bluuebunny/crossref_metadata_2025 huggingface dataset:
Shear Lag Model for Regularly Staggered Short Fuzzy Fiber Reinforced Composite
Authors: Kundalwal S. I. , Ray M. C. , Meguid S. A.
Published: June 2014

In this article, we investigate the stress transfer characteristics of a novel hybrid hierarchical nanocomposite in which the regularly staggered short fuzzy fibers are interlaced in the polymer matrix. The advanced fiber augmented with carbon nanotubes (CNTs) on its circumferential surface is known as “fuzzy fiber.” A three-phase shear lag model is developed to analyze the stress transfer characteristics of the short fuzzy fiber reinforced composite (SFFRC) incorporating the staggering effect of the adjacent representative volume elements (RVEs). The effect of the variation of the axial and lateral spacing between the adjacent staggered RVEs in the polymer matrix on the load transfer characteristics of the SFFRC is investigated. The present shear lag model also accounts for the application of the radial loads on the RVE and the radial as well as the axial deformations of the different orthotropic constituent phases of the SFFRC. Our study reveals that the existence of the non-negligible shear tractions along the length of the RVE of the SFFRC plays a significant role in the stress transfer characteristics and cannot be neglected. Reductions in the maximum values of the axial stress in the carbon fiber and the interfacial shear stress along its length become more pronounced in the presence of the externally applied radial loads on the RVE. The results from the newly developed analytical shear lag model are validated with the finite element (FE) shear lag simulations and found to be in good agreement.
Characterization of Variable Hydrodynamic Coefficients and Maximum Responses in Two-Dimensional Vortex-Induced Vibrations With Dual Resonances
Authors: Zanganeh Hossein , Srinil Narakorn
Published: June 2014

A phenomenological model and analytical–numerical approach to systematically characterize variable hydrodynamic coefficients and maximum achievable responses in two-dimensional vortex-induced vibrations with dual two-to-one resonances are presented. The model is based on double Duffing and van der Pol oscillators which simulate a flexibly mounted circular cylinder subjected to uniform flow and oscillating in simultaneous cross-flow/in-line directions. Depending on system quadratic and cubic nonlinearities, amplitudes, oscillation frequencies and phase relationships, analytical closed-form expressions are derived to parametrically evaluate key hydrodynamic coefficients governing the fluid excitation, inertia and added mass force components, as well as maximum dual-resonant responses. The amplification of the mean drag is ascertained. Qualitative validations of numerical predictions with experimental comparisons are discussed. Parametric investigations are performed to highlight the important effects of system nonlinearities, mass, damping, and natural frequency ratios.
Experimental Investigation of Friction Stir Seal Welding of Tube–Tubesheet Joints
Authors: Al-Badour Fadi A. , Merah Nesar , Shuaib Abdelrahman , Bazoune Abdelaziz
Published: June 2014

To ensure heat exchanger tube–tubesheet joints tightness, industrial standards may recommend performing a combination of roller expansion and seal welding, using conventional fusion welding processes. Solid state friction stir welding (FSW) has several advantages over the conventional fusion welding but has not yet proven its usefulness in seal and strength welding of heat exchanger tube–tubesheet joints where the available space is very limited and weld pass is of a relatively complex contour. In this work, a newly designed tool and procedure have been developed to friction stir seal weld tube–tubesheet joints. The effects of process conditions such as welding speed and tool offset on dependent process parameters including welding loads and joint quality have been investigated on a 6xxx-series aluminum three-tube test cell. The results of the investigation revealed that the quality of the seal weld of tube–tubesheet joints is affected by the above parameters. Lower weld speeds increase the size of the heat-affected zone while higher speeds lead to larger weld defects. Better weld quality is obtained when the center of the pin tool is offset from the tube–tubesheet interface by an amount lower than 40% of the pin diameter.
A Study on Measurement of Conformability of the Piston Oil Ring on the Cylinder Bore Under Engine Operating Condition by Laser Induced Fluorescence Method Using Optical Fiber
Authors: Ito Akemi , Mochiduki Kazuya , Kikuhara Koji , Inui Masatsugu , Akamatsu Hirotaka
Published: June 2014

It is known that a cylinder-bore shape affects engine oil consumption. This study aimed clarifying the conformability of an oil-ring under engine operating condition. Oil film thickness at the sliding surface of oil-ring rails was measured by laser induced fluorescence (LIF) method using optical fiber embedded in the oil-ring. Findings showed that the piston tilting motion affected oil film thickness. Furthermore, thicker oil film was found at the following rail than that at former rail. It suggested that oil was supplied to the following rail from not only the former ring sliding surface but also somewhere, for example, the oil ring groove.
Comparison of Microscale Rapid Prototyping Techniques
Authors: Hoople Gordon D. , Rolfe David A. , McKinstry Katherine C. , Noble Joanna R. , Dornfeld David A. , Pisano Albert P.
Published: June 2014

