bluuebunny/crossref_metadata_2025 huggingface dataset:
Perception of /ra/-/la/ contrast in different contexts: mono-syllable vs. sentence
Authors: Tomaru Kanako , Arai Takayuki
Published: May 2013

A strict assumption that underlies categorical perception hypotheses is that two speech sounds are discriminable only when they cross a categorical boundary emerging from an identification function. A number of researchers have attempted to show the categorical perception of the sounds in question (particularly consonants) through discrimination and identification tests. However, these tests are usually used for mono-syllables or mono-syllabic words. In this study, we first investigated whether the perception of /ra/-/la/ contrast indicate any categorical perception in a mono-syllabic CV context, using synthesized syllables. Next, we tested whether categorical perception can be also observed in a sentence through perceptual discrimination and identification experiments. Results showed that (1) a discrimination peak predicted by the identification function was obtained only for the mono-syllabic context, and (2) discrimination accuracy in the sentence condition was consistently low. These results suggest that categorical perception in a strict sense may not be evident in the perception of a sentence.
Pronunciation of German suffixes by Japanese native speakers of different proficiency levels
Authors: Kasuya Marino , Arai Takayuki
Published: May 2013

This study investigates an aspect of speech rhythm in German spoken by Japanese native speakers of different proficiency levels. Previous studies on the production of vowel reduction have indicated that this is an area of difficulty for non-native speakers. One study, working on the assumption that second language (L2) speech production is affected by first language (L1), suggested that Japanese native speakers tend to fail at producing the required vowel reductions in unstressed syllables. The present study further investigated this issue by dividing Japanese native speakers into two groups: advanced and elementary learners. The aim of the present study was to investigate acoustic properties of vowel quality (first and second formants) and quantity (durational ratio) of unstressed syllables in German suffixes on the basis of German proficiency levels and the influence of L1. From results, main effect was obtained for the proficiency levels; acoustic analysis showed significant differences between first two formants and durational ratio same to be the factors that caused the difference among the levels. This suggests that L2 learning process may accompany the acquisition of L2 sounds even when rhythmic structures differ between L1 and L2. [Work supported by JSPS.]
Acoustic characteristics of glottalized obstruents in Gitksan
Authors: Schwan Michael D.
Published: May 2013

Glottalized obstruents are a defining feature in the phonetic inventory of languages of the Pacific Northwest. Gitksan (Tsimshianic), an endangered and understudied language in this region, is no exception. However, these segments, which have typically been labelled as ejectives by fieldworkers, have also been variously described as implosives or even as voiced ejectives. Evidently, the ability of fieldworkers to perceive these segments has proven difficult, even by those who have worked on the language for many years. This project seeks to describe some of the salient acoustic cues associated with glottalized obstruents in Gitksan by comparing glottalized and plain stops. While previous work has examined these stops only in word-initial position, the present study compares stops across positions within the word and across stressed and non-stressed environments. Speech tokens were collected from three fluent native speakers of three dialects of Gitksan in order to describe the prominent acoustic cues which characterize glottalized obstruents in Gitksan.
Canadian oats and Canadian goats: Comparing distal cues to segmentation and segments
Authors: Heffner Christopher C. , Newman Rochelle S.
Published: May 2013

Distal timing cues (specifically, the speech rate of sentences temporally removed from a point of ambiguity in speech) have been shown to weakly modulate segmental perception [i.e., the perception of basic speech sounds, like “p” and “b”; Newman and Sawusch (1996)] but strongly affect the perception of word boundaries [i.e., the perception of separation between words in fluent speech; Dilley and Pitt (2010)]. However, no study as of yet has directly compared the two classes of percept using identical manipulations. In this study, we will examine the role of distal timing cues to segmental perception and word segmentation using the same distal contexts (e.g., “The merchant sold Canadian oats/notes,” a word boundary distinction, or “The merchant sold Canadian coats/goats,” a voicing-based segmental distinction). Distal speech rate will be artificially slowed to an identical extent for both types of contrast. We predict that categorical perception leads distal context effects to be much stronger on word segmentation (“…Canadian oats/notes”) than on segmental perception (“…Canadian coats/goats”). This research may help bridge speech perception theories that have been developed for each class of percept, and further clarify the role of distal cues in speech perception.
Exploiting data parallelism and population Monte Carlo on massively-parallel architectures for geoacoustic inversion
Authors: Dettmer Jan , Dosso Stan E. , Holland Charles W.
Published: May 2013

Bayesian inference algorithms in geoacoustic inversion have high computational requirements on multiple computational scales. Predicting (modeling) data to match observations represents fine-grained computations which often cannot be implemented efficiently on CPU clusters since high latency and communication overhead outweigh parallelization gains. However, GPUs, which operate efficiently on 100,000s of parallel threads with low latency and high bandwidth, can provide significant performance gains. Bayesian sampling is generally coarse-grained, and can be implemented efficiently in parallel on multi-core/cluster architectures. For example, population Monte Carlo simulates many Markov chains in parallel, with chains running independently between interactions (at predefined intervals) which exchange information throughout the population, substantially increasing sampling efficiency. This paper combines fine- and coarse-grained parallelization to profoundly improve the efficiency of geoacoustic inversion of seabed reflection data. Spherical-wave reflection-coefficient predictions, which require solving the Sommerfeld integral for a large number of grazing angles and frequencies, constitute fine-grained, data-parallel computations which are implemented efficiently on a GPU. Sampling is based on population Monte Carlo simulation with chain interactions as exchange and crossover moves.The algorithm is applied to Malta Plateau data to study frequency dependence of velocity and attenuation in marine sediments. [Work supported by ONR.]
Neuroacoustics: Study on the perception of stereo reverberant sound field at cortical level
Authors: Bidondo Alejandro
Published: May 2013

