Effect of ammonia on methane production pathways and reaction rates in acetate-fed biogas processes.

In order to understand the correlation between ammonia and methanogenesis metabolism, methane production pathways and their specific rates were studied at total ammonium nitrogen (TAN) concentrations of 0.14-9 g/L in three methanogenic sludges fed with acetate, at both mesophilic and thermophilic conditions. Results showed that high levels of TAN had significant inhibition on methanogenesis; this could, however, be recovered via syntrophic acetate oxidation (SAO) coupled with Hydrogenotrophic Methanogenesis (HM) performed by acetate oxidizing syntrophs or through Acetoclastic Methanogenesis (AM) catalyzed by Methanosarcinaceae, after a long lag phase >50 d. Free ammonia (NH3) was the active component for this inhibition, of which 200 mg/L is suggested as the threshold for the pathway shift from AM to SAO-HM. Methane production rate via SAO-HM at TAN of 7-9 g/L was about 5-9-fold lower than that of AM at TAN of 0.14 g/L, which was also lower than the rate of AM pathway recovered at TAN of 7 g/L in the incubations with a French mesophilic inoculum. Thermophilic condition favored the establishment of the SAO-catalyzing microbial community, as indicated by the higher reaction rate and shorter lag phase. The operational strategy is thus suggested to be adjusted when NH3 exceeds 200 mg/L.

Factors associated with antiretroviral treatment uptake and adherence: a review. Perspectives from Australia, Canada, and the United Kingdom.

International focus on reducing onward HIV transmission emphasizes the need for routine HIV testing and early uptake of antiretroviral treatment (ART). Strategic targets have been set for 2020 to achieve the goal of 90% of people infected with HIV diagnosed, 90% of identified cases on treatment, and 90% of persons on treatment virally suppressed (90-90-90). It is vital to understand the complexity of factors influencing a person's treatment decisions over time and the context which may enable better adherence. In this paper we present findings from the review of published and gray literature (2003-2013) on the documented factors associated with treatment initiation and adherence in the general adult population of Australia, Canada, and the UK. A framework developed by Begley, McLaws, Ross, and Gold [2008. Cognitive and behavioural correlates of non-adherence to HIV anti-retroviral therapy: Theoretical and practical insight for clinical psychology and health psychology. Clinical Psychologist, 12(1), 9-17] in Australia was adapted to summarize the findings. A systematic database search using keywords and a set of inclusion criteria yielded 17 studies (Australia = 6; Canada = 8; UK = 3). In addition 11 reports were included in the review. We found that a person's abilities and motivations (intrapersonal factors, reported in 7 studies) to start and continue ART are influenced by a host of interconnected factors spanning relationship (interpersonal, 3 studies) and broader structural (extrapersonal, 15 studies) factors that are situated within social determinants of health. People therefore evaluate various costs and benefits of starting and staying on treatment, in which biomedical concerns play an important yet often subsidiary role. In this review the economic barriers to care were found to be significant and under-reported, highlighting the persistent health inequities in terms of access to services. Our understanding of the context around people's use of ART remains poor. Qualitative social research within HIV-positive communities is urgently needed to capture people's lived experiences and may address some of this deficit in understanding.

Factors impacting HIV testing: a review--perspectives from Australia, Canada, and the UK.

With the current global focus on strengthening HIV prevention through greater testing and treatment uptake, it is increasingly salient to identify and address barriers to testing. A review of the published, peer-reviewed literature and national reports from Australia, Canada, and the UK (2003-2013) on barriers to HIV testing was conducted to provide new information relevant to Australia and to complement earlier reviews from Canada and the UK. A systematic database search using keywords and a set of inclusion criteria yielded 36 studies (Australia = 13; Canada = 6; and the UK = 17). In addition 17 unpublished reports were included in the review. Our study uses a novel, comprehensive framework to describe barriers to HIV testing, and thus contributes to moving beyond the traditional patient-provider-system categorization. Within that framework, barriers are categorized as either intrapersonal (reported in 15 studies), interpersonal (21), or extrapersonal (16) and conceptualized within wider sociocultural and structural contexts. People's abilities and motivations to test (intrapersonal factors) are influenced by a host of interconnected factors spanning relationship (interpersonal) and broader socioeconomic, political and cultural (extrapersonal) factors. We suggest that the relative effects of interventions targeting barriers to HIV testing at the intrapersonal and interpersonal levels are limited by the extent to which the social determinants of health are addressed. The framework may also lend itself to thinking about the enabling factors for HIV testing, and future research may investigate the application of that framework for strategizing the most effective response. Future studies should also capture the lived experiences of barriers to HIV testing experienced by patients, especially in populations which are hard to reach based on social and geographic distance. Context-specific studies to evaluate the feasibility and effectiveness of various interventions proposed in the literature to address barriers to HIV testing are needed.

