bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fast and direct screening of polyaromatic hydrocarbon (PAH)‐contaminated sand using a miniaturized membrane inlet mass spectrometer (mini‐MIMS)
Authors: Frandsen Helle , Janfelt Christian , Lauritsen Frants R. 
Published: April 2007

AbstractA miniaturized membrane inlet mass spectrometer (mini‐MIMS; total weight 10 kg everything included) was equipped with a small sample cell using a flat sheet silicone membrane mounted close to the ionizing region of a multipole mass spectrometer. Spiked sand samples were placed in small stainless steel vials and dropped into the heated sample cell (>150°C). A hole in the vial in front of the membrane and above the sand made it possible for the polyaromatic hydrocarbon (PAH) residuals to penetrate the membrane and enter the mass spectrometer as they evaporated from the sample. Using this simple setup we were able to quantitatively (≈10% relative standard deviation (RSD)) detect PAHs with up to five aromatic rings and with detection limits in the low parts‐per‐million (ppm) range. The vial system solves one of the major difficulties in analysis of larger PAHs using a MIMS. Normally, analysis of PAHs with more than two rings is hampered by a long memory effect due to the sticking of the PAHs to the inlet system, the membrane and surfaces in the vacuum system. By removing the vial from the sample cell within 2 min, we were able to analyze samples at 5–10 min intervals. The preliminary laboratory experiments presented here show much promise with respect to the development of a hand held (<10 kg) on‐site mass spectrometry system for PAH screening at contaminated sites. Copyright © 2007 John Wiley & Sons, Ltd.
Study on ion formation in electrospray droplet impact secondary ion mass spectrometry
Authors: Asakawa Daiki , Fujimaki Susumu , Hashimoto Yutaka , Mori Kunihiko , Hiraoka Kenzo 
Published: April 2007

AbstractA new type of cluster secondary ion mass spectrometry (SIMS), named electrospray droplet impact (EDI), has been developed in our laboratory. In general, rather strong negative ions as well as positive ions can be generated by EDI compared with conventional SIMS. In this work, various aspects of ion formation in EDI are investigated. The Brønsted bases (proton acceptor) and acids (proton donor) mixed in the analyte samples enhanced the signal intensities of deprotonated molecules (negative ions) and protonated molecules (positive ions), respectively, for analytes. This suggests the occurrence of heterogeneous proton transfer reactions (i.e. M + M′ → [M+H]+ + [M′H]−) in the shockwave‐heated selvedge of the colliding interface between the water droplet and the solid sample deposited on the metal substrate. EDI‐SIMS shows a remarkable tolerance to the large excess of salts present in samples. The mechanism for desorption/ionization in EDI is much simpler than those for MALDI and SIMS because only very thin sample layers take part in the shockwave‐heated selvedge and complicated higher‐order reactions are largely suppressed. Copyright © 2007 John Wiley & Sons, Ltd.
Academic and informal science education practitioner views about professional development in science education
Authors: Astor‐Jack Tamsin , McCallie Ellen , Balcerzak Phyllis 
Published: April 2007

AbstractThis study documents the views of effective professional development held by eight professional development (PD) providers, representing four informal science institutions (ISI) and four programs within two institutions of higher education (IHE) in a large midwestern metropolitan area in the United States. This study finds that, while the reported learning and outcome agendas of the providers were similar across the board, a dichotomy in approach to PD emerged according to the type of institution. This dichotomy between ISI and IHE was persistent across thematic categories: (1) language use and meaning, (2) teacher outcomes as a result of PD, (3) resource strengths for teaching and learning, and (4) determination of content and course offerings. The significance of this research is threefold. First, the identification and characterization of important features of teacher PD in ISI is an important contribution to the PD literature, since most previous studies focus on IHE. Second, this study elucidates important differences between the two types of providers with respect to their views of inquiry, currently a fundamental component of PD for science teachers. Third, previously unreported gaps and overlaps in belief systems of PD from two institutions types, ISI and IHE, are identified. © 2007 Wiley Periodicals, Inc. Sci Ed 91:604–628, 2007
Similarity of software system and its measurement tool SMMT
Authors: Yamamoto Tetsuo , Matsushita Makoto , Kamiya Toshihiro , Inoue Katsuro 
Published: April 2007

