Co-designed weight management intervention for women recovering from oestrogen-receptor positive breast cancer.

BACKGROUND: Weight gain is commonly observed during and after breast cancer treatment and is associated with poorer survival outcomes, particularly in women with oestrogen receptor-positive (ER +) disease. The aim of this study was to co-design (with patients) a programme of tailored, personalised support (intervention), including high-quality support materials, to help female breast cancer patients (BCPs) with ER + disease to develop the skills and confidence needed for sustainable weight loss.  METHODS: ER + BCPs were recruited from two UK National Health Service (NHS) Trusts. The selection criteria included (i) recent experience of breast cancer treatment (within 36 months of completing primary treatment); (ii) participation in a recent focus group study investigating weight management perceptions and experiences; (iii) willingness to share experiences and contribute to discussions on the support structures needed for sustainable dietary and physical activity behaviour change. Co-design workshops included presentations and interactive activities and were facilitated by an experienced co-design researcher (HH), assisted by other members of the research team (KP, SW and JS). RESULTS: Two groups of BCPs from the North of England (N = 4) and South Yorkshire (N = 5) participated in a two-stage co-design process. The stage 1 and stage 2 co-design workshops were held two weeks apart and took place between Jan-March 2019, with each workshop being approximately 2 h in duration. Guided by the Behaviour Change Wheel, a theoretically-informed weight management intervention was developed on the basis of co-designed strategies to overcome physical and emotional barriers to dietary and physical activity behaviour change. BCPs were instrumental in designing all key features of the intervention, in terms of Capability (e.g., evidence-based information, peer-support and shared experiences), Opportunity (e.g., flexible approach to weight management based on core principles) and Motivation (e.g., appropriate use of goal-setting and high-quality resources, including motivational factsheets) for behaviour change. CONCLUSION: This co-design approach enabled the development of a theoretically-informed intervention with a content, structure and delivery model that has the potential to address the weight management challenges faced by BCPs diagnosed with ER + disease. Future research is required to evaluate the effectiveness of the intervention for eliciting clinically-important and sustainable weight loss in this population.

How Can We Support the Use of Oral PrEP Among Young Women who Sell Sex? A PrEP Cascade Analysis.

BACKGROUND: We constructed self-reported pre-exposure prophylaxis (PrEP) cascades and explored factors associated with and barriers to PrEP use to inform efforts to support PrEP use among young women who sell sex. METHODS: Using self-reported data from HIV-negative young women who sell sex enrolled into a cohort study using respondent-driven sampling in Zimbabwe, we constructed PrEP cascades assessing knowledge of, ever offered, ever used, and current PrEP use in 2017 and 2019. We used logistic regression to examine factors associated with PrEP use by 2019. Through qualitative interviews with 43 women enrolled in the cohort, we investigated barriers to PrEP use. RESULTS: At enrollment, 50% of women had heard of PrEP, 12% had ever been offered PrEP, and 7% ever used PrEP. Over time, all cascade domains: 96% of women had heard of and 55% reported an active offer of PrEP. Among women retained in the study in 2019 (56%; n = 538), 34% ever took PrEP by 2019. PrEP use was associated with, at enrollment, reporting more clients in the past month (10+: 45% vs 1-3: 27% adjOR = 1.71 95% CI: 1.06 to 2.76), duration of selling sex (24% <2 years vs 38% 2-3 years; adjOR = 0.51 95% CI: 0.32 to 0.83), and having visited a female sex worker program in the past 12 months (55% vs 27%; adjOR = 2.92 95% CI: 1.91 to 4.46). Qualitative interviews revealed fear of disclosing sex work, HIV-related/ART-related stigma, and (opportunity) costs of accessing PrEP as barriers to use. CONCLUSION: PrEP use was associated with factors known to increase HIV risk. Fear of stigma, disclosure, and supply-side barriers need to be addressed to increase women's ability to use PrEP.

An Assessment of Earth's Climate Sensitivity Using Multiple Lines of Evidence.

