bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Pressure Cycles and Dissolved Air on the Viscosity of Water
Authors: Kestin J. , Whitelaw J. H.
Published: December 2004

Relative measurements on deaerated and air-saturated water with a sensitivity of about 0.1% show that its viscosity is unaffected by pressure cycles (absence of long-time relaxation) or the dissolution of air in it, the effect, if any, being less than the sensitivity of the instrument.
Capillary Instability of a Jet Carrying an Axial Current
Authors: Nayyar N. K. , Trehan S. K.
Published: December 2004

The inclusion of Hall current in Ohm's law leads to overstability for vericose deformation (m = 0) in the case of a capillary jet carrying axial volume current.
High-Field Steady-State Shock Wave in a Plasma
Authors: Frisch H. L. , Morrison J. A.
Published: December 2004

The high magnetic field limit, of a shock wave in a steady-state model plasma moving along the x axis, is studied transverse to the magnetic field, in which the only spatial dependence is that on the x coordinate. The collisions of the model plasma are described by (Krook-type) modified Boltzmann collision terms with constant relaxation times. What occurs is that drift velocity of both electrons and ions behind the transition is converted to an increase in temperature of both species ahead of the transition through ion momentum exchange resulting in Joule heating. First formulation of the equations describing this phenomenon is presented, and then an exact asymptotic development of the integro-differential transport equations, together with the Maxwell equations and subsidiary conditions. It is shown analytically, in the case for which the relaxation times of the ions and electrons are equal, that a shock wave is possible, provided the plasma is sufficiently dense, which means that the shock is bounded away from the low-temperature plasma limit. The case in which the relaxation times are unequal reduces to the investigation of a nonlinear ordinary differential equation which is not carried out here, but it is conjectured that a shock wave is still possible.
Electric Field Parallel to the Magnetic Field in a Low-Density Plasma
Authors: Persson Hans
Published: December 2004

Stationary states of a collisionless plasma in a one-dimensional magnetic mirror field are considered. Reflection and loss of particles in the presence of a parallel electric field are studied. In many cases the density can be expressed by Abelian integral transforms of monoenergetic distributions. The problem of determining the parallel electric field, necessary to maintain quasi-neutrality, is solved for a class of such distributions, and a couple of illustrating examples are presented. A few existence and uniqueness theorems for distributions and fields are proved.
Experiments in a Magnetically Driven Shock Tube with an Axial Magnetic Field
Authors: Heywood John B.
Published: December 2004

Experiments in a magnetically driven annular shock tube with hydrogen as test gas, with an axial magnetic field are reported. The initial pressure (50–500 μ), axial field (0–0.45 Wb/m2), and drive field (0.8–1.0 Wb/m2) were chosen to produce shock speeds and test times such that separation between shock front and current sheet was predicted. Measurements of magnetic and electric fields and intensity of continuum radiation showed that shock front and current sheet coincided both in the regimes where a gas-dynamic shock and a magnetohydrodynamic switch-on shock were predicted. Shock Alfvén Mach numbers covered the range 1.2 to 7.2. Axial and azimuthal momentum balances indicated that snowplow-type models adequately predict the shock tube performance. A radial electric field was measured upstream of the front when the Alfvén Mach number was in the switch-on regime, indicating that a model based on ionizing shock waves is more appropriate for predicting the flow pattern.
Plane Creeping Flows of Incompressible Second-Order Fluids
Authors: Tanner R. I.
Published: December 2004

It is shown that any plane creeping Newtonian velocity field is also a solution for second-order fluids under identical velocity boundary conditions.
Alfvén Waves in a Stratified Incompressible Fluid
Authors: Pridmore-Brown D. C.
Published: December 2004

Alfvén wave propagation is studied in an incompressible fluid stratified by an inhomogeneous fluid density or magnetic field strength. It is shown that any disturbance splits up into two components—an ordinary Alfvén mode and a modified Alfvén mode. The first of these propagates one-dimensionally along flux tubes at the local Alfvén speed while the second propagates three-dimensionally and carries a disturbance in the total (fluid plus magnetic) pressure.
Short-Circuit of Flute Disturbances at a Plasma Boundary
Authors: Lehnert B.
Published: December 2004

A plasma boundary is defined by magnetic field lines which are tangent to a conducting wall. For a sufficiently good contact between the outermost layers of the plasma and the wall, the boundary will become an equipotential surface. The joint effect of line-tying at the boundary and a finite ion Larmor radius then produces a stabilization of flute disturbances which is stronger than that arising from the finite Larmor radius alone. This effect is especially pronounced when the density increases steeply in a narrow boundary region and is nearly constant within the plasma interior. The present mechanism should have a marked influence on rotating plasma devices, but should hardly affect the rotational instability of theta pinches. An additional stabilization is provided by a velocity field which is sheared in the equilibrium state.
Plasma Decay Technique to Measure Density in Discharge Tubes
Authors: Alexeff Igor , Jones W. D. , Lohr John
Published: December 2004

