bluuebunny/crossref_metadata_2025_split huggingface dataset:
COMPARATIVE VALIDITY OF MULTIPLE‐CHOICE AND FREE‐RESPONSE ITEMS ON THE ADVANCED PLACEMENT EXAMINATION IN BIOLOGY
Authors: Bridgeman Brent 
Published: September 2014

ABSTRACTThe 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

ABSTRACTA 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

ABSTRACTFormulas 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

ABSTRACTWe 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

ABSTRACTA 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 imageScatter 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

ABSTRACT

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.
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

AbstractLead (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

AbstractBACKGROUNDInulin 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.RESULTSActive 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.CONCLUSIONIFTase 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

ABSTRACTThis 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

ABSTRACTA 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

ABSTRACTThis 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

ABSTRACTWe 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

ABSTRACTMushroom 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

ABSTRACTCompact 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

ABSTRACTIn 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

ABSTRACTIn 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

ABSTRACTA 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

ABSTRACTA 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