The cost-effectiveness of schistosomiasis screening and treatment among recently resettled refugees to Canada: an economic evaluation.

BACKGROUND: Many refugees and asylum seekers from countries where schistosomiasis is endemic are infected with the Schistosoma parasite when they arrive in Canada. We assessed, from a systemic perspective, which of the following management strategies by health care providers is cost-effective: testing for schistosomiasis and treating if the individual is infected, treating presumptively or waiting for symptoms to emerge. METHODS: We constructed a decision-tree model to examine the cost-effectiveness of 3 management strategies: watchful waiting, screening and treatment, and presumptive treatment. We obtained data for the model from the literature and other sources, to predict deaths and chronic complications caused by schistosomiasis, as well as costs and net monetary benefit. RESULTS: Presumptive treatment was cost-saving if the prevalence of schistosomiasis in the target population was greater than 2.1%. In our baseline analysis, presumptive treatment was associated with an increase of 0.156 quality-adjusted life years and a cost saving of $405 per person, compared with watchful waiting. It was also more effective and less costly than screening and treatment. INTERPRETATION: Among recently resettled refugees and asylum claimants in Canada, from countries where schistosomiasis is endemic, presumptive treatment was predicted to be less costly and more effective than watchful waiting or screening and treatment. Our results support a revision of the current Canadian recommendations.

The role of secondary minerals in remediation of acid mine drainage by Portland cement.

To test the effects of secondary mineral formation on cement neutralisation of acid mine drainage (AMD), cement samples were leached with AMD and dilute sulfuric acid of approximately equal acidity. In both cases the neutralising efficiency of the cements, due to dissolution of portlandite as well as the hydrated calcium silicate and aluminate phases, decreased as secondary minerals accumulated on the cement surfaces. The AMD-leached cement became coated with Fe hydroxides, whereas the H2SO4-leached cement was covered primarily with gypsum. Ettringite and thaumasite also formed within the cement in both cases, however in much greater amounts in cement leached with AMD. The AMD penetrated deeper into the cement than H2SO4 because the higher amounts of ettringite and thaumasite in AMD-leached cement caused expansion and cracking. The cracking, which resulted in a substantial loss of strength of the cement, was enhanced when the cement samples were allowed to dry out. This indicates that cement used for passive treatment of AMD will likely provide better long-term neutralisation in at least partially unsaturated conditions where the cement dries out periodically, facilitating cracking to allow deeper penetration of AMD.

Assessment of Wetland Hydrological Dynamics in a Modified Catchment Basin: Case of Lake Buninjon, Victoria, Australia.

The common method to estimate lake levels is the water balance equation, where water input and output result in lake storage and water level changes. However, all water balance components cannot always be quickly assessed, such as due to significant modification of the catchment area. A method that assesses general changes in lake level can be a useful tool in examining why lakes have different lake level variation patterns. Assessment of wetlands using the dynamics of the historical hydrological and hydrogeological data set can provide important insights into variations in wetland levels in different parts of the world. A case study from a saline landscape, Lake Buninjon, Australia, is presented. The aim of the present study was to determine how climate, river regime, and lake hydrological properties independently influence lake water levels and salinity, leaving the discrepancy, for the effect of the non-climatic/catchment modification in the past and the model shows that surface inflow is most sensitive variable. The method, together with the analysis and interpretation, might be of interest to wider community to assess its response to natural/anthropogenic stress and decision choices for its ecological, social, scientific value, and mitigation measures to safe guard the wetland biodiversity in a catchment basin.

Acidification and buffering mechanisms in acid sulfate soil wetlands of the Murray-Darling Basin, Australia.

The acid generation mechanisms and neutralizing capacities of sulfidic sediments from two inland wetlands have been studied in order to understand the response of these types of systems to drying events. The two systems show vastly different responses to oxidation, with one (Bottle Bend (BB) lagoon) having virtually no acid neutralizing capacity (ANC) and the other (Psyche Bend (PB) lagoon) an ANC that is an order of magnitude greater than the acid generation potential. While BB strongly acidifies during oxidation the free acid generation is less than that expected from the measured proton production and consumption processes, with additional proton consumption attributed to the formation of an acid-anion (chloride) FeIII (oxyhydr)oxide product, similar to akaganéite (Fe(OH)2.7Cl0.3). While such products can partially attenuate the acidification of these systems, resilience to acidification is primarily imparted by sediment ANC.

Gender differences in the mediated relationship between alcohol use and academic motivation among late adolescents.

