bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of gestational age and neuromaturation
Authors: Allen Marilee C. 
Published: April 2005

AbstractNeuromaturation is the functional development of the central nervous system (CNS). It is by its very nature a dynamic process, a continuous interaction between the genome and first the intrauterine environment, then the extrauterine environment. Understanding neuromaturation and being able to measure it is fundamental to infant neurodevelopmental assessment. Fetal and preterm neuromaturation has become easier to observe with the advent of prenatal ultrasonography and neonatal intensive care units. A number of measures of degree of fetal maturation have been developed and used to estimate gestational age (GA) at birth. The most reliable measures of GA are prenatal measures, especially from the first trimester. Postnatal GA measurements tend to be least accurate at the extremes of gestation, that is, in extremely preterm and post‐term infants. Observations of measures of neuromaturation in infants born to mothers with pregnancy complications, including intrauterine growth restriction, multiple gestation, and chronic hypertension, have led to the discovery that stressed pregnancies may accelerate fetal pulmonary and CNS maturation. This acceleration of neuromaturation does not occur before 30 weeks' gestation and has a cost with respect to cognitive limitations manifested in childhood. The ability to measure fetal and preterm neuromaturation provides an assessment of neurodevelopmental progress that can be used to reassure parents or identify at risk infants who would benefit from limited comprehensive follow‐up and early intervention services. In addition, measures of neuromaturation have the potential to provide insight into mechanisms of CNS injury and recovery, much‐needed early feedback in intervention or treatment trials and a measure of early CNS function for research into the relationships between CNS structure and function. © 2005 Wiley‐Liss, Inc. MRDD Research Reviews 2005;11:21–33.
A double structure generalized plasticity model for expansive materials
Authors: Sánchez Marcelo , Gens Antonio , do Nascimento Guimarães Leonardo , Olivella Sebastián 
Published: April 2005

AbstractThe constitutive model presented in this work is built on a conceptual approach for unsaturated expansive soils in which the fundamental characteristic is the explicit consideration of two pore levels. The distinction between the macro‐ and microstructure provides the opportunity to take into account the dominant phenomena that affect the behaviour of each structural level and the main interactions between them. The microstructure is associated with the active clay minerals, while the macrostructure accounts for the larger‐scale structure of the material. The model has been formulated considering concepts of classical and generalized plasticity theories. The generalized stress–strain rate equations are derived within a framework of multidissipative materials, which provides a consistent and formal approach when there are several sources of energy dissipation. The model is formulated in the space of stresses, suction and temperature; and has been implemented in a finite element code. The approach has been applied to explaining and reproducing the behaviour of expansive soils in a variety of problems for which experimental data are available. Three application cases are presented in this paper. Of particular interest is the modelling of an accidental overheating, that took place in a large‐scale heating test. This test allows the capabilities of the model to be checked when a complex thermo‐hydro‐mechanical (THM) path is followed. Copyright © 2005 John Wiley & Sons, Ltd.
Roles for USF‐2 in lung cancer proliferation and bronchial carcinogenesis
Authors: Ocejo‐Garcia Marta , Baokbah Tourki AS , Louise Ashurst H , Cowlishaw Debbie , Soomro Irshad , Coulson Judy M , Woll Penella J 
Published: April 2005

