bluuebunny/crossref_metadata_2025 huggingface dataset:
Empirical Study on the Dissipative Structure Model of Manufacturing Systems Based on Entropy Approach
Authors: Zhang Zhifeng
Published: September 2014

The operation of manufacturing systems can be effectively monitored through analysis and measurement of the information of various states of manufacturing systems. Based on analyzing the trait of dissipative structure of manufacturing systems, a sketch of dissipative structure of manufacturing systems is shown. By the correlation between control variables and state variables of cusp catastrophe theory, a dissipative structure model is established, making it possible to quantitatively determine when manufacturing systems may form dissipative structure. According to the definition of the information entropy of manufacturing systems, the models of expected state entropy, and actual state entropy are built up, respectively, thus serving the purpose of exactly assessing the operational states of the systems by the model of dissipative structure. Taking a job shop of implementing cellular manufacturing as an example, using established dissipative structure model and its solved method, this paper quantitatively determines whether the manufacturing systems may form dissipative structures under two different states. The result fairly validates the reasonableness of this method and also provides an effective approach for the optimization of manufacturing systems.
A Modified Smoothed Particle Hydrodynamics Scheme to Model the Stationary and Moving Boundary Problems for Newtonian Fluid Flows
Authors: Sefid Mohammad , Fatehi Rouhollah , Shamsoddini Rahim
Published: September 2014

A robust modified weakly compressible smoothed particle hydrodynamics (WCSPH) method based on a predictive corrective scheme is introduced to model the fluid flows engaged with stationary and moving boundary. In this paper, this model is explained and practically verified in three distinct laminar incompressible flow cases; the first case involves the lid driven cavity flow for two Reynolds numbers 400 and 1000. The second case is a flow generated by a moving block in the initially stationary fluid. The third case is flow around the stationary and transversely oscillating circular cylinder confined in a channel. These results in comparison with the standard benchmarks also confirm the good accuracy of the present solution algorithm.
Experimental Analysis of the Global Performance and the Flow Through a High-Bypass Turbofan in Windmilling Conditions
Authors: García Rosa Nicolás , Dufour Guillaume , Barènes Roger , Lavergne Gérard
Published: September 2014

A detailed study of the air flow through the fan stage of a high-bypass, geared turbofan in windmilling conditions is proposed, to address the key performance issues of this severe case of off-design operation. Experiments are conducted in the turbofan test rig of ISAE, specifically suited to reproduce windmilling operation in an ambient ground setup. The engine is equipped with conventional measurements and radial profiles of flow quantities are measured using directional five-hole probes to characterize the flow across the fan stage and derive windmilling performance parameters. These results bring experimental evidence of the findings of the literature that both the fan rotor and stator operate under severe off-design angle-of-attack, leading to flow separation and stagnation pressure loss. The fan rotor operates in a mixed fashion: spanwise, the inner sections of the rotor blades add work to the flow while the outer sections extract work and generate a pressure loss. The overall work is negative, revealing the resistive loads on the fan, caused by the bearing friction and work exchange in the different components of the fan shaft. The parametric study shows that the fan rotational speed is proportional to the mass flow rate, but the fan rotor inlet and outlet relative flow angles, as well as the fan load profile, remain constant, for different values of mass flow rate. Estimations of engine bypass ratio have been done, yielding values higher than six times the design value. The comprehensive database that was built will allow the validation of 3D Reynolds-averaged Navier–Stokes (RANS) simulations to provide a better understanding of the internal losses in windmilling conditions.
Secondary Flows, Endwall Effects, and Stall Detection in Axial Compressor Design
Authors: Banjac Milan , Petrovic Milan V. , Wiedermann Alexander
Published: September 2014

This paper describes a methodology and a fully tested and calibrated mathematical model for the treatment of endwall effects in axial compressor aerodynamic calculations. Additional losses and deviations caused by the clearance and secondary flows are analyzed. These effects are coupled with endwall boundary layer losses (EWBL) and blockage development. Stall/surge detection is included, and mutual interaction of different loss mechanisms is considered. Individual mathematical correlations for different effects have been created or adopted from earlier papers with the aim of forming one integral model that is completely described in this paper. Separate mathematical correlations and calibration measures are discussed in detail in the first part of the paper. The developed overall model is suitable for application in two-dimensional (2D) or mean-line compressor flow calculations. During the development, it was tested, calibrated, and validated using throughflow calculations comparing numerical results with experimental data for a large number of test cases. These test cases include compressors with very different configurations and operating ranges. The data on the compressors were taken from the open literature or obtained from industrial partners.
Self-Contained Image Recalibration in a Scanning Fiber Endoscope Using Piezoelectric Sensing
Authors: Yeoh I. L. , Reinhall P. G. , Berg M. C. , Seibel E. J.
Published: September 2014