Recent advances in manufacturing techniques have opened up new interest in rapid prototyping at the microscale. Traditionally microscale devices are fabricated using photolithography, however this process can be time consuming, challenging, and expensive. This paper focuses on three promising rapid prototyping techniques: laser ablation, micromilling, and 3D printing. Emphasis is given to rapid prototyping tools that are commercially available to the research community rather those only used in manufacturing research. Due to the interest in rapid prototyping within the microfluidics community a test part was designed with microfluidic features. This test part was then manufactured using the three different rapid prototyping methods. Accuracy of the features and surface roughness were measured using a surface profilometer, scanning electron microscope (SEM), and optical microscope. Micromilling was found to produce the most accurate features and best surface finish down to ∼100 μm, however it did not achieve the small feature sizes produced by laser ablation. The 3D printed part, though easily manufactured, did not achieve feature sizes small enough for most microfluidic applications. Laser ablation created somewhat rough and erratic channels, however the process was faster and achieved features smaller than either of the other two methods.
New Therapies for Coronary Artery Disease: Genetics Provides a Blueprint
Authors: Rader Daniel J.
Published: June 2014

Human genetics has the potential to identify future targets for successful therapeutic interventions for cardiovascular disease.
Common Therapeutic Targets in Cardiometabolic Disease
Authors: Fredman Gabrielle , Ozcan Lale , Tabas Ira
Published: June 2014

Cardiovascular disease and insulin resistance syndrome interactions provide joint therapeutic targets.
Mycobacterium tuberculosis Lsr2 Is a Global Transcriptional Regulator Required for Adaptation to Changing Oxygen Levels and Virulence
Authors: Bartek I. L. , Woolhiser L. K. , Baughn A. D. , Basaraba R. J. , Jacobs W. R. , Lenaerts A. J. , Voskuil M. I.
Published: June 2014

To survive a dynamic host environment,
Mycobacterium tuberculosis
must endure a series of challenges, from reactive oxygen and nitrogen stress to drastic shifts in oxygen availability. The mycobacterial Lsr2 protein has been implicated in reactive oxygen defense via direct protection of DNA. To examine the role of Lsr2 in pathogenesis and physiology of
M. tuberculosis
, we generated a strain deleted for
lsr2
. Analysis of the
M. tuberculosis
Δ
lsr2
strain demonstrated that Lsr2 is not required for DNA protection, as this strain was equally susceptible as the wild type to DNA-damaging agents. The
lsr2
mutant did display severe growth defects under normoxic and hyperoxic conditions, but it was not required for growth under low-oxygen conditions. However, it was also required for adaptation to anaerobiosis. The defect in anaerobic adaptation led to a marked decrease in viability during anaerobiosis, as well as a lag in recovery from it. Gene expression profiling of the Δ
lsr2
mutant under aerobic and anaerobic conditions in conjunction with published DNA binding-site data indicates that Lsr2 is a global transcriptional regulator controlling adaptation to changing oxygen levels. The Δ
lsr2
strain was capable of establishing an early infection in the BALB/c mouse model; however, it was severely defective in persisting in the lungs and caused no discernible lung pathology. These findings demonstrate
M. tuberculosis
Lsr2 is a global transcriptional regulator required for control of genes involved in adaptation to extremes in oxygen availability and is required for persistent infection.

IMPORTANCE
M. tuberculosis
causes nearly two million deaths per year and infects nearly one-third of the world population. The success of this aerobic pathogen is due in part to its ability to successfully adapt to constantly changing oxygen availability throughout the infectious cycle, from the high oxygen tension during aerosol transmission to anaerobiosis within necrotic lesions. An understanding of how
M. tuberculosis
copes with these changes in oxygen tension is critical for its eventual eradication. Using a mutation in
lsr2
, we demonstrate that the Lsr2 protein present in all mycobacteria is a global transcriptional regulator in control of genes required for adaptation to changes in oxygen levels.
M. tuberculosis
lacking
lsr2
was unable to adapt to both high and very low levels of oxygen and was defective in long-term anaerobic survival. Lsr2 was also required for disease pathology and for chronic infection in a mouse model of TB.
Genome-Wide Identification of Acinetobacter baumannii Genes Necessary for Persistence in the Lung
Authors: Wang Nengding , Ozer Egon A. , Mandel Mark J. , Hauser Alan R.
Published: June 2014

Acinetobacter baumannii
is a Gram-negative bacterium that causes diseases such as pneumonia, bacteremia, and soft tissue infections in hospitalized patients. Relatively little is known about how
A. baumannii
causes these infections. Thus, we used insertion sequencing (INSeq), a combination of transposon mutagenesis and massively parallel next-generation sequencing, to identify novel virulence factors of
A. baumannii
. To this end, we generated a random transposon mutant library containing 150,000 unique insertions in
A. baumannii
strain ATCC 17978. The INSeq analysis identified 453 genes required for growth in rich medium. The library was then used in a murine pneumonia model, and the relative levels of abundance of mutants before and after selection in the mouse were compared. When genes required for growth in rich medium were removed from the analysis, 157 genes were identified as necessary for persistence in the mouse lung. Several of these encode known virulence factors of
A. baumannii
, such as OmpA and ZnuB, which validated our approach. A large number of the genes identified were predicted to be involved in amino acid and nucleotide metabolism and transport. Other genes were predicted to encode an integration host factor, a transmembrane lipoprotein, and proteins involved in stress response and efflux pumps. Very few genes, when disrupted, resulted in an increase in
A. baumannii
numbers during host infection. The INSeq approach identified a number of novel virulence determinants of
A. baumannii
, which are candidate targets for therapeutic interventions.

