Applied Filters
- Article
Journal Title
Topics
- Integrative Sciences134
- Biological and Life Sciences108
- Earth and Environmental Sciences82
- Ecology and Evolution79
- Conservation and Sustainability71
- Marine and Aquatic Sciences65
- Science and Policy44
- Science and Society40
- Biomedical and Health Sciences38
- Zoology24
- Geosciences20
- Public Health17
- Genetics and Genomics14
- Epidemiology12
- Nutrition, Sport, and Exercise Sciences12
- Science Communication12
- Microbiology11
- Anatomy and Physiology10
- Engineering, Technology, and Mathematics10
- Physical Sciences9
- Engineering8
- Chemistry7
- Plant and Agricultural Sciences7
- Atmospheric and Climate Sciences6
- Pharmacology6
- Anatomy and Biomechanics5
- Cell and Developmental Biology4
- Clinical Sciences4
- Neuroscience4
- Science Education4
- Technology3
- Data Science2
- Materials Science2
- Mathematics and Statistics2
- Mental Health2
- Physics2
- Research Data Management2
- Data Science Theory and Methods1
- Ethics1
- Psychology1
Publication Date
Author
- Ban, Natalie C6
- Miller, Kristina M6
- Cheung, William W L5
- Tabata, Amy5
- Foster, Angel M4
- Li, Shaorong4
- Lotze, Heike K4
- Mallory, Mark L4
- Ariel, Ellen3
- Chan, Hing Man3
- Davy, Christina M3
- Hall, Britt D3
- Kaukinen, Karia H3
- Lemieux, Christopher J3
- Moher, David3
- Mordecai, Gideon3
- Vermaire, Jesse C3
- Westwood, Alana R3
- Addison, Jason A2
- Ardern, Clare L2
- Atlas, William I2
- Bailey, Megan2
- Barry, Tegan N2
- Bashandy, Mohamed A2
- Batal, Malek2
Access Type
21 - 40of274
Save this search
Please login to be able to save your searches and receive alerts for new content matching your search criteria.
Filters
Search Name | Searched On |
---|---|
Paper Type: Article (274) | 8 May 2024 |
You do not have any saved searches
- OPEN ACCESS
- J.L. McCune,
- Anja M. Carlsson,
- Sheila Colla,
- Christina Davy,
- Brett Favaro,
- Adam T. Ford,
- Kevin C. Fraser, and
- Eduardo G. Martins
Preventing the extinction of species will require limiting human activities in key areas, but it is unclear to what extent the public is committed to these limits and the associated costs. We commissioned an online survey of 1000 Canadians and asked them if it is important to prevent the extinction of wild species in Canada. We used specific scenarios illustrating the need for limits to personal activities, private property rights, and industrial development to further test their support. The respondents were strongly committed to species conservation in principle (89% agree), including the need to limit industrial development (80% agree). There was less support for limiting private property rights (63% agree), and more uncertainty when scenarios suggested potential loss of property rights and industry-based jobs. This highlights the high level of public concern regarding the economic impacts of preventing extinctions, and the need for more programs to encourage voluntary stewardship of endangered species on private land. Opinion polls that measure public support for conservation without acknowledging the concessions required may result in overly optimistic estimates of the level of support. Most Canadians in our sample supported endangered species conservation even when the necessity of limiting human activities was explicitly stated. - OPEN ACCESSOften the Before-After-Control-Impact (BACI) design is suggested as being a statistically powerful experimental design in environmental impact studies. If the timing and location of the impact are known and adequate pre-data are collected, the BACI design is considered optimal to help isolate the effect of the development from natural variability. This paper presents 9 years of results from a long-term BACI experiment tested using a range of statistical models and post-impact monitoring designs. To explore suboptimal designs that are often utilized in environmental effects monitoring, the same data were also explored assuming either no control system was available (Before-After only), or that no pre-impact data were available (Control-Impact only). The results of the BACI design were robust to the statistical model used, and the BACI design was able to detect effects from the impact that the two suboptimal designs failed to detect. However, the BACI design demonstrated different conclusions depending on the number and configuration of post-impact years included in the analysis. Our results reinforce the idea that caution should be employed when using, or interpreting results from, a BACI design in an environmental impact study, but demonstrate that a well-designed BACI remains one of the best models for environmental effects monitoring programs.
