bluuebunny/crossref_metadata_2025 huggingface dataset:
Ince’s limits for confluent and double-confluent Heun equations
Authors: Figueiredo B. D. Bonorino
Published: November 2005

We find pairs of solutions to a differential equation which is obtained as a special limit of a generalized spheroidal wave equation (this is also known as confluent Heun equation). One solution in each pair is given by a series of hypergeometric functions and converges for any finite value of the independent variable z, while the other is given by a series of modified Bessel functions and converges for ∣z∣>∣z0∣, where z0 denotes a regular singularity. For short, the preceding limit is called Ince’s limit after Ince who have used the same procedure to get the Mathieu equations from the Whittaker-Hill ones. We find as well that, when z0 tends to zero, the Ince limit of the generalized spheroidal wave equation turns out to be the Ince limit of a double-confluent Heun equation, for which solutions are provided. Finally, we show that the Schrödinger equation for inverse fourth- and sixth-power potentials reduces to peculiar cases of the double-confluent Heun equation and its Ince’s limit, respectively.
The interaction of C6H6 and C6H12 with noble metal surfaces: Electronic level alignment and the origin of the interface dipole
Authors: Bagus Paul S. , Hermann Klaus , Wöll Christof
Published: November 2005

The electronic interaction of two molecules, the aromatic benzene (C6H6) and the saturated hydrocarbon cyclohexane (C6H12) with a Cu(111) surface, have been determined using precise, ab initio electronic structure calculations. For the interaction of these adsorbates with the substrate, we present a detailed analysis and decomposition of various individual chemical mechanisms that contribute. A novel aspect of this analysis is the use of charge-density difference contour plots to graphically display the chemistry. A wave-function-based approach was used in order to avoid problems when the presently most commonly employed approach, density-functional theory, is applied to weakly chemisorbed molecules, where the interaction is dominated by van der Waals forces. The present information are not only relevant with regard to understanding the chemistry going on when molecules are adsorbed on a Cu surface but also have important consequences with regard to charge injection in molecular electronic devices, e.g., organic field-effect transistors and organic light-emitting diodes.
Synthesis of diamondlike carbon particles in/on a water substrate by laser irradiation
Authors: Hidai Hirofumi , Tokura Hitoshi
Published: November 2005

We proposed two-particle synthesis techniques using a liquid as a substrate. First, utilizing liquid instead of solid substrates, particle synthesis is expected on the liquid surface. Particles sink into the liquid before the particles grow into film, because of liquid fluidity. Second, the excitation of a gas dissolved in water was also attempted. An ArF excimer laser beam was focused in a chamber. The 60% volume of the chamber was filled with water, in which methane was dissolved and the remaining space of the chamber was filled with methane gas. As a result, diamondlike carbon particles could be synthesized in water. The particles synthesized from methane in the gas phase were 50–200 nm in diameter, and the particles synthesized from methane dissolved in water were 200–700 nm in diameter, and no structural differences were observed between the particles of two different diameters. Energy-dispersive spectroscopy, Raman spectroscopy analysis, and high-resolution transmission electron microscopy observations revealed that particles contained a diamondlike carbon component and that graphite was attached to them. These particles were harder than graphite particles.
Energy principle in the Boozer model
Authors: Pustovitov V. D.
Published: November 2005

The formulation of the energy principle proposed by Boozer [Phys. Plasmas 6, 831 (1999)] for the analysis of the toroidal plasma stability with respect to the resistive wall modes is discussed. One of its main features is the introduction of a surface current on the “control surface,” through which the influence of an external environment on the plasma is simulated. Here the classical example “ideal plasma-vacuum-the ideal wall” is used to show that, with such modeling, the energy conservation in the ideal magnetohydrodynamics is broken. This can be one of the possible reasons of the systematic discrepancy of plasma stability limits calculated with the VALEN code [Bialek et al. Phys. Plasmas 8, 2170 (2001)], where the discussed model is used, from the results of other codes.
Growth kinetics effects on self-assembled InAs∕InP quantum dots
Authors: Bansal Bhavtosh , Gokhale M. R. , Bhattacharya Arnab , Arora B. M.
Published: November 2005

A systematic manipulation of the morphology and the optical emission properties of metalorganic vapor phase epitaxy grown ensembles of InAs∕InP quantum dots is demonstrated by changing the growth kinetics parameters. Under nonequilibrium conditions of a comparatively higher growth rate and low growth temperature, the quantum dots’ density, their average size and hence the peak emission wavelength can be tuned by changing efficiency of the surface diffusion (determined by the growth temperature) relative to the growth flux. We further observe that the distribution of quantum dot heights, for samples grown under varying conditions, if normalized to the mean height, can be nearly collapsed onto a single Gaussian curve.
Using ultrasonic atomization to produce an aerosol of micron-scale particles
Authors: Donnelly T. D. , Hogan J. , Mugler A. , Schubmehl M. , Schommer N. , Bernoff A. J. , Dasnurkar S. , Ditmire T.
Published: November 2005

