bluuebunny/crossref_metadata_2025_split huggingface dataset:
Frame size selection in CSMA‐based cognitive radio wireless local area networks
Authors: Hasan Najam ul , Ejaz Waleed , Kim Hyung Seok 
Published: November 2014

AbstractThe performance of cognitive radio‐based wireless local area networks (WLANs) is affected by channel conditions, the contention processes of unlicensed/secondary users (SUs) and collisions between SUs and licensed/primary users (PUs). Given these effects, it is feasible to adjust the frame size to maximise goodput. Existing frame size adjustment mechanisms for WLANs are based on the assumption that optimal frame size depends on either the channel conditions or the contention among nodes. These approaches do not consider the collisions between SUs and PUs. Thus, they lead to suboptimal solutions and cannot be directly applied to cognitive radio‐based WLANs. In this paper, an analytical model to determine the optimal frame size for carrier sense multiple access/collision avoidance‐based cognitive radio networks based on the probability of frame error, the probability of collisions among SUs and the probability of collision between SUs and PUs is proposed. Numerical and simulation results indicate that selecting the optimal frame size significantly improves goodput. Copyright © 2014 John Wiley & Sons, Ltd.
Neural substrates of levodopa‐responsive gait disorders and freezing in advanced Parkinson's disease: A kinesthetic imagery approach
Authors: Maillet Audrey , Thobois Stéphane , Fraix Valérie , Redouté Jérôme , Le Bars Didier , Lavenne Franck , Derost Philippe , Durif Franck , Bloem Bastiaan R. , Krack Paul , Pollak Pierre , Debû Bettina 
Published: November 2014

AbstractGait disturbances, including freezing of gait, are frequent and disabling symptoms of Parkinson's disease. They often respond poorly to dopaminergic treatments. Although recent studies have shed some light on their neural correlates, their modulation by dopaminergic treatment remains quite unknown. Specifically, the influence of levodopa on the networks involved in motor imagery (MI) of parkinsonian gait has not been directly studied, comparing the off and on medication states in the same patients. We therefore conducted an [H2150] Positron emission tomography study in eight advanced parkinsonian patients (mean disease duration: 12.3 ± 3.8 years) presenting with levodopa‐responsive gait disorders and FoG, and eight age‐matched healthy subjects. All participants performed three tasks (MI of gait, visual imagery and a control task). Patients were tested off, after an overnight withdrawal of all antiparkinsonian treatment, and on medication, during consecutive mornings. The order of conditions was counterbalanced between subjects and sessions. Results showed that imagined gait elicited activations within motor and frontal associative areas, thalamus, basal ganglia and cerebellum in controls. Off medication, patients mainly activated premotor‐parietal and pontomesencephalic regions. Levodopa increased activation in motor regions, putamen, thalamus, and cerebellum, and reduced premotor‐parietal and brainstem involvement. Areas activated when patients are off medication may represent compensatory mechanisms. The recruitment of these accessory circuits has also been reported for upper‐limb movements in Parkinson's disease, suggesting a partly overlapping pathophysiology between imagined levodopa‐responsive gait disorders and appendicular signs. Our results also highlight a possible cerebellar contribution in the pathophysiology of parkinsonian gait disorders through kinesthetic imagery. Hum Brain Mapp 36:959–980, 2015. © 2014 Wiley Periodicals, Inc.
Abnormalities in orbitofrontal cortex gyrification and mental health outcomes in adolescents born extremely preterm and/or at an extremely low birth weight
Authors: Ganella Eleni P , Burnett Alice , Cheong Jeanie , Thompson Deanne , Roberts Gehan , Wood Stephen , Lee Katherine , Duff Julianne , Anderson Peter J , Pantelis Christos , Doyle Lex W , Bartholomeusz Cali ,   on behalf of the Victorian Infant Collaborative Study Group
Published: November 2014

