bluuebunny/crossref_metadata_2025 huggingface dataset:
Dependence of 19F chemical shielding on internal coordinates in CF4, SiF4, and BF3
Authors: Jameson Cynthia J.
Published: February 2003

The thermal average of chemical shielding for CF4-, BF3-, SF6-, HCN-, CO2-, and NH3-type molecules is explicitly expressed in terms of molecular constants such as fundamental frequencies and elements of the L matrix for the totally symmetric vibration, Coriolis constants, moments of inertia, and cubic force constants kss′s′. Expressions for the klss cubic force constants for a BF3-type molecule are derived and values of klss are calculated for CF4, SiF4, and BF3. The thermal average of chemical shielding calculated using these cubic force constants is compared with the experimental temperature dependence of the 19F NMR signal, yielding values of (∂σ/∂R) for CF4, SiF4, and BF3. Despite the large differences in chemical shifts the values of (∂σ/∂R) obtained are nearly identical: 1115, 1170, and 1115 ppm/Å, respectively.
Fermi resonance and vibrational relaxation in the A 2Σ state of NCO in solid argon
Authors: Bondybey V. E. , English J. H.
Published: February 2003

The overall rates of vibrational relaxation in the A 2Σ+ state of NCO are slow compared with its radiative lifetime of 170 nsec. There is, on the other hand, a fast relaxation between levels known to be in Fermi resonance and only the lowest level of each Fermi resonance group is observed in emission. Progressions in the ground state bending frequency can be observed in the emission spectra and demonstrate clearly the Renner splitting in the ground electronic state.
Orientational relaxation of a Fokker–Planck fluid of symmetric top molecules
Authors: Evans Glenn T.
Published: February 2003

Orientational correlation functions and correlation times are calculated for a dense fluid of symmetric top molecules using a rotational Fokker–Planck (FP) equation. The method of solution is a frequency domain cumulant expansion. In dense fluids, collisions dominate the dynamics wherein free rotational streaming can be treated perturbatively. Using an approximate resummation of the cumulant series it is shown that orientational correlation times for symmetric tops, rotors, and spherical tops display the structure τl =I⊥/[kBTl (l+i) τJ,⊥] +τJ,⊥(1−hl), where hl is a small correlation which depends on particle shape. The logarithm of the correlation function for long times depends linearly on time with a t=0 intercept which is greater than unity. On the basis of the intercept, one can easily distinguish FP correlation functions from those derived from the Gordon models.
Thermal rate constant for Ar+++Ar→2Ar+
Authors: Howorka F.
Published: February 2003

The thermal rate constant for partial charge exchange of Ar++ in collisions with Ar has been measured in the pressure range 0.1–0.55 Torr using the radial method in the negative glow of a cylindrical hollow cathode in pure argon. The rate constant is found to be k =4.1±2.1×10−13 cm s−1, independent of pressure.
Effect of diluent on dielectric relaxation time of polymers
Authors: Mashimo Satoru
Published: February 2003

The theory of concentration dependence of dielectric relaxation time for a polymer solution has been developed using the Kramers theory of rate constant and the free volume theory. A simple expression has been derived, which explains quite satisfactorily the experimental data for the concentration dependence of the relaxation time over the whole concentration range except in the dilute solution region.
Close-coupling studies of the orientation dependence of rotationally inelastic collisions
Authors: Alexander Millard H.
Published: February 2003

Orientation effects in rotationally-inelastic Ar–N2 collisions are investigated using a quantum close-coupling description of the collision dynamics to obtain differential and integral mj-dependent cross sections for the j=0→2,4,6 and j=2→4,6 transitions. For a model potential surface which contains a substantial degree of long-range anisotropy, the inelastically scattered products are significantly polarized with respect to a quantization axis perpendicular to the scattering plane. With respect to the initial relative velocity vector, the products are preferentially aligned in the mj=0 state, in agreement with earlier predictions based on the l-dominant limit. The mj-dependence of the integral cross sections corresponding to an initially unpolarized beam can be well fit by a Gaussian distribution when the anisotropy is long-ranged, but are essentially statistical when the anisotropy is primarily repulsive in nature. Independent of the nature of the anisotropy, the classical alignment angle appears to be conserved during inelastic collisions.
Vibrational spectra, structure, and barrier to planarity of perfluoro-1,3-butadiene
Authors: Wurrey C. J. , Bucy W. E. , Durig J. R.
Published: February 2003

The infrared spectra of gaseous and solid perfluoro-1,3-butadiene have been recorded from 4000 to 30 cm−1. Raman spectra of this compound have also been obtained for the gaseous, liquid, and solid phases. The vibrational data are shown to be consistent with a gauche (C2) structure for this molecule and a vibrational assignment has been proposed. Analysis of the torsional frequencies observed in both the Raman and far infrared spectra yields a barrier to planarity at the trans conformation of 986±150 cm−1 (2.85 kcal/mole).
Formation and predissociation of CO+2(? 2Σ+g)
Authors: Eland John H. D. , Berkowitz Joseph
Published: February 2003

The discrepancy between photoionization mass spectrometry and photoelectron spectroscopy in the CO+/O+ ratio from CO2 at 584 Å is resolved by new measurements. New features in the photoelectron spectrum of CO+2(? 2Σ+g) lead to a new vibrational analysis, with vibration frequencies close to those of CO2(?1 Σ+g). The observations are discussed in terms of a perturbation of the ? 2Σ+g state by the ionization continuum of either the ? 2Πg state or the 4Πu state of CO+2.
The percentage of bound–continuum character in the optical transition of trapped electron absorption bands, and the fate of quasifree electrons
Authors: Nguyen Tuan Q. , Walker David C.
Published: February 2003

