bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Study of a Quadrature DCSK Modulation Scheme for Cognitive Radio
Authors: Quyen Nguyen Xuan
Published: September 2017

The past decade has witnessed a boom of wireless communications which necessitate an increasing improvement of data rate, error-rate performance, bandwidth efficiency, and information security. In this work, we propose a quadrature (IQ) differential chaos-shift keying (DCSK) modulation scheme for the application in cognitive radio (CR), named CR-IQ-DCSK, which offers the above improvement. Chaotic signal is generated in frequency domain and then converted into time domain via an inverse Fourier transform. The real and imaginary components of the frequency-based chaotic signal are simultaneously used in in-phase and quadrature branches of an IQ modulator, where each branch conveys two bits by means of a DCSK-based modulation. Schemes and operating principle of the modulator and demodulator are proposed and described. Analytical BER performance for the proposed schemes over a typical multipath Rayleigh fading channel is derived and verified by numerical simulations. Results show that the proposed scheme outperforms DCSK, CDSK and performs better with the increment of the number of channel paths.
Hidden Symmetry in a Kuramoto–Sivashinsky Initial-Boundary Value Problem
Authors: Buono Pietro-Luciano , van Veen Lennaert , Frawley Eryn
Published: September 2017

We investigate the bifurcation structure of the Kuramoto–Sivashinsky equation with homogeneous Dirichlet boundary conditions. Using hidden symmetry principles, based on an extended problem with periodic boundary conditions and [Formula: see text] symmetry, we show that the zero solution exhibits two kinds of pitchfork bifurcations: one that breaks the reflection symmetry of the system with Dirichlet boundary conditions and one that breaks a shift-reflect symmetry of the extended system. Using Lyapunov–Schmidt reduction, we show both to be supercritical. We extend the primary branches by means of numerical continuation, and show that they lose stability in pitchfork, transcritical or Hopf bifurcations. Tracking the corresponding secondary branches reveals an interval of the viscosity parameter in which up to four stable equilibria and time-periodic solutions coexist. Since the study of the extended problem is indispensable for the explanation of the bifurcation structure, the Kuramoto–Sivashinsky problem with Dirichlet boundary conditions provides an elegant manifestation of hidden symmetry.
Noise-Induced Chaos in a Piecewise Linear System
Authors: Kong Chen , Liu Xian-Bin
Published: September 2017

In the present paper, the phenomenon of noise-induced chaos in a piecewise linear system that is excited by Gaussian white noise is investigated. Firstly, the global dynamical behaviors of the deterministic piecewise linear system are investigated numerically in advance by using the generalized cell-mapping digraph (GCMD) method. Then, based on these global properties, the system that is excited by Gaussian white noise is introduced. Then, it is simplified by the stochastic averaging method, through which, a four-dimensional averaged Itô system is finally obtained. In order to reveal the phenomenon of noise-induced chaos quantitatively, MFPT (the mean first-passage time) is selected as the measure. The expression for MFPT is formulated by using the singular perturbation method and then a rather simple representation is obtained via the Laplace approximation, and within which, the concept of quasi-potential is introduced. Furthermore, with the rays method, the MFPT under a certain set of parameters is estimated. However, within the process of analysis, the authors had to face a difficult problem concerning the ill-conditioned matrix, which is the obstacle for the estimation of MFPT, which was then solved by applying one more approximation. Finally, the result is compared with the numerical one that is obtained by the Monte Carlo simulation.
Different Families of Hidden Attractors in a New Chaotic System with Variable Equilibrium
Authors: Pham Viet-Thanh , Jafari Sajad , Volos Christos , Kapitaniak Tomasz
Published: September 2017

A new chaotic system having variable equilibrium is introduced in this paper. The presence of an infinite number of equilibrium points, a stable equilibrium, and no-equilibrium is observed in the system. Interestingly, this system is classified as a rare system with hidden attractors from the view point of computation. Complex dynamical behavior and a circuital implementation of the new system have been investigated in our work.
Topological Entropy and Mixing Invariant Extremal Distributional Chaos
Authors: Wang Lidong , Li Nan , Lei Fengchun , Chu Zhenyan
Published: September 2017

We show that there exists a mixing dynamical system with an invariant, extremal and transitive distributionally scrambled set. Meanwhile, we prove that such a complex dynamical system has zero topological entropy. Finally, we extend the method of constructing the “strong” distributionally scrambled set and show that the new dynamical system has a positive topological entropy.
The Real-Valued Maxwell–Bloch Equations with Controls: From a Hamilton–Poisson System to a Chaotic One
Authors: Lăzureanu Cristian
Published: September 2017

Applying parametric controls to the 3D real-valued Maxwell–Bloch equations, we obtain a Hamilton–Poisson system, a dissipative system with chaotic behavior, and a transitional system between the aforementioned states, which is a conservative system that has only one constant of motion. In the Hamiltonian case, we present some connections of the energy-Casimir mapping with the equilibrium states and the existence of the homoclinic orbits. We study the stability of the equilibrium points of the transitional system and the dissipative system. Furthermore, we point out the chaotic behavior of the introduced system.
KCC Analysis of the Normal Form of Typical Bifurcations in One-Dimensional Dynamical Systems: Geometrical Invariants of Saddle-Node, Transcritical, and Pitchfork Bifurcations
Authors: Yamasaki Kazuhito , Yajima Takahiro
Published: September 2017

