bluuebunny/crossref_metadata_2025 huggingface dataset:
Steric asymmetry and lambda-doublet propensities in state-to-state rotationally inelastic scattering of NO(2Π1/2) with He
Authors: de Lange Marc J. L. , Stolte Steven , Taatjes Craig A. , Kłos Jacek , Groenenboom Gerrit C. , van der Avoird Ad
Published: November 2004

Relative integrated cross sections are measured for rotationally inelastic scattering of NO(2Π1/2), hexapole selected in the upper Λ-doublet level of the ground rotational state (j=0.5), in collisions with He at a nominal energy of 514 cm−1. Application of a static electric field E in the scattering region, directed parallel or antiparallel to the relative velocity vector v, allows the state-selected NO molecule to be oriented with either the N end or the O end towards the incoming He atom. Laser-induced fluorescence detection of the final state of the NO molecule is used to determine the experimental steric asymmetry, SA≡(σv↑↓E−σv↑↑E)/(σv↑↓E+σv↑↑E), which is equal to within a factor of (−1) to the molecular steric effect, Si→f≡(σHe→NO−σHe→ON)/(σHe→NO+σHe→ON). The dependence of the integral inelastic cross section on the incoming Λ-doublet component is also observed as a function of the final rotational (j′), spin-orbit (Ω′), and Λ-doublet (ε′) state. The measured steric asymmetries are significantly larger than previously observed for NO-Ar scattering, supporting earlier proposals that the repulsive part of the interaction potential is responsible for the steric asymmetry. In contrast to the case of scattering with Ar, the steric asymmetry of NO-He collisions is not very sensitive to the value of Ω′. However, the Λ-doublet propensities are very different for [Ω=0.5(F1)→Ω′=1.5(F2)] and [Ω=0.5(F1)→Ω′=0.5(F1)] transitions. Spin-orbit manifold conserving collisions exhibit a propensity for parity conservation at low Δj, but spin-orbit manifold changing collisions do not show this propensity. In conjunction with the experiments, state-to-state cross sections for scattering of oriented NO(2Π) molecules with He atoms are predicted from close-coupling calculations on restricted coupled-cluster methods including single, double, and noniterated triple excitations [J. Klos, G. Chalasinski, M. T. Berry, R. Bukowski, and S. M. Cybulski, J. Chem. Phys. 112, 2195 (2000)] and correlated electron-pair approximation [M. Yang and M. H. Alexander, J. Chem. Phys. 103, 6973 (1995)] potential energy surfaces. The calculated steric asymmetry Si→f of the inelastic cross sections at Etr=514 cm−1 is in reasonable agreement with that derived from the present experimental measurements for both spin-manifold conserving (F1→F1) and spin-manifold changing (F1→F2) collisions, except that the overall sign of the effect is opposite. Additionally, calculated field-free integral cross sections for collisions at Etr=508 cm−1 are compared to the experimental data of Joswig et al. [J. Chem. Phys. 85, 1904 (1986)]. Finally, the calculated differential cross section for collision energy Etr=491 cm−1 is compared to experimental data of Westley et al. [J. Chem. Phys. 114, 2669 (2001)] for the spin-orbit conserving transition F1 (j=0.5)→F1f (j′=3.5).
Negative ion photoelectron spectroscopy of acridine molecular anion and its monohydrate
Authors: Kokubo Shinsuke , Ando Naoto , Koyasu Kiichirou , Mitsui Masaaki , Nakajima Atsushi
Published: November 2004

Negative ion photoelectron spectroscopy was employed to investigate the electronic structure of the acridine molecular anion and its monohydrated anion in the gas phase. Their adiabatic electron affinities were measured to be 0.896±0.010 and 1.18±0.05 eV, and the low-lying electronic excited states in both neutral acridine and in its monohydrate were revealed. The photoelectron spectra clearly exhibit the presence of low-lying singlet and triplet states having a (π,π*) configuration in an uncomplexed acridine molecule. Comparison of the photoelectron spectrum of acridine with that of anthracene shows that photodetachment processes into the excited states of (n,π*) configuration have little intensity, implying a relatively large intramolecular structural relaxation in the (n,π*) states.
Elastic behavior of adsorbed polymer chains
Authors: Chen Jin , Zhang Linxi , Cheng Jun
Published: November 2004

Elastic behaviors of single polymer chains adsorbed on the attractive surface are first investigated using Monte Carlo simulation method based on the bond fluctuation model. We investigate the chain size and shape of adsorbed chains, such as mean-square radius of gyration 〈S2〉, mean-square bond length 〈b2〉, shape factors 〈sfi〉 and 〈δ*〉, and the orientation of chain segments P2〈cos θ〉, to illuminate how the shape of polymer chains changes during the process of tensile elongation. There are some special behaviors of the chain size and shape at the beginning of elongation, especially for strong attraction interaction. For example, mean fraction of adsorbed segments decreases abruptly in the region of small elongation ratio and then decreases slowly with increasing elongation ratio. In fact, the chain size and shape also changes abruptly for small elongation ratio with strong attraction interaction. Some thermodynamics properties are also investigated here. Average Helmholtz free energy increases fast for elongation ratio λ<1.15, especially with strong attraction, and increases slowly for λ>1.15. Similar behaviors are obtained for average energy per bond. Elastic force (f ) and energy contribution to force (fU) are also studied, and we find that elastic force decreases abruptly for λ<1.15, and there is a minimum of elastic force for strong attraction interaction, then increases very slowly with increasing elongation ratio. However, there are different behaviors for weak attraction interaction. For energy contribution to force (fU), there is a maximum value for strong attraction interaction in the region of λ<1.15. Some comparisons with the atomic force microscopy experiments are also made. These investigations may provide some insights into the elastic behaviors of adsorbed polymer chains.
Electrokinetic instabilities in thin microchannels
Authors: Storey Brian D. , Tilley Burt S. , Lin Hao , Santiago Juan G.
Published: November 2004

