bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predicting infinite periodic structure properties from finite structure models
Authors: Ethier J. , McNamara D. A. 
Published: July 2012

AbstractMany techniques have been proposed for determining the properties of a finite‐sized periodic structure from one consisting of the same elements and lattice, but infinite in size. In this article, we do the opposite, and describe an easily implemented moment method approach to determine the infinite structure properties from a related finite one, but importantly without the necessity of finding the current distribution on any element other than a single central one, and only having to find the solution of a matrix equation whose size is determined by the number of unknowns associated with the central element only. This is useful if one has access to a formulation (and source code) to analyze a single element and wish to know the properties of an infinite periodic structure comprised of such elements. Numerical validation is provided. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2416–2420, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27094
Estimating T1 from multichannel variable flip angle SPGR sequences
Authors: Trzasko Joshua D. , Mostardi Petrice M. , Riederer Stephen J. , Manduca Armando 
Published: July 2012

AbstractQuantitative estimation of T1 is a challenging but important task inherent to many clinical applications. The most commonly used paradigm for estimating T1 in vivo involves performing a sequence of spoiled gradient‐recalled echo acquisitions at different flip angles, followed by fitting of an exponential model to the data. Although there has been substantial work comparing different fitting methods, there has been little discussion on how these methods should be applied for data acquired using multichannel receivers. In this note, we demonstrate that the manner in which multichannel data is handled can have a substantial impact on T1 estimation performance and should be considered equally as important as choice of flip angles or fitting strategy. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Simultaneous multislice inversion contrast imaging using power independent of the number of slices (PINS) and delays alternating with nutation for tailored excitation (DANTE) radio frequency pulses
Authors: Koopmans Peter J. , Boyacioğlu Rasim , Barth Markus , Norris David G. 
Published: July 2012

AbstractA method for simultaneous multislice (SMS) inversion contrast imaging is presented using a combination of the delays alternating with nutation for tailored excitation (DANTE) and the power independent of the number of slices (PINS) techniques. In SMS imaging, simultaneously excited slices result in an aliased image that is disentangled using parallel imaging reconstruction techniques. At high‐magnetic field strengths, the peak amplitude and specific absorption rate of conventional (summed) SMS radio frequency pulses can be prohibitively high. Using the PINS approach, specific absorption rate is independent of the number of slices allowing high SMS acceleration factors even at high fields. Using DANTE, adiabatic SMS radio frequency pulses can be created to be combined with PINS. This allows 2D imaging protocols that employ adiabatic pulses to also reap the benefits of low specific absorption rate SMS acceleration. As a proof‐of‐concept, simulations and measurements using hyperbolic secant inversion pulses are shown. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Hybrid ultra‐low‐field MRI and magnetoencephalography system based on a commercial whole‐head neuromagnetometer
Authors: Vesanen Panu T. , Nieminen Jaakko O. , Zevenhoven Koos C. J. , Dabek Juhani , Parkkonen Lauri T. , Zhdanov Andrey V. , Luomahaara Juho , Hassel Juha , Penttilä Jari , Simola Juha , Ahonen Antti I. , Mäkelä Jyrki P. , Ilmoniemi Risto J. 
Published: July 2012

AbstractUltra‐low‐field MRI uses microtesla fields for signal encoding and sensitive superconducting quantum interference devices for signal detection. Similarly, modern magnetoencephalography (MEG) systems use arrays comprising hundreds of superconducting quantum interference device channels to measure the magnetic field generated by neuronal activity. In this article, hybrid MEG‐MRI instrumentation based on a commercial whole‐head MEG device is described. The combination of ultra‐low‐field MRI and MEG in a single device is expected to significantly reduce coregistration errors between the two modalities, to simplify MEG analysis, and to improve MEG localization accuracy. The sensor solutions, MRI coils (including a superconducting polarizing coil), an optimized pulse sequence, and a reconstruction method suitable for hybrid MEG‐MRI measurements are described. The performance of the device is demonstrated by presenting ultra‐low‐field‐MR images and MEG recordings that are compared with data obtained with a 3T scanner and a commercial MEG device. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
The Gilbert arborescence problem
Authors: Volz M. G. , Brazil M. , Ras C. J. , Swanepoel K. J. , Thomas D. A. 
Published: July 2012

