bluuebunny/crossref_metadata_2025 huggingface dataset:
COMPARATIVE VALIDITY OF MULTIPLE‐CHOICE AND FREE‐RESPONSE ITEMS ON THE ADVANCED PLACEMENT EXAMINATION IN BIOLOGY
Authors: Bridgeman Brent
Published: September 2014

The Advanced Placement (AP) Program reports grades to students and colleges on a 1‐to‐5‐point scale derived by combining the separate scores on the multiple‐choice and free‐response sections of AP Examinations.

Predictions of grades in first‐semester college biology courses were made based on students' separate performances on the multiple‐choice and essay portions of the Advanced Placement Examination in Biology. In a sample of 432 students from 11 colleges, the multiple‐choice scores appeared to be more closely correlated to college grades. However, when analyses were run separately according to the gender of the candidate, performance on both the objective and the essay items predicted grades equally well for males (r [the correlation coefficient pooled across colleges] =.44 for the objective items and .46 for the essay section), whereas for females, predictions based on the essay portion were significantly less accurate (.49 versus .29). The current practice of reporting AP grades based on a combination of both essay and multiple‐choice test scores yields correlations that are generally higher and more comparable across gender than would be the case if only essays were used.
AN EVALUATION OF A KIT TO PREPARE HISPANIC STUDENTS FOR THE PSAT/NMSQT
Authors: Pennock‐Roman Maria , Powers Donald E. , Perez Monte
Published: September 2014

A collaborative effort to improve access to college for Hispanic youth on the part of the College Board, Educational Testing Service (ETS), and the Hispanic Higher Education Coalition resulted in a test‐familiarization pilot kit titled Preparing for the PSAT/NMSQT for Hispanic High School Students. The kit contains practice tests for the Preliminary Scholastic Aptitude Test/National Merit Scholarship Qualifying Test, 22 lesson plans that cover test‐taking skills, and a review of selected mathematics and English grammar concepts. The kit was designed to facilitate formal instruction by counselors and teachers at the junior and senior high school levels. It can also be used in college recruitment programs to help disadvantaged students prepare for other college admissions tests like the SAT. The current version is now titled Testskills: For Teachers of Hispanic Students.

This report is meant to provide some modest information about students' and teachers' reactions to a pilot version of the kit. In addition to describing the kit and how it was used in a number of school districts over the past year, we look at two key questions: (1) whether the test‐familiarization kit increased students' confidence and lessened their anxiety about test‐taking, and (2) whether the kit increased the likelihood that students would take the PSAT/NMSQT.

The project outlined here was not intended to be a rigorous experimental evaluation of how the kit affected student attitudes or posttreatment test scores. An evaluation of this nature would require control groups and standardized instruction across sites. In the present project, it was not possible to control design of the programs or how the kit was used.

Most targeted school districts were in California, where recent legislation (the Tanner Act) provided funding for demonstration sites to help disadvantaged students become more familiar with college admissions tests. These districts designed their own programs and, in addition to using the kit, incorporated other activities related to test preparation. Thus, it was not possible to separate the effects of the kit from the effects of the other activities. Therefore, the emphasis of this evaluation is on perceptions of the extent to which the kit was helpful. This information may have some value for refining the kit as new editions are produced and for helping to inform potential users of ways the kit may be used most effectively.
THE STANDARD ERROR OF EQUATING FOR THE KERNEL METHOD OF EQUATING SCORE DISTRIBUTIONS
Authors: Holland Paul W. , King Benjamin F. , Thayer Dorothy T.
Published: September 2014

Formulas for the standard error of equating (SEE) for a new equating technique, the kernel method, are developed in detail for three equating designs –two random groups, external anchor‐test and internal anchor‐test. The kernel method includes both linear and equipercentile methods as special cases. The SEEs developed in this paper make crucial use of log‐linear models to presmooth (i.e. estimate) score distributions. The resulting SEEs reflect the method of estimation, the equating design and the final shape of the resulting equating function. An example is given that compares the SEEs for several applications of the kernel method.
CLASSES OF MULTIVARIATE EXPONENTIAL AND MULTIAVARIATE GEOMETRIC DISTRIBUTIONS DERIVED FROM MARKOV PROCESSES
Authors: Longford Nicholas T.
Published: September 2014

We define a class of multivariate exponential distributions as the distributions of occupancy times in upwards skip‐free Markov processes in continuous time. These distributions are infinitely divisible, and the multivariate gamma class defined by convolutions and fractions is a substantial generalization of the class defined by Johnson & Kotz (1972). Parallel classes of multivariate geometric and multivariate negative binomial distributions are constructed from occupancy times in ‘instant’ upwards skip‐free Markov chains. Maximum likelihood estimation and times series applications are discussed.
A NOTE ON THE COVARIANCE OF THE MANTEL‐HAENSZEL LOG‐ODDS RATIO ESTIMATOR AND THE SAMPLE MARGINAL RATES
Authors: Holland Paul W.
Published: September 2014

A simple technique, developed in Phillips (1987), is used to approximate Cov(, p̂i) i = 1,2 where is the Mantel‐Haenszel log‐odds‐ratio estimator for a 2×2×K table and the p̂i are the sample marginal proportions. These results are then applied to obtain an approximate variance estimate of an adjusted risk difference based on the Mantel‐Haenszel odds‐ratio estimator.
Ensemble multivariate analysis to improve identification of articular cartilage disease in noisy Raman spectra
Authors: Richardson Wade , Wilkinson Dan , Wu Ling , Petrigliano Frank , Dunn Bruce , Evseenko Denis
Published: September 2014

