Experiments on microfluidic core–annular flows demonstrated a transition from a continuous core jet to core-fluid drops and slugs separated by the annular fluid films/slugs due to absolute instability. The flows in the higher-generation airways could be modelled as core–annular flow with the laminar core airflow and annular airway surface liquid (ASL). Thus, if an absolute instability exists in the higher-generation airways, then it could lead to ASL film/slug-induced airway closure, necessitating the present study. Taking cues from previous studies, we derive an evolution equation using the lubrication approximation. The analysis, using the dispersion relation obtained from the evolution equation, predicts the existence of the critical capillary number $Ca_c$ such that, for $Ca < Ca_c$, the flow will be absolutely unstable for vanishing Reynolds number $Re$. The parameter $Ca_c$ exhibits the scaling as $Ca_c \sim (1-H)^2/\mu _r$, where $1-H$ is the dimensionless thickness of the ASL, and $\mu _r$ is the ratio of the air viscosity to the ASL viscosity. In agreement with the experimental observations, for a healthy lung, the analysis predicts absolute instability triggered airway closure only at the end of expiration during a breathing cycle. For a diseased lung, the ASL thickness and viscosity drastically increase the possibility of absolutely unstable flow and, thus, airway closure. Increasing inertial effect (i.e. $Re$) exacerbates airway closure by curtailing the convectively unstable region. Similarly, the ASL shear thinning widens the absolute instability parametric region. Thus, the present analysis demonstrates a pathway for airway closure in the higher-generation airways due to absolute instability.

Indigenous Peoples in Canada are comprised of First Nations, Inuit and Métis and are the youngest and fastest growing population in the country. However, there is limited knowledge of how they are affected by multiple sclerosis (MS), the most common nontraumatic neurological disease of young adults, with Canada having one of the highest prevalences in the world. In this narrative review, we outline the limited studies conducted with Indigenous Peoples living with MS in Canada and the gaps in the literature. From the limited data we have, the prevalence of MS in Indigenous Peoples is lower, but the disease appears to be more aggressive. Given the dearth of Canadian data, we explore the worldwide MS studies of Indigenous populations. Lastly, we explore ways in which we can improve our understanding of MS among Indigenous Peoples in Canada, which entails building trust and meaningful relationships with these communities and acknowledging past and ongoing injustices. Furthermore, healthcare professionals conducting research with Indigenous Peoples should undergo training in cultural safety and data sovereignty, including principles of ownership, control, access and possession to have greater engagement with Indigenous communities to conduct more relevant research. With joint efforts between healthcare professionals and Indigenous communities, the scientific research community can be positioned to conduct better, more appropriate and desperately needed research, ultimately with improvements in the delivery of care to Indigenous Peoples living with MS in Canada.

Depression and anxiety are common mental health issues globally, yet limited research has focused on job seekers in Bangladesh. This study examines the prevalence and associated factors of depression and anxiety symptoms among Bangladeshi graduates seeking employment. A cross-sectional study was conducted among graduates from two public universities in Bangladesh, using face-to-face interviews and a semi-structured questionnaire. Data were collected between March and April 2024 through convenience sampling. Chi-square tests and logistic regression were used for analysis with SPSS software. Among the participants, 46.8% experienced depressive symptoms and 67.8% had anxiety symptoms, with 42.3% experiencing both. Factors associated with a reduced risk of depressive symptoms included being a first child (OR = 0.48, 95% CI: 0.25–0.93, p = 0.031) and exam satisfaction (OR = 0.22, 95% CI: 0.12–0.39, p < 0.001). Lower symptoms of anxiety were associated with being male (OR = 0.45, 95% CI: 0.25–0.80, p = 0.007), first-born status (OR = 0.45, 95% CI: 0.22–0.92, p = 0.030), financial contribution to family (OR = 0.40, 95% CI: 0.19–0.81, p = 0.011), over 12 months of preparation (OR = 0.37, 95% CI: 0.15–0.92, p = 0.034) and exam satisfaction (OR = 0.40, 95% CI: 0.22–0.71, p = 0.002). Intentionally unemployed participants had a higher risk of anxiety symptoms (OR = 1.70, 95% CI: 1.00–2.89, p = 0.046). This study reveals high rates of depressive and anxiety symptoms among job-seeking graduates in Bangladesh. Socio-demographic and job-related factors appear to significantly impact mental health, underscoring the need for a holistic approach to address these challenges. Targeted mental health interventions and increased public awareness are essential to support vulnerable groups in navigating the highly competitive job market.

We prove new fundamental lemma and arithmetic fundamental lemma identities for general linear groups over quaternion division algebras. In particular, we verify the transfer conjecture and the arithmetic transfer conjecture from Li and Mihatsch (2023, Preprint, arXiv:2307.11716) in cases of Hasse invariant $1/2$.

This article examines the lived experiences of the older body—the embodiment of old age—from the perspective of older people. It uses letters written from 1680 to 1820 by twenty-two women and men aged between sixty and eighty-nine, selected from a corpus of over 391 letter writers. We begin by exploring the embodied experiences discussed by older people, as well as their understanding of the relationship between these experiences and their later years. The article finds that old age was experienced as highly variable and was subject to an ongoing process of recalibration. Central to that process was the corporeality of the aging body as experienced in the context of a range of social factors. The corporeality of the body was a factor for all but was not always framed negatively or even situated in the context of aging. The article then turns to the responses of older people to the life-stage of old age. The article finds them self-directed and proactive in continuing to live well. This is significant evidence for a self-consciously active, engaged, and embodied old age in early modernity. These older letter writers tended not to disavow old age but to accommodate and even embrace it.