bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in human fetal oxygenation during maternal hyperoxia as estimated by BOLD MRI
Authors: Sørensen Anne , Peters David , Simonsen Carsten , Pedersen Michael , Stausbøl‐Grøn Brian , Christiansen Ole Bjarne , Lingman Göran , Uldbjerg Niels 
Published: December 2012

ABSTRACTObjectiveChanges in blood oxygen level dependent (BOLD) magnetic resonance imaging (MRI) signal are closely related to changes in fetal oxygenation. In this study, we aimed to investigate the changes in human fetal oxygenation during maternal hyperoxia by using the non‐invasive BOLD MRI technique.MethodEight healthy pregnant women in gestational week 28 to 34 were included. With the use of a facial oxygen mask, we induced maternal hyperoxia and measured changes in the BOLD MRI signal of selected fetal organs.ResultsIn a number of fetal organs, the BOLD MRI signal increased significantly (P < 0.01) during maternal hyperoxia (mean change in % ± SEM): liver (14.3 ± 3.7%), spleen (15.2 ± 3.5%) and kidney (6.2 ± 1.8%) as well as the placenta (6.5 ± 1.6%). In the fetal brain, however, the BOLD MRI signal remained constant (0.3 ± 0.2%).ConclusionDuring maternal hyperoxia, we demonstrated an increased oxygenation in a number of human fetal organs by using the non‐invasive BOLD technique. The oxygenation of the fetal brain remained constant, thus a ‘reversed’ brain sparing mechanism could be considered in healthy fetuses subjected to hyperoxia. © 2012 John Wiley & Sons, Ltd.
Dominant ion transport processes of ionic liquid electrolyte in poly(3,4‐ethylenedioxythiophene)
Authors: Irvin Jennifer A. , Carberry Jamie R. 
Published: December 2012

AbstractElectrochemical quartz crystal microgravimetry was used to study movement of the ionic liquid 1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIBTI) into and out of poly(3,4‐ethylenedioxythiophene) (PEDOT). In 0.1M EMIBTI/acetonitrile, anionic transport predominates, as is typical of solution‐based electrolytes. In pure EMIBTI, on the other hand, the minimal mass change observed during polymer oxidation/reduction was observed to be cation‐dominant. PEDOT deposition from dilute EMIBTI solution followed by cycling in neat EMIBTI resulted in rapid decrease of electroactivity. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013
Exploring the binding diversity of intrinsically disordered proteins involved in one‐to‐many binding
Authors: Hsu Wei‐Lun , Oldfield Christopher J. , Xue Bin , Meng Jingwei , Huang Fei , Romero Pedro , Uversky Vladimir N. , Dunker A. Keith 
Published: December 2012

AbstractMolecular recognition features (MoRFs) are intrinsically disordered protein regions that bind to partners via disorder‐to‐order transitions. In one‐to‐many binding, a single MoRF binds to two or more different partners individually. MoRF‐based one‐to‐many protein–protein interaction (PPI) examples were collected from the Protein Data Bank, yielding 23 MoRFs bound to 2–9 partners, with all pairs of same‐MoRF partners having less than 25% sequence identity. Of these, 8 MoRFs were bound to 2–9 partners having completely different folds, whereas 15 MoRFs were bound to 2–5 partners having the same folds but with low sequence identities. For both types of partner variation, backbone and side chain torsion angle rotations were used to bring about the conformational changes needed to enable close fits between a single MoRF and distinct partners. Alternative splicing events (ASEs) and posttranslational modifications (PTMs) were also found to contribute to distinct partner binding. Because ASEs and PTMs both commonly occur in disordered regions, and because both ASEs and PTMs are often tissue‐specific, these data suggest that MoRFs, ASEs, and PTMs may collaborate to alter PPI networks in different cell types. These data enlarge the set of carefully studied MoRFs that use inherent flexibility and that also use ASE‐based and/or PTM‐based surface modifications to enable the same disordered segment to selectively associate with two or more partners. The small number of residues involved in MoRFs and in their modifications by ASEs or PTMs may simplify the evolvability of signaling network diversity.
Effects of Gaussian disorder on charge carrier transport and recombination in organic semiconductors
Authors: Coehoorn R. , Bobbert P. A. 
Published: December 2012

