bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrasound Assessment of Ex Vivo Lung Tissue Properties Using a Fluid-Filled Negative Pressure Bath
Authors: Duenwald-Kuehl Sarah , Bates Melissa L. , Cortes Sonia Y. , Eldridge Marlowe W. , Vanderby Ray
Published: May 2014

A relationship between tendon stress and strain and ultrasonic echo intensity has previously been defined in tendons, demonstrating a correlation between tissue stiffness and echo intensity. An analogous relationship between volume-dependent pressure changes and echo intensity changes in inflating lungs would indicate a correlation between lung compliance and echo intensity. Lung compliance is an important metric to diagnose pathologies which affect lung tissue mechanics, such as emphysema and cystic fibrosis. The goal of this study is to demonstrate a correlation between ultrasound echo intensity and lung tissue mechanics in an ex vivo model using a fluid-filled negative pressure bath design which provides a controlled environment for ultrasonic and mechanical measurements. Lungs from 4 male Sprague-Dawley rats were removed and mechanically tested via inflation and deflation in a negative pressure chamber filled with hetastarch. Specific volumes (1, 2, 3, and 4 mL) were removed from the chamber using a syringe to create negative pressure, which resulted in lung inflation. A pressure transducer recorded the pressure around the lungs. From these data, lung compliance was calculated. Ultrasound images were captured through the chamber wall to determine echo intensity (grayscale brightness in the ultrasound image), which was then related to mechanical parameters. Ultrasound images of the lung were successfully captured through the chamber wall with sufficient resolution to deduce echo intensity changes in the lung tissue. Echo intensity (0–255 scale) increased with volumetric changes (18.4 ± 5.5, 22.6 ± 5.1, 26.1 ± 7.5, and 42.9 ± 19.5 for volumetric changes of 1, 2, 3, and 4 mL) in a pattern similar to pressure (−6.8 ± 1.7, −6.8 ± 1.4, −9.4 ± 0.7, and −16.9 ± 6.8 cm H2O for 1, 2, 3, and 4 mL), reflecting changes in lung compliance. Measured rat lung tissue compliance was comparable to reported values from ex vivo lungs (0.178 ± 0.067, 0.378 ± 0.051, 0.427 ± 0.062, and 0.350 ± 0.160 mL/cm H20 for 1, 2, 3, and 4 mL), supporting proof of concept for the experimental method. Changes in echo intensity reflected changes in lung compliance in this ex vivo model, thus, supporting our hypothesis that the stiffness-related changes in echo intensity originally seen in tendon can be similarly detected in lung tissue. The presented ultrasound-based methods allowed measurement of local lung tissue compliance in a controlled environment, however, the methods could be expanded to facilitate both ex vivo and in vivo studies.
In Vitro Quantification of Time Dependent Thrombus Size Using Magnetic Resonance Imaging and Computational Simulations of Thrombus Surface Shear Stresses
Authors: Taylor Joshua O. , Witmer Kory P. , Neuberger Thomas , Craven Brent A. , Meyer Richard S. , Deutsch Steven , Manning Keefe B.
Published: May 2014

Thrombosis and thromboembolization remain large obstacles in the design of cardiovascular devices. In this study, the temporal behavior of thrombus size within a backward-facing step (BFS) model is investigated, as this geometry can mimic the flow separation which has been found to contribute to thrombosis in cardiac devices. Magnetic resonance imaging (MRI) is used to quantify thrombus size and collect topographic data of thrombi formed by circulating bovine blood through a BFS model for times ranging between 10 and 90 min at a constant upstream Reynolds number of 490. Thrombus height, length, exposed surface area, and volume are measured, and asymptotic behavior is observed for each as the blood circulation time is increased. Velocity patterns near, and wall shear stress (WSS) distributions on, the exposed thrombus surfaces are calculated using computational fluid dynamics (CFD). Both the mean and maximum WSS on the exposed thrombus surfaces are much more dependent on thrombus topography than thrombus size, and the best predictors for asymptotic thrombus length and volume are the reattachment length and volume of reversed flow, respectively, from the region of separated flow downstream of the BFS.
The Effect of Static and Dynamic Loading on Degradation of PLLA Stent Fibers
Authors: Hayman Danika , Bergerson Christie , Miller Samantha , Moreno Michael , Moore James E.
Published: May 2014

Understanding how polymers such as PLLA degrade in vivo will enhance biodegradable stent design. This study examined the effect of static and dynamic loads on PLLA stent fibers in vitro. The stent fibers (generously provided by TissueGen, Inc.) were loaded axially with 0 N, 0.5 N, 1 N, or 0.125–0.25 N (dynamic group, 1 Hz) and degraded in PBS at 45 °C for an equivalent degradation time of 15 months. Degradation was quantified through changes in tensile mechanical properties. The mechanical behavior was characterized using the Knowles strain energy function and a degradation model. A nonsignificant increase in fiber stiffness was observed between 0 and 6 months followed by fiber softening thereafter. A marker of fiber softening, β, increased between 9 and 15 months in all groups. At 15 months, the β values in the dynamic group were significantly higher compared to the other groups. In addition, the model indicated that the degradation rate constant was smaller in the 1-N (0.257) and dynamic (0.283) groups compared to the 0.5-N (0.516) and 0-N (0.406) groups. While the shear modulus fluctuated throughout degradation, no significant differences were observed. Our results indicate that an increase in static load increased the degradation of mechanical properties and that the application of dynamic load further accelerated this degradation.
Influence of Surface Anomalies Following Hole Making Operations on the Fatigue Performance for a Nickel-Based Superalloy
Authors: Herbert C. , Axinte D. A. , Hardy M. , Withers P.
Published: May 2014

