bluuebunny/crossref_metadata_2025 huggingface dataset:
STEADY-STATE, HOPF AND STEADY-STATE-HOPF BIFURCATIONS IN DELAY DIFFERENTIAL EQUATIONS WITH APPLICATIONS TO A DAMPED HARMONIC OSCILLATOR WITH DELAY FEEDBACK
Authors: SONG YONGLI , JIANG JIAO
Published: January 2013

In this paper, employing the normal form theory of delay differential equations due to Faria and Magalhães, we present explicit formulas of the coefficients of a normal form associated with the flow on a center manifold with the unfolding for general delay differential equations under the cases of steady-state, Hopf and steady-state-Hopf singularities. The explicit conditions determining the transcritical and pitchfork bifurcations for steady-state singularity, determining the direction and stability of Hopf bifurcations, and determining the coefficients of a normal form with universal unfolding for steady-state-Hopf singularity up to third order are obtained. Using the obtained results, we give a complete description of bifurcation scenario of the damped harmonic oscillator with delay feedback near the zero equilibrium. Finally, numerical simulations are given to illustrate our theoretical results and some numerical extensions are obtained as a supplement to our theoretical analysis.
LOCAL BIFURCATIONS OF A QUASIPERIODIC ORBIT
Authors: BANERJEE SOUMITRO , GIAOURIS DAMIAN , MISSAILIDIS PETROS , IMRAYED OTMAN
Published: January 2013

We consider the local bifurcations that can occur in a quasiperiodic orbit in a three-dimensional map: (a) a torus doubling resulting in two disjoint loops, (b) a torus doubling resulting in a single closed curve with two loops, (c) the appearance of a third frequency, and (d) the birth of a stable torus and an unstable torus. We analyze these bifurcations in terms of the stability of the point at which the closed invariant curve intersects a "second Poincaré section". We show that these bifurcations can be classified depending on where the eigenvalues of this fixed point cross the unit circle.
ON THE PERFORMANCE OF LINEAR ADAPTIVE FILTERS DRIVEN BY THE ERGODIC CHAOTIC LOGISTIC MAP
Authors: MÜLLER ANDREAS
Published: January 2013

Chaotic dynamical systems are increasingly considered for use in coding and transmission systems. This stems from their parameter sensitivity and spectral characteristics. The latter are relevant for channel estimation methods. In particular, the logistic map fλ = λx(1 - x) has been employed in chaotic coding and spread spectrum transmission systems. For λ = 4, the statistical properties of sequences generated by f4 are considered as ideal drive signals for channel estimation schemes. This assumption is proven in the present paper. To this end, the higher order statistical moments and the autocorrelation of time series generated by f4 are derived. It is shown that for λ = 4 the zero mean time series is uncorrelated. The adaptation performance of finite impulse response (FIR) digital adaptive filters (DAF) used for channel estimation is analyzed. It is shown that using zero mean sequences of f4 leads to the maximal possible FIR DAF performance. An optimal value for the damping parameter in the LMS scheme is derived that leads to the maximal performance and ensures stability. The analytic considerations are confirmed by simulation results.
ANALYTICAL APPROXIMATION OF HETEROCLINIC BIFURCATION IN A 1:4 RESONANCE
Authors: FAHSI ABDELHAK , BELHAQ MOHAMED
Published: January 2013

Bifurcation of heteroclinic cycle near 1:4 resonance in a self-excited parametrically forced oscillator with quadratic nonlinearity is investigated analytically in this paper. This bifurcation mechanism leads to the disappearance of a slow flow limit cycle giving rise to frequency-locking near the resonance. The analytical approach used to approximate the bifurcation is based on a collision criterion between the slow flow limit cycle and saddles involved in the bifurcation. The amplitudes of the 1:4-subharmonic solution and the slow flow limit cycle are approximated using a double perturbation procedure and the heteroclinic bifurcation is captured applying the collision criterion. For validation, the analytical results are compared to those obtained by numerical simulations.
MULTI-SCALE DYNAMICS OF TWO COUPLED NONSMOOTH SYSTEMS
Authors: LAMARQUE C.-H. , SAVADKOOHI A. TURE , ETCHEVERRIA E. , DIMITRIJEVIC Z.
Published: January 2013

Dynamical behavior of a nonsmooth master system which is coupled to a nonsmooth Nonlinear Energy Sink (NES) during free and forced oscillations is studied analytically and numerically. Invariant manifolds of the system and their stable zones at different time scales are revealed and finally application of coupled nonsmooth NES to the passive control process of the main nonsmooth system is highlighted.
CENTER CONDITIONS FOR THREE CLASSES OF POINCARÉ SYSTEMS IN THE COMPLEX DOMAIN
Authors: LIU TAO , WU LIANGGANG , LIU YIRONG
Published: January 2013

By using the construction theorem of singular point values developed by [Liu & Li, 1990], the center conditions for three classes of Poincaré systems in the complex domain are obtained. Complete criteria are given. These general results show that in order to obtain the singular point values and simplify them, it is very important to analyze the construction of singular point values.
CHAOS VIA FRACTALITY IN GRAVITATIONAL SYSTEMS DYNAMICS: A NEW APPROACH (I)
Authors: AGOP M. , PAUN V. P. , DANDU-BIBIRE T.
Published: January 2013

