bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel spectroscopic probe for molecular chirality
Authors: Ji Na , Shen Yuen‐Ron 
Published: January 2006

AbstractRecent advances in developing sum frequency generation (SFG) as a novel spectroscopic probe for molecular chirality are reviewed. The basic principle underlying the technique is briefly described, in comparison with circular dichroism (CD). The significantly better sensitivity of the technique than CD is pointed out, and the reason is discussed. Bi‐naphthol (BN) and amino acids are used as representatives for two different types of chiral molecules; the measured chirality in their electronic transitions can be understood by two different molecular models, respectively, that are extensions of models developed earlier for CD. Optically active or chiral SFG from vibrational transitions are weaker, but with the help of electronic‐vibrational double resonance, the vibrational spectrum of a monolayer of BN has been obtained. Generally, optically active SFG is sufficiently sensitive to be employed to probe in‐situ chirality of chiral monolayers and thin films. © 2006 Wiley‐Liss, Inc. Chirality
Migration der kontinuierlichen Phase beim Trocknen von Suspensionstropfen in einer Trocknungskammer
Authors: Monse Karsten , Koch Markus , Walzel Peter 
Published: January 2006

AbstractEin Halbtropfen wird an einer gekühlten Glasscheibe aufgehängt, so dass durch diese die Umlagerungsprozesse im Inneren des trocknenden Tropfens beobachtet werden können. Diese bisher unbekannte Methode in der Verfahrenstechnik zum Trocknungsverhalten und der damit verbundenen Strukturbildung von Suspensions‐ oder Lösungstropfen erlaubt, die sprühtrocknungsrelevanten Einflussgrößen im kleinen Maßstab zu untersuchen und zu beurteilen.
Equivalent circuits for small signal performance of spin ½ particles
Authors: Civalleri Pier Paolo , Gilli Marco , Bonnin Michele 
Published: January 2006

AbstractA quantum system composed of a large number of non‐interacting spin ½ particles, biased by a large constant magnetic field along the z‐axis and excited by a small circularly polarized electromagnetic wave in the xy‐plane is considered. Its small signal reflectance about the equilibrium state resulting from the biasing field and a pumping activity is calculated in the complex frequency plane. It is suggested that the equilibrium state can be locally passive or active depending on the pumping sign and level. Equivalent circuits containing imaginary resistors, i.e. frequency independent reactances, are presented for both passive and active cases. Copyright © 2006 John Wiley & Sons, Ltd.
Self‐Assembly of a Tetranuclear CoIII‐Metallacycle from the Reaction of a Bis(benzene‐o‐dithiolato) Ligand with CoII and Subsequent Aerial Oxidation (Eur. J. Inorg. Chem. 3/2006)
Authors: Hahn F. Ekkehardt , Kreickmann Thorsten , Pape Tania 
Published: January 2006

AbstractThe cover picture shows the self‐assembly of a tetranuclear CoIII metallacycle from the reaction of a bis(benzene‐o‐dithiolato) ligand and CoII after aerial oxidation. Two differently coordinated metal centres (syn and anti) are observed in the metallacycle even though a ligand with two identical donor sites has been used. This unusual structural motif is formed in order to avoid strong steric interactions between the ortho‐sulfur atoms, which would result in a hypothetical dinuclear complex. Details are discussed in the article by F. E. Hahn et al. on p. 535 ff.
Prolonged seizures recruit caudal subventricular zone glial progenitors into the injured hippocampus
Authors: Parent Jack M. , von dem Bussche Nicolas , Lowenstein Daniel H. 
Published: January 2006