An important class of electrokinetic, microfluidic devices aims to pump and control electrolyte working liquids that have spatial gradients in conductivity. These high-gradient flows can become unstable under the application of a sufficiently strong electric field. In many of these designs, flow channels are thin in the direction orthogonal to the main flow and the conductivity gradient. Viscous stresses due to the presence of these walls introduce a stabilizing force that plays a major role in determining the overall instability. A thin channel model for fluid flow is developed and shown to provide good agreement with a complete three-dimensional model for channel aspect ratios ≲0.1.
Electron mobility exceeding 160000cm2∕Vs in AlGaN∕GaN heterostructures grown by molecular-beam epitaxy
Authors: Manfra M. J. , Baldwin K. W. , Sergent A. M. , West K. W. , Molnar R. J. , Caissie J.
Published: December 2004

We report on the transport properties of a two-dimensional electron gas (2DEG) confined in an AlGaN∕GaN heterostructure grown by plasma-assisted molecular-beam epitaxy on a semi-insulating GaN template prepared by hydride vapor phase epitaxy with a threading dislocation density of ∼5×107cm−2. Using a gated Hall bar structure, the electron density (ne) is varied from 4.1to9.1×1011cm−2. At T=300mK, the 2DEG displays a maximum mobility of 167000cm2∕Vs at a sheet density of 9.1×1011cm−2, corresponding to a mean-free-path of ∼3μm. Shubnikov–de Haas oscillations, typically not observed at magnetic fields below 2T in GaN, commence at B=0.6T.
Microstructural characterization of L1 FePt/MgO nanoparticles with perpendicular anisotropy
Authors: Zhang Y. , Wan J. , Skumryev V. , Stoyanov S. , Huang Y. , Hadjipanayis G. C. , Weller D.
Published: December 2004

L 1 0 FePt nanoparticles with perpendicular magnetic anisotropy were fabricated on a heated MgO substrate by using an atomic deposition technique. The microstructure of the FePt nanoparticles was studied by transmission electron microscopy and high resolution transmission electron microcopy. The as-made L10 FePt nanoparticles are isolated and have a faceted morphology with a bimodal distribution of particle size as small as 2.5 nm. A semicoherent atomic interface between the FePt nanoparticles and the MgO substrate is observed. The room temperature coercivity of these FePt nanoparticles was measured via both superconducting quantum interference device and magneto-optical Kerr effect techniques and found to be as high as 6.7 kOe.
Imaging based on the ultrasonic vibration potential
Authors: Beveridge Andrew C. , Wang Shougang , Diebold Gerald J.
Published: December 2004

An ultrasonic wave traversing a colloidal suspension causes distortion of the charge distributions at the sites of individual colloidal particles producing a voltage known as the ultrasonic vibration potential. We show how imaging of colloidal regions within a body can be carried out using a beam of ultrasound to produce a radio frequency vibration potential. A theory for image formation shows that Fourier transformation of vibration potential signals processed by a mixer and low pass filter gives the spatial distribution of colloid. The salient feature of the method, insofar as medical imaging is concerned, is its contrast mechanism.
Optical waveguiding in BaTiO3∕MgO∕AlxOy∕GaAs heterostructures
Authors: Chen D. , Murphy T. E. , Chakrabarti S. , Phillips J. D.
Published: December 2004

Thin films of BaTiO3 with MgO buffer layers were deposited on patterned GaAs substrates incorporating AlxOy for optical confinement. The inclusion of AlxOy layers are used to provide a means for obtaining thick optical confinement layers as a substitute for MgO cladding layers which have large thermal expansion mismatch with respect to GaAs and BaTiO3 that typically result in thin film cracking. Deposition on patterned features was found to reduce thin film cracking and is attributed to a reduction in thin film stress resulting from thermal expansion mismatch. A maximum ridge width of 10–20 μm is estimated for 1-μm-thick BaTiO3 thin films. Optical waveguiding was observed in BaTiO3∕MgO∕GaAs∕AlxOy∕GaAs ridges suggesting the potential application of these structures for integrated optoelectronics.
Subnanosecond magnetization reversal in magnetic nanopillars by spin angular momentum transfer
Authors: Tulapurkar A. A. , Devolder T. , Yagami K. , Crozat P. , Chappert C. , Fukushima A. , Suzuki Y.
Published: December 2004

Sub-ns magnetization switching has been triggered by spin momentum transfer in pulsed current in pillar shaped CoFe∕Cu∕CoFe trilayers. By analyzing the change in magneto-resistance induced after the application of individual short current pulses (100ps–10ns), we measured the probability of magnetization reversal as a function of the current pulse magnitude, polarity and duration, at various temperatures between 150 and 300K. At all studied temperatures, the reversal process can take place within a few 100ps. The energy cost of the reversal scales favorably with the switching speed and decreases in the 1pJ range when using 100ps current pulses at 300K. Significantly higher switching speeds are obtained at lower temperatures, which is opposite to a thermal activation of the reversal.
Optical properties of nanometer-sized gold spheres and rods embedded in anodic alumina matrices
Authors: Stoleru V. G. , Towe E.
Published: December 2004