AbstractIn this review, we discuss recent advances in our understanding of charge transport and exciton generation in disordered organic semiconductors with a Gaussian DOS, with a focus on applications to organic light‐emitting diodes (OLEDs). Three‐dimensional (3D) modeling shows that the actual current density in OLEDs based on materials with a Gaussian electron and hole DOS is filamentary. However, it is possible to accurately calculate the average current density by solving a one‐dimensional (1D) drift‐diffusion equation, making use of compact expressions for the temperature, electric field, and carrier density dependent mobility which have been derived from 3D‐modeling. For the cases of spatially uncorrelated energetic disorder and spatially correlated disorder due to random dipole fields, these models are called the extended Gaussian disorder model (EGDM) and extended correlated disorder model (ECDM), respectively. We discuss how the effects of trapping on guest molecules can be included, and how exciton generation is described. The application of these models to hole and electron transporting polymer and small molecule materials is discussed, with an emphasis on the modeling of the transport and emission of blue‐emitting OLEDs based on a polyfluorene‐derivative.
Deep level transient spectroscopy characterisation of defects in AlGaN/Si dual‐band (UV/IR) detectors grown by MBE
Authors: Aziz M. , Mari R. H. , Felix J. F. , Mesli A. , Taylor D. , Lemine M. O. , Henini M. , Pillai R. , Starikov D. , Boney C. , Bensaoula A. 
Published: December 2012

AbstractThis paper is based on the investigation of electrically active defects in dual band UV/IR photodiodes using Deep Level Transient Spectroscopy (DLTS). The UV/IR photodiodes were fabricated by growing Al0.7Ga0.3N layers on silicon substrate to obtain UV‐ sensitive photodiode structures on the front side, whereas on the back side of silicon IR‐sensitive photodiode structures were fabricated. Our studies reveal the existence of two defect levels in each detector. In order to determine accurately the position of these levels within the band gap of the respective layers, Laplace DLTS has been employed. The activation energies of defects in the UV photodetectors are 0.11±0.01 eV, and 0.31±0.01 eV, whereas, those in the IR detector are 0.25±0.01 eV and 0.47±0.02 eV. These energies are with respect to the conduction band energy of each detector. The effect of the junction electric field on the carrier emission rates of the deep traps was investigated by applying the double pulse Laplace DLTS technique. In particular it is found that the activation energy of the defect in the IR detector (0.47±0.02 eV) changes with electric field. Therefore, in this paper we will present detailed DLTS and Laplace DLTS investigations of deep traps in detectors based on AlGaN/Si (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural and electronic properties of InGaN/GaN nanowires by the use of EELS
Authors: Soumelidou Maria‐Marianna , Kioseoglou Joseph , Kirmse Holm , Komninou Philomela , Karakostas Theodoros 
Published: December 2012

AbstractElectron energy loss spectroscopy (EELS), in both the low loss and the core loss regions of the spectra, have been used to study local alloys composition, electronic transitions and bonding environment of different species in nanowires consisted of a GaN base‐part and a superlattice upper part of InxGa1–xN nanodisks (NDs)/GaN barriers. Experimental valence (low loss) electron energy loss spectroscopy (VEELS) spectra were taken from the GaN base‐part, the GaN barriers and the InxGa1–xN disks. Electron energy loss near edge structure (ELNES) spectra presenting the C K‐edge, the N K‐edge, the In M4,5‐edge were obtained from the GaN base‐part and spacer and the InxGa1–xN NDs. Variation of In concentration as well as different strain states change the intensity and result in the broadening and shifting of the edges in the spectra. The TELNES.2 program of the WIEN2k code (Blaha et al., Comp. Phys. Commun. 59, 399 (1990) [1]) was implemented in order to study the electronic properties of InxGa1–xN. The N K‐edge that represents the energy loss of the electron transition from the 2p to the 1s state is unique for each structure. Details on the bonding environment of the structure were extracted from the simulations of the ELNES spectra. Moreover, the influence of the In content in the InxGa1–xN NDs on the N‐K edge was interpreted. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Diffusion of implanted nitrogen in germanium
Authors: Skarlatos Dimitrios , Barozzi Mario , Bersani Massimo , Vouroutzis Nikos Z. , Ioannou‐Sougleridis Vassilios 
Published: December 2012