We assess evidence relevant to Earth's equilibrium climate sensitivity per doubling of atmospheric CO2, characterized by an effective sensitivity S. This evidence includes feedback process understanding, the historical climate record, and the paleoclimate record. An S value lower than 2 K is difficult to reconcile with any of the three lines of evidence. The amount of cooling during the Last Glacial Maximum provides strong evidence against values of S greater than 4.5 K. Other lines of evidence in combination also show that this is relatively unlikely. We use a Bayesian approach to produce a probability density function (PDF) for S given all the evidence, including tests of robustness to difficult-to-quantify uncertainties and different priors. The 66% range is 2.6-3.9 K for our Baseline calculation and remains within 2.3-4.5 K under the robustness tests; corresponding 5-95% ranges are 2.3-4.7 K, bounded by 2.0-5.7 K (although such high-confidence ranges should be regarded more cautiously). This indicates a stronger constraint on S than reported in past assessments, by lifting the low end of the range. This narrowing occurs because the three lines of evidence agree and are judged to be largely independent and because of greater confidence in understanding feedback processes and in combining evidence. We identify promising avenues for further narrowing the range in S, in particular using comprehensive models and process understanding to address limitations in the traditional forcing-feedback paradigm for interpreting past changes.

Quasi-periodic ripples in high latitude electron content, the geomagnetic field, and the solar wind.

In this study we present evidence for the existence of quasi-periodic ripples in the F-region electron content at high latitude, the magnetic flux density at geosynchronous orbit, and the solar wind dynamic pressure and IMF flux density at L1. The ripples are shown to be continually present during all 14 days of observations in different years and seasons, and at all local times, though they are generally small in magnitude relative to the background. The frequencies of all the parameters are, on average, remarkably similar, and the amplitudes of the selected peaks of some parameters show strong correlations for which regression formulae are given. These results support the proposition that the ripples propagate from the solar wind to the F-region, and that they are a related, persistent phenomenon.

The changing nature of aquatic animal production.

Aquaculture will continue to grow, but environmental constraints will interact with changing consumer profiles and regulatory frameworks such that future growth will look somewhat different from the trajectories of the past 30 years. Availability and price of land, fresh water, feeds and energy, and concerns about pollution and the introduction of non-native species will be major constraints to expansion. New technology will evolve in response to these concerns. This new technology will be based on the principle of sustainable intensification so as to reduce the environmental footprint per unit of production and limit volatility in markets precipitated by disease and other production system problems. Markets and consumer demand will be reflected in the economics of the industry under more sophisticated regulatory regimes. More sustainable sources of the proteins and oils in fish diets, improved genetic management, and better health and production systems will continue to underpin the expansion of aquaculture into the 21st century and beyond.

La croissance de l'aquaculture va se poursuivre mais les contraintes environnementales risquent d'interagir avec les mutations des profils des consommateurs et avec l'évolution des cadres réglementaires, de sorte que cette croissance empruntera à l'avenir des voies bien différentes de celles tracées au cours des 30 dernières années. Les principaux obstacles à la croissance concernent la disponibilité et le prix des terres, de l'eau douce, des aliments pour animaux et de l'énergie, les problèmes en lien avec la pollution et l'introduction d'espèces non natives. L'évolution des nouvelles technologies devrait apporter une réponse à ces préoccupations. Ces nouvelles technologies reposeront sur le principe d'une intensification durable de la production afin de réduire l'empreinte écologique par unité de production et de limiter la volatilité accélérée des marchés induite par les maladies ou par d'autres problèmes affectant les systèmes de production. Les exigences des marchés et des consommateurs se répercuteront dans la stratégie économique du secteur en vertu de dispositifs réglementaires plus sophistiqués. Grâce au recours à des sources plus durables de protéines et d'huiles pour l'alimentation des poissons, à une meilleure gestion des ressources génétiques et à des systèmes sanitaires et de production plus performants, l'expansion de l'aquaculture devrait se poursuivre tout au long du xxie siècle et au-delà.

