bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of Mercury in Low-Grade Ores
Authors: Henry H. G. , Stever K. R. , Barry W. L. , Heady H. H.
Published: October 2005

Two new rapid and accurate methods are presented for determining mercury in low-grade ores and tailings: (1) A combustion–atomic absorption technique is described wherein a small sample of finely pulverized ore is heated to about 700°C, and the vaporized Hg is detected by atomic absorption. This method is suitable for determining Hg in the 0.1–5.0 lb/ton range, and the precision is about 5% coefficient of variation; (2) an x-ray fluorescence method is described wherein the unweighed, finely ground sample is merely packed into a holder, and the Hg line-to-background ratio is obtained. The problem of matrix effects is avoided by preparing standards to simulate the type of ore being analyzed. The method is suitable for determining Hg over a wide concentration range, with a lower limit of about 0.1 lb/ton. The precision, based on the analysis of a 2.0 lb/ton Hg ore, is about 5% coefficient of variation. These two techniques are compared to the commonly used Whitton and Bureau of Mines methods.
Clouding of Pressed Potassium Bromide Powder
Authors: Norris William P. , Olsen Allen L. , Brophy Richard G.
Published: October 2005

The monomolecular layer of water adsorbed on KBr particles is responsible for clouding of disks pressed from finely ground powder. Cloudiness is caused by formation of a multitude of cracks in the disk. The initial cracking can be observed with a low power optical microscope and the extensive cracking in the fully cloudy region is observable with a scanning electron microscope. It is suggested that adsorbed water promotes recrystallization, generating weak zones in the workhardened, elastically stressed disk which fails by cracking.
π-π* Absorption Spectrum of Pyridine-D5
Authors: Shukla Jaya V. , Upodhya K. N. , Thakur S. N.
Published: October 2005

The absorption spectrum of π–π* system of pyridine-D5 molecule has been measured in the range 33790–36990 cm−1, on the Hilger large quartz spectrograph. A large number of sharp bands have been measured and analyzed in terms of ground and excited state frequencies which have been compared with the corresponding frequencies of pyridine-H5 molecule.
Effects of pH on the C-13 Magnetic Resonance Spectrum of Phenol
Authors: Nakashima Thomas T. , Maciel Gary E.
Published: October 2005

The C-13 chemical shift dependences of phenol on pH have been investigated and the shifts interpreted in terms of the phenol-phenoxide equilibrium and hydrogen bonding. In the low and high ranges of pH the carbon shifts have been related to subtle changes in the characteristics of solvent properties. The spectra were obtained using the Fourier transform technique.
NMR Chemical Shift Correlations for Chlorine Containing Groups
Authors: Brown V. A. , Brame E. G.
Published: October 2005

In applying high resolution NMR to structural analysis of the various data that can be obtained chemical shift data are the most useful. Proton resonance chemical shift data, compiled from the literature and from Elastomer files, are presented showing the effect of the presence of chlorine on shared and adjacent proton groups in a number of chlorine containing compounds. The data are presented in spectra-structure correlation tables.
An Evaluation of a Premixed Méker-Type Flame as an Atom Reservoir for Atomic Fluorescence
Authors: Slevin P. J. , Muscat V. I. , Vickers T. J.
Published: October 2005

The characteristics of a sheathed Méker-type burner (Alkemade burner) in producing a flame atom reservoir for atomic fluorescence measurements have been investigated. Comparative measurements of interferences, atomization efficiency, spatial distribution of atoms, and atomic fluorescence of Sn were made. The effect of phosphate anion on the alkaline earth elements has been used as the basis of comparison of interferences with the sheathed burner and several commercial premix burners. The efficiency of atomization of the burner has been compared with a Techtron burner with Méker-type head. Lateral and radial atom profiles for Ca have been measured in observing the effect of sheathing on the atomic distribution, and the benefits of sheathing are demonstrated in the measurement of the atomic fluorescence of Sn. It is concluded that the sheathed burner is markedly better than standard Méker-type burners for atomic fluorescence measurements.
An Experimental Technique for Studying Chemisorption Reactions by Means of Electron Paramagnetic Resonance Spectroscopy
Authors: Scheide Eugene P. , Guilbault George G.
Published: October 2005

A new experimental method and a specially designed EPR cell are described for use in the study of chemisorption reactions. By studying the EPR spectrum of a surface both before and after chemisorption, it can be shown whether unpaired d electrons are used in the chemisorption bond and the nature of this bond. The EPR spectra of a cupric chloride surface, both before and after a gaseous ligand (diisopropyl methyl phosphonate) is chemisorbed, are shown and the results are interpreted in terms of the type of bond formed.
Happiness is a Class II Spectrum
Authors: Smith A. Lee , Potts W. J.
Published: October 2005

In 1967, the Coblentz Society and the American Society for Testing Materials jointly initiated a pilot project to generate a limited number of research quality (class II) infrared reference spectra. Six infrared laboratories participated, each producing 25 spectra from samples selected from a group of 57 authentically pure chemical compounds. Three of the compounds were run by all laboratories in order to provide a basis for comparison and evaluation. This paper reports the results of the project. Points covered include a discussion of why class II spectra are important to the future of infrared spectroscopy; some of the difficulties encountered by the participating laboratories and ways of overcoming these difficulties; and a critical comparison of spectra from the same compounds produced on different spectrometers and under different sampling conditions.
The Correlation between Gaseous Atomic Spectra and the Absorption Spectra of Atoms Isolated in Noble-Gas Matrices
Authors: Carstens Dean H. W. , Brashear Wayne , Eslinger Delano R. , Gruen Dieter M.
Published: October 2005