The decay technique measures plasma density over a wide range; in particular, below 109 cm−3, where, for discharge tubes of a few liters in volume, Langmuir probes can give ambiguous results. The method is most easily used in systems of simple geometry; for example, spheres and cylinders. The ion current to the discharge-tube wall is sampled by a negatively-biased probe that forms a part of the wall. An average value for the positive charge density in the tube before turnoff is obtained by integrating the total ion current to the probe during decay, multiplying this quantity by the ratio of wall area to probe area, and dividing by the volume of the tube. An advantage of the decay technique is that the electron and the ion velocity distributions need not be known.
Experimental Observations on the Stability of Plasma Bounded by Slanted End-Plates
Authors: Decker John A.
Published: December 2004

Experiments in the cesium plasma of a Q-device have failed to find any effect on plasma stability due to the angle of a nonconducting end-plate with respect to the axial magnetic field.
Instability of Three-Component Plasma System
Authors: Ohnuma Toshiro , Hatta Yoshisuke
Published: December 2004

Unstable regions are determined mainly by means of a graphical analysis for three kinds of waves: electron beam-electron coupling; ion beam-electron (electron beam-ion) coupling; and ion beam-ion coupling.
Plasma Fluctuations and the Control of Pumpout
Authors: Fowler T. K.
Published: December 2004

Means of preventing low-frequency plasma instabilities possibly causing ``pumpout'' losses are discussed. The result is a prescription for determining experimentally a scaling law for stable confinement in toroidal magnetic wells. Based on measurement of fluctuations rather than instability thresholds, the method can be applied to existing unstable systems to help decide how best to modify them. Given an unstable stellarator or similar system, one measures 〈Ek2〉, the radial power spectrum of the electric field fluctuations averaged over other coordinates. Asymptotic behavior like 〈Ek2〉 ∝ k−3, confirmed in certain experiments, indicates instabilities susceptible to magnetic well stabilization and verifies applicability of the method. If applicable, magnetic well parameters sufficient for stability are given in terms of a measured quantity ∝ ∫ dk 〈Ek2〉. Preliminary application to the Model C stellarator indicates that an average well depth of only a few per cent would stabilize it if the length of locally unstable regions could be much reduced. Initial unsuccessful efforts to reduce pumpout by modifying the stellarator field did not achieve these goals, but the stable regime is perhaps not out of reach.
Spectroscopic Measurement of Temperatures in an Argon Plasma Arc
Authors: Bott J. F.
Published: December 2004

Temperature profiles across the Poiseuille plasma arc have been calculated from measured radiation intensities from the atmospheric argon plasma at arc currents from 1 to 400 A. The transition probabilities for several neutral argon lines were calculated from the measurements. The investigation shows the central core of the arc to be in local thermodynamic equilibrium but the sides of the arc to deviate from local thermodynamic equilibrium. The extent of this deviation was found to increase with decreasing current.
Periodic Vorticity and its Effect on Jet Mixing
Authors: McCormack P. D. , Cochran D. , Crane L.
Published: December 2004

A closed solution is derived for the mean velocity profile of a gas jet in the near-field region with a source of periodic vorticity at the orifice. A sort of pressure gradient is set up near the jet axis which results in more rapid transport of momentum in the radial direction. Thus the rate of mixing is accelerated and the core length shortened. It is postulated that this periodic vorticity (vortex shedding) can be supplied by mechanical vibration of the injector. This is confirmed by a hot-wire study of a gas jet emerging from a vibrated injector. It is found, moreover, that by using high acceleration values, vortex shedding can be driven at frequencies other than the natural frequency.
On the Percus-Yevick Equation
Authors: Barker A. A.
Published: December 2004

The range of application of the Percus-Yevick equation is analysed using an asymptotic form of the equation. The inconsistencies arising for mixtures of repulsive and attractive forces are removed by considering additional terms to the equation, but the equation still assumes an inconsistent form for many systems of attractive forces.
Motion of a Shock Wave through Tubes of Converging or Diverging Cross Section
Authors: Dvir M. , Low W. , Stricker J. , Maniv S.
Published: December 2004

The Mach speed behind converging and diverging transition sections is measured. Near the nozzle the values of the speed approach that predicted by the linear theory, and far downstream that calculated by the steady-state theory. Superimposed is a modulation of the shock speed.
Magnetohydrodynamic Channel Flows with Nonequilibrium Ionization
Authors: Sherman Arthur
Published: December 2004

The behavior of a magnetohydrodynamic channel, with finite segmented electrodes, when a plasma in a nonequilibrium state and with tensor conductivity flows through it with constant (uniform) velocity is presented. The nonequilibrium effect is taken into account by assuming the plasma electrical conductivity to be a linear function of the current density. The problem, which is highly nonlinear, is solved by expanding in powers of the proportionality constant to obtain a recursive set of linear equations. In this paper only the zeroth- and first-order solutions are presented. They are obtained numerically. For the cases studied, no shorting due to leakage between adjacent electrodes exists. Despite this inclusion of the nonequilibrium effect causes a reduction of the Hall (axial) electric field.
Computation of Hydromagnetic Equilibria with Finite Pressure in Minimum-B Systems
Authors: Killeen John , Whiteman Kenneth J.
Published: December 2004

