 2014

Background

Psychoeducation is an essential component of postdiagnostic care for people with ASD (autism spectrum disorder), but there is currently no evidence base for clinical practice. We designed, manualised and evaluated PEGASUS (psychoeducation group for autism spectrum understanding and support), a group psychoeducational programme aiming to enhance the self‐awareness of young people with ASD by teaching them about their diagnosis.

Methods

This single‐blind RCT (randomised control trial) involved 48 young people (9–14 years) with high‐functioning ASD. Half were randomly assigned to PEGASUS, administered in six weekly group sessions, with the others receiving no additional intervention. ASD‐related self‐awareness, the primary outcome, was evaluated using the bespoke Autism Knowledge Quiz (AKQ). Secondary outcome measures included the Rosenberg Self‐Esteem Scale. All measures were collected during home visits and scored by researchers blind to group assignment. The trial is registered on ClinicalTrials (NCT01187940, http://www.clinicaltrials.gov) and was funded by the Baily Thomas Charitable Trust.

Results

Bootstrap multiple regression showed ASD knowledge (β = .29, p < .001, 95% CIs [0.13, 0.44]) and ASD self‐awareness (β = .42, p = .001, 95% CIs [0.17, 0.67]), measured by number of ASD‐related personal strengths and difficulties listed by participants, increased for those who attended PEGASUS (n = 24) compared with controls (n = 24). There was no effect of PEGASUS on self‐esteem by self‐report (β = .10, p = .404, 95% CIs [−0.14, 0.35]) or parent report (β = .12, p = .324, 95% CIs [−0.12, 0.36]).

Conclusions

After PEGASUS, participants had more general knowledge about ASD, and showed a greater awareness of their collection of unique strengths and difficulties associated with ASD. Psychoeducation did not lower self‐esteem. This RCT provides initial evidence for PEGASUS's efficacy as a psychoeducation programme for people with ASD.
Practitioner Review: Diagnosing childhood resilience – a systemic approach to the diagnosis of adaptation in adverse social and physical ecologies
Authors: Ungar Michael
Published: August 2014

Background

With growing interest in resilience among mental health care providers globally, there is a need for a simple way to consider the complex interactions that predict adaptive coping when there is exposure to high levels of adversity such as family violence, mental illness of a child or caregiver, natural disasters, social marginalization, or political conflict.

Methods

This article presents diagnostic criteria for assessing childhood resilience in a way that is sensitive to the systemic factors that influence a child's wellbeing. The most important characteristics of children who cope well under adversity and avoid problems like depression, PTSD, and delinquency are highlighted.

Results

A multidimensional assessment of resilience is presented that examines, first, the severity, chronicity, ecological level, children's attributions of causality, and cultural and contextual relevance of experiences of adversity. Second, promotive and protective factors related to resilience are assessed with sensitivity to the differential impact these have on outcomes depending on a child's level of exposure to adversity. These factors include individual qualities like temperament, personality, and cognitions, as well as contextual dimensions of positive functioning related to the available and accessibility of resources, their strategic use, positive reinforcement by a child's significant others, and the adaptive capacity of the environment itself. Third, an assessment of resilience includes temporal and cultural factors that increase or decrease the influence of protective factors. A decision tree for the diagnosis of resilience is presented, followed by a case study and diagnosis of a 15‐year‐old boy who required treatment for a number of mental health challenges.