On the basis of the Ando's brain hemispheric specialization auditory model, spatial information is processed in the right hemisphere. When hearing a complex sound stimuli, like a monaural sound source reproduced in a reverberant sound field, several independent acoustic cues are processed in both hemispheres simultaneously. To study the brain specialization perceiving these types of sounds, it was developed the Auditory Evoked Potentials analysis for 2000 ms after the first 80 ms from the sound onset, even though the first 300 ms is normally analyzed, and Cortical Activity descriptors, which were applied to mismatch negativity electro-physiological signals taken from left and right hemispheres. It was possible to measure the specialization of hemispheres by using two different monaural and anechoic sound sources, one with a minimum effective duration of its autocorrelation function (tau e) as low as 0.2 ms and another with minimum tau e of 190 ms, both embedded into the same reverberant sound field and reproduced through headphones. This study opens the possibility to measure the perception of listener envelopment to further develop a subjective descriptor.
Production of child-like vowels with nonlinear interaction of glottal flow and vocal tract resonances
Authors: Story Brad H. , Bunton Kate
Published: May 2013

Acoustically, the mechanisms of vocal sound production may be considered to exist along a continuum. At one end, the glottal flow wave is weakly coupled to the resonances of the vocal tract such that the output is a linear combination of their respective acoustic characteristics, whereas at the other end there is strong nonlinear coupling of the flow source to the vocal tract resonances. To express phonetic properties in the output, such as formants, the linear case requires that the source produce sound that is rich in harmonic or broadband energy. In contrast, the nonlinear case allows for the possibility of an harmonically-rich source signal to be generated even when the glottal area variation is so simple that it may contain only one harmonic (i.e., a sinusoid) [Titze, J. Acoust. Soc. Am. 123 (2008)]. The latter case is most likely to occur when the fundamental frequency is relatively high, such as in children’s speech. The purpose of this study was to investigate the nonlinear end of the continuum with respect to the harmonic content of the glottal flow and pressure waveforms for vowels generated with a model of a child-like speech production system. [Research supported by NIH R01-DC011275, NSF BCS-1145011.]
Development of a small film sensor for the estimation of the contact pressure of artificial vocal folds
Authors: Weiss Sandra , Sutor Alexander , Rupitsch Stefan J. , Kniesburges Stefan , Doellinger Michael , Lerch Reinhard
Published: May 2013

Since voice production is the precondition for speech and, therefore, verbal communication, people suffering from voice disorders are limited in their everyday life. Physiological voice disorders, like vocal fold nodules are understood to result from increased contact pressure of the vocal folds during vibration. Thus, measurement of arising contact pressure during vocal fold oscillation helps quantify the collision forces and to substantiate previous assumptions. Due to limited access to the vocal folds, there is need for a small sensor that minimally influences air flow. For that purpose, we developed a small film sensor which is capable of measuring the contact pressure along the vocal fold contact areas. To investigate the suitability of the sensor, a hemi-larynx flow channel experiment with silicone replicas of the vocal folds was performed. Replicas of different elasticities were investigated. The contact sensor signals as well as the subglottal pressure were acquired. High-speed recordings of the vocal fold oscillation were synchronously performed to accurately relate the opening, closing and contact phases to the time signals. The measured contact pressures will be reported and compared to previous results. The advantages and limitations of the developed sensor will be discussed.
Decoding the Language of Phosphorylation Site Dynamics
Authors: Chylek Lily A.
Published: May 2013

Computational modeling sheds light on the interplay of phosphorylation and diffusion in cell signaling.
Old Dance with a New Partner: EGF Receptor as the Phenobarbital Receptor Mediating
Cyp2B
Expression
Authors: Meyer Sharon A. , Jirtle Randy L.
Published: May 2013

The direct interaction of phenobarbital with the epidermal growth factor receptor reveals a new network interface in nuclear receptor signaling.
Dissecting Serotonin Receptors
Authors: Ray L. Bryan
Published: May 2013

Structures of serotonin receptor family members in complex with the fungal alkaloid ergot offer clues for drug designers.
Extrinsic Resistance to Hedgehog Inhibition
Authors: Ferrarelli Leslie K.
Published: May 2013

The inflammatory cytokine osteopontin stimulates the transcription factor GLI1 to promote multidrug resistance and the epithelial-to-mesenchymal transition.
pH Dependence of Microbe Sterilization by Cationic Antimicrobial Peptides
Authors: Walkenhorst William F. , Klein J. Wolfgang , Vo Phuong , Wimley William C.
Published: May 2013

