bluuebunny/crossref_metadata_2025 huggingface dataset:
Pathways of allosteric regulation in Hsp70 chaperones
Authors: Kityk Roman , Vogel Markus , Schlecht Rainer , Bukau Bernd , Mayer Matthias P.
Published: September 2015

Central to the protein folding activity of Hsp70 chaperones is their ability to interact with protein substrates in an ATP-controlled manner, which relies on allosteric regulation between their nucleotide-binding (NBD) and substrate-binding domains (SBD). Here we dissect this mechanism by analysing mutant variants of the Escherichia coli Hsp70 DnaK blocked at distinct steps of allosteric communication. We show that the SBD inhibits ATPase activity by interacting with the NBD through a highly conserved hydrogen bond network, and define the signal transduction pathway that allows bound substrates to trigger ATP hydrolysis. We identify variants deficient in only one direction of allosteric control and demonstrate that ATP-induced substrate release is more important for chaperone activity than substrate-stimulated ATP hydrolysis. These findings provide evidence of an unexpected dichotomic allostery mechanism in Hsp70 chaperones and provide the basis for a comprehensive mechanical model of allostery in Hsp70s.
Compensatory T-type Ca2+ channel activity alters D2-autoreceptor responses of Substantia nigra dopamine neurons from Cav1.3 L-type Ca2+ channel KO mice
Authors: Poetschke Christina , Dragicevic Elena , Duda Johanna , Benkert Julia , Dougalis Antonios , DeZio Roberta , Snutch Terrance P. , Striessnig Joerg , Liss Birgit
Published: September 2015

The preferential degeneration of Substantia nigra dopamine midbrain neurons (SN DA) causes the motor-symptoms of Parkinson’s disease (PD). Voltage-gated L-type calcium channels (LTCCs), especially the Cav1.3-subtype, generate an activity-related oscillatory Ca2+burden in SN DA neurons, contributing to their degeneration and PD. While LTCC-blockers are already in clinical trials as PD-therapy, age-dependent functional roles of Cav1.3 LTCCs in SN DA neurons remain unclear. Thus, we analysed juvenile and adult Cav1.3-deficient mice with electrophysiological and molecular techniques. To unmask compensatory effects, we compared Cav1.3 KO mice with pharmacological LTCC-inhibition. LTCC-function was not necessary for SN DA pacemaker-activity at either age, but rather contributed to their pacemaker-precision. Moreover, juvenile Cav1.3 KO but not WT mice displayed adult wildtype-like, sensitised inhibitory dopamine-D2-autoreceptor (D2-AR) responses that depended upon both, interaction of the neuronal calcium sensor NCS-1 with D2-ARs and on voltage-gated T-type calcium channel (TTCC) activity. This functional KO-phenotype was accompanied by cell-specific up-regulation of NCS-1 and Cav3.1-TTCC mRNA. Furthermore, in wildtype we identified an age-dependent switch of TTCC-function from contributing to SN DA pacemaker-precision in juveniles to pacemaker-frequency in adults. This novel interplay of Cav1.3 L-type and Cav3.1 T-type channels and their modulation of SN DA activity-pattern and D2-AR-sensitisation, provide new insights into flexible age- and calcium-dependent activity-control of SN DA neurons and its pharmacological modulation.
Experimental hookworm infection and escalating gluten challenges are associated with increased microbial richness in celiac subjects
Authors: Giacomin Paul , Zakrzewski Martha , Croese John , Su Xiaopei , Sotillo Javier , McCann Leisa , Navarro Severine , Mitreva Makedonka , Krause Lutz , Loukas Alex , Cantacessi Cinzia
Published: September 2015

The intestinal microbiota plays a critical role in the development of the immune system. Recent investigations have highlighted the potential of helminth therapy for treating a range of inflammatory disorders, including celiac disease (CeD); however, the mechanisms by which helminths modulate the immune response of the human host and ameliorate CeD pathology are unknown. In this study, we investigated the potential role of alterations in the human gut microbiota in helminth-mediated suppression of an inflammatory disease. We assessed the qualitative and quantitative changes in the microbiota of human volunteers with CeD prior to and following infection with human hookworms and following challenge with escalating doses of dietary gluten. Experimental hookworm infection of the trial subjects resulted in maintenance of the composition of the intestinal flora, even after a moderate gluten challenge. Notably, we observed a significant increase in microbial species richness over the course of the trial, which could represent a potential mechanism by which hookworms can regulate gluten-induced inflammation and maintain intestinal immune homeostasis.
A field experiment with elevated atmospheric CO2-mediated changes to C4 crop-herbivore interactions
Authors: Xie Haicui , Liu Kaiqiang , Sun Dandan , Wang Zhenying , Lu Xin , He Kanglai
Published: September 2015

The effects of elevated CO2 (E-CO2) on maize and Asian corn borer (ACB), Ostrinia furnacalis, in open-top chambers were studied. The plants were infested with ACB and exposed to ambient and elevated (550 and 750 μl/l) CO2. E-CO2 increased the plant height and kernel number per ear. The plants had lower nitrogen contents and higher TNC: N ratios under E-CO2 than at ambient CO2. The response of plant height to E-CO2 was significantly dampened in plants with ACB infestation. However, the weight gain of the survivors declined in plants grown under E-CO2. Moreover, the plant damage caused by ACB was not different among the treatments. Overwintering larvae developed under E-CO2 had a lower supercooling point than those developed under ambient CO2. The results indicated that there was a positive effect of E-CO2 on the accumulation of maize biomass, i.e., the “air-fertilizer” effect, which led to a nutritional deficiency in the plants. The fitness-related parameters of ACB were adversely affected by the CO2-mediated decreased in plant nutritional quality and ACB might alter its food consumption to compensate for these changes. Larval damage to maize under E-CO2 appears to be offset by this “air-fertilizer” effect, with reductions in larval fitness.
RTB Lectin: a novel receptor-independent delivery system for lysosomal enzyme replacement therapies
Authors: Acosta Walter , Ayala Jorge , Dolan Maureen C. , Cramer Carole L.
Published: September 2015

