bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of alternative regression models for paired binary data
Authors: Glynn Robert J. , Rosner Bernard 
Published: April 2007

AbstractWe used simulated data, derived from real ophthalmologic examples, to evaluate the performance of alternative logistic regression approaches for paired binary data. Approaches considered were: standard logistic regression (ignoring the correlation between fellow eyes, treating individuals classified on the basis of their more impaired eye as the unit of analysis, or considering only right eyes); marginal logistic regression models fitted by the maximum likelihood approach of Lipsitz, Laird and Harrington or the estimating equation approach of Liang and Zeger; and conditional logistic regression models fitted by the maximum likelihood approach of Rosner or the estimating equation approach of Connolly and Liang. Taylor series approximations were used to compare conditional and marginal parameter estimates. Consideration of type I and II error rates found application of standard logistic regression to be inferior to methods that treated the eye as the unit of analysis and accounted for the correlation between fellow eyes. Among these latter approaches, none was uniformly superior to the others across the range of conditions considered.
A comparison of methods for testing homogeneity of proportions in teratologic studies
Authors: Donner Allan , Eliasziw Michael , Klar Neil 
Published: April 2007

AbstractWe consider teratologic studies in which the aim is to compare the survival rate of animals in a treatment group to the corresponding rate in a control group. The design of such studies often involves the allocation of intact litters of animals to treatment, invalidating the application of standard statistical methods. We review the strengths and weaknesses of several approaches for dealing with this problem including methodology recently developed for the analysis of clustered binary data. A simulation study is conducted in which litter sizes are generated from a distribution having specified mean and degree of imbalance. It is recommended on the basis of this study and on theoretical considerations that the choice of method should depend on whether the comparison of interest is experimental or observational. For experimental comparisons, involving the random assignment of litters to different treatment groups, methods based on the adjustment of standard chi‐square statistics are recommended unless the number of litters in each group is very large.
Triangular test and randomized trials: Practical problems in a small cell lung cancer trial
Authors: Pignon Jean‐Pierre , Tarayre Michèle , Auquier Ariane , Arriagada Rodrigo , le Chevalier Thierry , Ruffié Pierre , Rivière Alain , Monnet Isabelle , Chomy Pierre , Tuchais Claude 
Published: April 2007

AbstractThe triangular test has been used to monitor survival data from a randomized trial in patients with small cell lung cancer. The results of consecutive interim analyses and the problems met by the data monitoring committee and the co‐ordinators are described. The methods as well as the consequences of the early stopping on the analysis and the results of this trial are discussed. From this experience, we believe that statistical stopping rules ‐ only one of the factors to be taken into account when deciding to stop a trial ‐ should be used with caution. Independent data monitoring committees may be useful in helping to review the ongoing results and advise the participants in the trial.
Back‐projection of german AIDS data using information on dates of tests
Authors: Dietz Klaus , Seydel Johannes , Schwartländer Bernhard 
Published: April 2007

AbstractThe paper presents an application of back‐projection methods to the reported AIDS data which are collected by the AIDS Center in the Federal Office of Health, Berlin. The analysis is based on all data reported up to 31 December 1992. The data are broken down by major risk groups. Correction for reporting delays takes into account temporal changes in their distribution. The paper applies the EMS algorithm for the estimation of HIV incidence. The incubation period is modelled according to a convolution of several exponential distributions which describe time dependent phenomena like change of case definition and therapy effects. For each case it is reported whether an antibody test has been performed before diagnosis, and if yes, at what time this test was performed. The modelling of the incubation distribution takes into account the transition from a state ‘not yet tested’ into a state ‘tested’. Only tested individuals in three pre‐AIDS states are eligible for treatment. The model allows us to estimate not only the current total HIV prevalence but also a breakdown into those that are not yet tested, those that are tested but not yet treated and those that are under treatment. The results depend on the assumptions about the effect of treatment and on the degree of smoothing applied in the EMS algorithm.
Monitoring of a pilot toxicity study with two adverse outcomes
Authors: Etzioni Ruth , Pepe Margaret Sullivan 
Published: April 2007

