bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of functional properties of Enterococcus faecium strains isolated from human gut
Authors: İspirli Hümeyra , Demirbaş Fatmanur , Dertli Enes
Published: September 2015

The aim of this work was to characterize the functional properties of Enterococcus faecium strains identified after isolation from human faeces. Of these isolates, strain R13 showed the best resistance to low pH, bile salts, and survival in the simulated in vitro digestion assay, and demonstrated an important level of adhesion to hexadecane as a potential probiotic candidate. Analysis of the antibiotic resistance of E. faecium strains indicated that in general these isolates were sensitive to the tested antibiotics and no strain appeared to be resistant to vancomycin. Examination of the virulence determinants for E. faecium strains demonstrated that all strains contained the virulence genes common in gut- and food-originated enterococci, and strain R13 harboured the lowest number of virulence genes. Additionally, no strain contained the genes related to cytolysin metabolism and showed hemolytic activity. The antimicrobial role of E. faecium strains was tested against several pathogens, in which different levels of inhibitory effects were observed, and strain R13 was inhibitory to all tested pathogens. PCR screening of genes encoding enterocin A and B indicated the presence of these genes in E. faecium strains. Preliminary characterization of bacteriocins revealed that their activity was lost after proteolytic enzyme treatments, but no alteration in antimicrobial activity was observed at different pHs (3.5 to 9.5) and after heat treatments. In conclusion, this study revealed the functional characteristics of E. faecium R13 as a gut isolate, and this strain could be developed as a new probiotic after further tests.
Evaluation of a ship-based unoccupied aircraft system (UAS) for surveys of spotted and ribbon seals in the Bering Sea pack ice
Authors: Moreland Erin E. , Cameron Michael F. , Angliss Robyn P. , Boveng Peter L.
Published: September 2015

The remote pack ice of the arctic and subarctic seas is challenging to access, yet extremely important to understand and monitor. The pack ice holds the key to understanding ecosystem responses to climate change and is vital habitat for many species including ice-associated seals. Unoccupied aircraft systems (UAS) are a new class of tools that may overcome the traditional challenges associated with expansive offshore surveys. We conducted UAS flights over the pack ice during a spring 2009 National Oceanic and Atmospheric Administration (NOAA) cruise to the Bering Sea to determine whether advances in UAS technology can enable effective large-scale, systematic ship-based surveys for seals in the seasonal ice of the Bering, Beaufort, and Chukchi Seas. A fixed-wing ScanEagle UAS was successfully launched and recovered from the NOAA ship McArthur II to conduct small-scale transect surveys up to 5 nautical miles (M) from the ship's position. More than 27 000 images were collected from 10 flights over the Bering Sea pack ice and seals were identified in 110 of these images. Review of the images indicated a marked reduction in disturbance to seals when compared to images collected from occupied, low-altitude helicopter surveys. These results suggest that large-scale UAS surveys of arctic and subarctic habitat in United States airspace will be possible with improvements in technology, reduced operational costs, and the establishment of inclusive airspace regulations.
Quantitative Analysis of Rat Dorsal Root Ganglion Neurons Cultured on Microelectrode Arrays Based on Fluorescence Microscopy Image Processing
Authors: Mari João Fernando , Saito José Hiroki , Neves Amanda Ferreira , Lotufo Celina Monteiro da Cruz , Destro-Filho João-Batista , Nicoletti Maria do Carmo
Published: September 2015

Microelectrode Arrays (MEA) are devices for long term electrophysiological recording of extracellular spontaneous or evocated activities on in vitro neuron culture. This work proposes and develops a framework for quantitative and morphological analysis of neuron cultures on MEAs, by processing their corresponding images, acquired by fluorescence microscopy. The neurons are segmented from the fluorescence channel images using a combination of segmentation by thresholding, watershed transform, and object classification. The positioning of microelectrodes is obtained from the transmitted light channel images using the circular Hough transform. The proposed method was applied to images of dissociated culture of rat dorsal root ganglion (DRG) neuronal cells. The morphological and topological quantitative analysis carried out produced information regarding the state of culture, such as population count, neuron-to-neuron and neuron-to-microelectrode distances, soma morphologies, neuron sizes, neuron and microelectrode spatial distributions. Most of the analysis of microscopy images taken from neuronal cultures on MEA only consider simple qualitative analysis. Also, the proposed framework aims to standardize the image processing and to compute quantitative useful measures for integrated image-signal studies and further computational simulations. As results show, the implemented microelectrode identification method is robust and so are the implemented neuron segmentation and classification one (with a correct segmentation rate up to 84%). The quantitative information retrieved by the method is highly relevant to assist the integrated signal-image study of recorded electrophysiological signals as well as the physical aspects of the neuron culture on MEA. Although the experiments deal with DRG cell images, cortical and hippocampal cell images could also be processed with small adjustments in the image processing parameter estimation.
A Preclinical Study of Laryngeal Motor-Evoked Potentials as a Marker Vagus Nerve Activation
Authors: Grimonprez Annelies , Raedt Robrecht , De Taeye Leen , Larsen Lars Emil , Delbeke Jean , Boon Paul , Vonck Kristl
Published: September 2015