Enzyme replacement therapies have revolutionized patient treatment for multiple rare lysosomal storage diseases but show limited effectiveness for addressing pathologies in “hard-to-treat” organs and tissues including brain and bone. Here we investigate the plant lectin RTB as a novel carrier for human lysosomal enzymes. RTB enters mammalian cells by multiple mechanisms including both adsorptive-mediated and receptor-mediated endocytosis and thus provides access to a broader array of organs and cells. Fusion proteins comprised of RTB and human α-L-iduronidase, the corrective enzyme for Mucopolysaccharidosis type I, were produced using a tobacco-based expression system. Fusion products retained both lectin selectivity and enzyme activity, were efficiently endocytosed into human fibroblasts and corrected the disease phenotype of mucopolysaccharidosis patient fibroblasts in vitro. RTB-mediated delivery was independent of high-mannose and mannose-6-phosphate receptors, which are exploited for delivery of currently approved lysosomal enzyme therapeutics. Thus, the RTB carrier may support distinct in vivo pharmacodynamics with potential to address hard-to-treat tissues.
Mesoporous TiO2 Yolk-Shell Microspheres for Dye-sensitized Solar Cells with a High Efficiency Exceeding 11%
Authors: Li Zhao-Qian , Chen Wang-Chao , Guo Fu-Ling , Mo Li-E , Hu Lin-Hua , Dai Song-Yuan
Published: September 2015

Yolk-shell TiO2 microspheres were synthesized via a one-pot template-free solvothermal method building on the aldol condensation reaction of acetylacetone. This unique structure shows superior light scattering ability resulting in power conversion efficiency as high as 11%. This work provided a new synthesis system for TiO2 microspheres from solid to hollow and a novel material platform for high performance solar cells.
A moment from before 365 Ma frozen in time and space
Authors: Błażejowski Błażej , Gieszcz Piotr , Brett Carlton E. , Binkowski Marcin
Published: September 2015

This study presents a detailed analysis of an exceptionally well-preserved articulated specimen of the trilobite Trimerocephalus from the Late Devonian of the Holy Cross Mountains in Poland. X-ray microtomography reveals the oldest direct evidence for a moulting episode known from the fossil record. The process of moulting as well as associated features observed in the investigated specimen are interpreted by comparison with extinct and extant Xiphosurida arthropods, which survived global P/T extinction and are among the closest extant relatives of trilobites. A very special moment frozen in time and space millions years ago provides rare insights into the behavior and physiology of these long-extinct arthropods.
Pain modulation effect of breathing-controlled electrical stimulation (BreEStim) is not likely to be mediated by deep and fast voluntary breathing
Authors: Hu Huijing , Li Shengai , Li Sheng
Published: September 2015

Voluntary breathing-controlled electrical stimulation (BreEStim), a novel non-invasive and non-pharmacological treatment protocol for neuropathic pain management, was reported to selectively reduce the affective component of pain possibly by increasing pain threshold. The underlying mechanisms involved in the analgesic effect of BreEStim were considered to result from combination of multiple internal pain coping mechanisms triggered during BreEStim. Findings from our recent studies have excluded possible roles of acupuncture and aversiveness and habituation of painful electrical stimulation in mediating the analgesia effect of BreEStim. To further investigate the possible role of voluntary breathing during BreEStim, the effectiveness of fast and deep voluntary breathing-only and BreEStim on experimentally induced pain was compared in healthy human subjects. Results showed no change in electrical pain threshold after Breathing-only, but a significant increase in electrical pain threshold after BreEStim. There was no statistically significant change in other thresholds after Breathing-only and BreEStim. The findings suggest that the analgesic effect of BreEStim is not likely attributed to fast and deep voluntary breathing. Possible mechanisms are discussed.
Positive regulation of the Shewanella oneidensis OmpS38, a major porin facilitating anaerobic respiration, by Crp and Fur
Authors: Gao Tong , Ju Lili , Yin Jianhua , Gao Haichun
Published: September 2015

Major porins are among the most abundant proteins embedded in the outer membrane (OM) of Gram-negative bacteria, playing crucial roles in maintenance of membrane structural integrity and OM permeability. Although many OM proteins (especially c-type cytochromes) in Shewanella oneidensis, a research model for respiratory versatility, have been extensively studied, physiological significance of major porins remains largely unexplored. In this study, we show that OmpS38 and OmpA are two major porins, neither of which is responsive to changes in osmolarity or contributes to the intrinsic resistance to β-lactam antibiotics. However, OmpS38 but not OmpA is largely involved in respiration of non-oxygen electron acceptors. We then provide evidence that expression of ompS38 is transcribed from two promoters, the major of which is favored under anaerobic conditions while the other appears constitutive. The major promoter is under the direct control of Crp, the master regulator dictating respiration. As a result, the increase in the level of OmpS38 correlates with an elevated activity in Crp under anaerobic conditions. In addition, we show that the activity of the major promoter is also affected by Fur, presumably indirectly, the transcription factor for iron-dependent gene expression.
Replication of Leaf Surface Structures for Light Harvesting
Authors: Huang Zhongjia , Yang Sai , Zhang Hui , Zhang Meng , Cao Wei
Published: September 2015

