Dalhousie University

Spider silks are renowned for their mechanical properties. The notably tough Argiope trifasciata aciniform silk is spun from a protein predominantly comprising a series of identical 200 residue units (“W units”). In solution, each W unit has a globular 5‐helix domain connected to its neighbors by intrinsically disordered linkers while the fiber contains mixed α‐helical, β‐sheet and disordered structuring. Helix 5 is more dynamic and prone to denaturation than the remainder of the globular domain, implying that it may structurally transform during fiber spinning. Rational cysteine substitutions are introduced at a proximal pair of serines in helix 5 and in helix 1 of the globular domain. Upon disulfide formation, the helix 5 C‐terminal region loses helicity and experiences increased backbone dynamics, while the remainder of the globular structure is effectively unperturbed. Fiber formation by hand‐drawing and wet‐spinning is prevented in the disulfide‐locked state, but readily possible in the reduced (“unlocked”) state. The disulfide‐locked state differs from the unlocked state with much more heterogeneous pre‐fibrillar assembly in spinning dope and through prevention of β‐sheet formation upon cooling following thermal denaturation. This engineered protein thus provides a chemically‐reversible disulfide‐locked state of aciniform silk with modified self‐assembly propensity and fiber formation.

Having a regular medical doctor is associated with better process of care and health outcomes. The goal of this study was to harness the richness in health administrative data to create a measure which accurately predicted whether patients self-identified as having a regular medical doctor. The Canadian Community Health Survey (2007–2012) was linked with health administrative data (HAD) (2002–2012) from Quebec, Canada’s second largest province. The Canadian Community Health Survey includes respondents’ answer to whether they have a regular medical doctor, but health administrative data does not. We therefore used LASSO and Random Forests to build prediction models that predict whether a patient reports having a regular medical doctor using their data only available in the HAD. Our results show that predicting patient responses to ‘do you have a regular medical doctor?’ using an average of single-year Usual Provider Continuity over 3 years results in an area under the receiver operator characteristic curve of 0.782 (0.778–0.787). This was almost a 14% improvement in predictive accuracy compared to the frequently used single-year Usual Provider Continuity (0.688 (0.683–0.694)). We have called this new measure the Reporting a Regular Medical Doctor (RRMD) index. The RRMD index is easy to implement in HAD, is an elegant solution to the difficulties associated with low-users having unstable UPC scores, and brings a patient-oriented perspective to previous efforts to capture patient-physician affiliations in HAD. We recommend that researchers seeking to measure whether patients have a regular medical doctor using HAD consider using the RRMD index.

Natural language processing (NLP) has been used to extract information from and summarize medical reports. Currently, the most advanced NLP models require large training datasets of accurately labeled medical text. An approach to creating these large datasets is to use low resource intensive classical NLP algorithms. In this manuscript, we examined how an automated classical NLP algorithm was able to classify portions of bone marrow report text into their appropriate sections. A total of 1480 bone marrow reports were extracted from the laboratory information system of a tertiary healthcare network. The free text of these bone marrow reports were preprocessed by separating the reports into text blocks and then removing the section headers. A natural language processing algorithm involving n-grams and K-means clustering was used to classify the text blocks into their appropriate bone marrow sections. The impact of token replacement of numerical values, accession numbers, and clusters of differentiation, varying the number of centroids (1–19) and n-grams (1–5), and utilizing an ensemble algorithm were assessed. The optimal NLP model was found to employ an ensemble algorithm that incorporated token replacement, utilized 1-gram or bag of words, and 10 centroids for K-means clustering. This optimal model was able to classify text blocks with an accuracy of 89%, suggesting that classical NLP models can accurately classify portions of marrow report text.

High DoF mobile manipulation of robots is a nonlinear, nonchain redundant problem. In this article, we focus on two subissues of robot mobile manipulation: whole-body inverse kinematics (whole-body IK) and operation-oriented motion planning (OOMP). Whole-body IK solves the robot arm joint configuration and the mobile base position configuration according to the target pose. OOMP generates a feasible trajectory from the current pose to the target pose. The trajectory can avoid obstacles and touch operated objects. We introduce neural network optimization (NNO) methods with two variations to solve whole-body IK and OOMP, respectively. For whole-body IK, we design a fully connected network (FCN) to predict ten DoF of position and joint configurations based on the target pose. We use these ten DoF configurations to derive the predicted pose for online optimization. For OOMP, we design a GRU-based network to generate trajectories based on the initial and goal states. We mainly adopt sphere masks to modify the point cloud properties of the target object dynamically. During optimization, the trajectory keeps away from point clouds but approaches sphere masks. Finally, we conduct extensive experiments both on a Franka Panda robot and a mobile dual-arm robot. The results demonstrate the superior performance of our NNO method on whole body IK and OOMP, and implement mobile manipulation in different environments successfully.

