bluuebunny/crossref_metadata_2025 huggingface dataset:
Opportunities and challenges for analysis of wildlife trade using CITES data – seahorses as a case study
Authors: Foster Sarah , Wiswedel Stefan , Vincent Amanda
Published: September 2014

In principle, the database generated by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) offers an unparalleled opportunity to analyse trade in species of conservation concern.

The value of the database is assessed in the context of trade in 47 species of seahorse (Hippocampus spp.), all of which are included on CITES Appendix II. This listing requires that all 180 Parties to CITES (member Parties) limit exports to levels that do not damage wild populations, ensure they are obtained legally, and report their trade to CITES.

An evident need for greater universal compliance with CITES reporting requirements was identified. The most glaring problem was a substantial mismatch in species and volumes between export records and import records, indicating that neither dataset is complete nor reliable.

The evaluation also showed that Parties should increase compliance with CITES requirements to record all trade shipments, provide units for exports (e.g. individuals, kilograms) and identify exported taxa to species, perhaps supported by automated checking of entries.

The challenges with the CITES trade database were more evident for the global trade in dried seahorses than the smaller and more easily‐tracked trade in live seahorses. Nonetheless, CITES’ data from 2004–2011 revealed a seahorse trade involving millions of animals, tens of species, and scores of Parties.

CITES data have also proven invaluable in supporting CITES reviews of how Parties are implementing the Convention for seahorses, and in generating consequent action for their conservation.

Copyright © 2014 John Wiley & Sons, Ltd.
Internalization of Aquaporin‐4 After Collagenase‐Induced Intracerebral Hemorrhage
Authors: Xu Jin , Qiu Guo‐Ping , Huang Juan , Zhang Bo , Sun Shan‐Quan , Gan Sheng‐Wei , Lu Wei‐Tian , Wang Ke‐Jian , Huang Si‐Qin , Zhu Shu‐Juan
Published: September 2014

Brain edema formation following intracerebral hemorrhage (ICH) appears to be related with aquaporin‐4 (AQP4), which is critically involved in brain volume homeostasis and water balance. Despite its importance, the regulation of AQP4 expression involved in transmembrane water movements still remains rudimentary. Many studies suggest that the internalization of several membrane‐bound proteins, including AQP4, may occur with or without lysosomal degradation. Previously, we investigated the internalization of AQP4 in retinal ischemic‐reperfusion model. Here, we test the hypothesis that AQP4 is internalized post‐ICH and then degraded in the lysosome. The results demonstrated that both AQP4 and the mannose‐6‐phosphate receptor (MPR) co‐localized in perihematomal region at 6 hr post‐ICH. In addition, AQP4 and lysosomal‐associated membrane protein 1 (LAMP1) also co‐localized in perihematomal region, with co‐expression increasing followed by a gradual decrease at different time windows post‐ICH (6, 12, 24, 48, and 72 hr). After ICH, the Evans blue leakage happened very early at 1 hr and the brain swelling occurred at 3 hr. Moreover, we also found the AQP4 mRNA and AQP4 protein were increased post‐ICH. These results suggest that AQP4 is internalized and the lysosome is involved in degrading the internalized AQP4 post‐ICH. Both the AQP4 internalization and lysosomal degradation may provide biophysical insights regarding the potential of new treatments for brain edema. Anat Rec, 298:554–561, 2015. © 2014 Wiley Periodicals, Inc.
Advantage of the N‐Alkylation Strategy for Retaining the Molecular Planarity for Oligothiophene/Imidazole/1,10‐Phenanthroline‐Based Heterocyclic Semiconducting and Fluorescent Compounds
Authors: Peng Yu‐Xin , Tao Tao , Wang Xiao‐Xu , Ma Bin‐Bin , Zhang Kun , Huang Wei
Published: September 2014

A family of planar oligothiophene/imidazole/1,10‐phenanthroline (OTIP)‐based heterocyclic, aromatic, semiconducting, and fluorescent compounds with N‐substituted alkyl chains (allyl, n‐butyl, n‐octyl, n‐dodecyl, and n‐cetyl) have been designed and synthesized. They all have specific N‐coordination sites, various donor–acceptor spacers, good molecular planarity, suitable solubility, and high thermal stability. In comparison with conventional double β‐alkylation of the thiophene ring, our results reveal that the single imidazole N‐alkylation strategy for OTIPs has the advantage of maintaining the planarity of the whole molecule, in addition to improving the solubility, which can be clearly verified by the small dihedral angles between adjacent thiophene/imidazole/1,10‐phenanthroline (TIP) rings in eight X‐ray single‐crystal structures. In particular, n‐dodecyl‐ and n‐cetyl‐substituted OTIPs (7 and 8) with the same molecular length of 2.37 nm (MW=939 and 1052), show good molecular planarity with the aforementioned dihedral angles of 8.9(5) and 10.4(5)°. Furthermore, special attention has been paid to the physicochemical properties of seven symmetrical OTIPs (6–8, 13–15, and 19), including two to six thiophene rings in the middle of their molecular structures. To the best of our knowledge, this is the first synthetic, structural, and spectral investigation into the N‐alkylation of OTIP‐based compounds.
Enantioselective, Desymmetrizing, Bromolactonization Reactions of Symmetric Olefinic Dicarboxylic Acids
Authors: Murai Kenichi , Nakajima Junki , Nakamura Akira , Hyogo Norimichi , Fujioka Hiromichi
Published: September 2014