AbstractWe consider monitoring a pilot toxicity study in which the adverse outcome is bivariate and the goal is to terminate the trial if evidence of excessive toxicity is encountered. We develop a Bayesian monitoring rule, based on the posterior probability that the frequency of either adverse outcome exceeds that observed under standard therapy. This rule is intuitive and ethical, and extends in a straightforward fashion from the univariate to the multivariate case. Since p‐values and confidence intervals are standard methods for reporting the results of clinical trials, we also suggest how frequentist inferences may be drawn at the conclusion of a study monitored in this fashion. This work thus represents an integration of Bayesian and frequentist methodology for sequential clinical trials.
Sample sizes for phase ii clinical trials derived from Bayesian decision theory
Authors: Brunier Hazel C. , Whitehead John 
Published: April 2007

AbstractIn early phase clinical trials of a new medical treatment, patients are treated to decide whether there is sufficient promise to justify additional studies. A decision theoretic approach is proposed to help determine the number of patients that should be treated. The optimal sample size is obtained by maximizing a utility function which incorporates both the number of ‘gained successes’ and the costs of treatment. The method extends work of Sylvester and Staquet, and adopts a Bayesian formulation. Numbers of patients in later studies and in eventual routine use of the treatment are taken into account. We allow for the possibility that a later study might lead to an erroneous conclusion. The effects of these various influences on the recommended sampling plan for the early phase clinical trial are explored.
Location—scale cumulative odds models for ordinal data: A generalized non‐linear model approach
Authors: Cox Christopher 
Published: April 2007

AbstractProportional odds regression models for multinomial probabilities based on ordered categories have been generalized in two somewhat different directions. Models having scale as well as location parameters for adjustment of boundaries (on an unobservable, underlying continuum) between categories have been employed in the context of ROC analysis. Partial proportional odds models, having different regression adjustments for different multinomial categories, have also been proposed. This paper considers a synthesis and further generalization of these two families. With use of a number of examples, I discuss and illustrate properties of this extended family of models. Emphasis is on the computation of maximum likelihood estimates of parameters, asymptotic standard deviations, and goodness‐of‐fit statistics with use of non‐linear regression programs in standard statistical software such as SAS.
Adenosine A2A receptor antagonists improve deficits in initiation of movement and sensory motor integration in the unilateral 6‐hydroxydopamine rat model of Parkinson's disease
Authors: Pinna Annalisa , Pontis Silvia , Borsini Franco , Morelli Micaela 
Published: May 2007

AbstractEvidence obtained in rodent and primate models of Parkinson's disease (PD) and preliminary clinical trials, indicates that adenosine A2A receptor antagonists might represent a promising nondopaminergic therapeutic tool for the treatment of PD. Those studies demonstrated the ability of adenosine A2A receptor antagonists to potentiate l‐dopa‐mediated motor improvement, whereas very little is known about counteraction of specific motor deficits and on the effects of these compounds when administered alone. To this aim we evaluated the effects of different adenosine A2A receptor antagonists on initiation of movement deficits, gait impairment and sensory‐motor deficits, induced in rats by a unilateral 6‐hydroxydopamine lesion of dopaminergic nigrostriatal neurons. The following tests were used: (1) initiation time of stepping; (2) adjusting step (stepping with forelimb was measured as the forelimb was dragged laterally); (3) vibrissae‐elicited forelimb placing (as index of sensory‐motor integration deficits). Acute administration of the A2A receptor antagonists SCH 58261 (5 mg/kg i.p.) and ST 1535 (20 mg/kg i.p.) similarly to l‐dopa (6 mg/kg i.p.) counteracted the impairments in the initiation time of stepping test, in the adjusting step and in the vibrissae‐elicited forelimb placing induced by the lesion. The intensity of the effect was l‐dopa > SCH 58261 > ST 1535. The results provide the first evidence that blockade of A2A receptors is effective in antagonizing specific motor deficit induced by DA neuron degeneration, such as initiation of movement and sensory‐motor integration deficits, even without l‐dopa combined administration. Synapse 61:606–614, 2007. © 2007 Wiley‐Liss, Inc.
Ethanol's effect on intracellular signal pathways in prenatal rat cortical neurons is GABAB1 dependent
Authors: Lee H.Y. , Li S.P. , Park M.S. , Bahk Y.H. , Chung B.C. , Kim M.O. 
Published: May 2007

