bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reactivities and Properties of Lanthanide Catalysts Prepared by Thermal Degradation of Liquid Ammonia Solutions of Eu or Yb Metal
Authors: Imamura Hayao , Konishi Tomohiro , Suda Eisaku , Sakata Yoshihisa , Tsuchiya Susumu 
Published: June 2006

Abstract
Studies of X-ray diffraction, Fourier-transform infrared spectra and catalytic properties of lanthanide catalysts (Eu/AC and Yb/AC) prepared by impregnation of active carbon (AC) with liquid ammonia solutions of Eu or Yb metal were carried out for the catalytic hydrogenation of ethene. The lanthanides thus deposited on AC were changed through varied steps (metal, amide, imide or nitride) by thermal treatments and simultaneously the hydrogenation activity varied markedly. Eu/AC and Yb/AC which were subjected to the evacuation treatment around 573 and 773 K, respectively, showed a high activity even at 203 K. The catalytic properties of lanthanide amide (Eu(NH2)2, Yb(NH2)2, and Yb(NH2)3) prepared separately, imide and nitride were investigated for comparison. It was concluded that imide or imide-like species formed during the thermal decomposition processes of europium(II) and ytterbium(II and III) amides to nitride at 503—573 and 423—773 K was active catalysts for Eu/AC and Yb/AC, respectively.
Aqueous Media Effect on Molecular Recognition. II. Temperature Dependence of Chemical Selectivity in Alcohols and Water
Authors: Endo Tadashi , Aono Yoshihiro , Yazawa Takashi , Hayashi Munetoshi , Yokose Yuuichi , Iida Takahiro , Isago Takashi 
Published: June 2006

Abstract
Oxidation of a pair of associating thiols (1 and 2), each having the binding site [–C(=O)NHC(=O)NH–] and the recognition site (R1 or R2), is examined at several temperatures in alcohols (MeOH, EtOH, n-PrOH, and i-PrOH) and water. The selectivity (r), a measure of molecular recognition of 1 by 2 (or of 2 by 1), in the oxidation is defined as the logarithmic ratio of the yield of an unsymmetrical disulfide (4) to twice that of a symmetrical one (3). It is found that the selectivity in the alcohols each decreases markedly with increasing temperature except for one case, whereas that in water increases with increasing temperature. Correlation of the observed selectivity with factors affecting the selectivity (e.g., intermolecular association, physicochemical properties of solvents, and hydrophobic interaction) is discussed.
Catalysis by Organic Solids. Stereoselective Intramolecular Ene Reaction of Citronellal Promoted by Microporous Molecular Crystals Having an Extensive Hydrogen-Bonded Network
Authors: Sawaki Tomoya , Endo Ken , Kobayashi Kenji , Hayashida Osamu , Aoyama Yasuhiro 
Published: June 2006

Abstract
5,5′-(9,10-Anthracenediyl)diresorcinol (1) (host) and a terpenoid aldehyde citronellal (2, guest) form a 1 : 2 adduct 1·2(2), in which the guest molecules hydrogen-bonded to the host are closely packed in an extended conformation in the microporous crystal structure of the host. When heated in vacuo, the 1 : 2 adduct loses ca. 1 molecule of the guest to give a 1 : 1 adduct 1·2. The guest 2 included in both adducts undergoes a facilitated intra-adduct ene reaction to afford isopulegol as the main product. Such a reaction in the 1 : 1 adduct occurs smoothly and in a highly stereoselective (ca. 98%) manner. The reaction in the 1 : 2 adduct is less stereoselective and exhibits a sigmoidal progression curve having a significant “induction period”. The present ene reaction of citronellal (2) as either a neat liquid or in a cyclohexane solution is catalyzed by host 1 in the solid state. The allosteric cooperativity observed is discussed in view of a big conformational change associated with the present cyclization reaction.
Zur Rolle der Logik in der Linguistik: Formale Modellbildung und funktionale Sprachtheorie
Authors: Winkler Marco 
Published: June 2006