The actual percentage of bound–free character in the optical transition of the trapped electron in 9.5M LiCl/D2O aqueous glasses at 77 K has been measured at 694 nm and found to be 3.7%±1.8%. Consequently, about 96% of the transition probability must be to bound excited states at 694 nm, which is 100 nm (or 0.31 eV) on the red side of the band maximum. This measurement has taken account of the number of photoreleased electrons which are retrapped and of those electrons which are bleached by indirect secondary processes. It differs, therefore, from previous measurements of the quantum yield of net bleaching as obtained by ’’steady-state’’ methods. The information was procured by evaluating both the quantum yield for net loss of trapped electrons (e−vis) and the quantum yield for the production of the infrared-absorbing electron state (e−ir). The latter measurement was used to estimate the fraction of photoreleased electrons which were retrapped as e−vis, by assuming that the relative probability of forming e−ir or e−vis was the same regardless of whether quasifree electrons were generated by photolysis or radiolysis. Samples of e−vis were produced by γ radiolysis at 77 K in glasses made from various concentrations of LiCl in D2O. They were bleached by 15 ns pulses of 694 nm light from a Q-switched ruby laser and the resulting absorption changes within 100 ns were analysed at 633 and 1850 nm. For LiCl concentrations between 6.5 and 15M only 20% to 35% of the quasifree electrons which were generated by 694 nm photolysis were lost by reaction in these γ-irradiated glasses. The distribution between trapping as e−vis or e−ir on the other hand was strongly dependent on LiCl concentration.
Electron correlation effects on the excitation energies of the lowest triplet states of glyoxal
Authors: Dykstra Clifford E. , Lucchese Robert R. , Schaefer Henry F.
Published: February 2003

In an attempt to understand the ordering of excited states of glyoxal the 1Ag ground state and low-lying triplet states 3Au, 3Bu, and 3Bg have been studied with ab initio correlated wavefunctions. A double zeta basis set was used in the configuration interaction calculations, and ∼6000 Slater determinants were selected for each electronic state. The predicted CI adiabatic excitation energies Te are 21 800 cm−1 (3Au), 25 100 cm−1 (3Bu), and 29 300 cm−1 (3Bg). The effects of d functions and higher (than double) excitations (unlinked clusters) have also been evaluated. For the 3Bu state, both d functions and higher excitations raise the predicted Te value by perhaps as much as 5 000 cm−1. For the 3Bg state, d functions raise the predicted excitation energy but higher excitations have the opposite effect. It is concluded that the excitation energy of the 3Bu state is dramatically increased by correlation effects, while Te for the 3Au and 3Bg states is markedly decreased by correlation.
The spin-optimized SCF general spin orbitals. Theoretical formulation
Authors: Takatsuka K. , Nagase S. , Yamaguchi K. , Fueno T.
Published: February 2003

A new orbital theory is proposed, in which general spin orbitals (GSO) are introduced in the spin-optimized (SO) SCF scheme. In this SO–SCF–GSO theory, the effective Hamiltonian for each orbital takes the form of a 2×2 matrix composed of the eigenfunctions for two-component spinors. It is found that the GSO’s thus defined should still satisfy a general form of Koopmans’ theorem. The SO–SCF GSO’s are to be obtained by solving two sets of coupled SCF equations for the spin coupling coefficients and the linear combination coefficients for basis functions. Using an STO-6G basis set of the double ζ quality, sample calculations have been carried out for the doublet state of the linear H3 system for which the bond lengths are fixed at 1.470 and 2.984 bohr. The total energy obtained is ∼3 kcal/mole lower than the values which have resulted from the SO–SCF–DODS and the spin-extended Hartree–Fock (SEHF) GSO calculations with the same basis set. The resulting orbitals are found to be more delocalized over the entire system than those obtained by the SO–SCF–DODS theory.
Atomic recombination dynamics on solid surfaces: Effect of various potentials
Authors: McCreery Jane Hylton , Wolken George
Published: February 2003

A model potential for gas–solid interactions has been used to investigate the dynamics of recombination of two atoms initially adsorbed on a solid surface. In the spirit of Polanyi’s investigation into the effect of the potential energy surface on the dynamics of gas-phase reactions, a range of gas–solid potential energy surfaces has been constructed. Classical trajectories have been used to study the dynamics of reactions on those surfaces. It has been found that many of the rules postulated by Polanyi for energy requirements and disposal mechanisms for gas-phase systems are applicable also to the case of recombination of adsorbed atoms to form a gas-phase molecule. Previous work assumed a rigid surface providing a static background potential in which the adsorbed atoms moved. An extension of this model is described in which the rigid surface restriction is relaxed and one or more surface atoms are allowed to move interacting with the adsorbed atoms. Using this potential the rigid surface model is shown to be a good approximation for describing many aspects of recombination dynamics.
A quantum yield determination of O(1D) production from ozone via laser flash photolysis
Authors: Philen D. L. , Watson R. T. , Davis D. D.
Published: February 2003

The quantum yield for O(1D) production from ozone photolysis has been measured at 298 K from 293.0 to 316.5 nm. The O(1D) was monitored by its reaction with N2O to form excited NO2*. The photolysis source was a frequency doubled flashlamp pumped dye laser which provided tunable uv in the desired spectral region with 0.1 nm linewidth. The results show φ to be constant below 300 nm, taken to be unity, with a sharp decrease centered at 308 nm and a value of less than 0.1 above 313.5 nm.
Magnetic shielding and shielding anisotropies by semiempirical molecular orbital theory. I. Inclusion of two-center integrals of the type 〈φB‖𝒪A‖φB〉
Authors: Barfield Michael , Grant David M.
Published: February 2003

