bluuebunny/crossref_metadata_2025 huggingface dataset:
POTENTIAL IMPACT OF CONTEXT EFFECTS ON THE SCORING AND EQUATING OF THE MULTISTAGE GRE® REVISED GENERAL TEST
Authors: Davey Tim , Lee Yi‐Hsuan
Published: August 2014

Both theoretical and practical considerations have led the revision of the Graduate Record Examinations® (GRE®) revised General Test, here called the rGRE, to adopt a multistage adaptive design that will be continuously or nearly continuously administered and that can provide immediate score reporting. These circumstances sharply constrain the available options for equating or linking together the thousands of unique test forms that will need to be administered each year. The only practical method is to pre‐equate each form through item response theory (IRT) methods. Unfortunately, doing so means that item position and context effects are both vitally important and potentially difficult to control. This study examines item position effects in a GRE context and attempts to assess the extent to which they may affect the rGRE. It was found that position effects are in fact present in GRE data and that they can be particularly troublesome under multistage testing. Pretest strategies are able to mitigate effects to some degree, but complete control will require careful attention be paid to the time limits and associated test configuration details in the design of the rGRE.
HIGH SCHOOLS THAT WORK: PROGRAM DESCRIPTION, LITERATURE REVIEW, AND RESEARCH FINDINGS
Authors: Young John W. , Cline Frederick , King Teresa C. , Jackson Avis D. , Timberlake Allison
Published: August 2014

Interest in setting high educational standards is at the forefront of many school reform programs in the United States. States' pursuit of high standards can be advanced through implementation of programs such as High Schools That Work (HSTW), which emphasizes high expectations and rigorous academics for all students, including Career and Technical Education students. High Schools That Work is the largest comprehensive school reform program for high schools in the United States, with over 1,000 schools in more than 30 states currently participating. This report describes the program, previous research, and recent research studies conducted by ETS to ensure validity for the HSTW program.
THE IMPACT OF CHANGES IN THE TOEFL® EXAM ON TEACHING IN A SAMPLE OF COUNTRIES IN EUROPE: PHASE 3, THE ROLE OF THE COURSEBOOK PHASE 4, DESCRIBING CHANGE
Authors: Wall Dianne , Horák Tania
Published: August 2014

The aim of this report is to present the findings of the 3rd and 4th phases of a longitudinal study into the impact of changes in the TOEFL® exam on teaching in test preparation classrooms. Phase 1 (2003–2004) described the type of teaching taking place in 12 TOEFL preparation classrooms before the introduction of the new TOEFL. Phase 2 (2004–2006) followed 6 of the Phase 1 teachers as they became aware of the requirements of the new test and faced the challenges of designing new courses to help students to prepare for it effectively. The objectives of the Phase 3 study (2006–2007) were to analyze the coursebooks that 4 of these teachers were using as they continued to prepare students for the TOEFL computer‐based test (CBT) and began to plan courses for the TOEFL iBT®, and to find out how the teachers were using the coursebooks as they developed their courses and planned individual classroom sessions. The coursebook analysis revealed that the TOEFL iBT coursebooks differed considerably from the TOEFL CBT coursebooks in terms of content, with the inclusion of integrated writing tasks and independent and integrated speaking tasks and the absence of attention to grammatical form on its own. They did not differ greatly in terms of their general methodological approach, however. Information about how the teachers used their coursebooks was gathered via tracking questions and tasks eliciting self‐report data. The coursebooks seemed to be playing an important role in shaping the teachers' understanding of the requirements of the new TOEFL, and the teachers depended on them heavily as they developed their courses and planned their lessons. The objectives of Phase 4 (2007–2008) were to interview and observe 3 of the same teachers, to find out what their preparation classes looked like 1 year after the introduction of the TOEFL iBT in their countries. While some aspects of teaching seemed not to have changed greatly, considerable changes occurred in the amount of attention the teachers paid to the development of speaking and to the integration of different skills. The teachers differed from each other in how much they had changed their methods to develop their students' language skills. The report concludes with a discussion of the role the new test, new coursebooks, and other factors in the educational context played in shaping current practices in these TOEFL preparation classrooms.
EVALUATING ACADEMIC PROGRESS WITHOUT A VERTICAL SCALE
Authors: Yen Wendy M. , Lall Venessa F. , Monfils Lora
Published: August 2014

Alternatives to vertical scales are compared for measuring longitudinal academic growth and for producing school‐level growth measures. The alternatives examined were empirical cross‐grade regression, ordinary least squares and logistic regression, and multilevel models. The student data used for the comparisons were Arabic Grades 4 to 10 in Qatar, and results were examined in the scale score and performance level metrics. It is found that vertical scales and cross‐grade regressions can show different results at the individual student level, but at the school level, the different measures of growth were strongly correlated, particularly in the scale score metric. Differences between the methods appear more likely in the performance level metric than the scale score metric and for grade pairs with more extreme performance.
WHY THE MAJOR FIELD TEST IN BUSINESS DOES NOT REPORT SUBSCORES: RELIABILITY AND CONSTRUCT VALIDITY EVIDENCE
Authors: Ling Guangming
Published: August 2014