Although matrix perturbations affect the energies and intensities of atomic transitions, it has been found that the complex spectra of matrix-isolated metal atoms correlated remarkably well with electronic transitions involving the ground state of the analogous gaseous atoms. A series of line drawings is therefore presented which depict these transitions for 64 neutral gaseous elements. In addition a set of tables is included which gives the intensities and energies of all experimentally observed gaseous transitions involving the atomic ground state. The electronic configurations and state designations for the various states involved in these transitions are also listed. Two examples of the correlation between the spectra of gaseous and matrix-isolated atoms, are discussed, these being Cu and Pt in an Ar matrix.
Far-Infrared Group Frequencies. I. Aliphatic Alcohols
Authors: Craven Stephen M. , Bentley Freeman F.
Published: October 2005

The far-infrared spectra of a number of aliphatic alcohols have been recorded as dilute solutions in cyclohexane. A characteristic band is present at 210±5 cm−1 and is assigned to the hydroxyl torsion on the basis of the deuterium shifts. The position of the band is not sensitive to steric effects but is very sensitive to proximity of electron rich systems. The hydroxyl torsion shifts to ∼300 cm−1 in benzene. Uses of this group frequency for spectra structure correlations are discussed.
Spectroscopic Studies on Some Benzenethiols
Authors: Abu-Eittah R. H. , Hilal R. H.
Published: October 2005

The electronic absorption spectra of some derivatives of benzenethiol were studied in the visible-ultraviolet regions in a number of solvents. Solvent effects on the position of band maxima helped in identifying the different types of transitions obtained, namely n → π*, π → π*, and intramolecular charge transfer transitions. Energies of the charge transfer bands were computed theoretically and agreed well with the experimental results. Transition probability coefficients and oscillator strength were calculated for the different transitions. Numerical values of the oscillator strength helped to differentiate between the various types of transitions.
An Infrared and Raman Study of Benzylidenemalononitriles
Authors: Piffath Ronald J. , Sass Samuel
Published: October 2005

Infrared and Raman spectra have been determined and the nitrile and olefinic C=C stretching bands assigned for 35 benzylidenemalononitriles. The effect of aromatic ring substitution on the position of the nitrile stretching band is discussed. Data are presented relating the nitrile stretching frequency to Hammett substituent constants for meta- and para-substituted benzylidenemalononitriles in chloroform solutions.
n–π* Electronic Emission and Absorption Spectra of p-Fluorobenzaldehyde Vapor
Authors: Srivastava M. P. , Singh I. S.
Published: October 2005

The n–π* electronic emission and absorption spectra of p-fluorobenzaldehyde have been studied in vapor phase. Its Raman and infrared spectra have also been recorded. The spectra have been analyzed in terms of several ground and excited state fundamental vibrations. The C=0 stretching vibration is quite intense and dominates both the spectra. The transition has been ascribed to either A′- A′ or A′-A″ ( n–π*).
A Computerized System for Storing, Retrieving, and Correlating NMR Data
Authors: Skolnik Herman
Published: October 2005

A new indexing concept, using the author's notation system, is described for storing, retrieving, and correlating NMR data via computer processing.
Vibrational Spectra of Several Lanthanide Tris-2,2,6,6-tetramethyl-3,5-heptanedionates
Authors: Lee Hsien-Yu , Cleveland Forrest F. , Ziomek Joseph S. , Jarke Frank
Published: October 2005

The Raman spectra of La-, Pr-, and Gd(DPM)3 [Gd-tris-2,2,6,6-tetramethyl-3,5-heptanedionate] were measured at 300°K with powder samples in the region 3000–100 cm−1. An attempt also was made to obtain the Raman spectra of La-, Ce-, Pr-, Nd-, and Gd(DPM)3 in carbon tetrachloride solution, but no Raman lines for these compounds were found. The undisplaced mercury lines observed were unusually strong. This may have been caused by the photodecomposition of M (DPM)3 in carbon tetrachloride solution by exposure to the light. The infrared spectra of La-, Ce-, Pr-, Nd-, and Gd(DPM)3 were obtained in the region 4000–300 cm−1 by the KBr disk method at 300°K. For La-, Nd-, and Gd(DPM)3, the absorption spectra were measured in the far-infrared region (660–76 cm−1) by use of the polyethylene disk method at 300 and 77 °K. Assignments of the vibrational frequencies were made on the bases of the group theory selection rules and group frequencies, and these were compared with the known assignments of tris-(acetylacetonato) lanthanide (III) complexes for most of the bands.
A Microphotometer Digital Readout System
Authors: Mason Robert E.
Published: October 2005

Some of the advantages of an all-electronic digital readout system for microphotometry are high precision, reliability, speed, and ease of operation. Such a system is feasible if the scanning digital display can be automatically stopped at the point of minimum transmittance. One way to accomplish this is by means of a minimum-voltage memory circuit. The design and construction of such a circuit is described.
“Telephone Directory” Format for NMR Spectra Retrieval
Authors: Jacobs M. H. , van Derslice L.
Published: October 2005

