30921 research outputs found
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Landscape heterogeneity enhances Hymenoptera (Apoidea: Anthophila) abundance and diversity across Manitoba ecoregions
No full textAs natural ecosystems across Canada continue to experience habitat loss, the need to understand the impacts of fragmentation on key members of the ecological community increases. In this study, I determine the influence of compositional and configurational landscape heterogeneity on bee communities through landscape characteristics in natural, semi-natural, and agricultural ecosystems in four Manitoba ecoregions. Additionally, I compare the use of roadside verges for foraging and provisioning of forage by bee indicator species across four Southern Manitoba ecoregions in natural, semi-natural, and agricultural landscapes. For the combined sampling period, 2021 and 2022, 8781 bees were captured using pan traps, blue vane traps, and aerial netting. Results varied year to year, suggesting the impacts of fragmentation vary depending on other abiotic or biotic factors not captured in this study. Urban land, pastureland, mixed wood, and shrubland were identified as key compositional heterogeneity variables shown to affect bee abundance, with no effect on bee diversity. Mean Shape Index and Patch Area were the only configurational heterogeneity metrics identified, with only Mean Shape Index showing a significant impact on bee abundance. Since bee diversity was not impacted by either compositional or configurational heterogeneity, further research is needed to understand the factors that determine diversity in Southern Manitoba. Indicator species analysis was inconclusive in determining a key indicator, highlighting the need for improved detection of species in sampling regimes, although some trends were identified. Recommendations to continue the use of Bombus as indicators, with the introduction of some medium-body sized bee species as indicators where identified.Federal Student Work Experience ProgramOctober 202
Ecosystem engineering of tundra heath by Arctic fox (Vulpes lagopus) is driven by nutrient additions
No full textBackground: Soil nutrient availability is a limiting factor for tundra productivity. Therefore, consumer-driven alteration of nutrient availability can have a large effect on tundra communities. Previous work has demonstrated that Arctic foxes (Vulpes lagopus) act as ecosystem engineers in tundra heath communities by altering plant composition and increasing plant biomass on their dens, which then increases snow depth. To test the ability of increased nutrients and deeper snow to cause the ecosystem effects observed on fox dens, we set up a nutrient addition and snow fencing experiment on tundra heath in Wapusk National Park, Canada. Results: Changes in experimental plots were mainly driven by fertilizer application, not snow depth. After 2 years, the fertilizer plots were invaded by a dune grass (Elymus mollis), which increased to 12% cover by the end of the experiment, which is typical of fox dens. After 4 years, total plant cover was 26% higher on the fertilizer plots than on the control plots. After 7 years of treatments, the plots receiving both fertilizer and snow fencing had the greatest shift in plant species composition, although they still lacked the tall willow shrubs typical of fox dens. Fertilized plots and dens had five times more arthropods than control plots. Most wildlife, except caribou (Rangifer tarandus), spent more time on fertilized plots in years when they were abundant, with Canada geese (Branta canadensis) being present 20 times longer in fertilizer plots. Collared lemmings (Dicrostonyx richardsoni) also preferred fertilized plots in the summer, but winter use was more pronounced on snow fenced and fertilized plots, where they produced 20 latrines per plot in a peak population year. Conclusions: These results demonstrate that the nutrient limitation in tundra vegetation makes tundra ecosystems vulnerable to changes in nutrient availability, with changes in plant abundance and composition leading to increased animal activity, that has the potential to create a positive feedback in ecosystem productivity
Impact of water management by tile drainage on soybean yield and quality
No full textAs climate change leads to more frequent extreme weather events, including intense rainfall and prolonged droughts, effective water management becomes critical for increased crop productivity. This study examined the role of subsurface drainage systems in mitigating water availability extremes, optimizing crop productivity, and enhancing nutrient use by managing excess water during heavy rainfall, improving soil aeration, and water retention during dry periods. The objectives of this research were to (i) evaluate the yield and quality impact of free drainage at 15 m spacing (FD-15), 8 m spacing (FD-8), and no drainage in sandy loam soils at Winkler, MB (ii) assess the yield impact of different subsurface water table depths (i.e., over-the-tile, midway-between-tile, and no-tile) in heavy clay soils at Arborg, MB, and (iii) simulate the yield impact of different water table depths (WTD) under soybean production using the DRAINMOD model in clay soils. In sandy loam soils, the yield from FD-15 plots was significantly higher (p < 0.05) than that from FD-8 plots, with narrowly spaced tiles over-draining the limited available water. The 2021 results indicated soybean yield was twice as high compared to 2020, despite both years receiving similar amounts of rainfall. This suggests that soybean yield is significantly influenced by the timing of rainfall during critical growth stages.