The results of studies leading to the development of enantioselective desymmetrizing, bromolactonization reactions of symmetric olefinic dicarboxylic acids, which are promoted by a C3‐symmetric trisimidazoline catalyst, are described. These processes generated carboxylic‐acid‐containing bromolactones in moderately high enantiomeric excesses. The results of optimization studies showed that reactions in a mixed solvent system of toluene and acetone proceeded with the highest levels of enantioselectivity. NMR studies probing the interactions between the catalyst and dicarboxylic acid substrates, as well as the effect of acetone on the stereochemistry of the process, are also described.
Device therapy for atrial septal defects in a multicenter cohort: Acute outcomes and adverse events
Authors: El‐Said Howaida , Hegde Sanjeet , Foerster Susan , Hellenbrand William , Kreutzer Jacqueline , Trucco Sara M. , Holzer Ralf , Burch Grant , Mirani Ajay , Nicolas Ramzi , Porras Diego , Bergersen Lisa , Moore John
Published: September 2014

Background: Secundum atrial septal defect (ASD) closure devices were granted approval based on industry‐sponsored, prospective, nonrandomized, single device studies, demonstrating acceptable efficacy and safety in selected patients. We sought to report community practice and outcomes. Methods and Results: Procedure specific data was collected on cases considered for ASD closure in the congenital cardiac catheterization project on outcomes (C3PO) between February 1, 2007 and June 31, 2010. Eight centers contributed data during this time period. All adverse events (AE) were independently reviewed and classified by a five level severity scale. In 40 months (2/07–6/10), 653 of 688 ASDs were occluded with a single device using an AMPLATZER® Septal Occluder (ASO) in 566 (87%), GORE® HELEX® Septal Occluder (HSO) in 33 (5%), and a CardioSEAL® or STARFlex™ device (CSD) in 54 (8%). Most patients had an isolated ASD (93%). 85% were >2 years of age. The ASD median diameter was 12 mm [8,16] for ASO, with smaller diameters in HSO 8 mm [7,10] and CSD 8 mm [5,10] (P < 0.001). AE (n = 82) were recorded in 76 cases, 11.5% (95% CI 9.2%, 14.1%) and classified as high severity in 4.7% (95% CI 3.2%, 6.5%), with no mortality. A new conduction abnormality was detected during 15 cases and did not resolve in one. Transcatheter device retrieval was possible in 7 of 10 device embolizations. Device erosion occurred in 3 of 566, 0.5% (95% CI 0.1%, 1.5%), ASO implants. Conclusion: Although device closure of ASDs is associated with low morbidity and rare mortality, ongoing assessment of device safety profiles are warranted, and registries offer opportunities to facilitate the required surveillance. © 2014 Wiley Periodicals, Inc.
Iatrogenic left pulmonary artery to left atrium fistula
Authors: Abou Zahr Riad , Hellenbrand William E. , Asnes Jeremy D.
Published: September 2014

Trans‐catheter balloon angioplasty is a well‐established treatment modality for pulmonary artery (PA) stenosis in children with congenital heart disease. We report a case of an unusual complication where a fistula developed between the left PA and the left atrium during balloon angioplasty in a patient with history of tetralogy of Fallot. This was successfully treated with placement of a covered stent. © 2014 Wiley Periodicals, Inc.
Sandwich‐Nanostructured NiO–ZnO Nanowires@α‐Fe2O3 Film Photoanode with a Synergistic Effect and p–n Junction for Efficient Photoelectrochemical Water Splitting
Authors: Zhang Chao , Fan Weiqiang , Bai Hongye , Yu Xiaoqiang , Chen Chao , Zhang Rongxian , Shi Weidong
Published: September 2014

A new sandwich‐nanostructured film photoanode with synergistic effect and a p–n junction based on NiOZnO nanowires (NWs)@α‐Fe2O3 are synthesized for photoelectrochemical (PEC) water splitting. The sandwich‐nanostructured film photoanode is systematically characterized by scanning electron microscopy, X‐ray diffraction, transmission electron microscopy (TEM), and high‐resolution TEM. The PEC performances are characterized by the photocurrent densities versus potential curves, photocurrent densities versus time curves, and the incident photon to current efficiency curves. In addition, the sandwich‐nanostructured NiOZnO NWs@α‐Fe2O3 film photoanode shows significantly enhanced PEC performance compared with α‐Fe2O3 and ZnO NWs@α‐Fe2O3; this is mainly due to the synergistic effect and the construction of a p–n junction in NiOZnO NWs@α‐Fe2O3. Furthermore, the photoanode exhibits optimal PEC performance when the reacting concentration of nickel nitrate hexahydrate is 2.0 M.
Platinum‐Modified Gold Electrocatalysts for the Hydrogen Oxidation Reaction in Alkaline Electrolytes
Authors: Mahoney Elizabeth G. , Sheng Wenchao , Yan Yushan , Chen Jingguang G.
Published: September 2014

