bluuebunny/crossref_metadata_2025 huggingface dataset:
Three Dimensional Film Stability and Draw Resonance
Authors: Ahmed Zahir U. , Khayat Roger E.
Published: October 2012

In order to understand the effects of inertia and gravity on draw resonance and on the physical mechanism of draw resonance in three-dimensional Newtonian film casting, a linear stability analysis has been conducted. An eigenvalue problem resulting from the linear stability analysis is formulated and solved as a nonlinear two-point boundary value problem to determine the critical draw ratios. Neutral stability curves are plotted to separate the stable/unstable domain in different appropriate parameter spaces. Both inertia and gravity stabilize the process and the process is more unstable to two- than to three-dimensional disturbances. The effects of inertia and gravity on the physical mechanism of draw resonance have been investigated using the eigenfunctions from the eigenvalue problem. A new approach is introduced in order to evaluate the traveling times of kinematic waves from the perturbed thickness at the take-up, which satisfies the same stability criterion illustrating the general stability of the system.
Simulation of Sphere’s Motion Induced by Shock Waves
Authors: Igra Dan , Igra Ozer , Houas Lazhar , Jourdan Georges
Published: October 2012

Simulations of experimental results appearing in Jourdan et al. (2007, “Drag Coefficient of a Sphere in a Non-Stationary Flow: New Results,”Proc. R. Soc. London, Ser. A, 463, pp. 3323–3345) regarding acceleration of a sphere by the postshock flow were conducted in order to find the contribution of the various parameters affecting the sphere drag force. Based on the good agreement found between present simulations and experimental findings, it is concluded that the proposed simulation scheme could safely be used for evaluating the sphere’s motion in the postshock flow.
On the Analysis of Minimum Thickness in Circular Masonry Arches
Authors: Cocchetti Giuseppe , Colasante Giada , Rizzi Egidio
Published: October 2012

In this paper, the so-called Couplet–Heyman problem of finding the minimum thickness necessary for equilibrium of a circular masonry arch, with general opening angle, subjected only to its own weight is reexamined. Classical analytical solutions provided by J. Heyman are first rederived and explored in details. Such derivations make obviously use of equilibrium relations. These are complemented by a tangency condition of the resultant thrust force at the haunches' intrados. Later, given the same basic equilibrium conditions, the tangency condition is more correctly restated explicitly in terms of the true line of thrust, i.e., the locus of the centers of pressure of the resultant internal forces at each theoretical joint of the arch. Explicit solutions are obtained for the unknown position of the intrados hinge at the haunches, the minimum thickness to radius ratio and the nondimensional horizontal thrust. As expected from quoted Coulomb's observations, only the first of these three characteristics is perceptibly influenced, in engineering terms, by the analysis. This occurs more evidently at increasing opening angle of the arch, especially for over-complete arches. On the other hand, the systematic treatment presented here reveals the implications of an important conceptual difference, which appears to be relevant in the statics of masonry arches. Finally, similar trends are confirmed as well for a Milankovitch-type solution that accounts for the true self-weight distribution along the arch.
Dynamic Partial Least Square Path Modeling for the Front-end Product Design and Development
Authors: Withanage Chathura , Park Taezoon , Ton Hien Duc Truong , Choi Hae-Jin
Published: October 2012

The dynamic nature of today’s technology market requires new value-characteristic modeling methods; mainstream methods have limitations due to unrealistic assumptions, such as static customer preferences and no multicollinearity among product attributes. In particular, products with longer cycle times can suffer because the static model ignores changes in the market during the concept-to-customer lead time. This study proposes a dynamic, partial least squares path model for customer driven product design and development in order to reduce model uncertainty by formulating preference models to reflect market dynamics. The proposed dynamic model adopted partial least squares regression to handle the limited observations plagued by multicollinearity among product attributes. The main advantage of the proposed model is its ability to evaluate design alternatives during the front-end concept screening phase, using the overall product-value metric, customer-revealed value. A case study analyzing the US car market data for sedans from 1990 to 2010 showed the potential for the proposed method to be effective, with a 3.40 mean absolute percentage error.
Buckling and Vibration of Carbon Nanotubes Embedded in Polyethylene Polymers
Authors: Shi Dai , Wang Quan , Varadan Vijay K. , Duan Wenhui
Published: October 2012

The discovery of buckling instability and vibration of polyethylene (PE)/carbon nanotube (CNT) matrices is reported by molecular mechanics simulations. The buckling strains and the resonance frequencies are found to decrease with an increase in the number of polyethylene chains in the polyethylene/carbon nanotube matrices. The van der Waals forces between the polyethylene chains and the carbon nanotube in matrices are investigated to provide physical interpretations on the findings.
Driving Forces and Transportation Efficiency in Water Transportation Through Single-Walled Carbon Nanotubes
Authors: Zi Sun Meng , Hui Duan Wen , Wang Quan , Dowman Martin , Kodikara Jayantha
Published: October 2012

