bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of hydration status on cognitive performance and mood
Authors: Masento Natalie A. , Golightly Mark , Field David T. , Butler Laurie T. , van Reekum Carien M.
Published: January 2014

Although it is well known that water is essential for human homeostasis and survival, only recently have we begun to understand its role in the maintenance of brain function. Herein, we integrate emerging evidence regarding the effects of both dehydration and additional acute water consumption on cognition and mood. Current findings in the field suggest that particular cognitive abilities and mood states are positively influenced by water consumption. The impact of dehydration on cognition and mood is particularly relevant for those with poor fluid regulation, such as the elderly and children. We critically review the most recent advances in both behavioural and neuroimaging studies of dehydration and link the findings to the known effects of water on hormonal, neurochemical and vascular functions in an attempt to suggest plausible mechanisms of action. We identify some methodological weaknesses, including inconsistent measurements in cognitive assessment and the lack of objective hydration state measurements as well as gaps in knowledge concerning mediating factors that may influence water intervention effects. Finally, we discuss how future research can best elucidate the role of water in the optimal maintenance of brain health and function.
“The Rare White at the Window”: A Reappraisal of Mark Costello and David Foster Wallace'sSignifying Rappers
Authors: MORRISSEY TARA , THOMPSON LUCAS
Published: January 2014

Stay Fly, and Shit …

DF Fresh W

David Foster Wallace, letter to Bonnie Nadell (5 July 1989)

This article evaluates David Foster Wallace and Mark Costello'sSignifying Rappersin terms of its contribution to both early hip-hop and whiteness studies, as well as positioning the text in relation to Wallace's career. First, the article traces many of Wallace's subsequent thematic concerns and literary techniques back to this early text, locating the origin of some of his most characteristic stylistic devices withinSignifying Rappers.Ultimately, this retrospective reading shows that far from being a mere curiosity piece in Wallace's corpus, radically disconnected from anything he published either before or after, a close interrogation ofSignifying Rappersenriches our understanding of Wallace's work, revealing an oblique vision of Wallace striving to articulate a personal artistic agenda in response to the postmodern literary tradition. The essay proceeds to address Wallace and Costello's uncanny presaging of many of the preoccupations of institutional hip-hop and whiteness studies, offering an extended interpretation of the text in light of these disciplines. This analysis also explores representations of race within Wallace's work more generally, as well as addressing the underlying reasons behind the obscure status ofSignifying Rapperswithin these two related fields.
On the Relation between EGARCH Idiosyncratic Volatility and Expected Stock Returns
Authors: Guo Hui , Kassa Haimanot , Ferguson Michael F.
Published: January 2014

A spurious positive relation between exponential generalized autoregressive conditional heteroskedasticity (EGARCH) estimates of expected monthtidiosyncratic volatility and monthtstock returns arises when the monthtreturn is included in estimation of model parameters. We illustrate via simulations that this look-ahead bias is problematic for empirically observed degrees of stock return skewness and typical monthly return time series lengths. Moreover, the empirical idiosyncratic risk-return relation becomes negligible when expected monthtidiosyncratic volatility is estimated using returns only up to montht− 1.
An unusual cause of chronic otitis media with effusion
Authors: Cooper L , Ford K , Talwar R , Wareing M
Published: January 2014

Objective:

To describe an unusual cause for hearing loss in an adult.

Case report:

A 37-year-old man presented with a year's history of right-sided hearing loss. He had no history of trauma, or local or systemic infection. He was otherwise well, took no medication and had no allergies. He had a two-year history of low back pain. On examination, he had a retracted right tympanic membrane with no perforation, and a middle-ear effusion. Nasendoscopy was normal. Examination of other systems was unremarkable. Computed tomography of the temporal bones with contrast demonstrated a large, right, intra-cerebral internal carotid artery aneurysm compressing the eustachian tube. After a balloon occlusion test, he underwent endovascular occlusion of the parent vessel. He made a good post-operative recovery. A subsequent abdominal ultrasound excluded an abdominal aneurysm as a cause of his low back pain. His hearing had not improved three days post-operatively, and was to be formally assessed and monitored in the clinic.

Discussion:

A carotid aneurysm is a rare cause of eustachian tube compression but must be considered in the differential diagnosis of conductive hearing loss. Aneurysms may have systemic causes, and their presence in other systems should be excluded as they may be multiple.
The tracheostomy clinical nurse specialist: an essential member of the multidisciplinary team
Authors: Crosbie R , Cairney J , Calder N
Published: January 2014

Background:

Tracheostomies are a common procedure within the specialties of otolaryngology and intensive care. The ENT department at Monklands Hospital has developed the position of tracheostomy clinical nurse specialist to improve the management of tracheostomy patients. There is evidence to support the development of a multidisciplinary team for the management of tracheostomy patients following intensive care unit treatment; however, the creation of a specific tracheostomy clinical nurse specialist position has not been widely endorsed in the literature.