To assess the value of individual students' subscores on the Major Field Test in Business (MFT Business), I examined the test's internal structure with factor analysis and structural equation model methods, and analyzed the subscore reliabilities using the augmented scores method. Analyses of the internal structure suggested that the MFT Business measures a unidimensional construct, which does not support reporting individual students' subscores. Augmented score analyses revealed that the observed total score could approximate the true subscore more accurately than the observed subscores, which do not support reporting individuals' subscores either. The results from these two approaches provided consistent evidence in support of the current practice of not reporting individuals' subscores on the MFT Business. The relationship between the two approaches is discussed, followed by a recommendation of an alternate method for future research.
THE USE OF QUALITY CONTROL AND DATA MINING TECHNIQUES FOR MONITORING SCALED SCORES: AN OVERVIEW
Authors: von Davier Alina A.
Published: August 2014

Maintaining comparability of test scores is a major challenge faced by testing programs that have almost continuous administrations. Among the potential problems are scale drift and rapid accumulation of errors. Many standard quality control techniques for testing programs, which can effectively detect and address scale drift for small numbers of administrations yearly, are not always adequate to detect changes in a complex, rapid flow of scores. To address this issue, Educational Testing Service has been conducting research into applying data mining and quality control tools from manufacturing, biology, and text analysis to scaled scores and other relevant assessment variables. Data mining tools can identify patterns in the data and quality control techniques can detect trends. This type of data analysis of scaled scores is relatively new, and this paper gives a brief overview of the theoretical and practical implications of the issues. More in‐depth analyses to refine the approaches for matching the type of data from educational assessments are needed.
THE LANGUAGE MUSESM SYSTEM: LINGUISTICALLY FOCUSED INSTRUCTIONAL AUTHORING
Authors: Burstein Jill , Shore Jane , Sabatini John , Moulder Brad , Holtzman Steven , Pedersen Ted
Published: August 2014

In the United States, English learners (EL) often do not have the academic language proficiency, literacy skills, cultural background, and content knowledge necessary to succeed in kindergarten through 12th grade classrooms. This leads to large achievement gaps. Also, classroom texts are often riddled with linguistically unfamiliar elements, including: unfamiliar vocabulary, idioms, complex phrases or sentences, morphologically complex words, and unfamiliar discourse relations. Lack of familiarity with linguistic elements may result in gaps in a learner's comprehension of key content. It is not feasible for teachers to develop additional curriculum for the needs of all ELs in a classroom (who often come from culturally and linguistically diverse backgrounds.) However, it is feasible for teachers to develop instructional scaffolding (support) that helps ELs and can be used with all students. To develop effective scaffolding, teachers need to be able to reliably identify linguistic features in texts that could interfere with content comprehension. Language MuseSM is a web‐based application designed to support teachers in the identification of linguistic features in texts and in the development of linguistically focused instructional scaffolding. With regard to system itself, we will discuss (a) the system's motivation, (b) the system's linguistic feedback and instructional authoring components, which are driven by natural language processing, and (c) the system's infrastructure for capturing teachers' system use. In addition, we will also discuss preliminary pilot study findings with three teacher professional development programs. These findings suggest that exposure to Language Muse's linguistic feedback can support teachers in the development of lesson plan scaffolds designed to address language learning needs.
ETS RESEARCH ON COGNITIVE, PERSONALITY, AND SOCIAL PSYCHOLOGY: I
Authors: Stricker Lawrence J.
Published: August 2014

This is an account of a portion of the research on cognitive, personality, and social psychology at ETS since the organization's inception. The topics in cognitive psychology are the structure of abilities; in personality psychology, response styles and social and emotional intelligence; and in social psychology, prosocial behavior and stereotype threat. Research on motivation is also covered.
EXAMINING EVIDENCE OF RELIABILITY, VALIDITY, AND FAIRNESS FOR THE SUCCESSNAVIGATOR™ ASSESSMENT
Authors: Markle Ross , Olivera‐Aguilar Margarita , Jackson Teresa , Noeth Richard , Robbins Steven
Published: August 2014

The SuccessNavigator™ assessment is an online, 30 minute self‐assessment of psychosocial and study skills designed for students entering postsecondary education. In addition to providing feedback in areas such as classroom and study behaviors, commitment to educational goals, management of academic stress, and connection to social resources, it is also designed to predict a range of early academic outcomes. By indicating students' likely success, advisors, faculty, and staff can target their interactions with students to increase their likelihood of success. This report outlines evidence of reliability, validity, and fairness to demonstrate the appropriateness of SuccessNavigator for these purposes.
ASSESSING THE TEST INFORMATION FUNCTION AND DIFFERENTIAL ITEM FUNCTIONING FOR THE TOEFL JUNIOR® STANDARD TEST
Authors: Young John W. , Morgan Rick , Rybinski Paul , Steinberg Jonathan , Wang Yuan
Published: August 2014