The development of new methods for the early diagnosis of cartilage disease could offer significant improvement in patient care. Raman spectroscopy is an emerging biomedical technology with unique potential to recognize disease tissues, though difficulty in obtaining the samples needed to train a diagnostic and excessive signal noise could slow its development into a clinical tool. In the current report we detail the use of principal component analysis – linear discriminant analysis (PCA‐LDA) on spectra from pairs of materials modeling cartilage disease to create multiple spectral scoring metrics, which could limit the reliance on primary training data for identifying disease in low signal‐to‐noise‐ratio (SNR) Raman spectra. Our proof‐of‐concept experiments show that combinations of these model‐metrics has the potential to improve the classification of low‐SNR Raman spectra from human normal and osteoarthritic (OA) cartilage over a single metric trained with spectra from the same healthy and OA tissues.

Scatter plot showing the PCA‐LDA derived human‐disease‐metric scores versus rat‐model‐metric scores for 7656 low signal‐to‐noise spectra from healthy (blue) and osteoarthritic (red) cartilage. Light vertical and horizontal lines represent the optimized single metric classification boundary. Dark diagonal line represents the classification of boundary resulting from the optimized combination of the two metrics. Abbreviations: er (error rate), PCA‐LDA (principal component analysis – linear discriminant analysis), HOA (human osteoarthritis), HAC (human articular cartilage), RIF (rat injury fibrocartilage), RAC (rat articular cartilage).

magnified image

Scatter plot showing the PCA‐LDA derived human‐disease‐metric scores versus rat‐model‐metric scores for 7656 low signal‐to‐noise spectra from healthy (blue) and osteoarthritic (red) cartilage. Light vertical and horizontal lines represent the optimized single metric classification boundary. Dark diagonal line represents the classification of boundary resulting from the optimized combination of the two metrics. Abbreviations: er (error rate), PCA‐LDA (principal component analysis – linear discriminant analysis), HOA (human osteoarthritis), HAC (human articular cartilage), RIF (rat injury fibrocartilage), RAC (rat articular cartilage).
An Insulin-Sensitizing Thiazolidinedione, Which Minimally Activates PPARγ, Does Not Cause Bone Loss
Authors: Fukunaga Tomohiro , Zou Wei , Rohatgi Nidhi , Colca Jerry R , Teitelbaum Steven L
Published: September 2014

Rosiglitazone is an insulin-sensitizing thiazolidinedione (TZD) that activates the transcription factor peroxisome proliferator-activated receptor gamma (PPARγ). Although rosiglitazone effectively treats type II diabetes mellitus (T2DM), it carries substantial complications, including increased fracture risk. This predisposition to fracture is consistent with the fact that PPARγ preferentially promotes formation of adipocytes at the cost of osteoblasts. Rosiglitazone-activated PPARγ, however, also stimulates osteoclast formation. A new TZD analog with low affinity for binding and activation of PPARγ but whose insulin-sensitizing properties mirror those of rosiglitazone has been recently developed. Because of its therapeutic implications, we investigated the effects of this new TZD analog (MSDC-0602) on skeletal homeostasis, in vitro and in vivo. Confirming it activates the nuclear receptor in osteoclasts, rosiglitazone enhances expression of the PPARγ target gene, CD36. MSDC-0602, in contrast, minimally activates PPARγ and does not alter CD36 expression in the bone-resorptive cells. Consistent with this finding, rosiglitazone increases receptor activator of NF-κB ligand (RANKL)-induced osteoclast differentiation and number, whereas MSDC-0602 fails to do so. To determine if this new TZD analog is bone sparing, in vivo, we fed adult male C57BL/6 mice MSDC-0602 or rosiglitazone. Six months of a rosiglitazone diet results in a 35% decrease in bone mass with increased number of osteoclasts, whereas that of MSDC-0602–fed mice is indistinguishable from control. Thus, PPARγ sparing eliminates the skeletal side effects of TZDs while maintaining their insulin-sensitizing properties. © 2014 American Society for Bone and Mineral Research.
Synthesis and Antimicrobial Evaluation of Some New Spiroindolinone Derivatives
Authors: Refat Hala M.
Published: September 2014

In an attempt to find a new class of antimicrobial agents, a series of spiroindolinone compounds containing pyridine, pyrimidine, benzopyrans, pyrido, naphtodiazepines, pyrazole, and isoxazole ring systems were prepared via the reaction of 3‐(2‐oxo‐2‐(3‐oxo‐3H‐benzo[f]chromen‐2‐yl)ethylidene)indolin‐2‐one (4) with an appropriate nucleophilic reagent. Newly synthesized compounds were characterized by elemental analysis and spectral data (IR, 1H‐NMR, 13C‐NMR, and mass spectra). Representative compounds were tested and evaluated as antimicrobial agents.
Ligands involved in Pb immobilization and transport in lettuce, radish, tomato and Italian ryegrass
Authors: Massaccesi Luisa , Meneghini Carlo , Comaschi Tatiana , D'Amato Roberto , Onofri Andrea , Businelli Daniela
Published: September 2014