The system described expedites the identification of an unknown sample by facilitating retrieval of known NMR spectra from an in-house reference spectral library. A definitive signature is affixed to each compound. Computer facilities print out the encoded data, matching chemical name with NMR spectral signature. The resulting compendium may then be searched for a signature equivalent to that of the spectrum of the unknown compound. In actual use, identification of an unknown has been made in every case that a reference spectrum was present in the files.
Infrared Quantitative Analysis of Mixtures Containing Isopropenyl Stearate, Stearic Acid, Stearic Anhydride, and Mixed Stearic—Acetic Anhydride
Authors: Calhoun Mary Jo , DellaMonica Edward S.
Published: October 2005

A method for the determination of individual components of complex mixtures is presented. The technique used is based on ir-absorbance measurements for stearic acid at 1700 and at 935 cm−1 when the concentration range exceeds 0.50% wt/vol; for isopropenyl stearate at 1145 and at 865 cm−1; for stearic anhydride at 1030 cm−1 and mixed stearic-acetic anhydride at 1000 cm−1. The baseline method was used in all absorbance measurements. Absorbance-concentration relationships obeyed Beer's law from 0 to 2.0% wt/vol for most compounds; the exception being stearic acid (at 1700 cm−1), where linearity was limited to a maximum 0.50% wt/vol. Due to spectral interference between the two anhydrides at low concentration ratios, an empirical percent transmission ratio method was used to estimate the relative concentration of each. Binary and ternary systems were studied and the standard deviations of the differences between theoretical and calculated values indicate that this method is reliable.
Spectrographic Determination of Lead in Blood
Authors: Steiner R. L. , Anderson D. H.
Published: October 2005

A method is described for the determination of lead in blood covering the range 5 to 100 µg of lead per 100 g of blood (0.05 to 1 ppm). Lead is extracted from uncoagulated whole blood using a trichloroacetic acid (TCA) solution. A portion of the supernatant liquid is spectrographically analyzed using a dc arc technique.
Identification of Failing Mechanical Systems through Spectrometric Oil Analysis
Authors: Barr Donald R. , Larson Harold J.
Published: October 2005

The results obtained from spectrometric analyses may be viewed as being stochastic in nature, so that decisions based upon them are necessarily accompanied by uncertainties. A class of rules is developed for making decisions concerning whether a mechanical system may be failing, based upon spectroscopic analyses of the system's oil over a period of time. Some considerations that went into the development of these rules, including studies of past analysis records and experiments, are presented. Identification procedures of the type suggested should perform well in connection with a computerized analysis system, at least insofar as routinely monitoring the well behaved systems, while calling the attention of appropriate personnel to possibly discrepant systems.
The Determination of Mercury in Some American Coals
Authors: O'Gorman J. V. , Suhr N. H. , Walker P. L.
Published: October 2005

This study deals with the use of three different analytical methods for the determination of mercury in coals: (a) double gold amalgamation, nameless atomic absorption, (b) neutron activation and (c) combustion-solution, nameless atomic absorption. Ten coal samples of varying rank were analyzed and comparisons are drawn between the various analytical procedures. The distribution of mercury in coals is discussed briefly.
Emission Spectrographic Determination of Americium in Curium Oxide
Authors: Gaddy R. H.
Published: October 2005

Emission spectrographic procedures were developed for determining americium in high-purity oxide and in mixed americium-curium oxide containing 33%–60% americium.
Confirmation of SF3+ Vibrational Assignments by Raman Spectroscopic Polarization Measurements in HF Solution
Authors: Brownstein Morley , Shamir Jacob
Published: October 2005

The vibrational assignments of the trifluorosulfur (IV) cation (SP3+, previously determined from spectra of solids, are confirmed by polarization measurements on solutions of SF3+BF4-, SF3+PF6-, and SF3+AsF6- in anhydrous HF. Techniques and equipment have been developed to obtain Raman spectra of species dissolved in anhydrous hydrogen fluoride. Accurate polarization information can be obtained even though the FEP fluorocarbon plastic used as a container and window material is optically active.
Determination of Uranium in High-Grade Uranium Concentrates by an X-ray Emission Spectrographic Method
Authors: Jensen Chester L. , Baur Gretta S.
Published: October 2005

A fast, precise, and accurate x-ray emission spectrographic method has been developed for the determination of uranium in high-grade (70% to 99% U3O8) uranium concentrates. No chemical separations are required. After acid decomposition, yttrium is added as an internal standard, and the uranium in dilute acid solution is determined by x-ray emission techniques. The standard deviation obtained for the average of the mean by analysis of six portions of the same sample is 0.03% U3O8. Such precision is equivalent to that of the more complicated titrimetric methods conventionally used.
Raman Group Frequency Correlations: Phthalate Esters
Authors: Nyquist R. A.
Published: October 2005

Characteristic Raman bands for phthalate esters have been established from a study of 21 compounds. The characteristic bands resulting primarily from within the ortho-phenylene group are compared with corresponding bands and assignments for ortho-dichlorobenzene. The data for phthalate esters are summarized in a correlation chart.
High-Temperature Spectral Emittance of Oxides of Erbium, Samarium, Neodymium and Ytterbium
Authors: Guazzoni Guido E.
Published: October 2005