AbstractGiven two software systems, it is important to be able to objectively know how much those systems differ. However, it has not been easy to quantitatively measure the mutual differences between two systems. In this paper, the authors introduced similarity metrics for the similarity between software systems and the Similarity Metrics Measuring Tool (SMMT) for measuring them and applied SMMT to the source code of various UNIX‐type operating systems. They also performed a cluster analysis from the similarities of the source code of those operating systems to create a dendogram and checked whether the operating systems were classified correctly. The results confirmed that the similarity was an effective index for determining operating system transitions and that the family tree that was obtained represented the classification of the operating systems according to their derivations. © 2007 Wiley Periodicals, Inc. Syst Comp Jpn, 38(6): 91–99, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10379
Signal processing for brain temperature change detection by noninvasive measurement: An independent component analysis approach
Authors: Wakuya Hiroshi , Yamashita Kazuo , Shida Katsunori 
Published: April 2007

AbstractThe distribution of temperature inside the brain is an important piece of information for investigating brain activity. Up to now, various kinds of noninvasive measurement techniques have been proposed. Among them, there is a technique that treats the human head as a dielectric material and then makes use of the temperature dependence of this material. One of its major problems is that accurate numerical measurements of the brain temperature might not be possible because the entire brain is surrounded by the skull, which has a relatively low permittivity. It has been reported that when blood flow stops due to brain death, the brain temperature changes in response to external temperature variations, and the response of the brain and skull are thought to differ. This paper focuses on this point in particular, and attempts to separate the brain and skull signals based on an independent component analysis (ICA) approach. In order to mimic this situation, a full human head model is constructed that incorporates the two components from the brain and skull, and the differences in the impedance per unit length in response to external variations in temperature are treated as the original signals. Two different electrode configurations that have different brain and skull component ratios are provided, and the total potential difference between the electrodes when they are connected to a constant current power source is measured. ICA is then applied to the two observed signals. The results reveal that although a problem arises whereby the amplitudes of the restored signals are attenuated compared to the original signals, the waveforms are exceptionally similar, demonstrating the validity of the proposed method. © 2007 Wiley Periodicals, Inc. Syst Comp Jpn, 38(6): 80–90, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20232
A model of complex cell development by information separation
Authors: Date Akira , Kurata Koji 
Published: April 2007

AbstractNeurons in the primary visual cortex (V1) of primates are selective for location, orientation, and spatial frequency. Among them, complex cells are characterized by their selectivity to orientation and spatial frequency while lacking sensitivity to position or phase tuning (dark/bright line center) within a restricted range. The development of the shift invariance property of complex cells has been successfully explained by the temporal trace learning which takes advantage of the temporal coherence of visual stimuli (P. Földiák, Neural Computation 1991;3:194). We have carried out mathematical modeling of complex cell development without temporal trace mechanism. The model network consists of three layers of E, S, and C layer which model excitatory cells in LGN or V1, and simple cells, and complex cells in V1, respectively. Neurons in layer E have position selectivity, and neurons in layer S are line detectors for a specific position. During the learning phase, the network is exposed to randomly located short oriented bars, and neurons in layer C self‐organize its selectivity to the inputs. The learning rules are Hebbian or SOM (self‐organizing map) type between layers S and C, and anti‐Hebbian between layers E and C by which neurons are forced to represent uncorrelated aspect of the inputs. We demonstrate that neurons in layer C learn invariance to shift in input position. Our model explains complex cell development in terms of the principle of information separation. © 2007 Wiley Periodicals, Inc. Syst Comp Jpn, 38(7): 76– 83, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20483
Preparation for smooth pursuit eye movement based on expectation in humans
Authors: Tabata Hiromitsu , Miura Kenichiro , Kawano Kenji 
Published: April 2007

