bluuebunny/crossref_metadata_2025 huggingface dataset:
Auditory Temporal Processing Impairment
Authors: Bishop D. V. M. , Carlyon R. P. , Deeks J. M. , Bishop S. J.
Published: July 2014

Fourteen twin pairs, aged 8 to 10 years, were tested 3 times over 12 months; they included 11 children with language impairment (LI), 11 control children matched on nonverbal ability and age, and 6 co-twins who did not meet criteria for LI or control status. Thresholds were estimated for detecting a brief backward-masked tone (BM), detection of frequency modulation (FM), and pitch discrimination using temporal cues (Δ
f
0
). Both BM and FM thresholds improved with training, and by the 2nd test session, FM thresholds were in the adult range. There were marked individual differences on BM and Δ
f
0
, and, for both tasks, performance correlated with Tallal’s Auditory Repetition Task administered 2 years previously. However, no auditory measure gave significant differences between LI and control groups; performance was influenced more by nonverbal than language ability. Some children did have a stable pattern of poor performance on certain auditory tasks, but their good FM detection raised questions about whether processing of auditory temporal information is abnormal. We found no evidence that auditory deficits are a necessary or sufficient cause of language impairments.
Effects of Facial Paralysis and Audiovisual Information on Stop Place Identification
Authors: Nelson Monica A. , Hodge Megan M.
Published: July 2014

This study investigated how listeners' perceptions of bilabial and lingua-alveolar voiced stops in auditory (A) and audiovisual (AV) presentation modes were influenced by articulatory function in a girl with bilateral facial paralysis (BFP) and a girl with normal facial movement (NFM). The Fuzzy Logic Model of Perception (FLMP) was used to make predictions about listeners' identifications of stop place based on assumptions about the nature (clear, ambiguous, or conflicting) of the A or AV cues produced by each child during /b/ and /d/ CV syllables. As predicted, (a) listeners' identification scores for NFM were very high and reliable, regardless of presentation mode or stop place, (b) listeners' identification scores for BFP were high for lingua-alveolar place, regardless of presentation mode, but more variable and less reliable than for NFM; significantly lower (overall at a chance level) for bilabial place in the A mode; and lowest for bilabial place in the AV mode. Conflicting visual cues for stop place for BFP's productions of /bV/ syllables influenced listeners' perceptions, resulting in most of her bilabial syllables being misidentified in the AV mode. F2 locus equations for each child's /bV/ and /dV/ syllables showed patterns similar to those reported by previous investigators, but with less differentiation between stop place for BFP than NFM. These acoustic results corresponded to the perceptual results obtained. (That is, when presented with only auditory information, on average, listeners perceived BFP's target /b/ syllables to be near the boundary between /b/ and /d/.)
An Assessment Battery for Identifying Language Impairments in African American Children
Authors: Craig Holly K. , Washington Julie A.
Published: July 2014

This investigation compares the performances of 24 African American children, diagnosed as language impaired (LI) and receiving school-based language therapy, to 2 groups of typically developing peers (N= 48) on 5 traditional types of language assessment measures. Three of the measures were derived from child-centered free play language sample analyses and included average length of communication units (MLCU), frequencies of complex syntax, and numbers of different words. Two of the measures examined language comprehension and included responses to requests for information in the form of Wh-questions and responses to probes of active and passive sentence constructions. The performances of the group of children with language impairments were significantly lower on each measure than that of chronological age matched African American children who were typically developing. Sensitivity and specificity of the battery appeared excellent. The findings are discussed in terms of the potential of these informal language measures to contribute to a culturally fair assessment protocol for young African American children.
The Relationship Between Measures of Working Memory and Sentence Comprehension in Patients With Alzheimer’s Disease
Authors: Rochon Elizabeth , Waters Gloria S. , Caplan David
Published: July 2014

Patients with dementia of the Alzheimer’s type (DAT) and age- and education-matched older volunteers were tested on a battery of working memory tests, as well as on two tests of sentence comprehension. Patients had reduced spans and impaired central executive processes in working memory but showed normal effects of phonological and articulatory variables on span. On the sentence comprehension tasks, DAT patients showed effects of the number of propositions in a sentence but not of syntactic complexity. Impairment in the central executive processes of working memory in DAT patients was correlated with the effect of the number of propositions in a sentence on the sentence comprehension tasks. The results suggest that patients with DAT have working memory impairments that are related to their ability to map the meanings of sentences onto depictions of events in the world.
Kinematic Correlates of Speaking Rate Changes in Stuttering and Normally Fluent Adults
Authors: Smith Anne , Kleinow Jennifer
Published: July 2014

