bluuebunny/crossref_metadata_2025 huggingface dataset:
Membrane current and contraction in frog atrial fibres
Authors: Einwächter H. M. , Haas H. G. , Kern R.
Published: December 2015

1. Membrane current and mechanical activity were recorded from short segments of frog atrial muscle strips using a double sucrose gap voltage clamp arrangement. Experiments were performed at 4–7° C. Two types of contraction were observed dependent upon the duration of the clamp.

2. Short‐lasting depolarizations caused a flow of Ca inward current, ICa, and development of a phasic contraction. Time to peak tension approximated 400 msec. Both ICa and contraction, as functions of membrane potential, had a threshold of about — 40 mV and were maximal at inside positive potentials in normal Ringer fluid. Peak tension decreased at strong depolarizations.

3. The minimum time of depolarization required for initiation of a phasic contraction was 40–70 msec. The time necessary for full activation of contraction was 200–300 msec and comparable to the period of time covered by the flow of ICa.

4. There was no marked change in peak tension upon repetitive depolarization to the same membrane potential.

5. Restoration of (phasic) contractility after a preceding contraction was strongly dependent on the level of membrane potential between conditioning and test pulse. Restoration was half complete at potentials around — 45 mV.

6. Long‐lasting depolarizations generated tonic (sustained) contractions superimposed on the phasic (transient) ones. Threshold potential for initiation of tonic contractions was usually positive to the threshold of phasic contractions. The time taken to attain the final level of tension ranged between 0·7 and 3 sec. Plateau tension, as a function of membrane potential, increased with increasing depolarization and reached a flat maximum at about + 50 mV in normal Ringer fluid.

7. At membrane potentials near zero level, plateau tension developed by the tonic mechanism was about twice peak tension due to phasic contraction.

8. Removal of Ca ions from the external medium resulted in an almost complete abolition of phasic contraction within 1–2 min and a gradual decrease of tonic contraction during the first 10 min. Application of a ‘Ca inhibitor’ to normal Ringer fluid caused a strong reduction of both ICa and phasic contraction without affecting tonic contractions.

9. It is concluded that phasic contractions are directly activated by the flow of ICa. Generation of tonic contractions may be attributed to a Ca transfer mechanism different from ICa or a release of Ca from intracellular stores.
La contabilidad y los conflictos ambientales en el sistema financiero: estudio de caso en el sector bancario argentino*
Authors: Martínez Pulido Viviana Andrea , Gómez Villegas Mauricio
Published: December 2015

La contabilidad no es un conocimiento técnico

neutral. Es, por el contrario, una potente institución

social que participa en la construcción y comprensión del

universo social y económico. Por ello, la contabilidad puede

facilitar la visibilización o el ocultamiento de los conflictos

ambientales. De allí que paulatinamente se esté consolidando

el campo de la contabilidad ambiental y social. El sistema

financiero juega un rol determinante en la producción

y reproducción de los conflictos ambientales. Este trabajo

aborda el caso del sector bancario argentino y estudia el papel

de la información contable ambiental (informes de sostenibilidad)

en el tratamiento de los conflictos ambientales

en el sector financiero. Encontramos que, pese a los avances

de los bancos en materia de publicación de información

contable medioambiental, los conflictos ambientales no

son asimilados de manera adecuada para enfrentar los retos

que implica el desarrollo sostenible en su vertiente fuerte.
DIVERSIFICACIÓN DE INGRESOS EN EL SECTOR RURAL Y SU IMPACTO EN LA EFICIENCIA: EVIDENCIA PARA MÉXICO
Authors: Mora Rivera José Jorge , Cerón Monroy Hazael
Published: December 2015

Este artículo utiliza información de la Encuesta Nacional a Hogares Rurales de México2008 con el objetivo de analizar los factores que influyen en la diversificación de actividades y, a su vez, determinar el impacto de esta sobre los ingresos de los hogares rurales mexicanos. Las estimaciones econométricas señalan que la diversificación resulta clave para incrementar los ingresos y, por tanto, la eficiencia económica. Cerca del 80% de los hogares analizados en la Encuesta Nacional se diversifica por motivo de sobrevivencia, mientras que el resto lo hace por acumulación. Lo anterior indica que las políticas de apoyo a los hogares rurales mexicanos deben tener patrones claros de focalización, especialmente para los hogares con menores ingresos.
Double Duct Packed Bed Solar Air Heater Under Combined Single and Recyclic Double Air Pass
Authors: Singh Satyender , Dhiman Prashant
Published: December 2015

