bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetoresistance behavior of elliptical ring nanomagnets in close proximity with magnetic elements
Authors: Jain S. , Adeyeye A. O.
Published: February 2009

We have investigated the giant magnetoresistance (GMR) responses of the pseudospin valve elliptical rings in close proximity with individual magnetic elements. Significant modifications of the GMR responses were observed due to the effects of magnetostatic coupling between the rings and the magnetic elements. We observed that the vortex state stability is significantly sensitive to the position, orientation of the magnetic elements, and the direction of the applied field. We also investigated the switching field reproducibility of the rings for onion→vortex and vortex→onion transitions and observed that the ring with asymmetrically placed magnetic elements shows the most reproducible switching states.
Origin of the low-energy emission band in epitaxially grown para-sexiphenyl nanocrystallites
Authors: Kadashchuk A. , Schols S. , Heremans P. , Skryshevski Yu. , Piryatinski Yu. , Beinik I. , Teichert C. , Hernandez-Sosa G. , Sitter H. , Andreev A. , Frank P. , Winkler A.
Published: February 2009

A comparative study of steady-state and time-resolved photoluminescence of para-sexiphenyl (PSP) films grown by organic molecular beam epitaxy (OMBE) and hot wall epitaxy (HWE) under comparable conditions is presented. Using different template substrates [mica(001) and KCl(001) surfaces] as well as different OMBE growth conditions has enabled us to vary greatly the morphology of the PSP crystallites while keeping their chemical structure virtually untouched. We prove that the broad redshifted emission band has a structure-related origin rather than being due to monomolecular oxidative defects. We conclude that the growth conditions and type of template substrate impacts substantially on the film morphology (measured by atomic force microscopy) and emission properties of the PSP films. The relative intensity of the defect emission band observed in the delayed spectra was found to correlate with the structural quality of PSP crystallites. In particular, the defect emission has been found to be drastically suppressed when (i) a KCl template substrate was used instead of mica in HWE-grown films, and (ii) in the OMBE-grown films dominated by growth mounds composed of upright standing molecules as opposed to the films consisting of crystallites formed by molecules lying parallel to the substrate.
Multisite reversible geminate reaction
Authors: Park Soohyung , Agmon Noam
Published: February 2009

We provide an analytic solution for diffusion-influenced geminate reaction with multiple (N) reversible binding sites (of which one may be irreversible). The solution obtained in the Laplace domain, for two different initial conditions, is valid for the case when the sites are overlapping spheres with no long-range interactions with the diffusing particle. The possibility to invert into the time domain is determined by a characteristic polynomial. When all its roots are distinct, it is possible to apply the Lagrange interpolation formula and obtain a partial-fraction expansion that can be termwise inverted. At long times the occupancy of all sites, and for all initial conditions, decays as t−3/2. The behavior at short times depends on the initial condition: when starting from contact, the binding probability rises as t1/2, but if the particle is initially bound to one of the sites, the occupancy of the others rises as t3/2. In between these two power laws we observe an intermediate-time kinetics consisting of N decaying exponentials. Those which are slower than a characteristic diffusion time are in the reaction-control regime and fit a discrete-state kinetic approximation with no adjustable parameters, whereas the faster kinetic steps are diffusion controlled. The model solved herein may depict a wide range of physical situations, from multisite proton transfer kinetics to hydrogen-bond dynamics of liquid water.
The effects of plasma density and magnetic field on ion temperature and drift velocity in a LaB6 direct current plasma
Authors: Woo Hyun-Jong , Chung Kyu-Sun , Lee Myoung-Jae , Lho Taihyeop
Published: February 2009

In a LaB6 direct current plasma, parallel and perpendicular ion temperatures (Ti∥ and Ti⊥) were measured as a function of plasma density and magnetic field by a laser-induced fluorescence technique. In order to study the impacts of magnetic field and plasma density on ion temperature and drift velocity, the plasma density was controlled by a magnetic field and discharge current under the following plasma conditions: The magnetic field intensity at the measurement position, BD, was 186–405 G; discharge voltage, Vdis, was 29.9–32.1 V; discharge current, Idis, was 10–22 A; neutral pressures, Pn, were 130 mTorr (in the source region) and 2.2 mTorr (at diagnostic region); plasma density, np, was (2–8)×1012 cm−3; and electron temperature, Te, was ∼2.6 eV. Parallel ion temperature (Ti∥), perpendicular ion temperature (Ti⊥), and drift velocity, vD∥ (or drift kinetic energy, ED) all increase as a function of BD and Idis, such that the total ion energy, Et (=Ti⊥+Ti∥+ED), increases as a function of BD and Idis. From the relations of Ti∥, Ti⊥, and vD∥ to np, ion temperature and drift velocity were observed to be strongly depend on plasma density. In consideration of the collision time scales, ion gyrofrequency, and time of flight from the source to the measurement position, the dominant process for ion heating was observed to be the electron-ion collisions, although the magnetic field and ion-neutral collisions contribute to ion temperature anisotropy.
On a novel rate theory for transport in narrow ion channels and its application to the study of flux optimization via geometric effects
Authors: Abad E. , Reingruber J. , Sansom M. S. P.
Published: February 2009