AbstractTo confirm the modulation role of GABAB on ethanol' effects, we studied the effects of ethanol on the neuronal intracellular signals, protein kinase A (PKA) and cAMP‐response element binding protein (CREB), by using a system where GABAB1 receptors were specifically knocked down in the in vitro cultivated cortical neurons. The results showed that the PKA α subunit was increased with ethanol treatment, and could be further increased by administering baclofen and phaclofen. By contrast, baclofen and/or phaclofen could decrease ethanol's up‐regulation effects on PKA α subunit expression in primary cultured cortical neurons in which the GABAB1 receptor was specifically knocked down using GABAB1 receptor RNA interference. Furthermore, these effects could lead to changes of phospho (p)‐CREB expression, which showed the same expression pattern as PKA. Finally, we observed changes of GABAB1, PKA, and p‐CREB distribution within the same neuronal cells. These results showed that the GABAB receptors are critical to ethanol's cellular effects, which occur via modulating the PKA and CREB transcription pathway, and may be an underlying cause of ethanol's effects. Synapse 61:622–628, 2007. © 2007 Wiley‐Liss, Inc.
Distribution, diversity and regulation of alcohol oxidase isozymes, and phylogenetic relationships of methylotrophic yeasts
Authors: Ito Takashi , Fujimura Shuki , Uchino Masataka , Tanaka Naoto , Matsufuji Yoshimi , Miyaji Tatsuro , Takano Katsumi , Nakagawa Tomoyuki , Tomizuka Noboru 
Published: May 2007

AbstractIn this study, we attempted to classify the methylotrophic yeasts based on diversities of alcohol oxidase (AOD), i.e. zymogram patterns and partial amino acid sequences. According to zymogram patterns for AOD, members of the methylotrophic yeasts separate into two major lineages, one group involving strains having a single AOD and the other group, including Pichia methanolica, Candida pignaliae and C. sonorensis, showing nine AOD isozymes. Based on partial amino acid sequences of AOD, the methylotrophic yeasts could be divided into five groups, and this classification agrees mostly with grouping based on 26S domain D1/D2 rDNA nucleotide sequences, except for some strains. Moreover, the strains having AOD isozymes constitute one group with P. trehalophila, P. glucozyma and Pichia sp. strain BZ159, although these strains are divided into two types, based on amino acid sequences of second AODs. On the other hand, these AOD isozymes consist of two subunits; the first subunits are induced not only by methanol but also by glycerol and pectin, although the second subunits are mainly induced by methanol. These data indicate that AOD isozymes and second AOD genes distribute widely in several methylotrophic yeasts in the natural environment, and second AOD genes may have evolved as methylotrophic genes that can adapt to the environmental conditions of higher methanol concentrations. Copyright © 2007 John Wiley & Sons, Ltd.
An Efficient Methodology for the Preparation of Alkoxyglycerols Rich in Conjugated Linoleic Acid and Eicosapentaenoic Acid
Authors: Torres Carlos F. , Vazquez Luis , Señoráns Francisco J. , Reglero Guillermo 
Published: May 2007

AbstractSaponification of a raffinate obtained by supercritical fluid fractionation of shark liver oil was utilized for the production of an unsaponifiable fraction enriched in nonesterified alkoxyglycerols. Re‐esterification of the alkoxyglycerols produced with conjugated linoleic acid (CLA) and eicosapentaenoic acid in the presence of Candida antarctica lipase B was then studied. High yields (>90%) of diesterified alkoxyglycerols were obtained via esterification and transesterification with CLA, their respective ethyl ester, and eicosapentaenoic ethyl ester. The effect of a continuous purge stream of nitrogen on the kinetics of the reactions was also evaluated.
Meet the Abrahams: Colonial Law and a Mixed Race Family from Bellary, South India, 1810–63
Authors: MALLAMPALLI CHANDRA 
Published: May 2007

