bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlinear dual-mode instability of planar liquid sheets
Authors: Wang Chen , Yang Lijun , Ye Hanyu
Published: August 2015

The nonlinear temporal instability of gas-surrounded planar liquid sheets, whose linear instability contains both sinuous and varicose modes, is studied. Both the weakly nonlinear analysis using a second-order perturbation expansion and the numerical simulation using a boundary integral method have been applied. Their comparison shows that the weakly nonlinear analysis can precisely predict the shapes of sheets for most of the time of disturbance evolution and qualitatively explain the instability mechanism when sheets break up. Both the first harmonics of the linear sinuous mode and linear varicose mode are varicose; they contribute to the breakup of sheets, but the first harmonic generated by the coupling between the linear sinuous and varicose modes is sinuous; it plays an important role in modulating the wave profile. The instability with various initial phase differences between the upper and lower interfaces is examined. Except for the varicose initial disturbance, the linear sinuous mode dominates in the shapes of sheets when their amplitudes grow large. Within the second-order analysis, the major modes that can cause the breakup include the linear varicose mode, the first harmonic of the linear sinuous mode and the first harmonic of the linear varicose mode. The effects of various flow parameters have been investigated. At relatively large wavenumbers where approximate analytical and numerical results agree well when sheets break up, increasing the wavenumber reduces the wave amplitude. Reducing the initial disturbance amplitude makes the first harmonic of the linear sinuous mode the dominant mode in causing the breakup. Increasing the Weber number or gas-to-liquid density ratio significantly reduces breakup time and enhances instability.
Fugitive Monuments and Animal Pathways: Explaining the Stone Settings of Exmoor
Authors: Gillings Mark
Published: August 2015

As a result of the exclusive use of extremely small megaliths (miniliths), the prehistoric stone settings of Exmoor, south-west England, challenge current approaches to the interpretation of monumental stone architecture during the later Neolithic and Early Bronze Age. Whilst the broader context of the practice of erecting tiny upright stones (a seemingly diverse and widespread phenomenon) and the reasons why this diminutive architecture has tended to escape sustained critical comment have been explored (smaller stone elements being relegated to a generalised background or subsidiary role such as ‘packing’), attempts to explain the settings have been remarkably few. Drawing upon the results of ten years of piecemeal fieldwork on the moor the present paper seeks to rectify this, arguing that far from being generalised ritual structures or metaphorical expressions of hunting groups, the tiny stones were, instead, an integral part of a dynamic human–animal landscape of movement and pause.
Related Securities and Equity Market Quality: The Case of CDS
Authors: Boehmer Ekkehart , Chava Sudheer , Tookes Heather E.
Published: August 2015

We document that equity markets become less liquid and equity prices become less efficient when markets for single-name credit default swap (CDS) contracts emerge. This finding is robust across a variety of market quality measures. We analyze the potential mechanisms driving this result and find evidence consistent with negative trader-driven information spillovers that result from the introduction of CDS. These spillovers greatly outweigh the potentially positive effects associated with completing markets (e.g., CDS markets increase hedging opportunities) when firms and their equity markets are in “bad” states. In “good” states, we find some evidence that CDS markets can be beneficial.
Demosponges from the Northern Mid-Atlantic Ridge shed more light on the diversity and biogeography of North Atlantic deep-sea sponges
Authors: Cárdenas Paco , Rapp Hans Tore
Published: August 2015

In July–August 2004, the Mid-Atlantic Ridge Ecosystems (MAR-Eco) expedition collected Demospongiae (Porifera) from the Northern Mid-Atlantic Ridge (MAR) north of the Azores, between 41°N and 61°N. Demosponges were found at 10 stations, at depths ranging from 753 to 3046 m. Twenty-two species were identified: 17 Tetractinellida, one Polymastiida, one Suberitida, two Poecilosclerida and one Dendroceratida. The study of this material is an opportunity to revise the taxonomy and the North Atlantic distribution of each of these deep-sea species. Some species are particularly rare and poorly known (Tetilla longipilis, Tetilla sandalina, Craniella azorica, Polymastia corticata) and two are new to science:Forcepia(Forcepia)toxaferasp. nov. andIotroata paravaridenssp. nov. This study suggests that the MAR is not a longitudinal barrier for the dispersal of deep-sea demosponges while on the contrary, the Charlie-Gibbs Fracture Zone (CGFZ) may be a latitudinal border for the dispersal of deep-sea demosponges, due to great depths and currents.
Harnessing local ecological knowledge for conservation decision making via Wisdom of Crowds: the case of the Manus green tree snailPapustyla pulcherrima
Authors: Whitmore Nathan
Published: August 2015

The shell of the Manus green tree snailPapustyla pulcherrimais renowned for its beauty and is subject to international protection under CITES, having been harvested intensively in the past. To determine its threat status, and whether further conservation action is justified, an inexpensive Wisdom of Crowds approach was used to estimate the change in relative density of the snail between 1998 and 2013. Local men and women were approached around the main market on Manus Island, Papua New Guinea, and asked to map the relative abundance of the snail on an ordinal scale, based on their personal observations in 2013 and 1998 (a year of cultural significance). The spatial abundance data from 400 surveys were analysed using an information-theoretic approach. A suite of cumulative link models incorporating geographical factors was used to determine the magnitude of the change and to investigate possible biological influences underpinning the reported pattern. High abundance of the snail was associated with intact forested areas, high elevation and low population density. A slow decline was evident, with the median percentage of map cells where the snail was categorized as plentiful decreasing by c. 20% between the 2 years. On this basis a categorization of Near Threatened was advocated for the species. Although it is arguable that Wisdom of Crowds methods cannot be substituted for in situ quantification, the approach appears to have utility as a preliminary assessment for further conservation expenditure, and as a tool for determining threat status.
The Concept of Assisted Management of Large-Scale Disasters by Horizontal Organizations
Authors: Burkle Frederick M. , Hayden Robin
Published: August 2015