IMPORTANCE
A. baumannii
has emerged as a frequent cause of serious infections in hospitals and community settings. Due to increasing antibiotic resistance, alternative approaches, such as antivirulence strategies, are desperately needed to fight
A. baumannii
infections. Thorough knowledge of
A. baumannii
pathogenicity is essential for such approaches but is currently lacking. With the increasingly widespread use of massively parallel sequencing, a class of techniques known as transposon insertion sequencing has been developed to perform comprehensive virulence screens of bacterial genomes
in vivo
. We have applied one of these approaches (INSeq) to uncover novel virulence factors in
A. baumannii
. We identified several such factors, including those predicted to encode amino acid and nucleotide metabolism proteins, an integration host factor protein, stress response factors, and efflux pumps. These results greatly expand the number of
A. baumannii
virulence factors and uncover potential targets for antivirulence treatments.
Detecting Nitrous Oxide Reductase (
nosZ
) Genes in Soil Metagenomes: Method Development and Implications for the Nitrogen Cycle
Authors: Orellana L. H. , Rodriguez-R L. M. , Higgins S. , Chee-Sanford J. C. , Sanford R. A. , Ritalahti K. M. , Löffler F. E. , Konstantinidis K. T.
Published: June 2014

Microbial activities in soils, such as (incomplete) denitrification, represent major sources of nitrous oxide (N
2
O), a potent greenhouse gas. The key enzyme for mitigating N
2
O emissions is NosZ, which catalyzes N
2
O reduction to N
2
. We recently described “atypical” functional NosZ proteins encoded by both denitrifiers and nondenitrifiers, which were missed in previous environmental surveys (R. A. Sanford et al., Proc. Natl. Acad. Sci. U. S. A. 109:19709–19714, 2012, doi:10.1073/pnas.1211238109). Here, we analyzed the abundance and diversity of both
nosZ
types in whole-genome shotgun metagenomes from sandy and silty loam agricultural soils that typify the U.S. Midwest corn belt. First, different search algorithms and parameters for detecting
nosZ
metagenomic reads were evaluated based on
in silico
-generated (mock) metagenomes. Using the derived cutoffs, 71 distinct alleles (95% amino acid identity level) encoding typical or atypical NosZ proteins were detected in both soil types. Remarkably, more than 70% of the total
nosZ
reads in both soils were classified as atypical, emphasizing that prior surveys underestimated
nosZ
abundance. Approximately 15% of the total
nosZ
reads were taxonomically related to
Anaeromyxobacter
, which was the most abundant genus encoding atypical NosZ-type proteins in both soil types. Further analyses revealed that atypical
nosZ
genes outnumbered typical
nosZ
genes in most publicly available soil metagenomes, underscoring their potential role in mediating N
2
O consumption in soils. Therefore, this study provides a bioinformatics strategy to reliably detect target genes in complex short-read metagenomes and suggests that the analysis of both typical and atypical
nosZ
sequences is required to understand and predict N
2
O flux in soils.

IMPORTANCE
Nitrous oxide (N
2
O) is a potent greenhouse gas with ozone layer destruction potential. Microbial activities control both the production and the consumption of N
2
O, i.e., its conversion to innocuous dinitrogen gas (N
2
). Until recently, consumption of N
2
O was attributed to bacteria encoding “typical” nitrous oxide reductase (NosZ). However, recent phylogenetic and physiological studies have shown that previously uncharacterized, functional, “atypical” NosZ proteins are encoded in genomes of diverse bacterial groups. The present study revealed that atypical
nosZ
genes outnumbered their typical counterparts, highlighting their potential role in N
2
O consumption in soils and possibly other environments. These findings advance our understanding of the diversity of microbes and functional genes involved in the nitrogen cycle and provide the means (e.g., gene sequences) to study N
2
O fluxes to the atmosphere and associated climate change.
Eating seeds from the ‘be still’ tree, yet having lucky nut poisoning: a case of acute yellow oleander poisoning
Authors: Fentanes Emilio
Published: June 2014

A 25-year-old woman was evaluated and treated for ingestion ofThevetia peruvianaseeds and flower petals—a natural digoxin cross reacting cardinolide—with intent to cause self-harm. The following case report provides the clinical presentation, treatment and management of acute yellow oleander poisoning.
Miracle baby: managing extremely preterm birth in rural Uganda
Authors: Mitchell Hannah Katherine , Thomas Rhianne , Hogan Michael , Bresges Carolin
Published: June 2014

Preterm birth is an important cause of neonatal morbidity and mortality globally. Uganda has one of the highest rates of preterm birth in East Africa but few resources to care for these infants. This case highlights the clinical course of an extremely premature infant born at 26 weeks gestation to a nulliparous 24-year-old woman. Her mother was involved in her care and taught the principles of kangaroo mother care. After initial problems establishing feeds she progressed well and was discharged in the fifth week of life. The case describes some of the low technology conservative and medical measures which can be used to care for neonates, such as antenatal steroids and kangaroo care. The use of antibiotics and aminophylline are also discussed. The approach to the common challenges faced by premature infants such as respiratory disease, sepsis and necrotising enterocolitis in a resource-poor environment are discussed.
Evaluation of mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) by diffusion-weighted and diffusion tensor imaging
Authors: Shankar Balasubramanyam , Narayanan Ramakrishna , Muralitharan Pushkaran , Ulaganathan Balamurugan
Published: June 2014

Mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) is a clinicoradiological entity with varied aetiologies and having a typical course of evolution. We present a case of MERS evaluated with diffusion-weighted and diffusion tensor imaging along with various conventional sequences of MRI. At the time of presentation, the lesions in the splenium of corpus callosum and bilateral cerebral white matter showed diffusion restriction with reduced apparent diffusion coefficient and no reduction in fractional anisotropy (FA) values on diffusion tensor imaging; on follow-up diffusion restriction completely resolved with normalisation of the apparent diffusion coefficient. The normal to slightly increased FA values in the lesions may indicate that MERS is a non-degenerative disorder.
Kikuchi-Fujimoto disease and acute appendicitis
Authors: Patel Nirav , Philips Dahlia , Nigo Masayuki , Kaminsky Donald , Mildvan Donna
Published: June 2014

A 29-year-old Japanese man developed fever, nausea, vomiting, diarrhoea, right lower quadrant abdominal pain and rebound tenderness. With the clinical suspicion of appendicitis, an abdominal CT scan was performed, which revealed mesenteric lymphadenitis. The patient was hospitalised and treated with antibiotics, but was ultimately found to have Kikuchi-Fujimoto disease (KFD). This diagnosis was facilitated by the use of positron emission tomography scan that identified an accessible inguinal lymph node for biopsy and histopathological evaluation. Invasive abdominal surgery was thereby averted and the patient made a complete recovery on subsequent follow-up. Review of the published literature reveals that pseudoappendicitis due to KFD is a rare occurrence that has generally required abdominal surgery to establish the diagnosis, thus supporting the potential value of the approach taken here.
Physiological and hormonal changes during prolonged starvation in fish
Authors: Bar Nadav
Published: June 2014

Starvation periods are common for many animals, including fish, birds, and mammals. Many fish species exhibit extraordinary resilience to prolonged starvation, but the reasons for that and the mechanisms employed during these periods are poorly understood. This study shows that similar to mammals and birds, many fish species undergo three phases during starvation: (I) a short transient phase, (II) a long, protein conservation steady state phase with mainly fat oxidation as the primary energy source, and (III) a shift to protein mobilization as a main energy source. These starvation states and their transitions were quantified by a meta-analysis of large empirical data available in the literature, revealing that low critical levels of fat reserves trigger the transition to the third state. The critical fat level, denoted as γ (percentage of total lipid in body mass), ranges between 0.7% and 5%, depending on the species. It appears that these transitions in the energy mobilization phases are regulated by hormonal changes, including growth hormone (GH), leptin, cortisol, and ghrelin, but the exact mechanisms are still unclear and should be further investigated. Simulations in silico of starvation periods at various temperatures using a dynamic model indicated that temperature affects the length of Phase II because of changes in protein metabolism, with consequences on the ability to withstand prolonged starvation.
Energy metabolism and cytochrome oxidase activity: linking metabolism to gene expression
Authors: Bremer K. , Kocha K.M. , Snider T. , Moyes C.D.
Published: June 2014

Modification of mitochondrial content demands the synthesis of hundreds of proteins encoded by nuclear and mitochondrial genomes. The responsibility for coordination of this process falls to nuclear-encoded master regulators of transcription. DNA-binding proteins and coactivators integrate information from energy-sensing pathways and hormones to alter mitochondrial gene expression. In mammals, the signaling cascade for mitochondrial biogenesis can be described as follows: hormonal signals and energetic information are sensed by protein-modifying enzymes that in turn regulate the post-translational modification of transcription factors. Once activated, transcription-factor complexes form on promoter elements of many of the nuclear-encoded mitochondrial genes, recruiting proteins that remodel chromatin and initiate transcription. One master regulator in mammals, PGC-1α, is well studied because of its role in determining the metabolic phenotype of muscles, but also due to its importance in mitochondria-related metabolic diseases. However, relatively little is known about the role of this pathway in other vertebrates. These uncertainties raise broader questions about the evolutionary origins of the pathway and its role in generating the diversity in muscle metabolic phenotypes seen in nature.
DOUBLE SUPPLY, LINEAR, AND HIGH EFFICIENCY PUSH AMPLIFIER DESIGN FOR ENVELOPE TRACKING POWER AMPLIFIERS IN WiMAX APPLICATIONS
Authors: TABRIZI MOHAMMAD MOGHADDAM , MASOUMI NASSER
Published: June 2014

In this work, a novel and efficient approach is proposed to optimize linearity and efficiency of a power amplifier used in mobile communication applications. A linear and high performance push amplifier is designed and analyzed to extract design equations for an optimum performance. The proposed push amplifier has two sections; an analog section and a switching section. The analog section provides the required linearity and the switching section guarantees the satisfaction of the total efficiency level. Double power supply scheme is used in push amplifiers to enhance its performance. Two separate power supplies are employed for linear and switching sections of push amplifiers which have different voltage levels. The implemented circuit is simulated using HSPICERF with TSMC models for active and passive elements. The proposed power amplifier (PA) provides a maximum output power of 25 dBm and power added efficiency (PAE) as high as 51% at 2.5 GHz operation frequency. At 1-dB compression point, this PA exhibits output power of 25 dBm with 48% PAE and 4.5% error vector magnitude (EVM) which is appropriate for 64QAM OFDM signals.
Epithermal neutron formation for boron neutron capture therapy by adiabatic resonance crossing concept
Authors: Khorshidi A. , Ghafoori-Fard H. , Sadeghi M.
Published: June 2014