Objective:

This paper describes the role of the tracheostomy clinical nurse specialist, advocating this position within the multidisciplinary team.
Signatures of adaptation to plant parasitism in nematode genomes
Authors: BIRD DAVID McK. , JONES JOHN T. , OPPERMAN CHARLES H. , KIKUCHI TAISEI , DANCHIN ETIENNE G. J.
Published: January 2014

Plant-parasitic nematodes cause considerable damage to global agriculture. The ability to parasitize plants is a derived character that appears to have independently emerged several times in the phylum Nematoda. Morphological convergence to feeding style has been observed, but whether this is emergent from molecular convergence is less obvious. To address this, we assess whether genomic signatures can be associated with plant parasitism by nematodes. In this review, we report genomic features and characteristics that appear to be common in plant-parasitic nematodes while absent or rare in animal parasites, predators or free-living species. Candidate horizontal acquisitions of parasitism genes have systematically been found in all plant-parasitic species investigated at the sequence level. Presence of peptides that mimic plant hormones also appears to be a trait of plant-parasitic species. Annotations of the few genomes of plant-parasitic nematodes available to date have revealed a set of apparently species-specific genes on every occasion. Effector genes, important for parasitism are frequently found among those species-specific genes, indicating poor overlap. Overall, nematodes appear to have developed convergent genomic solutions to adapt to plant parasitism.
BUTRINT'S NORTHERN FRONTIER IN THE ELEVENTH CENTURY? THE DEMA WALL
Authors: Hodges Richard
Published: January 2014

This short article considers the reuse of the Hellenistic period Dema Wall in the light of recent research at nearby Butrint, ancient Buthrotum, and proposes that the refurbishment coincides with the revival of the town at Butrint in the early eleventh century. The larger political context of this reinterpretation is briefly considered.
Equi-exponential attraction and rate of convergence of attractors with application to a perturbed damped wave equation
Authors: Carvalho Alexandre N. , Cholewa Jan W. , Dłotko Tomasz
Published: January 2014

We consider a family of bounded dissipative asymptotically compact semigroups depending on a parameter, and study the continuity properties of the corresponding family of its global attractors. We exploit the idea of the uniform exponential attraction property to discuss the continuity properties of the family of attractors and estimate the rate of convergence of the approximating attractors to the limit one. Showing a range of applications of an abstract framework, we focus much of our attention on a perturbed damped wave equation. In this latter case our results involve nonlinearities with critical exponents, for which the continuity of the family of attractors is concluded, including the rate of convergence and the regularity of the limit attractor. This complements the results in the literature.
Infinitely many sign-changing solutions for a class of critical elliptic systems with Neumann conditions
Authors: Filho D. C. de Morais , Faria L. F. O. , Miyagaki O. H. , Pereira F. R.
Published: January 2014

In this work we study the multiplicity results for a class of critical elliptic systems related to the Brézis–Nirenberg problem with the Neumann boundary condition on a ball. Our approach relies on a minimization argument for an auxiliary problem with a mixed boundary condition and on suitable estimates of the critical level for the system case.
Radial symmetry of large solutions of semilinear elliptic equations with convection
Authors: Kamalinejad Ehsan , Moradifam Amir
Published: January 2014

We study the radial symmetry of large solutions of the semilinear elliptic problem Δu + ∇h · ∇u = f (∣x∣, u), and we provide sharp conditions under which the problem has a radial solution. The result is independent of the rate of growth of the solution at infinity.
On the open problems connected to the results of Lazer and Solimini
Authors: Hakl Robert , Zamora Manuel
Published: January 2014

A well-known theorem proved by Lazer and Solimini claims that the singular equation

has a periodic solution if and only if the mean value of the continuous external force is positive. In this paper, we show that this result cannot be extended to the case when h is an integrable function, unless additional assumptions are introduced. In addition, for each p ≥ 1 and h-integrable function in the pth power, we give a sharp condition guaranteeing the existence of periodic solutions to the above-mentioned equation, showing that there is a close relation between p and the order of the singularity λ.
Assessment and Mitigation of Ionospheric Disturbance Effects on GPS Accuracy and Integrity
Authors: Weng Duojie , Ji Shengyue , Chen Wu , Liu Zhizhao
Published: January 2014

Ionospheric disturbances affect Global Positioning System (GPS) performance in terms of accuracy and integrity, especially over the equatorial region. During the period of the disturbances, GPS receivers suffer from a high noise level. Not taken into account by the current stochastic model, the ionospheric disturbances degrade GPS positioning accuracy. In addition, non-Gaussian tails are observed in the distribution of the noise during the period of the disturbances; therefore the integrity of GPS can also be affected. This paper develops a statistical solution that is able to mitigate effects of ionospheric disturbances on GPS accuracy and integrity using a commercial dual frequency receiver. The Rate of Total Electron Content (TEC) change Index (ROTI), a parameter derived from the dual frequency receiver, is used to group the levels of ionospheric disturbances. The standard deviations of the pseudorange noise under different groups are evaluated. By incorporating both the ROTI and the satellite elevation, a modified stochastic model is proposed to reduce the effect of the disturbed observation on the positioning accuracy. The performance of the model is evaluated by a test and an inflated sigma for each group is recommended for over-bounding anomalies of observations to protect the user against threats from ionospheric disturbances. This technique, together with results in this paper, can be applied to mitigate the effects of ionospheric disturbances on GPS.
Shrinkage of X cells in the lateral geniculate nucleus after monocular deprivation revealed by FoxP2 labeling
Authors: DUFFY KEVIN R. , HOLMAN KAITLYN D. , MITCHELL DONALD E.
Published: January 2014

