bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Clone Sweeps Clean: the Enigmatic Emergence of Escherichia coli Sequence Type 131
Authors: Banerjee Ritu , Johnson James R.
Published: May 2014

Escherichia coli
sequence type 131 (ST131) is an extensively antimicrobial-resistant
E. coli
clonal group that has spread explosively throughout the world. Recent molecular epidemiologic and whole-genome phylogenetic studies have elucidated the fine clonal structure of ST131, which comprises multiple ST131 subclones with distinctive resistance profiles, including the (nested) H30, H30-R, and H30-Rx subclones. The most prevalent ST131 subclone, H30, arose from a single common fluoroquinolone (FQ)-susceptible ancestor containing allele 30 of
fimH
(type 1 fimbrial adhesin gene). An early H30 subclone member acquired FQ resistance and launched the rapid expansion of the resulting FQ-resistant subclone, H30-R. Subsequently, a member of H30-R acquired the CTX-M-15 extended-spectrum beta-lactamase and launched the rapid expansion of the CTX-M-15-containing subclone within H30-R, H30-Rx. Clonal expansion clearly is now the dominant mechanism for the rising prevalence of both FQ resistance and CTX-M-15 production in ST131 and in
E. coli
generally. Reasons for the successful dissemination and expansion of the key ST131 subclones remain undefined but may include increased transmissibility, greater ability to colonize and/or persist in the intestine or urinary tract, enhanced virulence, and more-extensive antimicrobial resistance compared to other
E. coli
. Here we discuss the epidemiology and molecular phylogeny of ST131 and its key subclones, possible mechanisms for their ecological success, implications of their widespread dissemination, and future research needs.
The
psm
α Locus Regulates Production of Staphylococcus aureus Alpha-Toxin during Infection
Authors: Berube Bryan J. , Sampedro Georgia R. , Otto Michael , Bubeck Wardenburg Juliane
Published: May 2014

Staphylococcus aureus
is a leading cause of human bacterial infection, causing a wide spectrum of disease ranging from skin and soft tissue infections to life-threatening pneumonia and sepsis.
S. aureus
toxins play an essential role in disease pathogenesis, contributing to both immunomodulation and host tissue injury. Prominent among these toxins are the membrane-active pore-forming cytolysin alpha-toxin (Hla) and the amphipathic α-helical phenol-soluble modulin (PSM) peptides. As deletion of either the
hla
or
psm
locus leads to a phenotypically similar virulence defect in skin and soft tissue infection, we sought to determine the relative contribution of each locus to disease pathogenesis. Here we show that production of Hla can be modulated by PSM expression. An
S. aureus
mutant lacking PSM expression exhibits a transcriptional delay in
hla
mRNA production and therefore fails to secrete normal levels of Hla at early phases of growth. This leads to attenuation of virulence
in vitro
and in murine skin and lung models of infection, correlating with reduced recovery of Hla from host tissues. Production of Hla and restoration of staphylococcal virulence can be achieved in the
psm
mutant by plasmid-driven overexpression of
hla
. Our study suggests the coordinated action of Hla and PSMs in host tissue during early pathogenesis, confirming a major role for Hla in epithelial injury during
S. aureus
infection. These findings highlight the possibility that therapeutics targeting PSM production may simultaneously prevent Hla-mediated tissue injury.
Gastric
De Novo
Muc13 Expression and Spasmolytic Polypeptide-Expressing Metaplasia during Helicobacter heilmannii Infection
Authors: Liu Cheng , Smet Annemieke , Blaecher Caroline , Flahou Bram , Ducatelle Richard , Linden Sara , Haesebrouck Freddy
Published: May 2014

Helicobacter heilmannii
is a zoonotic bacterium that has been associated with gastric disease in humans. In this study, the mRNA expression of mucins in the stomach of BALB/c mice was analyzed at several time points during a 1-year infection with this bacterium, during which gastric disease progressed in severity. Markers for acid production by parietal cells and mucous metaplasia were also examined. In the first 9 weeks postinfection, the mRNA expression of Muc6 was clearly upregulated in both the antrum and fundus of the stomach of
H. heilmannii
-infected mice. Interestingly, Muc13 was upregulated already at 1 day postinfection in the fundus of the stomach. Its expression level remained high in the stomach over the course of the infection. This mucin is, however, not expressed in a healthy stomach, and high expression of this mucin has so far only been described in gastric cancer. In the later stages of infection, mRNA expression of H
+
/K
+
-ATPase α/β and KCNQ1 decreased, whereas the expression of Muc4, Tff2, Dmbt1, and polymeric immunoglobulin receptor (pIgR) increased starting at 16 weeks postinfection onwards, suggesting the existence of spasmolytic polypeptide-expressing metaplasia in the fundus of the stomach. Mucous metaplasia present in the mucosa surrounding low-grade mucosa-associated lymphoid tissue (MALT) lymphoma-like lesions was also histologically confirmed. Our findings indicate that
H. heilmannii
infection causes severe gastric pathologies and alterations in the expression pattern of gastric mucins, such as Muc6 and Muc13, as well as disrupting gastric homeostasis by inducing the loss of parietal cells, resulting in the development of mucous metaplasia.
The Periodontal Pathogen Porphyromonas gingivalis Induces Expression of Transposases and Cell Death of Streptococcus mitis in a Biofilm Model
Authors: Duran-Pinedo Ana E. , Baker Vinesha D. , Frias-Lopez Jorge
Published: May 2014