AbstractIn the present work diffusion of implanted nitrogen in germanium is studied as a function of implantation energy and post‐implantation annealing temperature. Implantations have been performed at a constant dose and energies leading to the amorphization of the substrate. Nitrogen diffusion in Ge is anomalous (not obeying the 2nd Fick's law) towards the substrate surface on which an Al2O3 layer has been deposited before annealing for protection. There is evidence that N diffusion in Ge is interstitial‐assisted and takes place in the presence of Ge interstitials gradients between the Al2O3/Ge and the former amorphous/crystalline (a/c) interface of the substrate during annealing. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A macro method for measuring economic‐benefit returns on cybersecurity investments: The table top approach
Authors: Garvey Paul R. , Moynihan Richard A. , Servi Les 
Published: December 2012

AbstractCritical considerations in engineering today's systems are securing the collection, access, and dissemination of the information they contain. Advanced computing technologies, ubiquitous environments, and sophisticated networks enable globally distributed access to data and information repositories to an uncountable community of consumers. Engineering security into these systems is more challenging and sophisticated than ever before. Along with this, assuring the integrity of highly networked systems requires economic decisions in rapidly changing technology and threat environments. Recognizing that countermeasures effective against cyber intrusions today can be ineffective tomorrow, the systems engineering community needs a rapid and agile way to identify the efficacies of competing countermeasure investment decisions. This paper presents a macroanalytic method for measuring economic‐benefit returns on investments in cybersecurity. The method is called the Table Top Approach. The table top approach is designed to place light demands on the granularity of inputs to evaluate the impacts of cyber intrusion events and the benefits of countermeasure investments. The table top approach derives which investments in a set of competing choices offer the greatest cost‐benefit gains in cyber defense, and why. It finds sets of Pareto efficient cost‐benefit investments, and their economic returns, that capture tangible and intangible advantages of countermeasures that strengthen cybersecurity. ©2012 Wiley Periodicals, Inc. Syst Eng 16
Mathematical properties of System Readiness Levels
Authors: McConkie Eileen , Mazzuchi Thomas A. , Sarkani Shahram , Marchette D. 
Published: December 2012

AbstractSystems engineers need quantifiable metrics for measuring the readiness of a system. The recently developed System Readiness Level (SRL) is such a metric. SRL is a function of Technology Readiness Level (TRL) and Integration Readiness Level (IRL). The mathematical operations used to define this function have some inherent properties. Four desired mathematical properties of SRL models are developed from these inherent properties and other properties suggested from a review of the literature. Matrix algebra and tropical algebra are discussed in the literature as possible mathematical operations. These mathematical operations are reviewed to determine if they meet the desired properties. Tropical Algebra (TA) is found to inherently meet these desired properties. Future research will be conducted to determine if an SRL model using TA is a viable option. ©2012 Wiley Periodicals, Inc. Syst Eng 16:
Low‐cost laser disdrometer with the capability of hydrometeor imaging
Authors: Minda Haruya , Tsuda Norio 
Published: December 2012

AbstractPrecision of microwave precipitation remote sensing is ensured by studying different hydrometeor classes (raindrops, snowflakes, graupel, and so on), shapes, and drop size distribution (DSD). Recently, DSD estimates and hydrometeor classification algorithms using polarimetric radars were proposed. These algorithm developments require a validation tool providing in situ hydrometeor measurement. We are working toward the development of a low‐cost, light‐weight, and disposable ballooning hydrometeor imaging probe with DSD measurement capabilities. This paper describes the performance of a new line‐scanning laser hydrometeor imaging probe (called PROBE) and validates the DSD using a commercially available impact‐type disdrometer. PROBE captures raindrop images with 0.125 mm horizontal resolution and more than six slices at the 33‐kHz slice rate, providing a reasonable raindrop diameter. DSD validation shows that PROBE acquires adequate DSD shapes during every 2‐min interval. These results demonstrate PROBE's performance in hydrometeor imaging and DSD measurement capabilities in a rainfall. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
The Science and Technology of Phase Change Materials
Authors: Wuttig Matthias , Raoux Simone 
Published: December 2012