AbstractIt has been reported that a brief movement of a target during fixation elicited larger eye movement when primates were anticipating future smooth pursuit than when they were not, suggesting that the gain of visuomotor transmission was increased in association with the preparation for future tracking. Here, in order to investigate how the expectation for future tracking affects our preparation for smooth pursuit, we observed human eye movements elicited by a brief movement of a target when the probability to be required pursuit (target motion probability) was 0, 0.25, 0.5, 0.75, and 1. We found that the response to a brief target movement was continuously increased as the probability increased. This result suggests that the pursuit system determines the gain before the start of pursuit in accordance with the anticipated future need for tracking. We also showed that the relationship between the gain and the target motion probability could be derived from minimization of the trial‐by‐trial prediction error, suggesting that the preparatory gain was determined based on the least‐squares optimization. © 2007 Wiley Periodicals, Inc. Syst Comp Jpn, 38(6): 1–9, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20677 Copyright © 2004 Wiley Periodicals, Inc.
A fast algorithm for hyperplane‐intersection method on image registration
Authors: Chang Soonkeun , Shimizu Masao , Okutomi Masatoshi 
Published: April 2007

AbstractThis study presents an alternative method to estimate the motion parameters for the gradient‐based method. The proposed method is a faster version of a hyperplane‐intersection method. The hyperplane‐intersection method estimates the motion parameters between images as an intersection position of estimated hyperplanes in a parameter space. The hyperplanes approximate the zero positions of the partial derivatives of a continuous similarity measure with respect to each parameter. The method employs a straightforward computation to estimate the parameters, instead of using an iterative framework. The non‐iterative method could be suitable for hardware implementation. The method is the region‐ and intensity‐based technique using any dissimilarity or similarity measure such as sum of squared differences (SSD) or zeromean normalized cross correlation (ZNCC), which can be selected adequately in consideration of a property of input image sequence and a required computation time. The faster version of the method is realized with precomputed warped images of the template, which reduce the computational cost for each input frame. This study also compares the computational cost and the accuracy of the estimated parameters of the proposed algorithm with the gradient descent method. Experiments using synthesized‐motion sequences and real image sequences are performed to confirm the comparisons. The SSD and ZNCC are used for the faster version of the hyperplane‐intersection method to overcome a nonuniform illumination change in the image sequences to demonstrate the effectiveness of the method. © 2007 Wiley Periodicals, Inc. Syst Comp Jpn, 38(7): 23– 33, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20703
Analysis of a binary composite endpoint with missing data in components
Authors: Quan Hui , Zhang Daowen , Zhang Ji , Devlamynck Laure 
Published: April 2007

AbstractComposite endpoints are often used in clinical trials in order to increase the overall event rates, reduce the sizes of the trials and achieve desired power. For example, in a trial to study the effect of a treatment on the prevention of venous thromboembolic events after a major orthopaedic surgery of the lower limbs, the primary endpoint is usually a composite endpoint consisting of any deep vein thrombosis identified by systematic venography of lower limbs, symptomatic and well‐documented non‐fatal pulmonary embolism, and death from all causes. Just as any endpoints, missing data can occur in the components of the composite endpoint. If a patient has missing data on some of the components but not all the components, this patient may not have complete data but partial data for the composite endpoint. To be consistent with the intention‐to‐treat
principle, the patient should not be discarded from the analysis. In this research, we propose an approach for the analysis of a composite endpoint with missing data in components. The main idea is to first derive the probabilities of all possible study outcomes based on the appropriate model and then to construct the overall rate for the composite endpoint. Simulations are conducted to compare the approach with several naïve methods. A data example is used to illustrate the application of the approach. Copyright © 2007 John Wiley & Sons, Ltd.
Islamic takaful: Business models, Shariah concerns, and proposed solutions
Authors: Wahab Abdul Rahim Abdul , Lewis Mervyn K. , Hassan M. Kabir 
Published: April 2007