We present a novel rate theory based on the notions of splitting probability and mean first passage time to describe single-ion conduction in narrow, effectively one-dimensional membrane channels. In contrast to traditional approaches such as transition state theory or Kramers theory, transitions between different conduction states in our model are governed by rates which depend on the full geometry of the potential of mean force (PMF) resulting from the superposition of an equilibrium free energy profile and a transmembrane potential induced by a nonequilibrium constraint. If a detailed theoretical PMF is available (e.g., from atomistic molecular dynamics simulations), it can be used to compute characteristic conductance curves in the framework of our model, thereby bridging the gap between the atomistic and the mesoscopic level of description. Explicit analytic solutions for the rates, the ion flux, and the associated electric current can be obtained by approximating the actual PMF by a piecewise linear potential. As illustrative examples, we consider both a theoretical and an experimental application of the model. The theoretical example is based on a hypothetical channel with a fully symmetric sawtooth equilibrium PMF. For this system, we explore how changes in the spatial extent of the binding sites affect the rate of transport when a linear voltage ramp is applied. Already for the case of a single binding site, we find that there is an optimum size of the site which maximizes the current through the channel provided that the applied voltage exceeds a threshold value given by the binding energy of the site. The above optimization effect is shown to arise from the complex interplay between the channel structure and the applied electric field, expressed by a nonlinear dependence of the rates with respect to the linear size of the binding site. In studying the properties of current-voltage curves, we find a double crossover between sublinear and superlinear behaviors as the size of the binding site is varied. The ratio of unidirectional fluxes clearly deviates from the Ussing limit and can be characterized by a flux ratio exponent which decreases below unity as the binding site becomes wider. We also explore effects arising from changes in the ion bulk concentration under symmetric ionic conditions and the presence of additional binding sites in the hypothetical channel. As for the experimental application, we show that our rate theory is able to provide good fits to conductance data for sodium permeation through the gramicidin A channel. Possible extensions of the theory to treat the case of an asymmetric equilibrium PMF, fluctuations in the mean number of translocating ions, the case of fluctuating energy barriers, and multi-ion conductance are briefly discussed.
Effects of chlorine and oxygen coverage on the structure of the Au(111) surface
Authors: Baker Thomas A. , Friend Cynthia M. , Kaxiras Efthimios
Published: February 2009

We investigate the effects of Cl and O coverage on the atomic structure of the Au(111) surface using density functional theory calculations. We find that the release and incorporation of gold atoms in the adsorbate layer becomes energetically favorable only at high coverages of either O or Cl (>0.66 ML (monolayer) for O and >0.33 ML for Cl), whereas adsorption without the incorporation of gold is favorable at lower coverages. The bonding between the adsorbate and gold substrate changes significantly with coverage, becoming more covalent (less ionic) at higher Cl and O coverage. This is based on the fact that at higher coverages there is less ionic charge transfer to the adsorbate, while the electron density in the region between the adsorbate and a surface gold atom is increased. Our results illustrate that the O and Cl coverage on Au(111) can dramatically affect its structure and bonding, which are important features in any application of gold involving these adsorbates.
Stress tensors of multiparticle collision dynamics fluids
Authors: Winkler Roland G. , Huang Chien-Cheng
Published: February 2009

Stress tensors are derived for the multiparticle collision dynamics algorithm, a particle-based mesoscale simulation method for fluctuating fluids, resembling those of atomistic or molecular systems. Systems with periodic boundary conditions as well as fluids confined in a slit are considered. For every case, two equivalent expressions for the tensor are provided, the internal stress tensor, which involves all degrees of freedom of a system, and the external stress, which only includes the interactions with the confining surfaces. In addition, stress tensors for a system with embedded particles are determined. Based on the derived stress tensors, analytical expressions are calculated for the shear viscosity. Simulations illustrate the difference in fluctuations between the various derived expressions and yield very good agreement between the numerical results and the analytically derived expression for the viscosity.
Optical transition in self-assembled InAs/GaAs quantum lens under high hydrostatic pressure
Authors: Rodríguez Arezky H. , Trallero-Giner C. , Duque C. A. , Vázquez G. J.
Published: February 2009

We present a simulation to characterize the dependence on hydrostatic pressure for the photoluminescence spectra in self-assembled quantum dots with lens shape geometry. We have tested the physical effects of the band offset and electron-hole effective masses on the optical emission in dot lens. The model could be implemented to get qualitative information of the parameters involved in the quantum dot or the measured optical properties as function of pressure.
Migration of rigid particles in non-Brownian viscous suspensions
Authors: Lhuillier Daniel
Published: February 2009

There is an obvious need for obtaining a closed set of equations describing multiphase flows and the complexity of their configurations. Despite their “frozen” interfaces, suspensions of rigid particles are also concerned by this issue. The description of the relative motion between the two phases is still controversial, in particular, concerning the forces acting on the particles and involving their concentration gradient or a shear rate gradient. It is our purpose here (a) to develop a two-fluid model especially designed for particles dispersed in a viscous liquid and (b) to close the model for rigid particles with the help of low-Reynolds-number hydrodynamics. Besides the obvious role of gravity forces, the migration of particles relative to the fluid is shown to result from two different physical phenomena: (a) the inhomogeneity of the stress resulting from direct interparticle forces and (b) Fick-like terms in the hydrodynamic force acting on the particles.
Patterned boron nanowires and field emission properties
Authors: Tian Jifa , Hui Chao , Bao Lihong , Li Chen , Tian Yuan , Ding Hao , Shen Chengmin , Gao Hong-jun
Published: February 2009