Based on the concept of an energy pump, water transportation in a carbon nanotube (CNT) is studied by molecular dynamics simulations. The influences of CNT pretwist angle, water mass, environmental temperature, CNT diameter, CNT channel length, and CNT channel restrain condition on driving force and transportation efficiency are investigated. It is found that in order to initiate the transportation, the pretwist angle must be larger than certain threshold, 80 deg, for the case of one water molecule in a restrained (8,0) CNT. Furthermore, driving force decreases with increasing water mass and it is more efficient to transport multiple water molecules than one water molecules. The water molecule is found to have higher degrees of collisions in a (8,0) CNT in elevated environmental temperature. By comparing three CNT channel lengths, the channel length of 19.80 nm is identified as a faster and more efficient transporter in an unrestrained (8,8) CNT. Finally, molecular dynamics (MD) simulation indicates that a water molecule can only be transported below 300 K in an unrestrained (8,8) CNT due to the large friction caused by severely deformed channel and the Brownian motion.
Improving Identifiability in Model Calibration Using Multiple Responses
Authors: Arendt Paul D. , Apley Daniel W. , Chen Wei , Lamb David , Gorsich David
Published: October 2012

In physics-based engineering modeling, the two primary sources of model uncertainty, which account for the differences between computer models and physical experiments, are parameter uncertainty and model discrepancy. Distinguishing the effects of the two sources of uncertainty can be challenging. For situations in which identifiability cannot be achieved using only a single response, we propose to improve identifiability by using multiple responses that share a mutual dependence on a common set of calibration parameters. To that end, we extend the single response modular Bayesian approach for calculating posterior distributions of the calibration parameters and the discrepancy function to multiple responses. Using an engineering example, we demonstrate that including multiple responses can improve identifiability (as measured by posterior standard deviations) by an amount that ranges from minimal to substantial, depending on the characteristics of the specific responses that are combined.
Design of Long-Endurance Systems With Inherent Robustness to Partial Failures During Operations
Authors: Agte Jeremy , Borer Nicholas , de Weck Olivier
Published: October 2012

This article presents an integrated multistate method for the early-phase design of inherently robust systems; namely, those capable, as a prima facie quality, of maintaining adequate performance in the face of probabilistic system events or failures. The methodology merges integrated multidisciplinary analysis techniques for system design with behavioral-Markov analysis methods used to define probabilistic metrics such as reliability and availability. The result is a multistate approach that concurrently manipulates design variables and component failure rates to better identify key features for an inherently robust system. This methodology is demonstrated on the design of a long-endurance unmanned aerial vehicle for a three-month ice surveillance mission over Antarctica. The vehicle is designed using the multistate methodology and then compared to a baseline design created for the best performance under nominal conditions. Results demonstrated an improvement of 10–11% in system availability over this period with minimal impacts on cost or performance.
Stochastic Evaluation and Analysis of Free Vibrations in Simply Supported Piezoelectric Bimorphs
Authors: Borboni Alberto , Faglia Rodolfo
Published: October 2012

Piezoelectric bimorph benders are a particular class of piezoelectric devices, which are characterized by the ability to produce flexural deformation greatly larger than the length or thickness deformation of a single piezoelectric layer. Due to extensive dimensional reduction of devices and to the high accuracy and repeatability requested, the effect of erroneous parameter estimation and the fluctuation of parameters due to external reasons, sometimes, cannot be omitted. As such, we consider mechanical, electrical and piezoelectric parameters as uniformly distributed around a nominal value and we calculate the distribution of natural frequencies of the device. We consider an analytical model for the piezoelectric bimorph proposed in literature. The results show how the parameters errors are reflected on the natural frequencies and how an increment of the error is able to change the shape of the frequencies distribution.
Effect of Carbon Nanotube Waviness on the Elastic Properties of the Fuzzy Fiber Reinforced Composites
Authors: Kundalwal S. I. , Ray M. C.
Published: October 2012

A fuzzy fiber reinforced composite (FFRC) reinforced with wavy zig-zag single-walled carbon nanotubes (CNTs) and carbon fibers is analyzed in this study. The distinct constructional feature of this composite is that the wavy CNTs are radially grown on the surface of carbon fibers. To study the effect of the waviness of CNTs on the elastic properties of the FFRC, analytical models based on the mechanics of materials (MOM) approach is derived. Effective elastic properties of the FFRC incorporating the wavy CNTs estimated by the MOM approach have been compared with those predicted by the Mori–Tanaka (MT) method. The values of the effective elastic properties of this composite are estimated in the presence of an interphase between the CNT and the polymer matrix which models the nonbonded van dar Waals interaction between the CNT and the polymer matrix. The effect of waviness of CNTs on the effective properties of the FFRC is investigated when the wavy CNTs are coplanar with two mutually orthogonal planes. The results demonstrate that the axial effective elastic properties of the FFRC containing wavy CNTs can be improved over those of the FFRC with straight CNTs.
Eulerian Framework for Inelasticity Based on the Jaumann Rate and a Hyperelastic Constitutive Relation—Part II: Finite Strain Elastoplasticity
Authors: Eshraghi Amin , Jahed Hamid , Papoulia Katerina D.
Published: October 2012