The TOEFL Junior® Standard Test is an assessment that measures the degree to which middle school‐aged students learning English as a second language have attained proficiency in the academic and social English skills representative of English‐medium instructional environments. The assessment measures skills in three areas: listening comprehension, language form and meaning, and reading comprehension. This study focused on two specific psychometric characteristics of the assessment: (a) For which segments of its score scales does the assessment provide sufficient information to support the use of the scores in placement decisions? (b) Do items exhibit significant (or C‐level) differential item functioning (DIF) when comparisons are made between test‐takers from different countries? For the first question, both of the forms we analyzed appear to provide sufficient information to support placement decisions across the majority of the score scale for all 3 sections of the assessment. For the second question, we found that a moderate number of items exhibited significant DIF, while the linguistic analyses conducted on the DIF results showed plausible construct‐relevant explanations for most of the findings.
EVALUATION OF A CONDITION‐ADAPTIVE TEST OF READING COMPREHENSION FOR STUDENTS WITH READING‐BASED LEARNING DISABILITIES
Authors: Stone Elizabeth , Cook Linda , Laitusis Cara
Published: August 2014

This study presents secondary analyses on a 2–stage test of reading comprehension for students with reading‐based learning disabilities (RLD). The present paper describes student perceptions of the test and its features as well as analyses focused on the routing test and associated cut score. The routing test contained typical state assessment content and was designed to route the RLD participants into 1 of 2 accessible 2nd‐stage tests, 1 accommodated and 1 not accommodated, and we refer to this structure as condition‐adaptive. The accommodated test was presented with a read‐aloud accommodation, and an oral reading fluency subtest was also administered as part of that test to evaluate decoding skill that may have been masked by the read‐aloud accommodation. This design allowed for componentwise measurement of reading proficiency at the 2nd stage with the goal of creating an accessible tailored test that would provide more comparable accommodated and nonaccommodated test scores for possible use for accountability. Overall, student perceptions differed depending on which 2nd‐stage test was taken, but most students indicated that they tried as hard on this field test as they did on other tests, and many expressed a preference for the read‐aloud accommodation. We found that routing test length was more strongly correlated with 2nd‐stage test performance for the higher performing RLD students, that relatively similar routing decisions could be made using a shorter routing test made up of a smaller subset of the available passages, and that the percentage of students routed into each 2nd‐stage test was sensitive to perturbations of the cut score.
SYNTHESIZING FRAMEWORKS OF HIGHER EDUCATION STUDENT LEARNING OUTCOMES
Authors: Markle Ross , Brenneman Meghan , Jackson Teresa , Burrus Jeremy , Robbins Steven
Published: August 2014

The public, education, and workforce sectors all have expressed interest regarding the key knowledge, skills, and abilities that enable individuals to be productive members of society. Although past efforts have attempted to create frameworks of student learning outcomes, the results have varied due to different perspectives and goals. Thus, the purpose of this paper was to gather and review relevant higher education frameworks, determine their commonalities and create domains, and identify the assessments that Educational Testing Service (ETS) has developed in each of the domains. After a thorough review of the relevant frameworks, seven key domains were identified: creativity, critical thinking, teamwork, communication, digital and information literacy, citizenship, and life skills. Also discussed were the issues of education versus work contextualization and the assumption of foundational quantitative reasoning and literacy skills informing these seven domains.
AUTOMATED SCORING OF MATHEMATICS TASKS IN THE COMMON CORE ERA: ENHANCEMENTS TO M‐RATER IN SUPPORT OF CBAL™ MATHEMATICS AND THE COMMON CORE ASSESSMENTS
Authors: Fife James H.
Published: August 2014

The m‐rater scoring engine has been used successfully for the past several years to score CBAL™ mathematics tasks, for the most part without the need for human scoring. During this time, various improvements to m‐rater and its scoring keys have been implemented in response to specific CBAL needs. In 2012, with the general move toward creating innovative tasks for the Common Core assessment initiatives, in traditional testing programs, and with potential outside clients, and to further support CBAL, m‐rater was enhanced in ways that move ETS's automated scoring capabilities forward and that provide needed functionality for CBAL: (a) the numeric equivalence scoring engine was augmented with an open‐source computer algebra system; (b) a design flaw in the graph editor, affecting the way the editor graphs smooth functions, was corrected; (c) the graph editor was modified to give assessment specialists the option of requiring examinees to set the viewing window; and (d) m‐rater advisories were implemented in situations in which m‐rater either cannot score a response or may provide the wrong score. In addition, 2 m‐rater scoring models were built that presented some new challenges.
ETS CONTRIBUTIONS TO THE QUANTITATIVE ASSESSMENT OF ITEM, TEST, AND SCORE FAIRNESS
Authors: Dorans Neil J.
Published: August 2014

Quantitative fairness procedures have been developed and modified by ETS staff over the past several decades. ETS has been a leader in fairness assessment, and its efforts are reviewed in this report. The first section deals with differential prediction and differential validity procedures that examine whether test scores predict a criterion, such as performance in college, across different subgroups in a similar manner. The bulk of this report focuses on item level fairness, or differential item functioning, which is addressed in the various subsections of the second section. In the third section, I consider research pertaining to whether tests built to the same set of specifications produce scores that are related in the same way across different gender and ethnic groups. Limitations with the approaches reviewed here are discussed in the final section.
READING FOR UNDERSTANDING: HOW PERFORMANCE MODERATORS AND SCENARIOS IMPACT ASSESSMENT DESIGN
Authors: O'Reilly Tenaha , Sabatini John
Published: August 2014

