Department of Biological Sciences

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Now showing 1 - 5 of 85
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    Indirect effects on fitness between individuals that have never met via an extended phenotype
    (2019) Fisher, David N.; Haines, Jessica; Boutin, Stan; Dantzer, Ben; Lane, Jeffrey E.; Coltman, David W.; McAdam, Andrew G.
    Interactions between organisms are ubiquitous and have important consequences for phenotypes and fitness. Individuals can even influence those they never meet, if they have extended phenotypes that alter the environments others experience. North American red squirrels (Tamiasciurus hudsonicus) guard food hoards, an extended phenotype that typically outlives the individual and is usually subsequently acquired by non-relatives. Hoarding by previous owners can, therefore, influence subsequent owners. We found that red squirrels breed earlier and had higher lifetime fitness if the previous hoard owner was a male. This was driven by hoarding behaviour, as males and mid-aged squirrels had the largest hoards, and these effects persisted across owners, such that if the previous owner was male or died in mid-age, subsequent occupants had larger hoards. Individuals can, therefore, influence each other's resource-dependent traits and fitness without ever meeting, such that the past can influence contemporary population dynamics through extended phenotypes.
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    Soil respiration
    (2020) Elliott, Christina G.; Mewhort, Randi L.; Wakeford, Donna
    This guided inquiry laboratory exercise is an excellent opportunity to introduce carbon cycling and some of the issues associated with climate change. Students in our major/minor programs generate a class hypothesis using summarized research on soil respiration and vote on a treatment option: soil type, litter type, water levels or temperature. Respiration chambers incubate for a week, and the amount of CO2 produced over the seven days is determined the following week. This is an easy, low tech way to teach these concepts, but could be adapted to use probes to measure CO2 directly. This activity is very adaptable to highlight different skills such as hypothesis testing, statistical analysis and experimental design. In institutions with more space resources this could be easily adapted for more inquiry-based approaches.
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    Insights into Lake Baikal's ancient populations based on genetic evidence from the Early Neolithic Shamanka II and Early Bronze Age Kurma XI cemeteries
    (2021) Moussa, Nour; McKenzie, Hugh; Bazaliiskii, Vladimir I.; Goriunova, O. I.; Bamforth, F.; Weber, A. W.
    Although previous ancient DNA research has contributed to the investigation of middle Holocene culture history and population dynamics in the Cis-Baikal, most of this work has been limited to the Angara valley and southwest Baikal, with only restricted genetic analysis of skeletal materials from the Little Sea microregion. In this paper, we expand upon initial findings by analyzing new mtDNA results from the EN/EBA Kurma XI cemetery (Little Sea area) and the EN Shamanka II cemetery (southwest Baikal). Our results not only contribute to the regional dataset, but also challenge previous findings. First, haplogroup Z was found for the first time in the ancient population of Cis-Baikal. Second, our data provide tentative support for the idea that an exogamous and/or patrilocal marriage pattern might be detectable at the Early Bronze Age cemetery Kurma XI. Third, our results indicate that the EN population of Cis-Baikal may not be as homogeneous in maternal origin as was previously suggested. Similarly, there seems to be less continuity between the Late Neolithic and Early Bronze age samples than previously thought, which further justifies the separation of these groups for future analyses. Finally, our data indicate that the maternal genetic background of the Early Bronze Age sample from Kurma XI is closer to that of known Early Neolithic groups than it is to those from the Late Neolithic or Early Bronze Age. This observation is surprising and, if correct, would seem to directly contradict the previous suggestion of a Middle Neolithic genetic discontinuity. These new findings complicate our understanding of the relationships between middle Holocene populations in the Cis-Baikal.
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    Flexible electrochemical aptasensor for cortisol detection in human sweat
    (2021) Mugo, Samuel; Alberkant, Jonathan; Bernstein, Nina; Zenkina, Olena V.
    This communication demonstrates an electrochemical DNA aptasensor for the detection of cortisol in human sweat. The aptasensor was fabricated via layer-by-layer assembly on stretchable polydimethylsiloxane (PDMS) coated with conductive nanoporous carbon nanotube-cellulose nanocrystals (CNC/CNT) film using a linker to a cortisol specific DNA aptamer. The flexible cortisol aptasensor had a dynamic range of 2.5–35 ng mL−1. The aptasensor precision was determined to be 2.7% relative standard deviation (%RSD) across the concentration dynamic range. The aptasensor was determined to have a limit of detection (LOD) of ∼ 1.8 ng mL−1. The aptasensor was demonstrated to have high selectivity to cortisol and was unresponsive to interfering species including glucose, sodium lactate, and β-estradiol. The aptasensor was successfully evaluated for the detection of cortisol in human sweat indicative of its high specificity.
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    Faculty perspectives on UDL: exploring bridges and barriers for broader adoption in higher education
    (2022) Hills, Melissa; Overend, Alissa; Hildebrandt, Shawn
    Universal Design for Learning (UDL) strategies aim to reduce learning barriers in the classroom for all students and remove the need for students with disabilities to advocate on their own behalf. Leadership in Scholarship of Teaching and Learning has a role to play in advancing inclusive learning cultures in higher education. At the frontline of higher education delivery, faculty are best positioned to implement UDL practices. Initiatives to encourage broader implementation of UDL require an understanding of the barriers and opportunities in higher education. Published studies that investigate faculty understanding and implementation of UDL have been almost exclusively conducted in US institutions. Our study enriches the existing literature through a mixed methods approach withinterviews and a faculty survey in a Canadian context. Themes revealed in our interviews were reinforced by survey findings. Many of the issues raised by faculty, including time and resource constraints, a lack of institutional support, and a lack of understanding are consistent with previous research done in the US, highlighting the systemic challenges for UDL implementation in higher education. To conclude, we explore the limits of a strictly bottom-up approach and contend, in line with recent studies, that top-down initiatives are also vital to encouraging broader implementation of UDL practices.