AbstractThe upstream stimulatory factors USF‐1 and USF‐2 dimerize to regulate transcription through E‐box motifs in target genes. Although widely expressed, they can mediate tissue‐specific transcription and we previously reported that USF‐2 can enhance transcription of arginine vasopressin, a neuropeptide growth factor in small cell lung cancer. Here we determine the expression and role of USF‐2 in lung cancer subtypes and examine USF‐2 distribution in the bronchial epithelium. For a panel of 12 cell lines and 10 frozen human tumour samples, immunoblotting demonstrated that USF‐2 expression was more frequent and abundant in small cell lung cancer than in non‐small cell lung cancer. An immunohistochemical study of 108 formalin‐fixed and paraffin‐embedded human samples was undertaken to localize USF‐2 expression and included 44 small cell and 32 non‐small cell lung cancers, and 32 samples with bronchial dysplasia. USF‐2 was restricted to ciliated cells in normal bronchial epithelium, but was more strongly expressed in dysplastic epithelium (72%) and certain lung cancer types, including small cell lung cancer (71%), squamous cell carcinoma (69%) and a large cell neuroendocrine carcinoma, but was less common in adenocarcinoma (11%). In a small series, expression was assessed adjacent to positively staining tumours; in phenotypically normal bronchial tissues, USF‐2 was more highly expressed at 1 cm than at 5 cm from the tumour. Transient USF‐2 overexpression in non‐small cell lung cancer cell lines significantly stimulated in vitro cell proliferation; this response was most apparent for NCI‐H460 (p < 0.005), reducing the mean cell doubling time from 19 to 16 h. Dominant‐negative USF‐2 mutants had no significant effect on cell growth. Taken together, these data suggest that USF‐2 represents a relatively early molecular marker for the development of bronchial dysplasia and non‐adenocarcinoma lung cancer. USF may also play a role in bronchial carcinogenesis, perhaps through promoting cell proliferation, although the genes through which this is regulated remain to be determined. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Performance of steel–concrete composite structures in fire
Authors: Wang Y C 
Published: April 2005

AbstractThis paper presents a review of recent studies of the behaviour of steel–concrete composite structures in fire, including an assessment of research investigations and their implications on fire‐resistant design of composite structures. The paper focuses on the three main parts of composite structure: floor systems, columns and joints. The section on composite floor systems includes bending behaviour of conventional composite floor/beam system with composite slabs on top of a solid steel I‐beam; tensile membrane action in this system; slim‐floor construction; composite cellular beam; composite truss and composite beam with precast concrete slabs. The section on composite columns includes studies of concrete‐filled tubular (CFT) column; design of composite columns and performance of CFT columns within structures. The section on joints covers both steel and composite joints, including experiments on joints in fire; finite element simulation; the component method; behaviour of different joint components at elevated temperatures and implications of joint behaviour on steel and composite structural behaviour in fire. Within each section, wherever appropriate, the effects of whole structural behaviour are discussed. Furthermore, potential future research studies are identified to help understand the subject and develop improved performance‐based practical fire resistant design calculation methods.
Basic capacity calculation methods and benchmarking for MF‐TDMA and MF‐CDMA communication satellites
Authors: Chang Darren D. , de Weck Olivier L. 
Published: April 2005

AbstractThis paper introduces basic capacity calculation methods for circuit switched, multiple‐beam, low earth orbit (LEO) communication satellites that use MF‐TDMA and MF‐CDMA schemes. Capacity is defined as the number of simultaneous duplex channels that a satellite can support for a given data rate and bit error rate. This paper integrates the bandwidth limit and the power limit on capacity, and derives the equations by which the capacity of a MF‐TDMA or a MF‐CDMA system can be calculated using key system parameters. Therefore, these methods enable system designers to quickly estimate the communication system capacity when key system parameters are known. The paper uses the Iridium and Globalstar systems for benchmarking by comparing the results obtained from the analytical methods with the 1100 and 2500 simultaneous channels reported by Iridium and Globalstar, respectively. The analytic capacity estimate matches reported single satellite capacities to within 6%, but the predictions are sensitive to various loss assumptions made in the link budget. Copyright © 2005 John Wiley & Sons, Ltd.
Parenting style, individuation, and mental health of Egyptian adolescents
Authors: Dwairy Marwan , Menshar Kariman E. 
Published: April 2005