The scanning fiber endoscope (SFE) is a new ultrathin (1.2 mm diameter) medical imaging device that utilizes a unique mechanical scanning technique to image large (120 deg) fields of view (FOVs). A single 80 μm optical fiber is circularly vibrated by a piezo-electric tube to illuminate a field while the reflected light is collected to construct an image pixel-by-pixel. Accurate scanning of the optical fiber is paramount to image quality. Previously, an optical calibration chamber in the base station was used to calibrate the scanning of the optical fiber. This analytical and experimental work eliminates the use of the calibration chamber by implementing a new piezoelectric sensing approach enabling self-contained recalibration to maintain high-image quality during long medical procedures and also reducing the cost, size, and power consumption of the SFE. This work provides a major step toward self-calibration through adaptive control without additional sensors.
Nonlinear Passive Cam-Based Springs for Powered Ankle Prostheses
Authors: Realmuto Jonathan , Klute Glenn , Devasia Santosh
Published: September 2014

This article studies the design of passive elastic elements to reduce the actuator requirements for powered ankle prostheses. The challenge is to achieve most of the typically nonlinear ankle response with the passive element so that the active ankle-torque from the actuator can be small. The main contribution of this article is the design of a cam-based lower-limb prosthesis to achieve such a nonlinear ankle response. Results are presented to show that the addition of the cam-based passive element can reduce the peak actuator torque requirement substantially, by ∼74%. Moreover, experimental results are presented to demonstrate that the cam-based design can achieve a desired nonlinear response to within 10%.
Letters Home as an Alternative to Lab Reports
Authors: Lane W. Brian
Published: September 2014

The traditional lab report is known to create several pedagogical shortcomings in the introductory physics course, particularly with regard to promoting student engagement and encouraging quality writing. This paper discusses the use of a “letter home” written to a non-physicist as an alternative to lab reports that creates a more authentic writing experience.
Glow Sticks: Spectra and Color Mixing
Authors: Birriel Jennifer , Birriel Ignacio
Published: September 2014

Glow sticks are a popular Halloween staple familiar to most of our students. The production of light via a chemical reaction is called “chemiluminescence,” and glow sticks are often used as demonstrations and experiments in the chemistry classroom to study reaction rates as a function of temperature.1–3 A black light can be used to illuminate glow sticks that have not been cracked or those that are “dead” in order to demonstrate fluorescence in liquid chemicals.4 In this article, we present the use of glow sticks as an inexpensive demonstration of spectra and color addition.
Teaching Special Relativity to Lay Students
Authors: Egdall Ira Mark
Published: September 2014

In this paper, I describe a lay course in special relativity (SR) given at the Osher Lifelong Learning Institutes (OLLI's) at Florida International University and the University of Miami. Courses are also offered in general relativity1 quantum theory cosmology the nature of time, and the fine-tuned universe. Each course is presented in six hour-and-a-half weekly sessions. Students are mostly retired or semi-retired adults like me. Most are college educated, but with little or no formal physics education.
Interference and the Law of Energy Conservation
Authors: Drosd Robert , Minkin Leonid , Shapovalov Alexander S.
Published: September 2014

Introductory physics textbooks consider interference to be a process of redistribution of energy from the wave sources in the surrounding space resulting in constructive and destructive interferences. As one can expect, the total energy flux is conserved. However, one case of apparent non-conservation energy attracts great attention.1,2 Imagine that a pair of coherent, point-like wave sources (located at the same position) radiates sinusoidal waves of amplitude A, spreading in a uniform medium. Assume also that radiation of the two sources is in phase. Since the energy of oscillation, E, is proportional to amplitude squared, one quickly arrives at an apparent paradox. That is, the energy of oscillation in every point due to only one source is E0=CA2 (C is the coefficient of proportionality), while according to the linear superposition principle, the combined amplitude of oscillations from the two sources is 2A and the energy of oscillations is E=C(2A)2=4CA2=4E0, i.e., four (not two) times greater than the energy of oscillation of one isolated source in the absence of the second. In the general case, superposition of two waves with identical amplitudes and wavelengths produces a wave with an intensity somewhere between zero and four times the intensity of a single wave source (depending on relative phase of the two waves). This leads to the obvious question: how can we account for the extra (or missing) energy that necessarily results from in-phase (or anti-phase) wave interference? This apparent violation of the principle of conservation energy, due to the superposition of waves, is the primary topic of this paper.
Telemetry with an Optical Fiber Revisited: An Alternative Strategy
Authors: Kraftmakher Yaakov
Published: September 2014

With a new data-acquisition system developed by PASCO scientific, an experiment on telemetry with an optical fiber1,2 can be made easier and more accurate. For this aim, an alternative strategy of the remote temperature measurements is proposed: the frequency of light pulses transmitted via the light guide numerically equals the temperature using known manufacturer's data or an initial calibration step. The additional equipment for the experiment is reduced to a minimum.
Physics departments with women faculty members
Authors: White Susan C.
Published: September 2014

Last month we examined the representation of women among newly hired physics faculty members. This month we consider the proportion of physics departments with women on their faculties in the professorial ranks—assistant, associate, and full professors. There continue to be some physics departments that have no women faculty members. The percentage is higher at bachelor's-granting departments than at PhD-granting departments, largely because of the small number of faculty members at most bachelor's-granting departments. About 47% of bachelor's-granting departments had no women faculty members, while one percent of these departments had only women. We studied the number of physics departments with no women among their faculty and found that there are actually fewer of these than would be expected given the small number of faculty members in a typical department and given the overall proportion of women among current physics faculty members.1 Next month we will take a closer Proportion of Physics Departments with Women Faculty* by Highest Degree Granted, 2009–10 Academic Year look at the growth in the representation of women among faculty members in PhD-granting departments. If you have any questions or comments, please contact Susan White at the Statistical Research Center of the American Institute of Physics (swhite@aip.org).
Why you need a mentor
Authors: Riendeau Diane
Published: September 2014

