bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantum mechanical calculations of rotational-vibrational scattering in homonuclear diatom-atom collisions
Authors: Wagner Albert F. , McKoy Vincent
Published: February 2004

Most calculations of the vibrational scattering of diatom-atom collisions use the breathing sphere approximation (BSA) of orientation averaging the intermolecular potential. The resulting angularly symmetric potential can not cause rotational scattering. We determine the error introduced by the BSA into observables of the vibrational scattering of low-energy homonuclear diatom-atom collisions by comparing two quantum mechanical calculations, one with the BSA and the other with the full angularly asymmetric intermolecular potential. For reasons of economy the rotational scattering of the second calculation is restricted by the use of special incomplete channel sets in the expansion of the scattering wavefunction. Three representative collision systems are studied: H2–Ar, O2–He, and I2–He. From our calculations, we reach two conclusions. First, the BSA can be used to analyze accurately experimental measurements of vibrational scattering. Second, measurements most sensitive to the symmetric part of the intermolecular potential are, in order, elastic cross sections, inelastic cross sections, and inelastic differential cross sections. Elastic differential cross sections are sensitive to the potential only if the collision is ``sticky,'' with scattering over a wide range of angles; I2–He is such a collision. Otherwise the potential sensitivity of elastic differential cross sections is concentrated in the experimentally difficult region of very small angle scattering.
Depolarized light scattering from monatomic fluids
Authors: Berne Bruce J. , Bishop Marvin , Rahman A.
Published: February 2004

Computer experiments on dense argon are used to evaluate the depolarized spectrum of scattered light. Certain features of the spectrum can be associated with the dynamics of atomic motions in the fluid. The calculations show that the uncorrelated binary collision picture is inadquate since the major time dependence in the variation of the polarizability of the system comes from the correlated reorientation of pairs.
Resolution of the visible-infrared absorption spectrum of I2 into three contributing transitions
Authors: Tellinghuisen Joel
Published: February 2004

New extinction coefficient measurements are reported for I2 in the region 4200–8000 Å. An argon discharge source is used to estimate the underlying continuum absorption in the banded region. Together with other work these results locate the maximum in the 1 u(1Π) ← X[O+g(1Σ)] absorption at 4985 Å with a peak extinction of 200 liter  mole−1 · cm−1. From the shape of the spectrum the 1u (1Π) potential curve behaves as r−9 in the region of strong absorption. The A[1u(3Π)]← X absorption is found to be a factor of 2 stronger than previous estimates with a peak extinction of 41 liter mole−1 · cm−1 at 6730 Å. Earlier indications of a linear dependence of the dipole strength on r centroid for the B [O+u(3Π)]↔ X system are supported in this study. Spectroscopic data for the B↔ X transition are reviewed and new spectroscopic constants recommended for the B state.
Electron diffraction investigation of 1-methoxycyclohexene
Authors: Lowrey A. H. , George C. F. , D'Antonio P. , Karle J.
Published: February 2004

An electron diffraction investigation of 1-methoxycyclohexene was undertaken to determine if the molecule possesses a favored conformation for the vinyl ether portion. In the gas phase, the molecule was found to be predominantly, if not entirely, in the cis conformation. In the cyclohexene ring, the bonded parameters are found to be C=C=1.333± 0.009 A (lC=C=0.048± 0.007 A), C2–C3=1.503± 0.006 A (lC–C=0.051± 0.005 A), C3–C4=1.514± 0.006 A (lC–C=0.042± 0.005 A), C4–C5=1.539± 0.014 A (lC–C=0.041± 0.009 A), the single bonds becoming longer the larger the separation from the double bond. The bonded parameters associated with the methoxy group are C–O=1.364± 0.006 A (lC–O=0.039± 0.005 A) for the distance from the ring to the carbon atom and C–O=1.421± 0.006 A (lC–O=0.041± 0.005 A) for the distance from the oxygen atom to the methyl carbon atom. The ring angles are C6C1C2=124.2± 1.0°, C1C2C3=123.1± 1.0°, C2C3C4=112.1± 1.0°, C3C4C5=111.5± 1.0°. The angles associated with the methoxy group are OC1C2=122.5± 1.5°, C6C1O=113.3± 1.5°, C1OC7=119.7 ± 2.5°. The methoxy group is attached at C1 and the double bond is formed between C1 and C2. The distances are rg values and the errors are limits of error at a confidence level of 95%.
Hydrodynamic properties of supercoiled linear polymer molecules
Authors: Kumbar Mahadevappa
Published: February 2004

The Rouse-Bueche-Zimm spring-bead model has been extended to include both excluded volume and the chain stiffness. A dynamic model including the first- and the second-nearest neighbor spring-bead interactions together with the excluded volume forces between the nonadjacent beads is developed. The calculation is made using the normal coordinate method of Zimm, and applied to linear macromolecules. The sum and the square of the sum of the inverse eigenvalues are tabulated for various N (N being the number of chain elements) as a function of excluded volume and chain stiffness. These sums decrease as either the chain stiffness or the excluded volume increases. The Flory parameter (φC× 10−23) is computed as a function of increasing chain stiffness and excluded volume, and it is concluded that this parameter decreases as both chain stiffness and excluded volume increase. However, the effect of excluded volume is more pronounced than the chain stiffness.
On the calculation of force constants from mean amplitudes of vibration and isotope effect on mean amplitudes
Authors: Müller A. , Mohan N.
Published: February 2004