Articulatory kinematics were analyzed to determine if adults who stutter are generally poorer at speech movement pattern generation and if changing speech rate affects their stability in the same way that it affects normally fluent controls. Adults who stutter (
n
= 14) and a matched group of controls produced fluent repetitions of a simple phrase at normal, slow, and fast rates. A composite index of spatiotemporal stability (STI), as well as independent measures of timing and spatial variability, revealed that adults who stutter can operate within normal movement parameter ranges under low-demand speaking conditions. However, some of the stuttering participants showed evidence of abnormal instability even when repeating a simple utterance at habitual rate. Also, measures of relative timing indicated that adults who stutter, unlike their matched controls, are not better timers at habitual vs. nonpreferred speech rates. Overall, the results suggest that the kinematic characteristics of the fluent speech of adults who stutter generally overlap that of normally fluent speakers; however, subtle differences in kinematic parameters are interpreted to reveal their susceptibility to speech motor breakdown when performance demands increase.
Influences of Utterance Length and Complexity on Speech Motor Performance in Children and Adults
Authors: Maner Kimberly Jones , Smith Anne , Grayson Liane
Published: July 2014

The possible influences of utterance length and complexity on speech motor performance were examined by assessing the effects of increased processing demands on articulatory movement stability. Eight 5-year-old children and 8 young adults repeated a 6-syllable phrase in isolation (baseline condition) and embedded in sentences of low and high syntactic complexity. Lower lip movements for the target phrase were analyzed to produce the spatiotemporal index (STI), an index that reflects the stability of lip movement over 10 repetitions of the phrase. It was predicted that movement stability would be lower (reflected by higher values of the STI) for the phrase when it was spoken embedded in complex sentences and that, compared to adults, children’s movement output would be more negatively affected by increased processing demands. The STI was significantly increased for the phrase spoken in the complex sentences compared to the baseline condition, and STIs of the children were consistently higher than those of the adults across conditions. These findings provide novel evidence that speech motor planning, execution, or both are affected by processes often considered to be relatively remote from the motor output stage.
Personality and Voice Disorders
Authors: Roy Nelson , Bless Diane M. , Heisey Dennis
Published: July 2014

To determine whether personality factors play causal, concomitant, or consequential roles in common voice disorders, a vocally normal control group and four groups with voice disorders—functional dysphonia (FD), vocal nodules (VN), spasmodic dysphonia (SD), and unilateral vocal fold paralysis (UVFP)—were compared on measures of personality and psychological adjustment. Superfactor group comparisons revealed that the majority of FD and VN subjects were classified as introverts and extraverts, respectively. Comparisons involving the SD, UVFP, and control subjects did not identify consistent personality differences. The disability hypothesis, which suggests that personality features and emotional maladjustment are solely a negative consequence of vocal disability, was not supported. Personality variables and their behavioral consequences may therefore contribute to FD and VN. Results are presented within the context of a dispositional theory offered by Roy and Bless (2000a).
The Effect of Information on Listeners' Attitudes Toward Speakers With Voice or Resonance Disorders
Authors: Lallh Amarpreet K. , Rochet Anne Putnam
Published: July 2014

This study investigated university students' attitudes toward women with voice or resonance disorders and whether providing listeners with information about those disorders affected their attitudes towards the women. Eighty students listened to speech samples of 9 women: 3 with normal voice/resonance, 3 with moderate hoarseness/breathiness, and 3 with moderate hypernasality and nasal emission. Before listening to the speech samples, 40 students read two pages of information about the disorders, and 40 read two pages of neutral information. Attitudes were measured with 24 semantic differential scales. Results indicated that listeners perceived speakers with voice/resonance disorders more negatively than speakers without disorders. The attitudes of listeners who read voice and resonance information did not differ from those of listeners who read neutral information.
Specific Language Impairment in Swedish
Authors: Hansson Kristina , Nettelbladt Ulrika , Leonard Laurence B.
Published: July 2014

Several competing proposals have been offered to explain the grammatical difficulties experienced by children with specific language impairment (SLI). In this study, the grammatical abilities of Swedish-speaking children with SLI were examined for the purpose of evaluating these proposals and offering new findings that might be used in the development of alternative accounts. A group of preschoolers with SLI showed lower percentages of use of present tense copula forms and regular past tense inflections than normally developing peers matched for age and younger normally developing children matched for mean length of utterance (MLU). Word order errors, too, were more frequent in the speech of the children with SLI. However, these children performed as well as MLU-matched children in the use of present tense inflections and irregular past forms. In addition, the majority of their sentences containing word order errors showed appropriate use of verb morphology. None of the competing accounts of SLI could accommodate all of the findings. In particular, these accounts—or new alternatives —must develop provisions to explain both the earlier acquisition of present tense inflections than past tense inflections and word order errors that seem unrelated to verb morphology.
Individual and Consensus Judgments of Disfluency Types in the Speech of Persons Who Stutter
Authors: Cordes Anne K.
Published: July 2014