An Eulerian rate formulation of finite strain elastoplasticity is developed based on a fully integrable rate form of hyperelasticity proposed in Part I of this work. A flow rule is proposed in the Eulerian framework, based on the principle of maximum plastic dissipation in six-dimensional stress space for the case of J2 isotropic plasticity. The proposed flow rule bypasses the need for additional evolution laws and/or simplifying assumptions for the skew-symmetric part of the plastic velocity gradient, known as the material plastic spin. Kinematic hardening is modeled with an evolution equation for the backstress tensor considering Prager’s yielding-stationarity criterion. Nonlinear evolution equations for the backstress and flow stress are proposed for an extension of the model to mixed nonlinear hardening. Furthermore, exact deviatoric/volumetric decoupled forms for kinematic and kinetic variables are obtained. The proposed model is implemented with the Zaremba–Jaumann rate and is used to solve the problem of rectilinear shear for a perfectly plastic and for a linear kinematic hardening material. Neither solution produces oscillatory stress or backstress components. The model is then used to predict the nonlinear hardening behavior of SUS 304 stainless steel under fixed-end finite torsion. Results obtained are in good agreement with reported experimental data. The Swift effect under finite torsion is well predicted by the proposed model.
The Quantification of Hemodynamic Parameters Downstream of a Gianturco Zenith Stent Wire Using Newtonian and Non-Newtonian Analog Fluids in a Pulsatile Flow Environment
Authors: Walker Andrew M. , Johnston Clifton R. , Rival David E.
Published: October 2012

Although deployed in the vasculature to expand vessel diameter and improve blood flow, protruding stent struts can create complex flow environments associated with flow separation and oscillating shear gradients. Given the association between magnitude and direction of wall shear stress (WSS) and endothelial phenotype expression, accurate representation of stent-induced flow patterns is critical if we are to predict sites susceptible to intimal hyperplasia. Despite the number of stents approved for clinical use, quantification on the alteration of hemodynamic flow parameters associated with the Gianturco Z-stent is limited in the literature. In using experimental and computational models to quantify strut-induced flow, the majority of past work has assumed blood or representative analogs to behave as Newtonian fluids. However, recent studies have challenged the validity of this assumption. We present here the experimental quantification of flow through a Gianturco Z-stent wire in representative Newtonian and non-Newtonian blood analog environments using particle image velocimetry (PIV). Fluid analogs were circulated through a closed flow loop at physiologically appropriate flow rates whereupon PIV snapshots were acquired downstream of the wire housed in an acrylic tube with a diameter characteristic of the carotid artery. Hemodynamic parameters including WSS, oscillatory shear index (OSI), and Reynolds shear stresses (RSS) were measured. Our findings show that the introduction of the stent wire altered downstream hemodynamic parameters through a reduction in WSS and increases in OSI and RSS from nonstented flow. The Newtonian analog solution of glycerol and water underestimated WSS while increasing the spatial coverage of flow reversal and oscillatory shear compared to a non-Newtonian fluid of glycerol, water, and xanthan gum. Peak RSS were increased with the Newtonian fluid, although peak values were similar upon a doubling of flow rate. The introduction of the stent wire promoted the development of flow patterns that are susceptible to intimal hyperplasia using both Newtonian and non-Newtonian analogs, although the magnitude of sites affected downstream was appreciably related to the rheological behavior of the analog. While the assumption of linear viscous behavior is often appropriate in quantifying flow in the largest arteries of the vasculature, the results presented here suggest this assumption overestimates sites susceptible to hyperplasia and restenosis in flow characterized by low and oscillatory shear.
Pulse-Wave Propagation in Straight-Geometry Vessels for Stiffness Estimation: Theory, Simulations, Phantoms and In Vitro Findings
Authors: Shahmirzadi Danial , Li Ronny X. , Konofagou Elisa E.
Published: October 2012

Pulse wave imaging (PWI) is an ultrasound-based method for noninvasive characterization of arterial stiffness based on pulse wave propagation. Reliable numerical models of pulse wave propagation in normal and pathological aortas could serve as powerful tools for local pulse wave analysis and a guideline for PWI measurements in vivo. The objectives of this paper are to (1) apply a fluid-structure interaction (FSI) simulation of a straight-geometry aorta to confirm the Moens-Korteweg relationship between the pulse wave velocity (PWV) and the wall modulus, and (2) validate the simulation findings against phantom and in vitro results. PWI depicted and tracked the pulse wave propagation along the abdominal wall of canine aorta in vitro in sequential Radio-Frequency (RF) ultrasound frames and estimates the PWV in the imaged wall. The same system was also used to image multiple polyacrylamide phantoms, mimicking the canine measurements as well as modeling softer and stiffer walls. Finally, the model parameters from the canine and phantom studies were used to perform 3D two-way coupled FSI simulations of pulse wave propagation and estimate the PWV. The simulation results were found to correlate well with the corresponding Moens-Korteweg equation. A high linear correlation was also established between PWV2 and E measurements using the combined simulation and experimental findings (R2 = 0.98) confirming the relationship established by the aforementioned equation.
Methodology for registration of distended rectums in pelvic CT studies
Authors: Rodriguez‐Vila B. , Garcia‐Vicente F. , Gomez E. J.
Published: October 2012

Purpose:

Accurate delineation of the rectum is of high importance in off‐line adaptive radiation therapy since it is a major dose‐limiting organ in prostate cancer radiotherapy. The intensity‐based deformable image registration (DIR) methods cannot create a correct spatial transformation if there is no correspondence between the template and the target images. The variation of rectal filling, gas, or feces, creates a noncorrespondence in image intensities that becomes a great obstacle for intensity‐based DIR.