AbstractTo what extent did legal notions of identity conceal more porous and dynamic social relationships experienced outside of court? This article reconstructs events surrounding a famous court case,Abraham v. Abraham(1863), involving a property dispute within a mixed race family from Bellary, South India. Using the case's original documents it presents a narrative about the Abraham family, highlighting their negotiations of identity within the domains of family, market and law. The narrative shows how Indians, even under colonialism, could experience far more dynamic and flexible boundaries than what is often portrayed in the literature on communalism. At the same time, it demonstrates the very real impact of personal law categories upon the choices and litigation strategies of Indians. Indians had real agency in crafting their identities, but only as they adopted the conceptual tools of the colonial judiciary to pursue their interests.
The World of Workers' Politics: Some Issues of Railway Workers in Colonial India, 1918–1922
Authors: SINHA NITIN 
Published: May 2007

AbstractThis paper uses a study of strikes of railway workers in Bihar and Bengal from 1918 to 1922 to set out and examine the complexities of workers' politics. Three broad themes related with workers' politics,viz.racial ideology, actual ‘event’ of striking and the related activities of workers, and techniques of mobilization have been covered in this paper. In each of these cases, it has been argued that rigid categories like racialism or nationalism are of little help in unravelling the complexities of workers' choices and their politics. Their politics were more flexible than what meets the eye, and their choices were created through dialogue, if not determined by the various factors surrounding them. However such choices were also being limited by the larger context provided by the ideologies and institutions of racialism, nationalism, and colonialism.
The Paradox of Peasant Worker: Re-conceptualizing workers’ politics in Bengal 1890–1939
Authors: BASU SUBHO 
Published: May 2007

AbstractThis essay explores labor politics in Bengal in the period between 1890 and 1939. It investigates numerous supposed paradoxes in labor politics such as the coexistence of intense industrial action marked by workers’ solidarity and communal rioting between Hindus and Muslims, labor militancy and weak formal trade union organization. In existing historiography, these paradoxes are explained through a catch all phrase ‘peasant worker’—a concept that perceives Indian workers as not fully divorced from rural society and thus were susceptible to fragmentary pulls of natal ties that acted as a break on the emergence of class consciousness. In contradistinction to such historiography this paper argues that religion, language and region did not always act as a break on workers’ ability to unite. It demonstrates that workers’ politics was informed and influenced by notions of customary rights based on mutuality of shared interests at workplaces. When workers perceived that management violated such customary rights, they formed alliances among themselves and engaged in militant industrial action. In such circumstances, workers’ natal ties assisted in producing solidarities. By drawing upon Chandavarkar's works, this essay accords importance to the contingency of politics in the making and unmaking of alliances among workers and thus argues that in different political circumstances religious or other forms of natal ties acquired different meanings to different groups of workers.
Dynamics of Salmonella transmission on a British pig grower-finisher farm: a stochastic model
Authors: HILL A. A. , SNARY E. L. , ARNOLD M. E. , ALBAN L. , COOK A. J. C. 
Published: May 2007

SUMMARYPrevious modelling studies have estimated that between 1% and 10% of human salmonella infections are attributable to pig meat consumption. In response to this food safety threat the British pig industry have initiated a salmonella monitoring programme. It is anticipated that this programme will contribute to achieving a UK Food Standards Agency target for reducing salmonella levels in pigs at slaughter by 50% within 5 years. In order to better inform the monitoring programme, we have developed a stochastic transmission model for salmonella in a specialist grower-finisher pig herd, where data from a Danish longitudinal study have been used to estimate some of the key model parameters. The model estimates that about 17% of slaughter-age pigs will be infected with salmonella, and that of these infected pigs about 4% will be excreting the organism. In addition, the model shows that the most effective control strategies will be those that reduce between-pen transmission.
Proofs, denotational semantics and observational equivalences in Multiplicative Linear Logic
Authors: PAGANI MICHELE 
Published: May 2007