At the AAPT Summer Meeting in Minneapolis, I co-hosted the speed networking event with Sam Sampere (the current NY section representative). Before the event began, I met with Sam briefly to discuss how we anticipated the event running. One of the first things Sam did was show me a memorial flyer from John Fitzgibbons' (Fitz) funeral. Sam later became choked up as he shared with the group about how his mentor, Fitz, had changed his life professionally at Syracuse and as a member of the AAPT. Sam suggested to the new attendees that perhaps their mentor was in the room and they would meet him or her today. All “seasoned” teachers in the room were nodding their heads in agreement. They could relate because there was someone who nurtured them, someone who deserves half the credit for the people and teachers they became.
A Drug-Repositioning Screening Identifies Pentetic Acid as a Potential Therapeutic Agent for Suppressing the Elastase-Mediated Virulence of Pseudomonas aeruginosa
Authors: Gi Mia , Jeong Junhui , Lee Keehoon , Lee Kang-Mu , Toyofuku Masanori , Yong Dong Eun , Yoon Sang Sun , Choi Jae Young
Published: September 2014

Pseudomonas aeruginosa, a Gram-negative bacterium of clinical significance, produces elastase as a predominant exoprotease. Here, we screened a library of chemical compounds currently used for human medication and identified diethylene triamine penta-acetic acid (DTPA, pentetic acid) as an agent that suppresses the production of elastase. Elastase activity found in the prototypeP. aeruginosastrain PAO1 was significantly decreased when grown with a concentration as low as 20 μM DTPA. Supplementation with Zn2+or Mn2+ions restored the suppressive effect of DTPA, suggesting that the DTPA-mediated decrease in elastase activity is associated with ion-chelating activity. In DTPA-treated PAO1 cells, transcription of the elastase-encodinglasBgene and levels of thePseudomonasquinolone signal (PQS), a molecule that mediatesP. aeruginosaquorum sensing (QS), were significantly downregulated, reflecting the potential involvement of the PQS QS system in DTPA-mediated elastase suppression. Biofilm formation was also decreased by DTPA treatment. When A549 alveolar type II-like adenocarcinoma cells were infected with PAO1 cells in the presence of DTPA, A549 cell viability was substantially increased. Furthermore, the intranasal delivery of DTPA to PAO1-infected mice alleviated the pathogenic effects of PAO1 cells in the animals. Together, our results revealed a novel function for a known molecule that may help treatP. aeruginosaairway infection.
Cross-Genotypic Examination of Hepatitis C Virus Polymerase Inhibitors Reveals a Novel Mechanism of Action for Thumb Binders
Authors: Eltahla Auda A. , Tay Enoch , Douglas Mark W. , White Peter A.
Published: September 2014

Direct-acting antivirals (DAAs) targeting proteins encoded by the hepatitis C virus (HCV) genome have great potential for the treatment of HCV infections. However, the efficacy of DAAs designed to target genotype 1 (G1) HCV against non-G1 viruses has not been characterized fully. In this study, we investigated the inhibitory activities of nonnucleoside inhibitors (NNIs) against the HCV RNA-dependent RNA polymerase (RdRp). We examined the ability of six NNIs to inhibit G1b, G2a, and G3a subgenomic replicons in cell culture, as well as
in vitro
transcription by G1b and G3a recombinant RdRps. Of the six G1 NNIs, only the palm II binder nesbuvir demonstrated activity against G1, G2, and G3 HCV, in both replicon and recombinant enzyme models. The thumb I binder JTK-109 also inhibited G1b and G3a replicons and recombinant enzymes but was 41-fold less active against the G2a replicon. The four other NNIs, which included a palm I binder (setrobuvir), two thumb II binders (lomibuvir and filibuvir), and a palm β-hairpin binder (tegobuvir), all showed at least 40-fold decreases in potency against G2a and G3a replicons and the G3a enzyme. This antiviral resistance was largely conferred by naturally occurring amino acid residues in the G2a and G3a RdRps that are associated with G1 resistance. Lomibuvir and filibuvir (thumb II binders) inhibited primer-dependent but not
de novo
activity of the G1b polymerase. Surprisingly, these compounds instead specifically enhanced the
de novo
activity at concentrations of ≥100 nM. These findings highlight a potential differential mode of RdRp inhibition for HCV NNIs, depending on their prospective binding pockets, and also demonstrate a surprising enhancement of
de novo
activity for thumb RdRp binders. These results also provide a better understanding of the antiviral coverage for these polymerase inhibitors, which will likely be used in future combinational interferon-free therapies.
Properties of AdeABC and AdeIJK Efflux Systems of Acinetobacter baumannii Compared with Those of the AcrAB-TolC System of Escherichia coli
Authors: Sugawara Etsuko , Nikaido Hiroshi
Published: September 2014