The present work intended to investigate thermal and thermohydraulic efficiencies of two different models of recyclic double pass packed bed solar air heaters experimentally. Model-I consists of single air pass through two glass covers as well as double air pass caused due to recycle of the air exiting from the packed bed duct formed between the absorber plate and the glass cover through another duct integrated between the absorber and back plates to inlet of the packed bed duct. On the other hand, model-II consists of only double air pass originated due to recycle operation constituted between the similar solar air heater elements as that of model-I. Twelve numbers of wire mesh screens to form 95% bed porosity were used. Both solar air heater models were tested under the range of packed bed Reynolds number from 300 to 1500 for air mass flow rate and recycle ratio of 0.01 kg/s to 0.025 kg/s and 0.3 to 1.8, respectively. Results revealed that thermal performance of model-I is found to be 15% higher than that of model-II. The optimum value of the recycle ratio for model-I and model-II are obtained as 0.9 and 1.2, respectively, at a mass flow rate of 0.025 kg/s that yields the best thermohydraulic efficiency of 77% and 67%, respectively. Moreover, optimum solution for recycle ratio and air mass flow rate during off sun shine hours are also obtained and presented in the current work.
Thermocapillary Flow of a Thin Nanoliquid Film Over an Unsteady Stretching Sheet
Authors: Maity S. , Ghatani Y. , Dandapat B. S.
Published: December 2015

The two-dimensional flow of a thin nanoliquid film over an unsteady stretching sheet is studied under the assumption of planar film thickness when the sheet is heated/cooled along the stretching direction. The governing equations of momentum, energy are solved numerically by using finite difference method. The rate of film thinning decreases with the increase in the nanoparticle volume fraction. On the other hand, thermocapillary parameter influences the film thinning. A boundary within the film is delineated such that the sign of Tz changes depending on the stretching distance from the origin. Further the boundary for Tz > 0 enlarges when the volume fraction of the nanoparticle increases.
Dynamic Behavior of a Small Water Droplet Impact Onto a Heated Hydrophilic Surface
Authors: Negeed El-Sayed R. , Albeirutty M. , AL-Sharif Sharaf F. , Hidaka S. , Takata Y.
Published: December 2015

The aim of this study is to investigate the influence of the surface wettability on the dynamic behavior of a water droplet impacting onto a heated surface made of stainless steel grade 304 (Sus304). The surface wettability is controlled by exposing the surfaces to plasma irradiation for different time periods (namely, 0.0, 10, 60, and 120 s). The experimental runs were carried out by spraying water droplets on the heated surface where the droplet diameter and velocity were independently controlled. The droplet behavior during the collision with the hot surface has been recorded with a high-speed video camera. By analyzing the experimental results, the effects of surface wettability, contact angle between impacting droplet and the hot surface, droplet velocity, droplet size, and surface superheat on the dynamic behavior of the water droplet impacting on the hot surface were investigated. Empirical correlations are presented describing the hydrodynamic characteristics of an individual droplet impinging onto the heated hydrophilic surfaces and concealing the affecting parameters in such process.
Characterization of Turbulent Heat Transfer in Ribbed Pipe Flow
Authors: Kang Changwoo , Yang Kyung-Soo
Published: December 2015

In the current investigation, we performed large eddy simulation (LES) of turbulent heat transfer in circular ribbed-pipe flow in order to study the effects of periodically mounted square ribs on heat transfer characteristics. The ribs were implemented on a cylindrical coordinate system by using an immersed boundary method, and dynamic subgrid-scale models were used to model Reynolds stresses and turbulent heat flux terms. A constant and uniform wall heat flux was imposed on all the solid boundaries. The Reynolds number (Re) based on the bulk velocity and pipe diameter is 24,000, and Prandtl number is fixed at Pr = 0.71. The blockage ratio (BR) based on the pipe diameter and rib height is fixed with 0.0625, while the pitch ratio based on the rib interval and rib height is varied with 2, 4, 6, 8, 10, and 18. Since the pitch ratio is the key parameter that can change flow topology, we focus on its effects on the characteristics of turbulent heat transfer. Mean flow and temperature fields are presented in the form of streamlines and contours. How the surface roughness, manifested by the wall-mounted ribs, affects the mean streamwise-velocity profile was investigated by comparing the roughness function. Local heat transfer distributions between two neighboring ribs were obtained for the pitch ratios under consideration. The flow structures related to heat transfer enhancement were identified. Friction factors and mean heat transfer enhancement factors were calculated from the mean flow and temperature fields, respectively. Furthermore, the friction and heat-transfer correlations currently available in the literature for turbulent pipe flow with surface roughness were revisited and evaluated with the LES data. A simple Nusselt number correlation is also proposed for turbulent heat transfer in ribbed pipe flow.
Influence of an Enforced Fast Start on 10-km-Running Performance
Authors: do Carmo Everton C. , Barroso Renato , Renfree Andrew , Gil Saulo , Tricoli Valmor
Published: December 2015

