bluuebunny/crossref_metadata_2025 huggingface dataset:
Removal of Calcified Plaque Utilizing Orbital Atherectomy
Authors: Kohler Robert , Nguyen Tri , McBroom Jeffrey
Published: October 2014

Arterial disease occurs when plaque builds up in the arteries and limits flow of oxygen-rich blood to organs and other parts of the body reducing organ function. Atherectomy is a mechanical process in which plaque is removed from artery walls or modified to change vessel compliance. Various types of atherectomy systems exist to remove or modify plaque depending on plaque morphology. Orbital atherectomy (Diamondback 360® Orbital Atherectomy System) is a sanding process utilizing a diamond abrasive crown mounted eccentrically to a flexible drive shaft.

The effects of rotational speed, crown size, centrifugal forces and run time were evaluated. Finite element modeling and bench testing using carbon as a calcified plaque surrogate material were used.

The crown-simulated vessel wall force was calculated using a finite element model that included a rigid vessel wall and a rotating crown. Results show a small force when the crown begins to rotate at lower speeds, that increases to a peak force at maximum speed, and decreases as the orbit diameter increases with material removal.

A design of experiments plan was created and used to quantify the effects of crown size rotation speed and number of treatment passes on lumen diameter. Increasing the crown diameter increased lumen diameter nonlinearly at an increasing rate with crown rotation speed in the carbon model.

Scanning Electron Microscopy (SEM) analysis of the particulate material removed in the bench test demonstrated brittle fracture as the mode of material removal of the carbon surrogate.
Magnetic Impelled Arc Butt Welding Implementation on Truck Chassis Components
Authors: Balta Berna
Published: October 2014

This paper presents how to design and test vibration induced truck chassis brackets via magnetic impelled arc butt welding. Magnetic impelled arc butt welding is a technique which reduces the manufacturing costs, flexible in design and improved durability when compared to other welding techniques. Design of magnetic impelled arc butt welded parts using Finite element (FE) techniques and testing the parts with Road Load Data (RLD) tests is explained. Natural frequencies of the parts are calculated, and then, frequency response FE analysis has been performed for worst case conditions. Correlation of the design has been performed via real-life tests with RLD data. It has been shown that magnetic impelled arc butt welding can be applied for other parts working under vibration load.
Mobility based 3D simulation of selective, viscoelastic polymer reflow using surface evolver
Authors: Kirchner Robert , Schift Helmut
Published: October 2014

This work demonstrates implementation of the main effects of viscoelastic thermal polymer reflow in an efficient energy and mobility based simulation. The concept is based on a finite-element, soap-film method using the free software surface evolver. Properties of a homogeneous 3D volume are thereby represented by a corresponding 2D surface. The simulation only requires the contact angle between polymer and substrate for infinite long reflow times, obtained from fingerprint experiments, and a mobility value as input. The mobility value is a measure for the polymer-chain mobility and is directly linked to the polymer viscosity. This concept allows for an accurate and fast treatment of the thermomechanically complex polymer behavior close to the glass transition. The simulation time scale is linearly related to the experimental time scale allowing for accelerated-time simulations. Simulation and experiment showed a very good agreement. As a generalized concept, the approach presented here can be used for fast and full 3D shape computation during any complex, energy driven geometry optimization process like polymer reflow, viscoelastic wetting or dewetting and droplet coagulation. This simulation may facilitate a faster uptake of grayscale reflow technologies for industrial processes. Supplementary material supports a quick grasp of the simulation approach.
Quantitative characterization of pore stuffing and unstuffing for postporosity plasma protection of low-k materials
Authors: Heyne Markus H. , Zhang Liping , Liu Junjun , Ahmad Iftikar , Toma Dorel , de Marneffe Jean-François , De Gendt Stefan , Baklanov Mikhail R.
Published: October 2014

The problem of k-value degradation (plasma damage) is a key issue for the integration, and it is becoming more challenging as the dielectric constant of low-k materials scales down. One way to circumvent this issue is temporarily conversion of low-k material from a porous to a dense state by filling the pores with a sacrificial polymer after the deposition and curing of the low-k material. A detailed process scheme for the pore stuffing and postetch polymer removal of PMMA is described in this work. The filling temperature was optimized according to the molecular weight of the PMMA. To remove the polymer after plasma-etching in a purely thermal environment, a temperature of at least 430 °C had to be applied. Annealing assisted by variable frequency microwaves could remove the polymer already at 380 °C and with a He–H2 afterglow plasma the polymer could be removed at 280 °C. Laser annealing allowed the removal at a stage temperature of 200 °C with an only surface-limited heating of about 500 °C and higher to prevent the FEOL structures from damage. This work presents the results of the detailed study of stuffing and unstuffing processes, discusses mechanisms, and provides background for a robust stuffing and polymer removal process for the plasma damage reduction in porous low-k dielectrics.
Novel spin-electronic properties of BC7 sheets induced by strain
Authors: Xu Lei , Dai ZhenHong , Sui PengFei , Sun YuMing , Wang WeiTian
Published: October 2014