The parallel processing of visual features by distinct neuron populations is a central characteristic of the mammalian visual system. In the A laminae of the cat dorsal lateral geniculate nucleus (dLGN), parallel processing streams originate from two principal neuron types, called X and Y cells. Disruption of visual experience early in life by monocular deprivation has been shown to alter the structure and function of Y cells, but the extent to which deprivation influences X cells remains less clear. A transcription factor, FoxP2, has recently been shown to selectively label X cells in the ferret dLGN and thus provides an opportunity to examine whether monocular deprivation alters the soma size of X cells. In this study, FoxP2 labeling was examined in the dLGN of normal and monocularly deprived cats. The characteristics of neurons labeled for FoxP2 were consistent with FoxP2 being a marker for X cells in the cat dLGN. Monocular deprivation for either a short (7 days) or long (7 weeks) duration did not alter the density of FoxP2-positive neurons between nondeprived and deprived dLGN layers. However, for each deprived animal examined, measurement of the cross-sectional area of FoxP2-positive neurons (X cells) revealed that within deprived layers, X cells were smaller by approximately 20% after 7 days of deprivation, and by approximately 28% after 7 weeks of deprivation. The observed alteration to the cross-sectional area of X cells indicates that perturbation of this major pathway contributes to the functional impairments that develop from monocular deprivation.
When Two Paths Converge: Debonding and Clipping of DutchReuze
Authors: Van Goethem Kristel , Hiligsmann Philippe
Published: January 2014

Dutchreuze(n)(-)has a wide range of synchronic uses that form part of a broad categorical and semantic continuum. Derived from the nounreus‘giant’, it is often used to express a comparison in nominal and adjectival compounds (for example,reuzegroot‘as big as a giant’, lit. ‘giant-big’), but it can also have a merely intensifying function (for example,reuzeleuk‘very nice’, lit. ‘giant-nice’). Moreover, it currently occurs as a free adjective and adverb while keeping its morphological linking morpheme-e-and intensifying value (for example,Het feestje was reuze‘The party was great’). Drawing on synchronic and diachronic corpus data, this paper argues that the emergence ofreuzeas a free morpheme should be accounted for by debonding (an instance of degrammaticalization) and clipping.*
Making sense of apparent chaos: health-care provision in six country case studies
Authors: Pavignani Enrico , Michael Markus , Murru Maurizio , Beesley Mark E. , Hill Peter S.
Published: January 2014

This research examines the impact on health-care provision of advanced state failure and of the violence frequently associated with it, drawing from six country case studies. In all contexts, the coverage and scope of health services change when the state fails. Human resources expand due to unplanned increased production. Injury, threat, death, displacement, migration, insufficient salaries, and degraded skills all impact on performance. Dwindling public domestic funding for health causes increasing household out-of-pocket expenditure. The supply, quality control, distribution, and utilisation of medicines are severely affected. Health information becomes incomplete and unreliable. Leadership and planning are compromised as international agencies pursue their own agendas, frequently disconnected from local dynamics. Yet beyond the state these arenas are crowded with autonomous health actors, who respond to state withdrawal and structural violence in assorted ways, from the harmful to the beneficial. Integrating these existing resources into a cohesive health system calls for a deeper understanding of this pluralism, initiative, adaptation and innovation, and a long-term reorientation of development assistance in order to engage them effectively.
Ecogenomic sensor reveals controls on N2-fixing microorganisms in the North Pacific Ocean
Authors: Robidart Julie C , Church Matthew J , Ryan John P , Ascani François , Wilson Samuel T , Bombar Deniz , Marin Roman , Richards Kelvin J , Karl David M , Scholin Christopher A , Zehr Jonathan P
Published: January 2014

Nitrogen-fixing microorganisms (diazotrophs) are keystone species that reduce atmospheric dinitrogen (N2) gas to fixed nitrogen (N), thereby accounting for much of N-based new production annually in the oligotrophic North Pacific. However, current approaches to study N2 fixation provide relatively limited spatiotemporal sampling resolution; hence, little is known about the ecological controls on these microorganisms or the scales over which they change. In the present study, we used a drifting robotic gene sensor to obtain high-resolution data on the distributions and abundances of N2-fixing populations over small spatiotemporal scales. The resulting measurements demonstrate that concentrations of N2 fixers can be highly variable, changing in abundance by nearly three orders of magnitude in less than 2 days and 30 km. Concurrent shipboard measurements and long-term time-series sampling uncovered a striking and previously unrecognized correlation between phosphate, which is undergoing long-term change in the region, and N2-fixing cyanobacterial abundances. These results underscore the value of high-resolution sampling and its applications for modeling the effects of global change.
Genomic analysis of Chthonomonas calidirosea, the first sequenced isolate of the phylum Armatimonadetes
Authors: Lee Kevin C-Y , Morgan Xochitl C , Dunfield Peter F , Tamas Ivica , McDonald Ian R , Stott Matthew B
Published: January 2014

