bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth of AlInN/AlGaN distributed Bragg reflectors for high quality microcavities
Authors: Berger Christoph , Dadgar Armin , Bläsing Jürgen , Franke Alexander , Hempel Thomas , Goldhahn Rüdiger , Christen Jürgen , Krost Alois 
Published: March 2012

AbstractWe report on the growth of lattice‐matched AlInN/AlGaN distributed Bragg reflectors (DBRs) by metal‐organic vapor phase epitaxy. Growing these structures on a lattice‐matched AlGaN template, the formation of cracks was completely supressed and strain‐related structural degradations were avoided. A 35‐pair DBR provides a peak reflectivity of 99% at a wavelength of ∼360 nm with a stop band width of 18 nm. Thus, the DBRs are well suited for the application in high Q‐factor microcavities designed for the ultraviolet spectral region. However, spatially resolved X‐ray diffraction shows an increase of the DBR period thickness towards the edge of the wafer, leading to a strong red‐shift of the stop band of ∼35 nm. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetic field effect on charge transport in π‐d system (EDT‐TTFVO)2FeBr4
Authors: Kodama Kota , Kurita Nobuyuki , Tsuchiya Satoshi , Terashima Taichi , Uji Shinya , Noguchi Satoru , Sugimoto Toyonari 
Published: March 2012

AbstractCurrent‐voltage (I ‐V) characteristics and magnetoresistance have been measured to investigate the magnetic field effect on the charge transport in the π ‐d organic conductor (EDT‐TTFVO)2FeBr4. The I ‐V characteristics show nonlinear behavior at low temperatures, which is qualitatively explained by the transport of electrons and holes thermally excited from the charge ordered states in the EDT‐TTFVO molecule layers.At low temperatures, the magnetoresistance has a shape change at ∼0.3 T, likely due to the spin flop transition of the 3d spins, and then a broad minimum at 7.6 T. The absence of the field angle dependence shows that the broad minimum arises mainly from the Zeeman effect, but not from the orbital effect. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Development of chiral molecular crystals
Authors: Krivickas Sara J. , Hashimoto Chiho , Takahashi Kazuyuki , Wallis John D. , Mori Hatsumi 
Published: March 2012

AbstractThe synthesis of enantiopure donors (R,R) and (S,S)‐vic ‐bis(hydroxymethyl)‐BEDT‐TTF (BEDT‐TTF = bis(ethylenedithio)tetrathiafulvalene) and the crystal structure of novel chiral crystal α′‐[(S,S)‐vic ‐bis(hydroxymethyl)‐BEDT‐TTF]2ClO4 is described. The charge transfer complex is chiral with the polar space group P2, which affords the possibility of pyroelectricity. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Charge disproportionation in (TMTTF)2X (X = PF6, AsF6 and SbF6) investigated by infrared spectroscopy
Authors: Knoblauch Tobias , Dressel Martin 
Published: March 2012

AbstractThe charge‐transfer salts (TMTTF)2X (X = PF6, AsF6 and SbF6) undergo a charge‐order transition at different temperatures TCO. We have performed infrared measurements on the ac plane with light polarized in the c direction in the temperature range from 290 down to 10 K. Below TCO, we report the splitting of the ν28 (B1u) mode including the charge sensitive C=C double bond.From the spectra, we respectively derived a charge disproportionation of 2δ = 0.15 e, 0.21 e and 0.29 e for (TMTTF)2PF6, (TMTTF)2AsF6 and (TMTTF)2SbF6. The temperature‐dependent development of 2δ exhibits a steep increase below TCO resembling a mean‐field behaviour. We compare our results with previous infrared and NMR values. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Linearity condition for orbital energies in density functional theory (IV): Determination of range‐determining parameter
Authors: Imamura Yutaka , Kobayashi Rie , Nakai Hiromi 
Published: March 2012