Magnetic shielding components are obtained for a number of molecules by means of semiempirical molecular orbital theory in the INDO approximation with inclusion of two-center integrals of the type 〈φμB‖𝒪A‖φνB〉. Exceedingly good results are obtained for calculated values of the diamagnetic shielding as these . 98195
The linear dichroism in a liquid crystalline matrix of 2,4,6-trimethyl pyridine N-oxide. Evidence for out-of-plane components of the absorbed intensity in the region 270–350 nm
Authors: Bendazzoli G. L. , Gottarelli G. , Palmieri P. , Samorĭ B.
Published: February 2003

The linear dichroism of 2,4,6-trimethyl pyridine N-oxide has been measured in the range 270–350 nm in a liquid crystal matrix. With respect to the parent molecule pyridine N-oxide, the trimethyl derivative is closer to the model of a disc shaped molecule and presents a larger energy separation of the two lowest ππ* states. Between the first two absorptions of the molecule, underneath the second intense ππ* absorption, negative contributions to the linear dichroism are observed. Ab initio configuration interaction energies and wavefunctions are obtained with a minimal and a more extended orbital basis. The computed energies, transition intensities, and the dipole moments of the ground and excited states of the molecule are in better agreement with the available spectral properties than the theoretical values in the literature obtained by semiempirical procedures. The most likely assignment of the negative contribution to the linear dichroism is the first excited n→π* state (A2), allowed by vibronic interactions. It is suggested that, as in formaldehyde, an excited state of the molecule (A1,ππ*) exists with a bent structure at the nitrogen atom.
The LCAO representation of Xα-SW molecular orbitals
Authors: Bursten Bruce E. , Fenske Richard F.
Published: February 2003

The Xα-SW molecular orbital method generates one-electron orbitals which are numerical, and hence interpretation of the bonding characteristics of these orbitals must be inferred from electron density maps. In this paper a method is presented for the projection of LCAO MO’s out of the Xα-SW orbitals, based upon maximization of the total overlap. Lagrange multipliers in the method indicate how well the individual projected orbitals overlap the original orbitals. Numerical quadrature over direct space is used to calculate some of the required matrix elements. Results are presented for an extended Slater orbital projection applied to N2.
Thermodynamics of nucleation
Authors: Nishioka Kazumi
Published: February 2003

Employing thermodynamics of a liquid microcluster recently developed by the author the reversible work to form a critical nucleus and the steady state nucleation rate are calculated for argon at 84 and 80 °K. It is found that the capillarity approximation fortuitously gives the approximately correct answer.
Initial and final state effects in the ESCA spectra of cadmium and silver oxides
Authors: Gaarenstroom S. W. , Winograd N.
Published: February 2003

The factors which influence chemical shifts are examined in order to elucidate the cause of the anomalous chemical shifts for Cd and Ag oxides. The effects of extra-atomic relaxation are accounted for using a procedure employing experimental Auger and binding energies. Atomic partial ionic charges for some simple Cd, Ag, and Zn compounds are calculated from experimental binding energies using a model which includes the effects of lattice potentials and extra-atomic relaxation. Inclusion of extra-atomic relaxation effects did not have a drastic effect on the relative ionicities computed for these selected compounds. However, for CdO, a large extra-atomic relaxation energy contribution reduces the binding energy by 0.5 eV more than is predicted from nearest neighbor electronegativity arguments.
Comparison of the thermal and infrared laser induced unimolecular decompositions of allylmethylether, ethylacetate, and isopropylbromide
Authors: Gutman David , Braun Walter , Tsang Wing
Published: February 2003

The thermal and the infrared laser-induced unimolecular decompositions of three molecules, allylmethylether, ethylacetate, and isoproplybromide, have been studied. The thermal decompositions were studied using a single-pulse shock tube and the laser-induced reactions using a 0.63 cm i.d. gas cell with NaCl windows with radiation at 9.28 μ from a Lumonics 203 TEA laser and modest energy fluences (4.5J/cm2). In both studies the molecules were used in pairs (allylmethylether with ethylacetate and isopropylbromide with ethylacetate) so that relative unimolecular rate constants could be accurately determined. Although the products produced in the thermal [where equilibrium kinetics holds] and laser-induced reactions were identical, the relative rate constants showed variations. In the system in which only one reactant absorbed the laser light (ethylacetate in the mixture with isopropylbromide) the ratio of unimolecular rate constants almost reached the thermal value of this ratio at the highest pressures studied (50 torr), but the decomposition of the pumped reactant became dominant in the laser experiments at the lowest pressures (2 torr). A closer adherence to the ’’thermal’’ rate constants were observed in the analogous study of the decomposition of the two molecules which both absorbed the laser light (allylmethylether with ethylacetate). Details of the experiment, the data obtained, and the extent to which multiphoton decomposition of large molecules occur under these ’’mild’’ conditions are discussed.
Perturbation calculation of molecular correlation energy using Gaussian-type geminals. Second- and third-order pair energy of H2
Authors: Adamowicz Ludwik , Sadlej Andrzej J.
Published: February 2003

The perturbation calculations of molecular correlation energy are attempted using Gaussian-type geminals. The second and third order pairing energy of atomic hydrogen to form H2 is calculated. (AIP)
The viscosity of gaseous mixtures containing krypton
Authors: Kestin J. , Khalifa H. E. , Wakeham W. A.
Published: February 2003