This letter discusses theoretical studies of optical properties of gold nanospheres and nanorods with various aspect ratios; these are embedded in a porous anodic alumina matrix. The nanoparticles have potential applications in optical filters and sensors.
Controlling the electronic structure of nanocrystal assemblies by variation of the particle-particle interaction
Authors: Bostedt C. , van Buuren T. , Willey T. M. , Terminello L. J.
Published: December 2004

The change in the electronic structure of germanium nanocrystals is investigated as their concentration is increased from noninteracting, individual particles to assembled arrays of particles. The electronic structure of the individual nanoclusters shows clear effects due to quantum confinement which are lost in the concentrated assemblies of bare particles. When the surface of the individual particles is passivated, they retain their quantum confinement properties also upon assembly. These effects are interpreted in terms of a particle-particle interaction model.
Near-field-enhanced, mold-assisted, parallel direct nanostructuring of a gold thin film on glass
Authors: Shao D. B. , Li S. F. , Chen S. C.
Published: December 2004

In this report, near-field enhancement around nanoridges and nanotips upon 532nm pulsed laser irradiation is utilized to produce line or dot pattern on gold thin films deposited on glass substrates. The ridges and tips, which have end radii on the order of 50nm, were fabricated out of silicon dioxide thin film on silicon by microfabrication techniques. A 30nm chromium thin film was evaporated onto the ridges or tips by e-beam evaporation to enhance the near-field effect. Line and dot array were successfully patterned on the Au film with feature size ranging from 100 to 200nm. Results from numerical simulation using finite difference time domain method agree with experimental results.
In situ synthesis of MgB2 thin films for tunnel junctions
Authors: Schneider R. , Geerk J. , Ratzel F. , Linker G. , Zaitsev A. G.
Published: December 2004

An approach to the in situ preparation of as-grown MgB2 thin films is presented. It comprises a conventional B sputter gun and a special Mg evaporator that provides a high Mg vapor pressure at the position of the substrate. Thin films deposited on r-plane sapphire substrates at a temperature of 440°C had a zero resistance Tc of 33K and a residual resistivity of 111μΩcm. Sandwich-type tunnel junctions with a natural MgB2 oxide as the potential barrier were prepared for superconducting tunneling spectroscopy. Voltage-dependent conductance measurements revealed estimates of the barrier thickness, height, and shape.
Film-thickness-dependent Curie-Weiss behavior of (Ba,Sr)TiO3 thin-film capacitors having Pt electrodes
Authors: Park Woo Young , Hwang Cheol Seong
Published: December 2004

This study investigated the variations in the dielectric constant with film thickness and measurement temperature of (Ba0.48Sr0.52)TiO3 thin-film capacitors with thicknesses ranging from 65 to 273 nm. The films were prepared by an on-axis rf magnetron sputtering, having Pt top and bottom electrodes. The thicker film showed a higher dielectric constant with a larger temperature dependence of the dielectric constant, and the maximum dielectric constant was observed at a higher temperature. The thickness-dependent dielectric constant at a given measurement temperature was explained by using the previously reported interfacial capacitance model, containing the intrinsic dead layer and electrode polarization. The temperature-dependent dielectric property could be explained using a modified Curie-Weiss (C-W) behavior of the film taking the nonferroelectric interfacial capacitance components into consideration. However, the C-W constant and Curie temperature of the ferroelectric layer must be modified in order to obtain a reasonable interfacial layer thickness.
Hydrocarbon detection via ion implantation in metal–insulator–semiconductor devices
Authors: Medlin J. Will , Bastasz Robert , McDaniel Anthony H.
Published: December 2004

A method for using metal–insulator–semiconductor (MIS) sensors to detect hydrocarbons is described. In this method, hydrocarbon gases are ionized and focused in an energetic beam onto the surface of a MIS device using an ion gun. This detection scheme is found to be selective to hydrogen-containing compounds, with other species yielding no detectable response. The magnitude of the sensor response is found to be a strong function of the current flux and beam energy. These results suggest that ion implantation in MIS devices may be a useful sensing strategy for detection of various combustible gases.
The role of Auger recombination in the temperature-dependent output characteristics (T=∞) of p-doped 1.3 μm quantum dot lasers
Authors: Fathpour S. , Mi Z. , Bhattacharya P. , Kovsh A. R. , Mikhrin S. S. , Krestnikov I. L. , Kozhukhov A. V. , Ledentsov N. N.
Published: December 2004

Temperature invariant output slope efficiency and threshold current (T0=∞) in the temperature range of 5–75 °C have been measured for 1.3 μm p-doped self-organized quantum dot lasers. Similar undoped quantum dot lasers exhibit T0=69K in the same temperature range. A self-consistent model has been employed to calculate the various radiative and nonradiative current components in p-doped and undoped lasers and to analyze the measured data. It is observed that Auger recombination in the dots plays an important role in determining the threshold current of the p-doped lasers.
Free carrier absorption in Be-doped epitaxial AlGaAs thin films
Authors: Rinzan M. B. M. , Esaev D. G. , Perera A. G. U. , Matsik S. G. , Von Winckel G. , Stintz A. , Krishna S.
Published: December 2004