AbstractThis study explores the determination of the range‐determining parameter in the orbital‐specific (OS) range‐separated hybrid functional by the linearity condition for orbital energies. The OS range‐separated hybrid functionals with the optimized range‐determining parameters exhibit a less fractional‐occupation‐number electron dependence for orbital energies and successfully estimate ionization potentials for valence as well as inner valence and core orbitals in the sense of Koopmans' theorem. © 2012 Wiley Periodicals, Inc.
Rapid identification of synthetic cannabinoids in herbal samples via direct analysis in real time mass spectrometry
Authors: Musah Rabi A. , Domin Marek A. , Walling Maureen A. , Shepard Jason R. E. 
Published: March 2012

RATIONALEDozens of synthetic cannabinoid analogs purposefully meant to circumvent legal restrictions associated with controlled substances continue to be manufactured and promoted as producing 'legal highs'. These designer drugs are difficult to identify in conventional drug screens not only because routine protocols have not been developed for their detection, but also because their association with complex plant matrices during manufacture generally requires labor‐intensive extraction and sample preparation for analysis. To address this new and important challenge in forensic chemistry, Direct Analysis in Real Time Mass Spectrometry (DART‐MS) is applied to the analysis of these designer drugs.METHODSDART‐MS was employed to sample synthetic cannabinoids directly on botanical matrices. The ambient ionization method associated with DART‐MS permitted the analysis of solid herbal samples directly, without the need for extraction or sample preparation. The high mass resolution time‐of‐flight analyzer allowed identification of these substances despite their presence within a complex matrix and enabled differentiation of closely related analogs.RESULTSDART‐MS was performed to rapidly identify the synthetic cannabinoids AM‐251 and JWH‐015. For each cannabinoid, three hundred micrograms (300 µg) of material was easily detected within an excess of background matrix by mass.CONCLUSIONSNew variations of herbal blends containing a wide range of base components and laced with synthetic cannabinoids are being produced, making their presence difficult to track by conventional methods. DART‐MS permits rapid identification of trace synthetic cannabinoids within complex biological matrices, with excellent sensitivity and specificity compared with standard methods. Copyright © 2012 John Wiley & Sons, Ltd.
Analysis of select Dalbergia and trade timber using direct analysis in real time and time‐of‐flight mass spectrometry for CITES enforcement
Authors: Lancaster Cady , Espinoza Edgard 
Published: March 2012

RATIONALEInternational trade of several Dalbergia wood species is regulated by The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). In order to supplement morphological identification of these species, a rapid chemical method of analysis was developed.METHODSUsing Direct Analysis in Real Time (DART) ionization coupled with Time‐of‐Flight (TOF) Mass Spectrometry (MS), selected Dalbergia and common trade species were analyzed. Each of the 13 wood species was classified using principal component analysis and linear discriminant analysis (LDA). These statistical data clusters served as reliable anchors for species identification of unknowns.RESULTSAnalysis of 20 or more samples from the 13 species studied in this research indicates that the DART‐TOFMS results are reproducible. Statistical analysis of the most abundant ions gave good classifications that were useful for identifying unknown wood samples.CONCLUSIONSDART‐TOFMS and LDA analysis of 13 species of selected timber samples and the statistical classification allowed for the correct assignment of unknown wood samples. This method is rapid and can be useful when anatomical identification is difficult but needed in order to support CITES enforcement. Published 2012. This article is a US Government work and is in the public domain in the USA.
Invalidation of the structure of genetic network dynamics: a geometric approach
Authors: Porreca Riccardo , Cinquemani Eugenio , Lygeros John , Ferrari-Trecate Giancarlo 
Published: March 2012