As one of the most important hosts of natural light harvesting, foliage normally has complicated surface structures to capture solar radiances. Bio-mimicking leaf surface structures can provide novel designs of covers in photovoltaic systems. In this article, we reported on replicating leaf surface structures on poly-(methyl methacrylate) polymers to prompt harvesting efficiencies. Prepared via a double transfer process, the polymers were found to have high optical transparencies and transmission hazes, with both values exceeding 80% in some species. Benefiting from optical properties and wrinkled surfaces, the biomimetic polymers brought up to 17% gains to photovoltaic efficiencies. Through Monte-Carlo simulations of light transport, ultrahigh haze values and low reflections were attributed to lightwave guidance schemes lead by the nano- and micro-morphologies which are inherited from master leaves. Thus, leaf surface bio-mimicking can be considered as a strategic direction to design covers of light harvesting systems.
Enhancement of heat conduction in carbon nanotubes filled with fullerene molecules
Authors: Cui Liu , Feng Yanhui , Zhang Xinxin
Published: September 2015

C60-encapsulation-induced high thermal conductivity of carbon nanopeapods owing to phonon couplings at low frequencies and enhancement in mass transfer.
Artificial evolution of coumarin dyes for dye sensitized solar cells
Authors: Venkatraman Vishwesh , Abburu Sailesh , Alsberg Bjørn Kåre
Published: September 2015

This work reports the use of artificial evolution to the design of coumarin-based dye sensitizers.
Biomolecular engineering of virus-like particles aided by computational chemistry methods
Authors: Zhang Lin , Lua Linda H. L. , Middelberg Anton P. J. , Sun Yan , Connors Natalie K.
Published: September 2015

Multi-scale investigation of VLP self-assembly aided by computational methods is facilitating the design, redesign, and modification of functionalized VLPs.
Tin sulfide and selenide clusters soluble in organic solvents with the core structures of Sn4S6 and Sn4Se6
Authors: Zhong Mingdong , Yang Zhi , Yi Yafei , Zhang Dongxiang , Sun Kening , Roesky Herbert W. , Yang Ying
Published: September 2015

Reactions of LSnCl (1) (L = N(2,6-iPr2C6H3)(SiMe3)) with sulfur and selenium, respectively under mild conditions yielded two tin chalcogenide clusters. The two products show high catalytic activity in ROP catalysis.
One-pot catalytic conversion of microalgae (Chlorococcum sp.) into 5-hydroxymethylfurfural over the commercial H-ZSM-5 zeolite
Authors: Wang J. J. , Tan Z. C. , Zhu C. C. , Miao G. , Kong L. Z. , Sun Y. H.
Published: September 2015

A high yield of HMF is directly obtained from aquatic microalgae over a commercial acidic zeolite under mild conditions. Experimental results reveal that proteins and lipids in microalgal cells benefit the HMF stability in water.
Towards sustainable fuels and chemicals through the electrochemical reduction of CO2: lessons from water electrolysis
Authors: Martín Antonio J. , Larrazábal Gastón O. , Pérez-Ramírez Javier
Published: September 2015

This Perspective discusses target parameters for the electroreduction of CO2, based on its comparison with water splitting, which is to become a practical alternative for energy storage into fuels and chemicals.
Late stage modification of receptors identified from dynamic combinatorial libraries
Authors: Pinkin Nicholas K. , N. Power Amanie , Waters Marcey L.
Published: September 2015

Approaches for the late-stage modification of receptors discovered from dynamic combinatorial libraries and the investigation of the effects of simple modifications on receptor binding and selectivity.
Effects of replacing thiophene with 5,5-dimethylcyclopentadiene in alternating poly(phenylene), poly(3-hexylthiophene), and poly(fluorene) copolymer derivatives
Authors: Chen L. , Wang K. , Mahmoud S. M. , Li Y. , Huang H. , Huang W. , Xu J. , Dun C. , Carroll D. , Pietrangelo A.
Published: September 2015

Replacing alternating thiophene repeat units with 5,5-dimethylcyclopentadiene alternatives influences the physicochemical properties of π-conjugated copolymers.
A label free fluorescent assay for uracil-DNA glycosylase activity based on the signal amplification of exonuclease I
Authors: Ma Yefei , Zhao Jingjin , Li Xuejun , Zhang Liangliang , Zhao Shulin
Published: September 2015

A label free fluorescent assay for uracil-DNA glycosylase activity was developed based on the signal amplification of exonuclease I.
A highly reversible Li–O2battery utilizing a mixed electrolyte and a cathode incorporating Co3O4
Authors: Zeng J. , Francia C. , Amici J. , Bodoardo S. , Penazzi N.
Published: September 2015

Li–O2cell using a EMITFSI–DMSO electrolyte exhibited a low voltage gap and a long cycle life maintaining a satisfactory discharge capacity.
Spectroscopic exploration of drug–protein interaction: a study highlighting the dependence of the magnetic field effect on inter-radical separation distance formed during photoinduced electron transfer
Authors: Chakraborty Brotati , Mitra Piyali , Basu Samita
Published: September 2015