Normal spectral emittance data are reported for solid specimens of the oxides of erbium, samarium, neodymium, and ytterbium. The spectral emittance has been characterized over the spectral range of 0.5–5.0 µ and at sample temperatures from 1540 up to 1870 K.
Source Parameters and Excitation in a Spark Discharge
Authors: Walters J. P.
Published: October 2005

Experiments are reported for two key lines of aluminum, sparked in nitrogen against graphite for a variety of discharge current waveforms, that suggest that changes in spark source parameters do not fundamentally change the excitation processes in the spark. A straightforward, “either-or” excitation condition is imposed on a simple mass transport model, calculated from measured velocities of electrode vapor in the spark, to predict the time dependence of a primary feature of radiation emitted in the Al II spectrum. The data combine to suggest that parameter-dependent excitation indices require re-examination in terms of the manner in which radiation emitted from the discharge is viewed by the spectrometer.
Vibrational Analyses of N-Substituted Aziridines. II. Sulfinylbis(1-Aziridine)
Authors: Spell H. L. , Laane J.
Published: October 2005

The normal vibrations of sulfinylbis(1-aziridine) have been assigned assuming Cs symmetry for the molecule. The ir absorption peaks arising from the sulfoxide group were identified from the measurement of frequency shifts produced by intermolecular association of the sulfoxide linkage with chloroform. The remainder of the spectra were assigned by comparison with the analogous carbonyl compound and with ethyleneimine. The spectra of sulfinylbis(l-aziridine) recorded at room temperature and 77°K suggest the existence of rotational isomers at room temperature.
13C NMR Spectroscopy: A Brief Review
Authors: Stothers J. B.
Published: October 2005

An introduction to the chemical applications of 13C NMR spectroscopy is presented. The features of the basic instrumentation are outlined and a brief survey of 13C shieldings in hydrocarbons is given to show the general trends and to indicate the major contributing factors. Some recent applications are described to illustrate the potential of 13C techniques for solving chemical problems.
Low-Frequency Raman Spectra of Organic Liquids at Large Angular Dispersions of a Three-Prism Spectrograph
Authors: Blatz L. A.
Published: October 2005

A Steinheil three-prism spectrograph, used at large angular dispersions in the low-frequency Raman region (0 to 200 or 250 cm−1) has been found to give significantly better spectra, especially in the 0- to 40-cm−1 region, than the previous method. Starunov's theory of the low-frequency Raman spectra of liquids is found to systematize, qualitatively and for some liquids, the observed results, especially an effect of viscosity on the orientation spectra.
Infrared Emission Spectroscopy. I. Basic Considerations
Authors: Griffiths Peter R.
Published: October 2005

The basic principles behind the characterization of compounds by ir emission spectroscopy have been illustrated using surface films of silicone grease and gaseous samples. Anomalous features in the spectra are accounted for by considering the absorption of emitted radiation by less thermally excited molecules in the path to the detector. It is suggested that ir emission spectroscopy can be used easily to characterize thin layers on heated specular mirrors or hot vapors at low pressure, but care must be taken in the interpretation of results for thick layers of gases at high pressure, when the temperature of the emitter is close to that of the detector, or when molecules are to be characterized on substrates whose emissivity is high.
An Infrared Study of the Methyl Esters of Phenylglycolic Acids and Related Compounds
Authors: Piffath Ronald J. , Sass Samuel
Published: October 2005

The ir spectra of the methyl esters of both alkylarylglycolic and cycloalkylarylglycolic acids have been determined. The hydrogen bonding of these esters in carbon tetrachloride and in the condensed state was also studied. The hydroxyl and carbonyl stretching bands for related glycolic and acetic acids are discussed.
Immunohistochemical Detection of the Inducible Heat Shock Protein Hsp70: A Methodological Study
Authors: Malusecka Ewa , Zborek Anna , Krzyzowska-Gruca Stefania , Krawczyk Zdzislaw
Published: October 2005

Stress-inducible Hsp70i and constitutively expressed Hsc70 are highly related heat shock proteins. Aberrant expression levels and intracellular localization of these proteins has been suggested as a potential marker in certain tumors. The aim of our study was to work out a reliable, immunohistochemical detection of the stress-inducible Hsp70i protein and enabling discrimination between Hsp70i and Hsc70 proteins in paraffin-embedded human tissues. We tested the effect of several fixative procedures and antigen retrieval on the effectiveness of the Hsp70i detection in murine cells cultured in vitro and in liver of rats subjected to heat shock. For cells grown in vitro, specific Hsp70i immunoreactivity was obtained with all fixatives used. However, samples fixed in 10% formalin and 4% paraformaldehyde required antigen retrieval. In liver tissue embedded in paraffin, regardless the fixative used, positive Hsp70i staining could be visible only if antigen retrieval was applied. We applied this procedure for detection of Hsp70i in routine sections of breast and lung cancers fixed with 10% formalin and found that the application of thermal antigen retrieval significantly enhanced the SPA810 immunoreactivity and reduced background staining. This procedure enabled also the differential detection of Hsp70i and Hsc70 in routine histopathological preparations.
Structural and Functional Organization of Ribosomal Genes within the Mammalian Cell Nucleolus
Authors: Derenzini Massimo , Pasquinelli Gianandrea , O'Donohue Marie-Francçoise , Ploton Dominique , Thiry Marc
Published: October 2005