Management of large-scale disasters is impeded by inadequately designed organizational infrastructure. The vertical organizational structures of most agencies responding to disasters contribute to a poorly integrated response, especially when collaboration, information sharing, and coordination are required. Horizontal (or lateral) organizations have assisted traditionally vertical civilian and military agencies by enhancing their capacity to operate successfully in complex human emergencies and large-scale natural disasters. Because of the multiagency and highly technical multidisciplinary requirements for decision-making in chemical and biological disasters, similar horizontal management options must be considered.
Sharing Climate Information in the Himalayas
Authors: Panthi Jeeban , Krakauer Nir , Pradhanang Soni
Published: August 2015

International Conference on Climate Change Innovation and Resilience for Sustainable Livelihood (ClimDev15 Conference ); 12–14 January 2015, Kathmandu, Nepal
Silencing NFBD1/MDC1 enhances the radiosensitivity of human nasopharyngeal cancer CNE1 cells and results in tumor growth inhibition
Authors: Wang Z , Zeng Q , Chen T , Liao K , Bu Y , Hong S , Hu G
Published: August 2015

NFBD1 functions in cell cycle checkpoint activation and DNA repair following ionizing radiation (IR). In this study, we defined the NFBD1 as a tractable molecular target to radiosensitize nasopharyngeal carcinoma (NPC) cells. Silencing NFBD1 using lentivirus-mediated shRNA-sensitized NPC cells to radiation in a dose-dependent manner, increasing apoptotic cell death, decreasing clonogenic survival and delaying DNA damage repair. Furthermore, downregulation of NFBD1 inhibited the amplification of the IR-induced DNA damage signal, and failed to accumulate and retain DNA damage-response proteins at the DNA damage sites, which leaded to defective checkpoint activation following DNA damage. We also implicated the involvement of NFBD1 in IR-induced Rad51 and DNA-dependent protein kinase catalytic subunit foci formation. Xenografts models in nude mice showed that silencing NFBD1 significantly enhanced the antitumor activity of IR, leading to tumor growth inhibition of the combination therapy. Our studies suggested that a combination of gene therapy and radiation therapy may be an effective strategy for human NPC treatment.
Multiphoton harvesting metal–organic frameworks
Authors: Quah Hong Sheng , Chen Weiqiang , Schreyer Martin K. , Yang Hui , Wong Ming Wah , Ji Wei , Vittal Jagadese J.
Published: August 2015

Multiphoton upconversion is a process where two or more photons are absorbed simultaneously to excite an electron to an excited state and, subsequently, the relaxation of electron gives rise to the emission of a photon with frequency greater than those of the absorbed photons. Materials possessing such property attracted attention due to applications in biological imaging, photodynamic therapy, three-dimensional optical data storage, frequency-upconverted lasing and optical power limiting. Here we report four-photon upconversion in metal–organic frameworks containing the ligand, trans, trans-9,10-bis(4-pyridylethenyl)anthracene. The ligand has a symmetrical acceptor–π–donor–π–acceptor structure and a singlet biradical electronic ground state, which boosted its multiphoton absorption cross-sections. We demonstrate that the upconversion efficiency can be enhanced by Förster resonance energy transfer within host–guest metal–organic frameworks consisting of encapsulated high quantum yielding guest molecules. Using these strategies, metal–organic framework materials, which can exhibit frequency-upconverted photoluminescence excited by simultaneous multiphoton absorption, can be rationally designed and synthesized.
Low surface recombination velocity in solution-grown CH3NH3PbBr3 perovskite single crystal
Authors: Yang Ye , Yan Yong , Yang Mengjin , Choi Sukgeun , Zhu Kai , Luther Joseph M. , Beard Matthew C.
Published: August 2015

Organic-inorganic hybrid perovskites are attracting intense research effort due to their impressive performance in solar cells. While the carrier transport parameters such as mobility and bulk carrier lifetime shows sufficient characteristics, the surface recombination, which can have major impact on the solar cell performance, has not been studied. Here we measure surface recombination dynamics in CH3NH3PbBr3 perovskite single crystals using broadband transient reflectance spectroscopy. The surface recombination velocity is found to be 3.4±0.1 × 103 cm s−1, ∼2–3 orders of magnitude lower than that in many important unpassivated semiconductors employed in solar cells. Our result suggests that the planar grain size for the perovskite thin films should be larger than ∼30 μm to avoid the influence of surface recombination on the effective carrier lifetime.
Inhibition of stationary phase respiration impairs persister formation in E. coli
Authors: Orman Mehmet A. , Brynildsen Mark P.
Published: August 2015