Free hole absorption in doped AlxGa1−xAs films, grown by molecular-beam epitaxy on semi-insulating GaAs substrates, was investigated. Free carrier absorption for three different hole concentrations with the same Al fraction and for two different Al fractions with the same doping concentration was studied. Experimental absorption coefficients were obtained from the data using a model that includes multiple reflections in the substrate wafer. In the 100–400μm range, (3,5,8)×1018cm−3 Be-doped Al0.01Ga0.99As films have absorption coefficients of ∼(3,3.5,5)×103cm−1, respectively, where the magnitude of the absorption is found to be almost independent of the wavelength. This allows replacing doped GaAs emitters in heterojunction interfacial work function internal photoemission far-infrared (HEIWIP) detectors with p-AlxGa1−xAs layers with x<0.017 facilitating the extension of the threshold wavelength of HEIWIP detectors beyond the 92μm limit due to the practical Al fraction growth limit of 0.005 in molecular-beam epitaxy.
Enhancement of nonlocal spin-valve signal using spin accumulation in local spin-valve configuration
Authors: Kimura T. , Hamrle J. , Otani Y. , Tsukagoshi K. , Aoyagi Y.
Published: December 2004

We propose a nonlocal spin-valve measurement combined with a local spin-valve structure to enlarge spin signal. The probe configuration consists of a lateral spin valve with three Ni–Fe wires bridged by a Cu wire. The advantage is that the spin polarization in the Cu wire induced by the spin injection can be enhanced compared to the conventional method.
Thermal accumulation effect in three-dimensional recording by picosecond pulses
Authors: Juodkazis Saulius , Misawa Hiroaki , Maksimov Igor
Published: December 2004

In-bulk recording without cracking in borosilicate glass by high repetition rate (80 MHz) 12 ps pulses at 355 nm wavelength is demonstrated and discussed. The theoretical model of a “hot-line” scan and thermal accumulation qualitatively well describes the experimental results. The analytical expression of a thermally induced stress was obtained.
Magnetic nanobraids of iron-doped amorphous silica
Authors: Xu C. X. , Sun X. W. , Yu M. B. , Xiong Yong Zhong , Dong Z. L. , Chen J. S.
Published: December 2004

Using silicon, iron oxide, and graphite powders as source materials, braid-like nanostructures of iron-doped amorphous silica were fabricated by vapor-phase transport. Each braid was composed of a bunch of entangled nanowires with uniform size. The formation of the nanobraids was mainly due to simultaneous nucleation in a vapor–liquid–solid process. Magnetic measurement showed that the iron-doped silica nanobraids were ferromagnetic at room temperature.
Fragile-to-strong liquid transition in deeply supercooled confined water
Authors: Faraone A. , Liu L. , Mou C.-Y. , Yen C.-W. , Chen S.-H.
Published: November 2004

Confining water in lab synthesized nanoporous silica matrices MCM-41-S with pore diameters of 18 and 14 Å, we have been able to study the molecular dynamics of water in deeply supercooled states, down to 200 K. Using quasielastic neutron scattering and analyzing the data with the relaxing cage model, we determined the temperature variation of the average translational relaxation time and its Q-dependence. We find a clear evidence of an abrupt change of the relaxation time behavior at T≈225 K, which we interpreted as the predicted fragile-to-strong liquid–liquid transition.
The Use of Counterfactual Scenarios as a Means to Assess Policy Deadweight: An Irish Case Study
Authors: Lenihan Helena , Hart Mark
Published: November 2004

The evaluation of industrial policy interventions has attracted increasing policy and academic attention in recent years. Despite the widespread consensus regarding the need for evaluation, the issue of how to evaluate, and the associated methodological considerations, continue to be issues of considerable debate. The authors develop an approach to estimate the net additionally of financial assistance from Enterprise Ireland to indigenously owned firms in Ireland for the period 2000 to 2002. With a sample of Enterprise Ireland assisted firms, an innovative, self-assessment, in-depth, face-to-face, interview methodology was adopted. The authors also explore a way of incorporating the indirect benefits of assistance into derived deadweight estimates—an issue which is seldom discussed in the context of deadweight estimates. They conclude by reflecting on the key methodological lessons learned from the evaluation process, and highlight some pertinent evaluation issues which should form the focus of much future discussion in this field of research.
Women's Enterprise: A Critical Examination of National Policies
Authors: Wilson Laura , Whittam Geoff , Deakins David
Published: November 2004

Against a background of perceptions of women's low participation in entrepreneurship in the United Kingdom, this paper critically reviews recent policy developments in the provision of public sector support for women in enterprise. The available statistical evidence for women's participation in business ownership in the United Kingdom is reviewed against comparative data from the USA that is promoted by the UK government as a potential benchmark. We argue that programming and resource-issue problems are evidenced in new policies that are a direct consequence of lack of data. Next, policy is tested against various paradigmatic stances in women's enterprise support, and problematic areas in poverty alleviation, social inclusion, advocacy, access to finance, and gender mainstreaming are discussed. Selected literature that addresses barriers identified to women's enterprise is reviewed, and issues of confidence, risk, motivation to business start-up, and childcare are discussed in terms of programming. We conclude that, although the Department of Trade and Industry/Small Business Service Strategic Framework for Women's Enterprise in England is flawed, the framework has assembled a broad church of opinions and approaches to women's enterprise support in a democratic, participative, and cross-cutting fashion.
An in vitro study on the ability of polyethylene glycol to inhibit the effect of quebracho tannins and tannic acid on rumen fermentation in sheep, goats, cows, and deer
Authors: Frutos P. , Hervás G. , Giráldez F. J. , Mantecón A. R.
Published: November 2004