Conclusions

The diagnostic criteria for assessing resilience and its application to clinical practice demonstrate the potential usefulness of a systemic approach to understanding resilience among child populations.
OsMADS32 interacts with PI‐like proteins and regulates rice flower development
Authors: Wang Huanhuan , Zhang Liang , Cai Qiang , Hu Yun , Jin Zhenming , Zhao Xiangxiang , Fan Wei , Huang Qianming , Luo Zhijing , Chen Mingjiao , Zhang Dabing , Yuan Zheng
Published: August 2014

OsMADS32 is a monocot specific MIKCc type MADS‐box gene that plays an important role in regulating rice floral meristem and organs identity, a crucial process for reproductive success and rice yield. However, its underlying mechanism of action remains to be clarified. Here, we characterized a hypomorphic mutant allele of OsMADS32/CFO1, cfo1‐3 and identified its function in controlling rice flower development by bioinformatics and protein‐protein interaction analysis. The cfo1‐3 mutant produces defective flowers, including loss of lodicule identity, formation of ectopic lodicule or hull‐like organs and decreased stamen number, mimicking phenotypes related to the mutation of B class genes. Molecular characterization indicated that mis‐splicing of OsMADS32 transcripts in the cfo1‐3 mutant resulted in an extra eight amino acids in the K‐domain of OsMADS32 protein. By yeast two hybrid and bimolecular fluorescence complementation assays, we revealed that the insertion of eight amino acids or deletion of the internal region in the K1 subdomain of OsMADS32 affects the interaction between OsMADS32 with PISTILLATA (PI)‐like proteins OsMADS2 and OsMADS4. This work provides new insight into the mechanism by which OsMADS32 regulates rice lodicule and stamen identity, by interaction with two PI‐like proteins via its K domain.
Reducing the Risk of Injury from Table Saw Use: The Potential Benefits and Costs of Automatic Protection
Authors: Graham John D. , Chang Joice
Published: August 2014

The use of table saws in the United States is associated with approximately 28,000 emergency department (ED) visits and 2,000 cases of finger amputation per year. This article provides a quantitative estimate of the economic benefits of automatic protection systems that could be designed into new table saw products. Benefits are defined as reduced health‐care costs, enhanced production at work, and diminished pain and suffering. The present value of the benefits of automatic protection over the life of the table saw are interpreted as the switch‐point cost value, the maximum investment in automatic protection that can be justified by benefit‐cost comparison. Using two alternative methods for monetizing pain and suffering, the study finds switch‐point cost values of $753 and $561 per saw. These point estimates are sensitive to the values of inputs, especially the average cost of injury. The various switch‐point cost values are substantially higher than rough estimates of the incremental cost of automatic protection systems. Uncertainties and future research needs are discussed.
Expression of a nuclear‐encoded psbH gene complements the plastidic RNA processing defect in the PSII mutant hcf107 in Arabidopsis thaliana
Authors: Levey Tatjana , Westhoff Peter , Meierhoff Karin
Published: August 2014

The helical‐repeat RNA‐binding protein HCF107 is required for processing, stabilization and translation of plastid‐encoded psbH mRNA. The psbH gene encodes a small, hydrophilic subunit of the PSII complex and is part of the plastidic psbB–psbT–psbH–petB–petD transcription unit. In Arabidopsis hcf107 mutants, only trace amounts of PSII proteins can be detected. Beside drastically reduced synthesis of PsbH, the synthesis of CP47 was also reduced in these mutants, although the corresponding psbB transcripts accumulate to wild type levels. This situation raises the question, whether the reduction of CP47 is a direct consequence of the mutation, based on targeting of HCF107 to the psbB mRNA, or a secondary affect due to the absent PsbH. To clarify this issue we introduced a chimeric psbH construct comprising a sequence encoding a chloroplast transit peptide into the hcf107‐2 background. We found that the nucleus‐localized psbH was able to complement the mutant defect resulting in photoautotrophic plants. The PSII proteins CP47 and D1 accumulated to barely half of the wild type level. Further experiments showed that cytosolically synthesized PsbH was imported into chloroplasts and assembled into PSII complexes. Using this approach, we showed that the tetratricopeptide repeat protein HCF107 of Arabidopsis is only responsible for expression of PsbH and not for synthesis of CP47. In addition the data suggest the necessity of the small, one‐helix membrane spanning protein PsbH for the accumulation of CP47 in higher plants.
Combining Advanced Data Analysis Methods for the Constitution of an Integrated Gas Turbine Condition Monitoring and Diagnostic System
Authors: Tsalavoutas A. , Aretakis N. , Mathioudakis K. , Stamatis A.
Published: August 2014

This paper presents principles for the constitution of gas turbine monitoring and diagnostic systems which:

a. are integrated, namely manage all the tasks essential for achieving a diagnosis (measurement, analysis, interpretation, historical data management etc.)

b. employ different kind of processing methods in order to cover an extensive range of engine conditions, including direct data evaluation and data consistency checks, thermodynamic analysis, vibration analysis.