The magnetic field effect can be used as a “spectroscopic ruler” to assess inter-radical separation distances in photoinduced electron transfer.
On the morphology of MoS2slabs on MoS2/Al2O3catalysts: the influence of Mo loading
Authors: Chen Jianjun , Oliviero Laetitia , Portier Xavier , Maugé Françoise
Published: September 2015

The ratio of S-edge/Mo-edge on the MoS2phase supported by Al2O3increases on increasing the Mo loading.
The advances in applying inorganic fluorescent nanomaterials for the detection of hepatocellular carcinoma and other cancers
Authors: Chen Hetao , Shi Dongxing , Wang Yu , Zhang Liwen , Zhang Qiang , Wang Baiqi , Xia Chunhui
Published: September 2015

The advances, drawbacks and application suggestions of QDs, UCNPs and CDs in HCC and other cancer detection fields are discussed.
Development of antibacterial polyacrylonitrile membrane modified with a covalently immobilized lysozyme
Authors: Liu Wei , Cai Minhua , He Yuegui , Wang Shuai , Zheng Jinwang , Xu Xiaoping
Published: September 2015

A novel antibacterial polyacrylonitrile (PAN) membrane covalently immobilized with lysozyme was prepared.
Synthesis and evaluation of novel quinuclidinone derivatives as potential anti-proliferative agents
Authors: Soni Jigar Y. , Sanghvi Shridhar , Devkar R. V. , Thakore Sonal
Published: September 2015

In this study a new series of substituted (Z)-4-(3-oxoquinuclidin-2-ylidene) benzamides and substituted (Z)-4-((3-oxoquinuclidin-2-ylidene)methyl)benzoates have been designed and synthesised as potential anti-cancer agents.
Facile synthesis and comparative study of poly(l-lactide) with linear-comb and star-comb architecture
Authors: Leng Xuefei , Wei Zhiyong , Ren Yingying , Li Yang , Wang Yurong , Wang Qinyi
Published: September 2015

The crystallization ability of PLLA with different chain structures.
Enhanced photoluminescence up and downconversions of Sm3+ ions by Ag nanoparticles in chloroborosilicate glass nanocomposites
Authors: Shasmal Nilanjana , K Pradeep , Karmakar Basudeb
Published: September 2015

Variation of PL intensity with heat treatment duration of RE-doped (CBS-2) and nanometal/RE-doped (CBS-3) chloroborosilicate glasses.
Parameters affecting carbon nanofiber electrodes for measurement of cathodic current in electrochemical sensors: an investigation using artificial neural network
Authors: Adabi Mahdi , Saber Reza , Naghibzadeh Majid , Faridbod Farnoush , Faridi-Majidi Reza
Published: September 2015

Carbon nanofibers electrode.
Enhanced separation and antifouling properties of PVDF ultrafiltration membranes with surface covalent self-assembly of polyethylene glycol
Authors: Zhao Xinzhen , Xuan Huixia , He Chunju
Published: September 2015

A branched PEG layer on a PVDF membrane surface exhibited exclusion capability to pollutants.
Graphene exfoliation in ionic liquids: unified methodology
Authors: Chaban Vitaly V. , Fileti Eudes Eterno
Published: September 2015

Exfoliation constitutes a promising and straightforward technique to obtain a high-quality product (graphene, GRA) from an affordable source (graphite).
Magnetron sputtering deposition of TiO2 particles on polypropylene separators for lithium-ion batteries
Authors: Peng Kun , Wang Biao , Li Yueming , Ji Chengchang
Published: September 2015

After MSD of TiO2, the modified separators presented suppressed thermal shrinkage and improved wettability to electrolytes, resulting in better cell performances.
Towards near-infrared photosensitization of tungsten trioxide nanostructured films by upconverting nanoparticles
Authors: Venne Frédéric , Quintanilla Marta , Quenneville Francis , Işik Dilek , Baloukas Bill , Vetrone Fiorenzo , Santato Clara
Published: September 2015

Upconverting nanoparticles are explored in the field of solar energy conversion to extend the light harvesting properties of nanostructured metal oxide semiconducting thin films to near infrared light.
Solar-microbial hybrid device based on oxygen-deficient niobium pentoxide anodes for sustainable hydrogen production
Authors: Li Mingyang , He Xinjun , Zeng Yinxiang , Chen Meiqiong , Zhang Ziyang , Yang Hao , Fang Pingping , Lu Xihong , Tong Yexiang
Published: September 2015

A new solar-microbial hybrid device based on oxygen-deficient Nb2O5anodes for sustainable hydrogen generation without external bias was demonstrated.
Enhancing the photovoltaic performance of quinoxalino[2,3-b′]porphyrinatozinc-based donor–acceptor copolymers by using 4,4′-bipyridine as a linear bidentate ligand additive
Authors: Wang Liwei , Ma Di , Shi Shaowei , Chen Song , Li Yongfang , Li Xiaoyu , Wang Haiqiao
Published: September 2015

A strategy using Bipy as a linear bidentate ligand additive to significantly improve the photovoltaic performance of metalloporphyrin-based polymers is demonstrated.
Porous CoP concave polyhedron electrocatalysts synthesized from metal–organic frameworks with enhanced electrochemical properties for hydrogen evolution
Authors: Xu Miao , Han Lei , Han Yujie , Yu You , Zhai Junfeng , Dong Shaojun
Published: September 2015