AbstractExtremely preterm (EP, <28 weeks) and/or extremely low birth weight (ELBW, <1000 g) infants are at high risk of aberrant neurodevelopment. Sulcogyral folding patterns of the orbitofrontal cortex (OFC) are determined during the third trimester, however little is known about OFC patterning in EP/ELBW cohorts, for whom this gestational period is disturbed. This study investigated whether the distribution of OFC pattern types and frequency of intermediate and/or posterior orbital sulci (IOS/POS) differed between EP/ELBW and control adolescents. This study also investigated whether OFC pattern type was associated with mental illness or executive function outcome in adolescence. Magnetic resonance images of 194 EP/ELBW and 147 full term (>37 completed weeks) and/or normal birth weight (>2500 g) adolescents were acquired, from which the OFC pattern of each hemisphere was classified as Type I, II, or III. Compared with controls, more EP/ELBW adolescents possessed a Type II in the left hemisphere (P = 0.019). The EP/ELBW group had fewer IOS (P = 0.024) and more POS (P = 0.021) in the left hemisphere compared with controls. OFC pattern type was not associated with mental illness, however in terms of executive functioning, Type III in the left hemisphere was associated with better parent‐reported metacognition scores overall (P = 0.008) and better self‐reported behavioral regulation scores in the control group (P = 0.001) compared with Type I. We show, for the first time that EP/ELBW birth is associated with changes in orbitofrontal development, and that specific patterns of OFC folding are associated with executive function at age 18 years in both EP/ELBW and control subjects. Hum Brain Mapp 36:1138–1150, 2015. © 2014 Wiley Periodicals, Inc.
Strong rightward lateralization of the dorsal attentional network in left‐handers with right sighting‐eye: An evolutionary advantage
Authors: Petit Laurent , Zago Laure , Mellet Emmanuel , Jobard Gaël , Crivello Fabrice , Joliot Marc , Mazoyer Bernard , Tzourio‐Mazoyer Nathalie 
Published: November 2014

AbstractHemispheric lateralization for spatial attention and its relationships with manual preference strength and eye preference were studied in a sample of 293 healthy individuals balanced for manual preference. Functional magnetic resonance imaging was used to map this large sample while performing visually guided saccadic eye movements. This activated a bilateral distributed cortico‐subcortical network in which dorsal and ventral attentional/saccadic pathways elicited rightward asymmetrical activation depending on manual preference strength and sighting eye. While the ventral pathway showed a strong rightward asymmetry irrespective of both manual preference strength and eye preference, the dorsal frontoparietal network showed a robust rightward asymmetry in strongly left‐handers, even more pronounced in left‐handed subjects with a right sighting‐eye. Our findings brings support to the hypothesis that the origin of the rightward hemispheric dominance for spatial attention may have a manipulo‐spatial origin neither perceptual nor motor per se but rather reflecting a mechanism by which a spatial context is mapped onto the perceptual and motor activities, including the exploration of the spatial environment with eyes and hands. Within this context, strongly left‐handers with a right sighting‐eye may benefit from the advantage of having the same right hemispheric control of their dominant hand and visuospatial attention processing. We suggest that this phenomenon explains why left‐handed right sighting‐eye athletes can outperform their competitors in sporting duels and that the prehistoric and historical constancy of the left‐handers ratio over the general population may relate in part on the hemispheric specialization of spatial attention. Hum Brain Mapp 36:1151–1164, 2015. © 2014 Wiley Periodicals, Inc.
Combining isotopic tracers (222Rn and δ13C) for improved modelling of groundwater discharge to small rivers
Authors: Lefebvre K. , Barbecot F. , Larocque M. , Gillon M. 
Published: November 2014

AbstractIn regions where aquifers sustain rivers, the location and quantification of groundwater discharge to surface water are important to prevent pollution hazards, to quantify and predict low flows and to manage water supplies. 222Rn is commonly used to determine groundwater discharge to rivers. However, using this isotopic tracer is challenging because of the high diffusion capacity of 222Rn in open water. This study illustrates how a combination of isotopic tracers can contribute to an enhanced understanding of groundwater discharge patterns in small rivers. The aim of this paper is to combine 222Rn and δ13CDIC to better constrain the physical parameters related to the degassing process of these tracers in rivers. The Hallue River (northern France) was targeted for this study because it is sustained almost exclusively by a fractured chalk aquifer. The isotopes 222Rn, δ13CDIC, δ2H and δ18O were analysed along with other natural geochemical tracers. A mass balance model was used to simulate 222Rn and δ13CDIC. The results of δ2H and δ18O analyses prove that evaporation did not occur in the river. The calibration of a numerical model to reproduce 222Rn and δ13CDIC provides a best‐fit diffusive layer thickness of 3.21 × 10−5 m. This approach is particularly useful for small rivers flowing over carbonate aquifers with high groundwater DIC where the evolution of river DIC reflects the competing processes of groundwater inflow and CO2 degassing. This approach provides a means to evaluate groundwater discharge in small ungauged rivers. Copyright © 2014 John Wiley & Sons, Ltd.
Low‐level laser irradiation promotes the proliferation and maturation of keratinocytes during epithelial wound repair
Authors: Sperandio Felipe F. , Simões Alyne , Corrêa Luciana , Aranha Ana Cecília C. , Giudice Fernanda S. , Hamblin Michael R. , Sousa Suzana C.O.M. 
Published: November 2014