Most of the lineages of bacteria have remained unknown beyond environmental surveys using molecular markers. Until the recent characterisation of several strains, the phylum Armatimonadetes (formerly known as ‘candidate division OP10’) was a dominant and globally-distributed lineage within this ‘uncultured majority’. Here we report the first Armatimonadetes genome from the thermophile Chthonomonas calidirosea T49T and its role as a saccharide scavenger in a geothermal steam-affected soil environment. Phylogenomic analysis indicates T49T to be related closely to the phylum Chloroflexi. The predicted genes encoding for carbohydrate transporters (27 carbohydrate ATP-binding cassette transporter-related genes) and carbohydrate-metabolising enzymes (including at least 55 putative enzymes with glycosyl hydrolase domains) within the 3.43 Mb genome help explain its ability to utilise a wide range of carbohydrates as well as its inability to break down extracellular cellulose. The presence of only a single class of branched amino acid transporter appears to be the causative step for the requirement of isoleucine for growth. The genome lacks many commonly conserved operons (for example, lac and trp). Potential causes for this, such as dispersion of functionally related genes via horizontal gene transfer from distant taxa or recent genome recombination, were rejected. Evidence suggests T49T relies on the relatively abundant σ-factors, instead of operonic organisation, as the primary means of transcriptional regulation. Examination of the genome with physiological data and environmental dynamics (including interspecific interactions) reveals ecological factors behind the apparent elusiveness of T49T to cultivation and, by extension, the remaining ‘uncultured majority’ that have so far evaded conventional microbiological techniques.
Measuring the Brønsted acid strength of zeolites – does it correlate with the O–H frequency shift probed by a weak base?
Authors: Arean Carlos O. , Delgado Montserrat R. , Nachtigall Petr , Thang Ho Viet , Rubeš Miroslav , Bulánek Roman , Chlubná-Eliášová Pavla
Published: January 2014

ΔνOH(see the figure) can be a misleading indicator of zeolite Brønsted acidity, as shown by VTIR spectroscopy and calorimetry.
Enhancement of the cycling performance of Li3V2(PO4)3/C by stabilizing the crystal structure through Zn2+ doping
Authors: Wang Wenhui , Zhang Jiaolong , Jia Zheng , Dai Changsong , Hu Yongfeng , Zhou Jigang , Xiao Qunfeng
Published: January 2014

Zn doping was proven to be helpful in stabilizing the crystal structure of Li3V2(PO4)3/C upon repeated cycles.
Alkane activation on crystalline metal oxide surfaces
Authors: Weaver Jason F. , Hakanoglu Can , Antony Abbin , Asthagiri Aravind
Published: January 2014

Late transition-metal oxide surfaces that expose coordinatively-unsaturated metal atoms promote the formation and bond activation of alkane σ-complexes.
Conjugated porphyrin arrays: synthesis, properties and applications for functional materials
Authors: Tanaka Takayuki , Osuka Atsuhiro
Published: January 2014

Conjugated porphyrin arrays that possess delocalised electronic networks have, for the most part, been assembled by using alkene or alkyne type bridging units or by directly connecting individual porphyrin chromophores with multiple bonds to form fused porphyrin arrays.
Photodissociation mass spectrometry: new tools for characterization of biological molecules
Authors: Brodbelt Jennifer S.
Published: January 2014

Fragmentation of gas-phase ions by absorption of photons affords a versatile means to characterize the structures and sequences of biological molecules.
Three molybdophosphates based on Strandberg-type anions and Zn(ii)-H2biim/H2O subunits: syntheses, structures and catalytic properties
Authors: Li Zi-Liang , Wang Ying , Zhang Lan-Cui , Wang Jian-Ping , You Wan-Sheng , Zhu Zai-Ming
Published: January 2014

Three Zn(ii)-complex-supporting Strandberg-type molybdophosphates have been synthesized, and they represent the first example of Strandberg-type POMs used as catalysts for an organic reaction.
DFT studies on the mechanism of palladium-catalyzed carbon–silicon cleavage for the synthesis of benzosilole derivatives
Authors: Chen Wen-Jie , Lin Zhenyang
Published: January 2014

DFT calculations have been carried out to study the detailed mechanism of Pd-catalyzed intermolecular coupling reactions of 2-silylaryl bromides with alkynes via selective cleavage of C(sp3)–Si bonds.
Red emitting [Ir(C^N)2(N^N)]+complexes employing bidentate 2,2′:6′,2′′-terpyridine ligands for light-emitting electrochemical cells
Authors: Constable Edwin C. , Housecroft Catherine E. , Schneider Gabriel E. , Zampese Jennifer A. , Bolink Henk J. , Pertegás Antonio , Roldan-Carmona Cristina
Published: January 2014

A series of red emitting [Ir(C^N)2(N^N)][PF6] complexes in which N^N is a bidentate 2,2′:6′,2′′-terpyridine ligand are reported and screened in device configuration for application in LECs.
Early diagenetic processes generate iron and manganese oxide layers in the sediments of Lake Baikal, Siberia
Authors: Torres Natascha T. , Och Lawrence M. , Hauser Peter C. , Furrer Gerhard , Brandl Helmut , Vologina Elena , Sturm Michael , Bürgmann Helmut , Müller Beat
Published: January 2014

Extraordinary buried iron- and manganese oxide layers were investigated in early diagenetic Lake Baikal sediments. Porewater analyses were performed on-site with a portable capillary electrophoresis instrument.
Strategic innovation in the total synthesis of complex natural products using gold catalysis
Authors: Zhang Yun , Luo Tuoping , Yang Zhen
Published: January 2014

This review has been organized from the perspective of synthetic target families, with emphasis on the use of gold-catalyzed transformations and cascade reactions that significantly increase molecular complexity.
Recent progress with microtubule stabilizers: new compounds, binding modes and cellular activities
Authors: Rohena Cristina C. , Mooberry Susan L.
Published: January 2014

Nature has provided a diverse array of microtubule stabilizers. Marine, plant and microbial derived microtubule stabilizers of highly divergent chemical structures, interact with tubulin to cause microtubule stabilization and bundling.
Supramolecular control of selectivity in transition-metal catalysis through substrate preorganization
Authors: Dydio Paweł , Reek Joost N. H.
Published: January 2014

