How does climate variability affect water quality dynamics in Canada's oil sands region?

In Canada's oil sands region, classic boreal hydrology (i.e., winter low flow followed by peaks during spring freshet and then summer flow recession) combined with erosion of both natural and anthropogenically-exposed bitumen results in seasonal and inter-annual variability in stream water chemistry. Using data collected from all seasons over three years (2012-2015), we investigated the mechanisms driving spatial and temporal change in the concentration of 26 water quality parameters for six rivers draining Canada's oil sands region. Mantel tests showed a strong spatial aggregation of climatic drivers (average daily precipitation, accumulated precipitation, snow water equivalent) associated with west versus east discharge patterns. Wavelet analysis highlighted unique watershed attributes, in particular the importance of developed area in lowering responsiveness to seasonal precipitation. Concentrations of most chemical parameters (20 of 23) showed distinct temporal patterns that were correlated with seasonal changes in hydrology which, in turn, were related to changes in weather. Comparison of concentrations observed in this study with those reported in the scientific literature for the same watersheds showed 81% of comparisons differed significantly. This was likely due to the short duration of previous field campaigns and thus the sampling of a very narrow window of the annual streamflow regime.

Preliminary validation of a self-efficacy scale for pediatric chronic illness.

BACKGROUND: Tracking self-efficacy may be useful for identifying children at risk for medical noncompliance. We created the Pediatric Rating of Chronic Illness Self-Efficacy (PRCISE) to measure self-efficacy in youth dealing with a chronic illness. METHOD: Data were collected from 217 families where one child aged 7-20 (Mage  = 13.62, SDage  = 2.92; 62.7% Latino, 58.1% female) had a chronic illness. Parent participants provided demographic information. Youth completed a depression measure, the Patient Health Questionnaire for Adolescents and the PRCISE. To determine the underlying latent structure of the scale, an exploratory factor analysis was conducted using parallel analysis. We also carried out two multiple linear regressions to explore the data and establish preliminary predictive validity. RESULTS: The measure was reduced to 15 items, demonstrating a one-factor solution with strong reliability. Predictors of lower self-efficacy included having parents who had not attended college, being African American, and having higher Patient Health Questionnaire for Adolescents scores, R2  = .23, F(11, 174) = 5.62, p < .001. Main effects were qualified by a two-way interaction, such that the decrease in PRCISE scores associated with depressive symptoms was attenuated in children with less educated parents. In terms of predictive validity, higher PRCISE scores unexpectedly predicted more number of emergency room visits, R2  = .12, F(9, 113) = 2.73, p < .01. CONCLUSIONS: The PRCISE appears to be a reliable measure of a single self-efficacy construct. Secondary analyses revealed important health disparities in pediatric chronic illness self-efficacy. Next steps may include validation of the PRCISE using confirmatory factor analysis.

Innate immune cells and bacterial infection in zebrafish.

The physical attributes of the zebrafish, including optical transparency during embryogenesis, large clutch sizes, external development, and rapid organogenesis were features that initially attracted developmental biologists to use this vertebrate as an experimental model system. With the progressive development of an extensive genetic "tool kit" and an ever-growing number of transgenic reporter lines, the zebrafish model has evolved into an informative system in which to mimic and study aspects of human disease, including those associated with bacterial infections. This chapter provides detailed protocols for microinjection of bacterial strains into zebrafish larvae and subsequent experiments to investigate single-larva bacterial burdens, live imaging of specific neutrophil and macrophage bactericidal functions, and how these protocols may be applied to drug discovery approaches to uncover novel immunomodulatory drugs.

Boy or Girl: Does Gender Matter When Learning to Farm Safely?.

Based on a survey and face-to-face interview with 24 students who lived most of their lives on farms, this study extends the findings of previously reported research by examining similarities and differences between males' and females' beliefs, attitudes, and adoption of farm health and safety practices. The survey and interview asked participants to recall their experiences growing up on a farm and in particular how they learned to farm safely. Data were analyzed qualitatively, focusing on two potentially gendered farm chores: tractor operation and livestock handling. Particular emphasis was placed on identifying similarities and differences between boys' and girls' childhood farm experiences and transfer of farm health and safety knowledge. Main findings indicated that although there may be some differences between how boys and girls perceive the operational aspects of the farm (particularly parental roles), there seems to be little difference between genders in terms of tasks they were permitted to do and in their health and safety practices. The current study adds to a small but growing literature suggesting that gender differences play a relatively small role in farm health and safety practices among individuals strongly committed to and engaged in agriculture.

