bluuebunny/crossref_metadata_2025 huggingface dataset:
Examination of current handover practice: Evidence to support changing the ritual
Authors: Kerr Debra , Lu Sai , McKinlay Louise , Fuller Christine
Published: July 2011

Kerr D, Lu S, McKinlay L, Fuller C. International Journal of Nursing Practice 2011; 17: 342–350

Examination of current handover practice: Evidence to support changing the ritual

Examining systems of nursing handover provides the opportunity to identify areas in need of improvement and modification. The aim of this study was to describe nursing handover practices for one organization and explore clinical nurses' opinions regarding the quality of the current shift‐to‐shift handover style. One hundred and fifty‐three registered nurses employed in 23 wards in an acute tertiary hospital in Australia completed a survey. The survey collected information about demographic data, current methods and preferences for style of handover and opinions about the quality of nursing handover. This study found that existing handover practice is time‐consuming, lacks patient involvement and essential information, and is varied in style. Only one ward (4.3%) conducted handover at the bedside. The majority (82%) expressed reluctance to change their current handover style. Modification of existing nursing handover is needed but might be challenging in view of the reluctance to change this ritual.
Causes of illness—Constraining and facilitating beliefs
Authors: Järemo Pirjo , Arman Maria
Published: July 2011

Järemo P, Arman M. International Journal of Nursing Practice 2011; 17: 370–379

Causes of illness—Constraining and facilitating beliefs

The aim of this study was to enhance knowledge about patients' beliefs related to different kinds of illnesses and to describe and understand their beliefs as they relate to their outlook on their illnesses. Fifty‐two patients with various illness symptoms receiving integrative anthroposophic care answered an item in a questionnaire about their own thinking of the causes of their illness. The method used for analysis was qualitative content analysis. The result showed that from a patient's perspective a complex combination of causes led to illness. The most prominent causes were psychosocial factors, but personal attitudes, biological factors and chance were also mentioned. Beliefs act as either facilitating or constraining. The informants displayed more constraining than facilitating beliefs, which might prevent them from improving their health. Furthermore, the informants might improve their ability to deal with their illness by identifying their own personal internal resources.
Hand hygiene compliance of nurses: A 5‐unit observational study in North‐Eastern Anatolia
Authors: Polat Sevinç , Parlak Gürol Ayşe , Çevik Ümran
Published: July 2011

Polat S, Parlak Gürol A, Çevik Ü. International Journal of Nursing Practice 2011; 17: 435–440

Hand hygiene compliance of nurses: A 5‐unit observational study in North‐Eastern Anatolia

In five neonatal intensive care units (NICUs) in two cities, the hand hygiene applications of 72 nurses included in this observational study have been investigated. The research was conducted between February and June 2007. It was found that before entering the NICUs, majority of nurses have washed their hands but used much less alcohol‐based antiseptics; more than half of the nurses did not use gloves, and 50 of them did not wash their hands before care and one‐third of the nurses did not wash their hands after care after neonatal treatments. The results obtained from our research showed that most of the nurses paid more attention to hand washing before applying medical treatment.
New treatment for faecal incontinence using zinc–aluminium ointment: a double‐blind randomized trial
Authors: Pinedo G. , Zarate A. J. , Inostroza G. , Meneses X. , Falloux E. , Molina O. , Molina M. E. , Bellolio F. , Zúñiga A.
Published: July 2011

Aim  In a randomized double‐blind study the therapeutic effect of a novel zinc–aluminium ointment was compared with placebo in patients with faecal incontinence.

Method  A randomized double‐blind trial was performed. Patients who met the inclusion criteria were randomized to receive the ointment or a placebo. All were evaluated prior to and 3 weeks after ointment application, using the Wexner incontinence score and the Fecal Incontinence Quality of Life (FIQL) score.

Results  Fifty patients were randomized and six were lost to follow‐up, leaving 24 in the treatment and 20 in the placebo group. The average ages were 61.3 and 60.7 years. The respective Wexner scores prior to intervention were 16.6 and 16.7. They decreased significantly after treatment to 8.5 and 13.1 (P < 0.001 and P = 0.002 respectively). There was a significant difference in the final scores, favouring the treatment group (P = 0.001). The FIQL scores for the treatment group were also significantly better in all parameters compared with those of the placebo group.

Conclusion  The study shows that the zinc–aluminium based ointment decreases faecal incontinence significantly compared with placebo.
Emergent Transnational Spaces: Meat, Sweat and Global (Re)Production in the Heartland
Authors: MIRAFTAB FARANAK
Published: July 2011

This article asks whether locality and the varied resources, networks and racialized histories of local actors make a difference in the experience of immigrants and their transnational practices. Such questions are typically explored in metropolitan centers and global cities, but the present work results from an ethnographic study of a previously all‐white rural Illinois town, where the meat processing industry recruited a labor force translocally among Latin Americans and West Africans. The article reports on the experience of this rapidly diversifying town where both formal politics and the liberal‐democratic channels of citizens' participation in governance remain exclusionary. Despite this, the diverse immigrant populations have achieved a certain inclusion in public institutions and public spaces. Paying attention to the dynamics developing across immigrant groups through everyday spaces of interaction within their residential community, I argue that the kinds of mediating spaces local context offers are critical to the ability of diverse immigrant groups to renegotiate the interracial social and spatial relations they encounter in a highly contested and constrained context where a global corporation is the sole local employer.