The paper describes measurements of the viscosity of binary mixtures of krypton with CO2, CH4, CF4, and SF6 and of the two ternary mixtures, He–Ne–Kr and He–Ar–Kr. The measurements were performed in a high-precision oscillating disk viscometer at atmospheric pressure. The observations extend over the temperature range 25–200 °C for Kr–CH4 and Kr–SF6, 25–400 °C for Kr–CF4, 25–500 °C for Kr–CO2 and He–Ne–Kr, and 25–600 °C for He–Ar–Kr. The uncertainty in the reported viscosities ranges from one of ±0.1% at 25 °C to 0.3% at 600°C. In the case of all of the binary mixtures it is shown that the kinetic theory collision integral for viscosity can be represented by the universal functional Ω22, characteristic of the extended law of corresponding states developed by Kestin, Ro, and Wakeham. The values of the two scaling parameters σij and εij for each interaction, which secure the optimum representation of this kind, are presented. Diffusion coefficients for each binary system are also derived from the experimental data. In the case of the ternary mixtures it has already been established that the viscosity collision integral for each binary interaction conforms to the extended law of corresponding states. Consequently, the present measurements for these systems serve as a test of the ’’predictive’’ capability of a scheme based upon the Curtiss–Hirschfelder expression for the viscosity of multicomponent mixtures and the same law of corresponding states. The calculated and experimental values for the viscosity of these mixtures agree to within ±0.3%.
Raman study of vibrational relaxation in liquid benzene-d6 at high pressure
Authors: Tanabe K. , Jonas J.
Published: February 2003

The Raman line shapes of two totally symmetric bands, ν1 and ν2, and five degenerate bands, ν11, ν15, ν16, ν17, and ν18, have been measured in liquid benzene-d6 as a function of pressure from 50 bar to 4 kbar and over the temperature range 30–120 °C. Some results for liquid benzene are also given. An approximate procedure is used to estimate the vibrational relaxation width for the degenerate Raman bands. The experimental results on vibrational relaxation are interpreted in terms of the vibrational dephasing model. The finding that vibrational relaxation broadening contributes differently to the total width of individual bands represents the most important result of this study. For all bands measured the vibrational relaxation width increases with increasing pressure but the change with temperature seems to be specific for each individual band.
HX, N2 double doping experiments in monatomic matrices: Near infrared spectra and symmetry properties of the intermolecular potential
Authors: Maillard D. , Schriver A. , Perchard J. P. , Girardet C. , Robert D.
Published: February 2003

The infrared spectra of monomeric and dimeric hydrogen halides trapped in mixed nitrogen-rare gas matrices are recorded for various nitrogen–rare gas ratios. The analysis of the displacement of the monomer and dimer band frequencies strongly suggests the formation of HX–nN2 aggregates inside the monatomic crystal when varying this ratio from pure rare gas to pure nitrogen. A convenient analytical form is proposed in order to describe the interaction potential energy between the foreign molecules and the matrix. Numerical procedures based on realistic but tractable models for the representation of the doped crystal structure are then used in order to calculate the conformation of some aggregates inside the crystal and to prove the strong tendency for foreign molecules to agglomerate each other. We can thus explain the behavior of the HX monomer and dimer bands frequencies that decrease when doping with N2 molecules down to a minimum for a N2–rare gas ratio 60%–70% and then increase up to the HX–pure nitrogen frequencies, in terms of a symmetrization process in the conformation of the aggregates around the HX [or (HX)2] molecule.
Observation of new electronic transitions in O2, CO, NO, CO2, and N2O
Authors: Lee J. S.
Published: February 2003

Prominent new peaks in the spectra of O2, CO, NO, CO2, and N2O at energy losses from 18 to 40 eV have been observed by high energy (25 keV) low resolution (2.5 eV) electron impact spectroscopy at squared momentum transfer (K2) values larger than 2 a.u. However, no such isolated features were observed in CS2, C2H2, H2O, SO2, CH4, C2H6, C2H4, benzene, isobutane, methanol, acetone, and trichloroethylene in spite of the presence of significant background oscillator strength. For those molecules in which isolated peaks were observed possible electronic transitions have been suggested.
Unified treatment of intermolecular and thermodynamic potentials of polar fluids. I. Preaveraged intermolecular potential
Authors: von Bergen Rafael , von Bergen Yolanda , Linder Bruno
Published: February 2003

A unified treatment is presented of intermolecular and thermodynamics potentials of polar fluids. The treatment is based on a time-evolution approach which traces the propagation of electrical—and molecular density—fluctuations from the onset of the perturbation to the time equilibrium is fully established. Of prime importance in this development are the relative time scales for establishing electronic, rotational, and translational correlations. The theory is specialized to a system of axially symmetric polar molecules in which the translational correlation time greatly exceeds the rotational correlation time. It is shown that the latter condition leads naturally to an intermolecular potential which is preaveraged over the rotational states of the molecules. An approximate closed-form expression is derived for the fluid free energy in terms of the translational susceptibility of the unperturbed fluid and the intermolecular potential. The latter is formulated in terms of the rotational and dispersion susceptibilities of the molecules and the static (Coulomb) potential. The intermolecular potential can be decomposed into generalized dispersion, orientation, and induction potentials, from which the standard (dipolar) expressions are obtained as special cases. It is shown that in the classical limit, the fluid free energy is consistent with the standard statistical formula for the free energy except that the potential which appears in the configuration integral is angle independent and temperature dependent.
GenePath: a system for automated construction of genetic
networks from mutant data
Authors: Zupan Blaz , Demsar Janez , Bratko Ivan , Juvan Peter , Halter John A. , Kuspa Adam , Shaulsky Gad
Published: February 2003

Motivation: Genetic networks are often used in the analysis of biological phenomena. In classical genetics, they are constructed manually from experimental data on mutants. The field lacks formalism to guide such analysis, and accounting for all the data becomes complicated when large amounts of data are considered.