AbstractThree questionnaires that measure parenting style, adolescent‐family connectedness, and mental health were administered to 351 Egyptian adolescents. Results show that in rural communities the authoritarian style is more predominant in the parenting of male adolescents, while the authoritative style is more predominant in the parenting of female adolescents. In urban communities, on the other hand, the authoritarian style was more predominant in the parenting of female adolescents. The connectedness of all female adolescents with their family was stronger than that of male adolescents. The connectedness of girls was found to be more emotional and financial in villages and to be more functional in town. Female adolescents reported a higher frequency of psychological disorders. Mental health was associated with authoritative parenting, but not with authoritarian parenting. It seems that authoritarian parenting within an authoritarian culture is not as harmful as within a liberal culture.
Theory of Dielectric Relaxation for a Single-Axis Rotator in a Crystalline Field
Authors: Hoffman John D. , Pfeiffer Heinz G. 
Published: April 2005

The dielectric relaxation times associated with a single-axis polar rotator which may occupy several sites as it turns about its axis are calculated in terms of the probabilities of transition from one site to another. Two special cases are considered in detail: (a) that in which all of the sites are equivalent, and (b) that in which one site is stable with respect to the others. It is assumed that the only important elementary process is a rotational jump to an adjacent site (single-jump hypothesis). Fluctuations of barrier height are ignored.
If the dipole has three or more accessible sites, and one is more stable than the others, a distribution of relaxation times develops naturally. The corresponding dielectric loss peak will be somewhat asymmetric. If the sites are all equivalent, only a single dielectric relaxation time is found, and the corresponding dielectric loss peak will be of the simple Debye type. The theory predicts that the dielectric loss peaks in certain polar crystals will become narrower and more symmetrical as the temperature is raised.
Dielectric Properties of Wool-Water Systems at 3000 and 9300 Megacycles
Authors: Windle J. J. , Shaw T. M. 
Published: April 2005

The dielectric constant ε′ and dielectric loss ε″ for wool-water systems have been determined at frequencies of 3000 and 9300 Mc by a cavity resonator method. The water content of the wool fibers was varied between 0 and 14 percent of the weight of the dry wool. The upper limit of 14 percent is approximately one-half the amount of water wool will absorb in a saturated atmosphere at 25°C. The increased dielectric loss in the systems studied and the resultant attenuation of microwave power prevented measurements from being made at water contents in excess of approximately 14 percent.
The results of the measurements show that both ε′ and ε″ increase with increasing water content. The results have been analyzed in terms of a sorption theory proposed by Cassie which shows that the water sorbed by wool consists of localized water which is intimately bound to polar sites in the wool and mobile water which constitutes the remainder sorbed. The dielectric constant of the localized water is found to be 5.8 at both frequencies. This result compares favorably with the microwave dielectric constant of irrotationally bound water obtained by Buchanan et al. from studies of protein hydration. It has been found that ε′ and ε″ of the mobile water are less than for liquid water if the dielectric properties of the wool are assumed to be unaffected by water sorption. The alternate assumption (in which ε′ and ε″ for the mobile water are set equal to those of liquid water) is discussed.
Tables of Statistical Electron Distributions for Atoms with Degree of Ionization Zero to Four and of the Corresponding Electrostatic Potentials
Authors: Thomas L. H. 
Published: April 2005

The potential and electron density in statistical distributions for atoms according to Dirac's equation and Jensen's boundary conditions are given as functions of radial distance on a logarithmic scale for neutral atoms and for singly charged positive ions, at uniform interval of a parameter γ. A simple interpolation only is required to obtain them for any particular atomic number. The values of the separate terms in the energy of the distribution are also given.
Tables at a closer interval in radial distance and for positive ions up to charge four can be obtained from the Watson Laboratory, free of charge. They are also available on punched cards.
Investigation of Rotational Isomers with Ultrasound
Authors: Karpovich John 
Published: April 2005