Cet article s'interroge sur le fait que la nature locale et la diversité des ressources, réseaux et histoires racialisées des acteurs locaux puissent différencier l'expérience des immigrants et leurs pratiques transnationales. Généralement, ces questions portent sur des centres métropolitains ou des villes mondiales, mais ce travail s'appuie sur l'étude ethnographique d'une ville rurale de l'Illinois dont la population était auparavant entièrement blanche et où le secteur de la transformation de viande a choisi un recrutement translocal de main‐d'œuvre latino‐américaine et ouest‐africaine. L'expérience de cette ville qui a connu une rapide diversification montre que les politiques officielles, de même que les canaux libéral‐démocrates de participation citoyenne à la gouvernance, entretiennent l'exclusion. Les diverses populations immigrantes sont néanmoins parvenues à une certaine inclusion dans les institutions et les espaces publics. En étudiant les dynamiques qui se créent entre les groupes d'immigrants grâce aux espaces d'interaction quotidiens de leur communauté d'habitation, on peut avancer que les types d'espaces de médiation qu'offre le contexte local sont indispensables pour que des groupes d'immigrants différents puissent renégocier les relations sociales et spatiales interraciales propres à un cadre disputé et contraint où le seul employeur local est une entreprise mondialisée.
Cerebral ischemic pre‐conditioning enhances the binding characteristics and glutamate uptake of glial glutamate transporter‐1 in hippocampal CA1 subfield of rats
Authors: Liu Ai‐Ju , Hu Yu‐Yan , Li Wen‐Bin , Xu Jing , Zhang Min
Published: July 2011

J. Neurochem. (2011) 119, 202–209.

Glial glutamate transporter‐1 (GLT‐1) is the predominant subtype of glutamate transporters which are responsible for the homeostasis of extracellular glutamate. Our previous studies have shown that up‐regulation in GLT‐1 protein expression matches brain ischemic tolerance induced by cerebral ischemic preconditioning (CIP). To specify the role of functional changes of GLT‐1 in the induction of brain ischemic tolerance by CIP, the present study was undertaken to examine changes in the binding properties of GLT‐1 (including maximum binding and affinity for glutamate) and in GLT‐1 mediated glutamate uptake, using L‐3H‐glutamate assay in the rat hippocampus. The results indicated that CIP was able to increase the maximum binding and affinity, and uptake of GLT‐1 for glutamate in hippocampal CA1 subfield either with or without the presence of the subsequent severe brain ischemic insult. Simultaneously, accompanied with the above changes, CIP significantly reduced the delayed neuronal death (DND) in this region induced by lethal global cerebral ischemia. It could be concluded that up‐regulation in the maximum binding and affinity and glutamate uptake of GLT‐1 contributed to the neuronal protection of CIP against global cerebral ischemic insult.
Responsiveness of the Care Dependency Scale for Rehabilitation (CDS‐R)
Authors: Eichhorn‐Kissel Juliane , Dassen Theo , Lohrmann Christa
Published: August 2011

Scand J Caring Sci; 2012; 26; 194–202
 
Responsiveness of the Care Dependency Scale for Rehabilitation (CDS‐R)

Around 10% of Western Europe’s population suffer from a disability which can entail a decrease of independency and quality of life. However, the lives of these people can be improved by rehabilitative treatment and care. Changing the degree of dependency from dependent to independent is essential in rehabilitation, as is the assessment of these changes. To perform such kind of measurements, assessment instruments have to be responsive. In spite of this concern, responsiveness of assessment instruments is studied to a small extent only. This also applies to the Care Dependency Scale for Rehabilitation (CDS‐R), a short assessment instrument measuring the care dependency of patients regarding physical and psychosocial aspects. In this longitudinal‐study, the responsiveness of the CDS‐R, in general and related to different disease‐groups, should be determined. Therefore, a convenience sample of 1564 patients was assessed in an Austrian rehabilitation centre with the scale after admission and before discharge. Responsiveness was determined by descriptive analysis, calculation of effect‐sizes and significance tests. Differences between admission and discharge occurred on a statistically significant level for patients who changed. Kazis’ effect‐sizes can be considered as of small/medium effect for patients who changed (0.24/0.49), and as of large effect according to Liang (0.86/1.46). Eta squared was 0.10/0.19 which can be interpreted as of moderate/large effect for patients who changed. Responsiveness‐analyses related to different disease‐groups showed constantly large effect‐sizes for patients with musculoskeletal‐disorders. These results indicate that the CDS‐R can detect patient‐changes over time and discriminate between patients who change under rehabilitation or not. These aspects argue for the responsiveness of the scale, wherefore the CDS‐R seems to be appropriate for the assessment of treatment/health‐care effectiveness and the evaluation of individual patient‐changes. Nevertheless further research is recommended to confirm the level of responsiveness of the scale in general and for different disease‐groups.
Adolescents' experiences of psychosocial support after traumatisation in a school shooting
Authors: Murtonen Kalle , Suomalainen Laura , Haravuori Henna , Marttunen Mauri
Published: July 2011

Background:  In November 2007, a student shot and killed eight people and himself at Jokela High School, Finland.