The neutral particle motion in a composite field (gravitoelectromagnetic field overlapping a constant external gravitomagnetic field) is analyzed. A detailed nonlinear dynamics description, using temporal series, Poincaré sections, phase space, Lyapunov exponents, bifurcation diagrams and fractal analysis, is performed. New phenomena, e.g. the gravitational gun-type, gravitational chaotic gun-type and gravitational multigun-type effects are discovered, if the amplitude of the gravitoelectromagnetic field is sufficiently large. These effects induce a high acceleration of the neutral particles which lead to sudden jumps between different Larmor-type orbits. It results both in a chaotic behavior and patterns formation in gravitational systems.
ON THE CENTER CONDITIONS FOR ANALYTIC MONODROMIC DEGENERATE SINGULARITIES
Authors: GINÉ JAUME , LLIBRE JAUME
Published: January 2013

In this paper, we present two methods for detecting centers of monodromic degenerate singularities of planar analytic vector fields. These methods use auxiliary symmetric vector fields and can be applied independently so that the singularity is algebraic solvable or not, or has characteristic directions or not. We remark that these are the first methods which allow to study monodromic degenerate singularities with characteristic directions.
GEOMETRIC LIFT OF PATHS OF HAMILTONIAN EQUILIBRIA AND HOMOCLINIC BIFURCATION
Authors: BRIDGES THOMAS J.
Published: January 2013

A saddle-center transition of eigenvalues in the linearization about Hamiltonian equilibria, and the attendant planar homoclinic bifurcation, is one of the simplest and most well-known bifurcations in dynamical systems theory. It is therefore surprising that anything new can be said about this bifurcation. In this tutorial, the classical view of this bifurcation is reviewed and the lifting of the planar system to four dimensions gives a new view. The principal practical outcome is a new formula for the nonlinear coefficient in the normal form which generates the homoclinic orbit. The new formula is based on the intrinsic curvature of the lifted path of equilibria.
ONE-DIMENSIONAL DYNAMICS OF THE VAN DER POL CIRCUIT
Authors: KUDREWICZ JACEK
Published: January 2013

The van der Pol circuit with neon glow lamp operates as a relaxation oscillator driven by a sinusoidal voltage source. Its dynamics is described by the function which maps an arc of circle into itself, preserves orientation on this arc, and has at most one jump-discontinuity point on the circle. Properties of this mapping are discussed with emphasis on rotation numbers, types of periodic orbits, saddle-node and border-collision bifurcations. The so-called period-adding phenomenon is explained. Some remarks are given about dynamics, where the mapping does not preserve the orientation because of too long neon lamp lighting.
COMPLEX DYNAMICS IN A PENDULUM EQUATION WITH A PHASE SHIFT
Authors: CHEN XIANWEI , FU XIANGLING , JING ZHUJUN
Published: January 2013

Pendulum equation with a phase shift, parametric and external excitations is investigated in detail. By applying Melnikov's method, we prove the criteria of existence of chaos under periodic perturbation. Numerical simulations, including bifurcation diagrams of fixed points, bifurcation diagrams of the system in three- and two-dimensional spaces, homoclinic and heteroclinic bifurcation surfaces, Maximum Lyapunov exponents (ML), Fractal Dimension (FD), phase portraits, Poincaré maps are plotted to illustrate the theoretical analysis, and to expose the complex dynamical behaviors including the onset of chaos, sudden conversion of chaos to period orbits, interior crisis, periodic orbits, the symmetry-breaking of periodic orbits, jumping behaviors of periodic orbits, new chaotic attractors including two-three-four-five-six-eight-band chaotic attractors, nonchaotic attractors, period-doubling bifurcations from period-1, 2, 3 and 5 to chaos, reverse period-doubling bifurcations from period-3 and 5 to chaos, and so on.

By applying the second-order averaging method and Melnikov's method, we obtain the criteria of existence of chaos in an averaged system under quasi-periodic perturbation for Ω = nω + ϵν, n = 1, 2, 4, but cannot prove the criteria of existence of chaos in the averaged system under quasi-periodic perturbation for Ω = nω + ϵν, n = 3, 5 – 15, by Melnikov's method, where ν is not rational to ω. By using numerical simulation, we have verified our theoretical analysis and studied the effect of parameters of the original system on the dynamical behaviors generated under quasi-periodic perturbations, such as the onset of chaos, jumping behaviors of quasi-periodic orbits, interleaving occurrence of chaotic behaviors and nonchaotic behaviors, interior crisis, quasi-periodic orbits to chaotic attractors, sudden conversion of chaos to quasi-periodic behaviors, nonchaotic attractors, and so on. However, we did not find period-doubling and reverse period-doubling bifurcations. We found that the dynamical behaviors under quasi-periodic perturbations are different from that under periodic perturbations, and the dynamics with a phase shift are different from the dynamics without phase shift.
SUPERCRITICAL PITCHFORK BIFURCATION OF THE QUASI-PERIODIC SWITCHING SOLUTION IN A RING OF SIX-COUPLED, BISTABLE OSCILLATORS
Authors: KAMIYAMA KYOHEI , KOMURO MOTOMASA , ENDO TETSURO
Published: January 2013