The Perspective highlights possibilities to use supramolecular interactions between a substrate molecule and a (bifunctional) catalyst as a powerful tool to control the selectivity in transition-metal catalysis.
Novel up-conversion luminescent rare-earth-doped organic resins for cost-effective applications in 3D photonic devices
Authors: Ruiz-Morales J. C. , Méndez-Ramos J. , Acosta-Mora P. , Borges M. E. , Esparza P.
Published: January 2014

Novel up-conversion luminescent RE-doped organic resins, showing strong UV-Vis emission under infrared 980 nm laser excitation to bridge different band-gaps of main photocatalytic water-splitting semiconductors, with applications to cost-effective, room-temperature and endlessly shaped 3D photonic structures.
Multiband photoluminescence from carbon nanoflakes synthesized by hot filament CVD: towards solid-state white light sources
Authors: Wang B. B. , Ostrikov K. , Zheng K. , Wang L. , Zou S. S.
Published: January 2014

Carbon nanoflakes (CNFLs) are synthesized on silicon substrates deposited with carbon islands in a methane environment using hot filament chemical vapor deposition.
Rhodamine-labelled simple architectures for fluorometric and colorimetric sensing of Hg2+ and Pb2+ ions in semi-aqueous and aqueous environments
Authors: Ghosh Kumaresh , Sarkar Tanmay , Majumdar Anupam , Mandal Sushil Kumar , Khuda-Bukhsh Anisur Rahman
Published: January 2014

Two triazole motif linked rhodamine derivatives are reported for the determination of Hg2+ and Pb2+ ions in semi-aqueous and aqueous environments.
Structure determination of the theophylline–nicotinamide cocrystal: a combined powder XRD, 1D solid-state NMR, and theoretical calculation study
Authors: Li Ping , Chu Yueying , Wang Lin , Wenslow Robert M. , Yu Kaichao , Zhang Hailu , Deng Zongwu
Published: January 2014

The crystal structure of the theophylline–nicotinamide cocrystal is determined for the first time by using a combined multi-technique approach.
An exemplary relationship between the extent of cofacial aggregation and fluorescence quantum yield as exhibited by quaternized amphiphilic phthalocyanines
Authors: Teixeira Tasso Thiago , Yamasaki Yasuhiro , Furuyama Taniyuki , Kobayashi Nagao
Published: January 2014

A good correlation between aggregation and fluorescence properties of amphiphilic phthalocyanines can be observed.
Preparation of reduced graphene oxide–Ni(OH)2composites by electrophoretic deposition: application for non-enzymatic glucose sensing
Authors: Subramanian Palaniappan , Niedziolka-Jonsson Joanna , Lesniewski Adam , Wang Qian , Li Musen , Boukherroub Rabah , Szunerits Sabine
Published: January 2014

A sensitive and stable non-enzymatic sensing platform ford-glucose based on a reduced graphene oxide (rGO) matrix modified with Ni(OH)2nanostructures was established.
S-palmitoylation regulates biogenesis of core glycosylated wild-type and F508del CFTR in a post-ER compartment
Authors: McClure Michelle L. , Wen Hui , Fortenberry James , Hong Jeong S. , Sorscher Eric J.
Published: January 2014

Defects in CFTR (cystic fibrosis transmembrane conductance regulator) maturation are central to the pathogenesis of CF (cystic fibrosis). Palmitoylation serves as a key regulator of maturational processing in other integral membrane proteins, but has not been tested previously for functional effects on CFTR. In the present study, we used metabolic labelling to confirm that wild-type and F508del CFTR are palmitoylated, and show that blocking palmitoylation with the pharmacologic inhibitor 2-BP (2-bromopalmitate) decreases steady-state levels of both wild-type and low temperature-corrected F508del CFTR, disrupts post-ER (endoplasmic reticulum) maturation and reduces ion channel function at the cell surface. PATs (protein acyl transferases) comprise a family of 23 gene products that contain a DHHC motif and mediate palmitoylation. Recombinant expression of specific PATs led to increased levels of CFTR protein and enhanced palmitoylation as judged by Western blot and metabolic labelling. Specifically, we show that DHHC-7 (i) increases steady-state levels of wild-type and F508del CFTR band B, (ii) interacts preferentially with the band B glycoform, and (iii) augments radiolabelling by [3H]palmitic acid. Interestingly, immunofluorescence revealed that DHHC-7 also sequesters the F508del protein to a post-ER (Golgi) compartment. Our findings point to the importance of palmitoylation during wild-type and F508del CFTR trafficking.
Lattice‐reduction‐aided semidefinite relaxation detection algorithms for multiple‐input multiple‐output systems
Authors: Shao Zi Yun , Cheung Sing Wai , Yuk Tung Ip
Published: January 2014

Multiple‐input multiple‐output (MIMO) system is considered to be one of the key technologies of long‐term evolution, since it achieves requirements of high throughput and spectral efficiency. The semidefinite relaxation (SDR) detection for MIMO systems is an attractive alternative to the optimum maximum likelihood (ML) decoding because it is very computationally efficient. In the case of the binary phase shift keying and four quadrature amplitude modulation constellations, the block error rate (BLER) performance of SDR detection is fairly close to the optimum BLER performance. However, for high‐order modulation systems, their BLER performance is still unsatisfactory compared with the ML decoding. Lattice reduction technology can transform a matrix into a new equivalent one with more orthogonal and shorter basis vectors. It has been combined with linear decoders to improve their BLER performance. Inspired by this, the authors proposed two lattice‐reduction‐aided MIMO detection algorithms based on SDR. Simulation results demonstrate that they can provide near‐optimum BLER performance with polynomial time complexity.
Lower bound on the bit error rate of a decode‐and‐forward relay network under chaos shift keying communication system
Authors: Kaddoum Georges , Gagnon François
Published: January 2014