Method:  Availability and experiences of psychosocial support were investigated using data (N=231) collected with a questionnaire 4 months after the event.

Results:  Female gender, severity of trauma, psychiatric disturbance and post‐traumatic distress were associated with receiving psychosocial support. Over half of the students with a high level of trauma‐related symptoms reported immediate support as having been helpful. Additionally, support from family and friends was available to a majority of students.

Conclusions:  The factors associated with not receiving support or not feeling helped should be studied further for possible implications on crisis interventions.
Loyalty Rewards Facilitate Tacit Collusion
Authors: Fong Yuk‐fai , Liu Qihong
Published: July 2011

Using a dynamic overlapping‐generations model, we show that loyalty rewards robustly facilitate tacit collusion. We compare the sustainability of tacit collusion when uniform prices are used, when loyal customers are rewarded without using commitment, and when loyalty rewards are implemented by committing to offering customers either lower fixed repeat‐purchase prices or fixed repeat‐purchase discounts. We find that, relative to uniform prices, rewarding loyalty without using commitment on the equilibrium path makes tacit collusion easier to sustain, because a deviating firm is unable to steal one period of industry profit before losing all future profits. When loyalty rewards are offered by firms committing to repeat‐purchase prices, collusion is even easier to sustain, because a deviating firm cannot renege on its discounted price for repeat‐purchase customers. When firms commit to repeat‐purchase discounts, they also commit to lowering the price for their repeat‐purchase customers if they undercut the regular price, rendering tacit collusion to be even more readily sustainable. Our results hold whether products are homogeneous or horizontally differentiated as in a Hotelling model.
Product Line Choice in Retail Duopoly
Authors: Moner‐Colonques Rafael , Sempere‐Monerris José J. , Urbano Amparo
Published: July 2011

This paper develops a successive duopoly model to identify conditions under which differentiated retailers that compete in quantities, when deciding on the range of brands to offer, will carry overlapping product lines. They will do so when retail margins on each brand are not too asymmetric. Otherwise, the less profitable brand is foreclosed from the market. It is shown that welfare increases if the upstream industry is perfectly competitive, even though fewer brands may be sold. With price competition though, exclusive dealing arises when retailers are not too differentiated and in‐store competition is sufficiently intense.
Phase Transformation Properties of Highly (100)‐Oriented PLZST 2/85/12/3 Antiferroelectric Thin Films Deposited on Nb–SrTiO3 Single‐Crystal Substrates
Authors: Hao Xihong , Zhai Jiwei , Yue Zhenxing , Xu Jinbao
Published: July 2011

In this work, (Pb0.97La0.02)(Zr0.85Sn0.12Ti0.03)O3 (PLZST 2/85/12/3) antiferroelectric (AFE) thin films with a thickness of ~700 nm were successfully fabricated on (100)‐oriented Nb–SrTiO3 single crystal via a sol–gel technique. X‐ray diffraction and scanning electron microscopy results showed that the obtained AFE films had a highly (100)‐preferred orientation and displayed a uniform surface microstructure. Electrical measurements, such as P–E loops, the electric‐field, and temperature‐dependent dielectric properties, demonstrated a mixture of AFE and FE phases in PLZST 2/85/12/3 films deposited on Nb–SrTiO3 substrates.
Ternary Phase ZrxCuyCz in Reactively Infiltrated ZrC/W Composite
Authors: Zhao Yan‐Wei , Wang Yu‐Jin , Zhou Yu , Peng Hua‐Xin , Song Gui‐Ming
Published: July 2011

A new ternary ZrxCuyCz phase is observed in the reactively infiltrated ZrC/W composite. The X‐ray diffraction and transmission electron microscopy analyses reveal that the ZrxCuyCz phase has a same rocksalt structure as ZrC, but possesses sixfold long‐period structure with lattice constant of 2.88 ± 0.07 nm. This finding indicates the existence of ZrxCuyCz compound, which expands the ternary carbides and nitrides permutation space.
Sintering of Soda‐Lime Glass Microspheres Using Spark Plasma Sintering
Authors: Ramond Laure , Bernard‐Granger Guillaume , Addad Ahmed , Guizard Christian
Published: July 2011

Sintering experiments on soda‐lime glass microspheres have been performed using spark plasma sintering in the temperature range 485°C–560°C. Samples with relative densities between 64% and 99.6% have been obtained in about 10 min. For almost fully dense samples, the microstructure exhibits an unusual “interface‐like” aspect for a glass. The densification mechanism has been investigated. For temperatures below 522°C, densification proceeds by formation of necks between spheres. For temperatures of and above 522°C, it is proposed that densification proceeds by viscous flow, accommodated by plastic deformation of microspheres, and is controlled by diffusion of oxygen anions in the glass.
Expression of fatty acid synthase (FASN) in oral nevi and melanoma
Authors: de Andrade BAB , León JE , Carlos R , Delgado‐Azañero W , Mosqueda‐Taylor A , Graner E , de Almeida OP
Published: July 2011

Oral Diseases (2011) 17, 808–812

Objective:  The aim of this study was to determine the expression of fatty acid synthase (FASN) in oral nevi and melanomas, comparing the results with correspondent cutaneous lesions.