AbstractWe investigate the problem of designing a minimum‐cost flow network interconnecting n sources and a single sink, each with known locations in a normed space and with associated flow demands. The network may contain any finite number of additional unprescribed nodes from the space; these are known as the Steiner points. For concave increasing cost functions, a minimum‐cost network of this sort has a tree topology, and hence can be called a Minimum Gilbert Arborescence (MGA). We characterize the local topological structure of Steiner points in MGAs, showing, in particular, that for a wide range of metrics, and for some typical real‐world cost functions, the degree of each Steiner point is 3. © 2012 Wiley Periodicals, Inc. NETWORKS, 2013
Epigenetic regulation of DACT2, a key component of the Wnt signalling pathway in human lung cancer
Authors: Jia Yan , Yang Yunsheng , Brock Malcolm V , Zhan Qimin , Herman James G , Guo Mingzhou 
Published: July 2012

AbstractDapper, Dishevelled‐associated antagonist of β‐catenin (DACT), is involved in Xenopus embryonic development. Human DACT2 is localized on chromosome 6q27, a region of frequent loss of heterozygosity (LOH) in human cancers. However, the function and regulation of DACT2 in human lung cancer remain unclear. DNA sequencing, methylation‐specific PCR (MSP), semi‐quantitative RT‐PCR, western blotting, and xenograft models were employed in this study. Eight lung cancer cell lines, 106 cases of primary lung cancer, four specimens of normal lung from patients without cancer, and 99 blood samples from healthy individuals were examined. We found that while there was no SNP related to lung cancer, the DACT2 promoter region is frequently methylated in human lung cancer. DACT2 is silenced by promoter region hypermethylation and re‐expressed by 5‐aza‐2′‐deoxyazacytidine treatment of lung cancer cell lines. Methylation of DACT2 was associated with poor differentiation of lung cancer. Loss of DACT2 expression was associated with promoter region hypermethylation in primary lung cancer, and was associated with increased β‐catenin expression. Restoration of DACT2 expression suppressed tumour proliferation both in vitro and in vivo. DACT2 expression was down‐regulated by siRNA knockdown in H727 cells. DACT2 inhibited T‐cell factor/lymphoid enhancer factor (TCF/LEF) and its downstream genes. In conclusion, DACT2 methylation is a potential lung cancer detection marker. DACT2 is regulated by promoter region hypermethylation. DACT2 inhibits lung cancer proliferation by suppressing the Wnt signalling pathway in lung cancer. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
A chiral polymer‐based turn‐on fluorescent sensor for specific recognition of hydrogen sulfate
Authors: Chen Dan , Lu Wei , Du Ganhong , Jiang Liming , Ling Jun , Shen Zhiquan 
Published: July 2012

AbstractA new kind of polymeric chemosensor containing chiral naphthaldimine moiety in the side chain was synthesized by the reversible addition‐fragmentation chain transfer polymerization of N‐{[2‐(4‐vinylbenzyloxy)‐1‐naphthyl]‐methylene}‐(S)‐2‐phenylglycinol (VNP). The resulting polymers (PVNP) showed high selectivity for hydrogen sulfate relative to other anions including F−, Cl−, Br−, H2PO, CH3CO, and NO in tetrahydrofuran (THF) solution as judged from UV−vis, fluorescence, and circular dichroism spectrophotometric titrations. Compared with its monomer, the polymer has proven to be more attractive for detection of HSO in terms of sensitivity and reproducibility. Upon addition of the anion it gives remarkable spectral responses concomitant with detectable color change from colorless to pale yellow. Furthermore, the HSO‐induced CD or fluorescence signal can be totally reversed with addition of base and eventually recovered the initial state, leading to a reproducible molecular switch with two distinguished “on” and “off” states. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Domain organization of XAF1 and the identification and characterization of XIAPRING‐binding domain of XAF1
Authors: Tse Man Kit , Cho Chi Kong , Wong Wai Fung , Zou Bing , Hui Sin Kam , Wong Benjamin Chun Yu , Sze Kong Hung 
Published: July 2012