Low-energy protons from the cyclotron in the range of 15–30 MeV and low current have been simulated on beryllium ( Be ) target with a lead moderator around the target. This research was accomplished to design an epithermal neutron beam for Boron Neutron Capture Therapy (BNCT) using the moderated neutron on the average produced from 9 Be target via (p, xn) reaction in Adiabatic Resonance Crossing (ARC) concept. Generation of neutron to proton ratio, energy distribution, flux and dose components in head phantom have been simulated by MCNP5 code. The reflector and collimator were designed in prevention and collimation of derivation neutrons from proton bombarding. The scalp-skull-brain phantom consisting of bone and brain equivalent material has been simulated in order to evaluate the dosimetric effect on the brain. Results of this analysis demonstrated while the proton energy decreased, the dose factor altered according to filters thickness. The maximum epithermal flux revealed using fluental, Fe and bismuth ( Bi ) filters with thicknesses of 9.4, 3 and 2 cm, respectively and also the epithermal to thermal neutron flux ratio was 103.85. The potential of the ARC method to replace or complement the current reactor-based supply sources of BNCT purposes.
Weak convergence of the empirical process of intermittent maps in 𝕃2 under long-range dependence
Authors: Dedecker Jérôme , Dehling Herold , Taqqu Murad S.
Published: June 2014

We study the behavior of the empirical distribution function of iterates of intermittent maps in the Hilbert space of square integrable functions with respect to Lebesgue measure. In the long-range dependent case, we prove that the empirical distribution function, suitably normalized, converges to a degenerate stable process, and we give the corresponding almost sure result. We apply the results to the convergence of the Wasserstein distance between the empirical measure and the invariant measure. We also apply it to obtain the asymptotic distribution of the corresponding Cramér–von-Mises statistic.
Combustion waves and Riemann solutions in light porous foam
Authors: Chapiro G. , Marchesin D. , Schecter S.
Published: June 2014

We prove the existence of traveling waves, and identify the wave sequences appearing in Riemann solutions, for a system of three evolutionary partial differential equations that models combustion of light porous foam under air injection.
EVALUATION OF A BACTERIOPHAGE-RELATED CHIMERIC MARINE VIRUS ASSOCIATED WITH ABALONE MORTALITY IN TAIWAN
Authors: Chen Min-Hsiu , Chen I-Wen , Kuo Shu-Ting , Hsu Wen-Long , Chang Pen-Heng
Published: June 2014

In the past few years, a low-rate but persistent mortality was noted in the cultured abalone in the farms. This disease affected abalone reared in the summer, and resulted in an 80% cumulative mortality in the farms. The histopathology revealed various extensive fragmentation, hyaline degeneration and necrosis of the myofibers accompanying with moderate degree of hemocyte infiltration in the foot muscle. A negative-contrast electron microscopy was unable to detect viral particles from pooled tissues. No virions were observed via the electron microscopy using direct negative staining of pooled organs. Moribund abalones were performed DNA extraction, purified and DNA sequencing. These sequenced fragments had 3370/3378 (99%), 5666/5704 (99%) and 5945/5961 (99%) identities to abalone shriveling syndrome-associated virus of China isolate. Primer sets designed from the sequences of Taiwan isolate was able to amplify a 693 bp from moribund abalone. In this study, a retrospective study by using PCR revealed that 30% (12/48) of clinical chronic mortality cases had carried bacteriophage-related chimeric marine virus. Tissues from field cases of chronic mortality were applied in in situ hybridization, but without significant signal detected. Thus, etiology of mortality cases remained elusive.
Maximal height of divisors of xpqb – 1
Authors: Wang Shaozu
Published: June 2014

The height of a polynomial f(x) is the largest coefficient of f(x) in absolute value. Let B (n) be the largest height of a polynomial in ℤ[x] dividing xn - 1. In this paper, we investigate the maximal height of divisors of xpqb - 1 and prove that some conjectures on the maximal height of divisors of xpqb - 1 are true.
Quadratic approximation in ℚp
Authors: Bugeaud Yann , Pejković Tomislav
Published: June 2014

Let p be a prime number. Let w2and [Formula: see text] denote the exponents of approximation defined by Mahler and Koksma, respectively, in their classifications of p-adic numbers. It is well-known that every p-adic number ξ satisfies [Formula: see text], with [Formula: see text] for almost all ξ. By means of Schneider's continued fractions, we give explicit examples of p-adic numbers ξ for which the function [Formula: see text] takes any prescribed value in the interval (0, 1].
Nucleic Acid Aptamers for Living Cell Analysis
Authors: Xiong Xiangling , Lv Yifan , Chen Tao , Zhang Xiaobing , Wang Kemin , Tan Weihong
Published: June 2014

