bluuebunny/crossref_metadata_2025 huggingface dataset:
Light-trapping in Thin Film Silicon Solar Cells with a Combination of Periodic and Randomly Textured Back-reflectors
Authors: Pattnaik Sambit , Chakravarty Nayan , Biswas Rana , Slafer D. , Dalal Vikram
Published: November 2012

Light trapping is essential to harvest long wavelength red and near-infrared photons in thin film silicon solar cells. Traditionally light trapping has been achieved with a randomly roughened Ag/ZnO back reflector, which scatters incoming light uniformly through all angles, and enhances currents and cell efficiencies over a flat back reflector. A new approach using periodically textured photonic-plasmonic arrays has been recently shown to be very promising for harvesting long wavelength photons, through diffraction of light and plasmonic light concentration. Here we investigate the combination of these two approaches of random scattering and plasmonic effects to increase cell performance even further. An array of periodic conical back reflectors was fabricated by nanoimprint lithography and coated with Ag. These back reflectors were systematically annealed to generate different amounts of random texture, at smaller spatial scales, superimposed on a larger scale periodic texture. nc-Si solar cells were grown on flat, periodic photonic-plasmonic substrates, and randomly roughened photonic-plasmonic substrates. There were large improvements (>20%) in the current and light absorption of the photonic-plasmonic substrates relative to flat. The additional random features introduced on the photonic-plasmonic substrates did not improve the current and light absorption further, over a large range of randomization features.
Innovative Device Architecture for High Efficiency Thin Film Silicon Solar Cells
Authors: Boccard Mathieu , Despeisse Matthieu , Ballif Christophe
Published: November 2012

The challenge for all photovoltaic technologies is to maximize light absorption, convert photons with minimal losses to electrical charges and efficiently extract them towards the electrical circuit. For thin film silicon solar cells, a compromise must be found as light trapping is usually performed through textured interfaces, that are detrimental to the subsequent growth of dense and high quality silicon layers. We introduce here the concept of smoothening intermediate reflecting layers (IRL), enabling to combine high currents and good electrical quality in Micromorph devices in the superstrate configuration. After exposing the motivation for such structures, we validate the concept by showing a VOCenhancement when employing a polished silicon-oxide-based IRL. Shunting issues and additional reflection losses are pointed out with such technique, highlighting the need to develop alternative techniques for an efficient morphology adaptation before the microcrystalline silicon cell growth.
Amorphous silicon-germanium (a-Si0.01Ge0.99:H) doped with phosphorous deposited by LF PECVD and its electrical and optical characteristics
Authors: Delgadillo N. , Kosarev A. , Torres A. , Gonzales B.
Published: November 2012

Amorphous silicon-germanium (a-Si0.01Ge0.99:H) thin film, practically amorphous germanium with small concentration of silicon, were deposited by the low frequency PECVD technique under different flow gas of phosphine in the range of QPH3 = 20 to 100 sccm. In this range the phosphorous concentration in gas phase was calculated as XP= 4 to 20 % which resulted in a content in solid phase [P]sol=0.12% - 0.4%. The P content of the solid phase was measured by SIMS profiling and it was also observed a preferential incorporation of phosphorous in the range of [P]sol=0.12% - 0.3%. Hydrogen concentration in the films was determined from FTIR and SIMS measurements. The activation energy was determined by measuring the temperature dependence of conductivity in DC regime in a vacuum thermostat. For the a-Si0.01Ge0.99:H films it is found that the activation energy have a minimum, (Ea= 0.15eV), its conductivity at room temperature have a maximum and there is a minimum of of both band tail and deep localized state for a phosphorous incorporation in solid phase [P] =0.28%.
Formation of a single In(Ga)As/GaAs quantum dot embedded in a site-controlled GaAs nanowire by metalorganic chemical vapor deposition for application to single photon sources
Authors: Tatebayashi J. , Ota Y. , Karunathillake D. , Ishida S. , Nishioka M. , Iwamoto S. , Arakawa Y.
Published: November 2012

We report the formation and optical properties of site-controlled InAs/GaAs quantum dots (QDs) embedded in GaAs nanowires (NWs) by selective metalorganic chemical vapor deposition for application to single photon sources. InAs/GaAs QD-in-NWs with various InAs thicknesses are realized on patterned GaAs(111)B substrates in the form of InAs/GaAs heterostructures and identified by structural analyses using scanning transmission electron microscopy and photoluminescence characterization. Sharp excitonic emission peaks at 10 K from single QD-in-NWs with the narrowest exciton linewidth of 87 μeV are observed. Light emission from the single QD-in-NW shows photon antibunching which evidences single photon emission from high-quality QD-in-NWs.
Evaluation of crystal structure of porous Si nanowires prepared by metal assisted etching
Authors: Yamaguchi Takuya , Shimizu Tomohiro , Wang Chonge , Inada Mitsuru , Shingubara Shoso , Kuznetsov Aleksandr , Vanacken Johan , Moshchalkov Victor
Published: November 2012