Alkaline fuel cells offer advantages over acidic fuel cells because of the relaxed necessity for platinum (Pt) electrocatalysts and the increased stability of non‐Pt‐group metals at high pH values. While this offers the possibility of less expensive electrocatalysts, the activity of non‐Pt‐group metals is still low in comparison to Pt. Reducing the amount of Pt needed for fuel oxidation by modification can effectively lower the cost of the catalyst while maintaining a high oxidation activity. Here we compare Pt‐modified Au (Pt/Au), Pt, and Au disk electrodes for the oxidation of hydrogen. The Pt/Au surface exhibits a hydrogen oxidation activity similar to that of bulk Pt and far superior to that of a pure Au disk. Pt‐modified Au/C (Pt/Au/C) exhibits an activity similar to that of supported Pt/C.
Preferential Formation of SiOC over SiC Linkage upon Thermal Grafting on Hydrogen‐Terminated Silicon (111)
Authors: Khung Yit Lung , Ngalim Siti Hawa , Meda Laura , Narducci Dario
Published: September 2014

In a stringent and near oxygen‐free environment, SiH surfaces were introduced to a trifluoroalkyne, an alcohol‐derivatized alkyne, as well as an equal mixture of both alkynes at a temperature of 130 °C. Contact angle measurements, high‐resolution X‐ray photoelectron spectroscopy (XPS), and angle‐resolved XPS were performed to examine the system. SiH surfaces were found to have a strong preference towards the formation of SiOC rather than SiC bonds when the alcohol and alkyne reactivities were compared.
Saturated Red‐Light‐Emitting Gold(III) Triphenylamine Dendrimers for Solution‐Processable Organic Light‐Emitting Devices
Authors: Tang Man‐Chung , Chan Carmen Ka‐Man , Tsang Daniel Ping‐Kuen , Wong Yi‐Chun , Chan Maggie Mei‐Yee , Wong Keith Man‐Chung , Yam Vivian Wing‐Wah
Published: September 2014

A novel isoquinoline‐containing C^N^C ligand and its phosphorescent triphenylamine‐based alkynylgold(III) dendrimers have been synthesized. These alkynylgold(III) dendrimers serve as phosphorescent dopants in the fabrication of efficient solution‐processable organic light‐emitting devices (OLEDs). The photophysical, electrochemical, and electroluminescence properties were studied. A saturated red emission with CIE coordinates of (0.64, 0.36) and a high EQE value of 3.62 % were achieved. Unlike other red‐light‐emitting iridium(III) dendrimers, a low turn‐on voltage of less than 3 V and a reduced efficiency roll‐off at high current densities were observed; this can be accounted for by the enhanced carrier transporting ability and the relatively short lifetimes in the high‐generation dendrimers. This class of alkynylgold(III) dendrimers are promising candidates as phosphorescent dopants in the fabrication of solution‐processable OLEDs.
Thermodynamic and Mechanical Timescales Involved in Foam Film Rupture and Liquid Foam Coalescence
Authors: Rio Emmanuelle , Biance Anne‐Laure
Published: September 2014

Recent advances in the coalescence in liquid foams are reviewed, with a special focus on the multiscale structure of foams. Studies concerning the stability of isolated foam films, on the one hand, and the coalescence process in macroscopic foams, on the other hand, are not always in good agreement. This discrepancy reveals that two routes can induce coalescence in a foam. The first route is thermodynamic and shows that coalescence is governed by a stochastic rupture of foam films. The second route relies on a mechanically induced rupture of the films, due to the spontaneous evolution of foams. From a literature review, the evaluation of the different timescales involved in these mechanisms allows defining the limiting parameters of foam coalescence.
Fluorescence Confocal Polarizing Microscopy of a Fluorescent Bent‐Core Liquid Crystal Exhibiting Polarization Splay Modulated (B7) Structures and Defects
Authors: Deb Rajdeep , Oneill Matt , Rao Nandiraju. V. S. , Clark Noel A. , Smalyukh Ivan I.
Published: September 2014

The B7 phases of bent‐core molecules are polarization splay modulated fluid smectics that exhibit an unusually complex variety of exotic macroscopic structures, textures, and defects visible in polarized light microscopy. Herein we describe optical studies of these structures using fluorescence confocal polarizing microscopy (FCPM) and depolarized transmission optical microscopy to probe their organization in three dimensions. These experiments utilize recently reported fluorescent bent‐core molecules designed to give strong polarized fluorescence. This new bent‐core molecular family provides the means for probing a variety of bent‐core phases and structures by using FCPM and multiphoton fluorescence nonlinear imaging techniques. Comparative textural analysis of the B7 structures obtained using different types of imaging and the corresponding structural models are discussed.
A Theoretical Study of the Interaction of Hydrogen and Oxygen with Palladium or Gold Adsorbed on Pyridine‐Like Nitrogen‐Doped Graphene
Authors: Rangel Eduardo , Magana Luis Fernando , Sansores Luis Enrique
Published: September 2014

The interaction of H2 and O2 molecules in the presence of nitrogen‐doped graphene decorated with either a palladium or gold atom was investigated by using density functional theory. It was found that two hydrogen molecules were adsorbed on the palladium atom. The interaction of these adsorbed hydrogen molecules with two oxygen molecules generates two hydrogen peroxide molecules first through a Eley–Rideal mechanism and then through a Langmuir–Hinshelwood mechanism. The barrier energies for this reaction were small; therefore, we expect that this process may occur spontaneously at room temperature. In the case of gold, a single hydrogen molecule is adsorbed and dissociated on the metal atom. The interaction of the dissociated hydrogen molecule on the surface with one oxygen molecule generates a water molecule. The competitive adsorption between oxygen and hydrogen molecules slightly favors oxygen adsorption.
Cover Image
Authors: Miura Hirohito , Scott Jennifer K. , Harada Shuitsu , Barlow Linda A.
Published: September 2014