In our preceding study, we investigated the appearance and disappearance scenario of (quasi-periodic) switching solution in a ring of six-coupled, bistable oscillators. This system was expressed as twelve-dimensional phase space, which was divided into linear subspace H and its complimentary linear subspace H⊥. We investigated the stability of switching solution in H by calculating the conditional Lyapunov exponent to the direction of H⊥. As a result, we found a critical coupling factor αcrt at which switching solution lost its stability in the direction of H⊥. However, we did not know what type of bifurcation occurred at this point. In this study, we elucidate that switching solution causes a supercritical pitchfork bifurcation at αcrt.
PARAMETERIZATION OF NATURAL MODES OF COMPOSITE ROTATING CONICAL SHELLS WITH MULTIPLE DELAMINATION
Authors: DEY SUDIP , KARMAKAR AMIT
Published: January 2013

This paper describes a comparative study on free vibration of bending stiff, torsion stiff and quasi-isotropic graphite-epoxy composite conical shells with single and multiple delamination. The finite element formulation is based on Mindlin's theory and multi-point constraint algorithm neglecting the Coriolis effect for moderate rotational speeds. Computer codes are developed employing QR iteration method to obtain delaminated natural frequencies under combined effect of twist and rotation. Mode shapes are depicted for a typical laminate configuration. The non-dimensional natural frequencies obtained are the first known results which could serve as reference solutions for future investigators.
A self-tuning design methodology for power-efficient multi-core systems
Authors: Sun Jin , Zheng Rui , Velamala Jyothi , Cao Yu , Lysecky Roman , Shankar Karthik , Roveda Janet
Published: January 2013

This article aims to achieve computational reliability and energy efficiency through codevelopment of algorithms, device, and circuit designs for application-specific, reconfigurable architectures. The new methodology characterizes aging-switching activity and aging-supply voltage relationships that are applicable for minimizing power consumption and task execution efficiency in order to achieve low bit energy ratio (BER). In addition, a new dynamic management algorithm (DMA) is proposed to alleviate device degradation and to extend system lifespan. In contrast to traditional workload balancing schemes in which cores are regarded as homogeneous, the new algorithm ranks cores as “highly competitive,” “less competitive,” and “not competitive” according to their various competitiveness. Core competitiveness is evaluated based upon their reliability, temperature, and timing requirements. Consequently, “competitive” cores will take charge of the majority of the tasks at relatively high voltage/frequency without violating power and timing budgets, while “not competitive” cores will have light workloads to ensure their reliability. The new approach combines intrinsic device characteristics (aging-switching activity and aging-supply voltage curves) into an integrated framework to achieve high reliability and low energy level with graceful degradation of system performance. Experimental results show that the proposed method has achieved up to 20% power reduction, with about 4% performance degradation (in terms of accomplished workload and system throughput), compared with traditional workload balancing methods. The new method also improves system mean-time-to-failure (MTTF) by up to 25%.
Accelerating throughput-aware runtime mapping for heterogeneous MPSoCs
Authors: Singh Amit Kumar , Kumar Akash , Srikanthan Thambipillai
Published: January 2013

Modern embedded systems need to support multiple time-constrained multimedia applications that often employ multiprocessor-systems-on-chip (MPSoCs). Such systems need to be optimized for resource usage and energy consumption. It is well understood that a design-time approach cannot provide timing guarantees for all the applications due to its inability to cater for dynamism in applications. However, a runtime approach consumes large computation requirements at runtime and hence may not lend well to constrained-aware mapping.

In this article, we present a hybrid approach for efficient mapping of applications in such systems. For each application to be supported in the system, the approach performs extensive design-space exploration (DSE) at design time to derive multiple design points representing throughput and energy consumption at different resource combinations. One of these points is selected at runtime efficiently, depending upon the desired throughput while optimizing for energy consumption and resource usage. While most of the existing DSE strategies consider a fixed multiprocessor platform architecture, our DSE considers a generic architecture, making DSE results applicable to any target platform. All the compute-intensive analysis is performed during DSE, which leaves for minimum computation at runtime. The approach is capable of handling dynamism in applications by considering their runtime aspects and providing timing guarantees.

The presented approach is used to carry out a DSE case study for models of real-life multimedia applications: H.263 decoder, H.263 encoder, MPEG-4 decoder, JPEG decoder, sample rate converter, and MP3 decoder. At runtime, the design points are used to map the applications on a heterogeneous MPSoC. Experimental results reveal that the proposed approach provides faster DSE, better design points, and efficient runtime mapping when compared to other approaches. In particular, we show that DSE is faster by 83% and runtime mapping is accelerated by 93% for some cases. Further, we study the scalability of the approach by considering applications with large numbers of tasks.
Concurrency-aware compiler optimizations for hardware description languages
Authors: Saladi Kalyan , Somakumar Harikumar , Ganapathi Mahadevan
Published: January 2013

In this article, we discuss the application of compiler technology for eliminating redundant computation in hardware simulation. We discuss how concurrency in hardware description languages (HDLs) presents opportunities for expression reuse across different threads. While accounting for discrete event simulation semantics, we extend the data flow analysis framework to concurrent threads. In this process, we introduce a rewriting scheme named ∂VF and a graph representation to model sensitivity relationships among threads. An algorithm for identifying common subexpressions as applied to HDLs is presented. Related issues, such as scheduling correctness, are also considered.
Molecular Mechanisms Underlying theIn VitroAnti-Inflammatory Effects of a Flavonoid-Rich Ethanol Extract from Chinese Propolis (Poplar Type)
Authors: Wang Kai , Ping Shun , Huang Shuai , Hu Lin , Xuan Hongzhuan , Zhang Cuiping , Hu Fuliang
Published: January 2013