This paper represents the third installment of the Reading for Understanding (RfU) assessment framework. This paper builds upon the two prior installments (Sabatini & O'Reilly, 2013; Sabatini, O'Reilly, & Deane, 2013) by discussing the role of performance moderators in the test design and how scenario‐based assessment can be used as a tool for assessment delivery. Performance moderators are characteristics of students that impact reading performance but are not considered a part of the reading construct. These include (a) background and prior knowledge, (b) metacognitive and self‐regulatory strategies and behavior, (c) reading strategies, and (d) student motivation and engagement. In this paper, we argue there is added value in incorporating performance moderators into a reading test design. We characterize added value with respect to the validity of the claims derived from test scores, the interpretation of the test scores, and the relevance to instruction. As a second aim, we present a case for using scenario‐based assessments and how they can be used to integrate into the test design both the performance moderators as well as other features that make the assessment more instructionally relevant.
Hepatobiliary MR contrast agents in hypovascular hepatocellular carcinoma
Authors: Motosugi Utaroh , Bannas Peter , Sano Katsuhiro , Reeder Scott. B.
Published: August 2014

Hepatocellular carcinoma (HCC) develops via multistep hepatocarcinogenesis, during which hypovascular/early HCC precedes the typical hypervascular HCC. The hypovascular HCC lacks the typical hallmark imaging features of HCC, such as late arterial phase enhancement and portal venous washout, limiting early detection using conventional extracellular contrast agents for dynamic magnetic resonance imaging (MRI) or computed tomography (CT) imaging. In recent years, gadolinium‐based contrast agents with hepatobiliary uptake have garnered interest from radiologists and hepatologists due to their potential for improved detection of HCC during hepatobiliary phase MRI. Lesions with reduced or absent hepatocyte function appear hypointense in the hepatobiliary phase of gadoxetic acid‐enhanced MRI. This behavior can be exploited for earlier detection of hypovascular HCC. This review describes the general characteristics and advantages of gadoxetic acid for the diagnosis of HCC with a particular focus on hypovascular/early HCC. J. Magn. Reson. Imaging 2015;41:251–265.© 2013 Wiley Periodicals, Inc.
Noncontrast myocardial T1 mapping using cardiovascular magnetic resonance for iron overload
Authors: Sado Daniel M. , Maestrini Viviana , Piechnik Stefan K. , Banypersad Sanjay M. , White Steven K. , Flett Andrew S. , Robson Matthew D. , Neubauer Stefan , Ariti Cono , Arai Andrew , Kellman Peter , Yamamura Jin , Schoennagel Bjoern P. , Shah Farrukh , Davis Bernard , Trompeter Sara , Walker Malcolm , Porter John , Moon James C.
Published: August 2014

Purpose

To explore the use and reproducibility of magnetic resonance‐derived myocardial T1 mapping in patients with iron overload.

Materials and Methods

The research received ethics committee approval and all patients provided written informed consent. This was a prospective study of 88 patients and 67 healthy volunteers. Thirty‐five patients underwent repeat scanning for reproducibility. T1 mapping used the shortened modified Look–Locker inversion recovery sequence (ShMOLLI) with a second, confirmatory MOLLI sequence in the reproducibility group. T2* was performed using a commercially available sequence. The analysis of the T2* interstudy reproducibility data was performed by two different research groups using two different methods.

Results

Myocardial T1 was lower in patients than healthy volunteers (836 ± 138 msec vs. 968 ± 32 msec, P < 0.0001). Myocardial T1 correlated with T2* (R = 0.79, P < 0.0001). No patient with low T2* had normal T1, but 32% (n = 28) of cases characterized by a normal T2* had low myocardial T1. Interstudy reproducibility of either T1 sequence was significantly better than T2*, with the results suggesting that the use of T1 in clinical trials could decrease potential sample sizes by 7‐fold.

Conclusion

Myocardial T1 mapping is an alternative method for cardiac iron quantification. T1 mapping shows the potential for improved detection of mild iron loading. The superior reproducibility of T1 has potential implications for clinical trial design and therapeutic monitoring. J. Magn. Reson. Imaging 2015;41:1505–1511. © 2014 Wiley Periodicals, Inc.
Luminescence chronology of late Quaternary moraines and Last Glacial Maximum equilibrium‐line altitude reconstruction from Parlung Zangbo Valley, south‐eastern Tibetan Plateau
Authors: CHEN RENRONG , ZHOU SHANGZHE , LAI ZHONGPING , OU XIANJIAO , CHEN RONG , DENG YINGBIN
Published: August 2014