Background: Taste buds contain ∼60 elongate cells and several basal cells. Elongate cells comprise three functional taste cell types: I, glial cells; II, bitter/sweet/umami receptor cells; and III, sour detectors. Although taste cells are continuously renewed, lineage relationships among cell types are ill‐defined. Basal cells have been proposed as taste bud stem cells, a subset of which express Sonic hedgehog (Shh). However, Shh+ basal cells turn over rapidly suggesting that Shh+ cells are post‐mitotic precursors of some or all taste cell types. Results: To fate map Shh‐expressing cells, mice carrying ShhCreERT2 and a high (CAG‐CAT‐EGFP) or low (R26RLacZ) efficiency reporter allele were given tamoxifen to activate Cre in Shh+ cells. Using R26RLacZ, lineage‐labeled cells occur singly within buds, supporting a post‐mitotic state for Shh+ cells. Using either reporter, we show that Shh+ cells differentiate into all three taste cell types, in proportions reflecting cell type ratios in taste buds (I > II > III). Conclusions: Shh+ cells are not stem cells, but are post‐mitotic, immediate precursors of taste cells. Shh+ cells differentiate into each of the three taste cell types, and the choice of a specific taste cell fate is regulated to maintain the proper ratio within buds. Developmental Dynamics 243:1286–1297, 2014. © 2014 Wiley Periodicals, Inc.
Diversity of honey stores and their impact on pathogenic bacteria of the honeybee, Apis mellifera
Authors: Erler Silvio , Denner Andreas , Bobiş Otilia , Forsgren Eva , Moritz Robin F. A.
Published: September 2014

Honeybee colonies offer an excellent environment for microbial pathogen development. The highest virulent, colony killing, bacterial agents are Paenibacillus larvae causing American foulbrood (AFB), and European foulbrood (EFB) associated bacteria. Besides the innate immune defense, honeybees evolved behavioral defenses to combat infections. Foraging of antimicrobial plant compounds plays a key role for this “social immunity” behavior. Secondary plant metabolites in floral nectar are known for their antimicrobial effects. Yet, these compounds are highly plant specific, and the effects on bee health will depend on the floral origin of the honey produced. As worker bees not only feed themselves, but also the larvae and other colony members, honey is a prime candidate acting as self‐medication agent in honeybee colonies to prevent or decrease infections. Here, we test eight AFB and EFB bacterial strains and the growth inhibitory activity of three honey types. Using a high‐throughput cell growth assay, we show that all honeys have high growth inhibitory activity and the two monofloral honeys appeared to be strain specific. The specificity of the monofloral honeys and the strong antimicrobial potential of the polyfloral honey suggest that the diversity of honeys in the honey stores of a colony may be highly adaptive for its “social immunity” against the highly diverse suite of pathogens encountered in nature. This ecological diversity may therefore operate similar to the well‐known effects of host genetic variance in the arms race between host and parasite.
COGNITIVE ASSESSMENT AND THE MEDIA
Authors: Oltman Philip K.
Published: September 2014

The present‐day information environment is heavily saturated with electronic media. What are the properties of these media, and how does massive exposure to them affect the cognitive functioning of the audience? These and related issues are reviewed, and some implications for cognitive assessment are suggested.
REVIEW OF PROBLEM SOLVING SKILLS
Authors: Baird Leonard L.
Published: September 2014

This review considers the question as to whether there are generic problem‐solving skills that cut across fields or whether the skills are so embedded within specific fields that they can be identified only within the contexts of those fields. To answer this question, an attempt was made to define both “problems” and their “solution.” Then the evidence for the existence of general problem solving skills that are independent from any specific field was examined. Then the analyses of skills within disciplines were reviewed to see if the skills are common across fields. Finally, the implications of the research for the assessment of problem‐solving skills were discussed. In general, it was concluded that similar skills are used in different fields but that their implementation is so dependent on mastery of the specific fields that any assessment of problem‐solving skills would best be conducted within the fields.
SPANISH TRANSLATION AND FEASIBILITY STUDY OF RANGER RICK'S NATURE MAGAZINE
Authors: Shipman Virginia C.
Published: September 2014

The present study represented the interests of the National Science Foundation, The National Wildlife Federation and Educational Testing Service in instructional materials for students of Hispanic background with limited English language proficiency. The study was designed to (a) evaluate the acceptance, appropriateness, and use of an experimental Spanish edition of Ranger Rick's Nature Magazine; (b) identify similarities and differences in reaction by diverse groups within the Hispanic population; and (c) collect and analyze recommendations from the field test sample for the Spanish edition program materials and services. The findings were based on a large nationwide sample of students that varied on the following characteristics: Hispanic origin (Mexican American, Puerto Rican, and Cuban), type of community (urban, suburban, and rural), family socioeconomic status, grade level (four through eight), and level of Spanish and English proficiency. Information also was provided by school administrative and teaching staff. Data were collected by mailed questionnaires and by both interviews and observation at a sample of the study sites. The results indicated that the approach represented by the Spanish edition of Ranger Rick has merit, well serves a variety of pressing educational needs and should be pursued further. Acceptance of the magazine was high for the various ethnic groups represented. Variability within sites, however, reflected differences in students' Spanish competencies, teachers' attitudes and skills, and the particular sociocultural context.
AN INVESTIGATION OF METHODS FOR REDUCING SAMPLING ERROR IN CERTAIN IRT PROCEDURES*
Authors: Wingersky Marilyn S. , Lord Frederic M.
Published: September 2014

