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Dispersal limitation and seed predation drive rarity of a plant species at its range edge
No full textOpen access article. Creative Commons Attribution-NonCommercial 4.0 International license (CC BY-NC 4.0) applies1. Understanding the causes of species rarity is a central goal in ecology. The three
filters thought to predict if a species is present or not in a community are the suit-
ability of abiotic conditions, dispersal limitation and biotic interactions. Theory
emphasizes the importance of the availability of abiotically suitable habitat in de-
termining occurrence frequency, especially for species at their range edge, where
the amount of suitable habitat is predicted to decline. However, the relative influ-
ence of these filters in driving species rarity is mostly unknown.
2. We used species distribution models (SDMs) to estimate habitat suitability based
on broad-scale abiotic predictors for a rare plant species (Stylophorum diphyllum)
at the northern edge of its global distribution. We tested the role of dispersal limi-
tation by planting seeds in unoccupied sites that varied in their predicted habitat
suitability and measured seedling emergence and seedling survival over 2 years.
To manipulate the biotic interactions, we excluded seed predators by caging half
of the seeds. We also measured the microclimate at each microsite, including soil
moisture, temperature and canopy cover.
3. The habitat suitability estimated by the SDMs did not predict seedling emergence or
short-term seedling survival. We found that dispersal limitation coupled with seed pre-
dation was a significant predictor of seedling emergence, while microclimate, specifi-
cally microsite temperature, was a significant predictor of short-term seedling survival.
4. Synthesis. Contrary to the assumption that species occur at a low frequency near
their range edges due to a lack of suitable habitat, we found that dispersal limita-
tion coupled with biotic interactions can drive rarity. If this is the case for many
rare species at risk of extinction at their range edges, effective conservation
strategies must incorporate assisted dispersal (i.e. translocations) into appropri-
ate microsites and the management of biotic interactions to establish new popu-
lations and ensure long-term persistence.Ye
The effects of generation anxiety on post-secondary mental health outcomes: Implications for service providers and educators
No full textDespite increased access to mental health services, Generation Z reports the highest rates of depression, anxiety, and stress. Guided by Life Course Theory, this study examined how environmental, technological, and socioeconomic conditions influence youth mental health, with a focus on generation-specific anxieties related to climate change, artificial intelligence, and financial concerns. A mixed-methods design was employed, drawing on quantitative data from 586 post-secondary students using standardized mental health and anxiety scales, along with qualitative responses to open-ended questions. Pearson correlations and stepwise linear regressions revealed that financial anxiety was the strongest predictor of depression, anxiety, and stress. Eco-anxiety and AI anxiety also contributed to mental health outcomes in nuanced ways. Although proposed moderators did not significantly alter these relationships, factors such as social isolation, social support, and daily internet use were independently associated with mental health outcomes. Qualitative data reinforced these findings, with students expressing concern about financial insecurity, environmental degradation, and the impact of AI on job security. These findings highlight the need for clinicians, educators, and policymakers to develop targeted supports and policy responses that address the broader structural pressures affecting the psychological well-being of Generation Z
Altered behaviour and transmission ecology of fluke-infected zombie ants
No full textParasites can induce changes in the colour, morphology, and behaviour of their hosts. In some cases, the induced changes are extraordinary in their expression. In an iconic example, Formicid ants infected with the lancet liver fluke, Dicrocoelium dendriticum, attach their mandibles to a plant for hours or days. I described patterns of infection in two species of ants infected with D. dendriticum in a region of parasite emergence in southern Alberta and found that ants recruit parasites in clumps from their first intermediate host, terrestrial snails. Overall, infected ants contain, on average 27±25 (mean ± standard deviation) encysted metacercariae (n = 677). In a departure from classic examples of parasite manipulation, infected ants do not die on the plant. Rather, they detach, resume normal ant activities, then re-attach. This bizarre ‘attach/detach/repeat’ sequence of altered behaviour likely facilitates transmission into grazing mammals while also preventing desiccation of the ant hosts and their parasites. I conducted a field study monitoring the behaviour of infected ants and found that the timing of attachment and detachment of ants on plants is closely linked with environmental factors such as light intensity, relative humidity, temperature, and also with ant circadian rhythm. Additionally, I completed a spatiotemporal analysis of the distribution of infected ants on plants in the field and found that infected ants are often aggregated on plants adjacent to the nest that they originated from, representing the first reported case of “super aggregation” of parasites. Whereas a pattern of strong aggregation on plants was spatially and temporally consistent for one species of Formicid ant in this region of parasite emergence, the behavioural processes leading to aggregation are enigmatic, as are the consequences of aggregation for rates of fluke transmission from ants into definitive hosts.This research was supported by the National Scientific and Engineering Research Council of
Canada to Cam Goater and the Alberta Conservation Association Grants in Biodiversity Program to Lauren Edison
Using formative research to understand immigrant settlement in southern Alberta, Canada
No full textOpen access article. Creative Commons Attribution-NonCommercial 4.0 International license (CC BY-NC 4.0) appliesBackground
Worldwide migration is on the rise due to factors such as political turmoil and natural disasters, as well as personal desires for upward mobility and safety. New immigrants face many challenges throughout their settlement into a new community. As Canada welcomes record numbers of new immigrants, it is important that communities across Canada find ways to support new immigrants. The immigrant settlement experience can be improved by identifying key barriers during the settlement process and implementing social marketing approaches to overcome them.