We recently described a family of cationic antimicrobial peptides (CAMPs) selected from a combinatorial library that exhibited potent, broad-spectrum activity at neutral pH and low ionic strength. To further delimit the utility and activity profiles of these peptides, we investigated the effects of solution conditions, such as pH and ionic strength, on the efficacy of the peptide antimicrobials against a panel of microorganisms. Peptide minimum sterilizing concentrations (MSCs) varied linearly with pH for each subtype within our family of CAMPs for all organisms tested. The peptides were much less effective against Gram-negative bacteria at high pH, consistent with a decrease in net positive charge on the peptides. A similar trend was observed for the fungus
Candida albicans
. Surprisingly, the opposite pH trend was observed with the Gram-positive
Staphylococcus aureus
. In addition, an additive ionic strength effect was observed with increasing buffer strengths at identical pH values. The extreme difference in the observed pH behavior between Gram-negative and Gram-positive organisms is attributed to the presence of native charged molecules in the much thicker peptidoglycan layer of the Gram-positive organism. The novel species-specific effects of pH observed here have important implications for applications using CAMPs and for the design of novel CAMPs.
Hydrophobic Gentamicin-Loaded Nanoparticles Are Effective against Brucella melitensis Infection in Mice
Authors: Imbuluzqueta Edurne , Gamazo Carlos , Lana Hugo , Campanero Miguel Ángel , Salas David , Gil Ana Gloria , Elizondo Elisa , Ventosa Nora , Veciana Jaume , Blanco-Prieto María J.
Published: May 2013

The clinical management of human brucellosis is still challenging and demands
in vitro
active antibiotics capable of targeting the pathogen-harboring intracellular compartments. A sustained release of the antibiotic at the site of infection would make it possible to reduce the number of required doses and thus the treatment-associated toxicity. In this study, a hydrophobically modified gentamicin, gentamicin-AOT [AOT is bis(2-ethylhexyl) sulfosuccinate sodium salt], was either microstructured or encapsulated in poly(lactic-co-glycolic acid) (PLGA) nanoparticles. The efficacy of the formulations developed was studied both
in vitro
and
in vivo
. Gentamicin formulations reduced
Brucella
infection in experimentally infected THP-1 monocytes (>2-log
10
unit reduction) when using clinically relevant concentrations (18 mg/liter). Moreover,
in vivo
studies demonstrated that gentamicin-AOT-loaded nanoparticles efficiently targeted the drug both to the liver and the spleen and maintained an antibiotic therapeutic concentration for up to 4 days in both organs. This resulted in an improved efficacy of the antibiotic in experimentally infected mice. Thus, while 14 doses of free gentamicin did not alter the course of the infection, only 4 doses of gentamicin-AOT-loaded nanoparticles reduced the splenic infection by 3.23 logs and eliminated it from 50% of the infected mice with no evidence of adverse toxic effects. These results strongly suggest that PLGA nanoparticles containing chemically modified hydrophobic gentamicin may be a promising alternative for the treatment of human brucellosis.
Can Intermittent Dosing Optimize Prolonged Linezolid Treatment of Difficult Multidrug-Resistant Tuberculosis?
Authors: Chang Kwok-Chiu , Yew Wing-Wai , Cheung Siu-Wai , Leung Chi-Chiu , Tam Cheuk-Ming , Chau Chi-Hung , Wen Peter Kin-Ho , Chan Raphael Chiu-Yeung
Published: May 2013

We evaluated treatment with linezolid, dosed at 800 mg once daily for 1 to 4 months as guided by sputum culture status and tolerance and then at 1,200 mg thrice weekly until ≥1 year after culture conversion, in addition to individually optimized regimens among 10 consecutive patients with extensively drug-resistant tuberculosis or fluoroquinolone-resistant multidrug-resistant tuberculosis. All achieved stable cure, with anemia corrected and neuropathy stabilized, ameliorated, or avoided after switching to intermittent dosing. Serum linezolid profiles appeared better optimized.
SatR Is a Repressor of Fluoroquinolone Efflux Pump SatAB
Authors: Escudero Jose Antonio , San Millan Alvaro , Montero Natalia , Gutierrez Belen , Ovejero Cristina Martinez , Carrilero Laura , González-Zorn Bruno
Published: May 2013

Streptococcus suis
is an emerging zoonotic agent responsible for high-mortality outbreaks among the human population in China. In this species, the ABC transporter SatAB mediates fluoroquinolone resistance when overexpressed. Here, we describe and characterize
satR
, an open reading frame (ORF) encoding a MarR superfamily regulator that acts as a repressor of
satAB. satR
is cotranscribed with
satAB
, and its interruption entails the overexpression of the pump, leading to a clinically relevant increase in resistance to fluoroquinolones.
Intrapulmonary Pharmacokinetics of GSK2251052 in Healthy Volunteers
Authors: Tenero David , Bowers Gary , Rodvold Keith A. , Patel Apurva , Kurtinecz Milena , Dumont Etienne , Tomayko John , Patel Parul
Published: May 2013