- OPEN ACCESSAmmonium deposition at the International Institute for Sustainable Development Experimental Lakes Area (IISD–ELA), in northwestern Ontario, Canada, has doubled in the last 45 years and thus is no longer among the low nitrogen (N) deposition sites in North America. This may be related to the concurrent intensification of Manitoba agriculture to the west and upwind of the ELA. Large increases in ammonium deposition at the ELA were important in driving the observed trend and increased the NH4 + to NO3 − ratio of input to aquatic and terrestrial systems. Stable isotope analyses of two years of bulk (wet and dry) atmospheric deposition revealed very large ranges in δ15N−NH4 + (22‰ range), δ15N−NO3 − (18‰), and δ18O–NO3 − (19‰). Few other δ15N−NH4 +, δ15N−NO3 −, and δ18O–NO3 − values have been published for Canadian precipitation. Increases in δ15N of NH4 + and NO3 − in July occurred with increases in total N deposition. The wide range and seasonal trends of δ15N and δ18O values in ELA precipitation mean that studies characterizing N inputs to watersheds and lakes require an ongoing and comprehensive annual sampling regime. Global trends of declining δ15N of N deposition evident in lake sediment records may be a result of increases in NH4 + deposition with lower δ15N−NH4 + values. Similarly, the relationship in Lake Superior between increasing NO3 − and lower δ15N−NO3 − values may be explained by increased atmospheric deposition of N with low δ15N values.
- OPEN ACCESSThe diversity of insect parasitoids (Hymenoptera) has long been thought to be anomalous because it doesn’t appear to increase rapidly with decreasing latitude. However, due to the presence of undiscovered cryptic species and the under-sampling of hyper-diverse tropical areas, such apparently anomalous gradients may, in fact, be artifacts of limited geographic and taxonomic sampling. We attempted to circumvent such taxonomic impediments by elucidating a diversity/latitude relationship for parasitoid wasps, using publicly available DNA sequences to quantify diversity (via a species proxy molecular operational taxonomic unit (the DNA Barcode Index Number) and phylogenetic diversity) across a latitudinal gradient of ∼5000 km. We compared these diversity values to the abiotic factors (temperature and precipitation) that may drive the diversity/latitude relationship. We found no significant relationship between either diversity measure with latitude or with the environmental variables. Although ours is the first work to enumerate different DNA-based measures of parasitoid diversity across this geographic scale in a standardized fashion using publicly available sequences, further standardized collections over long time periods and a rapid movement of sequences into the public arena are needed to facilitate the further testing of macroecological trends elucidated with public DNA sequence libraries.
- OPEN ACCESSPrey individuals possess four basic strategies to manage predation risk while foraging: time allocation, space use, apprehension, and foraging tenacity. But there are no direct tests of theory detailing how spatial strategies change and covary from fine to coarse scales of environmental variability. We address this shortcoming with experiments that estimated space use and vigilance of snowshoe hares while we measured foraging tenacity in artificial resource patches placed in risky open versus safe alder habitat. Hares employed only two of eight a priori options to manage risk. Hares increased vigilance and reduced foraging in open areas as the distance from cover increased. Hares did not differentiate between open and alder habitats, increase vigilance at the coarse-grained scale, or reduce vigilance and foraging tenacity under supplemental cover. Hares were more vigilant in the putatively safe alder than in the purportedly risky open habitat. These apparently paradoxical results appear to reflect a trade-off between the benefit of alder as escape habitat and the cost of obscured sight lines that reduce predator detection. The trade-off also appears to equalize safety between habitats at small scales and suggests that common-sense predictions detailing how prey reduce risk may make no sense at all.
- OPEN ACCESSThis paper focuses on the multiple ways in which people who live along the rivers of the Brazilian Amazon, known as ribeirinhos, experience malaria outside of a clinical setting. It describes the local understanding of malaria, strategies to distinguish the illness from other febrile sicknesses, challenges for detecting the disease through biomedical diagnosis methods, and vicissitudes of having malaria. It draws on cases from ribeirinhos from a peri-urban community of Manaus and a rural community from Careiro, State of Amazonas, Brazil. Although malaria is biomedically characterized by the pathogens causing the disease, ribeirinhos have developed other standards to define malaria, including the intensity of the symptoms, the interval between the infections, and the types of medications dispensed to them. In the riverine communities studied, the etiology of malaria includes mosquitoes, microbes, water, wind, sun, and person-to-person transmission. Symptoms of malaria were found to overlap with other febrile sicknesses; hence, ribeirinhos developed skills to monitor how a malaise unfolds in their bodies. Experiential knowledge plays a key role in the early detection of malaria. Individuals who have no previous experience with malaria were found to spend more time seeking health care. Equally important, ribeirinhos perceive that malaria is part of the landscape they inhabit.