Vagus nerve stimulation (VNS) is a treatment for refractory epilepsy and depression. Previous studies using invasive recording electrodes showed that VNS induces laryngeal motor-evoked potentials (LMEPs) through the co-activation of the recurrent laryngeal nerve and subsequent contractions of the laryngeal muscles. The present study investigates the feasibility of recording LMEPs in chronically VNS-implanted rats, using a minimally-invasive technique, to assess effective current delivery to the nerve and to determine optimal VNS output currents for vagal fiber activation. Three weeks after VNS electrode implantation, signals were recorded using an electromyography (EMG) electrode in the proximity of the laryngeal muscles and a reference electrode on the skull. The VNS output current was gradually ramped up from 0.1 to 1.0 mA in 0.1 mA steps. In 13/27 rats, typical LMEPs were recorded at low VNS output currents (median 0.3 mA, IQR 0.2–0.3 mA). In 11/27 rats, significantly higher output currents were required to evoke electrophysiological responses (median 0.7 mA, IQR 0.5–0.7 mA, [Formula: see text]). The latencies of these responses deviated significantly from LMEPs ([Formula: see text]). In 3/27 rats, no electrophysiological responses to simulation were recorded. Minimally invasive LMEP recordings are feasible to assess effective current delivery to the vagus nerve. Furthermore, our results suggest that low output currents are sufficient to activate vagal fibers.
Framed 4-valent graph minor theory II: Special minors and new examples
Authors: Manturov Vassily Olegovich
Published: September 2015

In the present paper, we proceed with the study of framed 4-graph minor theory initiated in [V. O. Manturov, Framed 4-valent graph minor theory I: Intoduction planarity criterion, arxiv: 1402.1564v1 [Math.Co]] and justify the planarity theorem for arbitrary framed 4-graphs; besides, we prove analogous results for embeddability in [Formula: see text].
Virtual links in arbitrary dimensions
Authors: Winter Blake K.
Published: September 2015

We define a generalization of virtual links to arbitrary dimensions by extending the geometric definition due to Carter et al. We show that many homotopy type invariants for classical links extend to invariants of virtual links. We also define generalizations of virtual link diagrams and Gauss codes to represent virtual links, and use such diagrams to construct a combinatorial biquandle invariant for virtual [Formula: see text]-links. In the case of [Formula: see text]-links, we also explore generalizations of Fox–Milnor movies to the virtual case. In addition, we discuss definitions extending the notion of welded links to higher dimensions.
The Pre-Holiday Effect in China: Abnormal Returns or Compensation for Risk?
Authors: Yuan Tian , Gupta Rakesh , Bianchi Robert J.
Published: September 2015

This study examines the pre-holiday effect in the Chinese stock market. It provides new insights into the weak-form efficiency of China's equity market indexes. Using the GARCH (1,1) model, we find the pre-holiday effect in broad-based Chinese stock returns and in size, value and growth style indexes. Further analysis using a GARCH (1,1)-M model suggests that the pre-holiday effect at both market and industry/sector levels can be attributed to time-varying risk. We show the pre-holiday effect reflects abnormal returns in small-cap, large-cap and growth style indexes while this same effect reflects compensation for bearing risk in value stocks.
The functional Itō formula under the family of continuous semimartingale measures
Authors: Oberhauser Harald
Published: September 2015

Dupire [16] introduced a notion of smoothness for functionals of paths and arrived at a generalization of Itō’s formula that applies to functionals with a continuous dependence on the trajectories of the underlying process. In this paper, we study nonlinear functionals that do not have such continuity. By revisiting old work of Bichteler and Karandikar we show that one can construct pathwise versions of complex functionals like the quadratic variation, stochastic integrals or Itō processes that are still regular enough such that a functional Itō-formula applies.
Optimization problem under change of regime of interest rate
Authors: Iftimie Bogdan , Jeanblanc Monique , Lim Thomas
Published: September 2015

In this paper, we study the problem of maximization of the expected value of the sum of the utility of the terminal wealth and the utility of the consumption, in a case where some sudden jumps in the risk-free interest rate create incompleteness. To solve the problem we use the dual approach. We characterize the value function of the dual problem by a BSDE and the duality between the primal and the dual value functions is exploited to study the BSDE associated to the primal problem.
Non-uniform bound and finite time blow up for solutions to a drift–diffusion equation in higher dimensions
Authors: Ogawa Takayoshi , Wakui Hiroshi
Published: September 2015

We show the non-uniform bound for a solution to the Cauchy problem of a drift–diffusion equation of a parabolic–elliptic type in higher space dimensions. If an initial data satisfies a certain condition involving the entropy functional, then the corresponding solution to the equation does not remain uniformly bounded in a scaling critical space. In other words, the solution grows up at [Formula: see text] in the critical space or blows up in a finite time. Our presenting results correspond to the finite time blowing up result for the two-dimensional case. The proof relies on the logarithmic entropy functional and a generalized version of the Shannon inequality. We also give the sharp constant of the Shannon inequality.
DFT study and topological analysis of the bonding in DNA Hoogsteen-type base pairs
Authors: Amraoui Nour Elyakine , Hammoutène Dalila
Published: September 2015