The plasma and intrapulmonary pharmacokinetics (PK) of intravenous (i.v.) GSK2251052, a novel boron-containing antimicrobial, were evaluated in healthy adult subjects. Thirty subjects underwent bronchoscopy and timed bronchoalveolar lavage (BAL) either following a single dose (cohort 1) or after 5 twice-daily doses (cohort 2) of 1,500 mg GSK2251052 i.v. Serial PK and safety assessments were obtained throughout the study. Bronchoscopy was performed on a single occasion in each subject at 2, 6, or 12 h after start of infusion. Noncompartmental analysis was performed to calculate PK parameters. Thirty subjects completed the study. The mean clearance (CL), volume of distribution at steady state (
V
ss
), and half-life (
t
1/2
) values were 22 liters/h, 231 liters, and 10.7 h, respectively. Approximately 30% of the dose was excreted unchanged in urine. The GSK2251052 concentrations in epithelial lining fluid (ELF) and alveolar macrophages (AM) were approximately 50% and 500 to 600%, respectively, compared to the concentration in plasma. the GSK2251052 exposures in ELF and AM were comparable following single- and repeat-dose administration. The most frequently reported drug-related adverse event (AE) was mild to moderate infusion site reactions (7 subjects) that occurred primarily in the repeat-dose cohort. No serious drug-related AEs or clinically significant trends in laboratory values, vital signs, or electrocardiograms were observed. GSK2251052 given as a 1,500-mg infusion was generally tolerated following single- or repeat-dose administration. GSK2251052 distributes into both the ELF and AM of healthy volunteers, which supports further study in patients with pneumonia.
Novel Synthetic (Poly)Glycerolphosphate-Based Antistaphylococcal Conjugate Vaccine
Authors: Chen Quanyi , Dintaman Jay , Lees Andrew , Sen Goutam , Schwartz David , Shirtliff Mark E. , Park Saeyoung , Lee Jean C. , Mond James J. , Snapper Clifford M.
Published: May 2013

Staphylococcal infections are a major source of global morbidity and mortality. Currently there exists no antistaphylococcal vaccine in clinical use. Previous animal studies suggested a possible role for purified lipoteichoic acid as a vaccine target for eliciting protective IgG to several Gram-positive pathogens. Since the highly conserved (poly)glycerolphosphate backbone of lipoteichoic acid is a major antigenic target of the humoral immune system during staphylococcal infections, we developed a synthetic method for producing glycerol phosphoramidites to create a covalent 10-mer of (poly)glycerolphosphate for potential use in a conjugate vaccine. We initially demonstrated that intactStaphylococcus aureuselicits murine CD4+T cell-dependent (poly)glycerolphosphate-specific IgM and IgG responsesin vivo. Naive mice immunized with a covalent conjugate of (poly)glycerolphosphate and tetanus toxoid in alum plus CpG-oligodeoxynucleotides produced high secondary titers of serum (poly)glycerolphosphate-specific IgG. Sera from immunized mice enhanced opsonophagocytic killing of liveStaphylococcus aureusin vitro. Mice actively immunized with the (poly)glycerolphosphate conjugate vaccine showed rapid clearance of staphylococcal bacteremiain vivorelative to mice similarly immunized with an irrelevant conjugate vaccine. In contrast to purified, natural lipoteichoic acid, the (poly)glycerolphosphate conjugate vaccine itself exhibited no detectable inflammatory activity. These data suggest that a synthetic (poly)glycerolphosphate-based conjugate vaccine will contribute to active protection against extracellular Gram-positive pathogens expressing this highly conserved backbone structure in their membrane-associated lipoteichoic acid.
Redox Balance via Lactate Dehydrogenase Is Important for Multiple Stress Resistance and Virulence in Enterococcus faecalis
Authors: Rana Nosheen Fatima , Sauvageot Nicolas , Laplace Jean-Marie , Bao YinYin , Nes Ingolf , Rincé Alain , Posteraro Brunella , Sanguinetti Maurizio , Hartke Axel
Published: May 2013

Enterococcus faecalis
is a highly stress resistant opportunistic pathogen. The intrinsic ruggedness of this bacterium is supposed to be the basis of its capacity to colonize the hostile environments of hospitals and to cause several kinds of infections. We show in this work that general resistance to very different environmental stresses depends on the ability of
E. faecalis
to maintain redox balance via lactate dehydrogenase (LDH). Furthermore, LDH-deficient mutants are less successful than the wild type at colonizing host organs in a murine model of systemic infection. Taken together, our results, as well as those previously published for
Staphylococcus aureus
(A. R. Richardson, S. J. Libby, and F. C. Fang, Science 319:1672–1676, 2008), identify LDH as an attractive drug target. These drugs may have additional applications, as in the fight against glycopeptide antibiotic-resistant bacteria and even cancer.
Engaging Students in a Bioinformatics Activity to Introduce Gene Structure and Function
Authors: May Barbara J.
Published: May 2013

Bioinformatics spans many fields of biological research and plays a vital role in mining and analyzing data. Therefore, there is an ever-increasing need for students to understand not only what can be learned from this data, but also how to use basic bioinformatics tools. This activity is designed to provide secondary and undergraduate biology students to a hands-on activity meant to explore and understand gene structure with the use of basic bioinformatic tools. Students are provided an “unknown” sequence from which they are asked to use a free online gene finder program to identify the gene. Students then predict the putative function of this gene with the use of additional online databases.
Using Author Bylines and Concept Maps to Illustrate the Connectedness of Scientists
Authors: Liao Min-Ken
Published: May 2013