Bacterial persisters are rare phenotypic variants that temporarily tolerate high antibiotic concentrations. Persisters have been hypothesized to underlie the recalcitrance of biofilm infections, and strategies to eliminate these cells have the potential to improve treatment outcomes for many hospital-treated infections. Here we investigate the role of stationary phase metabolism in generation of type I persisters in Escherichia coli, which are those that are formed by passage through stationary phase. We find that persisters are unlikely to derive from bacteria with low redox activity, and that inhibition of respiration during stationary phase reduces persister levels by up to ∼1,000-fold. Loss of stationary phase respiratory activity prevents digestion of endogenous proteins and RNA, which yields bacteria that are more capable of translation, replication and concomitantly cell death when exposed to antibiotics. These findings establish bacterial respiration as a prime target for reducing the number of persisters formed in nutrient-depleted, non-growing populations.
Inherent structure length in metallic glasses: simplicity behind complexity
Authors: Wu Yuan , Wang Hui , Cheng Yongqiang , Liu Xiongjun , Hui Xidong , Nieh Taigang , Wang Yandong , Lu Zhaoping
Published: August 2015

One of the central themes in materials science is the structure-property relationship. In conventional crystalline metals, their mechanical behaviour is often dictated by well-defined structural defects such as dislocations, impurities and twins. However, the structure-property relationship in amorphous alloys is far from being understood, due to great difficulties in characterizing and describing the disordered atomic-level structure. Herein, we report a universal, yet simple, correlation between the macroscopic mechanical properties (i.e., yield strength and shear modulus) and a unique characteristic structural length in metallic glasses (MGs). Our analysis indicates that this characteristic length can incorporate effects of both the inter-atomic distance and valence electron density in MGs and result in the observed universal correlation. The current findings shed lights on the basic understanding of mechanical properties of MGs from their disordered atomic structures.
The variability and seasonality of the environmental reservoir of Mycobacterium bovis shed by wild European badgers
Authors: King Hayley C. , Murphy Andrew , James Phillip , Travis Emma , Porter David , Hung Yu-Jiun , Sawyer Jason , Cork Jennifer , Delahay Richard J. , Gaze William , Courtenay Orin , Wellington Elizabeth M.
Published: August 2015

The incidence of Mycobacterium bovis, the causative agent of bovine tuberculosis, has been increasing in UK cattle herds resulting in substantial economic losses. The European badger (Meles meles) is implicated as a wildlife reservoir of infection. One likely route of transmission to cattle is through exposure to infected badger urine and faeces. The relative importance of the environment in transmission remains unknown, in part due to the lack of information on the distribution and magnitude of environmental reservoirs. Here we identify potential infection hotspots in the badger population and quantify the heterogeneity in bacterial load; with infected badgers shedding between 1 × 103 − 4 × 105M. bovis cells g−1 of faeces, creating a substantial and seasonally variable environmental reservoir. Our findings highlight the potential importance of monitoring environmental reservoirs of M. bovis which may constitute a component of disease spread that is currently overlooked and yet may be responsible for a proportion of transmission amongst badgers and onwards to cattle.
Regional patterns of postglacial changes in the Palearctic mammalian diversity indicate retreat to Siberian steppes rather than extinction
Authors: Řičánková Věra Pavelková , Robovský Jan , Riegert Jan , Zrzavý Jan
Published: August 2015

We examined the presence of possible Recent refugia of Pleistocene mammalian faunas in Eurasia by analysing regional differences in the mammalian species composition, occurrence and extinction rates between Recent and Last Glacial faunas. Our analyses revealed that most of the widespread Last Glacial species have survived in the central Palearctic continental regions, most prominently in Altai–Sayan (followed by Kazakhstan and East European Plain). The Recent Altai–Sayan and Kazakhstan regions show species compositions very similar to their Pleistocene counterparts. The Palearctic regions have lost 12% of their mammalian species during the last 109,000 years. The major patterns of the postglacial changes in Palearctic mammalian diversity were not extinctions but rather radical shifts of species distribution ranges. Most of the Pleistocene mammalian fauna retreated eastwards, to the central Eurasian steppes, instead of northwards to the Arctic regions, considered Holocene refugia of Pleistocene megafauna. The central Eurasian Altai and Sayan mountains could thus be considered a present-day refugium of the Last Glacial biota, including mammals.
Reconstruction of micron resolution mouse brain surface from large-scale imaging dataset using resampling-based variational model
Authors: Li Jing , Quan Tingwei , Li Shiwei , Zhou Hang , Luo Qingming , Gong Hui , Zeng Shaoqun
Published: August 2015

Brain surface profile is essential for brain studies, including registration, segmentation of brain structure and drawing neuronal circuits. Recent advances in high-throughput imaging techniques enable imaging whole mouse brain at micron spatial resolution and provide a basis for more fine quantitative studies in neuroscience. However, reconstructing micron resolution brain surface from newly produced neuronal dataset still faces challenges. Most current methods apply global analysis, which are neither applicable to a large imaging dataset nor to a brain surface with an inhomogeneous signal intensity. Here, we proposed a resampling-based variational model for this purpose. In this model, the movement directions of the initial boundary elements are fixed, the final positions of the initial boundary elements that form the brain surface are determined by the local signal intensity. These features assure an effective reconstruction of the brain surface from a new brain dataset. Compared with conventional typical methods, such as level set based method and active contour method, our method significantly increases the recall and precision rates above 97% and is approximately hundreds-fold faster. We demonstrated a fast reconstruction at micron level of the whole brain surface from a large dataset of hundreds of GB in size within 6 hours.
Network analysis reveals a stress-affected common gene module among seven stress-related diseases/systems which provides potential targets for mechanism research
Authors: Guo Liyuan , Du Yang , Wang Jing
Published: August 2015