Low‐level laser therapy (LLLT) has been extensively employed to improve epithelial wound healing, though the exact response of epithelium maturation and stratification after LLLT is unknown. Thus, this study aimed to assess the in vitro growth and differentiation of keratinocytes (KCs) and in vivo wound healing response when treated with LLLT. Human KCs (HaCaT cells) showed an enhanced proliferation with all the employed laser energy densities (3, 6 and 12 J/cm2, 660 nm, 100 mW), together with an increased expression of Cyclin D1. Moreover, the immunoexpression of proteins related to epithelial proliferation and maturation (p63, CK10, CK14) all indicated a faster maturation of the migrating KCs in the LLLT‐treated wounds. In that way, an improved epithelial healing was promoted by LLLT with the employed parameters; this improvement was confirmed by changes in the expression of several proteins related to epithelial proliferation and maturation.
Immunofluorescent expression of cytokeratin 10 (red) and Cyclin D1 (green) in (A) Control keratinocytes and (B) Low‐level laser irradiated cells. Blue color illustrates the nuclei of the cells (DAPI staining).magnified imageImmunofluorescent expression of cytokeratin 10 (red) and Cyclin D1 (green) in (A) Control keratinocytes and (B) Low‐level laser irradiated cells. Blue color illustrates the nuclei of the cells (DAPI staining).
Nutritional values and bioactive components of under‐utilised vegetables consumed by indigenous people in Malaysia
Authors: Abdul Wahab Norsuhaila , Ahdan Rohaina , Ahmad Aufa Zabidah , Kong Kin Weng , Johar Mohd Hafizan , Shariff Mohd Zalilah , Ismail Amin 
Published: November 2014

AbstractBACKGROUNDDiverse plants species in the forest remain under‐utilised and they are mainly consumed only by local people. However, increasing issues in food security prompted the present study, which explores the nutritional and antioxidant aspects of Malaysian under‐utilised vegetables. The studied vegetables were Paku Nyai (Stenochlaena palustris), Cemperai (Champereia manillana), Maman Pasir (Cleome viscose), Dudung (Erechtites valerianifolia) and Semambuk (Ardisia pendula).RESULTSOverall, these vegetables exhibited a low proximal content but they were high in vitamin C [7.07–1263 mg kg−1 edible fresh sample (EFS)] and β‐carotene content (18.4–43.9 mg kg−1 kg−1 EFS). Cemperai had the highest calcium content (565 mg kg−1 EFS), whereas Semambuk had the highest total phenolic content [28.21 g gallic acid equivalents kg−1 edible dried sample (EDS)] and antioxidant activity (86.1%) measured using β‐carotene bleaching assay. Maman Pasir contained the highest total flavonoid content (39.99 g CE kg−1 EDS) and 1,1‐diphenyl‐2‐picryl hydrazyl radical scavenging activity (82.2%). The extracts of these vegetables had significantly prevented the oxidation of haemoglobin and low‐density lipoprotein, which yielded a reduced production of malondialdehyde.CONCLUSIONSemambuk and Maman Pasir are potent to be used as new food and functional food sources as they are rich in nutrients and antioxidants. © 2014 Society of Chemical Industry
Plasma Stimulation of Migration of Macrophages
Authors: Miller Vandana , Lin Abraham , Fridman Gregory , Dobrynin Danil , Fridman Alexander 
Published: November 2014

AbstractPlasma has been shown to be effective against cancer cells both in vitro and in vivo. Several studies have documented the selectivity of plasma against cancer cells with minimal or reduced damage to normal cells. However, complete remission of cancer following plasma treatment has not been achieved yet. In the body, the immune system plays a vital role in the prevention and control of cancer. Presence of cells of the adaptive immune system in the tumor microenvironment is usually an indicator of good prognosis. Since immune cell migration is a key initial step towards defense against diseases, it is important to evaluate the influence of plasma treatment on such cellular functions. Here we show that treatment with nanosecond‐pulsed non‐thermal dielectric barrier discharge enhances migration of macrophages in vitro.
Common functionally important motions of the nucleotide‐binding domain of Hsp70
Authors: Gołaś Ewa I. , Czaplewski Cezary , Scheraga Harold A. , Liwo Adam 
Published: November 2014