The extremal properties of both bonded and nonbonded mean amplitudes of vibration are discussed, with a view to see beforehand if real solutions for the force constants could be obtained using such data. A detailed study of the effect of small mass changes in isotopically substituted molecules on mean amplitudes of vibration is made using the first order perturbation theory. Several interesting facts are explained with the help of this approach. The utility of other simple, approximate formulas in this regard is tested using specific examples.
High resolution measurements of 14N, D quadrupole coupling in CH3CN and CD3CN
Authors: Kukolich S. G. , Ruben D. J. , Wang J. H. S. , Williams J. R.
Published: February 2004

A molecular beam maser spectrometer was used to measure hyperfine structure on the J=1→ 0 rotational transitions in CH3CN and CD3CN. Measured nitrogen quadrupole coupling strengths are 1eqaaQ(N)=−4224.4 ± 1.5 kHz for CH3CN and eqaaQ(N)=−4229.3 ± 1.5 kHz for CD3CN. The deuterium quadrupole coupling strength along the C–D bond direction is eqzzQ(D)=167.5 ± 4.0 kHz Nitrogen quadrupole coupling is discussed in relation to the electronic structure. Spin-rotation interaction strengths are reported. A convenient method for calculating matrix elements for hyperfine interactions in an arbitrary coupling scheme is presented.
ESR line shapes in the slow-motional region: Anisotropic liquids
Authors: Polnaszek C. F. , Bruno G. V. , Freed J. H.
Published: February 2004

It is shown how the analysis of Freed et al. for ESR lineshapes in the slow tumbling region may be generalized to include anisotropic liquids. Particular emphasis is given to the case of nitroxide radicals in liquid crystal environments with cylindrically symmetric restoring potentials U (β). It is found that when |U(β)|≲ kT, spectral appearances are qualitatively (but not quantitatively) similar to those for isotropic liquids. In particular, the spectra are sensitive to the model of reorientation. They are also predicted to be a very sensitive indicator of effects of anisotropic viscosity. The analysis given for the motional narrowing region yields analytic expressions for the needed spectral densities, where previously only numerical results had been obtained. The analytic expressions are valid when |U(β)|≲ kT. Analytic solutions to the rotational diffusion equation appropriate for |U(β)|≫kT are given and it is outlined how they may be applied to magnetic resonance.
Instability of the uniform antiferromagnetic chain. II. Heisenberg interaction in the Hartree-Fock approximation
Authors: Beni G.
Published: February 2004

We consider a linear antiferromagnetic chain of elastically coupled spins in the Hartree-Fock approximation to the Heisenberg Hamiltonian. The nuclear dynamics is neglected. The instability of the system is investigated and the results are compared with the X-Y model treated in I. It is shown that the Hartree-Fock approximation is essentially equivalent to a renormalization of the exchange integral in the X-Y model.
Semicontinuum model for the trapped dielectron in polar liquids and solids
Authors: Feng Da-Fei , Feuki Kenji , Kevan Larry
Published: February 2004

A semicontinuum model for trapped dielectrons, two electrons in the same cavity, has been developed and applied to liquid ammonia, water, ice at 77°K, and methyltetrahydrofuran and amine glasses at 77°K. In all matrices the configurational stability of the ground state of the dielectron has been established, and the dielectron is found to be stable with respect to two single trapped electrons. In general the cavity radius for the dielectron is slightly smaller than that for the single electron. The excited state of the dielectron is bound, and only slight shifts of the optical absorption band of the dielectron compared to the single electron are predicted.
Distorted-atoms-in molecules model for ordinary covalent molecules. I Description of model; connection with distinguishable electron method; and illustrative application to H2, LiH, and BeH+
Authors: Kirtman B. , Chang S. Y. , Scott W. R.
Published: February 2004

A simple, but accurate, unrestricted orbital product approximation for the spatial electronic wavefunction of ordinary covalent molecules is developed. Each orbital consists of a pure atomic function which is rescaled in the molecule and, then, polarized by a variable effective internal field. Thus, the molecular orbitals are expressed in terms of known atomic polarization functions. Illustrative calculations on H2, LiH, and BeH+, utilizing single Slater-type orbitals as the undistorted atomic functions, give 50%–75% of the maximum possible energy improvement over the restricted Hartree-Fock model. It is shown how our distorted-atoms-in-molecules (DAM) approximation can be employed together with the distinguishable electron perturbation method to determine first-and second-order physical properties to within about 10%. We also express the hope that the error in computed electron correlation energies can be reduced to less than 1 kcal/mole per electron pair. Of course, DAM may be used directly to estimate physical properties with medium (∼ 40%) accuracy.
Near-resonant vibration↔ rotation energy transfer
Authors: Poulsen Lise Lotte , Houston Paul L. , Steinfeld J. I.
Published: February 2004

A theory of vibration→ rotation energy transfer, which takes specific account of near resonances between quantized vibrator and rotor energy levels, is derived. This theory is in good agreement with experimental data on the deactivation of BCl3(ν4=1 Δ E=243 cm−1) by HCl and DCl, and in fair agreement with data for BCl3 with H2, HD, and D2. Theories that treat the rotor classically do not adequately predict these transition probabilities. The effect of using a first Born approximation is compared to a two-level close-coupled calculation, and the effect of a modified-wave-number approximation is examined; neither of these approximations materially affect the results. The PHCl/PDCl ratio is predicted to decrease from large values at low temperatures to nearly unity at higher temperatures.
Properties of the benzene molecule near the Hartree-Fock limit
Authors: Ermler W. C. , Kern C. W.
Published: February 2004