Based on first-principles calculations, the authors have investigated the electronic and magnetic properties of BC7 sheets with different planar strains. It is found that metal–semiconductor transition appears at the biaxial strain of 15.5%, and the sheets are characteristic of spin-polarized semiconductor with a zero band-gap. The band-gap rapidly increases with strain, and reaches a maximum value of 0.60 eV at the strain of 20%. Subsequently, the band-gap decreases until the strain reaches up to 22% and shows a semiconductor-half metal transformation. It will further present metal properties until the strain is up to the maximum value of 35%. The magnetic moments also have some changes induced by biaxial strain. The numerical analysis shows that the two-dimensional distortions have great influences on the magnetic moments. The novel spin-electronic properties make BC7 sheets have potential applications in future spintronic nanodevices.
Walking Reduces Postprandial Insulin Secretion in Obese Adolescents Consuming a High-Fructose or High-Glucose Diet
Authors: Heden Timothy D. , Liu Ying , Park Young-Min , Winn Nathan C. , Kanaley Jill A.
Published: October 2014

Background:

This study assessed if walking at a self-selected pace could improve postprandial glucose and insulin concentrations in obese adolescents consuming high-fructose (HF) or high-glucose (HG) diets.

Methods:

Seven obese male and female adolescents (18 ± 1 yr) performed 4, 15-day trials in a random order, including 1) HF-diet (50 g fructose/d added to normal diet) while being sedentary, 2) HG-diet (50 g glucose/d) while sedentary, 3) HF-diet with additional walking, and 4) HG-diet with additional walking. On the 15th day of each trial, the participants performed mixed meal testing in the laboratory in which they consumed three liquid shakes (either HF or HG) and during the HF and HG sedentary trials, the participants took < 4000 steps while in the laboratory but during the walking trials took ≥ 13,000 steps during testing.

Results:

Walking did not alter postprandial glucose concentrations. Although walking reduced insulin secretion by 34% and 25% during the HF- and HG-diet, respectively (P < .05), total insulin concentrations were only significantly reduced (P > .05) with walking during the HF trial, possibly because walking enhanced insulin clearance to a greater extent during the HF-diet.

Conclusions:

Walking reduces postprandial insulin secretion in obese adolescents consuming a high-fructose or high-glucose diet.
A double-edged sword for tropical forests
Authors: Carrasco L. R. , Larrosa C. , Milner-Gulland E. J. , Edwards D. P.
Published: October 2014

Contrary to expectation, high-yielding tropical crops may cause forest loss in the tropics
Structure of the large ribosomal subunit from human mitochondria
Authors: Brown Alan , Amunts Alexey , Bai Xiao-chen , Sugimoto Yoichiro , Edwards Patricia C. , Murshudov Garib , Scheres Sjors H. W. , Ramakrishnan V.
Published: October 2014

Making mitochondrial hydrophobic proteins

Mitochondria produce chemical energy for the cell. Human mitochondria have their own specific ribosomes—mitoribosomes, which are distinct from cytoplasmic ribosomes. Mitoribosomes synthesize the mitochondrial membrane proteins that generate the chemical energy. Brown
et al.
used cryo–electron microscopy to determine the high-resolution structure of the large subunit of the human mitoribosome. The mitoribosome has a number of unique features, including an exit tunnel lined with hydrophobic amino acid residues.

Science
, this issue p.
718
Observation of Majorana fermions in ferromagnetic atomic chains on a superconductor
Authors: Nadj-Perge Stevan , Drozdov Ilya K. , Li Jian , Chen Hua , Jeon Sangjun , Seo Jungpil , MacDonald Allan H. , Bernevig B. Andrei , Yazdani Ali
Published: October 2014

A possible sighting of Majorana states

Nearly 80 years ago, the Italian physicist Ettore Majorana proposed the existence of an unusual type of particle that is its own antiparticle, the so-called Majorana fermion. The search for a free Majorana fermion has so far been unsuccessful, but bound Majorana-like collective excitations may exist in certain exotic superconductors. Nadj-Perge
et al.
created such a topological superconductor by depositing iron atoms onto the surface of superconducting lead, forming atomic chains (see the Perspective by Lee). They then used a scanning tunneling microscope to observe enhanced conductance at the ends of these chains at zero energy, where theory predicts Majorana states should appear.

Science
, this issue p.
602
; see also p.
547
Genome Sequence of Coxiella burnetii Strain AuQ01 (Arandale) from an Australian Patient with Acute Q Fever
Authors: Walter Mathias C. , Vincent Gemma A. , Stenos John , Graves Stephen , Frangoulidis Dimitrios
Published: October 2014

Coxiella burnetii
strain AuQ01 was isolated from the serum of an Australian acute Q fever patient and represents the first whole genome from this historical Q fever country. This new genome shows distinct differences from existing genomic data and will enhance the understanding of this query pathogen.
Draft Genome Sequence of Burkholderia pyrrocinia Lyc2, a Biological Control Strain That Can Suppress Multiple Plant Microbial Pathogens
Authors: Wang Xiao-Qiang , Showmaker Kurt C. , Yu Xiao-Qing , Bi Tao , Hsu Chuan-Yu , Baird Sonya M. , Peterson Daniel G. , Li Xiang-Dong , Lu Shi-En
Published: October 2014

Burkholderia pyrrocinia
strain Lyc2 was isolated from the tobacco rhizosphere in China. This bacterium exhibits a remarkable capacity to inhibit the growth of multiple pathogens and shows strong suppression of cotton seedling damping-off. Here, we present the draft genome sequence of
Burkholderia pyrrocinia
strain Lyc2.
Draft Genome Sequence of the Organophosphorus-Degrading Bacterium
Pseudomonas
sp. Strain 1-7, Isolated from Organophosphorus-Polluted Sludge
Authors: Tian Jian , Xu Li , Zhang Shuangyu , Sun Wen , Chu Xiaoyu , Wu Ningfeng
Published: October 2014