Acinetobacter baumanniicontains RND-family efflux systems AdeABC and AdeIJK, which pump out a wide range of antimicrobial compounds, as judged from the MIC changes occurring upon deletion of the responsible genes. However, these studies may miss changes because of the high backgrounds generated by the remaining pumps and by β-lactamases, and it is unclear how the activities of these pumps compare quantitatively with those of the well-studied AcrAB-TolC system ofEscherichia coli. We expressedadeABCandadeIJKofA. baumannii, as well asE. coliacrAB, in anE. colihost from whichacrABwas deleted. TheA. baumanniipumps were functional inE. coli, and the MIC changes that were observed largely confirmed the substrate range already reported, with important differences. Thus, the AdeABC system pumped out all β-lactams, an activity that was often missed in deletion studies. When the expression level of the pump genes was adjusted to a similar level for a comparison with AcrAB-TolC, we found that bothA. baumanniiefflux systems pumped out a wide range of compounds, but AdeABC was less effective than AcrAB-TolC in the extrusion of lipophilic β-lactams, novobiocin, and ethidium bromide, although it was more effective at tetracycline efflux. AdeIJK was remarkably more effective than a similar level of AcrAB-TolC in the efflux of β-lactams, novobiocin, and ethidium bromide, although it was less so in the efflux of erythromycin. These results thus allow us to compare these efflux systems on a quantitative basis, if we can assume that the heterologous systems are fully functional in theE. colihost.
Administration of a Triple versus a Standard Double Antimicrobial Regimen for Human Brucellosis More Efficiently Eliminates Bacterial DNA Load
Authors: Vrioni Georgia , Bourdakis Adamantios , Pappas Georgios , Pitiriga Vassiliki , Mavrouli Maria , Pournaras Spyros , Tsakris Athanassios
Published: September 2014

The effects of doxycycline-streptomycin-rifampin versus a standard doxycycline-streptomycin regimen on residual
Brucella
DNA were compared in 36 acute brucellosis patients. At admission, all patients given triple (
n
= 22) and double (
n
= 14) regimens had detectable
Brucella
DNA with similar mean loads (
P
= 0.982). At follow-up, 14 to 20 months postpresentation, significantly more patients receiving triple than double regimens had undetectable
Brucella
DNA (
P
= 0.026). The doxycycline-streptomycin-rifampin regimen eliminates
Brucella
DNA more efficiently than doxycycline-streptomycin, which may result in superior long-term clearance of
Brucella
.
An
In Vitro
Deletion in
ribE
Encoding Lumazine Synthase Contributes to Nitrofurantoin Resistance in Escherichia coli
Authors: Vervoort Jascha , Xavier Basil Britto , Stewardson Andrew , Coenen Samuel , Godycki-Cwirko Maciek , Adriaenssens Niels , Kowalczyk Anna , Lammens Christine , Harbarth Stephan , Goossens Herman , Malhotra-Kumar Surbhi
Published: September 2014

Nitrofurantoin has been used for decades for the treatment of urinary tract infections (UTIs), but clinically significant resistance in
Escherichia coli
is uncommon. Nitrofurantoin concentrations in the gastrointestinal tract tend to be low, which might facilitate selection of nitrofurantoin-resistant (NIT-R) strains in the gut flora. We subjected two nitrofurantoin-susceptible intestinal
E. coli
strains (ST540-p and ST2747-p) to increasing nitrofurantoin concentrations under aerobic and anaerobic conditions. Whole-genome sequencing was performed for both susceptible isolates and selected mutants that exhibited the highest nitrofurantoin resistance levels aerobically (ST540-a and ST2747-a) and anaerobically (ST540-an and ST2747-an). ST540-a/ST540-an and ST2747-a (aerobic MICs of >64 μg/ml) harbored mutations in the known nitrofurantoin resistance determinants
nfsA
and/or
nfsB
, which encode oxygen-insensitive nitroreductases. ST2747-an showed reduced nitrofurantoin susceptibility (aerobic MIC of 32 μg/ml) and exhibited remarkable growth deficits but did not harbor
nfsA/nfsB
mutations. We identified a 12-nucleotide deletion in
ribE
, encoding lumazine synthase, an essential enzyme involved in the biosynthesis of flavin mononucleotide (FMN), which is an important cofactor for NfsA and NfsB. Complementing ST2747-an with a functional wild-type lumazine synthase restored nitrofurantoin susceptibility. Six NIT-R
E. coli
isolates (NRCI-1 to NRCI-6) from stools of UTI patients treated with nitrofurantoin, cefuroxime, or a fluoroquinolone harbored mutations in
nfsA
and/or
nfsB
but not
ribE
. Sequencing of the
ribE
gene in six intestinal and three urinary
E. coli
strains showing reduced nitrofurantoin susceptibility (MICs of 16 to 48 μg/ml) also did not identify any relevant mutations. NRCI-1, NRCI-2, and NRCI-5 exhibited up to 4-fold higher anaerobic MICs, compared to the mutants generated
in vitro
, presumably because of additional mutations in oxygen-sensitive nitroreductases.
The Small RNA RyhB Contributes to Siderophore Production and Virulence of Uropathogenic Escherichia coli
Authors: Porcheron Gaëlle , Habib Rima , Houle Sébastien , Caza Mélissa , Lépine François , Daigle France , Massé Eric , Dozois Charles M.
Published: September 2014

