bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct analysis in real time mass spectrometry with collision‐induced dissociation for structural analysis of synthetic cannabinoids
Authors: Musah Rabi A. , Domin Marek A. , Cody Robert B. , Lesiak Ashton D. , John Dane A. , Shepard Jason R. E.
Published: September 2012

RATIONALE

The emergence of numerous cannabinoid designer drugs has been tied to large spikes in emergency room visits and overdoses. Identifying these substances is difficult for the following reasons: (1) the compounds are novel, closely structurally related, and do not usually test positive in drug screens; (2) novel analogs rapidly appear on the market; (3) no standard protocols exist for their identification; and (4) customized and extensive sample preparation/extraction and analysis procedures are required to demonstrate their presence.

METHODS

Direct analysis in real time mass spectrometry (DART‐MS) employing collision‐induced dissociation (CID) provided confirmatory structural information that was useful in characterizing the various cannabinoid analogs, including those contained in mixtures. CID analysis illustrated that, although closely related compounds fragment in a similar fashion, their structural differences still resulted in multiple diagnostic peaks that provided additional confidence towards structural identification.

RESULTS

DART‐MS spectra were acquired under CID conditions to rapidly differentiate among five synthetic cannabinoids contained within 'herbal' products purchased locally in New York State (USA). The spectra exhibited [M+H]+ ions and product ions unique to each cannabinoid that corresponded to major structural features. Five different cannabinoid analogs, alone and as mixtures of at least two cannabinoids, were identified in six herbal products and differentiated by their CID product ion patterns.

CONCLUSIONS

Illicit synthetic cannabinoid products continue to be readily available despite national and international restrictions. These products contain a wide range of active components, and, in many cases, multiple active ingredients. DART‐MS allows rapid analyses of these synthetic cannabinoids based on the exact masses of their [M+H]+ ions and product ion peaks generated using CID. Copyright © 2012 John Wiley & Sons, Ltd.
Maxillary sinus augmentation using computer‐aided design/computer‐aided manufacturing (CAD/CAM) technology
Authors: Mangano F. , Zecca P. , Pozzi‐Taubert S. , Macchi A. , Ricci M. , Luongo G. , Mangano C.
Published: September 2012

Background

Maxillary sinus augmentation is a common method for increasing bone height for insertion of dental implants. In most cases, the graft is manually cut into a roughly appropriate shape by visual estimation during the operation; accordingly, the shape of the graft depends considerably on the experience of the surgeon. We have developed a computer‐aided design/computer‐aided manufacturing (CAD/CAM) technique to generate custom‐made block grafts for sinus augmentation, and a customized cutting guide to precisely position the lateral wall and facilitate membrane elevation, using cone‐beam computed tomography (CBCT).

Methods

Custom‐made blocks of hydroxyapatite (HA) were preoperatively cut to the required shape, based on a three‐dimensional (3D) simulation, using CAD/CAM technology. The custom‐made HA blocks were used for sinus augmentation.

Results

Five patients underwent bilateral sinus elevation with custom‐made HA blocks. Six months later, implants were placed. Two years after placement, all implants were in function. No clinical or prosthetic complications were encountered.

Conclusions

We present a CAD/CAM technique for the fabrication of custom‐made block grafts for sinus augmentation.

Copyright © 2012 John Wiley & Sons, Ltd.
Robust control approach for input–output linearizable nonlinear systems using high‐gain disturbance observer
Authors: Liu Yan , Söffker Dirk
Published: September 2012

This paper addresses a robust control approach for a class of input–output linearizable nonlinear systems with uncertainties and modeling errors considered as unknown inputs. As known, the exact feedback linearization method can be applied to control input–output linearizable nonlinear systems, if all the states are available and modeling errors are negligible. The mentioned two prerequisites denote important problems in the field of classical nonlinear control. The solution approach developed in this contribution is using disturbance rejection by applying feedback of the uncertainties and modeling errors estimated by a specific high‐gain disturbance observer as unknown inputs. At the same time, the nonmeasured states can be calculated from the estimation of the transformed system states. The feasibility and conditions for the application of the approach on mechanical systems are discussed. A nonlinear multi‐input multi‐output mechanical system is taken as a simulation example to illustrate the application. The results show the robustness of the control design and plausible estimations of full‐rank disturbances.Copyright © 2012 John Wiley & Sons, Ltd.
Noise Variance Estimation Using Image Noise Cross‐Correlation Model on SEM Images
Authors: Sim K. S. , Nia M. E. , Tso C. P.
Published: September 2012

A number of techniques have been proposed during the last three decades for noise variance and signal‐to‐noise ratio (SNR) estimation in digital images. While some methods have shown reliability and accuracy in SNR and noise variance estimations, other methods are dependent on the nature of the images and perform well on a limited number of image types. In this article, we prove the accuracy and the efficiency of the image noise cross‐correlation estimation model, vs. other existing estimators, when applied to different types of scanning electron microscope images. SCANNING 35: 205‐212, 2013. © 2012 Wiley Periodicals, Inc.
Bayesian multivariate growth curve latent class models for mixed outcomes
Authors: Leiby Benjamin E. , Ten Have Thomas R. , Lynch Kevin G. , Sammel Mary D.
Published: September 2012

