bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphological correlations to mechanical performance of hydroxyapatite‐filled HDPE/UHMWPE composites
Authors: Jaggi Harjeet S. , Kumar Sunil , Das Dibyendu , Satapathy Bhabani K. , Ray Alok R.
Published: August 2014

Melt mixed and injection molded hydroxyapatite (Hap) filled high‐density polyethylene/ultrahigh molecular weight polyethylene composites were assessed for their thermal, structural, morphological, and mechanical attributes. Differential scanning calorimetry was conducted to analyze the effect of Hap loading on various thermal transitions and their associated enthalpies. The microstructural attributes were characterized by conducting wide angle X‐ray diffraction and scanning electron microscopy (SEM) of cryo‐fractured surface. SEM micrographs of tensile fractured surface revealed the systematic reduction in the size of microfibrils indicating the suppression of local deformation. Improvement in low‐strain mechanical response and flexural properties accompanied with a consistent decrease in strain‐at‐break and toughness was witnessed with increasing Hap content. Toughness aspects were critically discussed in the realms of quasi‐static, dynamic mechanical and sudden impact testing approach. Dynamic mechanical analysis demonstrated the presence of prominent α and γ transitions in the crystalline and amorphous phase respectively. Tensile fractured surface morphologies of the investigated composites revealed a switch‐over from matrix dominated plastic deformation to Hap controlled quasi‐brittle fracture. Thus, our study fundamentally deals with the feasibility of designing polyethylene/Hap composites with superior mechanical properties for biomedical applications, especially for orthopedic implants. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41251.
Tensile strength of handsheets from recovered fibers treated with N‐Methylol melamine and 1,3‐dimethylol‐4,5‐dihydroxyethyleneurea
Authors: Hosseinpourpia Reza , Adamopoulos Stergios , Mai Carsten
Published: August 2014

The main objective of this study was to assess the effect of two amino resins, N‐methylol melamine (NMM) and 1,3‐dimethylol‐4,5‐dihydroxyethyleneurea (DMDHEU), on the intrafiber and interfiber strengths and water absorption of two types of waste paper categories, office paper (OP), and old corrugated containers (OCCs). The tensile strength of individual fibers measured at zero span was reduced by increases in the resin concentrations. The dry tensile strengths of the recovered handsheets measured at a finite span were enhanced with increases in the weight percentage gain of the resins. The increasing of the resin concentration also significantly improved the intrabonding of the OP and OCCs in moist measuring conditions. The water absorption of the handsheets considerably decreased at the higher concentration of the thermosetting resins, especially with NMM. The results are promising for the use of NMM‐ and DMDHEU‐treated recovered fibers as an alternative fiber resource for the production of laminated paper and also for the use of DMDHEU as a new N‐methylol compound for laminated paper. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41290.
Effect of Extended π‐Conjugation Structure of Donor–Acceptor Conjugated Copolymers on the Photoelectronic Properties
Authors: Wang Meng , Shi Shaowei , Ma Di , Shi Keli , Gao Chen , Wang Liwei , Yu Gui , Li Yongfang , Li Xiaoyu , Wang Haiqiao
Published: August 2014

New donor–acceptor conjugated copolymers based on alkylthienylbenzodithiophene (BDTT) and alkoxynaphthodithiophene (NDT) have been synthesized and compared with their benzo[1,2‐b:4,5‐b′]dithiophene (BDT)‐based analogues to investigate the effect of the extended π conjugation of the polymer main chain on the physicochemical properties of the polymers. A systematic investigation into the optical properties, energy levels, field‐effect transistor characteristics, and photovoltaic characteristics of these polymers was conducted. Both polymers demonstrated enhanced photovoltaic performance and increased hole mobility compared with the BDT‐based analogue. However, the BDTT‐based polymer (with π‐conjugation extension perpendicular to main chain) gave the highest power conversion efficiency of 5.07 % for the single‐junction polymer solar cell, whereas the NDT‐based polymer (with π‐conjugation extension along the main chain) achieved the highest hole mobility of approximately 0.1 cm2 V−1 s−1 based on the field‐effect transistor; this indicated that extending the π conjugation in different orientations would have a significant influence on the properties of the resulting polymers.
Estimation and residual analysis with R for a linear regression model with an interval‐censored covariate
Authors: Langohr Klaus , Melis Guadalupe Gómez
Published: August 2014

Interval‐censored covariates are sometimes encountered in longitudinal studies and considered as possible predictors in a regression model. This paper, motivated by an AIDS study, proposes an implementation in R for the estimation of parameters and the assessment of the assumptions of a linear regression model with an interval‐censored covariate. The properties of the parameters estimators and the behavior of three proposed residuals are addressed through two simulation studies. Also, guidelines are provided to check the goodness‐of‐fit of the fitted model in terms of the length of the censoring interval of the covariate. The methodology is illustrated with real data coming from the AIDS study. R functions and scripts are provided.
It's time to regulate: Coping with product‐induced nongenetic clonal instability in CHO cell lines via regulated protein expression
Authors: Misaghi Shahram , Chang Jennifer , Snedecor Brad
Published: August 2014