This study carries out the first‐ever investigation of the analysis of a cooperative decode‐and‐forward (DF) relay network with chaos shift keying (CSK) modulation. The performance analysis of DF‐CSK in this study takes into account the dynamical nature of chaotic signal, which is not similar to a conventional binary modulation performance computation methodology. The expression of a lower bound bit error rate (BER) is derived in order to investigate the performance of the cooperative system under independently and identically distributed Gaussian fading wireless environments. The effect of the non‐periodic nature of chaotic sequence leading to a non‐constant bit energy of the considered modulation is also investigated. A computation approach of the BER expression based on the probability density function of the bit energy of the chaotic sequence, channel distribution and number of relays is presented. Simulation results prove the accuracy of the authors BER computation methodology.
Alamouti space–time block coded hierarchical modulation with signal space diversity and MRC reception in Nakagami‐m fading channel
Authors: Saeed Ayesha , Xu Hongjun , Quazi Tahmid
Published: January 2014

This study presents a novel approach to an Alamouti transmission scheme for hierarchical modulation (HM) with signal space diversity (SSD) in a Nakagami‐m fading channel. The bit‐error‐rate (BER) performance of the proposed system is determined using the nearest neighbourhood (NN) approximation approach and is briefly discussed. In addition, a reduced complexity maximum likelihood‐based decoder is proposed. Simulation results verify a significant BER improvement of the proposed system when compared with previously implemented schemes as well as the accuracy of the NN approximation and the proposed detector. Specifically, gains of up to 8 dB at a BER of 1 × 10−5 for both base and refinement bits have been observed when comparing the proposed HM SSD Alamouti scheme with an HM SSD scheme without Alamouti transmit diversity at a hierarchy of α = 4, channel conditions at m = 1 and N = 1 receiver antennas. Additional results for varying hierarchy at increasing number of receiver antennas and improving channel conditions is also presented. The performance of the proposed reduced complexity decoder is also presented as well as its complexity reduction analysed.
Cooperative spectrum sharing systems with relay selection in the presence of multiple primary receivers
Authors: Guimarães Francisco Rafael Vasconcelos , da Costa Daniel Benevides , Benjillali Mustapha , Tsiftsis Theodoros A. , Karagiannidis George K.
Published: January 2014

In this study, the outage performance of a multi‐relay cooperative network operating in a spectrum sharing environment is analysed. Focusing on the secondary communication process, a relay selection procedure is performed prior to the communication process, where the selected relay is the one maximising the instantaneous end‐to‐end signal‐to‐noise ratio (SNR) and, at the same time, satisfying the power restrictions imposed by the primary receivers. The secondary destination employs a selection combining strategy, selecting the best path (direct link or relaying link) with the highest instantaneous SNR. Two kinds of relaying protocols are considered: decode‐and‐forward and amplify‐and‐forward. For the former, an exact closed‐form expression for the outage probability (OP) is derived, whereas for the latter an accurate approximation for the OP is obtained. Then, an asymptotic analysis is carried out and reveals that the system diversity order is N + 1 for both relaying protocols, with N denoting the number of relays. Monte Carlo simulations assess the accuracy of the authors’ results.
Hybrid computation of corrective security‐constrained optimal power flow problems
Authors: Zhang Rui , Dong Zhao Yang , Xu Yan , Wong Kit Po , Lai Mingyong
Published: January 2014

Corrective security‐constrained optimal power flow (CSCOPF) considers the use of corrective control to remove system security violations in the post‐contingency state. Its optimality not only depends on the pre‐contingency state, but also the post‐contingency state as well as the involved corrective control actions. This study first gives a comprehensive review on the relevant OPF models and then proposes a hybrid method to solve the CSCOPF problem. It makes use of the evolutionary algorithms to randomly search the maximum feasible region and state‐of‐the‐art OPF solution technique (interior‐point method) to provide deterministic solutions in the found region. The two interact iteratively to progressively approach the final solution. The proposed method is verified on the IEEE 14‐bus and 118‐bus systems. Comparison studies show that (i) CSCOPF can better balance the security and economy and (ii) the hybrid method is overall superior (in solution quality, robustness and convergence characteristic) over the single evolutionary algorithm. Parallel processing is applied to speed‐up the computations.
Estimation of target states and signal strength in the probabilistic multiple hypothesis tracking framework
Authors: Choi Won‐Yong , Hong Sun‐Mog
Published: January 2014

An approach is presented for simultaneously estimating target states and signal‐to‐noise ratio (SNR) in the framework of the probabilistic multiple hypothesis tracking (PMHT). The approach, named PMHT‐S, utilises the expectation‐maximisation (EM) algorithm to obtain the maximum a posteriori estimates of target states and SNR's of multiple targets in the presence of false measurements. The missing data of the EM algorithm consists of measurement‐to‐target assignments as well as a set of fictitious geometric and signal strength measurements each associated with a target under the hypothesis that the target has been undetected. This formulation creates new algorithmic approaches for solving PMHT problems such that information on missed targets may be exploited. It is shown that the auxiliary function of the PMHT‐S is additively separable as the sum of a function of target states and a function of target SNR's. The pair, as a result, can be independently maximised in each EM iteration to update target states and SNR's. The computational advantage of the separation is substantial even for a small number of targets. Explicit expressions of the auxiliary function of the PMHT‐S are given. Monte Carlo simulations were performed to assess estimation performance of the PMHT‐S for target tracking examples.
Land and sea clutter from FM‐based passive bistatic radars
Authors: Malanowski Mateusz , Haugen Reidar , Greco Maria S. , O'Hagan Daniel W. , Plšek Radek , Bernard Alan
Published: January 2014