Porous CoP concave polyhedrons were prepared by a topological conversion from Co-MOFs with enhanced electrochemical HER activities.
Chemical engineering of methylammonium lead iodide/bromide perovskites: tuning of opto-electronic properties and photovoltaic performance
Authors: Park Byung-wook , Philippe Bertrand , Jain Sagar M. , Zhang Xiaoliang , Edvinsson Tomas , Rensmo Håkan , Zietz Burkhard , Boschloo Gerrit
Published: September 2015

A convenient 1-step spincoating method for the hybrid perovskite MAPb(I1−xBrx)3(Cl)y, with PbCl2 as lead source, enables tuning of the bandgap.
Stackable, three dimensional carbon–metal oxide composite for high performance supercapacitors
Authors: Kim Joo Hyun , Lee Sangkyu , Choi Junghyun , Song Taeseup , Paik Ungyu
Published: September 2015

We report a stackable all-solid-state supercapacitor based on three dimensional PPy–NiO/RGO–CNT electrodes.
MxCo3−xO4 (M = Co, Mn, Fe) porous nanocages derived from metal–organic frameworks as efficient water oxidation catalysts
Authors: Wei Jie , Feng Yingying , Liu Yan , Ding Yong
Published: September 2015

MxCo3−xO4 (M = Co, Mn, Fe) porous nanocages derived from metal–organic frameworks showed efficient photochemical, chemical-driven (cerium(iv)-driven) and electrochemical water oxidation activity.
Synthesis of aqueous AgInS/ZnS@PEI as a self-indicating nonviral vector for plasmid DNA self-tracking delivery
Authors: Yang Wentao , Guo Weisheng , Zhang Tingbin , Yang Weitao , Su Lin , Fang Lei , Wang Hanjie , Gong Xiaoqun , Chang Jin
Published: September 2015

Synthesis of aqueous ZAIS@PEI QDs as versatile self-tracking gene vectors, allowing the real-time monitoring of gene transfection behavior in live cells without external fluorescence labeling.
A charge neutral iron(ii) complex with an above room temperature spin crossover (SCO) and hysteresis loop
Authors: Senthil Kumar Kuppusamy , Šalitroš Ivan , Heinrich Benoît , Fuhr Olaf , Ruben Mario
Published: September 2015

A luminescent charge neutral Fe(ii) complex [Fe(L1)2] with above room temperature hysteretic spin crossover (SCO) is reported; a phase transition is associated with SCO as inferred from thermal and SAXS studies.
Online Sentence Reading in People With Aphasia: Evidence From Eye Tracking
Authors: Knilans Jessica , DeDe Gayle
Published: September 2015

Purpose

There is a lot of evidence that people with aphasia have more difficulty understanding structurally complex sentences (e.g., object clefts) than simpler sentences (subject clefts). However, subject clefts also occur more frequently in English than object clefts. Thus, it is possible that both structural complexity and frequency affect how people with aphasia understand these structures.

Method

Nine people with aphasia and 8 age-matched controls participated in the study. The stimuli consisted of 24 object cleft and 24 subject cleft sentences. The task was eye tracking during reading, which permits a more fine-grained analysis of reading performance than measures such as self-paced reading.

Results

As expected, controls had longer reading times for critical regions in object cleft sentences compared with subject cleft sentences. People with aphasia showed the predicted effects of structural frequency. Effects of structural complexity in people with aphasia did not emerge on their first pass through the sentence but were observed when they were rereading critical regions of complex sentences.

Conclusions

People with aphasia are sensitive to both structural complexity and structural frequency when reading. However, people with aphasia may use different reading strategies than controls when confronted with relatively infrequent and complex sentence structures.
Verbal Description of Concrete Objects: A Method for Assessing Semantic Circumlocution in Persons With Aphasia
Authors: Antonucci Sharon M. , MacWilliam Colleen
Published: September 2015

Purpose

We investigated from a theoretically motivated perspective what information differentiated sufficient from insufficient descriptions of objects provided by persons with aphasia.

Method

Twenty-one adults with aphasia consequent to single left-hemisphere stroke verbally described 9 living and 9 nonliving objects. Responses were scored for accuracy (i.e., sufficiency) and tallied for type and quantity of semantic feature information provided. Main effects and interactions were identified using repeated measures analyses of variance, with significant findings followed up with planned comparisons.

Results

Differences between correct and incorrect descriptions were identified with respect to both feature type and feature distinctiveness for living and nonliving items, in particular highlighting the importance of distinctive features in descriptions of both domains.

Conclusions

These findings add to the relatively small body of literature investigating semantic feature processing in adults with aphasia. This is a critical gap to close when considered in light of the preponderance of semantically based treatments for word-retrieval impairment in stroke-aphasia. Our findings provide preliminary support for the notion that semantically guided treatments for word-retrieval impairment in stroke-aphasia may be geared toward increasing specificity of semantic circumlocution to increase semantic self-cueing and to improve communication of information to conversation partners.
Parent Telegraphic Speech Use and Spoken Language in Preschoolers With ASD
Authors: Venker Courtney E. , Bolt Daniel M. , Meyer Allison , Sindberg Heidi , Ellis Weismer Susan , Tager-Flusberg Helen
Published: September 2015

Purpose

There is considerable controversy regarding whether to use telegraphic or grammatical input when speaking to young children with language delays, including children with autism spectrum disorder (ASD). This study examined telegraphic speech use in parents of preschoolers with ASD and associations with children's spoken language 1 year later.

