bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of networks of custom processing elements for real-time physical system emulation
Authors: Huang Chen , Miller Bailey , Vahid Frank , Givargis Tony
Published: April 2013

Emulating a physical system in real-time or faster has numerous applications in cyber-physical system design and deployment. For example, testing of a cyber-device's software (e.g., a medical ventilator) can be done via interaction with a real-time digital emulation of the target physical system (e.g., a human's respiratory system). Physical system emulation typically involves iteratively solving thousands of ordinary differential equations (ODEs) that model the physical system. We describe an approach that creates custom processing elements (PEs) specialized to the ODEs of a particular model while maintaining some programmability, targeting implementation on field-programmable gate arrays (FPGAs). We detail the PE micro-architecture and accompanying automated compilation and synthesis techniques. Furthermore, we describe our efforts to use a high-level synthesis approach that incorporates regularity extraction techniques as an alternative FPGA-based solution, and also describe an approach using graphics processing units (GPUs). We perform experiments with five models: a Weibel lung model, a Lutchen lung model, an atrial heart model, a neuron model, and a wave model; each model consists of several thousand ODEs and targets a Xilinx Virtex 6 FPGA. Results of the experiments show that the custom PE approach achieves 4X-9X speedups (average 6.7X) versus our previous general ODE-solver PE approach, and 7X-10X speedups (average 8.7X) versus high-level synthesis, while using approximately the same or fewer FPGA resources. Furthermore, the approach achieves speedups of 18X-32X (average 26X) versus an Nvidia GTX 460 GPU, and average speedups of more than 100X compared to a six-core TI DSP processor or a four-core ARM processor, and 24X versus an Intel I7 quad core processor running at 3.06 GHz. While an FPGA implementation costs about 3X-5X more than the non-FPGA approaches, a speedup/dollar analysis shows 10X improvement versus the next best approach, with the trend of decreasing FPGA costs improving speedup/dollar in the future.
Resource-aware architectures for adaptive particle filter based visual target tracking
Authors: Forte Domenic , Srivastava Ankur
Published: April 2013

There are a growing number of visual tracking applications now being envisioned for mobile devices. However, since computer vision algorithms such as particle filtering have large computational demands, they can result in high energy consumption and temperatures in mobile devices. Conventional approaches for distributed target tracking with a camera node and a receiver node are either sender-based (SB) or receiver-based (RB). The SB approach uses little energy and bandwidth, but requires a sender with large computational resources. The RB approach fits applications where computational resources are completely unavailable to the sender, but requires very large energy and bandwidth. In this article, we propose three architectures for distributed particle filtering that (i) reduce particle filtering workload and (ii) allow for dynamic migration of workload between nodes participating in tracking. We also discuss an adaptive particle filtering extension that adapts particle filter computational complexity and can be applied to both the conventional and proposed architectures for improved energy efficiency. Results show that the proposed solutions require low additional overhead, improve on tracking system lifetime, balance node temperatures, maintain track of the desired target, and are more effective than conventional approaches in many scenarios.
Achieving autonomous power management using reinforcement learning
Authors: Shen Hao , Tan Ying , Lu Jun , Wu Qing , Qiu Qinru
Published: April 2013

System level power management must consider the uncertainty and variability that come from the environment, the application and the hardware. A robust power management technique must be able to learn the optimal decision from past events and improve itself as the environment changes. This article presents a novel on-line power management technique based on model-free constrained reinforcement learning (Q-learning). The proposed learning algorithm requires no prior information of the workload and dynamically adapts to the environment to achieve autonomous power management. We focus on the power management of the peripheral device and the microprocessor, two of the basic components of a computer. Due to their different operating behaviors and performance considerations, these two types of devices require different designs of Q-learning agent. The article discusses system modeling and cost function construction for both types of Q-learning agent. Enhancement techniques are also proposed to speed up the convergence and better maintain the required performance (or power) constraint in a dynamic system with large variations. Compared with the existing machine learning based power management techniques, the Q-learning based power management is more flexible in adapting to different workload and hardware and provides a wider range of power-performance tradeoff.
Low-power resource binding by postsilicon customization
Authors: Majzoobi Mehrdad , Kong Joonho , Koushanfar Farinaz
Published: April 2013

This article proposes the first postsilicon customization method for resource binding to achieve power reduction application specific integrated circuits (ASICs) design. Instead of committing to one configuration of resource binding during synthesis, our new synthesis method produces a diverse set of candidate bindings for the design. To ensure diversity of the resource usage patterns, we introduce a binding candidate formation method based on the orthogonal arrays. Additional control components are added to enable post manufacturing selection of one of the binding candidates. The resource binding candidate that minimizes the power consumption is selected by considering the specific power characteristics of each chip. An efficient methodology for embedding several binding candidates in one design is developed. Evaluations on benchmark designs show the low overhead and the effectiveness of the proposed methods. As an example, applying our method results in an average of 14.2% (up to 24.0%) power savings on benchmark circuits for a variation model in 45nm CMOS technology. The power efficiency of our customized postsilicon binding is expected to improve with scaling of the technology and the likely resulting higher process variations.
Low-power anti-aging zero skew clock gating
Authors: Huang Shih-Hsu , Tu Wen-Pin , Chang Chia-Ming , Pan Song-Bin
Published: April 2013