Materials and Methods:  Expression of FASN was evaluated by immunohistochemistry in 51 oral melanocytic lesions, including 38 intramucosal nevi and 13 primary oral melanomas, in 10 cutaneous nevi and in 14 melanomas.

Results:  Fatty acid synthase was strongly expressed only in melanomas, either of the oral mucosa or cutaneous. On the other hand, most oral and cutaneous nevi were negative, with a few oral cases showing focal and weak expression.

Conclusion:  Fatty acid synthase is expressed in malignant melanocytes, and it can be a helpful marker to distinguish oral melanomas from oral melanocytic nevi.
Identification of antibacterial mechanism of l‐amino acid oxidase derived from Trichoderma harzianum ETS 323
Authors: Yang Chia‐Ann , Cheng Chi‐Hua , Liu Shu‐Ying , Lo Chaur‐Tsuen , Lee Jeng‐Woei , Peng Kou‐Cheng
Published: July 2011

Although l‐amino oxidase (LAAO; EC 1.4.3.2) has been reported to be a potent antibacterial agent, the mechanism responsible for its antibacterial activity has not been identified. The present study aimed to identify the mechanism responsible for the antibacterial activity of Th‐LAAO, an LAAO recently isolated from the extracellular proteins of Trichoderma harzianum ETS 323, at the same time as elucidating the nature of this enzyme. The results obtained indicate that the enzyme activity and structure of Th‐LAAO are stable at pH 6–8 and less stable at both pH 4–5.5 and pH 9. At pH 7.0, the optimum temperature for Th‐LAAO was found to be 40 °C, comprising the temperature at which enzymatic activity is greatest, with enzymatic activity deceasing with further increases in temperature as a result of thermal denaturation of the enzyme, leading to partial denaturation at 50 °C. The results obtained by confocal microscopy and flow cytometry indicate that Th‐LAAO interacts with bacteria to cause membrane permeabilization, and this interaction may be promoted by the amphipathic sequence in Th‐LAAO and other cytotoxic LAAOs located at the N‐terminus. The findings of increased exogenous H2O2 production and reactive oxidative species accumulation in Th‐LAAO‐treated bacteria indicate that reactive oxidative species accumulation may trigger forms of cell damage, including lipid peroxidation and DNA strand breakage that results in bacterial growth inhibition. Taken together, the results indicate that the processes of bacterial interaction, membrane permeabilization and H2O2 production are involved in the mechanism responsible for the antibacterial activity of Th‐LAAO.
A STUDY OF SUBJECTIVE PROBABILITY
Authors: Dale H. C. A.
Published: August 2011

Adult subjects predicted the way a small number of items would be selected by chance from a long list of items. The frequencies of their predictions were then compared with the objective probabilities. The results suggest that the subjects avoided what they thought to be unlikely configurations, but that, in doing so, they considered certain aspects of a selection only, and in these appeared to be guided by one or two simple rules which showed only a limited accord with the laws of chance.
AN EXTENSION OF THE CHI‐SQUARED TEST FOR RANDOMNESS
Authors: Stone M.
Published: August 2011

The following note describes a statistical test for random allocation, which has the property of being invariant even when the labelling of cells is changed.
IS INTELLIGENCE DISTRIBUTED NORMALLY?
Authors: Burt Cyril
Published: August 2011

Frequency distributions obtained on applying intelligence tests to large samples of the school population are analysed, and compared with those given by the formulae for the commoner types of frequency curve. It is noted that the distributions actually observed are more asymmetrical and have longer tails than that described by the normal curve. The best fit is given by a curve of Type IV: this is in fact the type of distribution we should expect if (as has been argued in earlier papers) individual differences in general ability are determined partly by multifactorial and partly by unifactorial inheritance. It follows that the usual assumption of normality leads to a gross underestimate of the number of highly gifted individuals. The conclusions thus drawn are confirmed by a study of data from other sources; and various practical corollaries are deduced.
A CROSS‐OVER TRIAL WITH CATEGORIZED RESPONSE
Authors: Hawkes Alan G.
Published: August 2011

We consider a situation in which each subject receives two treatments at different times, the response being one of several categories. Some methods of analysis are discussed and two methods introduced which make non‐linear adjustments for the effect of order of administration.
EFFICIENCY OF ESTIMATION WHEN THERE IS ONLY ONE COMMON FACTOR
Authors: Lord Frederic M. , Wingersky Marilyn S.
Published: August 2011

Explicit formulae are derived for the asymptotic sampling variances and covariances of the maximum‐likelihood estimators for factor‐analysis parameters in the special case where there is just one common factor. The effect of the number of variables on these variances and covariances is indicated. A formula is given showing to what extent the usual covariance between two of a set of variables can be estimated more efficiently when there is known to be just one common factor.
LARGE SAMPLE AND OTHER MULTIPLE COMPARISONS AMONG MEANS
Authors: Ury Hans K. , Wiggins Alvin D.
Published: August 2011