The ground electronic state of the benzene molecule is studied with a (9s5p1d/4s1p)/[4s2p1d/2s1p] contracted Gaussian basis set in the traditional Hartree-Fock approximation. It is estimated that the Hartree-Fock limit is approached within 0.07 ± 0.02 a.u. Technical problems associated with large-scale calculations of this type are discussed. One-electron properties are determined, including second moments, average diamagnetic shielding constants, Hellmann-Feynman forces, electric-field gradients, and charge densities. Comparisons are made with the available experimental data and with other calculations.
Determination of proton affinity from the kinetics of proton transfer reactions. II. Kinetic analysis of the approach to the attainment of equilibrium
Authors: Bohme D. K. , Hemsworth R. S. , Rundle H. W. , Schiff H. I.
Published: February 2004

A detailed kinetic analysis of the approach to and attainment of equilibrium in proton transfer reactions proceeding in a flowing afterglow at 300°K has been developed by extending existing analyses for ion molecule reactions to include axial diffusion and back reaction. The analysis has been applied to the experimental data obtained for the reactions H3+ + N2⇄N2H+ + H2 and CO2H+ + CH4⇄CH5+ + CO2 proceeding in a large excess of H2 gas. The latter reaction was investigated independently in both directions. The forward and reverse rate constants, kf and kr, were uniquely determined under nonequilibrium conditions for both reaction systems, and in the case of the CO2H++CH4 system, this was accomplished both in the forward and in the reverse direction. The ratios of rate constants determined under nonequilibrium conditions were found to be equal, within experimental error, to the equilibrium constant, K, determined from the equilibrium concentrations. Furthermore, in the case of the CO2H++CH4 system, for which it was possible to attain equilibrium conditions from either side of the reaction, the rate constants and the equilibrium constant were observed to be independent of the direction of approach to equilibrium.
On the temperature dependence of the effective hard sphere diameter
Authors: Wilhelm Emmerich
Published: February 2004

For a number of solvents, the effective hard sphere diameter at several temperatures is determined from gas solubility data using the expression of the scaled particle theory of the work of cavity formation. From the results, the linear coefficients of expansion l1 of the effective hard core diameter are calculated and discussed in relation to values determined by other methods.
Fine structure of para-H2 d(3p) 3Πu (ν = 0–3) via microwave optical magnetic resonance induced by electrons
Authors: Freund Robert S. , Miller Terry A.
Published: February 2004

The MOMRIE (microwave optical magnetic resonance induced by electrons) spectrum of para-H2 d(3p) 3Πu has been measured in vibrational levels ν = 0–3 for the lowest rotational state (N = 1). The theory previously used to analyze the MOMRIE spectrum of ortho-H2 is also used here, but with the addition of terms to account for the effects of the magnetic and electric susceptibilities. Least squares fits of the MOMRIE spectral lines provide values of the so-called spin-orbit and spin-spin coupling constants, the orbital g factor, and the susceptibilities. Comparison of these values with corresponding values for ortho-H2 reveals significant breakdown of the Born-Oppenheimer approximation. Zero field fine structure separations and level crossing magnetic fields have been calculated from the molecular parameters. They agree with previous experimental measurements but are considerably more extensive and more accurate. The radiative lifetime, as determined from the MOMRIE linewidth, is 29.4±3.2 nsec.
Evaluation of linear chain partition functions by computer derivation of secular equations. I. General technique; Titration of rigid macromolecules
Authors: Poland Douglas
Published: February 2004

A technique is presented whereby the secular equation of a moderately large matrix whose elements are more or less complicated combinations of a few basic statistical weights is obtained by computer expansion of the appropriate determinant. Given the analytic form for the secular equation the numerical task of obtaining average quantities is greatly reduced: the computation of the largest eigenvalue reduces to a linear scan of the secular equation; and from the explicit form of the secular equation one can derive explicit analytic expressions for desired derivatives of any order in terms of the largest eigenvalue. As an example, the secular equations describing the titration of a rigid macromolecule are given for the correlation of up to five consecutive binding sites. The systematic variation of terms in the secular equations derived suggests a form for the leading terms of the secular equation in the general case of an infinite range of correlation. The possibilities and limitations of the technique are discussed.
Evaluation of linear chain partition functions by computer derivation of secular equations. II. Multiple adsorption on a linear lattice
Authors: Poland Douglas
Published: February 2004

The secular equations describing a simple model of multiple adsorption of particles on a linear lattice with interaction between neighboring stacks of adsorbed particles are derived by computer for varying number of particles permitted at a given site. The over-all form of the secular equation is easily generalized and as the number of particles correlated is increased the number of common terms in the respective secular equations also increases. The latter fact means that by examining successively larger and larger matrices, one obtains increasing information about the secular equation for the infinite matrix. While we are able to generalize in detail only the first two terms of the secular equation for the infinite matrix, we do obtain the leading terms of the complete secular equation and further detail for the beginning terms.
Absorption spectrum of BkCl3
Authors: Carnall W. T. , Fried S. , Wagner F.
Published: February 2004