AbstractNeurogenesis persists in the adult rat rostral forebrain subventricular zone (SVZ) and is stimulated by status epilepticus (SE). More caudal SVZ (cSVZ) neural progenitors migrate to the hippocampus after ischemic injury and contribute to CA1 pyramidal cell regeneration. Because SE also damages the hippocampus, we examined the effects of SE on cSVZ precursors. SE was induced in adult rats with pilocarpine, and cell proliferation in cSVZ and hippocampus was examined by bromodeoxyuridine (BrdU) and retroviral reporter labeling. Neural precursors were assayed by immunostaining for specfic markers between 1 and 35 days after SE. BrdU‐positive cells labeled prior to SE markedly increased in numbers within 1–2 weeks in the cSVZ and infracallosal region, but not in the corpus callosum. Doublecortin‐, polysialic acid neural cell adhesion molecule‐, and TUC‐4 (TOAD/Ulip/CRMP family‐4)‐immunostained cells with migrating morphology increased with a similar time course after SE and extended from the cSVZ to CA1 and CA3 regions. Retroviral reporters injected into the cSVZ of controls showed labeled cells with oligodendroglial morphology located in the cSVZ and corpus callosum; when injected 2 days prior to SE, many more reporter‐labeled cells appeared several weeks later and were located in the cSVZ, corpus callosum, and hippocampus. Labeled cells showed glial morphologies and expressed astrocyte or oligodendrocyte markers. Neither BrdU‐ nor retroviral reporter‐labeled cells coexpressed neuronal markers in controls or pilocarpine‐treated rats. These results indicate that SE increases cSVZ gliogenesis and attracts newly generated glia to regions of hippocampal damage. Further study of seizure‐induced gliogenesis may provide insight into mechanisms of adult neural progenitor regulation and epileptogenesis. © 2006 Wiley‐Liss, Inc.
On an anti‐Ramsey problem of Burr, Erdős, Graham, and T. Sós
Authors: Sárközy Gábor N. , Selkow Stanley 
Published: January 2006

AbstractGiven a graph L, in this article we investigate the anti‐Ramsey number χS(n,e,L), defined to be the minimum number of colors needed to edge‐color some graph G(n,e) with n vertices and e edges so that in every copy of L in G all edges have different colors. We call such a copy of L totally multicolored (TMC).In 7 among many other interesting results and problems, Burr, Erdős, Graham, and T. Sós asked the following question: Let L be a connected bipartite graph which is not a star. Is it true then that

In this article, we prove a slightly weaker statement, namely we show that the statement is true if L is a connected bipartite graph, which is not a complete bipartite graph. © 2006 Wiley Periodicals, Inc. J Graph Theory 52: 147–156, 2006
Effect of young woody plantations on carbon and nutrient accretion rates in a redeveloping soil on coalmine spoil in a dry tropical environment, India
Authors: Singh A. N. , Zeng D. H. , Chen F. S. 
Published: January 2006

AbstractWe compared the effects of young high‐density plantations of three native trees (legumes: Albizia lebbeck, A. procera and a non‐legume: Tectona grandis) and one fast growing woody grass species (Dendrocalamus strictus) on carbon and nutrients stock and their accretion rates in a redeveloping soil. This soil was the early phase of mine spoil restoration in a dry tropical environment. The soil bulk density and accumulation rates of C, N and P at 0–10 and 10–20 cm soil depth were determined in 4‐ to 5‐year‐old plantations. The total nutrient stock of soil C, N, P significantly varied in redeveloping soil according to plantation type, plantation age and soil depth. A. lebbeck greatly improved C and N content followed by D. strictus, A. procera and T. grandis plantations. However, accretion rates of C and N were substantially high in the D. strictus plantation. Therefore, D. strictus, contributed significantly to the redevelopment of mine spoil soils. In the case of total P nutrient, A. procera showed the greatest amount among the plantations but the accretion rate was also high for T. grandis followed by A. procera, A. lebbeck and D. strictus. This study indicates that all N‐fixing species may not be equally efficient in improving soil qualities especially N in the soil. Copyright © 2006 John Wiley & Sons, Ltd.
Did Gustav Mahler have Sydenham's chorea?
Authors: Cardoso Francisco , Lees Andrew J. 
Published: January 2006