Results: We have developed GenePath, an intelligent assistant that automates the analysis of genetic data. GenePath employs expert-defined patterns to uncover gene relations from the data, and uses these relations as constraints in the search for a plausible genetic network. GenePath formalizes genetic data analysis, facilitates the consideration of all the available data in a consistent manner, and the examination of the large number of possible consequences of planned experiments. It also provides an explanation mechanism that traces every finding to the pertinent data.

Availability: GenePath can be accessed at http://genepath.org

Contact: gadi@bcm.tmc.edu

Supplementary information: Supplementary material is available at http://genepath.org/bi-supp

* To whom correspondence should be addressed.
GSCope: a clipped fisheye viewer effective for highly complicated biomolecular network graphs
Authors: Toyoda Tetsuro , Mochizuki Yoshiki , Konagaya Akihiko
Published: February 2003

Summary: A graphical tool to visualize highly complicated biomolecular network graphs is described. It helps us to understand the graphs from macroscopic and microscopic viewpoints by incorporating continuous transition from global to clipped hyperbolic projection. GSCope also helps us to find a molecule in the graphs by offering several searching functions. It is useful to publish biomolecular network graphs on the internet.

Availability: GSCope is available at http://gscope.gsc.riken.go.jp

Contact: gscope@gsc.riken.go.jp

* To whom correspondence should be addressed.
Legal responsiveness: a contribution to a structural theory of economic crime
Authors: Hoffman Joan
Published: February 2003

Economic crime is too varied an activity to be explained by a single theory. Valuable insights are gained from theories that focus on individual characteristics and on the socio‐economic context of crime, but these theories are not sufficient explanations of economically motivated crime. They are usefully supplemented by legal responsiveness theory, which focuses on the capacity of the economic system to provide legal means to adapt to economic change. This theory acknowledges the insights of chaos and cellular automata theory into the inevitable and unpredictable nature of economic change. Variation in the system's capacity for legal responsiveness to unpredicted change is hypothesized to have an impact on crime. Economic crime can be an indication of dysfunction in the adaptation systems of the economy. The concepts of ecological and evolutionary economics such as stability, resilience, connectedness and adaptation offer an approach to analyzing the systemic property of legal responsiveness.
Training programmes as incubators
Authors: Erikson Truls , Gjellan Are
Published: February 2003

The point of departure is a temporary university incubator at a European technological university. These incubation programmes are held quarterly, and comprise six parallel developing teams nurturing and qualifying different business ideas into viable business plans. The programme has been successful, in technological, commercial and learning terms. Out of 102 business ideas, at least 57 successful new technology based firms have been created from the incubation programme, and more than 400 students have received significant practical real life hands‐on start‐up experiences, which have resulted in increased start‐up competence and motivation.
The Australian public service under the Keating Government
Authors: Kimber Megan , Maddox Graham
Published: February 2003

Managerial restructuring of the Australian public service during the period of the Keating Government was designed to provide greater responsiveness on the part of public servants to ministers. Increased use of ministerial advisers and the formalisation of contract employment for departmental secretaries pointed to a possible erosion of responsible government norms, but this process was moderated by tension between the private sector practices being introduced and an adherence to the traditions of responsible government. We suggest that a pragmatic approach to public sector reform partly accounted for this unease and we speculate that the more ideological commitment to managerialism displayed by the Howard Government might indicate that responsible government within the Commonwealth Public Service is in further danger of erosion.
Creep behaviour of composite lead‐free electronic solder joints
Authors: Guo F. , Lee J. , Subramanian K.N.
Published: February 2003

In an attempt to improve service life of lead‐free Sn‐based electronic solder joints, compatible reinforcements were introduced by in‐situ and mechanical mixing methods. The reinforcements affect the steady‐state creep rate and the strain for the onset of tertiary creep of the solder joints. However, neither of these parameters, when considered alone, can be used for evaluating the reliability of solder joints. The Larson‐Miller parameter, and a new parameter proposed in the paper, can incorporate test parameters to arrive at a reliability prediction methodology. The role of these reinforcements in homogenising creep strain within the joint is analysed. The observed creep behaviour of these composite solders is discussed on the basis of interfacial bonding strength between the reinforcement and the solder matrix.
Beef labelling: the emergence of transparency
Authors: van Dorp Kees‐Jan
Published: February 2003

Prior to the Bovine Spongiform Encephalopathy (BSE) crisis, detailed information on beef products seemed no real necessity. However, following the outbreak of BSE, the Government felt obliged to protect consumer interest with legislation. Obligatory product information became required for beef traceability. This paper describes how the emergence of beef product information became relevant against the background of BSE. The paper describes the beef sector over time, through two case studies. From both studies, the emergence of product information exchange can be clearly noted. The first study describes the type of information exchanged, before the BSE outbreak. The second study describes the type of information exchanged after the BSE outbreak, prior to compulsory labelling.
Role of Virus Receptor Hyal2 in Oncogenic Transformation of Rodent Fibroblasts by Sheep Betaretrovirus Env Proteins
Authors: Liu Shan-Lu , Duh Fuh-Mei , Lerman Michael I. , Miller A. Dusty
Published: February 2003