The requirements to be fulfilled by an industrial gas turbine monitoring system are briefly reviewed and ways to achieve them are discussed, indicating how they can be materialized by implementation of specific techniques. Techniques previously derived by the group of the authors are implemented, and the merits they offer when used in combination are discussed. Features of a system, materialized according to the principles discussed, into an operating industrial gas turbine is presented. On-line application of advanced analysis techniques, such as adaptive performance modeling is discussed, on the basis of observations of the collected data.

Data collected from an engine operating in the field are presented to substantiate the matters discussed, and cases of successful fault identification are shown.
Dual Fuel DLE Typhoon Commercial Operating Experience and Improvement Upgrades
Authors: Taylor P. , McMillan R. , Baker D.
Published: August 2014

The first Typhoon generator set fitted with ABB Alstom power’s dual fuel dry low emissions (DLE) system entered service in June 1998 at the Boots Company headquarters in Nottingham, England. Running on distillate fuel NOx emissions of 30 ppmvd at 15% O2 have been commercially demonstrated without water or steam injection. This paper describes the operating experience gained from the gas turbine manufacturers and operating customers point of view. The gas and liquid fuel burner configurations along with the operating concept are described. Discussion of the initial site issues encountered, the solutions introduced and the effect on operational impact are then explained in detail.
First Experiments on an Evaporative Gas Turbine Pilot Power Plant: Water Circuit Chemistry and Humidification Evaluation
Authors: Ågren Niklas D. , Westermark Mats O. , Bartlett Michael A. , Lindquist Torbjörn
Published: August 2014

The evaporative gas turbine (EvGT), also known as the humid air turbine (HAT) cycle, is a novel advanced gas turbine cycle that has attracted considerable interest for the last decade. This high efficiency cycle shows the potential to be competitive with Diesel engines or combined cycles in small and intermediate scale plants for power production — and/or cogeneration. A 0.6 MW natural gas fired EvGT pilot plant has been constructed by a Swedish national research group in cooperation between universities and industry. The plant is located at the Lund Institute of Technology, Lund, Sweden. The pilot plant uses a humidification tower with metallic packing in which heated water from the flue gas economizer is brought into direct counter current contact with the pressurized air from the compressor. This gives an efficient heat recovery and thereby a thermodynamically sound cycle.

As the hot sections in high temperature gas turbines are sensitive to particles and alkali compounds, water quality issues need to be carefully considered. As such, apart from evaluating the thermodynamic and part load performance characteristics of the plant, and verifying the operation of the high pressure humidifier, much attention is focused on the water chemistry issues associated with the recovery and reuse of condensate water from the flue gas. A water treatment system has been designed and integrated into the pilot plant. This paper presents the first water quality results from the plant.

The experimental results show that the condensate contains low levels of alkali and calcium, around 2 mg/l Σ(K,Na,Ca), probably originating from the unfiltered compressor intake. About 14 mg/l NO2− + NO3− comes from condensate absorption of flue gas NOx. Some Cu is noted, 16 mg/l, which originates from copper corrosion of the condenser tubes. After CO2-stripping, condensate filtration and a mixed bed ion exchanger, the condensate is of suitable quality for reuse as humidification water.