In many clinical studies, the disease of interest is multifaceted, and multiple outcomes are needed to adequately capture information about the characteristics of the disease or its severity. In the analysis of such diseases, it is often difficult to determine what constitutes improvement because of the multivariate nature of the outcome. Furthermore, when the disease of interest has an unknown etiology and/or is primarily a symptom‐defined syndrome, there is potential for the disease population to have distinct subgroups. Identification of population subgroups is of interest as it may assist clinicians in providing appropriate treatment or in developing accurate prognoses. We propose multivariate growth curve latent class models that group subjects on the basis of multiple symptoms measured repeatedly over time. These groups or latent classes are defined by distinctive longitudinal profiles of a latent variable, which is used to summarize the multivariate outcomes at each point. The mean growth curve for the latent variable in each class defines the features of the class. We develop this model for any combination of continuous, binary, ordinal, or count outcomes within a Bayesian hierarchical framework. We use simulation studies to validate the estimation procedures. We apply our model to data from a randomized clinical trial evaluating the efficacy of Bacillus Calmette–Guerin in treating symptoms of interstitial cystitis where we are able to identify a class of subjects for whom treatment is effective. Copyright © 2012 John Wiley & Sons, Ltd.
Practicable confidence intervals for current status data
Authors: Choi Byeong Yeob , Fine Jason P. , Brookhart M. Alan
Published: September 2012

Although confidence intervals (CIs) for binary isotonic regression and current status survival data have been well studied theoretically, their practical application has been limited, in part because of poor performance in small samples and in part because of computational difficulties. Ghosh, Banerjee, and Biswas (2008,Biometrics64, 1009‐1017) described three approaches to constructing CIs: (i) the Wald‐based method; (ii) the subsampling‐based method; and (iii) the likelihood‐ratio test (LRT)‐based method. In simulation studies, they found that the subsampling‐based method and LRT‐based method tend to have better coverage probabilities than a simple Wald‐based method that may perform poorly in realistic sample sizes. However, software implementing these approaches is currently unavailable. In this article, we show that by using transformations, simple Wald‐based CIs can be improved with small and moderate sample sizes to have competitive performance with LRT‐based method. Our simulations further show that a simple nonparametric bootstrap gives approximately correct CIs for the data generating mechanisms that we consider. We provide an R package that can be used to compute the Wald‐type and the bootstrap CIs and demonstrate its practical utility with two real data analyses. Copyright © 2012 John Wiley & Sons, Ltd.
Self‐reported Racial Discrimination and Endothelial Reactivity to Acute Stress in Women
Authors: Wagner Julie A. , Tennen Howard , Finan Patrick H. , Ghuman Nimrta , Burg Matthew M.
Published: September 2012

This study investigated the effect of self‐reported racial discrimination on endothelial responses to acute laboratory mental stress among post‐menopausal women. One‐hundred thirteen women (n = 94 self‐identified as White and n = 19 self‐identified as racial/ethnic minority), 43% with type 2 diabetes, reported lifetime experiences of racial/ethnic discrimination. Repeated assessments of flow‐mediated dilation were performed at baseline, immediately after 5 min of mental arithmetic and at 20‐min recovery. Both White and racial/ethnic minority women reported lifetime discrimination, with rates significantly higher among minorities. Self‐reported lifetime discrimination was associated with attenuated flow‐mediated dilation at recovery. Confounding variables, including clinical characteristics, mood, personality traits, other life stressors and general distress, did not better account for the effect of racial discrimination. Neither race/ethnicity nor diabetes status moderated the effect. The perceived stressfulness of the mental arithmetic was not associated with the endothelial response. In conclusion, self‐reported lifetime discrimination is associated with attenuated endothelial recovery from acute mental stress. Elucidating the effects of discrimination and the biological mechanisms through which it affects the vasculature may suggest interventions to improve health. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis of Manganese Ferrite/Graphene Oxide Nanocomposites for Biomedical Applications
Authors: Peng Erwin , Choo Eugene Shi Guang , Chandrasekharan Prashant , Yang Chang‐Tong , Ding Jun , Chuang Kai‐Hsiang , Xue Jun Min
Published: September 2012

In this study, MnFe2O4 nanoparticle (MFNP)‐decorated graphene oxide nanocomposites (MGONCs) are prepared through a simple mini‐emulsion and solvent evaporation process. It is demonstrated that the loading of magnetic nanocrystals can be tuned by varying the ratio of graphene oxide/magnetic nanoparticles. On top of that, the hydrodynamic size range of the obtained nanocomposites can be optimized by varying the sonication time during the emulsion process. By fine‐tuning the sonication time, MGONCs as small as 56.8 ± 1.1 nm, 55.0 ± 0.6 nm and 56.2 ± 0.4 nm loaded with 6 nm, 11 nm, and 14 nm MFNPs, respectively, are successfully fabricated. In order to improve the colloidal stability of MGONCs in physiological solutions (e.g., phosphate buffered saline or PBS solution), MGONCs are further conjugated with polyethylene glycol (PEG). Heating by exposing MGONCs samples to an alternating magnetic field (AMF) show that the obtained nanocomposites are efficient hyperthermia agents. At concentrations as low as 0.1 mg Fe mL−1 and under an 59.99 kA m−1 field, the highest specific absorption rate (SAR) recorded is 1588.83 W g−1 for MGONCs loaded with 14 nm MFNPs. It is also demonstrated that MGONCs are promising as magnetic resonance imaging (MRI) T2 contrast agents. A T2 relaxivity value (r2) as high as 256.2 (mM Fe)−1 s−1 could be achieved with MGONCs loaded with 14 nm MFNPs. The cytotoxicity results show that PEGylated MGONCs exhibit an excellent biocompatibility that is suitable for biomedical applications.
Polymersomes Containing a Hydrogel Network for High Stability and Controlled Release
Authors: Kim Shin‐Hyun , Kim Jin Woong , Kim Do‐Hoon , Han Sang‐Hoon , Weitz David A.
Published: September 2012