SUMMARYThis work concerns the identification of the structure of a genetic network model from measurements of gene product concentrations and synthesis rates. In earlier work, we developed a data preprocessing algorithm that is able to reject many hypotheses on the network structure by testing certain monotonicity properties for a wide family of network models. Here, we develop a geometric interpretation of the method. Then, for a relevant subclass of genetic network models, we extend our approach to the combined testing of monotonicity and convexity‐like properties associated with the network structures. The theoretical aspects and practical performance of the enhanced methods are illustrated by way of numerical results. Copyright © 2012 John Wiley & Sons, Ltd.
Influence of Strain Rate on Hot Ductility of a V‐Microalloyed Steel Slab
Authors: Großeiber Simon , Ilie Sergiu , Poletti Cecilia , Harrer Bernhard , Degischer Hans Peter 
Published: March 2012

AbstractThe hot ductility and malleability of a vanadium‐microalloyed steel is investigated by means of tensile and compression tests at temperatures ranging from 700 to 850°C and strain rates of 3 × 10−4 to 0.3 s−1. The deformation tests are performed after austenitization and cooling to test temperature. The so‐called second ductility minimum is located around 750°C for all strain rates except for the highest one, where no ductility trough is observed. Ductility steadily increases with strain rate at a given temperature, and the fracture mode progressively changes from intergranular to transgranular. In the region of minimum ductility, intergranular cracking occurs at low strain rates by void nucleation, growth and coalescence within thin layers of deformation induced ferrite covering the austenite grain boundaries. Cracking is favoured by V(C,N) precipitation associated with the γ/α phase transformation. Ductility remains low above the temperature of minimum ductility, where no apparent ferrite formation is observed (790 °C). Void formation takes place as a result of grain boundary sliding in combination with matrix and grain boundary precipitation. These voids are able to grow and link up forming intergranular cracks. Ductility increases with strain rate mainly due to the short time available for precipitation as well as for intergranular void growth and coalescence.
Virtual bronchoscopy for evaluating cervical tumors of the fetus
Authors: Werner H. , Lopes dos Santos J. R. , Fontes R. , Belmonte S. , Daltro P. , Gasparetto E. , Marchiori E. , Campbell S. 
Published: March 2012

AbstractWe report on four cases of fetal cervical tumor, comprising three lymphangiomas and one teratoma, evaluated by ultrasound and magnetic resonance imaging (MRI) between 26 and 37 weeks' gestation. The aim was to investigate the use of virtual bronchoscopy to evaluate fetal airway patency in each case. A three‐dimensional (3D) model of the airway was created from overlapping image layers generated by MRI. The files obtained were manipulated using 3D modeling software, allowing the virtual positioning of observation cameras, adjustment of lighting parameters and creation of simulated 3D movies for analysis of a virtual path through the model. In all fetuses, fetal airway patency was clearly demonstrated by virtual bronchoscopy and this was confirmed postnatally. MRI with virtual bronchoscopy could become a useful tool for studying fetal airway patency in cases of cervical tumor.
Improving MANET performance by a hop‐aware and energy‐based buffer management scheme
Authors: Lai Wei Kuang , Weng Mu‐Lung , Lin Yo‐Ho 
Published: March 2012

ABSTRACTA hop‐aware and energy‐based buffer management scheme (HEB) is proposed in this paper. HEB can provide better quality of service to packets with real‐time requirements and improve MANET power efficiency. In our algorithm, the buffer is divided into real‐time and non‐real‐time partitions. We consider the number of hops passed, the power levels of the transmitting node, the predicted number of remaining hops, and waiting time in the buffer to determine packet transmission priority. In addition, specialized queue management and a probabilistic scheduling algorithm are proposed to decrease retransmissions caused by packet losses. Mathematical derivations of loss rates and end‐to‐end delays are also proposed. Coincidence between mathematical and simulation results is also shown. Finally, the HEB is compared with first in first out, random early detection, and hop‐aware buffering scheme. Simulation results show that the proposed algorithm reduces loss rates, power consumption, and end‐to‐end delays for real‐time traffic, considerably improving the efficiency of queue management in MANET. Copyright © 2012 John Wiley & Sons, Ltd.
The tornadoes of spring 2011 in the USA: an historical perspective
Authors: Doswell III Charles A. , Carbin Gregory W. , Brooks Harold E. 
Published: March 2012