A device that uses ultrasonic atomization of a liquid to produce an aerosol of micron-scale droplets is described. This device represents a new approach to producing targets relevant to laser-driven fusion studies, and to rare studies of nonlinear optics in which wavelength-scale targets are irradiated. The device has also made possible tests of fluid dynamics models in a novel phase space. The distribution of droplet sizes produced by the device and the threshold power required for droplet production are shown to follow scaling laws predicted by fluid dynamics.
Interface engineering for lattice-matched epitaxy of ZnO on (La,Sr)(Al,Ta)O3(111) substrate
Authors: Ying M. J. , Du X. L. , Liu Y. Z. , Zhou Z. T. , Zeng Z. Q. , Mei Z. X. , Jia J. F. , Chen H. , Xue Q. K. , Zhang Z.
Published: November 2005

Zn O ∕ ( La , Sr ) ( Al , Ta ) O 3 ( LSAT ) heterointerface is engineered to control the crystallographic orientation of ZnO films grown by plasmas-assisted molecular beam epitaxy. Lattice-matched in-plane alignment of [112¯0]ZnO‖[112¯]LSAT has been realized using Mg modification of the substrate surface, which is confirmed with in situ reflection high-energy electron diffraction observation, and ex situ characterization of x-ray diffraction and transmission electron microscopy. The low-temperature deposition and high-temperature treatment of the Mg layer on the oxygen-terminated LSAT(111) surface results in selective nucleation of a MgO interface layer which serves as a template for single-domain epitaxy of ZnO. Oxygen-polar ZnO film with an atomically smooth surface has been obtained, which is favorable for metal-ZnO Schottky contact with high barrier height.
On the tensile strength distribution of multiwalled carbon nanotubes
Authors: Barber Asa H. , Andrews Rodney , Schadler Linda S. , Wagner H. Daniel
Published: November 2005

Individual multiwalled carbon nanotubes grown by chemical vapor deposition (CVD) were tensile tested within the chamber of an electron microscope using an atomic force microscope-based technique. Weibull–Poisson statistics could accurately model the nanotube tensile strength data. Weibull shape and scale parameters of 1.7 and 109GPa were obtained. The former reflects a wide variability in strength similar to that observed for high-modulus graphite fibers, while the latter indicates that the irregular CVD-grown tube wall structure requires, in some cases, higher breaking forces than more regular tube wall structures. This apparent strengthening mechanism is most likely caused by an enhanced interaction between the walls of the nanotube.
Cellular nonlinear networks for strike-point localization at JET
Authors: Arena P. , Fortuna L. , Bruno M. , Vagliasindi G. , Murari A. , Andrew P. , Mazzitelli G.
Published: November 2005

At JET, the potential of fast image processing for real-time purposes is thoroughly investigated. Particular attention is devoted to smart sensors based on system on chip technology. The data of the infrared cameras were processed with a chip implementing a cellular nonlinear network (CNN) structure so as to support and complement the magnetic diagnostics in the real-time localization of the strike-point position in the divertor. The circuit consists of two layers of complementary metal-oxide semiconductor components, the first being the sensor and the second implementing the actual CNN. This innovative hardware has made it possible to determine the position of the maximum thermal load with a time resolution of the order of 30 ms. Good congruency has been found with the measurement from the thermocouples in the divertor, proving the potential of the infrared data in locating the region of the maximum thermal load. The results are also confirmed by JET magnetic codes, both those used for the equilibrium reconstructions and those devoted to the identification of the plasma boundary.
Design and characteristics of a high-precision chopper wheel motor driver
Authors: Gu Xi Bin , Guo Ying , Chan Henry , Kawamura Ed , Kaiser Ralf I.
Published: November 2005

The circuit diagram and design principles of a high-stability chopper wheel motor driver are presented. Experimental results show that this unit can be interfaced to molecular-beam machines to generate supersonic beams with extremely stable root-mean-square and peak velocities fluctuating on a day-to-day basis by less than 0.2%.
Nanoscale patterning of thin liquid films on solid surfaces
Authors: Fukuzawa Kenji , Deguchi Takanori , Kawamura Jun , Mitsuya Yasunaga , Muramatsu Takuro , Zhang Hedong
Published: November 2005

A method for nanoscale patterning of molecularly thin liquids on solid surfaces has been demonstrated. A template surface structure was fabricated by a probe oxidation method and a molecularly thin liquid film was applied to it. The intermolecular interaction between the liquid and solid surfaces is varied by the thickness of the nano-oxide structure and this causes the local variations of the wettability. The method provides liquid patterns with desired shapes on nanometer scale, such as a line with a width of less than 100nm and a nanodroplet with a volume of less than 100-zeptoliters.
Shell structures in self-assembled InAs quantum dots probed by lateral electron tunneling structures
Authors: Jung M. , Machida T. , Hirakawa K. , Komiyama S. , Nakaoka T. , Ishida S. , Arakawa Y.
Published: November 2005

We have investigated electron filling in single InAs quantum dots (QDs) using a lateral electron transport structure, i.e., nanolithographically defined metallic leads with nanogaps. Elliptic InAs QDs with a diameter of ∼60∕80nm exhibited clear shell filling up to 12 electrons before the gate leakage became significant. Shell-dependent charging energies and level quantization energies for the s, p, and d states were determined from the addition energy spectra. Furthermore, it was found that the charging energies and the tunneling conductances strongly depend on the shell, reflecting that the electron wave functions for higher shells are more extended in space.
X-ray magnetic circular dichroism study of Re 5d magnetism in Sr2CrReO6
Authors: Majewski P. , Geprägs S. , Sanganas O. , Opel M. , Gross R. , Wilhelm F. , Rogalev A. , Alff L.
Published: November 2005