Influence of the geomembrane on time-lapse ERT measurements for leachate injection monitoring.

Leachate recirculation is a key process in the operation of municipal waste landfills as bioreactors. To quantify the water content and to evaluate the leachate injection system, in situ methods are required to obtain spatially distributed information, usually electrical resistivity tomography (ERT). However, this method can present false variations in the observations due to several parameters. This study investigates the impact of the geomembrane on ERT measurements. Indeed, the geomembrane tends to be ignored in the inversion process in most previously conducted studies. The presence of the geomembrane can change the boundary conditions of the inversion models, which have classically infinite boundary conditions. Using a numerical modelling approach, the authors demonstrate that a minimum distance is required between the electrode line and the geomembrane to satisfy the good conditions of use of the classical inversion tools. This distance is a function of the electrode line length (i.e. of the unit electrode spacing) used, the array type and the orientation of the electrode line. Moreover, this study shows that if this criterion on the minimum distance is not satisfied, it is possible to significantly improve the inversion process by introducing the complex geometry and the geomembrane location into the inversion tools. These results are finally validated on a field data set gathered on a small municipal solid waste landfill cell where this minimum distance criterion cannot be satisfied.

Use of the UriSwab collection device for testing of Chlamydia trachomatis and Neisseria gonorrhoeae: implications for a postal testing service.

In order to demonstrate the reliability of UriSwab, a trial was conducted using urine samples that had previously returned a detected result for Chlamydia trachomatis and/or Neisseria gonorrhoeae. Urine specimens (115 samples) were received from sexual health clinics and tested using the Roche Cobas 4800 CT/NG method. Concurrently, the urine samples were pipetted directly on to the sponge applicator of the UriSwab, simulating micturition, and the urine harvested from the UriSwab was tested using the Roche Cobas 4800 method. Of the 87 standard urine specimens that were C. trachomatis detected, 85 (98%) were also detected in the corresponding UriSwab specimen (sensitivity 97.7%, specificity 95.7%). Of the 34 standard specimens that were N. gonorrhoeae detected, 33 (97%) were also detected in the corresponding UriSwab specimen (sensitivity 97.1%, specificity 100%). The performance of the UriSwab in this trial was comparable with the testing of neat first-catch urine specimens for both C. trachomatis and N. gonorrhoeae.

A novel gel-based method for self-collection and ambient temperature postal transport of urine for PCR detection of Chlamydia trachomatis.

OBJECTIVES: The aim of this study was to develop a novel urine transport method to be used in self-collection-based screening for Chlamydia trachomatis. The method needed to be suitable for C trachomatis PCR detection, be economical and suitable for transport by standard envelope mailing. METHODS: An anhydrous gel composed of super-absorbent polymer and buffering agent was used to desiccate urine into a dry granulous state, which could subsequently be reconstituted upon arrival at a laboratory. DNA was then extracted from the reconstituted solution using the Roche MagNA Pure protocol for the detection of C trachomatis by PCR. Collections of urine specimens from three populations with widely differing chlamydia prevalence (100%,n = 56; 47%, n = 70; 3%, n = 97) were used. We determined the gel method's impact on C trachomatis PCR sensitivity and specificity using neat and gel-processed urine specimens. An equine herpes virus PCR was used to test for assay inhibition. RESULTS: Overall, the sensitivity of the gel-based method ranged from 94.6-100% compared with neat urine, with a specificity of 100%. No PCR inhibition or decrease in analytical sensitivity was observed using the gel-processed extracts. CONCLUSIONS: The gel-based method was found to be suitable for the detection of C trachomatis by PCR. In addition, its ease of use, effectiveness at ambient temperature and low cost makes it well-suited for self-collection kits used in population-based C trachomatis screening, particularly for geographically and socially isolated individuals.