The absorption spectrum of thin films of BkCl3 was measured in the region ∞ 3800–48 000 cm−1 at 298°, 77°, and 4°K. The absence of transitions from the ground state to excited J=0 and J=1 states, together with the number of crystal field components observed in several isolated groups, suggested that the ground level BkCl3 is characterized by the crystal quantum number μ=0, as is the case in LaCl3:Tb3+. Assignments were made based in part on a predicted energy level scheme which assumed a systematic variation in energy level parameters over the actinide series. The free-ion electrostatic, spin orbit, and configuration interaction parameters for Bk3+ were calculated by a least squares fitting process involving 23 level assignments.
Molecular dynamics study of dimer formation
Authors: Harrison Herman W. , Schieve William C.
Published: February 2004

Molecular dynamics studies have been conducted with a dilute atomic gas interacting with the Lennard-Jones (6–12) potential. Previously dimers, two particle-bound states, have been shown to form in these finite two-dimensional models. The dimer mole fraction is determined for nine systems with different temperatures and density and is found to agree with the theoretical dependences predicted by Stogryn and Hirschfelder. These results are also shown to be consistent with experimental measurements by Milne and Greene and by Leckenby and Robbins. The reaction rate constant, K3, for the formation of argon dimers was observed to vary as T−1/3 and be independent of density. The steric factor for formation of dimers varies from 0.07 to 0.18 in the temperature range considered.
Series expansions for Franck-Condon factors. I. Linear potential and the reflection approximation
Authors: Gislason E. A.
Published: February 2004

A series expansion for Franck-Condon factors is obtained for a bound-to-continuum transition in the case of a linear potential for the continuum state. The first term in the series is the result obtained from the ``reflection'' approximation. A similar series is obtained for a bound-to-bound transition. The effect of nonlinearity in the potential is considered, and an approximate correction factor is derived. These results are compared with exact calculations on real systems.
Dielectric tensor of anthracene as a function of temperature and pressure
Authors: Munn R. W. , Nicholson J. R. , Schwob H. P. , Williams Digby F.
Published: February 2004

The complete dielectric tensor of anthracene single crystals has been measured by a low-frequency capacitative technique at temperatures between −40 and 60°C and at pressures between 1 and 3000 bar. At 295°K the principal components are 2.62±0.03, 2.94±0.03, and 4.08±0.08, with the 1 axis making an angle of 26°± 2° with the + a-axis. In the range studied, the temperature reduces the anisotropy of the dielectric tensor, individual components changing by amounts of the order of 2% per 100°K. The pressure dependence is also linear except at the highest pressures; individual components change by no more than 1% per kbar. These results are discussed in terms of the packing of the molecules and their polarizability.
Raman intensity and conjugation. III. Conjugation and resonance Raman effect on the Raman intensities of diphenylpolyenes
Authors: Schmid E. D. , Brosa B.
Published: February 2004

We have measured the Raman intensities of the phenyl ring vibrations near 1600 cm−1 and the C=C stretching vibrations of the polyene chain of four diphenylpolyenes Ph-(CH=CH)n-Ph with n varying from 1 to 4. All measurements have been carried out in sufficiently dilute CCl4 solutions. The results we obtained can be interpreted quantitatively in terms of a simple relation by which the Raman intensity is given by S=const. fBK. By definition, the fB factor describes quantitatively the resonance Raman effect on the observed intensities whereas the value of the K factor is a measure of the conjugation effect. This relation can be justified empirically for the present investigation. The influence of the conjugation effect on the relative Raman intensities of the phenyl ring vibrations is particularly large. In contrast the conjugation effect on the relative intensities of the C=C stretching vibrations of the polyene chain is extremely small. Both vibrations exhibit clearly a near-resonance type behavior which turns out to be uniform.
Photodissociative production of O(1S) from CO2, O2, O3, and N2O at the 1216-Å Lyman-α line
Authors: Ridley B. A. , Atkinson R. , Welge K. H.
Published: February 2004

The production of O(1S) in the photodissociation of CO2, O2, O3, and N2O has been investigated at the 1216-Å Lyman-α line. Relative quantum yields at this wavelength have been determined: φN2O: φCO2:φO2: φO3=1.0:(0.31 ± 0.06):(0.03 ± 0.01):<0.03. These must be upper limits for the absolute quantum yields.
Perturbation theory and ionic models for alkali halide systems. I Diatomics
Authors: Brumer P. , Karplus M.
Published: February 2004

Exchange perturbation theory is used to analyze the interaction energy and dipole moment of alkali halide diatomics. It is shown that classical ionic models for these systems can be derived by introducing a well-defined set of assumptions to simplify the perturbation theory expressions. Further, it is demonstrated that extensions of the models to include distortion effects can be formulated and that these give rise to effective polarizabilities of the ions in the diatomic. Calculated spectroscopic properties based on a model including distortion effects show improved agreement with experimental data for the alkali halides.
Scattering of atomic oxygen from (001) LiF
Authors: Hoinkes H. , Nahr H. , Wilsch H.
Published: February 2004