The macro and micro morphology of the Si surface, depending on noble metal ion concentration in etching solution, prepared by metal assisted etching were investigated. We defined the morphology of etched Si in four types, and developed the phase diagram of Si morphology. Mixture of silver nitrate (AgNO3) and hydrofluoric acid (HF) was used as an electroless-plating bath of Ag, as well as etching solution of Si. The morphology of the etched Si surface as function of concentration of AgNO3 in etching solution was observed by SEM. With increasing concentration of the AgNO3 in the etching solution, the surface of etched Si tended to be porous structure with very fine pores of a few nm (porous Si). When concentration of AgNO3is low, single crystal Si nanowires with a smooth surface without pores were observed.
Thermodynamic Tuning of Calcium Hydride by Fluorine Substitution
Authors: Pinatel Eugenio R. , Rude Line H. , Corno Marta , Kragelund Maria , Ugliengo Piero , Jensen Torben R. , Baricco Marcello
Published: November 2012

Fluorine substitution in CaH2has been studied by means of experimental and theoretical methods. Samples with various compositions have been prepared by ball milling.In situX-ray diffraction analysis has been carried out as a function of temperature by synchrotron radiation experiments. An increase of mixing has been observed during heating, suggesting that mixing is thermodynamically favoured but it is kinetically hindered at low temperatures.Ab initioDFT calculations have been performed to estimate the thermodynamic mixing properties of both orthorhombic and cubic solid solutions. On the basis ofab initioresults and literature information, a thermodynamic assessment within the CALPHAD framework has been performed and the pseudo binary CaH2-CaF2phase diagram has been calculated. The formation of orthorhombic and cubic terminal solid solutions in the CaH2-CaF2system is predicted, in good agreement with experimental findings.
Copper Tungstate (CuWO4)–Based Materials for Photoelectrochemical Hydrogen Production
Authors: Gaillard Nicolas , Chang Yuancheng , Braun Artur , DeAngelis Alexander
Published: November 2012

We report in this communication on the photoelectrochemical (PEC) performances of copper tungstate (CuWO4) material class. This study was performed on 2-micron thick samples fabricated using a low-cost co-sputtering deposition process, followed by an 8-hour long annealing at 500°C in argon. Microstructural analysis pointed out that the post-deposition treatment was critical to achieve photocatalytic activity. Subsequent characterizations revealed that polycrystalline CuWO4 photoanodes owned promising characteristics for solar-assisted water splitting, i.e (i) an optical band-gap of 2.2 eV, (ii) a flat-band potential of -0.35 V vs. SCE and (iii) conduction and valence band-edges that straddle water splitting redox potentials. CuWO4 photoanodes generated 400 μA.cm-2 at 1.6V vs. SCE under simulated AM1.5G illumination in 0.33M H3PO4 with virtually no dark current up to this potential. Impedance analysis pointed out that large charge transfer resistances (2,500 Ω.cm2) could be the main weakness of this material class. Current research activity is focused on solving this issue to achieve higher PEC performances.
Metal Oxides as Catalyst Promoters for Methanol Oxidation
Authors: Kolla Praveen , Kerce Kimberly , Fong Hao , Smirnova Alevtina
Published: November 2012

The Transition metal oxides such as TiO2 and CeO2 as catalyst and co-catalyst materials were studied for methanol oxidation. The metal oxide nanoparticles were impregnated into carbon aerogel and Pt-Ru/C (Tanaka) by modified sol-gel Pechini method and heat-treated at different temperatures. Crystal structure, particle size and composition of the catalyst particles were studied using XRD, TEM and EDS techniques. The electrochemical activity and stability of these catalyst materials were studied in acidic medium and the results were compared to their corresponding specific and active surface areas. The aerogel supported metal oxides were stable and proved for better methanol oxidation, while a significant synergetic effect in electro-oxidation is observed when the metal oxides were impregnated into the structure of Pt-Ru/C catalyst. The methanol-oxidation was further improved after heat treatment due to its improved structural and surface properties.
Evaluation of Bioactive Glass (13-93) Scaffolds with an Oriented Microstructure for Regenerating Load-bearing Bones
Authors: Liu Xin , Rahaman Mohammed N.
Published: November 2012

Bioactive glass is an attractive scaffold material for use in filling bone defects because of its widely recognized ability to support the growth of bone cells and to bond firmly with hard and soft tissue. Use of bioactive glasses in the form of porous three-dimensional scaffolds for bone repair applications has been receiving considerable interest in recent years. However, bioactive glass scaffolds have been limited to the repair of low-load bone defects because of their low strength. In the present work, porous and strong bioactive glass scaffolds with an oriented microstructure were prepared by unidirectional freezing of camphene-based suspensions, and evaluated for their ability to regenerate bone in a non-healing rat calvarial defect model. Scaffolds of 13-93 glass (53SiO2, 6Na2O, 12K2O, 5MgO, 20CaO, 4P2O5; wt%) with a porosity of 50% and columnar pores of diameter 50–150 μm showed a compressive strength of 47 ± 5 MPa and an elastic modulus of 11 ± 3 GPa. Total bone regeneration in the oriented scaffolds, 18% after implantation for 12 weeks to 24% after 24 weeks, was not significantly different from that in 13-93 scaffolds with a microstructure similar to that of dry human trabecular bone (control group). The results indicated that these oriented bioactive glass (13-93) scaffolds could potentially be used in the regeneration of loaded bone.
Rapid Growth of Radish Sprouts Using Low Pressure O2Radio Frequency Plasma Irradiation
Authors: Kitazaki Satoshi , Koga Kazunori , Shiratani Masaharu , Hayashi Nobuya
Published: November 2012