Focus of the Article
This article focuses on identifying key barriers to immigrant settlement in Southern Alberta, Canada, using formative research, to provide a foundation for developing social marketing programs with strategic non-profit partners to facilitate immigrant settlement.
Research Question
What challenges do immigrants face when settling in Southern Alberta, and how can social marketing efforts facilitate immigrant settlement?
Program Design/Importance of the Social Marketing Field
Social marketing can help connect immigrants to resources during their settlement. In this study, we explore how new immigrants access information during their settlement and what barriers they face throughout their settlement experience. We identify ways that organizations can utilize social marketing to better assist newcomers in their settlement, and discuss the importance of taking a participatory research approach.
Methods
This research analyzes survey responses from 77 new immigrants in Southern Alberta, Canada. Surveys were conducted in English, Spanish, and Tagalog, primarily online through Qualtrics’ survey platform, augmented by eight hard copy responses. Participants were recruited through word of mouth, local non-profit organizations and government offices, and recruiting at community events. Additionally, interviews were conducted with representatives of an umbrella organization from the greater region that supports immigrant settlement and links settlement service providers. Finally, a community-based participatory research group provided additional insights.Ye
Rbm-od: a restricted Boltzmann machine framework for outlier detection
No full textThis thesis explores the use of Restricted Boltzmann Machines (RBMs), a class of unsupervised generative neural networks, for detecting outliers through data generation and representation-based comparison. Outlier detection (OD) is a critical task in domains where rare or anomalous patterns may indicate errors, fraud, or unexpected behaviour in data. The primary contribution of this work is a unified framework for RBM-based outlier detection that emphasizes data generation as a detection strategy. We explore multiple model variants, including single RBMs, ensembles of RBMs, stacked RBMs, and ensembles of stacked RBMs, each offering distinct advantages in representing complex data patterns. By generating synthetic samples from trained RBMs and comparing them to input data, the approach enables unsupervised detection of unusual or unexpected instances. This gener ative perspective distinguishes RBM-OD from traditional methods and provides a flexible foundation for future extensions
Regional differences in high elevation snowpack decline along the North American Rocky Mountains
No full textOpen access article. Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International license (CC BY-NC-ND 4.0) appliesThe Rocky Mountains (RM) provide the ‘water towers’ for western North America, with deep winter snowpack accumulations that melt to contribute flows for the extensively utilised Columbia, Colorado, Saskatchewan, Missouri and Rio Grande River systems. With climate change, winter and spring warming are increasing seasonal and elevational rain versus snow proportions and altering the annual patterns of snowpack accumulation and melt. Prior studies have reported declines in snowpack extent or water content, especially on an index date, April 1. These declines could reflect reductions in the total annual snowpacks or earlier transitions to snowmelt. To resolve these influences, we assessed daily snowpack patterns at 314 snow pillow stations in the higher elevations along the 2500 km transboundary RM corridor, over three decades from 1991 to 2020. We found regional differentiation, with little change in the maximum snow water equivalent (SWEmax) or its timing (Daymax) in the most-northerly, Canadian RM region (BC, AB); slight declines in the Northern US (ID, MT, WY) and Central US (UT, CO); and major declines in the Southern US (AZ, NM; average ΔSWEmax: −2%/yr; ΔDaymax: −0.75%/yr). With compound influences of declining SWEmax and earlier Daymax, the April 1 SWE (SWEApr1) was more responsive, with progressive decline at some Northern US and Central US stations, and steep decline in the Southern US region (ΔSWEApr1: −6.5%/yr). Due to these compound influences, we recommend that future analyses include snowpack maxima and seasonality as well as April 1 measures, since that precedes the peak snowpack for higher elevation and northern sites, but follows the peak for lower and southern sites, confounding trend comparisons. Thus, higher elevation RM snowpacks are declining but with considerable latitudinal variation, displaying slight change in magnitude and seasonality in the northern regions, and greater change southward. These patterns contrast with some other climate change patterns that display increasing responsivity with higher latitude.Ye
Intersectional impacts of sex and gender on employment outcomes in patients with atrial fibrillation: a systematic review and meta-analysis
No full textAbstract
Background
More than 33 million people worldwide suffer from Atrial Fibrillation (AF) (Chugh et al., 2014; Goren et al., 2013). The objective of this systematic review and meta-analysis was to explore the research question: How does sex and gender impact employment outcomes in adult patients with atrial fibrillation?