Previous research has suggested that the reliability with which judges identify individual disfluency types, such as repetitions or prolongations of speech sounds, may be very poor. The use of disfluency types judgments in research and clinical applications is also complicated by important differences among the several disfluency-based characterizations of stuttered speech. In an attempt to address these problems, this study arranged for 30 judges to identify all disfluency types that they perceived to be present in 5-s audiovisually recorded speech stimuli, each in an Individual task and then with a partner in a Consensus task. Intrapair agreement and interpair agreement for occurrences of disfluency types (from Consensus conditions) were significantly higher than intrajudge and interjudge agreement for occurrences (from Individual conditions). Despite being higher than individual values, however, intrapair and interpair agreement for occurrences both averaged less than 50%. Results also showed that disfluency types judgments, interpreted in terms of three common disfluency-based definitions of stuttering, were not strongly related to previous assessments of whether these speech tokens contained or did not contain stuttering. When combined with previously available data, the present findings suggest caution in the use of disfluency types to describe or define stuttered speech.
Changes in Normal Speech After Fatiguing the Tongue
Authors: Solomon Nancy Pearl
Published: July 2014

Detrimental effects of tongue fatigue on speech have been assumed to exist based on neuromotor speech disorders. However, to address whether fatigue is a contributing cause to impaired speech requires an experimental protocol with anuncomplicated population. This study induced tongue fatigue in eight neurologically normal persons and examined changes in speech perceptually and acoustically. The fatigue task consisted of repeated cycles of 6 s of sustained maximum voluntary contraction and 4 s of rest until 50% of maximum strength could not be achieved for three consecutive cycles. Participants then produced speech that was weighted heavily with lingual-palatal consonants. Perceptual analyses of the speech revealed a statistically significant deleterious effect of induced tongue fatigue on speech precision and an incomplete reversal of this effect after a recovery period. Acoustically, the first and third spectral moments (mean and skewness) of the spectral energy for /t/, /s/, and /ʃ/ differed significantly after fatigue but in directions opposite to a priori predictions. Tendencies were found for decreased stop-closure duration and increased voice onset time for /t/ after fatigue. Supplemental analyses revealed decreased second formant (F2) frequency for /u/ and /i/ and flattened F2 transition for the diphthong /@@@I/ after fatigue. These results indicate disruption of tongue positioning and transitioning for lingual-palatal consonants during speech after prolonged strenuous tongue exercises.
SIG 2 Perspectives Vol. 22, No. 3, October 2012
Authors: Guillamondegui Oscar D.
Published: July 2014

Sorry, this activity is no longer available for CEUs. Visit the SIG 2 page on the
ASHA Store
to see available CE activities.

Use the CE questions PDF here as study questions to guide your Perspectives reading.
Infant Airway Protection Mechanisms During Swallowing
Authors: Gosa Memorie
Published: July 2014

Infants have high caloric needs. Newborns will feed, on average, eight to 10 times per day and they depend exclusively on fluid intake to meet their caloric needs. Fluids represent the most commonly aspirated material. Understanding the high risk for aspiration due to proportion of liquid calories and the frequency with which the infant feeds, it is necessary for dysphagia professionals to understand the protective mechanisms available to the infant. The anatomic arrangement of the upper aerodigestive tract, resulting swallow physiology and laryngeal reflexes of the infant, optimally prepare the infant for safe swallowing during nipple feeding.
Lessons Learned From AAC Camp
Authors: Dodd Janet
Published: July 2014

Children who benefit from augmentative and alternative communication (AAC) need not only the support of individuals knowledgeable in the technologies themselves, but ones who understand the translation of language intervention principles to AAC. It is vital that school-based speech-language pathologists (SLPs) possess the knowledge and skills necessary for working with children who use AAC. The purpose of this article is to discuss what we have learned as we teach the new millennium of clinicians and how we can apply these lessons to the work we do with children with the most complex communication needs.
SIG 3 Perspectives Vol. 22, No. 3, November 2012
Authors: Barkmeier-Kraemer Julie
Published: July 2014

Sorry, this activity is no longer available for CEUs. Visit the SIG 3 page on the
ASHA Store
to see available CE activities.

Use the CE questions PDF here as study questions to guide your Perspectives reading.
Can ride‐sharing become attractive? A case study of taxi‐sharing employing a simulation modelling approach
Authors: d'Orey Pedro M. , Ferreira Michel
Published: July 2014

Improved urban mobility can be attained through more efficient vehicle usage and better road network utilisation, namely through increased vehicle occupancy and new operation modes. In this study, the authors focus on a dynamic and distributed taxi‐sharing system that takes advantage of nowadays widespread availability of communication and distributed computation to provide a cost‐efficient, door‐to‐door and flexible service, offering a quality of service similar to conventional taxis. This system has been evaluated following a simulation modelling approach, including a realistic and accurate replication of the taxi operation in the city of Porto using empirical data (real origin/destination data and average occupancy rates). Simulation results show improved performance in terms of reduced fares (up to 8%), reduced total travel distance (up to 9%) and smaller operation costs. Furthermore, they proposed that several trade‐offs (e.g. service performance against passengers’ transit times) should be considered during the system deployment and operation. In this study, it was also shown that increased system penetration rate and demand level can even further improve the system performance.
Comparison between resource reservation protocol and next steps in signalling in mobile IP networks
Authors: Mirzamany Esmat , Lasebae Aboubaker , Gemikonakli Orhan
Published: July 2014