- OPEN ACCESSA partial pterosaur pelvis from the Campanian Dinosaur Park Formation of Canada adds to our knowledge of Late Cretaceous pterosaurs. The pelvis is tentatively referred to Azhdarchidae and represents the first pelvic material from a North American azhdarchid. The morphology of the ilium is bizarre compared with other pterosaurs: it is highly pneumatized, the preacetabular process tapers anteriorly, and muscle scars show that it would have anchored strong adductor musculature for the hindlimb. The acetabulum is deep and faces ventrolaterally, allowing the limb to be positioned underneath the body. These features support previous suggestions that azhdarchids were well adapted to terrestrial locomotion.
- OPEN ACCESSLignin is the second most abundant natural biopolymer and potentially a valuable alternative energy source for conventional fossil fuels. In this study, Fourier-transform ion cyclotron resonance-mass spectrometry (FTICR-MS) in conjunction with phase correction was applied to study photooxidation products of lignin using a 7 Tesla (T) mass spectrometer. The application of 7 T FTICR-MS has often been inadequate for the analysis of complex natural organic matter because of insufficient resolving power as compared with high-field FTICR, which led to incorrect assignments of elemental formulae and discontinuous plots in graphical and statistical analyses. Here, the application of phase correction to the FTICR mass spectra of lignin oxidation products greatly improved the spectral quality, and thus, readily permitted characterization of photooxidation processes of lignin compounds under simulated solar radiation conditions.
- OPEN ACCESSMicroplastic pollution is prevalent in the Ottawa River, with all open water samples (n = 62) and sediment samples (n = 10) containing microplastics. The median microplastic concentration of nearshore 100 L water samples was 0.1 fragments per L (ranged between 0.05 and 0.24 fragments per L). The larger volume Manta trawls samples taken in the middle of the Ottawa River had an overall mean concentration of plastics of 1.35 fragments per m3. Plastic concentrations were significantly higher downstream of the wastewater treatment plant (1.99 fragments per m3) compared with upstream of the effluent output (0.71 fragments per m3), suggesting that the effluent plume is a pathway for plastic pollution to the Ottawa River. The mean concentration of microplastic fragments recovered in the sediment samples was 0.22 fragments per g dry weight. The abundance of microplastics in the sediment was not significantly related to the mean particle size or the organic content of the sediment. The most common form of plastic particles found was microfibers. These made up between 70% and 100% of all plastic particles observed, although plastic microbeads and secondary plastic fragments were also recovered.
- OPEN ACCESSOrnithomimid material from the Belly River Group (Campanian) of Alberta, Canada is described as sharing characters with Qiupalong henanensis from the Qiupa Formation of Henan Province, China. Derived characters and character combinations of the pubis and astragalocalcaneum were previously used to diagnose Q. henanensis and support the referral of this material to Qiupalong sp., representing the first known occurrences of Qiupalong outside of China. Qiupalong is the sixth ornithomimid taxon to be reported from the Dinosaur Park Formation and the first ornithomimid genus with a transcontinental distribution. The Alberta material represents the oldest known occurrences of Qiupalong, and a reconsideration of character evidence suggests that this genus is phylogenetically nested within other North American ornithomimids. A North American origin for Qiupalong and subsequent dispersal to Asia is proposed.
- OPEN ACCESSFear of predation can disappear rapidly in the absence of predators, as bolder individuals outcompete vigilant individuals for food and mates. To examine the evolution of fear in a seasonal environment, we exposed Drosophila melanogaster to mantid predators during the breeding season and the non-breeding season, and compared these with a control. We compared three Drosophila lineages that were maintained in captivity for (1) ∼45 years without mantid predators, (2) ∼5 years without mantid predators, and (3) ∼5 years with mantid predators (predator-evolved). The presence of a predator during the non-breeding season caused reduced fecundity in the following breeding season, independent of the evolutionary lineage. However, the presence of a predator during reproduction caused offspring to emerge earlier, and this effect was more pronounced in the predator-evolved lineage. Thus, the fear response was related to evolutionary lineage only during the larval life stage, which is when foraging competition, and hence the cost of fear, may be highest. We present one of the first experimental demonstrations that emotion (fear) can evolve in response to environmental context.
