Showing papers in "Eureka in 2021"

Bacterial signal peptides: structure, optimization, and applications

Abstract: Bacterial signal peptides are N-terminal tags that direct proteins for export through one of various transport pathways. These signal peptides are highly important as they are the key determinants of transport, ensuring that the correct protein ends up at the correct pathway. While these peptides consist of three domains with well conserved biochemical properties, there still remains a large amount of diversity between the signal sequences for different proteins, transport pathways, and bacterial species. Recent advancements have allowed us to predict signal sequences and manipulate them in an attempt to optimize export efficiency. This knowledge can then be exploited in the field of recombinant protein production wherein bacterial species can be used to produce and secrete proteins of interest. By fusing the protein with an optimized signal peptide, the yield or rate of export can be improved. This review focuses on signal peptides for two primary transport pathways (Sec and Tat) in E. coli specifically, with an emphasis on applications and the production of recombinant proteins.

Replication: Self-Compassion and Health-Promoting Lifestyle Behaviours in Albertan University Students During the COVID-19 Pandemic

Abstract: Self-compassion as a predictor for health-promoting behaviours has been the subject of several research studies. Self-kindness, common humanity, and mindfulness have been repeatedly positively correlated with health-promoting behaviours in individuals, such as eating well and doing physical activity (Gedik, 2019; Holden et al., 2020). We hypothesized that the positive components of self-compassion (self-kindness, common humanity, and mindfulness) would positively correlate with health-promoting behaviours. In an attempt to replicate Gedik’s (2019) study, researchers recruited 294 Albertan post-secondary students to respond to an online-based questionnaire. Participants filled out both the Self-Compassion Scale (SCS) (Neff, 2003b) and the Health Promoting Lifestyle Profile II (Walker et al., 1995). Findings revealed that, unlike Gedik (2019), isolating behaviours such as feeling cut-off from the world are indicative of improved stress management. Therefore, Gedik’s (2019) results were not replicated. This research’s implications are essential when considering the factorial breakdown of self-compassion and how the factorial relationships to health behaviours are affected by varying populations and contexts. Specifically, the occurrence of the COVID-19 pandemic and its resulting restrictions must be considered when interpreting the results presented in this current study.

The Neuroregenerative Effects of Intraspinal Microstimulation (ISMS) Following Spinal Cord Injury (SCI)

Abstract: Background Intraspinal microstimulation (ISMS) is a novel electrical stimulation technique that has demonstrated mobility restoration in animals with spinal cord injury (SCI). This project investigated: 1) the capacity of ISMS to restore functional walking in rats with SCI through 4 weeks of stimulation, and 2) the degree of walking deficit caused by ISMS surgery. Methods Thirteen Sprague Dawley rats were divided into three groups: 1) rats with hemi-section SCI (hSCI) and no implants (control group), 2) rats with hSCI and passive ISMS implants (ISMS sham group), and 3) rats with hSCI and implants with active electrical stimulation (ISMS group). All groups were trained to walk on a horizontal ladder and their performance was quantified pre- and post-surgery. Results We hypothesized that the rats with active ISMS implants would demonstrate the greatest improvement in functional walking compared to both control groups, and that the ISMS sham group would underperform the most. The preoperative functional walking scores of control, sham and ISMS rats were 5.7±0.2, 5.5±0.3 and 5.7±0.1, respectively (7-point scale; mean ± standard error). The post-surgery scores were 3.2±0.9, 2.6±0.6 and 3.3±0.8 for control, sham, and ISMS rats, respectively. Conclusions As the difference between the post-surgery functional walking scores of ISMS and control rats was not statistically significant, this may indicate that four weeks of ISMS stimulation is not enough to cause rehabilitative effects. Additionally, the ISMS sham group demonstrated impaired functional walking compared to the hSCI control group as predicted. Future studies will employ a larger sample size to fully elucidate this trend and utilize thinner microwires to mitigate cellular damage.