Providing an acceptable level of quality of service (QoS) for critical applications is one of the interesting topics in next generation wireless networks. Confronting the major criticisms of resource reservation protocol (RSVP), the next steps in signalling (NSIS) was introduced as a general framework to include not only the RSVP but other signalling services in IP‐based networks. It attempts to address the RSVP shortcomings and to offer additional features. It is widely believed that NSIS can be considered as a suitable alternative for RSVP. However, it worsens the scalability issue in the RSVP operation, inherits the RSVP problem in mobile environments and its appealing features come with a significant cost. This study develops an analytical framework to evaluate the RSVP and NSIS performances in proxy mobile IPv6 (PMIPv6) environment. The results obtained showed a significant increase in network signalling cost, more bandwidth consumption by resource reservation signalling messages and a high resource re‐establishment latency in NSIS operations. The authors believe these outcomes raise doubts over the NSIS eligibility as a suitable replacement for RSVP.
Free surface due to a flow driven by a rotating disk inside a vertical cylindrical tank: Axisymmetric configuration
Authors: Kahouadji L. , Witkowski L. Martin
Published: July 2014

The flow driven by a rotating disk at the bottom of an open fixed cylindrical cavity is studied numerically and experimentally. The steady axisymmetric Navier-Stokes equations projected onto a curvilinear coordinate system are solved by a Newton-Raphson algorithm. The free surface shape is computed by an iterative process in order to satisfy a zero normal stress balance at the interface. In previous studies, regarding the free surface deflection, there is a significant disagreement between a first-order approximation [M. Piva and E. Meiburg, “Steady axisymmetric flow in an open cylindrical container with a partially rotating bottom wall,” Phys. Fluids 17, 063603 (2005)] and a full numerical simulation [R. Bouffanais and D. Lo Jacono, “Unsteady transitional swirling flow in the presence of a moving free surface,” Phys. Fluids 21, 064107 (2009)]. For a small deflection, the first-order approximation matches with our numerical simulation and for a large deflection a good agreement is found with experimental measurements.
An uncertainty principle for unimodular quantum groups
Authors: Crann Jason , Kalantar Mehrdad
Published: July 2014

We present a generalization of Hirschman's entropic uncertainty principle for locally compact Abelian groups to unimodular locally compact quantum groups. As a corollary, we strengthen a well-known uncertainty principle for compact groups, and generalize the relation to compact quantum groups of Kac type. We also establish the complementarity of finite-dimensional quantum group algebras. In the non-unimodular setting, we obtain an uncertainty relation for arbitrary locally compact groups using the relative entropy with respect to the Haar weight as the measure of uncertainty. We also show that when restricted to q-traces of discrete quantum groups, the relative entropy with respect to the Haar weight reduces to the canonical entropy of the random walk generated by the state.
Universal tight binding model for chemical reactions in solution and at surfaces. III. Stoichiometric and reduced surfaces of titania and the adsorption of water
Authors: Lozovoi A. Y. , Pashov D. L. , Sheppard T. J. , Kohanoff J. J. , Paxton A. T.
Published: July 2014

We demonstrate a model for stoichiometric and reduced titanium dioxide intended for use in molecular dynamics and other atomistic simulations and based in the polarizable ion tight binding theory. This extends the model introduced in two previous papers from molecular and liquid applications into the solid state, thus completing the task of providing a comprehensive and unified scheme for studying chemical reactions, particularly aimed at problems in catalysis and electrochemistry. As before, experimental results are given priority over theoretical ones in selecting targets for model fitting, for which we used crystal parameters and band gaps of titania bulk polymorphs, rutile and anatase. The model is applied to six low index titania surfaces, with and without oxygen vacancies and adsorbed water molecules, both in dissociated and non-dissociated states. Finally, we present the results of molecular dynamics simulation of an anatase cluster with a number of adsorbed water molecules and discuss the role of edge and corner atoms of the cluster.
Local structure and intermolecular dynamics of an equimolar benzene and 1,3-dimethylimidazolium bis[(trifluoromethane)sulfonyl]amide mixture: Molecular dynamics simulations and OKE spectroscopic measurements
Authors: Lynden-Bell Ruth M. , Xue Lianjie , Tamas George , Quitevis Edward L.
Published: July 2014

The local structure and intermolecular dynamics of an equimolar mixture of benzene and 1,3-dimethylimidazolium bis[(trifluoromethane)sulfonyl]amide ([dmim][NTf2]) were studied using molecular dynamics (MD) simulations and femtosecond optical Kerr effect (OKE) spectroscopy. The OKE spectrum of the benzene/[dmim][NTf2] mixture at 295 K was analyzed by comparing it to an ideal mixture spectrum obtained by taking the volume-fraction weighted sum of the OKE spectra of the pure liquids. The experimental mixture spectrum is higher in frequency and broader than that of the ideal mixture spectrum. These spectral differences are rationalized in terms of the local structure around benzene molecules in the mixture and the intermolecular dynamics as reflected in the density of states from the MD simulations. Specifically, we attribute the deviation of the OKE spectrum of the mixture from ideal behavior to benzene molecules seeing a stiffer intermolecular potential due to their being trapped in cages comprised of ions in the first solvation shell.
Gas cell for in situ soft X-ray transmission-absorption spectroscopy of materials
Authors: Drisdell W. S. , Kortright J. B.
Published: July 2014