Aunque en el futuro la acuicultura seguirá creciendo, las limitaciones ambientales interactuarán del tal modo con la evolución de las modalidades de consumo y los ordenamientos reglamentarios que este crecimiento se apartará en cierta medida de las trayectorias observadas en los últimos 30 años. La disponibilidad y el precio de terrenos, agua dulce, piensos y energía, junto con las inquietudes por la contaminación y la introducción de especies no autóctonas, limitarán considerablemente la expansión. En respuesta a esas inquietudes surgirá una nueva tecnología basada en el principio de la intensificación sostenible, que servirá para reducir la «huella¼ ecológica por unidad de producción y para poner coto a la volatilidad de los mercados causada por enfermedades u otros problemas del sistema productivo. La demanda de mercados y consumidores incidirá en la economía del sector en forma de ordenamientos reglamentarios más sofisticados. En los primeros compases del siglo XXI, y también más adelante, la expansión de la acuicultura seguirá reposando en el uso de fuentes más sostenibles de proteínas y aceites para alimentar a los peces, en el perfeccionamiento de los procesos de selección genética y en sistemas productivos y sanitarios más eficaces.

Is home-based HIV testing universally acceptable? Findings from a case-control study nested within the HPTN 071 (PopART) trial.

OBJECTIVE: The HPTN 071 (PopART) trial is examining the impact of a package including universal testing and treatment on community-level HIV incidence in Zambia and South Africa. We conducted a nested case-control study to examine factors associated with acceptance of home-based HIV testing and counselling (HB-HTC) delivered by community HIV-care providers (CHiPs) in PopART intervention communities. METHODS: Of 295 447 individuals who were offered testing, random samples of individuals who declined HB-HTC (cases) and accepted HB-HTC (controls), stratified by gender and community, were selected. Odds ratios comparing cases and controls were estimated using multivariable logistic regression. RESULTS: Data from 642 participants (313 cases, 329 controls) were analysed. There were no differences between cases and controls by demographic or behavioural characteristics including age, marital or socio-economic position. Participants who felt they could be open with CHiPs (AOR: 0.46, 95% CI: 0.30-0.71, P < 0.001); self-reported as not previously tested (AOR: 0.64; 95% CI: 0.43-0.95, P = 0.03); considered HTC at home to be convenient (AOR: 0.38, 95% CI: 0.27-0.54, P = 0.001); knowing others who had accepted HB-HTC from the CHiPs (AOR: 0.49, 95% CI: 0.31-0.77, P = 0.002); or were motivated to get treatment without delay (AOR: 0.60, 95% CI: 0.43-0.85, P = 0.004) were less likely to decline the offer of HB-HCT. Those who self-reported high-risk sexual behaviour were also less likely to decline HB-HCT (AOR: 0.61, 95% CI: 0.39-0.93, P = 0.02). Having stigmatising attitudes about HB-HTC was not an important barrier to HB-HCT uptake. Men who reported fear of HIV were more likely to decline HB-HCT (AOR: 2.68, 95% CI: 1.33-5.38, P = 0.005). CONCLUSION: Acceptance of HB-HTC was associated with lack of previous HIV testing, positive attitudes about HIV services/treatment and perception of high sexual risk. Uptake of HB-HCT among those offered it was similar across a range of demographic and behavioural subgroups suggesting it was 'universally' acceptable.

Robust analysis of stepped wedge trials using cluster-level summaries within periods.

In stepped-wedge trials (SWTs), the intervention is rolled out in a random order over more than 1 time-period. SWTs are often analysed using mixed-effects models that require strong assumptions and may be inappropriate when the number of clusters is small. We propose a non-parametric within-period method to analyse SWTs. This method estimates the intervention effect by comparing intervention and control conditions in a given period using cluster-level data corresponding to exposure. The within-period intervention effects are combined with an inverse-variance-weighted average, and permutation tests are used. We present an example and, using simulated data, compared the method to (1) a parametric cluster-level within-period method, (2) the most commonly used mixed-effects model, and (3) a more flexible mixed-effects model. We simulated scenarios where period effects were common to all clusters, and when they varied according to a distribution informed by routinely collected health data. The non-parametric within-period method provided unbiased intervention effect estimates with correct confidence-interval coverage for all scenarios. The parametric within-period method produced confidence intervals with low coverage for most scenarios. The mixed-effects models' confidence intervals had low coverage when period effects varied between clusters but had greater power than the non-parametric within-period method when period effects were common to all clusters. The non-parametric within-period method is a robust method for analysing SWT. The method could be used by trial statisticians who want to emphasise that the SWT is a randomised trial, in the common position of being uncertain about whether data will meet the assumptions necessary for mixed-effect models.