Oral microbial communities are extremely complex biofilms with high numbers of bacterial species interacting with each other (and the host) to maintain homeostasis of the system. Disturbance in the oral microbiome homeostasis can lead to either caries or periodontitis, two of the most common human diseases. Periodontitis is a polymicrobial disease caused by the coordinated action of a complex microbial community, which results in inflammation of tissues that support the teeth. It is the most common cause of tooth loss among adults in the United States, and recent studies have suggested that it may increase the risk for systemic conditions such as cardiovascular diseases. In a recent series of papers, Hajishengallis and coworkers proposed the idea of the “keystone-pathogen” where low-abundance microbial pathogens (
Porphyromonas gingivalis
) can orchestrate inflammatory disease by turning a benign microbial community into a dysbiotic one. The exact mechanisms by which these pathogens reorganize the healthy oral microbiome are still unknown. In the present manuscript, we present results demonstrating that
P. gingivalis
induces
S. mitis
death and DNA fragmentation in an
in vitro
biofilm system. Moreover, we report here the induction of expression of multiple transposases in a
Streptococcus mitis
biofilm when the periodontopathogen
P. gingivalis
is present. Based on these results, we hypothesize that
P. gingivalis
induces
S. mitis
cell death by an unknown mechanism, shaping the oral microbiome to its advantage.
Nucleoside Diphosphate Kinase and Flagellin from Pseudomonas aeruginosa Induce Interleukin 1 Expression via the Akt/NF-κB Signaling Pathways
Authors: Kim Yong-Jae , Lee Jung-Hoon , Lee Yeji , Jia Jingyue , Paek Se-Hwan , Kim Hyong-Bai , Jin Shouguang , Ha Un-Hwan
Published: May 2014

Inflammatory responses are a first line of host defense against a range of invading pathogens, consisting of the release of proinflammatory cytokines followed by attraction of polymorphonuclear neutrophils (PMNs) to the site of inflammation. Among the many virulence factors that contribute to the pathogenesis of infections, nucleoside diphosphate kinase (Ndk) mediates bacterially induced toxicity against eukaryotic cells. However, no study has examined how Ndk affects inflammatory responses. The present study examined the mechanisms by which
Pseudomonas aeruginosa
activates inflammatory responses upon infection of cells. The results showed that bacterial Ndk, with the aid of an additional bacterial factor, flagellin, induced expression of the proinflammatory cytokines interleukin-1α (IL-1α) and IL-1β. Cytokine induction appeared to be dependent on the kinase activity of Ndk and was mediated via the NF-κB signaling pathway. Notably, Ndk activated the Akt signaling pathway, which acts upstream of NF-κB, as well as caspase-1, which is a key component of inflammasome. Thus, this study demonstrated that
P. aeruginosa
, through the combined effects of Ndk and flagellin, upregulates the expression of proinflammatory cytokines via the Akt/NF-κB signaling pathways.
Microbiota-Induced Changes in Drosophila melanogaster Host Gene Expression and Gut Morphology
Authors: Broderick Nichole A. , Buchon Nicolas , Lemaitre Bruno
Published: May 2014

To elucidate mechanisms underlying the complex relationships between a host and its microbiota, we used the genetically tractable model
Drosophila melanogaster
. Consistent with previous studies, the microbiota was simple in composition and diversity. However, analysis of single flies revealed high interfly variability that correlated with differences in feeding. To understand the effects of this simple and variable consortium, we compared the transcriptome of guts from conventionally reared flies to that for their axenically reared counterparts. Our analysis of two wild-type fly lines identified 121 up- and 31 downregulated genes. The majority of these genes were associated with immune responses, tissue homeostasis, gut physiology, and metabolism. By comparing the transcriptomes of young and old flies, we identified temporally responsive genes and showed that the overall impact of microbiota was greater in older flies. In addition, comparison of wild-type gene expression with that of an immune-deficient line revealed that 53% of upregulated genes exerted their effects through the immune deficiency (Imd) pathway. The genes included not only classic immune response genes but also those involved in signaling, gene expression, and metabolism, unveiling new and unexpected connections between immunity and other systems. Given these findings, we further characterized the effects of gut-associated microbes on gut morphology and epithelial architecture. The results showed that the microbiota affected gut morphology through their impacts on epithelial renewal rate, cellular spacing, and the composition of different cell types in the epithelium. Thus, while bacteria in the gut are highly variable, the influence of the microbiota at large has far-reaching effects on host physiology.

IMPORTANCE
The guts of animals are in constant association with microbes, and these interactions are understood to have important roles in animal development and physiology. Yet we know little about the mechanisms underlying the establishment and function of these associations. Here, we used the fruit fly to understand how the microbiota affects host function. Importantly, we found that the microbiota has far-reaching effects on host physiology, ranging from immunity to gut structure. Our results validate the notion that important insights on complex host-microbe relationships can be obtained from the use of a well-established and genetically tractable invertebrate model.
Uncommon side effect with a commonly used targeted agent: sunitinib-induced nephrotic syndrome in a patient with metastatic renal cell carcinoma
Authors: Quintyne Keith Ian , Neenan Triona , Casserly Liam , Gupta Rajnish
Published: May 2014

