Modal noise in an integrated photonic lantern fed diffraction-limited spectrograph.

In an attempt to develop a streamlined astrophotonic instrument, we demonstrate the realization of an all-photonic device capable of both multimode to single mode conversion and spectral dispersion on an 8-m class telescope with efficient coupling. The device was a monolithic photonic spectrograph which combined an integrated photonic lantern and an efficient arrayed waveguide grating device. During on-sky testing, we discovered a previously unreported type of noise that made spectral extraction and calibration extremely difficult. The source of the noise was traced to a wavelength-dependent loss mechanism between the feed fiber's multimode near-field pattern and the modal acceptance profile of the integrated photonic lantern. Extensive modeling of the photonic components replicates the wavelength-dependent loss, and demonstrates an identical effect on the final spectral output. We outline that this could be mitigated by directly injecting into the integrated photonic lantern.

Nineteen-port photonic lantern with multimode delivery fiber.

We demonstrate efficient multimode (MM) to single-mode (SM) conversion in a 19-port photonic lantern with a 50 µm core MM delivery fiber. The photonic lantern can be used within the field of astrophotonics for coupling MM starlight to an ensemble of SM fibers in order to perform fiber-Bragg-grating-based spectral filtering. An MM delivery fiber spliced to the photonic lantern offers the advantage that the delivery fiber guides the light from the focal plane of the telescope to the splitter. Therefore, it is no longer necessary to have the splitter mounted directly in the focal plane of the telescope. The coupling loss from a 50 µm core MM fiber to an ensemble of 19 SM fibers and back to a 50 µm core MM fiber is below 1.1 dB.

A complex multi-notch astronomical filter to suppress the bright infrared sky.

A long-standing and profound problem in astronomy is the difficulty in obtaining deep near-infrared observations due to the extreme brightness and variability of the night sky at these wavelengths. A solution to this problem is crucial if we are to obtain the deepest possible observations of the early Universe, as redshifted starlight from distant galaxies appears at these wavelengths. The atmospheric emission between 1,000 and 1,800 nm arises almost entirely from a forest of extremely bright, very narrow hydroxyl emission lines that varies on timescales of minutes. The astronomical community has long envisaged the prospect of selectively removing these lines, while retaining high throughput between them. Here we demonstrate such a filter for the first time, presenting results from the first on-sky tests. Its use on current 8 m telescopes and future 30 m telescopes will open up many new research avenues in the years to come.

The PLATO Dome A site-testing observatory: power generation and control systems.

The atmospheric conditions above Dome A, a currently unmanned location at the highest point on the Antarctic plateau, are uniquely suited to astronomy. For certain types of astronomy Dome A is likely to be the best location on the planet, and this has motivated the development of the Plateau Observatory (PLATO). PLATO was deployed to Dome A in early 2008. It houses a suite of purpose-built site-testing instruments designed to quantify the benefits of Dome A site for astronomy, and science instruments designed to take advantage of the observing conditions. The PLATO power generation and control system is designed to provide continuous power and heat, and a high-reliability command and communications platform for these instruments. PLATO has run and collected data throughout the winter 2008 season completely unattended. Here we present a detailed description of the power generation, power control, thermal management, instrument interface, and communications systems for PLATO, and an overview of the system performance for 2008.

How to contain generalized HIV epidemics? A plea for better evidence to displace speculation.

In the worst generalized HIV epidemics in East and Southern Africa, from one-quarter to three-quarters of women aged 15 years can expect to be living with HIV or to have died with AIDS by age 40 years. This disaster continues in the face of massive HIV prevention programmes based on current inexact knowledge of HIV transmission pathways and risks. To stop this disaster, both the public and public health experts need better information about the specific factors that allow HIV to propagate so extensively in countries with generalized epidemics. This knowledge could be acquired by tracing HIV infections to their source - especially tracing HIV infections in women of all ages, and tracing unexplained HIV infections in children with HIV-negative mothers.

Characterization and on-sky demonstration of an integrated photonic spectrograph for astronomy.

We present results from the first on-sky demonstration of a prototype astronomical integrated photonic spectrograph (IPS) using the Anglo-Australian Telescope near-infrared imaging spectrometer (IRIS2) at Siding Spring Observatory to observe atmospheric molecular OH emission lines. We have succeeded in detecting upwards of 27 lines, and demonstrated the practicality of the IPS device for astronomy. Furthermore, we present a laboratory characterization of the device, which is a modified version of a commercial arrayed-waveguide grating multiplexer. We measure the spectral resolution full-width-half-maximum to be 0.75 +/- 0.05 nm (giving R = lambda/deltalambda = 2100 +/- 150 at 1500 nm). We find the free spectral range to be 57.4 +/- 0.6 nm and the peak total efficiency to be approximately 65%. Finally, we briefly discuss the future steps required to realize an astronomical instrument based on this technology concept.