The effects of an enforced fast start on long-distance performance are controversial and seem to depend on the athlete’s capacity to delay and tolerate metabolic disruption. The aim of this study was to investigate the effects of an enforced start on 10-km-running performance and the influence of the some physiological and performance variables on the ability to tolerate an enforced fast start during the running. Fifteen moderately trained runners performed two 10-km time trials (TTs): free pacing (FP-TT) and fast start (FS-TT). During FS-TT, speed during the first kilometer was 6% higher than in FP-TT. Maximal oxygen uptake (VO2max), peak velocity (PV), velocity associated with VO2max (vVO2max), ventilatory threshold, and running economy at 10 and 12 km/h and FP-TT average velocity (AV-10 km) were individually determined. There were no differences between FP-TT and FS-TT performance (45:01 ± 4:08 vs 45:11 ± 4:46 min:s, respectively, P = .4). Eight participants improved (+2.2%) their performance and were classified as positive responders (PR) and 7 decreased (–3.3%) performance and were classified as negative responders (NR). Running speed was significantly higher for PR between 6 and 9.2 km (P < .05) during FS-TT. In addition, PR presented higher PV (P = .02) and vVO2max (P = .01) than NR, suggesting that PV and vVO2max might influence the ability to tolerate a fast-start strategy. In conclusion, there was an individual response to the enforced fast-start strategy during 10-km running, and those who improved performance also presented higher vVO2max and PV, suggesting a possible association between these variables and response to the strategy adopted.
The Effect of Body Mass on Eccentric Knee-Flexor Strength Assessed With an Instrumented Nordic Hamstring Device (Nordbord) in Football Players
Authors: Buchheit Martin , Cholley Yannick , Nagel Mark , Poulos Nicholas
Published: December 2015

Purpose:

To examine the effect of body mass (BM) on eccentric knee-flexor strength using the Nordbord and offer simple guidelines to control for the effect of BM on knee-flexor strength.

Methods:

Data from 81 soccer players (U17, U19, U21, senior 4th French division, and professionals) and 41 Australian Football League (AFL) players were used for analysis. They all performed 1 set of 3 maximal repetitions of the bilateral Nordic hamstring exercise, with the greatest strength measure used for analysis. The main regression equation obtained from the overall sample was used to predict eccentric knee-flexor strength from a given BM (moderate TEE, 22%). Individual deviations from the BM-predicted score were used as a BM-free index of eccentric knee- flexor strength.

Results:

There was a large (r = .55, 90% confidence limits .42;.64) correlation between eccentric knee-flexor strength and BM. Heavier and older players (professionals, 4th French division, and AFL) outperformed their lighter and younger (U17–U21) counterparts, with the soccer professionals presenting the highest absolute strength. Professional soccer players were the only ones to show strength values likely slightly greater than those expected for their BM.

Conclusions:

Eccentric knee-flexor strength, as assessed with the Nordbord, is largely BM-dependent. To control for this effect, practitioners may compare actual test performances with the expected strength for a given BM, using the following predictive equation: Eccentric strength (N) = 4 × BM (kg) + 26.1. Professional soccer players with specific knee-flexor-training history and enhanced neuromuscular performance may show higher than expected values.
High-Quality Draft Genome Sequence of Kallotenue papyrolyticum JKG1
T
Reveals Broad Heterotrophic Capacity Focused on Carbohydrate and Amino Acid Metabolism
Authors: Hedlund Brian P. , Murugapiran Senthil K. , Huntemann Marcel , Clum Alicia , Pillay Manoj , Palaniappan Krishnaveni , Varghese Neha , Mikhailova Natalia , Stamatis Dimitrios , Reddy T. B. K. , Ngan Chew Yee , Daum Chris , Duffy Kecia , Shapiro Nicole , Markowitz Victor , Ivanova Natalia , Kyrpides Nikos , Williams Amanda J. , Cole Jessica K. , Dodsworth Jeremy A. , Woyke Tanja
Published: December 2015

The draft genome of
Kallotenue papyrolyticum
JKG1
T
, a member of the order
Kallotenuales
, class
Chloroflexia
, consists of 4,475,263 bp in 4 contigs and encodes 4,010 predicted genes, 49 tRNA-encoding genes, and 3 rRNA operons. The genome is consistent with a heterotrophic lifestyle including catabolism of polysaccharides and amino acids.
Draft Whole-Genome Sequence of Serratia marcescens Strain RM66262, Isolated from a Patient with a Urinary Tract Infection
Authors: Bruna Roberto E. , Revale Santiago , García Véscovi Eleonora , Mariscotti Javier F.
Published: December 2015

Serratia marcescens
strains are ubiquitous bacteria isolated from environmental niches and also constitute emergent nosocomial opportunistic pathogens. Here, we report on the draft genome sequence of
S. marcescens
strain RM66262, which was isolated from a patient with urinary tract infection in the Bacteriology Service of the Rosario National University, Rosario, Argentina.
Finished Annotated Genome Sequence of Burkholderia pseudomallei Strain Bp1651, a Multidrug-Resistant Clinical Isolate
Authors: Bugrysheva Julia V. , Sue David , Hakovirta Janetta , Loparev Vladimir N. , Knipe Kristen , Sammons Scott A. , Ranganathan-Ganakammal Satishkumar , Changayil Shankar , Srinivasamoorthy Ganesh , Weil Michael R. , Tatusov Roman L. , Gee Jay E. , Elrod Mindy G. , Hoffmaster Alex R. , Weigel Linda M.
Published: December 2015