Pseudomonas
sp. strain 1-7, isolated from organophosphorus-polluted sludge, is able to degrade many organophosphorus compounds. Here, we report the draft genome sequence of
Pseudomonas
sp. strain 1-7.
Genome Sequence of
Maribius
sp. Strain MOLA 401, a Marine
Roseobacter
with a Quorum-Sensing Cell-Dependent Physiology
Authors: Doberva Margot , Sanchez-Ferandin Sophie , Ferandin Yoan , Intertaglia Laurent , Joux Fabien , Lebaron Philippe , Lami Raphaël
Published: October 2014

Maribius
sp. strain MOLA401 is an alphaproteobacterium isolated from a coral reef lagoon located in New Caledonia, France. We report the genome sequence and its annotation which, interestingly, reveals the presence of genes involved in quorum sensing. This is the first report of a full genome within the genus
Maribius
.
Complete Genome Sequence of Vibrio vulnificus 93U204, a Bacterium Isolated from Diseased Tilapia in Taiwan
Authors: Lo Wen-Sui , Chen Hwajiun , Chen Chun-Yao , Kuo Chih-Horng
Published: October 2014

Vibrio vulnificus
93U204 is a bacterium isolated from a moribund tilapia collected in Kaohsiung, Taiwan. Here, we report the complete genome sequence of this bacterium to facilitate the investigation of its pathogenicity and for comparative analyses with human-pathogenic strains within the same species.
Draft Genome Sequence of the Oyster Larval Probiotic Bacterium
Vibrio
sp. Strain OY15
Authors: Schreier Harold J. , Schott Eric J.
Published: October 2014

We report the draft genome sequence of
Vibrio
sp. strain OY15, a Gram-negative marine bacterium isolated from an oyster (
Crassostrea virginica
) digestive tract and shown to possess probiotic activity. The availability of this genome sequence will facilitate the study of the mechanisms of probiotic activity as well as virulence capacity.
Identification of Primary Drug Resistance to Rifampin in Mycobacterium leprae Strains from Leprosy Patients in Amazonas State, Brazil
Authors: Contreras Mejía Matilde del Carmen , Porto Dos Santos Maísa , Villarouco da Silva George Allan , da Motta Passos Isabella , Naveca Felipe Gomes , Souza Cunha Maria da Graça , Moraes Milton Ozório , de Paula Lucia
Published: October 2014

The aim of this study was to identify polymorphisms in thefolp1,gyrA, andrpoBgenes in leprosy patients treated in Amazonas State, Brazil. Among 197 slit-skin smear samples from untreated or relapsed patients, we found three cases of primary resistance to rifampin and one confirmed case of multidrug resistance.
Evaluation of the BD GeneOhm Methicillin-Resistant Staphylococcus aureus (MRSA) Assay as a Method for Detection of MRSA Isolates, Using a Large Collection of European and North African Isolates
Authors: Trouillet-Assant Sophie , Bes Michele , Meugnier Helene , Tigaud Sylvestre , Etienne Jérôme , Vandenesch François , Laurent Frédéric
Published: October 2014

Using a large collection of European and North African methicillin-resistant
Staphylococcus aureus
(MRSA) isolates with a variety of genetic backgrounds and staphylococcal cassette chromosome
mec
(SCC
mec
) types, we evaluated the reliability of the BD GeneOhm MRSA assay. Results revealed high performance of this test for detecting MRSA strains provided from Europe and North Africa (98.3%).
Point-Counterpoint: Can Newly Developed, Rapid Immunochromatographic Antigen Detection Tests Be Reliably Used for the Laboratory Diagnosis of Influenza Virus Infections?
Authors: Dunn James J. , Ginocchio Christine C.
Published: October 2014

Five years ago, the Point-Counterpoint series was launched. The initial article asked about the role of rapid immunochromatographic antigen testing in the diagnosis of influenza A virus 2009 H1N1 infection (D. F. Welch and C. C. Ginocchio, J Clin Microbiol 48:22–25, 2010,
http://dx.doi.org/10.1128/JCM.02268-09
). Since that article, not only have major changes been made in immunochromatographic antigen detection (IAD) testing for the influenza viruses, but there has also been rapid development of commercially available nucleic acid amplification tests (NAATs) for influenza virus detection. Further, a novel variant of influenza A, H7N9, has emerged in Asia, and H5N1 is also reemergent. In that initial article, the editor of this series, Peter Gilligan, identified two issues that required further consideration. One was how well IAD tests worked in clinical settings, especially in times of antigen drift and shift. The other was the role of future iterations of influenza NAATs and whether this testing would be available in a community hospital setting. James Dunn, who is Director of Medical Microbiology and Virology at Texas Children's Hospital, has extensive experience using IAD tests for diagnosing influenza. He will discuss the application and value of these tests in influenza diagnosis. Christine Ginocchio, who recently retired as the Senior Medical Director, Division of Infectious Disease Diagnostics, North Shore-LIJ Health System, and now is Vice President for Global Microbiology Affairs at bioMérieux, Durham, NC, wrote the initial counterpoint in this series, where she advocated the use of NAATs for influenza diagnosis. She will update us on the commercially available NAAT systems and explain what their role should be in the diagnosis of influenza infection.
HIV-1 Nef and Vpu Are Functionally Redundant Broad-Spectrum Modulators of Cell Surface Receptors, Including Tetraspanins
Authors: Haller Claudia , Müller Birthe , Fritz Joëlle V. , Lamas-Murua Miguel , Stolp Bettina , Pujol François M. , Keppler Oliver T. , Fackler Oliver T.
Published: October 2014