In advanced CMOS technology, the NBTI (negative bias temperature instability) effect results in delay degradations of PMOS transistors. Further, because of clock gating, PMOS transistors in a clock tree often have different active probabilities, leading to different delay degradations. If the degradation difference is not properly controlled, this clock skew may cause the circuit fails to function at some point later in time. Intuitively, the degradation difference can be eliminated, if we increase the active probability of the low-probability clock gates to ensure the clock gates at the same level always having the same active probability. However, this intuitive method may suffer from large power consumption overhead. In this article, we point out, by carefully planning the transistor-level clock signal propagation path, we can have many clock gates whose active probabilities do not affect the degradation difference. Based on that observation, we propose a critical-PMOS-aware clock tree design methodology to eliminate the degradation difference with minimum power consumption overhead. Benchmark data consistently show our approach achieves very good results in terms of both the NBTI-induced clock skew (i.e., the degradation difference) and the power consumption overhead.
Composable thermal modeling and simulation for architecture-level thermal designs of multicore microprocessors
Authors: Wang Hai , Tan Sheldon X.-D. , Li Duo , Gupta Ashish , Yuan Yuan
Published: April 2013

Efficient temperature estimation is vital for designing thermally efficient, lower power and robust integrated circuits in nanometer regime. Thermal simulation based on the detailed thermal structures no longer meets the demanding tasks for efficient design space exploration. The compact and composable model-based simulation provides a viable solution to this difficult problem. However, building such thermal models from detailed thermal structures was not well addressed in the past. In this article, we propose a new compact thermal modeling technique, called
ThermComp
, standing for thermal modeling with composable modules.
ThermComp
can be used for fast thermal design space exploration for multicore microprocessors. The new approach builds the composable model from detailed structures for each basic module using the finite difference method and reduces the model complexity by the sampling-based model order reduction technique. These composable models are then used to assemble different multicore architecture thermal models and realized into SPICE-like netlists. The resulting thermal models can be simulated by the general circuit simulator SPICE.
ThermComp
tries to preserve the accuracy of fine-grained models with the speed of coarse-grained models. Experimental results on a number of multicore microprocessor architectures show the new approach can easily build accurate thermal systems from compact composable models for fast architecture thermal analysis and optimization and is much faster than the existing HotSpot method with similar accuracy.
Revisiting automated physical synthesis of high-performance clock networks
Authors: Guthaus Matthew R. , Wilke Gustavo , Reis Ricardo
Published: April 2013

High-performance clock distribution has been a challenge for nearly three decades. During this time, clock synthesis tools and algorithms have strove to address a myriad of important issues helping designers to create faster, more reliable, and more power efficient chips. This work provides a complete discussion of the high-performance ASIC clock distribution using information gathered from both leading industrial clock designers and previous research publications. While many techniques are only briefly explained, the references summarize the most influential papers on a variety of topics for more in-depth investigation. This article also provides a thorough discussion of current issues in clock synthesis and concludes with insight into future research and design challenges for the community at large.
Robustness analysis for battery-supported cyber-physical systems
Authors: Zhang Fumin , Shi Zhenwu , Mukhopadhyay Shayok
Published: April 2013

This article establishes a novel analytical approach to quantify robustness of scheduling and battery management for battery supported cyber-physical systems. A dynamic schedulability test is introduced to determine whether tasks are schedulable within a finite time window. The test is used to measure robustness of a real-time scheduling algorithm by evaluating the strength of computing time perturbations that break schedulability at runtime. Robustness of battery management is quantified analytically by an adaptive threshold on the state of charge. The adaptive threshold significantly reduces the false alarm rate for battery management algorithms to decide when a battery needs to be replaced.
Partitioning sporadic task systems upon memory-constrained multiprocessors
Authors: Baruah Sanjoy
Published: April 2013

Most prior theoretical research on real-time partitioning algorithms for multiprocessor platforms has focused on ensuring that the cumulative computing requirements of the tasks assigned to each processor does not exceed the processor's processing power. However, computing capacity is often not the only limiting resource: on many multiprocessor platforms each individual computing unit may have limited amounts of multiple additional types of resources (such as local memory) in addition to having limited processing power. We present algorithms for partitioning a collection of sporadic tasks, each characterized by a WCET, a relative deadline, and a period, upon a multiprocessor platform in a manner that is cognizant of such additional constraints as well as the processing capacity constraints.
A hard real-time capable multi-core SMT processor
Authors: Paolieri Marco , Mische Jörg , Metzlaff Stefan , Gerdes Mike , Quiñones Eduardo , Uhrig Sascha , Ungerer Theo , Cazorla Francisco J.
Published: April 2013

Hard real-time applications in safety critical domains require high performance and time analyzability. Multi-core processors are an answer to these demands, however task interferences make multi-cores more difficult to analyze from a worst-case execution time point of view than single-core processors. We propose a multi-core SMT processor that ensures a bounded maximum delay a task can suffer due to inter-task interferences. Multiple hard real-time tasks can be executed on different cores together with additional non real-time tasks. Our evaluation shows that the proposed MERASA multi-core provides predictability for hard real-time tasks and also high performance for non hard real-time tasks.
Automated Anomaly Detector Adaptation using Adaptive Threshold Tuning
Authors: Ali Muhammad Qasim , Al-Shaer Ehab , Khan Hassan , Khayam Syed Ali
Published: April 2013