China produces the greatest amount of propolis but there is still lack of basic studies on its pharmacological mechanisms. Our previous study found that ethanol extract from Chinese propolis (EECP) exerted excellent anti-inflammatory effectsin vivobut mechanisms of action were elusive. To further clarify the possible mechanisms underlying the anti-inflammatory effects of Chinese propolis (poplar type), we utilized EECP to analyze its chemical composition and evaluated its potential anti-inflammatory effectsin vitro. High-performance liquid chromatography (HPLC) profile indicated that EECP contained abundant flavonoids, including rutin, myricetin, quercetin, kaempferol, apigenin, pinocembrin, chrysin, and galangin. Next we found that EECP could significantly inhibit the production of NO, IL-1β, and IL-6 in lipopolysaccharide- (LPS-) stimulated RAW 264.7 cells and suppress mRNA expression of iNOS, IL-1β, and IL-6 in a time- and dose-dependent manner. Furthermore, we found that EECP could suppress the phosphorylation of IκBαand AP-1 but did not affect IκBα’s degradation. In addition, using a reporter assay, we found that EECP could block the activation of NF-κB in TNF-α-stimulated HEK 293T cells. Our findings give new insights for understanding the mechanisms involved in the anti-inflammatory effects by Chinese propolis and provide additional references for using propolis in alternative and complementary therapies.
Improved Insulin Sensitivity during Pioglitazone Treatment Is Associated with Changes in IGF-I and Cortisol Secretion in Type 2 Diabetes and Impaired Glucose Tolerance
Authors: Arnetz Lisa , Rajamand Ekberg Neda , Höybye Charlotte , Brismar Kerstin , Alvarsson Michael
Published: January 2013

Background. Hypercortisolism and type 2 diabetes (T2D) share clinical characteristics. We examined pioglitazone's effects on the GH-IGF-I and HPA axes in men with varying glucose intolerance. Methods. 10 men with T2D and 10 with IGT received pioglitazone 30–45 mg for 12 weeks. OGTT with microdialysis in subcutaneous adipose tissue and 1 μg ACTH-stimulation test were performed before and after. Glucose, insulin, IGF-I, IGFBP1, and interstitial measurements were analyzed during the OGTT. Insulin sensitivity was estimated using HOMA-IR. Results. HOMA-IR improved in both groups. IGF-I was initially lower in T2D subjects () and increased during treatment ( to SD; ); no change was seen in IGT ( SD before and during treatment). Fasting glycerol decreased in T2D (), indicating reduced lipolysis. Fasting cortisol decreased in T2D ( to  nmol/L; ) but increased in IGT ( to  nmol/L; ). Peak cortisol was lower in T2D during treatment ( to , versus to  nmol/L in IGT; ). Conclusions. Pioglitazone improved adipose tissue and liver insulin sensitivity in both groups. This may explain increased IGF-I in T2D. Pioglitazone affected cortisol levels in both groups but differently, suggesting different mechanisms for improving insulin sensitivity between T2D and IGT.
A Protocol for Advanced Psychometric Assessment of Surveys
Authors: Squires Janet E. , Hayduk Leslie , Hutchinson Alison M. , Cranley Lisa A. , Gierl Mark , Cummings Greta G. , Norton Peter G. , Estabrooks Carole A.
Published: January 2013

Background and Purpose. In this paper, we present a protocol for advanced psychometric assessments of surveys based on the Standards for Educational and Psychological Testing. We use the Alberta Context Tool (ACT) as an exemplar survey to which this protocol can be applied.Methods. Data mapping, acceptability, reliability, and validity are addressed. Acceptability is assessed with missing data frequencies and the time required to complete the survey. Reliability is assessed with internal consistency coefficients and information functions. A unitary approach to validity consisting of accumulating evidence based on instrument content, response processes, internal structure, and relations to other variables is taken. We also address assessing performance of survey data when aggregated to higher levels (e.g., nursing unit).Discussion. In this paper we present a protocol for advanced psychometric assessment of survey data using the Alberta Context Tool (ACT) as an exemplar survey; application of the protocol to the ACT survey is underway. Psychometric assessment of any survey is essential to obtaining reliable and valid research findings. This protocol can be adapted for use with any nursing survey.
Ultrasound Diagnosis of Fetal Neck Masses: A Case Series
Authors: Rauff Shakina , Eng Kien Tan
Published: January 2013

Fetal neck masses are rare and may not be apparent during the second trimester fetal anomaly screening scan. It is essential to distinguish the different pathologies as it influences prenatal counseling, antenatal, and postnatal management. Furthermore, some causes may be amenable to in utero treatment. Others have a poor prognosis due to their association with congenital syndromes and aneuploidies. Differentiating the various neck masses and reaching an accurate diagnosis are a challenge. This requires a systematic approach, time and patience, together with an experienced sonographer. Ancillary investigations like karyotyping and magnetic resonance imaging may be used as well. It is important to attain an accurate diagnosis and to follow up the fetus with serial scans as this affects antenatal counselling and prognosis as well as the mode of delivery. Here, we present four cases of fetal neck masses that were seen at our antenatal diagnostic centre and highlight the distinguishing ultrasound features of each. This will enable one to approach the ultrasound diagnosis of fetal neck masses in a methodical and logical manner.
Leakage Power Analysis of Domino XOR Gate
Authors: Pandey A. K. , Mishra R. A. , Nagaria R. K.
Published: January 2013