A simple gas cell design, constructed primarily from commercially available components, enables in situ soft X-ray transmission-absorption spectroscopy of materials in contact with gas at ambient temperature. The cell has a minimum X-ray path length of 1 mm and can hold gas pressures up to ∼300 Torr, and could support higher pressures with simple modifications. The design enables cycling between vacuum and gas environments without interrupting the X-ray beam, and can be fully sealed to allow for measurements of air-sensitive samples. The cell can attach to the downstream port of any appropriate synchrotron beamline, and offers a robust and versatile method for in situ measurements of certain materials. The construction and operation of the cell are discussed, as well as sample preparation and proper spectral analysis, illustrated by examples of spectral measurements. Potential areas for improvement and modification for specialized applications are also mentioned.
Formation and the effect of resulting volatile fatty acids in food waste on bioethanol production
Authors: Jeong Seung-Mi , Kim Yong-Jin , Lee Dong-Hoon
Published: July 2014

Formation and the effect of volatile fatty acids (VFAs: acetic acid, propionic acid, iso-butyric acid, butyric acid, valeric acid, and hexanoic acid) generated in food waste (grains, fruits, and vegetables) on bioethanol production are studied. Acetic acid, which is the predominantly generated VFA in food waste, differs in production according to food waste composition and storage period. A multiple regression analysis revealed that the rate of formation of acetic acid was related to food waste composition rather than to storage period. Nevertheless, the amount of acetic acid produced naturally during the storage period (0–8 days) did not influence ethanol production.
Effects of metal ions on Pt electrode dissolution in H2SO4 solution enhanced by the presence of H2O2
Authors: Itaya Hayato , Shironita Sayoko , Nakazawa Akira , Inoue Mitsuhiro , Umeda Minoru
Published: July 2014

Successive potential cycling of a Pt plate electrode was conducted in H2O2-containing 0.5 mol dm−3 H2SO4 in the presence of metal ions such as Fe (Fe2+, Fe3+), Ce (Ce3+, Ce4+), and Mn (Mn2+) ions. First, the potential cycling in 294 mmol dm−3 H2O2 + 0.5 mol dm−3 H2SO4 without any metal ions confirmed the weight loss of the Pt electrode, which implies Pt dissolution. When the metal ions were added to the solution, the Pt electrode dissolution during the potential cycling was very significant; the Pt weight sharply decreased in the presence of both Fe2+ and H2O2. In addition, this enhanced Pt dissolution depended on both the Fe2+ and H2O2 concentrations, and the maximum Pt weight loss (257 μg) was obtained at the Fe2+ and H2O2 concentrations of 10 and 294 mmol dm−3, respectively. The Fe2+ and H2O2 concentration dependences of the Pt dissolution also correlated with the consumption rate of H2O2. These results revealed that the Fe2+ and H2O2 synergically enhanced the Pt dissolution rate.
Perennial pasture persistence: the economic perspective
Authors: Malcolm B. , Smith K. F. , Jacobs J. L.
Published: July 2014

Persistence of pasture in grazing systems has technical and economic dimensions. Profit from investment in pasture is maximised when the profit from the pasture is maximised over cycles of investments in pasture over the life of the farm business. The economic decision-rule is that an existing pasture should be replaced when the expected extra average addition to farm profit per year over the whole of the expected life of the next cycle of pasture investment exceeds the expected addition to farm profit from one more year of the existing pasture. This profit-maximising decision-rule means that the persistence of pasture is an economic phenomenon to be accounted for over several cycles of investment—a different concept to technical views that focus on the number of years of existence (i.e. persistence) of a pasture in one investment cycle. The number of years in which a pasture performs near peak potential annual dry matter (DM) production is a useful perspective on pasture persistence. The longer a pasture persists at peak level the more profitable. An empirical example was analysed of a pasture that had declined to carrying annually 6 dry sheep equivalents/ha (DSE/ha) and reinvestment occurred. The new pasture attained a peak of 11 000 kg/dry matter/ha in years 4–7, carrying an extra 15 DSE/ha.year, and declined to 50% of peak DM production by year 11, which was maintained until year 20. The modified internal rate of return for the base model of investing in pasture improvement was 12% real. The profit-maximising life of the pasture analysed was 8 years in repeated cycles over the life of the farm business. If this pasture produced at 65% of peak kg DM/ha for years 11–20, then the pasture was equally profitable whether the life of the pasture was any length from 8 to 20 years. If the pasture maintained production >65% of peak annual kg DM/ha, then longer pasture lives were more profitable than shorter lives.
Flow disturbances generated by feeding and swimming zooplankton
Authors: Kiørboe Thomas , Jiang Houshuo , Gonçalves Rodrigo Javier , Nielsen Lasse Tor , Wadhwa Navish
Published: July 2014