Oral morphine for pain management in paediatric patients after tonsillectomy and adenotonsillectomy.

OBJECTIVES: The withdrawal of codeine for use in children following tonsillectomy enforced a change in our practice of providing regular paracetamol and ibuprofen, with codeine for breakthrough pain relief. Our objectives were to; examine the effectiveness of paracetamol and ibuprofen; examine the effectiveness of the addition of rescue (PRN) morphine to regular paracetamol and ibuprofen. METHODS: A 2 cycle prospective audit was conducted on our unit. Telephone consultations were conducted with parents of 74 children undergoing tonsillectomy and adenotonsillectomy. Cycle 1 (C1, without morphine) contained 24 consecutive patients and cycle 2 (C2, with morphine) contained 50 consecutive patients. Postoperative health service contact and outcome was recorded: worst pain scores on days 4 and 7 were obtained using validated pain assessment tools scoring 0-10. Cycle 2 results underwent subgroup analysis by method of surgery i.e. coblation (C2C) and cold steel dissection (C2D) groups. RESULTS: More than half of parents felt simple analgesia was not effective enough in both cycles, this number was significantly higher in both 2nd cycle groups (C1=54%, C2C=74%, p=0.003, C2D=84%, p=0.0001). Mean worst pain reported at day 4 was similar for all groups, but the morphine groups reported higher pain at day 7 (C1 1.6, C2C 3.59, p=0.017, C2D 3.90, p=0.002). Antibiotic prescribing for children contacting a GP after surgery was significantly lower in the morphine groups (C1 24%, C2C 7%, p=0.0014, C2D 5%, p=0.0002). There was no difference in measured outcomes between the 2nd cycle groups. CONCLUSION: This service evaluation found that postoperative morphine on an as-required basis, in addition to regular paracetamol and ibuprofen, did not significantly alter initial pain profile, worst pain scores or rate of health service contact when compared to regular paracetamol and ibuprofen alone. The majority of children in this study felt additional analgesia required. Children in the morphine groups experienced significantly less pharmacological intervention when contacting the GP after surgery.

The farm apprentice: agricultural college students recollections of learning to farm "safely".

A consistent message in the farm safety literature is the need to develop effective interventions to manage the unacceptably high rate of injury and death among farm children. To better understand the influence of childhood farm experiences on safety beliefs, attitudes, and practices, semi-structured interviews were conducted with 24 farm youth attending the Nova Scotia Agricultural College. The interviews were designed to elicit information pertaining to participants' earliest memories of involvement in farm activities, the decision-making processes that led them to assume work-related responsibilities, and the roles that their parents played in their safety training. A common theme of experiencing childhood as a "farm apprentice" emerged across all narratives whereby farm activities were learned primarily through observational learning and modeling of parents and then mastered through repetition. As "farm apprentices," the youths' involvement in dangerous activities such as tractor driving and livestock handling began at early ages, with very little formal training and supervision. Although participants clearly described themselves as being exposed to dangerous activities, they believed that they had the capacity to control the risks and farm safely. Based on our findings, the concept of the "farm apprentice" appears to be integral to the social context of the farming community and should be considered in the design of interventions to reduce child injury and death.

Inhibition of glutamine synthetase during ammonia exposure in rainbow trout indicates a high reserve capacity to prevent brain ammonia toxicity.