Abstract. Batch cultures of rumen microorganisms, using rumen fluids from 4 ruminant species, sheep, goats, cows, and deer, were used to study the ability of polyethylene-glycol (PEG 6000) to inhibit the effect of 2 types of tannins, quebracho (QUE, a condensed tannin) and tannic acid (TA, a hydrolysable tannin) on several in vitro rumen fermentation characteristics. Both QUE and TA were able to impair ruminal fermentation (they reduced gas production, extent of degradation, ammonia-N, and volatile fatty acid concentrations, etc.; P < 0.05), with differences depending on the inoculum donor. The clearest effect of tannins was the reduction of the rates of fermentation, which was observed in all species (P < 0.05). The detrimental effects of tannins were removed by the presence of PEG in most cases, but there were important variations and noticeable exceptions. Thus, for instance, PEG failed to revert the negative effect of TA on the rate of fermentation and the extent of degradation (P < 0.05). The extent of the limited ability of PEG to completely inhibit the negative effects of tannins on in vitro ruminal fermentation seems to depend both on the type of tannin and the species of the rumen inoculum donor.
Identification and modulation of a caveolae-dependent signal pathway that regulates plasminogen activator inhibitor-1 in insulin-resistant adipocytes
Authors: Venugopal Joshi , Hanashiro Kazuhiko , Yang Zhong-Zhou , Nagamine Yoshikuni
Published: November 2004

Plasminogen activator inhibitor-1 (PAI-1) plays an important role in the pathogenesis of obesity-driven type 2 diabetes mellitus and associated cardiovascular complications. Here, we show that perturbation of caveolar microdomains leads to insulin resistance and concomitant up-regulation of PAI-1 in 3T3L1 adipocytes. We present several lines of evidence showing that the phosphatidylinositol 3-kinase (PI3K) pathway negatively regulates PAI-1 gene expression. Insulin-induced PAI-1 gene expression is up-regulated by a specific inhibitor of PI3K. In addition, serum PAI-1 level is elevated in protein kinase Bα-deficient mice, whereas it is reduced in p70 ribosomal S6 kinase 1-deficient mice. The PI3K pathway phosphorylates retinoblastoma protein (pRB), known to release free E2 (adenoviral protein) factor (E2F), which we have previously demonstrated to be a transcriptional repressor of PAI-1 gene expression. Accordingly, cell-penetrating peptides that disrupt pRB–E2F interaction, and thereby release free E2F, are able to suppress PAI-1 levels that are elevated during insulin-resistant conditions. This study identifies a caveolar-dependent signal pathway that up-regulates PAI-1 in insulin-resistant adipocytes and proposes a previously undescribed pharmacological paradigm of disrupting pRB–E2F interaction to suppress PAI-1 levels.
slo
K
+
channel gene regulation mediates rapid drug tolerance
Authors: Ghezzi Alfredo , Al-Hasan Yazan M. , Larios Leo E. , Bohm Rudolf A. , Atkinson Nigel S.
Published: November 2004

Changes in neural activity caused by exposure to drugs may trigger homeostatic mechanisms that attempt to restore normal neural excitability. In
Drosophila
, a single sedation with the anesthetic benzyl alcohol changes the expression of the
slo
K
+
channel gene and induces rapid drug tolerance. We demonstrate linkage between these two phenomena by using a mutation and a transgene. A mutation that eliminates
slo
expression prevents tolerance, whereas expression from an inducible
slo
transgene mimics tolerance in naïve animals. The behavioral response to benzyl alcohol can be separated into an initial phase of hyperkinesis and a subsequent phase of sedation. The hyperkinetic phase causes a drop in
slo
gene expression and makes animals more sensitive to benzyl alcohol. It is the sedative phase that stimulates
slo
gene expression and induces tolerance. We demonstrate that the expression level of
slo
is a predictor of drug sensitivity.
Striatin assembles a membrane signaling complex necessary for rapid, nongenomic activation of endothelial NO synthase by estrogen receptor α
Authors: Lu Qing , Pallas David C. , Surks Howard K. , Baur Wendy E. , Mendelsohn Michael E. , Karas Richard H.
Published: November 2004

Steroid hormone receptors (SHRs) are ligand-activated transcription factors that regulate gene expression. SHRs also mediate rapid, nongenomic cellular activation by steroids. In vascular endothelial cells, the SHR for estrogen, estrogen receptor (ER) α, is targeted by unknown mechanisms to a functional signaling module in membrane caveolae that enables estrogen to rapidly activate the mitogen-activated protein kinase and phosphatidylinositol 3–Akt kinase pathways, and endothelial NO synthase (eNOS). Here we identify the 110-kDa caveolin-binding protein striatin as the molecular anchor that localizes ERα to the membrane and organizes the ERα–eNOS membrane signaling complex. Striatin directly binds to amino acids 183–253 of ERα, targets ERα to the cell membrane, and serves as a scaffold for the formation of an ERα–Gαi complex. Disruption of complex formation between ERα and striatin blocks estrogen-induced rapid activation mitogen-activated protein kinase, Akt kinase, and eNOS, but has no effect on ER-dependent regulation of an estrogen response element-driven reporter plasmid. These findings identify striatin as a molecular scaffold required for rapid, nongenomic estrogen-mediated activation of downstream signaling pathways. Furthermore, by demonstrating independent regulation of nongenomic vs. genomic ER-dependent signaling, these findings provide conceptual support for the potential development of “pathway-specific” selective ER modulators.
Tyrosine phosphorylation sites on FRS2α responsible for Shp2 recruitment are critical for induction of lens and retina
Authors: Gotoh N. , Ito M. , Yamamoto S. , Yoshino I. , Song N. , Wang Y. , Lax I. , Schlessinger J. , Shibuya M. , Lang R. A.
Published: November 2004