The tile drainage research in heavy clay soils at Arborg, MB, during the 2020 and 2021 growing seasons, which were relatively dry years, showed a higher yield trend in tiled plots compared to the no-tile control plots. The higher yields in the tiled plots were due to the right amount of water being held back when needed and drained when in excess. Shallower water tables in the no-tile plots contributed to lower yields. In contrast, 2022, a wetter year, showed the over-the-tile treatment gave significantly higher yield (p < 0.05) compared to the no-tile treatment because the water was held back within the plot during critical stages in the over-the-tile treatments. Furthermore, the yield observed in the over-the-tile treatment exceeded the provincial average for the Interlake region. Although the total rainfall for 2020 and 2021 was the same, the soybean yield in 2021 was double that of 2020, indicating the timing of rainfall coinciding with critical growth stages led to higher yields. The 2020 data was used to calibrate and validate the DRAINMOD model to predict the water table depth in heavy clay soils at the Prairie East Sustainable Agriculture Initiative (PESAI) soybean plots. The calibrated DRAINMOD model was then used to predict the water table depth in 2021 and 2022, which statistically demonstrated strong agreement between measured and predicted water table depths. The validated DRAINMOD model was then used to predict relative yield for the different drainage treatments using weather data from 2012 to 2019. The predicted yield trends for the different drainage treatments showed a similar yield impact to what was observed from 2020 to 2022. The importance of water availability during critical growth stages (flowering, pod formation, and pod filling) on soybean yield is demonstrated. This research demonstrated the importance of managing the water table depth through controlled drainage to obtain higher soybean yield.SCAP - Sustainable Canadian Agricultural Partnership programOctober 202
Investigating evaluation and effects of partnered rehabilitation research: a mixed methods approach
No full textBackground
Findings from rehabilitation research may be under-utilized in part because of how they are produced, which may impact health outcomes or the economic costs of the healthcare system. An approach which could enhance the use of rehabilitation evidence is for researchers to partner with knowledge users (e.g., clinicians, policymakers, or decision makers) throughout the research process. This approach, known as partnered rehabilitation research, has potential to increase the uptake of rehabilitation research by aligning research designs and processes with knowledge users’ priorities and values. Studies on partnered rehabilitation research have reported on characteristics of the partnerships, strategies, and methods to involve knowledge users, when to involve knowledge users, factors affecting the partnerships, impacts, and outcomes. However, little is known about how partnered rehabilitation research was evaluated and its effects on knowledge use. Evaluation is important to confirm short, medium, or long-term effects of partnerships, ensure integrity of the partnering process, confirm assumptions of this approach, and assess how partners work together. Considering the importance of evaluation and knowledge gaps about the effects of partnering, my overarching research question was, “how has partnered rehabilitation research been evaluated and what are its effects on the research process and outcomes?”
Methods
I used an explanatory sequential mixed method design, underpinned by a pragmatic lens, to conduct a cross-sectional online survey followed by interviews. Individuals were eligible for either study if they were researchers or knowledge users who had experience in partnered rehabilitation research. I used non-probability convenience and snowball sampling to recruit participants to the survey. The survey was conducted in July 2023. I analyzed and reported survey findings descriptively. I situated the interviews in a qualitative descriptive study and used purposive and snowball sampling to recruit participants. The interviews were completed early 2024. I analyzed the findings inductively and deductively and reported results thematically. I kept field notes and used member checking and thick description to enhance trustworthiness. I integrated results from the survey and interviews via narrative weaving and presented them in a stand-alone chapter.