Clonal instability and titer loss during Chinese hamster ovary (CHO) cell line development (CLD) has several underlying causes, the most prominent of which are DNA copy number loss and DNA silencing. However, in some cases, clonal instability is due to the toxicity of the therapeutic protein(s) that clones express. Unlike DNA copy number loss, which may occur in some clones or DNA silencing that is prevalent in certain regions of the genome, the hallmark of product induced clonal instability is its manifestation in all the selected clones. To circumvent such product induced clonal instability, we have developed a vector construct that utilizes a regulated protein expression system in which the constitutive expression of the target protein(s) is prevented unless doxycycline is added to the culture. We have then successfully used this system to express, at high titers, an antibody for which constitutive expression results in clonal instability perhaps due to intracellular accumulation of the antibody. Our data shows that unlike the constitutively expressed or continuously induced clones, uninduced clones do not display instability. Furthermore, maintaining the uninduced clones in culture for months or subjecting them to freeze‐thaws did not have any effects on their titers. All together, our findings suggest that a regulated expression system could be suitable for production of difficult proteins that trigger instability. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:1432–1440, 2014
Component Selection in the Self‐Assembly of Palladium(II) Nanocages and Cage‐to‐Cage Transformations
Authors: Samanta Dipak , Mukherjee Partha Sarathi
Published: August 2014

Dynamic supramolecular systems involving a tetratopic palladium(II) acceptor and three different pyridine‐ and imidazole‐based donors have been used for self‐selection by a synergistic effect of morphological information and coordination ability of ligands through specific coordination interactions. Three different cages were first synthesized by two‐component self‐assembly of individual donor and acceptor. When all four components were allowed to interact in a reaction mixture, only one out of three cages was isolated. The preferential binding affinity towards a particular partner was also established by transforming a non‐preferred cage into a preferred cage by interaction with the appropriate ligand. Computational studies further supported the fact that coordination interaction of imidazole moiety to PdII is enthalpically more preferred compared to pyridine, which drives the selection process. Analysis of crystal packing of both complexes indicated the presence of strong hydrogen bonds between nitrate and water molecules and also H‐bonded 3D networks of water. Both complexes exhibit promising proton conductivity (10−5 to ca. 10−3 S cm−1) at ambient temperature under a relative humidity of circa 98 % with low activation energy.
Structural Biology of Cisplatin Complexes with Cellular Targets: The Adduct with Human Copper Chaperone Atox1 in Aqueous Solution
Authors: Calandrini Vania , Nguyen Trung Hai , Arnesano Fabio , Galliani Angela , Ippoliti Emiliano , Carloni Paolo , Natile Giovanni
Published: August 2014

Cisplatin is one of the most used anticancer drugs. Its cellular influx and delivery to target DNA may involve the copper chaperone Atox1 protein. Although the mode of binding is established by NMR spectroscopy measurements in solution—the Pt atom binds to Cys12 and Cys15 while retaining the two ammine groups—the structural determinants of the adduct are not known. Here a structural model by hybrid Car–Parrinello density functional theory‐based QM/MM simulations is provided. The platinated site minimally modifies the fold of the protein. The calculated NMR and CD spectral properties are fully consistent with the experimental data. Our in silico/in vitro approach provides, together with previous studies, an unprecedented view into the structural biology of cisplatin–protein adducts.
Serine versus Threonine Glycosylation with α‐O‐GalNAc: Unexpected Selectivity in Their Molecular Recognition with Lectins
Authors: Madariaga David , Martínez‐Sáez Nuria , Somovilla Víctor J. , García‐García Laura , Berbis M. Álvaro , Valero‐Gónzalez Jessika , Martín‐Santamaría Sonsoles , Hurtado‐Guerrero Ramon , Asensio Juan L. , Jiménez‐Barbero Jesús , Avenoza Alberto , Busto Jesús H. , Corzana Francisco , Peregrina Jesús M.
Published: August 2014

The molecular recognition of several glycopeptides bearing Tn antigen (α‐O‐GalNAc‐Ser or α‐O‐GalNAc‐Thr) in their structure by three lectins with affinity for this determinant has been analysed. The work yields remarkable results in terms of epitope recognition, showing that the underlying amino acid of Tn (serine or threonine) plays a key role in the molecular recognition. In fact, while Soybean agglutinin and Vicia villosa agglutinin lectins prefer Tn‐threonine, Helix pomatia agglutinin shows a higher affinity for the glycopeptides carrying Tn‐serine. The different conformational behaviour of the two Tn biological entities, the residues of the studied glycopeptides in the close proximity to the Tn antigen and the topology of the binding site of the lectins are at the origin of these differences.
Lewis Acid Mediated Tandem Reaction of Propargylic Alcohols to Tetrazoles Involving CO‐ and CC‐Bond Cleavage Reactions and a CN‐Bond Formation
Authors: Song Xian‐Rong , Han Ya‐Ping , Qiu Yi‐Feng , Qiu Zi‐Hang , Liu Xue‐Yuan , Xu Peng‐Fei , Liang Yong‐Min
Published: August 2014

A novel and direct synthesis of 1‐aryl‐5‐arylvinyl‐tetrazoles from easily prepared propargylic alcohols and TMSN3 is developed in the presence of TMSCl under mild conditions (TMS=trimethylsilyl). The process involves an allenylazide intermediate, followed by a CC‐bond cleavage and CN‐bond formation to afford the desired products. Moreover, this method offers a good functional‐group applicability and can be scaled‐up to grams (yield up to 85 %).
Selective Uptake of Cylindrical Poly(2‐Oxazoline) Brush‐AntiDEC205 Antibody‐OVA Antigen Conjugates into DEC‐Positive Dendritic Cells and Subsequent T‐Cell Activation
Authors: Bühler Jasmin , Gietzen Sabine , Reuter Anika , Kappel Cinja , Fischer Karl , Decker Sandra , Schäffel David , Koynov Kaloian , Bros Matthias , Tubbe Ingrid , Grabbe Stephan , Schmidt Manfred
Published: August 2014