Background There is a projected and growing gap of geriatricians in Canada. Geriatricians play a crucial role in addressing the health needs of older adults. We aimed to understand the factors that influence the choice of first-practice location for new geriatricians in the context of an aging Canadian population. Methods We distributed an online survey to geriatric medicine subspecialty residents and recently licensed geriatricians in Canada. The survey was developed through expert opinions, career planning sessions, and a literature review. There were nine survey sections: general characteristics, location determinants, practice determinants, colleague determinants, support and space, non-clinical opportunities, income models, lifestyle factors, and recruitment determinants. The data were analyzed descriptively. Results A total of 61 respondents (51 English, 10 French) completed the survey. The respondents were new practicing geriatricians (37) and geriatric medicine residents (24). Most planned to practice in Ontario (26.2%) or Quebec (27.9%), and 75.4% were women. Flexibility in work-life balance (95.1%), collegiality (93.4%) and reasonable call schedules (93.4%) were the most important factors influencing first practice location. Income did not rank among the highest priorities for choosing the first practice location relative to other factors but was mentioned in open-ended responses to recruitment questions. Conclusions This is the first survey identifying the determinants of first practice location in geriatric medicine in Canada. Work-life balance and collegial support are a priority for new geriatricians and may be the strongest incentives a program can provide. For recruitment, income incentives may be beneficial to building new specialized geriatric services. Future research will examine determinants of first practice location among Care of the Elderly clinicians.

Background There has been increasing concern over the growing number of Alternate Level of Care (ALC) patients in Canada who must wait in hospitals for more appropriate settings to meet their needs. ALC patients may have to stay in hospitals for days or months due to a lack of available long-term care capacity, home care services, or other discharge routes. Method We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR) method to review 35 papers on the topic of ALC patients and delayed discharge in Canada from different perspectives, including (1) the shared characteristics of ALC patients in Canada; and (2) their impact on the Canadian health-care system, medical staff, and family members. Furthermore, from the reviewed works, (3) we also investigate the factors that impact the length of the hospital stays. Results We highlighted how the ALC problem is increasing healthcare costs, disrupting services, increasing waiting times, and compromising access to valuable resources. We found evidence suggesting that this far-reaching crisis affects the patients, their families, and the medical personnel. We discovered several logistical issues (such as access to long-term care) affecting the patient’s hospital length of stay. Conclusions Our research contributes to understanding this intricate problem, and helps policymakers take steps to tackle this challenge to ensure timely and appropriate care for all patients.

Arctic ecotones contain dynamic freshwater ecosystems where aquatic biota vary across these transitions and as such can be especially susceptible to environmental change. Here, we examine the palaeoecology of two ponds in the ecotonal Hudson Bay Lowlands, subarctic Canada, to understand how aquatic biota have responded in an increasingly climate‐stressed Anthropocene, and to better anticipate future changes. Using a multi‐proxy palaeolimnological approach, we reconstruct past environmental conditions through the examination of subfossil chironomids (Diptera: Chironomidae) and compare these records to organic carbon and nitrogen elemental and isotope composition, and previously published cellulose‐inferred lake water oxygen isotope records. Despite their close proximity, we found different chironomid assemblages in each pond that reflected differences in hydrological trajectories since 1940; an isolated pond exposed to evaporative stress showed an increasingly littoral chironomid assemblage, while a nearby basin that began receiving waters from a channel fen lost semi‐terrestrial taxa associated with flooded grassy margins that became more permanently submerged. Even though large catchment‐mediated changes resulted in a shift in some chironomids of both ponds, chironomid‐based palaeo‐temperature reconstructions demonstrated similar warming trends. Shifts in the ecology of subarctic lakes and ponds are expected to increase as the effects of climate change become more severe.

SARS-CoV-2, primarily affecting the respiratory system, is also found in fecal samples from COVID-19 patients, demonstrating wastewater as a significant route for viral RNA transmission. During high prevalence periods, healthcare facility wastewater became a potential contamination source. Understanding the role of wastewater in epidemiology is crucial for public health risk assessment. In hospitals, with a specific number of COVID-19 cases, wastewater analysis offers a unique opportunity to link virus presence in wastewater with COVID-19 hospitalizations, a connection that is not possible in urban wastewater treatment plants (WWTPs). Shorter wastewater transit times enable more accurate virus tracking. With documented infection rates and rigorous testing, hospitals are ideal for wastewater monitoring, revealing practicalities and limitations. This review updates global efforts in quantifying SARS-CoV-2 in hospital wastewater, considering hospitalization rates' influence on viral RNA levels and comparing disinfection methods. Insights gleaned from this study contribute to Wastewater-based Epidemiology (WBE) and can be applied to other virus strains, enhancing our understanding of disease transmission dynamics and aiding in public health response strategies.