The need for large quantities of demineralized water has by many authors been identified as a drawback for the evaporative cycle. However, by cooling the humid flue gas, the recovery of condensed water cuts the need of water feed. A self supporting water circuit can be achieved, with no need for any net addition of water to the system. In the pilot plant, this was achieved by cooling the flue gas to around 35°C.
Experimental and Numerical Investigation of the Influence of Rotor Blades on Hot Gas Ingestion Into the Upstream Cavity of an Axial Turbine Stage
Authors: Bohn Dieter , Rudzinski Bernd , Sürken Norbert , Gärtner Wolfgang
Published: August 2014

The phenomenon of hot gas ingestion through turbine rim seals is experimentally and numerically investigated for a complete stage with nozzle guide vanes and uncooled helicopter turbine rotor blades.

In the experimental part, two different geometrical rim seal configurations are examined: 1. a simple axial gap between rotor and stator disk and 2. an axial gap between the rotor disk and a rim seal lip at the periphery of the stator disk. The results obtained are compared to experiments carried out for the same geometry but without rotor blades.

The influence of the presence of rotor blades on hot gas ingestion is examined for different parameters such as nondimensional seal flow rate, Reynolds number in the turbine annulus and rotational speed. For the determination of the sealing efficiency measurements of carbon dioxide gas concentration are carried out in the wheelspace. The static pressure distribution in the cavity is measured by means of pressure taps at the stator disk.

It is shown that for configuration 1 the presence of rotor blades causes a considerable drop in sealing efficiency whereas for configuration 2 the sealing efficiency increases significantly.

In the numerical part results of three-dimensional unsteady CFD calculations for configuration 2 are compared to steady calculations for the same configuration without blades. Predictions of hot gas ingestion and carbon dioxide gas concentration in the hub region and inside the cavity are presented. Special emphasis is put on unsteady effects arising from rotor movement.

A local ingestion zone rotating at approximately half rotor speed is numerically predicted. As indicated by the experimental results the rotor blades have a positive influence on the predicted sealing efficiency.
Influence of a Honeycomb Facing on the Flow Through a Stepped Labyrinth Seal
Authors: Schramm V. , Willenborg K. , Kim S. , Wittig S.
Published: August 2014

This paper reports numerical predictions and measurements of the flow field in a stepped labyrinth seal. The theoretical work and the experimental investigations were successfully combined to gain a comprehensive understanding of the flow patterns existing in such elements. In order to identify the influence of the honeycomb structure, a smooth stator as well as a seal configuration with a honeycomb facing mounted on the stator wall were investigated. The seal geometry is representative of typical three-step labyrinth seals of modern aero engines. The flow field was predicted using a commercial finite-volume code with the standard-k-ε-turbulence model. The computational grid includes the basic seal geometry as well as the three-dimensional honeycomb structures.
Friction Damper Mistuning of a Bladed Disk and Optimization With Respect to Wear
Authors: Jareland Martin H. , Csaba Gabor
Published: August 2014

Friction damper mistuning is an area in which less research has been done compared to blade mistuning of bladed disks. Inspection of contact areas, on used platform dampers, indicates that their environment is strongly varying. This is mostly due to geometrical imperfections of the damper and contact surfaces on the blades, but also due to variation in mechanical properties of the blades.

In this paper a parametric study is performed to investigate the effects of damper mistuning on blade vibrations. For this study a friction contact model which is valid for both microslip and macroslip is used. The result indicates that damper mistuning greatly affects the blade vibrations. It is also found that the optimal damper is the same for the tuned and the mistuned case.

A comparison of blade and damper mistuning is also performed. The result indicates that blade and damper mistuning together constitute a more severe case than only blade or damper mistuning.