Sound absorption measurements in organic liquids have revealed relaxation processes in some cyclohexane derivatives, cyclohexene, methyl formate, ethyl acetoacetate, acetic anhydride, and methyl benzoate. Additional absorption measurements have been made in the relaxation regions of formic acid, ethyl formate, methyl acetate, and ethyl acetate.
A study of cyclohexane derivatives and other similar ring molecules has led to the identification of the mechanism responsible for the relaxations in these liquids. The relaxation phenomena are attributed to the disturbance by the sound wave of equilibria between rotational isomers. The restricted rotation occurs about the single bonds in the ring during the conversion from one chair configuration to another.
The relaxation in cyclohexene is caused by the disturbance of the equilibrium between pseudochair and boat configurations, again involving rotation about single C–C bonds.
The relaxations in esters of the carboxylic acids are attributed to rotational isomers which arise from rotation about C–O bonds.
Infrared absorption bands at about 1160 and 1185 cm-1 in the formates and acetates are identified with rotational isomers of the type postulated for the relaxations in these liquids.
Ionization and Dissociation by Electron Impact; Methylene, Methyl, and Methane
Authors: Langer A. , Hipple J. A. , Stevenson D. P. 
Published: April 2005

The appearance potentials of C+, CH+, and CH2+ in the mass spectra of methylene, methyl, and methane are found to be mutually consistent and when combined with the spectroscopic value of the ionization potential of the carbon atom (11.26 ev) lead to 15.5±0.5 ev/molecule for the heat of atomization of methane. This value (15.5) when further combined with the heat of formation of methane (—0.78 ev/molecule) and the dissociation energy of H2 (4.48 ev/molecule) yields 5.76 ev/atmos or 133 kcal/mole for the heat of sublimation of graphite.
The set of appearance potentials confirmed the spectroscopic value for the heat of dissociation of CH+ (3.6 ev/molecule) and yield the following additional energetic quantities: D(CH2–H) = 3.75±0.3 ev/molecule, D(CH–H) = 3.99±0.3 ev/molecule, D(CH3+–H) = 1.34±0.1 ev/molecule, D(CH2+–H) = 5.54±0.2 ev/molecule, and D(CH+–H) = 3.37±0.2 ev/molecule. Earlier determinations of Iz(CH4), Iz(CH3) and D(CH3–H) are confirmed (within the experimental error) and the ionization potential of the methylene radical, Iz(CH2), is found to be 11.75±0.1 ev/molecule.
Combination of the appearance potentials of CH2+ in the methane and diazomethane mass spectra gives 46±6 kcal/mole for the heat of formation of diazomethane.
Force Constants for F2CO and Thermodynamic Properties for F2CO and FClCO
Authors: Lovell R. J. , Stephenson C. V. , Jones E. A. 
Published: April 2005

A set of force constants for F2CO has been calculated using the observed fundamental frequencies and a potential function consisting of valence force interaction terms and an additional term involving an interaction between the oxygen and fluorine atoms. The large values obtained for the interaction constant and the angle deformation constants were related to interaction forces between the terminal atoms.
Also included in this paper are calculations of the thermodynamic properties of F2CO and FClCO.
Nuclear Magnetic Resonance in Liquids under High Pressure
Authors: Benedek G. B. , Purcell E. M. 
Published: April 2005

The work reported here is an application of free precession or ``spin echo'' techniques in nuclear magnetic resonance to a study of the properties of liquids under high pressure. The proton relaxation time T1 was measured as a function of pressure, over the range 1 to 10 000 atmospheres, for six liquids: water, n-pentane, n-hexane, toluene, ethyl iodide, and methyl iodide. In addition to the relaxation time, the normalized values D(P)/D(1) of the self-diffusion constant were measured as a function of pressure for water and methyl iodide.
In each liquid T1 decreases with increasing pressure. However, comparison of the observed variation of T1 with pressure with Bridgman's data on the variation of viscosity η with pressure shows in all cases (except that of methyl iodide for which no viscosity data are available) that T1 is not simply proportional to 1/η, but instead T1η increases with pressure. Similarly, for water and methyl iodide, the diffusion constant D varies in such a way that T1/D increases with pressure. For water the Stokes-Einstein relation Dη = cT is obeyed within the errors of observation. The behavior of T1 can be understood if one assumes that the dominant relaxation mechanism involves intramolecular fields, whose correlation time is determined by the rotational freedom of the molecule, and that compression of the liquid inhibits migrational freedom more drastically than rotational freedom.
The necessity of making the present measurements has led to the discovery that BeCu, a heat treatable alloy, makes a very satisfactory high pressure, non-magnetic bomb which might well be used for other magnetic investigations under high pressure.
Ionic Components of Charge in the Electrical Double Layer
Authors: Grahame David C. , Soderberg Barbara A. 
Published: April 2005