The sampling errors of maximum likelihood estimates of item‐response theory parameters are studied in the case where both people and item parameters are estimated simultaneously. A check on the validity of the standard error formulas is carried out. The effect of varying sample size, test length, and the shape of the ability distribution is investigated. Finally, the effect of anchor‐test length on the standard error of item parameters is studied numerically for the situation, common in equating studies, where two groups of examinees each take a different test form together with the same anchor test. The results encourage the use of rectangular or bimodal ability distributions, also the use of very short anchor tests.
AN EXPLORATORY ANALYSIS OF PERFORMANCE ON THE SAT
Authors: Wainer Howard
Published: September 2014

Methods of exploratory data analysis are used to decompose data tables which portray the performance of various ethnic groups on the Scholastic Aptitude Test (the SAT). These analyses show: the size and structure of the differences in performance among the ethnic groups studied, the nature of changes across time, and the interactions between ethnic group membership and time. Suggestions regarding the clear display of results from data in this form are made and illustrated.
SURVEYS COMBINING PROBABILITY AND QUOTA METHODS OF SAMPLING
Authors: King Benjamin F.
Published: September 2014

The problem of choosing between full probability and quota sampling is discussed in terms of a Bayesian model of biased measurement. The original model is elaborated upon to better approximate the multistage cluster sampling that is used in actual national surveys. Allocation rules are developed that may involve devotion of resources to total quota sampling, or to total probability sampling, or to designs that combine both types of sampling. The sensitivity of the optimal allocation to the specification of the prior distribution and the cost parameters is investigated.
ASSESSMENT OF BEGINNING READING: A FRAMEWORK FOR CODING ERROR PATTERNS IN ORAL READING PERFORMANCE
Authors: Chittenden Edward A.
Published: September 2014

This project investigated error patterns in young children's oral reading behaviors for the purpose of constructing a rationale and set of preliminary procedures to code major dimensions in skill acquisition. Audiotaped reading samples, taken from the case study files of 21 children, constituted the raw data. Three performance indicators were analyzed: control of the reading process; selective use of knowledge resources in response to features of text; and strategies in reading as an expression of stylistic preferences. This work is an outgrowth of observational studies of beginning readers, and is intended to contribute to the development of performance‐sample techniques for classroom assessment of reading.
ESTIMATING ABILITY WITH THREE ITEM RESPONSE MODELS WHEN THE MODELS ARE WRONG AND THEIR PARAMETERS ARE INACCURATE
Authors: Jones Douglas H. , Wainer Howard , Kaplan Bruce
Published: September 2014

We investigate the accuracy of the maximum likelihood estimator of ability for the one‐ two‐ and three‐parameter logistic models. This is accomplished by fitting of those models to generated item characteristic curves derived from the Armed Services Vocational Aptitude Battery. The mathematical details as to how this is accomplished and our results are included. Among these results is the finding that the 3‐PL model is the least biased, but that for lower abilities it has both the highest M.S.E. and is the most fragile with respect to sampling fluctuations of the parameter estimates. It is recommended that the current practice of utilizing some method of restricting the variability of parameters continue to be employed (i.e., Bayesian priors, robust estimation, fixing some parameters to be constant).
MAXIMUM LIKELIHOOD AND BAYESIAN PARAMETER ESTIMATION IN ITEM RESPONSE THEORY*
Authors: Lord Frederic M.
Published: September 2014

Advantages and disadvantages of joint maximum likelihood, marginal maximum likelihood, and Bayesian methods of parameter estimation in item response theory are discussed and compared.
THE GRAPHICAL DISPLAY OF SIMULATION RESULTS WITH APPLICATIONS TO THE COMPARISON OF ROBUST IRT ESTIMATORS OF ABILITY
Authors: Thissen David , Wainer Howard
Published: September 2014

Simulation studies of the performance of (potentially) robust statistical estimators usually proceed by applying each of several estimators to several samples of datasets generated under a variety of circumstances. The estimators which do “best” (have the least bias or MSE or both) under many circumstances are declared “good”. Such studies produce large quantities of numbers, in the form of indices of the performance of the various estimators under various conditions. These numbers form the results of the study, and so must be examined in detail. In our current study of robust IRT ability estimators, tabular presentation of the results has become truly unmanageable; that is, obtaining the numbers or doing the simulation is only part of the problem, understanding the excessively plentiful results is another considerable part. To aid in the digestion of such a collection of numbers, we have turned to multivariate graphical display.
CONJUNCTIVE AND DISJUNCTIVE ITEM RESPONSE FUNCTIONS
Authors: Lord Frederic M.
Published: September 2014