We have measured Re 5d spin and orbital magnetic moments in the ferrimagnetic double perovskite Sr2CrReO6 by x-ray magnetic circular dichroism at the L2,3 edges. In fair agreement with recent band structure calculations [G. Vaitheeswaran, V. Kanchana, and A. Delin, Appl. Phys. Lett. 86, 032513 (2005)], at the Re site a large 5d spin magnetic moment of −0.68μB and a considerable orbital moment of +0.25μB have been detected. We found that the Curie temperature of the double perovskites A2BB′O6 scales with the spin magnetic moment of the “nonmagnetic” B′ ion.
α
-
Si
C
–
β
-
Si
C
heteropolytype structures on Si (111)
Authors: Morales F. M. , Förster Ch. , Ambacher O. , Pezoldt J.
Published: November 2005

Nanoscale α-SiC(0001) on β-SiC(111) heterostructures on Si (111) substrates fabricated by ultralow-pressure chemical vapor deposition are demonstrated. The intentional formation of the α-β structure was achieved by adjusting the SiH4 to C2H4 flux ratios to carbon rich conditions and by controlling the diffusion length. The developed method allows the formation of heteropolytypic structures with a controlled thickness of the intermediate cubic β-SiC layer.
Simultaneous stabilization of frequency and magnetic field with the tilted 0-0 state
Authors: Jau Y.-Y. , Happer W.
Published: November 2005

“Tilted” versions of axially symmetric states of alkali-metal atoms can be readily generated by pumping with D1 light of appropriate modulation format. Of particular interest is the tilted 0-0 state, that can be generated by push-pull pumping with additional pulse modulation at the Zeeman frequency. The tilted 0-0 state can be used to simultaneously lock a magnetic field and a clock frequency.
Trapped torsional vibrations in elastic plates
Authors: Knowles T. , Kang M. K. , Huang R.
Published: November 2005

We report observation and analysis of trapped torsional vibrations in elastic plates. Each trapping element consists of a circular mesa machined in cast aluminum plate, with an electromagnetic acoustic transducer used to generate oscillatory surface traction. Suitably applied traction induced torsional vibrations trapped in the mesa. The resonant frequencies, relative displacements and Q-values were measured, and an approximate theory was developed to analyze the trapping effect with good agreement between measurements and theory. It was found that these trapped torsional modes have Q-values exceeding 100 000 with pure in-plane motion, which is of practical importance for acoustic sensor applications.
Direct observation of the structure of defect centers involved in the negative bias temperature instability
Authors: Campbell J. P. , Lenahan P. M. , Krishnan A. T. , Krishnan S.
Published: November 2005

We utilize a very sensitive electron paramagnetic resonance technique called spin-dependent recombination to observe and identify defect centers generated by modest negative bias and moderately elevated temperatures in fully processed p-channel metal-oxide-silicon field-effect transistors. The defects include two Si∕SiO2 interface silicon dangling bond centers (Pb0 and Pb1) and may also include an oxide silicon dangling bond center (E′). Our observations strongly suggest that both Pb0 and Pb1 defects play major roles in the negative bias temperature instability.
The subtypes of human immunodeficiency virus in Australia and Asia
Authors: Oelrichs Robert
Published: November 2005

Worldwide, the human immunodeficiency virus exhibits a great genetic variability, with multiple circulating subtypes of the virus. This variability allows study of the movement of HIV strains within and between human populations but also has implications for diagnosis, treatment and monitoring. The type of HIV causing the epidemic in Australia is changing from being homogeneous subtype B, reflecting a greater regional diversity. In this paper the classification of HIV-1 subtypes and their distribution within the Australasian region are reviewed and the implications of these distribution patterns discussed.
The role of viral coreceptors and enhanced macrophage tropism in human immunodeficiency virus type 1 disease progression
Authors: Gorry Paul R. , Sterjovski Jasminka , Churchill Melissa , Witlox Kristie , Gray Lachlan , Cunningham Anthony , Wesselingh Steven
Published: November 2005

Despite numerous studies on the impact of viral diversity, human immunodeficiency virus type 1 (HIV-1)-specific immune responses and host factors on disease progression, we still do not have a firm understanding of the long-term pathogenesis of HIV-1 infection. Rapid depletion of CD4+ T-lymphocytes has been associated with a switch in viral coreceptor usage from CCR5 to CXCR4 in ~40 to 50% of infected individuals. However, the majority of infected individuals who progress to AIDS harbour only CCR5-dependent (R5) viral strains. The progression HIV-1 disease is associated with an enhanced tropism of R5 viral strains for monocyte/macrophage lineage cells (enhanced M-tropism). However, the underlying molecular mechanisms contributing to enhanced M-tropism by R5 HIV-1 strains, and how HIV-1 variants with enhanced M-tropism cause CD4+ T-cell depletion in vivo are unknown. This review examines the relationship between viral coreceptor usage, M-tropism, and pathogenicity of HIV-1. We highlight evidence supporting the hypothesis that enhanced M-tropism of R5 HIV-1 results from adaptive viral evolution, resulting in HIV-1 variants that have increased ability to utilise relatively low levels of CCR5 expressed on macrophages, by way of increased CCR5 affinity. The evidence also suggests that these late-emerging, R5 viral strains have reduced sensitivity to entry inhibitors, and increased ability to cause CD4+ T-lymphocyte loss. These variants are likely to impact HIV-1 disease progression, especially in patients who persistently harbour only R5 viral strains.
The tip of the iceberg: opportunistic screening for Chlamydia trachomatis in asymptomatic patients attending a young people's health clinic reveals a high prevalence — a pilot study
Authors: Jones Stephanie , Barker Sue , Athan Eugene , Graves Stephen
Published: November 2005