HIV-1 Nef and Vpu are thought to optimize virus replication in the infected host, at least in part via their ability to interfere with vesicular host cell trafficking. Despite the use of distinct molecular mechanisms, Nef and Vpu share specificity for some molecules such as CD4 and major histocompatibility complex class I (MHC-I), while disruption of intracellular transport of the host cell restriction factor CD317/tetherin represents a specialized activity of Vpu not exerted by HIV-1 Nef. To establish a profile of host cell receptors whose intracellular transport is affected by Nef, Vpu, or both, we comprehensively analyzed the effect of these accessory viral proteins on cell surface receptor levels on A3.01 T lymphocytes. Thirty-six out of 105 detectable receptors were significantly downregulated by HIV-1 Nef, revealing a previously unappreciated scope with which HIV-1 Nef remodels the cell surface of infected cells. Remarkably, the effects of HIV-1 Vpu on host cell receptor exposure largely matched those of HIV-1 Nef in breadth and specificity (32 of 105, all also targeted by Nef), even though the magnitude was generally less pronounced. Of particular note, cell surface exposure of all members of the tetraspanin (TSPAN) protein family analyzed was reduced by both Nef and Vpu, and the viral proteins triggered the enrichment of TSPANs in a perinuclear area of the cell. While Vpu displayed significant colocalization and physical association with TSPANs, interactions of Nef with TSPANs were less robust. TSPANs thus emerge as a major target of deregulation in host cell vesicular transport by HIV-1 Nef and Vpu. The conservation of this activity in two independent accessory proteins suggests its importance for the spread of HIV-1 in the infected host.

IMPORTANCE
In this paper, we define that HIV-1 Nef and Vpu display a surprising functional overlap and affect the cell surface exposure of a previously unexpected breadth of cellular receptors. Our analyses furthermore identify the tetraspanin protein family as a previously unrecognized target of Nef and Vpu activity. These findings have implications for the interpretation of effects detected for these accessory gene products on individual host cell receptors and illustrate the coevolution of Nef and Vpu function.
Genome Analysis of the First Marseilleviridae Representative from Australia Indicates that Most of Its Genes Contribute to Virus Fitness
Authors: Doutre Gabriel , Philippe Nadège , Abergel Chantal , Claverie Jean-Michel
Published: October 2014

The family
Marseilleviridae
consists of
Acanthamoeba
-infecting large DNA viruses with icosahedral particles ∼0.2 μm in diameter and genome sizes in the 346- to 380-kb range. Since the isolation of
Marseillevirus
from a cooling tower in Paris (France) in 2009, the family
Marseilleviridae
has expanded rapidly, with representatives from Europe and Africa. Five members have been fully sequenced that are distributed among 3 emerging
Marseilleviridae
lineages. One comprises
Marseillevirus
and
Cannes 8 virus
, another one includes
Insectomime virus
and
Tunisvirus
, and the third one corresponds to the more distant
Lausannevirus
. We now report the genomic characterization of
Melbournevirus
, the first representative of the
Marseilleviridae
isolated from a freshwater pond in Melbourne, Australia. Despite the large distance separating this sampling point from France,
Melbournevirus
is remarkably similar to
Cannes 8 virus
and
Marseillevirus
, with most orthologous genes exhibiting more than 98% identical nucleotide sequences. We took advantage of this optimal evolutionary distance to evaluate the selection pressure, expressed as the ratio of nonsynonymous to synonymous mutations for various categories of genes. This ratio was found to be less than 1 for all of them, including those shared solely by the closest
Melbournevirus
and
Cannes 8 virus
isolates and absent from
Lausannevirus
. This suggests that most of the 403 protein-coding genes composing the large
Melbournevirus
genome are under negative/purifying selection and must thus significantly contribute to virus fitness. This conclusion contrasts with the more common view that many of the genes of the usually more diverse large DNA viruses might be (almost) dispensable.

IMPORTANCE
A pervasive view is that viruses are fast-evolving parasites and carry the smallest possible amount of genomic information required to highjack the host cell machinery and perform their replication. This notion, probably inherited from the study of RNA viruses, is being gradually undermined by the discovery of DNA viruses with increasingly large gene content. These viruses also encode a variety of DNA repair functions, presumably slowing down their evolution by preserving their genomes from random alterations. On the other hand, these viruses also encode a majority of proteins without cellular homologs, including many shared only between the closest members of the same family. One may thus question the actual contribution of these anonymous and/or quasi-orphan genes to virus fitness. Genomic comparisons of
Marseilleviridae
, including a new
Marseillevirus
isolated in Australia, demonstrate that most of their genes, irrespective of their functions and conservation across families, are evolving under negative selection.
Advance Care Planning: practicalities, legalities, complexities and controversies
Authors: Horridge Karen A
Published: October 2014