Early development of the lens and retina depends upon reciprocal inductive interactions between the embryonic surface ectoderm and the underlying neuroepithelium of the optic vesicle. FGF signaling has been implicated in this signal exchange. The docking protein FRS2α is a major mediator of FGF signaling by providing a link between FGF receptors (FGFRs) and a variety of intracellular signaling pathways. After FGF stimulation, tyrosine-phosphorylated FRS2α recruits four molecules of the adaptor protein Grb2 and two molecules of the protein tyrosine phosphatase Shp2, resulting in activation of the Ras/extracellular signal-regulated kinase (ERK) and phosphatidylinositol-3 kinase/Akt signaling pathways. In this report, we explore the role of signaling pathways downstream of FRS2α in eye development by analyzing the phenotypes of mice that carry point mutations in either the Grb2-(
Frs2
α

4F

) or the Shp2-binding sites (
Frs2
α

2F

) of FRS2α. Although
Frs2
α

4F/4F

mice exhibited normal early eye development, all
Frs2
α

2F/2F

embryos were defective in eye development and showed anophthalmia or microphthalmia. Consistent with the critical role of FRS2α in FGF signaling, the level of activated extracellular signal-regulated kinase in
Frs2
α

2F/2F

embryos was significantly lower than that observed in wild-type embryos. Furthermore, expression of Pax6 and
Six3
, molecular markers for lens induction, were decreased in the
Frs2
α

2F/2F

presumptive lens ectoderm. Similarly, the expression of
Chx10
and
Bmp4
, genes required for retinal precursor proliferation and for lens development, respectively, was also decreased in the optic vesicles of
Frs2
α

2F/2F

mice. These experiments demonstrate that intracellular signals that depend on specific tyrosine residues in FRS2α lie upstream of gene products critical for induction of lens and retina.
General practitioners' detection and management of patients with a dual diagnosis: Implications for education and training
Authors: MARSHALL KELLIE L. , DEANE FRANK P.
Published: November 2004

General practitioners (GPs) are in a unique position to detect and manage patients with co‐morbid mental health and substance use disorders (dual diagnosis). It has been estimated that over 30% of patients presenting to general practice have a diagnosable mental disorder and 12% have dual diagnosis. Unfortunately, between 30 and 50% of these problems go undetected in general practice. Limited GP education and training in mental health may account for this deficit, with a little over 8% of GPs receiving any formal postgraduate training in mental health. Prior to developing an educational resource for GPs, the present study aimed to establish baseline estimates of GP treatment practices with patients who have dual diagnosis. Two GP division‐wide surveys of screening, assessment and treatment for dual diagnosis were conducted one year apart. In addition, five GPs conducted a clinical audit of 508 patient consultations. Results indicate that without ongoing targeted interventions, patient management activities such as GP counselling, use of screening devices, referral to specialist services, coordination and use of EPC items are not likely to improve and are at risk of declining.
Implementing integrated treatment for co‐existing substance use and severe mental health problems in assertive outreach teams: training issues
Authors: GRAHAM HERMINE L.
Published: November 2004

This study sought to evaluate systematically training and implementation of a specific integrated treatment approach for co‐occurring problem substance use and mental health within existing assertive outreach (AO) teams. The AO team was treated as a whole unit rather than as individual clinicians. They were provided with training and supervision to deliver a cognitive‐behavioural integrated treatment approach. In a quasi‐experimental time‐lag design three teams were trained immediately and two others after an 18‐month delay. There was evidence that teams acquired confidence and skills relevant to working with combined problems and that these gains were maintained over time. These results were replicated in the two teams trained after the delay. This study suggests that training mental health staff to use an integrated treatment approach is well Recieved and produces lasting changes in confidence and skills. However, there are a number of issues related to staff training, shifting attitudes and implementation of integrated approaches into routine mental health practice. These issues are considered and suggestions made for staff training.
Human Nature and Economic Institutions: Instinct Psychology, Behaviorism, and the Development of American Institutionalism
Authors: Asso Pier Francesco , Fiorito Luca
Published: November 2004

Recent articles have explored from different perspectives the psychological foundations of American institutionalism from its beginning to the interwar years (Hodgson 1999; Lewin 1996; Rutherford 2000a, 2000b; Asso and Fiorito 2003). Other authors had previously dwelled upon the same topic in their writings on the originsand development of the social sciences in the United States (Curti 1980; Degler 1991; Ross 1991). All have a common starting point: the emergence during the second half of the nineteenth century of instinct-based theories of human agency. Although various thinkers had already acknowledged the role of impulses and proclivities, it was not until Darwin's introduction of biological explanations into behavioral analysis that instincts entered the rhetoric of the social sciences in a systematic way (Hodgson 1999; Degler 1991). William James, William McDougall, and C. Lloyd Morgan gave instinct theory its greatest refinement, soon stimulating its adoption by those economists who were looking for a viable alternative to hedonism. At the beginning of the century, early institutionalists like Thorstein Veblen, Robert F. Hoxie, Wesley C. Mitchell, and Carleton Parker employed instinct theory in their analysis of economic behavior. Their attention wasdrawn by the multiple layers of interaction between instinctive motivation and intentional economic behavior. Debates on the role of instinctsin economicswere not confined to the different souls of American Institutionalism, and many more “orthodox” figures, like Irving Fisher or Frank Taussig, actively participated.
Differential Vaginal Expression of Interleukin‐1 System Cytokines in the Presence of Mycoplasma hominis and Ureaplasma urealyticum in Pregnant Women
Authors: Doh Kunihiko , Barton Parrin T. , Korneeva Irina , Perni Sriram C. , Bongiovanni Ann Marie , Tuttle Sara L. , Skupski Daniel W. , Witkin Steven S.
Published: November 2004

Objective: The genital mycoplasmas, Ureaplasma urealyticum and Mycoplasma hominis, are commonly identified in the vagina of healthy pregnant women. However, these microorganisms are the most common isolates from the amniotic fluids of women in preterm labor. The mechanisms responsible for vaginal colonization and ascent
to the uterus remain undetermined. We evaluated the association between U. urealyticum and M. hominis vaginal colonization and the presence of pro‐inflammatory and anti‐inflammatory interleukin‐1 system
components in asymptomatic pregnant women of different ethnicities.