Optically stimulated luminescence dating was applied to samples from glacial sediments in the Parlung Zangbo Valleys (Daba and Charao) of the south‐eastern Tibetan Plateau to better constrain the timing of Late Quaternary glaciation, which is thought to have been linked to the Indian monsoon. The single aliquot regenerative‐dose protocol on quartz was used for equivalent dose (De) determination using small aliquots. For samples from the Daba Valley, the comparison of ages using two grain size fractions, middle (38–63 µm) and coarse (90–250 µm) were conducted. The coarse grain ages in the Daba Valley (P3) and Charao Valley (P7) range from 16.4 to 26.0 ka, and are consistent with previously published cosmogenic radionuclide exposure ages in the Baiyu Valley (PB1). Our dating results reveal that these moraines were formed during the Last Glacial Maximum (LGM). We then reconstruct the past equilibrium‐line altitudes (ELAs) during the LGM for five glacial valleys in the study area, which range from 3286 to 4014 m with an average value of 3730 m, while the contemporary average ELA is 4655 m. After correction for terrain uplift (about 8 m since the LGM), the difference in the ELA values between the LGM and today is 917 m. According to these data, the estimated temperature during the LGM is 6.3 °C lower than present for the Parlung Zangbo River Valley.
Rapid screening of low‐molecular‐weight phenols from persimmon (Diospyros kaki) pulp using liquid chromatography/UV–visible/electrospray mass spectrometry analysis
Authors: Sentandreu Enrique , Cerdán‐Calero Manuela , Halket John M , Navarro José L
Published: August 2014

BACKGROUND

Persimmon fruits have been widely used in traditional medicine owing to their phenolic composition. This research aims to perform a rapid, detailed and affordable study of the profile of low‐molecular‐weight phenols from persimmon pulp.

RESULTS

Two different HPLC‐DAD/ESI‐MSn analyses were performed using a routine three‐dimensional ion trap mass spectrometer to analyze the ethanolic extract of persimmon pulp: (1) an untargeted data‐dependent analysis to identify the majority of small phenols that included full MS and MS2 scan events; (2) a targeted data‐dependent analysis to identify polymerized phenols (dimers and formic acid adducts) through a source‐induced dissociation analysis that included full MS and MS2 scan events. Thirty‐two low‐molecular‐weight phenols were detected, comprising gallic acid and its glycoside and acyl derivatives, glycosides of p‐coumaric, vanillic and cinnamic acids and different flavone di‐C‐hexosides, most of them reported for the first time in persimmon.

CONCLUSION

The use of a straightforward and affordable methodology of analysis led to obtain an up‐to‐date profiling of low‐molecular‐weight phenols in persimmon. The results can help future actions aimed to expand the understanding of the phenolic metabolome of persimmon cultivars. © 2014 Society of Chemical Industry
Purification and characterization of α‐acetolactate decarboxylase (ALDC) from newly isolated Lactococcus lactisDX
Authors: Guo Yuxing , Pan Daodong , Ding Haibing , Wu Zhen , Sun Yangying , Zeng Xiaoqun
Published: August 2014

BACKGROUND

Diacetyl (2,3‐butanedione) is a common flavor aroma from fermented dairy products. There is a need to screen new microorganisms that can efficiently produce large amounts of diacetyl.

RESULTS

A new lactic acid bacterium that produced high concentrations of diacetyl was identified based on Gram staining, microscopic examination and 16S rDNA sequence analysis as Lactococcus lactis DX. Its α‐acetolactate decarboxylase (ALDC) was purified using 0.45 g mL−1 ammonium sulfate precipitation, Sephacryl S‐300 and S‐200 HR and native‐PAGE. The purified ALDC displayed a monomer structure and had a molecular mass of about 73.1 kDa, which was estimated using SDS‐PAGE. IR analysis showed that the ALDC had a typical protein structure. The optimal temperature and pH for ALDC activity were 40 °C and 6.5 respectively. The ALDC of L. lactis DX was activated by Fe2+, Zn2+, Mg2+, Ba2+ and Ca2+, while Cu2+ significantly inhibited ALDC activity. Leucine, valine and isoleucine activated the ALDC.

CONCLUSION

A strain that had high ability to produce diacetyl was identified as L. lactis DX. The difference in diacetyl production may be due to the ALDC, which is different from other ALDCs. © 2014 Society of Chemical Industry
Mapping properties of the heat operator on edge manifolds
Authors: Bahuaud Eric , Dryden Emily B. , Vertman Boris
Published: August 2014

We consider the heat operator acting on differential forms on spaces with complete and incomplete edge metrics. In the latter case we study the heat operator of the Hodge Laplacian with algebraic boundary conditions at the edge singularity. We establish the mapping properties of the heat operator, recovering and extending the classical results from smooth manifolds and conical spaces. The estimates, together with strong continuity of the heat operator, yield short‐time existence of solutions to certain semilinear parabolic equations. Our discussion reviews and generalizes earlier work by Jeffres and Loya.
Modeling Thermal Properties for Copolymers Covering a Comonomer Composition Range up to 20%
Authors: Suárez Inmaculada , Ortega Jorge , Coto Baudilio
Published: August 2014