Screening for syphilis among men who have sex with men in various clinical settings.

OBJECTIVES: To assess the prevalence of syphilis infections among men who have sex with men (MSM) accessing the Brisbane Sexual Health Clinic during the period 1997 up to May 2003, data were collated through three clinical programmes conducted by the service-a large inner city mainstream sexual health clinic and two small outreach sessional clinics conducted on the site of male sex on premises venues (SOPV). Data analysis also provided the opportunity to evaluate the effectiveness of the smaller outreach clinics to access populations of MSM less likely to attend or identify at the larger mainstream clinic, and therefore enhance the detection of previously undiagnosed sexually transmissible infections. METHODS: Computerised records from 1997-2003 were collated for a statistical analysis of syphilis and other STI pathology results for all MSM accessing the mainstream clinic, and two outreach clinics. RESULTS: A review of client charts showed that 16 new syphilis diagnoses were made over the previous 5 years, but only two of these infections (both through the mainstream clinic) were early syphilis and therefore transmissible. All other cases were latent infections. A higher proportion of bisexual men was identified with positive syphilis serology but this was just below significance (p=0.06). Significantly, almost a third of syphilis diagnoses (all latent) were made at SOPV outreach clinics, despite the much lower proportion of clients seen overall through the SOPV clinics. For other sexually transmissible infections, the mainstream clinic demonstrated greater efficiency at case detection. CONCLUSION: Outreach clinics located in male saunas may serve an effective function in syphilis screening by facilitating access for a particular subpopulation of MSM (bisexual, married men). These outreach clinics may provide important outlets for education and opportunistic screening of asymptomatic MSM and foster a greater willingness for men to honestly self identify. However, larger, mainstream clinics serve a more anonymous venue for the testing of symptomatic men.

Detection of Chlamydia trachomatis in an Australian high school student population.

OBJECTIVE: To assess the prevalence of Chlamydia trachomatis infections among an Australian high school adolescent population. METHODS: Over a 4 year period, 14 high schools were selected in which an infertility prevention programme targeting C. trachomatis was delivered to senior student populations. Coded first catch urine specimens were analysed by Amplicor PCR and infected students treated. Data retrospectively obtained from chlamydia screening programmes conducted among disadvantaged young people detached from formal education were also collated for comparison. RESULTS: Of a total student test population of 1174, 15 (1.3%; 95% CI 0.7% to 2.1%) were diagnosed with C. trachomatis. Of 516 females and 658 males, 12 (2.3%; 95% CI 1.1% to 4.1%) and 3 (0.5%; 95% CI 0.1% to 1.4%) were tested positive respectively. Data collated for three populations of disadvantaged youth returned at total of 89 C. trachomatis infections out of 560 people (15.9% 95%CI 13.0-19.2%). CONCLUSION: The overall prevalence of C. trachomatis infection among this population of senior high school adolescents is low, and significantly differs from the higher chlamydia rates detected in disadvantaged adolescents detached from formal schooling (p<0.0001).

Reduced levels of gamma-interferon secretion in response to chlamydial 60 kDa heat shock protein amongst women with pelvic inflammatory disease and a history of repeated Chlamydia trachomatis infections.

Peripheral lymphocytes in uninfected fertile controls, women with various histories of Chlamydia trachomatis infection, pelvic inflammatory disease (PID) and infertility not due to C. trachomatis infection (endometriosis) were cultured overnight with PHA mitogen and the 60 kDa chlamydial heat shock protein. Plasma samples were then assayed for levels of gamma-interferon and IL-10 using a commercial ELISA system. Women with PID and those with a history of multiple C. trachomatis infections showed reduced gamma-interferon production in response to cHSP60, not seen in women infected only once and those with infertility due to other causes (endometriosis). Secretion of IL-10 in response to cHSP60 did not vary significantly across the various patient groups, though all patients showed elevated levels of total IL-10 compared with uninfected controls.