The authors report the case of a 67-year-old woman with metastatic renal cell carcinoma (RCC) without prior nephrectomy, who had received long-term exposure (38 months) to the oral multi-targeted tyrosine kinase inhibitor (TKI), sunitinib. She had a sustained clinical and radiological response to her therapy, but had this therapy discontinued due to the rare development of nephrotic syndrome.
Bilateral subhyaloid haemorrhage in a conscious patient: a new spectrum of ocular involvement byPlasmodium falciparum
Authors: Abdali Nasar , Malik Azharuddin Mohammed , Shamim Md Dilawez , Rizvi Syed Wajahat Ali
Published: May 2014

A 24-year-old woman presented with a history of high-grade fever with rigours since 3 days and bilateral sudden loss of vision since 6 h. She was conscious, oriented and her vitals were stable. She had a temperature of 101°F, anaemia, thrombocytopaenia, normal white cell count and moderate splenomegaly. On testing visual activity, she could only perceive hand movements although her pupils were bilaterally equal, and normal in size and reaction. On indirect ophthalmoscopy, optic discs were normal bilaterally; however, fovea of both eyes was masked by subhyaloid haemorrhage. Peripheral smear showed gametocytes ofPlasmodium falciparum.The patient was started on arteminsinin-combined therapy and advised to be in propped-up position to help resolution of the haemorrhage. The patient was afebrile in 4 days and follow-up fundus examination showed gradual resolution of the haemorrhage. After two months, the patient regained normal visual acuity in both eyes; however, it took nearly 3 months for complete resolution of the haemorrhage.
A rare case of racemose neurocysticercosis of the posterior fossa
Authors: Karegowda Lakshmikanth Halegubbi , Shenoy Poonam Mohan , Prakashini Koteshwara , Karur Gauri
Published: May 2014

A 43-year-old man presented with a 3 month history of headache, vertigo and swaying while walking. MRI of the brain showed cystic lesions involving the cerebellopontine angle cisterns, the right perimedullary cistern, the fourth ventricle and bilateral foramen of Luschka with resultant obstruction to cerebrospinal fluid outflow and hydrocephalus. The patient underwent right retromastoid craniotomy with endoscopic third ventriculostomy for cyst excision. The postoperative period was uneventful and he was able to carry out routine activities within a month. This case report stresses on the clinical importance, unique characteristics and imaging features of racemose neurocysticercosis.
Safe delivery of two parturient women in severe metabolic acidosis
Authors: Shariffuddin Ina Ismiarti , Rai Vineya , Chan Y K , Muniandy Rajesh Kumar
Published: May 2014

Care of an acutely ill parturient is particularly difficult when we have to balance the needs of both mother and the fetus to survive. The literature suggests there should be emphasis on stabilising the mother's condition. In dealing with metabolic acidosis, however, we believe delivering the baby early might not only relieve the threat of the acidosis on the mother, it may be the only way to deliver a live baby. We report two parturient women with severe metabolic acidosis which was considerably reduced very soon after the delivery and how our timely delivery resulted in the birth of two neurologically intact babies.
Traffic conflict techniques for road safety analysis: open questions and some insights
Authors: Zheng Lai , Ismail Karim , Meng Xianghai
Published: May 2014

Developing non-crash or surrogate measures of road safety has drawn considerable research interest over the past five decades. Traffic conflict techniques, which analyze the safety situations from the aspect of more observable traffic events than crashes, are the most prominent techniques to date. This study provides a comprehensive review of previous research on traffic conflict techniques, striving to find answers to the following open questions: What is a traffic conflict? How to collect the traffic conflict data? And what is the ground to claim that traffic conflicts can be valid surrogates for crashes? The strengths and weaknesses of available answers to these questions are assessed based on methodological and empirical grounds. Directions for the future research are identified and outlined. It is believed that following recommended future directions may offer convincing answers to identified open questions.
Review of recent measurements in the top quark sector at the Tevatron
Authors: Jung Andreas W.
Published: May 2014

Recent measurements in the top quark sector at the Fermilab Tevatron collider are discussed. Measurements at the Tevatron use up to 9.7 fb-1 of data corresponding to the full data sets recorded by each of the experiments, CDF and DØ. This review discusses the most recent measurements of inclusive and differential top quark cross-sections in strong and electroweak production of top quarks and related measurements, as well as measurements of angular distributions related to asymmetries in top quark production. Furthermore, the current status of precision measurements of the mass of the top quark is discussed. Where available, combinations of CDF and DØ results are presented.
Exact exponential solutions in Einstein–Gauss–Bonnet flat anisotropic cosmology
Authors: Chirkov Dmitry , Pavluchenko Sergey , Toporensky Alexey
Published: May 2014

In this paper, we are looking for the exponential solutions (i.e. the solutions with the scale factors change exponentially over time) in the Einstein–Gauss–Bonnet (EGB) gravity. We argue that we found all possible nonconstant-volume solutions (up to permutations) in lower dimensions ((4+1) and (5+1)) and developed a scheme which allows one to find necessary conditions in arbitrary dimension.
Baker Domains of Period Two for the Family $f_{\lambda,\mu}(z)=\lambda e^{z} + \frac{\mu}{z}$
Authors: Montes de Oca Balderas Marco A. , Sienra Loera Guillermo J. F. , King Davalos Jefferson E.
Published: May 2014