Real-time network- and host-based Anomaly Detection Systems (ADSs) transform a continuous stream of input data into meaningful and quantifiable anomaly scores. These scores are subsequently compared to a fixed detection threshold and classified as either benign or malicious. We argue that a real-time ADS’ input changes considerably over time and a fixed threshold value cannot guarantee good anomaly detection accuracy for such a time-varying input. In this article, we propose a simple and generic technique to adaptively tune the detection threshold of any ADS that works on threshold method. To this end, we first perform statistical and information-theoretic analysis of network- and host-based ADSs’ anomaly scores to reveal a consistent time correlation structure during benign activity periods. We model the observed correlation structure using Markov chains, which are in turn used in a stochastic target tracking framework to adapt an ADS’ detection threshold in accordance with real-time measurements. We also use statistical techniques to make the proposed algorithm resilient to sporadic changes and evasion attacks. In order to evaluate the proposed approach, we incorporate the proposed adaptive thresholding module into multiple ADSs and evaluate those ADSs over comprehensive and independently collected network and host attack datasets. We show that, while reducing the need of human threshold configuration, the proposed technique provides considerable and consistent accuracy improvements for all evaluated ADSs.
A-DFA
Authors: Becchi Michela , Crowley Patrick
Published: April 2013

Modern network intrusion detection systems need to perform regular expression matching at line rate in order to detect the occurrence of critical patterns in packet payloads. While Deterministic Finite Automata (DFAs) allow this operation to be performed in linear time, they may exhibit prohibitive memory requirements. Kumar et al. [2006a] have proposed Delayed Input DFAs (D2FAs), which provide a trade-off between the memory requirements of the compressed DFA and the number of states visited for each character processed, which in turn affects the memory bandwidth required to evaluate regular expressions.

In this article we introduce
Amortized time
 − 
bandwidth overhead DFAs
(
A
 − 
DFAs
), a general compression technique that results in at most
N
(
k
 + 1)/
k
state traversals when processing a string of length
N
,
k
being a positive integer. In comparison to the D2FA approach, our technique achieves comparable levels of compression with lower provable bounds on memory bandwidth (or greater compression for a given bandwidth bound). Moreover, the A-DFA algorithm has lower complexity, can be applied during DFA creation, and is suitable for scenarios where a compressed DFA needs to be dynamically built or updated. Finally, we show how to combine A-DFA with alphabet reduction and multistride DFAs, two techniques aimed at reducing the memory space and bandwidth requirement of DFAs, and discuss memory encoding schemes suitable for A-DFAs.
Modelling reconfigurable systems in event driven simulation
Authors: Tsoi Kuen Hung , Becker Tobias , Luk Wayne
Published: April 2013

Reconfigurable platforms allow hardware developers to customise their designs for specific applications. However, their adoption involves challenges in understanding and estimating the impact of various design parameters and approaches. This paper proposes a unified framework to model behaviour of reconfigurable systems using an event driven simulation approach. This provides an abstract yet informative method to capture both analytical relationships and empirical parameters of reconfigurable systems. It can be used to help making design decisions or verifying analytical models. We apply this approach to three models of reconfigurable applications to estimate the communication efficiency of networked clusters, and the performance and energy efficiency of runtime reconfigurable designs for software-defined radio and for option pricing in finance. The results show that, through this simulation framework, we can verify the accuracy of analytical models and also obtain practical information that is not provided by analytical models.
Internet nuggets
Authors: Thorson Mark
Published: April 2013

This column consists of selected traffic from the comp.arch newsgroup, a forum for discussion of computer architecture on the Internet---an international computer network.

As always, the opinions expressed in this column are the personal views of the authors, and do not necessarily represent the institutions to which they are affiliated.

Text which sets the context of a message appears underlined or in italics; this is usually text the author has quoted from earlier messages. The code-like expressions below the authors' names are their addresses on Internet.
Computational Fluid Dynamics Study of Swimmer's Hand Velocity, Orientation, and Shape: Contributions to Hydrodynamics
Authors: Bilinauskaite Milda , Mantha Vishveshwar Rajendra , Rouboa Abel Ilah , Ziliukas Pranas , Silva Antonio Jose
Published: April 2013

The aim of this paper is to determine the hydrodynamic characteristics of swimmer’s scanned hand models for various combinations of both the angle of attack and the sweepback angle and shape and velocity of swimmer's hand, simulating separate underwater arm stroke phases of freestyle (front crawl) swimming. Four realistic 3D models of swimmer's hand corresponding to different combinations of separated/closed fingers positions were used to simulate different underwater front crawl phases. The fluid flow was simulated using FLUENT (ANSYS, PA, USA). Drag force and drag coefficient were calculated using (computational fluid dynamics) CFD in steady state. Results showed that the drag force and coefficient varied at the different flow velocities on all shapes of the hand and variation was observed for different hand positions corresponding to different stroke phases. The models of the hand with thumb adducted and abducted generated the highest drag forces and drag coefficients. The current study suggests that the realistic variation of both the orientation angles influenced higher values of drag, lift, and resultant coefficients and forces. To augment resultant force, which affects swimmer's propulsion, the swimmer should concentrate in effectively optimising achievable hand areas during crucial propulsive phases.
Relationships among Energy Price Shocks, Stock Market, and the Macroeconomy: Evidence from China
Authors: Cong Rong-Gang , Shen Shaochuan
Published: April 2013