We compared growth enhancement of radish induced by O2, air, and Ar plasma irradiation. The average length of radish sprouts cultivated for 4 days after O2plasma irradiation is 70% longer than that of sprouts without irradiation. The O2plasma irradiation is more effective in enhancing growth than air and Ar radio frequency plasma irradiation. Cell morphology and cell size of sprouts with O2plasma irradiation is nearly the same as those without irradiation. These results suggest that plasma induced acceleration of cell proliferation brings about the rapid growth.
Detection and Damage-analysis of Bio-Particles and for Safety-Evaluation of Plasma-treated water using DNA-manipulation
Authors: Mizuno Akira , Yasuda Hachiro , Kurita Hirofumi , Takashima Kazunori
Published: November 2012

Effect of non-thermal plasma (NTP) on bio-particles has been studied using Bacillus subtilis (B. subtilis), Escherichia coli (E. coli) and bacteriophages. NTP has been used, and states of different biological components were monitored during the course of the exposure. Analysis of green fluorescent protein (GFP), introduced into E.coli cells proved that NTP causes a prominent protein damages without cutting peptide bonds. We have developed a biological assay which evaluates in vivo DNA damage of the bacteriophages. Different doses of the plasma were applied to wet state of λ phages. From the plasma-exposed λ phages, DNA was purified and subjected to in vitro DNA packaging reactions. The re-packaged phages consist of the DNA from discharged phages and brand-new coat proteins. Survival curves of the re-packaged phages showed extremely large D value (D = 25 s) compared to the previous D value (D = 3 s) from the discharged phages. The results indicate that DNA damage hardly contributed to the inactivation, and the damage in coat proteins is responsible for inactivation of the phages. We also report a single-molecule-based analysis of strand breakages on large DNA molecules induced by the plasma exposure. Single-molecule observation of DNA that involved molecular combing was used to measure the length of individual DNA molecules. The measured DNA length showed that plasma exposure caused a marked change in length of DNA molecules. The rate of plasmainduced strand breakage on large random-coiled DNA molecules was determined using a simple mathematical model. The measured rate shows good relation with the plasma exposure time, and could be used for safety evaluation of the plasma treated water.
Aero-Sol-Gel Synthesis of Mesoporous TiO2 Nanoparticles and Their Photovoltaic Properties in Dye-Sensitized Solar Cells
Authors: Ahn Ji Young , Moon Kook Joo , Kim Ji Hoon , Kim Soo Hyung
Published: November 2012

Highly mesoporous TiO2 nanoparticles (NPs) were synthesized by an aero-sol-gel process in this approach. By varying the mass fraction of inorganic templates, the formation of mesoporous TiO2 NPs with optimized surface area and pore volume distributions was examined. Then, the photovoltaic properties of the resulting mesoporous TiO2 NPs were systematically investigated by applying them into the photoanode of dye-sensitized solar cells (DSSCs). The mesoporous TiO2 NP-based DSSCs fabricated in this study showed an improved short circuit current density and power conversion efficiency compared with solid TiO2 NP-based DSSCs due to the increase of the amount of inorganic dye (N719) adsorption in the mesoporous TiO2 NPs. These mesoporous TiO2 NPs fabricated have a strong potential as an effective dye supporting and electron transfer medium to improve the photovoltaic performance of DSSCs.
Supported Ni catalyst made by electroless Ni-B plating for diesel autothermal reforming
Authors: Xia Zetao , Hong Liang , Wang Wei , Liu Zhaolin
Published: November 2012

CexGd1-xO2-δ (CGO)-supported Ni nano grains were prepared initially by electrolessly depositing Ni-B alloy nano particles onto an activated carbon (AC). The as-deposited Ni-B particles were then transferred from AC to CGO through the metallo-organic precursor approach. The resultant Ni/CGO catalysts displayed excellent catalytic activity and chemical stability against coking and sulfur poisoning in catalyzing autothermal reforming (ATR) of a surrogate diesel fuel, comprising dodecane, tetralin and a substituted thiophene. For comparison purpose, a Ni/CGO catalyst prepared by the conventional impregnation method was employed in the same ATR system. These two catalytic systems exhibited rather discrepant outcomes. It was found that the Ni(B)/CGO catalyst was capable of repressing selectivity of ethylene during the reforming process. In addition to this, CGO played a critical role in thermal cracking hydrocarbon chains and inhibiting sulfur poisoning.
Response of Kudzu (Pueraria montanavar.lobata) Seedlings and Naturalized Plants to Simulated Herbivory
Authors: Frye Matthew J. , Hough-Goldstein Judith , Kidd Kathleen A.
Published: November 2012