Incorporating reading and discussing primary articles in undergraduate courses has been shown to enhance students’ learning, stimulate their interests in science, and retain them as science majors. While instructors diligently coach students to scrutinize every section in an article thoroughly and critically, the author byline is often overlooked. In this study, the author bylines of primary articles were used to illustrate the connectedness of scientists and the collaborative nature of science. First year college students first learned how to construct a concept map and used concept maps to connect 14 scientists with 14 primary articles that these scientists authored. In doing so, students visualized and understood science as human activity and science progresses as a community effort. Pre- and post-activity questionnaires were used to evaluate whether the activity objectives were met. Students further examined the structure and organization of a primary article after the activity and they were engaged in discussions such as how research ideas developed and evolved, the advantages and disadvantages of collaborative research, the ethics of authorships, graduate schools, and careers in science. Hopefully, perceiving the authors of primary articles as real people in a social network and science as the collaborative efforts may help students see themselves being a part of the scientific advancement and inspire them to pursue careers in science.
Making the Basic Microbiology Laboratory an Exciting and Engaging Experience
Authors: Engohang-Ndong Jean , Gerbig Donald G.
Published: May 2013

Teaching basic microbiology laboratory techniques to non-biology majors can be challenging. The students take the microbiology laboratory only because it is a requirement for their program and not by personal choice. Recently, we have developed a teaching approach that has shown to increase the interest and involvement of students in learning basic microbiology laboratory techniques. This approach consists of incorporating basic microbiology laboratory techniques in a semester long project that involves isolating an unknown bacterium from their environment at the beginning of the semester. Students apply basic microbiology techniques learned throughout the course to characterize and identify “their organism”. This approach encourages the inquisitiveness of students and provides relevance to the use of laboratory techniques.
Looking for the Forest and the Trees : Exercises to Provoke Abstract Thinking
Authors: Marintcheva Boriana
Published: May 2013

It is probably hard to find an educator who would hesitate to agree that abstract thinking and comfort in asking questions are pivotal to scientific inquiry and advancement of knowledge. Yet, most of the time the mechanics of fostering these skills is as challenging as photographing dense fog. As biologists we constantly reevaluate what we know, how we think about what we know, and how we communicate our knowledge about the living world. These short engaging exercises challenge students to appreciate the central role of abstract thinking and question asking in scientific inquiry. In the first exercise the classroom is presented with an optical illusion image and challenged to evaluate it using concrete and abstract thinking tools. In a follow up exercise, students are prompted to evaluate the process of making assumptions, asking questions and coming to conclusions using the example of a small popular culture article. Both exercises are used as primers to stimulate discussion emphasizing that abstract thinking and question asking are critical tools in the tool set of 21st century budding biologists.
Journal Watch
Authors: Herzog Jennifer A. , Archer Kathleen
Published: May 2013

In this section, I provide articles on recent developments and new technology used in microbiology and related fields. I also post articles that may help you bring new information or techniques into your laboratory or classroom via case studies or lab exercises. New to this issue is a “Featured Article,” highlighted by my colleague, Kathleen Archer. I hope you find this information useful, and I encourage you to send suggestions, questions or comments to me at
kathleen.archer@trincoll.edu
. I look forward to hearing from you!
Two Virtual Labs to Study Genetic Inheritance in the Fruit Fly
Authors: Cresiski Robin Herlands
Published: May 2013

A comparative review of two virtual labs to study genetic inheritance in the fruit fly: Virtual Courseware for Inquiry-based Science Education - Drosophila and Virtual Genetics Laboratory II (UMass Boston).
Review of:
Rabid: A Cultural History of the World’s Most Diabolical Virus
Review of:	Rabid: A Cultural History of the World’s Most Diabolical Virus;	WasikBill and	MurphyMonica; (	2012).	Viking Press,	New York, NY.	240 pages.
Authors: Boury Nancy
Published: May 2013

Review of:
Rabid: A Cultural History of the World’s Most Diabolical Virus;
Bill Wasik and Monica Murphy; (2012). Viking Press, New York, NY. 240 pages.
Data structures resilient to memory faults
Authors: Ferraro-Petrillo Umberto , Grandoni Fabrizio , Italiano Giuseppe F.
Published: May 2013

We address the problem of implementing data structures resilient to memory faults, which may arbitrarily corrupt memory locations. In this framework, we focus on the implementation of dictionaries and perform a thorough experimental study using a testbed that we designed for this purpose. Our main discovery is that the best-known (asymptotically optimal) resilient data structures have very large space overheads. More precisely, most of the space used by these data structures is not due to key storage. This might not be acceptable in practice, since resilient data structures are meant for applications where a huge amount of data (often of the order of terabytes) has to be stored. Exploiting techniques developed in the context of resilient (static) sorting and searching, in combination with some new ideas, we designed and engineered an alternative implementation, which, while still guaranteeing optimal asymptotic time and space bounds, performs much better in terms of memory without compromising the time efficiency.
Floating-Point Exponentiation Units for Reconfigurable Computing
Authors: de Dinechin Florent , Echeverría Pedro , López-Vallejo Marisa , Pasca Bogdan
Published: May 2013

The high performance and capacity of current FPGAs makes them suitable as acceleration co-processors. This article studies the implementation, for such accelerators, of the floating-point power function
x
y
as defined by the C99 and IEEE 754-2008 standards, generalized here to arbitrary exponent and mantissa sizes. Last-bit accuracy at the smallest possible cost is obtained thanks to a careful study of the various subcomponents: a floating-point logarithm, a modified floating-point exponential, and a truncated floating-point multiplier. A parameterized architecture generator in the open-source FloPoCo project is presented in details and evaluated.
A Look Back at TCC 2013
Authors: Venable Melissa A.
Published: May 2013