Thermal beams of atomic oxygen were scattered from the (001) cleavage plane of a LiF crystal. The cleanliness of the surface was monitored by atomic hydrogen diffraction and resonance transitions to bound surface states. The angular distributions of the scattered oxygen atoms consist of a relatively large cosine distribution and a lobe shifted from the specular direction towards the surface normal. The shift depends on surface-temperature and angle of incidence. This dependence can be reproduced quite well by cubes-model calculations. The amount of isotropic scattering is compared to that arising in the scattering of other gases and explained by an adsorption-desorption process.
bcc hard-sphere lattice gas with second-neighbor exclusions
Authors: Riemenschneider Bert R. , Huckaby Dale A.
Published: February 2004

The series method is used to approximate the equation of state of a hard-sphere, body-centered cubic (bcc) lattice gas with second-neighbor exclusions. Padé approximants constructed from the series indicate that an order-disorder phase transition, probably of the first-order type, occurs at ρ1≈ 0.56 ρ0 and Pt/kT=1.4 ρ0, where ρ0 is the density at closest packing.
Factors associated with Hb concentration in children aged 6–59 months in the State of Pernambuco, Brazil
Authors: Osório Mônica M. , Lira Pedro I. C. , Ashworth Ann
Published: February 2004

In 1997, the prevalence of anaemia was 40·9 % among children aged 6–59 months in the State of Pernambuco, north-east Brazil. Using the same sample of children, we have investigated possible reasons for this high prevalence. A representative sample was selected through a three-stage process: proportional systematic random sampling of municipalities in the State, systematic random sampling of census sectors within these municipalities, and finally, simple random sampling of households with children aged 6–59 months to obtain the sample of 650 children. Data collection included demographic, environmental, socio-economic and maternal variables, and nutritional status and dietary intakes of the children. Multiple linear regression analysis was based on a hierarchical model of factors associated with Hb concentration. The mean Hb concentration of children aged 6–23 months was 10 g/l lower than that of older children. In the regression analysis, child age explained 8·3 % of the variance in Hb concentration. The intake of bioavailable Fe explained a further 3·3, serum retinol 2·7, diarrhoea 2·4, water treatment 1·7, sanitation 1·3 and low birth-weight 0·5 %. The final model explained 23·4 % of the variance in Hb concentration. We conclude that child age, bioavailable-Fe intake, serum retinol concentration, diarrhoea, water treatment, sanitation and low birth-weight are independently associated with Hb concentration. In north-east Brazil, anaemia prevention programmes among children should focus on those aged <2 years and should consider feasible strategies to improve intakes of bioavailable Fe and vitamin A, and reduce infection. Supplemental Fe should be given to low birth-weight infants.
Effective Hand Function Assessment After Burn Injuries
Authors: Umraw Nisha , Chan Yvonne , Gomez Manuel , Cartotto Robert C. , Fish Joel S.
Published: January 2004

This study compared two methods of hand function assessment, the Michigan Hand Outcomes Questionnaire (MHQ) and the Test d'Evaluation des Membres Supérieurs des Personnes Agées (TEMPA) in 20 patients discharged from a regional adult burn center (1995–1999). Spearman's rank correlation coefficient analysis was used to compare the MHQ and TEMPA scores, with P < .05 considered significant. The MHQ revealed that 68% of patients reported hand function deterioration, mainly with the nondominant hand (65%). Activities of daily living (76%) and work (59%) were the most affected. According to the MHQ, patient satisfaction correlated with work performance (r = .66, P = .002), aesthetics (r = .64, P = .003), pain (r = .59, P = .008), and activities of daily living (r = .54, P = .017). The MHQ indicated more hand function deterioration than the TEMPA. There was a significant correlation between the MHQ and TEMPA total scores (r = .68, P = .001). This study supports using the MHQ to determine which patients would benefit from the more resource-consuming TEMPA.
Self-Reported Quality of Life After Electrical and Thermal Injury
Authors: Cochran Amalia , Edelman Linda S. , Saffle Jeffrey R. , Morris Stephen E.
Published: January 2004

Electrical injury patients (EI) often require more procedures and longer hospital stays than their thermal injury counterparts. We hypothesized that postinjury quality of life might be better in thermal injury patients (TIs) than in EI. Each EI recorded in our institution's TRACS™/ABA registry between 1995 and 2000 was matched with a TI for age and TBSA involvement. We compared SF-36 scores of EI and TIs to evaluate quality of life. Age and TBSA injury were similar between groups. SF-36 results demonstrated no significant differences in self-reported quality of life indices. Return to full-time employment did not differ significantly between groups. EI and TIs do not differ significantly in quality of life after their burn injuries. Self-evaluated function for EI and TIs is comparable. Quality of life in both EI and TIs are above population means on many dimensions.
Blood Transfusion in Burns: What Do We Do?
Authors: Palmieri Tina L. , Greenhalgh David G.
Published: January 2004