Lead (Pb) and other heavy metals represent a great source of concern in agriculture because they may disperse from polluted sources and accumulate in crop organs. This research study was performed with three edible crops and one pasture species (lettuce: Lactuca sativa L. cv. Romana; radish: Raphanus sativus L. var. radicicola; tomato: Lycopersicon lycopersicum L. Karst.; Italian ryegrass: Lolium multiflorum Lam). It was aimed at (1) assessing how species affect Pb distribution among plant organs, (2) determining the extent to which Pb is localized in edible organs, and (3) ascertaining whether it could be possible to distinguish which compounds are responsible for the transport of Pb from one plant organ to another and which compounds are responsible for the accumulation of this metal inside each plant organ. The experiment was conducted in the greenhouse. Plants were grown in plastic pots using a Pb‐spiked sandy soil as substrate. Total Pb concentrations in different plant organs and in soil were determined. Within plants, the maximum accumulation of Pb was found in roots while the remaining part of Pb was mainly located in leaves. Pb LIII edge XANES (X‐ray Absorption Near Edge Spectroscopy) was applied to identify the principal Pb carrier molecules in the different plant organs. The data suggest that in roots Pb immobilization is mainly due to the complexing ability of histidine, which binds the metal and, to a lesser extent, to precipitation of Pb as carbonate. The transport to the upper plant organs is mainly attributed to Pb complexes with organic acids. In stems and leaves, Pb bonding is mainly carboxylic and amino acid‐like, thus confirming the role of these substances in promoting Pb mobility. Thio amino acidic (glutathione and cysteine‐like) Pb complexes, which in this study were only found in stems, can also be held responsible for Pb long‐distance transport from roots to shoots.
High‐level extracellular expression of inulin fructotransferase in Pichia pastoris for DFA III production
Authors: Zhan Rongrong , Mu Wanmeng , Jiang Bo , Li Yungao , Zhou Liuming , Zhang Tao
Published: September 2014

BACKGROUND

Inulin fructotransferase (IFTase) catalyzes inulin conversion to difructose anhydride (DFA III), which is a natural low‐calorie sweetener. Although heterologous expression of IFTase was achieved in Escherichia coli, the extracellular enzyme activity was very low, which limited the commercialization of IFTase.

RESULTS

Active IFTase of about 43 kDa molecular mass of subunit was extracellularly expressed by Pichia pastoris and was greatly regulated by the IFTase gene copy number integrated into the P. pastoris genome and by the methanol concentration in the induction phase. Under optimized culture conditions, multicopy P. pastoris exhibited a maximum extracellular IFTase activity of 105.4 U mL−1 in a 5 L fermenter, which was 8.9‐fold the activity in shake flasks and 5.3‐fold that obtained from wild‐type strain.

CONCLUSION

IFTase was expressed in a eukaryotic P. pastoris system for the first time and achieved high‐level extracellular expression using a high‐cell‐density fed‐batch cultivation strategy. This demonstrated that P. pastoris was a good candidate for potential DFA III production as a novel IFTase expression system. © 2014 Society of Chemical Industry
Graphene loaded waveguide for millimeter‐wave applications
Authors: Attiya Ahmed M.
Published: September 2014

This article presents a full wave analysis of a rectangular wave guide loaded with a double‐layered graphene sheet mounted on a finite‐thickness dielectric slab. The chemical potential of the graphene sheet is controlled by the applied electrical potential between the two layers of the graphene sheet which subsequently controls the surface conductivity of the graphene sheet. This property is found to have a significant effect at frequencies above 50 GHz. By controlling the conductivity of the graphene sheet it would be possible to control the amplitude and phase of the transmission and refraction coefficients along the waveguide section. This feature can be used in different applications in mm‐wave range like switches, attenuators, filters, resonators, and modulators. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2762–2766, 2014
Self‐biased inductorless wideband LNA with interleaving feedback network
Authors: Lai Mu‐Tsung , Tsao Hen‐Wai
Published: September 2014

A self‐biased inductorless wideband low‐noise amplifier (LNA) is proposed in this article. Both passive shunt feedback and interleaving active‐loop techniques are used to achieve enhanced bandwidth (BW), wideband input matching, and a low noise figure (NF). The LNA is implemented using a standard 0.18 μm CMOS process. The measured maximum power gain is 19.4 dB with a −3 dB BW between 0.1 and 6 GHz and the minimum NF is 3.2 dB. The input and output return losses are both below −10 dB over entire 0.1–6.8 GHz. The power consumption is 52 mW from a supply of 1.8 V and the core area is only 0.016 mm2. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2755–2758, 2014
K‐band reconfigurable 4 × 4 balanced power amplifier for flexible satellite communication applications
Authors: Lee Han Lim , Moon Seong‐Mo , Lee Moon‐Que , Yu Jong‐Won
Published: September 2014