Capillary microfluidic devices are used to prepare monodisperse polymersomes consisting of a hydrogel core and a bilayer membrane of amphiphilic diblock‐copolymers. To make polymersomes, water‐in‐oil‐in‐water double‐emulsion drops are prepared as templates through single‐step emulsification in a capillary microfluidic device. The amphiphile‐laden middle oil phase of the double‐emulsion drop dewets from the surface of the innermost water drop, which contains hydrogel prepolymers; this dewetting leads to the formation of a bilayer membrane. Subsequently, the oil phase completely separates from the innermost water drop, leaving a polymersome. Upon UV illumination of the polymersome, the prepolymers encapsulated within the interior are crosslinked, forming a hydrogel core. The hydrogel network within the polymersomes facilitates sustained release of the encapsulated materials and increases the stability of the polymersomes through the formation of a scaffold to support the bilayer. In addition, this approach provides a facile method to make monodisperse hydrogel particles directly dispersed in water.
ROCK1 Inhibition Promotes the Self-Renewal of a Novel Mouse Mammary Cancer Stem Cell
Authors: Castro David J. , Maurer Jochen , Hebbard Lionel , Oshima Robert G.
Published: September 2012

The differentiation of stem-like tumor cells may contribute to the cellular heterogeneity of breast cancers. We report the propagation of highly enriched mouse mammary cancer stem cells that retain the potential to differentiate both in vivo and in culture and their use to identify chemical compounds that influence both self-renewal and differentiation. We identify epithelial tumor-initiating cells (ETICs) that express lineage markers of both basal and luminal mammary cell lineages and retain the potential, from even single cells, to generate heterogeneous tumors similar to the tumor of origin. ETICs can progress through a Rho-associated coiled-coil containing protein kinase 1 dependent, epithelial to mesenchymal transition to generate mesenchymal tumor-initiating cells capable of initiating tumors of limited heterogeneity. The propagation of ETICs may allow for the identification of new therapeutic compounds that may inhibit or prevent progression of some types of breast cancer.
Combining CdTe and Si detectors for Energy‐Dispersive X‐Ray Fluorescence
Authors: Redus R. , Huber A. , Pantazis T. , Pantazis J. , Cross B.
Published: September 2012

Most energy‐dispersive X‐ray fluorescence (EDXRF) instruments use Si diodes as X‐ray detectors. These provide very high energy resolution, but their sensitivity falls off at energies of 10–20 keV. They are well suited for measuring the K lines of elements with Z < 40, but for heavier elements, one must use K lines at low efficiency or use L or M lines that often overlap other lines. Either is a challenge for accurate quantitative analysis. CdTe detectors offer much higher efficiency at high energy but poorer energy resolution compared with Si diodes.

In many important EDXRF measurements, both high and low Z elements are present. In this paper, we will compare the precision and accuracy of systems using the following: (1) a high resolution Si detector, (2) a high efficiency CdTe detector, and (3) a composite system using both detectors. We will show that CdTe detectors generally offer better analytical results than even a high resolution silicon drift detectors for K lines greater than 20 or 25 keV, whereas the high resolution Si detectors are much better at lower energies. We will also show the advantages of a combined system, using both detectors. Although a combined system would be more expensive, the increased accuracy, precision, and throughput will often outweigh the small increase in cost and complexity. The systems will be compared for representative applications that include both high and low Z elements. Copyright © 2012 John Wiley & Sons, Ltd.
Figure of merit for spectrometers for EDXRF
Authors: Redus R. , Huber A.
Published: September 2012

How should one select the best detector for a particular measurement in energy dispersive X‐ray fluorescence (EDXRF)? How should one select the optimum system configuration, i.e. the best shaping time and beam current? Manufacturers provide a variety of specifications, such as energy resolution and maximum count rate, but these are indirectly related to the end use of an EDXRF instrument, the measurement and detection limit of the measured elemental concentrations.

We suggest in this paper using the time required to achieve a given statistical uncertainty as a figure of merit. We derive scaling rules for this figure of merit based on conventional specifications, including energy resolution, peaking time, maximum count rate, detector area, and intrinsic efficiency. These scaling rules also include the peak to background ratio of a photopeak and the number of overlapping peaks. We then show how this figure of merit can be used to select the optimum detector and spectrometer configuration for specific applications and compare the results to data obtained with typical systems. Copyright © 2012 John Wiley & Sons, Ltd.
Intercalation of Sulfanilic Acid‐Phenol‐Formaldehyde Polycondensate into Hydrocalumite Type Layered Double ­Hydroxide
Authors: Zou Nan , Plank Johann
Published: September 2012