To achieve specific cell targeting by various receptors for oligosaccharides or antibodies, a carrier must not be taken up by any of the very many different cells and needs functional groups prone to clean conjugation chemistry to derive well‐defined structures with a high biological specificity. A polymeric nanocarrier is presented that consists of a cylindrical brush polymer with poly‐2‐oxazoline side chains carrying an azide functional group on each of the many side chain ends. After click conjugation of dye and an anti‐DEC205 antibody to the periphery of the cylindrical brush polymer, antibody‐mediated specific binding and uptake into DEC205+‐positive mouse bone marrow‐derived dendritic cells (BMDC) was observed, whereas binding and uptake by DEC205− negative BMDC and non‐DC was essentially absent. Additional conjugation of an antigen peptide yielded a multifunctional polymer structure with a much stronger antigen‐specific T‐cell stimulatory capacity of pretreated BMDC than application of antigen or polymer–antigen conjugate.
Gamut evaluation of an n‐colour printing process with the minimum number of measurements
Authors: Deshpande Kiran , Green Phil , Pointer Michael R
Published: August 2014

The aim of this study was to use a minimum number of measured colour patches to evaluate the colour gamut of an n‐colour printing process. Traditionally, the colour gamut of a printing system has been derived by printing and then measuring a gamut target for example, a profiling chart. For an n‐colour printing (printing with more than four process inks), it is desirable to know the colour gamut of the given set of inks without having to print a large number of test patches. Different spectral printer models were used to predict the gamut of a 7‐colour printing process. The colorant space was divided into sectors each containing four inks. For each printer model, the colour gamut of the each four‐ink sector was predicted. All sector‐gamuts were then combined to predict the overall colour gamut of the n‐colour process. This predicted gamut was then compared with the gamut obtained by measurement using a gamut comparison index (GCI). The Yule–Nielsen modified spectral Neugebauer (YNSN) model gave the best accuracy, at the cost of a larger number of input measurements, than other models. A combination of the Kubelka–Munk (KM) and YNSN models performed well with the fewest input measurements. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 408–415, 2015
Artwork imaging from 370 to 1630 nm using a novel multispectral system based on light‐emitting diodes
Authors: Herrera‐Ramirez Jorge , Vilaseca Meritxell , Burgos Francisco J. , Font Lídia , Senserrich Rosa , Pujol Jaume
Published: August 2014

The recent use of multispectral systems as a noncontact method for analysis of artworks has already shown promising results. This study explains the application of a novel portable multispectral system based on light‐emitting diodes (LEDs) for artwork imaging. This method provides spectral information in a spectral range from 370 to 1630 nm with a 25 cm × 25 cm field of view by using two different image sensors in synchrony with 23 bands of irradiation. The spectral information for each point is estimated and validated using the pseudo‐inverse and spline interpolation methods for spectral estimation and three different evaluation metrics. The results of the metrics obtained with both estimation methods show a general good performance of the system over the whole spectral range. The experiments also showed that the selection of the training set for the pseudo‐inverse estimation has a great influence in its performance, and thus, it defines whether or not the pseudo‐inverse outperforms the spline interpolation method. The system is applied in situ to the study of Catalan art masterpieces, and the results demonstrate the potential of a cost‐effective and versatile system using various off‐the‐shelf elements to reconstruct color information and to reveal features not previously identified. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 398–407, 2015
On‐Line Monitoring of Chemical Reactions by using Bench‐Top Nuclear Magnetic Resonance Spectroscopy
Authors: Danieli E. , Perlo J. , Duchateau A. L. L. , Verzijl G. K. M. , Litvinov V. M. , Blümich B. , Casanova F.
Published: August 2014

Real‐time nuclear magnetic resonance (NMR) spectroscopy measurements carried out with a bench‐top system installed next to the reactor inside the fume hood of the chemistry laboratory are presented. To test the system for on‐line monitoring, a transfer hydrogenation reaction was studied by continuously pumping the reaction mixture from the reactor to the magnet and back in a closed loop. In addition to improving the time resolution provided by standard sampling methods, the use of such a flow setup eliminates the need for sample preparation. Owing to the progress in terms of field homogeneity and sensitivity now available with compact NMR spectrometers, small molecules dissolved at concentrations on the order of 1 mmol L−1 can be characterized in single‐scan measurements with 1 Hz resolution. Owing to the reduced field strength of compact low‐field systems compared to that of conventional high‐field magnets, the overlap in the spectrum of different NMR signals is a typical situation. The data processing required to obtain concentrations in the presence of signal overlap are discussed in detail, methods such as plain integration and line‐fitting approaches are compared, and the accuracy of each method is determined. The kinetic rates measured for different catalytic concentrations show good agreement with those obtained with gas chromatography as a reference analytical method. Finally, as the measurements are performed under continuous flow conditions, the experimental setup and the flow parameters are optimized to maximize time resolution and signal‐to‐noise ratio.
Stable Single‐Molecule Lines of Terrylene in Polycrystalline para‐Dichlorobenzene at 1.5 K
Authors: Navarro Pedro , Tian Yuxi , van Stee Marijn , Orrit Michel
Published: August 2014

