Naïve and induced tolerance of 15 amphibian populations to three commonly applied insecticides.

Human impacts on ecological communities are pervasive and species must either move or adapt to changing environmental conditions. For environments polluted by contaminants, researchers have found hundreds of target pest species evolving increased tolerance, but we have substantially fewer cases of evolved tolerance in non-target species. When species do evolve increased tolerance, inducible tolerance can provide immediate protection and favor the evolution of increased tolerance over generations via genetic assimilation. Using a model larval amphibian (wood frogs, Rana sylvatica), we examined the tolerance of 15 populations from western Pennsylvania and eastern New York (USA), when first exposed to no pesticide or sublethal concentrations and subsequently exposed to lethal concentrations of three common insecticides (carbaryl, chlorpyrifos, and diazinon). We found high variation in naïve tolerance among the populations for all three insecticides. We also discovered that nearly half of the populations exhibited inducible tolerance, though the degree of inducible tolerance (magnitude of tolerance plasticity; MoTP) varied. We observed a cross-tolerance pattern of the populations between chlorpyrifos and diazinon, but no pattern of similar MoTP among the pesticides. With populations combined from two regions, increased tolerance was not associated with proximity to agricultural fields, but there were correlations between proximity to agriculture and MoTP. Collectively, these results suggests that amphibian populations possess a wide range of naïve tolerance to common pesticides, with many also being able to rapidly induce increased tolerance. Future research should examine inducible tolerance in a wide variety of other taxa and contaminants to determine the ubiquity of these responses to anthropogenic factors.

Trajectories of health system use and survival for community-dwelling persons with dementia: a cohort study.

OBJECTIVES: To determine the long-term trajectories of health system use by persons with dementia as they remain in the community over time. DESIGN: Population-based cohort study using health administrative data. SETTING: Ontario, Canada from 1 April 2007 to 31 March 2014. PARTICIPANTS: 62 622 community-dwelling adults aged 65+ years with prevalent dementia on 1 April 2007 matched 1:1 to persons without dementia based on age, sex and comorbidity. MAIN OUTCOME MEASURES: Rates of health service use, long-term care placement and mortality over time. RESULTS: After 7 years, 49.0% of persons with dementia had spent time in long-term care (6.8% without) and 64.5% had died (30.0% without). Persons with dementia were more likely than those without to use home care (rate ratio (RR) 3.02, 95% CI 2.93 to 3.11) and experience hospitalisations with a discharge delay (RR 2.36, 95% CI 2.30 to 2.42). As they remained in the community, persons with dementia used home care at a growing rate (10.7%, 95% CI 10.0 to 11.3 increase per year vs 6.7%, 95% CI 4.3 to 9.0 per year among those without), but rates of acute care hospitalisation remained constant (0.6%, 95% CI -0.6 to 1.9 increase per year). CONCLUSIONS: While persons with dementia used more health services than those without dementia over time, the rate of change in use differed by service type. These results, particularly enumerating the increased intensity of home care service use, add value to capacity planning initiatives where limited budgets require balancing services.

Timing and frequency of sublethal exposure modifies the induction and retention of increased insecticide tolerance in wood frogs (Lithobates sylvaticus).

Although the paradigm for increased tolerance to pesticides has been by selection on constitutive (naïve) traits, recent research has shown it can also occur through phenotypic plasticity. However, the time period in which induction can occur, the duration of induced tolerance, and the influence of multiple induction events remain unknown. We hypothesized that the induction of increased pesticide tolerance is limited to early sensitive periods, the magnitude of induced tolerance depends on the number of exposures, and the retention of induced tolerance depends on the time elapsed after an exposure and the number of exposures. To test these hypotheses, we exposed wood frog tadpoles to either a no-carbaryl control (water) or 0.5 mg/L carbaryl at 4 time periods, and later tested their tolerance to carbaryl using time-to-death assays. We discovered that tadpoles induced increased tolerance early and midway but not late in our experiment and their constitutive tolerance increased with age. We found no difference in the magnitude of induced tolerance after a single or 2 exposures. Finally, induced pesticide tolerance was reversed within 6 d but was retained only when tadpoles experienced all 4 consecutive exposures. Phenotypic plasticity provides an immediate response for sensitive amphibian larvae to early pesticide exposures and reduces phenotypic mismatches in aquatic environments contaminated by agrochemicals. Environ Toxicol Chem 2018;37:2188-2197. © 2018 SETAC.