We studied the response of naturalized kudzu plants to simulated herbivory at three locations: Delaware (DE), Pennsylvania (PA), and North Carolina (NC). At the DE and PA sites, plant mortality after the first yr was 14 and 50%, respectively, and was highest for plants that had a small starting root crown size. At both sites, 50 and 75% leaf and shoot clipping, and drilling one or two large holes from the root crown into roots, had no effect on aboveground biomass. In NC, all plants survived for 3 yr. Plants subject to 50% vine removal at this site showed significant decrease in aboveground biomass compared to the control, but 50% leaf cutting and root drilling had no effect. In the greenhouse, kudzu seedlings grown in 60 and 100% light compensated for 50% leaf removal, but 75% damage reduced aboveground biomass. Plants survived for 1 to 2 mo in 0% direct light, but only one of 53 plants survived to the end of the experiment. Results suggest that established kudzu plants are able to compensate for biomass removal, seedlings can survive for several weeks without light, and that effective biocontrol might require more than 2 to 3 yr of continuous damage.
Soil–Occupancy Effects of Invasive and Native Grassland Plant Species on Composition and Diversity of Mycorrhizal Associations
Authors: Jordan Nicholas R. , Aldrich-Wolfe Laura , Huerd Sheri C. , Larson Diane L. , Muehlbauer Gary
Published: November 2012

Diversified grasslands that contain native plant species can produce biofuels, support sustainable grazing systems, and produce other ecosystem services. However, ecosystem service production can be disrupted by invasion of exotic perennial plants, and these plants can have soil-microbial “legacies” that may interfere with establishment and maintenance of diversified grasslands even after effective management of the invasive species. The nature of such legacies is not well understood, but may involve suppression of mutualisms between native species and soil microbes. In this study, we tested the hypotheses that legacy effects of invasive species change colonization rates, diversity, and composition of arbuscular-mycorrhizal fungi (AMF) associated with seedlings of co-occurring invasive and native grassland species. In a glasshouse, experimental soils were conditioned by cultivating three invasive grassland perennials, three native grassland perennials, and a native perennial mixture. Each was grown separately through three cycles of growth, after which we used T-RFLP analysis to characterize AMF associations of seedlings of six native perennial and six invasive perennial species grown in these soils. Legacy effects of soil conditioning by invasive species did not affect AMF richness in seedling roots, but did affect AMF colonization rates and the taxonomic composition of mycorrhizal associations in seedling roots. Moreover, native species were more heavily colonized by AMF and roots of native species had greater AMF richness (number of AMF operational taxonomic units per seedling) than did invasive species. The invasive species used to condition soil in this experiment have been shown to have legacy effects on biomass of native seedlings, reducing their growth in this and a previous similar experiment. Therefore, our results suggest that successful plant invaders can have legacies that affect soil-microbial associations of native plants and that these effects can inhibit growth of native plant species in invaded communities.
Briefing: Geoengineering – serious options to address climate change?
Authors: Campen Richard
Published: November 2012

Geoengineering is the term used to describe environmental manipulation at a planetary scale. It is generally described as having two main categories: solar radiation management and carbon dioxide removal, with an aim to reduce or neutralise the effects of climate change and global warming. Techniques include carbon capture and storage, fertilising the oceans and sunshields in space. The deployment of such technologies would present ethical challenges and potential environmental and social problems. As a species we have already manipulated and impacted on the environment and a key issue remains: it is not possible to predict all of the consequences of interventions in natural systems. If such technologies were to be deployed we would be ‘locked-in’ to cycles; we would be committed to trying to innovate and engineer solutions to new problems.
Enhancing accuracy and precision of transparent synthetic soil modelling
Authors: Stanier Samuel A. , Black Jonathan A , Hird Charles C
Published: November 2012

Over recent years non-intrusive modelling techniques have been developed to investigate soil–structure interaction problems of increasingly complex geometry. This paper concerns the development of a small-scale, 1 g, modelling technique using a transparent analogue for soil with particle image velocimetry for internal displacement measurement. Larger model geometry achieved in this research using fine-grained transparent synthetic soils has led to an increased need for rigorous photogrammetric correction techniques. A correction framework, based upon a modified version of the pinhole camera model, is presented that corrects for lens and camera movement induced errors as well as scaling from image space to object space. An additional statistical approach is also developed to enhance the system precision, by minimising the impact of increased non-coplanarity between the photogrammetry control plane and the target plane. The enhanced data correction and statistical precision is demonstrated using a case study examining the failure mechanism around a double helical screw pile installed in transparent synthetic soil representative of a soft clay.
Assessment of seawater intrusion in Langat basin, Malaysia
Authors: Nusari Mohammed S. , Soom Mohd A. M. , Mohammad Thamer A. , Ghazali Abdul H. , Wayayok Aimrun , Zawawi Mohamed A. M.
Published: November 2012

Seawater intrusion is threatening freshwater resources in coastal regions worldwide. Modelling this phenomenon can help in the management and control of such problems. This study presents a numerical model of seawater intrusion in a semi-confined aquifer in the lowland area of the Langat basin, Selangor, Malaysia, where groundwater is the only source of water supply for mega industrial projects. To provide useful measures for protecting groundwater from pollution by seawater intrusion, a three-dimensional numerical model, Seawat-2000, was applied. The numerical model incorporates regional geological, geographical, and hydrogeological features. The input parameters to the model were determined from well logs, well drillers' reports, and pumping tests. After the model was calibrated using data for the year 2010, the model was used to predict the extent of seawater intrusion for the future (2011–2045) assuming that the current condition of the Langat basin remains unchanged. The results show that the aquifer in the study area will be significantly influenced by seawater intrusion for the next 35 years.
An estimation from within of the reachable set of nonlinear R. Brockett integrator with small nonlinearity
Authors: Moussa Aboubacar , Nikolskii Mikhail
Published: November 2012