The Jacobi stability of the normal form of typical bifurcations in one-dimensional dynamical systems is analyzed by introducing the concept of the production process (time-like potential) to KCC theory. This KCC theory approach shows that the geometric invariants of the system characterize the nonequilibrium dynamics of the bifurcations. For example, the deviation curvature that is one of the geometric invariants shows that the well-known two hysteresis jumps in subcritical pitchfork bifurcations differ qualitatively from each other. In the nonequilibrium region, the deviation curvature in the saddle-node and the transcritical bifurcations are a function of the bifurcation parameter alone; thus, the Jacobi stability does not depend on time. However, the deviation curvature in a pitchfork bifurcation is a function of the time-like potential, so the Jacobi stability does depend on time. This time dependence can be described by the Douglas tensor, which is a useful geometric invariant to consider how the higher-order term in the bifurcation system affects the stability structure.
Constructing Higher-Dimensional Nondegenerate Hyperchaotic Systems with Multiple Controllers
Authors: He Jianbin , Yu Simin , Lü Jinhu
Published: September 2017

This paper proposes a new approach for constructing higher-dimensional nondegenerate hyperchaotic system with multiple controllers. Here, the so-called higher-dimensional nondegenerate hyperchaotic system means that it can be provided with a maximum number of positive Lyapunov exponents, which has been an open problem for research in recent years. The details of design are given by three steps as follows: (i) Design an [Formula: see text]-dimensional nominal matrix and similarity transformation matrix, and get an asymptotic stable nominal system; (ii) Add a master controller for the nominal matrix and get the controlled system. Then, find suitable control positions such that the controlled system satisfies the average eigenvalue criterion, i.e. the number of average eigenvalues with positive real parts of all Jacobi matrices over a given period of time is equal to ([Formula: see text]), and the maximum value of average eigenvalues with positive real parts is greater than a given threshold [Formula: see text]; (iii) Add nonmaster controllers, and the control positions are fixed and parameters are given in advance. So it can generate nondegenerate hyperchaotic systems with ([Formula: see text]) positive Lyapunov exponents. Finally, two typical examples are given to show the feasibility and effectiveness of the proposed method.
The Trade-Off Mechanism in Mammalian Circadian Clock Model with Two Time Delays
Authors: Yan Jie , Kang Xiaxia , Yang Ling
Published: September 2017

Circadian clock is an autonomous oscillator which orchestrates the daily rhythms of physiology and behaviors. This study is devoted to explore how a positive feedback loop affects the dynamics of mammalian circadian clock. We simplify an experimentally validated mathematical model in our previous work, to a nonlinear differential equation with two time delays. This simplified mathematical model incorporates the pacemaker of mammalian circadian clock, a negative primary feedback loop, and a critical positive auxiliary feedback loop, [Formula: see text] loop. We perform analytical studies of the system. Delay-dependent conditions for the asymptotic stability of the nontrivial positive steady state of the model are investigated. We also prove the existence of Hopf bifurcation, which leads to self-sustained oscillation of mammalian circadian clock. Our theoretical analyses show that the oscillatory regime is reduced upon the participation of the delayed positive auxiliary loop. However, further simulations reveal that the auxiliary loop can enable the circadian clock gain widely adjustable amplitudes and robust period. Thus, the positive auxiliary feedback loop may provide a trade-off mechanism, to use the small loss in the robustness of oscillation in exchange for adaptable flexibility in mammalian circadian clock. The results obtained from the model may gain new insights into the dynamics of biological oscillators with interlocked feedback loops.
A window into the Cambrian basement and early Carboniferous sedimentation of the Hathern Shelf: the British Geological Survey borehole at Ticknall, South Derbyshire, UK
Authors: Carney John N. , Ambrose Keith
Published: September 2017

The Ticknall Borehole was drilled in 1995 to a depth of 209 m in order to investigate the succession on the Hathern Shelf, a fault-bounded structural province that lies on the southern margin of the Widmerpool Half-graben, part of a major early Carboniferous rift system. The borehole demonstrated a ‘basement’ of Upper Cambrian cleaved mudrocks, correlated with the Stockingford Shale Group. Unconformably overlying this is a basal Carboniferous unit, the Calke Abbey Sandstone Formation, of probable Visean (?Holkerian) age, comprising 82.34 m of fluvial sandstones and conglomerates, with interbedded red-grey palaeosols exhibiting highly distinctive ‘pseudogley’ fabrics indicative of emergent episodes. The unit may have been deposited in a localized, possibly fault-controlled basin and was in part sourced from the Precambrian volcanic terrain of Charnwood Forest. As rifting and subsidence proceeded, the encroachment of nearshore/peritidal environments is indicated at the top of the formation by interbedded calcilutites that have yielded marine faunas. Fully marine conditions were established during deposition of the overlying Peak Limestone Group, comprising the early Asbian Cloud Hill Dolostone Formation succeeded by the Ticknall Limestone Formation, of Brigantian age. Comparisons between the Ticknall Borehole and Peak Limestone strata exposed in quarries farther east, around Breedon, show major changes in water depths over a distance of only 4.5 km. Such variations can be reconciled with seismostratigraphical studies in the adjacent Widmerpool Half-graben, which show that sedimentation on the Hathern Shelf was in part controlled by movements along nearby rift-bounding faults.
Molecular Evolution of Antifungal Drug Resistance
Authors: Robbins Nicole , Caplan Tavia , Cowen Leah E.
Published: September 2017