The spectroscopic properties of single terrylene (Tr) molecules are studied in a polycrystalline matrix of para‐dichlorobenzene (p‐DCB) at 1.5 K. Samples grown in a glass capillary show a very strong site at 597 nm, which is redshifted by more than 700 cm−1 from the observed transition energy for Tr in p‐DCB prepared as a film on a coverslip (572 nm). Each of these two sites is characterized by measuring their single‐molecule spectroscopic parameters at 1.5 K. Lifetime‐limited linewidths of 45±5 MHz are found for both sites. Fluorescence detection rates reach 8×104 count s−1 at saturation. The spectral trails of the majority of single molecules show no spectral jumps, indicating an absence of interacting two‐level systems; however, the small distribution of linewidths may indicate weak interactions with low‐frequency modes. Frequency jumps are observed for 10 % of the molecules. The complete emission spectra from two different single molecules at the center of each of the two sites is presented. Debye–Waller factors of αDW=0.33±0.05 for the normal site (572 nm) and αDW=0.30±0.05 for the red site (597 nm) are reported. This new host–guest system provides a quick and easy way to obtain lifetime‐limited single‐molecule lines.
Strongly Correlated Alignment of Fluorinated 5,11‐Bis(triethylgermylethynyl)anthradithiophene Crystallites in Solution‐Processed Field‐Effect Transistors
Authors: Kim Chang‐Hyun , Hlaing Htay , Payne Marcia M. , Yager Kevin G. , Bonnassieux Yvan , Horowitz Gilles , Anthony John E. , Kymissis Ioannis
Published: August 2014

The crystallinity of an organic semiconductor film determines the efficiency of charge transport in electronic devices. This report presents a micro‐to‐nanoscale investigation on the crystal growth of fluorinated 5,11‐bis(triethylgermylethynyl)anthradithiophene (diF‐TEG‐ADT) and its implication for the electrical behavior of organic field‐effect transistors (OFETs). diF‐TEG‐ADT exhibits remarkable self‐assembly through spin‐cast preparation, with highly aligned edge‐on stacking creating a fast hole‐conducting channel for OFETs.
Interplay between Resonance‐Assisted Hydrogen Bonding and Coordination in Sulfo‐Functionalized Arylhydrazones of Active Methylene Compounds
Authors: Mahmudov Kamran T. , Kopylovich Maximilian N. , Guedes da Silva M. Fátima C. , Pombeiro Armando J. L.
Published: August 2014

The interaction of sodium(I) and copper(II) with sodium (E,Z)‐2‐[2‐(1‐cyano‐2‐methoxy‐2‐oxoethylidene)hydrazinyl]benzenesulfonate (NaHL1), sodium 4‐[2‐(2,4‐dioxopentan‐3‐ylidene)hydrazinyl]benzenesulfonate (NaHL2), and sodium 2‐[2‐(2,4‐dioxopentan‐3‐ylidene)hydrazinyl]benzenesulfonate (NaHL3) is studied on the basis of competition between intra‐ and intermolecular hydrogen bonding and coordination. The interplay between such interactions provides an unprecedented strategy towards an easy ((E,Z)→E or Z) isomeric resolution of NaHL1 to give the new coordination polymers [Na(H2O)2(μ‐HL1)]n (1) (E form) and [Na2(H2O)4(μ‐HL1)2]n⋅nH2O (2) (Z form). It is also applied to the synthesis of the new compounds [Cu(H2O)6](HL2)2⋅4 H2O (3) and [Cu(A)L3]⋅H2O (4) (A=2‐(pyridin‐2‐yl)ethanol). The intra‐ and intermolecular structural relevance of hydrogen bonding is detailed by X‐ray diffraction.
A Vanadium–Cerium Redox Flow Battery with an Anion‐Exchange Membrane Separator
Authors: Yun Sukhwan , Parrondo Javier , Ramani Vijay
Published: August 2014

Cardo‐poly(etherketone)‐based anion‐exchange membranes (AEMs) were prepared and employed as separators in a vanadium–cerium redox flow battery (V‐Ce RFB). V‐Ce RFBs with AEM separators yielded energy efficiencies (EEs) ranging from 67 to 84 % at current densities between 20 and 80 mA cm−2. V‐Ce RFBs using Nafion 212 as the separator had EEs ranging from 50 to 84 % and displayed a capacity and efficiency loss as a result of cation intermixing. Over 20 charge/discharge cycles, the RFB with the AEM separator yielded unchanged efficiencies and capacity, whereas the loss of capacity was 50 % with the Nafion separator. There was no substantial change in the ionic conductivity, ultimate tensile strength, and Young’s modulus of AEMs after 50 charge/discharge cycles. This suggests that AEMs are promising candidates as V‐Ce RFB separators that: 1) are chemically and mechanically stable during cycling, and 2) act as efficient barriers that preclude the intermixing of vanadium and cerium cations.
Photocatalytic Water Oxidation by Molecular Assemblies Based on Cobalt Catalysts
Authors: Zhou Xu , Li Fei , Li Hua , Zhang Biaobiao , Yu Fengshou , Sun Licheng
Published: August 2014