Burkholderia pseudomallei
strain Bp1651, a human isolate, is resistant to all clinically relevant antibiotics. We report here on the finished genome sequence assembly and annotation of the two chromosomes of this strain. This genome sequence may assist in understanding the mechanisms of antimicrobial resistance for this pathogenic species.
Draft Genome Sequence of the Marine Pathogen Vibrio coralliilyticus RE22
Authors: Spinard Edward , Kessner Linda , Gomez-Chiarri Marta , Rowley David C. , Nelson David R.
Published: December 2015

Vibrio coralliilyticus
RE22 is a causative agent of vibriosis in larval bivalves. We report here the draft genome sequence of
V. coralliilyticus
RE22 and describe additional virulence factors that may provide insight into its mechanism of pathogenicity.
Scattering in quantum mechanics under quaternionic Dirac delta potential
Authors: Sobhani Hadi , Hassanabadi Hasan
Published: December 2015

In this paper, the Schrödinger equation for quaternionic quantum mechanics with a Dirac delta potential has been investigated. The derivative discontinuity condition for the quaternionic wave function has been derived and the boundary conditions for the quaternionic wave function have been applied. Probability current densities for different regions of the problem have been determined along with reflection and transmission coefficients.
Semiparametric Inference of the Complier Average Causal Effect with Nonignorable Missing Outcomes
Authors: Chen Hua , Ding Peng , Geng Zhi , Zhou Xiao-Hua
Published: December 2015

Noncompliance and missing data often occur in randomized trials, which complicate the inference of causal effects. When both noncompliance and missing data are present, previous papers proposed moment and maximum likelihood estimators for binary and normally distributed continuous outcomes under the latent ignorable missing data mechanism. However, the latent ignorable missing data mechanism may be violated in practice, because the missing data mechanism may depend directly on the missing outcome itself. Under noncompliance and an outcome-dependent nonignorable missing data mechanism, previous studies showed the identifiability of complier average causal effect for discrete outcomes. In this article, we study the semiparametric identifiability and estimation of complier average causal effect in randomized clinical trials with both all-or-none noncompliance and outcome-dependent nonignorable missing continuous outcomes, and propose a two-step maximum likelihood estimator in order to eliminate the infinite dimensional nuisance parameter. Our method does not need to specify a parametric form for the missing data mechanism. We also evaluate the finite sample property of our method via extensive simulation studies and sensitivity analysis, with an application to a double-blinded psychiatric clinical trial.
An Expressive Mechanism for Auctions on the Web
Authors: Dütting Paul , Henzinger Monika , Weber Ingmar
Published: December 2015

Auctions are widely used on the Web. Applications range from sponsored search to platforms such as eBay. In these and in many other applications the auctions in use are single-/multi-item auctions with unit demand. The main drawback of standard mechanisms for this type of auctions, such as VCG and GSP, is the
limited expressiveness
that they offer to the bidders. The General Auction Mechanism (GAM) of Aggarwal et al. [2009] takes a first step toward addressing the problem of limited expressiveness by computing a bidder optimal, envy-free outcome for linear utility functions with identical slopes and a single discontinuity per bidder-item pair. We show that in many practical situations this does not suffice to adequately model the preferences of the bidders, and we overcome this problem by presenting the first mechanism for
piecewise linear
utility functions with
nonidentical slopes
and
multiple discontinuities
. Our mechanism runs in polynomial time. Like GAM it is incentive compatible for inputs that fulfill a certain nondegeneracy assumption, but our requirement is more general than the requirement of GAM. For discontinuous utility functions that are nondegenerate as well as for continuous utility functions the outcome of our mechanism is a
competitive equilibrium
. We also show how our mechanism can be used to compute approximately bidder optimal, envy-free outcomes for a general class of continuous utility functions via piecewise linear approximation. Finally, we prove hardness results for even more expressive settings.
Understanding Integer Overflow in C/C++
Authors: Dietz Will , Li Peng , Regehr John , Adve Vikram
Published: December 2015

Integer overflow bugs in C and C++ programs are difficult to track down and may lead to fatal errors or exploitable vulnerabilities. Although a number of tools for finding these bugs exist, the situation is complicated because not all overflows are bugs. Better tools need to be constructed, but a thorough understanding of the issues behind these errors does not yet exist. We developed IOC, a dynamic checking tool for integer overflows, and used it to conduct the first detailed empirical study of the prevalence and patterns of occurrence of integer overflows in C and C++ code. Our results show that intentional uses of wraparound behaviors are more common than is widely believed; for example, there are over 200 distinct locations in the SPEC CINT2000 benchmarks where overflow occurs. Although many overflows are intentional, a large number of accidental overflows also occur. Orthogonal to programmers' intent, overflows are found in both well-defined and undefined flavors. Applications executing undefined operations can be, and have been, broken by improvements in compiler optimizations. Looking beyond SPEC, we found and reported undefined integer overflows in SQLite, PostgreSQL, SafeInt, GNU MPC and GMP, Firefox, LLVM, Python, BIND, and OpenSSL; many of these have since been fixed.
Intelligent Code Completion with Bayesian Networks
Authors: Proksch Sebastian , Lerch Johannes , Mezini Mira
Published: December 2015

Code completion is an integral part of modern
Integrated Development Environments
(IDEs). Developers often use it to explore
Application Programming Interfaces
(APIs). It is also useful to reduce the required amount of typing and to help avoid typos. Traditional code completion systems propose all type-correct methods to the developer. Such a list is often very long with many irrelevant items. More intelligent code completion systems have been proposed in prior work to reduce the list of proposed methods to relevant items.