Patterns of assembled Fe3O4 nanoparticles on Si(111) wafer were formed by the self-assembly technique. Three factors, concentration of the Fe3O4 nanoparticles solution, dosage of the solution, and temperature of the Si wafer, were found to affect the quality of the Fe3O4 nanoparticle patterns. The prepared Si(111) wafer was used as the substrate to grow the patterned boron nanowires by thermoreduction method. Furthermore, a notable field emission property with moderate turn on field was obtained on the patterned boron nanowires. Our results indicate that the patterned boron nanowires have a great potential of applications in flat plane display and electron emission nanodevices.
Multifrequency frequency-domain spectrometer for tissue analysis
Authors: Spichtig Sonja , Hornung René , Brown Derek W. , Haensse Daniel , Wolf Martin
Published: February 2009

In this paper we describe the modification and assessment of a standard multidistance frequency-domain near infrared spectroscopy (NIRS) instrument to perform multifrequency frequency-domain NIRS measurements. The first aim of these modifications was to develop an instrument that enables measurement of small volumes of tissue such as the cervix, which is too small to be measured using a multidistance approach. The second aim was to enhance the spectral resolution to be able to determine the absolute concentrations of oxy-, deoxy- and total hemoglobin, water, and lipids. The third aim was to determine the accuracy and error of measurement of this novel instrument in both in vitro and in vivo environments. The modifications include two frequency synthesizers with variable, freely adjustable frequency, broadband high-frequency amplifiers, the development of a novel avalanche photodiode (APD) detector and demodulation circuit, additional laser diodes with additional wavelengths, and a respective graphic user interface to analyze the measurements. To test the instrument and algorithm, phantoms with optical properties similar to those of biological tissue were measured and analyzed. The results show that the absorption coefficient can be determined with an error of <10%. The error of the scattering coefficient was <31%. Since the accuracy of the chromophore concentrations depends on the absorption coefficient and not on the scattering coefficient, the <10% error is the clinically relevant parameter. In addition, the new APD had similar accuracy as the standard photomultiplier tubes. To determine the accuracy of chromophore concentration measurements we employed liquid Intralipid® phantoms that contained 99% water, 1% lipid, and an increasing concentration of hemoglobin in steps of 0.010 mM. Water concentration was measured with an accuracy of 6.5% and hemoglobin concentration with an error of 0.0024 mM independent of the concentration. The measured lipid concentration was negative, which shows that the current setup is not suitable for measuring lipids. Measurements on the forearm confirmed reasonable values for water and hemoglobin concentrations, but again not for lipids. As an example of a future application, chromophore concentrations in the cervix were measured and comparable values to the forearm were found. In conclusion the modified instrument enables measurement of water concentration in addition to oxy- and deoxyhemoglobin concentrations with a single source-detector distance in small tissue samples. Future work will focus on resolving the lipid component.
Enhanced sensitivity in detection of Kerr rotation by double modulation and time averaging based on Allan variance
Authors: Joshua Arjun , Venkataraman V.
Published: February 2009

Experiments in spintronics necessarily involve the detection of spin polarization. The sensitivity of this detection becomes an important factor to consider when extending the low temperature studies on semiconductor spintronic devices to room temperature, where the spin signal is weaker. In pump-probe experiments, which optically inject and detect spins, the sensitivity is often improved by using a photoelastic modulator (PEM) for lock-in detection. However, spurious signals can arise if diode lasers are used as optical sources in such experiments, along with a PEM. In this work, we eliminated the spurious electromagnetic coupling of the PEM onto the probe diode laser, by the double modulation technique. We also developed a test for spurious modulated interference in the pump-probe signal, due to the PEM. Besides, an order of magnitude enhancement in the sensitivity of detection of spin polarization by Kerr rotation, to 3×10−8 rad was obtained by using the concept of Allan variance to optimally average the time series data over a period of 416 s. With these improvements, we are able to experimentally demonstrate at room temperature, photoinduced steady-state spin polarization in bulk GaAs. Thus, the advances reported here facilitate the use of diode lasers with a PEM for sensitive pump-probe experiments. They also constitute a step toward detection of spin-injection in Si at room temperature.
Laser annealed composite titanium dioxide electrodes for dye-sensitized solar cells on glass and plastics
Authors: Pan Heng , Ko Seung Hwan , Misra Nipun , Grigoropoulos Costas P.
Published: February 2009

We report a rapid and low temperature process for fabricating composite TiO2 electrodes for dye-sensitized solar cells on glass and plastics by in tandem spray deposition and laser annealing. A homogenized KrF excimer laser beam (248 nm) was used to layer-by-layer anneal spray deposited TiO2 nanoparticles. The produced TiO2 film is crack free and contains small particles (30 nm) mixed with different fractions of larger particles (100–200 nm) controlled by the applied laser fluence. Laser annealed double-layered structure is demonstrated for both doctor-blade deposited and spray-deposited electrodes and performance enhancement can be observed. The highest demonstrated all-laser-annealed cells utilizing ruthenium dye and liquid electrolyte showed power conversion efficiency of ∼3.8% under simulated illumination of 100 mW/cm2.
Enhanced thermal stability and nanoparticle-mediated surface patterning: Pt/TiO2(110)
Authors: Naitabdi A. , Behafarid F. , Cuenya B. Roldan
Published: February 2009