AbstractThis paper discusses the relationship of logic and linguistics and pleads for logic-based formal model building in linguistic theory. At first, I describe the assignments and the purpose of logic in arts in general and the interrelation between logic and linguistics. Taking into account philosophical conditions and the subject of both, language, I argue for a functional-linguistic point of view. A detailed investigation is devoted to the concept of predicates. Based on logical theory, namely the non-traditional theory of predication and the term-theory developed by A. A. Sinowjew and H. Wessel, a formal approach to modelling linguistic comprehensions of predicates is devised. On this base I carry out a logical reconstruction of some concepts of linguistic theory, like the quantitative and qualitative features of arguments and their thematic roles, and explain their relations to logical predicate-argument-structures. In a further step predicate forming operations are used to describe and to reconstruct diatheses, argument deletion and the influence of mass terms on predication. By this, I want to introduce formal tools for the explanation of such natural-language phenomena and line out how the formal results allow to solve several puzzles.
Pneumatic Impact Ignition of Sebum Oil Film in High-Pressure Oxygen
Authors: Tapia SA , Smith SR , Hshieh F-Y , Stoltzfus JM 
Published: June 2006

Abstract
Whenever oxygen systems are assembled or maintained, a risk of introducing contamination arises. Potential contaminants include oils from a person's hands and body left behind in the form of fingerprints. The oil on the surface of skin is a complex mixture of sebum oil, lipids, sweat, and environmental materials. In high-pressure systems, heat from rapid pressurization is a high-risk ignition mechanism for the sebum contaminant. The rapid pressurization or pneumatic impact ignition of hydrocarbon-based oil contaminant in high-pressure oxygen has been widely studied. This study investigated the rapid pressurization ignition of sebum contaminant in high-pressure oxygen. The pneumatic impact ignition test of sebum contaminant was conducted according to NASA-STD-6001 Test 14. The ends of stainless steel cylindrical rods were coated with synthetic sebum at varying surface concentrations, and impacted with 27.6 MPa oxygen. The results show that there is a threshold level of sebum contaminant for ignition by rapid pressurization. The level of sebum contaminant that can be expected to be deposited by handling oxygen system components, an analysis on sebum oil properties and associated fire hazards, and the threshold levels of sebum contaminant required for rapid pressurization ignition in a high-pressure oxygen system are presented and discussed.
Statistical Analysis of Pathogenicity of Somatic Mutations in Cancer
Authors: Greenman Chris , Wooster Richard , Futreal P Andrew , Stratton Michael R , Easton Douglas F 
Published: June 2006

Abstract
Recent large-scale sequencing studies have revealed that cancer genomes contain variable numbers of somatic point mutations distributed across many genes. These somatic mutations most likely include passenger mutations that are not cancer causing and pathogenic driver mutations in cancer genes. Establishing a significant presence of driver mutations in such data sets is of biological interest. Whereas current techniques from phylogeny are applicable to large data sets composed of singly mutated samples, recently exemplified with a p53 mutation database, methods for smaller data sets containing individual samples with multiple mutations need to be developed. By constructing distinct models of both the mutation process and selection pressure upon the cancer samples, exact statistical tests to examine this problem are devised. Tests to examine the significance of selection toward missense, nonsense, and splice site mutations are derived, along with tests assessing variation in selection between functional domains. Maximum-likelihood methods facilitate parameter estimation, including levels of selection pressure and minimum numbers of pathogenic mutations. These methods are illustrated with 25 breast cancers screened across the coding sequences of 518 kinase genes, revealing 90 base substitutions in 71 genes. Significant selection pressure upon truncating mutations was established. Furthermore, an estimated minimum of 29.8 mutations were pathogenic.
New Alleles of SIR2 Define Cell-Cycle-Specific Silencing Functions
Authors: Matecic Mirela , Martins-Taylor Kristen , Hickman Merrit , Tanny Jason , Moazed Danesh , Holmes Scott G 
Published: June 2006

Abstract
The establishment of transcriptional silencing in yeast requires cell-cycle progression, but the nature of this requirement is unknown. Sir2 is a protein deacetylase that is required for gene silencing in yeast. We have used temperature-sensitive alleles of the SIR2 gene to assess Sir2's contribution to silencing as a function of the cell cycle. When examined in vivo, these conditional alleles fall into two classes: one class exhibits a loss of silencing when raised to the nonpermissive temperature regardless of cell-cycle position, while the second class exhibits a mitosis-specific silencing defect. Alleles of the first class have a primary defect in protein deacetylase activity, while the alleles of the second class are specifically defective in Sir2–Sir4 interactions at nonpermissive temperatures. Using a SIR2 temperature-sensitive allele, we show that silencing can be established at the HML locus during progression through the G2/M–G1 interval. These results suggest that yeast heterochromatin undergoes structural transitions as a function of the cell cycle and support the existence of a critical assembly step for silent chromatin in mitosis.
The RAD6/BRE1 Histone Modification Pathway in Saccharomyces Confers Radiation Resistance Through a RAD51-Dependent Process That Is Independent of RAD18
Authors: Game John C , Williamson Marsha S , Spicakova Tatiana , Brown J Martin 
Published: June 2006