Given that the examinee knows the answer to item i if and only if he knows the answer to both item g and item h, a ‘conjunctive’ item response model is required such that items g, h, and i all have the same mathematical form of response function. Since such items may occur in practice, it is desirable that item response models satisfy this condition. For models with two parameters per item, the most general functional form satisfying this condition is found. A third, ‘guessing’ parameter may be added. The corresponding disjunctive model is also derived.
REDUCED RANK CLASSIFICATION
Authors: Dorans Neil J.
Published: September 2014

Two reduced rank classification procedures, principal components classification and equal weights classification, are described and compared via a simulation study to the standard classification procedure to determine their feasibilities as alternative classification procedures. First, a justification for the development of these two reduced rank procedures is provided. Then, the two reduced rank rules are derived. The simulation design is described in detail. The simulation results demonstrate that the reduced rank procedures are preferable to the standard procedure under certain conditions, i.e., when they appropriately incorporate prior information about population structure into their classification rules. Suggestions for future research are offered.
AN ASSESSMENT OF THE RELATIONSHIP BETWEEN THE ASSUMPTION OF UNIDIMENSIONALITY AND THE QUALITY OF IRT TRUE‐SCORE EQUATING1,2,3
Authors: Cook Linda L. , Dorans Neil J. , Eignor Daniel R. , Petersen Nancy S.
Published: September 2014

A strong assumption made by most commonly used item response theory (IRT) models is that the data are unidimensional, i.e., statistical dependence among item scores can be explained by a single ability dimension. One of the major practical applications of item response theory models to testing has been in the area of score equating. This research assesses the relationship between violations of the assumption of unidimensionality and the quality of IRT true‐score equating. First‐order and second‐order factor analyses were conducted on correlation matrices among item parcels. The item parcels were constructed to yield correlation matrices that were amenable to linear factor analyses. The first‐order analyses were employed to assess the effective dimensionality of the item parcel data. Second‐order analyses were employed to test meaningful hypotheses about the structure of the data, hypotheses that were suspected to be pertinent to the quality of equating results. Parcels were constructed for three SAT‐verbal forms and three forms of the Mathematics Level II Achievement test. The quality of IRT true‐score equating was assessed by score scale drift. Scale drift is said to have occurred if the results of equating test form D directly to test form A is not the same as that obtained by equating test form D to test form A through intervening forms B and C. Scale drift was less evident in the Mathematics Level II chain of equatings than it was in the SAT‐verbal chain. The factor analyses uncovered structural similarities and differences across test forms that were consistent with the scale drift results. The dimensionality analyses revealed that the Mathematics Level II item parcels were more nearly unidimensional than the SAT‐verbal item parcels. In addition, the dimensionality analyses revealed that one SAT‐verbal test form and one Mathematics Level II form were each less parallel to the other two forms in their respective equating chains than these other forms were to each other. Refinements in the dimensionality methodology and a more systematic dimensionality assessment are logical extensions of the present research.
SOME PITFALLS ENCOUNTERED WHILE TRYING TO COMPARE STATES ON THEIR SAT SCORES: PAGE AND FEIFS AS AN EXAMPLE*
Authors: Wainer Howard
Published: September 2014

Page and Feifs attempt to draw inferences about the relative standing of the states on the basis of their mean SAT scores. They point out that this cannot be done without statistically adjusting for various differences among the states. In this paper we identify five serious errors that they made in their analysis which calls to question the validity of their findings. In addition we describe some plausible paths toward a solution.
A COMPARATIVE STUDY OF CURRICULUM EFFECTS ON THE STABILITY OF IRT AND CONVENTIONAL ITEM PARAMETER ESTIMATES1,2,3
Authors: Cook Linda L. , Eignor Daniel R. , Taft Hessy L.
Published: September 2014

One very practical problem facing practitioners in the area of item response theory (IRT) is how to define the population from which samples will be drawn for parameter estimation purposes. A major concern of individuals interested in using IRT with achievement test data is that such tests have been specifically designed to reflect course content, and students taking the tests at different points in their course work may not constitute samples from the same population. This situation is most likely to exist for large scale admissions testing programs that offer achievement tests, to be used by colleges for admissions and placement purposes, at multiple administrations which span the school year. Students who elect to take the tests at one of the spring administrations typically have recently completed, or are about to complete, a course of instruction in the content area measured by the test, whereas, those electing to take the test at a fall administration may have completed their formal instruction in the content area six to eighteen months prior to taking the test. Because of these curriculum effects, it is quite likely that these two groups of students are not members of the same population, and that item parameter estimates (either IRT or conventional) obtained from say, the group of students who took the test after recently completing their coursework, may not be appropriate when applied to data obtained from students who took the test six months to a year after completing their coursework.