Methane Cracking over Cobalt Molybdenum Carbides.

ABSTRACT: The catalytic behaviour of Co3Mo3C, Co6Mo6C, Co3Mo3N and Co6Mo6N for methane cracking has been studied to determine the relationship between the methane cracking activity and the chemical composition. The characterisation of post-reaction samples showed a complex phase composition with the presence of Co3Mo3C, α-Co and ß-Mo2C as catalytic phases and the deposition of different forms of carbon during reaction.

Secondary analysis of tuberculosis stigma data from a cluster randomised trial in Zambia and South Africa (ZAMSTAR).

SETTING: Zambian and South African TB and HIV Reduction (ZAMSTAR) cluster-randomised trial (CRT) communities, 2006-2009. OBJECTIVES: To develop TB stigma items, and evaluate changes in them in response to a household intervention aimed at reducing TB transmission and prevalence but not tailored to reduce stigma. DESIGN: TB stigma was measured at baseline and 18 months later among 1826 recently diagnosed TB patients and 1235 adult members of their households across 24 communities; 12 of 24 communities were randomised to receive the household intervention. We estimated the impact of the household intervention on TB stigma using standard CRT analytical methods. RESULTS: Among household members, prevalence of blame and belief in transmission myths fell in both study arms over time: adjusted prevalence ratios (aPRs) comparing the household intervention with the non-household intervention arm were respectively 0.61 (95%CI 0.26-1.44) and 0.77 (95%CI 0.48-1.25) at 18-month follow-up. Among TB patients, at baseline a low percentage experienced social exclusion and poor treatment by health staff and a relatively high percentage reported 'being made fun of', with little change over time. Disclosure of TB status increased over time in both study arms. Internalised stigma was less prevalent in the household arm at both baseline and follow-up, with an aPR of 0.85 (95%CI 0.41-1.76). Variability in stigma levels between countries and across communities was large. CONCLUSION: Robust TB stigma items were developed. TB stigma was not significantly reduced by the household intervention, although confidence intervals for estimated intervention effects were wide. We suggest that stigma-specific interventions are required to effectively address TB stigma.

Overlapping HIV and sex-work stigma among female sex workers recruited to 14 respondent-driven sampling surveys across Zimbabwe, 2013.

HIV stigma can inhibit uptake of HIV testing and antiretroviral therapy as well as negatively affect mental health. Efforts to reduce discrimination against people living with HIV (LWH) have contributed to greater acceptance of the infection. Female sex workers (FSW) LWH may experience overlapping stigma due to both their work and HIV status, although this is poorly understood. We examined HIV and sex-work stigma experienced by FSW LWH in Zimbabwe. Using the SAPPH-IRe cluster-randomised trial baseline survey, we analysed the data from 1039 FSW self-reporting HIV. The women were recruited in 14 sites using respondent-driven sampling. We asked five questions to assess internalised and experienced stigma related to working as a sex worker, and the same questions were asked in reference to HIV. Among all FSW, 91% reported some form of sex-work stigma. This was not associated with sociodemographic or sex-work characteristics. Rates of sex-work stigma were higher than those of HIV-related stigma. For example, 38% reported being "talked badly about" for LWH compared with 77% for their involvement in sex work. Those who reported any sex-work stigma also reported experiencing more HIV stigma compared to those who did not report sex-work stigma, suggesting a layering effect. FSW in Zimbabwe experience stigma for their role as "immoral" women and this appears more prevalent than HIV stigma. As HIV stigma attenuates, other forms of social stigma associated with the disease may persist and continue to pose barriers to effective care.

Systematic review of risk prediction models for diabetes after bariatric surgery.