The purpose of our work is to characterize and present a theoretical comparative study of a variety of compounds based on DNA base pairs linked with some transition metal ions in gas phase: C–M–G (Cytosine–metal–Guanine) where [Formula: see text](I), Zn(II), Cd(II) and A–M–T (Adenine–metal–Thyminate) where [Formula: see text](II), Ru(I), Ni(I), Y(II), Zn(I), Cd(I), Cu(II). Geometry optimization and frequency calculations were carried out at DFT/ZORA/BLYP-D/TZ2P level. M–N and M–O bonds were investigated with the quantum chemical topology (QCT): Quantum theory of atoms in molecules (QTAIM) and electron localization functions (ELF). The hydrogen bonds: N10–H[Formula: see text]O7 for A–M–T complexes and N7–H[Formula: see text]O10 for C–M–T ones were visualized and discussed, QTAIM and ELF prove the existence of O7–H[Formula: see text]N10 hydrogen bond for some A–M–T systems, since the bond critical point (BCP) of N7–H having [Formula: see text], so it has a covalent character confirming the existence of a tautomer process of these complexes. Bonding energy [Formula: see text], Pauli repulsion [Formula: see text], electrostatic [Formula: see text], and orbital [Formula: see text] interactions were represented and compared together. Hirschfeld’s charges showed the existence of charge transfer process in the bridge moieties. It seems that, in contrast to natural base pairs that are stabilized by hydrogen bonding, Hoogsteen-type base pairs are held together by coordinative bond with metal ions.
Fluorescent Realgar Quantum Dots: New Life for an Old Drug
Authors: Wu J. Z. , Chen G. , Shao Y. B. , Liu J. , Sun Y. C. , Lin H. S. , Ho Paul C.
Published: September 2015

Quantum dots (QDs) possess unique properties that are expected for various applications. Herein, realgar (As4S4) QDs were synthesized via a wet chemical method in a coordinating solvent (e.g., ethanolamine (EA)) with assistance of an acid (e.g., citric acid (CA)). The as-prepared realgar QDs using EA and CA have a narrow size distribution with a mean value of 5.48[Formula: see text]nm and a relative standard deviation of [Formula: see text]20%, and exhibit bright photoluminescence (PL) in a short wavelength window ([Formula: see text] 480[Formula: see text]nm) with high quantum yield up to 70%. Moreover, realgar QDs can retain their high PL after one-year storage, indicating their excellent stability. Bulk realgar is a commonly used traditional medicine, however, its water-insolubility limits its broad applications. Realgar QDs could be an alternative for the bulk realgar owing to their excellent water-solubility and efficient PL. In preliminary in vivo toxic and pharmaceutical experiments, the synthesized realgar QDs at a single oral dose of 10.0[Formula: see text]mg realgar/kg body weight for 21 days showed tolerability in healthy mice and effective against tumor-bearing nude mice, respectively. In this study, assembly of realgar QDs into specific hollow nanospheres was first constructed by introducing an acid into their original colloidal solution. Simple dissolution of such assemblies in EA can partially return them into the fluorescent QDs. Such property is desired for a variety of media-responsive luminescence materials. In addition, a flexible inorganic/organic hybrid composite film was fabricated for the first time by incorporation of realgar QDs into polyvinyl alcohol matrix. The resulting film presents excellent PL, good transparency, intense mechanical strength and facile processibility, which meet the requirements for device integration.
Cr-Doped TiO2 Core–Shell Nanospheres with Enhanced Photocatalytic Activity and Lithium Storage Capacity
Authors: Xu Hui , Zeng Min , Li Jing , Li Fuyun
Published: September 2015

Cr-doped TiO2 core-shell nanospheres have been prepared by a facile one-pot hydrothermal process. The as-prepared Cr–TiO2 nanospheres exhibit not only a high visible light activity, but also an excellent lithium storage capacity. Various characterization methods indicate that Cr[Formula: see text] ions are uniformly distributed into the TiO2 lattice and a doping level emerges in the bandgap of TiO2, which leads to a prominent photocatalytic activity. When the Cr–TiO2 nanospheres are employed as lithium battery electrodes, the high lithium storage capacity of Cr2O3 and the p-type conductivity of TiO2 due to doping may be beneficial to improve the electrochemical performances of these electrodes.
A ppb-Level Formaldehyde Gas Sensor Based on Rose-Like Nickel Oxide Nanoparticles Prepared Using Electrodeposition Process
Authors: Zhang Yong , Xie Long-Zhen , Yuan Chao-Xin , Zhang Chun-Lin , Liu Su , Peng Ying-Quan , Li Hai-Rong , Zhang Miao
Published: September 2015

In this study, rose-like nickel oxide nanoparticles (diameter of 400–500[Formula: see text]nm) were prepared on indium tin oxide (ITO) glass substrates by a simple electrodeposition in NiSO[Formula: see text]6H2O solution. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscope (TEM) were used for analysis of the NiO nanoparticles. The effects of operating temperature on the sensor response and the response versus gas concentration properties of the NiO nanorose-based sensors were investigated. We determined the operating temperature of the gas sensors to be 230[Formula: see text]C, considering the proper sensitivity and a rapid response. In addition, gas-sensing characteristics of rose-like NiO nanoparticles to formaldehyde were investigated. It was shown that the sensors exhibited good response ([Formula: see text]/[Formula: see text]) properties to formaldehyde gas at 230[Formula: see text]C, making them to be promising candidates for practical detectors to formaldehyde gas.
A characterization of the weighted version of McEliece–Rodemich–Rumsey–Schrijver number based on convex quadratic programming
Authors: Luz Carlos J.
Published: September 2015