Objectives: We implemented an opportunistic screening programme for Chlamydia trachomatis amongst patients presenting to a young peoples’ health service in the city of Geelong, Australia, to define the prevalence of infection and to identify specific risk factors. Methods: Over a 7-month period sexually active patients attending the young peoples’ clinic were offered C. trachomatis screening by nucleic acid amplification test. There was 100% acceptance rate among those offered the test. Patient demographics, reason for presentation at the clinic and reported symptoms were documented by the clinicians and correlated with laboratory findings. Results: 163 patients between the ages of 12–25 were tested, nine males and 154 females. The prevalence of chlamydia infection was 5.8% and was highest (16.0%) among patients presenting for the morning after pill. Inhibition of the nucleic acid amplification test occurred in 11.0% of urine samples. All patients with inhibited tests were asked to provide a repeat sample for retesting, but only 50% complied with this request. The majority of repeat samples (88.9%) had no inhibitors present and yielded a negative result. There was no correlation between symptoms and a positive chlamydia result. Conclusions: Chlamydia infection is common in young people engaging in unsafe sexual practice and cannot be predicted by the presence of symptoms. The high prevalence of infection in Geelong would make screening cost effective in this age group. Ongoing population screening of sexually active young people should be encouraged in community health centres. Inhibition of the nucleic acid amplification test was common but repeat testing of urine a few days later usually gave satisfactory results.
Socio-demographic correlates of desire for HIV testing in Tanzania
Authors: Mbago Maurice C.Y.
Published: November 2005

Background: Over 60% of women and men interviewed in the Tanzania Demographic Health Survey (TDHS) of 1996 and the Tanzania Reproductive and Child Health Survey (TRCHS) of 1999 indicated that they would like to be tested for AIDS virus (HIV-antibody test). This is encouraging in view of the fact that voluntary HIV testing coupled with appropriate counselling is now believed to be quite effective for the prevention of HIV infection. This paper seeks to identify some socio-demographic factors that are associated with desire for HIV testing in Tanzania. Methods: The study used data from the 1999 Tanzania Reproductive and Health Survey in which 4029 women and 3542 men were interviewed. A logistic regression analysis was used to identify correlates of desire for HIV testing for both men and women. Results: For both men and women the logistic regression results show that significant correlates of desire for HIV testing are education, residence and knowledge of HIV prevention. In particular the odds of desire for AIDS test were found to be lower for respondents with secondary school education than those with primary school education. The odds were also significantly lower for urban respondents than for rural ones. The findings further show that the odds of desire for having an AIDS test were lowest for respondents with no knowledge of HIV prevention. Conclusions: Strategic campaigns to convince people to go for HIV testing should put more emphasis on radio programmes since these are effective means of communication in rural areas where desire for testing seems to be high. Such programmes should also focus on raising awareness on HIV prevention. HIV testing facilities should also be extended to the rural areas and be offered at affordable prices.
Diagnosis of sexually transmitted infections (STI) using self-collected non-invasive specimens
Authors: Garland Suzanne M. , Tabrizi Sepehr N.
Published: November 2005

Paramount in control of transmission of sexually transmitted infections (STIs) is their prompt recognition and appropriate treatment. In countries where definitive diagnoses are difficult, a ‘syndromic approach’ to management of STIs is recommended and practiced, yet many STIs have common symptoms or are asymptomatic and therefore go undetected and untreated. This is of particular concern with the recognition that HIV transmission is increased with co-existent STIs: the attributable risk for each STI varying with the prevalence within a particular population. Hence, HIV public health prevention approaches must include STI preventative strategies to be effective. Even then, microbiological screening is incorporated into STI control strategies; lack of access to appropriate services (especially in rural and remote areas), reluctance of at-risk populations to attend for treatment, fear of invasive genital examinations, and lower sensitivities of conventional diagnostic assays reduces the effectiveness of such programmes. Therefore, accurate, cost-effective, reliable diagnostic assays (preferably those which can be used in the field) are needed to impact on the incidence of the various STIs, as well as HIV. With the advent of molecular technologies, including target and signal amplification methods, diagnoses of STIs have been revolutionised and allow the use of non or minimally invasive sampling techniques, some of which are self-collected by the patient, e.g. first-void urine, cervico-vaginal lavage, low vaginal swabs, and tampons. Most studies evaluating such self-sampling with molecular diagnostic techniques have demonstrated an equivalent or superior detection of STIs as compared to conventional sampling and detection methods. These sampling methods can also be used to determine prevalence of STIs in various populations, but particularly those with difficult access to medical care. In this article, the utility of self-sampling collection devices for detection of various STIs, particularly in women, is reviewed as one step towards formulating appropriate strategies in control of STIs, and which are especially suited for remote areas.
Is screening for anal cancer warranted in homosexual men?
Authors: Anderson Jonathan StC. , Vajdic Claire , Grulich Andrew E.
Published: November 2005