Methods:

In this study the authors have designed and implemented a semiautomatic method to create a rectum mask in pelvic computed tomography (CT) images. The method, that includes a DIR based on the demons algorithm, has been tested in 13 prostate cancer cases, each comprising of two CT scans, for a total of 26 CT scans.

Results:

The use of the manual segmentation in the planning image and the proposed rectum mask method (RMM) method in the daily image leads to an improvement in the DIR performance in pelvic CT images, obtaining a mean value of overlap volume index = 0.89, close to the values obtained using the manual segmentations in both images.

Conclusions:

The application of the RMM method in the daily image and the manual segmentations in the planning image during prostate cancer treatments increases the performance of the registration in presence of rectal fillings, obtaining very good agreement with a physicianˈs manual contours.
A Single, Plastic Population of Mycosphaerella pinodes Causes Ascochyta Blight on Winter and Spring Peas (Pisum sativum) in France
Authors: Le May Christophe , Guibert Michèle , Leclerc Aurélie , Andrivon Didier , Tivoli Bernard
Published: October 2012

Plant diseases are caused by pathogen populations continuously subjected to evolutionary forces (genetic flow, selection, and recombination). Ascochyta blight, caused byMycosphaerella pinodes, is one of the most damaging necrotrophic pathogens of field peas worldwide. In France, both winter and spring peas are cultivated. Although these crops overlap by about 4 months (March to June), primary Ascochyta blight infections are not synchronous on the two crops. This suggests that the disease could be due to two differentM. pinodespopulations, specialized on either winter or spring pea. To test this hypothesis, 144 pathogen isolates were collected in the field during the winter and spring growing seasons in Rennes (western France), and all the isolates were genotyped using amplified fragment length polymorphism (AFLP) markers. Furthermore, the pathogenicities of 33 isolates randomly chosen within the collection were tested on four pea genotypes (2 winter and 2 spring types) grown under three climatic regimes, simulating winter, late winter, and spring conditions.M. pinodesisolates from winter and spring peas were genetically polymorphic but not differentiated according to the type of cultivars. Isolates from winter pea were more pathogenic than isolates from spring pea on hosts raised under winter conditions, while isolates from spring pea were more pathogenic than those from winter pea on plants raised under spring conditions. These results show that disease developed on winter and spring peas was initiated by a single population ofM. pinodeswhose pathogenicity is a plastic trait modulated by the physiological status of the host plant.
Effect of Frequency and Waveform on Inactivation of Escherichia coli O157:H7 and Salmonella enterica Serovar Typhimurium in Salsa by Ohmic Heating
Authors: Lee Su-Yeon , Ryu Sangryeol , Kang Dong-Hyun
Published: October 2012

The effect of frequency of alternating current during ohmic heating on electrode corrosion, heating rate, inactivation of food-borne pathogens, and quality of salsa was investigated. The impact of waveform on heating rate was also investigated. Salsa was treated with various frequencies (60 Hz to 20 kHz) and waveforms (sine, square, and sawtooth) at a constant electric field strength of 12.5 V/cm. Electrode corrosion did not occur when the frequency exceeded 1 kHz. The heating rate of the sample was dependent on frequency up to 500 Hz, but there was no significant difference (
P
> 0.05) in the heating rate when the frequency was increased above 1 kHz. The electrical conductivity of the sample increased with a rise in the frequency. At a frequency of 60 Hz, the square wave produced a lower heating rate than that of sine and sawtooth waves. The heating rate between waveforms was not significantly (
P
> 0.05) different when the frequency was >500 Hz. As the frequency increased, the treatment time required to reduce
Escherichia coli
O157:H7 and
Salmonella enterica
serovar Typhimurium to below the detection limit (1 log CFU/g) decreased without affecting product quality. These results suggest that ohmic heating can be effectively used to pasteurize salsa and that the effect of inactivation is dependent on frequency and electrical conductivity rather than waveform.
Bacteriophage Ecology in a Commercial Cucumber Fermentation
Authors: Lu Z. , Pérez-Díaz I. M. , Hayes J. S. , Breidt F.
Published: October 2012

To reduce high-salt waste from cucumber fermentations, low-salt fermentations are under development. These fermentations may require the use of starter cultures to ensure normal fermentations. Because potential phage infection can cause starter culture failure, it is important to understand phage ecology in the fermentations. This study investigated the phage ecology in a commercial cucumber fermentation. Brine samples taken from a fermentation tank over a 90-day period were plated onto deMan-Rogosa-Sharpe agar plates. A total of 576 lactic acid bacterial isolates were randomly selected to serve as potential hosts for phage isolation. Filtered brine served as a phage source. Fifty-seven independent phage isolates were obtained, indicating that 10% of the bacterial isolates were sensitive to phage attack. Phage hosts include
Lactobacillus brevis
(67% of all hosts),
Lactobacillus plantarum
(21%),
Weissella paramesenteroides
,
Weissella cibaria
, and
Pediococcus ethanolidurans
. Nearly 50% of phages were isolated on day 14, and the majority of them attacked
L. brevis
. Some phages had a broad host range and were capable of infecting multiple hosts in two genera. Other phages were species specific or strain specific. About 30% of phage isolates produced turbid pinpoint plaques or only caused reduced cell growth on the bacterial lawns. Six phages with distinct host ranges were characterized. The data from this study showed that abundant and diverse phages were present in the commercial cucumber fermentation, which could cause significant mortality to the lactic acid bacteria population. Therefore, a phage control strategy may be needed in low-salt cucumber fermentations.
Chromosomal
tet
(O)-Harboring Regions in Campylobacter coli Isolates from Turkeys and Swine
Authors: Crespo M. D. , Olson J. W. , Altermann E. , Siletzky R. M. , Kathariou S.
Published: October 2012