Method

Parent–child dyads (n= 55) participated when children were, on average, 3 (Time 1) and 4 years old (Time 2). The rate at which parents omitted obligatory determiners was derived from transcripts of parent–child play sessions; measures of children's spoken language were obtained from these same transcripts.

Results

Telegraphic speech use varied substantially across parents. Higher rates of parent determiner omissions at Time 1 were significantly associated with lower lexical diversity in children's spoken language at Time 2, even when controlling for children's baseline lexical diversity and nonverbal IQ. Findings from path analyses supported the directionality of effects assumed in our regression analyses, although these results should be interpreted with caution due to the limited sample size.

Conclusions

Telegraphic input may have a negative impact on language development in young children with ASD. Future experimental research is needed to directly investigate how telegraphic input affects children's language learning and processing.
Variability and Diagnostic Accuracy of Speech Intelligibility Scores in Children
Authors: Hustad Katherine C. , Oakes Ashley , Allison Kristen
Published: September 2015

Purpose

We examined variability of speech intelligibility scores and how well intelligibility scores predicted group membership among 5-year-old children with speech motor impairment (SMI) secondary to cerebral palsy and an age-matched group of typically developing (TD) children.

Method

Speech samples varying in length from 1–4 words were elicited from 24 children with cerebral palsy (mean age 60.50 months) and 20 TD children (mean age 60.33 months). Two hundred twenty adult listeners made orthographic transcriptions of speech samples (
n
= 5 per child).

Results

Variability associated with listeners made a significant contribution to explaining the variance in intelligibility scores for TD and SMI children, but the magnitude was greater for TD children. Intelligibility scores differentiated very well between children who have SMI and TD children when intelligibility was at or below approximately 75% and above approximately 85%.

Conclusions

Intelligibility seems to be a useful clinical tool for differentiating between TD children and children with SMI at 5 years of age; however, there is considerable variability within and between listeners, highlighting the need for more than one listener per child to ensure validity of an intelligibility measure.
Design of validation experiment for analysing impacts of background ionosphere on geosynchronous SAR using GPS signals
Authors: Dong Xichao , Hu Cheng , Tian Weiming , Tian Ye , Long Teng
Published: September 2015

Geosynchronous synthetic aperture radar (GEO SAR) is susceptible to the ionosphere due to its ultra‐long integration time and ultra‐wide coverage, resulting in image defocusing and drift. A design of a validation experiment for analysing ionospheric impacts on GEO SAR focusing using global position system (GPS) signals is presented. The experiment consists of data acquisition and equivalent pre‐processing of the GPS signals, along with the following contaminated GEO SAR signal modelling, imaging and evaluation. The key step is the pre‐processing part for the equivalent transformation of the recorded data into the space–time frame of GEO SAR. Thereafter, the phase errors induced by the ionosphere in GEO SAR can be generated from the pre‐processed GPS data and then incorporated into the simulated GEO SAR signals. Finally, the image focusing and impacts analysis are accomplished. In cases of the current inclined L‐band GEO SAR system configuration, the existence of the ionosphere will induce image drifts but these can be corrected through image registration techniques. Another aspect is that the image can be well focused in range direction; however, the azimuth focusing is dependent on the second and higher derivatives of TEC, the thresholds would be determined based on the specific GEO SAR system configuration.
Vertical‐cavity surface‐emitting lasers with birefringence splitting above 250 GHz
Authors: Pusch T. , Lindemann M. , Gerhardt N.C. , Hofmann M.R. , Michalzik R.
Published: September 2015

Using the elasto‐optic effect, increase of the frequency difference between the two orthogonally polarised modes, the so‐called birefringence splitting, in standard single‐mode oxide‐confined AlGaAs‐based vertical‐cavity surface‐emitting lasers is achieved to values beyond 250 GHz. A large birefringence is required for the generation of ultra‐fast polarisation oscillations for potential future high‐speed communication applications.
Hybrid topology of symmetrical multilevel inverter using less number of devices
Authors: Gautam Shivam Prakash , Kumar Lalit , Gupta Shubhrata
Published: September 2015

The interest in development of newer topologies of multilevel inverter has been increasing rapidly in past few years. Recently introduced topologies achieve higher number of output voltage steps with reduced number of switches, DC voltage sources, voltage stress across switches and losses as compared with the conventional topologies. In this study, a new structure of symmetrical multilevel inverter is proposed. The proposed structure offers reduced number of controlled switches, power diodes and DC sources as compared with classical and recently proposed topologies in the literature. Reduction of switch count and DC voltage sources reduces the size, cost, complexity and enhances overall performance. Proposed topology is capable of producing 7, 9 and 11 levels of output voltage with seven switches only. Moreover, significant reduction in voltage stress across the switches can be achieved. A comparative analysis of proposed topology with the conventional topology and recently published topologies has been made in terms of controlled switches, power diodes, driver circuit requirement, DC voltage sources and blocking voltage. Multi‐carrier pulse‐width modulation strategy is adopted for generating the switching pulses. Simulation study of the proposed topology has been carried out using Matlab/Simulink and feasibility of topology has been validated experimentally.
Sensorless speed measurement for brushed DC motors
Authors: Radcliffe Pj , Kumar Dinesh
Published: September 2015