Process, efficacy and sample demographics of three approaches to behavioural surveillance for gonorrhoea: case interviews, place surveys, and network studies.

We investigated the process and time required to collect 450 interviews in a project to determine the most efficacious behavioural surveillance approaches to detect changes in gonorrhoea prevalence. In total, 150 respondents were recruited in each method. For each of place surveys (bars), gonorrhoea case interviews, and network studies based on seeds from the case and place interviews, we determined the recruitment rate and process. Urine testing for gonorrhoea and chlamydia took place in the place interviews. We present data from Houston, Texas that illustrate the sample characteristics, recruitment rates, and, where appropriate, infection rates. Data indicate that there was high uptake and a rapid recruitment rate from the place surveys, an intermediate rate from the network studies, and that the gonorrhoea case interviews were the most inefficient accrual method for behavioural surveillance. Sample characteristics and biases in each method are described, and conclusions drawn for the relative efficacy of each method for gonorrhoea behavioural surveillance.

Factors associated with HIV prevalence in a pre-partum cohort of Zambian women.

An ongoing study of mother-to-child human herpes virus-8 (HHV-8) transmission in Zambian women (n = 3160) allowed us to examine the association of medical injections with HIV serostatus while simultaneously accounting for other factors known to be correlated with HIV prevalence. Multi-method data collection included structured interviews, medical record abstraction, clinical examinations, and biological measures. Medically administered intramuscular or intravenous injections in the past five years (but not blood transfusions) were overwhelmingly correlated with HIV prevalence, exceeding the contribution of sexual behaviours in a multivariable logistic regression. Statistically significant associations with HIV also were found for some demographic variables, sexual behaviours, alcohol use, and sexually transmitted diseases (STD). The results confirmed that iatrogenic needle exposure, sexual behaviour, demographic factors, substance use, and STD history are all implicated in Zambian women's HIV+ status. However, the disproportionate association of medical injection history with HIV highlights the need to investigate further and prospectively the role of health-care injection in sub-Saharan Africa's HIV epidemic.

Sex work in Tallinn, Estonia: the sociospatial penetration of sex work into society.

BACKGROUND: It is important to describe and understand the underlying patterns and dynamics that govern sex work in societies undergoing rapid political and social changes, its heterogeneity across populations, and its evolution through time in order to inform future research, sound policy formation, and programme delivery. OBJECTIVES: To describe the socioeconomic and cultural determinants, organisational structure, distinct categories, and spatial patterning of sex work in Tallinn, Estonia, and identify recent temporal changes in sex work patterns. METHODS: In-depth interviews with key informants; naturalistic observations of sex work and drug use venues, geo-mapping of sex work sites, review of media, public policy, and commissioned reports, and analyses of existing data. RESULTS: Sex work takes place in a hierarchy of locations in Tallinn ranging from elite brothels and "love flats" to truck stops. These sites vary in terms of their public health importance and social organisation. There are full time, part time, and intermittent male and female sex workers. Among others, the taxi driver, madam and the bartender are central roles in the organisation of sex work in Tallinn. Cell phone and internet technology enable sex work to be highly dispersed and spatially mobile. CONCLUSION: Future research and programmatic service delivery or outreach efforts should respond to the changing profile of sex work in Tallinn and its implications for STD/HIV epidemiology.

Sex work, drug use, HIV infection, and spread of sexually transmitted infections in Moscow, Russian Federation.

Rates of HIV-1 infection are growing rapidly, and the epidemic of sexually transmitted infections is continuing at an alarming rate, in the Russian Federation. We did a cross-sectional study of sexually transmitted infections, HIV infection, and drug use in street youth at a juvenile detention facility, adults at homeless detention centres, and women and men at a remand centre in Moscow. 160 (79%) women at the remand centre were sex workers. 91 (51%) homeless women had syphilis. At least one bacterial sexually transmitted infection was present in 97 (58%) female juvenile detainees, 120 (64%) women at the remand centre, and 133 (75%) homeless women. HIV seroprevalence was high in women at the remand centre (n=7 [4%]), adolescent male detainees (5 [3%]), and homeless women (4 [2%]). In view of the interaction between sexually transmitted infections and HIV infection, these findings of high prevalence of sexually transmitted infections show that these disenfranchised populations have the potential to make a disproportionately high contribution to the explosive growth of the HIV epidemic unless interventions targeting these groups are implemented in the Russian Federation.

Physicians' opinions about partner notification methods: case reporting, patient referral, and provider referral.