BACKGROUND: Diabetes remission is an important outcome after bariatric surgery. The purpose of this study was to identify risk prediction models of diabetes remission after bariatric surgery. METHODS: A systematic literature review was performed in MEDLINE, MEDLINE-In-Process, Embase and the Cochrane Central Register of Controlled Trials databases in April 2015. All English-language full-text published derivation and validation studies for risk prediction models on diabetic outcomes after bariatric surgery were included. Data extraction included population, outcomes, variables, intervention, model discrimination and calibration. RESULTS: Of 2330 studies retrieved, eight met the inclusion criteria. Of these, six presented development of risk prediction models and two reported validation of existing models. All included models were developed to predict diabetes remission. Internal validation using tenfold validation was reported for one model. Two models (ABCD score and DiaRem score) had external validation using independent patient cohorts with diabetes remission assessed at 12 and 14 months respectively. Of the 11 cohorts included in the eight studies, calibration was not reported in any cohort, and discrimination was reported in two. CONCLUSION: A variety of models are available for predicting risk of diabetes following bariatric surgery, but only two have undergone external validation.

Frequency of HIV-testing and factors associated with multiple lifetime HIV-testing among a rural population of Zambian men.

BACKGROUND: Across sub-Saharan Africa, men's levels of HIV-testing remain inadequate relative to women's. Men are less likely to access anti-retroviral therapy and experience higher levels of morbidity and mortality once initiated on treatment. More frequent HIV-testing by men at continued risk of HIV-infection is required to facilitate earlier diagnosis. This study explored the frequency of HIV-testing among a rural population of men and the factors associated with more frequent HIV-testing. METHODS: We conducted a secondary analysis of a population-based survey in three rural district in Zambia, from February-November, 2013. Households (N = 300) in randomly selected squares from 42 study sites, defined as a health facility and its catchment area, were invited to participate. Individuals in eligible households were invited to complete questionnaires regarding demographics and HIV-testing behaviours. Men were defined as multiple HIV-testers if they reported more than one lifetime test. Upon questionnaire completion, individuals were offered rapid home-based HIV-testing. RESULTS: Of the 2376 men, more than half (61%) reported having ever-tested for HIV. The median number of lifetime tests was 2 (interquartile range = 1-3). Just over half (n = 834; 57%) of ever-testers were defined as multiple-testers. Relative to never-testers, multiple-testers had higher levels of education and were more likely to report an occupation. Among the 719 men linked to a spouse, multiple-testing was higher among men whose spouse reported ever-testing (adjusted prevalence ratio = 3.02 95% CI: 1.37-4.66). Multiple-testing was higher in study sites where anti-retroviral therapy was available at the health facility on the day of a health facility audit. Among ever-testers, education and occupation were positively associated with multiple-testing relative to reporting one lifetime HIV-test. Almost half (49%) of ever-testers accepted the offer of home-based HIV-testing. DISCUSSION: Reported HIV-testing increased among this population of men since a 2011/12 survey. Yet, only 35% of all men reported multiple lifetime HIV-tests. The factors associated with multiple HIV-testing were similar to factors associated with ever-testing for HIV. Men living with HIV were less likely to report multiple HIV-tests and employment and education were associated with multiple-testing. The offer of home-based HIV-testing increased the frequency of HIV-testing among men. CONCLUSION: Although men's levels of ever-testing for HIV have increased, strategies need to increase the lifetime frequency of HIV-testing among men at continued risk of HIV-infection.

Simulated lesion, human observer performance comparison between thin-section dedicated breast CT images versus computed thick-section simulated projection images of the breast.