In
Escherichia coli
, the small regulatory noncoding RNA (sRNA) RyhB and the global ferric uptake regulator (Fur) mediate iron acquisition and storage control. Iron is both essential and potentially toxic for most living organisms, making the precise maintenance of iron homeostasis necessary for survival. While the roles of these regulators in iron homeostasis have been well studied in a nonpathogenic
E. coli
strain, their impact on the production of virulence-associated factors is still unknown for a pathogenic
E. coli
strain. We thus investigated the roles of RyhB and Fur in iron homeostasis and virulence of the uropathogenic
E. coli
(UPEC) strain CFT073. In a murine model of urinary tract infection (UTI), deletion of
fur
alone did not attenuate virulence, whereas a Δ
ryhB
mutant and a Δ
fur
Δ
ryhB
double mutant showed significantly reduced bladder colonization. The Δ
fur
mutant was more sensitive to oxidative stress and produced more of the siderophores enterobactin, salmochelins, and aerobactin than the wild-type strain. In contrast, while RyhB was not implicated in oxidative stress resistance, the Δ
ryhB
mutant produced lower levels of siderophores. This decrease was correlated with the downregulation of
shiA
(encoding a transporter of shikimate, a precursor of enterobactin and salmochelin biosynthesis) and
iucD
(involved in aerobactin biosynthesis) in this mutant grown in minimal medium or in human urine.
iucD
was also downregulated in bladders infected with the Δ
ryhB
mutant compared to those infected with the wild-type strain. Our results thus demonstrate that the sRNA RyhB is involved in production of iron acquisition systems and colonization of the urinary tract by pathogenic
E. coli
.
FNR Regulates Expression of Important Virulence Factors Contributing to Pathogenicity of Uropathogenic Escherichia coli
Authors: Barbieri Nicolle L. , Nicholson Bryon , Hussein Ashraf , Cai Wentong , Wannemuehler Yvonne M. , Dell'Anna Giuseppe , Logue Catherine M. , Horn Fabiana , Nolan Lisa K. , Li Ganwu
Published: September 2014

Uropathogenic
Escherichia coli
(UPEC) is responsible for the majority of urinary tract infections (UTIs), which are some of the world's most common bacterial infections of humans. Here, we examined the role of FNR (
f
umarate and
n
itrate
r
eduction), a well-known global regulator, in the pathogenesis of UPEC infections. We constructed an
fnr
deletion mutant of UPEC CFT073 and compared it to the wild type for changes in virulence, adherence, invasion, and expression of key virulence factors. Compared to the wild type, the
fnr
mutant was highly attenuated in the mouse model of human UTI and showed severe defects in adherence to and invasion of bladder and kidney epithelial cells. Our results showed that FNR regulates motility and multiple virulence factors, including expression of type I and P fimbriae, modulation of hemolysin expression, and expression of a novel pathogenicity island involved in α-ketoglutarate metabolism under anaerobic conditions. Our results demonstrate that FNR is a key global regulator of UPEC virulence and controls expression of important virulence factors that contribute to UPEC pathogenicity.
Investigation of the Essentiality of Glutamate Racemase in Mycobacterium smegmatis
Authors: Li Yang , Mortuza Roman , Milligan Daniel L. , Tran Sieu L. , Strych Ulrich , Cook Gregory M. , Krause Kurt L.
Published: September 2014

The mycobacterial cell wall frequently has been used as a target for drug development, andd-glutamate, synthesized by glutamate racemase (MurI), is an important component of peptidoglycan. While the essentiality of themurIgene has been shown in several bacterial species, includingEscherichia coli,Bacillus anthracis, andStreptococcus pneumoniae, studies in mycobacteria have not yet provided definitive results. This study aimed to determine whethermurIis indeed essential and can serve as a possible target for structure-aided drug design. We have achieved this goal by creating a ΔmurIstrain ofMycobacterium smegmatis, a close relative ofMycobacterium tuberculosis. The deletion of themurIgene inM. smegmatiscould be achieved only in minimal medium supplemented withd-glutamate, demonstrating that MurI is essential for growth and that glutamate racemase is the only source ofd-glutamate for peptidoglycan synthesis inM. smegmatis.
The Cpx Envelope Stress Response Regulates and Is Regulated by Small Noncoding RNAs
Authors: Vogt Stefanie L. , Evans Alex D. , Guest Randi L. , Raivio Tracy L.
Published: September 2014

The
Escherichia coli
genome encodes approximately 30 two-component systems that are required for sensing and responding to a variety of environmental and physiological cues. Recent studies have revealed numerous regulatory connections between two-component systems and small noncoding RNAs (sRNAs), which posttranscriptionally regulate gene expression by base pairing with target mRNAs. In this study, we investigated the role of sRNAs in the CpxAR two-component system, which detects and mediates an adaptive response to potentially lethal protein misfolding in the Gram-negative bacterial envelope. Here, we showed for the first time that sRNAs are members of the Cpx regulon. We found that CpxR binds to the promoter regions and regulates expression of two sRNA genes,
cyaR
and
rprA
. We also investigated the roles that these sRNAs play in the Cpx response. Cpx repression of
cyaR
expression creates a feed-forward loop, in which CpxAR increases expression of the inner membrane protein YqaE both directly at the transcriptional level and indirectly at the translational level. Moreover, we found that RprA exerts negative feedback on the Cpx response, reducing Cpx activity in a manner that is dependent on the response regulator CpxR but independent of all of RprA's previously described targets. sRNAs therefore permit the fine-tuning of Cpx pathway activity and its regulation of target genes, which could assist bacterial survival in the face of envelope stress.
Characterization of Biochemical Properties of Bacillus subtilis RecQ Helicase
Authors: Qin Wei , Liu Na-Nv , Wang Lijun , Zhou Min , Ren Hua , Bugnard Elisabeth , Liu Jie-Lin , Zhang Lin-Hu , Vendôme Jeremie , Hu Jin-Shan , Xi Xu Guang
Published: September 2014