This work extends one of these existing approaches, the
Best Matching Neighbor
(BMN) algorithm. We introduce Bayesian networks as an alternative underlying model, use additional context information for more precise recommendations, and apply clustering techniques to improve model sizes. We compare our new approach,
Pattern-based Bayesian Networks
(PBN), to the existing BMN algorithm. We extend previously used evaluation methodologies and, in addition to prediction quality, we also evaluate model size and inference speed.

Our results show that the additional context information we collect improves prediction quality, especially for queries that do not contain method calls. We also show that PBN can obtain comparable prediction quality to BMN, while model size and inference speed scale better with large input sizes.
Layout Decomposition with Pairwise Coloring and Adaptive Multi-Start for Triple Patterning Lithography
Authors: Zhang Ye , Luk Wai-Shing , Yang Yunfeng , Zhou Hai , Yan Changhao , Pan David Z. , Zeng Xuan
Published: December 2015

In this article we present a
pairwise coloring
(PWC) approach to tackle the layout decomposition problem for
triple patterning lithography
(TPL). The main idea is to reduce the problem to a set of bi-coloring problems. The overall solution is refined by applying a bi-coloring method for pairs of color sets per pass. One obvious advantage of this method is that the existing
double patterning lithography
(DPL) techniques can be reused effortlessly. Moreover, we observe that each pass can be fulfilled efficiently by integrating an SPQR-tree-graph-division-based bi-coloring method. In addition, to prevent the solution getting stuck in the local minima, an
adaptive multi-start
(AMS) approach is incorporated. Adaptive starting points are generated according to the vote of previous solutions. The experimental results show that our method is competitive with other works on both solution quality and runtime performance.
A New Uncertainty Budgeting-Based Method for Robust Analog/Mixed-Signal Design
Authors: Sun Jin , Talarico Claudio , Gupta Priyank , Roveda Janet
Published: December 2015

This article proposes a novel methodology for robust analog/mixed-signal IC design by introducing a notion of budget of uncertainty. This method employs a new conic uncertainty model to capture process variability and describes variability-affected circuit design as a set-based robust optimization problem. For a prespecified yield requirement, the proposed method conducts uncertainty budgeting by associating performance yield with the size of uncertainty set for process variations. Hence the uncertainty budgeting problem can be further translated into a tractable robust optimization problem. Compared with the existing robust design flow based on ellipsoid model, this method is able to produce more reliable design solutions by allowing varying size of conic uncertainty set at different design points. In addition, the proposed method addresses the limitation that the size of the ellipsoid model is calculated solely relying on the distribution of process parameters, while neglecting the dependence of circuit performance upon these design parameters. The proposed robust design framework has been verified on various analog/mixed-signal circuits to demonstrate its efficiency against the ellipsoid model. Up to 24% reduction of design cost has been achieved by using the uncertainty budgeting-based method.
A Finite-Point Method for Efficient Gate Characterization Under Multiple Input Switching
Authors: Subramaniam Anupama R. , Roveda Janet , Cao Yu
Published: December 2015

Timing characterization of standard cells is one of the essential steps in VLSI design. The traditional static timing analysis (STA) tool assumes single input switching models for the characterization of multiple input gates. However, due to technology scaling, increasing operating frequency, and process variation, the probability of the occurrence of multiple input switching (MIS) is increasing. On the other hand, considering all possible MIS scenarios for the characterization of multiple input logic gates, is computationally intensive. To improve the efficiency, this work proposes a finite-point-based characterization methodology for multiple input gates with the effects of MIS. Furthermore, delay variation due to MIS is integrated into the STA flow through propagation of switching windows. The proposed modeling methodology is validated using benchmark circuits at the 45nm technology node for various operating conditions. Experimental results demonstrate significant reduction in computation cost and data volume with less than ∼10% error compared to that of traditional SPICE simulation.
Complementary Synthesis for Encoder with Flow Control Mechanism
Authors: Qin Ying , Shen Shengyu , Wu Qingbo , Dai Huadong , Jia Yan
Published: December 2015

Complementary synthesis automatically generates an encoder's decoder with the assumption that the encoder's all input variables can always be uniquely determined by its output symbol sequence. However, to prevent the faster encoder from overwhelming the slower decoder, many encoders employ flow control mechanism that fails this assumption. Such encoders, when their output symbol sequences are too fast to be processed by the decoders, will stop transmitting data symbols, but instead transmitting idle symbols that can only uniquely determine a subset of the encoder's input variables. And the decoder should recognize and discard these idle symbols. This mechanism fails the assumption of all complementary synthesis algorithms, because some input variables can't be uniquely determined by the idle symbol.