The distortion of a magnetic well in a minimum-B system by a plasma is calculated. The equations of hydromagnetic equilibria with a tensor pressure are used. The pressure tensor is assumed to be a function of B only. The axisymmetric case is considered in detail by using a stream function for the magnetic field. The resulting partial differential equation is solved by finite-difference methods. Numerical solutions are presented for the stuffed-cusp configuration. The effect of increasing the magnitude of the plasma pressure is discussed.
Approximate Calculation of the Speed of Sound in a Plasma
Authors: Ahlborn Boye
Published: December 2004

The speed of sound in a plasma can approximately be calculated when enthalpy, density, and pressures are known.
Genome sequence of the deep-sea γ-proteobacterium
Idiomarina loihiensis
reveals amino acid fermentation as a source of carbon and energy
Authors: Hou Shaobin , Saw Jimmy H. , Lee Kit Shan , Freitas Tracey A. , Belisle Claude , Kawarabayasi Yutaka , Donachie Stuart P. , Pikina Alla , Galperin Michael Y. , Koonin Eugene V. , Makarova Kira S. , Omelchenko Marina V. , Sorokin Alexander , Wolf Yuri I. , Li Qing X. , Keum Young Soo , Campbell Sonia , Denery Judith , Aizawa Shin-Ichi , Shibata Satoshi , Malahoff Alexander , Alam Maqsudul
Published: December 2004

We report the complete genome sequence of the deep-sea γ-proteobacterium,
Idiomarina loihiensis
, isolated recently from a hydrothermal vent at 1,300-m depth on the Lōihi submarine volcano, Hawaii. The
I. loihiensis
genome comprises a single chromosome of 2,839,318 base pairs, encoding 2,640 proteins, four rRNA operons, and 56 tRNA genes. A comparison of
I. loihiensis
to the genomes of other γ-proteobacteria reveals abundance of amino acid transport and degradation enzymes, but a loss of sugar transport systems and certain enzymes of sugar metabolism. This finding suggests that
I. loihiensis
relies primarily on amino acid catabolism, rather than on sugar fermentation, for carbon and energy. Enzymes for biosynthesis of purines, pyrimidines, the majority of amino acids, and coenzymes are encoded in the genome, but biosynthetic pathways for Leu, Ile, Val, Thr, and Met are incomplete. Auxotrophy for Val and Thr was confirmed by
in vivo
experiments. The
I. loihiensis
genome contains a cluster of 32 genes encoding enzymes for exopolysaccharide and capsular polysaccharide synthesis. It also encodes diverse peptidases, a variety of peptide and amino acid uptake systems, and versatile signal transduction machinery. We propose that the source of amino acids for
I. loihiensis
growth are the proteinaceous particles present in the deep sea hydrothermal vent waters.
I. loihiensis
would colonize these particles by using the secreted exopolysaccharide, digest these proteins, and metabolize the resulting peptides and amino acids. In summary, the
I. loihiensis
genome reveals an integrated mechanism of metabolic adaptation to the constantly changing deep-sea hydrothermal ecosystem.
Mouse Models of Human Familial Cancer Syndromes
Authors: Ward Jerrold M. , Devor-Henneman Deborah E.
Published: December 2004

As many as 5% of human cancers appear to be of hereditable etiology. Of the more than 50 characterized familial cancer syndromes, most involve disease affecting multiple organs and many can be traced to one or more abnormalities in specific genes. Studying these syndromes in humans is a difficult task, especially when it comes to genes that may manifest themselves early in gestation. It has been made somewhat easier with the development of genetically engineered mice (GEM) that phenotypically mimic many of these inheritable human cancers. The past 15 years has seen the establishment of mouse lines heterozygous or homozygous null for genes known or suspected of being involved in human cancer syndromes, including APC, ATM, BLM, BRCA1, BRCA2, LKB1, MEN1, MLH, MSH, NF1, TP53, PTEN, RB1, TSC1, TSC2, VHL, and XPA. These lines not only provide models for clinical disease and pathology, but also provide avenues to investigate molecular pathology, gene-gene and protein-tissue interaction, and, ultimately, therapeutic intervention. Possibly of even greater importance, they provide a means of looking at placental and fetal tissues, where genetic abnormalities are often first detected and where they may be most easily corrected. We will review these mouse models, examine their usefulness in medical research, and furnish sources of animals and references.
The Genetics of Cancer Susceptibility: From Mouse to Man
Authors: Ewart-Toland Amanda , Balmain Allan
Published: December 2004