Aero-engine manufacturers are continuously striving to improve component performance and reliability while seeking to increase the efficiency of manufacturing to reduce costs. Efficiency gains by using higher rates of material removal, however, can be counter-productive if they give rise to surface anomalies that distort the material microstructure and reduce the resistance of the material to fatigue crack nucleation. This paper investigates the effect of hole making processes and parameters on surface integrity and the initiation of cracks from low-cycle fatigue (LCF). It reports the dependence of elevated temperature (600 °C) low-cycle fatigue performance of nickel alloy RR1000 from surfaces produced from hole making and subsequent surface conditioning. As-machined surfaces include a reference “damage-free” surface, and two distorted microstructures: (i) a white layer, produced to a depth of 5 and 10 μm and (ii) a distorted gamma prime (γ') structure, produced to a depth of 10 and 15 μm. The effect of shot peening damage-free and 10 μm deep white layer surfaces was also evaluated. It was found that the presence of white layer significantly reduced fatigue performance compared with that shown by the damage-free surface, regardless of whether the white layer was subsequently shot peened or not. In contrast, surfaces showing distorted γ' structures produced much less debit in fatigue life and only from a depth of 15 μm. These results have been rationalized from an examination of fracture surfaces and from measurement of residual stresses before and after fatigue testing. This research is of particular importance as it is among the few reports that quantify the effect of different levels of work piece surface integrity on the fatigue life of a nickel-based superalloy that has been developed for critical rotating components in aero-engine applications.
The Effect of Wear on the Performance of a Rotary Lip Seal
Authors: Guo Fei , Jia Xiaohong , Longke Wang , Salant Richard F. , Wang Yuming
Published: May 2014

Theoretical analysis, combined with experimental verification, is used to study the effect of wear on the performance of a rotary lip seal as characterized by the pumping rate and friction torque. The performance of a rotary lip seal is determined by the sealing lip surface microscopic characteristics and contact characteristics at the sealing zone. The variation of the contact characteristics with wear has been established based on the variation of the sealing lip profiles measured by using a trilinear coordinate measuring instrument. The impression method is used to copy the lip surface microtopography at different wear times and then an optical interferometer is used to measure the impression surface microtopography to obtain the variation of roughness with wear. The variations of the roughness, contact characteristics, and approximate contact temperature with wear are inserted into a mixed lubrication model to obtain the variations of the pumping rate and friction torque. A comparison of the simulated results with those from experimental measurement verifies the validity of the theoretical analysis.
Particle Transport and Deposition in a Turbulent Square Duct Flow With an Imposed Magnetic Field
Authors: Liu Rui , Vanka Surya P. , Thomas Brian G.
Published: May 2014

In this paper, we study particle transport and deposition in a turbulent square duct flow with an imposed magnetic field using direct numerical simulations (DNS) of the continuous flow and Lagrangian tracking of particles. The magnetic field and the velocity induce a current and the interaction of this current with the magnetic field generates a Lorentz force that brakes the flow and modifies the flow structure. A second-order accurate finite volume method is used to integrate the coupled Navier–Stokes and magnetohydrodynamic (MHD) equations and the solution procedure is implemented on a graphics processing unit (GPU). Magnetically nonconducting particles of different Stokes numbers are continuously injected at random locations in the inlet cross section of the duct and their rates of deposition on the duct walls are studied with and without a magnetic field. Because of the modified instantaneous turbulent flow structures as a result of the magnetic field, the deposition rates and patterns on the walls perpendicular to the magnetic field are lower than those on the walls parallel to the magnetic field.
Detection of Nonlinearities in Plates Via Higher-Order-Spectra: Numerical and Experimental Studies
Authors: Pasquali M. , Lacarbonara W. , Marzocca P.
Published: May 2014

Higher-order spectral (HOS) analysis tools are employed to extract the nonlinear dynamic response features of elastic and laminated plates by using both physics-based mechanical plate models and experimental data. Bispectral and trispectral densities are computed to highlight the presence and relative importance of quadratic and cubic nonlinearities. The former are associated with the presence of asymmetry either in the excitation or in the mechanical response of predeflected plates while the latter are due to midplane stretching effects. Besides the detection of these structural nonlinearities in perfect (baseline) fully clamped plates, the changes of such nonlinearities induced by the presence of small inertial imperfections (i.e., lumped masses) are identified and exploited to localize the imperfections. The numerical and experimental investigations are carried out both on isotropic and laminated composite plates subject to Gaussian white noise excitation. The effectiveness of the HOS-based procedure for detection of the nonlinearities is fully demonstrated for both types of plates.
Systematic Review of Interventions Aiming to Improve Involvement in Physical Activity Among Adults With Intellectual Disability
Authors: Brooker Katie , van Dooren Kate , McPherson Lyn , Lennox Nick , Ware Robert
Published: May 2014

Background:

Evidence suggests that most adults with intellectual disability do not participate in sufficient amounts of physical activity (PA). A systematic review of peer-reviewed studies that reported an intervention aiming to improve PA levels of adults with intellectual disability was conducted.