In turkey-derived
Campylobacter coli
isolates of a unique lineage (cluster II), the tetracycline resistance determinant
tet
(O) was chromosomal and was part of a gene cassette (transposon) interrupting a
Campylobacter jejuni
-associated putative citrate transporter gene. In contrast, the swine-derived
C. coli
strain 6461 harbored a chromosomal
tet
(O) in a different genomic location.
The Two-Component Sensor KinB Acts as a Phosphatase To Regulate Pseudomonas aeruginosa Virulence
Authors: Chand Nikhilesh S. , Clatworthy Anne E. , Hung Deborah T.
Published: October 2012

Pseudomonas aeruginosais an opportunistic pathogen that is capable of causing both acute and chronic infections.P. aeruginosavirulence is subject to sophisticated regulatory control by two-component systems that enable it to sense and respond to environmental stimuli. We recently reported that the two-component sensor KinB regulates virulence in acuteP. aeruginosainfection. Furthermore, it regulates acute-virulence-associated phenotypes such as pyocyanin production, elastase production, and motility in a manner independent of its kinase activity. Here we show that KinB regulates virulence through the global sigma factor AlgU, which plays a key role in repressingP. aeruginosaacute-virulence factors, and through its cognate response regulator AlgB. However, we show that rather than phosphorylating AlgB, KinB's primary role in the regulation of virulence is to act as a phosphatase to dephosphorylate AlgB and alleviate phosphorylated AlgB's repression of acute virulence.
Coordinated Regulation of
gnd
, Which Encodes 6-Phosphogluconate Dehydrogenase, by the Two Transcriptional Regulators GntR1 and RamA in Corynebacterium glutamicum
Authors: Tanaka Yuya , Ehira Shigeki , Teramoto Haruhiko , Inui Masayuki , Yukawa Hideaki
Published: October 2012

The transcriptional regulation of
Corynebacterium glutamicum gnd
, encoding 6-phosphogluconate dehydrogenase, was investigated. Two transcriptional regulators, GntR1 and RamA, were isolated by affinity purification using
gnd
promoter DNA. GntR1 was previously identified as a repressor of gluconate utilization genes, including
gnd
. Involvement of RamA in
gnd
expression had not been investigated to date. The level of
gnd
mRNA was barely affected by the single deletion of
ramA
. However,
gnd
expression was downregulated in the
ramA gntR1
double mutant compared to that of the
gntR1
single mutant, suggesting that RamA activates
gnd
expression. Two RamA binding sites are found in the 5′ upstream region of
gnd
. Mutation proximal to the transcriptional start site diminished the gluconate-dependent induction of
gnd
-
lacZ
. DNase I footprinting assay revealed two GntR1 binding sites, with one corresponding to a previously proposed site that overlaps with the −10 region. The other site overlaps the RamA binding site. GntR1 binding to this newly identified site inhibits DNA binding of RamA. Therefore, it is likely that GntR1 represses
gnd
expression by preventing both RNA polymerase and RamA binding to the promoter. In addition, DNA binding activity of RamA was reduced by high concentrations of NAD(P)H but not by NAD(P), implying that RamA senses the redox perturbation of the cell.
Brain Areas Involved in Acupuncture Needling Sensation of de qi: A single-photon emission computed tomography (SPECT) study
Authors: Chen Jia-Rong , Li Gan-Long , Zhang Gui-Feng , Huang Yong , Wang Shu-Xia , Lu Na
Published: October 2012

Background

De qi is a sensory response elicited by acupuncture stimulation. According to traditional Chinese medicine (TCM), de qi is essential for clinical efficacy. However, the understanding of the neurobiological basis of de qi is still limited.

Objective

To investigate the relationship between brain activation and de qi by taking a single-photon emission computed tomography (SPECT) scan while applying acupuncture at TE5.

Methods

A total of 24 volunteers were randomly divided into 4 groups, and received verum or sham acupuncture at true acupuncture point TE5 or a nearby sham point according to grouping. All subjects then received a 99mTc-ethylcysteinate dimer (ECD) SPECT scan.

Results

All six subjects in the verum acupuncture at true acupuncture point group experienced de qi sensation; in contrast, all six subjects in the sham acupuncture at the sham point group responded with nothing other than non-sensation. Compared to the scan results from subjects who experienced non-sensation, SPECT scans from subjects with de qi sensation demonstrated significant activated points mainly located in brodmann areas 6, 8, 19, 21, 28, 33, 35, 37, 47, the parahippocampal gyrus, lentiform nucleus, claustrum and red nucleus; deactivated points were seen in brodmann areas 9 and 25.