Chronic stress (CS) was reported to associate with many complex diseases and stress-related diseases show strong comorbidity; however, molecular analyses have not been performed to date to evaluate common stress-induced biological processes across these diseases. We utilized networks constructed by genes from seven genetic databases of stress-related diseases or systems to explore the common mechanisms. Genes were connected based on the interaction information of proteins they encode. A common sub-network constructed by 561 overlapping genes and 8863 overlapping edges among seven networks was identified and it provides a common gene module among seven stress-related diseases/systems. This module is significantly overlapped with network that constructed by genes from the CS gene database. 36 genes with high connectivity (hub genes) were identified from seven networks as potential key genes in those diseases/systems, 33 of hub genes were included in the common module. Genes in the common module were enriched in 190 interactive gene ontology (GO) functional clusters which provide potential disease mechanism. In conclusion, by analyzing gene networks we revealed a stress-affected common gene module among seven stress-related diseases/systems which provides insight into the process of stress induction of disease and suggests potential gene and pathway candidates for further research.
Single molecule array (Simoa) assay with optimal antibody pairs for cytokine detection in human serum samples
Authors: Wu Danlu , Milutinovic Milena Dumont , Walt David R.
Published: August 2015

By employing optimal antibody pairs, ultrasensitive Simoa assays were developed to measure ten cytokine profiles in healthy human serum samples.
Correction: Bisphosphonate-functionalized hyaluronic acid showing selective affinity for osteoclasts as a potential treatment for osteoporosis
Authors: Kootala Sujit , Ossipov Dmitri , van den Beucken Jeroen J. J. P. , Leeuwenburgh Sander , Hilborn Jöns
Published: August 2015

Correction for ‘Bisphosphonate-functionalized hyaluronic acid showing selective affinity for osteoclasts as a potential treatment for osteoporosis’ by Sujit Kootala et al., Biomater. Sci., 2015, 3, 1197–1207.
Amphiphilic hollow porous shell encapsulated Au@Pd bimetal nanoparticles for aerobic oxidation of alcohols in water
Authors: Zou Houbing , Wang Runwei , Dai Jinyu , Wang Yu , Wang Xue , Zhang Zongtao , Qiu Shilun
Published: August 2015

Amphiphilic hollow porous shell encapsulated Au@Pd bimetal nanoparticles have been developed for application in aerobic oxidation of alcohols in water.
A ternary hybrid of carbon nanotubes/graphitic carbon nitride nanosheets/gold nanoparticles used as robust substrate electrodes in enzyme biofuel cells
Authors: Gai Panpan , Song Rongbin , Zhu Cheng , Ji Yusheng , Chen Yun , Zhang Jian-Rong , Zhu Jun-Jie
Published: August 2015

A novel ternary hybrid of carbon nanotubes/graphitic carbon nitride nanosheets/gold nanoparticles was prepared and used as robust substrate electrodes for improving the performance of the glucose/O2enzyme biofuel cell (EBFC).
Enhanced catalytic activity of a hierarchical porous metal–organic framework CuBTC
Authors: Hu Zhigang , Peng Yongwu , Tan Kai Min , Zhao Dan
Published: August 2015

A hierarchical porous metal–organic framework CuBTC with mesopores of 3.9 nm pore size has been facilely obtained as Lewis acid catalyst.
Interactional behavior of the polyelectrolyte poly sodium 4-styrene sulphonate (NaPSS) with imidazolium based surface active ionic liquids in an aqueous medium
Authors: Sharma Renu , Kamal Ajar , Kang Tejwant Singh , Mahajan Rakesh Kumar
Published: August 2015

Interactions between the anionic polyelectrolyte NaPSS and the cationic surface active imidazolium based ionic liquids (SAILs) [Cnmim][Cl] (n = 10, 12, 14) were studied using a multi-technique approach.
Energy-dependent gas-phase fragmentation of fluorofullerene multiply charged anions (MCAs)
Authors: Kirschbaum Rolf W. , Hausmann Markus , Boltalina Olga V. , Strauss Steven H. , Drewello Thomas
Published: August 2015

The fragmentation behavior of fluorofullerene di- and trianions is governed by their electronic stability. Ions with the less stable odd-electron configuration dissociate into species with the more stable even-electron configuration.
Depolymerizable poly(benzyl ether)-based materials for selective room temperature recycling
Authors: Baker Matthew S. , Kim Hyungwoo , Olah Michael G. , Lewis Gregory G. , Phillips Scott T.
Published: August 2015

Straightforward modifications to quinone methide monomers creates self-immolative poly(benzyl ethers) that enable room temperature separation and recycling of plastics.
Estimating the grade of Mg corrosion using laser-induced breakdown spectroscopy
Authors: Pořízka P. , Ročňáková I. , Klus J. , Prochazka D. , Sládková L. , Šperka P. , Spotz Z. , Čelko L. , Novotný K. , Kaiser J.
Published: August 2015