The rate of change with concentration of the capacity of the electrical double layer on mercury has been measured. From this there have been calculated Γ+, the excess of cations in the double layer, and Γ—, the excess of anions. The latter has been subdivided into η—d, the excess of anions in the diffuse double layer, and η—i, the excess of anions in the inner part of the double layer. From these data it has also been possible to evaluate ψ0, the potential of the outer Helmholtz plane.
It is found that fluoride ion remains unadsorbed on mercury at all potentials investigated, including potentials anodic to the e.c.max. Other anions are strongly adsorbed (chemisorbed) when the mercury is positively charged, and sometimes even when it is negatively charged. The ``hump'' in the capacity curves of salts of such anions as chloride, bromide, acetate, and nitrate, are found to be present in curves of C—, the capacity attributable to anions alone. No chemisorption of monatomic cations could be detected.
The kinetic theory of the diffuse double layer with constant dielectric constant is found to fit the experimental results within the expected accuracy. This fit extends to electrolytes of the 1:2 and 2:1 types also.
A new method of evaluating salt adsorption at the potential of the electrocapillary maximum (e.c.max.) is described and results are given. Likewise a new method of determining C+ at the e.c.max. is described and used.
A Microwave Investigation of the Ionization of Hydrogen-Oxygen and Acetylene-Oxygen Flames
Authors: Shuler Kurt E. , Weber Joseph 
Published: April 2005

The ionization of premixed hydrogen-oxygen and acetylene-oxygen flames burning at atmospheric pressure was studied by a microwave method. The attenuation of electromagnetic radiation by the flames was employed to determine the free electron concentration. To obtain a high sensitivity for these measurements, a microwave bridge operating slightly off balance was employed, with the flames positioned between two electromagnetic horns in one of the bridge arms. This method permits the determination of electron densities down to about 5·108 electrons per cm3 at atmospheric pressure.
In interpreting the data obtained in this study it was found necessary to take a quantitative account of the ``background ionization'' resulting from the presence of alkali salts as contaminants in the air and the flame gases. After the appropriate background measurements and corrections were made, it was found that the ionization of the hydrogen-oxygen flames and of lean and stoichiometric oxy-acetylene flames was thermal and agreed well with the electron concentration values obtained from equilibrium calculations using the adiabatic flame temperatures. A complete equilibration and equipartition of the internal energy for H2–O2 flames is indicated by the good agreement between the effective ionization temperature and the rotational, vibrational, and electronic temperatures determined previously.
The background corrected ionization of the rich acetylene-oxygen flames (C2H2/O2=1.5/1 to 4/1) was found to be higher by a factor of 10 to 100 than that calculated for a purely thermal flame ionization. This can very plausibly be accounted for on the basis that the high electron concentration in these rich hydrocarbon flames is primarily due to the thermal evaporation of electrons from the carbon atom aggregates (soot particles) formed in these flames. A calculation showed that a work function of 8.5 ev for the small carbon particles in the flame accounts well for all the observed electron concentrations. This value stands in a reasonable relationship to the ionization potential of gaseous carbon atoms (11.265 ev) and the work function of graphite (4.35 ev).
It is suggested on the basis of these results that the ionization in hydrogen-oxygen and acetylene-oxygen flames, at least as far as the hot combustion gases are concerned, is an equilibrium process which can be accounted for by purely thermal considerations. Whether or not this holds true also for the reaction zone proper must remain open to question for the present, since the measurements described here pertain by necessity to an ionization density averaged over a rather extensive region of the flame.