This study examines ground and sea clutter from three different FM‐based passive bistatic radars (PBRs). Measurement data has been obtained for low‐grazing angles. The PBRs used to collect the displayed data, with all their relevant parameters, are defined and clutter analysis procedures are described. This work, based on measured data, yields valuable insight into the nature of VHF bistatic clutter.
Three‐dimensional TiO2/Bi2WO6 hierarchical heterostructure with enhanced visible photocatalytic activity
Authors: Junqi Li , Zhanyun Guo , Yu Wang , Zhenfeng Zhu
Published: January 2014

A three‐dimensional TiO2/Bi2WO6 hierarchical heterostructure was successfully prepared by a simple and practical liquid phase method. The as‐synthesised nanostructure consisted of TiO2 nanoparticles growing on the surface of flower‐like Bi2WO6 microspheres. The UV–vis diffuse reflectance spectra indicated that the TiO2/Bi2WO6 composites have a significantly enhanced optical absorption in the visible light region and red‐shift phenomenon compared with that of pure Bi2WO6 microspheres. The photocatalytic activity of the TiO2/Bi2WO6 composites increases first and then decreases with increasing loading content of TiO2 under 500 W Xe lamp light irradiation. The composite coated with 3 ml content tetrabutyl titanate showed the highest photocatalytic activity compared with that of the other samples in the decomposition of Rhodamine B in water which is a typical model pollutant. The improved light harvesting ability and efficient separation of photo‐generated electron and hole pairs could be responsible for the improved photocatalytic performance.
Biological Standards for Potency Assignment to Fibrinolytic Agents Used in Thrombolytic Therapy
Authors: Thelwell Craig
Published: January 2014

Thrombolytic drugs are used for the treatment of thrombotic disorders such as acute myocardial infarction, acute ischemic stroke, and pulmonary embolism. Biological standards are used for potency assignment to the range of fibrinolytic proteins used in thrombolytic therapy. The World Health Organization (WHO) International Standards are primary reference materials, calibrated in arbitrary units (international unit), assigned by collaborative study using the range of assay methods available at the time. Provided the standard and test material are equivalent, adhering to the principle of measuring like versus like, the exact nature of the assay method is unimportant. This approach has been applied successfully for several decades since the advent of fibrinolytic treatment, ensuring consistency for potency labeling and the correct dosing of patients. The emergence of generic biosimilar products and new recombinant variants poses a challenge to this system, where functional differences impact on the relative biological activity in different assay systems. A more demanding system of standardization may therefore be required on the basis of international reference materials with associated reference methods. WHO recognizes this, and where possible and practical is seeking to incorporate concepts of traceability, uncertainty, and commutability to International Standards. However, some caution is needed because limitations on the characterization of many complex biologicals remain real, and a flexible approach is required on the basis of real-world needs.
Numerical simulation of electromagnetic fields and impedance of CERN LINAC4 H− source taking into account the effect of the plasma
Authors: Grudiev A. , Lettry J. , Mattei S. , Paoluzzi M. , Scrivens R.
Published: January 2014

Numerical simulation of the CERN LINAC4 H− source 2 MHz RF system has been performed taking into account a realistic geometry from 3D Computer Aided Design model using commercial FEM high frequency simulation code. The effect of the plasma has been added to the model by the approximation of a homogenous electrically conducting medium. Electric and magnetic fields, RF power losses, and impedance of the circuit have been calculated for different values of the plasma conductivity. Three different regimes have been found depending on the plasma conductivity: (1) Zero or low plasma conductivity results in RF electric field induced by the RF antenna being mainly capacitive and has axial direction; (2) Intermediate conductivity results in the expulsion of capacitive electric field from plasma and the RF power coupling, which is increasing linearly with the plasma conductivity, is mainly dominated by the inductive azimuthal electric field; (3) High conductivity results in the shielding of both the electric and magnetic fields from plasma due to the skin effect, which reduces RF power coupling to plasma. From these simulations and measurements of the RF power coupling on the CERN source, a value of the plasma conductivity has been derived. It agrees well with an analytical estimate calculated from the measured plasma parameters. In addition, the simulated and measured impedances with and without plasma show very good agreement as well demonstrating validity of the plasma model used in the RF simulations.
Water and ion transport in ultra-adsorbing porous magnesium carbonate studied by dielectric spectroscopy
Authors: Pochard Isabelle , Frykstrand Sara , Ahlström Olle , Forsgren Johan , Strømme Maria
Published: January 2014