RecQ family helicases function as safeguards of the genome. Unlike
Escherichia coli
, the Gram-positive
Bacillus subtilis
bacterium possesses two RecQ-like homologues, RecQ[Bs] and RecS, which are required for the repair of DNA double-strand breaks. RecQ[Bs] also binds to the forked DNA to ensure a smooth progression of the cell cycle. Here we present the first biochemical analysis of recombinant RecQ[Bs]. RecQ[Bs] binds weakly to single-stranded DNA (ssDNA) and blunt-ended double-stranded DNA (dsDNA) but strongly to forked dsDNA. The protein exhibits a DNA-stimulated ATPase activity and ATP- and Mg
2+
-dependent DNA helicase activity with a 3′→5′ polarity. Molecular modeling shows that RecQ[Bs] shares high sequence and structure similarity with
E. coli
RecQ. Surprisingly, RecQ[Bs] resembles the truncated
Saccharomyces cerevisiae
Sgs1 and human RecQ helicases more than RecQ[Ec] with regard to its enzymatic activities. Specifically, RecQ[Bs] unwinds forked dsDNA and DNA duplexes with a 3′-overhang but is inactive on blunt-ended dsDNA and 5′-overhung duplexes. Interestingly, RecQ[Bs] unwinds blunt-ended DNA with structural features, including nicks, gaps, 5′-flaps, Kappa joints, synthetic replication forks, and Holliday junctions. We discuss these findings in the context of RecQ[Bs]'s possible functions in preserving genomic stability.
Chronic necrotising pulmonary aspergillosis: an uncommon aetiology of pneumothorax
Authors: Desgranges François-Pierrick , Hernu Romain , Philit François , Argaud Laurent
Published: September 2014

Pneumothorax is a frequent cause of admission in an emergency department. It can be due to a leakage of air from an air-filled lung cavitation into the pleural space. We report the unusual case of pneumothorax in a patient with a pulmonary cavitary infectious process mimicking tuberculosis. A 30-year-old asthmatic man, treated for several years with low-dose inhaled corticosteroids, presented a complete left tension pneumothorax and chronic necrotising pulmonary aspergillosis that mimicked initial pulmonary tuberculosis. Antifungal treatment by voriconazole was started and continued for 1 year, with a favourable outcome. This case highlights that chronic necrotising pulmonary aspergillosis is a diagnosis that should be considered in patients with a clinical presentation of pulmonary tuberculosis or in patients experiencing pneumothorax, especially in the context of corticosteroid treatment.
Chryseobacterium indologenespneumonia in a patient with non-Hodgkin's lymphoma
Authors: Shahul Hameed Aboobackar , Manu Mohan K , Mohapatra Aswini Kumar , Chawla Kiran
Published: September 2014

A 42-year-old man diagnosed with gastric non-Hodgkin's lymphoma 2 years earlier, for which he had undergone treatment, presented with expectorative cough, exertional shortness of breath and left-sided chest pain of 3 months duration. Respiratory system examination was suggestive of left-sided pneumonia with pleural effusion. Routine haemogram showed leukocytosis with high erythrocyte sedimentation rate. Chest radiograph showed blunting of left-sided cardiophrenic angle. Sputum culture grewChryseobacterium indologenes. Diagnostic thoracocentesis was suggestive of lymphomatous metastasis. Pleural fluid culture was sterile. Contrast-enhanced CT (CECT) of the thorax showed left lower lobe consolidation with bilateral pleural effusion. The patient was treated with antibiotics, following which his cough improved and total leukocyte count normalised. Sputum culture repeated after the antibiotic course showed no growth ofC. indologenes. However, the pleural effusion soon aggravated along with features suggestive of multiple metastasis. The patient finally succumbed to his underlying advanced malignancy.
Caecum lipoma: a rare cause of lower gastrointestinal bleeding
Authors: Martinez-Mier Gustavo , Ortiz-Bayliss Arturo B , Alvarado-Arenas Ruben , Carrasco-Arroniz Miguel A
Published: September 2014

Gastrointestinal bleeding caused by benign tumours of the colon is rare. A 70-year-old woman with a significant medical history of diabetes, hypertension and ischaemic heart disease was presented in consultation with marked anaemia secondary to lower gastrointestinal bleeding with a right colonic tumour found by CT. The patient underwent a right colectomy without complications. Histopathological examination revealed a 4 cm transmural caecum lipoma with mucosal ulceration. The patient is asymptomatic without anaemia at 6 months follow-up.
Physical impairments and activity limitations in people with femoroacetabular impingement: a systematic review
Authors: Diamond Laura E , Dobson Fiona L , Bennell Kim L , Wrigley Tim V , Hodges Paul W , Hinman Rana S
Published: September 2014

Background

Femoroacetabular impingement (FAI) is a morphological hip condition that can cause hip and/or groin pain in younger active adults. Understanding the nature of physical impairments and activity limitations associated with symptomatic FAI is important to evaluate outcomes and guide development of rehabilitation strategies. The purpose of this systematic review was to establish: (1) whether people with symptomatic FAI demonstrate physical impairments and/or activity limitations compared with people without FAI; and (2) whether treatment affects these parameters.