Two new XOR gates are proposed. First proposed circuits adopt hybrid transistor topology in the pull-down network with all transistors being low threshold voltages. A second proposed circuit adopts hybrid topology with dual threshold voltage transistors. Simulation parameters are measured at 25°C and 110°C. First proposed circuit reduces leakage power consumption up to 50% at 25°C and 58% at 110°C as compared to standard N-type domino XOR gate. It also reduces active mode power consumption by 14% as compared to standard N-type domino XOR gate. Similarly, second proposed circuit reduces leakage power consumption up to 73% at 25°C and 90% at 110°C as compared to standard N-type domino XOR gate. It also reduces active mode power consumption by 39% as compared to standard N-type domino XOR gate.
Pathophysiology of Diabetic Retinopathy
Authors: Tarr Joanna M. , Kaul Kirti , Chopra Mohit , Kohner Eva M. , Chibber Rakesh
Published: January 2013

Diabetes is now regarded as an epidemic, with the population of patients expected to rise to 380 million by 2025. Tragically, this will lead to approximately 4 million people around the world losing their sight from diabetic retinopathy, the leading cause of blindness in patients aged 20 to 74 years. The risk of development and progression of diabetic retinopathy is closely associated with the type and duration of diabetes, blood glucose, blood pressure, and possibly lipids. Although landmark cross-sectional studies have confirmed the strong relationship between chronic hyperglycaemia and the development and progression of diabetic retinopathy, the underlying mechanism of how hyperglycaemia causes retinal microvascular damage remains unclear. Continued research worldwide has focussed on understanding the pathogenic mechanisms with the ultimate goal to prevent DR. The aim of this paper is to introduce the multiple interconnecting biochemical pathways that have been proposed and tested as key contributors in the development of DR, namely, increased polyol pathway, activation of protein kinase C (PKC), increased expression of growth factors such as vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 (IGF-1), haemodynamic changes, accelerated formation of advanced glycation endproducts (AGEs), oxidative stress, activation of the renin-angiotensin-aldosterone system (RAAS), and subclinical inflammation and capillary occlusion. New pharmacological therapies based on some of these underlying pathogenic mechanisms are also discussed.
Energy-Efficient Hardware Architectures for the Packet Data Convergence Protocol in LTE-Advanced Mobile Terminals
Authors: Traboulsi Shadi , Frascolla Valerio , Pohl Nils , Hausner Josef , Bilgic Attila
Published: January 2013

In this paper, we present and compare efficient low-power hardware architectures for accelerating the Packet Data Convergence Protocol (PDCP) in LTE and LTE-Advanced mobile terminals. Specifically, our work proposes the design of two cores: a crypto engine for the Evolved Packet System Encryption Algorithm (128-EEA2) that is based on the AES cipher and a coprocessor for the Least Significant Bit (LSB) encoding mechanism of the Robust Header Compression (ROHC) algorithm. With respect to the former, first we propose a reference architecture, which reflects a basic implementation of the algorithm, then we identify area and power bottle-necks in the design and finally we introduce and compare several architectures targeting the most power-consuming operations. With respect to the LSB coprocessor, we propose a novel implementation based on a one-hot encoding, thereby reducing hardware’s logic switching rate. Architectural hardware analysis is performed using Faraday’s 90 nm standard-cell library. The obtained results, when compared against the reference architecture, show that these novel architectures achieve significant improvements, namely, 25% in area and 35% in power consumption for the 128-EEA2 crypto-core, and even more important reductions are seen for the LSB coprocessor, that is, 36% in area and 50% in power consumption.
Subcutaneous Splenosis of the Abdominal Wall: Report of a Case and Review of the Literature
Authors: Papakonstantinou Evangelia , Kalles Vasileios , Papapanagiotou Ioannis , Piperos Theodoros , Karakaxas Dimitrios , Bonatsos Vasileios , Tsoumakas Konstantinos , Orfanos Filotheos , Mariolis-Sapsakos Theodoros
Published: January 2013

Splenosis is a common benign condition that occurs after splenic rupture via trauma or surgery. The mechanism behind splenic cell autotransplantation begins with the splenic rupture, either from trauma or surgical removal. Splenosis is usually found incidentally and, unless symptomatic, surgical therapy is not indicated. Subcutaneous splenosis is an extremely rare form of splenosis, mostly observed in abdominal surgical scars. We report a case of subcutaneous splenosis, as well as a comprehensive review of the literature. In our case, a 43-year-old woman who had splenectomy after traumatic splenic rupture at the age of 7 years old presented for plastic reconstruction of her postoperative scar. Upon surgery, two asymptomatic subcutaneous nodules were incidentally discovered. The presence of splenic tissue was confirmed by the histological study. The nodules were not excised, as the patient was not symptomatic.
Multiple Sclerosis and the Blood-Central Nervous System Barrier
Authors: Palmer Alan M.
Published: January 2013