Significance

Plankton compromise their survival when they swim and feed because the fluid disturbances that they generate may be perceived by predators. Because the abundance and population dynamics of zooplankton in the ocean are governed by their access to food and exposure to predators, an important question is to what extent and how zooplankton may minimize the fluid disturbances that they generate. We show that when swimming and feeding are integrated processes, zooplankton generate fluid disturbances that extend much farther in the water than is the case for zooplankton that swim only to relocate. Quiet swimming is achieved through “breast swimming” or by swimming by jumping, whereas other propulsion modes are much noisier. This pattern applies independent of organism size and species.
Shape recognition and classification in electro-sensing
Authors: Ammari Habib , Boulier Thomas , Garnier Josselin , Wang Han
Published: July 2014

Significance

Weakly electric fish orient themselves in complete darkness by using their active electrolocation system. They generate a weak electric field and perceive the transdermal potential modulations caused by a nearby target with different electromagnetic properties than the surrounding water. The main result of this paper is a scheme that explains how weakly electric fish might identify and classify living biological organisms. This scheme exploits the frequency dependence of the electromagnetic properties of living organisms, which comes from the capacitive effects generated by the cell membrane structure.
Spin-dependent electron transport in protein-like single-helical molecules
Authors: Guo Ai-Min , Sun Qing-Feng
Published: July 2014

Significance

The control of electron spin transport in molecular systems has been receiving lots of attention among different scientific communities because of possible applications in spintronics and understanding of the spin effects in biological systems. Recent experiments have demonstrated that α-helical protein acts as an efficient spin filter and the chiral-induced spin selectivity may be a general phenomenon. However, no spin selectivity was measured in single-stranded DNA above the experimental noise. In the present study, we propose a physical model to rationalize the above phenomena, and provide an unambiguous physical mechanism for spin-selective phenomenon observed in α-helical protein and for the contradictory behaviors between protein and single-stranded DNA. These results may facilitate engineering of chiral-based spintronic devices.
Eradication of metastatic mouse cancers resistant to immune checkpoint blockade by suppression of myeloid-derived cells
Authors: Kim KiBem , Skora Andrew D. , Li Zhaobo , Liu Qiang , Tam Ada J. , Blosser Richard L. , Diaz Luis A. , Papadopoulos Nickolas , Kinzler Kenneth W. , Vogelstein Bert , Zhou Shibin
Published: July 2014

Significance

Recent clinical trials have shown highly promising responses in a subset of patients treated with immune checkpoint inhibitory anti–programmed cell death-1, anti–programmed cell death ligand-1, and anti–cytotoxic T-lymphocyte-associated antigen-4 antibodies, but the majority of patients in these trials remained unresponsive. Our results show that elevated myeloid-derived suppressor cells(MDSCs) are responsible for the resistance and that elimination of MDSCs can lead to cures of experimental, metastatic tumors.
Synthesis and folding of a mirror-image enzyme reveals ambidextrous chaperone activity
Authors: Weinstock Matthew T. , Jacobsen Michael T. , Kay Michael S.
Published: July 2014

Significance

This paper addresses a fundamental question: Can natural chaperones fold mirror-image proteins? Mirror-image proteins (composed of
d
-amino acids) are only accessible by chemical synthesis, but are protease resistant and therefore have tremendous potential as long-lived drugs. Many large/complex proteins depend on chaperones for efficient folding. Here we describe the total chemical synthesis of a 312-residue chaperone-dependent protein (DapA) in natural (
l
-) and mirror-image (
d
-) forms, the longest fully synthetic proteins yet reported. Using these proteins we show that the natural bacterial GroEL/ES chaperone is “ambidextrous”—i.e., it can fold both natural and mirror-image proteins via nonspecific hydrophobic interactions. Our study also provides proof-of-concept for the use of natural GroEL/ES to fold
d
-proteins for mirror-image drug discovery and synthetic biology applications.
CLAMPing down on microtubules in migratory cells
Authors: Leslie Mitch
Published: July 2014

Par complex and “sperm” protein crucial for embryonic cell relocation.
Approximating functions on stratified sets
Authors: Drusvyatskiy D. , Larsson M.
Published: July 2014

We investigate smooth approximations of functions, with prescribed gradient behavior on a distinguished stratified subset of the domain. As an application, we outline how our results yield important consequences for a recently introduced class of stochastic processes, called the matrix-valued Bessel processes.
Experimental and numerical investigations on the use of polymer Hopkinson pressure bars
Authors: Harrigan John J. , Ahonsi Bright , Palamidi Elisavet , Reid Steve R.
Published: July 2014