BACKGROUND: The United States has relied upon partner notification strategies to help break the chain of infection and re-infection for sexually transmitted diseases (STD). Physicians are a vital link in the system of STD control, but little is known of physician opinions about partner notification strategies. METHODS: We collected opinions about partner notification from a national probability sample of physicians in specialties diagnosing STDs. Physicians responded to 17 questions about three relevant forms of STD partner notification: patient based referral, provider based referral, and case reporting. RESULTS: Exploratory factor analyses showed that responses for each form of partner notification could be grouped into four categories: perceived practice norms, infection control, patient relationships, and time/money. Multivariate analyses of the factors showed that physicians endorsed patient based referral most favourably and provider based referral least favourably. CONCLUSION: Physicians' opinions about partner notification strategies appear to reflect objective reality in some areas, but not in others. Strategies that improve the fit between physicians' opinions and effective notification are needed: some are discussed here.

National survey of doctors' actions following the diagnosis of a bacterial STD.

OBJECTIVES: Little is known about the post-STD diagnosis management practices of community based doctors. The purpose of this study was to describe the reported actions that doctors take after diagnosing gonorrhoea, chlamydia, or syphilis and to determine if these actions differ across the three STDs. METHODS: A random national sample of 7300 doctors (70% response rate) practising in five medical specialties responded to 13 questions related to STD management. Mean differences across STDs were examined using the General Linear Model function of SPSS. RESULTS: Most doctors reported instructing patients to abstain from sex during treatment, to use condoms, and to inform their sexual partners of their exposure after diagnosing gonorrhoea, chlamydia, or syphilis. For syphilis, however, doctors were less likely to treat the patients presumptively and to give them drugs for their partners; and more likely to collect partner information, to follow up with the patient to see if the partner was referred for treatment and to send patient information to the health department. CONCLUSIONS: Doctors' post-STD diagnosis actions were similar for gonorrhoea and chlamydia compared to syphilis. Study findings suggest low levels of STD case reporting and partner follow up by doctors in the sample. Interventions are needed to educate community based doctors about the importance of partner follow up and case reporting in the management of STDs.

The effects of variations in mode of delivery and monetary incentive on physicians' responses to a mailed survey assessing STD practice patterns.

High response rates from physicians are key to obtaining valid and generalizable data regarding their sexually transmitted disease (STD) diagnosis, treatment, and control practices. A factorial (3 x 2) study was designed using varying cash incentives ($0, $15, $25) and delivery modes (Federal Express, U.S. mail). Surveys, with three follow-up mailings, were sent to a national probability sample of 311 physicians in OB-GYN, family practice, internal and emergency medicine, and pediatrics specialties. Overall, 156 physicians returned completed surveys (56% overall response rate). Significant effects for incentive level (F = 28.2, df = 2, p < .01) and delivery mode (F = 4.1, df = 1, p < .05) existed. Highest response was among physicians in the $25-FedEx condition (81%). High response rates from busy practicing physicians can be achieved if surveys are relevant to clinical practice, sponsored by a reputable organization (the Centers for Disease Control and Prevention), include a monetary incentive, and are delivered by courier.

Community-based interventions to reduce low income, African American women's risk of sexually transmitted diseases: a randomized controlled trial of three theoretical models.

A community-based sample of disadvantaged African American women (n = 445) was recruited to participate in 1 of 3 theoretically driven experimental interventions based on either the theory of gender and power, social learning theory, or cognitive behavioral theory. Intervention outcomes were compared with a waiting list control condition. From baseline to postintervention, women in the experimental interventions showed differential change on cognitive indices (knowledge and attitudes) and skill acquisition (partner negotiation skills, correct condom application, lubricant selection, and information-provision to social networks) whereas control participants were unchanged. Women in the 3 experimental interventions also completed follow-up assessments for 1 year following the interventions. In all 3 experimental conditions, condom use increased relative to the control group and there were no differences between the experimental interventions. Women who participated in one of the theoretically grounded interventions continued to increase condom use over the following year. Women entering new relationships reported significantly more condom use than did women who remained in ongoing relationships. The findings suggest that intervention models that have proven effective for women who engage in high-risk behavior may be less effective for women in established relationships for whom risk is primarily derived from the extrarelationship behavior of their partners.

Normative studies with the Scale for Interpersonal Behaviour (SIB): II. US students. A cross-cultural comparison with Dutch data.