Glutamine synthetase (GSase), the enzyme that catalyses the conversion of glutamate and ammonia to glutamine, is present at high levels in vertebrate brain tissue and is thought to protect the brain from elevated ammonia concentrations. We tested the hypothesis that high brain GSase activity is critical in preventing accumulation of brain ammonia and glutamate during ammonia loading in the ammonia-intolerant rainbow trout. Trout pre-injected with saline or the GSase inhibitor methionine sulfoximine (MSOX, 6 mg kg(-1)), were exposed to 0, 670 or 1000 micromol l(-1) NH(4)Cl in the water for 24 and 96 h. Brain ammonia levels were 3- to 6-fold higher in ammonia-exposed fish relative to control fish and MSOX treatment did not alter this. Brain GSase activity was unaffected by ammonia exposure, while MSOX inhibited GSase activity by approximately 75%. Brain glutamate levels were lower and glutamine levels were higher in fish exposed to ammonia relative to controls. While MSOX treatment had little impact on brain glutamate, glutamine levels were significantly reduced by 96 h. With ammonia treatment, significant changes in the concentration of multiple other brain amino acids occurred and these changes were mostly reversed or eliminated with MSOX. Overall the changes in amino acid levels suggest that multiple enzymatic pathways can supply glutamate for the production of glutamine via GSase during ammonia exposure and that alternative transaminase pathways can be recruited for ammonia detoxification. Plasma cortisol levels increased 7- to 15-fold at 24 h in response to ammonia and MSOX did not exacerbate this stress response. These findings indicate that rainbow trout possess a relatively large reserve capacity for ammonia detoxification and for preventing glutamate accumulation during hyperammonaemic conditions.

Plasma pharmacokinetics and metabolism of the histone deacetylase inhibitor trichostatin a after intraperitoneal administration to mice.

Trichostatin A is a potent and specific histone deacetylase inhibitor with promising antitumor activity in preclinical models. Plasma pharmacokinetics of trichostatin A were studied following single-dose intraperitoneal administration of 80 mg/kg (high dose) or 0.5 mg/kg (low dose) to female BALB/c mice. Plasma trichostatin A concentrations were quantified by high performance liquid chromatography (HPLC)-UV assay (high dose) or by HPLC-multiple reaction monitoring assay (low dose). Trichostatin A was rapidly absorbed from the peritoneum and detectable in plasma within 2 min. Cmax of 40 microg/ml and 8 ng/ml occurred within 5 min, followed by rapid exponential decay in plasma trichostatin A concentration with t1/2 of 6.3 min and 9.6 min (high and low doses, respectively). Phase I metabolites at the high dose were identified by simultaneous UV and positive ion electrospray mass spectrometry. Trichostatin A underwent extensive metabolism: primary metabolic pathways were N-demethylation, reduction of the hydroxamic acid to the corresponding trichostatin A amide, and oxidative deamination to trichostatic acid. N-Monomethyl trichostatin A amide was the major plasma metabolite. No didemethylated compounds were identified. Trichostatic acid underwent further biotransformation: reduction and beta-oxidation of the carboxylic acid, with or without N-demethylation, resulted in formation of dihydro trichostatic acid and dinor dihydro trichostatic acids. HPLC fractions corresponding to trichostatin A and N-demethylated trichostatin A exhibited histone deacetylase-inhibitory activity; no other fractions were biologically active. We conclude that trichostatin A is rapidly and extensively metabolized in vivo following intraperitoneal administration to mice, and N-demethylation does not compromise histone deacetylase-inhibitory activity.

In vitro and in vivo studies on the bioactivity of a ginger (Zingiber officinale) extract towards adult schistosomes and their egg production.

The bioactivity of an ethyl acetate extract of ginger (Zingiber officinale) towards Schistosoma mansoni adult pairs, both cultured in vitro and in vivo in laboratory mice, was investigated by monitoring worm mortality and fecundity. In vitro, a concentration of 200 mg l(-1) of extract killed almost all worms within 24 h. Male worms seemed more susceptible than female under these conditions. Cumulative egg output of surviving worm pairs in vitro was considerably reduced when exposed to the extract. For example, after 4 days of exposure to 50 mg l(-1), cumulative egg output was only 0.38 eggs per worm pair compared with 36.35 for untreated worms. In vivo efficacy of the extract was tested by oral and subcutaneous delivery of 150 mg kg(-1) followed by assessment of worm survival and fecundity. Neither delivery route produced any significant reduction in worm numbers compared with untreated controls. Worm fecundity was assessed in vivo by cumulative egg counts per liver at 55 days post infection with mice treated subcutaneously. Such infections showed egg levels in the liver of about 2000 eggs per worm pair in 55 days, in both treated and control mice, with no significant difference between the two groups. To ensure that density-dependent effects did not confound this analysis, a separate experiment demonstrated no such influence on egg output per worm pair, at intensities between 1 and 23 worms per mouse.

Maternal exposure to trichloroethylene in drinking water and birth-weight outcomes.