Increasing numbers, complexities and technology dependencies of children and young people with life-limiting conditions require paediatricians to be well prepared to meet their changing needs. Paediatric Advance Care Planning provides a framework for paediatricians, families and their multidisciplinary teams to consider, reflect and record the outcome of their conversations about what might happen in the future in order to optimise quality of clinical care and inform decision-making. For some children and young people this will include discussions about the possibility of death in childhood. This may be unexpected and sudden, in the context of an otherwise active management plan or may be expected and necessitate discussions about the process of dying and attention to symptoms. Decision-making about appropriate levels of intervention must take place within a legal and ethical framework, recognising that the UK Equality Act (2010) protects the rights of disabled children and young people and infants and children of all ages to the same high quality healthcare as anyone else.
A severe manifestation of primary HIV-1 infection in an adolescent
Authors: Morgado Joana , Póvoas Marta Isabel , Cruz Carla , Teixeira Andrea
Published: October 2014

Primary HIV infection (PHI) is symptomatic in 50–90% of patients with symptoms resembling infectious mononucleosis. The diagnosis, however, is seldom made at first presentation. Clinically severe presentations during primary HIV type 1 infection are considered to occur infrequently. We report a case of a severe manifestation of PHI with meningoencephalitis in the setting of HIV seroconversion in an adolescent girl.
Susac's syndrome: the value of fundus fluorescein angiography
Authors: Khan Imran Joseph , Allroggen Holger , Pagliarini Sergio
Published: October 2014

A 19-year-old woman presented with a 4-week history of headache, ataxia, vertigo, confusion, intermittent blurred vision in the right eye and intermittent hearing loss. MRI revealed white matter lesions and ‘pepper pot’ lesions of the corpus callosum. The cerebrospinal fluid had raised protein and lymphocytes. Fundal examination revealed multiple peripheral arterial occlusions in the both eyes confirmed with fundus fluorescein angiography (FFA). A diagnosis of Susac's syndrome was made. The patient was initially treated with steroids, followed by azathioprine and intravenous immunoglobulins (IVIg). Clinical improvement was noted, associated with improvement of the retinal circulation on FFA.
Individual differences in cognitive ability at age 20 predict pulmonary function 35 years later
Authors: Vasilopoulos Terrie , Kremen William S , Grant Michael D , Panizzon Matthew S , Xian Hong , Toomey Rosemary , Lyons Michael J , Jacobson Kristen C , Franz Carol E
Published: October 2014

Background

Poor pulmonary function is associated with mortality and age-related diseases, and can affect cognitive performance. However, extant longitudinal studies indicate that early cognitive ability also affects later pulmonary function. Despite the multifaceted nature of pulmonary function, most longitudinal studies were limited to a single index of pulmonary function: forced expiratory volume in 1 s (FEV1). In this study, we examined whether early adult cognitive ability predicted five different indices of pulmonary function in mid-life.

Methods

Mixed modelling tested the association between young adult general cognitive ability (mean age=20), measured by the Armed Forces Qualification Test (AFQT), and mid-life pulmonary function (mean age=55), in 1019 men from the Vietnam Era Twin Study of Aging. Pulmonary function was indexed by per cent predicted values for forced vital capacity (FVC%p), FEV1%p, maximum forced expiratory flow (FEFmax%p), and maximal voluntary ventilation (MVV%p), and by the ratio of FEV1 to FVC (FEV1/FVC), an index of lung obstruction.

Results

After adjusting for smoking, pulmonary disease, occupation, income and education, age 20 AFQT was significantly (p<0.05) associated with mid-life FVC%p (β=0.10), FEV1%p (β=0.13), FEFmax%p (β=0.13), and MVV%p (β=0.13), but was not significantly associated with FEV1/FVC (β=0.03, p=0.34).

Conclusions

Early adult cognitive ability is a predictor of multiple indices of aging-related pulmonary function 35 years later, including lung volume, airflow and ventilator capacity. Cognitive deficits associated with impaired aging-related lung function may, thus, be partly pre-existing. However, results also highlight that early life risk factors may be differentially related to different metrics of later-life pulmonary health.
Modelling the financial performance of construction companies using neural network via genetic algorithm
Authors: Mohamad H.H. , Ibrahim A.H. , Massoud H.H.
Published: October 2014

Net profit, annual work volume, and working capital can be considered as the main financial performance indicators for any construction company. Sufficient liquidity must be properly assessed to ensure the survival of the business in both short-term and long-term bases. Large amount of working capital simply means idle funds in a form of current assets that does not gain any profit for the company. On other hand, small amount of working capital means that the company is unable to meet its liabilities and it faces complexity to participate in new project tenders, as a consequence its annual work volume might be decreased. Then, the excess or shortage of working capital affects badly the companies’ profitability. Hence, it is obvious that the construction companies’ working capital, net profit, and annual work volume constitute three interrelated financial performance indicators that have to be appropriately assessed. The present study aims to develop a model to help the construction companies’ managers to assess and forecast their companies’ financial performance indicators: working capital, net profit, and annual work volume. Through this research, the genetic algorithm technique (GA) will be integrated with the neural network technique (NN) to develop the proposed model. The developed model will be able to predict the three financial performance indicators: working capital, net profit, and annual work volume, for an upcoming year based on previously published financial statements data. A comprehensive literature review was conducted and 23 factors were identified as the most influencing factors on the construction companies’ financial indicators: working capital, net profit, and annual work volume. One hundred and sixty four Egyptian construction companies’ financial statements were gathered and analyzed to extract data regarding the identified 23 factors. The extracted data were used to develop a NN–GA hybrid and NN only models to assess the construction companies’ financial indicators. The two developed model outputs are compared to evaluate their predictive capability. This comparison showed that, the NN–GA hybrid model predictive capability is better than the NN only model predictive capability. Incorporating the GA enhances the predicting capability of the developed model by an average of 4.0%.
Dynamic of the Gaussian quantum discord and effect of non-Markovian degree
Authors: Liu Xin , Wu Wei , Hu Changkui
Published: October 2014