Chromophore‐catalyst molecular assemblies towards visible light‐driven water oxidation were synthesized by covalent integration of a light‐harvesting complex [Ru(bpy)3]2+ (bpy=2,2′‐bipyridine) and a Co4O4 cubane water oxidation catalyst. The two components were assembled either in linear or macrocyclic configurations. In the presence of the sacrificial reagent, the Ru–Co metallocycle exhibits remarkable photocatalytic activity for oxygen evolution, which is one order of magnitude higher than that of a multicomponent system and exceeds that of a linear assembly by a factor of five, offering access to highly active photocatalyst through molecular design.
Deciphering TGF‐β3 function in medial edge epithelium specification and fusion during mouse secondary palate development
Authors: Jin Jiu‐Zhen , Warner Dennis R. , Lu Qingxian , Pisano M. Michele , Greene Robert M. , Ding Jixiang
Published: August 2014

Background: Transforming growth factor‐β3 (TGF‐β3) plays a central role in mediating secondary palate fusion along the facial midline. However, the mechanisms by which TGF‐β3 functions during secondary palate fusion are still poorly understood. Results: We found that mouse cytokeratin 6α and 17 mRNAs were expressed exclusively in the palate medial edge epithelium on embryonic day 14.5, and this expression was completely abolished in Tgf‐β3 mutant embryos. In contrast, we found that Jagged2 was initially expressed throughout the palate epithelium, but was specifically down‐regulated in the medial edge epithelium during palatal fusion. Jagged2 down‐regulation was regulated by TGF‐β3, since Jagged2 was persistently expressed in palatal medial edge epithelium in Tgf‐β3 null mutant embryos. Moreover, addition of DAPT, a specific inhibitor of Notch signaling, partially rescued the fusion defects in Tgf‐β3 null mutant palatal shelves. Conclusions: Based on these results, together with the previous study indicating that the loss of Jagged2 function promotes embryonic oral epithelial fusion, we concluded that TGF‐β3 mediates palate fusion in part by down‐regulating Jagged2 expression in palatal medial edge epithelium. In addition, cytokeratin 6α and 17 are two TGF‐β3 downstream target genes in palate medial edge epithelium differentiation. Developmental Dynamics 243:1536–1543, 2014. © 2014 Wiley Periodicals, Inc.
Reducing Cache Hardware by Focusing on Data Redundancy
Authors: Kobayashi Ryotaro , Matsukawa Daisuke , Shimomura Yoshio , Ochiai Hiroya , Shimada Hajime
Published: August 2014

There is one reason to utilize cache that mitigates processor performance limitation comes from data transfer bandwidth. Recently, cache size expansion is required in this use because data transfer bandwidth requirement is increasing for recent large data size and multi‐core trends. However, cache size expansion is unwelcome because it causes problems arising from circuit area and power consumption viewpoint. This paper focuses a data redundancy with the goal of reducing cache size and proposes a mechanism that does not store redundant data into cache. The proposed mechanism divides data into higher bit and lower bit that stored into higher cache and lower cache, respectively. We reduced higher cache size to half size by keeping 46% redundant data in higher bit area not to store into higher cache. The evaluation results show that the proposed mechanism increases IPC by 3.3% on average compared with same circuit area conventional cache under SPECCPU2000 benchmarks.
The Glucose Concentration‐Dependency of Spontaneous Activity in a Cultured Neuronal Network
Authors: Minoshima Wataru , Ito Hidekatsu , Kudoh Suguru N.
Published: August 2014

Cultured rat hippocampal network on a multielectrode array (MEA) dish is a useful model for analyzing network electrical dynamics and its developmental changes. Neurons autonomously form a complex network on an MEA dish and spontaneous electrical activity is often observed without any input from the external world. The spontaneous activity is generated by synaptic interactions between neurons and reflects an internal biochemical state of a whole neuronal network. The origin of electrical activity is electrochemical potential generated by active transport of ions, which requires catabolism of ATP. We elucidated the relationship between spontaneous electrical activity and external glucose concentration. The spontaneous activity changed transiently, depending on glucose concentrations. The number of electrical spikes in spontaneous activity increases depending on the concentration of external glucose concentration. Interestingly, this increase is not only suppressed but turn to decrease. In the case of glucose concentration is 17.56 mM, the number of activity is the most, and then it decreases in the case of glucose concentration is more than 20 mM. In addition, the decrease of neuronal activity at a high glucose concentration is not influenced by the blockade of inhibitory synaptic activity. These results suggest that a cultured neuronal network has optimal glucose concentration 17.56 mM, which corresponds to the concentration of glucose in a culture medium.
Impact of the Presence of Octadecylamine on the Properties of Hydrothermally Prepared CoFe2O4 Nanoparticles
Authors: Georgiadou Violetta , Dendrinou‐Samara Catherine
Published: August 2014

Invited for the cover of this issue is the group of Catherine Dendrinou‐Samara at Aristotle University of Thessaloniki, Greece. The cover image shows CoFe2O4 nanoparticles (NPs) synthesized hydrothermally in the presence of octadecylamine. These bimodal CoFe2O4 NPs show fluorescence and relaxometric properties.
Total Synthesis of a Pyrrole Lactone Alkaloid, Longanlactone
Authors: Reddy Chada Raji , Reddy Motatipally Damoder , Dilipkumar Uredi
Published: August 2014