This letter reports (i) the enhanced thermal stability (up to 1060 °C) against coarsening and/or desorption of self-assembled Pt nanoparticles synthesized by inverse micelle encapsulation and deposited on TiO2(110) and (ii) the possibility of taking advantage of the strong nanoparticle/support interactions present in this system to create patterned surfaces at the nanoscale. Following our approach, TiO2 nanostripes with tunable width, orientation, and uniform arrangement over large surface areas were produced.
In the pursuit of small “red shift” of C–H stretching vibrational frequency of C–H⋯π interactions for benzene dimer: How to amend MP2 calculations to reproduce the experimental results
Authors: Dinadayalane T. C. , Leszczynski Jerzy
Published: February 2009

For the bent T-shaped benzene dimer, the vibrational frequencies at the MP2/aug-cc-pVDZ level with counterpoise correction reproduce experimental results of the small “red shifts” of C–H stretching, while those without counterpoise correction yield considerable “blue shift.” Counterpoise correction also affects the C–H bond distances of C–H⋯π interactions as well as intermoiety distances.
Current-driven vortex formation in a magnetic multilayer ring
Authors: Nam Chunghee , Ng B. G. , Castaño F. J. , Mascaro M. D. , Ross C. A.
Published: February 2009

Current-driven domain wall (DW) motion has been studied in the NiFe layer of a Co/Cu/NiFe thin film ring using giant-magnetoresistance measurements in a four-point contact geometry. The NiFe layer is initially in an onion state configuration with two 180° DWs. An electric current drives the walls around the ring so that they annihilate and the NiFe layer forms a DW-free vortex state. The direction of motion of the two DWs is determined by the current polarity, enabling the vortex chirality to be selected.
Aging effect in paraelectric state of ferroelectrics: Implication for a microscopic explanation of ferroelectric deaging
Authors: Xue Dezhen , Gao Jinghui , Zhang Lixue , Bao Huixin , Liu Wenfeng , Zhou Chao , Ren Xiaobing
Published: February 2009

Most ferroelectric materials exhibit aging effect (a time-dependent change in physical properties) in their ferroelectric state; however, aging is not reported to exist in the paraelectric state. In this letter we report the existence of a “paraelectric aging effect” in Mn-doped (Ba0.80Sr0.20)TiO3 ceramics. We found that when the paraelectric state is formed from an aged ferroelectric state through a reverse ferroelectric transition, the paraelectric state shows a gradual increase in the dielectric permittivity and decrease in dielectric loss with time. Such paraelectric aging effect exists only in acceptor-doped samples, not in undoped samples. The kinetics of the paraelectric aging follows a simple relaxation function with activation energy of 0.43 eV. Our results suggest that the paraelectric aging stems from the migration of oxygen vacancies, being the same as the case of ferroelectric aging. We show that such a migration is driven by a symmetry-conforming short-range ordering tendency of point defects. Such a microscopic mechanism also provides a microscopic explanation for the well-observed “ferroelectric deaging effect.”
Integrated plasmonic lens photodetector
Authors: Shackleford James A. , Grote Richard , Currie Marc , Spanier Jonathan E. , Nabet Bahram
Published: February 2009

We present a fabricated metal-semiconductor-metal (MSM) photodetector exhibiting an enhanced photocurrent by integrating a nanoscale metallic grating into its contacts. This serves to increase the incident photon flux about the aperture of the device by guiding incident photons as surface plasmon polaritons. High speed time response data shows that the device responsivity may be increased without sacrificing speed. We demonstrate both a photocurrent enhancement and responsivity increase of about 90% at the design wavelength in comparison to otherwise identical MSM photodetectors without integrated nanoscale gratings. The device retains the MSM advantages of simplicity, planarity, and monolithic integrability.
Rectification of force-distance curve using capacitance measurement
Authors: Naitou Y. , Ogiso H. , Ookubo N.
Published: February 2009

We demonstrate the rectification of force spectroscopy in noncontact atomic force microscopy. The resonant frequency shift (Δf) in the probe oscillation and distance-modulated capacitance (dC/dZ) are simultaneously measured on thin dielectric films as a function of externally applied bias voltage and tip-sample distance Z. Analysis of dC/dZ spectroscopy has revealed that the probe-tip position shifts due to the attractive force acting between the tip and a sample. We show that the shifted Δf-Z curve can be rectified and the deformation of the probe tip can be quantitatively assessed.
Polarization dependent transmission through asymmetric C-shaped holes
Authors: Lee J. W. , Seo M. A. , Kim D. S. , Kang J. H. , Park Q-Han
Published: February 2009