The 18th Annual TCC Worldwide Online Conference featured more than 1000 participants and 200 presenters all focused on emerging technologies in education. Highlights from the 2013 event are provided along with details about how organizers fostered a supportive atmosphere and active exchange of ideas through a variety of communication tools, social media use, and a system of digital badges.
Three-Field Modelling of Nonlinear Nonsmooth Boundary Value Problems and Stability of Differential Mixed Variational Inequalities
Authors: Gwinner J.
Published: May 2013

The purpose of this paper is twofold. Firstly we consider nonlinear nonsmooth elliptic boundary value problems, and also related parabolic initial boundary value problems that model in a simplified way steady-state unilateral contact with Tresca friction in solid mechanics, respectively, stem from nonlinear transient heat conduction with unilateral boundary conditions. Here a recent duality approach, that augments the classical Babuška-Brezzi saddle point formulation for mixed variational problems to twofold saddle point formulations, is extended to the nonsmooth problems under consideration. This approach leads to variational inequalities of mixed form for three coupled fields as unknowns and to related differential mixed variational inequalities in the time-dependent case. Secondly we are concerned with the stability of the solution set of a general class of differential mixed variational inequalities. Here we present a novel upper set convergence result with respect to perturbations in the data, including perturbations of the associated nonlinear maps, the nonsmooth convex functionals, and the convex constraint set. We employ epiconvergence for the convergence of the functionals and Mosco convergence for set convergence. We impose weak convergence assumptions on the perturbed maps using the monotonicity method of Browder and Minty.
Positive Solutions for Some Competitive Fractional Systems in Bounded Domains
Authors: Bachar Imed , Mâagli Habib , Zeddini Noureddine
Published: May 2013

Using some potential theory tools and the Schauder fixed point theorem, we prove the existence and precise global behavior of positive continuous solutions for the competitive fractional system(−Δ|D)α/2u+p(x)uσvr=0,(−Δ|D)α/2v+q(x)usvβ=0in a boundedC1,1-domainDinℝn (n≥3), subject to some Dirichlet conditions, where0<α<2,σ,β≥1,s,r≥0.The potential functionsp,qare nonnegative and required to satisfy some adequate hypotheses related to the Kato class of functionsKα(D).
Option Pricing under Risk-Minimization Criterion in an Incomplete Market with the Finite Difference Method
Authors: Ruan Xinfeng , Zhu Wenli , Li Shuang , Huang Jiexiang
Published: May 2013

We study option pricing with risk-minimization criterion in an incomplete market where the dynamics of the risky underlying asset is governed by a jump diffusion equation with stochastic volatility. We obtain the Radon-Nikodym derivative for the minimal martingale measure and a partial integro-differential equation (PIDE) of European option. The finite difference method is employed to compute the European option valuation of PIDE.
Adaptive Fuzzy Robust Control for a Class of Nonlinear Systems via Small Gain Theorem
Authors: Wang Xingjian , Wang Shaoping
Published: May 2013

Practical nonlinear systems can usually be represented by partly linearizable models with unknown nonlinearities and external disturbances. Based on this consideration, we propose a novel adaptive fuzzy robust control (AFRC) algorithm for such systems. The AFRC effectively combines techniques of adaptive control and fuzzy control, and it improves the performance by retaining the advantages of both methods. The linearizable part will be linearly parameterized with unknown but constant parameters, and the discontinuous-projection-based adaptive control law is used to compensate these parts. The Takagi-Sugeno fuzzy logic systems are used to approximate unknown nonlinearities. Robust control law ensures the robustness of closed-loop control system. A systematic design procedure of the AFRC algorithm by combining the backstepping technique and small-gain approach is presented. Then the closed-loop stability is studied by using small gain theorem, and the result indicates that the closed-loop system is semiglobally uniformly ultimately bounded.
Dissipative Sturm-Liouville Operators with Transmission Conditions
Authors: Tuna Hüseyin , Eryılmaz Aytekin
Published: May 2013

In this paper we study dissipative Sturm-Liouville operators with transmission conditions. By using Pavlov’s method (Pavlov 1947, Pavlov 1981, Pavlov 1975, and Pavlov 1977), we proved a theorem on completeness of the system of eigenvectors and associated vectors of the dissipative Sturm-Liouville operators with transmission conditions.
Asymptotic Behavior of Switched Stochastic Delayed Cellular Neural Networks via Average Dwell Time Method
Authors: Kuang Hanfeng , Liu Jinbo , Chen Xi , Mao Jie , He Linjie
Published: May 2013

The asymptotic behavior of a class of switched stochastic cellular neural networks (CNNs) with mixed delays (discrete time-varying delays and distributed time-varying delays) is investigated in this paper. Employing the average dwell time approach (ADT), stochastic analysis technology, and linear matrix inequalities technique (LMI), some novel sufficient conditions on the issue of asymptotic behavior (the mean-square ultimate boundedness, the existence of an attractor, and the mean-square exponential stability) are established. A numerical example is provided to illustrate the effectiveness of the proposed results.
Granuloma Annulare, Autoimmune Thyroiditis, and Lichen Sclerosus in a Woman: Randomness or Significant Association?
Authors: De Paola Mariele , Batsikosta Anastasia , Feci Luca , Benedetti Mattia , Bilenchi Roberta
Published: May 2013