Purpose We performed this study to explore family member experiences with restrictions to family presence during their child’s PICU admission, leveraging the unique context of the COVID-19 pandemic to aid in future ethical and informed decision-making. Methods Qualitative interpretive descriptive study with family members of Canadian PICU patients admitted from March 2020 to April 2021 who experienced restricted family presence (RFP) policies. Respondents were purposively sampled for demographic-based maximum variation.We generated themes through inductive thematic analysis of open-ended interviews. Results Fourteen parental figures from five regions across Canada participated. We identified four themes associated with the lived experience and impact of the restrictions on family members of critically ill children: (1) challenges to fulfilling the parent role, (2) isolation from primary supports during a time of crisis, (3) navigating increased logistical difficulties, and (4) seeking compassionate approaches within the healthcare system. Conclusion: RFP policies created a range of barriers for family members of critically ill children. Healthcare organizations and teams may play a role in removing barriers through consistent and empathetic application of rules with consideration for the duality of the parent role in PICUs, providing important post-pandemic policy and practice implications. What is known: • Parental presence with critically ill children may improve health outcomes for patients and their families. • Restrictions to family presence in PICUs continue to occur internationally and, during COVID-19, resulted in parental isolation, anxiety, and increased stress. What is new: • By isolating family members and removing supports, COVID-19-related restrictions in Canadian PICUs challenged family members’ ability to fulfil their parent roles while meeting their own needs. • Families need empathetic, advocacy-based approaches from clinicians and healthcare systems to maintain trust and therapeutic relationships in a family-centered organization.

The COVID-19 pandemic disproportionately affected African, Caribbean, and Black (ACB) people in Canada. Despite higher SARS-CoV-2 exposure risks, likelihood of being quarantined, and risk of severe disease outcomes, little is known about the pandemic’s effects on this community’s mental health. This study aims to identify factors associated with changes in ACB Canadians’ mental health during the pandemic and provide guidance for improved access to mental health resources. Data was collected from May to July 2021 using a cross-sectional, national, online survey. Eligible participants for this community-based study were ACB adults residing in Canada. Survey measures included demographics, pandemic-related experiences, mental health status, and access to mental health services. Bivariate analyses and multinomial logistic regression examined associations between variables. Among the 1,556 participants, 25.4% reported improved mental health and 33.1% reported worsened mental health since the pandemic’s onset. Improved mental health was associated with younger age, receiving at least one pandemic-related benefit, and living in a home that became safer. In contrast, worsened mental health was associated with younger age, working less, the pandemic having a major impact on ability to pay bills, not receiving pandemic-related benefits, home becoming less safe, and increased substance use. Barriers to accessing mental health services included difficulty getting an appointment, cost, pandemic measures, and lack of culturally competent care. These insights underscore the positive impact of pandemic-related emergency relief, the challenges in accessing mental health services, and the gaps in culturally competent mental health care.

KANK1 is expressed in epithelial cells and connects focal adhesions with the adjacent cortical microtubule stabilizing complex. Although KANK1 was shown to suppress cancer cell growth in vitro, TCGA database points to high KANK1 levels associated with poor prognosis in a wide spectrum of human malignancies. Here, we address this discrepancy and report that KANK1 promotes proliferation and survival of PyMT-transformed mammary tumor cells in vivo. Mechanistically, KANK1 localizes to the basal side of basement membrane (BM)-attached transformed luminal epithelial cells. When these cells lose the contact with the BM and disassemble integrin adhesions, KANK1 is found at cell-cell junctions where it competes with the polarity and tumor suppressor Scribble for NOS1AP binding, which curbs the ability of Scribble to promote Hippo pathway activity. The consequences are stabilization and nuclear accumulation of TAZ, growth and survival of tumor cells and elevated breast cancer development.

Background Perfectionism is a pivotal factor in the etiology and prognosis of major depression. Nevertheless, there is a scarcity of longitudinal research examining the association between perfectionism and major depressive disorder (MDD). The objective of this study was to explore the impact of perfectionism on MDD among a cohort of first-year Chinese university students. Methods This study employed a longitudinal design to investigate the relationship between perfectionism and MDD in a sample of first-year Chinese university students (n=8079). Socially prescribed perfectionism and almost perfectionism were measured using the Multidimensional Perfectionism Scale (MPS) and the Almost Perfect Scale-Revised (APS-R), while MDD was assessed using the Composite International Diagnostic Interview (CIDI-3.0). Random effects logistic regression modeling was utilized to estimate the associations between the variables. Results The findings revealed that the incidence of MDD was 0.6%. Lifetime exposure to severe traumatic events (≥10) (OR=2.619, 95% CI: 1.502–4.565) and almost perfectionism (OR=1.015, 95% CI: 1.004–1.026) were identified as significant risk factors for MDD. Conclusion It is evident that perfectionism is linked to an increased susceptibility to MDD. However, additional longitudinal studies focusing on university students are imperative to delve deeper into the influence of perfectionism on the initial manifestation of MDD.