Cells as the building blocks of life determine the basic functions and properties of a living organism. Understanding the structure and components of a cell aids in the elucidation of its biological functions. Moreover, knowledge of the similarities and differences between diseased and healthy cells is essential to understanding pathological mechanisms, identifying diagnostic markers, and designing therapeutic molecules. However, monitoring the structures and activities of a living cell remains a challenging task in bioanalytical and life science research. To meet the requirements of this task, aptamers, as “chemical antibodies,” have become increasingly powerful tools for cellular analysis. This article reviews recent advances in the development of nucleic acid aptamers in the areas of cell membrane analysis, cell detection and isolation, real-time monitoring of cell secretion, and intracellular delivery and analysis with living cell models. Limitations of aptamers and possible solutions are also discussed.
Energetics-Based Methods for Protein Folding and Stability Measurements
Authors: Geer M. Ariel , Fitzgerald Michael C.
Published: June 2014

Over the past 15 years, a series of energetics-based techniques have been developed for the thermodynamic analysis of protein folding and stability. These techniques include Stability of Unpurified Proteins from Rates of amide H/D Exchange (SUPREX), pulse proteolysis, Stability of Proteins from Rates of Oxidation (SPROX), slow histidine H/D exchange, lysine amidination, and quantitative cysteine reactivity (QCR). The above techniques, which are the subject of this review, all utilize chemical or enzymatic modification reactions to probe the chemical denaturant– or temperature-induced equilibrium unfolding properties of proteins and protein-ligand complexes. They employ various mass spectrometry-, sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE)-, and optical spectroscopy–based readouts that are particularly advantageous for high-throughput and in some cases multiplexed analyses. This has created the opportunity to use protein folding and stability measurements in new applications such as in high-throughput screening projects to identify novel protein ligands and in mode-of-action studies to identify protein targets of a particular ligand.
Nano/Micro and Spectroscopic Approaches to Food Pathogen Detection
Authors: Cho Il-Hoon , Radadia Adarsh D. , Farrokhzad Khashayar , Ximenes Eduardo , Bae Euiwon , Singh Atul K. , Oliver Haley , Ladisch Michael , Bhunia Arun , Applegate Bruce , Mauer Lisa , Bashir Rashid , Irudayaraj Joseph
Published: June 2014

Despite continuing research efforts, timely and simple pathogen detection with a high degree of sensitivity and specificity remains an elusive goal. Given the recent explosion of sensor technologies, significant strides have been made in addressing the various nuances of this important global challenge that affects not only the food industry but also human health. In this review, we provide a summary of the various ongoing efforts in pathogen detection and sample preparation in areas related to Fourier transform infrared and Raman spectroscopy, light scattering, phage display, micro/nanodevices, and nanoparticle biosensors. We also discuss the advantages and potential limitations of the detection methods and suggest next steps for further consideration.
Microfluidics-Based Single-Cell Functional Proteomics for Fundamental and Applied Biomedical Applications
Authors: Yu Jing , Zhou Jing , Sutherland Alex , Wei Wei , Shin Young Shik , Xue Min , Heath James R.
Published: June 2014

We review an emerging microfluidics-based toolkit for single-cell functional proteomics. Functional proteins include, but are not limited to, the secreted signaling proteins that can reflect the biological behaviors of immune cells or the intracellular phosphoproteins associated with growth factor–stimulated signaling networks. Advantages of the microfluidics platforms are multiple. First, 20 or more functional proteins may be assayed simultaneously from statistical numbers of single cells. Second, cell behaviors (e.g., motility) may be correlated with protein assays. Third, extensions to quantized cell populations can permit measurements of cell–cell interactions. Fourth, rare cells can be functionally identified and then separated for further analysis or culturing. Finally, certain assay types can provide a conduit between biology and the physicochemical laws. We discuss the history and challenges of the field then review design concepts and uses of the microchip platforms that have been reported, with an eye toward biomedical applications. We then look to the future of the field.
Photocontrollable Fluorescent Proteins for Superresolution Imaging
Authors: Shcherbakova Daria M. , Sengupta Prabuddha , Lippincott-Schwartz Jennifer , Verkhusha Vladislav V.
Published: June 2014

Superresolution fluorescence microscopy permits the study of biological processes at scales small enough to visualize fine subcellular structures that are unresolvable by traditional diffraction-limited light microscopy. Many superresolution techniques, including those applicable to live cell imaging, utilize genetically encoded photocontrollable fluorescent proteins. The fluorescence of these proteins can be controlled by light of specific wavelengths. In this review, we discuss the biochemical and photophysical properties of photocontrollable fluorescent proteins that are relevant to their use in superresolution microscopy. We then describe the recently developed photoactivatable, photoswitchable, and reversibly photoswitchable fluorescent proteins, and we detail their particular usefulness in single-molecule localization–based and nonlinear ensemble–based superresolution techniques. Finally, we discuss recent applications of photocontrollable proteins in superresolution imaging, as well as how these applications help to clarify properties of intracellular structures and processes that are relevant to cell and developmental biology, neuroscience, cancer biology and biomedicine.
Thinking Outside the Triangle: Replication Fidelity of the Largest RNA Viruses
Authors: Smith Everett Clinton , Sexton Nicole R. , Denison Mark R.
Published: June 2014