AbstractX‐linked inhibitor of apoptosis protein (XIAP)‐associated factor 1 (XAF1) has been implicated as a novel tumor suppressor, which was proposed to exert pro‐apoptotic effect by antagonizing the anticaspase activity of XIAP. Here, we delineated the domain architecture of XAF1 by applying limited proteolysis and peptide mass fingerprinting analysis. Our results indicated that XAF1 has a distinct domain organization, with a highly compact N‐terminal domain (XAF1NTD) followed by a middle domain (XAF1MD), a 42‐residue unstructured linker and a C‐terminal domain (XAF1CTD). The search of XIAP binding region within XAF1 revealed that a modest affinity XIAPRING binding site (dissociation constant, Kd, ∼18 μM) is located at the C‐terminal portion of XAF1. This C‐terminal region, embracing XAF1CTD and a flexible tail at C‐terminus (residue Thr251‐Ser301), is functionally identified as XIAPRING‐binding domain of XAF1 (XAF1RBD) in the present study. We have also mapped the interaction sites for XAF1RBD on XIAPRING by using NMR spectroscopy. By applying in vitro ubiquitination assay, we observed that XAF1RBD/XIAP interaction is essential for the ubiquitination of GST‐XAF1RBD fusion protein. In addition, the C‐terminal XAF1 fragment harboring XAF1RBD was found to be substantially ubiquitinated by XIAPRING. Base on these observations, we speculate a possible role of XAF1RBD in targeting XAF1 for XIAP‐mediated ubiquitination.
Spin hamiltonian models for artificial and native water splitting systems revealed by hybrid DFT calculations. Oxygen activation by high‐valent Mn and Ru ions
Authors: Yamaguchi K. , Yamanaka S. , Isobe H. , Tanaka K. , Ueyama N. 
Published: July 2012

AbstractElectronic and spin states of putative ruthenium (Ru)–quinine(Q) complex(1) mononuclear[Ru(trpy)(3,5‐t‐Bu2Q)(OH2)(trpy = 2,2′:6′,2″‐terpyridine, 3,5‐di‐tert‐butyl‐1,2‐benzoquinone)(2) and binuclear [Ru2(btpyan)(3,6‐di‐Bu2Q)2(OH2)](SbF6)2 (btpyan = 1,8‐bis(2,2′:6′,2″‐terpyrid‐4′‐yl)anthracene,3,6‐t‐Bu2Q = 3,6‐di‐tert‐butyl‐1,2‐benzoquinone) (3) were investigated by broken‐symmetry (BS) hybrid density functional (DFT) methods. BS DFT computations for 3 have elucidated that the closed‐shell structure (3b): Ru(II)–quinone (Q) complex is less stable than the open‐shell structure (3bb) consisted of Ru(III) and semiquinone fragments. These computations have also elucidated eight different electronic and spin structures of tetraradical intermediates generated in the course of water splitting reaction. The Heisenberg spin Hamiltonian model has been derived to elucidate common theoretical pictures for these systems. Effective exchange interactions for four spin systems have been determined using total energies of the 15 different DFT functionals. The natural orbital (NO) analysis of these BS DFT solutions have also been performed to elucidate the NOs and their occupation numbers that are useful for lucid understanding of the nature of chemical bonds of these Ru complexes (1, 2, and 3). Implications of the computational results are discussed in relation to proposed reaction mechanisms of water splitting reaction in artificial photosynthesis systems, similarity between artificial and native water splitting systems, and elements science of water splitting reaction. © 2012 Wiley Periodicals, Inc.
Evaluation of diagnostic results by Bayes' theorem
Authors: Shindo Takatoshi , Takahashi Tsuguhiro , Okamoto Tatsuki , Kuraishi Takashi 
Published: July 2012

AbstractApplication of Bayes' theorem for the evaluation of diagnostic results of electric facilities is described. A concept of risk assessment method based on the diagnosis results is proposed and the effects of various parameters on the risk are clarified. Based on these results, a rational renewal scheme using diagnostic results is proposed. In addition, the prior probability based on the data of actual facilities is investigated and it is found that the data available so far is insufficient and more data are required for the detailed analysis. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Prediction of early and late pre‐eclampsia from maternal characteristics, uterine artery Doppler and markers of vasculogenesis during first trimester of pregnancy
Authors: Parra‐Cordero M. , Rodrigo R. , Barja P. , Bosco C. , Rencoret G. , Sepúlveda‐Martinez A. , Quezada S. 
Published: July 2012