This study describes two new methods of sensing the speed of a pulse‐width modulation‐driven brushed DC motor based on measuring the inductive spikes generated when the motor is turned off. The research has studied the relationship between the rise time or duration of the inductive spike, and the motor current and speed. Computationally inexpensive algorithms have been developed that use either rise time or duration to estimate speed. The algorithms have been implemented on an inexpensive microprocessor and show a speed error of approximately 10% over most of the motor's range of operation. The spike rise time implementation requires an analog‐to‐digital converter (ADC) as found in many microprocessors, while the spike duration implementation requires only a single digital input thus reducing the cost of the controlling microprocessor. This work has shown that sensorless speed measurement can be based on the inductive spike and has also raised future research questions, such as to the best way to optimise the speed measurement in dynamic situations, and measurement errors to be expected in a mass production environment.
Spectrum sensing and sharing for cognitive radars
Authors: Stinco Pietro , Greco Maria S. , Gini Fulvio
Published: September 2015

This study deals with the problem of spectrum sensing and spectrum sharing for cognitive radar operating in spectrally dense environments. The authors focus on how compressed sensing in spectrum sensing can allow a significant reduction in acquisition time reducing the cost for high‐resolution analogue‐to‐digital converters. They derive an algorithm for estimating the channel parameters that characterise the behaviour of the primary user of the channel and also define a spectrum‐sharing method to minimise the interference between the radar and the primary user.
Investigation of reliability analysis algorithms for effective reliability‐based optimal design of electromagnetic devices
Authors: Ren Ziyan , Zhang Dianhai , Koh Chang‐Seop
Published: September 2015

To extend the reliability‐based optimal design to engineering electromagnetic problems, the essential prerequisite is to develop a numerically efficient method of reliability calculation. From a practical point of view, this study presents a comparative study on different algorithms of reliability analysis. For reliability analysis of electromagnetic problems, the author proposed one sensitivity‐assisted Monte Carlo simulation (SA‐MCS) method in the previous research. To seek a higher accuracy of reliability analysis, in this study, the second‐order derivatives are incorporated into the SA‐MCS method. About calculation of second‐order derivatives (also called sensitivity analysis in the finite element analysis), a hybrid direct differentiation–adjoint variable method is applied. Finally, analysis performances of the suggested SA‐MCS and traditional methods such as the reliability index approach and the performance measure approach are investigated through applications to analytic examples and a superconducting magnetic energy storage system.
Mode analysis and research on graphene nanoribbons parallel‐plate waveguide
Authors: Qin Kang , Xiao Binggang , Sun Runliang
Published: September 2015

A graphene nanoribbon parallel‐plate waveguide (GNPPW) in the infrared band is reported. Owing to the large loss, difficulty of control and shortages of traditional metals, graphene has been considered as a novel plasmonic material as the substitute for metals. In this reported work, the relationship between the dispersion characteristics, the propagation loss of the GNPPW's surface plasmon and the filled dielectric into the GNPPW are analysed. The results show that filling dielectric with a large permittivity can improve the confinement of the symmetric mode supported by the GNPPW. Moreover, the transmission distance and dispersion characteristics of the GNPPW under different chemical potentials are analysed. The performance of the waveguide can be effectively controlled by the filling dielectric and external means such as static voltage, achieving easy regulation and control of graphene. This research has some reference values for the production of novel graphene waveguide devices.
Improved multi-objective model predictive control of permanent magnetic synchronous generator wind power system
Authors: Wang Yi , Yu Ming , Li Yonggang
Published: September 2015

A novel sorting-based multi-objective model predictive control strategy for controlling converters of permanent magnetic synchronous generator wind turbines is proposed in this paper. To avoid the nontrivial process of scale factors tuning which is typical in traditional multi-objective model predictive control, sorting and ranking is incorporated in this method where quicksort is utilized to sort the multiple control variables with the principle of variable that has smaller objective function value ranking higher. In addition, predictive direct torque control and direct power control are adopted separately for the generator-side and the grid-side converters in which one-step delay in digital implementation and switching losses are compensated without deterioration of system stability. In order to verify the effectiveness of the proposed method, simulations and experimental tests are conducted separately with results showing that the proposed method can get excellent steady and dynamic performance with lowered fluctuations and switching frequencies while avoiding the tedious scale factors tuning process.
Effect of the tetrahedral groups on the optical properties of LaBRO5 (R = Si and Ge): A first-principles study
Authors: Li Linping , Jing Qun , Yang Zhihua , Su Xin , Lei Bing-Hua , Pan Shilie , Zhang Fangfang , Zhang Jun
Published: September 2015

As potential candidates for deep-UV nonlinear optical (NLO) crystals, borosilicates and borogermanates, which contain NLO-active groups such as B-O, Si-O, and Ge-O groups, have fascinated many material scientists' research enthusiasm. In this paper, the electronic structures and optical properties of two isostructural noncentrosymmetric crystals LaBRO5 (R = Si and Ge) have been studied by the first-principles method. Combined with the analyses of the SHG-density and the localized electron-density difference, contributions of the constituent tetrahedra to the total NLO responses are investigated. Eventually, BO4 and GeO4 groups give nearly equal contributions to the SHG effect of LaBGeO5, but for LaBSiO5, SiO4 groups express stronger SHG response than that of BO4. Such interesting conclusion is consistent with the distortion index analyses and dipole moment.
Finite-size and truncation effects for microscopic expressions for the temperature at equilibrium and nonequilibrium
Authors: Lervik Anders , Wilhelmsen Øivind , Trinh Thuat T. , Nagel Henrik Rojas
Published: September 2015