Polycondensates containing sulfonate groups, referred to as concrete superplasticizers, are widely used in the construction industry. A sulfanilic acid–phenol–formaldehyde polycondensate (SPF) with Mw ≈ 100.000 g·mol–1 was synthesized from sulfanilic acid, phenol and formaldehyde by polycondensation reaction, and its intercalation into hydrocalumite type Layered Double Hydroxide (LDH) was investigated. Preparation was done by rehydration of tricalcium aluminate, a cement constituent, in the presence of the polymer. According to the XRD pattern, SPF was successfully intercalated. A d value of approx. 2.6 nm was found. Elemental composition of the new organo‐mineral phase reveals charge balancing of the cationic LDH main layers by the polycondensate. Thermogravimetry indicates that thermal degradation of intercalated SPF occurs at higher temperature, compared to non‐intercalated SPF. According to SEM imaging, the novel Ca‐Al‐LDH phase exhibits the morphology of intergrown platelets. Ultra‐thin nanosheets (foils) with approx. 50 nm thickness were obtained. The layered structure and d value obtained from diffraction analysis were confirmed by TEM imaging. The new hydride can be used as cement and concrete additive.
Copper‐Rich Framework Selenoarsenates Based on Icosahedral Cu8Se13 Clusters
Authors: Zhang Ren‐Chun , Zhang Chi , Zhang Dao‐Jun , Wang Jun‐Jie , Zhang Zhi‐Fei , Ji Min , An Yong‐Lin
Published: September 2012

Three copper‐rich framework selenoarsenates, (H2en)1.5[Cu8(μ8‐Se)(AsSe4)6/2] (1), (H2dap)1.5[Cu8(μ8‐Se)(AsSe4)6/2] (2), and Na2(H2dap)0.5[Cu8(μ8‐Se)(AsSe4)6/2] (3), were synthesized under solvothermal conditions. These three compounds are isostructural and contain a 3D Cu‐As‐Se framework constructed from novel icosahedral Cu8Se13 clusters linked by As5+, with counterions located in the cavities. The icosahedral Cu8Se13 clusters represent the first icosahedral Cu‐Se unit found in 3D framework chalcogenides, and contain an unusual μ8‐cubic bridging Se2– ion at the core site. The covalent 3D Cu‐As‐Se framework is rigid and not sensitive to the shape and charge density of counterions.
Preparation, Crystal Structure, Electronic Structure, Impedance Spectroscopy, and Raman Spectroscopy of Li3SbS3 and Li3AsS3
Authors: Huber Sebastian , Preitschaft Christian , Weihrich Richard , Pfitzner Arno
Published: September 2012

Li3SbS3 was synthesized by solid‐state reaction of stoichiometric amounts of Li2S and Sb2S3 in the ratio 3:1. The product is air and moisture sensitive. The crystal structure was determined from single crystals at room temperature. Pale grey Li3SbS3 crystallizes in the orthorhombic space group Pna21 (no. 33) with a = 7.9671(5) Å, b = 6.7883(5) Å, c = 10.0912(8) Å, V = 545.76(7) Å3, and Z = 4 (data at 20 °C). Antimony and sulfur atoms build isolated, trigonal pyramidal [SbS3]3– units, which are stacked along [100]. These [SbS3]3– units are connected by [LiSx]‐polyhedra. The lithium ions have either a distorted tetrahedral coordination by sulfur in the case of Li2 and Li3 or a distorted square pyramidal environment in the case of Li1. The crystal structure is isotypic with Li3AsS3, which was obtained by reaction of stoichiometric amounts of lithium, arsenic, and sulfur in the ratio 3:1:3 in an excess of LiI. LiI serves only as a flux and is not incorporated in the crystal structure. Li3AsS3 crystallizes as colorless rods, space group Pna21 (no. 33) with a = 8.090(1) Å, b = 6.658(1) Å, c = 9.868(1) Å, V = 531.5(1) Å3, and Z = 4 (data at 20 °C). Both compounds are confirmed as semiconductors with bandgaps close to 3 eV from DFT‐calculations with GGA and hybrid functionals. Impedance spectroscopic measurements of Li3SbS3 show a specific conductivity of σ = 1.6 × 10–9 Ω–1 cm–1 at 323 K and of σ = 5.4 × 10–5 Ω–1 cm–1 at 573 K. The activation energy is EA = 0.72 eV. Raman spectra of Li3SbS3 are dominated by the stretching modes of the [SbS3]3– units at 333, 317, and 301 cm–1 at room temperature.
Adapting School‐Based Substance Use Prevention Curriculum Through Cultural Grounding: A Review and Exemplar of Adaptation Processes for Rural Schools
Authors: Colby Margaret , Hecht Michael L. , Miller-Day Michelle , Krieger Janice L. , Syvertsen Amy K. , Graham John W. , Pettigrew Jonathan
Published: September 2012

A central challenge facing twenty‐first century community‐based researchers and prevention scientists is curriculum adaptation processes. While early prevention efforts sought to develop effective programs, taking programs to scale implies that they will be adapted, especially as programs are implemented with populations other than those with whom they were developed or tested. The principle of cultural grounding, which argues that health message adaptation should be informed by knowledge of the target population and by cultural insiders, provides a theoretical rational for cultural regrounding and presents an illustrative case of methods used to reground the keepin’ it REAL substance use prevention curriculum for a rural adolescent population. We argue that adaptation processes like those presented should be incorporated into the design and dissemination of prevention interventions.
Therapie mitochondrialer Erkrankungen
Authors: Kornblum C.
Published: September 2012