Some investigators have proposed screening homosexual men for anal cancer and its probable precursor, high grade anal intraepithelial neoplasia (AIN). Using widely accepted criteria for the introduction of screening programmes, this paper reviews the current evidence for screening for this condition in this high risk population and highlights areas where additional research is required.
While it is accepted that the incidence of anal cancer is at least 20 times higher in homosexual men than the general population, the natural history of anal cancer and its precise relationship with AIN is not clearly understood. Anal intraepithelial neoplasia is a very highly prevalent disease among homosexual men, but little is known about what predicts progression to invasive disease. The screening tests, exfoliate cytology and high resolution anoscopy, have a sensitivity of between 45 and 70%. Treatment options for AIN are limited by morbidity and high recurrence rates and there are no randomised controlled trials studying the efficacy of therapeutic agents or surgery for high grade AIN, although immunotherapies show very early promise. Theoretically, early detection may lead to better treatment outcomes. Studies of the potential negative consequences of screening programmes on the homosexual population are needed. The currently available data does not support the implementation of a screening programme for AIN and anal cancer in homosexual men in Australia.
Improving adolescent sexual and reproductive health. A view from Australia: learning from world's best practice
Authors: Williams Henrietta , Davidson Sandra
Published: November 2005

There is increasing awareness worldwide of the importance of sexual and reproductive health in adolescents. Australia's high rates of teenage pregnancy and increasing rates of sexually transmitted infections in young people reflect a failure to prioritise adolescent sexual and reproductive health on the public health agenda. This paper reviews adolescent sexual and reproductive health in Australia in comparison with international data, and examines the systemic, social and cultural factors that influence it. Based on comparisons with international best practice, recommendations are included for improvement in adolescent sexual and reproductive health within the Australian context.
Risk factors for cervical cancer development: what do women think?
Authors: Baay M. F. D. , Verhoeven V. , Avonts D. , Vermorken J. B.
Published: November 2005

Background: The current cervical cancer prevention strategy is exclusively directed towards screening, without taking into account any relationship with sexual risk factors. The introduction of human papillomavirus (HPV) detection into the screening procedure implicates that we should give attention to this relationship. The aim of this study was to investigate what knowledge women have of the relation between HPV and cervical cancer. Methods: Rather than asking about HPV specifically, we suggested 20 risk factors for the development of cervical cancer, including viral infection, and asked 73 women visiting their general practitioner, 67 women visiting a lecture on risk factors for cervical cancer and 28 female students in biomedical sciences to rate the importance of these risk factors on a scale of 1–5. Results: Genetic factors were rated highest with a mean score of 4.5. Bacterial infection ranked second highest with a mean score of 3.8. Smoking ranked fourth at a mean score of 3.6, whereas viral infection shared the sixth place with number of sexual partners with a mean score of 3.4. The presence of high voltage power lines and physical activity appropriately scored the last two places at 2.4 and 2.2, respectively. Twenty-one women suggested a role for sexually transmitted agents, but only five women (3.1%) could actually pinpoint HPV. Conclusion: This enquiry indicates that the risk factor ‘genetic factors’ was over-rated, while knowledge of the most important risk factors, i.e. smoking and sexual habits and (sexually transmitted) infections, would appear to be present to a moderate level in our population. However, knowledge of the role of HPV in cervical cancer development is lacking.
A sexual health strategy for Australia — time for action
Authors: Chan D. J. , Bradford D. L.
Published: November 2005

Australia still does not have a national sexual health strategy. Sexually transmissible infections such as chlamydia continue to plague the community, and the incidence of HIV is increasing. But a cohesive sexual health strategy cannot merely be disease-focussed, it must include the broader social and cultural aspects of sexual behaviour and sexuality. We propose a public health framework for the development of a national sexual health strategy that will bring Australia in line with the United Kingdom and New Zealand.
Safer sex or pleasurable sex? Rethinking condom use in the AIDS era
Authors: Khan Sharful Islam , Hudson-Rodd Nancy , Saggers Sherry , Bhuiyan Mahbubul Islam , Bhuiya Abbas
Published: November 2005

Background:
Condom use in Bangladesh is low despite nationwide family planning initiatives and HIV interventions.
Methods:
Fifty men aged between 18 and 55 years from diverse socio-demographic backgrounds and five key informants were interviewed in a qualitative male sexuality study.
Results:
Refusal to use condoms is not only a personal choice, but pertains to relationships. The meanings of reduced bodily pleasure associated with condom use are socially constructed. Men’s emotions and trust expressed through understanding of direct penile–vaginal contact and ejaculation inside the vagina as ‘pure’ and ‘natural’ sex oppose condom use. Sexual prowess in the form of prolonged intercourse without condoms, as depicted in Western pornography, was perceived as a ‘real man’s’ sexual skill. Men sought to preserve a ‘good man’s’ image by avoiding condoms, which symbolised promiscuous men in AIDS educational messages.
Conclusion:
Social dimensions of masculine sexuality, pleasure, eroticism and the emotional aspect of men’s lives have to be addressed for effective condom promotion.
Investigating widely available substances as vaginal microbicides
Authors: Holmes Wendy
Published: November 2005