ABSTRACTThe 70 kDa heat shock proteins (Hsp70) are a family of molecular chaperones involved in protein folding, aggregate prevention, and protein disaggregation. They consist of the substrate‐binding domain (SBD) that binds client substrates, and the nucleotide‐binding domain (NBD), whose cycles of nucleotide hydrolysis and exchange underpin the activity of the chaperone. To characterize the structure–function relationships that link the binding state of the NBD to its conformational behavior, we analyzed the dynamics of the NBD of the Hsp70 chaperone from Bos taurus (PDB 3C7N:B) by all‐atom canonical molecular dynamics simulations. It was found that essential motions within the NBD fall into three major classes: the mutual class, reflecting tendencies common to all binding states, and the ADP‐ and ATP‐unique classes, which reflect conformational trends that are unique to either the ADP‐ or ATP‐bound states, respectively. “Mutual” class motions generally describe “in‐plane” and/or “out‐of‐plane” (scissor‐like) rotation of the subdomains within the NBD. This result is consistent with experimental nuclear magnetic resonance data on the NBD. The “unique” class motions target specific regions on the NBD, usually surface loops or sites involved in nucleotide binding and are, therefore, expected to be involved in allostery and signal transmission. For all classes, and especially for those of the “unique” type, regions of enhanced mobility can be identified; these are termed “hot spots,” and their locations generally parallel those found by NMR spectroscopy. The presence of magnesium and potassium cations in the nucleotide‐binding pocket was also found to influence the dynamics of the NBD significantly. Proteins 2015; 83:282–299. © 2014 Wiley Periodicals, Inc.
Multiple proton relay routes in the reaction mechanism of RNAP II: Assessing the effect of structural model
Authors: Zhang Rui , Bhattacharjee Anirban , Field Martin J. , Salahub Dennis R. 
Published: November 2014

ABSTRACTRNA polymerase II catalyzes the nucleotidyl transfer reaction for messenger RNA synthesis in eukaryotes. Two crystal structures of this system have been resolved, each with its own defects in the coordination sphere of Mg2+(A) resulting from chemical modifications. We have used both structures and also a novel hybrid of the two that allows a better exploration of the parts of configuration space that reflect substrate–enzyme interactions. MD and QM/MM calculations have been performed, the latter with the semiempirical AM1/d‐PhoT method, calibrated against density functional theory. Reaction path scans in 1‐D provided insights about the role of Mg2+ (A) which turns out to be more structural than catalytic. In contrast, 1‐D scans of the incorporation of the nucleotidyl group yielded barriers that were much too high, necessitating the use of 2‐D reaction coordinates. Three different proton acceptors for the initial reaction step were examined. For those models based on the two PDB structures the 2‐D scans continued to yield very high barriers, indicating that the reaction is unlikely to proceed from these configurations. On the other hand, two hybrid models, chosen from the early and late parts of a 12ns molecular dynamics simulation yielded greatly reduced barriers in the range of ∼17 to ∼27 kcal/mol for the three proton acceptors, as compared to the experimental estimate of 18 kcal/mol. The final step, release of pyrophosphate, was found to be facile. Our overall mechanism involves only active site residues or water without the need for external reactive agents such as the hydroxide ion previously proposed. Proteins 2015; 83:268–281. © 2014 Wiley Periodicals, Inc.
Memristive sorting networks
Authors: Frátrik Milan , Klimo Martin , Šuch Ondrej , Škvarek Ondrej 
Published: November 2014

AbstractResistive switching in thin‐film solid state devices is a rapidly progressing research area. Several new devices and applications, based on resistive switching, were proposed. The devices fall into realm of unconventional computing. In this paper we present memristor implementation of fuzzy logic. We describe fuzzy logic operations, simulation method used in our experiments and finally we compare two sorting algorithms implemented in memristive network. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Formation of nanodimensional structures on surfaces of GaAs and Si by means of ion implantation
Authors: Donaev S. B. , Djurabekova F. , Tashmukhamedova D. A. , Umirzakov B. E. 
Published: November 2014