Methods:

Keywords related to intellectual disability and physical activity were used to search relevant databases. Studies were excluded if they did not measure PA as an outcome for adults with intellectual disability, were non-English, and were not peer-reviewed. All relevant studies were included in the review regardless of methodological quality and design.

Results:

Six articles met the inclusion criteria. These included health education or health promotion programs with PA, nutrition, and weight loss components. The quality of studies included in this review was generally poor. Most studies used a prepost design, sample sizes were small, and measurement tools were used that are not valid and reliable for the population assessed.

Conclusions:

PA interventions have the potential to improve the health and wellbeing of people with intellectual disability, a vulnerable group who require attention from public health practitioners and researchers. Given the health inequities that exist, public health researchers should target efforts to improve PA levels among this group.
“How Hard Could it Be?” A Descriptive Analysis of Errors Made on a Validated Lifetime Physical Activity Questionnaire
Authors: Anderton Natalie , Newhouse Megan E. , Ainsworth Barbara E. , Nygaard Ingrid E. , Egger Marlene J. , Shaw Janet M.
Published: May 2014

Background:

Measuring historical physical activity in epidemiologic research depends on self-report. We aimed to describe data reporting errors women made in completing 2 validated questionnaires: Lifetime Physical Activity Questionnaire (LPAQ) and Occupational Questionnaire (OQ).

Methods:

Participants—229 women aged 38 to 65 years—completed questionnaires on paper (n = 160) or by web interface (n = 69). One research assistant collected questionnaire data, identified potential errors and contacted participants to trouble-shoot errors.

Results:

Women made mean 9.7 (SD 11.2) errors on paper and 7.1 (SD 6.2) errors on electronic versions of the LPAQ and 2.6 (SD 3.8) and 1.1 (SD 1.4) errors on paper and electronic versions of the OQ, respectively. Fewer mistakes were made on electronic versions of both questionnaires combined (8.5 ± 6.1) when compared with the paper versions (12.7 ± 13.1). Only ~2% of the sample completed all questionnaires without detectable errors. The most common errors were reporting activities or frequencies inconsistently between past year survey and the current age epoch, reporting more years than allowed by age epoch and missing information.

Conclusions:

Despite the implications of “self-report” questionnaires, we recommend researchers provide participants with additional instructions, either verbally or as written tip sheet or both, and follow-up after questionnaire completion to correct mistakes as needed.
CpG ODN Nanorings Induce IFNα from Plasmacytoid Dendritic Cells and Demonstrate Potent Vaccine Adjuvant Activity
Authors: Gungor Bilgi , Yagci Fuat Cem , Tincer Gizem , Bayyurt Banu , Alpdundar Esin , Yildiz Soner , Ozcan Mine , Gursel Ihsan , Gursel Mayda
Published: May 2014

Nanorings act as CpG oligodeoxynucleotide surrogates that may function as vaccine adjuvants and anticancer and antiviral agents.
Expression of the Iron Hormone Hepcidin Distinguishes Different Types of Anemia in African Children
Authors: Pasricha Sant-Rayn , Atkinson Sarah H. , Armitage Andrew E. , Khandwala Shivani , Veenemans Jacobien , Cox Sharon E. , Eddowes Lucy A. , Hayes Theodore , Doherty Conor P. , Demir Ayse Y. , Tijhaar Edwin , Verhoef Hans , Prentice Andrew M. , Drakesmith Hal
Published: May 2014

The iron hormone hepcidin correctly identifies African children in whom iron supplementation is most likely to be beneficial.
A Long Academic Journey
Authors: Şeker Erkin , Onaral Banu
Published: May 2014

An early-career electrical engineer interviews an established biomedical engineer about translating engineering science, training future innovators, and building partnerships.
Somatic Cell Nuclear Transfer Is All Grown Up
Authors: Tesar Paul J.
Published: May 2014

Adult human somatic cells were reprogrammed to pluripotent stem cells by nuclear transfer to enucleated human oocytes.
Enzymatic Synthesis of Bioinformatically Predicted Microcin C-Like Compounds Encoded by Diverse Bacteria
Authors: Bantysh Olga , Serebryakova Marina , Makarova Kira S. , Dubiley Svetlana , Datsenko Kirill A. , Severinov Konstantin
Published: May 2014

The Trojan horse
Escherichia coli
antibiotic microcin C (McC) consists of a heptapeptide attached to adenosine through a phosphoramidate linkage. McC is synthesized by the MccB enzyme, which terminally adenylates the ribosomally synthesized heptapeptide precursor MccA. The peptide part is responsible for McC uptake; it is degraded inside the cell to release a toxic nonhydrolyzable aspartyl-adenylate. Bionformatic analysis reveals that diverse bacterial genomes encoding
mccB
homologues also contain adjacent short open reading frames that may encode MccA-like adenylation substrates. Using chemically synthesized predicted peptide substrates and recombinant cognate MccB protein homologs, adenylated products were obtained
in vitro
for predicted MccA peptide-MccB enzyme pairs from
Helicobacter pylori
,
Streptococcus thermophilus
,
Lactococcus johnsonii
,
Bartonella washoensis
,
Yersinia pseudotuberculosis
, and Synechococcus sp. Some adenylated products were shown to inhibit the growth of
E. coli
by targeting aspartyl-tRNA synthetase, the target of McC.