- OPEN ACCESS
- Dewey W. Dunnington,
- Hilary White,
- Ian S. Spooner,
- Mark L. Mallory,
- Chris White,
- Nelson J. O’Driscoll, and
- Nic R. McLellan
We used a paleolimnological approach at Long Lake, Nova Scotia, to construct a 10 500-year record of metal deposition in lakebed sediments and elucidate the influence of both natural and anthropogenic environmental changes. Aquatic sediment concentrations of mercury (Hg), arsenic (As), and chromium (Cr) in Long Lake fluctuated substantially and, during some periods, exceeded guidelines for the protection of aquatic life. Increases in lead (Pb), Hg, Cr, trace metals, and nitrogen stable isotopes (δ15N) were broadly coincident with a period of widespread drying from ca. 8000 to 4000 cal BP and were likely a consequence of regional fires. From ca. 4000 cal BP until 1700 AD, metal levels in general were low due to decreased erosion, increased precipitation, and reduced fire activity. Water level lowering and forced sediment aggradation (tiding) in the 1800s led to increases in minerogenic Pb and Cr, though fossil fuel combustion also likely contributed to total Pb concentrations. Stratigraphic proxies indicated increased inorganic sedimentation rates, and reduced autochthonous productivity were coincident with lower Hg and As concentrations in the Long Lake sediment. Our data indicate that natural phenomena (fire) can result in sediment contaminant exceedances, that most metals have multiple sources, and that both human-induced disturbance and emissions have contributed to Pb contamination in the last 200 years. In addition, wetter and generally cooler climate appeared to favour lower concentrations of contaminants in lake sediments. Although wetland sediments in the Cumberland Basin Marshes are not heavily polluted with metals, the development of constructed wetlands and the disruption of aquatic sediments have the potential to concentrate, mobilize, and increase the bioavailability of metals. - OPEN ACCESSLife history theory predicts selection for higher reproductive investment in response to increased mortality among mature individuals. We tested this prediction over the period from 1978 to 2013 for three populations of Atlantic cod (Gadus morhua) off Newfoundland. These populations were heavily fished for a long period. We considered changes in standardized gonad weight as a proxy for changes in gonadal investment. We accounted for the allometry between gonad and body weight, individual body condition, water temperature, and potential spatial and density-dependent effects. Males display significant temporal trends in gonadal investment in all populations; in agreement with theoretical predictions, these trends show increased gonadal investments during the earlier part of the time series when mortality was high, with the trends leveling off or reversing after the later imposition of fishing moratoria. In contrast, females display patterns that are less consistent and expected; significant trends are detected only when accounting for density-dependent effects, with females in two populations unexpectedly showing a long-term decline in gonadal investment. Our results support the hypothesis that fisheries-induced evolution has occurred in gonadal investment in males, but not in females, and suggest that gonadal investment is more important for male reproductive success than expected in this lekking species.