In this paper, the nonlinear R. Brockett integrator with small nonlinear
addition to the right-hand side of the corresponding differential equations
is considered. More precisely, investigating the possibility to estimate from
within the corresponding reachable set, we have obtained an efficient form of
the ellipsoidal estimation from within. We used our previous results on the
similar theme.
Governing Education in Europe: A ‘New’ Policy Space of European Schooling
Authors: Carlos Sofia
Published: November 2012

European Schools are a particular type of school that are not integrated into any national education system but are nonetheless official educational establishments that constitute a European Schools System (ESS) governed jointly by the Member States of the European Union. This positioning creates particularly interesting issues of governance that mirror aspects of governing education in Europe, albeit on a smaller scale. This article makes the argument that the ESS, like the European Commission (EC), operates within and across formal national boundaries in a ‘new’ Policy Space of European Schooling. It suggests that analysis of this ‘space’ as a microcosm of European governance of education is enabled through integrating interdisciplinary concepts such as re-spatialisation with attention to new approaches to governance that stress fluid and mobile relations in analysing Europeanisation. The article argues that the ESS is an interesting policy case in itself, but also suggests that it has value as a microcosm of the extremely complex and novel forms of policy relations in education in Europe, in which elements of the local, the national and the European are merging and emerging in different ways.
Suitable Enemies? Governmentality of Youth: Youth as a Threat
Authors: Ostrowicka Helena
Published: November 2012

This article is a contribution to the discourse of politics towards (for) youth, which the author defines as the ‘cultural politics of risk’. The article begins with scientific representations of youth as a threat, as a group inclined to engage in risky behaviours. It then focuses on theoretical approaches called the ‘risk paradigm’, providing a framework for recognising anxieties and rationalities supporting them. The following section is concerned with the analysis of selected programmes which determine the strategies of Polish state politics towards (for) youth. The author attempts to show the relations between scientific risk knowledge and political projects justified by expert rationality. The article concludes with an interpretation of governmentality of youth portrayed as a threat in the context of the conception of ‘suitable enemies’.
A Special Thanks to 2012 JOSPT Contributors
Authors: Simoneau Guy G.
Published: November 2012

Editor-in-Chief Dr. Guy Simoneau recognizes the authors, associate editors, International Editorial Review Board members, and manuscript and musculoskeletal imaging reviewers who contributed to the various aspects of the Journal over the past 12 months.

J Orthop Sports Phys Ther 2012;42(12):982–984. doi:10.2519/jospt.2012.0112
Task Motivation in Process: A Complex Systems Perspective
Authors: Poupore Glen
Published: November 2012

Abstract:

While many studies into task-based interaction have been conducted within a cognitive-linguistic perspective, few have been conducted with the aim of investigating learners’ task motivation. Framed within a complex systems approach, the principle objectives of this classroom-based study were to provide a complexity description of task motivation and to identify how various socio-affective and task condition-related elements interact together to influence learner motivation during different types of tasks. The elements include task enjoyment, effort, success expectancy, relevance, emotional state, perceived difficulty, perceived group work dynamic, and specific aspects related to the structure and content of tasks. Participants for the study consisted of 38 Korean intermediate learners of English in a conversation course as part of a TESOL certificate program. Data were collected through questionnaires during the course, at pre- and post-task, and as well, through post-task interviews. Supporting the notion that task motivation functions as a complex system, learners’ motivation decreased as a result of different combinations of socio-affective variables acting together rather than in isolation. Task conditions related to cognitive complexity and topic, furthermore, were shown to function as important control parameters in the shaping of the motivational patterns.
Evaluating the cognitive consequences of mild traumatic brain injury and concussion by using electrophysiology
Authors: Gosselin Nadia , Bottari Carolina , Chen Jen-Kai , Huntgeburth Sonja Christina , De Beaumont Louis , Petrides Michael , Cheung Bob , Ptito Alain
Published: November 2012

Object

Mild traumatic brain injury (MTBI), often referred to as concussion when it occurs in sports, produces persistent cognitive problems in at least 15% of patients. Unfortunately, conventional neuropsychological tests usually yield results within normal limits in this population. The main objective of this event-related potential (ERP) study was to understand brain functioning during the performance of a working memory (WM) task in patients who have sustained an MTBI, mostly due to motor vehicle accident or sports concussion. This study also aimed for a better understanding of the association between brain functioning as measured with ERP, behavioral performance on the WM task, postconcussion symptoms, type of injury (that is, sports concussion vs other types), and time since the injury.

Methods

Forty-four patients with MTBI (7.6 ± 8.4 months postinjury) were tested on a visual WM task with simultaneous recording of ERP, and were compared with 40 control volunteers who were their equivalent for age and sex. Amplitude and latency of frontal (N200 and N350) and parietal (P200 and P300) ERP waves were measured and were compared between groups. Correlation analyses were also performed between ERP characteristics, clinical variables, and behavioral performance.

Results

A significant group difference was found for behavioral performance on the WM task, in which the MTBI group had a lower percentage of correct answers than the control group (p < 0.05). The patients with MTBI also had smaller amplitudes of both frontal N350 and parietal P300 ERP components when compared with control volunteers (p < 0.05). No changes were found for latency of ERP components. Smaller ERP amplitudes were associated with slower reaction times and worse accuracy on the WM task among patients with MTBI (p < 0.05). Types of injury (that is, sports concussion vs other mechanisms) were not associated with different ERP characteristics.