We report that asymmetric c-shaped holes show mode switching between single- and double-resonance frequencies in the terahertz region, when the polarization direction of the incident light is controlled. The number of resonant frequencies is attributed to fundamental shape modes such as circle-, coaxial-, and rectangular-shaped holes activated under each polarization condition. All of these resonant peaks also show a transmission of over 90% with the assistance of the periodically arranged holes. These experimental results are in close agreement with theoretical simulations.
Strong field hole transport in 6H-SiC
Authors: Sankin V. I. , Shkrebiy P. P. , Yakimova R.
Published: February 2009

In materials with a small degree of ionicity ranging 10%–15%, such as in SiC, carrier scattering on polar optical potential is plausible. J-F characteristics of hot hole transport in 6H-SiC with Na−Nd∼5×1017 cm−3 are studied at electrical fields of 1–150 kV/cm and temperatures from 300 to 600 K. In this work possible mechanisms contributing to the J-F characteristics are considered: scattering on ionized impurities, impurity breakdown due to Al acceptors, hole transport in the light valence subband formed due to splitting by crystal field, and dielectric breakdown related to polar optical scattering.
Gender, Ethnicity, and Constrained Mobility: Insights into the Resultant Social Exclusion
Authors: Uteng Tanu Priya
Published: February 2009

I posit that a comprehensive picture of transport-related social exclusion can be drawn only by a simultaneous examination of place-based, people-based, and infrastructure and system-based exclusionary mechanisms. The overlap of these three factors has been examined here through the case study of non-Western immigrant women in Norway. It is known that immobility serves the aim of segregating roles and household responsibilities in different sociocultural domains. But what happens when these roles are operated in a society with a varying outlook? For example, how are the immigrant women of non-Western cultures dealing with constrained mobility in a modern society like Norway? Is it leading to their social exclusion? Following a combination of quantitative and qualitative research methods, this paper furthers the discussion on constrained mobility as a constitutive factor of social exclusion.
The Public Nature of High-Rise Buildings in Taiwan
Authors: Chen Lin-Wei , Shih Chih-Ming
Published: February 2009

The public nature of a high-rise building can be understood in two ways. Visually, it is an expression of architectural imagery. Physically, it is a layout of attached public spaces in which people can interact. Recently, high-rise buildings in Taiwan have grown in terms of their aesthetics as well as their height. With the aid of a survey of the aesthetics and layouts of high-rise buildings in Taiwan, the symbolic representation and public nature of high-rise buildings are examined. In addition, the Taipei 101 International Financial Centre is illustrated to show that high-rise building in Asia is moving away from a focus on construction technology and building style toward concern with architectural imagery and cultural identification which emphasise autonomous cultural representation.
Bestiality and the Queering of the Human Animal
Authors: Brown Michael , Rasmussen Claire
Published: February 2009

We provide an account of a bizarre sex panic from rural Washington State, USA. There, a man died after having sex with a horse and a panic ensued because there was no law against human – animal sex. Quickly a law was placed on the books outlawing bestiality, but only after a series of interlocking-yet-disparate arguments enjoined the local public sphere over just why a law prohibiting sex with animals was necessary. We deconstruct those shifting arguments with respect to their imaginative geographies, and their political theories. Tracing the borders between, and hybridities of, nature – culture, we show that there are broader issues at stake than just sex acts in otherwise moral, rural space. Resisting liberationist accounts of sexuality that buy into assumptions of sexuality as one's authentic self, we suggest that these borders and hybrids around nature might be one tack towards a queerer queer geography.
The Bog in Our Brain and Bowels: Social Attitudes to the Cartography of Icelandic Wetlands
Authors: Huijbens Edward H , Pálsson Gísli
Published: February 2009

This paper discusses the social history, attitudes, and understanding of approaches to the utilisation of wetlands, their drainage, preservation, management, and research. The analysis is in two phases; the manifestation of wetlands in map making in Iceland; and the social history of wetlands. Both phases focus on the 20th century until the present. Maps and the history of mapmaking are used as a heuristic devise to gauge and set the scene for the perception and experience of wetlands in the thinking of people. In order to illustrate this development, examples are taken from literature and travel accounts. Current endeavour in the utilisation of land and biotopic classification, best demonstrated in maps today, foregrounds the nature of the striations, making maps, and drainage ditches. Thus wetlands are viewed differently today, but nonetheless lingering traces of the modernist logic of progress remain, as we aim to demonstrate. The lines that form the tufts on the Icelandic maps are thus never stable, the striation never an end but constantly motile.
An increase in overseas acquired HIV infections among heterosexual people in Western Australia
Authors: Combs Barry C. , Giele Carolien M.
Published: February 2009