Abstract
We examine ionizing radiation (IR) sensitivity and epistasis relationships of several Saccharomyces mutants affecting post-translational modifications of histones H2B and H3. Mutants bre1Δ, lge1Δ, and rtf1Δ, defective in histone H2B lysine 123 ubiquitination, show IR sensitivity equivalent to that of the dot1Δ mutant that we reported on earlier, consistent with published findings that Dot1p requires H2B K123 ubiquitination to fully methylate histone H3 K79. This implicates progressive K79 methylation rather than mono-methylation in IR resistance. The set2Δ mutant, defective in H3 K36 methylation, shows mild IR sensitivity whereas mutants that abolish H3 K4 methylation resemble wild type. The dot1Δ, bre1Δ, and lge1Δ mutants show epistasis for IR sensitivity. The paf1Δ mutant, also reportedly defective in H2B K123 ubiquitination, confers no sensitivity. The rad6Δ, rad51null, rad50Δ, and rad9Δ mutations are epistatic to bre1Δ and dot1Δ, but rad18Δ and rad5Δ show additivity with bre1Δ, dot1Δ, and each other. The bre1Δ rad18Δ double mutant resembles rad6Δ in sensitivity; thus the role of Rad6p in ubiquitinating H2B accounts for its extra sensitivity compared to rad18Δ. We conclude that IR resistance conferred by BRE1 and DOT1 is mediated through homologous recombinational repair, not postreplication repair, and confirm findings of a G1 checkpoint role for the RAD6/BRE1/DOT1 pathway.
Implant Treatment in an Urban General Dentistry Residency Program: A 7-year Retrospective Study
Authors: Starr Clifford B. , Maksoud Mohamed A. 
Published: June 2006

Abstract
Survival rates of multiple implant designs placed in various clinical situations average more than 90%. However, little data have been published on the survival rates of implants placed in dental residency programs. This study reports on the outcome of dental implants placed by first-year general dentistry residents in the University of Florida College of Dentistry–Jacksonville Clinic. The patients for this study received both surgical and restorative implant therapy from 1998 to 2005. A total of 263 patients (147 women, 116 men) were treated with dental implants. On average, a patient was 55.5 years old and received 3 implants. A variety of simple and complex restorative procedures were performed. Advanced general dentistry residents in conjunction with supervisory faculty treated all cases. The cumulative implant survival was 96.6%. Follow-up varied from 6 months to 7 years after placement. Cases included implants not yet loaded as well as implants loaded for 6 years or more. The findings of this study compare favorably with published studies and were unexpected in light of the residents' limited clinical experience.
Effect of Practical Diets with Animal or Vegetable Protein Sources and Poultry Oil or Menhaden Fish Oil on Adult Fathead Minnow in Tanks
Authors: Lochmann Rebecca , Kumaran Sathyanand 
Published: June 2006

Abstract
The fathead minnow Pimephales promelas is one of the main species cultured in ponds in the southern United States for bait and is widely used as a toxicological and biomedical model in the laboratory. Diet can have a major impact on performance criteria, both in laboratory and production settings. However, the nutrient requirements of fathead minnow are unknown and cannot be used to formulate optimal diets. To facilitate applied nutrition research for this species, we measured the growth, survival, feed conversion, and response to low dissolved oxygen exhibited by adults that were held in tanks and fed practical diets with animal (menhaden Brevoortia spp. fish meal and poultry by-product meal) or plant (mostly soybean) protein sources and either poultry oil or menhaden fish oil for 12 weeks. Good weight gain (0.6–0.8 g) was obtained either with vegetable or animal protein sources. Poultry oil enhanced growth relative to menhaden fish oil in diets with either vegetable or animal protein sources. Mean survival rates of fish fed the animal and vegetable protein diets were 88% and 96%, respectively, and survival was not affected by lipid source. Survival during the low-oxygen stress test was high (≥90%) across diets, and there were no treatment effects. Vegetable proteins and poultry oil are promising alternatives to more costly feed ingredients in practical diets for fathead minnow.
A comparison of equally spaced designs with different correlation structures in one and more dimensions
Authors: Herzberg Agnes M. , Huda S. 
Published: June 2006