The fungal pathogens Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus have transitioned from a rare curiosity to a leading cause of human mortality. The management of infections caused by these organisms is intimately dependent on the efficacy of antifungal agents; however, fungi that are resistant to these treatments are regularly isolated in the clinic, impeding our ability to control infections. Given the significant impact fungal pathogens have on human health, it is imperative to understand the molecular mechanisms that govern antifungal drug resistance. This review describes our current knowledge of the mechanisms by which antifungal drug resistance evolves in experimental populations and clinical settings. We explore current antifungal treatment options and discuss promising strategies to impede the evolution of drug resistance. By tackling antifungal drug resistance as an evolutionary problem, there is potential to improve the utility of current treatments and accelerate the development of novel therapeutic strategies.
A Life inBacillus subtilisSignal Transduction
Authors: Hoch James A.
Published: September 2017

This is a tale of how technology drove the discovery of the molecular basis for signal transduction in the initiation of sporulation in Bacillus subtilis and in bacterial two-component systems. It progresses from genetics to cloning and sequencing to biochemistry to structural biology to an understanding of how proteins evolve interaction specificity and to identification of interaction surfaces by statistical physics. This is about how the people in my laboratory accomplished this feat; without them little would have been done.
Copper Acquisition and Utilization in Fungi
Authors: Smith Aaron D. , Logeman Brandon L. , Thiele Dennis J.
Published: September 2017

Fungal cells colonize and proliferate in distinct niches, from soil and plants to diverse tissues in human hosts. Consequently, fungi are challenged with the goal of obtaining nutrients while simultaneously elaborating robust regulatory mechanisms to cope with a range of availability of nutrients, from scarcity to excess. Copper is essential for life but also potentially toxic. In this review we describe the sophisticated homeostatic mechanisms by which fungi acquire, utilize, and control this biochemically versatile trace element. Fungal pathogens, which can occupy distinct host tissues that have their own intrinsic requirements for copper homeostasis, have evolved mechanisms to acquire copper to successfully colonize the host, disseminate to other tissues, and combat host copper bombardment mechanisms that would otherwise mitigate virulence.
Microbial Expansins
Authors: Cosgrove Daniel J.
Published: September 2017

Expansins are small proteins that loosen plant cell walls and cellulosic materials without lytic activity. First discovered in plants, expansin genes are found in the genomes of numerous bacteria and fungi that interact with plants in pathogenic and mutualistic patterns, as well as in microbes that feed on plant debris. Horizontal gene transfer from plants to microbes and between microbes accounts for expansins’ irregular taxonomic distribution. Expansins facilitate plant colonization by Bacillus, Clavibacter, and Trichoderma species, a list likely to grow as knowledge of microbial expansin function deepens. Studies have documented a synergistic action of expansins for cellulose digestion by cellulases, but only rarely to an extent that is commercially relevant. Expansins’ biophysical actions remain enigmatic because of limited understanding of cell wall structure. Deeper understanding of microbial expansins may lead to novel approaches for biomass deconstruction and biocontrol of plant diseases.
“Fleaing” the Plague: Adaptations of Yersinia pestis to Its Insect Vector That Lead to Transmission
Authors: Hinnebusch B. Joseph , Jarrett Clayton O. , Bland David M.
Published: September 2017

Interest in arthropod-borne pathogens focuses primarily on how they cause disease in humans. How they produce a transmissible infection in their arthropod host is just as critical to their life cycle, however. Yersinia pestis adopts a unique life stage in the digestive tract of its flea vector, characterized by rapid formation of a bacterial biofilm that is enveloped in a complex extracellular polymeric substance. Localization and adherence of the biofilm to the flea foregut is essential for transmission. Here, we review the molecular and genetic mechanisms of these processes and present a comparative evaluation and updated model of two related transmission mechanisms.
Predator Versus Pathogen: How Does Predatory Bdellovibrio bacteriovorus Interface with the Challenges of Killing Gram-Negative Pathogens in a Host Setting?
Authors: Negus David , Moore Chris , Baker Michelle , Raghunathan Dhaarini , Tyson Jess , Sockett R. Elizabeth
Published: September 2017

Bdellovibrio bacteriovorus is a small deltaproteobacterial predator that has evolved to invade, reseal, kill, and digest other gram-negative bacteria in soils and water environments. It has a broad host range and kills many antibiotic-resistant, clinical pathogens in vitro, a potentially useful capability if it could be translated to a clinical setting. We review relevant mechanisms of B. bacteriovorus predation and the physiological properties that would influence its survival in a mammalian host. Bacterial pathogens increasingly display conventional antibiotic resistance by expressing and varying surface and soluble biomolecules. Predators coevolved alongside prey bacteria and so encode diverse predatory enzymes that are hard for pathogens to resist by simple mutation. Predators do not replicate outside pathogens and thus express few transport proteins and thus few surface epitopes for host immune recognition. We explain these features, relating them to the potential of predatory bacteria as cellular medicines.
Elongation Factor P and the Control of Translation Elongation
Authors: Rajkovic Andrei , Ibba Michael
Published: September 2017