Our main theorem establishes that the Fatou set of the functions fλ,μ(z) = λez + μ/z contains a two-cycle of Baker domains {F∞, F0} if Re(λ) < 0 and |Im(λ)| < 1/2|Re(λ)|. We show that under [Formula: see text] every point in F∞ tends to infinity and in F0 tends to zero. Moreover, if |Im(λ)| < 1/2|Re(λ)| - 4, the set F∞ contains infinitely many critical points of fλ,μ and F0 contains infinitely many critical values; also, infinitely many critical values of [Formula: see text] are contained in both F∞ and F0. Finally, the images of the Baker domains are displayed for some parameters.
Dynamic Environment Coupling Induced Synchronized States in Coupled Time-Delayed Electronic Circuits
Authors: Suresh R. , Srinivasan K. , Senthilkumar D. V. , Murali K. , Lakshmanan M. , Kurths J.
Published: May 2014

We experimentally demonstrate the effect of dynamic environment coupling in a system of coupled piecewise linear time-delay electronic circuits with mutual and subsystem coupling configurations. Time-delay systems are essentially infinite-dimensional systems with complex phase-space properties. Dynamic environmental coupling with mutual coupling configuration has been recently theoretically shown to induce complete (CS) and inverse synchronizations (IS) [Resmi et al., 2010] in low-dimensional dynamical systems described by ordinary differential equations (ODEs), for which no experimental confirmation exists. In this paper, we investigate the effect of dynamic environment for the first time in mutual as well as subsystem coupling configurations in coupled time-delay differential equations theoretically and experimentally. Depending upon the coupling strength and the nature of feedback, we observe a transition from asynchronization to CS via phase synchronization and from asynchronization to IS via inverse-phase synchronization in both coupling configurations. The results are corroborated by snapshots of the time evolution, phase projection plots and localized sets as observed from the oscilloscope. Further, the synchronization is also confirmed numerically from the largest Lyapunov exponents, correlation of probability of recurrence and correlation coefficient of the coupled time-delay system. We also present a linear stability analysis and obtain conditions for different synchronized states.
Chaos of Discrete Spatiotemporal Systems on a Bidirectional Metric Space
Authors: Tian Chuanjun
Published: May 2014

This paper is concerned with chaos of discrete spatiotemporal systems of the form [Formula: see text] where k is a positive integer, I is a bounded subset of R = (-∞, ∞), and f : Ik+1→ I is a function, m, n ∈ N0= {0, 1, 2, …}. Some new sufficient conditions for this system to be chaotic in the sense of Devaney on I∞with a bidirectional metric are derived.
Bifurcation Trees of Periodic Motions to Chaos in a Parametric, Quadratic Nonlinear Oscillator
Authors: Luo Albert C. J. , Yu Bo
Published: May 2014

In this paper, bifurcation trees of periodic motions to chaos in a parametric oscillator with quadratic nonlinearity are investigated analytically as one of the simplest parametric oscillators. The analytical solutions of periodic motions in such a parametric oscillator are determined through the finite Fourier series, and the corresponding stability and bifurcation analyses for periodic motions are completed. Nonlinear behaviors of such periodic motions are characterized through frequency–amplitude curves of each harmonic term in the finite Fourier series solution. From bifurcation analysis of the analytical solutions, the bifurcation trees of periodic motion to chaos are obtained analytically, and numerical illustrations of periodic motions are presented through phase trajectories and analytical spectrum. This investigation shows period-1 motions exist in parametric nonlinear systems and the corresponding bifurcation trees to chaos exist as well.
Binding Site Extraction by Similar Subgraphs Mining from Protein Molecular Surfaces and Its Application to Protein Classification
Authors: Kurumatani Natsumi , Monji Hiroyuki , Ohkawa Takenao
Published: May 2014

Most proteins express their functions by binding with other proteins or molecular compounds (ligands). Since the characteristics of the local portion involved in binding (binding site) often determine the function of the protein, clarifying the location of the binding site of the protein helps analyze the function of proteins. Binding sites that bind to similar ligands often have common surface structures (surface motifs). Extracting the surface motifs among several proteins with similar functions improves binding site prediction.

We propose a method that predicts binding sites by extracting the surface motifs that are frequently observed in only a specific set of proteins that bind to the same ligand (group). Since most binding sites have concave structures (pockets), the pockets are compared and common structures are searched for to extract the surface motifs by applying similar graph mining to the pocket data, which are represented as graphs. Common binding sites across several groups can be predicted in such a way to integrate more than one group. We also proposed a method of protein classification, in which the surface motifs extracted using the above method are evaluated on the assumption that a protein belongs to each one of the groups.
Plasma boundary determination in Damavand tokamak by using current filament method
Authors: Ghadiri Rasoul , Sadeghi Yahya , Esteki Mohammad Hossein
Published: May 2014

The shape and position of the plasma and consequently the plasma boundary are determined by using the Current Filament (CF) method from the experimental data of the magnetic measurements in Damavand tokamak. The method can calculate the magnetic flux without solving the equilibrium equation directly by coupling with the Current Moment (CM) method. The plasma and current-carrying coils in the tokamak will be modeled by using this method as some virtual filaments that will enable us to calculate the flux and consequently the plasma boundary. To calculate the flux of these virtual filaments, one needs to determine the Green Function and the inverse by means of the Singular Value Decomposition (SVD) method. Finally, the model was evaluated by employing 12 independent pickup coils with mean error of less than 2%. The aim of this paper is to give a brief exposition of CF method applied in Damavand tokamak.
Vibration of Elastic Beams in the Presence of an Inviscid Fluid Medium
Authors: Soltani Helnaz , Payette Gregory S. , Reddy J. N.
Published: May 2014