AbstractEqually spaced designs are compared using the generalized variance as a measure of efficiency. Results for polynomial models are derived on the increased efficiency arising from increasing the number of design points when the regions are fixed and when the regions are expanded. The effects of dependence among the observations on these results are studied by considering a particular family of stationary correlated error structures.
Distributions of order statistics and estimation of mean life when an outlier may be present
Authors: Sinha S. K. 
Published: June 2006

AbstractConsider a random sample (X1, X2,…, Xn) where one observation (or out‐lier) is determined by the density f(x, θ/α), θ >0, 0 < α ≤ l, while the remaining observations have a common density f(x, θ) = (l/θ)exp(‐x/θ), with θ > 0. The statistic Tmn = 1/m+1 [Σmi=1 x(i)+(n‐m)x(m)], 0 <m ≤n, was proposed by Kale and Sinha [1] as an estimator of θ treating α as a nuisance parameter. When α= 1, we refer to the above model as homogeneous. In this paper we derive the variance of X(k) the distribution and covariance of (X(k), X(j)), k<j, and show that while the mean‐square error mse(tnn|α→∞, as α→0. the mean‐square error MSE(Tmn|α) remains bounded as α→0.
Categorical information and the singular linear model
Authors: Feuerverger A. , Fraser D. A. S. 
Published: June 2006

AbstractC. R. Rao (1978) discusses estimation for the common linear model in the case that the variance matrix σ2Q has known singular form Q. In the more general context of inference, this model exhibits certain special features and illustrates how information concerning unknowns can separate into a categorical component and a statistical component. The categorical component establishes that certain parameters are known in value and thus are not part of the statistical inference.
Stochastic game models of brand switching
Authors: Laughland A.R. , Nair K.P.K. 
Published: June 2006

AbstractIn the study of the dynamic nature of brand switching, Markov chain theory has been used extensively. The conflicting interests of the companies involved have, however, not been explicitly incorporated. In this paper, two competing companies, each engaged in marketing a brand product, are considered. Brand switching by a consumer is influenced jointly but probabilistically by the two companies through their respective promotional actions and by the consumer's immediately preceding purchase. A stochastic game model is developed for determining the optimal promotional strategies of the companies, and the unique minimax value of the game in terms of market share. The structure of the model developed is that of a two‐person, zero‐sum, two‐state stochastic game. A method of solution and a few useful variations of the model are présentés. Practical interpretations of the solution are also included.
The distributions of sufficient statistics of truncated generalized logarithmic series, poisson and negative binomial distributions
Authors: Charalambides Ch.A. 
Published: June 2006

AbstractIn this paper the distribution of Z = Σni=1Xi and the joint distribution of Y = min{X1,…,Xn} and Z are obtained in the cases in which X1,…,Xn is a random sample (i) from the left‐truncated generalized logarithmic series distribution in terms of the Stirling numbers of the first kind, (ii) from the left‐truncated generalized Poisson distribution in terms of the Stirling numbers of the second kind and (iii) from the left‐truncated generalized negative binomial in terms of linear combinations of the Stirling numbers of both kinds. These distributions are utilized in order to obtain the minimum variance unbiased estimators of θm, m ≫ 1 when the truncation point r is assumed to be known and of rm and θm when r is unknown.
Exponential models, brownian motion, and independence
Authors: Seshadri V. 
Published: June 2006

AbstractSome examples of steep, reproductive exponential models are considered. These models are shown to possess a τ‐parallel foliation in the terminology of Barndorff‐Nielsen and Blaesild. The independence of certain functions follows directly from the foliation. Suppose X(t) is a Wiener process with drift where X(t) = W(t) + ct, 0 < t < T. Furthermore let Y = max [X(s), 0 < s < T]. The joint density of Y and X = X(T), the end value, is studied within the framework of an exponential model, and it is shown that Y(Y – X) is independent of X. It is further shown that Y(Y – X) suitably scaled has an exponential distribution. Further examples are considered by randomizing on T.
Improved set estimators for the coefficients of a linear model when the error distribution is spherically symmetric with unknown variances
Authors: Chen Jeesen , Hwang Jiunn T. 
Published: June 2006