IMPORTANCE
Our results prove that McC-like adenylated peptides are widespread and are encoded by both Gram-negative and Gram-positive bacteria and by cyanobacteria, opening ways for analyses of physiological functions of these compounds and for creation of microcin C-like antibiotics targeting various bacteria.
Chromosome Segregation Proteins of Vibrio cholerae as Transcription Regulators
Authors: Baek Jong Hwan , Rajagopala Seesandra V. , Chattoraj Dhruba K.
Published: May 2014

Bacterial ParA and ParB proteins are best known for their contribution to plasmid and chromosome segregation, but they may also contribute to other cell functions. In segregation, ParA interacts with ParB, which binds to
parS
centromere-analogous sites. In transcription, plasmid Par proteins can serve as repressors by specifically binding to their own promoters and, additionally, in the case of ParB, by spreading from a
parS
site to nearby promoters. Here, we have asked whether chromosomal Par proteins can likewise control transcription. Analysis of genome-wide ParB1 binding in
Vibrio cholerae
revealed preferential binding to the three known
parS1
sites and limited spreading of ParB1 beyond the
parS1
sites. Comparison of wild-type transcriptomes with those of Δ
parA1
, Δ
parB1
, and Δ
parAB1
mutants revealed that two out of 20 genes (VC0067 and VC0069) covered by ParB1 spreading are repressed by both ParB1 and ParA1. A third gene (VC0076) at the outskirts of the spreading area and a few genes further away were also repressed, particularly the gene for an outer membrane protein,
ompU
(VC0633). Since ParA1 or ParB1 binding was not evident near VC0076 and
ompU
genes, the repression may require participation of additional factors. Indeed, both ParA1 and ParB1 proteins were found to interact with several
V. cholerae
proteins in bacterial and yeast two-hybrid screens. These studies demonstrate that chromosomal Par proteins can repress genes unlinked to
parS
and can do so without direct binding to the cognate promoter DNA.

IMPORTANCE
Directed segregation of chromosomes is essential for their maintenance in dividing cells. Many bacteria have genes (
par
) that were thought to be dedicated to segregation based on analogy to their roles in plasmid maintenance. It is becoming clear that chromosomal
par
genes are pleiotropic and that they contribute to diverse processes such as DNA replication, cell division, cell growth, and motility. One way to explain the pleiotropy is to suggest that Par proteins serve as or control other transcription factors. We tested this model by determining how Par proteins affect genome-wide transcription activity. We found that genes implicated in drug resistance, stress response, and pathogenesis were repressed by Par. Unexpectedly, the repression did not involve direct Par binding to cognate promoter DNA, indicating that the repression may involve Par interactions with other regulators. This pleiotropy highlights the degree of integration of chromosomal Par proteins into cellular control circuitries.
Improving Production of Malonyl Coenzyme A-Derived Metabolites by Abolishing Snf1-Dependent Regulation of Acc1
Authors: Shi Shuobo , Chen Yun , Siewers Verena , Nielsen Jens
Published: May 2014

Acetyl coenzyme A (acetyl-CoA) carboxylase (ACCase) plays a central role in carbon metabolism and has been the site of action for the development of therapeutics or herbicides, as its product, malonyl-CoA, is a precursor for production of fatty acids and other compounds. Control of Acc1 activity in the yeast
Saccharomyces cerevisiae
occurs mainly at two levels, i.e., regulation of transcription and repression by Snf1 protein kinase at the protein level. Here, we demonstrate a strategy for improving the activity of ACCase in
S. cerevisiae
by abolishing posttranslational regulation of Acc1 via site-directed mutagenesis. It was found that introduction of two site mutations in Acc1, Ser659 and Ser1157, resulted in an enhanced activity of Acc1 and increased total fatty acid content. As Snf1 regulation of Acc1 is particularly active under glucose-limited conditions, we evaluated the effect of the two site mutations in chemostat cultures. Finally, we showed that our modifications of Acc1 could enhance the supply of malonyl-CoA and therefore successfully increase the production of two industrially important products derived from malonyl-CoA, fatty acid ethyl esters and 3-hydroxypropionic acid.

IMPORTANCE
ACCase is responsible for carboxylation of acetyl-CoA to produce malonyl-CoA, which is a crucial step in the control of fatty acid metabolism. ACCase opened the door for pharmaceutical treatments of obesity and diabetes as well as the development of new herbicides. ACCase is also recognized as a promising target for developing cell factories, as its malonyl-CoA product serves as a universal precursor for a variety of high-value compounds in white biotechnology. Yeast ACCase is a good model in understanding the enzyme’s catalysis, regulation, and inhibition. The present study describes the importance of protein phosphorylation in regulation of yeast ACCase and identifies potential regulation sites. This study led to the generation of a more efficient ACCase, which was applied in the production of two high-value compounds derived from malonyl-CoA, i.e., fatty acid ethyl esters that can be used as biodiesel and 3-hydroxypropionic acid that is considered an important platform chemical.
Effects of clopidogrel, prasugrel and ticagrelor on endothelial function, inflammatory and oxidative stress parameters and platelet function in patients undergoing coronary artery stenting for an acute coronary syndrome. A randomised, prospective, controlled study
Authors: Schnorbus Boris , Daiber Andreas , Jurk Kerstin , Warnke Silke , König Jochem , Krahn Ulrike , Lackner Karl , Munzel Thomas , Gori Tommaso
Published: May 2014