The objective of this study was to compare the lesion detection performance of human observers between thin-section computed tomography images of the breast, with thick-section (>40 mm) simulated projection images of the breast. Three radiologists and six physicists each executed a two alterative force choice (2AFC) study involving simulated spherical lesions placed mathematically into breast images produced on a prototype dedicated breast CT scanner. The breast image data sets from 88 patients were used to create 352 pairs of image data. Spherical lesions with diameters of 1, 2, 3, 5, and 11 mm were simulated and adaptively positioned into 3D breast CT image data sets; the native thin section (0.33 mm) images were averaged to produce images with different slice thicknesses; average section thicknesses of 0.33, 0.71, 1.5 and 2.9 mm were representative of breast CT; the average 43 mm slice thickness served to simulate simulated projection images of the breast.The percent correct of the human observer's responses were evaluated in the 2AFC experiments. Radiologists lesion detection performance was significantly (p < 0.05) better in the case of thin-section images, compared to thick section images similar to mammography, for all but the 1 mm lesion diameter lesions. For example, the average of three radiologist's performance for 3 mm diameter lesions was 92% correct for thin section breast CT images while it was 67% for the simulated projection images. A gradual reduction in observer performance was observed as the section thickness increased beyond about 1 mm. While a performance difference based on breast density was seen in both breast CT and the projection image results, the average radiologist performance using breast CT images in dense breasts outperformed the performance using simulated projection images in fatty breasts for all lesion diameters except 11 mm. The average radiologist performance outperformed that of the average physicist observer, however trends in performance were similar. Human observers demonstrate significantly better mass-lesion detection performance on thin-section CT images of the breast, compared to thick-section simulated projection images of the breast.

Biodegradation of chitosan and its effect on metal bioavailability.

The microbial breakdown of chitosan, a fishery waste-based material, and its derivative cross-linked chitosans, in both non-contaminated and contaminated conditions was investigated in a laboratory incubation study. Biodegradation of chitosan and cross-linked chitosans was affected by the presence of heavy metals. Zn was more pronounced in inhibiting microbial activity than Cu and Pb. It was estimated that a longer period is required to complete the breakdown of the cross-linked chitosans (up to approximately 100 years) than unmodified chitosan (up to approximately 10 years). The influence of biodegradation on the bioavailable fraction of heavy metals was studied concurrently with the biodegradation trial. It was found that the binding behaviour of chitosan for heavy metals was not affected by the biodegradation process.

Factors associated with HIV-testing and acceptance of an offer of home-based testing by men in rural Zambia.

The objective of this study is to describe HIV-testing among men in rural Lusaka Province, Zambia, using a population-based survey for a cluster-randomized trial. Households (N = 120) were randomly selected from each of the 42 clusters, defined as a health facility catchment area. Individuals aged 15-60 years were invited to complete questionnaires regarding demographics and HIV-testing history. Men testing in the last year were defined as recent-testers. After questionnaire completion adults were offered home-based rapid HIV-testing. Of the 2,828 men, 53 % reported ever-testing and 25 % recently-testing. Factors independently associated with ever- and recent-testing included age 20+ years, secondary/higher education, being married or widowed, a history of TB-treatment and higher socioeconomic position. 53 % of never-testers and 57 % of men who did not report a recent-test accepted home-based HIV-testing. Current HIV-testing approaches are inadequate in this high prevalence setting. Alternative strategies, including self-testing, mobile- or workplace-testing, may be required to complement facility-based services.

The measurement of household socio-economic position in tuberculosis prevalence surveys: a sensitivity analysis.

OBJECTIVE: To assess the robustness of socio-economic inequalities in tuberculosis (TB) prevalence surveys. DESIGN: Data were drawn from the TB prevalence survey conducted in Lusaka Province, Zambia, in 2005-2006. We compared TB socio-economic inequalities measured through an asset-based index (Index 0) using principal component analysis (PCA) with those observed using three alternative indices: Index 1 and Index 2 accounted respectively for the biases resulting from the inclusion of urban assets and food-related variables in Index 0. Index 3 was built using regression-based analysis instead of PCA to account for the effect of using a different assets weighting strategy. RESULTS: Household socio-economic position (SEP) was significantly associated with prevalent TB, regardless of the index used; however, the magnitude of inequalities did vary across indices. A strong association was found for Index 2, suggesting that the exclusion of food-related variables did not reduce the extent of association between SEP and prevalent TB. The weakest association was found for Index 1, indicating that the exclusion of urban assets did not lead to higher extent of TB inequalities. CONCLUSION: TB socio-economic inequalities seem to be robust to the choice of SEP indicator. The epidemiological meaning of the different extent of TB inequalities is unclear. Further studies are needed to confirm our conclusions.