This paper investigates the interactive relationships among China energy price shocks, stock market, and the macroeconomy using multivariate vector autoregression. The results indicate that there is a long cointegration among them. A 1% rise in the energy price index can depress the stock market index by 0.54% and the industrial value‐adding growth by 0.037%. Energy price shocks also cause inflation and have a 5‐month lag effect on stock market, which may result in the stock market “underreacting.” The energy price can explain stock market fluctuations better than the interest rate over a longer time period. Consequently, investors should pay greater attention to the long‐term effect of energy on the stock market.
On Dimension Extension of a Class of Iterative Equations
Authors: Su Juan , Dong Xinhan
Published: April 2013

This investigation aims at studying some special properties (convergence, polynomial preservation order, and orthogonal symmetry) of a class ofr-dimension iterative equations, whose state variables are described by the following nonlinear iterative equation:ϕn(x)=T(ϕn−1(x)):=∑j=0mHjϕn−1(2x−k). The obtained results in this paper are complementary to some published results. As an application, we construct orthogonal symmetric multiwavelet with additional vanishing moments. Two examples are also arranged to demonstrate the correctness and effectiveness of the main results.
Stationarity Testing of Accumulated Ethernet Traffic
Authors: Lu Zhiping , Li Ming , Zhao Wei
Published: April 2013

We investigate the stationarity property of the accumulated Ethernet traffic series. We applied several widely used stationarity and unit root tests, such as Dickey-Fuller test and its augmented version, Phillips-Perron test, as well as the Kwiatkowski-Phillips-Schmidt-Shin test and some of its generalizations, to the assessment of the stationarity of the traffic traces at the different time scales. The quantitative results in this research provide evidence that when the time scale increases, the accumulated traffic series are more stationary.
Aerodynamic Reduced-Order Modeling without Static Correction Requirement Based on Body Vortices
Authors: Sleesongsom Suwin , Bureerat Sujin
Published: April 2013

The objective of this research is to propose a new reduced-order modeling method. This approach is based on fluid eigenmodes and body vortices without using static correction. The vortex lattice method (VLM) is used to analyze unsteady flows over two-dimensional airfoil and three-dimensional wing. Eigenanalysis and reduced-order modeling are performed using a conventional method with static correction and an unconventional one without the static correction. Numerical examples are proposed to demonstrate the performance of the present method. The results show that the new method can be considered an alternative way to perform the reduced-order models of unsteady flow.
Removing Regional Trends in Microgravity in Complex Environments: Testing on 3D Model and Field Investigations in the Eastern Dead Sea Coast (Jordan)
Authors: Al-Zoubi A. , Eppelbaum L. , Abueladas A. , Ezersky M. , Akkawi E.
Published: April 2013

Microgravity investigations are now recognized as a powerful tool for subsurface imaging and especially for the localization of underground karsts. However numerous natural (geological), technical, and environmental factors interfere with microgravity survey processing and interpretation. One of natural factors that causes the most disturbance in complex geological environments is the influence of regional trends. In the Dead Sea coastal areas the influence of regional trends can exceed residual gravity effects by some tenfold. Many widely applied methods are unable to remove regional trends with sufficient accuracy. We tested number of transformation methods (including computing gravity field derivatives, self-adjusting and adaptive filtering, Fourier series, wavelet, and other procedures) on a 3D model (complicated by randomly distributed noise), and field investigations were carried out in Ghor Al-Haditha (the eastern side of the Dead Sea in Jordan). We show that the most effective methods for regional trend removal (at least for the theoretical and field cases here) are the bilinear saddle and local polynomial regressions. Application of these methods made it possible to detect the anomalous gravity effect from buried targets in the theoretical model and to extract the local gravity anomaly at the Ghor Al-Haditha site. The local anomaly was utilized for 3D gravity modeling to construct a physical-geological model (PGM).
Comparison of Explant-Derived and Enzymatic Digestion-Derived MSCs and the Growth Factors from Wharton’s Jelly
Authors: Yoon Jong Hyun , Roh Eun Youn , Shin Sue , Jung Nam Hee , Song Eun Young , Chang Ju Young , Kim Byoung Jae , Jeon Hye Won
Published: April 2013

Wharton’s jelly is not only one of the most promising tissue sources for mesenchymal stem cells (MSCs) but also a source of natural growth factors. To prove that we can get both natural growth factors and MSCs from Wharton’s jelly, we compared cellular characteristics and the level of basic fibroblast growth factor (bFGF) from samples using the explant culture method to those derived from the traditional enzymatic culture method. The levels of bFGF were27.0±11.7 ng/g on day 3,15.6±11.1 ng/g on day 6, and decreased to2.6±1.2 ng/g on day 14. The total amount of bFGF released was55.0±25.6 ng/g on explant culture. Compared with the traditional enzymatic digestion method, the explant culture method showed a tendency to release higher levels of bFGF in supernatant media for the first week of culture, and the higher cellular yield at passage 0 (4.89±3.2×105/g versus1.75±2.2×105/g,P=0.01). In addition, the genes related to mitosis were upregulated in the explant-derived MSCs.
BRAFV600E-Negative Hairy Cell Leukaemia
Authors: Langabeer Stephen E. , O'Brien David , McElligott Anthony M. , Lavin Michelle , Browne Paul V.
Published: April 2013