Methods

Four databases (Pubmed, CINAHL, SportDISCUS and Cochrane Library) were searched until the 21 June 2013. Studies evaluated measures of physical impairment and/or activity limitations in people with symptomatic FAI and included either: (1) a comparison control group; or (2) a pretreatment and post-treatment comparison. Methodological quality was assessed using the Newcastle-Ottawa Scale.

Results

16 studies were included. The most commonly reported physical impairment was decreased range of motion (ROM) into directions of hip joint impingement. Other impairments included altered sagittal and frontal plane hip ROM during gait, altered sagittal plane hip ROM during stair climbing, and decreased hip adductor and flexor muscle strength. Effects of surgery on physical impairments are inconsistent but suggest improved hip ROM during gait, but not during stair climbing. Squatting depth improves following surgical intervention for symptomatic FAI.

Conclusions

People with symptomatic FAI demonstrate physical impairments and activity limitations. Surgical intervention may restore some deficiencies, but not all. Further studies of physical impairment and activity limitation are needed to evaluate outcomes from surgical and conservative interventions and to inform rehabilitation programmes.
Effectiveness of customised foot orthoses for Achilles tendinopathy: a randomised controlled trial
Authors: Munteanu Shannon E , Scott Lisa A , Bonanno Daniel R , Landorf Karl B , Pizzari Tania , Cook Jill L , Menz Hylton B
Published: September 2014

Aim

To evaluate the effectiveness of customised foot orthoses in chronic mid-portion Achilles tendinopathy.

Methods

This was a participant-blinded, parallel-group randomised controlled trial at a single centre (La Trobe University, Melbourne, Australia). One hundred and forty participants aged 18–55 years with mid-portion Achilles tendinopathy were randomised to receive eccentric calf muscle exercises with either customised foot orthoses (intervention group) or sham foot orthoses (control group). Allocation to intervention was concealed. The Victorian Institute of Sports Assessment-Achilles (VISA-A) questionnaire was completed at baseline, then at 1, 3, 6 and 12 months, with 3 months being the primary end point. Differences between groups were analysed using intention to treat with analysis of covariance.

Results

After randomisation into the customised foot orthoses group (n=67) or sham foot orthoses group (n=73), there was 70.7% follow-up of participants at 3 months. There were no significant differences between groups at any time point. At 3 months, the mean (SD) VISA-A score was 82.1 (16.3) and 79.2 (20.0) points for the customised and sham foot orthosis groups, respectively (adjusted mean difference (95% CI)=2.6 (−2.9 to 8.0), p=0.353). There were no clinically meaningful differences between groups in any of the secondary outcome measures.

Conclusions

Customised foot orthoses, prescribed according to the protocol in this study, are no more effective than sham foot orthoses for reducing symptoms and improving function in people with mid-portion Achilles tendinopathy undergoing an eccentric calf muscle exercise programme.

Trial Registration Number

Australian New Zealand Clinical Trials Registry: number ACTRN12609000829213.
Alcohol and drug use among adolescents: and the co-occurrence of mental health problems. Ung@hordaland, a population-based study
Authors: Skogen Jens Christoffer , Sivertsen Børge , Lundervold Astri J , Stormark Kjell Morten , Jakobsen Reidar , Hysing Mari
Published: September 2014

Objectives

The use of alcohol and drugs is prevalent among adolescents, but too little is known about the association between debut of alcohol and drug use, problematic use and concurrent mental health. The aim of the study was to investigate the cross-sectional association between debut of any alcohol or drug use and alcohol-related and drug-related problems and mental health. We also wanted to examine potential interactions between gender and age, and alcohol-related and drug-related variables.

Design

Cross-sectional study.

Setting

Population-based sample of Norwegian adolescents.

Participants

Data stem from the large population-based ung@hordaland study (N=9203), where all adolescents aged 17–19 years living in Hordaland county (Norway) were invited to participate. The main independent variables were debut of alcohol and drug use, alcohol consumption and the presence of alcohol and drug problems as measured by CRAFFT.

Outcomes

The dependent variables were self-reported symptoms of anxiety, depression, inattention and hyperactivity. Statistical analyses included logistic regression models.

Results

Debut of alcohol and drug use were associated with symptoms of depression, inattention and hyperactivity (crude ORs 1.69–2.38, p<0.001), while only debut of drug use was associated with increased symptoms of anxiety (OR=1.33, CI 95% 1.05 to 1.68, p=0.017). Alcohol-related and drug-related problems as measured by CRAFFT were associated with all mental health problems (crude ORs 1.68–3.24, p<0.001). There was little evidence of any substantial age or gender confounding on the estimated associations between alcohol-related and drug-related measures and mental health problems.