Cancer affects approximately 1 in 3 individuals. An individual's susceptibility to cancer is partly determined by environmental exposures and by the combination of inherited cancer susceptibility and resistance genes. Initial mapping of these low penetrance cancer susceptibility genes has been done in the mouse because human low penetrance genes are extremely difficult to find using traditional methods due to heterogeneity and interacting factors. Also, the choice of candidate genes for human association studies can miss the unknown or unexpected. Mouse models also have limitations; it can be difficult to identify causal polymorphisms in the mouse because linkage disequilibrium often extends across several genes. To exploit the strengths of both systems, we outline a cross-species strategy to identify human variants associated with increased cancer risk. This approach uses linkage analysis and haplotyping, allelic imbalance in tumors, and gene expression studies in the mouse, combined with association studies and tumor imbalance studies in humans to identify causal cancer susceptibility variants. Allelic variants in both mouse and human can then be used to better understand the mechanisms behind cancer risk and as targets for intervention.
Pharmacogenetics to Predict Drug-Related Adverse Events
Authors: Hosford David A. , Lai Eric H. , Riley John H. , Xu Chun-Fang , Danoff Theodore M. , Roses Allen D.
Published: December 2004

Identification of reliable markers to predict drug-related adverse events (DRAEs) is an important goal of the pharmaceutical industry and others within the healthcare community. We have used genetic polymorphisms, including the most frequent source of variation (single nucleotide polymorphisms, SNPs) in the human genome, in pharmacogenetic approaches designed to predict DRAEs. Three studies exemplify the principles of using polymorphisms to identify associations in progressively larger genomic regions: polymorphic repeats within the UDP-glucuronysltransferase I (UGT1A1) gene in patients experiencing hyperbilirubinemia after administration of tranilast, an experimental drug to prevent re-stenosis following coronary revascularization; high linkage disequilibrium within the Apolipoprotein E (ApoE) gene in patients with Alzheimer Disease (AD); and the polymorphic variant HLA-B57 in patients with hypersensitivity reaction after administration of abacavir, a nucleoside reverse transcriptase inhibitor for the treatment of HIV. Together, these studies demonstrate in a stepwise manner the feasibility of using pharmacogenetic approaches to predict DRAEs.
Application of Toxicogenomics to Toxicology: Basic Concepts in the Analysis of Microarray Data
Authors: Irwin Richard D. , Boorman Gary A. , Cunningham Michael L. , Heinloth Alexandra N. , Malarkey David E. , Paules Richard S.
Published: December 2004

Toxicology and the practice of pathology are rapidly evolving in the postgenomic era. Observable treatment related changes have been the hallmark of toxicology studies. Toxicogenomics is a powerful new tool that may show gene and protein changes earlier and at treatment levels below the limits of detection of traditional measures of toxicity. It may also aid in the understanding of toxic mechanisms. It is important to remember that it is only a tool and will provide meaningful results only when properly applied. As is often the case with new experimental tools, the initial utilization is driven more by the technology than application to problem solving. Toxicogenomics is interdisciplinary in nature including at a minimum, pathology, toxicology, and genomics. Most studies will require the input from the disciplines of toxicology, pathology, molecular biology, bioinformatics, biochemistry, and others depending on the types of questions being asked.
Use of Transgenic Mice in Carcinogenicity Hazard Assessment
Authors: Jacobson-Kram David , Sistare Frank D. , Jacobs Abigail C.
Published: December 2004

Determining the carcinogenic potential of materials to which humans have significant exposure is an important, complex and imperfect exercise. Not only are the methods for such determinations protracted, expensive and utilize large numbers of animals, extrapolation of data from such studies to human risk is imprecise. Toxicologists have long recognized these shortcomings but the 2-year chronic rodent study has remained the gold standard. Recent developments in the field of molecular oncology and development of methods to insert or inactivate specific genes in animals have provided the tools with which to develop the next generation of carcinogenicity assays. With improved understanding of oncogene activation and tumor suppressor gene inactivation a number of animal models have been developed to dramatically reduce latency for chemically induced cancers. This has led to the development of shorter carcinogenicity assays. Also, because the spontaneous tumor frequencies in these animals are low during the in-life portion of the study, and studies are terminated well before the health complications of advanced aging are observed, it has been possible to reduce the group sizes and reduce animal usage. FDA's adoption of ICH S1B in 1997, (ICH, 1997) “Testing for the Carcinogenicity of Pharmaceuticals,” opened the door for the use of such transgenic models in regulatory toxicology. This presentation reviews the current state of the science and its application to regulatory issues.
Trials, Tribulations, and Trends in Tumor Modeling in Mice
Authors: Schuh Joann C.L.
Published: December 2004

Selection of mouse models of cancer is often based simply on availability of a mouse strain and a known compatible tumor. Frequently this results in use of tumor models long on history but short on homology and quality control. Other factors including genetics, sex, immunological status, method and site of tumor implantation, technical competence, biological activity of the tumor, protocol sequence and timing, and selection of endpoints interact to produce outcomes in tumor models. Common reliance on survival and tumor burden data in a single mouse model often skews expectations towards high remission and cure rates; a finding seldom duplicated in clinical trials. Inherent limitations of tumor models coupled with the advent of new therapeutic targets reinforce need for careful attention to design, conduct, and stringent selection of in vivo and ex vivo endpoints. Preclinical efficacy testing for anti-tumor therapies should progress through a series of models of increasing sophistication that includes incorporation of genetically engineered animals, and orthotopic and combination therapy models. Pharmacology and safety testing in tumor-bearing animals may also help to improve predictive value of these models for clinical efficacy. Trends in bioinformatics, genetic refinements, and specialized imaging techniques are helping to maintain mice as the most scientifically and economically powerful model of malignant neoplasms.
Relevance of Animal Carcinogenesis Findings to Human Cancer Predictions and Prevention
Authors: Maronpot R.R. , Flake G. , Huff And J.
Published: December 2004