This article presents a K‐band reconfigurable 4 × 4 balanced high power amplifier (HPA) adopting voltage‐controlled phase inverters which can precisely provide relative phase shifts of 0° and 180°. By properly adjusting the relative phases in the 4 × 4 array paths of the proposed structure, a fixed input‐to‐output port relationship of the conventional balanced PA can be overcome through the improvement in output flexibility. The proposed 4 × 4 balanced HPA is configured by four K‐band HPA microwave monolithic integrated circuits (MMICs), four phase inverter MMICs, and two 4 × 4 waveguide‐Butler matrices as input and output passive networks. Each K‐band HPA is fabricated with 0.15‐μm pHEMT process and has the size of 4.26 × 2.35 mm2. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2820–2822, 2014
Q‐switched thulium‐doped fiber laser operating at 1920 nm region with multiwalled carbon nanotubes embedded in polyvinyl alcohol
Authors: Ahmad M. T. , Latiff A. A. , Zakaria Z. , Zen D. I. M. , Saidin N. , Haris H. , Ahmad H. , Harun S. W.
Published: September 2014

We demonstrate a Q‐switched Thulium‐doped fiber laser operating at approximately 1912 nm region using multiwalled carbon nanotubes (MWCNT) embedded in polyvinyl alcohol (PVA) as the passive saturable absorber (SA). The SA is fabricated by mixing the dispersed MWCNTs suspension into a PVA solution MWCNT and let the precursor to dry in the room temperature to form the film. The film is sandwiched between two FC/PC fiber connectors before it is incorporated in a ring laser cavity to produce self‐started pulse train with repetition rate that can tuned from 13.07 to 21.67 kHz as the 1552 nm pump power is increased from 302 to 382 mW. At 382 mW pump, the Q‐switched laser has a pulse width of 7.93 µs and pulse energy of 103.37 nJ. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2817–2820, 2014
Design of a novel triplexer using multiband EBG mushroom structure with suspending microstrip line
Authors: Wang Shi‐Yung , Chen Fu‐Chiarng
Published: September 2014

Mushroom structure exhibits unique electromagnetic properties that have led to a wide range of applications in the microwave and antenna community. This article concentrates on the electromagnetic band‐gap characteristic of the mushroom structure with the suspending microstrip line, and a new concept of the mushroom interlaced periodic arrayal is proposed. Furthermore, we utilize the new concept to design a triband bandstop filter and a triplexer. The triplexer can integrate three kinds of communication systems with each other, which operate at frequencies including GSM 1800 MHz, WiFi 2.45 GHz, and WiMAX 3.5 GHz, respectively. Therefore, the novel triplexer would be good potential candidate not only for nowadays but also for future applications in communication systems. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2789–2795, 2014
A dual‐band diversity antenna for LTE devices and human body effect
Authors: Mouffok Lila
Published: September 2014

Compact dual‐band diversity antenna for handheld devices is presented. Two orthogonal antennas are designed in LTE bands: 790–862 MHz, 2.5–2.69 GHz. To enhance isolation, a neutralization line is inserted. Aiming size reduction, we propose a structure integrable into mobile phone. Good antennas performances are obtained near a human model. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2795–2799, 2014
Design, analysis, and fabrication of a novel multiband folded edge compact size fractal PIFA for WiFi/LTE/WiMAX/ WLAN application
Authors: Saluja Nitin , Khanna Rajesh
Published: September 2014

In this article, multiband fractal planar inverted F antenna with two folded edges is designed and fabricated. The proposed antenna resonates at two different bands of frequencies with lower band at frequency 2.25–2.863 GHz and upper band at frequency 4.81–6.21 GHz. The proposed design offers broad bandwidth of (613‐MHz impedance bandwidth) 25% at lower band and (impedance bandwidth 1400 MHz) 26.4% bandwidth at upper band of frequency. The gain of antenna at lower frequency band (centered at 2.45 GHz) is 3.8 dBi and the gain at upper frequency band (centered at 5.3 GHz) is 7.2 dBi. The overall dimensions of the proposed antenna are 19.8 × 19.8 mm2. The antenna patch is folded under itself to achieve compactness in design and also to configure frequency of resonance for antenna. The designed antenna is best candidate for the WiFi, LTE, WiMAX, and WLAN applications in mobile phones. The antenna is fabricated and results are compared with simulation results. The measured and simulated results shows good agreement for proposed design proves validity of design for practical usage. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2836–2841, 2014
Novel design of multiband branch‐line coupler using multiband transmission lines
Authors: Ren Han , Shao Jin , Zhou Mi , Arigong Bayaner , Ding Jun , Zhang Hualiang
Published: September 2014

In this article, a novel multiband branch‐line coupler employing multiband transmission lines is designed to operate at three different frequencies. To realize multiband operations, a Pi‐type‐based multiband transmission line network with open‐ and short‐ended stubs is employed. Specifically, the Pi‐type line is applied to realize the dual‐band operation at the first two working frequencies. For the third operating frequency, the open‐ and short‐ended stubs are tapped at the center of the Pi‐type line. ABCD‐matrix is employed to derive the design formulas for the proposed triband transmission line. To verify the design concept, a planar coupler operating at 1/2.5/4.5GHz is designed and fabricated. The simulation and measurement results show good agreement with the design theory. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2841–2845, 2014
Zero voltage switching high efficiency power amplifier with parallel coupled line load
Authors: Lim Hong Yi , Ng Geok Ing , Leong Yoke Choy
Published: September 2014