Elongation factor P (EF-P) binds to ribosomes requiring assistance with the formation of oligo-prolines. In order for EF-P to associate with paused ribosomes, certain tRNAs with specific d-arm residues must be present in the peptidyl site, e.g., tRNAPro. Once EF-P is accommodated into the ribosome and bound to Pro-tRNAPro, productive synthesis of the peptide bond occurs. The underlying mechanism by which EF-P facilitates this reaction seems to have entropic origins. Maximal activity of EF-P requires a posttranslational modification in Escherichia coli, Pseudomonas aeruginosa, and Bacillus subtilis. Each of these modifications is distinct and ligated onto its respective EF-P through entirely convergent means. Here we review the facets of translation elongation that are controlled by EF-P, with a particular focus on the purpose behind the many different modifications of EF-P.
Outer Membrane Biogenesis
Authors: Konovalova Anna , Kahne Daniel E. , Silhavy Thomas J.
Published: September 2017

The hallmark of gram-negative bacteria and organelles such as mitochondria and chloroplasts is the presence of an outer membrane. In bacteria such as Escherichia coli, the outer membrane is a unique asymmetric lipid bilayer with lipopolysaccharide in the outer leaflet. Integral transmembrane proteins assume a β-barrel structure, and their assembly is catalyzed by the heteropentameric Bam complex containing the outer membrane protein BamA and four lipoproteins, BamB–E. How the Bam complex assembles a great diversity of outer membrane proteins into a membrane without an obvious energy source is a particularly challenging problem, because folding intermediates are predicted to be unstable in either an aqueous or a hydrophobic environment. Two models have been put forward: the budding model, based largely on structural data, and the BamA assisted model, based on genetic and biochemical studies. Here we offer a critical discussion of the pros and cons of each.
Rapid estrogen receptor-α signaling mediated by ERK activation regulates vascular tone in male and ovary-intact female mice
Authors: Kim Seong Chul , Boese Austin C. , Moore Matthew H. , Cleland Rea M. , Chang Lin , Delafontaine Patrice , Yin Ke-Jie , Lee Jean-Pyo , Hamblin Milton H.
Published: September 2017

Estrogen has been shown to affect vascular reactivity. Here, we assessed the estrogen receptor-α (ERα) dependency of estrogenic effects on vasorelaxation via a rapid nongenomic pathway in both male and ovary-intact female mice. We compared the effect of a primary estrogen, 17β-estradiol (E2) or 4,4′,4″-(4-propyl-[1H]pyrazole-1,3,5-triyl)tris-phenol (PPT; selective ERα agonist). We found that E2and PPT induced greater aortic relaxation in female mice than in male mice, indicating ERα mediation, which was further validated by using ERα antagonism. Treatment with 1,3-bis(4-hydroxyphenyl)-4-methyl-5-[4-(2-piperidinylethoxy)phenol]-1H-pyrazole dihydrochloride (MPP dihydrochloride; ERα antagonist) attenuated PPT-mediated vessel relaxation in both sexes. ERα-mediated vessel relaxation was further validated by the absence of significant PPT-mediated relaxation in aortas isolated from ERα knockout mice. Treatment with a specific ERK inhibitor, PD-98059, reduced E2-induced vessel relaxation in both sexes but to a lesser extent in female mice. Furthermore, PD-98059 prevented PPT-induced vessel relaxation in both sexes. Both E2and PPT treatment activated ERK as early as 5–10 min, which was attenuated by PD-98059 in aortic tissue, cultured primary vascular smooth muscle cells (VSMCs), and endothelial cells (ECs). Aortic rings denuded of endothelium showed no differences in vessel relaxation after E2or PPT treatment, implicating a role of ECs in the observed sex differences. Here, our results are unique to show estrogen-stimulated rapid ERα signaling mediated by ERK activation in aortic tissue, as well as VSMCs and ECs in vitro, in regulating vascular function by using side-by-side comparisons in male and ovary-intact female mice in response to E2or PPT.

NEW & NOTEWORTHY Here, we assessed the estrogen receptor-α dependency of estrogenic effects in vasorelaxation of both male and ovary-intact female mice by performing side-by-side comparisons. Also, we describe the connection between estrogen-stimulated rapid estrogen receptor-α signaling and downstream ERK activation in regulating vascular function in male and ovary-intact female mice.
Segment-specific responses of intestinal epithelium transcriptome to in-feed antibiotics in pigs
Authors: Yu Kaifan , Mu Chunlong , Yang Yuxiang , Su Yong , Zhu Weiyun
Published: September 2017

Despite widespread use of antibiotics for treatment of human diseases and promotion of growth of agricultural animals, our understanding of their effects on the host is still very limited. We used a model in which pigs were fed with or without a cocktail of antibiotics and found, based on the denaturing gradient gel electrophoresis (DGGE) patterns, that the fecal bacteria from the treatment and control animals were distinct. Furthermore, the total bacterial population in the feces tended to be decreased by the antibiotic treatment ( P = 0.07), and the counts of Lactobacillus and Clostridium XIVa were significantly reduced ( P < 0.05). To explore the effects of antibiotics on host intestinal epithelium, we assessed gene expression profiles of the jejunum and ileum and their response to antibiotic administration. The results indicate that in-feed antibiotics increased expression of genes involved in immune functions in both the jejunum and ileum, some of which were clustered in the coexpression network. Gene ontology terms of metabolic processes were altered predominantly in the jejunum but not in the ileum. Notably, antibiotics diminished intestinal segment-specific transcriptional changes, especially for genes associated with metabolic functions. This study reveals segment-specific responses of host intestinal epithelium to in-feed antibiotics, which can be a valuable resource for deciphering antibiotic-microbiota-host interactions.
Robust Centered Element Concentric Circular Antenna Array with Low Side Lobe Using Variable Loading and Tapering Windows in the Presence of Array Imperfections
Authors: Reza M. F. , Hossain M. S. , Rashid M. M.
Published: September 2017