Use of laboratory animals to identify carcinogenic potential of chemicals, mixtures, and other agents has a modern history of greater than 40 years from which much useful scientific and public health information can be derived. While laboratory animals differ from humans in some respects that may affect responses to hazardous exposures, use of such models is based on experimental evidence indicating that there are more genetic, genomic, physiological, biochemical, and metabolic similarities than differences among mammalian species. Issues of concordance of responses between rodent species and between rodents and humans as well as repeatability and site-specificity are important considerations in evaluating laboratory animal carcinogenicity results. Variables in experimental design such as animal strain, diet, route of exposure, and study duration as well as single-site versus multisite carcinogenic responses all influence interpretation and intelligent use of study data. Similarities and differences in site-specific laboratory animal and corresponding human cancers should also be considered in study evaluation. Recent attempts to explore genetically engineered mice and to humanize the mouse for more relevant identification of carcinogen hazard identification have yielded mixed results. In the end we are confronted by the realization that virtually all animal cancer models are useful but imperfect surrogates for humans. Assuming the percentage of chemicals currently in commerce that are estimated to be potent animal or human carcinogens is quite low, the task of identifying agents with significant carcinogenic potential is daunting and important. The biological conundrum of scientific debate regarding the relevance of carcinogenicity studies in laboratory animals is likely to continue. Nonetheless public health considerations must take precedence when deciding human safety issues.
Development and Use of Biomarkers in Oncology Drug Development
Authors: Floyd Eugenia , Mcshane Teresa M.
Published: December 2004

Successful development and use of biomarkers will improve the productivity of oncology drug development. Recognition of the importance of biomarkers for speeding drug development is reflected in the precise definitions and concepts proposed by an NIH Working Group to standardize terminology and promote a more coherent and systematic approach to the development and use of biomarkers. Potential clinical biomarkers of drug efficacy are often identified through pre-clinical studies or basic research. Identification of potential biomarkers for use in oncology is moving rapidly forward through continuing advances in clinical imaging technologies, especially molecular and functional imaging. Other rapid advances are a product of the growing availability of new scientific reagents for established technologies and of high-throughput genomic and proteomic technologies that can generate hundreds of potential biomarkers for further evaluation. In certain cases, conventional clinical diagnostic techniques or assays can be adapted for use in pre-clinical models to evaluate their ability to serve as biomarkers for predicting clinical responses to new drug candidates. Evaluation (pre-clinical and clinical) of a potential biomarker is often the longest stage of biomarker development, and standards for evaluation or validation depend on the intended use and stage of clinical development. Biomarkers verified for use in preclinical studies can be used to help select appropriate animal models and lead compounds. Biomarkers verified for use in clinical trials can confirm a drug's pharmacological or biological mechanism of action, guide protocol design, aid patient and dose selection, and help to minimize safety risks. Oncology drug development can be optimized by using a tiered set of clinical biomarkers that predict compound efficacy and safety with increasing confidence at each rise in tier thereby aiding corporate decision-making about advancing compounds. In oncology, a special class of extensively evaluated biomarkers of efficacy (surrogate endpoints) that generally correlate with desired clinical outcomes can be used as a basis for corporate decisions as well as for gaining accelerated provisional regulatory approval of a drug.
Biomarkers of Cancer Risk and Therapeutic Benefit: New Technologies, New Opportunities, and Some Challenges
Authors: Macgregor James T.
Published: December 2004

The biotechnology revolution offers unprecedented opportunities for identification of mechanistically-based biomarkers that report and predict cancer and other pathologies. The combination of genomic technologies with a knowledge of gene sequence and sequence conservation has made available markers that facilitate the correlation of genetic variation with biological outcomes, and “-omic” technologies allow efficient biochemical characterization of functional pathways—providing new markers of the susceptibility of individuals to cancer development, and of tumor susceptibility to specific therapies. New therapeutic agents targeted to individuals with specific genetic or biochemical characteristics already exist. The powerful -omic technologies allow efficient monitoring of gene transcripts, proteins, and intermediary metabolites, making it possible to monitor a large number of key cellular pathways simultaneously. This has enabled the identification of key biomarkers and signaling molecules associated with cell growth, cell death, and cellular metabolism. These new markers are facilitating monitoring of functional disturbance, molecular and cellular damage, and damage-response. Improved imaging technologies have made it feasible to image some of these molecular events noninvasively. To meet the challenge of evaluating and developing consensus criteria for the application of these new technologies and biomarkers, consortium approaches are being increasingly undertaken to share resources and to build a common understanding among the research, industry, and regulatory communities. These developments promise more efficient pharmaceutical product development, safer and more efficacious drugs, and provide clinical practitioners with new and better biomarkers for cancer screening, patient monitoring, and choice of therapy.
Identification and Quantitation of Flavanols and Proanthocyanidins in Foods: How Good are the Datas?
Authors: Kelm Mark A. , Hammerstone John F. , Schmitz Harold H.
Published: December 2004