AbstractPhase Change Materials are solids which are characterized by a unique combination of properties. They exist in an amorphous and a crystalline phase with remarkably different optical and electrical properties caused by an unusual change of bonding when the amorphous phase is crystallized. It is possible to change the phase of such a material in very short times (nanoseconds) and repeatedly between the two phases which makes phase change materials ideal candidates for data storage. This paper reviews in detail the relationship between the bonding mechanisms and the resulting physical properties of phase change materials. It describes the change of bonding from ordinary covalent bonding in the amorphous phase to resonance bonding in the crystalline phase with additional disorder, resulting in unconventional physical properties of phase change materials. These properties lead to the development of phase change data storage applications. Phase change optical data storage, phase change random access memory, and emerging applications including neuromorphic computing are described with particular emphasis on material requirements and material engineering for phase change random access memory.
Preadaptation for parthenogenetic colony foundation in subterranean termites Reticulitermes spp. (Isoptera: Rhinotermitidae)
Authors: Kawatsu Kazutaka , Matsuura Kenji 
Published: December 2012

AbstractThelytokous (all-female producing) parthenogenesis, in some cases, involves reproductive advantages against obligate sexual reproduction. However, the completion of parthenogenesis takes multiple steps without the help of males, and thus preadaptation that meets those requirements will be an important factor for the evolution of parthenogenesis. The Japanese subterranean termite,Reticulitermessperatus, is known to have the ability of parthenogenetic colony foundation, where females that failed to mate with males found colonies cooperatively with partner females and reproduce by parthenogenesis. In this study, we compared the parthenogenetic ability and the colony initiation behavior among sixReticulitermesspecies in Japan. All species other thanR. speratuswere not able to reproduce parthenogenetically. Nevertheless, females of these species without the parthenogenetic ability performed homosexual female–female colony initiation and produced eggs without fertilization. In addition, in one species without parthenogenetic reproduction,R. kanmonensis, female–female pair initiated founding behavior as quickly as a heterosexual pair. These results suggest that female–female colony initiation and virgin egg-laying are predominant characters among the genusReticulitermesand provide a preadaptive condition for parthenogenetic colony foundation inR. speratus.
Changes in litter decomposition and soil organic carbon in a reforested tropical deciduous cover (India)
Authors: Mehta Nirav , Dinakaran J. , Patel Shrena , Laskar A. H. , Yadava M. G. , Ramesh R. , Krishnayya N. S. R. 
Published: December 2012

AbstractSoil organic carbon (SOC) up to 1 m depth originates from contemporary vegetation cover dating from past millennia. Deforestation and reforestation with economically important species is influencing soil carbon sequestration. An attempt has been made in this study to evaluate the impact of vegetation cover change (due to replacement of natural heterogeneous cover by teak and bamboo) on SOC using carbon isotopes (δ13C, 14C) in a tropical system (India). A litter decomposition study was carried out to understand the impact of differences in vegetation characteristics (specifically of leaves) on decomposition. Both experiments were carried out to look at the impact of changes in vegetation characteristics (specifically of leaves) on litter decomposition, and how these influence near term litter decomposition rates (k values) and long‐term SOC content of the soil system beneath. Leaves of teak, bamboo and eight other species were selected for this study. The proportion of structural carbohydrates (lignin and cellulose) in leaves significantly (at 5 % level) influenced k values. The SOC and carbon isotope data collected in this study indicate that C3 vegetation cover in the study area could be contemporary and dominant for the past few centuries. This can be extended up to ~2,200 years from the recorded 14C values of teak cover. The study confirms that k values of leaf litter influence SOC present beneath the vegetation cover at the decadal/century time scale.
Tests of Measurement Invariance Without Subgroups: A Generalization of Classical Methods
Authors: Merkle Edgar C. , Zeileis Achim 
Published: December 2012