AbstractTornado activity during spring of 2011 in the USA was of historic proportions; a series of major outbreaks of tornadoes in April and May produced hundreds of fatalities and thousands of millions of $US in damage. These events are considered in terms of the history of tornadoes in the USA and are seen to approach the worst ever recorded. With all the current concern for the effects of global climate change, this raises a number of questions about why such devastation occurred during this spring's severe weather season. This paper attempts to provide scientifically justifiable answers to those questions.
P2X4R and P2X7R in neuropathic pain
Authors: Makoto Tsuda , Hidetoshi Tozaki‐Saitoh , Kazuhide Inoue 
Published: March 2012

AbstractNeuropathic pain is often a consequence of nerve injury or of diseases such as diabetes, infection, autoimmune disease, or cancer. Neuropathic pain can be agonizing, can persist over long periods, and, unfortunately, is often resistant to known painkillers. There is a rapidly growing body of evidence indicating that signaling by extracellular nucleotides through purinergic P2 receptors [ionotropic P2X receptors (P2XRs) and metabotropic P2Y receptors (P2YRs)] play crucial roles in neuropathic pain. Following peripheral nerve injury, the expression of purinergic receptors (e.g., P2X4R) is markedly upregulated specifically in microglia, a type of glial cells known as resident macrophages in the central nervous system. Activation of P2X4R and P2X7R in microglia causes release of diffusible factors (such as brain‐derived neurotrophic factor, interleukin‐1β, interleukin‐6, and tumor necrosis factor‐α) involved in nerve‐injury‐induced pain behaviors and hyperexcitability of dorsal horn neurons. Suppression of the function or expression of these purinergic receptors strongly suppresses neuropathic pain. Recent advances further our understanding of mechanisms by which microglial purinergic receptors contribute to the pathogenesis of neuropathic pain. WIREs Membr Transp Signal 2012, 1:513–521. doi: 10.1002/wmts.47For further resources related to this article, please visit the WIREs website.
An Alternative Approach: Teaching Evolution in a Natural History Museum Through the Topic of Vector-Borne Disease
Authors: Pickering Jane , Fawcett Laura , Munstermann Leonard 
Published: March 2012

AbstractMuseums play a vitally important role in supporting both informal and formal education and are important venues for fostering public understanding of evolution. The Yale Peabody Museum has implemented significant education programs on evolution for many decades, mostly focused on the museum’s extensive collections that represent the past and present tree of life. Twelve years ago, the Peabody began a series of new programs that explored biodiversity and evolution as it relates to human health. Modern evolutionary theory contributes significantly to our understanding of health and disease, and medical topics provide many excellent and relevant examples to explore evolutionary concepts. The Peabody developed a program on vector-borne diseases, specifically Lyme disease and West Nile virus, which have become endemic in the United States. Both of these diseases have complex transmission cycles involving an intricate interplay among the pathogen, host, and vector, each of which is subject to differing evolutionary pressures. Using these stories, the museum explored evolutionary concepts of adaptation (e.g., the evolution of blood feeding), coevolution (e.g., the “arms race” between host and vector), and variation and selection (e.g., antibiotic resistance) among others. The project included a temporary exhibition and the development of curriculum materials for middle and high school teachers and students. The popularity of the exhibit and some formal evaluation of student participants suggested that this educational approach has significant potential to engage wide audiences in evolutionary issues. In addition it demonstrated how natural history museums can incorporate evolution into a broad array of programs.
A “rutter for piracy” in 2012
Authors: Menefee Samuel Pyeatt , Mejia Maximo Q. 
Published: March 2012