An ecological epidemiological study was conducted with data obtained from an environmental dose-reconstruction study and the Arizona Birth Information Tapes. Before 1981, a portion of the city of Tucson water-distribution system was contaminated with trichloroethylene (i.e., < 5 micrograms per liter of water to 107 micrograms per liter of water). Target and comparison populations were selected with a Geographic Information System. Logistical-regression analysis revealed an association between maternal exposure to trichloroethylene via drinking water and very-low-birth-weight babies (i.e., < 1,501 grams) (odds ratio = 3.3; 95% confidence interval = 0.5, 20.6; and Wald chi-square p value = 0.2). No association was found between maternal exposure to trichloroethylene via drinking water and low birth weight or full-term low-birth-weight infants (gestational period > 35 wk and < 46 wk).

Control of water-borne parasitic diseases with natural products: the potential of Dialium guineense as a molluscicide.

The molluscicidal activity of the fruit and leaves of Dialium guineense was found to be due to glycosides of the triterpenoid oleanolic acid. Three glycosides were isolated from the fruit and a fourth from the leaves and are known compounds. The amount of total saponins present in D. guineense makes it a good candidate for a readily available molluscicide in Nigerian villages.

Language background and communication skills of medical students.

OBJECTIVE: The increasing proportion of medical students whose primary language is other than English and recent reports of poor communication skills of medical graduates has generated community concern about the methods of selection of students and their communication skills training. This paper examines the relationship between language background and examination performance in oral communication skills in Year 5 medical students. METHOD: Questionnaire data from all Year 5 students in the 1992 general practice terms were matched to examination results. RESULTS: Seventy percent of students responded. Most students whose primary language was not English passed, although some required remedial communication skills tuition. The most powerful predictors of poor performance were recent arrival in Australia and living in an environment where English was not spoken at home. CONCLUSION: Students with poor English oral communication skills should be encouraged to speak English away from the medical school and should be offered additional tuition so that their skills in other languages are not lost to the health-care system.

The plant molluscicide Millettia thonningii (Leguminosae) as a topical antischistosomal agent.

The West African legume Millettia thonningii is used in Ghana as an anthelmintic and as a purgative agent. A chloroform extract of the seeds of Millettia thonningii which is known to be molluscicidal and cercaricidal was topically applied to mouse skin 2 and 24 h prior to exposure to Schistosoma mansoni cercariae. The presence of Millettia thonningii extract components on the surface of the skin appeared to be effective in preventing subsequent establishment of infection. The compound responsible for the activity is thought to be the isoflavonoid alpinumisoflavone.

Developing group practices: a management challenge.

The advantages and disadvantages of forming larger professional practices are often debated. This paper reports an exploration of the issues through three case studies involving clusters of Sydney general medical practitioners who had expressed a desire to amalgamate their solo or small group practices. Their most frequently stated goals were to reduce financial overheads, to improve the range of services offered to their patients and to improve the opportunities for recreational and study leave. Several barriers to successful amalgamation were identified, and methods of overcoming these were explored. Practices can successfully amalgamate, but only where there is a group of like-minded general practitioners who are willing to invest time to achieve mutually agreed objectives. Amalgamation will not be appropriate in all circumstances. Larger group practices should benefit from the employment of a professional practice manager. These findings may be relevant to veterinary and dental practices.

Attenuation of Schistosoma mansoni cercariae with a molluscicide derived from Millettia thonningii.

A chloroform extract of molluscicidal plant secondary compounds from the seeds of a West African legume Millettia thonningii was used to attenuate cercariae of Schistosoma mansoni prior to infection of NMRI female mice. Exposure of cercariae to 0.3, 0.6, 1.3, 2.5, 10 or 20 mg/l concentrations of extract for 30 min, immediately before standardized infection, was associated with a concentration-dependent decline in worm establishment at 55 days post-infection. The mean numbers of adult worms established declined from about 17 worms/mouse with control cercariae and those exposed to 0.3 mg/l Millettia to 0.1 worms/mouse after 10 mg/l pre-treatment. Mice exposed to cercariae after 20 mg/l pre-treatment had no adult worms at 55 days post-infection. The activities of cercariae 30 min after exposure to Millettia extract at concentrations up to 2.5 mg/l were similar to those of control larvae: none was immobile. Exposure to higher concentrations of Millettia progressively reduced swimming activity and increased the proportion of immobile cercariae. After pretreatment with 20 mg/l Millettia the majority of larvae were immobile. Levels of anti-parasite antibodies (estimated by ELISA assay using an adult worm-based antigen preparation) rose between 21 and 55 days p.i. with control cercariae and those pre-treated with 2.5 mg/l Millettia. After 5 mg/l pre-treatment, cercariae induced a reduced antibody rise, while mice exposed to cercariae after 10 mg/l pre-treatment showed no rise in anti-parasite antibody levels. These results are discussed in the context of protocols which could possibly use Millettia-attenuated cercariae to induce useful levels of protection in mice towards further cercarial challenge.