Microbicides to protect women from HIV are urgently needed. Several potential pharmaceutical microbicides are now undergoing obligatory clinical trials to check safety, acceptability and efficacy before approval for use. Microbicides may have side-effects and, paradoxically, their use may increase the risk of acquiring HIV. Several widely available substances have been suggested as microbicides, including substances with a low pH such as lemon juice, vinegar, soft drinks and lactobacillus dairy products. Because of the potential for harm it is important that these substances are tested before their use is widely promoted. After small scale safety and acceptability studies, their promotion needs to be evaluated as a communication intervention.
Understandings of the 'natural' body: a comparison of the views of users and providers of emergency contraception
Authors: Keogh L. A.
Published: November 2005

Background: ‘Natural’ is a pervasive discourse with mixed meanings in contemporary society. I was interested in how users and providers of emergency contraception conceptualised the ‘natural’ body in contraceptive decision making. Method: Thirty-two users and 19 providexxrs of emergency contraception from three sites in metropolitan Melbourne were interviewed, or participated in focus groups, about emergency contraceptive use, contraceptive decision making and perceptions of risk. The qualitative data were transcribed and coded to identify the key ways that both users and providers perceived the ‘natural’ body. Results: Providers and users adopted different frameworks for interpreting the discourse of the ‘natural’ body. Thirteen of the 32 users identified the ‘natural’ body as a factor in their decision making. They identified a ‘natural’ body as a body experiencing no interruption with ovulation, and/or free from unwanted side effects. Six of the 13 women who discussed the ‘natural’ body used a contraceptive that allowed them to preserve their natural body (e.g. condoms). The remaining seven women identified it as an ideal that they could not achieve. Providers in general discredited the idea of a ‘natural’ body and instead conceptualised contraceptive decision making as a ‘simple’ risk–benefit analysis. Conclusions: The differences between the two groups can be understood in a number of different ways. The important conclusion however, is that the different perspectives present a potential barrier to effective communication in the contraceptive consultation, and may be able to be resolved through the development of an embodied risk–benefit analysis that may be meaningful to both groups.
Sexual behaviour and human herpesvirus 8 infection in homosexual men in Australia
Authors: Grulich Andrew E. , Cunningham Philip , Munier Mee-Ling , Prestage Garrett , Amin Janaki , Ringland Clare , Whitby Denise , Kippax Susan , Kaldor John M. , Rawlinson William
Published: November 2005

Background: Human herpesvirus 8 (HHV-8) is a common sexually transmitted agent among homosexual men, but there are few Australian data. We aimed to describe the prevalence and risk factors for seropositivity to HHV-8 in Australian homosexual men. Methods: We conducted a prospective cohort study of 179 homosexual men in Sydney Australia in 1992–1998. Detailed data on sexual behaviour was collected annually, and HHV-8 status was determined at the end of the study by an algorithm based on results of an immunofluorescence assay and an enzyme-linked immunoassay to the K8.1 protein of HHV-8. HHV-8 DNA was detected in buffy coats using a nested qualitative PCR. Results: Data on sexual behaviour in at least three interviews and HHV-8 status were available in 174 (97%) of 179 men who agreed to participate. Of these, 31 (18%) were HHV-8 seropositive, and HHV-8 DNA was detected in 5 (16%) of these. The prevalence of HHV-8 infection was much higher in HIV positive (52%) than HIV negative (11%) men (OR 8.60, 95% CI 3.55–20.86). HHV-8 infection was related to more frequent reporting of unprotected receptive anal sex (OR for most frequent versus least frequent category 3.03, 95% CI 1.01–9.03, P trend 0.02), insertive oro–anal sex (OR for most frequent v. least frequent category 3.02, 95% CI 1.15–7.93, P trend 0.02) and receptive oro–anal sex (OR for most frequent v. least frequent category 3.09, 95% CI 1.11–8.60, P trend 0.05) with casual partners. Conclusions: These data are consistent with sexual transmission of HHV-8, but the precise mode of HHV-8 transmission remains unclear. Studies to elucidate the precise mode of sexual transmission of HHV-8 need to focus on potential salivary transmission, and should collect data on the HHV-8 infection and excretion status of the sexual partner.
Epidemiology of HIV and sexually transmitted infections in Thailand
Authors: Chandeying V.
Published: November 2005

There are very few developing countries in the world where public policy has been effective in preventing the spread of HIV/AIDS on a national scale. Thailand is an exception, a massive program to control HIV has reduced visits to commercial sex workers by half, raised condom usage, decreased sexually transmitted infections dramatically, and achieved substantial reductions in new HIV infections. However, unless past efforts are sustained and new sources of infection are addressed, the striking achievements made in controlling the epidemic could be put at risk. There is a need in Thailand to continue strong HIV/AIDS prevention and education efforts in the future, as well as to provide treatment and care for those living with HIV/AIDS.
Correlates of perceived difficulty in potentially disclosing HIV-positive test results: a study of low-income women attending an urban clinic
Authors: Crosby Richard , Bonney Elizabeth A. , Odenat Lydia
Published: November 2005