Since the initial report of theBRAFV600E mutation in hairy cell leukemia, numerous investigators have demonstrated the presence of this activating mutation in nearly all cases of this disease. A case of hairy cell leukemia is documented with a classical clinical, morphological, immunophenotypic, and cytochemical profile in which theBRAFV600E was not detected. The diagnostic and therapeutic implications are discussed.
Nanocomposites of Polyaniline and Cellulose Nanocrystals Prepared in Lyotropic Chiral Nematic Liquid Crystals
Authors: Zhang Dawei , Zhang Lihong , Wang Bingzhe , Piao Guangzhe
Published: April 2013

Stable lyotropic chiral nematic liquid crystals (N*-LCs) of cellulose nanocrystals (CNs) were prepared via hydrolysis using sulfuric acid. The lyotropic N*-LCs were used as an asymmetric reaction field to synthesize polyaniline (PANI) onto CNs by in situ polymerization. As a primary step, we examined the mesophase transition of the N*-LCs of CNs suspension before and after in situ polymerization of aniline (ANI) by polarizing optical microscopy. The structure of nanocomposites of PANI/CNs was investigated at a microscopic level using Fourier transform infrared spectroscopy and X-ray diffraction. Influence of the CNs-to-ANI ratio on the morphology of the nanocomposites was also investigated at macroscopic level by scanning electron and transmission electron microscopies. It is found that the weight ratio of CNs to aniline in the suspension significantly influenced the size of the PANI particles and interaction between CNs and PANI. Moreover, electrical properties of the obtained PANI/CNs films were studied using standard four-probe technique. It is expected that the lyotropic N*-LCs of CNs might be available for an asymmetric reaction field to produce novel composites of conjugated materials.
A Compact Gas-Cooled Fast Reactor with an Ultra-Long Fuel Cycle
Authors: Choi Hangbok , Schleicher Robert W. , Gupta Puja
Published: April 2013

In an attempt to allow nuclear power to reach its full economic potential, General Atomics is developing the Energy Multiplier Module (EM2), which is a compact gas-cooled fast reactor (GFR). The EM2augments its fissile fuel load with fertile materials to enhance an ultra-long fuel cycle based on a “convert-and-burn” core design which converts fertile material to fissile fuel and burns it in situ over a 30-year core life without fuel supplementation or shuffling. A series of reactor physics trade studies were conducted and a baseline core was developed under the specific physics design requirements of the long-life small reactor. The EM2core performance was assessed for operation time, fuel burnup, excess reactivity, peak power density, uranium utilization, etc., and it was confirmed that an ultra-long fuel cycle core is feasible if the conversion is enough to produce fissile material and maintain criticality, the amount of matrix material is minimized not to soften the neutron spectrum, and the reactor core size is optimized to minimize the neutron loss. This study has shown the feasibility, from the reactor physics standpoint, of a compact GFR that can meet the objectives of ultra-long fuel cycle, factory-fabrication, and excellent fuel utilization.
Cytotoxic Activity of Six Samples of Brazilian Propolis on Sea Urchin (Lytechinus variegatus) Eggs
Authors: Fernandes-Silva C. C. , Freitas J. C. , Salatino A. , Salatino M. L. F.
Published: April 2013

The cytotoxic activities of extracts of four samples of propolis from the state of Minas Gerais (Southeast Brazil) and two from the state of Paraná (South Brazil) were evaluated using sea urchin (Lytechinus variegatus) eggs. Cytotoxic activity was observed, characterized mainly by the inhibition of the first cleavage of newly fertilized eggs. Methanol extracts at 32 µg mL−1of all samples were highly active (97–100%). Extracts were also prepared by successive treatments of the samples with hexane, chloroform, ethyl acetate, and methanol. High activity was observed using the ethyl acetate fractions of all samples, but hexane and chloroform fractions of some samples also had high activity. Based on the chemical composition of the extracts and fractions (published previously), it is hypothesized that the cytotoxic activities observed are due mainly to artepillin C,p-coumaric acid, and kaempferide. The results suggest that caffeoylquinic acids have no cytotoxic activity in sea urchin eggs.
Differentiating Blood, Lymph, and Primo Vessels by Residual Time Characteristic of Fluorescent Nanoparticles in a Tumor Model
Authors: Lee Sungwoo , Lim Jaekwan , Cha Jinmyung , Lee Jin-Kyu , Ryu Yeon Hee , Kim SungChul , Soh Kwang-Sup
Published: April 2013