AbstractSydenham's chorea (SC), a major manifestation of acute rheumatic fever (RF), is characterized by chorea and other motor and nonmotor features. Among the latter are behavioral symptoms, including obsessive–compulsive disorder. Although SC is typically a self‐limited condition, up to 50% of patients may evolve with persistent chorea. There is evidence that Gustav Mahler had a movement disorder, but its nature remains undetermined. There are witnesses describing him as having facial dyskinesia and a gait disorder consistent with chorea. His conducting performance was notorious for obsessive attention to details of the staging and musical production. Mahler was diagnosed with a valvulopathy in 1907 and died of subacute bacterial endocarditis in 1911. It is possible that the composer suffered from RF in childhood with carditis and SC, which may left him with valvulopathy, obsessive–compulsive disorder, and persistent chorea. © 2006 Movement Disorder Society
Medical and non‐medical barriers to outpatient treatment of fever and neutropenia in children with cancer
Authors: Quezada Gerardo , Sunderland Theresa , Chan Ka Wah , Rolston Kenneth , Mullen Craig A. 
Published: January 2006

AbstractBackgroundA number of clinical trials have employed clinical criteria that can identify pediatric patients at low‐risk for complicated episodes of fever and neutropenia (F&N) and have successfully treated low‐risk patients in the outpatient setting. Despite this, inpatient management remains the standard of care. This trial tested the hypothesis that a strategy of initial hospitalization followed by continuation of therapy in the outpatient setting could be practically implemented in the majority of episodes.ProcedurePatients presenting with F&N were initially evaluated to determine if they had high‐risk clinical criteria that would exclude them from this approach. Eligible patients were then hospitalized and treated with iv antibiotics. On subsequent days the attending physician determined whether the patient had exhibited improvement and could continue therapy in the outpatient setting with oral antibiotics. Outpatients were seen three times weekly and continued antibiotics until recovery from F&N.ResultsOutpatient oral antibiotic therapy was practically implemented in less than one‐quarter of episodes of pediatric F&N. Forty‐nine percent of episodes were excluded from study by medical and social protocol exclusion criteria. One hundred five episodes were enrolled and among these 59 episodes included outpatient management. Common barriers to outpatient care included serious medical comorbidities, non‐medical barriers including language and distance of residence from the medical center, and lack of interest. The average duration of outpatient care was 3.6 days following an average of 3.5 days of hospitalization. Ninety percent did not require rehospitalization. They experienced no complications.ConclusionsIn only a minority of episodes can outpatient antibiotic management be implemented. Medical comorbidities and social barriers can make the transition to outpatient care difficult. However, initial hospitalization followed by oral antibiotic outpatient management appears safe and effective for low‐risk patients who exhibit good responses to initial antibiotic therapy in hospital. Pediatr Blood Cancer 2007;48:273–277. © 2006 Wiley‐Liss, Inc.
The evolution of ATPase activity in SMC proteins
Authors: Cobbe Neville , Heck Margarete M.S. 
Published: January 2006

AbstractThe SMC (structural maintenance of chromosomes) proteins are a highly conserved and ubiquitous family of ATPases, found in nearly all living organisms examined, where they play crucial roles in transmission of the hereditary material. However, the extent to which efficient ATP hydrolysis is required for SMC function has been a matter of some debate. Here we investigate the potential functional significance of ATP binding and hydrolysis in different eukaryotic SMC proteins, both by comparing the conservation of conserved ATPase motifs and by exploring potential coevolution between associated domains. In this way, we have been able to account for the reduced requirement for ATPase activity in cohesin's SMC3 and demonstrate the greater apparent conservation requirements for such activity in condensin SMC proteins. Finally, we explore possible interactions between the SMC and non‐SMC components of the condensin complex that are required for full condensin activity and may modulate ATPase activity in the holocomplex. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Data and Graph Mining in Chemical Space for ADME and Activity Data Sets
Authors: Wegner Jörg K. , Fröhlich Holger , Mielenz Holger M. , Zell Andreas 
Published: January 2006