Methods: Vaginal specimens, obtained from 224 first trimester pregnant women, were assayed for interleukin‐ 1β (IL‐1β) and IL‐1 receptor antagonist (IL‐1ra) concentrations by ELISA. U. urealyticum and M. hominis vaginal colonization were identified by polymerase chain reaction (PCR).

Results: Vaginal colonization with M. hominis was identified in 37 (16.5%) women, and was more prevalent in black (18.9%) and Hispanic (20.9%) than in white (4.2%) women (p = 0.01). U. urealyticum was present in 84 (37.5%) women and there was no ethnic disparity in its detection. M. hominis colonization was associated with elevated median vaginal IL‐1β concentrations in both black women (p=0.02) and Hispanic women (p = 0.04), and was unrelated to vaginal IL‐1ra concentrations. In marked contrast, U. urealyticum colonization was associated with elevations in vaginal IL‐1ra levels, but not with IL‐1β concentrations, in black women (p = 0.02) and Hispanic women (p < 0.0001) and marginally in white women (p = 0.06).

Conclusion:M. hominis colonization in healthy pregnant women is associated with localized pro‐inflammatory immune activation, while U. urealyticum colonization is associated with immune suppression.
Usage of Antifungal Drugs for Therapy of Genital CandidaInfections, Purchased as Over‐the‐Counter Products or by Prescription: 1. Analyses of a Unique Database
Authors: Mårdh Per-Anders , Wågström Jolanta , Landgren Maria , Holmén Jan
Published: November 2004

Objectives: To present sales figures of antifungal drugs for treatment of genital Candida infections in females, which had been purchased in the Swedish county of Skåne (with approximately 1.2 million inhabitants) during
the 1990s. To study the relative proportions of the drugs sold by prescription and as over‐the‐counter (OTC) products.

Methods: Sales figures of antifungal drugs for therapy of vulvovaginal candidiasis (VVC) and such recurrent infections (RVVC), for the years 1990–99, were collected from the ‘ACS’ database of the National Corporation
of Swedish Pharmacies.

Results: The study showed an increase in sales of the type of drugs studied from 45 000 packages in 1990 until mid‐93/94, when approximately 70 000 packages were sold (mainly azoles for topical use and fluconazole for oral intake). Thereafter there was a decrease until the end of November 1999, when 54 000 packages were
purchased. Of the total sales, 93% were OTC products. Sales of clotrimazole and econazole (for vaginal installation) in 1993–1994 were equal to 85–90 packages/1000 women in the age group 15–45 years. Extremely high sales volumes of fluconazole and itraconazole, for one single year each, could be explained by marketingrelated activities directed to the medical community.

Conclusions: As many women with RVVC are not cured by iatrogenic initiatives and women consider themselves able to diagnose episodes of genital Candida infection, affected women generally turn to selfmedication
with antifungal OTC products. This stresses the role of pharmacy counseling. Short‐term marked alterations in sales volumes may be due to marketing factors rather than changes in the epidemiology of genital Candida infections.
Experience With Routine Vaginal pH Testing in a Family Practice Setting
Authors: Pavletic Adriana J. , Hawes Stephen E. , Geske Jenenne A. , Bringe Kathy , Polack Susan H.
Published: November 2004

Background: Despite recommendations by Centers for Disease Control and the American College of Obstetricians and Gynecologists, pH testing is infrequently performed during the evaluation of vaginitis. Consequently, little information exists on its use in a primary care setting.

Objective: The aim of this study was to describe our experience with routine pH testing, particularly the relationship between symptoms, pH and wet‐mount microscopy.

Method: A retrospective chart review was performed on 203 consecutive cases evaluated for vaginitis by wet‐mount microscopy.

Results: Of the 203 cases, 21 had normal pH and no symptoms and 182 had symptoms, elevated pH or both; 85% of cases had abnormal wet‐mount findings, including 75% with clue cells, 14% withTrichomonas vaginalis, 13% with yeast and 14% with mixed infections. Asymptomatic infection was present in 42% of cases with clue cells alone, 44% of cases with Trichomonas vaginalis alone, 38% of all trichomoniasis cases and 33% of cases with mixed infections. Elevated pH was associated with clue cells (p < 0.001), trichomoniasis (p = 0.01) and mixed infections (p = 0.003). Normal pH was associated with negative wet mount (p < 0.001) and to a lesser degree with uncomplicated vulvovaginal candidiasis (p = 0.06).