Walking the Path Together: Indigenous Health Data at ICES.

Indigenous data governance principles assert that Indigenous communities have a right to data that identifies their people or communities, and a right to determine the use of that data in ways that support Indigenous health and self-determination. Indigenous-driven use of the databases held at the Institute for Clinical Evaluative Sciences (ICES) has resulted in ongoing partnerships between ICES and diverse Indigenous organizations and communities. To respond to this emerging and complex landscape, ICES has established a team whose goal is to support the infrastructure for responding to community-initiated research priorities. ICES works closely with Indigenous partners to develop unique data governance agreements and supports processes, which ensure that ICES scientists must work with Indigenous organizations when conducting research that involves Indigenous peoples.

Inducible Tolerance to Agrochemicals Was Paved by Evolutionary Responses to Predators.

Recent research has reported increased tolerance to agrochemicals in target and nontarget organisms following acute physiological changes induced through phenotypic plasticity. Moreover, the most inducible populations are those from more pristine locations, far from agrochemical use. We asked why do populations with no known history of pesticide exposure have the ability to induce adaptive responses to novel agrochemicals? We hypothesized that increased pesticide tolerance results from a generalized stressor response in organisms, and would be induced following sublethal exposure to natural and anthropogenic stressors. We exposed larval wood frogs (Lithobates sylvaticus) to one of seven natural or anthropogenic stressors (predator cue (Anax spp.), 0.5 or 1.0 mg carbaryl/L, road salt (200 or 1000 mg Cl-/L), ethanol-vehicle control, or no-stressor control) and subsequently tested their tolerance to a lethal carbaryl concentration using time-to-death assays. We observed induced carbaryl tolerance in tadpoles exposed to 0.5 mg/L carbaryl and also in tadpoles exposed to predator cues. Our results suggest that the ability to induce pesticide tolerance likely arose through evolved antipredator responses. Given that antipredator responses are widespread among species, many animals might possess inducible pesticide tolerance, buffering them from agrochemical exposure.

Increasing Access to Health Administrative Data with ICES Data & Analytic Services.

The Institute for Clinical Evaluative Sciences (ICES) is one of only a few organizations in Ontario permitted to access, link and analyze health administrative data for the purpose of generating evidence to inform decisions in policy and practice. Although ICES is a leading research institute, its access to the data has historically been restricted to scientists with an ICES affiliation. This requirement, designed to meet ICES' data privacy and security obligations, created barriers with respect to the widespread use of Ontario's data assets. In 2014, as part of the government's commitment to the Strategy for Patient-Oriented Research, ICES launched the Data & Analytic Services platform, which is aimed at increasing access to data and analytic services to investigators external to ICES. In making the data widely available to the broader research community, this initiative engages investigators involved in front-line care, stimulates new avenues of research and fosters collaboration that was previously challenging or unfeasible.

Exposure to sublethal concentrations of a pesticide or predator cues induces changes in brain architecture in larval amphibians.

Naturally occurring environmental factors shape developmental trajectories to produce variable phenotypes. Such developmental phenotypic plasticity can have important effects on fitness, and has been demonstrated for numerous behavioral and morphological traits. However, surprisingly few studies have examined developmental plasticity of the nervous system in response to naturally occurring environmental variation, despite accumulating evidence for neuroplasticity in a variety of organisms. Here, we asked whether the brain is developmentally plastic by exposing larval amphibians to natural and anthropogenic factors. Leopard frog tadpoles were exposed to predator cues, reduced food availability, or sublethal concentrations of the pesticide chlorpyrifos in semi-natural enclosures. Mass, growth, survival, activity, larval period, external morphology, brain mass, and brain morphology were measured in tadpoles and after metamorphosis. Tadpoles in the experimental treatments had lower masses than controls, although developmental rates and survival were similar. Tadpoles exposed to predator cues or a high dose of chlorpyrifos had altered body shapes compared to controls. In addition, brains from tadpoles exposed to predator cues or a low dose of chlorpyrifos were narrower and shorter in several dimensions compared to control tadpoles and tadpoles with low food availability. Interestingly, the changes in brain morphology present at the tadpole stage did not persist in the metamorphs. Our results show that brain morphology is a developmentally plastic trait that is responsive to ecologically relevant natural and anthropogenic factors. Whether these effects on brain morphology are linked to performance or fitness is unknown.