Im Verständnis pathogenetischer Grundlagen mitochondrialer Erkrankungen sind bedeutende Fortschritte zu verzeichnen. Die Therapie ist dagegen noch überwiegend symptomatisch, kurative Behandlungen stehen nicht zur Verfügung. Allerdings befinden sich zahlreiche Substanzen, diätetische Modifikationen und Interventionen in Untersuchung, die verschiedene Ziele wie eine antioxidative Wirkung, Supplementation von Metaboliten oder Elimination toxischer Stoffwechselprodukte verfolgen. Aktuell gibt es keine klare Evidenz für eine gesicherte Wirksamkeit dieser vielfältigen Therapieansätze. Ausnahmen bilden möglicherweise der Ausgleich von metabolischen Mangelzuständen oder die Elimination toxischer Metabolite, zudem liegen Hinweise auf einen Nutzen von Idebenon bei hereditärer Leber-Optikusneuropathie (LHON) vor. Die Datenlage hinsichtlich methodisch hochwertiger Studien ist aber noch limitiert, kontrollierte Studien an homogenen Patientenkollektiven sind zukünftig zu fordern. Erfolgversprechende gentherapeutische Ansätze werden verfolgt, sind aber noch nicht praxisrelevant.
Parents as a resource: Communication quality affects the relationship between adolescents' internet use and loneliness
Authors: Appel Markus , Holtz Peter , Stiglbauer Barbara , Batinic Bernad
Published: September 2012

The authors examined the influence of parent–adolescent communication quality, as perceived by the adolescents, on the link between adolescents' Internet use and loneliness, controlling for perceived family support in general terms. Adolescents (N = 216, Mage = 15.80 years) provided data on Internet use, loneliness, Internet‐related parent–adolescent communication, and perceived family support. Moderated regression analyses showed that Internet‐related communication quality determined whether more extensive Internet use was associated with more loneliness. This moderation effect remained significant when perceived family support in general terms was controlled for. Gender and age of the participants did not influence the findings. Implications for successful Internet‐related parenting strategies are discussed.
Crystal structure analysis of the translation factor RF3 (release factor 3)
Authors: Kihira Kiyohito , Shimizu Yoshihiro , Shomura Yasuhito , Shibata Naoki , Kitamura Masaya , Nakagawa Atsushi , Ueda Takuya , Ochi Kozo , Higuchi Yoshiki
Published: September 2012

The bacterial translational GTPases release factor RF3 promotes translation termination by recycling RF1 or RF2. Here, we present the crystal structures of RF3 complexed with GDP and guanosine 3′,5′‐(bis)diphosphate (ppGpp) at resolutions of 1.8 and 3.0 Å, respectively. ppGpp is involved in the so‐called “stringent response” of bacteria. ppGpp binds at the same site as GDP, suggesting that GDP and ppGpp are two alternative physiologically relevant ligands of RF3. We also found that ppGpp decelerates the recycling of RF1 by RF3. These lines of evidence suggest that RF3 functions both as a cellular metabolic sensor and as a regulator.
Stochastic Processes
Authors: Bass Richard F.
Published: September 2012

This comprehensive guide to stochastic processes gives a complete overview of the theory and addresses the most important applications. Pitched at a level accessible to beginning graduate students and researchers from applied disciplines, it is both a course book and a rich resource for individual readers. Subjects covered include Brownian motion, stochastic calculus, stochastic differential equations, Markov processes, weak convergence of processes and semigroup theory. Applications include the Black–Scholes formula for the pricing of derivatives in financial mathematics, the Kalman–Bucy filter used in the US space program and also theoretical applications to partial differential equations and analysis. Short, readable chapters aim for clarity rather than full generality. More than 350 exercises are included to help readers put their new-found knowledge to the test and to prepare them for tackling the research literature.
On the steady-state fully resonant progressive waves in water of finite depth
Authors: Xu Dali , Lin Zhiliang , Liao Shijun , Stiassnie Michael
Published: September 2012

The steady-state fully resonant wave system, consisting of two progressive primary waves in finite water depth and all components due to nonlinear interaction, is investigated in detail by means of analytically solving the fully nonlinear wave equations as a nonlinear boundary-value problem. It is found that multiple steady-state fully resonant waves exist in some cases which have no exchange of wave energy at all, so that the energy spectrum is time-independent. Further, the steady-state resonant wave component may contain only a small proportion of the wave energy. However, even in these cases, there usually exist time-dependent periodic exchanges of wave energy around the time-independent energy spectrum corresponding to such a steady-state fully resonant wave, since it is hard to be exactly in such a balanced state in practice. This view serves to deepen and enrich our understanding of the resonance of gravity waves.
On generalized complete elliptic integrals and modular functions
Authors: Bhayo B. A. , Vuorinen M.
Published: September 2012

This paper deals with generalized elliptic integrals and generalized modular functions. Several new inequalities are given for these and related functions.
Gender, Uyghur Identity, and the Story of Nuzugum
Authors: Abramson Kara
Published: September 2012

This article examines the relationship between gender and Uyghur identity through the story of Nuzugum, the allegory of a Kashgar woman who kills an enemy outsider she is forced to marry rather than yield her chastity and bear his children. Tracing the story from its nineteenth-century roots to literary, artistic, and political incarnations in recent decades, the article argues that the story's prominence in the canon of Uyghur literature and its eponymous protagonist's place among Uyghur national heroes highlights the integral but overlooked role of gender in the construction of modern Uyghur identity. The resiliency of the story's gendered themes also underscores gender's importance in contemporary Uyghur political advocacy, especially advocacy about the transfer of Uyghur women to factories in China's coastal cities, an issue connected to the July 2009 protests and riots in the Xinjiang Uyghur Autonomous Region.
Sample size estimation to substantiate freedom from disease for clustered binary data with a specific risk profile
Authors: KOSTOULAS P. , NIELSEN S. S. , BROWNE W. J. , LEONTIDES L.
Published: September 2012