The ovine betaretroviruses jaagsiekte sheep retrovirus (JSRV) and enzootic nasal tumor virus (ENTV) cause contagious cancers in the lungs and upper airways of sheep and goats. Oncogenic transformation assays using mouse and rat fibroblasts have localized the transforming activity to the Env proteins encoded by these viruses, which require the putative lung and breast cancer tumor suppressor hyaluronidase 2 (Hyal2) to promote virus entry into cells. These results suggested the hypothesis that the JSRV and ENTV Env proteins cause cancer by inhibiting the tumor suppressor activity of Hyal2. Consistent with this hypothesis, we show that human Hyal2 and other Hyal2 orthologs that can promote virus entry, including rat Hyal2, can suppress transformation by the Env proteins of JSRV and ENTV. Furthermore, we provide direct evidence for binding of the surface (SU) region of JSRV Env to human and rat Hyal2. However, mouse Hyal2 did not mediate entry of virions bearing JSRV or ENTV Env proteins, bound JSRV SU poorly if at all, and did not suppress transformation by the JSRV or ENTV Env proteins, indicating that mouse Hyal2 plays no role in transformation of mouse fibroblasts and that the Env proteins can transform at least some cells by a Hyal2-independent mechanism. Expression of human Hyal2 in mouse cells expressing JSRV Env caused a marked reduction in Env protein levels, indicating that human Hyal2 suppresses Env-mediated transformation in mouse cells by increasing Env degradation rather than by exerting a more general Env-independent tumor suppressor activity.
In Vitro and In Vivo Characterization of a Murine Cytomegalovirus with a Mutation at Open Reading Frame m166
Authors: Zhu Jiaming , Chen Jennifer , Hai Rong , Tong Tuong , Xiao Jianqiao , Zhan Xiaoyan , Lu Sangwei , Liu Fenyong
Published: February 2003

We have recently generated a pool of murine cytomegalovirus (MCMV) mutants by using a Tn
3
-based transposon mutagenesis approach. In this study, one of the mutants, Rvm166, which contained the transposon sequence at open reading frame m166, was characterized both in tissue culture and in immunocompetent BALB/c mice and immunodeficient SCID mice. The viral mutant replicated as well as the wild-type Smith strain in vitro in NIH 3T3 cells, whereas the transposon insertion precluded the expression of >65% of the m166 open reading frame. Compared to the wild-type strain and a rescued virus that restored the m166 region, the viral mutant was significantly attenuated in growth in both BALB/c and SCID mice that were intraperitoneally infected with the viruses. At 21 days postinfection, the titers of the viral mutant in the salivary glands, lungs, spleens, livers, and kidneys of the infected SCID mice were lower than the titers of the Smith strain and the rescued virus by about 30,000-, 10,000-, 1,000-, 300-, and 800-fold, respectively. Moreover, the virulence of the mutant virus appears to be severely attenuated because no death was found in SCID mice infected with the viral mutant up to 90 days postinfection, whereas all of the animals infected with the wild-type and rescued viruses died at 27 days postinfection. Our results suggest that m166 probably encodes a virulence factor and is required for MCMV virulence in killing SCID mice and for optimal viral growth in vivo.
Blood Pressure, Risk of Ischemic Cerebrovascular and Ischemic Heart Disease, and Longevity in α
1
-Antitrypsin Deficiency
Authors: Dahl Morten , Tybjærg-Hansen Anne , Sillesen Henrik , Jensen Gorm , Steffensen Rolf , Nordestgaard Børge G.
Published: February 2003

Background—

Because elastase in α
1
-antitrypsin deficiency may attack elastin in the arterial wall, we tested whether α
1
-antitrypsin deficiency is associated with reduced blood pressure, risk of ischemic cerebrovascular (ICVD) and ischemic heart disease (IHD), and longevity.

Methods and Results—

We genotyped 7963 control subjects from the adult general population of Denmark, 1131 Danish patients with ICVD, and 2221 Danish patients with IHD. Compared with
MM/MS
individuals, systolic blood pressure was lower by 15 mm Hg in
ZZ
homozygotes (n=6,
P
=0.03) and 9 mm Hg in
MZ
heterozygotes with IHD (n=39,
P
=0.02). Odds ratios for ICVD and IHD in
MZ
versus
MM/MS
individuals were 0.70 (0.51 to 0.96) and 0.77 (0.61 to 0.98). Finally, mean ages of
MZ
and
MM/MS
control subjects were 58 and 56 years (Mann-Whitney:
P
=0.008), and relative α
1
-antitrypsin
MZ
genotype frequencies increased from 20 to 93 years among control subjects (χ
2
,
P
=0.002).

Conclusions—

ZZ
α
1
-antitrypsin deficiency and
MZ
intermediate deficiency in the context of IHD are associated with reduced blood pressure, and
MZ
is associated with reduced risk of ICVD and IHD. Because
MZ
heterozygosity was associated with increased age,
MZ
heterozygosity could be a beneficial condition.
Statin Use and Leg Functioning in Patients With and Without Lower-Extremity Peripheral Arterial Disease
Authors: McDermott Mary McGrae , Guralnik Jack M. , Greenland Philip , Pearce William H. , Criqui Michael H. , Liu Kiang , Taylor Lloyd , Chan Cheeling , Sharma Leena , Schneider Joseph R. , Ridker Paul M , Green David , Quann Maureen
Published: February 2003

Background—

We determined whether statin use (versus nonuse) is associated with superior lower-extremity functioning independently of cholesterol levels and other confounders in patients with and without peripheral arterial disease.