AbstractThe usual confidence set for p (p ≥ 3) coefficients of a linear model is known to be dominated by the James‐Stein confidence sets under the assumption of spherical symmetric errors with known variance (Hwang and Chen 1986). For the same confidence‐set problem but for the unknown‐variance case, naturally one replaces the unknown variance by an estimator. For the normal case, many previous studies have shown numerically that the resultant James‐Stein confidence sets dominate the resultant usual confidence sets, i.e., the F confidence sets. In this paper we provide a further asymptotic justification, and we discover the same advantage of the James‐Stein confidence sets for normal error as well as spherically symmetric error.
Recursive improvement of estimates in a Gauss‐Markov model with linear restrictions
Authors: Kala Radoslaw , Kłaczyński Krzysztof 
Published: June 2006

AbstractThe minimum‐dispersion linear unbiased estimator of a set of estimable functions in a general Gauss‐Markov model with double linear restrictions is considered. The attention is focused on developing a recursive formula in which an initial estimator, obtained from the unrestricted model, is corrected with respect to the restrictions successively incorporated into the model. The established formula generalizes known results developed for the simple Gauss‐Markov model.
Estimation in an empirical bayes model for longitudinal and cross‐sectionally clustered binary data
Authors: Sashegyi Andreas I. , Brown K. Stephen , Farrell Patrick J. 
Published: June 2006

AbstractSome studies generate data that can be grouped into clusters in more than one way. Consider for instance a smoking prevention study in which responses on smoking status are collected over several years in a cohort of students from a number of different schools. This yields longitudinal data, also cross‐sectionaliy clustered in schools. The authors present a model for analyzing binary data of this type, combining generalized estimating equations and estimation of random effects to address the longitudinal and cross‐sectional dependence, respectively. The estimation procedure for this model is discussed, as are the results of a simulation study used to investigate the properties of its estimates. An illustration using data from a smoking prevention trial is given.
Comparing confidence intervals for the logarithmic series distribution
Authors: Wani J. K. , Lo H. P. 
Published: June 2006

AbstractIt is assumed that a small random sample of fixed size n is drawn from a logarithmic series distribution with parameter θ and that it is desired to estimate θ by means of a two‐sided confidence interval. In this note Crow's system of confidence intervals is compared, in shortness of intervals, with Clopper and Pearson's, and the corresponding randomized counterparts.
Asymptotic results for empirical and partial‐sum processes: A review
Authors: Pyke Ronald 
Published: June 2006

AbstractTwo processes of importance in statistics and probability are the empirical and partial‐sum processes. Based on d‐dimensional data X1, … Xa the empirical measure is defined for any A ⊂ Rd by

the sample proportion of observations in A. When normalized, Fn yields the empirical process Wn: = n1/2 (Fn ‐ F), where F denotes the “true” probability measure.To define partial‐sum processes, one needs data that are assigned to specified locations (in contrast to the above, where specified unit masses are assigned to random locations). A suitable context for many applications is that of data attached to points of a lattice, say {Xj:j ϵ Jd} where J = {1, 2,…}, for which the partial sums are defined for any A ⊂ Rd by

Thus S(A) is the sum of the data contained in A. When normalized, S yields the partial‐sum process. This paper provides an overview of asymptotic results for empirical and partial‐sum processes, including strong laws and central limit theorems, together with some indications of their inferential implications.
Least squares theory for possibly singular models
Authors: Rao C. Radhakrishna 
Published: June 2006

AbstractIn a recent paper, Scobey (1975) observed that the usual least squares theory can be applied even when the covariance matrix σ2V of Y in the linear model Y = Xβ + e is singular by choosing the Moore‐Penrose inverse (V+XX′)+ instead of V‐1 when V is nonsingular. This result appears to be wrong. The appropriate treatment of the problem in the singular case is described.
Change of origin and scale in ratio and difference methods of estimation in sampling
Authors: Srivenkataramana T. 
Published: June 2006

AbstractThis paper discusses two estimators of the mean of a finite population based on a simple random sample from it, when supplementary information on a variable positively correlated with the variable of interest is available. Simultaneous reductions in absolute bias and mean square error of the estimator are seen as compared with those of the traditional estimator in the ratio method of estimation. The suggested estimators are simple for computation and there is no appreciable increase in the cost as well.