Conclusions

Abnormal ERP results are observed in patients after MTBI or sports concussion, even for those in the nonacute stage after their injury. Current standard clinical evaluations most often fail to detect cerebral dysfunction after MTBI, even when patients or athletes report symptoms. Clinicians should be aware that patients with MTBI, including sports concussion, probably have underlying mild but persistent cerebral dysfunctions that require further investigation.
Magnetoencephalographic virtual recording: a novel diagnostic tool for concussion
Authors: Tormenti Matthew , Krieger Donald , Puccio Ava M. , McNeil Malcolm R. , Schneider Walter , Okonkwo David O.
Published: November 2012

Object

Heightened recognition of the prevalence and significance of head injury in sports and in combat veterans has brought increased attention to the physiological and behavioral consequences of concussion. Current clinical practice is in part dependent on patient self-report as the basis for medical decisions and treatment. Magnetoencephalography (MEG) shows promise in the assessment of the pathophysiological derangements in concussion. The authors have developed a novel MEG-based neuroimaging strategy to provide objective, noninvasive, diagnostic information in neurological disorders. In the current study the authors demonstrate a novel task protocol and then assess MEG virtual recordings obtained during task performance as a diagnostic tool for concussion.

Methods

Ten individuals (5 control volunteers and 5 patients with a history of concussion) were enrolled in this pilot study. All participants underwent an MEG evaluation during performance of a language/spatial task. Each individual produced 960 responses to 320 sentence stimuli; 0.3 sec of MEG data from each word presentation and each response were analyzed: the data from each participant were classified using a rule constructed from the data obtained from the other 9 participants.

Results

Analysis of response times showed significant differences (p < 10−4) between concussed and normal groups, demonstrating the sensitivity of the task. The MEG measures enabled the correct classification of 8 of 10 individuals as concussed versus nonconcussed (p = 0.055). Analysis of single-trial data classified 70% of trials correctly (p < 10−10). Concussed patients showed increased activation in the occipitoparietal and temporal regions during evaluation.

Conclusions

These pilot findings are the first evidence of the utility of MEG virtual recording in diagnosing concussion. With further refinements, MEG virtual recordings may represent a noninvasive test to diagnose concussion and monitor its resolution.
Association of a higher density of specialist neuroscience providers with fewer deaths from stroke in the United States population
Authors: Desai Atman , Bekelis Kimon , Zhao Wenyan , Ball Perry A. , Erkmen Kadir
Published: November 2012

Object

Stroke is a leading cause of death and disability. Given that neurologists and neurosurgeons have special expertise in this area, the authors hypothesized that the density of neuroscience providers is associated with reduced mortality rates from stroke across US counties.

Methods

This is a retrospective review of the Area Resource File 2009–2010, a national county-level health information database maintained by the US Department of Health and Human Services. The primary outcome variable was the 3-year (2004–2006) average in cerebrovascular disease deaths per million population for each county. The primary independent variable was the combined density of neurosurgeons and neurologists per million population in the year 2006. Multiple regression analysis was performed, adjusting for density of general practitioners (GPs), urbanicity of the county, and socioeconomic status of the residents of the county.

Results

In the 3141 counties analyzed, the median number of annual stroke deaths was 586 (interquartile range [IQR] 449–754), the median number of neuroscience providers was 0 (IQR 0–26), and the median number of GPs was 274 (IQR 175–410) per million population. On multivariate adjusted analysis, each increase of 1 neuroscience provider was associated with 0.38 fewer deaths from stroke per year (p < 0.001) per million population. Rural location (p < 0.001) and increased density of GPs (p < 0.001) were associated with increases in stroke-related mortality.

Conclusions

Higher density of specialist neuroscience providers is associated with fewer deaths from stroke. This suggests that the availability of specialists is an important factor in survival after stroke, and underlines the importance of promoting specialist education and practice throughout the country.
Intramedullary spinal cord ganglioglioma presenting as hyperhidrosis: unique symptoms and magnetic resonance imaging findings
Authors: Murakami Tomohiro , Koyanagi Izumi , Kaneko Takahisa , Yoneta Akihiro , Keira Yoshiko , Wanibuchi Masahiko , Hasegawa Tadashi , Mikuni Nobuhiro
Published: November 2012

Hyperhidrosis is caused by a sympathetic dysfunction of the central or peripheral nervous system. Intramedullary spinal cord lesions can be a cause of hyperhidrosis. The authors report a rare case of intramedullary thoracic spinal cord ganglioglioma presenting as hyperhidrosis. This 16-year-old boy presented with abnormal sweating on the right side of the neck, chest, and the right arm that had been occurring for 6 years. Neurological examination revealed mild motor weakness of the right lower extremity and slightly decreased sensation in the left lower extremity. Hyperhidrosis was observed in the right C3–T8 dermatomes. Magnetic resonance imaging showed an intramedullary tumor at the right side of the spinal cord at the T2–3 level. The tumor showed partial enhancement after Gd administration. The patient underwent removal of the tumor via hemilaminectomy of T2–3. Only subtotal resection was achieved because the margins of the tumor were unclear. Histopathological examination revealed ganglioglioma. Hyperhidrosis gradually improved after surgery. Hyperhidrosis is a rare clinical manifestation of intramedullary spinal cord tumors, and only a few cases have been reported in the literature. The location of the tumor origin, around the right gray matter of the lateral spinal cord, may account for the hyperhidrosis as the initial symptom in this patient. Physicians should examine the spinal cord using MRI studies when a patient has hyperhidrosis with some motor or sensory symptoms of the extremities.
Reduction of brain edema and expression of aquaporins with acute ethanol treatment after traumatic brain injury
Authors: Wang Tony , Chou David Yu-Te , Ding Jamie Y. , Fredrickson Vance , Peng Changya , Schafer Steven , Guthikonda Murali , Kreipke Christian , Rafols José A. , Ding Yuchuan
Published: November 2012