Evidence suggesting that dietary polyphenols, flavanols, and proanthocyanidins
in particular offer significant cardiovascular health benefits is rapidly increasing.
Accordingly, reliable and accurate methods are needed to provide qualitative and
quantitative food composition data necessary for high quality epidemiological and
clinical research. Measurements for flavonoids and proanthocyanidins have
employed a range of analytical techniques, with various colorimetric assays still
being popular for estimating total polyphenolic content in foods and other biological
samples despite advances made with more sophisticated analyses. More crudely,
estimations of polyphenol content as well as antioxidant activity are also reported
with values relating to radical scavenging activity. High‐performance liquid
chromatography (HPLC) is the method of choice for quantitative analysis of
individual polyphenols such as flavanols and proanthocyanidins. Qualitative
information regarding proanthocyanidin structure has been determined by
chemical methods such as thiolysis and by HPLC‐mass spectrometry (MS)
techniques at present. The lack of appropriate standards is the single most
important factor that limits the aforementioned analyses. However, with ever
expanding research in the arena of flavanols, proanthocyanidins, and health
and the importance of their future inclusion in food composition databases, the
need for standards becomes more critical. At present, sufficiently well‐characterized
standard material is available for selective flavanols and proanthocyanidins,
and construction of at least a limited food composition database is feasible.
New Community Schools and Inter-Agency Working: assessing the effectiveness of social justice initiatives
Authors: Riddell Sheila , Tett Lyn
Published: December 2004

This paper considers the meaning of social justice as reflected by New Communities Schools (NCS). It reviews the role of NCS in the modernisation of welfare, considers the criteria used to judge their effectiveness and assesses the outcomes of the NCS programme. Problems in assessing
social justice outcomes are explored in terms of pilot or mainstream approaches; the focus on the most disadvantaged; local diversity versus over-arching approaches; soft or hard measures. It is concluded that there are major problems in addressing major problems of structural inequalities
through pilot initiatives. However, although the NCS was not transformative it was sustaining for the schools that participated in it and led to modest improvements in the lives of staff, pupils and parents.
The Possible Role of Natural Idiotopes in Immune Memory
Authors: Dimitrijević Ljiljana , Živanević-Simonović Snezana , Stojanović Marijana , Inić-Kanada Aleksandra , Živković Irena
Published: December 2004

In this paper we report on the generation of Abs possessing specificities
similar to those of Abs used in immunization, and on the generation of Id and
anti‐Id
specificities in the sera of mice immunized with commensal bacterial antigens.

The human monoclonal antibody IgM DJ (VH3/VL2) expresses natural
antibody properties, natural idiotope (Y7), and specificity towards Lactic acid
bacteria (LAB). When used in immunization it generates LAB‐specific antibodies.
Immunization with LAB, as detected in the presence of biotin‐labelled mouse
monoclonal anti‐idiotopic antibodies Y7 and IgM DJ generates Abs1 and Abs2,
respectively. These findings may imply that the recognition of bacterial motifs
accords with the rules of idiotypic network theory. This theory, first proposed by
Jerne in 1974 and often overlooked since, has been subject to change during the
course of immunological research. Recent experiments concerning the recognition
of bacterial motifs and natural memory in the immune system have inspired us in
our attempt at explaining the possible role of natural Id in immune memory.
Early Appearance of TNF‐α and Other Cytokines in Bronchus Associated Lymphoid Tissues (BALT) from Growing Wistar Rats. What is the Role of TNF‐α?
Authors: Delettieres Dreanina , Frecha Cecilia A. , Roux Maria E.
Published: December 2004

Several different cytokines trigger the development of determined cell subsets
in BALT of growing Wistar rats. Early appearance (4 days post partum) of γδT cells in
BALT has been shown, as well as its role in up‐regulating TNF‐α production. In the
present report, we studied in the BALT: (1) the profile of the cytokines, TNF‐α, INF‐γ
and IL‐10 and (2) in TCR γδ+ cells, the existence of a colocalization with TNF‐α as well
as with INF‐γ. All the cytokines studied were observed at an early stage of BALT
development by immunohistochemistry and in bronchoalveolar cells (BAL cells) by
flow cytometry and western blot. (1) The principal cytokine found at 4 days of age in
BALT cells was TNF‐α that increases along BALT development. The same behavior
was found for cells containing IL‐10 and INF‐γ. (2) TCR γδ+ cells colocalize mainly with
TNF‐α as it has been shown by immunohistochemistry in BALT and by flow cytometry
when we studied BAL.