Background: There has been a recent increase in the number of heterosexually acquired HIV infections among non-Aboriginal people in Western Australia (WA), which has not been reported in other Australian jurisdictions. This report describes the epidemiological features of this increase. Methods: A descriptive analysis was conducted of newly diagnosed HIV infections among non-Aboriginal WA residents notified to the Department of Health from 2002 to 2006. Analysis outcomes included demographics, exposure categories, and place of HIV acquisition. Results: From 2002 to 2006, 258 new HIV diagnoses were notified among non-Aboriginal WA residents. Over this period, the number of notifications increased from 41 cases in 2002 (2.2 cases/100 000 population) to 66 cases in 2006 (3.4 cases/100 000 population). Overall, 107 (42%) of the cases were heterosexually acquired, and the annual number increased threefold from 2002 to 2006 (12 to 36 cases, respectively). Of these cases, 64 (60%) were male and 43 (40%) were female. The majority (89%) of male cases acquired HIV overseas, mostly in countries other than their region of birth; South-east Asia was the most common place of acquisition reported. Over half (56%) of the female cases acquired HIV overseas, mainly in their region of birth (83%), and sub-Saharan Africa was the most common place of acquisition. Conclusion: There has been a recent increase in heterosexually acquired HIV infections among male and female WA residents, many of whom reported acquiring HIV overseas. Safe sex campaigns in WA should continue to reinforce safe sex messages among people travelling overseas.
Monitoring inequalities in the National Chlamydia Screening Programme in England: added value of ACORN, a commercial geodemographic classification tool
Authors: Sheringham Jessica , Sowden Sarah , Stafford Mai , Simms Ian , Raine Rosalind
Published: February 2009

Background: Monitoring socioeconomic inequalities in sexual health service use is needed to ensure equitable service provision. There are limitations to current methods, particularly when applied to young people. The present study examined the validity and added value of combining ACORN, a commercial tool, with an established deprivation index to improve monitoring of inequalities in the National Chlamydia Screening Programme (NCSP) in England. Methods: ACORN categories and the Index of Multiple Deprivation 2004 (IMD 2004) quintiles were linked to England population estimates and 145 975 records from the NCSP. Results: ACORN’s validity was demonstrated by moderate agreement between IMD 2004 and ACORN in segmenting the population and consistent gradients in the relative risk of chlamydia positivity between the most and least deprived areas assessed by IMD 2004 (relative risk (RR) 1.32; 95% confidence interval (CI) 1.23, 1.40) and ACORN (RR 1.32; 95% CI 1.25, 1.40). ACORN’s fine level of geographic resolution demonstrated that the NCSP was reaching the most deprived neighbourhoods within larger areas classified overall as deprived by IMD 2004. Within the most deprived IMD 2004 quintile, areas classified as most deprived by ACORN had higher chlamydia screening coverage (3.15%; 95% CI 3.11, 3.19%) than the least deprived (1.81%; 95% CI 1.56, 2.08%). Furthermore, ACORN identified highest screening coverage (9.2%) in areas classified as ‘communal housing.’ Conclusions: These findings illustrate that a commercial geodemographic tool in combination with an established deprivation index may overcome limitations in monitoring inequalities in sexual health service use. ACORN had value as a supplementary deprivation marker for monitoring inequalities in chlamydia screening in England.
Influence of traditional Vietnamese culture on the utilisation of mainstream health services for sexual health issues by second-generation Vietnamese Australian young women
Authors: Rawson Helen , Liamputtong Pranee
Published: February 2009

Background: The present paper discusses the impact the traditional Vietnamese culture has on the uptake of mainstream health services for sexual health matters by Vietnamese Australian young women. It is part of a wider qualitative study that explored the factors that shaped the sexual behaviour of Vietnamese Australian young women living in Australia. Methods: A Grounded Theory methodology was used, involving in-depth interviews with 15 Vietnamese Australian young women aged 18 to 25 years who reside in Victoria, Australia. Results: The findings demonstrated that the ethnicity of the general practitioner had a clear impact on the women utilising the health service. They perceived that a Vietnamese doctor would hold the traditional view of sex as held by their parents’ generation. They rationalised that due to cultural mores, optimum sexual health care could only be achieved with a non-Vietnamese health professional. Conclusion: It is evident from the present study that cultural influences can impact on the sexual health of young people from culturally diverse backgrounds and in Australia’s multicultural society, provision of sexual health services must acknowledge the specific needs of ethnically diverse young people.
Gender differences in knowledge about chlamydia among rural high school students in Nova Scotia, Canada
Authors: Langille Donald B. , Flowerdew Gordon , Aquino-Russell Catherine , Strang Robert , Proudfoot Kathryn , Forward Kevin
Published: February 2009

Background: Chlamydia is the most prevalent sexually transmissible infection (STI) in Canadian adolescents. STI account for 20% of cases of infertility in Canada and 42% of ectopic pregnancies are attributable to previous chlamydia infection. Despite the importance of this infection, little is understood about young people’s knowledge of it. Methods: A survey was conducted at a rural high school in Nova Scotia, Canada, to assess students’ knowledge of chlamydia and associations of knowledge with gender and protective behaviours. Knowledge was assessed using true–false responses to 15 statements about chlamydia. Each statement was examined for differences in the percentage of correct responses by sex. Correct responses were summed, creating a knowledge score. Socioeconomic status variables and age were included in multivariate regression models to determine if they modified associations between knowledge score and protective behaviours seen in simple regression. Results: Eighty-six percent of registered students (n = 538) participated in the survey. Girls responded to 10 of the 15 knowledge statements significantly more often than boys. Respondents were least knowledgeable about their rights to confidential health services for chlamydia infection. Knowledge score was associated with use of both condoms and oral contraception at last intercourse in girls (odds ratio 1.15; 95% confidence interval 1.01–1.31). No association of knowledge score was seen with having had an STI test in the previous year. Conclusions: School sexual health programs should make special efforts to meet the needs of male students, and programs and health professionals should include information about the confidential nature of sexual health services for adolescents.
Primary health care providers surveyed commonly misinterpret 'first void urine' for chlamydia screening
Authors: Lusk M. Josephine , Uddin Ruby , Ferson Mark , Rawlinson William , Konecny Pam
Published: February 2009