The issue of measurement invariance commonly arises in factor-analytic contexts, with methods for assessment including likelihood ratio tests, Lagrange multiplier tests, and Wald tests. These tests all require advance definition of the number of groups, group membership, and offending model parameters. In this paper, we study tests of measurement invariance based on stochastic processes of casewise derivatives of the likelihood function. These tests can be viewed as generalizations of the Lagrange multiplier test, and they are especially useful for: (i) identifying subgroups of individuals that violate measurement invariance along a continuous auxiliary variable without prespecified thresholds, and (ii) identifying specific parameters impacted by measurement invariance violations. The tests are presented and illustrated in detail, including an application to a study of stereotype threat and simulations examining the tests’ abilities in controlled conditions.
Biosynthesis of Long Chain Polyunsaturated Fatty Acids in the Marine Ichthyosporean Sphaeroforma arctica
Authors: Vrinten Patricia , Mavraganis Ioannis , Qiu Xiao , Senger Toralf 
Published: December 2012

AbstractSphaeroforma arctica is a unique, recently discovered marine protist belonging to a group falling close to the yeast/animal border. S. arctica is found in cold environments, and accordingly has a fatty acid composition containing a high proportion of very long chain polyunsaturated fatty acids, including the ω3 polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA). Two elongases and five desaturases, representing the complete set of enzymes necessary for the synthesis of DHA from oleic acid, were isolated from this species and characterized in yeast. One elongase showed high conversion rates on a wide range of 18 and 20 carbon substrates, and was capable of sequential elongation reactions. The second elongase had a strong preference for the 20‐carbon fatty acids EPA and arachidonic acid, with over 80 % of EPA converted to docosapentaenoic acid (DPA) in the heterologous yeast host. The isolation of a Δ8‐desaturase, along with the detection of eicosadienoic acid in S. arctica cultures indicated that this species uses the alternate Δ8‐pathway for the synthesis of long‐chain polyunsaturated fatty acids. S. arctica also carried a Δ4‐desaturase that proved to be very active in the production of DHA from DPA. Finally, a long chain acyl‐CoA synthetase from S. arctica improved DHA uptake in the heterologous yeast host and led to an improvement in desaturation and elongation efficiencies.
Swim cast versus traditional cast in pediatric distal radius fractures: A prospective randomized controlled trial
Authors: Derksen Robert Jan , Commandeur Joris P. , Deij Ronald , Breederveld Roelf S. 
Published: December 2012

Purpose Non-displaced distal radius fractures in children are traditionally treated in a forearm cast. However, a traditional cast does not tolerate getting wet, with skin lesions and bad smell as result. A Swim cast, which has the ability to dry quickly, is an airy cast that is applied using the MOKcast technique. We hypothesize that Swim casts contribute to higher patient satisfaction scores than traditional casts, without any adverse effects on fracture healing or skin condition. Methods A prospective, randomized, single-center, blinded study was conducted to compare traditional and Swim cast treatment in children aged 5–15 years with greenstick or torus fractures of the distal radius. Primary endpoint was the patient and parent satisfaction, as determined by a questionnaire. Secondary endpoints were radiographic and clinical bone healing and cast-related skin conditions. Results A total of 68 patients, divided into two treatment groups (traditional case and Swim cast; n = 34 per group). Baseline characteristics were similar between the groups. The overall satisfaction score (0–10) reported by the patients was 8.6 in the Swim cast group versus 7.5 in the traditional cast group ( p < 0.002); the overall satisfaction score reported by the parents was 8.3 and 7.7, respectively ( p < 0.02). There was no difference in radiographic or clinical healing between groups, and skin conditions also did not differ significantly between groups. Conclusion In our patient group, treatment of non-displaced, pediatric, distal radius fractures by Swim cast yielded better patient satisfaction results compared to treatment with the traditional, cotton-lined cast, without adverse effects on fracture healing or skin condition.