Over 11 million units of blood are transfused yearly in the United States. Although blood transfusion is common in burns, data are lacking on appropriate transfusion thresholds. The purpose of the study was to identify current burn center physician blood transfusion practices. A 30-question survey of blood transfusion practices was developed and sent to burn center directors. The survey assessed demographics, burn experience, and blood transfusion thresholds. Physicians were asked to list factors affecting their blood transfusion thresholds and then to give their blood transfusion threshold for patients based on age and percent burn. The final section presents three case scenarios with alterations in one physiological parameter to assess the effect on transfusion thresholds. A total of 55 of the 180 surveys (31%) were returned. Mean number of burn beds was 15.7 ± 1.4, with 264 ± 25 burn admissions per year. The respondents had been in burn care for 15.9 ± 1.4 years. Their mean hemoglobin transfusion threshold was 8.12 ± 1.7g/dl. The most frequent reasons for transfusion were ongoing blood loss (22%), anemia (20%), hypoxia (13%), and cardiac disease (12%). Inhalation injury influenced the decision to transfuse blood in 34%. The hemoglobin level below which respondents would transfuse blood increased with increasing TBSA burn, history of cardiac disease, acute respiratory distress syndrome, and age. Blood transfusion thresholds in burns vary based on burn percentage, age, and presence of cardiac disease. To date, no standard of care exists for blood transfusions in burns. Future prospective studies are needed to determine the appropriate use of blood in burns.
Procalcitonin in Pediatric Burn Patients: An Early Indicator of Sepsis?
Authors: Neely Alice N. , Fowler Laura A. , Kagan Richard J. , Warden Glenn D.
Published: January 2004

To determine whether changes in procalcitonin (PCT) could be used to predict the onset of sepsis, daily PCT levels were monitored in 20 burned children. Analysis indicated a PCT rise of 5 ng/ml or greater as the best indication of sepsis. We compared the surgeons' determination of sepsis, which was based on changes in platelet count, C-reactive protein (CRP), and other clinical manifestations, with the prediction of sepsis from PCT. There were 26 septic episodes and 36 nonseptic episodes in the 20 patients. PCT results were classified as to true positives, false positives, true negatives, and false negatives. As an indicator of sepsis, the PCT assay had a sensitivity of 42%, a specificity of 67%, and an efficiency of 57%. Even when the assay correctly identified sepsis, the determination was made an average of 0.8 days after the surgeon had already made the diagnosis based on CRP and/or platelet count. We conclude that PCT is not as effective as CRP and/or platelet count in the early detection of sepsis in burned children.
Toxic Epidermal Necrolysis: Does Immunoglobulin Make a Difference?
Authors: Brown K. M. , Silver G. M. , Halerz M. , Walaszek P. , Sandroni A. , Gamelli Richard L.
Published: January 2004

Experimental evidence implicates Fas ligand–mediated keratinocyte apoptosis as an underlying mechanism of toxic epidermal necrolysis syndrome (TEN). In vitro studies indicate a potential role for immunoglobulin (Ig) therapy in blocking Fas ligand signaling, thus reducing the severity of TEN. Anecdotal reports have described successful treatment of TEN patients with Ig; however, no study to date has analyzed outcome data in a large series of patients treated with Ig using institutional controls. The SCORTEN severity-of-illness score ranks severity and predicts prognosis in TEN patients using age, heart rate, TBSA slough, history of malignancy, and admission blood urea nitrogen, serum bicarbonate, and glucose levels. A retrospective chart review was performed that included all patients treated for TEN at our burn center since 1997. Ig therapy was instituted for all patients with biopsy-proven TEN beginning in January 2000. Twenty-one TEN patients were treated before Ig (no-Ig group), and 24 patients have been treated with Ig. SCORTEN data were collected, as well as length of stay (LOS) and status upon discharge. Each patient was given a SCORTEN of 0 to 6, with 1 point each for age greater than 40, TBSA slough greater than 10%, history of malignancy, admission BUN greater than 28 mg/dl, HCO3 less than 20 mg/dl, and glucose greater then 252 mg/dl. Outcome was compared between patients treated with Ig and without Ig. Overall mortality for patients treated before Ig was 28.6% (6/21), and with Ig, mortality was 41.7%% (10/24). There was no significant difference in age or TBSA slough. The average SCORTEN between the groups was equivalent (2.2 in no-Ig group vs 2.7 in Ig group, P = 0.3), and no group of patients with any SCORTEN score showed a significant benefit from Ig therapy. Overall LOS as well as LOS for survivors was longer in the Ig group. This series represents the largest single-institution analysis of TEN patient outcome after institution of Ig therapy. Our data do not show a significant improvement in mortality for TEN patients treated with Ig at any level of severity and may indicate a potential detriment in using Ig. Ig should not be given to TEN patients outside of a clinical trial. A multicenter, prospective, double-blinded randomized trial is necessary and urgently indicated to determine whether Ig therapy is beneficial or harmful in the care of TEN patients.
Burn Injury in Patients With Early-Onset Neurological Impairments
Authors: Alden N. E. , Rabbitts A. , Rolls J. A. , Bessey P. Q. , Yurt R. W.
Published: January 2004

Many patients suffer from sensorimotor deficits that may contribute to burn injury. This retrospective study examines burn injuries in the subgroup of patients that suffer from the early onset neurological impairments of mental retardation, cerebral palsy, spina bifida, autism, and attention deficit–hyperactivity disorder. Fifty-one patients who suffered from the above-mentioned early-onset neurological impairments were admitted to our burn center during a 4-year period. The average TBSA burned was 8.9% yet resulted in prolonged hospitalizations. This study describes our burn center's experience in treating patients admitted with early-onset neurological impairments.
Insulin-Like Growth Factor-I Blocks Dexamethasone-Induced Protein Degradation in Cultured Myotubes by Inhibiting Multiple Proteolytic Pathways
Authors: Li Bing-Guo , Hasselgren Per-Olof , Fang Cheng-Hui , Warden Glenn D.
Published: January 2004