Split Hopkinson pressure bar (SHPB) testing has traditionally been carried out using metal bars. For testing low stiffness materials such as rubbers or low strength materials such as low density cellular solids considered primarily herein, there are many advantages to replacing the metal bars with polymer bars. An investigation of a number of aspects associated with the accuracy of SHPB testing of these materials is reported. Test data are used to provide qualitative comparisons of accuracy using different bar materials and wave-separation techniques. Sample results from SHPB tests are provided for balsa, Rohacell foam and hydroxyl-terminated polybutadiene. The techniques used are verified by finite-element (FE) analysis. Experimentally, the material properties of the bars are determined from impact tests in the form of a complex elastic modulus without curve fitting to a rheological model. For the simulations, a rheological model is used to define the bar properties by curve fitting to the experimentally derived properties. Wave propagation in a polymer bar owing to axial impact of a steel bearing ball is simulated. The results indicate that the strain histories can be used to determine accurately the viscoelastic properties of polymer bars. An FE model of the full viscoelastic SHPB set-up is then used to simulate tests on hyperelastic materials.
Towards a shock tube method for the dynamic calibration of pressure sensors
Authors: Downes Stephen , Knott Andy , Robinson Ian
Published: July 2014

In theory, shock tubes provide a pressure change with a very fast rise time and calculable amplitude. This pressure step could provide the basis for the calibration of pressure transducers used in highly dynamic applications. However, conventional metal shock tubes can be expensive, unwieldy and difficult to modify. We describe the development of a 1.4 MPa (maximum pressure) shock tube made from unplasticized polyvinyl chloride pressure tubing which provides a low-cost, light and easily modifiable basis for establishing a method for determining the dynamic characteristics of pressure sensors.
Most courses are not born digital
Authors: Marlos Varonis Evangeline
Published: July 2014

Purpose

– The purpose of this paper is to discuss benefits of and barriers to online learning and describe utilization of the Quality Matters (QM) peer review process as a method to assure the quality of online courses. It outlines the QM higher education rubric, explains how the collaborative QM peer review process facilitates online course design and certification, reports on the development of a statewide consortium in Ohio, and explores future directions in online courses.

Design/methodology/approach

– This paper offers a brief historical review of the incorporation of technology into teaching and learning. It describes attitudes toward online learning and the creation of the non-profit QM program as a vehicle for improving online course design. It summarizes the eight standards of the QM rubric, describes the QM peer review process, and discusses the implementation of the Ohio QM Consortium (OQMC) as a shared services model.

Findings

– Given existing barriers to online learning, the QM program can improve learning outcomes by offering best practices in online course design, validating the quality of online courses, encouraging faculty buy-in through a focus on design rather than content, and facilitating degree completion through recognition of quality courses.

Practical implications

– Institutions that seek to validate online course quality in a cost-effective manner can explore a shared services model such as that developed by the OQMC.

Originality/value

– This paper introduces to an international audience a program and process, widely implemented in the USA, which encourages inter-institutional cooperation and promotes a supportive culture among online educators.
The use of social networking and learning management systems in English language teaching in higher education
Authors: Dogoriti Evriklea , Pange Jenny , S. Anderson Gregory
Published: July 2014

Purpose

– The use of web-enhanced teaching of the English as a foreign language in higher education in Greece is addressed in this case study which examines the student's perceptions of online instruction using Moodle as a learning management system (LMS), with and without the use of Facebook (FB) as an adjunctive learning platform. The merging of this collaborative and interactive social platform with a LMS is explored, examining the attitudes of higher education foreign language learners toward Moodle as a LMS, and FB as an adjunctive informal learning environment. The paper aims to discuss these issues.

Design/methodology/approach

– Results are drawn from a pre-FB questionnaire after a term using Moodle only, and a post-FB questionnaire following a term using Moodle and FB.

Findings

– Results suggest that the use of web-based tools and social media changed the way students viewed the role of internet technology in the development of their English language learning. Most students (76 percent) agreed that the addition of FB to the course helped build a sense of community within a learning environment, while 69 percent suggested it enhanced the learning process.

Originality/value

– Results suggest FB may reinforce communication skills and engagement in the learning process and may support participation and collaborative learning in the formal learning environment provided by Moodle.
Blowing the whistle on workplace sexual harassment
Authors: Tseng Lu-Ming
Published: July 2014

Purpose

– The purpose of this paper is to investigate service workers’ intention to report the “customer harasses colleague” and “colleague harasses customer” problems, and how the intention is influenced by the service workers’ perception of conflict, company integrity and criminal evidence.

Design/methodology/approach

– Questionnaires were used as the research instrument, and full-time life insurance salespeople were taken as a research sample. The research design helps us to see to what extent the respondents rely on the harasser's status and the types of sexual harassment to form their whistle-blowing intention.

Findings

– The main findings showed that: sexual harassment problems are likely to be evaluated from a “who is the harasser” perspective. The respondents appeared more tolerant of the “colleague harasses customer” problems as opposed to the “customer harasses colleague” problems. The respondents exhibited higher intention to report the hostile environment sexual harassment as opposed to quid pro quo sexual harassment.

Originality/value

– Sexual harassment has been described as an extremely harmful behavior in organizations. However, relevant discussions about the “customer harasses colleague” problems and “colleague harasses customer” problems are rare. The research provided an examination of these issues.
Centipede Game network model of investment in real estate market based on grey integration and forwards induction
Authors: Shui Lulu
Published: July 2014

Purpose

– The purpose of this paper is to attempt the construct of a Centipede Game network model of investment in real estate market based on grey integration and forwards induction.