We report a 60-year-old Caucasian female with a 2-year history of diffused granuloma annulare (GA), who presented for the simultaneous occurrence of genital lichen sclerosus (LS) and autoimmune thyroiditis (AT). In our opinion this combination is not just coincidental but may share similar immunopathological mechanisms.
Hazmats Transportation Network Design Model with Emergency Response under Complex Fuzzy Environment
Authors: Xu Jiuping , Gang Jun , Lei Xiao
Published: May 2013

A bilevel optimization model for a hazardous materials transportation network design is presented which considers an emergency response teams location problem. On the upper level, the authority designs the transportation network to minimize total transportation risk. On the lower level, the carriers first choose their routes so that the total transportation cost is minimized. Then, the emergency response department locates their emergency service units so as to maximize the total weighted arc length covered. In contrast to prior studies, the uncertainty associated with transportation risk has been explicitly considered in the objective function of our mathematical model. Specifically, our research uses a complex fuzzy variable to model transportation risk. An improved artificial bee colony algorithm with priority-based encoding is also applied to search for the optimal solution to the bilevel model. Finally, the efficiency of the proposed model and algorithm is evaluated using a practical case and various computing attributes.
A Facile Synthesis of Granular ZnO Nanostructures for Dye-Sensitized Solar Cells
Authors: Rahman Md. Mahbubur , Nath Narayan Chandra Deb , Noh Kwang-Mo , Kim Jaecheon , Lee Jae-Joon
Published: May 2013

Granular ZnO nanostructures of single-crystalline wurtzite hexagonal phases were synthesized by a facile and low-cost chemical method in aqueous condition. The average size of ZnO nanograin increased with reflux time, and it significantly affected the open circuit potential(Voc)while the short circuit current density(Jsc)was not changed much. The overall energy conversion efficiency was 1.82% with the smaller grain size ofca.250 nm when it was used as photoelectrode of DSSCs. The positive shifting of the Fermi energy (EF) and low density of surface states (DOS) were consistent with the reduction of the recombination of excited electron with electrolyte for smaller grains.
A Legendre Wavelet Spectral Collocation Method for Solving Oscillatory Initial Value Problems
Authors: Dizicheh A. Karimi , Ismail F. , Tavassoli Kajani M. , Maleki Mohammad
Published: May 2013

In this paper, we propose an iterative spectral method for solving differential equations with initial values on large intervals. In the proposed method, we first extend the Legendre wavelet suitable for large intervals, and then the Legendre-Guass collocation points of the Legendre wavelet are derived. Using this strategy, the iterative spectral method converts the differential equation to a set of algebraic equations. Solving these algebraic equations yields an approximate solution for the differential equation. The proposed method is illustrated by some numerical examples, and the result is compared with the exponentially fitted Runge-Kutta method. Our proposed method is simple and highly accurate.
A Note on the Observability of Temporal Boolean Control Network
Authors: Shi Wenping , Wu Bo , Han Jing
Published: May 2013

Temporal Boolean network is a generalization of the Boolean network model that takes into account the time series nature of the data and tries to incorporate into the model the possible existence of delayed regulatory interactions among genes. This paper investigates the observability problem of temporal Boolean control networks. Using the semi tensor product of matrices, the temporal Boolean networks can be converted into discrete time linear dynamic systems with time delays. Then, necessary and sufficient conditions on the observability via two kinds of inputs are obtained. An example is given to illustrate the effectiveness of the obtained results.
NAG-1/GDF15 Transgenic Mouse Has Less White Adipose Tissue and a Reduced Inflammatory Response
Authors: Kim J. M. , Kosak J. P. , Kim J. K. , Kissling G. , Germolec D. R. , Zeldin D. C. , Bradbury J. A. , Baek S. J. , Eling T. E.
Published: May 2013

NAG-1/GDF15 is a TGF-βsuperfamily member with poorly characterized biological activity proposed to inhibit inflammatory cytokine production. Transgenic mice expressing human NAG-1/GDF15 (NAG-1Tg/Lox) are leaner with lower body weight and are resistant to chemically or genetically induced intestinal tumors. Because of the link between obesity, inflammation, and cancer, we examined whether these mice exhibit a reduced response to inflammatory stimuli. TheNAG-1Tg/Loxmice had a reduced inflammatory response to LPS based on the serum levels of cytokines KC, IL-6, MCP-1, and TNFα. In contrast to literature reports and ourin vivoresults, NAG-1 did not inhibit LPS-induced cytokine expressionin vitroin RAW264.7 cells, mouse peritoneal macrophages, or mouse liver Kupffer cells, suggesting that NAG-1/GDF15 does not directly inhibit LPS-induced inflammatory cytokine production. However,NAG-1Tg/Loxmice have less white adipose tissue, the major source of inflammatory adipokines including leptin. Basal and LPS-treated serum leptin and mRNA levels in the adipose tissue ofNAG-1Tg/Loxmice were lower than those in WT mice. We propose that the reduced white adipose tissue and reduced leptin expression may be responsible, in part, for the reduced inflammatory response to LPS and the decrease in intestinal tumors observed inNAG-1Tg/Loxmice.
Widening Socioeconomic, Racial, and Geographic Disparities in HIV/AIDS Mortality in the United States, 1987–2011
Authors: Singh Gopal K. , Azuine Romuladus E. , Siahpush Mohammad
Published: May 2013