The first asymmetric total synthesis of the natural pyrrole lactone longanlactone has been achieved. The key reactions, a Barbier propargylation and a Paal–Knorr pyrrole synthesis, have provided easy access to the target natural product from L‐aspartic acid in six steps and 31 % overall yield. The C‐4 epimer of the natural product and propionyllonganlactone have also been prepared by this strategy.
COMPARATIVE PREDICTION OF SUCCESS AND SATISFACTION IN COLLEGE MAJOR FIELDS
Authors: French John W.
Published: August 2014

This bulletin completes the report of the Comparative Prediction Study ‐ College Level. It is to be regarded as a second part of RB‐59‐10, which described the background and method of the study, the aptitude tests, interest scales and personality scales, the administration to college freshman, the intercorrelations that were computed, and the need for averaging validity coefficients. The results of the testing are presented here as if the study had been done at the “average college.” Even this requires rather voluminous tables. The analysis shows the multiple validities that can be obtained from the battery and evaluates the battery's capability for differential and comparative prediction by computing the intercorrelations among predicted criteria and the validity of the predicted differences between criteria. An explanation and a demonstration is made of statistical corrections for the length of the tests, restriction of range in the major‐field groups, and “shrinkage” expected when the multiple validities are tried out on new groups. The battery is evaluated according to specifications laid down previously. A summary of the evaluation is as follows:

The general level of prediction of major‐field grades is good (over .62) for some fields, but lower than this for too many others. Both the aptitude tests and interest scales contribute to the general validity; the personality scales were found to be much less useful. Validity for freshman grades is somewhat poorer; validity for satisfaction is low and limited entirely to the interest scales.

Differential prediction of major‐field grades is good, mainly because of the presence of the interest scales.
THE MEDICAL HISTORY TEST – A BEHAVIORAL MEASURE OF ATTITUDE
Authors: Cliff Norman , Frederiksen Norman , Stokes Joseph , Riche Charles V.
Published: August 2014

A Medical History Test was constructed with the primary purpose of assessing the effect of an experimental program in medical education on the medical student's interpretative skill and “whole patient”‐oriented attitude. The test was composed of a series of tape recordings from which the examinee was to note the relevant information and questions he would want to ask, and to write a differential diagnosis and plan of management. The written responses were scored by comparing each statement in them to a set of keyed statements and summing the scores for each scorable item to arrive at Skill and Attitude scores.

The Skill score was found to have a reliability of about .49 and .56 in two classes and to have low positive correlations with other measures of aptitude and achievement. The Attitude score had reliabilities of .73 and .74; it did not relate to any measure but the Skill score, and that in only one class. Neither score differentiated experimental from control groups.

A revised format of the test was found to yield a more reliable Skill score, but it was highly influenced by response sets.
BAYESIAN INDIFFERENCE PROCEDURES
Authors: Novick Melvin R. , Hall W. J.
Published: August 2014

In a logical probability approach to inference, distributions on a parameter space are interpreted as representing states of knowledge, and any prevailing state of knowledge is taken to have been arrived at from a previous state of ignorance (indifference) followed by the accumulation of prior data. Previous attempts at describing indifference and states of knowledge by use of the principle of insufficient reason and by use of natural conjugate distributions are discussed, and it is shown that they are not sufficient in themselves. Specifically, if one permits order‐preserving reparametrization, any prior distribution whatsoever for one parameter implies that another parameter is uniformly distributed and yet another has a natural conjugate distribution relative to an arbitrary sample. An indifference principle that requires postulating what size and what kind of samples will permit statistical inference is then introduced‐‐e.g., one observation from a two‐parameter normal model is not sufficient to permit inference about the variance but two (noncoinciding) observations are. With some limitation on the class of priors considered, it is then shown that this principle permits unique specification of indifference for the more commonly encountered statistical models. It is also shown that this specification does not depend on the scale of measurement of the random variable. The consistency of this principle with recent work of the authors on prediction theory is also demonstrated.
RELATIVE CONTRIBUTIONS OF MOTIVATOR AND HYGIENE FACTORS TO OVERALL JOB SATISFACTION1
Authors: Halpern Gerald
Published: August 2014

Ratings of four motivator job aspects, four hygiene job aspects, and overall job satisfaction were obtained from 93 male subjects who were equally satisfied with both the motivator and the hygiene aspects of their jobs. Two of the job aspects (work itself and opportunity for achievement), both motivators, were sufficient to account for the variance in overall satisfaction.
ITEM SAMPLING IN TEST THEORY AND IN RESEARCH DESIGN
Authors: Lord Frederic M.
Published: August 2014

New and less new concepts and results in the item‐sampling model for mental test theory are summarized. It is shown that certain research studies–typically those concerned with group means–could use item‐sampling methods to improve their efficiency of experimental design. Various sampling error formulas are derived, making it possible to determine whether and to what extent various uses of item sampling will increase the information gained by the research worker.
PREDICTIVE VALIDITY OF A BRIEF TEST OF ACADEMIC APTITUDE
Authors: Peterson Richard E.
Published: August 2014

This paper reports intercorrelations among Control Test for Academic Aptitude (CTAA) scores, SAT‐V, SAT‐M, student reported high school GPA, and student reported high school class rank for entering freshmen at three liberal arts colleges. Given the research purpose to which the 30‐item, 12‐minute CTAA is limited–providing a statistical control for aptitude in research using the College Student Questionnaires–the test was concluded to be adequately valid (r's with freshman GPA of .40, .51 and .39).
MATCHING, DISCRIMINATION, AND PAYOFFS1,2
Authors: Zinnes Joseph L. , Kurtz Ronald
Published: August 2014