The early appearance of TNF‐α concomitant with TCR γδ+ cell suggests
an important role for this cytokine along BALT development. Moreover, mutual
regulation between them exists taking
part in the immune surveillance and repair of damaged epithelia.
Older Adults Encode—But Do Not Always Use—Perceptual Details
Authors: Koutstaal Wilma
Published: December 2004

Investigations of memory deficits in older individuals have concentrated on their increased likelihood of forgetting events or details of events that were actually encountered (errors of omission). However, mounting evidence demonstrates that normal cognitive aging also is associated with an increased propensity for errors of commission—shown in false alarms or false recognition. The present study examined the origins of this age difference. Older and younger adults each performed three types of memory tasks in which details of encountered items might influence performance. Although older adults showed greater false recognition of related lures on a standard (identical) old/new episodic recognition task, older and younger adults showed parallel effects of detail on repetition priming and meaning-based episodic recognition (decreased priming and decreased meaning-based recognition for different relative to same exemplars). The results suggest that the older adults encoded details but used them less effectively than the younger adults in the recognition context requiring their deliberate, controlled use.
On the Broad Applicability of the Affective Circumplex
Authors: Kring Ann M. , Barrett Lisa Feldman , Gard David E.
Published: December 2004

Studies of affective experience are guided by the assumption that the structure of affect generalizes across people. Yet this assumption has not been tested among educationally and economically diverse community residents or among individuals with psychopathology. This study explicitly examined the broad applicability of the valence-arousal circumplex and whether schizophrenia patients and nonpatients have comparable knowledge structures of affective phenomena. Patients and nonpatients completed similarity ratings of 120 pairs of affect words. Similarity judgments were analyzed separately for each group using a multidimensional scaling procedure, and solutions were compared. Results revealed the same two-dimensional valence-arousal solution for schizophrenia patients and nonpatients, although there were subtle differences between the groups. These findings provide additional evidence that the circumplex model is a useful formalism for representing affective phenomena across diverse populations, and they bolster confidence in existing interpretations of schizophrenia patients' reports of affective experience.
Good Pitch Memory Is Widespread
Authors: Schellenberg E. Glenn , Trehub Sandra E.
Published: December 2004

Here we show that good pitch memory is widespread among adults with no musical training. We tested unselected college students on their memory for the pitch level of instrumental soundtracks from familiar television programs. Participants heard 5-s excerpts either at the original pitch level or shifted upward or downward by 1 or 2 semitones. They successfully identified the original pitch levels. Other participants who heard comparable excerpts from unfamiliar recordings could not do so. These findings reveal that ordinary listeners retain fine-grained information about pitch level over extended periods. Adults' reportedly poor memory for pitch is likely to be a by-product of their inability to name isolated pitches.
Hong Kong Chinese Kindergartners Learn to Read English Analytically
Authors: McBride-Chang Catherine , Treiman Rebecca
Published: December 2004

We examined the extent to which young Hong Kong Chinese children, taught to read English as a second language via a logographic “look and say” method, used information about letter names and letter sounds to learn English words. Forty children from each of three kindergarten grade levels (mean ages 3.8, 5.0, and 5.9 years old, respectively) were taught to pronounce novel English spellings that were based on letter-name (e.g., DK = Deke), letter-sound (DK = Dick), or visual (DK = Jean) cues. By the 2nd year of kindergarten, children performed significantly better in the name condition than the other conditions. The 3rd-year kindergartners performed better in the sound condition than the visual condition as well. The results point to the importance of letter-name and letter-sound knowledge for learning to read English, regardless of native-language background or method of instruction.
Status, Testosterone, and Human Intellectual Performance
Authors: Josephs Robert A. , Newman Mathew L. , Brown Ryan P. , Beer Jeremy M.
Published: December 2004

Results from two experiments suggest that stereotype-threat effects are special cases of a more general process involving the need to maintain or enhance status. We hypothesized that situations capable of confirming a performance stereotype might represent either a threat to status or an opportunity for enhancement of status, depending on the nature of the stereotype. The positive relationship between baseline testosterone and status sensitivity led us to hypothesize that high testosterone levels in males and females would amplify existing performance expectations when gender-based math-performance stereotypes were activated. In Study 1, high-testosterone females performed poorly on a math test when a negative performance stereotype was primed. In Study 2, high-testosterone males excelled on a math test when a positive performance stereotype was primed. The moderating effect of testosterone on performance suggests that a stereotype-relevant situation is capable of conferring either a loss or a gain of status on targets of the stereotype.
Levels of Reality
Authors: Heil John
Published: December 2004

Philosophers and non‐philosophers have been attracted to the idea that the world incorporates levels of being: higher‐level items – ordinary objects, artifacts, human beings – depend on, but are not in any sense reducible to, items at lower levels. I argue that the motivation for levels stems from an implicit acceptance of a Picture Theory of language according to which we can ‘read off’ features of the world from ways we describe the world. Abandonment of the Picture Theory opens the way to a ‘no levels’ conception of reality, a conception that honors anti‐reductionist sentiments and preserves the status of the special sciences without the ontological baggage.
Intentionality and Self‐Awareness
Authors: Perrett Roy W.
Published: December 2004