We report on the analysis of Mg corrosion using Laser-Induced Breakdown Spectroscopy.
Scavenging of nitrate ions from water using hybrid Al2O3/bio-TiO2nanocomposite impregnated thermoplastic polyurethane nanofibrous membrane
Authors: Suriyaraj S. P. , Pillai Mamatha M. , Bhattacharyya Amitava , Selvakumar R.
Published: August 2015

Nitrate scavenging by hybrid Al2O3/bio-TiO2nanocomposite impregnated thermoplastic polyurethane nanofibrous membrane.
Characterization of stress degradation products of blonanserin by UPLC-QTOF-tandem mass spectrometry
Authors: Kalariya Pradipbhai D. , Patel Prinesh N. , Sharma Mahesh , Garg Prabha , Srinivas R. , Talluri M. V. N. Kumar
Published: August 2015

Forced degradation study of blonanserin and structural elucidation of its degradation products was performed using high resolution tandem mass spectrometry.
Chemical sensor development based on poly(o-anisidine)silverized–MWCNT nanocomposites deposited on glassy carbon electrodes for environmental remediation
Authors: Rahman Mohammed M. , Khan Anish , Asiri Abdullah M.
Published: August 2015

POAS–Ag/MWCNT nanocomposites were prepared by an adsorption process. A selective 3-methoxyphenolic sensor was developed by an I–V technique for the first time. It displays the highest sensitivity (∼3.829 μA cm−2 mM−1) ever published in the literature.
Ultra-sensitive polyaniline–iron oxide nanocomposite room temperature flexible ammonia sensor
Authors: Bandgar D. K. , Navale S. T. , Naushad M. , Mane R. S. , Stadler F. J. , Patil V. B.
Published: August 2015

We report for the first time a room temperature smart NH3sensor based on PAni–Fe2O3nanocomposite loading on flexible PET substrate byin situchemical oxidative polymerization method.
TiO2 surface engineering with multifunctional oligomeric polystyrene coadsorbent for dye-sensitized solar cells
Authors: Lee Yong-Gun , Song Donghoon , Jung June Hyuk , Wooh Sanghyuk , Park Suil , Cho Woohyung , Wei Wei , Char Kookheon , Kang Yong Soo
Published: August 2015

Oligomeric, hydrophobic coadsorbents based on polystyrene (Mn = 2400) terminated by a carboxylic acid exhibit dual functions in dye-sensitized solar cells: passivation of the TiO2 surface, and promotion of the strongly-anchored N719 dyes.
Incorporation of graphene oxide into C12E4/C12mimBr hybrid lyotropic liquid crystal and its thermo-sensitive properties
Authors: Wang Lin , Xin Xia , Yang Mengzhou , Shen Jinglin , Yuan Shiling
Published: August 2015

Schematic illustration of the formation of GO/C12E4/C12mimBr lamellar and hexagonal LLC composites.
Viscoelastic deformation of lipid bilayer vesicles
Authors: Wu Shao-Hua , Sankhagowit Shalene , Biswas Roshni , Wu Shuyang , Povinelli Michelle L. , Malmstadt Noah
Published: August 2015

A dual-beam optical trap (DBOT, left) is used to characterize a viscoelastic stress–strain response in a lipid bilayer vesicle (right).
Voltage-responsive reversible self-assembly and controlled drug release of ferrocene-containing polymeric superamphiphiles
Authors: Chang Xueyi , Cheng Zhiyu , Ren Biye , Dong Renfeng , Peng Jun , Fu Shiyu , Tong Zhen
Published: August 2015

A voltage-responsive comb-like superamphiphilic block polymer PEG113-b-PAA30/FTMA was prepared based on the electrostatic interactions of a ferrocenyl surfactant (FTMA) and an oppositely charged poly-(ethylene glycol)-b-poly(acrylic acid) (PEG113-b-PAA30) in aqueous solution.
Correction: Ultrafast high-performance extraction of uranium from seawater without pretreatment using an acylamide- and carboxyl-functionalized metal–organic framework
Authors: Wang Ling Ling , Luo Feng , Dang Li Long , Li Jian Qiang , Wu Xiao Liu , Liu Shu Juan , Luo Ming Biao
Published: August 2015

Correction for ‘Ultrafast high-performance extraction of uranium from seawater without pretreatment using an acylamide- and carboxyl-functionalized metal–organic framework’ by Ling Ling Wang et al., J. Mater. Chem. A, 2015, 3, 13724–13730.
Metalloprotease meprin β is activated by transmembrane serine protease matriptase-2 at the cell surface thereby enhancing APP shedding
Authors: Jäckle Felix , Schmidt Frederike , Wichert Rielana , Arnold Philipp , Prox Johannes , Mangold Martin , Ohler Anke , Pietrzik Claus U. , Koudelka Tomas , Tholey Andreas , Gütschow Michael , Stirnberg Marit , Becker-Pauly Christoph
Published: August 2015