Introduction

Particularly in the setting of acute coronary syndromes, the interplay between vascular and platelet function has been postulated to have direct clinical implications. The present trial is designed to test the effect of clopidogrel, prasugrel and ticagrelor on multiple parameters of vascular function, platelet aggregation, oxidative and inflammatory stress before and up to 4 weeks after coronary artery stenting.

Methods and analysis

The study is designed as a three-arm, parallel design, randomised, investigator-blinded study. Patients with unstable angina or non-ST elevation myocardial infarction undergoing coronary intervention with a drug-eluting stent will be randomised to receive 600 mg clopidogrel, 60 mg prasugrel or 180 mg ticagrelor followed by oral therapy with the same drug. The primary endpoint of the trial is the impact of antiplatelet treatments on endothelial function as assessed by flow-mediated dilation at 1 day, 1 week and 1 month in patients who have undergone stenting. Secondary endpoints include the impact of study medications on parameters of macrovascular and microvascular function, platelet reactivity, oxidative and inflammatory stress. The study recruitment is currently ongoing and, after an interim analysis which was performed at 50% of the initially planned population, it is planned to continue until July 2015.

Ethics and dissemination

The protocol was approved by the local ethics committee. The trial will provide important pathophysiological insight on the relationship between platelet aggregation and endothelial function, two parameters that have been shown to influence patients’ prognosis.

Trial registration number

ClinicalTrials.gov Identifier:NCT01700322; EudraCT-Nr.: 2011-005305-73. Current V.1.3, from 24 February 2014.
Development of a-Si solar cells using “liquid–Si printing”
Authors: Murayama Hiroko , Ohyama Tatsushi , Terakawa Akira , Takagishi Hideyuki , Masuda Takashi , Ohdaira Keisuke , Shimoda Tatsuya
Published: May 2014

Film properties of hydrogenated amorphous silicon (a-Si:H) fabricated by “liquid–Si printing” (LSP) were investigated in detail and compared to the conventional plasma enhanced chemical deposition (plasma–CVD) method. LSP a-Si:H films (LSP films) had lower film density and larger size void than the a-Si:H films deposited by plasma–CVD (CVD films). On the other hand, the LSP films had high photoconductivity comparable to device grade a-Si:H films and higher photostability than the CVD films. Thus, the LSP films were drastically different from conventional CVD films. The conversion efficiency of the bifacial solar cells (glass/TCO/n(LSP film)/i(LSP film)/p(CVD film)/TCO/electrode), which was a problem because of the missing link between high photoconductivity and low cell performance, were improved. Undoped CVD film was inserted between the i- and p-layers to suppress the plasma damage to the active layer printed by LSP when depositing a B doped a-Si:H by plasma–CVD. As a result, we achieved conversion efficiencies of 1.1% with n side incidence and 3.1% with p side incidence.
Novel symmetries in vector Schwinger model
Authors: Gupta Saurabh
Published: May 2014

We derive nilpotent and absolutely anticommuting (anti-)co-BRST symmetry transformations for the bosonized version of (1+1)-dimensional (2D) vector Schwinger model. These symmetry transformations turn out to be the analog of co-exterior derivative of differential geometry as the total gauge-fixing term remains invariant under it. The exterior derivative is realized in terms of the (anti-)BRST symmetry transformations of the theory whereas the bosonic symmetries find their analog in the Laplacian operator. The algebra obeyed by these symmetry transformations turns out to be exactly same as the algebra obeyed by the de Rham cohomological operators of differential geometry.
Physical naturalness and dynamical breaking of classical scale invariance
Authors: Heikinheimo Matti , Racioppi Antonio , Spethmann Christian , Raidal Martti , Tuominen Kimmo
Published: May 2014

We propose a model of a confining dark sector, dark technicolor, that communicates with the Standard Model (SM) through the Higgs portal. In this model electroweak (EW) symmetry breaking and dark matter (DM) share a common origin, and the EW scale is generated dynamically. Our motivation to suggest this model is the absence of evidence for new physics from recent Large Hadron Collider (LHC) data. Although the conclusion is far from certain at this point, this lack of evidence may suggest that no mechanism exists at the EW scale to stabilize the Higgs mass against radiative corrections from ultraviolet (UV) physics. The usual reaction to this puzzling situation is to conclude that the stabilizing new physics is either hidden from us by accident, or that it appears at energies that are currently inaccessible, such that nature is indeed fine-tuned. In order to re-examine the arguments that have led to this dichotomy, we review the concept of naturalness in effective field theories, discussing in particular the role of quadratic divergences in relation to different energy scales. This leads us to suggest classical scale invariance as a guideline for model building, implying that explicit mass scales are absent in the underlying theory.
In2O3-ZnO heterostructure development in electrical and photoluminescence properties of In2O3 1-D nanostructures
Authors: Shariati M. , Ghafouri V.
Published: May 2014