A load network for zero voltage switching high efficiency power amplifier design consisting of a parallel coupled line has been demonstrated. The load network was able to present the terminations required for a zero voltage switching class‐E power amplifier load topology. Simulated time domain voltage and current waveforms for the designed power amplifier at the transistor output terminal proved the workings of the proposed load network topology. The fabricated power amplifier designed at 1.2 GHz with the proposed load network was measured with different levels of input rf power. At the designed input rf power of 30 dBm, the power amplifier recorded an output power of 42 dBm with a power added efficiency of 67%. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2926–2929, 2014
Wideband slot‐loaded dipole for base station antenna element
Authors: Yang Wenxia , Wong Hang
Published: September 2014

A low‐profile wideband unidirectional dipole antenna with L‐shaped slots loaded is presented. The antenna is simply excited by a 50 Ω coaxial cable on the dipole. A wide impedance bandwidth of 54% (|S11| < −10 dB) from the frequency of 1.57–2.74 GHz is achieved. Stable radiation pattern with low cross‐polarization, nearly identical E‐ and H‐plane patterns is observed over the entire operating frequency band. The average gain of the antenna is about 8.5 dBi over the frequency range 1.7–2.7 GHz. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2933–2937, 2014
Extinction ratio and wavelength flatness for imbalanced Mach–Zehnder interferometer in silicon‐on‐insulator
Authors: Hsu Shih‐Hsiang , Chung Yi , Wang Chih‐Ming , Yang Yung‐Chia
Published: September 2014

The imbalanced Mach–Zehnder interferometer typically uses two multimode interferences individually connected with different path length for interferometric applications. When the optical loss difference between two phase arms is significant, the new splitting scheme using Mach–Zehnder based directional coupler could compensate loss discrepancy for higher extinction ratio and wavelength independence. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2950–2952, 2014
An inductorless CMOS single‐to‐differential transimpedance amplifier with gain‐enhanced topology and postamplifier
Authors: Lai Mu‐Tsung , Tsao Hen‐Wai
Published: September 2014

This article presents an inductorless single‐to‐differential (S2D) transimpedance amplifier (TIA) with gain‐enhanced topology and postamplifier (PA) for the front‐end of an optical communication receiver. Using the regulated cascode topology with S2D converter, the proposed TIA can avoid the use of extra balance–unbalance (balun) converter. In addition, by incorporating dual active feedback in the cascaded gain stages of PA, the bandwidth of the proposed circuit can be effectively extended without using any inductor. Using a standard 90 nm CMOS process, the proposed circuit exhibits a maximum transimpedance gain of 59 dB Ω and the −3 dB bandwidth of 9.6 GHz. Operated at a supply voltage of 1.2 V, the power consumption of the fabricated circuit is only 45 mW, and maximum usable data rate is 12.5‐Gb/s. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2953–2958, 2014
Myocardial perfusion assessment in humans using steady‐pulsed arterial spin labeling
Authors: Capron Thibaut , Troalen Thomas , Robert Benjamin , Jacquier Alexis , Bernard Monique , Kober Frank
Published: September 2014

Purpose

Although arterial spin labeling (ASL) has become a routinely performed method in the rodent heart, its application to the human heart remains challenged by low tissue blood flow and cardiac and respiratory motion. We hypothesized that an alternative steady‐pulsed ASL (spASL) method would provide more efficient perfusion signal averaging by driving the tissue magnetization into a perfusion‐dependent steady state.

Methods

We evaluated the feasibility of spASL in the human heart by combining pulsed labeling in the aortic root with a balanced steady state free precession sequence. The spASL scheme was applied to 13 subjects under free breathing. Breathing motion was addressed using retrospective image exclusion based on a contour‐based cross‐correlation algorithm.

Results

The measured signal with spASL was due to labeled blood. We found that the perfusion signal was larger than that obtained with the earlier flow‐sensitive alternating inversion recovery (FAIR) method. Averaged myocardial blood flow (MBF) over four myocardial regions was 1.28 ± 0.36 mL·g−1·min−1.

Conclusion

spASL was able to quantify MBF in healthy subjects under free breathing. Because quantification with ASL is more direct than with first‐pass perfusion MRI, it appears particularly suited for pathologies with diffuse microvascular alterations, MBF reserve, and follow‐up studies. Magn Reson Med 74:990–998, 2015. © 2014 Wiley Periodicals, Inc.
Effect of silane coupling agent on the structure and mechanical properties of nano‐dispersed clay filled styrene butadiene rubber
Authors: He Shaojian , Xue Yang , Lin Jun , Zhang Liqun , Du Xiaoze , Chen Lin
Published: September 2014

In rubber nanocomposites containing inorganic clay, the reinforcement effect has always been relatively insignificant due to the poor interfacial interaction between the rubber matrix and clay fillers. In this work, the silane coupling agent bis[3‐(triethoxysilyl)propyl]tetrasulfide (Si‐69) was employed through mechanically blending with styrene butadiene rubber (SBR)/clay (100/30) nanocompound that was prepared by combined latex compounding and spray‐drying technique, to serve as the molecular bridge between SBR matrix and clay filler and strengthen the interfacial interaction. TEM and XRD characterization indicated that Si‐69 significantly improved the dispersion of the silicate layers in the SBR matrix. The RPA analysis and the mechanical property study of the SBR/clay nanocomposites revealed that the filler network interaction was weakened while the filler–rubber interaction was strengthened upon the addition of Si‐69. POLYM. COMPOS., 37:890–896, 2016. © 2014 Society of Plastics Engineers
Titanium Dioxide/Germanium Core–Shell Nanorod Arrays Grown on Carbon Textiles as Flexible Electrodes for High Density Lithium‐Ion Batteries
Authors: Fang Shan , Shen Laifa , Nie Ping , Xu Guiyin , Yang Liang , Zheng Hao , Zhang Xiaogang
Published: September 2014