AbstractThis "rutter for piracy" begins with a brief update on contemporary piratical incidents and a short review of books and collections of articles dedicated to the topic of piracy, before presenting the ground-breaking group of scholarly essays which make upWMU Journal of Maritime Affairs' special issue on piracy at sea.
Gaining precision on the Alzheimer's Disease Assessment Scale‐cognitive: A comparison of item response theory‐based scores and total scores
Authors: Balsis Steve , Unger Alexis A. , Benge Jared F. , Geraci Lisa , Doody Rachelle S. 
Published: March 2012

AbstractBackgroundThe Alzheimer's Disease Assessment Scale‐cognitive (ADAS‐cog) is a commonly used measure for assessing cognitive dysfunction in patients with Alzheimer's disease (AD). The measure has 11 subscales, each of which captures an important aspect of cognitive dysfunction in AD. Traditional scoring of the ADAS‐cog involves adding up the scores from the subscales without regarding their varying difficulty or their strength of relationship to AD‐associated cognitive dysfunction. The present article analyzes problems associated with this approach and offers solutions for gaining measurement precision by modeling how the subscales function.MethodsWe analyzed data collected at the Baylor College of Medicine Alzheimer's Disease and Memory Disorders Clinic from 1240 patients diagnosed with varying degrees of dementia. Item response theory was used to determine the relationship between total scores on the ADAS‐cog and the underlying level of cognitive dysfunction reflected by the scores.ResultsResults revealed that each total score corresponded to a spectrum of cognitive dysfunction, indicating that total scores were relatively imprecise indicators of underlying cognitive dysfunction. Furthermore, it was common for two individuals with the same total score to have significantly different degrees of cognitive dysfunction.ConclusionsThese findings suggest that item response theory scoring of the ADAS‐cog may measure cognitive dysfunction more precisely than a total score method.
Test‐Retest Reliability of 3D Ultrasound Measurements of the Thoracic Spine
Authors: Fölsch Christian , Schlögel Stefanie , Lakemeier Stefan , Wolf Udo , Timmesfeld Nina , Skwara Adrian 
Published: March 2012

ObjectiveTo explore the reliability of the Zebris CMS 20 ultrasound analysis system with pointer application for measuring end‐range flexion, end‐range extension, and neutral kyphosis angle of the thoracic spine.SettingThe study was performed within the School of Physiotherapy in cooperation with the Orthopedic Department at a University Hospital.ParticipantsThe thoracic spines of 28 healthy subjects were measured.MethodsMeasurements for neutral kyphosis angle, end‐range flexion, and end‐range extension were taken once at each time point. The bone landmarks were palpated by one examiner and marked with a pointer containing 2 transmitters using a frequency of 40 kHz. A third transmitter was fixed to the pelvis, and 3 microphones were used as receiver. The real angle was calculated by the software. Bland‐Altman plots with 95% limits of agreement, intraclass correlations (ICC), standard deviations of mean measurements, and standard error of measurements were used for statistical analyses. The test‐retest reliability in this study was measured within a 24‐hour interval.Main Outcome MeasurementsStatistical parameters were used to judge reliability.ResultsThe mean kyphosis angle was 44.8° with a standard deviation of 17.3° at the first measurement and a mean of 45.8° with a standard deviation of 16.2° the following day. The ICC was high at 0.95 for the neutral kyphosis angle, and the Bland‐Altman 95% limits of agreement were within clinical acceptable margins. The ICC was 0.71 for end‐range flexion and 0.34 for end‐range extension, whereas the Bland‐Altman 95% limits of agreement were wider than with the static measurement of kyphosis. Compared with static measurements, the analysis of motion with 3‐dimensional ultrasound showed an increased standard deviation for test‐retest measurements.ConclusionsThe test‐retest reliability of ultrasound measuring of the neutral kyphosis angle of the thoracic spine was demonstrated within 24 hours. Bland‐Altman 95% limits of agreement and the standard deviation of differences did not appear to be clinically acceptable for measuring flexion and extension.