This study utilized structural equation modeling to examine the relationship between alcohol use and academic motivation controlling for potentially mediating variables of deviant behavior, depressive cognitions, family communication, and peer relations. The study also examined the manner in which these relationships were moderated by gender. Results indicated that alcohol use was directly related to deviance for both males and females, but was not associated with depressive cognitions for either males or females. Deviant behavior was directly associated with depressive cognitions for both males and females, but this effect was significantly stronger for females. Deviance was significantly, inversely related to family communication among males, but not females. Depressive cognitions were significantly, inversely related to family communication for both males and females. Family communication and peer relations were directly related to academic motivation for both males and females, and the relationship between family communication and academic motivation was also mediated through peer relations. The necessity of providing information that focuses on minimizing involvement in deviant behaviors for females and the differential importance of family and peer relations is discussed.

Chemical stability of acid rock drainage treatment sludge and implications for sludge management.

To assess the chemical stability of sludges generated by neutralizing acid rock drainage (ARD) with alkaline reagents, synthetic ARD was treated with hydrated lime (batch and high-density sludge process), limestone, and two proprietary reagents (KB-1 and Bauxsol). The amorphous metal hydroxide sludge produced was leached using deionized water, U.S. EPA methods (toxicity characteristic leaching procedure, synthetic precipitation leaching procedure), and the new strong acid leach test (SALT), which leaches the sludge with a series of sulfuric acid extractant solutions; the pH decreases by approximately 1 pH unit with each test, until the final pH is approximately 2. Sludges precipitated by all reagents had very similar leachabilities except for KB-1 and Bauxsol, which released more aluminum. SALT showed that lowering the pH of the leaching solution mobilized more metals from the sludges. Iron, aluminum, copper, and zinc began to leach at pH 2.5-3, approximately 4.5, approximately 5.5, and 6-6.5, respectively. The leachability of ARD treatment sludges is determined by the final pH of the leachate. A higher neutralization potential (e.g., a greater content of unreacted neutralizing agent) makes sludges inherently more chemically stable. Thus, when ARD or any acidic metalliferous wastewater is treated, a choice must be made between efficient reagent use and resistance to acid attack.

Psychosocial and medical predictors of colorectal cancer screening among low-income medical outpatients.

BACKGROUND: Identification of factors related to colorectal cancer screening (CRC) and intent to obtain fecal occult blood tests (FOBTs) among low-income persons are important because CRC incidence and mortality are higher among socioeconomically disadvantaged populations. METHOD: Participants were 193 individuals 50 years of age and older. CRC screening and intent to obtain FOBTs were dependent measures. Demographic variables, objective risk factors, and health beliefs were independent measures. RESULTS: Digital rectal examinations and FOBTs were obtained by 41% and 22%, respectively, during the previous year. Flexible sigmoidoscopies were obtained by only 19% of those 55 years of age and older during the previous five years. Multivariate analyses showed that family history of CRC, personal history of polyps, and physician recommendation were the strongest predictors of CRC screening. Family history of CRC and self-efficacy were related to intent to obtain FOBTs. CONCLUSIONS: Results suggest the importance of physician assessment of personal and family CRC risk factors, as well as recommendation of CRC screening, to all patients as part of routine medical care.

Primary care physicians' attitudes and practices regarding cancer genetics: a comparison of 2001 with 1996 survey results.

BACKGROUND: To determine whether Texas primary care physicians' attitudes and practices regarding cancer genetics changed over a five-year period, a follow-up survey was conducted and the results obtained in 1996 were compared with those obtained in 2001. METHODS: A survey was mailed in 2001 to a random sample of 350 primary care physicians in Texas. RESULTS: More primary care physicians in 2001 were discussing the subject of genetic screening with their patients and more physicians were referring their patients for genetic evaluations and testing for cancer risk, compared with 1996. Cost of genetic testing continues to be the most frequently cited barrier to using genetic testing for cancer susceptibility. CONCLUSION: Results suggest a continuing need for more educational programs for physicians regarding genetic testing for cancer susceptibility.

Gender, perceived parental monitoring, and behavioral adjustment: influences on adolescent alcohol use.

This study examined relationships among gender, perceived parental monitoring, externalizing behaviors, and adolescent alcohol use in a 2-wave longitudinal study. Females reported more perceived parental monitoring and less alcohol use than males. Perceived maternal and paternal monitoring were related to less alcohol use over time. Increases in alcohol use were associated with increases in externalizing behaviors over time. Perceived maternal monitoring mediated the relationship between gender and youth drinking and was also a significant predictor of changes in adolescent drinking over time. Perceived paternal monitoring was not a predictor of adolescent drinking in the context of perceived maternal monitoring and externalizing behaviors. The importance of gender in implementation of prevention programs is discussed.