Friction damper wear is investigated for a tuned bladed disk. The result demonstrates that the resonance amplitude can either increase or decrease depending on the properties of the damper. The wear process is also investigated for an initially blade mistuned case. The simulation result is compared to measurements from bench tests with a military jet engine. For a designer of a new damper it is important to know what should be expected when the damper is in use and gets worn.
F110-GE-129 EFE — Enhanced Power Through Low Risk Derivative Technology
Authors: Wadia A. R. , James F. D.
Published: August 2014

The F110-GE-129 EFE (Enhanced Fighter Engine), presently undergoing qualification testing, is being offered at two different thrust/inspection levels with a maximum augmented thrust of 34,000 pounds. The EFE has been developed using low risk derivative engine technology. It features a new increased airflow, high efficiency, three-stage long chord blisk fan and an advanced radial augmentor that reduces complexity, improves maintainability and provides increased parts life. The paper first provides a historical background of the F110 engines to relate the heritage of the F110-GE-129 EFE. The F110 engine model development roadmap is shown to illustrate the incremental low risk approach used to provide thrust growth with improved product reliability. A detailed description of the unique power management features of the EFE engine to meet individual customer thrust and life requirements is outlined. The long chord blisk fan design, development and test results are presented followed by a description of the radial augmentor and the exhaust nozzle. The EFE engine has successfully completed sea level static and altitude development testing and fan aero mechanical qualification at the AEDC in Tullahoma, Tennessee.
EBC Protection of SiC/SiC Composites in the Gas Turbine Combustion Environment
Authors: Eaton Harry E. , Linsey Gary D. , More Karren L. , Kimmel Joshua B. , Price Jeffrey R. , Miriyala Narendernath
Published: August 2014

Silicon carbide fiber reinforced silicon carbide composites (SiC/SiC) are attractive for use in gas turbine engines as combustor liner materials, in part, because the temperature capability allows for reduced cooling. This enables the engine to operate more efficiently and to meet very stringent emission goals for NOx and CO. It has been shown, however, that SiC/SiC and other silica formers can degrade with time in the high steam environment of the gas turbine combustor due to accelerated oxidation and subsequent volatilization of the silica due to reaction with high pressure water (ref.s 1 & 2). As a result, an environmental barrier coating (EBC) is required in conjunction with the SiC composite in order to meet long life goals. Under the U.S. Department of Energy (DOE) sponsored Solar Turbines Incorporated Ceramic Stationary Gas Turbine (CSGT) engine program (ref. 3), EBC systems developed under the HSCT EPM program (NASA contract NAS3-23685) were applied to both SiC/SiC composite coupons and SiC/SiC combustion liners which were then evaluated in long term laboratory testing and in ground based turbine power generation, respectively. This paper discusses the application of the EBC’s to SiC/SiC composites and the results from laboratory and engine test evaluations.
Integrated Lifing Analysis Tool for Gas Turbine Components
Authors: Tinga Tiedo , Visser Wilfried P. J. , de Wolf Wim B. , Broomhead Michael J.
Published: August 2014

A method to predict gas turbine component life based on analysis of engine performance is presented. Engine performance history is obtained from in-flight monitored engine parameters and flight conditions and downloaded for processing by a tool integrating a number of software tools and models. These subsequently include a comprehensive thermodynamical engine system model, heat transfer, thermal and mechanical load models, and finally, a life consumption model.

Thermal and mechanical load distributions in the component as well as component life can be predicted. At this stage, the overall life prediction inaccuracy of the tool is dominated by the relatively high inaccuracy of the lifing model, and therefore, component life can only be predicted relative to a reference life.

The tool is demonstrated with an analysis of the F100-PW-220 engine 3rd stage turbine rotor blade life consumption during a recorded RNLAF F-16 mission. Using the engine system model with a detailed control system, deterioration effects on engine performance were analyzed and the effect of engine deterioration on blade life consumption rate was determined.