Indium Oxide quasi one-dimensional (1D) nanostructures known as nanowires and nanorods synthesis using the thermal evaporation method, has been articulated. To nucleate growth sites, substrate seeding promoted 1D nanostructures growth. The catalyst-mediated growth mechanism showed more favorable morphologies and physical properties in under vacuum conditions associated with bottom-up technique. Scanning electron microscopy (SEM) results showed that the Zn -doped 1D nanostructures had spherical caps. The X-ray diffraction (XRD) pattern and energy-dispersive X-ray (EDX) spectrum indicated that these caps intensively associated with ZnO . Therefore, it was reasonable that the vapor–liquid–solid mechanism (VLS) was responsible for the growth of the In 2 O 3- ZnO heterostructure nanowires. This technique enhances optical and electrical properties in nanostructures. The photoluminescence (PL) analysis in Zn -doped In 2 O 3 nanowires and nanorods shows that the intensity of the visible and UV-region emissions overwhelmingly increases and resistance measurement professes the improvement of linear conductance in VLS growth mechanism.
Vibrational resonance in a discrete neuronal model with time delay
Authors: Wang Canjun , Yang Keli , Qu Shixian
Published: May 2014

The effects of time delay on the vibrational resonance (VR) in a discrete neuron system with a low-frequency signal and a high-frequency signal are investigated by numerical simulations. The results show that there exists a delay time that optimizes the phase synchronization between the low-frequency input signal and the output signal. VR is induced by the time delay. Furthermore, the time delay can improve the response to a low-frequency input signal. Therefore, the time delay plays a constructive role in the transmission of a low-frequency signal by inducing and enhancing VR.
A comprehensive investigation of structural, morphological, hydrogen absorption and magnetic properties of MmNi4.22Co0.48Mn0.15Al0.15 alloy
Authors: Zareii Seyyed Mojtaba , Arabi Hadi , Pourarian Faiz
Published: May 2014

A comprehensive study of structural, morphological, hydrogen absorption and magnetic properties of MmNi 4.22 Co 0.48 Mn 0.15 Al 0.15 alloy as a promising hydrogen storage media was investigated. The X-ray diffraction (XRD) profiles show that the alloy maintains its crystal structure (hexagonal LaNi 5-type) even after 30 hydrogenation/dehydrogenation (H/D) cycles. However, the XRD peaks are found to be slightly broadened after cycling. SEM images reveal that particles size of the cycled sample decreases, with more uniform particle size distribution compared to noncycled ones. The pressure-composition (PC) isotherms and kinetics curves of hydrogen absorption reaction were obtained at different working temperatures by using a homemade Sievert apparatus. The enthalpy and entropy of hydride formation of the alloy were evaluated. Furthermore, the Jander diffusion and Johnson–Mehl–Avrami models as the fitting models were employed to study the kinetic mechanism of hydriding reaction and its activation energy. The room temperature magnetic measurements indicate that the milling and H/D cycling change the magnetic properties of the as-annealed alloy.
Vortex states in mesoscopic superconductors with a complex geometry: A finite element analysis
Authors: Peng Lin , Wei Zejiang , Xu Danhua
Published: May 2014

The time-dependent Ginzburg–Landau equations have been solved numerically by a finite-element analysis for a mesoscopic superconducting square structure with four nanoscale holes in two-dimensional space. For given applied magnetic fields we have simulated the dynamical behavior of the penetrating magnetic vortices into the superconductor. Our results show that the mesoscopic superconductor can be tuned to exhibit the clear separation of the multivortex by properly introducing the nanoscale holes in a mesoscopic superconductor.
Chemically- and mechanically-tunable porated polyethylene glycol gels for leukocyte integrin independent and dependent chemotaxis
Authors: Lauridsen Holly M. , Walker Bryan J. , Gonzalez Anjelica L.
Published: May 2014

The extracellular matrix (ECM) is a highly complex mixture of protein, proteoglycans and growth factors that biochemically and mechanically regulates leukocyte migration during inflammation. Perturbations in ECM composition and mechanical properties are associated with the pathogenesis of chronic inflammatory diseases ranging from asthma to diabetes. The limited availability of in vitro models of human ECM has impeded inflammatory research, as current methods rely heavily on polycarbonate transwells and glass coverslips, which cannot accurately replicate the combined mechanical and biochemical properties of human ECM. Polyethylene glycol (PEG) hydrogels offer a highly tunable substrate, with respect to both mechanical properties (as a function of molecular weight) and protein conjugation; unmodified PEG, however, cannot be used for leukocyte migration studies due to its impenetrable pore networks. We present a modifi ed PEG membrane in which hydrogel pore size, pore density, mechanical stiffness, and protein presentation can be easily controlled to mimic various human ECM, providing a new technology for investigating leukocyte recruitment.
Excavation-induced fractures network surrounding tunnel: properties and evolution under loading
Authors: De La Vaissière R. , Morel J. , Noiret A. , Côte P. , Helmlinger B. , Sohrabi R. , Lavanchy J.-M. , Leveau F. , Nussbaum C. , Morel J.
Published: May 2014