We study the dynamic of the Gaussian quantum discord in a continuous-variable system subject to a common non-Markovian environment with zero-temperature. By considering an initial two-mode Gaussian symmetric squeezed thermal state, we show that Gaussian discord has a very different dynamic characteristic in a non-Markovian evolution versus a Markov process, and can be created by the memory effect, which features non-Markovianity. We also study the relationship between Gaussian discord and the non-Markovian degree of the environment. The results may offer us an effective experimental method to get more quantum correlations.
Application of optimization method to the x4 model in the Tsallis nonextensive statistics
Authors: Ishihara Masamichi
Published: October 2014

We study the effects of the environment described by the Tsallis nonextensive statistics on physical quantities using an optimization method in the case of small deviation from the Boltzmann–Gibbs statistics. The x4 model is used and the density operator is restricted to be a Gaussian form. The variational parameter is the frequency Ω of a harmonic oscillator in the optimization method. We obtain an approximate expression of free energy and of the expectation value of βmΩ2 x2/2, where β is the inverse of the temperature T and m is the mass. The optimized frequency is estimated numerically. The expectation value of βmΩ2 x2/2 and the derivative of the energy with respect to the temperature [Formula: see text] are also calculated numerically. The effects of the Tsallis nonextensive statistic in the case of small deviation from the Boltzmann–Gibbs statistics are found: (1) the frequency modulation, (2) the variation of the expectation value of βm Ω2 x2/2 and (3) the variation of [Formula: see text].
Vibration Dynamics of an Inclined Cable Excited Near Its Second Natural Frequency
Authors: Tzanov Vassil V. , Krauskopf Bernd , Neild Simon A.
Published: October 2014

Inclined cables are essential structural elements that are used most prominently in cable-stayed bridges. When the bridge deck oscillates due to an external force, such as passing traffic, cable vibrations can arise not only in the plane of excitation, but also in the perpendicular plane. This undesirable phenomenon can be modeled as an auto-parametric resonance between the in-plane and out-of-plane modes of vibration of the cable. In this paper, we consider a three-mode model, capturing the second in-plane, and first and second out-of-plane modes, and use it to study the response of an inclined cable that is vertically excited at its lower (deck) support at a frequency close to the second natural frequency of the cable. Averaging is applied to the model and then the solutions and bifurcations of the resulting averaged differential equations are investigated and mapped out with numerical continuation. In this way, we present a detailed bifurcation study of the different possible responses of the cable. We first consider the equilibria of the averaged model, of which there are four types that are distinguished by whether each of the two out-of-plane modes is present or not in the cable response. Each type of equilibrium is computed and represented as a surface over the plane of amplitude and frequency of the forcing. The stability of the equilibria changes and different surfaces meet along curves of bifurcations, which are continued directly. Overall, we present a comprehensive geometric picture of the two-parameter bifurcation diagram of the constant-amplitude coupled-mode response of the cable. We then focused on bifurcating periodic orbits, which correspond to cable dynamics with varying amplitudes of the participating second in-plane and second out-of-plane modes. The range of excitation amplitude and frequency is determined where such whirling cable motion can occur. Further bifurcations — period-doubling cascades and a Shilnikov homoclinic bifurcation — are found that lead to a chaotic cable response. Whirling and chaotic cable dynamics are confirmed by time-step simulations of the full three-mode model. The different cable responses are characterized, and can be distinguished clearly, by their motion at the quarter-span and by their frequency spectra.
The Negative Side of Chua's Circuit Parameter Space: Stability Analysis, Period-Adding, Basin of Attraction Metamorphoses, and Experimental Investigation
Authors: Medrano-T Rene O. , Rocha Ronilson
Published: October 2014

Although Chua's circuit is one of the most studied nonlinear dynamical systems, its version with negative parameters remains practically untouched. This work reports an interesting and rich dynamic scenery that was hidden in this almost unexplored region. The study is focused on 2D parameter space and presents an analysis of stability based on describing functions. Numerical investigations present a gallery of period-adding cascades and a strong presence of basin boundary metamorphoses. The key to this new scenario is that for negative parameters, Chua's system does not satisfy the Shilnikov condition and it is shown that the homoclinic orbit organizes the parameter space completely different from as known. The obtained experimental results corroborate with the numerical and theoretical investigations.
Chua's Circuit Dynamics Controlled by Using a Water Electrolytic Cell Component
Authors: Buscarino Arturo , Famoso Carlo , Fortuna Luigi , Frasca Mattia
Published: October 2014