For any graph [Formula: see text] Luz and Schrijver [A convex quadratic characterization of the Lovász theta number, SIAM J. Discrete Math. 19(2) (2005) 382–387] introduced a characterization of the Lovász number [Formula: see text] based on convex quadratic programming. A similar characterization is now established for the weighted version of the number [Formula: see text] independently introduced by McEliece, Rodemich, and Rumsey [The Lovász bound and some generalizations, J. Combin. Inform. Syst. Sci. 3 (1978) 134–152] and Schrijver [A Comparison of the Delsarte and Lovász bounds, IEEE Trans. Inform. Theory 25(4) (1979) 425–429]. Also, a class of graphs for which the weighted version of [Formula: see text] coincides with the weighted stability number is characterized.
The singular values of the GUE (less is more)
Authors: Edelman Alan , La Croix Michael
Published: September 2015

Some properties that nominally involve the eigenvalues of the Gaussian Unitary Ensemble (GUE) can instead be phrased in terms of singular values. By discarding the signs of the eigenvalues, we gain access to a surprising decomposition: the singular values of the GUE are distributed as the union of the singular values of two independent ensembles of Laguerre type. This independence is remarkable given the well-known phenomenon of eigenvalue repulsion. The structure of this decomposition reveals that several existing observations about large [Formula: see text] limits of the GUE are in fact manifestations of phenomena that are already present for finite random matrices. We relate the semicircle law to the quarter-circle law by connecting Hermite polynomials to generalized Laguerre polynomials with parameter [Formula: see text]. Similarly, we write the absolute value of the determinant of the [Formula: see text] GUE as a product [Formula: see text] independent random variables to gain new insight into its asymptotic log-normality. The decomposition also provides a description of the distribution of the smallest singular value of the GUE, which in turn permits the study of the leading order behavior of the condition number of GUE matrices. The study is motivated by questions involving the enumeration of orientable maps, and is related to questions involving powers of complex Ginibre matrices. The inescapable conclusion of this work is that the singular values of the GUE play an unpredictably important role that had gone unnoticed for decades even though, in hindsight, so many clues had been around.
Moving Object Detection in Real-Time Using Stereo from a Mobile Platform
Authors: Derome Maxime , Plyer Aurelien , Sanfourche Martial , Besnerais Guy Le
Published: September 2015

This paper presents a mobile object detection algorithm which performs with two consecutive stereo images. Like most motion detection methods, the proposed one is based on dense stereo matching and optical flow (OF) estimation. Noting that the main computational cost of existing methods is related to the estimation of OF, we propose to use a fast algorithm based on Lucas–Kanade paradigm. We then derive a comprehensive uncertainty model by taking into account all the estimation errors occurring during the process. In contrast with most previous works, we rigorously expand the error related to vision based ego-motion estimation. Finally, we present a comparative study of performance on the challenging KITTI dataset which demonstrates the effectiveness of the proposed approach.
An Automatic Self-Calibration Approach for Wide Baseline Stereo Cameras Using Sea Surface Images
Authors: Wang Han , Mou Wei , Mou Xiaozheng , Yuan Shenghai , Ulun Soner , Yang Shuai , Shin Bok-Suk
Published: September 2015

Stereo rig with wide baseline is necessary when accurate depth estimation for distant object is desired. However, in order to make calibration pattern to be viewed from both left and right cameras, the wider the baseline the bigger the calibration pattern is required.

In contrast to the traditional stereo calibration method using calibration pattern, we propose a self-calibration approach that can estimate cameras' rotation matrices for stereo rig with wide baseline (3 m). Given images taken from left and right cameras, the relative roll and pitch angles between two cameras are recovered by aligning sea horizon in left and right images. The pitch angle is estimated by making the projections of one point at infinite distance appear at the same location in both images. A photometric minimization is applied to refine the rotation parameters. Compared with conventional checkerboard-based calibration techniques which require extra equipments or personnel, our approach only needs a pair of sea images. Moreover, unlike most self-calibration approaches, feature detection and matching are not required which makes it possible to apply our approach on featureless images. As a result, it is flexible and easy to implement our approach on sea surface images. Real world experiments demonstrate the feasibility of our approach.
Low-Overhead FPGA Middleware for Application Portability and Productivity
Authors: Kirchgessner Robert , George Alan D. , Stitt Greg
Published: September 2015