The Scale for Interpersonal Behaviour (SIB), a multidimensional, self-report measure of state assertiveness, was administered to a nationwide sample of 2375 undergraduates enrolled at 11 colleges and universities across the USA. The SIB was developed in the Netherlands for the independent assessment of both distress associated with self-assertion in a variety of social situations and the likelihood of engaging in a specific assertive response. This is done with four factorially-derived, first-order dimensions: (i) Display of negative feelings (Negative assertion); (ii) Expression of and dealing with personal limitations; (iii) Initiating assertiveness; and (iv) Praising others and the ability to deal with compliments/praise of others (Positive assertion). The present study was designed to determine the cross-national invariance of the original Dutch factors and the construct validity of the corresponding dimensions. It also set out to develop norms for a nationwide sample of US students. The results provide further support for the reliability, factorial and construct validity of the SIB. Compared to their Dutch equivalents, US students had meaningfully higher distress in assertiveness scores on all SIB scales (medium to large effect sizes), whereas differences on the performance scales reflected small effect sizes. The cross-national differences in distress scores were hypothesized to have originated from the American culture being more socially demanding with respect to interpersonal competence than the Dutch, and from the perceived threats and related cognitive appraisals that are associated with such demands.

Measuring perceived barriers to condom use: psychometric evaluation of the Condom Barriers Scale.

A programmatic series of three studies developed and evaluated the Condom Barriers Scale (CBS), an instrument measuring women s perceived barriers to condom use for prevention of HIV and other sexually transmitted diseases. Following item generation and selection, Study 1 evaluated the CBS in a sample of minority women (N = 178), reduced the number of items, assessed the factor structure, evaluated the internal consistency, and explored the convergent validity of the CBS. In Study 2, the CBS was administered to a cross-validation sample (N = 278). Confirmatory factor analysis and internal consistency were compared against the original sample and construct, criterion, and discriminant validity were assessed. In Study 3 (N = 30), temporal stability of the CBS was evaluated. The resulting instrument appears to have sound psychometric properties and can be used to measure a key construct in the leading theoretical models of health behavior for which a measure with known psychometric properties previously has not been available.

Adolescents' recall of sexual behavior: consistency of self-report and effect of variations in recall duration.

PURPOSE: To describe the relationship between adolescents' 2-week, 2-month, and 12-month recall of sexual behavior; to assess the variability of adolescents' self-reported sexual behaviors over a period of 1 year; and to draw conclusions regarding the use of recall periods in measuring self-reported sexual behavior in adolescents. METHODS: Data from 296 African-American adolescents (age 12-19 years; 28% male) were analyzed. Baseline data comprise 2-week, 2-month, and 12-month recall of number of partners and frequency of condom-protected and unprotected vaginal, oral, and anal sex. Self-reported frequency of refusal of unprotected sex during the 2-week and 2-month recall periods are also included. To assess variability in self-reports of number of partners and frequency of behaviors over time, repeated measures of 2-week and 2-month recall were collected from a subset of the sample (n = 129; 24% male). RESULTS: The strength of correlation among responses from the three recall periods was dependent upon (a) the difference in length of the recall periods, and (b) the nature of the construct being recalled (e.g., number of partners vs. number of behaviors). Longitudinally, the variability of 2-week recall responses was generally larger than the variability in 2-month recall responses. CONCLUSIONS: Consistent estimates of adolescents' sexual behavior over a 1-year period may be obtained from several assessments of 2-week recall, or from relatively fewer assessments of 2-month recall data.

Emerging behavioral strategies for the prevention of HIV in rural areas.

HIV/AIDS prevention efforts have been concentrated in urban areas, despite increases in HIV in nonmetropolitan areas. This study reviews behavioral prevention programs initiated in rural areas and programs that could be adapted for rural contexts. Outcomes from these interventions demonstrate that preventive interventions at the population, community, targeted populations subgroups, and small group levels can reduce high-risk behavior in rural environments and are cost effective to deliver.

Behavioral and psychosocial consequences of HIV antibody counseling and testing with African American women.

This study compared a sample of low-income African American women in the southeastern United States who had and had not yet undergone HIV counseling and testing on risk-related cognitive mediating variables and self-reported sexual behaviors. Four hundred sixty (N = 460) African American women were recruited from health clinics and community settings in a southern city. Forty-five percent of the women (n = 207) had undergone HIV counseling and testing, whereas 55% (n = 253) had never been tested. Women who were seropositive were excluded from the analyses. After providing informed consent, the women completed a battery of cognitive mediating measures assessing AIDS knowledge, attitudes theoretically relevant to risk reduction, and self-reported sexual behavior. In addition, each participant demonstrated condom application skills using a penile model. Women who had undergone testing were younger, rated HIV disease as more serious, considered AIDS a greater health concern, had more positive attitudes toward HIV prevention, expressed greater intentions to use condoms, and evidenced a greater commitment to self-protective behavior than women who were not yet tested. Women who had undergone HIV antibody testing, however, showed no differences in sexual behavior from women who were never tested. Sexual behavior, including numbers of partners, frequency of unprotected intercourse, and inconsistent condom use, left women in both groups at significant and comparable risk for HIV and sexually transmitted disease infection. HIV counseling and testing alone may not be effective primary prevention strategies for promoting risk reduction among African American women.