Five different models for matching judgments are described. Each one is applied to an experiment employing both matching and ordered discrimination tasks, three payoff matrices, and three levels of stimulus discriminability. Under the matching instructions, subjects indicated whether two patterns of lights had the same or a different number of lights. Under the ordered discrimination instructions, subjects indicated which one of two patterns had more lights. One of the models consistently gives a better account of the individual and the pooled group data than the others, but even for this model the goodness‐of‐fit chi‐squares are generally too large.
NEGOTIATION IN LEADER AND DELEGATE GROUPS1
Authors: Hermann Margaret G. , Kogan Nathan
Published: August 2014

Negotiations among leaders were compared with negotiations among delegates in order to investigate the effect of role in the reference group on intergroup bargaining behavior. The negotiations of ten groups of leaders and ten groups of delegates matched on initial positions were examined. Because of their greater flexibility and authority, leaders were expected to spend less time negotiating and have fewer deadlocks than delegates. Neither of these hypotheses was supported. Leaders and delegates, however, were found to resolve their conflicts in different ways. While delegates more often reached agreement through compromise, leaders were more likely to choose one party's position. Thus, delegates tended to converge upon the average of their initial positions while leaders showed a significant change in the risky direction. Leaders' and delegates' reactions to their negotiations were also analyzed. In general, the results suggested that leaders can be influenced more by other leaders than delegates can by other delegates.
RATIONALITY AND ACHIEVEMENT: A COMPARISON OF THE ATKINSON‐McCLELLAND AND KOGAN‐WALLACH FORMULATIONS
Authors: Alker Henry A.
Published: August 2014

This comparison concerns the prediction of (1) success at complex tasks and (2) the presence of unusual shifts in aspiration level following success or failure. The Kogan‐Wallach formulation generates predictions concerning these dependent variables without recourse to a concept of the need for achievement. These predictions, furthermore, both yield empirical results that account for significantly more variance (p < .05) in the responses of a sample of 96 high school boys than do comparable predictions from need achievement theory. The interpretation stresses a distinction between merely trying hard and learning from one's mistakes.
THE EFFECT OF REINFORCEMENT OF STATEMENTS OF PUPIL–TEACHER RELATIONSHIPS IN A FREE RESPONSE SITUATION ON MINNESOTA TEACHER ATTITUDE INVENTORY SCORES1,2
Authors: Lantz Donald L.
Published: August 2014

This study was designed to apply reinforcement theory to changing attitudes as measured by the MTAI of teacher education students. Subjects consisted of 93 educational psychology students who were randomly assigned to one of the three groups (Treatment, Hawthorne, and Control), The experimental treatment consisted of inviting students in for five brief “get‐acquainted” interviews in which any statement expressing positive attitudes toward teacher‐pupil relationships was reinforced. Two control groups were used; one received no special treatment, while the other was invited in for five “get‐acquainted” interviews, but was not reinforced for expressing favorable attitudes toward pupil‐teacher relationships. Results indicated no significant differences among the three groups.

This study indicates that for students enrolled in an educational psychology course those who receive reinforcement outside of class for verbalizing appropriate attitudes of teacher‐pupil relationships do not show significant gain in MTAI scores over those students in the course who do not receive such reinforcement outside of class.
RELEVANCE OF RATER‐RATEE ACQUAINTANCE IN THE VALIDITY AND RELIABILITY OF RATINGS1
Authors: Freeberg Norman E.
Published: August 2014

Unacquainted Ss worked in three‐man groups under relevant (mathematical tasks) and irrelevant (socializing) acquaintance conditions. The Ss rated one another on scales that defined several cognitive skills. They were also rated on these same scales by observers who were dependent on visual information, exclusively, and were unacquainted with the group members or the specific nature of the tasks being performed. As hypothesized, group members under the relevant acquaintance condition achieved consistently good validity for all three cognitive areas—with the best validity for ratings of math ability. Validity under the irrelevant acquaintance condition was nil on all scales. Observers, surprisingly, achieved significant validity (although at lower levels than participating group members) for ratings under the relevant acquaintance condition. Levels of inter‐ and intrarater reliability were not associated with levels of validity under the various rating conditions.
MEASUREMENT OF COLLEGE ACHIEVEMENT BY THE COLLEGE‐LEVEL EXAMINATION PROGRAM
Authors: Sharon Amiel T.
Published: August 2014

The criterion‐related and construct validity of the College‐Level Examination Program's General Examinations are discussed primarily in terms of research studies conducted at institutions of higher education. While most of the research provides support for the validity of the examinations as measures of academic achievement in college, the results of many of the studies have alternative explanations. The examinations correlate positively with course grades and amount of previous college instruction. Significant gains on the tests are generally made by students over the first two years of college and the highest scores on each test are obtained by students intending to major in the subject covered by the test. There is some question as to whether each of the five examinations is measuring a unique factor.
SIMULTANEOUS FACTOR ANALYSIS IN SEVERAL POPULATIONS*
Authors: Jöreskog K. G.
Published: August 2014

This paper is concerned with the study of similarities and differences in factor structures between different groups. A common situation is when a battery of tests has been administered to samples of examinees from several populations.