Disease cases are often clustered within herds or generally groups that share common characteristics. Sample size formulae must adjust for the within-cluster correlation of the primary sampling units. Traditionally, the intra-cluster correlation coefficient (ICC), which is an average measure of the data heterogeneity, has been used to modify formulae for individual sample size estimation. However, subgroups of animals sharing common characteristics, may exhibit excessively less or more heterogeneity. Hence, sample size estimates based on the ICC may not achieve the desired precision and power when applied to these groups. We propose the use of the variance partition coefficient (VPC), which measures the clustering of infection/disease for individuals with a common risk profile. Sample size estimates are obtained separately for those groups that exhibit markedly different heterogeneity, thus, optimizing resource allocation. A VPC-based predictive simulation method for sample size estimation to substantiate freedom from disease is presented. To illustrate the benefits of the proposed approach we give two examples with the analysis of data from a risk factor study on Mycobacterium avium subsp. paratuberculosis infection, in Danish dairy cattle and a study on critical control points for Salmonella cross-contamination of pork, in Greek slaughterhouses.
Colistinvs. the combination of colistin and rifampicin for the treatment of carbapenem-resistantAcinetobacter baumanniiventilator-associated pneumonia
Authors: AYDEMIR H. , AKDUMAN D. , PISKIN N. , COMERT F. , HORUZ E. , TERZI A. , KOKTURK F. , ORNEK T. , CELEBI G.
Published: September 2012

The aim of this study was to compare the responses of colistin treatment alonevs. a combination of colistin and rifampicin in the treatment of ventilator-associated pneumonia (VAP) caused by a carbapenem-resistantA. baumanniistrain. Forty-three patients were randomly assigned to one of two treatment groups. Although clinical (P = 0·654), laboratory (P = 0·645), radiological (P = 0·290) and microbiological (P = 0·597) response rates were better in the combination group, these differences were not significant. However, time to microbiological clearance (3·1 ± 0·5 days,P = 0·029) was significantly shorter in the combination group. The VAP-related mortality rates were 63·6% (14/22) and 38·1% (8/21) for the colistin and the combination groups (P = 0·171), respectively. Our results suggest that the combination of colistin with rifampicin may improve clinical and microbiological outcomes of VAP patients infected withA. baumannii.
Enzyme-linked immunosorbent assay to diagnose human leptospirosis: a meta-analysis of the published literature
Authors: SIGNORINI M. L. , LOTTERSBERGER J. , TARABLA H. D. , VANASCO N. B.
Published: September 2012

We report an evaluation of the accuracy of ELISA for the detection ofLeptospira-specific antibodies in humans. Eighty-eight studies published in 35 articles met all inclusion criteria and were submitted to meta-analysis. Pooled sensitivity and specificity were 0·779 (95% CI 0·770–0·789) and 0·913 (95% CI 0·908–0·917), respectively, and the area under the curve was 0·964. Heterogeneity across studies was statistically significant, but none of the sources of heterogeneity (disease stage, antigen used, antibody detected) could fully explain this finding. Although the convalescent stage of disease was significantly associated with higher diagnostic accuracy, IgM ELISA was the best choice, regardless of the stage of disease. Negative ELISAs (IgG or IgM) applied in the acute phase do not rule out leptospirosis due to the possibility of false-negative results. In this case it is advisable to request a second blood sample or to apply a direct method for leptospiral DNA.
A NOTE ON FOREIGN EXCHANGE INTERVENTIONS AT ZERO INTEREST RATES
Authors: Iwata Shigeru , Wu Shu
Published: September 2012

This note uses a nonlinear structural vector autoregression model to empirically investigate the effectiveness of official foreign exchange (FX) interventions in an economy when interest rates are constrained to the zero level, based on Japanese data in the 1990s. The model allows us to estimate the effects of FX interventions operating through different channels. We find that FX interventions are still capable of influencing the foreign exchange rate in a zero-interest-rate environment, even though their effects are greatly reduced by the zero lower bound on interest rates. Our results suggest that although it might be feasible to use the exchange rate as an alternative monetary policy instrument at zero interest rates as proposed by McCallum (Inflation Targeting and the Liquidity Trap, NBER working paper 8225, 2000), the exchange rate–based Taylor rule may not be very effective in achieving the ultimate policy goals.
Prevalence and factors associated with overweight and obesity in French primary-school children
Authors: Thibault Hélène , Carriere Caroline , Langevin Coralie , Kossi Déti Edouard , Barberger-Gateau Pascale , Maurice Sylvie
Published: September 2012

Objective

To determine the prevalence of, and identify associated factors with, overweight and obesity in two samples of French children.

Design

We conducted two cross-sectional studies among two samples of children. Weight status, eating behaviour, sedentary activity, physical activity and parents’ socio-economic status (SES) were collected using questionnaires filled by doctors during school health check-ups. Overweight and obesity were defined according to the age- and sex-specific BMI cut-off points of the International Obesity Taskforce. Multivariate analysis (logistic regression) was used to identify independent factors associated with overweight including obesity and obesity alone.

Setting

Aquitaine region (south-west France).