AbstractWe present a classification method, which is based on a coordinate‐free chemical space. Thus, it does not depend on descriptor values commonly used by coordinate‐based chemical space methods. In our method the molecular similarity of chemical structures is evaluated by a generalized maximum common graph isomorphism, which supports the usage of numerical physicochemical atom property labels in addition to discrete‐atom‐type labels. The Maximum Common Substructure (MCS) algorithm applies the Highest Scoring Common Substructure (HSCS) ranking of Sheridan and co‐workers, which penalizes discontinuous fragments. For all compared classification algorithms used in this work we analyze their usefulness based on two objectives. First, we are interested in highly accurate and general hypotheses and second, the interpretation ability is highly important to increase our structural knowledge for the ADME data sets and the activity data set investigated in this work.
Correlation and Prediction in Ordinal Test Theory
Authors: Schulman Robert S. 
Published: January 2006

Based on the test theory model for ordinal measurements proposed by Schulman and Haden, the present paper considers correlations between tests, attenuation, regressions involving true and observed scores, and prediction of test reliability.The population correlation between tests is shown to be related to the expected sample correlation for samples of size n1 and n2. Errors of estimation, measurement and prediction are found to be similar to their counterparts in interval test theory, while attenuation is identical to its counterpart. The bias in estimating population reliability from sample data is compared for Kendall's tau and Spearman's rho.
Latent Roots of Random Data Correlation Matrices with Squared Multiple Correlations on the Diagonal: A Monte Carlo Study
Authors: Montanelli Richard G. , Humphreys Lloyd G. 
Published: January 2006

In order to make the parallel analysis criterion for determining the number of factors easy to use, regression equations for predicting the logarithms of the latent roots of random correlation matrices, with squared multiple correlations on the diagonal, are presented. The correlation matrices were derived from distributions of normally distributed random numbers. The independent variables arelog (N − 1) and log {[n(n − 1)/2] − [(i − 1)n]},where N is the number of observations; n, the number of variables; and i, the ordinal position of the eigenvalue. The results were excellent, with multiple correlation coefficients ranging from .9948 to .9992.
Differential Ordering of Objects and Attributes
Authors: Sutcliffe J. P. 
Published: January 2006

By reference to nominated attributes, a genus, being a population of objects of one specified kind, may be partitioned into species, being subpopulations of different kinds. A prototype is an object representative of its species within the genus. Using this framework, the paper describes how objects can be relatively differentiated with respect to attributes, and how attributes can be relatively differentiating with respect to objects. Methods and rationale for such differential ordering of objects and attributes are presented by example, formal development, and application.For a genus Ω comprising n species of object there is a subset P ofn distinct prototypes. With respect to m nominated attributes, each object in Ω has an m-element characterization. Together these determine an n × m objects × attributes matrix, the rows of which are the characterizations of the prototypical objects. Over then species in Ω, an associated relative frequency vector gives the distribution of objects (and of their characterizations). The matrix and vector associate the objects in Ω with points in a metric space (P, δ); and it is with respect to various sums of distances in this attribute space that one can differentially order objects and attributes.The definition of the distance function δ is generalized across kinds of difference, types of characterization, scale-types of measurement, Minkowski index ≧ 1, and any form of distribution of objects over species. Explanatory and taxonomic applications in psychology and other fields are discussed, with focus on classification, identification, recognition, and search. The Braille code and the identification of its characters provide illustration.
The Many Null Distributions of Person Fit Indices
Authors: Molenaar Ivo W. , Hoijtink Herbert 
Published: January 2006