A very general model is presented, in which any parameter in the factor analysis models (factor loadings, factor variances, factor covariances, and unique variances) for the different groups may be assigned an arbitrary value or constrained to be equal to some other parameter. Given such a specification, the model is estimated by the maximum likelihood method yielding a large sample χ2 of goodness of fit. By computing several solutions under different specifications one can test various hypotheses.

The method is capable of dealing with any degree of invariance, from the one extreme, where nothing is invariant, to the other extreme, where everything is invariant. Neither the number of tests nor the number of common factors need to be the same for all groups, but to be at all interesting, it is assumed that there is a common core of tests in each battery that is the same or at least content‐wise comparable.
DATA TRANSFORMATION IN TWO‐WAY ANALYSIS OF VARIANCE
Authors: Schlesselman James J.
Published: August 2014

One purpose of data transformation is to better satisfy the fundamental assumptions of statistical analysis by linear models: (a) additivity, (b) homogeneity of variance, and (c) normality. If the original data do not satisfy (a)‐(c), a nonlinear transformation may improve approximation to these ideal conditions.

This paper considers estimation of the parameter λ of the family of power transformations

for data conforming to a replicated two‐way crossed classification. The transformation family y(λ)defined by

though having the advantage of being continuous through λ = 0, is shown to yield likelihood procedures which are scale invariant only if the design matrix allows for removal of an additive constant. Several alternative definitions for (ii) are given which yield both scale invariant likelihood procedures and continuity through λ = 0. By using (ii) in the case of a linear regression through the origin, numerical examples show how point estimates of λ can be shifted and how confidence intervals on λ can be shrunk and stretched almost arbitrarily, simply by rescaling the original observations.

Two procedures for choosing a transformation for data from a replicated two‐way crossed classification are compared by empirical sampling. The statistic Lmax(λ), proposed by Box and Cox (1964), is based upon the likelihood of the transformed observations. The statistic Z(λ), proposed in this paper, is a linear combination of test statistics for removable nonadditivity and variance trending with mean. The null distribution of Z(λ) is approximately N(0,l).

Two cases of empirical sampling from a 3 × 4 crossed classification with four replications were studied. In samples from the truncated Gaussian distribution, the coefficient of variation was roughly 0.23. In samples from the truncated Cauchy distribution, the coefficient of variation was roughly 0.91. The points of truncation depended upon the cell population means. The scale for the Cauchy distribution with location 0 was chosen so that the 95% points matched those of N(0,l).

In Gaussian Samples:

The 5% test based on Lmax(λ) was extremely conservative, the actual size being more like 0.3%.

The estimated size of the nominal 5% test based on Z(λ) was 4.4%

In Cauchy Samples:

The 5% test based on Lmax(λ) was very non‐conservative. The estimated size was 15%.

The estimated size of the nominal 5% test based on Z(λ) was 5.6%.

A procedure for choosing a weighting for the components of Z(λ) based upon the sample data is also derived and investigated. Sampling shows that it works well for the two cases studied. This procedure should also work well in practice.
A CLASS OF TESTS FOR MULTIVARIATE NORMALITY BASED ON LINEAR FUNCTIONS OF ORDER STATISTICS
Authors: Aitkin Murray A.
Published: August 2014

A class of tests for normality using the ratio of two estimates of the Standard deviation is generalized to provide a class of tests for multivariate normality using a characterization of the multivariate normal. The powers of some of the tests are examined numerically and compared with the power of a recent similar test.
GRADIENT METHODS FOR ANALYTIC ROTATION
Authors: Browne Michael W.
Published: August 2014

Gradient methods are employed in orthogonal and oblique analytic rotation. Constraints are imposed on the elements of the transformation matrix by means of reparameterisations.
RANGE RESTRICTION ASSUMPTIONS ASSUMING QUADRATIC CONDITIONAL VARIANCES
Authors: Boldt Robert F.
Published: August 2014

This paper is concerned with range restriction corrections where (a) the regressions of variables subject to selection on explicit selection variables are linear, and (b) the variance‐covariance matrix of errors of prediction is a quadratic function of the regression estimates. Assumption (b) seems warranted in some data and replaces the homoscedasticity assumption often used in range restriction problems. Computations for range restriction corrections which use assumption (b) are presented. These computations also apply when homoscedasticity applies.
THE VALIDITY OF A MEASURE OF “ACADEMIC MOTIVATION” FOR FORECASTING FRESHMAN ACHIEVEMENT AT SEVEN LIBERAL ARTS COLLEGES1
Authors: Wilson Kenneth M.
Published: August 2014

Seven liberal arts colleges participated in exploratory studies designed to determine the predictive value vis‐à‐vis freshman grades of scores from a 208‐item, self‐report inventory (the Personal Values Inventory or PVI), developed by George E. Schlesser and John A. Finger to yield scores that are relatively independent of traditional measures of scholastic aptitude but at the same time related to academic performance in schools and colleges.

Scores from several PVI scales, particularly that labelled Persistence, were moderately correlated with Freshman Average Grade in every college. The PVI scale‐scores studied were relatively independent of SAT scores.

Predictions of Freshman Average Grade based on a battery which included PVI scale‐scores along with four academic predictors (SAT‐V, SAT‐M, class rank, and the average of CEEB Achievement scores) were more closely related to Freshman Grades than predictions based only on the four academic predictors.