In this paper, experimental results showing that the dynamics of Chua's circuit can be controlled by using water electrolytic cell based devices are reported. A Chua's circuit where one of the electrical components is replaced by an electrolytic cell device has been realized and its dynamics has been studied showing how different regimes appear when the parameters of the cell (in particular, the level of immersion of the electrode plates and the distance between them) are changed. The results obtained pave the way to the possibility of coupling nonlinear electronic components with electrochemical devices so as to develop a new hybrid technology for implementing a new class of nonlinear circuits.
Impact of Prey Refuge on a Discrete Time Predator–Prey System with Allee Effect
Authors: Rana Sourav , Bhowmick Amiya Ranjan , Bhattacharya Sabyasachi
Published: October 2014

We study the impact of the Allee effect and prey refuge on the stability of a discrete time predator–prey system. We focus on the stability behavior of the system with the Allee effect in predator, prey and both populations. Based on the combination of analytical and numerical results, we observe that: (1) the Allee effect stabilizes the systems dynamics in a moderate value of prey refuge. (2) For a large fraction of prey refuge no significant improvement in stability is observed due to Allee effect. (3) Refuge may play an important role in managing the populations which are subject to the Allee effect. The population remains stable at an intermediate level of refuge parameter, whereas at relatively low and high refuge effect, prey exhibits chaotic oscillation. Such chaotic behavior is suppressed in the presence of Allee effect. The Allee mechanism and refuge are considered simultaneously on the populations and is shown to have a significant impact on the predator–prey dynamics that may be helpful in the conservation of endangered species.
Strange Attractors in a Three-Dimensional Autonomous Polynomial Equation
Authors: Chen Fengjuan , Li Jibin
Published: October 2014

We studied a three-dimensional autonomous polynomial equation. This equation is with a parameter, which we denote as μ. At μ = 0, the system has two saddles, the stable and unstable manifolds of which coincide. We present a comprehensive study on the dynamics of the system for small μ ≠ 0 in a small neighborhood of the unperturbed stable and unstable manifolds, where one of the heteroclinic connections of the two saddles are broken by small perturbations and strange attractors are created.
Stability Switches and Bifurcation Analysis of a Time Delay Model for the Diffusion of a New Technology
Authors: Ballestra Luca Vincenzo , Guerrini Luca , Pacelli Graziella
Published: October 2014

We deal with the time delay model for the diffusion of innovation technologies proposed by Fanelli and Maddalena [2012]. For this model, the stability switches and the occurrence of Hopf bifurcations are still largely undetermined, and in the present paper we perform some analysis on these topics. In particular, by applying the theory of delay differential equations and the analytical-geometrical approach developed by Beretta and Kuang [2002], we show that the equilibrium may lose stability and Hopf bifurcations may occur. Moreover, using the normal form theory and the center manifold theorem, we derive closed-form expressions that allow us to determine the direction of the Hopf bifurcations and the stability of the periodic solutions. Numerical results are presented which confirm and illustrate the theoretical predictions obtained.
Influence of Tool Flank Forces on Complex Dynamics of Cutting Process
Authors: Rusinek Rafal , Wiercigroch Marian , Wahi Pankaj
Published: October 2014

We study complex dynamics of a cutting process, a recently developed frictional model of cutting process in [Rusinek et al., 2014] to gain better insight into the mechanics of frictional chatter and the factors affecting it. The new model takes into account the forces acting on the tool face as well as on the tool flank. We first present nonlinear dynamic behavior using bifurcation diagrams for nominal cutting depth and cutting velocity as the bifurcation parameters. Finally, the influence of the various forces on the tool flank on the system dynamics has been systematically studied. This has been performed by comparing the bifurcation diagrams with and without the forces on the flank. These flank forces have been found to largely have a stabilizing effect. These forces however increase the complexity of the solutions and are responsible for some instabilities in the low cutting velocity regime.
Advances in Computational Radiation Biophysics for Cancer Therapy: Simulating Nano-Scale Damage by Low-Energy Electrons
Authors: Kuncic Zdenka
Published: October 2014

Computational radiation biophysics is a rapidly growing area that is contributing, alongside new hardware technologies, to ongoing developments in cancer imaging and therapy. Recent advances in theoretical and computational modeling have enabled the simulation of discrete, event-by-event interactions of very low energy (≪ 100 eV) electrons with water in its liquid thermodynamic phase. This represents a significant advance in our ability to investigate the initial stages of radiation induced biological damage at the molecular level. Such studies are important for the development of novel cancer treatment strategies, an example of which is given by microbeam radiation therapy (MRT). Here, new results are shown demonstrating that when excitations and ionizations are resolved down to nano-scales, their distribution extends well outside the primary microbeam path, into regions that are not directly irradiated. This suggests that radiation dose alone is insufficient to fully quantify biological damage. These results also suggest that the radiation cross-fire may be an important clue to understanding the different observed responses of healthy cells and tumor cells to MRT.
Cumulation of a spherically converging shock wave in metals and its dependence on elastic-plastic properties, phase transitions, spall and shear fractures
Authors: Kozlov Evgeny A. , Petrovtsev Alexsander V.
Published: October 2014