Differential scanning calorimetry (DSC) analysis for ethylene/propylene copolymers synthesized in the whole composition range with a supported metallocene catalyst has been carried out. The melting/crystallization process can be determined both in the ethylene and propylene rich regions covering a comonomer composition range of up to 20%. Two peaks are detected showing two different transitions (Tm1 and Tm2). A procedure is developed for modeling DSC melting curves by using a model previously reported by Kissin. Two contributions are considered for the copolymer crystallization in connection with a random comonomer distribution. Such model favourably describes experimental DSC curves and Tm1 and Tm2 values. The obtained parameters follow a regular trend in accordance with its physical meaning. Standard deviation for melting temperatures reveals accurate calculated values. The analysis of the parameter trend allows a fit against composition and predicting melting temperatures, yielding also accurate values.
Signaling in Takeover Auctions with Flexible Reserve Price
Authors: Khoroshilov Yuri
Published: August 2014

This paper develops a model of takeover auctions with a two‐step information acquisition process. It shows that the threat of extra information acquisition allows the existence of the signaling jump‐bidding equilibrium even when the seller is able to change its reserve price on the basis of the bidding history. The paper shows that although a higher cost of the secondary information leads to a higher expected price, the precision of the preliminary information has an ambiguous effect on the target's expected profit and that such an effect depends on the number of potential acquirers. Copyright © 2014 John Wiley & Sons, Ltd.
Electrical Properties of Microdischarge in Porous Zeolites
Authors: Koseoglu Kivilcim , Ozer Metin , Salamov Bahtiyar G.
Published: August 2014

The gas breakdown processes in dc microdischarges with a zeolite cathode (ZC) have been investigated. The electric field has a pronounce effect on the electrical characteristics of the ZC. The effects of electric field and secondary emission were discussed in atmospheric plasmas (AP). A nanoporous surface used as microreactor could enhance the electron emission from the cathode surface, thus reducing the breakdown voltage (UB). Results indicate that the UB decreases with increasing ZC diameter and decreasing with gap distance. Microdischarges in spatially confined geometries, such as the nanoporous structure of ZCs, present a promising method for the generation and maintenance of stable AP.
Deposition of Hydroxyl Functionalized Films by Means of Water Aerosol‐Assisted Atmospheric Pressure Plasma
Authors: Yang Yi‐Wei , Camporeale Giuseppe , Sardella Eloisa , Dilecce Giorgio , Wu Jong‐Shinn , Palumbo Fabio , Favia Pietro
Published: August 2014

The atmospheric pressure plasma deposition of hydroxyl functionalized hydrocarbon films is reported in this work, with a reactor fed with water aerosol and ethylene. The effects of power and feed flow rates onto film chemistry have been investigated. Coatings produced with this approach can find application in the biomedical field, among others, as platforms for cell adhesion and proliferation. Results show that operating at 4 kHz provides a much higher amount of hydroxyl group in the coating compared with samples obtained at 11 kHz. After water immersion, the stability of the films and their amount of hydroxyl groups remain high. A simplified deposition mechanism is proposed.
Dynamical string tension in string theory with spacetime Weyl invariance
Authors: Bars I. , Steinhardt P.J. , Turok N.
Published: August 2014

The fundamental string length, which is an essential part of string theory, explicitly breaks scale invariance. However, in field theory we demonstrated recently that the gravitational constant, which is directly related to the string length, can be promoted to a dynamical field if the standard model coupled to gravity (SM+GR) is lifted to a locally scale (Weyl) invariant theory. The higher gauge symmetry reveals previously unknown field patches whose inclusion turn the classically conformally invariant SM+GR into a geodesically complete theory with new cosmological and possibly further physical consequences. In this paper this concept is extended to string theory by showing how it can be “Weyl lifted” with a local scale symmetry acting on target space background fields. In this process the string tension (fundamental string length) is promoted to a dynamical field, in agreement with the parallel developments in field theory. We then propose a string theory in a geodesically complete cosmological stringy background which suggests previously unimagined directions in the stringy exploration of the very early universe.
Electron beam silicon purification
Authors: Kravtsov Anatoly , Kravtsov Alexey
Published: August 2014

Purification of heavily doped electronic grade silicon by evaporation of N‐type impurities with electron beam heating was investigated in process with a batch weight up to 50 kilos.

Effective temperature of the melt, an indicative parameter suitable for purification process characterization was calculated and appeared to be stable for different load weight processes. Purified material was successfully approbated in standard CZ processes of three different companies. Each company used its standard process and obtained CZ monocrystals applicable for photovoltaic application.

These facts enable process to be successfully scaled up to commercial volumes (150‐300 kg) and yield solar grade silicon. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An EBIC and SRP study on thermal donors in proton implanted p‐type magnetic Czochralski silicon
Authors: Faccinelli Martin , Kirnstoetter Stefan , Schustereder Werner , Laven Johannes G. , Hadley Peter
Published: August 2014