Three‐dimensional (3D) titanium dioxide@germanium (TiO2@Ge) core–shell nanorod arrays on carbon textiles are fabricated by a facile two‐step method and further investigated as flexible electrode for Li‐ion batteries (LIBs). The synthesis of TiO2@Ge composite involves the hydrothermal growth of TiO2 nanorod arrays on carbon textiles and a subsequent coat with a thin layer of germanium with radio frequency (RF) magnetron sputtering. The TiO2 nanorod arrays can effectively not only increase the unit mass loading as a role of skeleton but also remarkably enhance the electrical conductivity via control the lithiation/delithiation voltage in the range of 0.01–1.0 V, where TiO2 can be in situ lithiated to LixTiO2 after the first discharge cycle. Moreover, each TiO2@Ge nanorod has enough space to accommodate the large volume expansion of Ge during charge and discharge cycles. Benefiting from unique electrode architectures, this additive free, self‐supported electrode exhibits the high reversible capacity, outstanding rate capability, and the extremely long cycling stability even at a high rate (700.3 mAh g−1 is still retained at 5 A g−1 after 600 cycles).
Cn‐AMP2 from green coconut water is an anionic anticancer peptide
Authors: Prabhu Saurabh , Dennison Sarah R. , Mura Manuela , Lea Robert W. , Snape Timothy J. , Harris Frederick
Published: September 2014

Globally, death due to cancers is likely to rise to over 20 million by 2030, which has created an urgent need for novel approaches to anticancer therapies such as the development of host defence peptides. Cn‐AMP2 (TESYFVFSVGM), an anionic host defence peptide from green coconut water of the plant Cocos nucifera, showed anti‐proliferative activity against the 1321N1 and U87MG human glioma cell lines with IC50 values of 1.25 and 1.85 mM, respectively. The membrane interactive form of the peptide was found to be an extended conformation, which primarily included β‐type structures (levels > 45%) and random coil architecture (levels > 45%). On the basis of these and other data, it is suggested that the short anionic N‐terminal sequence (TES) of Cn‐AMP2 interacts with positively charged moieties in the cancer cell membrane. Concomitantly, the long hydrophobic C‐terminal sequence (YFVFSVGM) of the peptide penetrates the membrane core region, thereby driving the translocation of Cn‐AMP2 across the cancer cell membrane to attack intracellular targets and induce anti‐proliferative mechanisms. This work is the first to demonstrate that anionic host defence peptides have activity against human glioblastoma, which potentially provides an untapped source of lead compounds for development as novel agents in the treatment of these and other cancers. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.
Using imaging ToF‐SIMS data to determine the cell wall thickness of fibers in wood
Authors: Gerber Lorenz , Hoang Viet Mai , Tran Linh , Kiet Hoang Anh Tuan , Malmberg Per , Hanrieder Jörg , Ewing Andrew
Published: September 2014

Here, we demonstrate the use of time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) imaging data for estimation of cell wall thickness in wood samples. Current research in forest biotechnology focuses on transgenic trees with wood properties tailored to specific applications. Appropriate analytical methods to characterize the very heterogeneous wood material are constantly being developed and improved. Chemical imaging of wood by ToF‐SIMS represents an interesting tool for this purpose with many applications. In addition to wood chemistry, the impact of specific genetic modifications on wood anatomy needs to be assessed. Cell wall thickness is an important anatomical parameter that among others is used for assessing biomass accumulation. We developed a strategy to estimate cell wall thickness from ToF‐SIMS images and implemented it in the open source programming language ‘R’. In brief, random lines are projected over the black and white mask of a ToF‐SIMS image, and length values of all line sections that cut across a cell wall are collected. After enough iteration, the shortest values of the obtained count distribution represent the crossing sections normal to the cell walls, hence cell wall thickness. Compared with conventional light microscopy image analysis, TOF‐SIMS data offers many advantages such as submicron resolution and additional spectral information for automated annotation of distinct anatomical features. This work underlines the importance of SIMS imaging for studies of wood chemistry and anatomy and provides a new approach to obtain an important wood anatomical parameter from ToF‐SIMS data. © 2014 The Authors. Surface and Interface Analysis published by John Wiley & Sons, Ltd.
Volatility analysis in high‐frequency financial data
Authors: Wang Yazhen , Zou Jian
Published: September 2014

In this paper we provide a detailed review of univariate and multivariate volatility analysis within the framework of high‐frequency financial data setting. The field of volatility modeling and analysis for high‐frequency financial data has experienced a rapid development over the past decade. High‐frequency financial data pose tremendous challenges on volatility modeling and analysis, such as microstructure noise, non‐synchronization, irregularly spaced times between observations, nonstationarity, and jumps. We present models for asset prices and high‐frequency financial data. We discuss common volatility estimators such as realized volatility, two‐time scale and multi‐scale realized volatility estimators, realized kernel volatility estimator and pre‐averaging volatility estimator in the univariate setting. For estimating co‐volatility, we illustrate data synchronization methods including previous tick, refresh time, and generalized sampling time and present two‐time scale and multi‐scale realized volatility matrix estimators, realized kernel volatility estimator, and the quasi‐maximum likelihood method built on the synchronized data. We also feature pre‐averaging volatility and Hayashi‐Yoshida estimators which are based on inexplicit data synchronization. We provide detailed formulation and properties for each estimator or method and point out their relationships and differences. Given the recent interests in big data and high‐dimensional statistics, large volatility matrix inference approaches are highlighted in the end. WIREs Comput Stat 2014, 6:393–404. doi: 10.1002/wics.1330