Reconfigurable computing devices such as field-programmable gate arrays (FPGAs) offer advantages over fixed-logic CPU and GPU architectures, including improved performance, superior power efficiency, and reconfigurability. The challenge of FPGA application development, however, has limited their acceptance in high-performance computing and high-performance embedded computing applications. FPGA development carries similar difficulties to hardware design, requiring that developers iterate through register-transfer level designs with cycle-level accuracy. Furthermore, the lack of hardware and software standards between FPGA platforms limits productivity and application portability, and makes porting applications between heterogeneous platforms a time-consuming and often challenging process. Recent efforts to improve FPGA productivity using high-level synthesis tools and languages show promise, but platform support remains limited and typically is left as a challenge for developers. To address these issues, we present RC Middleware (RCMW), a novel middleware that improves productivity and enables application and tool portability by abstracting away platform-specific details. RCMW provides an application-centric development environment, exposing only the resources and standardized interfaces required by an application, independent of the underlying platform. We demonstrate the portability and productivity benefits of RCMW using four heterogeneous platforms from three vendors. Our results indicate that RCMW enables application productivity and improves developer productivity, and that these benefits are achieved with less than 7% performance and 3% area overhead on average.
A Sliding Window Phase-Only Correlation Method for Side-Channel Alignment in a Smartphone
Authors: Gebotys Catherine H. , White Brian A.
Published: September 2015

Future wireless embedded devices will be increasingly powerful, supporting many more applications including one of the most crucial, security. Although many embedded devices offer resistance to bus probing attacks due to their compact size and high levels of integration, susceptibility to attacks on their electromagnetic side channel must be analyzed. This side channel is often quite complex to analyze due to the complexities of the embedded device including operating system, interrupts, and so forth. This article presents a new methodology for analyzing a complex system's vulnerability to the EM side channel. The methodology proposes a sliding window phase-only correlation method for aligning electromagnetic emanations from a complex smartphone running native code utilizing an on-chip cache. Unlike previous research, experimental results demonstrate that data written to on-chip cache within an advanced 312MHz 0.13um processor executing AES can be attacked utilizing this new methodology. Furthermore, for the first time, it has been shown that the point of side-channel attack is not a spike of increased EM but an area of low EM amplitude, unlike what is noted in previous findings. This research is important for advancing side-channel analysis understanding in complex embedded processors and ensuring secure implementations in future embedded ubiquitous devices.
STM-HRT
Authors: Cotard Sylvain , Queudet Audrey , Béchennec Jean-Luc , Faucou Sébastien , Trinquet Yvon
Published: September 2015

This article introduces STM-HRT, a nonblocking wait-free software transactional memory (STM) for hard real-time (HRT) multicore embedded systems. Resource access control in HRT systems is usually implemented with lock-based synchronization. However, these mechanisms may lead to deadlocks or starvations and do not scale well with the number of cores. Most existing nonblocking STM are not suitable for HRT systems, because it is not possible to find an upper bound of the execution time for each task. In this article, we show how STM-HRT can be a robust solution for resource sharing in HRT multicore systems. We provide a detailed description of STM-HRT architecture. We propose a set of arguments to establish the functional correctness of its concurrency control protocol. Finally, as part of a real-time analysis, we derive upper bounds on the computations required to access shared data under STM-HRT.
On the Role of Structural Holes in Requirements Identification
Authors: Bhowmik Tanmay , Niu Nan , Singhania Prachi , Wang Wentao
Published: September 2015

Requirements identification is a human-centric activity that involves interaction among multiple stakeholders. Traditional requirements engineering (RE) techniques addressing stakeholders’ social interaction are mainly part of a centralized process intertwined with a specific phase of software development. However, in open-source software (OSS) development, stakeholders’ social interactions are often decentralized, iterative, and dynamic. Little is known about new requirements identification in OSS and the stakeholders’ organizational arrangements supporting such an activity. In this article, we investigate the theory of structural hole from the context of contributing new requirements in OSS projects. Structural hole theory suggests that stakeholders positioned in the structural holes in their social network are able to produce new ideas. In this study, we find that structural hole positions emerge in stakeholders’ social network and these positions are positively related to contributing a higher number of new requirements. We find that along with structural hole positions, stakeholders’ role is also an important part in identifying new requirements. We further observe that structural hole positions evolve over time, thereby identifying requirements to realize enriched features. Our work advances the fundamental understanding of the RE process in a decentralized environment and opens avenues for improved techniques supporting this process.
On-the-Fly Pipeline Parallelism
Authors: Lee I-Ting Angelina , Leiserson Charles E. , Schardl Tao B. , Zhang Zhunping , Sukha Jim
Published: September 2015

Pipeline parallelism organizes a parallel program as a linear sequence of stages. Each stage processes elements of a data stream, passing each processed data element to the next stage, and then taking on a new element before the subsequent stages have necessarily completed their processing. Pipeline parallelism is used especially in streaming applications that perform video, audio, and digital signal processing. Three out of 13 benchmarks in PARSEC, a popular software benchmark suite designed for shared-memory multiprocessors, can be expressed as pipeline parallelism.

Whereas most concurrency platforms that support pipeline parallelism use a “construct-and-run” approach, this article investigates “on-the-fly” pipeline parallelism, where the structure of the pipeline emerges as the program executes rather than being specified
a priori
. On-the-fly pipeline parallelism allows the number of stages to vary from iteration to iteration and dependencies to be data dependent. We propose simple linguistics for specifying on-the-fly pipeline parallelism and describe a provably efficient scheduling algorithm, the P
iper
algorithm, which integrates pipeline parallelism into a work-stealing scheduler, allowing pipeline and fork-join parallelism to be arbitrarily nested. The P
iper
algorithm automatically throttles the parallelism, precluding “runaway” pipelines. Given a pipeline computation with
T
1
work and
T
∞
span (critical-path length), P
iper
executes the computation on
P
processors in

T
P

≤
T
1
/
P
+
O
(
T
∞+lg
P
) expected time. P
iper
also limits stack space, ensuring that it does not grow unboundedly with running time.

