ABSTRACT
Echolocation is the primary sense used by most bats to navigate their environment. However, the influence of echolocating behaviors upon the morphology of the auditory apparatus remains largely uninvestigated. While it is known that middle ear ossicle size scales positively with body mass across mammals, and that peak call frequency scales negatively with body mass among bats, there are still large gaps in our understanding of the degree to which allometry or ecology influences the morphology of the chiropteran auditory apparatus. To investigate this, we used µCT datasets to quantify three morphological components of the inner and middle ear: ossicle size, ossicle shape, and cochlear spirality. These data were collected across 27 phyllostomid species, spanning a broad range of body sizes, habitats, and dietary categories, and the relationships between these variables and ear morphology were assessed using a comparative phylogenetic approach. Ossicle size consistently scaled with strong negative allometry relative to body mass. Cochlear spirality was significantly (p = .025) associated with wing aspect ratio (a proxy for habitat use) but was not associated with body mass. From a morphological perspective, the malleus and incus exhibited some variation in kind with diet and call frequency, while stapes morphology is more closely tied to body size. Future work will assess these relationships within other chiropteran lineages, and investigate potential morphological differences in the middle and inner ear of echolocating-vs-non-echolocating taxa.
Subject(s)
Chiroptera , Ear, Inner , Echolocation , Animals , Phylogeny , Chiroptera/anatomy & histology , Ear, Inner/diagnostic imaging , Ear, Inner/anatomy & histology , IncusABSTRACT
OBJECTIVE: To explore experiences participating in a group-based physiotherapist (PT)-led exercise programme among people living with HIV and complex multimorbidity. DESIGN: We conducted a qualitative descriptive study using semistructured interviews. RECRUITMENT AND SETTING: We recruited community-dwelling adults living with HIV who engaged in a group-based PT-led exercise programme within an HIV-specialty hospital in Toronto, Canada. Interviews were conducted in-person or by telephone. PARTICIPANTS: Eight men and two women with a median age of 58 years and median of six concurrent conditions in addition to HIV, who had attended ≥2 classes of the exercise programme. DATA COLLECTION: Interviews explored (1) reasons for engaging in the programme, (2) experiences with exercise prior to and after joining the programme, (3) facilitators and barriers to engagement and (4) perceived impacts of participation on health and disability. We administered the HIV Disability Questionnaire and a demographic questionnaire. RESULTS: Experiences spanned perspectives prior to, during and after the PT-led exercise programme. Reasons for engaging in the programme included addressing health-related goals. Participants identified accessibility, the flexible schedule, interprofessional staff and the HIV-specific, group-based environment as facilitators to engagement. Participants reported high attendance rates, but identified episodic health challenges and overcrowded space as potential barriers to attending exercise classes. Perceived impacts on health and disability outcomes included improved physical, mental, social and cognitive health, and activities of daily living. Anticipated or actual experiences transitioning to independent exercise included facilitators (supportive programme leaders) and barriers (challenges motivatiing self to exercise alone). CONCLUSIONS: Features of the programme that facilitated engagement included the interprofessional, group-based environment that offered tailored exercise in an HIV-specific facility, whereby participants perceived benefits in domains of health and disability. However, challenges transitioning to independent exercise remain. Group-based PT-led exercise programmes may facilitate engagement in exercise among adults living with HIV and complex multimorbidity.