If the number of multiple comparisons for K large samples is limited to the (k/2) differences between pairs of means plus ‘a few’ for possible post hoc multiple comparisons, one can frequently obtain shorter confidence intervals using a t statistic than through the use of Marascuilo's procedure (1966) for large samples. The savings in the length of the confidence interval increase with the number of samples and with the confidence level. The length of the t intervals is compared with the length of Marascuilo's intervals under various conditions in Tables 1–6. Modifications are given for use in the case of moderate and small samples. A numerical example (Marascuilo's Example 1 (1966)) is presented, and two non‐parametric analogues of the procedure are given.
ESTIMATION OF THE PROPORTION OF EXAMINATION CANDIDATES WHO ARE WRONGLY GRADED
Authors: Please N. W.
Published: August 2011

It is suggested that the proportion of examination candidates who are wrongly graded may be estimated from the examination reliability coefficient by the bivariate normal integral. As an illustration estimates of this proportion are calculated for the present G.C.E. A level grading system over a range of values of the reliability coefficient. Some alternative grading schemes are examined.
A NOTE ON THE REPRESENTATION OF ORDERED METRIC SCALING†
Authors: Phillips J. P. N.
Published: August 2011

A unidimensional ordered metric scaling (Coombs, 1964) of a set of objects is an ordinal scaling of them and also a (partial or complete) ordinal scaling of the distances between them. The problem of representing such a scaling reduces to that of finding the general solution of a system of strict homogeneous linear inequalities. There are two possible approaches to the latter problem.

The purely algebraic approach of Fourier (1890), which is a modification of the usual method (systematic elimination) for the solution of systems of linear equations, is computationally simple, but does not give a satisfactory representation of the general solution, only an inconvenient and non‐unique set of back substitutions.

The coordinate‐geometric approach of Minkowski (1896), upon which Stokes' (1931) method of solution is based, gives a matrix representation of the general solution, but is computationally very laborious. However, an unpublished algorithm due to Goode (Coombs, 1964), although incomplete in its original form, turns out, when completed by the application of a theorem of Farkas (1902), to be essentially equivalent to Stokes' method, but computationally very simple, the only (slight) disadvantage being that it may give superfluous solutions, which are easily excluded by a simple check.
AN EXACT MULTIPLE COMPARISONS TEST FOR A MULTINOMIAL DISTRIBUTION
Authors: Shaffer Juliet Popper
Published: August 2011

An exact procedure is developed for testing directional hypotheses concerning pairwise differences between category probabilities when the data can be considered a sample from a multinomial distribution. The procedure is illustrated in the case of three and four categories, and is compared with the exact test of the hypothesis of equal category probabilities proposed by Chapanis and modified by Gridgman.
ESTIMATING MULTIPLE REGRESSIONS IN m GROUPS: A CROSS‐VALIDATION STUDY
Authors: Novick Melvin R. , Jackson Paul H. , Thayer Dorothy T. , Cole Nancy S.
Published: August 2011

An improved Bayesian method, due to Lindley, for the simultaneous estimation of multiple regressions in m groups is studied by applying the method to test data. Evidence is found to support the belief that in many testing applications the collateral information obtained from each subset of m − 1 colleges will be useful for estimating the regression in the mth college, especially when the sample sizes are small. Using a 25 per cent sample, the Bayesian prediction equations achieved an average 9.7 per cent reduction in mean square error, as compared with the within‐group least squares equations, when cross‐validated with a later sample. More importantly, the mean square error for the Bayesian equations based on the 25 per cent sample was only barely greater than that for the least squares equations based on the full sample data. Thus the main virtue of the method is that it permits predictions to be made separately for relevant subpopulations (e.g. male‐female) where sample sizes would otherwise be too small to achieve an acceptable degree of accuracy.
SOME MODELS FOR SUCCESSIVE DISCRIMINATION LEARNING AND TRANSFER
Authors: Robbins Donald
Published: August 2011

A variety of models dealing with two‐choice successive discrimination learning are considered. The basic approach involves assuming that an organism selects a subset of the stimulation available, a stimulus element, as a basis for a response, and then a choice response is made. This selection process, when added to stimulus sampling theory, yields a class of models, of which a subset can account for the acquisition of successive discrimination, stimulus generalization or transfer, and can be extended to multidimensional discriminations.
MATHEMATICAL ANALYSIS OF A MULTIPLE‐LOOK CONCEPT IDENTIFICATION MODEL
Authors: Cotton John W.
Published: August 2011

The behaviour of focus samples, central to the multiple‐look model of Trabasso & Bower (1968), is examined by three methods. First, exact probabilities of success conditional upon a certain brief history of stimulation are determined. Second, possible states of the organism during the experiment are defined and a transition matrix for those states determined, permitting prediction over all possible numbers of trials. Third, Fisher's (1971) generalizations and corrections of the Trabasso & Bower focus sample theory are examined. A general solution for the conditional probability of success is derived from Fisher's equation for the probability of n successes between any two errors. One very strong implication of the theory is given in Section 5.
COMPARISON OF FACTOR LOADINGS IN DIFFERENT POPULATIONS
Authors: Please N. W.
Published: August 2011