Methods and Results—

Participants included 392 men and women with an ankle brachial index (ABI) <0.90 and 249 with ABI 0.90 to 1.50. Functional outcomes included 6-minute walk distance and 4-meter walking velocity. A summary performance score combined performance in walking speed, standing balance, and time for 5 repeated chair rises into an ordinal score ranging from 0 to 12 (12=best). Adjusting for age, sex, ABI, comorbidities, education level, medical insurance status, cholesterol, and other confounders, participants taking statins had better 6-minute walk performance (1276 versus 1218 feet,
P
=0.045), faster walking velocity (0.93 versus 0.89 m/s,
P
=0.006), and a higher summary performance score (10.2 versus 9.4,
P
<0.001) than participants not taking statins. Positive associations were attenuated slightly after additional adjustment for C-reactive protein level but remained statistically significant for walking velocity and the summary performance score. We did not find significant associations between lower-extremity functioning and aspirin, ACE inhibitors, vasodilators, or β-blockers.

Conclusions—

Statin use is associated with superior leg functioning compared with no statin use, independent of cholesterol levels and other potential confounders. These data suggest that non–cholesterol-lowering properties of statins may favorably influence functioning in persons with and without peripheral arterial disease.
Cyclophosphamide metabolism, liver toxicity, and mortality following hematopoietic stem cell transplantation
Authors: McDonald George B. , Slattery John T. , Bouvier Michelle E. , Ren Song , Batchelder Ami L. , Kalhorn Thomas F. , Schoch H. Gary , Anasetti Claudio , Gooley Ted
Published: February 2003

Liver toxicity caused by high-dose myeloablative therapy leads to significant morbidity after hematopoietic cell transplantation. We examined the hypothesis that liver toxicity after cyclophosphamide and total body irradiation is related to cyclophosphamide through its metabolism to toxins. Cyclophosphamide was infused at 60 mg/kg over 1 to 2 hours on each of 2 consecutive days, followed by total body irradiation. Plasma was analyzed for cyclophosphamide and its major metabolites. Liver toxicity was scored by the development of sinusoidal obstruction syndrome (veno-occlusive disease) and by total serum bilirubin levels. The hazards of liver toxicity, nonrelapse mortality, tumor relapse, and survival were calculated using regression analysis that included exposure to cyclophosphamide metabolites (as the area under the curve). Of 147 patients, 23 (16%) developed moderate or severe sinusoidal obstruction syndrome. The median peak serum bilirubin level through day 20 was 2.6 mg/dL (range, 0.5-41.1 mg/dL). Metabolism of cyclophosphamide was highly variable, particularly for the metaboliteo-carboxyethyl-phosphoramide mustard, whose area under the curve varied 16-fold. Exposure to this metabolite was statistically significantly related to sinusoidal obstruction syndrome, bilirubin elevation, nonrelapse mortality, and survival, after adjusting for age and irradiation dose. Patients in the highest quartile ofo-carboxyethyl-phosphoramide mustard exposure had a 5.9-fold higher risk for nonrelapse mortality than did patients in the lowest quartile. Engraftment and tumor relapse were not statistically significantly related to cyclophosphamide metabolite exposure. Increased exposure to toxic metabolites of cyclophosphamide leads to increased liver toxicity and nonrelapse mortality and lower overall survival after hematopoietic cell transplantation.
von Willebrand factor cleaving protease and ADAMTS13mutations in childhood TTP
Authors: Schneppenheim Reinhard , Budde Ulrich , Oyen Florian , Angerhaus Dorothea , Aumann Volker , Drewke Elke , Hassenpflug Wolf , Häberle Johannes , Kentouche Karim , Kohne Elisabeth , Kurnik Karin , Mueller-Wiefel Dirk , Obser Tobias , Santer René , Sykora Karl-Walter
Published: February 2003

Thrombotic thrombocytopenic purpura (TTP) is caused by the persistence of the highly reactive high-molecular-weight multimers of von Willebrand factor (VWF) due to deficiency of the specific VWF-cleaving protease (VWF-CP) ADAMTS13, resulting in microangiopathic disease. The acquired form is caused by autoantibodies against VWF-CP, whereas homozygous or compound heterozygous mutations of ADAMTS13 are responsible for recessively inherited TTP. We investigated 83 children with hemolytic or thrombocytopenic episodes with or without additional neurologic symptoms or renal failure. The presumed diagnosis was chronic idiopathic thrombocytopenic purpura (ITP; n = 50), TTP (n = 8), hemolytic uremic syndrome (HUS; n = 24), and Evans syndrome (n = 1). A severe deficiency of VWF-CP (≤ 5%) was found in all investigated patients with TTP and in none of those with HUS. Additionally, 2 of 50 patients with a prior diagnosis of ITP were deficient for VWF-CP. Antibodies against VWF-CP were found in 4 children. Mutation analysis of the ADAMTS13 gene in the patients deficient in VWF-CP by direct sequencing of all 29 exons identified 8 different mutations, suggesting the hereditary form of TTP in 1 patient with ITP, in the patient with Evans syndrome, and in 5 of the 8 patients with TTP. The phenotype of TTP in childhood can be rather variable. Besides the classical clinical picture, oligosymptomatic forms may occur that can delay the identification of patients at risk.
Validation and application of a high‐performance liquid chromatography/tandem mass spectrometry assay for sumatriptan in human plasma
Authors: Boulton David W. , Duncan Glenn F. , Vachharajani Nimish N.
Published: February 2003