The investigation of the induced fractures network around seals in drifts or shafts, and in particular its evolution, is a key issue for the performance assessment of an underground waste repository. Within this framework, a specific experiment was designed and implemented in the Meuse/Haute-Marne Underground Research Laboratory (URL). This experiment, called CDZ (Compression of the Damaged Zone), is dedicated to studying the effect of mechanical compression within the induced fractures zone of the Callovo-Oxfordian claystone (COx). An unequalled level of knowledge in the 3D structure of the fractures network has been attained. A multidisciplinary approach was applied to observe not only the initial state of the induced fracture zone but also its evolution during a loading cycle. The investigations show that the fracture network which composed the Excavation Damaged Zone (EDZ) was initially interconnected and open for flow and then partially closed progressively following the increasing mechanical stress applied on the drift wall. Moreover, the evolution of the EDZ after unloading indicates a self-sealing process.
Formalizing Negotiations Using Logic Programming
Authors: Son Tran Cao , Pontelli Enrico , Nguyen Ngoc-Hieu , Sakama Chiaki
Published: May 2014

The article introduces a logical framework for negotiation among dishonest agents. The framework relies on the use of abductive logic programming as a knowledge representation language for agents to deal with incomplete information and preferences. The article shows how intentionally false or inaccurate information of agents can be encoded in the agents' knowledge bases. Such disinformation can be effectively used in the process of negotiation to have desired outcomes by agents. The negotiation processes are formulated under the answer set semantics of abductive logic programming, and they enable the exploration of various strategies that agents can employ in their negotiation. A preliminary implementation has been developed using the ASP-Prolog platform.
Preferred First-Order Answer Set Programs
Authors: Asuncion Vernon , Zhang Yan , Zhou Yi
Published: May 2014

In this article, we consider the issue of how first-order answer set programs can be extended for handling preference reasoning. To this end, we propose a progression-based preference semantics for first-order answer set programs while explicit preference relations are presented. We study essential properties of the proposed preferred answer set semantics. To understand the expressiveness of preferred first-order answer set programming, we further specify a second-order logic representation which precisely characterizes the progression-based preference semantics.
Pebble Weighted Automata and Weighted Logics
Authors: Bollig Benedikt , Gastin Paul , Monmege Benjamin , Zeitoun Marc
Published: May 2014

We introduce new classes of weighted automata on words. Equipped with pebbles, they go beyond the class of recognizable formal power series: they capture weighted first-order logic enriched with a quantitative version of transitive closure. In contrast to previous work, this calculus allows for unrestricted use of existential and universal quantifications over positions of the input word. We actually consider both two-way and one-way pebble weighted automata. The latter class constrains the head of the automaton to walk left-to-right, resetting it each time a pebble is dropped. Such automata have already been considered in the Boolean setting, in the context of data words. Our main result states that two-way pebble weighted automata, one-way pebble weighted automata, and our weighted logic are expressively equivalent. We also give new logical characterizations of standard recognizable series.
Exposure
Authors: Bilge Leyla , Sen Sevil , Balzarotti Davide , Kirda Engin , Kruegel Christopher
Published: May 2014

A wide range of malicious activities rely on the domain name service (DNS) to manage their large, distributed networks of infected machines. As a consequence, the monitoring and analysis of DNS queries has recently been proposed as one of the most promising techniques to detect and blacklist domains involved in malicious activities (e.g., phishing, spam, botnets command-and-control, etc.). EXPOSURE is a system we designed to detect such domains in real time, by applying 15 unique features grouped in four categories.

We conducted a controlled experiment with a large, real-world dataset consisting of billions of DNS requests. The extremely positive results obtained in the tests convinced us to implement our techniques and deploy it as a free, online service. In this article, we present the
Exposure
system and describe the results and lessons learned from 17 months of its operation. Over this amount of time, the service detected over 100K malicious domains. The statistics about the time of usage, number of queries, and target IP addresses of each domain are also published on a daily basis on the service Web page.
An Anti-Phishing System Employing Diffused Information
Authors: Chen Teh-Chung , Stepan Torin , Dick Scott , Miller James
Published: May 2014

The phishing scam and its variants are estimated to cost victims billions of dollars per year. Researchers have responded with a number of anti-phishing systems, based either on blacklists or on heuristics. The former cannot cope with the churn of phishing sites, while the latter usually employ decision rules that are not congruent to human perception. We propose a novel heuristic anti-phishing system that explicitly employs gestalt and decision theory concepts to model perceptual similarity. Our system is evaluated on three corpora contrasting legitimate Web sites with real-world phishing scams. The proposed system’s performance was equal or superior to current best-of-breed systems. We further analyze current anti-phishing warnings from the perspective of warning theory, and propose a new warning design employing our Gestalt approach.
Cross-Domain Password-Based Authenticated Key Exchange Revisited
Authors: Chen Liqun , Lim Hoon Wei , Yang Guomin
Published: May 2014