The purposes of this study were three‐fold: 1) to examine and compare the stability of IRT item difficulty parameter estimates with conventional item difficulty estimates for a set of items from an admissions testing program Biology achievement test given to a group of students recently completing a biology course and another group of students who, for the most part, had received no formal instruction in the content area from 6 to 18 months prior to taking the test; 2) to assess the impact of the lack of stability of the item difficulty estimates on score equating for both IRT and conventional equating methods; and 3) using confirmatory factor analytic techniques, to assess differences in the factor structures of the set of common items given to the groups of interest in an attempt to determine the specific curriculum effects leading to a lack of stability in the item difficulty estimates.
AN EVALUATION OF THREE APPROXIMATE ITEM RESPONSE THEORY MODELS FOR EQUATING TEST SCORES1
Authors: Marco Gary L. , Wingersky Marilyn S. , Douglass James B.
Published: September 2014

The primary purpose of this study was to determine the extent to which three item response theory (IRT) models could be used to approximate the three‐parameter logistic model in estimating item parameters and in equating test scores. These approximate models were less expensive to apply and in some cases used less data than the full‐blown three‐parameter model.

The approximations to the three‐parameter model used in this study were (1) the Rasch one‐parameter model, as operationalized in the BICAL computer program, (2) an approximate three‐parameter logistic model based on grouped data divided into fifths and twentieths, and (3) a modified three‐parameter logistic model with fixed a's and c/s. The LOGIST computer program was used to estimate parameters for the modified three‐parameter model; Quantile, a modified version of LOGIST that accepted coarsely grouped data, was used to estimate item parameters for the approximate three‐parameter model.

In the case of the approximate models involving BICAL and LOGIST, results of separate item calibrations were used to place item parameter estimates on the same scale. In the case of the approximate model involving Quantile, a method of scaling the item parameter estimates indirectly through existing SAT scaled scores was used.

The data for the study came from a recent study (Petersen, Cook, & Stocking, 1983) of scale stability for the Scholastic Aptitude Test. As in the previous study, this study involved the chain equating of a test to itself through five intermediary forms. The sample consisted of approximately 2,670 cases for each of the SAT forms used.

The results of the study were as follows: (1) the item calibrations based on twentieths were closer to the true values and to LOGIST estimates than item calibrations based on fifths; (2) the equating results based on twentieths, however, were not more accurate generally than those based on fifths; (3) the three‐parameter model using coarse groupings yielded highly accurate score conversions in equating a test to itself, more accurate in fact than the full‐blown three‐parameter models studied by Petersen, Cook, and Stocking; and (4) all of the approximate models yielded very accurate equating results. A follow‐up analysis indicated that these unexpected equating results were due in large part to the indirect method used to place item parameter estimates on scale through existing score conversions derived from conventional equating methods. The success of the approximate models raises a question about the adequacy of equating a test to itself as a criterion for evaluating equating results. Further research is recommended before any of the approximate models are used operationally.
ASSESSMENT OF THE DIMENSIONALITY OF NAEP YEAR 15 READING DATA
Authors: Zwick Rebecca
Published: September 2014

The reading data from the 1983–1984 NAEP survey were scaled using a unidimensional item response theory model. To determine whether the responses to the reading items were consistent with unidimensionality, four methods were applied: principal component analysis of phi and tetrachoric correlation matrices; principal component analysis of the image correlation matrix, a method based on the work of Guttman (1953); Bock's full‐information factor analysis (Bock, Gibbons, and Muraki, 1985); and Rosenbaum's (1984a) test of unidimensionality, monotonicity, and conditional independence. Results indicated that it was not unreasonable to regard the reading items as measures of a single dimension.
IMPROVING MINORITY RETENTION IN HIGHER EDUCATION: A SEARCH FOR EFFECTIVE INSTITUTIONAL PRACTICES
Authors: Clewell Beatriz C. , Ficklen Myra S.
Published: September 2014

Attrition of minority students from postsecondary education represents a major obstacle to attainment of equal educational opportunity. Gains in admission rates of minority students that have been made over the past decade have been eroded by their higher attrition rate. From a policy perspective, the most important issue is not merely why students drop out, but what can be done to prevent withdrawal.

This study examined programs and policies at four four‐year predominantly White institutions with good minority retention in an attempt to identify variables that enhance minority retention. The institutions studied were: Boston College, California State University‐Fresno, University of North Carolina‐Greensboro, and Purdue University. These schools varied in terms of institutional environment, including selectivity, size, and proportion of minorities on campus; rationale for developing minority retention efforts; grade level of students served by special programs; and scope and type of services. The differences we found across institutions demonstrate that retention efforts for minority students can be developed and carried out successfully in many different ways, at different types of institutions.

Although we found much diversity among the programs, we also found that there were certain common characteristics across programs–characteristics that appear to be elements of successful retention efforts. These characteristics are: the presence of a stated policy on minority enrollments; a high level of institutional commitment; a substantial degree of institutionalization of the program; comprehensiveness of services; dedicated staff; systematic collection of data, monitoring, and follow‐up; strong faculty support; and non‐stigmatization of participants.

From our study, we developed a general model that represents steps needed to formulate a retention program. The steps are: making a policy decision to enhance minority retention, conducting a needs assessment and developing a data base to examine minority enrollment patterns, implementing a program and monitoring and evaluating this program. This model emphasizes that retention efforts include all parts of the institution and constitute an ongoing process in which changes are made as needed.