- OPEN ACCESS
- Daniela Gomez Martin,
- Carolina David Wiener,
- Caroline Xavier de Freitas,
- Joice Luisa Costa,
- Airton José Rombaldi, and
- Jean Pierre Oses
Objectives: This work aims to assess changes in brain-derived neurotrophic factor (BDNF) levels in women after the practice of a specific short duration 10-session aquatic physical therapy protocol in patients with fibromyalgia (FB). Methods: Case–control study. Thirteen women diagnosed with FB and 11 controls with the same age group, 35–55 years. Patients were evaluated according to the visual analog scale of pain and the fibromyalgia impact questionnaire (FIQ). All were subjected to a short protocol totaling 10 sessions of 40 min twice a week for five weeks. Heart rate and pain were monitored. BDNF levels were measured using enzyme immunoassay. Results: A statistically significant increase in BDNF values was noted in patients with FB between the pre- and post-10th session assessments (mean of 35.52–41.96; p = 0.041). Conclusion: BDNF values may present fluctuations during a short duration moderate aerobic exercise protocol, when measured and analyzed in a longitudinal design. Further studies with a more frequent BDNF evaluation could help in understanding its behavior more accurately and are warranted. - OPEN ACCESSIntroduction: Food insecurity at the individual level has been shown to be associated with the adoption of risky behavior and poor healthcare-seeking behavior. However, the impact of household food insecurity (HFI) on the utilization of maternal healthcare services (MHS) remains unexplored. In this study, we aimed to investigate whether or not household food insecurity was associated with non/inadequate utilization of MHS. Methods: Participants consisted of 3562 mothers aged between 15 and 49 years and with at least one child. The outcome variable was the utilization of MHS, e.g., institutional delivery, attendance ante-, and pre-natal visits. The explanatory variables included various sociodemographic factors (e.g., age, residence, education, wealth) apart from HFI. HFI was measured using the Household Food Insecurity Access Scale (HFIAS). Result: The prevalence of non- and under-utilization of MHS was 5.3 and 36.5, respectively. In the multivariate analysis, HFI, wealth index, and educational level were independently associated with MHS status. The odds of non- and under-utilization of MHS were 3.467 (CI = 1.058–11.354) and 4.104 (CI = 1.794–9.388) times higher, respectively, among women from households reporting severe food insecurity. Conclusion: Severe HFI was significantly associated with both under- and non-utilization of MHS. Interventions programs that address HFI and the empowerment of women can potentially contribute to an increased utilization of MHS.
- OPEN ACCESSContemporary approaches to market-oriented agricultural development focus on increasing production and economic efficiency to improve livelihoods and well-being. For seed system development, this has meant a focus on seed value chains predicated on standardized economic transactions and improved variety seeds. Building formal seed systems requires establishing and strengthening social institutions that reflect the market-oriented values of efficiency and standardization, institutions that often do not currently exist in many local and informal seed systems. This paper describes and analyzes efforts to develop formal seed systems in Sahelian West Africa over the past 10 years, and identifies the impacts for farmers of the social institutions that constitute formal seed systems. Using qualitative and spatial data and analysis, the paper characterizes farmers’ and communities’ experiences with seed access through the newly established formal seed system. The results demonstrate that the social and spatial extents of the formal and informal seed systems are extended and integrated through social institutions that reflect values inherent in both systems. The impacts of current market-oriented agricultural development projects are, therefore, more than in the past, in part because the social institutions associated with them are less singular in their vision for productive and economic efficiency.
- OPEN ACCESS
- Ben J.G. Sutherland,
- Jennifer M. Covello,
- Sarah E. Friend,
- Jordan D. Poley,
- Kim W. Koczka,
- Sara L. Purcell,
- Tara L. MacLeod,
- Bridget R. Donovan,
- Jorge Pino,
- Jose Luis González-Vecino,
- Javier Gonzalez,
- Jose Troncoso,
- Ben F. Koop,
- Simon L. Wadsworth, and
- Mark D. Fast
Salmon lice (Lepeophtheirus salmonis) are important ectoparasites of wild and farmed salmonids and cause major losses to the salmon farming industry throughout the Northern Hemisphere. With the emergence of resistance to several commonly used parasiticides, novel control strategies and integration of multiple treatment options are needed, including host immunostimulation. Here, we investigate the effects of a functional feed containing a peptidoglycan and nucleotide formulation on L. salmonis infection of Atlantic salmon (Salmo salar) by characterizing lice infection levels, the expression of several host immune genes, and the parasite transcriptomic response to the immunostimulated host. Although initial infection intensities were low, the low dose (LD) immunostimulant diet reduced the total lice burden by 50% relative to controls. Immunostimulant fed hosts up-regulated interleukin-1β in the skin and spleen. This gene has been implicated in successful responses of several salmonid species to salmon lice but is typically not observed in Atlantic salmon, suggesting a favorable influence on the immune response. Lice infecting LD immunostimulated salmon overexpressed genes putatively involved in parasite immunity, including carboxylesterases, and underexpressed genes putatively involved in feeding (e.g., proteases). These lice response genes further improve the characterization of the transcriptome of the non-model parasite by identifying genes potentially involved in evading host immunity. - OPEN ACCESS