The physical interaction of fluids and solids is of practical significance in engineering (e.g. flutter of aerodynamic structures, vortex induced vibrations of sub-sea pipelines and risers, inflatable dams, parachute dynamics and blood flow through arteries). In this paper, a finite element formulation is developed for determining the vibration characteristics of beams in contact with inviscid incompressible fluid. The classical, first-order and third-order shear deformation beam theories are used to model the structural response. Numerical results for vibration frequencies are presented showing the parametric effect of thickness and immersion depth on the frequency response. The results indicate that the presence of fluid interaction has significant effect on the dynamic response. The formulation presented herein is also applicable to a vast number of vibration problems related to beams under a variety of excitations.
Photochemical properties of substituted tetraazachlorins
Authors: Lastovoy Anton P. , Kuznetsova Nina A. , Slivka Ludmila K. , Makarova Elena A.
Published: May 2014

The photochemical properties of water-insoluble metal-free tetraazachlorin derivatives in organic solvents and aqueous micellar solutions of nonionic surfactants were investigated. The quantum yields of fluorescence, singlet oxygen generation and photodegradation were evaluated in benzene. The highest photostability and singlet oxygen quantum yield (ΦΔ = 0.7) was found for 2,2,3,3-tetramethyl-7,8,12,13,17,18-hexaphenyltetraazachlorin. The moderate ΦΔ values (0.21–0.35) of triarenotetraazachlorins in benzene were established. Expansion of tetraazachlorin π-system by fusion of three aromatic rings leads to reduction of efficiency of singlet oxygen generation. The study of photodegradation mechanism shows that radical photooxidation apparently is most plausible, though 1 O 2 may partly contribute to photodestruction of some tetraazachlorins. In aqueous colloidal solution of nonionic surfactant (Cremophor EL) the same, as in benzene, effect of sensitizer structure upon efficacy of singlet oxygen production was observed. It was shown that 1 O 2 diffusion from micelle core into solution and then to target slows its oxidation rate substantially in comparison to the case where sensitizer and target are localized in the same micelle.
STRUCTURAL CHANGES ASSOCIATED WITH TEMPORAL DISPERSION IN SOFTWARE DEVELOPMENT TEAMS: EVIDENCE FROM OPEN SOURCE SOFTWARE PROJECT TEAMS
Authors: COLAZO JORGE
Published: May 2014

Collaboration structure and temporal dispersion (TD) in teams have been studied independently so far. This study uses Media Synchronicity Theory (MST) to derive hypotheses positing that the structure of collaboration networks in distributed teams changes when those teams are more temporally dispersed. The empirical test of hypotheses using ordinary least squares with archival data from 230 open source software (OSS) projects shows that the collaboration structure networks of those OSS teams that are more temporally dispersed are sparser and more centralised, and these associations are stronger in those teams exhibiting higher relative performance. Theoretical and practical consequences are discussed.
Asymptotic normality and greatest common divisors
Authors: Fernández José L. , Fernández Pablo
Published: May 2014

We report on some statistical regularity properties of greatest common divisors: for large random samples of integers, the number of coprime pairs and the average of the gcd's of those pairs are approximately normal, while the maximum of those gcd's (appropriately normalized) follows approximately a Fréchet distribution. We also consider r-tuples instead of pairs, and moments other than the average.
Schmidt's subspace theorem for moving hypersurface targets
Authors: Le Giang
Published: May 2014

Our goal is to give Schmidt's subspace theorem for moving hypersurface targets in (weakly) general position.
Spatial pattern in a diffusive predator–prey model with sigmoid ratio-dependent functional response
Authors: Guin Lakshmi Narayan , Mandal Prashanta Kumar
Published: May 2014

In this paper, spatial patterns of a diffusive predator–prey model with sigmoid (Holling type III) ratio-dependent functional response which concerns the influence of logistic population growth in prey and intra-species competition among predators are investigated. The (local and global) asymptotic stability behavior of the corresponding non-spatial model around the unique positive interior equilibrium point in homogeneous steady state is obtained. In addition, we derive the conditions for Turing instability and the consequent parametric Turing space in spatial domain. The results of spatial pattern analysis through numerical simulations are depicted and analyzed. Furthermore, we perform a series of numerical simulations and find that the proposed model dynamics exhibits complex pattern replication. The feasible results obtained in this paper indicate that the effect of diffusion in Turing instability plays an important role to understand better the pattern formation in ecosystem.
Could the Virtual be Similar to the Real? A First Look from an Efficient Markets Perspective
Authors: Yang Ruoke
Published: May 2014

In recent years, increasing effort has been devoted to the study of virtual world economies due to their potential of increasing our understanding of the real world economy, and vice versa. Due to a scarce availability of reliable global data, previous virtual world economic studies have been largely limited to qualitative observations. This paper presents novel financial data and is the first to apply a time series approach to the forecasting of virtual commodity prices. The results are assessed against the random walk and, from an efficient markets perspective, evaluates the potential of virtual worlds becoming experimental simulations for the real.
ENGINEERING PLASMONIC COLORS IN METAL NANOSTRUCTURES
Authors: TAN SHAWN J. , GOH XIAO MING , WANG YING MIN , YANG JOEL K. W. , TENG JINGHUA
Published: May 2014