This paper presents centered element concentric circular antenna array (CECCAA) using variable diagonal loading (VDL) technique and different filtering windows. The different filtering windows are modified to apply in the CECCAA system. The modified novel technique not only is able to reduce the side lobe level (SLL) but also has the ability to detect and highly attenuate the directional interferences. However, the performance of CECCAA system is degraded in the presence of array imperfections. This performance degradation problem due to array imperfections can be improved by using robust techniques. The proposed technique is also robust against array imperfections and improves the performance. Moreover, the performance of the proposed structure is better than a concentric circular antenna array (CCAA). Several examples are presented to analyze the performance of proposed beamformer by using different tapering windows.
Diabetes‐Related Induction of the Heme Oxygenase System and Enhanced Colocalization of Heme Oxygenase 1 and 2 with Neuronal Nitric Oxide Synthase in Myenteric Neurons of Different Intestinal Segments
Authors: Chandrakumar Lalitha , Bagyánszki Mária , Szalai Zita , Mezei Diána , Bódi Nikolett
Published: September 2017

Increase in hyperglycaemia‐induced oxidative stress and decreased effectiveness of endogenous defense mechanisms plays an essential role in the initiation of diabetes‐related neuropathy. We demonstrated that nitrergic myenteric neurons display different susceptibilities to diabetic damage in different gut segments. Therefore, we aim to reveal the gut segment‐specific differences in the expression of heme oxygenase (HO) isoforms and the colocalization of these antioxidants with neuronal nitric oxide synthase (nNOS) in myenteric neurons. After ten weeks, samples from the duodenum, ileum, and colon of control and streptozotocin‐induced diabetic rats were processed for double‐labelling fluorescent immunohistochemistry and ELISA. The number of both HO‐immunoreactive and nNOS/HO‐immunoreactive myenteric neurons was the lowest in the ileal and the highest in the colonic ganglia of controls; it increased the most extensively in the ileum and was also elevated in the colon of diabetics. Although the total number of nitrergic neurons decreased in all segments, the proportion of nNOS‐immunoreactive neurons colocalizing with HOs was enhanced robustly in the ileum and colon of diabetics. We presume that those nitrergic neurons which do not colocalize with HOs are the most seriously affected by diabetic damage. Therefore, the regional induction of the HO system is strongly correlated with diabetes‐related region‐specific nitrergic neuropathy.
Hepatocyte CYP2B6 Can Be Expressed in Cell Culture Systems by Exerting Physiological Levels of Shear: Implications for ADME Testing
Authors: Hammond Timothy G. , Birdsall Holly H.
Published: September 2017

Cytochrome 2B6 (CYP2B6) has substantial clinical effects on morbidity and mortality and its effects on drug metabolism should be part of hepatotoxicity screening. Examples of CYP2B6’s impacts include its linkage to mortality during cyclophosphamide therapy and its role in determining hepatotoxicity and CNS toxicity during efavirenz therapy for HIV infection. CYP2B6 is key to metabolism of many common drugs from opioids to antidepressants, anesthetics, and anticonvulsants. But CYP2B6 has been extremely difficult to express in cell culture, and as a result, it has been largely deemphasized in preclinical toxicity studies. It has now been shown that CYP2B6 expression can be supported for extended periods of time using suspension culture techniques that exert physiological levels of shear. New understanding of CYP2B6 has identified five clinically significant genetic polymorphisms that have a high incidence in many populations and that convey a substantial dynamic range of activity. We propose that, with the use of culture devices exerting physiological shear levels, CYP2B6 dependent drug testing, including definition of polymorphisms and application of specific inhibitors, should be a standard part of preclinical absorption, distribution, metabolism, and excretion (ADME) testing.
Automatic Segmentation of Ultrasound Tomography Image
Authors: Wu Shibin , Yu Shaode , Zhuang Ling , Wei Xinhua , Sak Mark , Duric Neb , Hu Jiani , Xie Yaoqin
Published: September 2017

Ultrasound tomography (UST) image segmentation is fundamental in breast density estimation, medicine response analysis, and anatomical change quantification. Existing methods are time consuming and require massive manual interaction. To address these issues, an automatic algorithm based on GrabCut (AUGC) is proposed in this paper. The presented method designs automated GrabCut initialization for incomplete labeling and is sped up with multicore parallel programming. To verify performance, AUGC is applied to segment thirty-two in vivo UST volumetric images. The performance of AUGC is validated with breast overlapping metrics (Dice coefficient (D), Jaccard (J), and False positive (FP)) and time cost (TC). Furthermore, AUGC is compared to other methods, including Confidence Connected Region Growing (CCRG), watershed, and Active Contour based Curve Delineation (ACCD). Experimental results indicate that AUGC achieves the highest accuracy (D=0.9275 and J=0.8660 and FP=0.0077) and takes on average about 4 seconds to process a volumetric image. It was said that AUGC benefits large-scale studies by using UST images for breast cancer screening and pathological quantification.
Modelling and Optimal Control of Typhoid Fever Disease with Cost-Effective Strategies
Authors: Tilahun Getachew Teshome , Makinde Oluwole Daniel , Malonza David
Published: September 2017