The central nervous system (CNS) is isolated from the blood system by a physical barrier that contains efflux transporters and catabolic enzymes. This blood-CNS barrier (BCNSB) plays a pivotal role in the pathophysiology of multiple sclerosis (MS). It binds and anchors activated leukocytes to permit their movement across the BCNSB and into the CNS. Once there, these immune cells target particular self-epitopes and initiate a cascade of neuroinflammation, which leads to the breakdown of the BCNSB and the formation of perivascular plaques, one of the hallmarks of MS. Immunomodulatory drugs for MS are either biologics or small molecules, with only the latter having the capacity to cross the BCNSB and thus have a propensity to cause CNS side effects. However, BCNSB penetration is a desirable feature of MS drugs that have molecular targets within the CNS. These are nabiximols and dalfampridine, which target cannabinoid receptors and potassium channels, respectively. Vascular cell adhesion molecule-1, present on endothelial cells of the BCNSB, also serves as a drug discovery target since it interacts with α4-β1-integrin on leucocytes. The MS drug natalizumab, a humanized monoclonal antibody against α4-β1-integrin, blocks this interaction and thus reduces the movement of immune cells into the CNS. This paper further elaborates on the role of the BCNSB in the pathophysiology and pharmacotherapy of MS.
The Application of Optical Coherence Tomography in Musculoskeletal Disease
Authors: Rashidifard Christopher , Vercollone Christopher , Martin Scott , Liu Bin , Brezinski Mark E.
Published: January 2013

Many musculoskeletal disorders (MDs) are associated with irreversible bone and cartilage damage; this is particularly true for osteoarthritis (OA). Therefore, a clinical need exists for modalities which can detect OA and other MDs at early stages. Optical coherence tomography (OCT) is an infrared-based imaging, currently FDA approved in cardiology and ophthalmology, which has a resolution greater than 10 microns and acquisition rate of 120 frames/second. It has shown feasibility for imaging early OA, identifying changes prior to cartilage thinning both in vitro and in vivo in patients and in OA animal models. In addition, OCT has shown an ability to identify early rheumatoid arthritis (RA) and guide tendon repair, but has the potential for an even greater impact. Clinical trials in OA are currently underway, as well as in several other MDs.
Influences of Movement Behavior on Animal Distributions at Edges of Homogeneous Patches
Authors: Young Hilary C. , Reid Tyler G. , Randall Lea A. , Lachowsky Leanna E. , Foster Danusha J. , Pengelly Chris J. , Latty Tanya , Reid Mary L.
Published: January 2013

We propose that changes in movement behavior may be a proximate mechanism that influences the accumulation of animals at habitat edges. We tested this idea with a combination of empirical and simulation experiments in a resource-free landscape. The movements of individual flour beetles,Tribolium confusum, were tracked across a paper arena edged with invisible tape until beetles crossed the edge. Movement behavior (step lengths and turn angles) and cumulative occupancy were analyzed according to distance from the edge. We found that beetles took smaller steps with larger turn angles near edges than in the center of the arena and that beetle distribution was highly biased towards the edge of the arena. We then tested two agent-based simulation models for each beetle: an edge-independent model and an edge-dependent model. Both models predicted less time spent at the edge than was observed. The proportion of time spent at edges depended on the propensity to cross the edge, which could not be explained by beetle body size or energetic condition. The distribution of animals with respect to habitat edges depends on many factors, but we suggest that proximate mechanisms such as movement behavior should be explicitly considered when interpreting animal distributions.
Inhibition ofHelicobacter pyloriCagA-Induced Pathogenesis by Methylantcinate B fromAntrodia camphorata
Authors: Lin Chun-Jung , Rao Yerra Koteswara , Hung Chiu-Lien , Feng Chun-Lung , Lane Hsien-Yuan , Tzeng David T. W. , Hsu Ping-Ning , Lai Chih-Ho , Tzeng Yew-Min
Published: January 2013

The bacterial pathogenHelicobacter pylori(Hp) is the leading risk factor for the development of gastric cancer. Hp virulence factor, cytotoxin-associated gene A (CagA) interacted with cholesterol-enriched microdomains and leads to induction of inflammation in gastric epithelial cells (AGS). In this study, we identified a triterpenoid methylantcinate B (MAB) from the medicinal mushroomAntrodia camphoratawhich inhibited the translocation and phosphorylation of CagA and caused a reduction in hummingbird phenotype in HP-infected AGS cells. Additionally, MAB suppressed the Hp-induced inflammatory response by attenuation of NF-κB activation, translocation of p65 NF-κB, and phosphorylation of IκB-α, indicating that MAB modulates CagA-mediated signaling pathway. Additionally, MAB also suppressed the IL-8 luciferase activity and its secretion in HP-infected AGS cells. On the other hand, molecular structure simulations revealed that MAB interacts with CagA similarly to that of cholesterol. Moreover, binding of cholesterol to the immobilized CagA was inhibited by increased levels of MAB. Our results demonstrate that MAB is the first natural triterpenoid which competes with cholesterol bound to CagA leading to attenuation of Hp-induced pathogenesis of epithelial cells. Thus, this study indicates that MAB may have a scope to develop as a therapeutic candidate against Hp CagA-induced inflammation.
Improving Passivation Process of Si Nanocrystals Embedded in SiO2Using Metal Ion Implantation
Authors: Bornacelli Jhovani , Reyes Esqueda Jorge Alejandro , Rodríguez Fernández Luis , Oliver Alicia
Published: January 2013