Data on the in situ structural–functional organization of ribosomal genes in the mammalian cell nucleolus are reviewed here. Major findings on chromatin structure in situ come from investigations carried out using the Feulgen-like osmium ammine reaction as a highly specific electron-opaque DNA tracer. Intranucleolar chromatin shows three different levels of organization: compact clumps, fibers ranging from 11 to 30 nm, and loose agglomerates of extended DNA filaments. Both clumps and fibers of chromatin exhibit a nucleosomal organization that is lacking in the loose agglomerates of extended DNA filaments. In fact, these filaments constantly show a thickness of 2–3 nm, the same as a DNA doublehelix molecule. The loose agglomerates of DNA filaments are located in the fibrillar centers, the interphase counterpart of metaphase NORs, therefore being constituted by ribosomal DNA. The extended, non-nucleosomal configuration of this rDNA has been shown to be independent of transcriptional activity and characterizes ribosome genes that are either transcribed or transcriptionally silent. Data reviewed are consistent with a model of control for ribosome gene activity that is not mediated by changes in chromatin structure. The presence of rDNA in mammalian cells always structurally ready for transcription might facilitate a more rapid adjustment of the ribosome production in response to the metabolic needs of the cell.
‘$4000 a screw’: the prostituted art of F. Scott Fitzgerald and Ernest Hemingway
Authors: Churchwell Sarah
Published: October 2005

F. Scott Fitzgerald and Ernest Hemingway wrote to and about each other, from their meeting shortly after the publication of The Great Gatsby in 1925, until Hemingway’s A Moveable Feast was published posthumously in 1964. Their correspondence reveals a consistently
deployed sexualized discourse in order to trope anxieties about the relationship of masculinity to commercialism and to art. The code these writers developed enabled them to negotiate shifting power relations as they vied with each other to be the better artist, and the more successful man
of business. Trying to reconcile high art with commercialism, they sought to manage conflicting cultural ideologies that declared commerce masculine but vulgar, and art feminine but pure. Mixing the language of the Puritan work ethic with sexual metaphors, they measured their success against
each other and their culture’s shifting definitions of value. The notorious ‘matter of measurements’ episode in A Moveable Feas only becomes fully legible when it is read within this history of competitive ‘measuring’.
Editorial: The American culture-industry of image-making; part II
Authors: Hadjiafxendi Kyriaki , Rapatzikoui Tatiani
Published: October 2005

This special issue aims to map the terrain of the American culture-industry of image-making between the First and Second World Wars. It argues that the attempt to critically understand the challenges that this period had posed to a post-war generation of male writers was not solely
a characteristic of a specific high European form of modernism as Jaqueline Fear-Segal and Helen McNeil have argued (1998: 199). Rather, such critical awareness, which coincided with the dream of material success in the 1920s and 1930s, was the product of transatlantic crossings (literal,
ideological, metaphorical) between American modernists and their European contemporaries. By focusing on authors from both sides of the Atlantic who manifested a potent masculinity, the articles by John Worthen and Sarah Churchwell suggest that the marketability of modernism constitutes a
vital site for the interrogation of gender and sexuality. Their investigation forms the basis of an exploration of image-making as mode of self-positioning before audiences that the next EJAC issue will be examining in greater depth in relation to (post-)modernist aesthetics.
‘Wild Turkeys’: some versions of America by D.H. Lawrence
Authors: Worthen John
Published: October 2005

D.H. Lawrence’s desire to go to the United States led in 1917-18 to his planning and then writing of the essays that were finally published as Studies in Classic American Literature (1923): all of them were conceived and written with ambivalence. He revised the essays for
the last time in New Mexico in the autumn and early winter of 1922, and ‘Americanized’ them for his new American market. In particular, his essay on Walt Whitman now refused to allow the great writer to be an iconic figure. Lawrence’s satirical version of Whitman set out
to undermine the seriousness with which Whitman took himself and with which he was generally taken. Lawrence was attacked for his ignorance of American writing, but he had set out to track the American obsession with power and death, satirically; he remained in an uneasy and finally unresolved
relationship with American writing.
Feature Fatigue: When Product Capabilities Become Too Much of a Good Thing
Authors: Thompson Debora Viana , Hamilton Rebecca W. , Rust Roland T.
Published: October 2005

As technology advances, it becomes more feasible to load products with a large number of features, each of which individually might be perceived as useful. However, too many features can make a product overwhelming for consumers and difficult to use. Three studies examine how consumers balance their desires for capability and usability when they evaluate products and how these desires shift over time. Because consumers give more weight to capability and less weight to usability before use than after use, they tend to choose overly complex products that do not maximize their satisfaction when they use them, resulting in ”feature fatigue.” An analytical model based on these results provides additional insights into the feature fatigue effect. This model shows that choosing the number of features that maximizes initial choice results in the inclusion of too many features, potentially decreasing customer lifetime value. As the emphasis on future sales increases, the optimal number of features decreases. The results suggest that firms should consider having a larger number of more specialized products, each with a limited number of features, rather than loading all possible features into one product.
Nicotinic Cholinergic Receptors in the Rat Cerebellum: Multiple Heteromeric Subtypes
Authors: Turner Jill R. , Kellar Kenneth J.
Published: October 2005