ABSTRACTObjectiveTo develop a predictive model for pre‐eclampsia using clinical, biochemical and ultrasound markers during the first trimester of pregnancy.MethodsThis was a nested case–control study within a pre‐eclampsia screening project that involved 5367 asymptomatic pregnant women undergoing routine transvaginal uterine artery (UtA) Doppler at 11 + 0 to 13 + 6 weeks. Following exclusions, there were 70 pregnant women who later developed pre‐eclampsia and 289 control patients enrolled during the first trimester who had serum or plasma samples taken at enrolment available for the purposes of this study. Of these, 17 pregnancies were diagnosed with early‐onset (delivery < 34 weeks) pre‐eclampsia and 53 with late‐onset (delivery ≥ 34 weeks) pre‐eclampsia. The lowest, highest and mean of left and right UtA pulsatility indices (PI) were calculated. Blood samples were stored at −84 °C until biochemical analysis for markers of vasculogenesis was performed. The distributions of the lowest UtA‐PI and the biochemical markers were adjusted for maternal characteristics, expressed as multiples of the median (MoM), and compared between groups. Logistic regression analysis was used to evaluate if any variable was significantly associated with pre‐eclampsia.ResultsPregnancies that later developed pre‐eclampsia were associated with higher maternal prepregnancy body mass index. An increased lowest UtA‐PI was significantly associated with both early‐ and late‐onset disease. Placental growth factor (PlGF) MoM was significantly reduced in women who later developed early‐ or late‐onset pre‐eclampsia compared with controls (median (interquartile range), 0.69 (0.33–1.46) and 1.10 (0.39–1.56), respectively, vs 1.19 (0.65–1.84), P < 0.05). Different combined models were generated by logistic regression analysis, and the detection rate with a fixed 10% false‐positive rate was 47% and 29% for early‐ and late‐onset pre‐eclampsia, respectively.ConclusionPregnancies that later developed early or late pre‐eclampsia were characterized by impaired placentation and an anti‐angiogenic state during the first trimester of pregnancy. Regression models which include maternal characteristics, UtA Doppler and PlGF can apparently predict approximately half of pregnancies that will be complicated by early‐onset pre‐eclampsia. We believe more research in several areas is needed to aid in the creation of a better and more population‐specific screening test for pre‐eclampsia during the first trimester of pregnancy. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Expanding the Series of [RE2Ca(OQ)8] Structures: New Heterobimetallic Rare Earth/Alkaline Earth 8‐Quinolinolate Complexes
Authors: Deacon Glen B. , Junk Peter C. , Leary Stuart G. , Urbatsch Aron 
Published: July 2012

AbstractAbstract. A series of heterobimetallic complexes [RE2Ca(OQ)8]·nHOQ(RE = Sm, Gd, Tb, Ho, Tm, Yb, Lu, Y, Sc) and the isostructural [Gd2Mg(OQ)8] were synthesised and structurally characterised. They were mainly obtained after direct reactions of the elemental rare earth metals with calcium metal in the presence of 8‐hydroxyquinoline (HOQ) and a 1, 3, 5‐tri‐tert‐butyl‐benzene (tBuB) flux, and some complexes were synthesised by pseudo solid‐state rearrangement reactions between powdered RE(OQ)3 and AE(OQ)2 (AE = Mg, Ca) in a 1, 2, 4, 5‐tetramethylbenzene (TMB) flux, at elevated temperatures. The linear trinuclear [RE2Ca(OQ)8] moieties show a six‐coordinate central calcium atom flanked by two eight‐coordinate rare earth atoms surrounded by six chelating‐bridging OQ and two terminal chelating OQ ligands. The structurally novel [Sc2Ca(OQ)8] has a bent Sc‐Ca‐Sc backbone and exhibits an eight‐coordinate central calcium and two seven‐coordinate scandium ions.
Foliar herbivory and its effects on plant growth in native and exotic species in the Patagonian steppe
Authors: Pirk Gabriela Inés , Farji‐Brener Alejandro G. 
Published: July 2012

AbstractStudies of herbivory and its consequences on the growth of native and exotic plants could help elucidate some processes involved in plant invasions. Introduced species are likely to experience reduced herbivory in their new range due to the absence of specialist enemies and, thus, may have higher benefits if they reduce the investment in resistance and increase their compensatory capacity. In order to evaluate the role of herbivory in disturbed areas within the Patagonian steppe, we quantified and compared the leaf levels of herbivory of four native and five exotic species and recorded the associated insect fauna. We also performed greenhouse experiments in which we simulated herbivory in order to evaluate the compensatory capacity of native and exotic species under different herbivory levels that resembled naturally occurring damage. Natural herbivory levels in the field were similar between the studied exotic and native plants. Field observations confirmed that they both shared some herbivore insects, most of which are generalists. In the greenhouse experiments, both exotic and native plants fully compensated for herbivory. Our results suggest that the studied exotic plants are not released from herbivory in the Patagonian steppe but are able to fully compensate for it. The capacity to recover from herbivory coupled with other potential adaptations, such as a better performance under disturbance and greater competitive ability than that of the native species, may represent some of the mechanisms responsible for the success of plant invasion in the Patagonian steppe.
Genetische Epidemiologie: Über kleine und große genetische Risiken
Authors: Heid Iris M. 
Published: July 2012