A sensitive and convenient high‐performance liquid chromatography–tandem mass spectrometry(HPLC‐MS/MS) assay is described for the (5‐HTlB/lD) receptor agonist sumatriptan in human plasma. Sumatriptan was recovered from plasma (81.8 ± 6.8%) by liquid–liquid extraction. The mobile phase flow rate was 0.3 mL/min and consisted of methanol:water:formic acid (90:10:0.1, v/v/v). The analytical column (4.6 × 100 mm) was packed with Partisil C8 (5 µm). The standard curve was linear from 0.7 to 70.4 ng/mL (r2 > 0.99). The lower limit of quantitation was 0.7 ng/mL. The assay was specific, accurate (percentage deviation from nominal concentrations were <15%), precise and reproducible (within‐ and between‐day coefficients of variation <10.3%). Sumatriptan in plasma was stable over three freeze/thaw cycles and at room temperature for one day. The utility of the assay was demonstrated by following sumatriptan plasma concentrations in two healthy subjects for 8–12 h following a single 20 mg intranasal dose. Copyright © 2003 John Wiley & Sons, Ltd.
Wein — Qualität entscheidet sich in Nanogramm: Zur Biochemie des sortentypischen Weinaromas
Authors: Wüst Matthias
Published: February 2003

Das sortentypische Aroma der meisten Weine wird durch eine relative kleine Anzahl von geruchsaktiven Verbindungen geprägt, die in der reifenden Weinbeere gebildet werden und im ppb‐bis ppt‐Bereich vorliegen. Es handelt sich hierbei in erster Linie um Monoterpene, C13‐Norisoprenoide, Thiole und Pyrazine. Die Identifizierung dieser Verbindungen sowie die Aufklärung ihrer Biosynthesewege sind wichtige Beiträge zur Entschlüsselung des komplexen Weinaromas.
Crystallographic shear defect in molybdenum oxides: Structure and TEM of molybdenum sub‐oxides Mo18O52 and Mo8O23
Authors: Wang Di , Su Dangsheng , Schlögl Robert
Published: February 2003

Molybdenum trioxide and molybdenum sub‐oxides are of great interests in catalysis due to their utilities as model system to elucidate the correlations between the structure and the catalytic performance. The suboxides are usually an intermediate phase during catalytic reaction in which the lattice oxygen is involved. We show the identification of the two common molybdenum sub‐oxides Mo18O52 and Mo8O23, derived from MoO3 by crystallographic shearing (CS), by means of electron diffraction and High‐Resolution Transmission Electron Microscopy (HRTEM) in combination with image simulation. The coincidence of simulated electron diffraction patterns and high‐resolution images with the experimental ones indicates the feasibility of CS structure determination by these techniques.
Investigation of one‐dimensionally disordered structures of AIIBVI crystals by Monte Carlo technique III. 4H structure with different kinds of stacking faults
Authors: Gosk J. B.
Published: February 2003

To investigate one‐dimensionally disordered (ODD) structures in close packed (cp) crystals, the Monte Carlo computer simulation technique has been applied. Calculations of diffraction intensity distributions along the 10.L reciprocal lattice row from 4H structure with four different kinds of stacking faults (SFs): growth, deformation, layer displacement and extrinsic fault are presented. In particular, using simple frequency function of fault to fault distances, both random and non‐random distributions of SFs are considered. Distinctive features of the diffraction patterns corresponding to the chosen examples of transformations from the parent 4H structure into another small‐period polytypes are discussed in detail.
Synthesis of Amidines Derived from Phosphonates and Phosphane Oxides − Amidine‐Mediated Preparation of Phosphorylated Oxazolines
Authors: Palacios Francisco , Ochoa de Retana Ana María , Pagalday Jaione
Published: February 2003

Alkylation of N‐(phosphorylalkyl)phosphazenes 2 with methyl iodide and allyl bromide and acylation with ethyl chloroformate leads to the formation of aminophosphonium salts 4 derived from (aminoalkyl)phosphonates. N‐(Phosphorylalkyl)amidines 8 were obtained by reaction of phosphazenes derived from aminophosphonates with benzoyl chloride and subsequent addition of amines. These functionalized amidines were used as key intermediates in the synthesis of oxazolin‐4‐ylphosphonates 9 and 10. In a similar manner, oxazolin‐4‐ylphosphane oxides 17 and 18 were prepared from N‐(phosphanylalkyl)amidines 16, which were obtained by reaction of phosphazenes derived from phosphane oxides 15 with benzoyl chloride and amines. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Copper(II) Ion‐Selective Electrodes Based on Dithiosalicylic and Thiosalicylic Acids
Authors: Gismera Ma Jesús , Procopio Jesús Rodriguez , Sevilla Ma Teresa , Hernández Lucas
Published: February 2003

Potentiometric carbon paste electrodes for copper(II) based on dithiosalicylic and thiosalicylic acids are described. The sensor based on dithiosalicylic acid (DTS) exhibits a linear response with a nearly Nernstian slope of 27.7 mV per decade, whereas the electrode based on thiosalicylic acid (TS) shows a super‐Nernstian slope. The limits of detection for the DTS sensor and the TS sensor are 10−7.9and 10−6.3 M for copper(II) activity, respectively. Selectivity coefficients are tabulated, and the influence of the pH on the response of these ISEs is studied. The DTS electrode is successfully used for potentiometric titration of humic acids with copper in order to get more information about complexing properties of these acids.