Methods
A systematic search was conducted in accordance with the PRISMA 2020 guidelines using keywords and MeSH terms related to atrial fibrillation, employment, sex and gender. Studies were included if they presented sex or gender-specific outcomes or employment outcomes for adults with AF. Data was presented in forest plots and using I² statistics.
Data Synthesis and Analysis
A fixed-effects meta-analysis was conducted using R software. Results were expressed as Odds Ratios (ORs) and 95% confidence intervals (95% CIs). The I² statistic was used to assess statistical heterogeneity. Forest plots were generated to represent effect sizes and heterogeneity visually
Results
A total of twenty studies met the inclusion criteria for qualitative synthesis, and eight were included in the quantitative meta-analysis. Pooled data indicated that males with atrial fibrillation (AF) had 24% lower odds of unemployment compared to females (OR = 0.76, 95% CI: 0.65–0.86). Unemployment was associated with a 44% increased risk of AF (OR = 1.44, 95% CI: 1.29–1.59). Shift work was linked to an 11% higher risk of incident AF (OR = 1.11, 95% CI: 1.05–2.17), although heterogeneity was substantial (I² = 90.59%). Many studies conflated sex and gender.
Conclusions
The findings from this study suggest that structural inequities tied to sex and gender exacerbate employment challenges and health risks for AF patients. Policies that provide flexible scheduling, caregiving support, and equitable labour conditions may reduce the socioeconomic and cardiovascular burdens associated with AF
Becoming neoliberal: myths, memory and subjectivity in Los 80
No full textThis thesis examines the Chilean television series Los 80 as a cultural text that negotiates the tensions of neoliberal subjectivity in Chile. Through critical discourse analysis, and a variety of qualitative approaches appropriate to the study of multimodal texts, this thesis identifies and analyzes three cultural myths articulated in the series and investigates their part in reinforcing or disrupting neoliberal values. By evaluating the interplay of material culture, dialogue and imagery, I argue that Los 80 functions as both a reflection and a critique of the enduring neoliberal framework installed during the dictatorship. I explore the ways in which nostalgia and material culture intersect to naturalize or challenge these ideologies. This work contributes to the broader ongoing discussions between memory, images and identity, which shape the collective understanding of Chile’s present, past and future through popular culture
Evaluation of the Cannabidiolic Acid Synthase (CBDAS) variant’s activity from hemp in transgenic Nicotiana benthamiana plants.
No full textCannabis sativa L., historically controversial, has gained economic and scientific significance in Canada following legalization, primarily due to its primary cannabinoids: cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC). High-THC cannabis serves recreational and medicinal purposes, while high-CBD cultivars are increasingly valued in medical and cosmetic industries. Hemp, legally defined as cannabis containing less than 0.3% THC, is widely used in food, textiles, and biodegradable materials. Both cannabidiol and delta-9-tetrahydrocannabinol are synthesized through decarboxylation of their acidic precursors, cannabidiolic acid (CBDA) and delta-9-tetrahydrocannabinolic acid (THCA), respectively, which are derived from a common precursor, cannabigerolic acid (CBGA), through the enzymatic action of cannabidiolic acid synthase (CBDAS) and delta-9-tetrahydrocannabinolic acid synthase (THCAS). These enzymes exhibit partial promiscuity, meaning they can convert CBGA into multiple cannabinoids, including CBDA, THCA, and cannabichromenic acid (CBCA), typically in ratios ranging from 10:1:1 to 20:1:1. Thus, even in plants lacking the THCAS gene, trace amounts of THCA can be produced, potentially complicating regulatory classification under Health Canada’s guidelines. Despite their structural similarities, bioinformatic analyses have identified unique functional variants of the CBDAS enzyme with differing specificity and activity.
This study evaluated four CBDAS variants, Del_1_108, X59_1_117, Joe_1_129, and CRS1_105, by expressing them in Nicotiana benthamiana via stable genetic transformation. After optimizing assay conditions (including incubation time, temperature, and buffer composition), only Joe_1_129 and X59_1_117 showed enzymatic activity. Both variants catalyzed the exclusive conversion of CBGA to CBDA, with no production of THCA or CBCA, indicating enhanced specificity. Extended incubation (12–16 hours) further improved enzyme efficiency. While Joe_1_129 demonstrated higher conversion efficiency (2.46%), X59_1_117 exhibited better catalytic performance (1.14 vs. 0.89), suggesting functional specialization.
These results provide valuable insights into the evolution and function of CBDAS enzymes and support metabolic engineering strategies aimed at producing hemp cultivars with high CBDA and negligible THC content. Such advances have practical implications for pharmaceutical, cosmetic, and industrial applications, and future research integrating genomic, transcriptomic, and metabolomic approaches could further refine cannabinoid biosynthesis pathways