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This article is categorized under:

Applications of Computational Statistics > Computational Finance

Statistical and Graphical Methods of Data Analysis > Nonparametric Methods

Data: Types and Structure > Time Series, Stochastic Processes, and Functional Data
Structural basis for the specific recognition of IL‐18 by its alpha receptor
Authors: Wei Hui , Wang Dongli , Qian Yun , Liu Xi , Fan Shilong , Yin Hsien-Sheng , Wang Xinquan
Published: September 2014

Interleukin 18 (IL‐18), a member of the IL‐1 family of cytokines, is an important regulator of innate and acquired immune responses. It signals through its ligand‐binding primary receptor IL‐18Rα and accessory receptor IL‐18Rβ. Here we report the crystal structure of IL‐18 with the ectodomain of IL‐18Rα, which reveals the structural basis for their specific recognition. It confirms that surface charge complementarity determines the ligand‐binding specificity of primary receptors in the IL‐1 receptor family. We suggest that IL‐18 signaling complex adopts an architecture similar to other agonistic cytokines and propose a general ligand‐receptor assembly and activation model for the IL‐1 family.
African‐American TOMM40'523‐APOEhaplotypes are admixture of West African and Caucasian alleles
Authors: Roses Allen D. , Lutz Michael W. , Saunders Ann M. , Goldgaber Dmitry , Saul Robert , Sundseth Scott S. , Akkari P. Anthony , Roses Stephanie M. , Gottschalk W. Kirby , Whitfield Keith E. , Vostrov Alexander A. , Hauser Michael A. , Allingham R. Rand , Burns Daniel K. , Chiba‐Falek Ornit , Welsh‐Bohmer Kathleen A.
Published: September 2014

Background

Several studies have demonstrated a lower apolipoprotein E4 (APOEε4) allele frequency in African‐Americans, but yet an increased age‐related prevalence of AD. An algorithm for prevention clinical trials incorporating TOMM40'523 (Translocase of Outer Mitochondria Membrane) andAPOEdepends on accurate TOMM40'523‐APOEhaplotypes.

Methods

We have compared theAPOEand TOMM40'523 phased haplotype frequencies of a 9.5 kb TOMM40/APOEgenomic region in West African, Caucasian, and African‐American cohorts.

Results

African‐American haplotype frequency scans of poly‐T lengths connected in phase with eitherAPOEε4 orAPOEε3 differ from both West Africans and Caucasians and represent admixture of several distinct West African and Caucasian haplotypes. A new West African TOMM40'523 haplotype, withAPOEε4 connected to a short TOMM40'523 allele, is observed in African‐Americans but not Caucasians.

Conclusion

These data have therapeutic implications for the age of onset risk algorithm estimates and the design of a prevention trial for African‐Americans or other mixed ethnic populations.
TNF‐α promotes invasive growth through the MET signaling pathway
Authors: Bigatto Viola , De Bacco Francesca , Casanova Elena , Reato Gigliola , Lanzetti Letizia , Isella Claudio , Sarotto Ivana , Comoglio Paolo M. , Boccaccio Carla
Published: September 2014

The inflammatory cytokine Tumor Necrosis Factor Alpha (TNF‐α) is known to trigger invasive growth, a physiological property for tissue healing, turning into a hallmark of progression in cancer. However, the invasive response to TNF‐α relies on poorly understood molecular mechanisms. We thus investigated whether it involves the MET oncogene, which regulates the invasive growth program by encoding the tyrosine kinase receptor for Hepatocyte Growth Factor (HGF). Here we show that the TNF‐α pro‐invasive activity requires MET function, as it is fully inhibited by MET‐specific inhibitors (small‐molecules, antibodies, and siRNAs). Mechanistically, we show that TNF‐α induces MET transcription via NF‐κB, and exploits MET to sustain MEK/ERK activation and Snail accumulation, leading to E‐cadherin downregulation. We then show that TNF‐α not only induces MET expression in cancer cells, but also HGF secretion by fibroblasts. Consistently, we found that, in human colorectal cancer tissues, high levels of TNF‐α correlates with increased expression of both MET and HGF. These findings suggest that TNF‐α fosters a HGF/MET pro‐invasive paracrine loop in tumors. Targeting this ligand/receptor pair would contribute to prevent cancer progression associated with inflammation.
The effect of reducing dietary energy density via the addition of water to a dry diet, on body weight, energy intake and physical activity in adult neutered cats
Authors: Alexander Janet E. , Colyer Alison , Morris Penelope J.
Published: September 2014