An open question survey of general practitioners (GP) and hospital emergency department (ED) doctors revealed that the term ‘FVU’ (first void urine) used for urine chlamydia testing, is ambiguous, potentially leading to incorrect urine sample collection and barriers to effective screening. The results of this survey indicate that only 4.3% (95% confidence interval [CI] 0.5–14.5%) of GP and 6.9% (95% CI 0.9–22.8%) of ED doctors respectively, correctly interpreted the meaning of FVU. The majority of clinicians surveyed misunderstood ‘FVU’ to require the first urine void of the day, accounting for 68.1% (95% CI 52.9–80.9%) of GP responses and 37.9% (95% CI 20.7–57.7%) of ED doctors responses. This highlights the need for clarification and standardisation of terminology used in urine chlamydia screening for health care providers, in order to optimise strategies for diagnosis and control of the ongoing chlamydia epidemic.
Regulation of chemokine receptor by Toll-like receptor 2 is critical to neutrophil migration and resistance to polymicrobial sepsis
Authors: Alves-Filho Jose C. , Freitas Andressa , Souto Fabricio O. , Spiller Fernando , Paula-Neto Heitor , Silva Joao S. , Gazzinelli Ricardo T. , Teixeira Mauro M. , Ferreira Sergio H. , Cunha Fernando Q.
Published: February 2009

Patients with sepsis have a marked defect in neutrophil migration. Here we identify a key role of Toll-like receptor 2 (TLR2) in the regulation of neutrophil migration and resistance during polymicrobial sepsis. We found that the expression of the chemokine receptor CXCR2 was dramatically down-regulated in circulating neutrophils from WT mice with severe sepsis, which correlates with reduced chemotaxis to CXCL2 in vitro and impaired migration into an infectious focus in vivo. TLR2 deficiency prevented the down-regulation of CXCR2 and failure of neutrophil migration. Moreover, TLR2
−/−
mice exhibited higher bacterial clearance, lower serum inflammatory cytokines, and improved survival rate during severe sepsis compared with WT mice. In vitro, the TLR2 agonist lipoteichoic acid (LTA) down-regulated CXCR2 expression and markedly inhibited the neutrophil chemotaxis and actin polymerization induced by CXCL2. Moreover, neutrophils activated ex vivo by LTA and adoptively transferred into naïve WT recipient mice displayed a significantly reduced competence to migrate toward thioglycolate-induced peritonitis. Finally, LTA enhanced the expression of G protein–coupled receptor kinases 2 (GRK2) in neutrophils; increased expression of GRK2 was seen in blood neutrophils from WT mice, but not TLR2
−/−
mice, with severe sepsis. Our findings identify an unexpected detrimental role of TLR2 in polymicrobial sepsis and suggest that inhibition of TLR2 signaling may improve survival from sepsis.
Calculation of strong and weak interactions in TDA1 and RangDP52 by the kernel energy method
Authors: Huang Lulu , Massa Lou , Karle Isabella , Karle Jerome
Published: February 2009

Using the Kernel Energy Method we apply ab initio quantum mechanics to study the relative importance of weak and strong interactions (including hydrogen bonds) in the crystal structures of the title compounds TDA1 and RangDP52. Perhaps contrary to widespread belief, in these compounds the weak interaction energies, because of their large number and cooperativity, can be significant to the binding energetics of the crystal, and thus also to its other properties.
Hepcidin-induced internalization of ferroportin requires binding and cooperative interaction with Jak2
Authors: De Domenico Ivana , Lo Eric , Ward Diane M. , Kaplan Jerry
Published: February 2009

Hepcidin is a hormone secreted in response to iron loading and inflammation. Hepcidin binds to the iron exporter ferroportin, inducing its degradation and thus preventing iron entry into plasma. We determined that hepcidin binding to ferroportin leads to the binding and activation of the protein Janus Kinase2 (Jak2), which is required for phosphorylation of ferroportin. Ferroportin is a dimer and both monomers must be capable of binding hepcidin for Jak2 to bind to ferroportin. Once Jak2 is bound to the ferroportin dimer, both ferroportin monomers must be functionally competent to activate Jak2 and for ferroportin to be phosphorylated. These results show that cooperativity between the ferroportin monomers is required for hepcidin-mediated Jak2 activation and ferroportin down-regulation. These results provide a molecular explanation for the dominant inheritance of hepcidin resistant iron overload disease.
Temporal bone imaging
Authors: Abildgaard Andreas
Published: February 2009

Temporal Bone Imaging. Edited by Ellen G. Hoeffner & Suresh K. Mukherji. New York: Thieme Medical Publishers, 2008. ISBN 978-1-58890-401-0/ 978-3-13-140231-8. 220 pages, 244 illustrations.