In previous studies, insulin-like growth factor-I (IGF-I) inhibited glucocorticoid-induced muscle protein breakdown, but the intracellular mechanisms of this effect of IGF-I are not well understood. The purpose of the present study was to test the hypothesis that IGF-I inhibits multiple proteolytic pathways in dexamethasone-treated cultured L6 myotubes. Myotubes were treated with 1 μM dexamethasone for 6 hours in the absence or presence of 0.1 μg/ml of IGF-I. Protein degradation was determined by measuring the release of trichloroacetic acid–soluble radioactivity from proteins prelabeled with 3H-tyrosine. The contribution of lysosomal, proteasomal-dependent, and calpain-dependent proteolysis to the inhibitory effect of IGF-I on protein degradation was assessed by using inhibitors of the individual proteolytic pathways (methylamine, β-lactone, and E64, respectively). In addition, the influence of IGF-I on cathepsin B, proteasome, and calpain activities was determined. Treatment of L6 myotubes with dexamethasone resulted in an approximately 20% increase in protein degradation. This effect of dexamethasone was completely blocked by IGF-I. When the different protease inhibitors were used, results showed that IGF-I inhibited lysosomal, proteasomal-dependent, and calpain-dependent proteolysis by 70, 44, and 41%, respectively. Additionally, IGF-I blocked the dexamethasone-induced increase in cathepsin B, proteasome, and calpain activities. The present results suggest that IGF-I inhibits glucocorticoid-induced muscle proteolysis by blocking multiple proteolytic pathways.
Aquacel Ag® in the Management of Partial-Thickness Burns: Results of a Clinical Trial
Authors: Caruso Daniel M. , Foster Kevin N. , Hermans Michel H.E. , Rick Christina
Published: January 2004

Aquacel® Hydrofiber® is a moisture retentive topical dressing that has been demonstrated to be safe and efficacious for the management of partial-thickness burns, showing parity for most dressing related aspects to cadaver skin for this indication. Recently, 1.2% w/w silver has been added to the Aquacel ® Hydrofiber®, to create Aquacel Ag®. This new material releases silver within the dressing for up to two weeks, and it is this duration that differentiates it from other sustained release silver delivery products indicated for burn management. The dressing was tested in a phase II noncomparative trial in superficial, mid dermal, and mixed partial-thickness burns. Percentage and speed of reepithelialization were satisfactory and appear to be similar at least to results noted with silver sulfadiazine, although, no direct comparisons were performed in this study. Pain reduction between baseline and postburn day number three and five was statistically significant. Conformability, general ease of use and other functional dressing properties were rated very positively. Overall, Aquacel Ag® combines several properties known to be beneficial for the management of partial-thickness burns and is a very good choice for superficial and mid-thickness burn injuries.
Developing an account‐management lifecycle for advertising agency‐client relationships
Authors: Waller David S.
Published: February 2004

This paper will discuss the concept of account management in the area of advertising agency‐client relationships. The main theoretical issues regarding agency‐client relationships are discussed by means of a review of the literature to identify an account‐management lifecycle for agency‐client relationships. Three main stages were identified: agency evaluation/selection; relationship development and maintenance; and agency review/termination. Discussing the literature will also provide a greater understanding of agency‐client relationships and identify possible areas for further research.
Influencing the future of TQM: internal and external driving factors
Authors: McAdam Rodney , Henderson Joan
Published: February 2004

The aim of this paper is to investigate the future of total quality management (TQM) by determining the scope and depth of the influencing or driving factors that will shape the body of knowledge, known as TQM, into the future. The rapid rate of change in global and niche markets has increased pressure on organisations to become more competitive. TQM is not immune from such changes. Rather, TQM theory and practice must continually adapt to be in the vanguard of such change and potential future changes. The research to determine the influencing/driving factors for the future of TQM involved a panoptic literature review and an inductive grounded theory approach using multiple case studies. Overall, the research indicates that both the mechanistic and organismic aspects of TQM will continue into the future, along with the continual representative development of initiatives to meet current and future organisational change. Furthermore, the TQM discourse will remain a challenging research area for both academics and practitioners.
European perspectives on the learning organisation
Authors: Nyhan Barry , Cressey Peter , Tomassini Massimo , Kelleher Michael , Poell Rob
Published: February 2004

This paper, based on a publication entitledFacing up to the Learning Organisation Challenge, published in April 2003, provides an overview of the main questions emerging from recent European research projects related to the topic of the learning organisation. The rationale for focusing on this topic is the belief that the European Union goals related to “lifelong learning” and the creation of a “knowledge‐based society” can only be attained if the organisations in which people work are also organisations in which they learn. Work organisations must become, at the same time, learning organisations. This paper has four main messages. The first is that, in order to build learning organisations, one has to ensure that: there is coherence between the “tangible” (formal/objective) and the “intangible” (informal/subjective) dimensions of an organisation; and that the organisation's learning goals are reconciled with individuals’ learning needs. The complexity involved in ensuring the right balance between these different dimensions, means that in the final analysis one cannot realistically expect more than incomplete or imperfect learning organisations. However, this does not in any way negate the validity of the quest to reconcile these competing but “real” interests. The second message is that challenging or developmental work is a prerequisite for implementing a learning organisation. One of the keys to promoting learning organisations is to organise work in such a way that it promotes human development. The third message is that the provision of support and guidance is essential to ensure that developmental work does in fact provide opportunities for developmental learning. The fourth message is that to address organisational learning there is a need for boundary‐crossing and interdisciplinary partnerships between the vocational education and training and human resource development communities.
Managing service quality in banks: customers’ gender effects
Authors: Spathis Charalambos , Petridou Eugenia , Glaveli Niki
Published: February 2004