We propose and analyze a compartmental nonlinear deterministic mathematical model for the typhoid fever outbreak and optimal control strategies in a community with varying population. The model is studied qualitatively using stability theory of differential equations and the basic reproductive number that represents the epidemic indicator is obtained from the largest eigenvalue of the next-generation matrix. Both local and global asymptotic stability conditions for disease-free and endemic equilibria are determined. The model exhibits a forward transcritical bifurcation and the sensitivity analysis is performed. The optimal control problem is designed by applying Pontryagin maximum principle with three control strategies, namely, the prevention strategy through sanitation, proper hygiene, and vaccination; the treatment strategy through application of appropriate medicine; and the screening of the carriers. The cost functional accounts for the cost involved in prevention, screening, and treatment together with the total number of the infected persons averted. Numerical results for the typhoid outbreak dynamics and its optimal control revealed that a combination of prevention and treatment is the best cost-effective strategy to eradicate the disease.
Expectant Management Leading to Successful Vaginal Delivery following Intrauterine Fetal Death in a Woman with an Incarcerated Uterus
Authors: Yamamoto Masafumi , Takami Mio , Shindo Ryosuke , Kasai Michi , Aoki Shigeru
Published: September 2017

Expectant management leads to successful vaginal delivery following intrauterine fetal death in a woman with an incarcerated uterus. Management of intrauterine fetal death in the second or third trimester of pregnancy in women with an incarcerated uterus is challenging. We report a case of successful vaginal delivery following intrauterine fetal death by expectant management in a woman with an incarcerated uterus. In cases of intrauterine fetal death in women with an incarcerated uterus, vaginal delivery may be possible if the incarceration is successfully reduced. If the reduction is impossible, expectant management can reduce uterine retroversion, thereby leading to spontaneous reduction of the incarcerated uterus. Thereafter, vaginal delivery may be possible.
Amyotrophic Lateral Sclerosis, a Multisystem Pathology: Insights into the Role of TNFα
Authors: Tortarolo Massimo , Lo Coco Daniele , Veglianese Pietro , Vallarola Antonio , Giordana Maria Teresa , Marcon Gabriella , Beghi Ettore , Poloni Marco , Strong Michael J. , Iyer Anand M. , Aronica Eleonora , Bendotti Caterina
Published: September 2017

Amyotrophic lateral sclerosis (ALS) is considered a multifactorial, multisystem disease in which inflammation and the immune system play important roles in development and progression. The pleiotropic cytokine TNFαis one of the major players governing the inflammation in the central nervous system and peripheral districts such as the neuromuscular and immune system. Changes in TNFαlevels are reported in blood, cerebrospinal fluid, and nerve tissues of ALS patients and animal models. However, whether they play a detrimental or protective role on the disease progression is still not clear. Our group and others have recently reported opposite involvements of TNFR1 and TNFR2 in motor neuron death. TNFR2 mediates TNFαtoxic effects on these neurons presumably through the activation of MAP kinase-related pathways. On the other hand, TNFR2 regulates the function and proliferation of regulatory T cells (Treg) whose expression is inversely correlated with the disease progression rate in ALS patients. In addition, TNFαis considered a procachectic factor with a direct catabolic effect on skeletal muscles, causing wasting. We review and discuss the role of TNFαin ALS in the light of its multisystem nature.
Well-Dispersed Nanoscale Zero-Valent Iron Supported in Macroporous Silica Foams: Synthesis, Characterization, and Performance in Cr(VI) Removal
Authors: Zhao Chaoxia , Yang Jie , Wang Yihan , Jiang Bo
Published: September 2017

Well-dispersed nanoscale zero-valent iron (NZVI) supported inside the pores of macroporous silica foams (MOSF) composites (Mx-NZVI) has been prepared as the Cr(VI) adsorbent by simply impregnating the MOSF matrix with ferric chloride, followed by the chemical reduction with NaHB4 in aqueous solution at ambient atmosphere. Through the support of MOSF, the reactivity and stability of NZVI are greatly improved. Transmission electron microscopy (TEM) results show that NZVI particles are spatially well-dispersed with a typical core-shell structure and supported inside MOSF matrix. The N2 adsorption-desorption isotherms demonstrate that the Mx-NZVI composites can maintain the macroporous structure of MOSF and exhibit a considerable high surface area (503 m2·g−1). X-ray photoelectron spectroscopy (XPS) and powder X-ray diffraction (XRD) measurements confirm the core-shell structure of iron nanoparticles composed of a metallic Fe0 core and an Fe(II)/Fe(III) species shell. Batch experiments reveal that the removal efficiency of Cr(VI) can reach 100% when the solution contains 15.0 mg·L−1 of Cr(VI) at room temperature. In addition, the solution pH and the composites dosage can affect the removal efficiency of Cr(VI). The Langmuir isotherm is applicable to describe the removal process. The kinetic studies demonstrate that the removal of Cr(VI) is consistent with pseudo-second-order kinetic model.
Evaluating Mechanical Properties of Few Layers MoS2 Nanosheets-Polymer Composites
Authors: Khan Muhammad Bilal , Jan Rahim , Habib Amir , Khan Ahmad Nawaz
Published: September 2017