Subjects

Analyses were conducted among children aged 5–7 years (n 4048) and 7–11 years (n 3619).

Results

Overweight prevalence was 9·5 % including 2·2 % of obesity in 5–7-year-old children and 15·6 % including 2·9 % of obesity in 7–11-year-old children. In both samples, overweight and obesity prevalence were higher in children whose parents had low or medium SES (P < 0·05). Factors associated significantly (P < 0·05) and independently with higher overweight or obesity prevalence were female gender, low or medium parental SES, never or sometimes having breakfast, never eating at the school canteen, never having a morning snack, never or sometimes having a light afternoon meal and having high sedentary activity.

Conclusions

Our data confirm that low SES, absence of breakfast and high sedentary activity are associated with a higher risk of being overweight or obese, but also highlight original potential protective factors such as eating at the canteen and high meal frequency.
Fossils and astrobiology: new protocols for cell evolution in deep time
Authors: Brasier Martin D. , Wacey David
Published: September 2012

The study of life remote in space has strong parallels with the study of life remote in time. Both are dependent on decoding those historic phenomena called ‘fossils’, here taken to include biogenic traces of activity and waste products. There is the shared problem of data restoration from incomplete data sets; the importance of contextual analysis of potentially viable habitats; the centrality of cell theory; the need to reject the null hypothesis of an abiogenic origin for candidate cells via morphospace analysis; the need to demonstrate biology-like behaviour (e.g., association with biofilm-like structures; tendency to form clusters and ‘mats’; and a preference for certain substrates), and of metabolism-like behaviour (e.g., within the candidate cell wall; within surrounding ‘waste products’; evidence for syntrophy and metabolic cycles; and evidence for metabolic tiers). We combine these ideas into a robust protocol for demonstrating ancient or extra-terrestrial life, drawing examples from Earth's early geological record, in particular from the earliest known freshwater communities of the 1.0 Ga Torridonian of Scotland, from the 1.9 Ga Gunflint Chert of Canada, from the 3.4 Ga Strelley Pool sandstone of Australia, and from the 3.46 Ga Apex Chert also of Australia.
Manufacturing of diamond windows for synchrotron radiation
Authors: Schildkamp W. , Nikitina L.
Published: September 2012

A new diamond window construction is presented and explicit manufacturing details are given. This window will increase the power dissipation by about a factor of 4 over present day state of the art windows to absorb 600 W of power. This power will be generated by in-vacuum undulators with the storage ring ALBA operating at a design current of 400 mA. Extensive finite element (FE) calculations are included to predict the windows behavior accompanied by explanations for the chosen boundary conditions. A simple linear model was used to cross-check the FE calculations.
How are the behaviors of piezoelectric inertial sliders interpreted?
Authors: Wang Junting , Lu Qingyou
Published: September 2012

We report on the effect of different driving signal waveforms on the positioning response of piezoelectric inertial sliders. Surprisingly, a delayed retraction waveform is found to perform better than the more widely adopted undelayed retraction, which is opposite to the expected behavior because the former has a less sharp turning point with lower inertial force. This is confirmed in both piezoelectric tube driven and shear piezo stack driven inertial sliders. We explain that this effect is owing to the creeping property of piezoelectric materials, as indicated by our simulated response including the creeping effect.
Reactive quenching of OH A 2Σ+ by O2 and CO: Experimental and nonadiabatic theoretical studies of H- and O-atom product channels
Authors: Lehman Julia H. , Lester Marsha I. , Yarkony David R.
Published: September 2012

The outcomes following collisional quenching of electronically excited OH A 2Σ+ by O2 and CO are examined in a combined experimental and theoretical study. The atomic products from reactive quenching are probed using two-photon laser-induced fluorescence to obtain H-atom Doppler profiles, O (3PJ) atom fine structure distributions, and the relative yields of these products with H2, O2, and CO collision partners. The corresponding H-atom translational energy distributions are extracted for the H + O3 and H + CO2 product channels, in the latter case revealing that most of the available energy is funneled into internal excitation of CO2. The experimental product branching ratios show that the O-atom producing pathways are the dominant outcomes of quenching: the OH A 2Σ+ + O2 → O + HO2 channel accounts for 48(3)% of products and the OH A 2Σ+ + CO → O + HCO channel yields 76(5)% of products. In addition, quenching of OH A 2Σ+ by O2 generates H + O3 products [12(3)%] and returns OH to its ground X 2Π electronic state [40(1)%; L. P. Dempsey, T. D. Sechler, C. Murray, and M. I. Lester, J. Phys. Chem. A 113, 6851 (2009)10.1021/jp902935c]. Quenching of OH A 2Σ+ by CO also yields H + CO2 reaction products [26(5)%]; however, OH X 2Π (v″ = 0,1) products from nonreactive quenching are not observed. Theoretical studies characterize the properties of energy minimized conical intersections in four regions of strong nonadiabatic coupling accessible from the OH A 2Σ+ + CO asymptote. Three of these regions have the O-side of OH pointing toward CO, which lead to atomic H and vibrationally excited CO2 products and/or nonreactive quenching. In the fourth region, energy minimized points are located on a seam of conical intersection from the OH A 2Σ+ + CO asymptote to an energy minimized crossing with an extended OH bond length and the H-side of OH pointing toward CO in a bent configuration. This region, exoergic with respect to the reaction asymptote, is likely to be the origin of the dominant O + HCO product channel.
The influence of excited state topology on wavepacket delocalization in the relaxation of photoexcited polyatomic molecules
Authors: Krause Pascal , Matsika Spiridoula , Kotur Marija , Weinacht Thomas
Published: September 2012