Object

Previous studies have demonstrated that traumatic brain injury (TBI) causes brain edema by allowing excessive water passage through aquaporin (AQP) proteins. To establish the potential neuroprotective properties of ethanol as a post-TBI therapy, in the present study the authors determined the effect of ethanol on brain edema, AQP expression, and functional outcomes in a post-TBI setting.

Methods

Adult male Sprague-Dawley rats weighing between 425 and 475 g received a closed head TBI in which Maramarou's impact-acceleration method was used. Animals were given a subsequent intraperitoneal injection of 0.5 g/kg or 1.5 g/kg ethanol at 60 minutes post-TBI and were killed 24 hours after TBI. Brains were subsequently examined for edema along with AQP mRNA and protein expression. Additional animals treated with either 0.5 g/kg or 1.5 g/kg ethanol at 60 minutes post-TBI were designated for cognitive and motor testing for 3 weeks.

Results

Ethanol administration post-TBI led to significantly (p < 0.05) lower levels of brain edema as measured by brain water content. This downregulation in brain edema was associated with significantly (p < 0.05) reduced levels of AQP mRNA and protein expression as compared with TBI without treatment. These findings concur with cognitive studies in which ethanol-treated animals exhibited significantly (p < 0.05) faster radial maze completion times. Motor behavioral testing additionally demonstrated significant (p < 0.05) beneficial effects of ethanol, with treated animals displaying improved motor coordination when compared with untreated animals.

Conclusions

The present findings suggest that acute ethanol administration after a TBI decreases AQP expression, which may lead to reduced cerebral edema. Ethanol-treated animals additionally showed improved cognitive and motor outcomes compared with untreated animals.
Large-scale ice thickness distribution of first-year sea ice in spring and summer north of Svalbard
Authors: Renner Angelika H. H. , Hendricks Stefan , Gerland Sebastian , Beckers Justin , Haas Christian , Krumpen Thomas
Published: November 2012

The large-scale thickness distribution of sea ice was measured during several campaigns in the European Arctic north of Svalbard from 2007 using an airborne electromagnetic induction device. In August 2010 and April-May 2011, this was complemented by extensive on-ice work including measurements of snow thickness and freeboard. Ice thicknesses show a clear difference between the seasons, with thicker ice during spring than in summer. In spring 2011, negative freeboard and flooding were observed as a result of the extensive snow cover. We find that the characteristics of the first-year sea ice allow combining observations from different years. The ice thickness in the marginal ice zone increases with increasing latitude and increasing distance to the ice edge; however, in the inner ice pack from ∼100 km from the ice edge the thickness remains almost constant. Modal ice thickness in spring reaches 2.4 m whereas in summer it is 1.0–1.4 m. Our study provides new insight into ice thickness distributions of a typical ice cover consisting of mainly first- and second-year ice, which may become the dominant ice type in the Arctic in the future.
Förster Resonance Energy Transfer (FRET) between Heterogeneously Distributed Probes: Application to Lipid Nanodomains and Pores
Authors: Šachl Radek , Johansson Lennart , Hof Martin
Published: November 2012

The formation of membrane heterogeneities, e.g., lipid domains and pores, leads to a redistribution of donor (D) and acceptor (A) molecules according to their affinity to the structures formed and the remaining bilayer. If such changes sufficiently influence the Förster resonance energy transfer (FRET) efficiency, these changes can be further analyzed in terms of nanodomain/pore size. This paper is a continuation of previous work on this theme. In particular, it is demonstrated how FRET experiments should be planned and how data should be analyzed in order to achieve the best possible resolution. The limiting resolution of domains and pores are discussed simultaneously, in order to enable direct comparison. It appears that choice of suitable donor/acceptor pairs is the most crucial step in the design of experiments. For instance, it is recommended to use DA pairs, which exhibit an increased affinity to pores (i.e., partition coefficients KD,A > 10) for the determination of pore sizes with radii comparable to the Förster radius R0. On the other hand, donors and acceptors exhibiting a high affinity to different phases are better suited for the determination of domain sizes. The experimental setup where donors and acceptors are excluded from the domains/pores should be avoided.
Isolation and Characterization of Saponin-Producing Fungal Endophytes from Aralia elata in Northeast China
Authors: Wu Hao , Yang Hongyan , You Xiangling , Li Yuhua
Published: November 2012