The reinforcement effects of liquid exfoliated molybdenum disulphide (MoS2) nanosheets, dispersed in polystyrene (PS) matrix, are evaluated here. The range of composites (0~0.002 volume fraction (Vf) MoS2-PS) is prepared via solution casting. Size selected MoS2 nanosheets (3~4 layers), with a lateral dimension L 0.5~1 µm, have improved Young’s modulus up to 0.8 GPa for 0.0002 Vf MoS2-PS as compared to 0.2 GPa observed for PS only. The ultimate tensile strength (UTS) is improved considerably (~×3) with a minute addition of MoS2 nanosheets (0.00002 Vf). The MoS2 nanosheets lateral dimension and number of layers are approximated using atomic force microscopy (AFM). The composites formation is confirmed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Theoretical predicted results (Halpin-Tsai model) are well below the experimental findings, especially at lower concentrations. Only at maximum concentrations, the experimental and theoretical results coincide. The high aspect ratio of MoS2 nanosheets, homogeneous dispersion inside polymer, and their probable planar orientation are the possible reasons for the effective stress transfer, resulting in enhanced mechanical characteristics. Moreover, the micro-Vickers hardness (HV) of the MoS2-PS is also improved from 19 (PS) to 23 (0.002 Vf MoS2-PS) as MoS2 nanosheets inclusion may hinder the deformation more effectively.
Trichloroacetic Acid Ingestion: Self-Harm Attempt
Authors: Black E. R.
Published: September 2017

Objective. Trichloroacetic acid (TCAA), or trichloroethanoic acid, is a chemical analogue of acetic acid where three methyl group hydrogen atoms are replaced by chlorine. TCAAs are also abbreviated and referred to as TCAs, causing confusion with the psychiatric antidepressant drug class, especially among patients. TCAAs exist in dermatological treatments such as chemical peels or wart chemoablation medication. TCAA ingestion or overdose can cause gastric irritation symptoms including vomiting, diarrhea, or lassitude. This symptomatology is less severe than TCA overdose, where symptoms may include elevated body temperature, blurred vision, dilated pupils, sleepiness, confusion, seizures, rapid heart rate, and cardiac arrest. Owing to the vast difference in symptoms, the need for clinical intervention differs greatly. While overdose of either in a self-harm attempt can warrant psychiatric hospital admission, the risk of death in TCAA ingestion is far less. Case Report. A patient ingested TCAA in the form of a commercially available dermatological chemical peel as a self-harm attempt, thinking that it was a more injurious TCA. Conclusion. Awareness among physicians, particularly psychiatrists, regarding this relatively obscure chemical compound (TCAA) and its use by suicidal patients mistakenly believing it to be a substance that can be significantly more lethal (TCA), is imperative.
Mammary and Extramammary Paget’s Disease Presented Different Expression Pattern of Steroid Hormone Receptors
Authors: Zhou Songxia , Zhong Weixiang , Mai Ruiqin , Zhang Guohong
Published: September 2017

Background and Objectives. Paget’s disease (PD) is a rare intraepithelial adenocarcinoma, which is composed of mammary (MPD) and extramammary Paget’s disease (EMPD). Currently, the published literature contains scant data on expression pattern of steroid hormone receptors in MPD and EMPD. Methods. Expression of estrogen receptor (ER) and androgen receptor (AR) was evaluated in 88 MPD and 72 EMPD by using immunohistochemical staining and H-score method. Results. Positive expression of AR was significantly higher in EMPD (61.11%, 44/72) than in MPD (32.95%, 29/88) (P<0.001), while ER expression was positive 19.44% (14/72) in EMPD and only 9.09% (8/88) in MPD (P=0.059). ER-AR expression pattern was significantly different between MPD (3.41%, 3/88) and EMPD (16.67%, 12/72) (P<0.001). No difference of AR (P=0.301) or ER (P=0.239) expression was identified between invasive (48.57%, 51/105 of AR, and 11.43%, 12/105 of ER) and noninvasive PD. In MPD, no difference of AR expression between MPD alone (7/18, 38.89%) and MPD with underling ductal carcinoma of breast (22/70, 31.43%) was identified (P=0.548). In EMPD, expression of AR was 63.33% (38/60) in penoscrotal EMPD. Conclusion. Our current results indicate that MPD and EMPD presented different expression pattern of AR and ER and would help to further identify the molecular subtype of MPD and EMPD for adjuvant hormonal therapy, especially for patients with penoscrotal EMPD.
An ARM-Compliant Architecture for User Privacy in Smart Cities: SMARTIE—Quality by Design in the IoT
Authors: Beltran V. , Skarmeta A. F. , Ruiz P. M.
Published: September 2017

Much has been said about the benefits that the Internet of Things (IoT) will bring to citizens’ life. Countless smart objects will be soon offering autonomous behavior in smart environments by sensing the physical world around us, collecting information about us, and taking proactive actions (many times without our consent) with the ultimate goal of improving our wellness. Without a strong guarantee on user privacy, the IoT may sound scary for many citizens. Indeed, the IoT-Architecture Reference Model (IoT-ARM) is a European effort for promoting IoT quality aspects such as security and privacy. This paper paves the way to the adoption of reference architectures by describing the application of the IoT-ARM within a European-funded project, SMARTIE. The SMARTIE architecture has been designed to empower citizens to take control of their IoT devices and privacy, while guaranteeing scalability for large deployments in smart cities.
Accommodative Stimulus-Response Curve with Emoji Symbols
Authors: Montés-Micó Robert , Esteve Taboada José J. , Bernal-Molina Paula , Ferrer-Blasco Teresa
Published: September 2017