AbstractWe obtained the two‐ and three‐component nanostructures by means of ion implantation of low‐energy Co and Ba ions in the surface layers of Si and GaAs in combination with the post‐implantation annealing. We show that flat shaped nanocrystals (nanoislands) of two‐ and three‐component composition, Co‐Si and Ga‐Ba‐As, start forming at ion fluences of Φ = (6¸8)×1014 cm‐2. After the laser annealing and short time electron heating we observed the formation of CoSi2 and Ga0.4Ba0.6As nanocrystals. Our results show that the size effects are clearly seen in electronic properties (opening of the band gap) when the lateral size of nanocrystals is less than 15‐30 nm, or in case of solid nanofilms, similar effect is observed at the thickness less than 3‐4 nm. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Charged defects and defect‐induced processes in nitrogen films
Authors: Savchenko Elena , Khyzhniy Ivan , Uyutnov Sergey , Barabashov Andrey , Gumenchuk Galina , Ponomaryov Alexey , Bondybey Vladimir 
Published: November 2014

AbstractRadiation effects in solid nitrogen irradiated with an electron beam were studied with emphasis on the role of charged centers in radiation‐induced phenomena. The experiments were performed employing luminescence method and activation spectroscopy techniques – spectrally resolved thermally stimulated luminescence TSL and thermally stimulated exoelectron emission. Samples were probed in depth by varying electron energy, thus discriminating radiation‐induced processes in the bulk and at the surface. Spectroscopic evidence of the excited N2* (C3Πu) molecule desorption was obtained for the first time and mechanism of the phenomenon based on recombination of electron with intrinsic charged center N4+ was proposed. The key role of N3+ center dissociative recombination in generation of N radicals is suggested. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Defect‐enhanced F– ion conductivity in layer‐structured nanocrystalline BaSnF4 prepared by high‐energy ball milling combined with soft annealing
Authors: Preishuber‐Pflügl Florian , Epp Viktor , Nakhal Suliman , Lerch Martin , Wilkening Martin 
Published: November 2014

AbstractFast ion conductors play one of the most important roles in solid state ionics as there is a great demand for their application in safe and powerful electrochemical energy storage systems. For such materials, it is known that the synthesis conditions may have significant impact on the final properties of the materials prepared. In this contribution, we made use of mechanosynthesis, carried out via high‐energy ball milling, to influence the ionic transport parameters of tetragonal, i.e., layer‐structured, BaSnF4. X‐ray powder diffraction (XRD) revealed that mechanical treatment of the binary fluorides BaF2 and SnF2 leads to a powder pointing to a nanocrystalline fluoride with (distorted) cubic symmetry. Differential scanning calorimetry (DSC) as well as preliminary in situ XRD measurements were used to follow the transformation towards the tetragonal modification with the composition BaSnF4. Broadband impedance spectroscopy was used to measure the overall electrical conductivity of the ternary fluoride. Remarkably, the layered form shows a room temperature conductivity of 7 × 10–4 S cm–1. Further emphasis was put on the characterization of the dielectric properties of the material, which was investigated by using different electrode materials to distinguish artefacts from intrinsic properties. Since we found a strong dependence of the real part of the permittivity on the electrode materials applied (carbon paste or sputtered Pt), we tend to assign the huge increase in permittivity, which was recently interpreted as giant dielectric constant, to interfacial polarization effects rather than to intrinsic properties. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hepatoprotective effects of sesamol loaded solid lipid nanoparticles in carbon tetrachloride induced sub‐chronic hepatotoxicity in rats
Authors: Singh Neha , Khullar Neeraj , Kakkar Vandita , Kaur Indu Pal 
Published: November 2014

ABSTRACTSesamol is a phenolic component of sesame seed oil, which has been established as an antioxidant and also possesses potential for hepatoprotection. However, its protective role in carbon tetrachloride (CCl4) induced sub‐chronic hepatotoxicity has not been studied. Limited oral bioavailability (BA) and rapid elimination (as conjugates) in rats is reported for sesamol. Considering its significant antioxidant potential and compromised BA, we packaged sesamol into solid lipid nanoparticles (S‐SLNs) to enhance its hepatoprotective bioactivity. S‐SLNs prepared by microemulsification method were nearly spherical in shape with an average particle size of 120.30 nm and their oral administration at 8 mg/kg body weight (BW) showed significantly (p < 0.001) better hepatoprotection than free sesamol (FS) and a well established hepatoprotective antioxidant silymarin [SILY (25 mg/kg BW); p < 0.05) in CCl4 induced sub‐chronic liver injury in rats. Evaluations were done in terms of histological changes in the liver tissue, liver injury markers (serum alanine aminotransferase, serum aspartate aminotransferase, and serum lactate dehydrogenase); oxidative stress markers (lipid peroxidation, superoxide dismutase, and reduced glutathione) and proinflammatory response marker (tumor necrosis factor‐alpha). © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 520–532, 2016.