Fluorescent nanoparticles (FNPs) which were injected into a tumor tissue flowed out through the blood and lymph vessels. The FNPs in blood vessels remained only in the order for few minutes while those in lymph vessels remained for a long time disappearing completely in 25 hours. We found a primo vessel inside a lymph vessel near a blood vessel, and FNPs remained in the primo vessel for longer than 25 hours. In addition, we examined in detail the residual time characteristics of lymph vessels because it could be useful in a future study of fluid dynamical comparison of the three conduits. These residual time characteristics of FNPs in the three kinds of vessels may have implications for the dynamics of nanoparticle drugs for cancer chemotherapy.
Transplantation of Bone Marrow-Derived Mesenchymal Stem Cells Promotes Delayed Wound Healing in Diabetic Rats
Authors: Wan Jiangbo , Xia Liulu , Liang Wenjia , Liu Yi , Cai Qian
Published: April 2013

In this paper, we established a delayed wound healing model on diabetic rat to mimic the pathophysiology of clinical patients who suffered from diabetic foot ulcers. We also evaluated if transplantation of allogeneic bone marrow-derived mesenchymal stem cells could promote the delayed wound healing and investigated the possible underlying biological mechanisms and stem cell behavior involved in this process. The results showed that bone marrow-derived mesenchymal stem cells had a positive effect on delayed wound healing in diabetic rats. Intramuscular transplantation demonstrated the best efficacy. This effect is associated with granulation tissue formation, angiogenesis, cellular proliferation, and high vascular endothelial growth factor expression in wound tissues. In addition, bone marrow-derived mesenchymal stem cells have been shown to mobilize and find home for ischemic and wounded tissues to participate in the process of wound healing. Intramuscular transplantation of exogenous isogeneic stem cells may be suitable for clinical application in the treatment of diabetic foot ulcers although the safety of this therapy should be considered.
Periodic Solution for Impulsive Cellar Neural Networks with Time-Varying Delays in the Leakage Terms
Authors: Liu Bingwen , Gong Shuhua
Published: April 2013

This paper is concerned with impulsive cellular neural networks with time-varying delays in leakage terms. Without assuming bounded and monotone conditions on activation functions, we establish sufficient conditions on existence and exponential stability of periodic solutions by using Lyapunov functional method and differential inequality techniques. Our results are complement to some recent ones.
The Neural Plasticity Theory of Depression: Assessing the Roles of Adult Neurogenesis and PSA-NCAM within the Hippocampus
Authors: Wainwright Steven R. , Galea Liisa A. M.
Published: April 2013

Depression is a devastating and prevalent disease, with profound effects on neural structure and function; however the etiology and neuropathology of depression remain poorly understood. Though antidepressant drugs exist, they are not ideal, as only a segment of patients are effectively treated, therapeutic onset is delayed, and the exact mechanism of these drugs remains to be elucidated. Several theories of depression do exist, including modulation of monoaminergic neurotransmission, alterations in neurotrophic factors, and the upregulation of adult hippocampal neurogenesis, and are briefly mentioned in the review. However none of these theories sufficiently explains the pathology and treatment of depression unto itself. Recently, neural plasticity theories of depression have postulated that multiple aspects of brain plasticity, beyond neurogenesis, may bridge the prevailing theories. The term “neural plasticity” encompasses an array of mechanisms, from the birth, survival, migration, and integration of new neurons to neurite outgrowth, synaptogenesis, and the modulation of mature synapses. This review critically assesses the role of adult hippocampal neurogenesis and the cell adhesion molecule, PSA-NCAM (which is known to be involved in many facets of neural plasticity), in depression and antidepressant treatment.
Hepatitis C Virus Infection: Looking for Interferon Free Regimens
Authors: González-Moreno J. , Payeras-Cifre A.
Published: April 2013

Recent developments of new drugs′ combinations are changing the treatment paradigm in hepatitis C virus infection. Due to the side effect profile of pegylated interferons, interferon‐sparing regimens have become the main target in chronic hepatitis C treatment research. Recent proofs of concept studies have suggested that cure of chronic hepatitis C can be achieved without interferon. The purpose of this paper is to provide an overview of the clinical results recently reported for the treatment of hepatitis C virus infection with interferon‐free regimens, focusing on the most promising new compounds and combinations.
Adaptive Exponential Synchronization of Coupled Complex Networks on General Graphs
Authors: Liu Song , Zhou Xianfeng , Jiang Wei , Fan Yizheng
Published: April 2013

We investigate the synchronization in complex dynamical networks, where the coupling configuration corresponds to a weighted graph. An adaptive synchronization method on general coupling configuration graphs is given. The networks may synchronize at an arbitrarily given exponential rate by enhancing the updated law of the variable coupling strength and achieve synchronization more quickly by adding edges to original graphs. Finally, numerical simulations are provided to illustrate the effectiveness of our theoretical results.
Spinal Cord Injury and Pressure Ulcer Prevention: Using Functional Activity in Pressure Relief
Authors: Stinson May , Schofield Rachel , Gillan Cathy , Morton Julie , Gardner Evie , Sprigle Stephen , Porter-Armstrong Alison
Published: April 2013