Conclusion: Routine pH testing increased detection of trichomoniasis and bacterial vaginosis by prompting microscopy in a significant proportion of asymptomatic cases.
Early literacy achievement of children with a history of speech problems
Authors: Hesketh Anne
Published: November 2004

Background: There are conflicting reports in the research literature of the literacy outcome of children with speech disorder. The link between phonological awareness and literacy in typically developing and literacy delayed children is well established, but there is less research specifically into children with an isolated speech disorder (i.e. with age‐appropriate language skills). There is a clinical need for clarification on their likely outcome as a group and for a means of predicting those individuals who might need support in literacy development.

Aims: To assess literacy and phonological awareness skills at age 6;6–7;6 years in children with a history of speech disorder, and to identify factors in their early profile that were predictive of later achievement.

Methods & Procedures: Thirty‐five children who had participated in an earlier therapy research study agreed to further assessment of their speech, language and literacy abilities. The children had originally been recruited between the ages of 3;6 and 5;0 years as having a moderate‐to‐severe speech disorder, and there were measures at that time of their non‐verbal, language, phonological output and phonological awareness abilities. Follow‐up assessments of phonological awareness, speech and early literacy were undertaken.

Outcomes & Results: As a group, the children had made good progress in speech and showed phonological awareness and literacy development at an age‐appropriate level. However, a small number of children had phonological awareness and literacy delay. Phonological awareness at 3;6–5;0 years was the best predictor of literacy achievement.

Conclusions: Speech and language therapists can be confident about the early literacy achievement of most children with isolated speech disorder, but should undertake assessment of phonological awareness to identify those children whose phonological awareness skills after speech intervention continue to be low.
Adenylyl Cyclase Expression and Regulation During the Differentiation of Dictyostelium Discoideum
Authors: Kriebel Paul , Parent Carole
Published: November 2004

Cyclic AMP metabolism is essential for the survival of the social amoebae Dictyostelium discoideum. Three distinct adenylyl cyclases are expressed and required for the normal development of this simple eukaryote. The adenylyl cyclase expressed during aggregation, ACA, is related to the mammalian and Drosophila G protein‐coupled enzymes and is responsible for the synthesis of cAMP that is required for cell‐cell signaling in early development. ACB harbors histidine kinase and response‐regulator domains and is required for terminal differentiation. Finally, the adenylyl cyclase expressed during germination, ACG, acts as an osmosensor and is involved in controlling spore germination. Together, these enzymes generate the various levels of cAMP that are required for D. discoideum to transition from uni‐ to multi‐cellularity. This review will highlight the properties of these enzymes and describe the signaling cascades that lead to their activation. IUBMB Life, 56: 541‐546, 2004
Kinetochore-driven formation of kinetochore fibers contributes to spindle assembly during animal mitosis
Authors: Maiato Helder , Rieder Conly L. , Khodjakov Alexey
Published: November 2004

It is now clear that a centrosome-independent pathway for mitotic spindle assembly exists even in cells that normally possess centrosomes. The question remains, however, whether this pathway only activates when centrosome activity is compromised, or whether it contributes to spindle morphogenesis during a normal mitosis. Here, we show that many of the kinetochore fibers (K-fibers) in centrosomal Drosophila S2 cells are formed by the kinetochores. Initially, kinetochore-formed K-fibers are not oriented toward a spindle pole but, as they grow, their minus ends are captured by astral microtubules (MTs) and transported poleward through a dynein-dependent mechanism. This poleward transport results in chromosome bi-orientation and congression. Furthermore, when individual K-fibers are severed by laser microsurgery, they regrow from the kinetochore outward via MT plus-end polymerization at the kinetochore. Thus, even in the presence of centrosomes, the formation of some K-fibers is initiated by the kinetochores. However, centrosomes facilitate the proper orientation of K-fibers toward spindle poles by integrating them into a common spindle.
A Highly Ca2+-sensitive Pool of Granules Is Regulated by Glucose and Protein Kinases in Insulin-secreting INS-1 Cells
Authors: Yang Yan , Gillis Kevin D.
Published: November 2004

We have used membrane capacitance measurements and carbon-fiber amperometry to assay exocytosis triggered by photorelease of caged Ca2+ to directly measure the Ca2+ sensitivity of exocytosis from the INS-1 insulin-secreting cell line. We find heterogeneity of the Ca2+ sensitivity of release in that a small proportion of granules makes up a highly Ca2+-sensitive pool (HCSP), whereas the bulk of granules have a lower sensitivity to Ca2+. A substantial HCSP remains after brief membrane depolarization, suggesting that the majority of granules with high sensitivity to Ca2+ are not located close to Ca2+ channels. The HCSP is enhanced in size by glucose, cAMP, and a phorbol ester, whereas the Ca2+-sensitive rate constant of exocytosis from the HCSP is unaffected by cAMP and phorbol ester. The effects of cAMP and phorbol ester on the HCSP are mediated by PKA and PKC, respectively, because they can be blocked with specific protein kinase inhibitors. The size of the HCSP can be enhanced by glucose even in the presence of high concentrations of phorbol ester or cAMP, suggesting that glucose can increase granule pool sizes independently of activation of PKA or PKC. The effects of PKA and PKC on the size of the HCSP are not additive, suggesting they converge on a common mechanism. Carbon-fiber amperometry was used to assay quantal exocytosis of serotonin (5-HT) from insulin-containing granules following preincubation of INS-1 cells with 5-HT and a precursor. The amount or kinetics of release of 5-HT from each granule is not significantly different between granules with higher or lower sensitivity to Ca2+, suggesting that granules in these two pools do not differ in morphology or fusion kinetics. We conclude that glucose and second messengers can modulate insulin release triggered by a high-affinity Ca2+ sensor that is poised to respond to modest, global elevations of [Ca2+]i.