The purpose of this study was to investigate the diversity of endophytic fungi of Aralia elata distributed in Northeast China as well as their capacity to produce saponins. Ninety-six strains of endophytic fungi were isolated, and polymerase chain reaction (PCR) and sequencing were employed to identify the isolates. The saponin concentrations of the culture filtrates of representative strains were measured. The agar diffusion method was used to test antimicrobial activity, while high-performance liquid chromatography (HPLC) was employed to identify the saponins produced by representative strains. Alternaria, Botryosphaeria, Camarosporium, Cryptosporiopsis, Diaporthe, Dictyochaeta, Penicillium, Fusarium, Nectria, Peniophora, Schizophyllum, Cladosporium and Trichoderma species were isolated in this study. Overall, 25% of the isolates belonged to Diaporthe (Diaporthe eres), and 12.5% belonged to Alternaria. The highest concentration of saponins was produced by G22 (2.049 mg/mL). According to the results of the phylogenetic analysis, G22 belonged to the genus Penicillium. The culture filtrate of G22 exhibited antibacterial activity against Staphylococcus aureus, and ginsenosides Re and Rb2 were detected in G22 culture filtrates by HPLC.
Estimation of Physical Layer Performance in WSNs Exploiting the Method of Indirect Observations
Authors: Colistra Giuseppe , Atzori Luigi
Published: November 2012

Wireless Sensor Networks (WSNs) are used in many industrial and consumer applications that are increasingly gaining impact in our day to day lives. Still great efforts are needed towards the definition of methodologies for their effective management. One big issue is themonitoring of the network status, which requires the definition of the performance indicators and methodologies and should be accurate and not intrusive at the same time. In this paper, we present a new process for the monitoring of the physical layer in WSNs making use of a completely passive methodology. From data sniffed by external nodes, we first estimate the position of the nodes by applying the Weighted Least Squares (WLS) to the method of indirect observations. The resulting node positions are then used to estimate the status of the communication links using the most appropriate propagation model. We performed a significant number of measurements on the field in both indoor and outdoor environments. From the experiments, we were able to achieve an accurate estimation of the channel links status with an average error lower than 1 dB, which is around 5 dB lower than the error introduced without the application of the proposed method.
Synthesis and Antifungal Activity of N-(Substituted pyridinyl)-1-methyl(phenyl)-3-(trifluoromethyl)-1H-pyrazole-4-carboxamide Derivatives
Authors: Wu Zhibing , Hu Deyu , Kuang Jiqing , Cai Hua , Wu Shixi , Xue Wei
Published: November 2012

A series of N-(substituted pyridinyl)-1-methyl(phenyl)-3-trifluoromethyl-1H-pyrazole-4-carboxamide derivatives were synthesized. All target compounds were characterized by spectral data (1H-NMR, 13C-NMR, IR, MS) and elemental analysis and were bioassayed in vitro against three kinds of phytopathogenic fungi (Gibberella zeae, Fusarium oxysporum, Cytospora mandshurica). The results showed that some of the synthesized N-(substituted pyridinyl)-1-methyl-3-trifluoromethyl-1H-pyrazole-4-carboxamides exhibited moderate antifungal activities, among which compounds 6a, 6b and 6c displayed more than 50% inhibition activities against G. zeae at 100 µg/mL, which was better than that of the commercial fungicides carboxin and boscalid.
An Improved Method for Removal of Azo Dye Orange II from Textile Effluent Using Albumin as Sorbent
Authors: Ohashi Tadashi , Jara Alícia , Batista Anabelle , Franco Luciana , Lima Marcos , Benachour Mohand , Da Silva Carlos , Campos-Takaki Galba
Published: November 2012

Azo dyes are generally resistant to biodegradation due to their complex structures. Acid orange II is one of the most widely used dyes in the textile industry. The influence of bovine serum albumin (BSA) in different concentrations, pH, and time of contact on Orange II was investigated using kinetics and adsorption-isotherm experiments. The results showed that the maximum colour removed from dye/albumin was 99.50% and that a stable dye-protein complex had been formed at pH 3.5 and in a proportion of 1:3 (v/v), respectively. The synthetic effluent did not show toxicity to the microcrustacean Artemia salina, and showed a CL50 equal to 97 µg/mL to azo dye orange II. Additionally, the methodology was effective in removing the maximum of orange II using BSA by adsorption at pH 3.5 which mainly attracted ions to the azo dye during the adsorption process. This suggests that this form of treatment is economical and easy to use which potentially could lead to bovine serum albumin being used as a sorbent for azo dyes.
Signal Transmission in a Human Body Medium-Based Body Sensor Network Using a Mach-Zehnder Electro-Optical Sensor
Authors: Song Yong , Hao Qun , Zhang Kai , Wang Jingwen , Jin Xuefeng , Sun He
Published: November 2012

The signal transmission technology based on the human body medium offers significant advantages in Body Sensor Networks (BSNs) used for healthcare and the other related fields. In previous works we have proposed a novel signal transmission method based on the human body medium using a Mach-Zehnder electro-optical (EO) sensor. In this paper, we present a signal transmission system based on the proposed method, which consists of a transmitter, a Mach-Zehnder EO sensor and a corresponding receiving circuit. Meanwhile, in order to verify the frequency response properties and determine the suitable parameters of the developed system, in-vivo measurements have been implemented under conditions of different carrier frequencies, baseband frequencies and signal transmission paths. Results indicate that the proposed system will help to achieve reliable and high speed signal transmission of BSN based on the human body medium.