Background. People with spinal cord injury (SCI) are at increased risk of pressure ulcers due to prolonged periods of sitting. Concordance with pressure relieving movements is poor amongst this population, and one potential alternative to improve this would be to integrate pressure relieving movements into everyday functional activities.Objectives.To investigate both the current pressure relieving behaviours of SCI individuals during computer use and the application of an ergonomically adapted computer-based activity to reduce interface pressure.Design.Observational and repeated measures design.Setting.Regional Spinal Cord Injury Unit.Participants.Fourteen subjects diagnosed with SCI (12 male, 2 female).Intervention.Comparing normal sitting to seated movements and induced forward reaching positions.Main Outcome Measures.Interface pressure measurements: dispersion index (DI), peak pressure index (PPI), and total contact area (CA). The angle of trunk tilt was also measured.Results.The majority of movements yielded less than 25% reduction in interface pressure compared to normal sitting. Reaching forward by 150% of arm length during an adapted computer activity significantly reduced DI (P<0.05), angle of trunk tilt (p<0.05), and PPI for both ischial tuberosity regions (P<0.001) compared to normal sitting.Conclusion.Reaching forward significantly redistributed pressure at the seating interface, as evidenced by the change in interface pressures compared to upright sitting.
Image Denoising via Nonlinear Hybrid Diffusion
Authors: Ji Xiaoping , Zhang Dazhi , Guo Zhichang , Wu Boying
Published: April 2013

A nonlinear anisotropic hybrid diffusion equation is discussed for image denoising, which is a combination of mean curvature smoothing and Gaussian heat diffusion. First, we propose a new edge detection indicator, that is, the diffusivity function. Based on this diffusivity function, the new diffusion is nonlinear anisotropic and forward-backward. Unlike the Perona-Malik (PM) diffusion, the new forward-backward diffusion is adjustable and under control. Then, the existence, uniqueness, and long-time behavior of the new regularization equation of the model are established. Finally, using the explicit difference scheme (PM scheme) and implicit difference scheme (AOS scheme), we do numerical experiments for different images, respectively. Experimental results illustrate the effectiveness of the new model with respect to other known models.
Improved Performance of the Piezoelectric Monomorph with Perpendicular Electrode Connections for Sensing and Energy Harvesting
Authors: Ma Ming , Li Zhenrong , Wei Xiaoyong , Xu Zhuo , Yao Xi
Published: April 2013

Piezoelectric monomorph, which has only one element, is a potential structure for piezoelectric applications in some extreme conditions. But as the restriction of the strain neutral layer, the traditional parallel electrode connection is not effective for sensing and energy harvesting. In this paper, perpendicular electrode connections were designed to utilize the nonuniform shear piezoelectric effect in the cross section of the monomorph, which made the monomorph avoid the restriction of the strain neutral layer. The PZT5 ceramic monomorph was preliminarily studied in this experiment. By comparing seven forms of perpendicular electrode connections with the traditional parallel electrode connection, the whole superposed perpendicular electrode connection is considered as the optimal output way for the monomorph. It can produce 13 V peak-to-peak (pk-pk) voltage in open circuit and 14.56 μW maximum power with the matching resistance, which are much more than the parallel electrode connection 0.78 V and 0.14 μW.
The North American Fetal Therapy Network Registry Data on Outcomes of Radiofrequency Ablation for Twin-Reversed Arterial Perfusion Sequence
Authors: Lee Hanmin , Bebbington Michael , Crombleholme Timothy M. ,   for the North American Fetal Therapy Network (NAFTNet)
Published: April 2013

Objective: To report the North American Fetal Therapy Network (NAFTNet) Registry data on the outcomes of using radiofrequency ablation to treat twin-reversed arterial perfusion (TRAP). Methods: This was a retrospective review of the records of all patients who underwent percutaneous radiofrequency ablation of an acardiac twin after referral to 12 NAFTNet institutions between 1998 and 2008. Maternal, fetal and neonatal data were analyzed. The primary outcome was neonatal survival to 30 days of age. All participating sites conducted this study under institutional review board approval. Results: Of the 98 patients identified, there were no maternal deaths and no women required blood transfusions. Most women (76 of 98; 78%) stayed in the hospital for ≤1 day after the procedure. Mean gestational age at delivery was 33.4 weeks overall and 36.0 weeks for survivors. Median gestational age at delivery was 37.0 weeks. Survival of the pump twin to 30 days was 80% in the overall cohort. Conclusion: The NAFTNet registry data suggest that radiofrequency ablation of the acardiac twin is an effective treatment for TRAP sequence.
Increased Expression of Connective Tissue Growth Factor and Transforming Growth Factor-Beta-1 in Atrial Myocardium of Patients with Chronic Atrial Fibrillation
Authors: Li Yong , Jian Zhao , Yang Zong Ying , Chen Lin , Wang Xue Feng , Ma Rui Yan , Xiao Ying Bin
Published: April 2013