A novel algorithm is proposed to handle such encoders. First, it identifies all input variables that can be uniquely determined, and takes them as flow control variables. Second, it infers a predicate over these flow control variables that enables all other input variables to be uniquely determined. Third, it characterizes the decoder's Boolean function with Craig interpolant.

Experimental results on several complex encoders indicate that this algorithm can always correctly identify the flow control variables, infer the predicates and generate the decoder's Boolean functions.
Lowering Minimum Supply Voltage for Power-Efficient Cache Design by Exploiting Data Redundancy
Authors: Jung Dongha , Lee Hokyoon , Kim Seon Wook
Published: December 2015

Voltage scaling is known to be an efficient way of saving power and energy within a system, and large caches such as LLCs are good candidates for voltage scaling considering their constantly increasing size. However, the V

CCMIN

problem, in which the lower bound of scalable voltage is limited by process variation, has made it difficult to exploit the benefits of voltage scaling. Lowering V

CCMIN

incurs multibit faults, which cannot be efficiently resolved by current technologies due to their high complexity and power consumption. We overcame the limitation by exploiting the data redundancy of memory hierarchy. For example, cache coherence states and several layers of cache organization naturally expose the existence of redundancy within cache blocks. If blocks have redundant copies, their V

CCMIN

can be lowered; although more faults can occur in the blocks, they can be efficiently detected by simple error detection codes and recovered by reloading the redundant copies. Our scheme requires only minor modifications to the existing cache design. We verified our proposal on a cycle accurate simulator with SPLASH-2 and PARSEC benchmark suites and found that the V

CCMIN

of a 2MB L2 cache can be further lowered by 0.1V in 32nm technology with negligible degradation in performance. As a result, we could achieve 15.6% of reduction in dynamic power and 15.4% of reduction in static power compared to the previous minimum power.
Offline Washing Schemes for Residue Removal in Digital Microfluidic Biochips
Authors: Mitra Debasis , Ghoshal Sarmishtha , Rahaman Hafizur , Chakrabarty Krishnendu , Bhattacharya Bhargab B.
Published: December 2015

A digital microfluidic biochip (DMB) is often deployed for multiplexing several assays in space and in time. The residue left by one assay may contaminate the droplets used for subsequent assays. Biochemical assays involving cell culture and those based on particle microfluidics also require sweeping of residual media from an active droplet on-chip. Thus, fluidic operations such as washing or residue removal need to be performed routinely either to clean contamination from the droplet pathways or to rinse off certain droplets on the chip. In this work, several graph-based techniques are presented for offline washing of biochips that may have either a regular geometry (e.g., a 2D array of electrodes), or an irregular geometry (e.g., an application-specific layout). The schemes can be used for total washing, that is, for cleaning the entire biochip or for selective washing of sites or pathways located sparsely on the chip. The problem of reducing the path length and washing time of the droplets is investigated with or without capacity constraints. The proposed algorithms for offline washing make use of several techniques such as graph traversal, integer linear programming (ILP) modeling, and customized heuristics based on the nature of the geometric distribution of the contamination profile. The contaminated pathways are assumed to be Manhattan or curved, and hence the techniques are applicable to the conventional field-actuated DMBs as well as to the emerging classes of light-actuated and active-matrix DMBs. These techniques will be useful in enhancing the reliability of a wide class of emerging digital microfluidic healthcare devices
Boa
Authors: Dyer Robert , Nguyen Hoan Anh , Rajan Hridesh , Nguyen Tien N.
Published: December 2015

In today's software-centric world, ultra-large-scale software repositories, such as SourceForge, GitHub, and Google Code, are the new library of Alexandria. They contain an enormous corpus of software and related information. Scientists and engineers alike are interested in analyzing this wealth of information. However, systematic extraction and analysis of relevant data from these repositories for testing hypotheses is hard, and best left for
mining software repository
(MSR) experts! Specifically, mining source code yields significant insights into software development artifacts and processes. Unfortunately, mining source code at a large scale remains a difficult task. Previous approaches had to either limit the scope of the projects studied, limit the scope of the mining task to be more coarse grained, or sacrifice studying the history of the code. In this article we address mining source code: (a) at a very large scale; (b) at a fine-grained level of detail; and (c) with full history information. To address these challenges, we present domain-specific language features for source-code mining in our language and infrastructure called
Boa
. The goal of
Boa
is to ease testing MSR-related hypotheses. Our evaluation demonstrates that
Boa
substantially reduces programming efforts, thus lowering the barrier to entry. We also show drastic improvements in scalability.
The Effectiveness of Test Coverage Criteria for Relational Database Schema Integrity Constraints
Authors: Mcminn Phil , Wright Chris J. , Kapfhammer Gregory M.
Published: December 2015