Nicotinic receptors (nAChRs) in the cerebellum have been implicated in the pathology of autism spectrum disorders (Lee et al., 2002; Martin-Ruiz et al., 2004). The subtypes of nAChRs in the cerebellum are not known in any detail, except that, in addition to the homomeric α7 subtype, there appears to be one or more heteromeric subtypes consisting of combinations of α and β subunits. To begin to better understand the potential roles of these heteromeric nAChRs in cerebellar circuitry and their potential as targets for nicotinic drugs, we investigated their subunit composition. Using subunit-selective antibodies in sequential immunoprecipitation assays, we detected six structurally distinct heteromeric nAChR populations in the rat cerebellum. Among these were several subtypes that have not been encountered previously, including α3α4β2 and α3α4β4 nAChRs. This diversity suggests that nAChRs play multiple roles in cerebellar physiology.
Inbreeding Depression and Male Survivorship in Drosophila: Implications for Senescence Theory
Authors: Swindell William R , Bouzat Juan L
Published: October 2005

The extent to which inbreeding depression affects longevity and patterns of survivorship is an important issue from several research perspectives, including evolutionary biology, conservation biology, and the genetic analysis of quantitative traits. However, few previous inbreeding depression studies have considered longevity as a focal life-history trait. We maintained laboratory populations of Drosophila melanogaster at census population sizes of 2 and 10 male-female pairs for up to 66 generations and performed repeated assays of male survivorship throughout this time period. On average, significant levels of inbreeding depression were observed for median life span and age-specific mortality. For age-specific mortality, the severity of inbreeding depression increased over the life span. We found that a baseline inbreeding load of 0.307 lethal equivalents per gamete affected age-specific mortality, and that this value increased at a rate of 0.046 per day of the life span. With respect to some survivorship parameters, the differentiation of lineages was nonlinear with respect to the inbreeding coefficient, which suggested that nonadditive genetic variation contributed to variation among lineages. These findings provide insights into the genetic basis of longevity as a quantitative trait and have implications regarding the mutation-accumulation evolutionary explanation of senescence.
The RSC Chromatin Remodeling Complex Bears an Essential Fungal-Specific Protein Module With Broad Functional Roles
Authors: Wilson Boris , Erdjument-Bromage Hediye , Tempst Paul , Cairns Bradley R
Published: October 2005

RSC is an essential and abundant ATP-dependent chromatin remodeling complex from Saccharomyces cerevisiae. Here we show that the RSC components Rsc7/Npl6 and Rsc14/Ldb7 interact physically and/or functionally with Rsc3, Rsc30, and Htl1 to form a module important for a broad range of RSC functions. A strain lacking Rsc7 fails to properly assemble RSC, which confers sensitivity to temperature and to agents that cause DNA damage, microtubule depolymerization, or cell wall stress (likely via transcriptional misregulation). Cells lacking Rsc14 display sensitivity to cell wall stress and are deficient in the assembly of Rsc3 and Rsc30. Interestingly, certain rsc7Δ and rsc14Δ phenotypes are suppressed by an increased dosage of Rsc3, an essential RSC member with roles in cell wall integrity and spindle checkpoint pathways. Thus, Rsc7 and Rsc14 have different roles in the module as well as sharing physical and functional connections to Rsc3. Using a genetic array of nonessential null mutations (SGA) we identified mutations that are sick/lethal in combination with the rsc7Δ mutation, which revealed connections to a surprisingly large number of chromatin remodeling complexes and cellular processes. Taken together, we define a protein module on the RSC complex with links to a broad spectrum of cellular functions.
Identification and Analysis of Escherichia coli Ribonuclease E Dominant-Negative Mutants
Authors: Briegel Karoline J , Baker Asmaa , Jain Chaitanya
Published: October 2005

The Escherichia coli (E. coli) ribonuclease E protein (RNase E) is implicated in the degradation and processing of a large fraction of RNAs in the cell. To understand RNase E function in greater detail, we developed an efficient selection method for identifying nonfunctional RNase E mutants. A subset of the mutants was found to display a dominant-negative phenotype, interfering with wild-type RNase E function. Unexpectedly, each of these mutants contained a large truncation within the carboxy terminus of RNase E. In contrast, no point mutants that conferred a dominant-negative phenotype were found. We show that a representative dominant-negative mutant can form mixed multimers with RNase E and propose a model to explain how these mutants can block wild-type RNase E function in vivo.
The Pediatric Subspecialty Workforce: Public Policy and Forces for Change
Authors: Jewett Ethan Alexander , Anderson Michael R. , Gilchrist Gerald S.
Published: October 2005

Policy has not adequately addressed the unique circumstances of pediatric subspecialties, many of which are facing workforce shortages. Pediatric subspecialties, which we define to include all medical and surgical subspecialties, are discrete disciplines that differ significantly from each other and from adult medicine subspecialties. Concerns about a current shortage of pediatric subspecialists overall are driven by indicators ranging from recruitment difficulties to long wait times for appointments. The future supply of pediatric subspecialists and patient access to pediatric subspecialty care will be affected by a number of key factors or forces for change. We discuss 5 of these factors: changing physician and patient demographics; debt load and lifestyle considerations; competition among providers of subspecialty care; equitable reimbursement for subspecialty services; and policy to regulate physician supply. We also identify issues and strategies that medical and specialty societies, pediatric subspecialists, researchers, child advocates, policy makers, and others should consider in the development of subspecialty-specific workforce-policy agendas.
Clostridial Myonecrosis in an Adolescent Male
Authors: Langhan Melissa , Arnold Linda
Published: October 2005