AbstractIslamic insurance (takaful) is nearly as old as the Islamic banking system and dates back to 1979, when the concept was launched in Sudan and later in Saudi Arabia. Yet, unlike its banking counterpart, takaful has been covered less in the literature on Islamic finance, and its workings are not fully understood. Shariah scholars have raised a num‐ber of concerns about the Shariah permissibility of the business models employed in the industry. This article examines the basic principles of takaful and then analyzes the mechanics of the two models most commonly used in the industry— namely, the mudarabah system that was developed by the Malaysians and the wakala (agency) system that is now being used by most takaful operators and has achieved tremendous popularity and acceptance in recent years even in countries where the mudarabah model was earlier implemented. Shariah scholars have, however, expressed some misgivings about both approaches, but because of its wider acceptability among Shariah scholars in the case of the wakala approach, this is more urgent. With regards to the mudarabah model for risk management, there are major discrepancies that have been highlighted by Shariah scholars effec‐tively rendering it inappropriate to apply this for insurance contracts. For this reason, the article outlines a third model, a wakala with waqf fund, that seeks to remain within the wakala framework while incorpo‐rating modifications that may render it more acceptable from a Shariah perspective. © 2007 Wiley Periodicals, Inc.
Two‐acceptor levels in the band gap of boron‐doped diamond semiconductors analyzed by soft x‐ray absorption spectroscopy and DV–Xα calculations
Authors: Muramatsu Yasuji , Takebe Toshihiko , Sawamura Akitaka , Iihara Junji , Nanba Akihiko , Imai Takahiro , Denlinger Jonathan D. , Perera Rupert C. C. 
Published: April 2007

AbstractTo clarify the electronic structure of semiconducting boron‐doped diamond, especially the two‐acceptor levels observed in the soft x‐ray absorption spectra in the C K region, the density of states (DOS) of a B‐doped diamond cluster model, BC146H148, were calculated using discrete variational (DV)‐Xα MO methods. The results were compared to the measured x‐ray spectra. In the calculations, the localized acceptor levels (lowest unoccupied molecular orbitals: (LUMOs)) appeared just above the highest occupied molecular orbitals (HOMOs) of the C atom that was directly bonded to the B atom, and the other C atoms that were bonded to the C atoms next to the B atom. However, a chemical shift of the LUMOs was not observed between the C atoms. On the other hand, a chemical shift of the occupied C 1s orbitals was observed between these C atoms. Therefore, it is concluded that the two‐acceptor levels in the C atoms result from the chemical shift of the inner C 1s orbitals due to the local structure differences between the C atoms in B‐doped diamond. Copyright © 2007 John Wiley & Sons, Ltd.
XANES analysis of Fe valence in iron gall inks
Authors: Arčon Iztok , Kolar Jana , Kodre Alojz , Hanžel Darko , Strlič Matija 
Published: April 2007

AbstractIn this study, we investigate the feasibility and reliability of Fe K‐edge XANES spectroscopy as a tool in determination of Fe2+/Fe3+ ratio in historic inks. We have measured Fe K‐edge XANES spectra of several historic and model iron gall inks with different Fe2+/Fe3+ ratios, together with some standard reference Fe2+ and Fe3+ compounds with known local atomic structure and symmetry around Fe atoms. We examine different approaches to determine relative amount of Fe2+ in iron gall inks from the Fe K‐edge shifts, and demonstrate that a proper choice of the Fe reference compounds with similar symmetry, same type of neighbour atoms in nearest coordination shells, arranged in a similar local structure is crucial for the absolute calibration of the Fe K‐edge shift and consequently a reliable determination of Fe2+/Fe3+ ratio in the sample. Best results, with the accuracy of ± 2%, are obtained by a linear combination fit with XANES spectrum of FeSO4· 7H2O as a reference for Fe2+ and spectrum of an iron gall ink containing predominantly Fe3+. Copyright © 2007 John Wiley & Sons, Ltd.
Dietary long‐chain polyunsaturated fatty acid supplementation in infants with phenylketonuria: a randomized controlled trial
Authors: Koletzko B. , Sauerwald T. , Demmelmair H. , Herzog M. , von Schenck U. , Böhles H. , Wendel U. , Seidel J. 
Published: April 2007