Plasmonic nanostructures hold immense potential for structure-based color engineering at the subwavelength length scale. In this paper, we will review representative works that demonstrate promising strategies to exploit the rich mechanisms of surface plasmons for color engineering across the visible spectrum. By varying the structural design and material composition of plasmonic nanostructures through chemical synthesis or lithography, these approaches can achieve highly controllable and tunable colors for a wide variety of applications. We will also critically discuss the applications of these state-of-the-art technologies in color filtering, color printing and color-based chemical and biological sensing.
Impairments of hepatic gluconeogenesis and ketogenesis in PPARα-deficient neonatal mice
Authors: Cotter David G. , Ercal Baris , André d'Avignon D. , Dietzen Dennis J. , Crawford Peter A.
Published: May 2014

Peroxisome proliferator activated receptor-α (PPARα) is a master transcriptional regulator of hepatic metabolism and mediates the adaptive response to fasting. Here, we demonstrate the roles for PPARα in hepatic metabolic adaptations to birth. Like fasting, nutrient supply is abruptly altered at birth when a transplacental source of carbohydrates is replaced by a high-fat, low-carbohydrate milk diet. PPARα-knockout (KO) neonatal mice exhibit relative hypoglycemia due to impaired conversion of glycerol to glucose. Although hepatic expression of fatty acyl-CoA dehydrogenases is imparied in PPARα neonates, these animals exhibit normal blood acylcarnitine profiles. Furthermore, quantitative metabolic fate mapping of the medium-chain fatty acid [13C]octanoate in neonatal mouse livers revealed normal contribution of this fatty acid to the hepatic TCA cycle. Interestingly, octanoate-derived carbon labeled glucose uniquely in livers of PPARα-KO neonates. Relative hypoketonemia in newborn PPARα-KO animals could be mechanistically linked to a 50% decrease in de novo hepatic ketogenesis from labeled octanoate. Decreased ketogenesis was associated with diminished mRNA and protein abundance of the fate-committing ketogenic enzyme mitochondrial 3-hydroxymethylglutaryl-CoA synthase (HMGCS2) and decreased protein abundance of the ketogenic enzyme β-hydroxybutyrate dehydrogenase 1 (BDH1). Finally, hepatic triglyceride and free fatty acid concentrations were increased 6.9- and 2.7-fold, respectively, in suckling PPARα-KO neonates. Together, these findings indicate a primary defect of gluconeogenesis from glycerol and an important role for PPARα-dependent ketogenesis in the disposal of hepatic fatty acids during the neonatal period.
Generating Moving Average Trading Rules on the Oil Futures Market with Genetic Algorithms
Authors: Wang Lijun , An Haizhong , Xia Xiaohua , Liu Xiaojia , Sun Xiaoqi , Huang Xuan
Published: May 2014

The crude oil futures market plays a critical role in energy finance. To gain greater investment return, scholars and traders use technical indicators when selecting trading strategies in oil futures market. In this paper, the authors used moving average prices of oil futures with genetic algorithms to generate profitable trading rules. We defined individuals with different combinations of period lengths and calculation methods as moving average trading rules and used genetic algorithms to search for the suitable lengths of moving average periods and the appropriate calculation methods. The authors used daily crude oil prices of NYMEX futures from 1983 to 2013 to evaluate and select moving average rules. We compared the generated trading rules with the buy‐and‐hold (BH) strategy to determine whether generated moving average trading rules can obtain excess returns in the crude oil futures market. Through 420 experiments, we determine that the generated trading rules help traders make profits when there are obvious price fluctuations. Generated trading rules can realize excess returns when price falls and experiences significant fluctuations, while BH strategy is better when price increases or is smooth with few fluctuations. The results can help traders choose better strategies in different circumstances.
Existence of Positive Solutions of Lotka-Volterra Competition Model with Nonlinear Boundary Conditions
Authors: Zhang Yang , Wang Mingxin , Wang Yuwen
Published: May 2014

A Lotka-Volterra competition model with nonlinear boundary conditions is considered. First, by using upper and lower solutions method for nonlinear boundary problems, we investigate the existence of positive solutions in weak competition case. Next, we prove that-d1Δu=u(a1-b1u-c1v),x∈Ω;-d2Δv=v(a2-b2u-c2v),x∈Ω;∂u/∂ν+f(u)=0,x∈∂Ω;∂v/∂ν+g(v)=0,x∈∂Ω, has no positive solution when one of the diffusion coefficients is sufficiently large.
Saliva: A Cutting Edge in Diagnostic Procedures
Authors: Sindhu Senthamil , Jagannathan Nithya
Published: May 2014

The ability to monitor the health and disease status of the patient through saliva is a highly desirable goal for the health professionals. Considering the microconcentration of salivary constituents, saliva is explored to be diagnostic tool as it also meets the demands for an inexpensive, noninvasive and easy to use screening method. The incorporation of salivary diagnostics into clinical practice is gaining reality and will be of diagnostic value in the prospective future. The investigative use of saliva is not being applied only in dental health but also in various other systemic disorders. The advent of molecular techniques is gaining attention and this has triggered its application as a specific and sensitive biomarker in proteomics, genomics, and transcriptomics. This review discusses the basics of salivary diagnostics, expectoration techniques, and its application in various local and systemic disorders.
Modeling and Dynamical Analysis of the Water Resources Supply-Demand System: A Case Study in Haihe River Basin
Authors: Di Chongli , Yang Xiaohua
Published: May 2014