Forming large group practices: is it worth it?

OBJECTIVE: To investigate means of successful general practice amalgamation. PARTICIPANTS: Three clusters of Sydney general practitioners who wished to amalgamate their solo or small group practices. DESIGN: Structured interviews were conducted with individual general practitioners and group meetings were held with members of each cluster. RESULT: Successful amalgamation of solo/small practices starts with choosing compatible participants. Next, aims must be agreed upon and clearly spelt out. Commonly expressed goals of amalgamation were to reduce financial overheads, improve the range of patient services and increase opportunities for recreational and study leave. Financial and legal aid is essential for intending amalgamators. "Trial amalgamation" may be a safe option for those uncertain as to whether to commit themselves and their practices. CONCLUSIONS: Practices can successfully amalgamate, but only with a group of like-minded general practitioners who are willing to invest time to achieve mutually agreed objectives. Amalgamation is not always appropriate.

The influence of safety belt laws on self-reported safety belt use in the United States.

We assessed rates and trends in safety belt use by presence and type of safety belt law using data from states participating in the 1984-1989 Behavioral Risk Factor Surveillance System. State(s) with a safety belt law allowing law enforcement officers to stop vehicles for occupants' failure to use safety belts (primary enforcement law) had greater and more rapid increases in safety belt use rates than did states with laws requiring that vehicles must first be stopped for some other violation before a citation or fine for occupants' failure to use safety belts could be imposed (secondary enforcement law). Larger and sustained increases in safety belt use occurred when safety belt laws became effective or when fines were imposed for violations than when laws were first enacted. These data suggest that primary enforcement laws result in greater and more rapid increases in safety belt use than do secondary enforcement laws, and that initial increases in safety belt use following implementation of laws are sustained.

Cancer screening behaviors among U.S. women: breast cancer, 1987-1989, and cervical cancer, 1988-1989.

Data from the Behavioral Risk Factor Surveillance System (BRFSS) were used to examine trends in breast and cervical cancer screening behaviors among U.S. women in selected states. Data reported are from the 1987, 1988, and 1989 BRFSS for breast cancer screening (mammography) and from the 1988 and 1989 BRFSS for cervical cancer screening (Papanicolaou [Pap] smear). Results are presented as either state-specific or state-aggregate data for the years noted above. State-specific analyses indicated that self-reported mammography utilization increased between 1987 and 1989. Although whites and blacks reported similar mammography utilization rates both for screening and for a current or previous breast problem, disparities were evident among women of different ages and incomes. The proportion of women who reported ever having had a Pap smear and having heard of a Pap smear were extremely high and remained fairly consistent across the 2 survey years. State-aggregate analyses, however, showed that the percentage of women who had had a Pap smear within the previous year was negatively associated with age and positively associated with income. A higher proportion of blacks than whites obtained Pap smears. These results indicate that certain segments of the population are not taking full advantage of available breast and cervical cancer screening technologies. Public health strategies, such as those outlined in the Breast and Cervical Cancer Mortality Prevention Act of 1990 (Public Law 101-354), should enhance screening opportunities for these women.

Behavioral risk factor surveillance, 1986-1990.

Since 1984, an increasing number of states (including the District of Columbia) have participated in the Behavioral Risk Factor Surveillance System (BRFSS). This report provides state-specific estimates of the prevalence of selected health-risk behaviors for the years 1986 through 1990. Apparent trends and progress toward several of the year 2000 national health objectives are discussed, both for the entire adult population (persons ages greater than or equal to 18 years) and selected high-risk demographic subgroups. Now that BRFSS includes 45 states and covers over 90% of the nation's adult population, it can be used both as a measure of state-specific risk factor prevalence and an indicator of national trends.