We have incorporated on-the-fly pipeline parallelism into a Cilk-based work-stealing runtime system. Our prototype Cilk-P implementation exploits optimizations such as “lazy enabling” and “dependency folding.” We have ported the three PARSEC benchmarks that exhibit pipeline parallelism to run on Cilk-P. One of these,
x264
, cannot readily be executed by systems that support only construct-and-run pipeline parallelism. Benchmark results indicate that Cilk-P has low serial overhead and good scalability. On
x264
, for example, Cilk-P exhibits a speedup of 13.87 over its respective serial counterpart when running on 16 processors.
Measures for Predicting Software Reliability using Time Recurrent Neural Networks with Back-propagation
Authors: Bhuyan Manmath Kumar , Mohapatra Durga Prasad , Sethi Srinivas
Published: September 2015

Recurrent Neural Network (RNN)
has been known to be very useful in predicting software reliability. A number of parametric models and reliability growth models, have been proposed, but developing a model that can predict reliability in all types of data sets, in any environment, and at any phase of software development is still a challenge. In this paper, we propose a model that explores the applicability of
Recurrent Neural Network with Back- propagation Through Time (RNNBPTT)
learning rule to predict software reliability. The detailed procedure of reliability prediction using recurrent neural networks is explained. The model has been applied on data sets collected across several standard software projects during system testing phase with fault removal. Though the procedure is relatively complicated, the results depicted in this work suggest that Fully Recurrent Neural Networks (FRNN) exhibits an accurate and consistent behavior in reliability prediction.
Trends in empirical research
Authors: Falessi Davide , Codabux Zadia , Rong Guoping , Stamelos Ioannis , Ferreira Waldemar , Wiese Igor Scaliante , Barreiros Emanoel , Quesada-Lopez Christian , Tsirakidis Periklis
Published: September 2015

The 12th Doctoral Symposium on Empirical Software Engineering (IDOESE), was organized as a full day event prior to the ACM / IEEE International Symposium on Empirical Software Engineering and Measurement (ESEM) program. Seven PhD candidates came from different research institutes across the globe to present their research proposals at the symposium. The symposium was run in a lively and interactive manner. The candidates received constructive feedback on their proposals from all the symposium participants. In this report, we describe the presented proposals, focusing on the content and feedback. Through them, we can take a peek at the trends and emerging areas of empirical software engineering research.
Information Systems in Distributed Environments
Authors: Mishra Alok , Münch Jürgen , Mishra Deepti
Published: September 2015

This is a report from a one-day fourth international workshop on "Information Systems in Distributed Environments" (ISDE), which was organized in conjunction with the OnTheMove Federated Conferences & Workshops (OTM 2014) October 29-30, 2014, Amantea, Calabria, Italy. The main focus of this event was to provide a venue for the discussion of challenges related to the development, operation, and maintenance of distributed information systems, and their creation in the context of global development projects. Further dissemination of research results will lead to an improvement of distributed information system development and deployment across the globe.
Summary of 2nd International Workshop on Requirements Engineering and Testing (RET 2015)
Authors: Bjarnason Elizabeth , Borg Markus , Morandini Mirko , Unterkalmsteiner Michael , Felderer Michael , Staats Matthew
Published: September 2015

The RET (Requirements Engineering and Testing) workshop series provides a meeting point for researchers and practitioners from the two separate fields of Requirements Engineering (RE) and Testing. The goal is to improve the connection and alignment of these two areas through an exchange of ideas, challenges, practices, experiences and results. The long term aim is to build a community and a body of knowledge within the intersection of RE and Testing, i.e. RET. The 2nd workshop was held in co-location with ICSE 2015 in Florence, Italy. The workshop continued in the same interactive vein as the 1st one and included a keynote, paper presentations with ample time for discussions, and a group exercise. For true impact and relevance this cross-cutting area requires contribution from both RE and Testing, and from both researchers and practitioners. A range of papers were presented from short experience papers to full research papers that cover connections between the two fields. One of the main outputs of the 2nd workshop was a categorization of the presented workshop papers according to an initial definition of the area of RET which identifies the aspects RE, Testing and coordination effect.
Twin Peaks goes Agile
Authors: Galster Matthias , Mirakhorli Mehdi , Koziolek Anne
Published: September 2015

Activities related to software requirements engineering and software architecture significantly contribute to the success of software development projects. In software engineering practice, requirements and architecture affect each other and should not be treated in isolation. However, from a research and conceptual perspective, the dependencies between requirements and architecture are usually investigated by focusing on either requirements engineering or software architecture. Therefore, the Fifth International Workshop on the Twin Peaks of Requirements and Architecture explored the relationship between requirements and software architecture in the broader context of software engineering in general. Based on the outcomes of previous editions of the workshop, this edition aimed at exploring the relationship between requirements and architecture in the context of agile software development. In general, the discussions at the workshop centered on proactive versus reactive software architecture engineering. We found that proactive architecture engineering provides benefits in certain contexts and domains. However, in order to succeed in competitive and fast-moving markets, reactive software architecture engineering may be more suitable, even though reactive architecture engineering could be difficult to in practice since it may require a different mindset from requirements engineers and architects.
SIGCSE conference report
Authors: Decker Adrienne , Eiselt Kurt
Published: September 2015