The tool has significant potential to enhance on-condition maintenance and optimize aircraft operational use.
Detailed Flow and Heat Transfer Coefficient Measurements in a Model of an Internal Cooling Geometry Employing Orthogonal Intersecting Channels
Authors: Gillespie David R. H. , Ireland Peter T. , Dailey Geoff M.
Published: August 2014

Cast interconnecting passage Lattice cooling geometries offer the gas turbine designer higher structural integrity and improved convective efficiency when compared to traditional aerofoil rear cooling strategies. In this paper, local heat transfer coefficient distributions were measured in a model of an idealised engine lattice cooling geometry, with flow ejection through film-cooling holes. The measurements were made using the transient liquid crystal technique in a large-scale perspex model at low temperature. The technique allows very high data resolution. Heat transfer patterns on all surfaces of the device including the internal web are presented at engine representative Reynolds numbers. The results are discussed in terms of the interpreted flow field. Furthermore, a subsequent analysis which accounted for the changing driving gas temperature and mass flow rate through the model has allowed the heat transfer coefficients to be derived based on the mixed bulk temperature, and local passage Reynolds number.
Process‐based quality management for clinical implementation of adaptive radiotherapy
Authors: Noel Camille E. , Santanam Lakshmi , Parikh Parag J. , Mutic Sasa
Published: August 2014

Purpose:

Intensity‐modulated adaptive radiotherapy (ART) has been the focus of considerable research and developmental work due to its potential therapeutic benefits. However, in light of its unique quality assurance (QA) challenges, no one has described a robust framework for its clinical implementation. In fact, recent position papers by ASTRO and AAPM have firmly endorsed pretreatment patient‐specific IMRT QA, which limits the feasibility of online ART. The authors aim to address these obstacles by applying failure mode and effects analysis (FMEA) to identify high‐priority errors and appropriate risk‐mitigation strategies for clinical implementation of intensity‐modulated ART.

Methods:

An experienced team of two clinical medical physicists, one clinical engineer, and one radiation oncologist was assembled to perform a standard FMEA for intensity‐modulated ART. A set of 216 potential radiotherapy failures composed by the forthcoming AAPM task group 100 (TG‐100) was used as the basis. Of the 216 failures, 127 were identified as most relevant to an ART scheme. Using the associated TG‐100 FMEA values as a baseline, the team considered how the likeliness of occurrence (O), outcome severity (S), and likeliness of failure being undetected (D) would change for ART. New risk priority numbers (RPN) were calculated. Failures characterized by RPN ≥ 200 were identified as potentially critical.

Results:

FMEA revealed that ART RPN increased for 38% (n = 48/127) of potential failures, with 75% (n = 36/48) attributed to failures in the segmentation and treatment planning processes. Forty‐three of 127 failures were identified as potentially critical. Risk‐mitigation strategies include implementing a suite of quality control and decision support software, specialty QA software/hardware tools, and an increase in specially trained personnel.

Conclusions:

Results of the FMEA‐based risk assessment demonstrate that intensity‐modulated ART introduces different (but not necessarily more) risks than standard IMRT and may be safely implemented with the proper mitigations.
Muscle Synergies During a Single-Leg Drop-Landing in Boys and Girls
Authors: Kipp Kristof , Pfeiffer Ron , Sabick Michelle , Harris Chad , Sutter Jeanie , Kuhlman Seth , Shea Kevin
Published: August 2014

The purpose of this study was to investigate muscle activation patterns during a landing task in boys and girls through the use of muscle synergies. Electromyographical data from six lower extremity muscles were collected from 11 boys and 16 girls while they performed single-leg drop-landings. Electromyographical data from six leg muscles were rectified, smoothed, and normalized to maximum dynamic muscle activity during landing. Data from 100 ms before to 100 ms after touchdown were submitted to factor analyses to extract muscle synergies along with the associated activation and weighing coefficients. Boys and girls both used three muscle synergies. The activation coefficients of these synergies captured muscle activity during the prelanding, touchdown, and postlanding phases of the single-leg drop-landing. Analysis of the weighing coefficients indicated that within the extracted muscle synergies the girls emphasized activation of the medial hamstring muscle during the prelanding and touchdown synergy whereas boys emphasized activation of the vastus medialis during the postlanding synergy. Although boys and girls use similar muscle synergies during single-leg drop-landings, they differed in which muscles were emphasized within these synergies. The observed differences in aspects related to the muscle synergies during landing may have implications with respect to knee injury risk.
Unusual sequelae of adult-onset dermatomyositis
Authors: Naffaa Mohammad Ebrahim , Bishara Rema , Braun-Moscovici Yolanda , Balbir-Gurman Alexandra
Published: August 2014