SummaryBackgroundPre‐ and postnatal tissue accretion of long‐chain polyunsaturated fatty acids (LCPUFA) has been related to visual and cognitive development in healthy children in several studies. Children with phenylketonuria (PKU) consume diets with very low contents of preformed LCPUFA. We studied prospectively the LCPUFA status in infants with PKU without or with LCPUFA supplementation during the first year of life.Subjects and methodsInfants with PKU were enrolled at diagnosis (<4 weeks of age) and randomized double blind to phenylalanine‐free amino acid supplements without LCPUFA (n=11) or with both arachidonic (AA, 0.46 wt%) and docosahexaenoic acids (DHA, 0.27 wt%) (n=10). At enrolment and again at 1, 2, 3, 4, 6, 9 and 12 months, plasma phospholipid fatty acids were measured and dietary intakes were calculated from dietary protocols.ResultsUnsupplemented patients showed a marked LCPUFA depletion to levels clearly below those observed in healthy breast‐fed infants. In contrast, supplemented infants had stable and higher LCPUFA levels than unsupplemented infants, reaching significant differences for AA values at 3, 4 and 6 months, and for DHA values at 1, 3, 4, 6, 9 and 12 months. Plasma phospholipid levels correlated closely with estimated dietary intakes of preformed LCPUFA.ConclusionLow LCPUFA intakes with PKU diets induce marked depletion of AA and particularly of DHA in the first year of life. Thus endogenous synthesis of LCPUFA from precursors supplied by diet seems unable to compensate for low LCPUFA intakes. LCPUFA supplementation of PKU diets during the first year of life effectively enhances LCPUFA status to levels comparable to those of healthy breast‐fed infants.
NON-COMMUTATIVE CHARACTERISTIC POLYNOMIALS AND COHN LOCALIZATION
Authors: SHEIHAM DESMOND 
Published: April 2007

Almkvist proved that for a commutative ring A the characteristic polynomial of an endomorphism α : P → P of a finitely generated projective A-module determines (P, α) up to extensions. For a
non-commutative ring A the generalized characteristic polynomial of an endomorphism of an endomorphism α : P → P of a finitely generated projective A-module is defined to be the Whitehead torsion [1 − xα] ∈ K1(A[[x]]), which is an equivalence
class of formal power series with constant coefficient 1.The paper gives an example of a non-commutative ring A and an endomorphism α : P → P for which the
generalized characteristic polynomial does not determine (P, α) up to extensions. The
phenomenon is traced back to the non-injectivity of the natural map [sum ]−1A[x] → A[[x]] where [sum ]−1A[x] is the Cohn localization of A[x] inverting the set [sum ] of matrices in A[x] sent to an invertible matrix by A[x] → A;x [map ] 0.
Evolutionary diversity in polystomatids infecting tetraploid and octoploid Xenopus in East African highlands: biological and molecular evidence
Authors: JACKSON J. A. , TINSLEY R. C. 
Published: April 2007

SUMMARYSpecies of Protopolystoma are monogenean flukes that only infect allopolyploid hosts in the anuran genus Xenopus. Multivariate analyses of morphometric sclerite characters in the nominal species Protopolystoma simplicis suggest that morphologically distinguishable populations occur in the tetraploid host, Xenopus laevis victorianus, and in each of the octoploid hosts, X. vestitus and X. wittei. The species-level divergence of a lineage specific to X. laevis is supported by sequence variation in the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. Protopolystoma simplicis from X. laevis is redesignated P. microsclera n. sp., with P. simplicis being retained for populations in octoploid hosts. This division is consistent with large differences in egg hatching schedule, fixed differences at the mannose-6-phosphate isomerase and fumarate hydratase loci, and host-specificity in experimental analyses. Although the respective P. simplicis populations in X. vestitus and X. wittei also show significant diversity in allozyme expression, morphometrics and egg hatching schedule, they are retained in the same species because their level of mitochondrial DNA divergence is similar to that found within other Protopolystoma species. The consequences of splitting P. simplicis for a recent interpretation of the origin of Protopolystoma faunas in octoploid Xenopus spp. is discussed.