- Christina M. Davy,
- Michael E. Donaldson,
- Yessica Rico,
- Cori L. Lausen,
- Kathleen Dogantzis,
- Kyle Ritchie,
- Craig K.R. Willis,
- Douglas W. Burles,
- Thomas S. Jung,
- Scott McBurney,
- Allysia Park,
- Donald F. McAlpine,
- Karen J. Vanderwolf, and
- Christopher J. Kyle
The fungus that causes bat white-nose syndrome (WNS) recently leaped from eastern North America to the Pacific Coast. The pathogen’s spread is associated with the genetic population structure of a host (Myotis lucifugus). To understand the fine-scale neutral and immunogenetic variation among northern populations of M. lucifugus, we sampled 1142 individuals across the species’ northern range. We used genotypes at 11 microsatellite loci to reveal the genetic structure of, and directional gene flow among, populations to predict the likely future spread of the pathogen in the northwest and to estimate effective population size (Ne). We also pyrosequenced the DRB1-like exon 2 of the class II major histocompatibility complex (MHC) in 160 individuals to explore immunogenetic selection by WNS. We identified three major neutral genetic clusters: Eastern, Montane Cordillera (and adjacent sampling areas), and Haida Gwaii, with admixture at intermediate areas and significant substructure west of the prairies. Estimates of Ne were unexpectedly low (289–16 000). Haida Gwaii may provide temporary refuge from WNS, but the western mountain ranges are not barriers to its dispersal in M. lucifugus and are unlikely to slow its spread. Our major histocompatibility complex (MHC) data suggest potential selection by WNS on the MHC, but gene duplication limited the immunogenetic analyses. - OPEN ACCESS
- Lesya Marushka,
- Malek Batal,
- Donald Sharp,
- Harold Schwartz,
- Amy Ing,
- Karen Fediuk,
- Andrew Black,
- Constantine Tikhonov, and
- Hing Man Chan
Consumption of fish and n-3 fatty acids (n-3 FAs) has been postulated to prevent type 2 diabetes (T2D). Objective: To explore the association between self-reported T2D and fish consumption, dietary n-3 FAs, and persistent organic pollutants (POP) intake in a regionally representative sample of First Nations (FNs) in Manitoba. Design: Data from the cross-sectional First Nations Food, Nutrition and Environment Study (FNFNES) collected from 706 members of 8 Manitoba FNs in 2010 were used. Household interviews were used to collect social and lifestyle data. The consumption of fish was estimated using a traditional food frequency questionnaire. Fish samples were analyzed for the presence of POP. Multiple logistic regression models adjusted for potential risk factors for T2D were developed. Results: A negative, dose–response relationship was found between fish intake and self-reported T2D. Fish consumptions of 2–3 portions per month and ≥1/week were inversely associated with T2D with odds ratio (OR) values of 0.51 (95% CI: 0.28–0.91) and 0.40 (95% CI: 0.19–0.82), respectively, compared with no fish intake. Similarly, intake of n-3 FAs was negatively associated with T2D (OR = 0.48 (95% CI: 0.30–0.77). Dietary POP intake was not associated with T2D. Conclusion: These findings suggest that the consumption of traditionally harvested fish may have a beneficial effect on T2D in Manitoba FNs. - OPEN ACCESSIntroduction: In Canada, the progestin-only dedicated pill is the most widely used method of emergency contraception (EC). This method gained over-the-counter status in Ontario in 2008. Our mixed methods study explored the progestin-only EC knowledge, attitudes, and provision practices of Ontario pharmacists. Methods: From June 2015 to October 2015, we collected 198 mailed surveys from Ontarian pharmacy representatives and conducted 17 in-depth interviews with a subset of respondents. We analyzed these data using descriptive statistics and for content and themes. Results: Results from our English/French bilingual survey indicate that respondents’ knowledge is generally accurate, but confusion persists about the mechanism of action and the number of times the drug can be used in one menstrual cycle. Nearly half (49%) of our survey respondents indicated that progestin-only EC pills are only available behind the counter. Interviewees strongly supported the introduction and promotion of more effective methods of EC in Ontario. Conclusion: Continuing education focusing on both the regulatory status of progestin-only EC and information about the medication appears warranted. Health Canada’s recent approval of ulipristal acetate for use as a post-coital contraceptive may provide a window of opportunity for engaging with health service providers, including pharmacists, about all available modalities of EC in Canada.