In this essay I defend both the individual plausibility and conjoint consistency of two theses. One is the Intentionality Thesis: that all mental states are intentional (object‐directed, exhibit ‘aboutness’). The other is the Self‐Awareness Thesis: that if a subject is aware of an object, then the subject is also aware of being aware of that object. I begin by arguing for the individual prima facie plausibility of both theses. I then go on to consider a regress argument to the effect that the two theses are incompatible. I discuss three responses to that argument, and defend one of them.
Minimum and maximum entitlements: literature at Key Stage 2
Authors: Martin Tony
Published: December 2004

How far does the difference between a child's minimum reading entitlement (“I can read different types of text for different purposes – and I've got level 4 to prove it”) and maximum entitlement (“I recognise the power of literature and want to read it for the rest of my life”) encapsulate a tension present in many primary classrooms? In England, literature (poetry, narrative, plays) is taught as part of the National Literacy Strategy and a child's knowledge of how it works may be assessed if literary texts are included in the end of Key Stage 2 reading test. The requirements of the Strategy and especially the reading test may well impact on the maximum entitlement of a child to become a reader for life. This article explores some of the dangers which result from viewing the minimum entitlement as the maximum being aimed at in the classroom.
Using Difference-Based Methods for Inference in Nonparametric Regression with Time Series Errors
Authors: Hall Peter , Keilegom Ingrid Van
Published: December 2004

We show that difference-based methods can be used to construct simple and explicit estimators of error covariance and autoregressive parameters in nonparametric regression with time series errors. When the error process is Gaussian our estimators are efficient, but they are available well beyond the Gaussian case. As an illustration of their usefulness we show that difference-based estimators can be used to produce a simplified version of time series cross-validation. This new approach produces a bandwidth selector that is equivalent, to both first and second orders, to that given by the full time series cross-validation algorithm. Other applications of difference-based methods are to variance estimation and construction of confidence bands in nonparametric regression.
Iterated Residuals and Time-Varying Covariate Effects in Cox Regression
Authors: Winnett Angela , Sasieni Peter
Published: December 2004

The Cox proportional hazards model, which is widely used for the analysis of treatment and prognostic effects with censored survival data, makes the assumption that the hazard ratio is constant over time. Nonparametric estimators have been developed for an extended model in which the hazard ratio is allowed to change over time. Estimators based on residuals are appealing as they are easy to use and relate in a simple way to the more restricted Cox model estimator. After fitting a Cox model and calculating the residuals, one can obtain a crude estimate of the time-varying coefficients by adding a smooth of the residuals to the initial (constant) estimate. Treating the crude estimate as the fit, one can re-estimate the residuals. Iteration leads to consistent estimation of the nonparametric time-varying coefficients. This approach leads to clear guidelines for residual analysis in applications. The results are illustrated by an analysis of the Medical Research Council’s myeloma trials, and by simulation.
Classical Model Selection via Simulated Annealing
Authors: Brooks S. P. , Friel N. , King R.
Published: December 2004

The classical approach to statistical analysis is usually based upon finding values for model parameters that maximize the likelihood function. Model choice in this context is often also based on the likelihood function, but with the addition of a penalty term for the number of parameters. Though models may be compared pairwise by using likelihood ratio tests for example, various criteria such as the Akaike information criterion have been proposed as alternatives when multiple models need to be compared. In practical terms, the classical approach to model selection usually involves maximizing the likelihood function associated with each competing model and then calculating the corresponding criteria value(s). However, when large numbers of models are possible, this quickly becomes infeasible unless a method that simultaneously maximizes over both parameter and model space is available. We propose an extension to the traditional simulated annealing algorithm that allows for moves that not only change parameter values but also move between competing models. This transdimensional simulated annealing algorithm can therefore be used to locate models and parameters that minimize criteria such as the Akaike information criterion, but within a single algorithm, removing the need for large numbers of simulations to be run. We discuss the implementation of the transdimensional simulated annealing algorithm and use simulation studies to examine its performance in realistically complex modelling situations. We illustrate our ideas with a pedagogic example based on the analysis of an autoregressive time series and two more detailed examples: one on variable selection for logistic regression and the other on model selection for the analysis of integrated recapture–recovery data.
A Note on the Prospective Analysis of Outcome-Dependent Samples
Authors: Chen Hua Yun
Published: December 2004

Two likelihood representations corresponding to the prospective and retrospective analyses of the case–control design are derived for general outcome-dependent samples with arbitrary discrete or continuous outcomes and possibly non-multiplicative models. Parameter identification in the general outcome-dependent design is reduced to the simple problem of parameter identification in the general odds ratio function. Both likelihoods are shown to generate the same profile likelihood for the common parameter of interest. Maximum likelihood estimators based on either likelihood are semiparametric efficient for the identifiable parameters.
A General Condition for Avoiding Effect Reversal after Marginalization
Authors: Cox D. R. , Wermuth Nanny
Published: December 2004

The paper examines the effect of marginalizing over a possibly unobserved background variable on the conditional relation between a response and an explanatory variable. In particular it is shown that some conclusions derived from least squares regression theory apply in general to testing independence for arbitrary distributions. It is also shown that the general condition of independence of the explanatory variable and the background ensures that monotonicity of dependence is preserved after marginalization. Relations with effect reversal and with collapsibility are sketched.