From caution to urgency: the evolution of HIV testing and counselling in Africa.

OBJECTIVE: To describe recent changes in policy on provider-initiated testing and counselling (PITC) for human immunodeficiency virus (HIV) infection in African countries and to investigate patients' experiences of and views about PITC. METHODS: A review of the published literature and of national HIV testing policies, strategic frameworks, plans and other relevant documents was carried out. FINDINGS: Of the African countries reviewed, 42 (79.2%) had adopted a PITC policy. Of the 42, all recommended PITC for the prevention of mother-to-child HIV transmission, 66.7% recommended it for tuberculosis clinics and patients, and 45.2% for sexually transmitted infection clinics. Moreover, 43.6% adopted PITC in 2005 or 2006. The literature search identified 11 studies on patients' experiences of and views about PITC in clinical settings in Africa. The clear majority regarded PITC as acceptable. However, women in antenatal clinics were not always aware that they had the right to decline an HIV test. CONCLUSION: Policy and practice on HIV testing and counselling in Africa has shifted from a cautious approach that emphasizes confidentiality to greater acceptance of the routine offer of HIV testing. The introduction of PITC in clinical settings has contributed to increased HIV testing in several of these settings. Most patients regard PITC as acceptable. However, other approaches are needed to reach people who do not consult health-care services.

Metal accumulation in Lolium perenne and Brassica napus as affected by application of chitosans.

The effects of chitosan, a fishery waste-based material, and its derivative glutaraldehyde cross-linked chitosan (chitosan-GLA) on metal uptake by Lolium perenne (perennial ryegrass) and Brassica napus (rapeseed) were studied in a greenhouse pot experiment. Metal uptake by perennial ryegrass was highly dependent on the rate of addition of the chitosans. Low application rate (1% w/w) enhanced metal uptake, whereas 10% (w/w) addition decreased metal uptake. It was estimated that chitosan 1% (w/w) treatment could assist perennial ryegrass to remove approximately 3.2 kg Zn/ha and 0.29 kg Pb/ha. For rapeseed, metal uptake was decreased at all rates of application of chitosans. The ammonium acetate extractable metals in soil decreased following application of chitosans and plant growth.

Low frequency sound propagation in activated carbon.

Activated carbon can adsorb and desorb gas molecules onto and off its surface. Research has examined whether this sorption affects low frequency sound waves, with pressures typical of audible sound, interacting with granular activated carbon. Impedance tube measurements were undertaken examining the resonant frequencies of Helmholtz resonators with different backing materials. It was found that the addition of activated carbon increased the compliance of the backing volume. The effect was observed up to the highest frequency measured (500 Hz), but was most significant at lower frequencies (at higher frequencies another phenomenon can explain the behavior). An apparatus was constructed to measure the effective porosity of the activated carbon as well as the number of moles adsorbed at sound pressures between 104 and 118 dB and low frequencies between 20 and 55 Hz. Whilst the results were consistent with adsorption affecting sound propagation, other phenomena cannot be ruled out. Measurements of sorption isotherms showed that additional energy losses can be caused by water vapor condensing onto and then evaporating from the surface of the material. However, the excess absorption measured for low frequency sound waves is primarily caused by decreases in surface reactance rather than changes in surface resistance.

Carbonised red mud--a new water treatment product made from a waste material.

Proposals to use red mud, the waste produced by the extraction of alumina from bauxite ore in the Bayer process, as a material for treatment of heavy metal-contaminated water are limited by its inherent alkalinity and variability. Attempts to lower its pH have been largely unreliable. However, an alternative strategy is carbonisation of red mud by catalytic hydrocarbon cracking, which results in a magnetic material of greater surface area. The efficacy of this material has been compared with that of the untreated parent red mud and acidified red mud for the sorption of CrO(4)(2-), Cu(2+) and Pb(2+). Carbonised red mud does not remove CrO(4)(2-) from solution, but shows enhancement of Cu(2+) and Pb(2+) removal. There is an approximate ten-fold increase in removal of Cu(2+) and Pb(2+) by carbonised red mud compared with acidified red mud.