This paper discusses the service quality of Greek banks on the basis of their customers’ perceptions, and analyses how gender differences affect customers’ perceptions of service quality dimensions such as effectiveness and assurance, access, price, tangibles, service portfolio, and reliability. The results of an empirical study of 1,260 customers of Greek banks generally support the hypothesis that gender affects service quality perceptions and the relative importance attached to various banking service quality dimensions. This paper provides important information for bank managers to use in developing operational, human resource, and marketing strategies, and in targeting those strategies in terms of the gender differences in quality perceptions among their customers.
Plate 435. Lygeum spartum
Authors: Cope Tom , Nesbitt Mark
Published: January 2004

The taxonomy, distribution and uses of the Mediterranean grass, Lygeum spartum (Gramineae), are discussed; an illustration is provided, together with a full description of the species
Plate 436. Betula papyrifera
Authors: Clennett Chris , Sanderson Helen
Published: January 2004

The taxonomy, distribution, uses and cultural requirements of the North American paper birch, Betula papyrifera Marshall (Betulaceae), are discussed; an illustration is provided, together with a full description.
Plate 438. Pachyphytum coeruleum
Authors: Lucas E. J.
Published: January 2004

Pachyphytum coeruleum J. Meyrán (Crassulaceae), a little–known succulent perennial from Mexico is illustrated. A full description is provided and its taxonomy, relationships, purported distribution and cultivation requirements are discussed.
Plate 439. Glandularia platensis
Authors: Compton James
Published: January 2004

The taxonomy, distribution and cultural requirements of Glandularia platensis (Spreng.) Schnack & Covas (Verbenaceae), are discussed; an illustration and a full description of the species are provided.
Plate 441. Angraecum compactum
Authors: La Croix Isobyl
Published: January 2004

The taxonomy, distribution and cultural requirements of the Madagascan endemic Angraecum compactum Schltr. (Orchidaceae) are discussed; an illustration and a full description of the species are provided.
Chiropterophily: On bat‐flowers and flower‐bats
Authors: Tschapka Marco , Dressler Stefan
Published: January 2004

This paper presents a short introduction to bat pollination (chiropterophily) with emphasis on the Neotropics. Adaptations of plants to the pollination by bats include robustness, specific strategies for advertisement, structures for efficient transmission of pollen and a comparably large nutritional reward. Adaptations of specialised flower–visiting bats improved their ability to find and to exploit flowers in a highly efficient way.
p‐Nonylphenol, 4‐tert‐Octylphenol and Bisphenol A Increase the Expression of Progesterone Receptor mRNA in the Frontal Cortex of Adult Ovariectomized Rats
Authors: Funabashi T. , Nakamura T. J. , Kimura F.
Published: February 2004

Alkylphenols, such as p‐nonylphenol (NP) and 4‐tert‐octylphenol (OP) and bisphenol A (BPA) are thought to mimic oestrogens in their action, and are called endocrine disrupters. We examined whether these endocrine disrupters affected progesterone receptor (PR) mRNA expression in the adult female rat neocortex. In one experiment, at 12.00 h, ovariectomized rats were given a subcutaneous injection of 10 mg of NP, 10 mg of OP or 10 mg of BPA, or sesame oil alone as control. Twenty‐four hours after injection, the left side of the frontal cortex, parietal cortex and temporal cortex was collected. In a second experiment to study the time‐course of the effects of BPA on PR mRNA, the ovariectomized rats were given a subcutaneous injection of 10 mg of BPA and killed 0, 6, 12 and 24 h after injection. In addition to the frontal cortex and temporal cortex, the occipital cortex was also collected. Northern blotting revealed that, in the first experiment, injection of NP, OP or BPA significantly increased PR mRNA expression in the frontal cortex but not in the parietal cortex. In the temporal cortex, BPA significantly decreased PR mRNA, but NP and OP produced no significant changes. The second experiment revealed that, in the frontal cortex, BPA induced a significant increase in PR mRNA expression at 6 h after injection, which lasted until 24 h after injection. In the temporal cortex, PR mRNA expression was significantly decreased 6 h after injection of BPA and was still significantly low 24 h after injection. No significant change was observed in the occipital cortex. These results suggest that, even in adult rats, endocrine disrupters alter the neocortical function by affecting the PR system, although the physiological significance of PR in the affected area is unknown.
Seeing the Light … in a New Way
Authors: Foster Russell G.
Published: February 2004

Summary Research over the past decade has shown that the rods and cones are not the only photoreceptors of the eye. There also exists a population of directly light sensitive ganglion cells that act as brightness detectors and regulate a wide variety of different photosensory tasks, including the regulation of 24‐h circadian clocks, synthesis of the hormone melatonin, pupil size and behaviour. These receptors may even help modulate our mood and sense of well‐being.