Purpose. To evaluate the static measurement of the accommodative stimulus-response curve with emoji symbols. Methods. The accommodative stimulus-response curve was measured in 18 subjects using a Hartmann-Shack sensor to obtain the objective accommodative response from the Zernike defocus term. Measurements were acquired at different accommodative demands, from 0 to 3 D with a step of 0.5 D. Detailed and nondetailed emoji targets were used with two different sizes, corresponding to the two most common visual angles used in smartphones. Results. A regression analysis was performed to fit the mean results obtained for each target. The determination coefficient was R2≥0.988 for all targets. For the detailed targets, the slopes for the averaged stimulus-response curve were 0.65 and 0.66 for the bigger and smaller sizes, respectively. For the nondetailed targets, the slopes were 0.60 and 0.58 for the bigger and smaller sizes, respectively. p values for these slopes were statistically significant for the two types of targets (p<0.01). Conclusions. Our results reveal that the replacement of a word or several words by detailed or nondetailed emoji symbols seems not to provoke a different accommodative response in normal subjects and under standard viewing conditions in the use of smartphones.
Maternal Nutritional Deficiencies and Small-for-Gestational-Age Neonates at Birth of Women Who Have Undergone Bariatric Surgery
Authors: Hazart J. , Le Guennec D. , Accoceberry M. , Lemery D. , Mulliez A. , Farigon N. , Lahaye C. , Miolanne-Debouit M. , Boirie Y.
Published: September 2017

The aim is to compare the prevalence of maternal deficiencies in micronutrients, the obstetrical and neonatal complications after bariatric surgery according to surgical techniques, the time between surgery and conception, and BMI at the onset of pregnancy. A retrospective cohort study concerned 57 singleton pregnancies between 2011 and 2016 of 48 adult women who have undergone bariatric surgery. Small-for-gestational-age neonates were identified in 36.0% of pregnancies. With supplements intake (periconceptional period: 56.8%, trimester 1 (T1): 77.8%, T2: 96.3%, and T3: 100.0%), nutritional deficiencies involved vitamins A (T1: 36.4%, T2: 21.1%, and T3: 40.0%), D (T1: 33.3%, T2: 26.3%, and T3: 8.3%), C (T1: 66.7%, T2: 41.2%, and T3: 83.3%), B1 (T1: 45.5%, T2: 15.4%, and T3: 20.0%), and B9 (T1: 14.3%, T2: 0%, and T3: 9.1%) and selenium (T1: 77.8%, T2: 22.2%, and T3: 50.0%). There was no significant difference in the prevalence of nutritional deficiencies and complications according to surgery procedures and in the prevalence of pregnancy issues according to BMI at the beginning of the pregnancy and time between surgery and pregnancy. Prevalence of micronutritional deficiencies and small-for-gestational-age neonates is high in pregnant women following bariatric surgery. Specific nutritional programmes should be recommended for these women.
Pharmacological Basis for Use of Armillaria mellea Polysaccharides in Alzheimer’s Disease: Antiapoptosis and Antioxidation
Authors: An Shengshu , Lu Wenqian , Zhang Yongfeng , Yuan Qingxia , Wang Di
Published: September 2017

Armillaria mellea, an edible fungus, exhibits various pharmacological activities, including antioxidant and antiapoptotic properties. However, the effects of A. mellea on Alzheimer’s disease (AD) have not been systemically reported. The present study aimed to explore the protective effects of mycelium polysaccharides (AMPS) obtained from A. mellea, especially AMPSc via 70% ethanol precipitation in a L‐glutamic acid‐ (L‐Glu‐) induced HT22 cell apoptosis model and an AlCl3 plus D‐galactose‐ (D‐gal‐) induced AD mouse model. AMPSc significantly enhanced cell viability, suppressed nuclear apoptosis, inhibited intracellular reactive oxygen species accumulation, prevented caspase‐3 activation, and restored mitochondrial membrane potential (MMP). In AD mice, AMPSc enhanced horizontal movements in an autonomic activity test, improved endurance times in a rotarod test, and decreased escape latency time in a water maze test. Furthermore, AMPSc reduced the apoptosis rate, amyloid beta (Aβ) deposition, oxidative damage, and p‐Tau aggregations in the AD mouse hippocampus. The central cholinergic system functions in AD mice improved after a 4‐week course of AMPSc administration, as indicated by enhanced acetylcholine (Ach) and choline acetyltransferase (ChAT) concentrations, and reduced acetylcholine esterase (AchE) levels in serum and hypothalamus. Our findings provide experimental evidence suggesting A. mellea as a neuroprotective candidate for treating or preventing neurodegenerative diseases.
CO Gas-Induced Resonance Frequency Shift of ZnO-Functionalized Microcantilever in Humid Air
Authors: Aprilia Lia , Nuryadi Ratno , Gustiono Dwi , Nurmahmudi  , Udhiarto Arief , Hartanto Djoko , Yuliarto Brian , Hosoda Makoto , Neo Yoichiro , Mimura Hidenori
Published: September 2017

Resonance frequency shift of a zinc oxide- (ZnO-) functionalized microcantilever as a response to carbon monoxide (CO) gas has been investigated. Here, ZnO microrods were grown on the microcantilever surface by a hydrothermal method. The measurement of resonance frequency of the microcantilever vibrations due to the gas was carried out in two conditions, that is, gas flow with and without air pumping into an experiment chamber. The results show that the resonance frequency of the ZnO-functionalized microcantilever decreases because of CO in air pumping condition, while it increases when CO is introduced without air pumping. Such change in the resonance frequency is influenced by water vapor condition, and a possible model based on water-CO combination was proposed.