Increasingly domestic cats live in an overfeeding and underexercising environment where obesity is a major health concern. One strategy to aid healthy body weight maintenance is dietary energy dilution. Published data indicate that increasing dietary moisture content leads to a reduction in energy intake and increased activity. However, a number of different methodologies were employed in these studies and associated changes in physical activity have only been measured once. The aim of the present study was to determine the effect of diets of three different moisture contents offered in excess of energy requirements, on body weight, energy intake and physical activity in adult neutered cats. Sixty-nine adult cats randomised into three groups, received 100 % of their daily individual maintenance energy requirements (IMER) of dry diet or dry diet hydrated to 40 or 80 % total moisture content (tmc). Baseline activity, intake, body weight and body composition were measured. Following this baseline phase, the cats received the same diets at 200 % of daily IMER and the measurements repeated over the next 28 d. When offered the diets at 200 % IMER, cats fed the dry diet significantly increased body weight and percentage of body fat (P < 0·01), while those offered the hydrated diets did not (P > 0·01). The levels of physical activity in cats offered the hydrated 80 % tmc diet were significantly (P < 0·01) higher than those offered the dry or 40 % tmc diet. We suggest that dietary energy dilution by addition of water may be a useful strategy for healthy body weight maintenance in overfed cats.
Alterations to oxidative stress markers in dogs after a short-term stress during transport
Authors: Ferreira Chayanne S. , Vasconcellos Ricardo S. , Pedreira Raquel S. , Silva Flavio L. , Sá Fabiano C. , Kroll Fernanda S. A. , Maria Ana P. J. , Venturini Katiani S. , Carciofi Aulus C.
Published: September 2014

While methods to evaluate antioxidant capacity in animals exist, one problem with the models is induction of oxidative stress. It is necessary to promote a great enough challenge to induce measurable alterations to oxidative parameters while ensuring the protocol is compatible with animal welfare. The aim of the present study was to evaluate caged transport as a viable short-term stress that would significantly affect oxidative parameters. Twenty adult Beagle dogs, maintained on the same diet for 60 d prior to the transport, were included in the study. To simulate the stress, the dogs were housed in pairs in transport cages (1·0 m × 1·0 m × 1·5 m), placed on a truck coupled to a trailer and transported for a period of 15 min. Blood collection was performed immediately before and again 3 h after the transportation to evaluate oxidative parameters in blood serum, including thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (TAC), sequestration activity of the radical 2,2-diphenyl-1-picryl-hydrazyl (DPPH•), protein carbonylation (PC), total sulfhydryl groups (SH), alpha-tocopherol (αToc) and retinol (Ret). PC, SH and αToc were not significantly changed in the study; however, TBARS, TAC and DPPH increased, whereas Ret decreased after the transport. Although the lack of a control group of dogs not submitted to transport is a limitation to be considered, we conclude that the transport model is effective in inducing an antioxidant response in dogs and relevant blood parameters show sensitivity to this proposed model.
Japanese Musicians Between Music and Politics During WWII: Japanese Propaganda in the Third Reich
Authors: Lee Kyungboon
Published: September 2014

Even before signing the pact between Japan and Germany, Japanese musicians performed in the concert halls of the Third Reich. In particular, there was an active demand due to propagandistic performances such as German–Japanese concerts or concerts for German soldiers on the Eastern front or occupied territories. This study describes the activities of two “Japanese” conductors who became members of the Reich Chamber of Culture and performed with the Berliner Philharmonic orchestra: Ahn Ekitai (Iktae) from colonial Korea and Konoye Hidemaro, a high-ranking Japanese peer. Extracted from documents of the German–Japanese Society at the Federal Archives Koblenz (Germany), this article explores the cultural and political functions that these conductors faced in terms of German war propaganda and how their different musical compositions, both named “Etenraku”, related to propagandistic values. This essay further shows that Ahn, whom Koreans considered a patriot and fighter against Japanese colonial power in Europe for a long time, was active as a Japanese conductor in the Third Reich, calling Konoye's assertion that he was pursued by the Nazis into question.
Memory in Progress
Authors: Mesnard Philippe
Published: September 2014

This article traces the evolution in the discourses and representations of victimhood, citing a range of examples from across Europe. Beginning with a macro approach to the question of memory groups, which examines the representation of the victim via collective memory, the article then goes on to discuss how these groups, which are related to historical violence, have presented themselves in the public realm from the 1950s to the present day. Particular attention is paid to the manner in which different memories work together within systems of representation, the function of analogy, metaphor and allegory as rhetorical devices and how one memory often serves as a ‘screen’ or a prism via which to approach another.
A Zebrafish Embryo Behaves both as a “Cortical Shell – Liquid Core” Structure and a Homogeneous Solid when Experiencing Mechanical Forces
Authors: Liu Fei , Wu Dan , Chen Ken
Published: September 2014

Mechanical properties are vital for living cells, and various models have been developed to study the mechanical behavior of cells. However, there is debate regarding whether a cell behaves more similarly to a “cortical shell – liquid core” structure (membrane-like) or a homogeneous solid (cytoskeleton-like) when experiencing stress by mechanical forces. Unlike most experimental methods, which concern the small-strain deformation of a cell, we focused on the mechanical behavior of a cell undergoing small to large strain by conducting microinjection experiments on zebrafish embryo cells. The power law with order of 1.5 between the injection force and the injection distance indicates that the cell behaves as a homogenous solid at small-strain deformation. The linear relation between the rupture force and the microinjector radius suggests that the embryo behaves as membrane-like when subjected to large-strain deformation. We also discuss the possible reasons causing the debate by analyzing the mechanical properties of F-actin filaments.