Objectives: This study aimed to investigate the roles of connective tissue growth factor (CTGF) and transforming growth factor-β1 (TGF-β1) in atrial fibrosis in patients with chronic atrial fibrillation. Methods: Up to 40 cases involving simple mitral valve replacement surgery were divided into 2 groups: the chronic atrial fibrillation (cAF) group (n = 28) and the sinus rhythm group (n = 12). Echocardiography was used to measure the cardiac cavity size and analyze the cardiac function. Right atrial specimens were obtained during the operation. The collagen volume fraction in the atrial specimens was examined. The mRNA and protein levels of TGF-β1, Smad3 and CTGF were also investigated. Results: Compared with the sinus rhythm group, the cAF group had higher collagen content in the right atrial tissues. The mRNA and protein levels of TGF-β1, Smad3 and CTGF were also significantly elevated in the cAF group (p < 0.05). The mRNA and protein levels of TGF-β1 and CTGF in the cAF group correlated positively with the collagen volume fraction. The positive correlation between the expression of TGF-β1 and CTGF was also demonstrated. Conclusions: CTGF is upregulated via the TGF-β1/Smad pathway in the atrial myocardium of cAF patients. Furthermore, the TGF-β1/Smad pathway may play an important role in the structural remodeling during atrial fibrosis.
Infantile Hypertrophic Cardiomyopathy Associated with a Novel MYL3 Mutation
Authors: Jay Allison , Chikarmane Rashmi , Poulik Janet , Misra Vinod K.
Published: April 2013

Mutations in genes encoding cardiac sarcomeric proteins are thought to be a very rare cause of hypertrophic cardiomyopathy (HCM) in infants and young children. We report on genetic and histopathological findings in a 3-month-old infant presenting with severe progressive HCM arising from a mutation in the gene encoding the essential light chain of myosin (MYL3). The patient was found to have a novel, paternally inherited pathogenic c.530 A>G mutation in exon 5 of the MYL3 gene. His father was asymptomatic. Although, MYL3 mutations have been previously associated with adult-onset HCM, it has not been seen in infantile forms. As such, this case adds to the emerging evidence demonstrating that familial disease associated with mutations in cardiac sarcomere protein genes may have an important role in infants and children with HCM. In addition, this case highlights the marked phenotypic heterogeneity associated with sarcomeric protein mutations both within and between families.
Renin Angiotensin Antagonists Normalize Aberrant Activation of Epithelial Sodium Channels in Sodium-Sensitive Hypertension
Authors: Ushio-Yamana Hisako , Minegishi Shintaro , Ishigami Tomoaki , Araki Naomi , Umemura Masanari , Tamura Koichi , Maeda Emi , Kakizoe Yutaka , Kitamura Kenichiro , Umemura Satoshi
Published: April 2013

Epithelial sodium channels (ENaC) are ion transporters in the aldosterone-sensitive distal nephron that play an important role in sodium reabsorption in the terminal nephron. Our study of inbred C57Bl6/J mice given a high-sodium diet showed increased ENaC expression accompanied by tubular renin activation on qRT-PCR of laser-captured tubule specimens and Western blotting of membrane proteins, despite inhibition of aldosterone. Treatment with an angiotensin-converting-enzyme inhibitor (ACEI) or an angiotensin receptor blocker (ARB) effectively lowered blood pressure. In addition to lowering blood pressure, ACEI and ARB inhibition downregulated ENaC and renin expression in renal tubules. These effects would act to suppress sodium reabsorption via ENaC and normalize molecular mechanisms that elevate blood pressure in response to increased salt intake.
Secondary Membranous Nephropathy Associated with Guillain-Barré Syndrome
Authors: Filippone Edward J. , Kanzaria Mitul , Bell Rodney , Newman Eric , Farber John L.
Published: April 2013

Membranous nephropathy (MN) is one of the most common causes of nephrotic syndrome (NS) in adults. It may be primary, usually mediated by IgG4 anti-phospholipase A2 autoantibodies or secondary to various other conditions. Guillain- Barré syndrome (GBS) has been associated with MN, but a cause and effect relation has not been proven. We present a case of concurrent development of GBS and severe NS, with renal biopsy demonstrating MN. IgG4 stain was negative, indicating that most likely, the MN was secondary and probably caused by the underlying GBS.
Bleeding symptoms at disease presentation and prediction of ensuing bleeding in inherited FVII deficiency
Authors: Dolce Alberto , Mariani Guglielmo , Di Minno Matteo Nicola ,   the STER Study Group
Published: April 2013

Individuals with inherited factor VII (FVII) deficiency display bleeding phenotypes ranging from mild to severe, with 30% of patients having always been asymptomatic (non-bleeding). In 626 FVII-deficient individuals, by analysing data from the International Factor VII (IF7) Registry and the Seven Treatment Evaluation Registry (STER), we determined whether bleeding type at disease presentation and FVII coagulant activity (FVIIc) predict ensuing bleeds. At disease presentation/diagnosis, 272 (43.5%) individuals were non-bleeding, 277 (44.2%) had minor bleeds, and 77 (12.3%) had major bleeds. During a median nine-year index period (IP) observation, 87.9% of non-bleeding individuals at presentation remained asymptomatic, 75.1% of minor-bleeders had new minor bleeds, and 83.1% of major-bleeders experienced new major bleeds. After adjusting for FVIIc levels and other clinical and demographic variables, the relative risk (RR) for ensuing bleedings during the IP was 6.02 (p <0.001) and 5.87 (p <0.001) in individuals presenting with major and minor bleeds, respectively. Conversely, compared to non-bleeding individuals, a 10.95 (p = 0.001) and 28.21 (p <0.001) RR for major bleedings during the IP was found in those with minor and with major bleeds at presentation, respectively. In conclusion, in FVII deficiency, the first major bleeding symptom is an independent predictor of the risk of subsequent major bleeds.