Results
Participants from the survey (n = 14) and interviews (n = 13) were predominantly female (n = 24, 89%) and white (n = 21, 78%). No survey respondents were knowledge users, but six (46%) interview participants were. Many survey respondents indicated the partnership will be/ had been evaluated (n = 8, 56%). However, no interview participants evaluated the partnerships. Most survey respondents (n = 10, 71%) perceived partnering significantly influenced the research questions, and interview participants discussed how partnering resulted in clinically applicable research questions. Many survey respondents (n = 9, 64%) believed the partnership significantly influenced research outcomes such as the production of useful research findings or evidence-informed clinical decision making (n = 8, 57%). However, interview participants offered few insights and examples of how and when partnering enhanced evidence uptake in clinical decision making.
Conclusion
Findings from the survey and interviews suggest that partnering influences the research process and research outcomes. However, there was discordance specific to findings about evaluation of partnered rehabilitation research. Many survey respondents evaluated the partnering process, but no interview participants did. Findings from this mixed methods study confirm some assumptions about partnered rehabilitation research, however; more research is needed to substantiate the effects of partnering and extent of evaluation in partnered rehabilitation research.October 202
Signal and noise: a comprehensive assessment of the relationship between medication use and Alzheimer’s Disease
Get PDFDespite a large body of research examining the associations between medication use and dementia, the issue remains unresolved. This thesis uses administrative healthcare data to examine two drug classes, proton pump inhibitors (PPIs) and benzodiazepines, and dementia risk using a methodological sensitivity analysis approach to better understand why the evidence remains equivocal, and whether these drugs do increase the risk of dementia. Cox regression models were used to model risk using a population level cohort. Subgroup analysis was used when needed to reduce indication bias. Finally, high dimensional propensity score matched cohorts were used to reduce unmeasured confounding.
We found that while PPI users had modestly higher risk of dementia, this increased risk was due to higher rates of baseline comorbid conditions that are also risk factors for dementia. An analysis of PPI initiators also found that these conditions were predictors of treatment initiation and increased duration of use. After adjusting for the comorbid conditions, the association between PPIs and dementia was null.
Similarly, benzodiazepine users had higher risk of dementia but also higher rates of dementia risk factors at baseline. Adjusting for these conditions reduced the estimated increased risk, although it remained significant. However, this class of drugs is most used in those with depression and anxiety, risk factors for dementia, resulting in potential indication bias. When this bias was reduced by examining cohorts of depressed persons, or of those with anxiety no increase in dementia risk was found.
The pharmacoepidemiological research into dementia risk associated with prescription drugs is messy. Insufficiently controlling for the noise present in non-randomized and observational data can lead to detecting signals of uncertain validity. It is hoped that this systematic approach will raise the bar for future research in this area, and that future researchers would, before publishing alarming findings, assess more closely whether they have truly controlled for confounding, reduce the risk of bias, and that their study design can answer the question they are trying to ask.May 202
Exploring epigenetic links: stress and albuminuria in youth with type 2 diabetes
Get PDFBackground:
Youth with Type 2 Diabetes (T2D) often develop early-onset kidney disease, with albuminuria
as the initial biomarker. Psychological factors, including perceived stress, are associated with the
progression of kidney disease, although the mechanisms remain unclear. This study investigated
DNA methylation changes in youth with T2D and albuminuria compared to those without
albuminuria and examined whether changes in DNA methylation existed in genes known to be
associated with stress functions.
Methods:
This cross-sectional study analyzed data from 213 youth with T2D enrolled in the national
iCARE cohort study. Kidney injury was assessed by non-orthostatic albuminuria, and perceived
stress was measured using the PSS-14 questionnaire. Whole blood DNA methylation patterns
were analyzed using an epigenome-wide association study (EWAS) to identify differentially
methylated sites. Associations with albuminuria were tested with multiple linear regression
models. A differentially methylated region (DMR) analysis explored broader DNA methylation
differences across the genome in areas related to kidney injury. A candidate gene analysis
compared CpG sites from our study to the EWAS Atlas, with significance assessed using t-tests.
Results:
Based on the EWAS, no significant sites were associated with albuminuria. Six significant
DMRs were identified, corresponding to the genes: TNXB, TSPAN32, ZNF486, ZNF562,
ATP5E, and TNFRSF6B. These genes are linked to energy metabolism, immune regulation, and
extracellular matrix maintenance. In the candidate gene analysis, we identified 56 CpG sites with
significant differences at a p-value < 0.05 and 18 sites at a p-value < 0.01.