Conclusions

Verum acupuncture at true acupuncture points is more likely to elicit de qi sensation. De qi sensations mainly resulted in brain area activations, but not deactivations. These brain areas are related to the curative effect of Te5. The acupuncture needle sensations of de qi and sharp pain are associated with different patterns of activations and deactivations in the brain.
Sports and exercise physicians as medical assessors
Authors: Milne Chris , Harcourt Peter , Bolzonello David
Published: October 2012

Objective

To clarify the role of sports and exercise physicians as medical assessors.

Methods

Group discussion between senior doctors at a previous annual conference of the Australasian College of Sports Physicians, followed by further discussion between the authors. Clarification of the key requirements of insurers, and formulation of practical advice for those performing this work.

Results

Our expertise in performing medical assessments for the purpose of fitness to play sport is a transferable skill. It can also be used to provide medical assessments for injured workers. Our expertise in rehabilitation is also of value to insurers and other interested parties.

Conclusion

The work is both challenging and rewarding, and can provide additional variety in the working week.
Are socioeconomic disparities in tobacco consumption increasing in India? A repeated cross-sectional multilevel analysis
Authors: Bhan Nandita , Srivastava Swati , Agrawal Sutapa , Subramanyam Malavika , Millett Christopher , Selvaraj Sakthivel , Subramanian S V
Published: October 2012

Objectives

India bears a significant portion of the global tobacco burden with high prevalence of tobacco use. This study examines the socioeconomic patterning of tobacco use and identifies the changing gender and socioeconomic dynamics in light of theCigarette Epidemic Model.

Design

Secondary analyses of second and third National Family Health Survey (NFHS) data.

Setting and participants

Data were analysed from 201 219 men and 255 028 women over two survey rounds.

Outcomes and methods

Outcomes includedsmoking(cigarettes,bidisand pipes/cigar),chewed tobacco(paan masala,gutkhaand others) anddual use, examined by education, wealth, living environment and caste. Standardised prevalence and percentage change were estimated. Pooled multilevel models estimated the effect of socioeconomic covariates on the log odds of tobacco use by gender, along with fixed and random parameters.

Findings

Among men (2005−2006), gradients in smoking by education (illiterates: 44% vs postgraduates: 15%) and chewing (illiterates: 47% vs postgraduates: 19%) were observed. Inverse gradients were also observed by wealth, living environment and caste. Chewed tobacco use by women showed inverse socioeconomic status (SES) gradients comparing the illiterates (7.4%) versus postgraduates (0.33%), and poorest (17%) versus richest (2%) quintiles. However, proportional increases in smoking were higher among more educated (postgraduates (98%) vs high schooling only (17%)) and chewing among richer (richest quintile (49%) vs poorest quintile (35%)). Among women, higher educated showed larger declines for smoking—90% (postgraduates) versus 12% (illiterates). Younger men (15–24 years) showed increasing tobacco use (smoking: 123% and chewing: 112%). Older women (35–49 years) show higher prevalence of smoking (3.2%) compared to younger women (0.3%).

Conclusions

Indian tobacco use patterns show significant diversions from theCigarette Epidemic Model—from gender and socioeconomic perspectives. Separate analysis by type is needed to further understand social determinants of tobacco use in India.
Physicians’ response to computerised alerts for psychotropic drugs in older persons: a multilevel analysis of the associated alert, patient and physician characteristics
Authors: Tamblyn Robyn , Reidel Kristen , Patel Vaishali
Published: October 2012

Objective

Computerised drug alerts are expected to reduce patients’ risk of adverse drug events. However, physicians over-ride most drug alerts, because they believe that the benefit exceeds the risk. The purpose of this study was to determine the drug alert, patient and physician characteristics associated with the: (1) occurrence of psychotropic drug alerts for elderly patients and the (2) response to these alerts by their primary care physicians.

Setting

Primary care, Quebec, Canada.

Design

Prospective cohort study.

Participants

Sixty-one physicians using an electronic prescribing and drug alert decision-support system in their practice, and 3413 elderly patients using psychotropic drugs.

Primary and secondary measures

Psychotropic drug class, alert severity, patient risk for fall injuries and physician experience, practice volume and computer use were evaluated in relationship to the likelihood of having: (1) a psychotropic drug alert, (2) the prescription revised in response to an alert. Cluster-adjusted alternating logistic regression was used to assess multilevel predictors of alert occurrence and response.

Results

In total 13 080 psychotropic drug alerts were generated in 8931 visits. Alerts were more likely to be generated for male patients at higher risk of fall-related injury and for physicians who established the highest alert threshold. In 9.9% of alerts seen, the prescription was revised. The highest revision rate was for antipsychotic alerts (22.6%). Physicians were more likely to revise prescriptions for severe alerts (OR 2.03; 95%CI 1.39 to 2.98), if patients had cognitive impairment (OR 1.95; 95%CI 1.13 to 3.36), and if they made more visits to their physician (OR 1.05 per 5 visits; 95%CI 1 to 1.09).

Conclusions

Physicians view and respond to a small proportion of alerts, mainly for higher-risk patients. To reduce the risk of psychotropic drug-related fall injuries, a new generation of evidence-based drug alerts should be developed.
The Cancer Patient Experiences Questionnaire (CPEQ): reliability and construct validity following a national survey to assess hospital cancer care from the patient perspective
Authors: Iversen Hilde Hestad , Holmboe Olaf , Bjertnæs Øyvind Andresen
Published: October 2012

Objectives

Patient experience questionnaires have been criticised owing to the lack of supporting psychometric evidence. The objective of this study was to describe the development and psychometric evaluation of the Cancer Patient Experiences Questionnaire (CPEQ) in Norway.