This paper compares the relaxation dynamics of several molecules that display internal conversion on ultrafast time scales. We find that the degree of wavefunction localization during relaxation is strongly correlated with the rate of relaxation. We discuss our experimental findings in terms of two-dimensional model simulations which try to capture the essential features of the potential energy landscapes relevant to the relaxation dynamics. Our model calculations show how relaxation can be local or nonlocal depending on basic features of the potential energy surface traversed by the wavepacket en route back to the ground state.
Comparative band alignment of plasma-enhanced atomic layer deposited high-k dielectrics on gallium nitride
Authors: Yang Jialing , Eller Brianna S. , Zhu Chiyu , England Chris , Nemanich Robert J.
Published: September 2012

Al2O3 films, HfO2 films, and HfO2/Al2O3 stacked structures were deposited on n-type, Ga-face, GaN wafers using plasma-enhanced atomic layer deposition (PEALD). The wafers were first treated with a wet-chemical clean to remove organics and an in-situ combined H2/N2 plasma at 650 °C to remove residual carbon contamination, resulting in a clean, oxygen-terminated surface. This cleaning process produced slightly upward band bending of 0.1 eV. Additional 650 °C annealing after plasma cleaning increased the upward band bending by 0.2 eV. After the initial clean, high-k oxide films were deposited using oxygen PEALD at 140 °C. The valence band and conduction band offsets (VBOs and CBOs) of the Al2O3/GaN and HfO2/GaN structures were deduced from in-situ x-ray and ultraviolet photoemission spectroscopy (XPS and UPS). The valence band offsets were determined to be 1.8 and 1.4 eV, while the deduced conduction band offsets were 1.3 and 1.0 eV, respectively. These values are compared with the theoretical calculations based on the electron affinity model and charge neutrality level model. Moreover, subsequent annealing had little effect on these offsets; however, the GaN band bending did change depending on the annealing and processing. An Al2O3 layer was investigated as an interfacial passivation layer (IPL), which, as results suggest, may lead to improved stability, performance, and reliability of HfO2/IPL/GaN structures. The VBOs were ∼0.1 and 1.3 eV, while the deduced CBOs were 0.6 and 1.1 eV for HfO2 with respect to Al2O3 and GaN, respectively.
Direct first-principles chemical potential calculations of liquids
Authors: Hong Qi-Jun , van de Walle Axel
Published: September 2012

We propose a scheme that drastically improves the efficiency of Widom's particle insertion method by efficiently sampling cavities while calculating the integrals providing the chemical potentials of a physical system. This idea enables us to calculate chemical potentials of liquids directly from first-principles without the help of any reference system, which is necessary in the commonly used thermodynamic integration method. As an example, we apply our scheme, combined with the density functional formalism, to the calculation of the chemical potential of liquid copper. The calculated chemical potential is further used to locate the melting temperature. The calculated results closely agree with experiments.
Statistical theory and applications of lock-in carrierographic image pixel brightness dependence on multi-crystalline Si solar cell efficiency and photovoltage
Authors: Mandelis Andreas , Zhang Yu , Melnikov Alexander
Published: September 2012

A solar cell lock-in carrierographic image generation theory based on the concept of non-equilibrium radiation chemical potential was developed. An optoelectronic diode expression was derived linking the emitted radiative recombination photon flux (current density), the solar conversion efficiency, and the external load resistance via the closed- and/or open-circuit photovoltage. The expression was shown to be of a structure similar to the conventional electrical photovoltaic I-V equation, thereby allowing the carrierographic image to be used in a quantitative statistical pixel brightness distribution analysis with outcome being the non-contacting measurement of mean values of these important parameters averaged over the entire illuminated solar cell surface. This is the optoelectronic equivalent of the electrical (contacting) measurement method using an external resistor circuit and the outputs of the solar cell electrode grid, the latter acting as an averaging distribution network over the surface. The statistical theory was confirmed using multi-crystalline Si solar cells.
Thermal stability and the magnetic properties of hybrid vanadium oxide-tetradecylamine nanotubes
Authors: Saleta M. E. , López C. A. , Granada M. , Troiani H. E. , Sánchez R. D. , Malta M. , Torresi R. M.
Published: September 2012

Vanadium oxide nanotubes (NTs) were synthesized by the sol-gel method followed by a long-term hydrothermal treatment. The obtained nanotubes have a multiwall structure, and 70% of vanadium ions are in the V4+ state. This percentage was derived by evaluating three components of the magnetic susceptibility; namely, (i) the paramagnetic Curie-Weiss behavior, (ii) antiferromagnetic dimers, and (iii) magnetic trimers. The as-made NTs were annealed in situ in the cavity of the electron paramagnetic resonance (EPR) spectrometer. The line shape changes irreversibly at 390 K, and the EPR susceptibility presents an anomaly at 425 K. These changes are interpreted as a partial oxidation of the V4+ ions and consequently a decrease in the concentration of the magnetic species. The quantification of the V4+ ions of the annealed NTs reveals a diminution to 39% of V4+, a weakening of the Curie-Weiss and antiferromagnetic dimers contributions, and the suppression of magnetic trimers. Vibrational studies confirm the decrease of V4+ amount.