When judged by ubiquity, adaptation, and emergence of new diseases, RNA viruses are arguably the most successful biological organisms. This success has been attributed to a defect of sorts: high mutation rates (low fidelity) resulting in mutant swarms that allow rapid selection for fitness in new environments. Studies of viruses with small RNA genomes have identified fidelity determinants in viral RNA-dependent RNA polymerases and have shown that RNA viruses likely replicate within a limited fidelity range to maintain fitness. In this review we compare the fidelity of small RNA viruses with that of the largest RNA viruses, the coronaviruses. Coronaviruses encode the first known viral RNA proofreading exoribonuclease, a function that likely allowed expansion of the coronavirus genome and that dramatically increases replication fidelity and the range of tolerated variation. We propose models for regulation of coronavirus fidelity and discuss the implications of altered fidelity for RNA virus replication, pathogenesis, and evolution.
Role of the Vector in Arbovirus Transmission
Authors: Conway Michael J. , Colpitts Tonya M. , Fikrig Erol
Published: June 2014

Many arboviral diseases are uncontrolled, and the viruses that cause them are globally emerging or reemerging pathogens that produce significant disease throughout the world. The increased spread and prevalence of disease are occurring during a period of substantial scientific growth in the vector-borne disease research community. This growth has been supported by advances in genomics and proteomics, and by the ability to genetically alter disease vectors. For the first time, researchers are elucidating the molecular details of vector host-seeking behavior, the susceptibility of disease vectors to arboviruses, the immunological control of infection in disease vectors, and the determinants that facilitate transmission of arboviruses from a vector to a host. These discoveries are facilitating the development of novel strategies to combat arboviral disease, including the release of transgenic mosquitoes harboring dominant lethal genes, the introduction of arbovirus-blocking microbes into mosquito populations, and the development of acquisition- and transmission-blocking therapeutics. Understanding the role of the vector in arbovirus transmission has provided critical practical and theoretical tools to control arboviral disease.
Calcium signaling recruits substrate transporters GLUT4 and CD36 to the sarcolemma without increasing cardiac substrate uptake
Authors: Angin Yeliz , Schwenk Robert W. , Nergiz-Unal Reyhan , Hoebers Nicole , Heemskerk Johan W. M. , Kuijpers Marijke J. , Coumans Will A. , van Zandvoort Marc A. M. J. , Bonen Arend , Neumann Dietbert , Glatz Jan F. C. , Luiken Joost J. F. P.
Published: June 2014

Activation of AMP-activated protein kinase (AMPK) in cardiomyocytes induces translocation of glucose transporter GLUT4 and long-chain fatty acid (LCFA) transporter CD36 from endosomal stores to the sarcolemma to enhance glucose and LCFA uptake, respectively. Ca2+/calmodulin-activated kinase kinase-β (CaMKKβ) has been positioned directly upstream of AMPK. However, it is unknown whether acute increases in [Ca2+]istimulate translocation of GLUT4 and CD36 and uptake of glucose and LCFA or whether Ca2+signaling converges with AMPK signaling to exert these actions. Therefore, we studied the interplay between Ca2+and AMPK signaling in regulation of cardiomyocyte substrate uptake. Exposure of primary cardiomyocytes to inhibitors or activators of Ca2+signaling affected neither AMPK-Thr172phosphorylation nor basal and AMPK-mediated glucose and LCFA uptake. Despite their lack of an effect on substrate uptake, Ca2+signaling activators induced GLUT4 and CD36 translocation. In contrast, AMPK activators stimulated GLUT4/CD36 translocation as well as glucose/LCFA uptake. When cardiomyocytes were cotreated with Ca2+signaling and AMPK activators, Ca2+signaling activators further enhanced AMPK-induced glucose/LCFA uptake. In conclusion, Ca2+signaling shows no involvement in AMPK-induced GLUT4/CD36 translocation and substrate uptake but elicits transporter translocation via a separate pathway requiring CaMKKβ/CaMKs. Ca2+-induced transporter translocation by itself appears to be ineffective to increase substrate uptake but requires additional AMPK activation to effectuate transporter translocation into increased substrate uptake. Ca2+-induced transporter translocation might be crucial under excessive cardiac stress conditions that require supraphysiological energy demands. Alternatively, Ca2+signaling might prepare the heart for substrate uptake during physiological contraction by inducing transporter translocation.
Trends in Pulmonary Hypertension Mortality and Morbidity
Authors: Mehari Alem , Valle Orlando , Gillum Richard F.
Published: June 2014

Context.Few reports have been published regarding surveillance data for pulmonary hypertension, a debilitating and often fatal condition.Aims.We report trends in pulmonary hypertension.Settings and Design.United States of America; vital statistics, hospital data.Methods and Material.We used mortality data from the National Vital Statistics System (NVSS) for 1999–2008 and hospital discharge data from the National Hospital Discharge Survey (NHDS) for 1999–2009.Statistical Analysis Used.We present age-standardized rates.Results.Since 1999, the numbers of deaths and hospitalizations as well as death rates and hospitalization rates for pulmonary hypertension have increased. In 1999 death rates were higher for men than for women; however, by 2002, no differences by gender remained because of the increasing death rates among women and the declining death rates among men; after 2003 death rates for women were higher than for men. Death rates throughout the reporting period 1999–2008 were higher for blacks than for whites. Hospitalization rates in women were 1.3–1.6 times higher than in men.Conclusions.Pulmonary hypertension mortality and hospitalization numbers and rates increased from 1999 to 2008.
Determination of Residual Nonsteroidal Anti-Inflammatory Drugs in Aqueous Sample Using Magnetic Nanoparticles Modified with Cetyltrimethylammonium Bromide by High Performance Liquid Chromatography
Authors: Khoeini Sharifabadi Malihe , Saber-Tehrani Mohammad , Waqif Husain Syed , Mehdinia Ali , Aberoomand-Azar Parviz
Published: June 2014