Consideration is given to results of experimental and theoretical investigations how alpha-epsilon phase transition in the unalloyed iron and the 30 KhGSA steel and its absence in the austenitic 12Kh18N10T stainless steel influence processes under explosive deformation of spheres made of these materials. Polymorphous transition is shown to significantly effect on: amount of explosion-products energy transferred to a sphere, evolution of the converging-wave structure and its parameters, profiles of stress wave and temperature T(R, t) for some Lagrangian particles along the sphere radius, character of energy cumulation under spherical convergence of waves.
Study of through Plane Cation Contamination in Polymer Electrolyte Fuel Cell
Authors: Uddin Md. Aman , Qi Jing , Wang Xiaofeng , Ozdemir M. Ozan , Khajeh Hosseini Dalasm Navvab , Bonville Leonard J. , Pasaogullari Ugur , Molter Trent
Published: October 2014

Through plane distribution of cationic contamination on polymer electrolyte fuel cell (PEFC) was investigated at a fixed concentration of 5 ppm of Ca2+ in the air stream of an operating fuel cell. A special purpose MEA was prepared using five layers of membrane, and four Pt wires (electrodes) were inserted between the membrane layers. Pt electrodes were used to monitor the through plane potential due to the permeation of hydrogen and oxygen from anode and cathode, respectively and the resistance distribution across the membrane thickness. At the beginning of the test, oxygen permeated from cathode to the first layer of membrane. After 32 hours, oxygen continued to permeate from cathode to the other layers of membrane. The cell performance deteriorated, when CaSO4 solution was injected as a contaminant. Within 21 hours of contaminant injection, the cell voltage dropped more than 200 mV. High frequency resistance (HFR) increased more than 50% in the membrane layer close to the cathode.
Peak Power Optimization of Solid Oxide Fuel Cells with Particle Size and Porosity Grading
Authors: Abdullah Taufiq , Liu Lin
Published: October 2014

Solid oxide fuel cells (SOFCs) are blessed with high efficiency, the capability of using a variety of hydrocarbon fuels, and high impurity tolerance. Functionally graded electrodes have previously been investigated to improve SOFCs performance with controlled microstructure. However, little investigation has been focused on the cell-level optimization of power output for nonlinearly graded electrode microstructures. In this work, a multiscale electrode polarization model of SOFCs has been expanded and developed to a cell-level model. The cell-level SOFCs model has been utilized to disclose the complex relationship among the transport phenomena, which include the transports of electron, ion and gas molecules through the electrode and the electrochemical reaction at the triple phase boundaries. The work advances the understanding of the cell performance with graded microstructures. The performance of functionally graded electrodes has been analyzed to understand the effects of tailored electrode microstructures on cell power output.
Modeling of Transport Mechanisms of OH- in Electrolyte of Alkaline Fuel Cell
Authors: Takaba Hiromitsu , Shimizu Nobuyuki , Hisabe Tomoya , Alam Md. Khorshed
Published: October 2014

In the recent years, interest has grown in the development of anion exchange membranes (AEMs) for alkaline fuel cells, which have advantage over proton exchange membranes (PEM) fuel cells including cost and performance. In this work, we present molecular dynamics (MD) and first principles molecular dynamics (FPMD) studies to investigate transport mechanisms of OH- using quanternized multiblock copoly(arylene ether) (QPE) and poly (phthalazinone ether sulfone keton) (PPESK) anion exchange polymers. We report here Grotthus and vehicle mechanisms for OH- transport by molecular modeling. From our MD study for OH- diffusion in the QPE and PPESK, diffusion properties is comparable to experimental report and OH- transport mechanisms from FPMD simulation significantly differ with proton transport processes.
Development of 3-D Chemical Mechanical Polishing Process for Nanostructuring of Bioimplant Surfaces
Authors: Ozdemir Zeynep , Orhan Orcun , Bebek Ozkan , Basim G. Bahar
Published: October 2014

This study focuses on the development of a three dimensional chemical mechanical polishing (CMP) process to induce smoothness or controlled nano-roughness on the bio-implant material surfaces, particularly for an application on the dental implants. CMP helps produce implant surfaces that are cleaned from potentially contaminated surface layers by removing a nano-scale top layer while simultaneously creating a protective oxide film on the surface to limit any further contamination to minimize risk of infection. Hence, we propose CMP as a synergistic method of nano-structuring on the implant surfaces and focus on extending the process to a 3-D platform to implement it on the dental implants.
Voltammetric Behavior of Carbon Paste Electrodes with Native and Chemical Modified Porphyrans
Authors: Cavalcanti Henrique Elache , Lima Dhesmon , Pessoa Christiana Andrade , Viana Adriano Gonçalves
Published: October 2014

Porphyran is a sulfated polysaccharide obtained from Porphyra genus. Carbon paste electrodes (CPEs) containing natural ionic polysaccharides have been studied. This study describes the voltammetric behavior of porphyran modified CPE obtained before and after chemical desulfation of the polysaccharides by alkaline treatment (PA) and solvolysis (PD) from the native fraction (PN). The cyclic voltammograms for all porphyran modified electrodes indicated a redox current peaks increase in the same potential range when compared to the unmodified CPEs. The CPEs were modified with different amounts of porphyran and those which showed the most intense anodic peaks were: 10 (EN), 20 (EA) and 40 µg (ED). In addition, the anodic peak current increased linearly with the square root of the scan rate, indicating that the redox process was diffusion-controlled. In conclusion, the electrochemical experiments demonstrated that electron transfer on the porphyran-modified CPEs surface is more efficient, conducting higher current and offering lower resistivity.