Despite industry advice to the contrary, there has been little work that has sought to test that a relational database's schema has correctly specified integrity constraints. These critically important constraints ensure the coherence of data in a database, defending it from manipulations that could violate requirements such as “usernames must be unique” or “the host name cannot be missing or unknown.” This article is the first to propose coverage criteria, derived from logic coverage criteria, that establish different levels of testing for the formulation of integrity constraints in a database schema. These range from simple criteria that mandate the testing of successful and unsuccessful INSERT statements into tables to more advanced criteria that test the formulation of complex integrity constraints such as multi-column PRIMARY KEYs and arbitrary CHECK constraints. Due to different vendor interpretations of the structured query language (SQL) specification with regard to how integrity constraints should actually function in practice, our criteria crucially account for the underlying semantics of the database management system (DBMS). After formally defining these coverage criteria and relating them in a subsumption hierarchy, we present two approaches for automatically generating tests that satisfy the criteria. We then describe the results of an empirical study that uses mutation analysis to investigate the fault-finding capability of data generated when our coverage criteria are applied to a wide variety of relational schemas hosted by three well-known and representative DBMSs—HyperSQL, PostgreSQL, and SQLite. In addition to revealing the complementary fault-finding capabilities of the presented criteria, the results show that mutation scores range from as low as just 12% of mutants being killed with the simplest of criteria to 96% with the most advanced.
Combining Genetic Algorithms and Constraint Programming to Support Stress Testing of Task Deadlines
Authors: Alesio Stefano Di , Briand Lionel C. , Nejati Shiva , Gotlieb Arnaud
Published: December 2015

Tasks in real-time embedded systems (RTES) are often subject to hard deadlines that constrain how quickly the system must react to external inputs. These inputs and their timing vary in a large domain depending on the environment state and can never be fully predicted prior to system execution. Therefore, approaches for stress testing must be developed to uncover possible deadline misses of tasks for different input arrival times. In this article, we describe stress-test case generation as a search problem over the space of task arrival times. Specifically, we search for worst-case scenarios maximizing deadline misses, where each scenario characterizes a test case. In order to scale our search to large industrial-size problems, we combine two state-of-the-art search strategies, namely, genetic algorithms (GA) and constraint programming (CP). Our experimental results show that, in comparison with GA and CP in isolation, GA+CP achieves nearly the same effectiveness as CP and the same efficiency and solution diversity as GA, thus combining the advantages of the two strategies. In light of these results, we conclude that a combined GA+CP approach to stress testing is more likely to scale to large and complex systems.
Evolution and Disruption in Network Processing for the Internet of Things
Authors: Gregorio Lorenzo Di
Published: December 2015

Between prophecies of revolutions and inertiae of legacies, the Internet of Things (IoT) has already become the brand under which light processing units communicate over complex networks. Network processing is caught between demands for computation, raised by the growing complexity of the networks, and limitations imposed by performance of lightweight devices on processing. In this contribution the potential for disruptive changes against the scaling of existing technologies is discussed, specifically three main aspects of the IoT that impact network protocols and their processing: the reversal of the client/server architectures, the scavenging of spectral bands, and the federation of Internet gateways.
Type-Based Call Graph Construction Algorithms for Scala
Authors: Ali Karim , Rapoport Marianna , Lhoták Ondřej , Dolby Julian , Tip Frank
Published: December 2015

Call graphs have many applications in software engineering. For example, they serve as the basis for code navigation features in integrated development environments and are at the foundation of static analyses performed in verification tools. While many call graph construction algorithms have been presented in the literature, we are not aware of any that handle Scala features such as traits and abstract type members. Applying existing algorithms to the JVM bytecodes generated by the Scala compiler produces very imprecise results because type information is lost during compilation. We adapt existing type-based call graph construction algorithms to Scala and present a formalization based on Featherweight Scala. An experimental evaluation shows that our most precise algorithm generates call graphs with 1.1--3.7 times fewer nodes and 1.5--17.3 times fewer edges than a bytecode-based RTA analysis.
Estimating Semantic Relatedness in Source Code
Authors: Mahmoud Anas , Bradshaw Gary
Published: December 2015

Contemporary software engineering tools exploit semantic relations between individual code terms to aid in code analysis and retrieval tasks. Such tools employ word similarity methods, often used in natural language processing (
nlp
), to analyze the textual content of source code. However, the notion of similarity in source code is different from natural language. Source code often includes unnatural domain-specific terms (e.g., abbreviations and acronyms), and such terms might be related due to their structural relations rather than linguistic aspects. Therefore, applying natural language similarity methods to source code without adjustment can produce low-quality and error-prone results. Motivated by these observations, we systematically investigate the performance of several semantic-relatedness methods in the context of software. Our main objective is to identify the most effective semantic schemes in capturing association relations between source code terms. To provide an unbiased comparison, different methods are compared against human-generated relatedness information using terms from three software systems. Results show that corpus-based methods tend to outperform methods that exploit external sources of semantic knowledge. However, due to inherent code limitations, the performance of such methods is still suboptimal. To address these limitations, we propose Normalized Software Distance (
nsd
), an information-theoretic method that captures semantic relatedness in source code by exploiting the distributional cues of code terms across the system.
nsd
overcomes data sparsity and lack of context problems often associated with source code, achieving higher levels of resemblance to the human perception of relatedness at the term and the text levels of code.
Complexity Theory Column 89
Authors: Rossman Benjamin , Servedio Rocco A. , Tan Li-Yang
Published: December 2015