This study examined the extent to which socioeconomic and racial and geographic disparities in HIV/AIDS mortality in the United States changed between 1987 and 2011. Census-based deprivation indices were linked to county-level mortality data from 1987 to 2009. Log-linear, least-squares, and Poisson regression were used to model mortality trends and differentials. HIV/AIDS mortality rose between 1987 and 1995 and then declined markedly for all groups between 1996 and 2011. Despite the steep mortality decline, socioeconomic gradients and racial and geographic disparities in HIV/AIDS mortality increased substantially during the study period. Compared to whites, blacks had 3 times higher HIV/AIDS mortality in 1987 and 8 times higher mortality in 2011. In 1987, those in the most-deprived group had 1.9 times higher HIV/AIDS mortality than those in the most-affluent group; the corresponding relative risks increased to 2.9 in 1998 and 3.6 in 2009. Socioeconomic gradients existed across all race-sex groups, with mortality risk being 8–16 times higher among blacks than whites within each deprivation group. Dramatic reductions in HIV/AIDS mortality represent a major public health success. However, slower mortality declines among more deprived groups and blacks contributed to the widening gap. Mortality disparities reflect inequalities in incidence, access to antiretroviral therapy, and patient survival.
Magnetic and Electric Properties of , () Layered Perovskites
Authors: Ali A. I. , Hassen A.
Published: May 2013

The electric and magnetic properties of layered perovskites have been investigated systematically over the doping range . It was found that both Sr1.5Y0.5CoO4and Sr1.4Y0.6CoO4undergo ferromagnetic (FM) transition around 145 K and 120 K, respectively. On the other hand, Sr1.3Y0.7CoO4and Sr1.2Y0.8CoO4compounds showed paramagnetic behavior over a wide range of temperatures. In addition, spin-glass transition () was observed at 10 K for Sr1.3Y0.7CoO4. All investigated samples are semiconducting-like within the temperature range of 10–300 K. The temperature dependence of the electrical resistivity, , was described by two-dimensional variable range hopping (2D-VRH) model at 50 K < ≤ 300 K. Comparison with other layered perovskites was discussed in this work.
Passivity and Passification for Delay Fuzzy System Based on Delay Partitioning Approach
Authors: Liu Xiangjie , Yue Dan , Yao Xiuming
Published: May 2013

A delay partitioning approach is introduced to solve problems of passivity and passification for continuous T-S fuzzy system with time delay. Our aim is to design a state feedback controller such that the resulting closed system is passive. By constructing a Lyapunov-Krasovskii functional, delay-dependent passivity/passification performance conditions are formulated in terms of linear matrix inequalities (LMIs). Finally, numerical examples are used to illustrate the effectiveness of the proposed approaches which can further reduce conservatism and become more obvious with partitioning getting thinner.
Permanence, Extinction, and Almost Periodic Solution of a Nicholson's Blowflies Model with Feedback Control and Time Delay
Authors: Wu Haihui , Yu Shengbin
Published: May 2013

A Nicholson's blowflies model with feedback control and time delay is studied. By applying the comparison theorem of the differential equation and fluctuation lemma and constructing a suitable Lyapunov functional, sufficient conditions which guarantee the permanence, extinction, and existence of a unique globally attractive positive almost periodic solution of the system are obtained. It is proved that the feedback control variable and time delay have no influence on the permanence and extinction of the system.
Activation of the Nrf2 Pathway by Inorganic Arsenic in Human Hepatocytes and the Role of Transcriptional Repressor Bach1
Authors: Liu Dan , Duan Xiaoxu , Dong Dandan , Bai Caijun , Li Xin , Sun Guifan , Li Bing
Published: May 2013

Previous studies have proved that the environmental toxicant, inorganic arsenic, activates nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in many different cell types. This study tried to explore the hepatic Nrf2 pathway upon arsenic treatment comprehensively, since liver is one of the major target organs of arsenical toxicity. Our results showed that inorganic arsenic significantly induced Nrf2 protein and mRNA expression in Chang human hepatocytes. We also observed a dose-dependent increase of antioxidant response element- (ARE-) luciferase activity. Both the mRNA and protein levels of NAD(P)H:quinone oxidoreductase 1 (NQO1) and heme oxygenase-1 (HO-1) were all upregulated dramatically. On the other hand, entry and accumulation of Nrf2 protein in the nucleus, while exportting the transcriptional repressor BTB and CNC homology 1 (Bach1) from nucleus to cytoplasm, were also confirmed by western blot and immunofluorescence assay. Our results therefore confirmed the arsenic-induced Nrf2 pathway activation in hepatocytes and also suggested that the translocation of Bach1 was associated with the regulation of Nrf2 pathway by arsenic. Hepatic Nrf2 pathway plays indispensable roles for cellular defenses against arsenic hepatotoxicity, and the interplay of Bach1 and Nrf2 may be helpful to understand the self-defensive responses and the diverse biological effects of arsenicals.