We studied the photoluminescence (PL) of Si nanocrystals (Si-NCs) embedded in SiO2obtained by ion implantation at MeV energy. The Si-NCs are formed at high depth (1-2 μm) inside the SiO2achieving a robust and better protected system. After metal ion implantation (Ag or Au), and a subsequent thermal annealing at 600°C under hydrogen-containing atmosphere, the PL signal exhibits a noticeable increase. The ion metal implantation was done at energies such that its distribution inside the silica does not overlap with the previously implanted Si ion . Under proper annealing Ag or Au nanoparticles (NPs) could be nucleated, and the PL signal from Si-NCs could increase due to plasmonic interactions. However, the ion-metal-implantation-induced damage can enhance the amount of hydrogen, or nitrogen, that diffuses into the SiO2matrix. As a result, the surface defects on Si-NCs can be better passivated, and consequently, the PL of the system is intensified. We have selected different atmospheres (air, H2/N2and Ar) to study the relevance of these annealing gases on the final PL from Si-NCs after metal ion implantation. Studies of PL and time-resolved PL indicate that passivation process of surface defects on Si-NCs is more effective when it is assisted by ion metal implantation.
A General Approximation Scheme for Solutions of Various Problems in Fixed Point Theory
Authors: Ofoedu Eric U.
Published: January 2013

It is our aim to prove strong convergence of a new iterative sequence to a common element of the solution set of a generalized mixed equilibrium problem; the null space of an inverse strongly monotone operator; the set of common fixed points of a countable infinite family of nonexpansive mappings; and the set of fixed points of a continuous pseudocontractive mapping. Moreover, the common element is also a unique solution of a variational inequality problem and optimality condition for a certain minimization problem. Our theorems generalize, improve, and unify several recently announced results.
Mulberry Leaf Reduces Oxidation and C-Reactive Protein Level in Patients with Mild Dyslipidemia
Authors: Aramwit Pornanong , Supasyndh Ouppatham , Siritienthong Tippawan , Bang Nipaporn
Published: January 2013

C-reactive protein (CRP) is the inflammatory marker that could represent the inflammation in blood vessels resulted from dyslipidemia. The objective of this study was to evaluate the antioxidative activity of mulberry leaf powder using DPPH assay and the effect of mulberry leaf powder on lipid profile, CRP level, and antioxidative parameters in mild dyslipidemia patients. A within-subjects design was conducted and patients received three tablets of 280 mg mulberry leaf powder three times a day before meals for 12 weeks. Total of 25 patients were enrolled but one subject was excluded. After three months of mulberry leaf consumption, serum triglyceride and low-density lipoprotein (LDL) level were significantly reduced and more than half of all patients’ CRP levels decreased every month as well as the mean CRP level but no statistically significant difference was found. The average erythrocyte glutathione peroxidase activity of patients was increased but not at significant level; however, the mean serum 8-isoprostane level was significantly lower after mulberry treatment for 12 weeks. It can be concluded that mulberry leaf powder exhibited antioxidant activity and mulberry leaf powder has potential to decrease serum triglyceride, LDL, and CRP levels in mild dyslipidemia patients without causing severe adverse reactions.
Hydraphiles: A Rigorously Studied Class of Synthetic Channel Compounds withIn VivoActivity
Authors: Negin Saeedeh , Smith Bryan A. , Unger Alexandra , Leevy W. Matthew , Gokel George W.
Published: January 2013

Hydraphiles are a class of synthetic ion channels that now have a twenty-year history of analysis and success. In early studies, these compounds were rigorously validated in a wide range ofin vitroassays including liposomal ion flow detected by NMR or ion-selective electrodes, as well as biophysical experiments in planar bilayers. During the past decade, biological activity was observed for these compounds including toxicity to bacteria, yeast, and mammalian cells due to stress caused by the disruption of ion homeostasis. The channel mechanism was verified in cells using membrane polarity sensitive dyes, as well as patch clamping studies. This body of work has provided a solid foundation with which hydraphiles have recently demonstrated acute biological toxicity in the muscle tissue of living mice, as measured by whole animal fluorescence imaging and histological studies. Here we review the critical structure-activity relationships in the hydraphile family of compounds and thein vitroandin celluloexperiments that have validated their channel behavior. This report culminates with a description of recently reported efforts in which these molecules have demonstrated activity in living mice.
Unified Theory of Bacterial Sialometabolism: How and Why Bacteria Metabolize Host Sialic Acids
Authors: Vimr Eric R.
Published: January 2013

Sialic acids are structurally diverse nine-carbon ketosugars found mostly in humans and other animals as the terminal units on carbohydrate chains linked to proteins or lipids. The sialic acids function in cell-cell and cell-molecule interactions necessary for organismic development and homeostasis. They not only pose a barrier to microorganisms inhabiting or invading an animal mucosal surface, but also present a source of potential carbon, nitrogen, and cell wall metabolites necessary for bacterial colonization, persistence, growth, and, occasionally, disease. The explosion of microbial genomic sequencing projects reveals remarkable diversity in bacterial sialic acid metabolic potential. How bacteria exploit host sialic acids includes a surprisingly complex array of metabolic and regulatory capabilities that is just now entering a mature research stage. This paper attempts to describe the variety of bacterial sialometabolic systems by focusing on recent advances at the molecular and host-microbe-interaction levels. The hope is that this focus will provide a framework for further research that holds promise for better understanding of the metabolic interplay between bacterial growth and the host environment. An ability to modify or block this interplay has already yielded important new insights into potentially new therapeutic approaches for modifying or blocking bacterial colonization or infection.
Transmitted Drug Resistance among People Living with HIV/Aids at Major Cities of Sao Paulo State, Brazil
Authors: Ferreira Joao Leandro Paula , Rodrigues Rosangela , Lança Andre Minhoto , de Almeida Valeria Correia , Rocha Simone Queiroz , Ragazzo Taisa Grotta , Estevam Denise Lotufo , Brigido Luis Fernando de Macedo
Published: January 2013