Conclusion/Importance:
Although no significant site-level differences were found, the six significant DMRs suggest
potential regions of epigenetic variation that could be associated with stress and kidney injury in
youth with T2D. Given the exploratory nature of these findings and the limitations of bloodbased
DNA methylation studies, further research is needed to clarify the role of DNA
methylation changes. These findings may help guide future investigations into the role of
epigenetics in kidney injury and stress in youth-onset T2D.Rady Faculty of Health Sciences Graduate Studentship Award
University of Manitoba Graduate Fellowship
Manitoba Training Program for Health Services ResearchMay 202
Evaluation of the antimicrobial activity of grape extract against Bacillus cereus in rice
Get PDFThe antimicrobial potential of grape extract was assessed in cooked rice against Bacillus cereus. Grape extract efficacy was tested at 1, 5 and 10 mL/L, at pH 4.5, 5.5 and 6.5; and at incubation temperatures simulating different storage scenarios, specifically temperature abuse (10 ◦C), cool chain break (20 ◦C) and optimal B. cereus growth temperature (30 ◦C). Survival curves for grape extract concentration versus time were obtained. The results indicate that antimicrobial activity of grape extract was dependent on temperature, pH and grape extract concentration. A bactericidal effect of the grape extract was shown at concentration levels ≥ 5 mL/L at all temperatures and pHs studied. Inactivation curves of B. cereus under grape extract exposure were fitted to a Weibull distribution function for 5–10 mL/L grape extract concentration. Observations showed that the higher the incubation temperature and grape extract concentration, the lower the kinetic rate value. In other words, lower resistance of the microorganism to environmental conditions. The maximum inactivation level was 6 log10 cycles after 24 h of exposure at 10 mL/L of grape extract concentration and pH 4.5. Results indicate that the grape extract could be a good additional control measure for preventing Bacillus cereus growth in cooked rice during storage
Incorporating Citation Justice within Citation Instruction
Get PDFAs librarians, we spend a great deal of time teaching students how to create proper citations and abide by the rules set out in various style guides. When participating in this kind of work, it can be easy to focus on the advantages, such as helping learners avoid academic misconduct and gain skills that will benefit them in assignment completion and even beyond their academic studies. This type of support is frequently requested by students and instructors alike, but it does not come without its challenges.
In recent years, there has been much attention on issues related to diversity, equity, and inclusion (DEI) including the emergence of citation justice. Citation justice aims to address the citation gap of minority researchers due to systemic failures. This concept involves “the deliberate act of citing more work authored by people from marginalized communities in society and in academia” such as individuals who identify as BIPOC or S2LGBTQIA+ (Coalter, 2023, p. 62). According to Mott and Cockayne (2017), “the choices we make about whom to cite – and who is then left out of the conversation – directly impact the cultivation of a rich and diverse discipline” (p. 955). Therefore, citation justice offers students an opportunity to establish positive change by highlighting scholars in their own work that have traditionally been excluded.
This topic has the potential to influence the types of sources our students find, read, use, and ultimately cite. Citation justice affects our students’ research and writing processes in profound and complex ways, yet are these elements integrated into citation-related resources and services? And if not, why is replicating appropriate style guide information our only goal? How can we foster critical thinking and encourage students to reflect on why and how citations are disseminated? In considering such questions, two librarians began a research project focused on these very things. In the fall of 2023, they completed an evaluation of citation support offered by the top 15 research-intensive Canadian universities (known as the U15) combined with a thorough literature review. Inspired by their findings, the librarians decided to introduce citation justice by adding new content to the library's primary citation LibGuide as well as integrating it into a new workshop for undergraduate and graduate students.
Citing is so much more than simply writing a reference, and as librarians, it is crucial for our practice to evolve to help students understand and learn from historical and emerging citation challenges . Librarians can assist students in developing the skills to make informed and thoughtful decisions about which citations they use, and how to be aware of and apply citation justice within their own writing. As scholars themselves, it is only right for students to learn to be critical, curious and informed about the sources they encounter.