Increased expression of metalloprotease meprin β is associated with fibrotic syndromes and Alzheimer's disease (AD). Hence, regulation of meprin activity might be a suitable strategy for the treatment of these conditions. Meprin β is a type 1 transmembrane protein, but can be released from the cell surface by ectodomain shedding. The protease is expressed as an inactive zymogen and requires proteolytic maturation by tryptic serine proteases. In the present study, we demonstrate, for the first time, the differences in the activation of soluble and membrane bound meprin β and suggest transmembrane serine protease 6 [TMPRSS6 or matriptase-2 (MT2)] as a new potent activator, cleaving off the propeptide of meprin β between Arg61 and Asn62 as determined by MS. We show that MT2, but not TMPRSS4 or pancreatic trypsin, is capable of activating full-length meprin β at the cell surface, analysed by specific fluorogenic peptide cleavage assay, Western blotting and confocal laser scanning microscopy (CLSM). Maturation of full-length meprin β is required for its activity as a cell surface sheddase, releasing the ectodomains of transmembrane proteins, as previously shown for the amyloid precursor protein (APP).
Factors Influencing Hearing Aid Use in the Classroom: A Pilot Study
Authors: Gustafson Samantha J. , Davis Hilary , Hornsby Benjamin W. Y. , Bess Fred H.
Published: August 2015

Purpose

This pilot study examined factors influencing classroom hearing aid use in school-age children with hearing loss.

Method

The research team visited classrooms of 38 children with mild-to-moderate hearing loss (Grades 1–7) on 2 typical school days, twice per day, to document hearing aid use. In addition, parents reported the number of hours their children used hearing aids at school.

Results

Nearly 24% of children were observed not wearing their hearing aids in the classroom on either observation day. Both grade level and degree of hearing loss appeared to affect hearing aid use. Children in Grades 5–7 and those with milder hearing losses were less likely to wear hearing aids. Overall, parents accurately reported classroom hearing aid use; however, those with children in Grades 5–7 were less accurate than those with children in earlier grades.

Conclusions

These preliminary results suggest that children with milder hearing loss and those in Grades 5–7 are at increased risk for reduced hearing aid use in the classroom. Also, parents of school-age children in these later grades are less accurate reporters of classroom hearing aid use compared to parents of children in earlier grades.
Using Spoken Language Benchmarks to Characterize the Expressive Language Skills of Young Children With Autism Spectrum Disorders
Authors: Ellawadi Allison Bean , Weismer Susan Ellis
Published: August 2015

Purpose

Spoken language benchmarks proposed by Tager-Flusberg et al. (2009) were used to characterize communication profiles of toddlers with autism spectrum disorders and to investigate if there were differences in variables hypothesized to influence language development at different benchmark levels.

Method

The communication abilities of a large sample of toddlers with autism spectrum disorders (N= 105) were characterized in terms of spoken language benchmarks. The toddlers were grouped according to these benchmarks to investigate whether there were differences in selected variables across benchmark groups at a mean age of 2.5 years.

Results

The majority of children in the sample presented with uneven communication profiles with relative strengths in phonology and significant weaknesses in pragmatics. When children were grouped according to one expressive language domain, across-group differences were observed in response to joint attention and gestures but not cognition or restricted and repetitive behaviors.

Conclusion

The spoken language benchmarks are useful for characterizing early communication profiles and investigating features that influence expressive language growth.
A Case Study on Vocal Loudness With a Young Adult With Autism Spectrum Disorder and Developmental Delay
Authors: Pack Amanda , Colozzo Paola , Bernhardt B. May , Radanov Bosko , Rosebush Riley , Marinova-Todd Stefka H.
Published: August 2015

Purpose

This clinical focus article describes an exploratory case study addressing reduction of vocal loudness in a young adult with a history of autism spectrum disorder and developmental delay. The need for a short-term pullout individual intervention arose from his participation in the Advancing Language and Literacy group, a program that provides support for enhancement of speech, language, and literacy skills for young adults with developmental disabilities.

Method

The participant attended individual treatment sessions weekly for 9 sessions, all of which were digitally audio-recorded. Client awareness of different loudness levels was first established using nonspeech sounds and speech samples. Loudness in spontaneous speech was monitored with support of verbal and visual feedback in the individual sessions and tracked in individual sessions as well as sessions of the Advancing Language and Literacy group, which served as a generalization context.

Results

In the individual sessions, the participant's spontaneous production of acceptable volume improved from 42% to 92% of utterances. Observation of group participation indicated generalization, with the majority of utterances produced posttreatment at an acceptable volume.

Conclusions

This clinical focus article emphasizes suprasegmental aspects as a dimension of communicative competence and highlights the need for continued intervention research and services for young adults with developmental disabilities.
Effects of Alphabet-Supplemented Speech on Brain Activity of Listeners: An fMRI Study
Authors: Fercho Kelene , Baugh Lee A. , Hanson Elizabeth K.
Published: August 2015

Purpose

The purpose of this article was to examine the neural mechanisms associated with increases in speech intelligibility brought about through alphabet supplementation.

Method

Neurotypical participants listened to dysarthric speech while watching an accompanying video of a hand pointing to the 1st letter spoken of each word on an alphabet display (treatment condition) or a scrambled display (control condition). Their hemodynamic response was measured with functional magnetic resonance imaging, using a sparse sampling event-related paradigm. Speech intelligibility was assessed via a forced-choice auditory identification task throughout the scanning session.

Results

Alphabet supplementation was associated with significant increases in speech intelligibility. Further, alphabet supplementation increased activation in brain regions known to be involved in both auditory speech and visual letter perception above that seen with the scrambled display. Significant increases in functional activity were observed within the posterior to mid superior temporal sulcus/superior temporal gyrus during alphabet supplementation, regions known to be involved in speech processing and audiovisual integration.