Extremity pain is a common complaint in adolescents. Pain out of proportion to examination findings should raise suspicion of deep tissue infection. Clostridial myonecrosis is a rapidly progressive disease consisting of muscle necrosis and systemic toxicity. It is usually seen in elderly and immunocompromised patients. Here we report a case of clostridial myonecrosis in an adolescent male.
Nucleated Red Blood Cells in Preterm Infants With Retinopathy of Prematurity
Authors: Lubetzky Ronit , Stolovitch Chaim , Dollberg Shaul , Mimouni Francis B. , Salomon Mazal , Mandel Dror
Published: October 2005

Objective. The aim of this retrospective study was to examine hematologic indices of potential intrauterine hypoxia, including circulating nucleated red blood cells, lymphocytes, and platelets in preterm infants who developed retinopathy of prematurity (ROP) compared with suitable controls. We hypothesized that higher neonatal absolute nucleated red blood cell (ANRBC) and lymphocyte counts and lower platelets would be found in infants who developed ROP, compared with control infants.

Methods. Each of 23 infants with ROP was pair matched for gestational age and Apgar scores with a control without ROP. Criteria for exclusion in both groups included factors that may influence the ANRBCs at birth. Venous ANRBC counts were obtained within 1 hour of life. Statistical analyses used paired t tests, a paired Wilcoxon test, and backward stepwise-regression analysis.

Results. Groups did not differ in birth weight, gestational age, Apgar scores, or hematocrit, white blood cell, or platelets counts. The ANRBC counts at birth were significantly higher in infants who developed ROP than in controls.

Conclusions. Infants who develop ROP have higher ANRBC counts at birth than matched controls. We suggest that increased fetal erythropoiesis exists in preterm infants who later on will develop ROP. If correct, our interpretation supports the theory that long-lasting fetal hypoxia and/or ischemia may play a role in the pathogenesis of ROP.
Size effect in shear strength of large beams—behaviour and finite element modelling
Authors: Tan K. H. , Cheng G. H. , Cheong H. K.
Published: October 2005

This paper investigates the effects of the shear span:depth a/d ratio and effective depth d on the behaviour and shear strength of large reinforced concrete deep and shallow beams. A total of seven large- and medium-sized specimens were tested to failure under two-point symmetric top loading to determine their diagonal cracking and ultimate shear strengths. It was found that the beams' ultimate shear strength reduced sharply when the overall height increased from 500 to 1000 mm. The diagonal cracking strength was, however, not size dependent. The shear strength reduction is related to the a/d ratio: that is, at a critical a/d value, the size effect becomes very pronounced; beyond it, the size effect is not as apparent. After diagonal cracking has occurred, deep beams behave like a tied arch, with uncracked concrete as compression struts and main longitudinal reinforcement as tension ties. A finite element program ‘WCOMD’ was used to supplement the experimental investigation on size effect. Based on test results, finite element modelling (FEM) and a tied arch analogy, the myth of size effect is unravelled.
Relationship Between Type of Treatment and Degree of Wound Healing Among Institutionalized Geriatric Patients With Stage II Pressure Ulcers
Authors: Yastrub Diane J.
Published: October 2005

The prevention and treatment of pressure ulcers has always been of paramount concern to geriatric health care providers. The purpose of this study was to examine the relationship between two types of treatments and the degree of wound healing among status postcerebral vascular accident (CVA) institutionalized geriatric patients with stage II pressure ulcers. Wound dressings were evaluated according to the National Pressure Advisory Panels Pressure Ulcer Scale for Healing (NPUAP, 1997). Fifty long-term care residents were recruited for the study in Queens, New York. A convenience sample was randomly assigned to either of the treatment protocols: polymeric membrane dressing (polymem) or the antibiotic ointment and dry clean dressing (DCD). The findings from the study revealed a significant difference in wound healing scores in the polymeric membrane-dressing group. These findings are limited due to the small sample size and they cannot be generalized to other populations. As this is an initial study, further research is recommended.
The Importance of Planning for the Future
Authors: Lowder Janet L. , Buzney Sandra J. , French Catherine M. , Loue Sana
Published: October 2005

This article explains various mechanisms that are available to plan for the future prior to the development of incapacity. These include powers of attorney, revocable living trusts, advance medical directives such as powers of attorney for health care and living wills, psychiatric advance directives, and guardianships and conservatorships. Case examples are utilized to illustrate the consequences of a failure to plan and what can be accomplished through advance planning. The suitability of each such mechanism is dependent on the situation of each individual. Additionally, the specific details of each mechanism may vary across states.
Mass Proportion of Microaggregates and Bulk Density in a Brazilian Clayey Oxisol
Authors: Volland-Tuduri Nathalie , Bruand Ary , Brossard Michel , Balbino Luíz Carlos , de Oliveira Maria Inês Lopes , de Souza Martins Éder
Published: October 2005