A 44-year-old woman diagnosed with dermatomyositis 5 years ago based on progressive proximal muscle weakness, elevated creatine kinase, typical findings on electromyography and muscle biopsy. Despite the treatment, in contrast to improvement in her muscle symptoms, the heliotrope rash of her eyelids persisted. After several years, the patient developed multiple limited skin retraction lesions with hyperpigmentation on both lower limbs. Palpation of these lesions revealed dry, cold and very firm skin on both thighs and calves, particularly in the distal areas. X-ray and ultrasound imaging of the calves showed multiple subcutaneous calcifications in the distal muscles.
Tuberculosis risk from exposure to solid fuel smoke: a systematic review and meta-analysis
Authors: Kurmi Om P , Sadhra Charandeep S , Ayres Jon G , Sadhra Steven S
Published: August 2014

Background

Studies, particularly from low-income and middle-income countries, suggest that exposure to smoke from household air pollution (HAP) may be a risk factor for tuberculosis. The primary aim of this study was to quantify the risk of tuberculosis from HAP and explore bias and identify possible causes for heterogeneity in reported effect sizes.

Methods

A systematic review was conducted from original studies. Meta-analysis was performed using a random effects model, with results presented as a pooled effect estimate (EE) with 95% CI. Heterogeneity between studies was assessed.

Results

Twelve studies that considered active tuberculosis and reported adjusted effect sizes were included in the meta-analyses. The overall pooled EE (OR, 95% CI) showed a significant adverse effect (1.43, 1.07 to 1.91) and with significant heterogeneity between studies (I2=70.8%, p<0.001). When considering studies of cases diagnosed microbiologically, the pooled EE approached significance (1.26, 0.95 to 1.68). The pooled EE (OR, 95% CI) was significantly higher among those exposed only to biomass smoke (1.49, 1.08 to 2.05) when compared with the use of kerosene only (0.70, 0.13 to 3.87). Similarly, the pooled EE among women (1.61, 0.73 to 3.57) was greater than when both genders were combined (1.39, 1.01 to 1.92). There was no publication bias (Egger plot, p=0.136). Significant heterogeneity was observed in the diagnostic criteria for tuberculosis (coefficient=0.38, p=0.042).

Conclusions

Biomass smoke is a significant risk factor for active tuberculosis. Most of the studies were small with limited information on measures of HAP.
Approximate Semantic Matching of Events for the Internet of Things
Authors: Hasan Souleiman , Curry Edward
Published: August 2014

Event processing follows a decoupled model of interaction in space, time, and synchronization. However, another dimension of semantic coupling also exists and poses a challenge to the scalability of event processing systems in highly semantically heterogeneous and dynamic environments such as the Internet of Things (IoT). Current state-of-the-art approaches of content-based and concept-based event systems require a significant agreement between event producers and consumers on event schema or an external conceptual model of event semantics. Thus, they do not address the semantic coupling issue. This article proposes an approach where participants only agree on a distributional statistical model of semantics represented in a corpus of text to derive semantic similarity and relatedness. It also proposes an approximate model for relaxing the semantic coupling dimension via an approximation-enabled rule language and an approximate event matcher. The model is formalized as an ensemble of semantic and top-
k
matchers along with a probability model for uncertainty management. The model has been empirically validated on large sets of events and subscriptions synthesized from real-world smart city and energy management systems. Experiments show that the proposed model achieves more than 95% F
1
Score of effectiveness and thousands of events/sec of throughput for medium degrees of approximation while not requiring users to have complete prior knowledge of event semantics. In semantically loosely-coupled environments, one approximate subscription can compensate for hundreds of exact subscriptions to cover all possibilities in environments which require complete prior knowledge of event semantics. Results indicate that approximate semantic event processing could play a promising role in the IoT middleware layer.
Decreasing mitochondrial fission alleviates hepatic steatosis in a murine model of nonalcoholic fatty liver disease
Authors: Galloway Chad A. , Lee Hakjoo , Brookes Paul S. , Yoon Yisang
Published: August 2014