The concentration of defects in silicon can be changed by ion implantations and thermal annealing steps. Some of the defects incorporated during these processes form complexes which can act as donors or acceptors and their concentration can even overcome the initial doping concentration of the material, and hence, cause an inversion of the doping type. One way to introduce defects and also to catalyse the formation of defect complexes is by proton implantation. For our project, a high resistivity p‐type magnetic Czochralski (m:Cz) grown silicon wafer was implanted with 4 MeV protons at an implantation dose of 2 ×1014 cm–2. The wafer was broken into pieces and these pieces were annealed at different temperatures resulting in different concentrations of defect complexes. The defects were investigated in the proton implanted region and in the substrate region beyond the penetration depth of the protons (where only the heat treatment caused a change in the defect concentrations). The local doping type and the relative change of the minority carrier diffusion length were measured using Electron Beam Induced Current (EBIC). Furthermore, resistivity profiles were measured using Spreading Resistance Profiling (SRP). The results show several changes of the doping type, the minority carrier diffusion length and the resistivity profile. In addition to donor complexes already reported in the literature, the formation of additional high temperature donor complexes has been observed. The data shows that the presence of hydrogen in silicon has a far higher influence on the changes of the electrical properties of the material at annealing temperatures between 400 °C and 510 °C than at higher annealing temperatures. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrically detected magnetic resonance study on defects in Si pn‐junctions created by proton implantation
Authors: Gruber Gernot , Kirnstoetter Stefan , Hadley Peter , Koch Markus , Aichinger Thomas , Schulze Holger , Schustereder Werner
Published: August 2014

The present study focuses on electrically detected magnetic resonance (EDMR) investigations of proton implanted silicon. The samples were prepared on n‐type silicon wafers highly doped diffused boron (B) p‐region, forming a pn‐junction. A large additional n‐type doping was introduced by proton (H+) implantation. We compare samples with implantation doses up to 1015 H+/cm–2 and investigate the effects of anneals at 350 °C. We observe different types of defects in the differently prepared samples. One doublet with 118.5 G HF splitting and a g ‐value of 2.0095(4) is only observed in the samples implanted with the highest dose and is assigned to hydrogen. The structure of the other observed defects remains unidentified and can only tentatively be assigned to hydrogen. More extensive measurements would have to be performed to get a better picture. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Band engineering and absorption spectra in compressively strained Ge0.92Sn0.08/Ge (001) double quantum well for infrared photodetection
Authors: Yahyaoui N. , Sfina N. , Lazzari J.‐L. , Bournel A. , Said M.
Published: August 2014

We report a theoretical investigation of strained Ge1−xSnx/Ge (001)‐oriented quantum wells as a bulding block in active region of infrared photodetector. The electronic band parameters, gaps, discontinuities and effective masses for heterointerfaces between compressively strained Ge1−xSnx and relaxed Ge have beencomputed at room temperature. From this preliminary and mendatory work, we conclude that pseudomorphic Ge1−xSnx alloys become direct band gap semiconductors at a Sn‐fraction of 15.3%, e.g. a lattice mismatch as high as 2.3%. Due to achievable critical layer thickness and mainly solid solubility limit, a type‐I compressively strained Ge/Ge0.92Sn0.08/Ge (double) quantum well is studied by solving Schrödinger equation without and applied bias voltage. A strong absorption coefficient (> 1×104 cm−1) and a Stark shift of the direct transition between 2.01 μm and 2.25 μm at large external fields (40kV/cm) are attractive characteristics for the design of infrared photodetectors (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multi‐frequency electron spin resonance study of inherent Si dangling bond defects at the thermal (211)Si/SiO2 interface
Authors: Iacovo S. , Stesmans A.
Published: August 2014

Multifrequency low temperature electron spin resonance (ESR) studies were carried out to atomically assess inherent point defects at the thermal ‘higher index' (211)Si/SiO2 interface. This reveals, as dominant imperfections, Pb‐type centers (generic entity Si3≡Si•, the dot representing an unpaired sp3‐like hybrid) occurring in densities of ∼1 × 1013 cm–2 for oxidation temperatures ∼400 °C. On the basis of the pertinent ESR characteristics, the inherent basic defect is typified as the Pb0(211) variant, resembling closely the Pb0 center in standard (100)Si/SiO2. At the higher index (211)Si/SiO2 interface, these defects predominantly pertain to defected Si atoms located at (111)‐face terraces. Combination of angular and frequency (ν) dependent studies show the Pb0(211) peak‐to‐peak line width ΔBpp to be composed of a residual width (ν→0) of 2.2 ± 0.1 G, to which dipolar broadening contributes an essential part, and a substantial inhomogeneous broadening component due to g distribution, predominantly in g⊥, induced by non‐uniform interface strain –also similar to the Pb0(100) properties. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Design of secure access control scheme for personal health record‐based cloud healthcare service
Authors: Liu Chia‐Hui , Lin Fong‐Qi , Chen Chin‐Sheng , Chen Tzer‐Shyong
Published: August 2014

With the development of information technology and medical technology, many developed countries have established organizations to develop electronic medical standards in response to apply the development of technology information, and they gradually develop the emerging patterns of personal health records (PHRs). PHR can integrate different kinds of health information and can offer the integrity and accuracy of personal health and medical records. Using the cloud computing environment to implement the PHR system; we can decrease the infrastructure management costs, adjusting the dynamic resources immediately on the basis of the changes of client's demand and other advantages. To assure that the security information in cloud computing environment is important to users, this paper provides efficient and safe access managing mechanism to solve PHR implement on cloud environment's security problem, avoiding possibility that the information security being threatened in the Cloud may lead to the collapse of medical care, patients' stolen data, loss of personal privacy, and financial or other serious consequences. This paper presents bilinear pairing that was constructed in the cloud computing environment of the new PHR access control mechanism, which suited for deploying a large‐scale and multiple identities of users, and users are safe and efficient in accessing the PHR information. Copyright © 2014 John Wiley & Sons, Ltd.
Mitochondria-targeted therapies for acute kidney injury
Authors: Tábara Luis Carlos , Poveda Jonay , Martin-Cleary Catalina , Selgas Rafael , Ortiz Alberto , Sanchez-Niño Maria D.
Published: August 2014