Background: The study identified correlates of women’s perception that testing positive for HIV would be very difficult to communicate to friends, family members and sex partners. We also determined whether perceived disclosure difficulty was associated with HIV-testing intent. Methods: Face-to-face interviews were conducted with 143 women attending an urgent care centre in Atlanta, Georgia. The centre served primarily low-income or indigent African–American women. A three-item scale (α = 0.81) assessed disclosure difficulty. Assessed correlates included selected social/contextual factors and intrapersonal factors. Results: In controlled multivariate analyses, only the social/contextual factors were associated with HIV disclosure difficulty. Women perceiving an inability to cope with positive results were more likely to report high disclosure difficulty (P = 0.01). Women perceiving an inadequate support system and those believing that HIV would substantially complicate their lives were more likely to anticipate high disclosure difficulty (P = 0.006 and P = 0.03, respectively). Disclosure difficulty was not associated with intent for HIV-testing ‘today’ (P = 0.50) or within the next 12 months (P = 0.27). Conclusion: Findings provide initial evidence suggesting that selected social/contextual factors rather than intrapersonal factors are associated with anticipated disclosure difficulty of HIV-positive test results among low-income minority women, residing in the urban south. High levels of anticipated disclosure difficulty may not preclude HIV test acceptance.
Managing patients with sexual transmission of drug-resistant HIV
Authors: Tozzi Valerio , Corpolongo Angela , Bellagamba Rita , Narciso Pasquale
Published: November 2005

The transmission of drug-resistant HIV-1 (primary HIV resistance) is a cause of growing concern. The prevalence of drug-resistant variants in patients with primary HIV-1 infection (PHI) ranges from 10 to 36%. Unlike patients with secondary resistance, patients with primary HIV resistance do not show a rapid conversion to wild-type drug-sensitive virus in the absence of treatment. Moreover, primary HIV-1 resistance is associated with higher rates of treatment failure. Rapid diagnosis is important, since early events in PHI may have a critical role in disease progression. An early diagnosis is also essential to prevent HIV-1 transmission during the high viremic phase of PHI. This review focuses on prevalence, basic principles, diagnostic markers, and approaches for the treatment of PHI due to sexual transmission of drug-resistant HIV-1. The aim of the paper is to help clinicians to deal with patients presenting a PHI due to drug-resistant variants.
Evaluating the utility of surveillance data to decision makers in Victoria, Australia
Authors: Pope Jeanette , Counahan Megan
Published: November 2005

Objective. Evaluating the utility of surveillance data to decision makers in Victoria, Australia. Methods. A survey of all sexually transmitted infection program directors in Victoria, Australia, was undertaken to examine readership and use of annual and quarterly reports. Results. One hundred and sixteen programs in 86 organisations were identified as undertaking sexually transmitted infection control activities in Victoria. Around 17% of the directors never read the reports and others reported not finding the information contained in them useful. While we found the information generated from the surveillance system has an important role in triggering action for epidemics and pervades more general decision making by improving the general knowledge of sexually transmitted infection trends, the indicators are not seen as useful by most key stakeholders. Conclusions. Significant improvements in the utility of the system could be made by changes to the data output and key suggestions made by the stakeholders are outlined.
HIV testing of pregnant women—what is needed to protect positive women's needs and rights?
Authors: de Bruyn Maria , Paxton Susan
Published: November 2005

With increased availability of antiretroviral therapy, there is an escalating global trend to test all pregnant women for HIV in order to stop perinatal transmission. However, insufficient consideration is given to the impact this may have on the lives of these women and their families. Many women feel pressured into HIV testing during pregnancy, do not receive adequate pre-test counselling or do not give truly informed consent. Some women who test positive experience significantly more discrimination from their partners, families and community members than HIV-positive men do. As a consequence, large numbers of women diagnosed during pregnancy do not tell their husband their status because they fear blame, abandonment or abuse, including physical assault. Women who do disclose their HIV status may face dramatic negative repercussions on their own and their children’s wellbeing. Consequently, it is unfair to test women during pregnancy solely or mainly to help prevent perinatal transmission if there are no available support services to protect the women’s rights, enable them to live healthily after an HIV-positive diagnosis and engage them in the policies and programmes that affect women’s lives. We need to create a climate that encourages HIV testing before pregnancy so that women can make informed reproductive choices. Men must be brought into the testing process through couple counselling before pregnancy and scaling up of voluntary counselling and testing programmes outside the antenatal care setting. In addition, people living with HIV have unique expertise and are very effective as peer counsellors. They have been under-utilised in the health care sector to provide support to newly-diagnosed people and to help eliminate AIDS-related shame and stigma.
Genetic influences on HIV infection: implications for vaccine development
Authors: Smith Miranda Z. , Kent Stephen J.
Published: November 2005

Human HIV infection is characterised by great variability in outcome. Much of this variability is due either to viral variation or host genetic factors, particularly major histocompatibility complex differences within genetically diverse populations. The study of non-human primates infected with well characterised simian immunodeficiency virus strains has recently allowed further dissection of the critical role of genetic influences on both susceptibility to infection and progression to AIDS. This review summarises the important role of many host genetic factors on HIV infection and highlights important variables that will need to be taken into account in evaluating effective HIV vaccines.
Genital self-mutilation by radio-frequency in a male-to-female transsexual
Authors: Russell Darren B , McGovern Gillian , Harte Fintan B
Published: November 2005