Design

Questionnaire development was based on a literature review of existing questionnaires, patient interviews, expert-group consultations, pretesting of questionnaire items and a national survey. Psychometric evaluation included exploratory and confirmatory factor analysis, and tests of internal consistency reliability and test–retest reliability.

Setting

Data were collected using a postal survey of cancer patients attending 54 hospitals in all 4 health regions. The subjects were 14 227 adult cancer patients who had attended an outpatient clinic or who had been discharged from an inpatient ward. Patients with all types of cancer were included. Data quality, internal consistency reliability and construct validity were assessed.

Results

Of the 13 846 patients who received the CPEQ, 7212 (52%) responded. Exploratory factor analysis identified six scales of outpatient experiences relating to nurse contact, doctor contact, information, organisation, patient safety and contact with next of kin, and seven scales of inpatient experiences, with the addition of hospital standard to the aforementioned scales. All but two of the scales met the criterion of 0.70 for Cronbach's α testing, and test–retest correlations ranged from 0.57 to 0.85. Confirmatory factor analysis supported the interpretation of six and seven scales for outpatients and inpatients, respectively. Statistically significant associations based on explicit hypotheses provided evidence for the construct validity of the scales. One additional scale measuring the hospital level was identified (α=0.85).

Conclusions

The CPEQ is a self-report instrument that includes the most important aspects of patient experiences with cancer care at hospitals. The instrument was tested following a national survey in Norway; good evidence is provided herein for the internal consistency reliability, test–retest reliability and construct validity.
Response time evaluation for emergency medical service as a part of its performance
Authors: Duchateau François-Xavier , Garnier-Connois Delphine , Ricard-Hibon Agnès , Josseaume Julien , Casalino Enrique
Published: October 2012

The study aimed to evaluate the response time (RT) of a French physician-staffed emergency medical service unit in both first-line and second-line service zones a part of its performance and how best to integrate it into its geographical specificity and showed acceptable RTs (mostly <10 min). Interestingly, because of the particular location next to other districts, RTs are in the same range for some municipalities that are adjacent to the first-line and area. In a new system in which catching areas would not only be based on administrative criteria anymore but also on performance evaluation, RTs for emergency medical service might be optimised.
Risk factors for burns at home in Kurdish preschool children: a case-control study
Authors: Othman Nasih , Kendrick Denise
Published: October 2012

Background

It is globally reported that young children are at a higher risk of burns but little is known about the individual risk factors. This study was undertaken in 2008 to investigate factors associated with burn injuries in children aged 0–5 years.

Methods

This was a case-control study with cases recruited prospectively from children attending hospital for a new burn injury and controls recruited from children admitted for other conditions.

Results

A total of 248 cases and 248 controls were recruited. Cases included scalds (79%), contact burns (17%) and flame injuries (4%). Burns were most commonly caused by tea utensils (42%) and kerosene stoves (36%). Multivariable analyses found that a poor living standard (OR 5.4, 95% CI 2.6 to 11.7), having a child with a higher activity score (OR 5.3, 95% CI 3.4 to 8.5), having a history of burns in other family members (OR 2.8, 95% CI 1.5 to 5.2) and a higher number of home hazards (OR for a one unit increase in hazards score 1.32, 95% CI 1.02 to 1.70) were all associated with a significant increase in the odds of a burn injury. The presence of a second carer (OR 0.42, 95% CI 0.2 to 0.7) and having disability (OR 0.14, 95% CI 0.03 to 0.6) were protective factors.

Conclusions

This information about risk factors for burn injuries can be used to target preventive interventions towards families at the greatest risk of injury.
Changing associations between partnership history and risk of accidents, violence and suicides
Authors: Silventoinen Karri , Moustgaard Heta , Peltonen Riina , Martikainen Pekka
Published: October 2012

Background

Lower mortality has been systematically found in married when compared with non-married, especially in men, but little is known about marital status differences in mortality from external causes. Furthermore, the role of cohabitation and partnership history in the formation of these differences and how they have been changed over time are poorly understood.

Methods

The incidence of fatal and non-fatal cases of accidents, violence and suicides by partnership history was analysed during 1991–1997 and 2001–2007 in a representative sample of the Finnish population aged 26–59 years. HRs were calculated using Cox proportional hazards models.

Results

Incidence rates in accidents, violence and suicides were generally lower in men and women living with a partner than those living alone. Current cohabitation and previous divorce increased the risk of all of these outcomes when compared with married without previous divorce. Higher incidence rates were found in men who had divorced 3 years ago or earlier when compared with those who had divorced later. Generally, these differences were larger in fatal than in non-fatal cases and significantly larger in men. There was little change in these differences between 1991–1997 and 2001–2007. These differences were partly explained by socioeconomic factors but remained statistically significant also after these adjustments.