Einleitung
Die Genetische Epidemiologie untersucht genetische Komponenten für komplexe Erkrankungen und deren Interaktionen mit nicht-genetischen Faktoren. In den letzten Jahren war die Methode der genomweiten Assoziationsstudien sehr erfolgreich, um zahlreiche Genorte für komplexe Erkrankungen zu identifizieren. Am Beispiel der altersbedingten Maculadegeneration und der Adipositas wird dargelegt, wie groß diese genetischen Effekte sind.
Experimental characterization of three-dimensional corner flows at low Reynolds numbers
Authors: Sznitman J. , Guglielmini L. , Clifton D. , Scobee D. , Stone H. A. , Smits A. J. 
Published: July 2012

AbstractWe investigate experimentally the characteristics of the flow field that develops at low Reynolds numbers ($\mathit{Re}\ll 1$) around a sharp $9{0}^{\ensuremath{\circ} } $ corner bounded by channel walls. Two-dimensional planar velocity fields are obtained using particle image velocimetry (PIV) conducted in a towing tank filled with a silicone oil of high viscosity. We find that, in the vicinity of the corner, the steady-state flow patterns bear the signature of a three-dimensional secondary flow, characterized by counter-rotating pairs of streamwise vortical structures and identified by the presence of non-vanishing transverse velocities (${u}_{z} $). These results are compared to numerical solutions of the incompressible flow as well as to predictions obtained, for a similar geometry, from an asymptotic expansion solution (Guglielmini et al., J. Fluid Mech., vol. 668, 2011, pp. 33–57). Furthermore, we discuss the influence of both Reynolds number and aspect ratio of the channel cross-section on the resulting secondary flows. This work represents, to the best of our knowledge, the first experimental characterization of the three-dimensional flow features arising in a pressure-driven flow near a corner at low Reynolds number.
New genetic resource in Capsicum L. from Eastern Himalayas
Authors: Baran Jha Timir , Dafadar Arpita , Ghorai Animesh 
Published: July 2012

A well-documented karyo-morphological analysis has been presented in one unexplored cultivar of Capsicum annuum L., collected from South Sikkim, India, to determine the chromosome number. This report confirms that the cultivar contains 2n = 48 chromosomes, which are not produced through self-duplication. More studies are required to determine its actual taxonomic position and genetic relationship with other cultivars and species. This cultivar of C. annuum provides a new, unexplored genetic resource with a high chromosome number.
Functional Characterization of the GATA Transcription Factors GNC and CGA1 Reveals Their Key Role in Chloroplast Development, Growth, and Division in Arabidopsis
Authors: Chiang Yi-Hsuan , Zubo Yan O. , Tapken Wiebke , Kim Hyo Jung , Lavanway Ann M. , Howard Louisa , Pilon Marinus , Kieber Joseph J. , Schaller G. Eric 
Published: July 2012

Abstract
Chloroplasts develop from proplastids in a process that requires the interplay of nuclear and chloroplast genomes, but key steps in this developmental process have yet to be elucidated. Here, we show that the nucleus-localized transcription factors GATA NITRATE-INDUCIBLE CARBON-METABOLISM-INVOLVED (GNC) and CYTOKININ-RESPONSIVE GATA1 (CGA1) regulate chloroplast development, growth, and division in Arabidopsis (Arabidopsis thaliana). GNC and CGA1 are highly expressed in green tissues, and the phytohormone cytokinin regulates their expression. A gnc cga1 mutant exhibits a reduction in overall chlorophyll levels as well as in chloroplast size in the hypocotyl. Ectopic overexpression of either GNC or CGA1 promotes chloroplast biogenesis in hypocotyl cortex and root pericycle cells, based on increases in the number and size of the chloroplasts, and also results in expanded zones of chloroplast production into the epidermis of hypocotyls and cotyledons and into the cortex of roots. Ectopic overexpression also promotes the development of etioplasts from proplastids in dark-grown seedlings, subsequently enhancing the deetiolation process. Inducible expression of GNC demonstrates that GNC-mediated chloroplast biogenesis can be regulated postembryonically, notably so for chloroplast production in cotyledon epidermal cells. Analysis of the gnc cga1 loss-of-function and overexpression lines supports a role for these transcription factors in regulating the effects of cytokinin on chloroplast division. These data support a model in which GNC and CGA1 serve as two of the master transcriptional regulators of chloroplast biogenesis, acting downstream of cytokinin and mediating the development of chloroplasts from proplastids and enhancing chloroplast growth and division in specific tissues.