The physical properties of Brazilian Oxisols are closely related to the development of their microstructure, which typically consists of stable microaggregates >1 mm. There is no model available to predict changes in microstructure in Oxisols. The objective of this work was to relate the proportion of microaggregates to the bulk density (Db) in the soil studied. Five sites of a typic Haplustox under native vegetation (two sites) and pasture (three sites) were sampled. Soil bulk density, sand, silt, and clay content and aggregate‐size distribution were measured from the surface to 1.6 m deep in increments of 0.1 m. Thin sections were prepared from undisturbed samples collected in duplicate from 0‐ to 0.1‐, 0.3‐ to 0.4‐, 0.8‐ to 0.9‐, and 1.5‐ to 1.6‐m depths, and backscattered electron scanning images (BESI) were generated. Clay content ranged from 672 to 798 g kg−1 and bulk density between 0.87 and 1.18 g cm−3 among the 80 samples studied. Bulk density was poorly correlated with clay content (R2 = 0.358) and at any depth was not significantly smaller under native vegetation than under pasture. Visual assessment of BESI revealed that soil material corresponded to either microaggregates (<0.1 mm) in loose arrangement or to much larger aggregates. Quantification of BESI from the deepest sampling depth of all soils showed that 96.2 and 95.7% of microaggregates were <0.8 mm with 73.2 and 95.7% between 0.1 and 0.5 mm under native vegetation and pasture, respectively. The mass proportion of microaggregates can be estimated using the <0.84‐mm soil material that is obtained by dry sieving (Φ < 0.84). Finally, our results showed that Φ < 0.84 varied with Db Linear regression coefficients were calculated for the relationship between Φ < 0.84 and the reciprocal of bulk density (1/Db) [Φ < 0.84 = 1.97 (1/Db) − 1.52, R2 = 0.82], assuming no interaction between microaggregates and macroaggregates, the porosity of these two structural types was estimated as 0.71 and 0.51, respectively.
Formation of Polyaniline Nanorod/Liquid Crystalline Epoxy Composite Nanowires Using a Temperature‐Gradient Method
Authors: Jang J. , Bae J.
Published: October 2005

Liquid crystalline epoxy/polyaniline (LCE/PANI) composite nanowires have been fabricated using an anodic aluminum oxide (AAO) membrane by a temperature‐gradient curing process. PANI nanorods with an average diameter of 30 nm have been synthesized by dispersion polymerization in order to employ them as a curing agent for LCE and as a reinforcement filler for the LCE/PANI composite nanowires. Differential scanning calorimetry and Fourier‐transform infrared spectroscopy indicate that the LCE crosslinking reaction occurred inside the channels of the AAO membrane via the curing of LCE with PANI nanorods. The LCE/PANI composite nanowires exhibit an enhanced electrical conductivity and thermal stability, comparable with a LCE/PANI composite monolith. In addition, these polymer‐composite nanowires also display the characteristics of a functionally gradient conducting material.
Antibody variable region interactions with Protein A: Implications for the development of generic purification processes
Authors: Ghose Sanchayita , Allen Martin , Hubbard Brian , Brooks Clayton , Cramer Steven M
Published: October 2005

In this paper, a wide range of antibodies from various subclasses and subfamilies are employed to evaluate the creation of generic separation processes using Protein A chromatography. The reasons for elution pH differences amongst several IgG1s, IgG2s, antibody fragments, and Fc‐fusion proteins during Protein A chromatography are investigated using several complimentary techniques. The results indicate that variable region interactions play a major role in determining elution pH for VH3 subfamily antibodies while using traditional protein A chromatographic materials. On the other hand, experiments with a resin which employs a ligand consisting solely of B domain of Protein A indicate that variable region interactions can be mitigated, enabling the use of a single elution pH for a range of antibodies. Finally, the moderation of elution conditions associated with this engineered ligand are shown to minimize problems associated with low pH induced aggregation. It is expected that the findings reported in this paper will facilitate faster process development cycle times for this important class of human therapeutics. © 2005 Wiley Periodicals, Inc.
Stochasticity of Manganese Superoxide Dismutase mRNA Expression in Breast Carcinoma Cells by Molecular Beacon Imaging
Authors: Drake Timothy J. , Medley Colin D. , Sen Arup , Rogers Richard J. , Tan Weihong
Published: October 2005

Visual and quantitative monitoring of cell‐to‐cell variation in the expression of manganese superoxide dismutase (MnSOD) mRNA by using novel ratiometric imaging with molecular beacons (MB) reveals a distinct change in patterns following induction of human breast‐carcinoma cells with lipopolysaccharide. Interestingly, the pattern of cell‐to‐cell variation in a cell line stably transfected with a plasmid bearing a cDNA clone of MnSOD and overproducing the enzyme is significantly different from the pattern associated with MnSOD induction. The levels and the patterns of cell‐population heterogeneity for β‐actin mRNA expression do not show distinct changes either following induction or in stably transfected cells. These results are significant in light of the reported relationship between this enzyme and malignant phenotype of breast‐carcinoma cells. Use of MBs in ratiometric image analyses for cytoplasmic mRNAs represents a novel means of directly examining the stochasticity of transcription of MnSOD and other genes implicated in cellular phenotype regulation.