The relationship between water resources supply and demand is very complex and exhibits nonlinear characteristics, which leads to fewer models that can adequately manage the dynamic evolution process of the water resources supply-demand system. In this paper, we propose a new four-dimensional dynamical model to simulate the internal dynamic evolution process and predict future trends of water supply and demand. At the beginning, a new four-dimensional dynamical model with uncertain parameters is established. Then, the gray code hybrid accelerating genetic algorithm (GHAGA) is adopted to identify the unknown parameters of the system based on the statistic data (1998–2009). Finally, the dynamical analysis of the system is further studied by Lyapunov-exponent, phase portraits, and Lyapunov exponent theory. Numerical simulation results demonstrate that the proposed water resources supply-demand system is in a steady state and is suitable for simulating the dynamical characteristics of a complex water supply and demand system. According to the trends of the water supply and demand of several nonlinear simulation cases, the corresponding measures can be proposed to improve the steady development of the water resources supply-demand system.
Generalized Preconditioned MHSS Method for a Class of Complex Symmetric Linear Systems
Authors: Li Cui-Xia , Liang Yan-Jun , Wu Shi-Liang
Published: May 2014

Based on the modified Hermitian and skew-Hermitian splitting (MHSS) and preconditioned MHSS (PMHSS) methods, a generalized preconditioned MHSS (GPMHSS) method for a class of complex symmetric linear systems is presented. Theoretical analysis gives an upper bound for the spectral radius of the iteration matrix. From a practical point of view, we have analyzed and implemented inexact GPMHSS (IGPMHSS) iteration, which employs Krylov subspace methods as its inner processes. Numerical experiments are reported to confirm the efficiency of the proposed methods.
Coupling of Algal Biofuel Production with Wastewater
Authors: Bhatt Neha Chamoli , Panwar Amit , Bisht Tara Singh , Tamta Sushma
Published: May 2014

Microalgae have gained enormous consideration from scientific community worldwide emerging as a viable feedstock for a renewable energy source virtually being carbon neutral, high lipid content, and comparatively more advantageous to other sources of biofuels. Although microalgae are seen as a valuable source in majority part of the world for production of biofuels and bioproducts, still they are unable to accomplish sustainable large-scale algal biofuel production. Wastewater has organic and inorganic supplements required for algal growth. The coupling of microalgae with wastewater is an effective way of waste remediation and a cost-effective microalgal biofuel production. In this review article, we will primarily discuss the possibilities and current scenario regarding coupling of microalgal cultivation with biofuel production emphasizing recent progress in this area.
Estimated Interval-Based Checkpointing (EIC) on Spot Instances in Cloud Computing
Authors: Jung Daeyong , Lim JongBeom , Yu Heonchang , Suh Taeweon
Published: May 2014

In cloud computing, users can rent computing resources from service providers according to their demand. Spot instances are unreliable resources provided by cloud computing services at low monetary cost. When users perform tasks on spot instances, there is an inevitable risk of failures that causes the delay of task execution time, resulting in a serious deterioration of quality of service (QoS). To deal with the problem on spot instances, we propose an estimated interval-based checkpointing (EIC) using weighted moving average. Our scheme sets the thresholds of price and execution time based on history. Whenever the actual price and the execution time cross over the thresholds, the system saves the state of spot instances. The Bollinger Bands is adopted to inform the ranges of estimated cost and execution time for user's discretion. The simulation results reveal that, compared to the HBC and REC, the EIC reduces the number of checkpoints and the rollback time. Consequently, the task execution time is decreased with EIC by HBC and REC. The EIC also provides the benefit of the cost reduction by HBC and REC, on average. We also found that the actual cost and execution time fall within the estimated ranges suggested by the Bollinger Bands.
The Bifixation Field as a Function of Viewing Distance
Authors: Grove Philip M. , Mapp Alistair P. , Ono Hiroshi
Published: May 2014

Hering reported that the area over which he could bifixate a target was smaller at near convergence distances than far convergence distances and predicted that in extreme horizontal gaze positions, the temporally directed eye lags behind the nasally directed eye. We tested these predictions using a subjective index of eye position. Experiment  1 confirmed that the bifixation field was significantly smaller at near convergence distances. When bifixation broke down at the near distance, the nasally directed eye lagged behind the temporally directed eye for all observers. At the far distance, the nasally directed eye preceded the temporally directed eye for four of six observers. Experiment  2 also confirmed that the bifixation field was smaller at near convergence distances but the nasally directed eye always lagged behind the temporally directed eye at the limits of the bifixation field. We confirmed Hering’s first prediction that the bifixation field is smaller at near convergence distances than at far ones. However, the majority of our results indicate that the nasally directed eye lags behind the temporally directed eye at the limits of the bifixation field, contrary to Hering’s prediction. We conclude that the eyes drift toward their tonic state of vergence when fusion breaks.
Molecular Identification of Necrophagous Muscidae and Sarcophagidae Fly Species Collected in Korea by Mitochondrial Cytochrome c Oxidase Subunit I Nucleotide Sequences
Authors: Kim Yu-Hoon , Shin Sang Eon , Ham Chan Seon , Kim Seong Yoon , Ko Kwang Soo , Jo Tae-Ho , Son Gi Hoon , Park Seong Hwan , Hwang Juck-Joon
Published: May 2014