Mitochondria produce the majority of cellular ATP through oxidative phosphorylation, and their capacity to do so is influenced by many factors. Mitochondrial morphology is recently suggested as an important contributor in controlling mitochondrial bioenergetics. Mitochondria divide and fuse continuously, which is affected by environmental factors, including metabolic alterations. Underscoring its bioenergetic influence, altered mitochondrial morphology is reported in tissues of patients and in animal models of metabolic dysfunction. In this study, we found that mitochondrial fission plays a vital role in the progression of nonalcoholic fatty liver disease (NAFLD). The development of hepatic steatosis, oxidative/nitrative stress, and hepatic tissue damage, induced by a high-fat diet, were alleviated in genetically manipulated mice suppressing mitochondrial fission. The alleviation of steatosis was recapitulated in primary hepatocytes with the inhibition of mitochondrial fission. Mechanistically, our study indicates that fission inhibition enhances proton leak under conditions of free fatty acid incubation, implicating bioenergetic change through manipulating mitochondrial fission. Taken together, our results suggest a mechanistic role for mitochondrial fission in the etiology of NAFLD. The efficacy of decreasing mitochondrial fission in the suppression of NAFLD suggests that mitochondrial fission represents a novel target for therapeutic treatment of NAFLD.
5-Lipoxygenase Is a Candidate Target for Therapeutic Management of Stem Cell–like Cells in Acute Myeloid Leukemia
Authors: Roos Jessica , Oancea Claudia , Heinssmann Maria , Khan Dilawar , Held Hannelore , Kahnt Astrid S. , Capelo Ricardo , la Buscató Estel , Proschak Ewgenij , Puccetti Elena , Steinhilber Dieter , Fleming Ingrid , Maier Thorsten J. , Ruthardt Martin
Published: August 2014

Nonsteroidal anti-inflammatory drugs such as sulindac inhibit Wnt signaling, which is critical to maintain cancer stem cell–like cells (CSC), but they also suppress the activity of 5-lipoxygenase (5-LO) at clinically feasible concentrations. Recently, 5-LO was shown to be critical to maintain CSC in a model of chronic myeloid leukemia. For these reasons, we hypothesized that 5-LO may offer a therapeutic target to improve the management of acute myeloid leukemia (AML), an aggressive disease driven by CSCs. Pharmacologic and genetic approaches were used to evaluate the effects of 5-LO blockade in a PML/RARα-positive model of AML. As CSC models, we used Sca-1+/lin− murine hematopoietic stem and progenitor cells (HSPC), which were retrovirally transduced with PML/RARα. We found that pharmacologic inhibition of 5-LO interfered strongly with the aberrant stem cell capacity of PML/RARα-expressing HSPCs. Through small-molecule inhibitor studies and genetic disruption of 5-LO, we also found that Wnt and CSC inhibition is mediated by the enzymatically inactive form of 5-LO, which hinders nuclear translocation of β-catenin. Overall, our findings revealed that 5-LO inhibitors also inhibit Wnt signaling, not due to the interruption of 5-LO–mediated lipid signaling but rather due to the generation of a catalytically inactive form of 5-LO, which assumes a new function. Given the evidence that CSCs mediate AML relapse after remission, eradication of CSCs in this setting by 5-LO inhibition may offer a new clinical approach for immediate evaluation in patients with AML. Cancer Res; 74(18); 5244–55. ©2014 AACR.