SIGCSE 2015, held in Kansas City March 4-7, brought together 1,285 computer science educators. Keynote speaker Jessica Hodgins, Vice President of Disney Research and Professor at Carnegie Mellon University, opened the conference talking about blending the creative and the technical in courses at Carnegie Mellon. Keith Hampton, Associate Professor at Rutgers University, closed SIGCSE with the luncheon talk about his work on the impact of social media on its users and its ability to keep us connected.
ICER preview
Authors: Dorn Brian , Cutts Quintin , Sheard Judy
Published: September 2015

We are thrilled to welcome our colleagues to ICER 2015 in Omaha, Nebraska!

The youngest of the SIGCSE-sponsored conferences, the ACM International Computing Education Research (ICER), is just beginning its second decade, but it has already has developed a unique character. This year is shaping up to be another exciting conference, filled with late-breaking computing education research results, and our host city has a lot to offer attendees.
SIGCSE chair's report
Authors: Rodger Susan
Published: September 2015

Each year the SIGCSE Chair writes an annual report to submit to ACM. The current report is under development for July 2014-June 2015. Below are excerpts from the report. The complete report will be posted at sigcse.org when it is finalized.
SIGCSE BP
Authors: Barnes Tiffany
Published: September 2015

In 2005, Jan Cuny started the "Broadening Participation in Computing" (BPC) program at the U.S. National Science Foundation with a thought-provoking question: do we need different approaches to engage diverse people in computing? The answer might seem to be yes --- with alliances including the National Center for Women & Information Technology (NCWIT), the Computing Alliance for Hispanic-Serving Institutions (CAHSI), AccessComputing (for people with disabilities), and the Institute for African American Mentoring in Computer Sciences (IAAMCS). On the other hand, STARS builds university leadership to serve local communities, while Expanding Computing Education Pathways (ECEP) works to build capacity in schools for teaching computing, and Into the Loop engages deeply with high schools in Los Angeles to integrate rigorous computing courses into this highly diverse district.
SIGCSE computer science education awards
Authors: Tymann Paul
Published: September 2015

SIGCSE has a tradition of recognizing individuals who have made outstanding contributions to computer science education. The first SIGCSE Award for Outstanding Contribution to Computer Science Education was given to William Atchison in 1981 for chairing the committee that produced the curriculum '68 report. Last year the award was given to Mark Allen Weiss recognizing Mark for authoring textbooks that have had a profound impact on students. The first SIGCSE Award for Lifetime Service to the Computer Science Education Community was given to Dick Austing in 1997. Last year we honored Frank Young for over 40 years of service to the computer science education community.
NPY1–36and PYY1–36activate cardiac fibroblasts: an effect enhanced by genetic hypertension and inhibition of dipeptidyl peptidase 4
Authors: Zhu Xiao , Gillespie Delbert G. , Jackson Edwin K.
Published: September 2015

Cardiac sympathetic nerves release neuropeptide Y (NPY)1–36, and peptide YY (PYY)1–36is a circulating peptide; therefore, these PP-fold peptides could affect cardiac fibroblasts (CFs). We examined the effects of NPY1–36and PYY1–36on the proliferation of and collagen production ([3H]proline incorporation) by CFs isolated from Wistar-Kyoto (WKY) normotensive rats and spontaneously hypertensive rats (SHRs). Experiments were performed with and without sitagliptin, an inhibitor of dipeptidyl peptidase 4 [DPP4; an ectoenzyme that metabolizes NPY1–36and PYY1–36(Y1receptor agonists) to NPY3–36and PYY3–36(inactive at Y1receptors), respectively]. NPY1–36and PYY1–36, but not NPY3–36or PYY3–36, stimulated proliferation of CFs, and these effects were more potent than ANG II, enhanced by sitagliptin, blocked by BIBP3226 (Y1receptor antagonist), and greater in SHR CFs. SHR CF membranes expressed more receptor for activated C kinase (RACK)1 [which scaffolds the Gi/phospholipase C (PLC)/PKC pathway] compared with WKY CF membranes. RACK1 knockdown (short hairpin RNA) and inhibition of Gi(pertussis toxin), PLC (U73122), and PKC (GF109203X) blocked the proliferative effects of NPY1–36. NPY1–36and PYY1–36stimulated collagen production more potently than did ANG II, and this was enhanced by sitagliptin and greater in SHR CFs. In conclusion, 1) NPY1–36and PYY1–36, via the Y1receptor/Gi/PLC/PKC pathway, activate CFs, and this pathway is enhanced in SHR CFs due to increased localization of RACK1 in membranes; and 2) DPP4 inhibition enhances the effects of NPY1–36and PYY1–36on CFs, likely by inhibiting the metabolism of NPY1–36and PYY1–36. The implications are that endogenous NPY1–36and PYY1–36could adversely affect cardiac structure/function by activating CFs, and this may be exacerbated in genetic hypertension and by DPP4 inhibitors.
Vagal nerve stimulation activates vagal afferent fibers that reduce cardiac efferent parasympathetic effects
Authors: Yamakawa Kentaro , Rajendran Pradeep S. , Takamiya Tatsuo , Yagishita Daigo , So Eileen L. , Mahajan Aman , Shivkumar Kalyanam , Vaseghi Marmar
Published: September 2015