A simple and sensitive solid-phase extraction method for separation and preconcentration of trace amount of four nonsteroidal anti-inflammatory drugs (naproxen, indomethacin, diclofenac, and ibuprofen) using Fe3O4magnetic nanoparticles modified with cetyltrimethylammonium bromide has been developed. For this purpose, the surface ofMNPswas modified with cetyltrimethylammonium bromide (CTAB) as a cationic surfactant. Effects of different parameters influencing the extraction efficiency of drugs including the pH, amount of salt, shaking time, eluent type, the volume of solvent, amount of adsorbent, sample volume, and the time of desorption were investigated and optimized. Methanol has been used as desorption solvent and the extracts were analysed on a reversed-phase octadecyl silica column using 0.02 M phosphate-buffer (pH = 6.02) acetonitrile (65 : 35 v/v) as the mobile phase and the effluents were measured at 202 nm with ultraviolet detector. The relative standard deviation (RSD%) of the method was investigated at three concentrations (25, 50, and 200 ng/mL) and was in the range of 3.98–9.83%(n=6)for 50 ng/mL. The calibration curves obtained for studied drugs show reasonable linearity(R2>0.99)and the limit of detection(LODs)ranged between 2 and 7 ng/mL. Finally, the proposed method has been effectively employed in extraction and determination of the drugs in biological and environmental samples.
Formal Modeling and Analysis of Fairness Characterization of E-Commerce Protocols
Authors: Zhang Chengwei , Li Xiaohong , Hu Jing , Feng Zhiyong , Song Jiaojiao
Published: June 2014

In the past, fairness verification of exchanges between the traders in E-commerce was based on a common assumption, so-called nonrepudiation property, which says that if the parties involved can deny that they have received or sent some information, then the exchanging protocol is unfair. So, the nonrepudiation property is not a sufficient condition. In this paper, we formulate a new notion of fairness verification based on the strand space model and propose a method for fairness verification, which can potentially determine whether evidences have been forged in transactions. We first present an innovative formal approach not to depend on nonrepudiation, and then establish a relative trader model and extend the strand space model in accordance with traders’ behaviors of E-commerce. We present a case study to demonstrate the effectiveness of our verification method.
An Integrative Approach with Sequential Game to Real‐Time Gate Assignment under CDM Mechanism
Authors: Liu Jun-qiang , Zhang Ma-lan , Chen Peng-chao , Xie Ji-wei , Zuo Hong-fu
Published: June 2014

This paper focuses on real‐time airport gate assignment problem when small‐scale or medium‐ to large‐scale flight delays occur. Taking into account the collaborative decision making (CDM) of the airlines and the airport, as well as the interests of multiagent (airlines, airports, and passengers), especially those influenced by flight banks, slot assignment and gate assignment are integrated into mixed set programming (MSP), and a real‐time gate assignment model is built and solved through MSP coupled with sequential game. By this approach, the delay costs of multiagent can be minimized simultaneously; the fuel consumption of each airline can be basically equalized; the computation time can be significantly saved by sequential game; most importantly, the collaboration of the airlines and the airport is achieved so that the transferring cost caused by the delay of flight banks can be decreased as much as possible. A case study on small‐scale flight delays verifies that the proposed approach is economical, robust, timesaving, and collaborative. A comparison of the traditional staged method and the proposed approach under medium‐ to large‐scale flight delays proves that the integrative method is much more economical and timesaving than the traditional staged method.
Design of an Aperture-Coupled Frequency-Reconfigurable Microstrip Stacked Array Antenna for LTE and WiMAX Applications
Authors: Ramli N. , Ali M. T. , Islam M. T. , Yusof A. L. , Muhamud-Kayat S. , Azlan A. A.
Published: June 2014

The aim of this paper is to design a novel structure of a frequency-reconfigurable microstrip array antenna by using a combination of aperture-coupled and the stacked patch technology. The four sets of two different aperture slot shapes (I-shaped and H-shaped) are printed on the ground and are functional to transfer the wave and the signal to the selected radiating layers. Both aperture slot positions are based on the bottom patches (layer 2) and top patches (layer 1), respectively. To achieve the frequency reconfigurability, four PIN diode switches are integrated on the feed line layer positioned between both aperture slots on the ground. The activation of the selected patches will determine the current operating frequency of the proposed antenna. A 2.6 GHz or 3.5 GHz frequency is achieved by switching all the PIN diode switches to ON or OFF mode synchronously. The advantage of the proposed antenna is that it can minimize the usage of the antenna’s surface area, with different size of the patch having different operating frequencies, sorted in different layer. The measured results of the return losses, radiation patterns, and the practical indoor propagation measurement achieved good agreement with the simulated results.