We hope that other colleges and universities will view the programs described in this report as models from which to gain ideas for adaptation in their own settings.
A NEW ESTIMATOR OF THE VARIANCE OF THE MANTEL‐HAENSZEL LOG‐ODDS‐RATIO ESTIMATOR
Authors: Phillips Abraham , Holland Paul W.
Published: September 2014

A new variance estimate for the Mantel‐Haenszel log‐odds‐ratio is proposed and compared to the proposals of Hauck, Breslow, and Flanders in two special settings where reasonable variance estimates are known. The new variance estimate is symmetric in the sense proposed by Ury and is derived in a similar manner to the proposal of Flanders. A second variance estimate that is only valid for the special case of (1,M)‐matching is also discussed and compared to the more general estimator.
USING ESTIMATED ITEM OBSERVED‐SCORE REGRESSIONS TO TEST GOODNESS‐OF‐FIT OF IRT MODELS
Authors: Wingersky Marilyn S. , Sheehan Kathleen M.
Published: September 2014

This paper presents an investigation of a method for assessing the goodness‐of‐fit of IRT models using estimated item‐observed score regressions. An advantage of this method is that examinees are assigned to cells on the basis of an observed quantity, their observed number‐right score. The method for assessing goodness‐of‐fit currently used assigns examinees to cells on the basis of an estimated quantity, their estimated ability. Comparisons are made between the two methods using simulated and actual data. A disadvantage of the new method is that it cannot easily handle tests where many examinees do not finish.
THE VALIDITY OF VARIOUS METHODS OF TREATING MULTIPLE SAT® SCORES
Authors: Boldt R. F. , Centra J. A. , Courtney R. G.
Published: September 2014

A review of the literature concerned with validity data and policies for various methods of treating multiple scores is reported, as are analyses of data from the College Board Validity Study Service. The analyses evaluated the use of SAT‐V alone, SAT‐M alone, and the use of both in combination. The methods for treating multiple scores that were studied were to use the score from the administration with the highest V + M, the highest score, the most recent score, and the average. Best results, in terms of the highest average validity, were achieved using average V + M. Also evaluated were weighted combinations where all scores were used, but the highest or most recent received a unique, empirically determined weight. The use of the empirically determined weights was not superior in cross‐validation.

The combinations of variables, and the four methods of treating multiple scores that did not involve the determination of empirical weights, were evaluated in regression equations developed using one‐time testers. All treatments of multiple scores resulted in underprediction of actual grades, with the highest score providing the least amount of underprediction. However, the discrepancy between predicted and actual grades varied greatly across institutions.

Data from the Student Descriptive Questionnaire (SDQ) were cross tabulated with the number of retests. It was found that first test score‐level, income, and race were all related to the frequency of retesting.
DIFFERENTIAL ITEM FUNCTIONING AND THE MANTEL‐HAENSZEL PROCEDURE
Authors: Holland Paul W. , Thayer Dorothy T.
Published: September 2014

The Mantel‐Haenszel procedure is a noniterative contingency table method for estimating and testing a common two‐factor association parameter in a 2×2×k table. As such it may be used to study “item bias” or differential item functioning in two groups of examinees. This technique is discussed in this context and compared to other related techniques as well as to item response theory methods.
PLOTTING IN THE MODERN WORLD
Authors: Wainer Howard , Thissen David
Published: September 2014

This paper reviews standards for effective graphical presentation and then surveys microcomputer software currently available vis‐a‐vis their adherence to those standards. This review spans IBM PC (and compatibles) as well as Apple MacIntosh software. We conclude that software designers are more concerned with ‘the quality of the stroke’ than they are with the quality of the graph. This is analogous in writing to be more concerned with caligraphy than with language. We found that the best of the available packages could be twisted to yield good graphs, but that their default options were very poorly chosen. The major exception to this rule was MacSpin D2 Software, Austin, Texas), which provided an enormously helpful graphic tool to the data analyst.

Included in the review is a discussion of both software and hardware considerations as well as numerous examples.
ANOTHER LOOK AT INTER‐RATER AGREEMENT
Authors: Zwick Rebecca
Published: September 2014

Most currently used measures of inter‐rater agreement for the nominal case incorporate a correction for ‘chance agreement.’ The definition of chance agreement is not the same for all coefficients, however. Three chance‐corrected coefficients are Cohen's κ, Scott's Π, and the S index of Bennett, Goldstein and Alpert, which has reappeared in many guises. For all three measures, chance is defined to include independence between raters. Scott's Π involves a further assumption of homogeneous rater marginals under chance. For the S coefficient, uniform marginals for both raters under chance are assumed. Because of these disparate formulations, κ, Π, and S can lead to different conclusions about rater agreement. Consideration of the properties of these measures leads to the recommendation that a test of marginal homogeneity be conducted as a first step in the assessment of rater agreement. Rejection of the hypothesis of homogeneity is sufficient to conclude that agreement is poor. If the homogeneity hypothesis is retained, Π can be used as an index of agreement.
CULTURAL INFLUENCES ON PATTERNS OF ABILITIES IN NORTH AMERICA1
Authors: Vernon Philip A. , Jackson Douglas N. , Messick Samuel
Published: September 2014

The chapter examines cultural influences on patterns of abilities in North America or, more specifically, in the United States. After a brief review of the major models of intelligence and mental ability, the evidence for and against the “patterns‐of‐abilities hypothesis” is discussed, along with the major shortcomings of this interpretation as it pertains to between‐group differences in ability profiles within the United States. Next examined are cultural influences on cognitive styles as potential organizers of ability patterns and, finally, cultural influences not on profiles but on average levels of ability performance.