We study full completeness and syntactical separability of MLL proof nets with the mix rule. The general method we use consists of first addressing these two questions in the less restrictive framework of proof structures, and then adapting the results to proof nets.At the level of proof structures, we find a semantical characterisation of their interpretations in relational semantics, and define an observational equivalence that is proved to be the equivalence induced by cut elimination. Hence, we obtain a semantical characterisation (in coherent spaces) and an observational equivalence for the proof nets with the mix rule.
3-body, classical–quantum, discrete–continuous
Authors: PAUL THIERRY 
Published: May 2007

This special issue of Mathematical Structures in Computer Science contains several contributions to the Workshop3 corps, classique-quantique, discret-continu.The Workshop was held at the Ecole Normale Supérieure, Paris on 28–29 September 2004 in the framework of the Collectif Histoire Philosophie Sciences. The Workshop was organised by Giuseppe Longo and Thierry Paul with the aim of bringing together mathematicians, physicists, computer scientists and philosophers.
Mutual geometry of confocal Keplerian orbits: uncertainty of the MOID and search for virtual PHAs
Authors: Gronchi Giovanni F. , Tommei Giacomo , Milani Andrea 
Published: May 2007

AbstractThe Minimum Orbit Intersection Distance (MOID) between two confocal Keplerian orbits is a useful tool to know if two celestial bodies can collide or undergo a very close approach. We describe some results and open problems on the number of local minimum points of the distance between two points on the two orbits and the position of such points with respect to the mutual nodes. The errors affecting the observations of an asteroid result in uncertainty in its orbit determination and, consequently, uncertainty in the MOID. The latter is always positive and is not regular where it vanishes; this prevents us from considering it as a Gaussian random variable, and from computing its covariance by standard tools. In a recent work we have introduced a regularization of the maps giving the local minimum values of the distance between two orbits. It uses a signed value of the distance, with the sign given to the MOID according to a simple orientation property. The uncertainty of the regularized MOID has been computed for a large database of orbits. In this way we have searched for Virtual PHAs, i.e. asteroids which can belong to the category of PHAs (Potentially Hazardous Asteroids) if the errors in the orbit determination are taken into account. Among the Virtual PHAs we have found objects that are not even NEA, according to their nominal orbit.
Dynamical evolution of Oort cloud comets to near-Earth space
Authors: Mazeeva Olga A. 
Published: May 2007

AbstractThe dynamical evolution of 2⋅105 hypothetical Oort cloud comets by the action of planetary, galactic and stellar perturbations during 2⋅109 years is studied numerically. The evolution of comet orbits from the outer (104 AU <a<5⋅104 AU, a is semimajor axes) and the inner Oort cloud (5⋅103 AU <a<104 AU) to near-Earth space is investigated separately. The distribution of the perihelion (q) passage frequency in the planetary region is obtained calculating the numbers of comets in every interval of Δ q per year. The flux of long-period (LP) comets (orbital periods P>200 yr) with perihelion distances q<1.5 AU brighter than visual absolute magnitude H10=7 is ∼ 1.5 comets per year, and ∼18 comets with H10<10.9. The ratio of all LP comets with q<1.5 AU to ‘new’ comets is ∼5. The frequency of passages of LP comets from the inner Oort cloud through region q<1.5 AU is ∼3.5⋅10−13 yr−1, that is roughly one order of magnitude less than frequency of passages of LP comets from the outer cloud (∼5.28⋅10−12 yr−1). We show that the flux of ‘new’ comets with 15<q<31 AU is higher than with q<15 AU, by a factor ∼1.7 for comets from the outer Oort cloud and, by a factor ∼7 for comets from the inner cloud. The perihelia of comets from the outer cloud previously passed through the planetary region are predominated in the Saturn-Uranus region. The majority of inner cloud comets come in the outer solar system (q>15 AU), and a small fraction (∼0.01) of them can reach orbits with q<1.5 AU. The frequency of transfer of comets from the inner cloud (a<104 AU) to the outer Oort cloud (a>104 AU), from where they are injected to the region q<1.5 AU, is ∼6⋅10−14 yr−1.