We revisit the problem of secure cross-domain communication between two users belonging to different security domains within an open and distributed environment. Existing approaches presuppose that either the users are in possession of public key certificates issued by a trusted
certificate authority
(CA), or the associated domain authentication servers share a long-term secret key. In this article, we propose a generic framework for designing
four-party password-based authenticated key exchange
(4PAKE) protocols. Our framework takes a different approach from previous work. The users are not required to have public key certificates, but they simply reuse their login passwords, which they share with their respective domain authentication servers. On the other hand, the authentication servers, assumed to be part of a standard PKI, act as ephemeral CAs that certify some key materials that the users can subsequently use to exchange and agree on as a session key. Moreover, we adopt a compositional approach. That is, by treating any secure two-party password-based key exchange (2PAKE) protocol and two-party asymmetric-key/symmetric-key-based key exchange (2A/SAKE) protocol as black boxes, we combine them to obtain generic and provably secure 4PAKE protocols.
Off-Path TCP Injection Attacks
Authors: Gilad Yossi , Herzberg Amir
Published: May 2014

We present practical off-path TCP injection attacks for connections between current, nonbuggy browsers and Web servers. The attacks allow
Web-cache poisoning
with malicious objects such as spoofed Web pages and scripts; these objects can be cached for a long period of time, exposing any user of that cache to
cross-site scripting
,
cross-site request forgery
, and
phishing
attacks.

In contrast to previous TCP injection attacks, we do not require MitM capabilities or malware running on the client machine. Instead, our attacks rely on a weaker assumption, that the user only enters a malicious Web site, but does not download or install any application. Our attacks exploit subtle details of the TCP and HTTP specifications, and features of legitimate (and very common) browser implementations. An empirical evaluation of our techniques with current versions of browsers shows that connections with most popular Web sites are vulnerable.

We conclude this work with practical client- and server-end defenses against our attacks.
Activation of glucagon-like peptide-1 receptor inhibits growth and promotes apoptosis of human pancreatic cancer cells in a cAMP-dependent manner
Authors: Zhao Hejun , Wei Rui , Wang Liang , Tian Qing , Tao Ming , Ke Jing , Liu Ye , Hou Wenfang , Zhang Lin , Yang Jin , Hong Tianpei
Published: May 2014

Glucagon-like peptide-1 (GLP-1) promotes pancreatic β-cell regeneration through GLP-1 receptor (GLP-1R) activation. However, whether it promotes exocrine pancreas growth and thereby increases the risk of pancreatic cancer has been a topic of debate in recent years. Clinical data and animal studies published so far have been controversial. In the present study, we report that GLP-1R activation with liraglutide inhibited growth and promoted apoptosis in human pancreatic cancer cell lines in vitro and attenuated pancreatic tumor growth in a mouse xenograft model in vivo. These effects of liraglutide were mediated through activation of cAMP production and consequent inhibition of Akt and ERK1/2 signaling pathways in a GLP-1R-dependent manner. Moreover, we examined GLP-1R expression in human pancreatic cancer tissues and found that 43.3% of tumor tissues were GLP-1R-null. In the GLP-1R-positive tumor tissues (56.7%), the level of GLP-1R was lower compared with that in tumor-adjacent normal pancreatic tissues. Furthermore, the GLP-1R-positive tumors were significantly smaller than the GLP-1R-null tumors. Our study shows for the first time that GLP-1R activation has a cytoreductive effect on human pancreatic cancer cells in vitro and in vivo, which may help address safety concerns of GLP-1-based therapies in the context of human pancreatic cancer.
mTORC1 and JNK coordinate phosphorylation of the p70S6K1 autoinhibitory domain in skeletal muscle following functional overloading
Authors: Martin Tony D. , Dennis Michael D. , Gordon Bradley S. , Kimball Scot R. , Jefferson Leonard S.
Published: May 2014

The present project was designed to investigate phosphorylation of p70S6K1 in an animal model of skeletal muscle overload. Within 24 h of male Sprague-Dawley rats undergoing unilateral tenotomy to induce functional overloading of the plantaris muscle, phosphorylation of the Thr389and Thr421/Ser424sites on p70S6K1 was significantly elevated. Since the Thr421/Ser424sites are purportedly mammalian target of rapamycin complex 1 (mTORC1) independent, we sought to identify the kinase(s) responsible for their phosphorylation. Initially, we used IGF-I treatment of serum-deprived HEK-293E cells as an in vitro model system, because IGF-I promotes phosphorylation of p70S6K1 on both the Thr389and Thr421/Ser424sites in skeletal muscle and in cells in culture. We found that, whereas the mTOR inhibitor TORIN2 prevented the IGF-I-induced phosphorylation of the Thr421/Ser424sites, it surprisingly enhanced phosphorylation of these sites during serum deprivation. JNK inhibition with SP600125 attenuated phosphorylation of the Thr421/Ser424sites, and in combination with TORIN2 both the effect of IGF-I and the enhanced Thr421/Ser424phosphorylation during serum deprivation were ablated. In contrast, both JNK activation with anisomycin and knockdown of the mTORC2 subunit rictor specifically stimulated phosphorylation of the Thr421/Ser424sites, suggesting that mTORC2 represses JNK-mediated phosphorylation of these sites. The role of JNK in mediating p70S6K1 phosphorylation was confirmed in the animal model noted above, where rats treated with SP600125 exhibited attenuated Thr421/Ser424phosphorylation. Overall, the results provide evidence that the mTORC1 and JNK signaling pathways coordinate the site-specific phosphorylation of p70S6K1. They also identify a novel role for mTORC1 and mTORC2 in the inhibition of JNK.