Price (hardback): EUR 89.95
The intellectual community of La Rivoluzione Liberale
Authors: Cullen Niamh
Published: February 2009

While Piero Gobetti has often been the subject of historical attention in Italy since his death in 1926, the existing literature on this anti-fascist intellectual and editor has almost always considered him in the context of political tradition and focused on his theories and historical studies rather than on his editorial activities. This article aims to redress this balance, by situating Gobetti within the context of the socio-economic environment of post First World War and early fascist Turin, and by examining his role as an editor and cultural organiser with respect to his most well known periodical: La Rivoluzione Liberale. Drawing on the personal correspondences of Gobetti and the administrative archives of the periodical, an account of its circulation and readership will be constructed in order to determine the nature (in geography, education, profession and political affiliation) of the community of the ‘Liberal Revolution’.
Moveable identities: Migration, subjectivity and cinema in contemporary Italy
Authors: Capussotti Enrica
Published: February 2009

Images and stories of migration within contemporary culture in Italy are shaped by several interconnections between the past (memories of Italian emigration, Italian poverty and rural society) and the present (Italy's postindustrial and multicultural realities). Analysing different texts, this article explores how the construction of the ‘official memory’ of the Italian emigration is used both to recall an anti-racist and sympathetic reception of today migrants and to conceal the specificity of today's mobility. In this context, the temporal categories of Eurocentric modernity are functional to the maintenance of hierarchical differences between ‘self’ (Italian and European) and different ‘others’ (the migrants). Although the system of representations is articulated around traditional dichotomies between North and South, East and West, and self and other, the article shows the crucial role of ‘migrancy’ cinema. It offers new trajectories, alliances and exchanges, which are significantly represented through the multiple crossings that challenge the walls of Fortress Europe in the Mediterranean.
The ecological impacts of fragmentation and vegetation removal in Lake Huron’s coastal wetlands
Authors: Uzarski Donald G. , Burton Thomas M. , Kolar Rebecca E. , Cooper Matthew J.
Published: February 2009

Many Great Lakes coastal wetlands that remain today have been heavily fragmented by anthropogenic activities. The rate of fragmentation tends to increase during periods of low lake levels, especially in areas of low-gradient bathymetry where wetland area expands substantially and prompts the desire to dredge channels and groom shorelines. We sampled fish and invertebrates, using fyke nets and dipnets respectively, from wetland fragments paired with either areas where wetland vegetation was mowed or removed completely. Our concurrent studies showed that removal of vegetation by beach grooming and channel dredging created conduits for pelagic water to infiltrate the marsh and disrupt the ambient chemical/physical conditions. Alterations to both fish and macroinvertebrate communities were also evident where a significant amount of vegetation was removed. However, where only enough vegetation was removed to allow for boat access, impacts on fish communities were generally non-detectable. Mowing seemed to impact fish, but not invertebrates. Our data suggest that wetland fragmentation may have substantial and long lasting effects on wetland biota, but the magnitude of the impact is likely associated with the area of vegetation removed coupled with the potential for pelagic water to penetrate remaining fragments.
The ‘Narcissistic‐We’ model: A conceptual framework for multidisciplinary team working, researching and decision‐making with traumatised individuals
Authors: Dorahy Martin J. , Hamilton Geraldine
Published: February 2009

Greater emphasis is being placed on multidisciplinary team (MDT) working for complex clinical presentations in the NHS. Whilst such integrated working has the potential for considerable benefits for clients, it also raises the issue of constructive and destructive decision‐making within teams that bring together different individuals and professional groupings. This paper outlines a model which attempts to address how individuals in a MDT can hold onto their own personal and professional identity whilst simultaneously adopting a team identity. Thus how the ‘me’ and the ‘we’ operate to assist the client. The model, termed the ‘Narcissistic‐We’, was developed out of multidisciplinary team working with traumatised individuals in Belfast and has particular relevance for decision‐making in MDTs. The model argues that MDTs operate along two continua, the first running from ‘me’ to ‘team’ and the second running from ‘me’ to ‘client’. When overlaid these continua create four quadrants. It is suggested that no clinical decisions should be made in the ‘Me‐Me’ quadrant and most decisions should come from the ‘Client‐Team’ quadrant. However, there are times when decisions are required from the ‘Me‐Client’ and ‘Me‐Team’ quadrants. The development, practical implications and research possibilities of this model are discussed.
‘I had no family, but I made family’. Immediate post‐war coping strategies of adolescent survivors of the Holocaust
Authors: Goldenberg Jennifer
Published: February 2009

Increasingly, mental health professionals are confronted with survivors of ethnic conflict and genocide, many of whom were adolescents when they experienced such extreme, prolonged trauma. Holocaust survivor interviews provide an important window into the process of post‐traumatic coping and adaptation by adolescent survivors of genocide. The immediate post‐genocide years have been a particularly neglected field of inquiry among trauma researchers. This study of the immediate coping strategies used by adolescent survivors of the Holocaust is part of a larger secondary analysis of the long‐term coping and adaptation of 18 adolescent survivors – 14 women and four men – who were between the ages of 12 and 18 at the start of World War II. It found that the major coping strategies used in the immediate post‐war period were social support, community with other survivors, revenge and the pursuit of justice. These findings have important implications for the treatment of survivors of ethnic conflict seeking asylum in countries in the West.