In this session, presenters will share their own experiences in moving beyond traditional citation instruction and share strategies to help participants transform their own resources and services to support student learning in a holistic way
Interview and Focus Group Summary Report
No full textThe representation and experiences of women in Engineering and Information and Computer Technologies (EICT) fields have been a subject of extensive research and discussion. This report provides a summary of the experiences of women in these fields across Canada, Sweden, and Germany. By examining 58 semi-structured interviews and 4 focus groups, this report identifies commonalities and differences in their experiences, challenges, and opportunities. This report sheds light onto factors that influence women's participation and retention in Engineering and ICT and provides recommendations for improving gender equity in these fields.
We find that the experiences of women in ICT and Engineering fields in Canada, Sweden, and Germany reveal challenges and differences that align with Esping-Andersen's (1989) Welfare State typology. Sweden's social democratic welfare state offers extensive support for work-life balance and gender equality, reflected in the positive experiences of women in ICT and Engineering. Canada's liberal welfare state provides some support but lacks the comprehensive policies seen in Sweden, leading to challenges in balancing work and family responsibilities. Germany's conservative welfare state shows more traditional gender roles and less flexibility in work arrangements, contributing to the greater challenges faced by women in these fields. Addressing gender bias, improving work-life balance, and providing better access to mentorship and career development opportunities are crucial steps in supporting women in Engineering and ICT. By learning from the successes and challenges in each country, we can develop more effective strategies to promote gender equity and create a more inclusive environment for women in Engineering and ICT. This may help to retain women in their Engineering and ICT careers
Performance investigation of piezoelectric PVDF-TrFE polymer for it's mechanical and electrical response and use as vibration sensor
No full textPiezoelectric polymers, such as PVDF-TrFE, are increasingly studied for their potential to replace traditional ceramic based piezoelectric materials due to their flexibility, ease of processing, and strong adhesion properties. This study focuses on PVDF-TrFE with a 75/25 molar concentration, emphasizing the enhancement of the β-phase to improve piezoelectric output. The research explores various techniques to increase the β-phase without requiring extensive stretching or polling processes. Notably, the addition of the TrFE co-polymer to PVDF negates the need for such processes, inherently boosting piezoelectric performance. The experimental study utilized PVDF-TrFE dissolved in two different solvents: MIBK (Methyl Isobutyl Ketone) and DMSO (Dimethyl Sulfoxide).
In the initial phase of the experiments, piezoelectric solutions based on MIBK and a combination of MIBK and DMSO were spin-coated onto flexible KAPTON cantilevers and annealed to form thin films. The mechanical properties were then assessed using a vibration test system. It was observed that films created with MIBK
alone exhibited higher vibrational amplitudes than those formed with a mixture of MIBK and DMSO. Additionally, higher concentrations of PVDF-TrFE resulted in greater vibrational amplitudes, suggesting a direct correlation between polymer concentration and mechanical responsiveness. Notably, the films made by a 1.25% MIBK+ DMSO based polymer solution produced an equivalent sensitivity to the films made by a 3% polymer solution. The equivalency is due to the presence of DMSO (polar nature) solvent and its ability to form long chains during the baking process. In contrast, the latter solution produced thicker films than the former due to the increased quantity of polymer. The performance of laboratory based vibration sensors fabricated using PVDF-TrFE was compared with existing ceramic based devices and commercial vibration sensors. The results indicated that PVDF-TrFE sensors generated comparable, if not higher, piezoelectric voltages than their ceramic counterparts. This finding underscores the potential of polymer based sensors in practical applications, offering advantages in flexibility and adhesion without sacrificing performance.
Further experiments involved fabricating a 5 x 2 mm cantilever on a PCB using a laser cut process. This cantilever responded to acoustic signals ranging from 400 Hz to 1200 Hz and produced a 0.011 V output voltage during vibration tests. Another U-shaped sensor, incorporating electroplated copper, spin-coated PVDF-TrFE,
and silver sputtering, was tested as a Lorentz force actuator and sensor. The sensor exhibited responsiveness to magnetic elds and sinusoidal voltages, highlighting its multifunctional capabilities. Additionally, a vibration sensor was made on a bearing surface and subjected to motor induced vibrations, demonstrating a clear output signal, driven purely by the motor's rod vibrations.May 202