Design/methodology/approach

– The investment process of decision making in the real estate market is a multi-agent-stage dynamic process. The behavior of the game are interdependent and the ultimated equilibrium is an outcome of every the game adjust themselves comprehensively in certain conditions. The paper constructs a Centipede Game network model of investment in real estate market based on grey integration and forwards induction, regulars the method framework based on grey integration and forwards induction.

Findings

– The results verifies that the validity of Centipede Game network model by taking N's real estate market as an example.

Practical implications

– Most of the existing real estate market game researches study it from the view of pairwise game or one-to-many game, in fact, the game tend to be developed in the form of a network. And the paper puts forward Centipede Game network model based on the mode of players game in real estate market.

Originality/value

– The paper succeeds in providing a new and systematic framework of studying the real estate market game by using game theory.
Multi-phase information aggregation and dynamic synthetic evaluation based on grey inspiriting control lines
Authors: Guo San-dang , Liu Sifeng , Fang Zhigeng , Wang Lingling
Published: July 2014

Purpose

– The purpose of this paper is to put forward a multi-stage information aggregation method based on grey inspiriting control lines to evaluate the objects dynamically and comprehensively.

Design/methodology/approach

– According to the evaluation value of the objects, the positive and negative incentive lines were set up and the predicted values were solved based on the grey GM(1, 1) model, so the value with expected information could be evaluated. In the evaluation, the part above the positive incentive line should be “rewarded” and that below the negative incentive line should be “punished” appropriately. Thereby the double incentive effects of “the current development situation and future development trend” to objects could be implemented on the basis of control.

Findings

– This method can primarily describe the decision maker's expectancy of the development of evaluation objects and make the evaluation results have better practical application value.

Research limitations/implications

– Many comprehensive evaluations were always based on the past information. However, the future development trend of the evaluated object is also very important. This study can be used in the evaluation for future application and development.

Originality/value

– The paper succeeds in providing not only a method of multi-phase information aggregation with expectancy information, but also a simple and convenient method solving nonlinear inspiring lines objectively.
Property of derived grey verhulst model with multiple transformation
Authors: Cui Jie , Xie Naiming , Ma Hongyan , liang Hu Hong , Yang Zhengya , Yuan Chaoqing
Published: July 2014

Purpose

– The purpose of this paper is to study the properties of derived grey verhulst prediction model with multiplication transformation and reduce its modeling complexity.

Design/methodology/approach

– The paper discussed the parameter characteristics of grey derived verhulst model under multiple transformation, and demonstrated its effect on its simulative value and predictive value by investigating the multiple transformation acting on the raw data sequence of this grey model. The parameter characteristics of this model under multiple transformations and its effect of the simulation value and forecasting value are analyzed by studying the properties of multiply transformation of this model.

Findings

– The research finding shows that the modeling accuracy of derived grey verhulst model is in no relation to multiple transformations.

Practical implications

– The above results imply that the data level can be reduced; the process of building derived grey verhulst model can be simplified; but the simulative and predictive accuracy of this model remain unchanged.

Originality/value

– The paper succeeds in realising the properties of derived grey verhulst model by using the method of multiplication transformation, which is helpful to understand the modeling mechanism and expand the application range of derived grey verhulst model.
Integrated vision-based system for efficient, semi-automated control of a robotic manipulator
Authors: Jiang Hairong , P. Wachs Juan , S. Duerstock Bradley
Published: July 2014

Purpose

– The purpose of this paper is to develop an integrated, computer vision-based system to operate a commercial wheelchair-mounted robotic manipulator (WMRM). In addition, a gesture recognition interface system was developed specially for individuals with upper-level spinal cord injuries including object tracking and face recognition to function as an efficient, hands-free WMRM controller.

Design/methodology/approach

– Two Kinect® cameras were used synergistically to perform a variety of simple object retrieval tasks. One camera was used to interpret the hand gestures and locate the operator's face for object positioning, and then send those as commands to control the WMRM. The other sensor was used to automatically recognize different daily living objects selected by the subjects. An object recognition module employing the Speeded Up Robust Features algorithm was implemented and recognition results were sent as a commands for “coarse positioning” of the robotic arm near the selected object. Automatic face detection was provided as a shortcut enabling the positing of the objects close by the subject's face.

Findings

– The gesture recognition interface incorporated hand detection, tracking and recognition algorithms, and yielded a recognition accuracy of 97.5 percent for an eight-gesture lexicon. Tasks’ completion time were conducted to compare manual (gestures only) and semi-manual (gestures, automatic face detection, and object recognition) WMRM control modes. The use of automatic face and object detection significantly reduced the completion times for retrieving a variety of daily living objects.

Originality/value

– Integration of three computer vision modules were used to construct an effective and hand-free interface for individuals with upper-limb mobility impairments to control a WMRM.