When measurements of the same variates are made on individuals sampled from different populations, factor analysis may be used to examine whether there is evidence of common underlying factors. A factor model suitable for this situation is discussed and two methods given for obtaining the estimated loadings of the common factors from the loadings obtained from separate factor analyses. The first method is appropriate when all the factors are common to all the populations; the second when some factors are specific to certain populations or groups of populations. Estimators are given of the factor mean vectors and covariance matrices in the various populations and, with the second method, indications of the populations in which each factor operates. An iterative procedure for obtaining the maximum‐likelihood estimates is explained in detail and some tests of significance are mentioned. Possible rotations of the common factors are discussed and the results of applying these methods to some numerical data are reported.
SOME HIERARCHICAL SCALING METHODS FOR CONFUSION MATRIX ANALYSIS II. APPLICATIONS TO LARGE MATRICES
Authors: Smith Philip T. , Jones Keith F.
Published: August 2011

Extends the theory presented in Smith et al. (1975) to larger confusion matrices. Stimuli and responses are described by a series of features which take a discrete set of values. Processing models are proposed where each feature is tested independently (Independence model), where the processing of a given feature depends on the responses that have been made in testing for other features (Response Conditional model) or where the processing of a given feature depends on whether other features have been correctly identified or not (Correct Conditional model). Computer programs are described which fit these models to arbitrarily large confusion matrices. Difficulties in interpreting the behaviour of these models with real data are reviewed and solutions are offered. These points are illustrated by detailed analyses of confusion matrices obtained in studies of speech perception, memory for speech and semantic memory.
Likelihood and posterior identification: Implications for mathematical psychology
Authors: Chechile Richard
Published: August 2011

From a Bayesian framework the classical or likelihood definition of model identification is shown to be too restrictive since there exist some classically unestimable and unidentifiable models that have unique Bayes estimates. Consequently, another definition of identification is developed. Finally, the general issue of model complexity and estimation techniques is discussed.
A model for the dominance between classes of items in choice behaviour of individuals
Authors: Schulz Ulrich , Albert D.
Published: August 2011

A strength model for class dominance based on Luce's choice axiom is proposed for the analysis of finite individual sequences of items, which can be divided into homogeneous classes. Procedures for estimating the dominance parameters, which are by definition independent of the number of events, and for model testing are given. An example of an application of the model to the free recall of nouns, divided into classes by list membership during presentation, is provided.
On Wilcox's latent structure model for guessing
Authors: Molenaar Ivo W.
Published: August 2011

Wilcox (1979) has presented in this journal a model for achievement testing where a population of examinees is described in terms of a domain of skills. In most of his paper each examinee knows a proportion ζ of all items from this domain, and has a probability β of guessing the correct response given that he/she does not know it. Across examinees, the parameters ζ and β (1 — ζ) have a bivariate Dirichlet distribution. Per examinee, ζ and β are estimated from the results on pairwise equivalent item pairs. The present note explores the feasibility of the assumptions and the usefulness of the results of Wilcox's paper. It thus attempts to show the obstacles between the present psychometric model and a fully satisfactory treatment of guessing.
Methods and recent advances in measuring achievement: A response to Molenaar
Authors: Wilcox Rand R.
Published: August 2011

Commenting on a paper I published in this journal (Wilcox, 1979a), Molenaar (1981) has raised some questions about the usefulness and feasibility of measuring achievement with latent structure models. In the last two or three years, considerable progress has been made regarding the issues mentioned by Molenaar. The purpose of this note is to indicate the progress that has been made, to describe alternative solutions that have been recently proposed, and to comment on some of Molenaar's suggestions on how the model might be improved.
Circularity and multiple comparisons in repeated measure designs
Authors: Mitzel Howard C. , Games Paul A.
Published: August 2011

In an RS × T design, MST/MSRST is distributed as F with the usual df only if the population variance‐covariance matrix has ε = 1.0. This same condition is needed for the usual multiple comparison procedures to be accurate. When testing K — 1 orthogonal contrasts the conventional estimate of the variance of the contrasts is the mean of the K — 1 different true variance estimates. This condition also is observed when testing all pairwise contrasts. A Monte Carlo study demonstrates that with reasonable ns, little power is lost using a robust general matrix solution. The conventional solution will often be inaccurate when ε < 1.0.
Some empirical and theoretical results on an answer‐until‐correct scoring procedure†
Authors: Wilcox Rand R.
Published: August 2011

Wilcox (1981a) proposed a model for an answer‐until‐correct scoring procedure that solves various measurement problems. The purpose of this paper is to check empirically an implication of the model, and to propose and investigate some strong true‐score models. One of the strong true‐score models assumes the probability of guessing the correct response to an item is a strictly increasing function of an examinee's ability level, and the model gives a reasonable fit to the data. The paper illustrates that this new model is easily applied to situations where the beta‐binomial model is typically used. The other models, including the Dirichlet‐multinomial model, proved to be unsatisfactory. Finally, potential difficulties with the new model are discussed, and possible directions for future research are described.
The weight matrix in asymptotic distribution‐free methods
Authors: Mooijaart Ab , Bentler P. M.
Published: August 2011

An important problem with asymptotic distribution‐free (ADF) methods is the size of the weight matrix. Whereas under the assumption of normality of the observed variables the weight matrix can nicely be decomposed into two matrices of smaller order, under non‐normality this cannot be done straightforwardly. In this paper we propose a method in which the weight matrix can be decomposed into matrices of smaller order, which makes inverting the matrix computationally less heavy and extends the usefulness of ADF methods to applications with a larger number of variables.