We report the case of a male-to-female transgender individual who inflicted radio-frequency injuries to her testicles in an attempt to damage them. Important consideration should be given by medical practitioners when they are faced with an individual who believes he or she is transgender. A sympathetic approach should be taken and a referral made to a clinician or service experienced in dealing with transgender patients.
Do the characteristics of sexual health centre clients predict chlamydia infection sufficiently strongly to allow selective screening?
Authors: Hocking Jane , Fairley Christopher K.
Published: November 2005

Objectives: This study aimed to estimate chlamydia prevalence and risk factors for infection and to assess the performance of chlamydia-selective screening criteria among clients attending a large sexually transmitted infection (STI) clinic. Methods: Computerised records for all attendances between 1 July 2002 and 30 June 2003 were analysed. Chlamydia prevalence and risk factors for infection were determined for all new clients. The sensitivity and specificity of risk factors for chlamydia were assessed. Results: 2642 male and 2084 female new clients were tested for chlamydia with a prevalence of 7.3% (95% CI: 6.3%, 8.4%) among men and 3.9% (95% CI: 3.1%, 4.9%) among women. Screening heterosexual men based on a positive contact or symptoms of non-specific urethritis or any two of age < 25 years, 4+ partners last 12 months, inconsistent condom use or not presenting for an asymptomatic screen detected 88% of infections by screening 62%. Screening women based on a positive contact or injecting drug use or any two of age < 25 years, 2+ partners last 12 months or inconsistent condom use would detect 86% of infections by screening 57%. Conclusions: Selective screening could be used to more efficiently identify heterosexual men and women at risk of chlamydia.
The prevalence of genital Chlamydia trachomatis in Australia 1997 - 2004: a systematic review
Authors: Vajdic Claire M. , Middleton Melanie , Bowden Francis J. , Fairley Christopher K. , Kaldor John M.
Published: November 2005

Objectives: To determine by systematic review the prevalence of genital chlamydial infection in Australia between 1997 and 2004. Methods: Electronic literature databases, reference lists, and conference proceedings were searched and health agencies and jurisdictions were contacted for published and unpublished reports. Studies were eligible if they offered a diagnostic nucleic acid amplification test to consecutive individuals presenting during the study period. As a summary measure of the available data, mean prevalence rates, weighted by sample size and irrespective of participant age, were calculated for the population sub-groups. Results: 40 studies of 50 populations and 40587 individuals met the inclusion criteria, but only one of these was population-based. The use of non-systematic methodologies prevented an assessment of time trends and a statistical comparison of population sub-groups. The mean overall prevalence of genital chlamydial infection was 4.6% (95% CI 4.4–4.8%), reflecting over-sampling of high-risk groups. The mean community-based rates were 7.5% (95% CI 6.4–8.6%) and 8.7% (95% CI 7.9–9.7%) for Indigenous men and women, and 1.5% (95% CI 1.1–1.9%) and 1.4% (95% CI 0.9–2.0%) for non-Indigenous men and women. The overall mean estimates for other groups were 3.3% (95% CI 3.0–3.7%) for female attendees of sexual health and related clinics, 5.6% (95% CI 4.9–6.4%) for adolescents and young adults, 3.3% (95% CI 2.8–3.9%) for sex workers, and 1.6% (95% CI 1.2–2.0%) for urethral infection in men who have sex with men. Clinic-based estimates were generally, although not consistently, higher than community-based estimates. There is no serial population-based data for sexually active young men and women, but the available age-specific rates suggest under-ascertainment by the routine surveillance systems. Conclusions: The prevalence of genital chlamydial infection in Indigenous Australians and young adults is unacceptably high and quality epidemiological studies are urgently required to supplement the routinely collected national notification data.
Sex differences in brain activation elicited by humor
Authors: Azim Eiman , Mobbs Dean , Jo Booil , Menon Vinod , Reiss Allan L.
Published: November 2005

With recent investigation beginning to reveal the cortical and subcortical neuroanatomical correlates of humor appreciation, the present event-related functional MRI (fMRI) study was designed to elucidate sex-specific recruitment of these humor related networks. Twenty healthy subjects (10 females) underwent fMRI scanning while subjectively rating 70 verbal and nonverbal achromatic cartoons as funny or unfunny. Data were analyzed by comparing blood oxygenation-level-dependent signal activation during funny and unfunny stimuli. Males and females share an extensive humor-response strategy as indicated by recruitment of similar brain regions: both activate the temporal-occipital junction and temporal pole, structures implicated in semantic knowledge and juxtaposition, and the inferior frontal gyrus, likely to be involved in language processing. Females, however, activate the left prefrontal cortex more than males, suggesting a greater degree of executive processing and language-based decoding. Females also exhibit greater activation of mesolimbic regions, including the nucleus accumbens, implying greater reward network response and possibly less reward expectation. These results indicate sex-specific differences in neural response to humor with implications for sex-based disparities in the integration of cognition and emotion.