The role of TORC1 in muscle development in Drosophila.

Myogenesis is an important process during both development and muscle repair. Previous studies suggest that mTORC1 plays a role in the formation of mature muscle from immature muscle precursor cells. Here we show that gene expression for several myogenic transcription factors including Myf5, Myog and Mef2c but not MyoD and myosin heavy chain isoforms decrease when C2C12 cells are treated with rapamycin, supporting a role for mTORC1 pathway during muscle development. To investigate the possibility that mTORC1 can regulate muscle in vivo we ablated the essential dTORC1 subunit Raptor in Drosophila melanogaster and found that muscle-specific knockdown of Raptor causes flies to be too weak to emerge from their pupal cases during eclosion. Using a series of GAL4 drivers we also show that muscle-specific Raptor knockdown also causes shortened lifespan, even when eclosure is unaffected. Together these results highlight an important role for TORC1 in muscle development, integrity and function in both Drosophila and mammalian cells.

Patterns of cigarillo use among Canadian young adults in two urban settings.

OBJECTIVES: Current estimates indicate that cigarillo use has become commonplace among young adults in Canada despite the established risks to health. However, little else is known about patterns of cigarillo use in this subpopulation. The intent of this research was to examine the patterns, attitudes, and beliefs regarding cigarillo use and co-use of cigarillos and cigarettes among Canadian young adults. METHODS: Canadians aged 19-29 years from the Greater Toronto Area, Ontario and Edmonton, Alberta were recruited from September 2009 to February 2010 and in June 2010, respectively (n=133). Eligible participants completed questionnaires assessing cigarillo, cigarette, and cannabis use; social influence of usage; and beliefs about cigarillo use. RESULTS: Cigarillo use was common in social settings, with friends, and during leisure time. The majority of participants were co-users of cigarillos and cigarettes (82%), and currently used cannabis (72%). Respondents reported "replacing cigarette smoking" and "flavour" as main reasons for smoking cigarillos; and half (52%) believed they were not at all addicted to cigarillos. Disconcertingly, participants perceived the risk of cancer attributed to smoking cigarillos as significantly less than the risk of cancer attributed to smoking cigarettes (p<0.0001). CONCLUSION: These findings highlight the social nature of cigarillo use, and suggest a lack of awareness of the health risks associated with cigarillo and polytobacco use in this small convenience sample of Canadian young adults. Population-level analyses are needed to further investigate cigarillo, polytobacco and concurrent cannabis use patterns and beliefs among Canadian young adults.

Secular trends in the diagnosis and treatment of obesity among US adults in the primary care setting.

Excess weight afflicts the majority of the US adult population. Research suggests that the role of primary care physicians in reducing overweight and obesity is essential; moreover, little is known about self-care of obesity. This report assessed the secular trends in the care of overweight and investigated the secular association between obesity with care of overweight in primary care and self-care of overweight. Cross-sectional evaluation of the National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and the Continuous NHANES (1999-2008) was employed; the total sample comprised 31,039 nonpregnant adults aged 20-90 years. The relationship between diagnosed overweight, and directed weight loss with time and obesity was assessed. Despite the combined secular increase in the prevalence of overweight and obesity (BMI >25.0 kg/m(2)) between 1994 and 2008 (56.1-69.1%), there was no secular change in the odds of being diagnosed overweight by a physician when adjusted for covariates; however, overweight and obese individuals were 40 and 42% less likely to self-diagnose as overweight, and 34 and 41% less likely to self-direct weight loss in 2008 compared to 1994, respectively. Physicians were also significantly less likely to direct weight loss for overweight and obese adults with weight-related comorbidities across time (P < 0.05). Thus, the surveillance of secular trends reveals that the likelihood of physician- and self-care of overweight decreased between 1994 and 2008 and further highlights the deficiencies in the management of excess weight.