Acute kidney injury (AKI) is a serious clinical condition with no effective treatment. Tubular cells are key targets in AKI. Tubular cells and, specifically, proximal tubular cells are extremely rich in mitochondria and mitochondrial changes had long been known to be a feature of AKI. However, only recent advances in understanding the molecules involved in mitochondria biogenesis and dynamics and the availability of mitochondria-targeted drugs has allowed the exploration of the specific role of mitochondria in AKI. We now review the morphological and functional mitochondrial changes during AKI, as well as changes in the expression of mitochondrial genes and proteins. Finally, we summarise the current status of novel therapeutic strategies specifically targeting mitochondria such as mitochondrial permeability transition pore (MPTP) opening inhibitors (cyclosporine A (CsA)), quinone analogues (MitoQ, SkQ1 and SkQR1), superoxide dismutase (SOD) mimetics (Mito-CP), Szeto-Schiller (SS) peptides (Bendavia) and mitochondrial division inhibitors (mdivi-1). MitoQ, SkQ1, SkQR1, Mito-CP, Bendavia and mdivi-1 have improved the course of diverse experimental models of AKI. Evidence for a beneficial effect of CsA on human cardiac ischaemia–reperfusion injury derives from a clinical trial; however, CsA is nephrotoxic. MitoQ and Bendavia have been shown to be safe for humans. Ongoing clinical trials are testing the efficacy of Bendavia in AKI prevention following renal artery percutaneous transluminal angioplasty.
Religious Revival and the Politics of Nation Building: Reinterpreting the 1963 ‘Buddhist crisis’ in South Vietnam
Authors: MILLER EDWARD
Published: August 2014

Scholars have portrayed the 1963 ‘Buddhist crisis’ in South Vietnam as a struggle for religious freedom, as a political conspiracy, or as a manifestation of ancient religious beliefs and practices. This paper, in contrast, argues that the crisis emerged from a clash of modernizing visions. The Buddhist-led protests that took place in South Vietnam in 1963 were linked to the Vietnamese Buddhist revival, a nationalist reform movement that began during the early twentieth century. The protests also reflected growing Buddhist anxieties about the Ngo Dinh Diem government's nation-building agenda for South Vietnam. By the time the crisis began, Buddhist leaders had concluded that this agenda (which Diem referred to as the ‘Personalist Revolution’) was incompatible with their plans to realize Vietnam's destiny as a ‘Buddhist nation’. In addition to reinterpreting the origins of the crisis, this paper examines how the course of events was shaped by the personalities and agendas of particular Buddhist and government leaders, and especially by fierce rivalries among members of Diem's family. These internal tensions help to explain the failure of attempts to end the crisis through negotiations, as well as Diem's decision to crush the movement by force in August 1963.
Cities Where Women Rule: Female Political Incorporation and the Allocation of Community Development Block Grant Funding
Authors: Smith Adrienne R.
Published: August 2014

While individual women representatives in government have been found to behave differently than men, the causal connection between the increased presence of women in elected offices and the production of women-friendly policies is tenuous at best. This study leverages the variation in women's office holding, government structures, and policy outputs found in American cities to address that puzzle. It argues that when women obtain leadership positions in municipal government and when the positions they hold have greater power relative to other municipal positions, cities will be more likely to produce policy outputs that are often associated with women's interests and needs. Utilizing an original city-level dataset and modeling women's presence as mayors and policy outputs endogenously, the results reveal that empowered female executives in municipal governments influence expenditure decisions made as part of the federal Community Development Block Grant program. The findings suggest that political scientists should consider not only the presence of an underrepresented group, but also the relative amount of power that group has when assessing the effects on substantive representation.
Gender Stereotypes and Corruption: How Candidates Affect Perceptions of Election Fraud
Authors: Barnes Tiffany D. , Beaulieu Emily
Published: August 2014

How do stereotypes of female candidates influence citizens' perceptions of political fraud and corruption? Because gender stereotypes characterize female politicians as more ethical, honest, and trustworthy than male politicians, there are important theoretical reasons for expecting female politicians to mitigate perceptions of fraud and corruption. Research using observational data, however, is limited in its ability to establish a causal relationship between women's involvement in politics and reduced concerns about corruption. Using a novel experimental survey design, we find that the presence of a female candidate systematically reduces the probability that individuals will express strong suspicion of election fraud in what would otherwise be considered suspicious circumstances. Results from this experiment also reveal interesting heterogeneous effects: individuals who are not influenced by shared partisanship are even more responsive to gender cues; and male respondents are more responsive to those cues than females. These findings have potential implications for women running for office, both with respect to election fraud and corruption more broadly, particularly in low-information electoral settings.