Objective Examination of the impact of the COVID-19 pandemic on rates of antipsychotic medication use, initiation and discontinuation, among newly admitted long-term care residents. Design Repeated cross-sectional study. Settings and Participants Long-term care home residents in Alberta, British Columbia and Ontario, Canada assessed with the Minimum Data Set (MDS) 2.0 assessment. The cohort was segmented according to admission during the pandemic (March 2020/2021) and 2 pre-pandemic (March 2018/2019 and March 2019/2020) periods. Methods Multivariable logistic regression models were fit to characterize the association between long-term care admission during the COVID-19 pandemic and the use of antipsychotic medications. A second set of logistic regression models were fit among residents with follow-up assessments to characterize the association between long-term care admission and antipsychotic initiation/discontinuation at follow-up. All models were adjusted for resident characteristics including sex, age group, Aggressive Behaviour Scale score, Cognitive Performance Scale score, and diagnoses of Alzheimer’s disease and related dementias, anxiety disorder, depression, and bipolar disorder. Results 21 612 residents admitted during the pandemic and over 30 000 in each pre-pandemic period were included. Antipsychotic use increased during the pandemic period among newly admitted residents from both community (adjusted odds ratio [aOR] 1.20-1.29) and hospital settings (aOR 1.21-1.23). Residents admitted during the pandemic period were more likely to have antipsychotic medications initiated (aOR 1.25-1.26) and less likely to have had them discontinued (aOR 0.74-0.76) at the time of follow-up assessment. Conclusion and Implications Multiple factors contributed to the observed increase in antipsychotic medication use among newly admitted long-term care home residents during the COVID-19 pandemic: increased medication use at the time of admission, increased medication initiation at follow-up, and decreased medication discontinuation at follow-up. A whole-systems approach that extends beyond long-term care into hospital and community settings is necessary to address this prevalent issue.

About 15% of the global population is considered neurodivergent (having different ways of sensory processing than what are perceived as neurotypical persons). Persons with neurodivergence typically include those with autism, attention-deficit hyperactivity disorder (ADHD), and Down Syndrome. Studies have shown that many neurodivergent persons experience sensory processing disorder (SPD). Noise, lighting, temperature, and aesthetics are some factors that can significantly impact the quality of interaction with the built environment for these individuals. A significantly lower proportion of youths with SPD enter higher educational institutions (HEI), hindered in part by physical design on university campuses. Universities in Canada are now mandated to address barriers in the campus environments for persons with disability. However, space design needs of neurodivergent students are often overlooked. We interviewed eight neurodivergent persons with SPD (NPSPD) about their experiences as students navigating a university campus located in Halifax, Canada. We asked what specific spaces on campus pose barriers to them (to enter, traverse, and use), and how the design should be improved. The participant responses revealed many elements on campus that act as barriers—largely consistent with existing literature. However, the participants’ comments illustrated more complex dynamics of these factors, which can exacerbate their stress and anxiety. Oftentimes, barriers are more to do with lack of information about the characteristics of the space prior to using it, which would otherwise allow students to plan ahead their journey to destinations and use of given spaces. A wayfinding aid that informs what to expect in spaces or pathways on campus would be a potential area for innovation, along with multiple services to comprehensively and flexibly cater to individual needs to alleviate sensory overload. Ongoing communications about barriers across campus by all users of the university campus would facilitate implementation of pragmatic solutions needed to address diverse needs existing in HEI.

The aryloxyamine motif is a prominent pharmacophore in drug design and development. While these biologically relevant structures could in principle be sustainably assembled from the base metal‐catalyzed O‐arylation of inexpensive and abundant amino alcohols with (hetero)aryl chlorides, reports of such challenging C–O bond formations with useful scope are lacking. In response, we report herein the hitherto unknown Ni‐catalyzed C–O cross‐coupling of N‐protected amino alcohols (primary, secondary, and tertiary) with (hetero)aryl chlorides. Also presented are chemoselective sequential/telescoped C–N and C–O cross‐couplings of the unprotected amino alcohol prolinol to afford an unsymmetrical diarylated product.