Conclusion

Alphabet supplementation is an effective tool for increasing the intelligibility of degraded speech and is associated with changes in activity within audiovisual integration sites. Changes in activity within the superior temporal sulcus/superior temporal gyrus may be related to the behavioral increases in intelligibility brought about by this augmented communication method.

Supplemental Material

https://doi.org/10.23641/asha.14963610
Voltage equilibration for reactive atomistic simulations of electrochemical processes
Authors: Onofrio Nicolas , Strachan Alejandro
Published: August 2015

We introduce electrochemical dynamics with implicit degrees of freedom (EChemDID), a model to describe electrochemical driving force in reactive molecular dynamics simulations. The method describes the equilibration of external electrochemical potentials (voltage) within metallic structures and their effect on the self-consistent partial atomic charges used in reactive molecular dynamics. An additional variable assigned to each atom denotes the local potential in its vicinity and we use fictitious, but computationally convenient, dynamics to describe its equilibration within connected metallic structures on-the-fly during the molecular dynamics simulation. This local electrostatic potential is used to dynamically modify the atomic electronegativities used to compute partial atomic changes via charge equilibration. Validation tests show that the method provides an accurate description of the electric fields generated by the applied voltage and the driving force for electrochemical reactions. We demonstrate EChemDID via simulations of the operation of electrochemical metallization cells. The simulations predict the switching of the device between a high-resistance to a low-resistance state as a conductive metallic bridge is formed and resistive currents that can be compared with experimental measurements. In addition to applications in nanoelectronics, EChemDID could be useful to model electrochemical energy conversion devices.
Neoclassical toroidal plasma viscosity in the vicinity of the magnetic axis in tokamaks with broken symmetry
Authors: Shaing K. C. , Lee H. , Seol J. , Aydemir A. Y.
Published: August 2015

Theory for neoclassical toroidal plasma viscosity in the low collisionality regime is extended to the vicinity of the magnetic axis in tokamaks with broken symmetry. The toroidal viscosity is induced by particles drifting off the perturbed magnetic surface under the influence of the symmetry breaking magnetic field. In the region away from the magnetic axis, the drift orbit dynamics is governed by the bounce averaged drift kinetic equation in the low collisionality regimes. In the vicinity of the magnetic axis, it is the drift kinetic equation, averaged over the trapped particle orbits, i.e., potato orbits, that governs the drift dynamics. The orbit averaged drift kinetic equation is derived when collision frequency is low enough for trapped particles to complete their potato trajectories. The resultant equation is solved in the 1/ν regime to obtain transport fluxes and, thus, toroidal plasma viscosity through flux-force relation. Here, ν is the collision frequency. The viscosity does not vanish on the magnetic axis, and has the same scalings as that in the region away from magnetic axis, except that the fraction of bananas is replaced by the fraction of potatoes. It also has a weak radial dependence. Modeling of plasma flow velocity V for the case where the magnetic surfaces are broken is also discussed.
Development and testing of an active high voltage saturation probe for characterization of ultra-high voltage silicon carbide semiconductor devices
Authors: Bilbao Argenis V. , Schrock James A. , Ray William B. , Kelley Mitchell D. , Holt Shad L. , Giesselmann Michael G. , Bayne Stephen B.
Published: August 2015

Obtaining accurate collector to emitter voltage measurements when characterizing high voltage silicon carbide (SiC) devices requires the ability to measure voltages in the range of zero to 10 V while the device is in the on-state and the ability to withstand ultra-high voltages while the device is in the off-state. This paper presents a specialized voltage probe capable of accurately measuring the aforementioned range. A comparison is made between the proposed probe and other commonly used high voltage probe alternatives in relation to high voltage SiC device testing. Testing of the probe was performed to ensure linearity, high accuracy, and high bandwidth.
8-band and 14-band kp modeling of electronic band structure and material gain in Ga(In)AsBi quantum wells grown on GaAs and InP substrates
Authors: Gladysiewicz M. , Kudrawiec R. , Wartak M. S.
Published: August 2015

The electronic band structure and material gain have been calculated for GaAsBi/GaAs quantum wells (QWs) with various bismuth concentrations (Bi ≤ 15%) within the 8-band and 14-band kp models. The 14-band kp model was obtained by extending the standard 8-band kp Hamiltonian by the valence band anticrossing (VBAC) Hamiltonian, which is widely used to describe Bi-related changes in the electronic band structure of dilute bismides. It has been shown that in the range of low carrier concentrations n < 5 × 1018 cm−3, material gain spectra calculated within 8- and 14-band kp Hamiltonians are similar. It means that the 8-band kp model can be used to calculate material gain in dilute bismides QWs. Therefore, it can be applied to analyze QWs containing new dilute bismides for which the VBAC parameters are unknown. Thus, the energy gap and electron effective mass for Bi-containing materials are used instead of VBAC parameters. The electronic band structure and material gain have been calculated for 8 nm wide GaInAsBi QWs on GaAs and InP substrates with various compositions. In these QWs, Bi concentration was varied from 0% to 5% and indium concentration was tuned in order to keep the same compressive strain (ε = 2%) in QW region. For GaInAsBi/GaAs QW with 5% Bi, gain peak was determined to be at about 1.5 μm. It means that it can be possible to achieve emission at telecommunication windows (i.e., 1.3 μm and 1.55 μm) for GaAs-based lasers containing GaInAsBi/GaAs QWs. For GaInAsBi/Ga0.47In0.53As/InP QWs with 5% Bi, gain peak is predicted to be at about 4.0 μm, i.e., at the wavelengths that are not available in current InP-based lasers.
Shear-flow trapped-ion-mode interaction revisited. I. Influence of low-frequency zonal flow on ion-temperature-gradient driven turbulence
Authors: Ghizzo A. , Palermo F.
Published: August 2015