Several expressions have been proposed for the temperature in molecular simulations, where some of them have configurational contributions. We investigate how their accuracy is influenced by the number of particles in the simulation and the discontinuity in the derivatives of the interaction potential introduced by truncation. For equilibrium molecular dynamics with fixed total volume and fixed average total energy per particle, all the evaluated expressions including that for the kinetic temperature give a dependence on the total number of particles in the simulation. However, in a partitioned simulation volume under the same conditions, the mean temperature of each bin is independent of the number of bins. This finding is important for consistently defining a local temperature for use in nonequilibrium simulations. We identify the configurational temperature expressions which agree most with the kinetic temperature and find that they give close to identical results in nonequilibrium molecular dynamics (NEMD) simulations with a temperature gradient, for high and low density bulk-systems (both for transient and steady-state conditions), and across vapor-liquid interfaces, both at equilibrium and during NEMD simulations. The work shows that the configurational temperature is equivalent to the kinetic temperature in steady-state molecular dynamics simulations if the discontinuity in the derivatives of the interaction potential is handled properly, by using a sufficiently long truncation-distance or tail-corrections.
Inclined gravity currents filling basins: The influence of Reynolds number on entrainment into gravity currents
Authors: Hogg Charlie A. R. , Dalziel Stuart B. , Huppert Herbert E. , Imberger Jörg
Published: September 2015

In many important natural and industrial systems, gravity currents of dense fluid feed basins. Examples include lakes fed by dense rivers and auditoria supplied with cooled air by ventilation systems. As we will show, the entrainment into such buoyancy driven currents can be influenced by viscous forces. Little work, however, has examined this viscous influence and how entrainment varies with the Reynolds number, Re. Using the idea of an entrainment coefficient, E, we derive a mathematical expression for the rise of the front at the top of the dense fluid ponding in a basin, where the horizontal cross-sectional area of the basin varies linearly with depth. We compare this expression to experiments on gravity currents with source Reynolds numbers, Res, covering the broad range 100 < Res < 1500. The form of the observed frontal rises was well approximated by our theory. By fitting the observed frontal rises to the theoretical form with E as the free parameter, we find a linear trend for E(Res) over the range 350 < Res < 1100, which is in the transition to turbulent flow. In the experiments, the entrainment coefficient, E, varied from 4 × 10−5 to 7 × 10−2. These observations show that viscous damping can be a dominant influence on gravity current entrainment in the laboratory and in geophysical flows in this transitional regime.
Narayanaswamy’s 1971 aging theory and material time
Authors: Dyre Jeppe C.
Published: September 2015

The Bochkov-Kuzovlev nonlinear fluctuation-dissipation theorem is used to derive Narayanaswamy’s phenomenological theory of physical aging, in which this highly nonlinear phenomenon is described by a linear material-time convolution integral. A characteristic property of the Narayanaswamy aging description is material-time translational invariance, which is here taken as the basic assumption of the derivation. It is shown that only one possible definition of the material time obeys this invariance, namely, the square of the distance travelled from a configuration of the system far back in time. The paper concludes with suggestions for computer simulations that test for consequences of material-time translational invariance. One of these is the “unique-triangles property” according to which any three points on the system’s path form a triangle such that two side lengths determine the third; this is equivalent to the well-known triangular relation for time-autocorrelation functions of aging spin glasses [L. F. Cugliandolo and J. Kurchan, J. Phys. A: Math. Gen. 27, 5749 (1994)]. The unique-triangles property implies a simple geometric interpretation of out-of-equilibrium time-autocorrelation functions, which extends to aging a previously proposed framework for such functions in equilibrium [J. C. Dyre, e-print arXiv:cond-mat/9712222 (1997)].
Flow regimes in a vertical Taylor-Couette system with a radial thermal gradient
Authors: Guillerm R. , Kang C. , Savaro C. , Lepiller V. , Prigent A. , Yang K.-S. , Mutabazi I.
Published: September 2015

A rich variety of flow regimes in a Newtonian fluid inside a vertical large-aspect ratio and a wide-gap Taylor-Couette system with a radial temperature gradient has been determined in experiments and in direct numerical simulations (DNSs). Compared to previous experiments and numerical studies, a wider range of temperature differences (i.e., of the Grashof number Gr) and of the rotation rate (the Taylor number Ta) has been covered. The combined effect of rotation and of the radial temperature gradient is the occurrence of helicoidal vortices or modulated waves at the onset. Stationary axisymmetric vortices are found for very weak temperature differences. A good agreement was found for critical states between results from experiments, linear stability analysis, and DNS. Higher instability modes have been determined for a wide range of parameters and a state diagram of observable flow regimes has been established in the plane spanned by Gr and Ta. Some higher states observed in experiments were retrieved in DNS.
On the calculation of complete dissociation curves of closed-shell pseudo-onedimensional systems via the complete active space method of increments
Authors: Fertitta E. , Paulus B. , Barcza G. , Legeza Ö.
Published: September 2015

The method of increments (MoI) has been employed using the complete active space formalism in order to calculate the dissociation curve of beryllium ring-shaped clusters Ben of different sizes. Benchmarks obtained through different quantum chemical methods including the ab initio density matrix renormalization group were used to verify the validity of the MoI truncation which showed a reliable behavior for the whole dissociation curve. Moreover we investigated the size dependence of the correlation energy at different interatomic distances in order to extrapolate the values for the periodic chain and to discuss the transition from a metal-like to an insulator-like behavior of the wave function through quantum chemical considerations.