Human immunodeficiency virus type 1 (HIV-1) transmitted drug resistance (TDR) is an important public health issue. In Brazil, low to intermediate resistance levels have been described. We assessed 225 HIV-1 infected, antiretroviral naïve individuals, from HIV Reference Centers at two major metropolitan areas of Sao Paulo (Sao Paulo and Campinas), the state that concentrates most of the Brazilian Aids cases. TDR was analyzed by Stanford Calibrated Population Resistance criteria (CPR), and mutations were observed in 17 individuals (7.6%, 95% CI: 4.5%–11.9%). Seventy-six percent of genomes (13/17) with TDR carried a nonnucleoside reverse transcriptase inhibitor (NNRTI) resistance mutation, mostly K103N/S (9/13, 69%), potentially compromising the preferential first-line therapy suggested by the Brazilian HIV Treatment Guideline that recommends efavirenz-based combinations. Moreover, 6/17 (35%) had multiple mutations associated with resistance to one or more classes. HIV-1 B was the prevalent subtype (80%); other subtypes include HIV-1 F and C, mosaics BC, BF, and single cases of subtype A1 and CRF02_AG. The HIV Reference Center of Campinas presented more cases with TDR, with a significant association of TDR with clade B infection (P<0.05).
Magnetic Resonance Imaging versus Electrophysiologic Tests in Clinical Diagnosis of Lower Extremity Radicular Pain
Authors: Hasankhani E. G. , Omidi-Kashani F.
Published: January 2013

Introduction. Radicular low back pain is one of the most common medical problems. The aim of this study was to evaluate the diagnostic accuracy of MRI and electrodiagnosis in lower extremity radicular pain in relation to history and clinical findings.
Methods. In this cross-sectional study, we studied 165 sciatalgic subjects. A comprehensive history and physical examinations were taken from the subjects and recorded, and then MRI scanning and electrodiagnostic (nerve conduction velocity and electromyography) tests were performed. Results. From 152 subjects who remained in the study, 67 cases (44.1%) had radicular pain in left lower limb, 46 (30.3%) in right, and 39 (25.6%) in both lower limbs. 104 cases (68.4%) had shown some type of abnormalities in both MRI and electrodiagnosis, 30 (19.7%) had shown this abnormality only in MRI, and 21 (13.8%) only in electrodiagnosis, while 10 cases (6.5%) had both normal MRI and electrodiagnostic studies. Coordination rates of MRI and electrodiagnosis with clinical findings were 58.6% and 89.5%, respectively. Conclusion. In many MRI negative but symptomatic subjects, electrodiagnosis has an important diagnostic value.
Impact of Comorbidities on Racial/Ethnic Disparities in Hypertension in the United States
Authors: Opara Franklin , Hawkins Kimberly , Sundaram Aparna , Merchant Munira , Rasmussen Sandra , Holmes Laurens
Published: January 2013

Background. Racial/ethnic disparities in hypertension (HTN) prevalence continue to persist in United States. We aimed in this study to examine the racial/ethnic disparities in hypertension prevalence and to determine whether or not health disparities may be explained by racial/ethnic disparities in co-morbidities. Materials and Methods. A cross-sectional design was used to examine the prevalence of hypertension among African Americans (AAs), Caucasians, and Hispanics in the National Health Interview Survey, 2003. The overall sample comprised 30, 852 adults. Results. There was a statistically significant racial/ethnic variability in hypertension prevalence, with AA/Blacks with the highest prevalence, χ2=393.0
(3), P<0.01. Hypertension was associated with co-morbidities, age, education, physical inactivity, marital status, income, sex, alcohol, and cigarette consumption, but not insurance. Relative to Caucasians, AAA/Blacks were 43% more likely while Hispanics were 40% less likely to report being diagnosed with high blood pressure, prevalence odds ratio (POR)  =  1.43, 99% CI, 1.25–1.64, P=0.002, and POR  =  0.60, 99% CI, 0.55–0.66, P<0.001, respectively. After adjustment for the relevant covariates including co-morbidities, racial/ethnic disparities in hypertension persisted; thus compared to Caucasians, African Americans were 61% more likely to be told by their health care providers that they were hypertensive, adjusted prevalence odds ratio (APOR)  =  1.61, 99% CI, 1.39–1.86, P<0.001. In contrast, Hispanics were 27% less likely to be diagnosed with hypertension compared to Caucasians, APOR  =  0.73, 99% CI, 0.68–0.79, P<0.001. Conclusions. There was racial/ethnic variability in hypertension prevalence in this large sample of non-institutionalized US residents, with the highest prevalence of hypertension observed among African Americans. These disparities were not removed after controlling for relevant covariates including co-morbidities.
The Diurnal Temperature Range for Europe: A Search for Cosmic Ray Forbush Decrease Manifestations and the DTR Periodicities
Authors: Erlykin A. D. , Wolfendale A. W.
Published: January 2013

Following on previous work by others, which gave evidence for few days’ changes in the European Diurnal Temperature Range (DTR) apparently correlated with Cosmic Ray Forbush Decreases, we have made an independent study. We find no positive evidence. An analysis has also been made of the Fourier components of the time series of the DTR value (taken as deviations from a ±10 day running mean). Evidence for a number of interesting periods is found, including one at about 27 days, albeit with a variability with time. The same period of solar irradiance (particularly in the UV) is favoured as the explanation.