Collisionless trapped ion modes (CTIMs) turbulence exhibits a rich variety of zonal flow physics. The coupling of CTIMs with shear flow driven by the Kelvin-Helmholtz (KH) instability has been investigated. The work explores the parametric excitation of zonal flow modified by wave-particle interactions leading to a new type of resonant low-frequency zonal flow. The KH-CTIM interaction on zonal flow growth and its feedback on turbulence is investigated using semi-Lagrangian gyrokinetic Vlasov simulations based on a Hamiltonian reduction technique, where both fast scales (cyclotron plus bounce motions) are gyro-averaged.
Vlasov tokamak equilibria with sheared toroidal flow and anisotropic pressure
Authors: Kuiroukidis Ap , Throumoulopoulos G. N. , Tasso H.
Published: August 2015

By choosing appropriate deformed Maxwellian ion and electron distribution functions depending on the two particle constants of motion, i.e., the energy and toroidal angular momentum, we reduce the Vlasov axisymmetric equilibrium problem for quasineutral plasmas to a transcendental Grad-Shafranov-like equation. This equation is then solved numerically under the Dirichlet boundary condition for an analytically prescribed boundary possessing a lower X-point to construct tokamak equilibria with toroidal sheared ion flow and anisotropic pressure. Depending on the deformation of the distribution functions, these steady states can have toroidal current densities either peaked on the magnetic axis or hollow. These two kinds of equilibria may be regarded as a bifurcation in connection with symmetry properties of the distribution functions on the magnetic axis.
Soft mean spherical approximation for dusty plasma liquids: Level of accuracy and analytic expressions
Authors: Tolias P. , Ratynskaia S. , de Angelis U.
Published: August 2015

The soft mean spherical approximation is employed for the study of the thermodynamics of dusty plasma liquids, the latter treated as Yukawa one-component plasmas. Within this integral theory method, the only input necessary for the calculation of the reduced excess energy stems from the solution of a single non-linear algebraic equation. Consequently, thermodynamic quantities can be routinely computed without the need to determine the pair correlation function or the structure factor. The level of accuracy of the approach is quantified after an extensive comparison with numerical simulation results. The approach is solved over a million times with input spanning the whole parameter space and reliable analytic expressions are obtained for the basic thermodynamic quantities.
Genetic diversity for root plasticity and nitrogen uptake in wheat seedlings
Authors: Melino Vanessa J. , Fiene Gabriele , Enju Akiko , Cai Jinhai , Buchner Peter , Heuer Sigrid
Published: August 2015

Enhancing nitrogen use efficiency (NUE) of wheat is a major focus for wheat breeding programs. NUE may be improved by identifying genotypes that are competitive for nitrogen (N) uptake in early vegetative stages of growth and are able to invest that N in grain. Breeders tend to select high yielding genotypes under conditions of medium to high N supply, but it is not known whether this influences the selection of root plasticity traits or whether, over time, breeders have selected genotypes with higher N uptake efficiency. To address this, genotypes were selected from CIMMYT (1966–1985) and Australian (1999–2007) breeding programs. Genotypes from both programs responded to low N supply by expanding their root surface area through increased total root number and/or length of lateral roots. Australian genotypes were N responsive (accumulated more N under high N than under low N) whereas CIMMYT genotypes were not very N responsive. This could not be explained by differences in N uptake capacity as shown by 15N flux analysis of two representative genotypes with contrasting N accumulation. Expression analysis of nitrate transporter genes revealed that the high-affinity transport system accounted for the majority of root nitrate uptake in wheat seedlings under both low and high N conditions.
Anaerobic spirochaetes and animals
Authors: Hampson David J , Phillips Nyree D , La Tom
Published: August 2015

Anaerobic spirochaetes colonise the large intestine of many avian and mammalian host species. The most well known pathogenic species is the strongly haemolytic Brachyspira hyodysenteriae that was first isolated from pigs with swine dysentery (SD) in the early 1970s. Classical SD is a severe mucohaemorrhagic colitis that occurs in growing pigs and is endemic in most pig-rearing areas of the world. The spirochaete acts in concert with other components of the colonic microbiota to disrupt the integrity of the colonic epithelium and induce inflammation. In recent years two new strongly haemolytic species, the proposed ‘Brachyspira suanatina' and ‘Brachyspira hampsonii', both with reservoirs in migratory water birds, have been described as new and emerging agents of SD in the northern hemisphere. Weakly haemolytic species also have been described, some of which have pathogenic potential. In particular Brachyspira pilosicoli causes a mild colitis and diarrhoea in many species, including human beings, whilst Brachyspira intermedia is a common pathogen in adult poultry. Infection with B. intermedia and/or B. pilosicoli can cause wet litter, faecal staining of eggshells and delays in reaching peak egg production. Options for control of these widespread and economically significant anaerobic infections are limited.