Porous materials are used in application areas ranging from drug and vaccine delivery, medical implants, molecular sieves and cosmetics to catalysis and humidity control. In the present work, we employed an alternative approach to gain in-depth understanding about water interaction properties in such materials by the use of dielectric spectroscopy and thereby show that it is possible to obtain information that is not accessible from the more commonly employed water interaction analysis techniques. Specifically, the complex dielectric response of Upsalite, a novel, super-hydroscopic, high-surface area, porous magnesium carbonate material was measured in isothermal frequency scans between 10−3 and 106 Hz at controlled relative humidity (RH). We found the dielectric constant of the dry material to be 1.82. The ratio of bound to free water present in Upsalite after adsorption at room temperature was found to be high irrespective of the surrounding humidity with values ranging from ∼67% to ∼90%. We further found that OH− ions are the charge carriers responsible for the electrode polarization observed in the dielectric response and that the amount of these ions that are free to move in the material corresponds to a concentration of the order of 1–10 μmol l−1 independent of RH. Finally, the OH− diffusion coefficient displayed a drastic decrease with decreasing RH, typical of transport in unsaturated conditions. The presented results provide detailed insight about water interactions in the novel water adsorbing material under study and it is foreseen that the employed analysis methods can be used to evaluate other types of moisture adsorbing materials as well as the movement of functional species in the pores of inorganic drug delivery materials and materials tailored for adsorption of harmful charged species.
The direct injection of intense ion beams from a high field electron cyclotron resonance ion source into a radio frequency quadrupole
Authors: Rodrigues G. , Becker R. , Hamm R. W. , Baskaran R. , Kanjilal D. , Roy A.
Published: January 2014

The ion current achievable from high intensity ECR sources for highly charged ions is limited by the high space charge. This makes classical extraction systems for the transport and subsequent matching to a radio frequency quadrupole (RFQ) accelerator less efficient. The direct plasma injection (DPI) method developed originally for the laser ion source avoids these problems and uses the combined focusing of the gap between the ion source and the RFQ vanes (or rods) and the focusing of the rf fields from the RFQ penetrating into this gap. For high performance ECR sources that use superconducting solenoids, the stray magnetic field of the source in addition to the DPI scheme provides focusing against the space charge blow-up of the beam. A combined extraction/matching system has been designed for a high performance ECR ion source injecting into an RFQ, allowing a total beam current of 10 mA from the ion source for the production of highly charged 238U40+ (1.33 mA) to be injected at an ion source voltage of 60 kV. In this design, the features of IGUN have been used to take into account the rf-focusing of an RFQ channel (without modulation), the electrostatic field between ion source extraction and the RFQ vanes, the magnetic stray field of the ECR superconducting solenoid, and the defocusing space charge of an ion beam. The stray magnetic field is shown to be critical in the case of a matched beam.
Algebraic vs physical N = 6 3-algebras
Authors: Cantarini Nicoletta , Kac Victor G.
Published: January 2014

In our previous paper, we classified linearly compact algebraic simple N = 6 3-algebras. In the present paper, we classify their “physical” counterparts, which actually appear in the N = 6 supersymmetric 3-dimensional Chern-Simons theories.
A short note on the chaoticity of a weight shift on concrete orthonormal basis associated to some Fock-Bargmann space
Authors: Intissar Abdelkader
Published: January 2014

Let $\mathfrak {F}_{\alpha }(\mathbb {C})$Fα(C) be the Hilbert space generated by the orthonormal basis ${e_{n}^{\alpha , \nu }(z) = (\frac{2\nu }{\pi })^{1/4}e^{\frac{\nu }{2}z^{2}}e^{-\frac{\pi ^{2}}{\nu }(n +\alpha )^{2} +2i\pi (n +\alpha )z}; n \in \mathbb {N}}$enα,ν(z)=(2νπ)1/4eν2z2e−π2ν(n+α)2+2iπ(n+α)z;n∈N where ν > 0 and α are real numbers, this space is a particular case of (Γ, χ)-theta Fock-Bargmann spaces recently constructed by Ghanmi-Intissar [J. Math. Phys. 54, 063514 (2013)]. In the present work, we consider on $\mathfrak {F}_{\alpha }(\mathbb {C})$Fα(C) the weight shift operator $\mathbb {M}$M defined by ${\mathbb {M}e_{n}^{\alpha ,\nu } = \omega _{n}e_{n+1}^{\alpha ,\nu }, n\in \mathbb {N}}$Menα,ν=ωnen+1α,ν,n∈N where $\omega _{n} = c_{\alpha ,\nu }e^{\frac{2\pi }{\nu }n}$ωn=cα,νe2πνn and $c_{\alpha , \nu }=e^{\frac{\pi }{\nu }+ 2\alpha }$cα,ν=eπν+2α and we show the chaoticity of the operator $\mathbb {H}_{p} = \mathbb {M}^{p}\mathbb {D}^{p+1}; p=0, 1, 2, ...$Hp=MpDp+1;p=0,1,2,... where $\mathbb {D}$D is adjoint of $\mathbb {M}$M.
Bound states for multiple Dirac-δ wells in space-fractional quantum mechanics
Authors: Tare Jeffrey D. , Esguerra Jose Perico H.
Published: January 2014

Using the momentum-space approach, we obtain bound states for multiple Dirac-δ wells in the framework of space-fractional quantum mechanics. Introducing first an attractive Dirac-comb potential, i.e., Dirac comb with strength −g (g > 0), in the space-fractional Schrödinger equation we show that the problem of obtaining eigenenergies of a system with N Dirac-δ wells can be reduced to a problem of obtaining the eigenvalues of an N × N matrix. As an illustration we use the present matrix formulation to derive expressions satisfied by the bound-state energies of N = 1, 2, 3 delta wells. We also obtain the corresponding wave functions and express them in terms of Fox's H-function.