This paper deals with the situation of an investigator who has collected the scores of n persons to a set of k dichotomous items, and wants to investigate whether the answers of all respondents are compatible with the one parameter logistic test model of Rasch. Contrary to the standard analysis of the Rasch model, where all persons are kept in the analysis and badly fitting items may be removed, this paper studies the alternative model in which a small minority of persons has an answer strategy not described by the Rasch model. Such persons are called anomalous or aberrant. From the response vectors consisting of k symbols each equal to 0 or 1, it is desired to classify each respondent as either anomalous or as conforming to the model. As this model is probabilistic, such a classification will possibly involve false positives and false negatives. Both for the Rasch model and for other item response models, the literature contains several proposals for a person fit index, which expresses for each individual the plausibility that his/her behavior follows the model. The present paper argues that such indices can only provide a satisfactory solution to the classification problem if their statistical distribution is known under the null hypothesis that all persons answer according to the model. This distribution, however, turns out to be rather different for different values of the person's latent trait value. This value will be called “ability parameter”, although our results are equally valid for Rasch scales measuring other attributes.As the true ability parameter is unknown, one can only use its estimate in order to obtain an estimated person fit value and an estimated null hypothesis distribution. The paper describes three specifications for the latter: assuming that the true ability equals its estimate, integrating across the ability distribution assumed for the population, and conditioning on the total score, which is in the Rasch model the sufficient statistic for the ability parameter.Classification rules for aberrance will be worked out for each of the three specifications. Depending on test length, item parameters and desired accuracy, they are based on the exact distribution, its Monte Carlo estimate and a new and promising approximation based on the moments of the person fit statistic. Results for the likelihood person fit statistic are given in detail, the methods could also be applied to other fit statistics. A comparison of the three specifications results in the recommendation to condition on the total score, as this avoids some problems of interpretation that affect the other two specifications.
Limited Information Estimation and Testing of Thurstonian Models for Paired Comparison Data Under Multiple Judgment Sampling
Authors: Maydeu-Olivares Albert 
Published: January 2006

We relate Thurstonian models for paired comparisons data to Thurstonian models for ranking data, which assign zero probabilities to all intransitive patterns. We also propose an intermediate model for paired comparisons data that assigns nonzero probabilities to all transitive patterns and to some but not all intransitive patterns.There is a close correspondence between the multidimensional normal ogive model employed in educational testing and Thurstone's model for paired comparisons data under multiple judgment sampling with minimal identification restrictions. Alike the normal ogive model, Thurstonian models have two formulations, a factor analytic and an IRT formulation. We use the factor analytic formulation to estimate this model from the first and second order marginals of the contingency table using estimators proposed by Muthén. We also propose a statistic to assess the fit of these models to the first and second order marginals of the contingency table. This is important, as a model may reproduce well the estimated thresholds and tetrachoric correlations, yet fail to reproduce the marginals of the contingency table if the assumption of multivariate normality is incorrect.A simulation study is performed to investigate the performance of three alternative limited information estimators which differ in the procedure used in their final stage: unweighted least squares (ULS), diagonally weighted least squares (DWLS), and full weighted least squares (WLS). Both the ULS and DWLS show a good performance with medium size problems and small samples, with a slight better performance of the ULS estimator.
Reliability and Expected Loss: A Unifying Principle
Authors: Cooil Bruce , Rust Roland T. 
Published: January 2006

We provide a unified, theoretical basis on which measures of data reliability may be derived or evaluated, for both quantitative and qualitative data. This approach evaluates reliability as the “proportional reduction in loss” (PRL) that is attained in a sample by an optimal estimator. The resulting measure is between 0 and 1, linearly related to expected loss, and provides a direct way of contrasting the measured reliability in the sample with the least reliable and most reliable data-generating cases. The PRL measure is a generalization of many of the commonly-used reliability measures.We show how the quantitative measures from generalizability theory can be derived as PRL measures (including Cronbach's alpha and measures proposed by Winer). For categorical data, we develop a new measure for the general case in which each of N judges assigns a subject to one of K categories and show that it is equivalent to a measure proposed by Perreault and Leigh for the case where N is 2.