An additional advantage of our method is that the weight matrix is formulated in terms of model parameters. As a consequence, one should expect the weight matrix to be more stable than in cases in which the weight matrix is computed from the data itself. In addition, estimates of the parameters may be less biased, a problem which often arises in ADF methods.
Comparing distributions of item responses for two groups
Authors: Rosenbaum Paul R.
Published: August 2011

If one group of examinees can be described as having generally higher ability to respond correctly to the items on an exam than some other group—where ability is defined by a unidimensional item response model—then the observable distributions of item responses must satisfy certain constraints. Standard statistical methods for discrete data may be used to test the consistency of these constraints with observed data. In an example, the observed pattern of item responses is found to be inconsistent with a difference in the distribution of a unidimensional latent variable.
Credible conceptions and implausible probabilities
Authors: Macdonald Ranald R.
Published: August 2011

Tversky and Kahneman's demonstrations of people's inability to handle probabilities are examined in detail. The inherent ambiguity in the concept of probability and the rules of conversational logic are used to justify subjects' apparent fallacies. Moreover even in the framework of mathematical probability some of Tversky and Kahneman's subjects' behaviour is defended. The relevance of mathematical probability to everyday decisions is seen as being open to question. Conceptualizing a problem sensibly is held to be more important than having beliefs which are demonstrably consistent with a quantitative probabilistic model. The conceptualization should have regard to the sense in which probability is being used, how different possibilities should be categorized and the reliability of the presented information.
Completely randomized factorial analysis of variance using ranks
Authors: Harwell Michael R.
Published: August 2011

Several rank tests are available for the completely randomized, fixed effects multifactor design; however, none has been widely adopted nor has a systematic evaluation of the characteristics of these tests been undertaken. Rank tests due to Hettmansperger (1984), McSweeney (1967) and Puri & Sen (1985) are illustrated and evaluated on the basis of their extension to designs with more than two factors and small sample distributional properties (i.e. Type I error rate and power). The rank transform procedure of Conover & Iman (1981) is also discussed. Simulation results indicate that the F test is robust and shows good power across a variety of conditions. Among the non‐parametric procedures, the Hettmansperger test produced the largest power.
The cold equations: Spearman and Wilson on factor indeterminacy
Authors: Lovie P. , Lovie A. D.
Published: August 2011

In 1928, the American mathematician E.B. Wilson had the ammunition to kill off Charles Spearman's two‐factor theory of mental ability — at least according to certain recent commentators. In their view, the two‐factor theory, and indeed factor analysis as a general technique, was dealt the coup de grâce by Wilson's demonstration of the indeterminacy of the factor solution and only survived by, in effect, denying the problem. However, a rather different story emerges of the ensuing interchange between Spearman and Wilson when we examine not just the public record but unpublished correspondence between the two principals and with other interested parties. We have, thus, been able to paint a richer and more historically complete picture of the Spearman‐Wilson episode than previous chronicles have achieved. In addition, we argue that the spirit in which their protracted interchange was conducted illustrates the socially negotiated nature of science.
ANCOVA based on comparing a robust measure of location at empirically determined design points
Authors: Wilcox Rand R.
Published: August 2011

For two independent groups, let (Yij), Xij), i = 1, …, nj; J = 1, 2 be a random sample of nj observations from the jth group. Suppose that for the jth group, the population trimmed mean of Y, given that X = x, is given by some unknown function mj(x). The paper describes a method of comparing the two regression lines at q design points determined empirically. The proposed procedure is based in part on a simple application of the running interval smoother which allows mj(x) to be modelled non‐parametrically. In contrast to extant methods, it is not assumed that the error term associated with the jth group has constant variance, nor is it assumed that the variance of Y, given X, is the same for both groups. The power of the new method compares well to the conventional method when the standard assumptions of normality, parallel regression lines, and homogeneity of variance are true. The new method can have substantially higher power when standard assumptions are violated, it provides good control over the probability of a Type I error for a much wider range of situations, and it provides a more detailed indication of where regression lines differ and by how much.
Counting to one: The qualitative researcher's ‘magic’
Authors: Hickson, III Mark
Published: July 2011

This article is a commentary on ‘Assessing ‘good’ qualitative research in the work psychology field: A narrative analysis’ (Cassell & Symon, 2011).
Narratives of quality in qualitative research: Putting them in context
Authors: Locke Karen
Published: July 2011

This article is a commentary on ‘Assessing ‘good’ qualitative research in the work psychology field: A narrative analysis’ (Cassell & Symon, 2011).
Endovascular therapy for acute basilar artery occlusion: a review of the literature
Authors: Mortimer A M , Bradley M , Renowden S A
Published: July 2011