We give an overview of a recent result [RST15] showing that the polynomial hierarchy is in finite relative to a random oracle. Since the early 1980s it has been known that this result would follow from a certain "average-case depth hierarchy theorem" for Boolean circuits. In this article we present some background and history of related relativized separations; sketch the argument showing how the polynomial hierarchy result follows from the circuit lower bound; and explain the techniques underlying the new circuit lower bound.
Community Detection in Multi-Layer Graphs
Authors: Kim Jungeun , Lee Jae-Gil
Published: December 2015

Community detection, also known as graph clustering, has been extensively studied in the literature. The goal of community detection is to partition vertices in a complex graph into densely-connected components socalled communities. In recent applications, however, an entity is associated with multiple aspects of relationships, which brings new challenges in community detection. The multiple aspects of interactions can be modeled as a multi-layer graph comprised of multiple interdependent graphs, where each graph represents an aspect of the interactions. Great efforts have therefore been made to tackle the problem of community detection in multi-layer graphs. In this survey, we provide readers with a comprehensive understanding of community detection in multi-layer graphs and compare the state-of-the-art algorithms with respect to their underlying properties.
TRIM72 modulates caveolar endocytosis in repair of lung cells
Authors: Nagre Nagaraja , Wang Shaohua , Kellett Thomas , Kanagasabai Ragu , Deng Jing , Nishi Miyuki , Shilo Konstantin , Oeckler Richard A. , Yalowich Jack C. , Takeshima Hiroshi , Christman John , Hubmayr Rolf D. , Zhao Xiaoli
Published: December 2015

Alveolar epithelial and endothelial cell injury is a major feature of the acute respiratory distress syndrome, in particular when in conjunction with ventilation therapies. Previously we showed [Kim SC, Kellett T, Wang S, Nishi M, Nagre N, Zhou B, Flodby P, Shilo K, Ghadiali SN, Takeshima H, Hubmayr RD, Zhao X. Am J Physiol Lung Cell Mol Physiol 307: L449–L459, 2014.] that tripartite motif protein 72 (TRIM72) is essential for amending alveolar epithelial cell injury. Here, we posit that TRIM72 improves cellular integrity through its interaction with caveolin 1 (Cav1). Our data show that, in primary type I alveolar epithelial cells, lack of TRIM72 led to significant reduction of Cav1 at the plasma membrane, accompanied by marked attenuation of caveolar endocytosis. Meanwhile, lentivirus-mediated overexpression of TRIM72 selectively increases caveolar endocytosis in rat lung epithelial cells, suggesting a functional association between these two. Further coimmunoprecipitation assays show that deletion of either functional domain of TRIM72, i.e., RING, B-box, coiled-coil, or PRY-SPRY, abolishes the physical interaction between TRIM72 and Cav1, suggesting that all theoretical domains of TRIM72 are required to forge a strong interaction between these two molecules. Moreover, in vivo studies showed that injurious ventilation-induced lung cell death was significantly increased in knockout (KO) TRIM72KO and Cav1KO lungs compared with wild-type controls and was particularly pronounced in double KO mutants. Apoptosis was accompanied by accentuation of gross lung injury manifestations in the TRIM72KO and Cav1KO mice. Our data show that TRIM72 directly and indirectly modulates caveolar endocytosis, an essential process involved in repair of lung epithelial cells through removal of plasma membrane wounds. Given TRIM72's role in endomembrane trafficking and cell repair, we consider this molecule an attractive therapeutic target for patients with injured lungs.
Pseudomonas aeruginosa exoenzymes U and Y induce a transmissible endothelial proteinopathy
Authors: Morrow K. Adam , Ochoa Cristhiaan D. , Balczon Ron , Zhou Chun , Cauthen Laura , Alexeyev Mikhail , Schmalzer Katherine M. , Frank Dara W. , Stevens Troy
Published: December 2015

We tested the hypothesis that Pseudomonas aeruginosa type 3 secretion system effectors exoenzymes Y and U (ExoY and ExoU) induce release of a high-molecular-weight endothelial tau, causing transmissible cell injury characteristic of an infectious proteinopathy. Both the bacterial delivery of ExoY and ExoU and the conditional expression of an activity-attenuated ExoU induced time-dependent pulmonary microvascular endothelial cell gap formation that was paralleled by the loss of intracellular tau and the concomitant appearance of high-molecular-weight extracellular tau. Transfer of the high-molecular-weight tau in filtered supernatant to naïve endothelial cells resulted in intracellular accumulation of tau clusters, which was accompanied by cell injury, interendothelial gap formation, decreased endothelial network stability in Matrigel, and increased lung permeability. Tau oligomer monoclonal antibodies captured monomeric tau from filtered supernatant but did not retrieve higher-molecular-weight endothelial tau and did not rescue the injurious effects of tau. Enrichment and transfer of high-molecular-weight tau to naïve cells was sufficient to cause injury. Thus we provide the first evidence for a pathophysiological stimulus that induces release and transmissibility of high-molecular-weight endothelial tau characteristic of an endothelial proteinopathy.