Vagal nerve stimulation (VNS) has been shown to have antiarrhythmic effects, but many of these benefits were demonstrated in the setting of vagal nerve decentralization. The purpose of this study was to evaluate the role of afferent fiber activation during VNS on efferent control of cardiac hemodynamic and electrophysiological parameters. In 37 pigs a 56-electrode sock was placed over the ventricles to record local activation recovery intervals (ARIs), a surrogate of action potential duration. In 12 of 37 animals atropine was given systemically. Right and left VNS were performed under six conditions: both vagal trunks intact ( n = 25), ipsilateral right ( n = 11), ipsilateral left ( n = 14), contralateral right ( n = 7), contralateral left ( n = 10), and bilateral ( n = 25) vagal nerve transection (VNTx). Unilateral VNTx significantly affected heart rate, PR interval, Tau, and global ARIs. Right VNS after ipsilateral VNTx had augmented effects on hemodynamic parameters and increase in ARI, while subsequent bilateral VNTx did not significantly modify this effect (%change in ARI in intact condition 2.2 ± 0.9% vs. ipsilateral VNTx 5.3 ± 1.7% and bilateral VNTx 5.3 ± 0.8%, P < 0.05). Left VNS after left VNTx tended to increase its effects on hemodynamics and ARI response ( P = 0.07), but only after bilateral VNTx did these changes reach significance (intact 1.1 ± 0.5% vs. ipsilateral VNTx 3.6 ± 0.7% and bilateral VNTx 6.6 ± 1.6%, P < 0.05 vs. intact). Contralateral VNTx did not modify VNS response. The effect of atropine on ventricular ARI was similar to bilateral VNTx. We found that VNS activates afferent fibers in the ipsilateral vagal nerve, which reflexively inhibit cardiac parasympathetic efferent electrophysiological and hemodynamic effects.
The Significance of Serum CA-125 Elevation in Chinese Patients with Primary Budd-Chiari Syndrome: A Multicenter Study
Authors: Cheng De-lei , Xu Hao , Lv Wei-fu , Hua Rong , Du Hongtao , Zhang Qing-qiao
Published: September 2015

Objective. To investigate the serum level of CA-125 and its corresponding clinical significance in Chinese patients with primary BCS.Methods. Serum CA-125 was measured in 243 patients with primary BCS receiving interventional treatment in the participating hospitals and in 120 healthy volunteers. The correlation between serum CA-125 levels and ascites volume, liver function, and prognosis was analyzed.Results. Serum CA-125 was significantly elevated in BCS patients compared to healthy volunteers (P<0.001). Higher levels of CA-125 were found in BCS patients with abnormal hepatic function and low serum albumin levels and in patients with high volume of ascites compared to patients without these abnormalities. Serum CA-125 levels significantly correlated with ascites volume, serum level of alanine aminotransferase, aspartate aminotransferase, albumin, and Rotterdam BCS scores. The follow-up study indicated that the survival rate and asymptomatic survival rate after interventional treatment were lower in BCS patients with serum CA-125 > 175 U/mL (P<0.05).Conclusion. Serum CA-125 was significantly higher in patients with primary BCS and had a positive correlation with the volume of ascites, severity of liver damage, and poor prognosis. Thus the serum CA-125 levels may be used to estimate the severity and prognosis of BCS in Chinese patients.
Radioguided Parathyroidectomy with Portable Mini Gamma-Camera for the Treatment of Primary Hyperparathyroidism
Authors: Casella Claudio , Rossini Pierluigi , Cappelli Carlo , Nessi Chiara , Nascimbeni Riccardo , Portolani Nazario
Published: September 2015

Background. A proper localisation of pathological parathyroid glands is essential for a minimally invasive approach in the surgical treatment of primary hyperparathyroidism (PHP). The recent introduction of portable mini gamma-cameras (pMGCs) enabled intraoperative scintigraphic scanning. The aim of our study is to evaluate the efficacy of this new method and compare it with the preoperative localisation surveys.Methods. 20 patients were studied; they were evaluated preoperatively by neck ultrasound andTc-sestaMIBI-scintigraphy and intraoperatively with the pMGC IP Guardian 2. The results obtained from the three evaluations were compared.Results. The pMGC presented a sensitivity of 95%, a specificity of 98.89%, and a diagnostic accuracy of 98.18%, which were higher than those of preoperative ultrasound (sensitivity 55%; specificity 95%; diagnostic accuracy 87%) and scintigraphy withTc-sestaMIBI (sensitivity 73.68%; specificity 96.05%; diagnostic accuracy 91.58%).Conclusions. The pMGC can be used effectively as an intraoperative method to find the correct location of the pathological parathyroid glands. The pMGC is more reliable than the currently used preoperative and intraoperative localisation techniques.