Identification of insect species is an important task in forensic entomology. For more convenient species identification, the nucleotide sequences of cytochrome c oxidase subunit I (COI) gene have been widely utilized. We analyzed full-length COI nucleotide sequences of 10 Muscidae and 6 Sarcophagidae fly species collected in Korea. After DNA extraction from collected flies, PCR amplification and automatic sequencing of the whole COI sequence were performed. Obtained sequences were analyzed for a phylogenetic tree and a distance matrix. Our data showed very low intraspecific sequence distances and species-level monophylies. However, sequence comparison with previously reported sequences revealed a few inconsistencies or paraphylies requiring further investigation. To the best of our knowledge, this study is the first report ofCOInucleotide sequences fromHydrotaea occulta, Muscina angustifrons, Muscina pascuorum, Ophyra leucostoma, Sarcophaga haemorrhoidalis, Sarcophaga harpax, andPhaonia aureola.
A Large-Scale Network Data Analysis via Sparse and Low Rank Reconstruction
Authors: Lu Liang Fu , Huang Zheng-Hai , Ambusaidi Mohammed A. , Gou Kui-Xiang
Published: May 2014

With the rapid growth of data communications in size and complexity, the threat of malicious activities and computer crimes has increased accordingly as well. Thus, investigating efficient data processing techniques for network operation and management over large-scale network traffic is highly required. Some mathematical approaches on flow-level traffic data have been proposed due to the importance of analyzing the structure and situation of the network. Different from the state-of-the-art studies, we first propose a new decomposition model based on accelerated proximal gradient method for packet-level traffic data. In addition, we present the iterative scheme of the algorithm for network anomaly detection problem, which is termed as NAD-APG. Based on the approach, we carry out the intrusion detection for packet-level network traffic data no matter whether it is polluted by noise or not. Finally, we design a prototype system for network anomalies detection such as Probe and R2L attacks. The experiments have shown that our approach is effective in revealing the patterns of network traffic data and detecting attacks from large-scale network traffic. Moreover, the experiments have demonstrated the robustness of the algorithm as well even when the network traffic is polluted by the large volume anomalies and noise.
Synthesis of Copper Nanoparticles Coated with Nitrogen Ligands
Authors: Sierra-Ávila Rubén , Pérez-Alvarez Marissa , Cadenas-Pliego Gregorio , Ávila-Orta Carlos Alberto , Betancourt-Galindo Rebeca , Jiménez-Regalado Enrique , Jiménez-Barrera Rosa Martha , Martínez-Colunga Juan Guillermo
Published: May 2014

The synthesis of copper nanoparticles was studied by wet chemical methods using copper sulfate pentahydrate (CuSO4·5H2O) and nitrogen ligands allylamine (AAm) and polyallylamine (PAAm) as stabilizers. The results suggest that the use of these ligands leads to the exclusive formation of metallic copper nanoparticles (Cu‐NPs). The use of partially crosslinked polyallylamine (PAAmc) leads to nanoparticles (NPs) with low yields and high coating content, while linear PAAm leads to NPs with high yields and low coating content. The chemical composition of the particles was determined by XRD and average particle diameters were determined by the Debye‐Scherrer equation. TGA analysis provided evidence of the content and thermal stability of the coating on the nanoparticles and PAAm. The morphology, particle size distribution, and presence of PAAm coating were observed through TEM. The use of AAm in the synthesis of NPs could be a good alternative to reduce costs. By using TGA, TEM, and DSC techniques, it was determined that synthesized NPs with AAm presented a coating with similar characteristics to NPs with PAAm, suggesting that AAm underwent polymerization during the synthesis.
Male Involvement in Family Planning: Challenges and Way Forward
Authors: Adelekan Ademola , Omoregie Philomena , Edoni Elizabeth
Published: May 2014

Public health officials have advocated the involvement of men as a strategy for addressing the dismal performance of family planning (FP) programmes. This study was therefore designed to explore the challenges and determine way forward to male involvement in FP in Olorunda Local Government Area, Osogbo, Nigeria. This cross-sectional study involved the use of a four-stage sampling technique to select 500 married men and interviewed them using semistructured questionnaire. In addition, four focus group discussions (FGDs) were also conducted. Mean age of respondents was 28.5 ± 10.3 years. Some (37.9%) of the respondents’ spouse had ever used FP and out of which 19.0% were currently using FP. Only 4.8% of the respondents had ever been involved in FP. Identified barriers to male involvement included the perception that FP is woman’s activity and was not their custom to participate in FP programme. More than half of the FGD discussants were of the view that men should provide their wives with transport fare and other resources they may need for FP. The majority of the respondents had never been involved in family planning with their wives. Community sensitization programmes aimed at improving male involvement in FP should be provided by government and nongovernmental agencies.
Stability Analysis of a Class of Higher Order Difference Equations
Authors: Liu Yuanyuan , Meng Fanwei
Published: May 2014

We consider the sufficient conditions for asymptotic stability and instability of certain higher order nonlinear difference equations with infinite delays in finite-dimensional spaces. With the aid of the general comparison condition on the right-hand side functionfk(·), we generalize the stability and instability result.
Approximate Quadratic-Additive Mappings in Fuzzy Normed Spaces
Authors: Chang Ick-Soon , Lee Yang-Hi
Published: May 2014

We examine the generalized Hyers-Ulam stability of the following functional equation:2fx+y+z+w+f-x-y+z+w+f-x+y-z+w+f-x+y+z-w+fx-y-z+w+fx-y+z-w+fx+y-z-w-5fx-3f-x-5fy-3f-y-5fz-3f-z-5fw-3f-w=0,in the fuzzy normed spaces with the fixed point method.