Conclusions

Early debut of alcohol and drug use and drug problems is consistently associated with more symptoms of mental health problems, indicating that these factors are an important general indicator of mental health in adolescence.
Primary pulmonary artery osteosarcoma in a dog
Authors: Bryan Jill , De Swarte Marie , Tamborini Alice , Jahns Hanne
Published: September 2014

An eight‐year‐old neutered female Golden Retriever presented for evaluation of lethargy, coughing, haemoptysis and pyrexia. Thoracic radiography identified a diffuse nodular pattern affecting all lung lobes and echocardiography revealed a hyperechoic intraluminal mass within the pulmonary artery. Postmortem examination confirmed the presence of a small irregular raised non‐occluding sessile intraluminal mass infiltrating the wall of the pulmonary artery. It was composed of plump spindle shaped or polygonal cells interspersed between and occasionally lining variably sized trabeculae of osteoid consistent with a diagnosis of osteoblastic osteosarcoma. Secondary pulmonary masses of similar size to the primary neoplasm and large tumour emboli within pulmonary vessels suggested early metastasis. Primary osteosarcoma of the pulmonary artery has not been reported in the dog and its clinical presentation, gross and microscopic features, biological behaviour and tissue of origin are discussed.
Testing a simple method for computing directly the bulk modulus by NPT simulation: The case of polydisperse hard sphere solids
Authors: Li Da , Xu Hong
Published: September 2014

The bulk modulus of hard sphere solids has been computed directly by constant pressure Monte-Carlo simulations, using the histogram of the volume fluctuations. In considering first the one-component system, we show that the method is accurate in a large range of pressures, including high-pressure regime. The method is then applied to a polydisperse solid with relatively low polydispersity index. For illustrative purpose, we took a three-component mixture with symmetric size-distribution, and we studied the solid phase (fcc crystal) of this system. Our results show that the equation of state is very sensitive to the polydispersity. Furthermore, in the high-pressure region, where no (accurate) analytical fit for the equation of state exists, our simulations are able to predict the bulk modulus of such systems.
Geodesic motion in a charged 2D stringy black hole spacetime
Authors: Uniyal Rashmi , Nandan Hemwati , Purohit K. D.
Published: September 2014

We study the time-like geodesics and geodesic deviation for a two-dimensional (2D) stringy black hole (BH) spacetime in Schwarzschild gauge. We have analyzed the properties of effective potential along with the structure of the possible orbits for test particles with different settings of BH parameters. The exactly solvable geodesic deviation equation is used to obtain corresponding deviation vector. The nature of deviation and tidal force is also examined in view of the behavior of corresponding deviation vector. The results are also compared with an another 2D stringy BH spacetime.
EXPERIMENTAL ASSESSMENT OF LUMPED-PARAMETER HUMAN BODY MODELS EXPOSED TO WHOLE BODY VIBRATION
Authors: ARSLAN YUNUS ZIYA
Published: September 2014

Whole body vibration (WBV) is uncontrolled vibrations in occupational settings such as vehicle driving or hand tool operating. Chronic occupational WBV exposure may cause many health problems such as fatigue, lower back pain, spinal degenerations, vision problems and so on. In order to simulate and observe the adverse effects of WBV on the human body, many lumped-parameter human body models were proposed. The objective of this study is to provide quantified assessments of human body biodynamic models which were designed to characterize the response of real human body exposed to WBV. To do so, direct measurements of vibration accelerations obtained from different segments of human body and vehicle seat were carried out during riding on roads with different unevenness levels. Recorded experimental acceleration data were compared with those obtained from simulations of different human body models. Root mean square difference and correlation coefficient values were calculated between theoretical and experimental accelerations for a quantitative assessment of the existing models. According to the comparison results, biodynamic model proposed by Boileau and Rakheja [Boileau P-É, Rakheja S, Whole-body vertical biodynamic response characteristics of the seated vehicle driver: Measurement and model development, Int J Ind Ergonom22:449–472, 1998] showed the best correlation with the experimental acceleration data.
Noether's Second Theorem on natural bundles
Authors: Navarro J. , Sancho J. B.
Published: September 2014

Following work by Anderson, in this paper we present a formulation of Noether's Second Theorem that is valid on any natural bundle.
STRATEGIC MANAGEMENT OF INNOVATION IN MANUFACTURING SMEs: EXPLORING THE PREDICTIVE VALIDITY OF STRATEGY-INNOVATION RELATIONSHIP
Authors: CHEREAU PHILIPPE
Published: September 2014

This research investigates strategy-innovation relationship in manufacturing SMEs. The scope of investigation encompasses the technical, marketing, and organisational dimensions of innovation. Our work extends research on Miles and Snow's framework of strategy configurations by exploring the relationship between attributes of strategic posture and innovation behaviour. This approach aims to provide a more accurate representation of strategic management of innovation in manufacturing SMEs. Results (1) confirm the differentiated propensity to adopt specific innovation behaviours among strategic postures, thus confirming posture-specific innovation characteristics, and (2) highlight differentiated associations between strategic attributes and innovation attributes among strategic postures, thus bringing new insights on strategy-innovation fit. Results also emphasise the influence of hybridisation of strategic profiles on the predictive validity of strategy-innovation relationship. Finally, this research provides useful managerial inputs on the strategic management of innovation in SMEs from an innovation effectiveness standpoint.