Basilar artery occlusion is an infrequent form of acute stroke; clinical outcomes are heterogeneous, but the condition can be fatal. There is a lack of randomized controlled trial data in this field. Case series suggest that patients who are recanalized have much better outcomes than those who are not, and it is generally accepted that intra-arterial techniques achieve high rates of recanalization. Controversially, several studies, including a meta-analysis and registry-based investigation, that have compared intravenous thrombolysis (IVT) and intra-arterial treatment suggest similar outcomes. However, there are many potential sources of bias in each of these studies, precluding a firm conclusion. Indeed, there are many confounding factors that can influence the outcome including severity of presentation, site of occlusion, clot load, degree of collateral flow, timing of therapy, agent used for recanalization and dose of thrombolytic agent. Additionally, pretreatment infarct core imaging using diffusion-weighted imaging and the posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS) scoring systems have been shown to predict outcome and therefore may be useful in selecting patients for aggressive therapy. Protocols combining intravenous agents such as glycoprotein IIb/IIIa receptor antagonists or thombolytics agents with intra-arterial techniques (‘bridging’ therapy) have shown encouraging improvements in neurological outcome and survival. Furthermore, initial case series describing the use of mechanical clot extraction devices or aspiration catheters suggest high rates of recanalization. What would be useful is a randomized trial comparing IVT, endovascular approaches and a combined IVT/endovascular approach. However, the small numbers of patients and multiple confounding factors are barriers to the development of such a trial.
Investigation of the disorder of dibromo- and dichloromethane in their tri-ortho-thymotide clathrates using X-ray diffraction and solid-state 2H NMR spectroscopy
Authors: Facey Glenn A. , Korobkov Ilia
Published: August 2011

The tri-ortho-thymotide (TOT) clathrates of dibromo- and dichloromethane were characterized by single crystal X-ray diffraction at 200 K and solid-state 2H NMR spectroscopy as a function of temperature. The host structure was found to be typical of other cage-type TOT clathrates. The X-ray results showed a substantial amount of disorder among the guest molecules. In both clathrates, multiple guest molecule positions could be modeled. The heavy atoms of all the guest molecule positions lie approximately in the same plane, with some out-of-plane distortion. The guest molecules were of two different types in positions symmetric about the crystallographic twofold rotation axis: type A guests, with carbon atoms well removed from the crystallographic twofold axis, and type B guests, with carbon atoms very close to the twofold axis. The 2H NMR spectra for the guests confirmed that the disorder was dynamic. The experimental results could be accounted for by the presence of three simultaneous types of molecular motion, all fast with respect to the 2H quadrupolar interaction: (i) twofold molecular flips about the molecular C2 symmetry axis, (ii) exchange between the type A and type B sites in a single plane, and (iii) a two-site libration of the plane containing the heavy atoms of the A and B guest sites with a temperature-dependent amplitude.
High-sweat Na+ in cystic fibrosis and healthy individuals does not diminish thirst during exercise in the heat
Authors: Brown M. B. , McCarty N. A. , Millard-Stafford M.
Published: August 2011

Sweat Na+ concentration ([Na+]) varies greatly among individuals and is particularly high in cystic fibrosis (CF). The purpose of this study was to determine whether excess sweat [Na+] differentially impacts thirst drive and other physiological responses during progressive dehydration via exercise in the heat. Healthy subjects with high-sweat [Na+] (SS) (91.0 ± 17.3 mmol/l), Controls with average sweat [Na+] (43.7 ± 9.9 mmol/l), and physically active CF patients with very high sweat [Na+] (132.6 ± 6.4 mmol/l) cycled in the heat without drinking until 3% dehydration. Serum osmolality increased less ( P < 0.05) in CF (6.1 ± 4.3 mosmol/kgH2O) and SS (8.4 ± 3.0 mosmol/kgH2O) compared with Control (14.8 ± 3.5 mosmol/kgH2O). Relative change in plasma volume was greater ( P < 0.05) in CF (−19.3 ± 4.5%) and SS (−18.8 ± 3.1%) compared with Control (−14.3 ± 2.3%). Thirst during exercise and changes in plasma levels of vasopressin, angiotensin II, and aldosterone relative to percent dehydration were not different among groups. However, ad libitum fluid replacement was 40% less, and serum NaCl concentration was lower for CF compared with SS and Control during recovery. Despite large variability in sweat electrolyte loss, thirst appears to be appropriately maintained during exercise in the heat as a linear function of dehydration, with relative contributions from hyperosmotic and hypovolemic stimuli dependent upon the magnitude of salt lost in sweat. CF exhibit lower ad libitum fluid restoration following dehydration, which may reflect physiological cues directed at preservation of salt balance over volume restoration.
Characterizations of Generalized Entropy Functions by Functional Equations
Authors: Furuichi Shigeru
Published: July 2011

We will show that a two‐parameter extended entropy function is characterized by
a functional equation. As a corollary of this result, we obtain that Tsallis entropy function is
characterized by a functional equation, which is a different form that used by Suyari and Tsukada, 2009, that is, in a proposition
2.1 in the present paper. We give an interpretation of the functional equation in our main
theorem.
Efficient CT Metal Artifact Reduction Based on Fractional‐Order Curvature Diffusion
Authors: Zhang Yi , Pu Yi-Fei , Hu Jin-Rong , Liu Yan , Chen Qing-Li , Zhou Ji-Liu
Published: July 2011

We propose a novel metal artifact reduction method based on a fractional‐order curvature driven diffusion model for X‐ray computed tomography. Our method treats projection data with metal regions as a damaged image and uses the fractional‐order curvature‐driven diffusion model to recover the lost information caused by the metal region. The numerical scheme for our method is also analyzed. We use the peak signal‐to‐noise ratio as a reference measure. The simulation results demonstrate that our method achieves better performance than existing projection interpolation methods, including linear interpolation and total variation.