Conclusions

Currently living without a partner and cohabitation and previous divorce increased the risk of accidents, violence and suicides. This indicates that also other mechanisms than immediate support from a partner are important in the formation of marital status differences in mortality.
Sensitivity, specificity and likelihood ratios of PCR in the diagnosis of syphilis: a systematic review and meta-analysis
Authors: Gayet-Ageron Angèle , Lautenschlager Stephan , Ninet Béatrice , Perneger Thomas V , Combescure Christophe
Published: October 2012

Objective

To systematically review and estimate pooled sensitivity and specificity of the polymerase chain reaction (PCR) technique compared to recommended reference tests in the diagnosis of suspected syphilis at various stages and in various biological materials.

Design

Systematic review and meta-analysis.

Data sources

Search of three electronic bibliographic databases from January 1990 to January 2012 and the abstract books of five congresses specialized in the infectious diseases' field (1999–2011). Search key terms included syphilis,Treponema pallidumor neurosyphilis and molecular amplification, polymerase chain reaction or PCR.

Review methods

We included studies that used both reference tests to diagnose syphilis plus PCR and we presented pooled estimates of PCR sensitivity, specificity, and positive and negative likelihood ratios (LR) per syphilis stages and biological materials.

Results

Of 1160 identified abstracts, 69 were selected and 46 studies used adequate reference tests to diagnose syphilis. Sensitivity was highest in the swabs from primary genital or anal chancres (78.4%; 95% CI: 68.2–86.0) and in blood from neonates with congenital syphilis (83.0%; 55.0–95.2). Most pooled specificities were ∼95%, except those in blood. A positive PCR is highly informative with a positive LR around 20 in ulcers or skin lesions. In the blood, the positive LR was <10.

Conclusions

The pooled values of LR showed thatT. pallidumPCR was more efficient to confirm than to exclude syphilis diagnosis in lesions. PCR is a useful diagnostic tool in ulcers, especially when serology is still negative and in medical settings with a high prevalence of syphilis.
Chlamydia screening, retesting and repeat diagnoses in Cornwall, UK 2003–2009
Authors: Turner Katy M E , Horner Paddy J , Trela-Larsen Lea , Sharp Matt , May Margaret
Published: October 2012

Objectives

This study aims to describe the patterns of testing and retesting for chlamydia in Cornwall during the first 5 years of the National Chlamydia Screening Programme. We evaluate the factors associated with retesting and estimate the incidence of chlamydia diagnosis and repeat diagnosis.

Methods

Study design: Secondary database analysis. Selection criteria: men and women tested for chlamydia between March 2003 and January 2009 in Cornwall, aged ≥12 years and ≤25 years at the first test. The factors associated with retesting in those with at least one known test result and at least 14 days follow-up time were analysed using Cox regression and the incidence of diagnosis and repeat diagnosis were calculated.

Results

The final dataset consisted of 71 066 records from 49 941 individuals; of whom 59.0% were female and 75.4% were only tested once. There were 48 375 individuals with at least one known test result (negative or positive) and at least 14 days follow-up, included in the Cox regression analysis. Factors associated with testing more than once were (adjusted HR, 95% CI): being female (2.24; 2.14 to 2.34) and initially testing positive (1.43; 1.35 to 1.51). The positivity at first episode declined from 13.2% (1077 cases) in 2003/2004 to 5.8% (843 cases) in 2008/2009. The incidence of diagnosis at the second test was 5.9 per 100 person years in those testing negative at the first test compared with 18.1 per 100 person years in those initially positive.

Discussion

Most individuals in this analysis were tested only once, but the testing volume and proportion of repeat tests were highest at the end of the study period. As the testing rate stabilises to 30% coverage, maintaining retesting rates in those previously tested and especially in those previously diagnosed with chlamydia will be necessary for the sustainability of the screening programme.

Conclusions

A key feature of the next 5 years of the screening programme will be to maintain screening and rescreening.
PARTICLE PHYSICS FROM ALMOST-COMMUTATIVE SPACETIMES
Authors: VAN DEN DUNGEN KOEN , VAN SUIJLEKOM WALTER D.
Published: October 2012

Our aim in this review paper is to present the applications of Connes' noncommutative geometry to elementary particle physics. Whereas the existing literature is mostly focused on a mathematical audience, in this paper we introduce the ideas and concepts from noncommutative geometry using physicists' terminology, gearing towards the predictions that can be derived from the noncommutative description. Focusing on a light package of noncommutative geometry (so-called "almost-commutative manifolds"), we shall introduce in steps: electrodynamics, the electroweak model, culminating in the full Standard Model. We hope that our approach helps in understanding the role noncommutative geometry could play in describing particle physics models, eventually unifying them with Einstein's (geometrical) theory of gravity.
MODIFIED GRAVITY AS A COMMON CAUSE FOR COSMIC ACCELERATION AND FLAT GALAXY ROTATION CURVES
Authors: MISHRA PRITI , SINGH TEJINDER P.
Published: October 2012

Flat galaxy rotation curves and the accelerating Universe both imply the existence of a critical acceleration, which is of the same order of magnitude in both the cases, in spite of the galactic and cosmic length scales being vastly different. Yet, it is customary to explain galactic acceleration by invoking gravitationally bound dark matter, and cosmic acceleration by invoking a "repulsive" dark energy. Instead, might it not be the case that the flatness of rotation curves and the acceleration of the Universe have a common cause? In this essay we propose a modified theory of gravity. By applying the theory on galactic scales we demonstrate flat rotation curves without dark matter, and by applying it on cosmological scales we demonstrate cosmic acceleration without dark energy.